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1 | ------------------------------------------------------------------------------ |
2 | -- -- | |
3 | -- GNAT COMPILER COMPONENTS -- | |
4 | -- -- | |
5 | -- C H E C K S -- | |
6 | -- -- | |
7 | -- B o d y -- | |
8 | -- -- | |
b785e0b8 | 9 | -- Copyright (C) 1992-2014, Free Software Foundation, Inc. -- |
70482933 RK |
10 | -- -- |
11 | -- GNAT is free software; you can redistribute it and/or modify it under -- | |
12 | -- terms of the GNU General Public License as published by the Free Soft- -- | |
b5c84c3c | 13 | -- ware Foundation; either version 3, or (at your option) any later ver- -- |
70482933 RK |
14 | -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
15 | -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- | |
16 | -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- | |
17 | -- for more details. You should have received a copy of the GNU General -- | |
b5c84c3c RD |
18 | -- Public License distributed with GNAT; see file COPYING3. If not, go to -- |
19 | -- http://www.gnu.org/licenses for a complete copy of the license. -- | |
70482933 RK |
20 | -- -- |
21 | -- GNAT was originally developed by the GNAT team at New York University. -- | |
71ff80dc | 22 | -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
70482933 RK |
23 | -- -- |
24 | ------------------------------------------------------------------------------ | |
25 | ||
26 | with Atree; use Atree; | |
f7ea2603 | 27 | with Casing; use Casing; |
70482933 RK |
28 | with Debug; use Debug; |
29 | with Einfo; use Einfo; | |
aca670a0 AC |
30 | with Elists; use Elists; |
31 | with Eval_Fat; use Eval_Fat; | |
32 | with Exp_Ch11; use Exp_Ch11; | |
70482933 | 33 | with Exp_Ch2; use Exp_Ch2; |
fdfcc663 | 34 | with Exp_Ch4; use Exp_Ch4; |
d8b9660d | 35 | with Exp_Pakd; use Exp_Pakd; |
70482933 | 36 | with Exp_Util; use Exp_Util; |
a40ada7e | 37 | with Expander; use Expander; |
70482933 | 38 | with Freeze; use Freeze; |
fbf5a39b | 39 | with Lib; use Lib; |
70482933 RK |
40 | with Nlists; use Nlists; |
41 | with Nmake; use Nmake; | |
42 | with Opt; use Opt; | |
fbf5a39b | 43 | with Output; use Output; |
980f237d | 44 | with Restrict; use Restrict; |
6e937c1c | 45 | with Rident; use Rident; |
70482933 RK |
46 | with Rtsfind; use Rtsfind; |
47 | with Sem; use Sem; | |
a4100e55 | 48 | with Sem_Aux; use Sem_Aux; |
5d09245e | 49 | with Sem_Ch3; use Sem_Ch3; |
fbf5a39b | 50 | with Sem_Ch8; use Sem_Ch8; |
aca670a0 | 51 | with Sem_Eval; use Sem_Eval; |
70482933 RK |
52 | with Sem_Res; use Sem_Res; |
53 | with Sem_Util; use Sem_Util; | |
54 | with Sem_Warn; use Sem_Warn; | |
55 | with Sinfo; use Sinfo; | |
fbf5a39b | 56 | with Sinput; use Sinput; |
70482933 | 57 | with Snames; use Snames; |
fbf5a39b | 58 | with Sprint; use Sprint; |
70482933 | 59 | with Stand; use Stand; |
baed70ac | 60 | with Stringt; use Stringt; |
07fc65c4 | 61 | with Targparm; use Targparm; |
70482933 RK |
62 | with Tbuild; use Tbuild; |
63 | with Ttypes; use Ttypes; | |
70482933 RK |
64 | with Validsw; use Validsw; |
65 | ||
66 | package body Checks is | |
67 | ||
68 | -- General note: many of these routines are concerned with generating | |
69 | -- checking code to make sure that constraint error is raised at runtime. | |
70 | -- Clearly this code is only needed if the expander is active, since | |
71 | -- otherwise we will not be generating code or going into the runtime | |
72 | -- execution anyway. | |
73 | ||
74 | -- We therefore disconnect most of these checks if the expander is | |
75 | -- inactive. This has the additional benefit that we do not need to | |
76 | -- worry about the tree being messed up by previous errors (since errors | |
77 | -- turn off expansion anyway). | |
78 | ||
79 | -- There are a few exceptions to the above rule. For instance routines | |
80 | -- such as Apply_Scalar_Range_Check that do not insert any code can be | |
81 | -- safely called even when the Expander is inactive (but Errors_Detected | |
82 | -- is 0). The benefit of executing this code when expansion is off, is | |
83 | -- the ability to emit constraint error warning for static expressions | |
84 | -- even when we are not generating code. | |
85 | ||
637a41a5 AC |
86 | -- The above is modified in gnatprove mode to ensure that proper check |
87 | -- flags are always placed, even if expansion is off. | |
88 | ||
fbf5a39b AC |
89 | ------------------------------------- |
90 | -- Suppression of Redundant Checks -- | |
91 | ------------------------------------- | |
92 | ||
93 | -- This unit implements a limited circuit for removal of redundant | |
94 | -- checks. The processing is based on a tracing of simple sequential | |
95 | -- flow. For any sequence of statements, we save expressions that are | |
96 | -- marked to be checked, and then if the same expression appears later | |
97 | -- with the same check, then under certain circumstances, the second | |
98 | -- check can be suppressed. | |
99 | ||
100 | -- Basically, we can suppress the check if we know for certain that | |
101 | -- the previous expression has been elaborated (together with its | |
102 | -- check), and we know that the exception frame is the same, and that | |
103 | -- nothing has happened to change the result of the exception. | |
104 | ||
105 | -- Let us examine each of these three conditions in turn to describe | |
106 | -- how we ensure that this condition is met. | |
107 | ||
108 | -- First, we need to know for certain that the previous expression has | |
308e6f3a | 109 | -- been executed. This is done principally by the mechanism of calling |
fbf5a39b AC |
110 | -- Conditional_Statements_Begin at the start of any statement sequence |
111 | -- and Conditional_Statements_End at the end. The End call causes all | |
112 | -- checks remembered since the Begin call to be discarded. This does | |
113 | -- miss a few cases, notably the case of a nested BEGIN-END block with | |
114 | -- no exception handlers. But the important thing is to be conservative. | |
115 | -- The other protection is that all checks are discarded if a label | |
116 | -- is encountered, since then the assumption of sequential execution | |
117 | -- is violated, and we don't know enough about the flow. | |
118 | ||
119 | -- Second, we need to know that the exception frame is the same. We | |
120 | -- do this by killing all remembered checks when we enter a new frame. | |
121 | -- Again, that's over-conservative, but generally the cases we can help | |
122 | -- with are pretty local anyway (like the body of a loop for example). | |
123 | ||
124 | -- Third, we must be sure to forget any checks which are no longer valid. | |
125 | -- This is done by two mechanisms, first the Kill_Checks_Variable call is | |
126 | -- used to note any changes to local variables. We only attempt to deal | |
127 | -- with checks involving local variables, so we do not need to worry | |
128 | -- about global variables. Second, a call to any non-global procedure | |
129 | -- causes us to abandon all stored checks, since such a all may affect | |
130 | -- the values of any local variables. | |
131 | ||
132 | -- The following define the data structures used to deal with remembering | |
133 | -- checks so that redundant checks can be eliminated as described above. | |
134 | ||
135 | -- Right now, the only expressions that we deal with are of the form of | |
136 | -- simple local objects (either declared locally, or IN parameters) or | |
137 | -- such objects plus/minus a compile time known constant. We can do | |
138 | -- more later on if it seems worthwhile, but this catches many simple | |
139 | -- cases in practice. | |
140 | ||
141 | -- The following record type reflects a single saved check. An entry | |
142 | -- is made in the stack of saved checks if and only if the expression | |
143 | -- has been elaborated with the indicated checks. | |
144 | ||
145 | type Saved_Check is record | |
146 | Killed : Boolean; | |
147 | -- Set True if entry is killed by Kill_Checks | |
148 | ||
149 | Entity : Entity_Id; | |
150 | -- The entity involved in the expression that is checked | |
151 | ||
152 | Offset : Uint; | |
153 | -- A compile time value indicating the result of adding or | |
154 | -- subtracting a compile time value. This value is to be | |
155 | -- added to the value of the Entity. A value of zero is | |
156 | -- used for the case of a simple entity reference. | |
157 | ||
158 | Check_Type : Character; | |
159 | -- This is set to 'R' for a range check (in which case Target_Type | |
160 | -- is set to the target type for the range check) or to 'O' for an | |
161 | -- overflow check (in which case Target_Type is set to Empty). | |
162 | ||
163 | Target_Type : Entity_Id; | |
164 | -- Used only if Do_Range_Check is set. Records the target type for | |
165 | -- the check. We need this, because a check is a duplicate only if | |
308e6f3a | 166 | -- it has the same target type (or more accurately one with a |
fbf5a39b AC |
167 | -- range that is smaller or equal to the stored target type of a |
168 | -- saved check). | |
169 | end record; | |
170 | ||
171 | -- The following table keeps track of saved checks. Rather than use an | |
172 | -- extensible table. We just use a table of fixed size, and we discard | |
173 | -- any saved checks that do not fit. That's very unlikely to happen and | |
174 | -- this is only an optimization in any case. | |
175 | ||
176 | Saved_Checks : array (Int range 1 .. 200) of Saved_Check; | |
177 | -- Array of saved checks | |
178 | ||
179 | Num_Saved_Checks : Nat := 0; | |
180 | -- Number of saved checks | |
181 | ||
182 | -- The following stack keeps track of statement ranges. It is treated | |
183 | -- as a stack. When Conditional_Statements_Begin is called, an entry | |
184 | -- is pushed onto this stack containing the value of Num_Saved_Checks | |
185 | -- at the time of the call. Then when Conditional_Statements_End is | |
186 | -- called, this value is popped off and used to reset Num_Saved_Checks. | |
187 | ||
188 | -- Note: again, this is a fixed length stack with a size that should | |
189 | -- always be fine. If the value of the stack pointer goes above the | |
190 | -- limit, then we just forget all saved checks. | |
191 | ||
192 | Saved_Checks_Stack : array (Int range 1 .. 100) of Nat; | |
193 | Saved_Checks_TOS : Nat := 0; | |
194 | ||
195 | ----------------------- | |
196 | -- Local Subprograms -- | |
197 | ----------------------- | |
70482933 | 198 | |
a7f1b24f | 199 | procedure Apply_Arithmetic_Overflow_Strict (N : Node_Id); |
acad3c0a | 200 | -- Used to apply arithmetic overflow checks for all cases except operators |
3ada950b | 201 | -- on signed arithmetic types in MINIMIZED/ELIMINATED case (for which we |
a7f1b24f RD |
202 | -- call Apply_Arithmetic_Overflow_Minimized_Eliminated below). N can be a |
203 | -- signed integer arithmetic operator (but not an if or case expression). | |
204 | -- It is also called for types other than signed integers. | |
acad3c0a AC |
205 | |
206 | procedure Apply_Arithmetic_Overflow_Minimized_Eliminated (Op : Node_Id); | |
207 | -- Used to apply arithmetic overflow checks for the case where the overflow | |
a7f1b24f RD |
208 | -- checking mode is MINIMIZED or ELIMINATED and we have a signed integer |
209 | -- arithmetic op (which includes the case of if and case expressions). Note | |
210 | -- that Do_Overflow_Check may or may not be set for node Op. In these modes | |
211 | -- we have work to do even if overflow checking is suppressed. | |
acad3c0a | 212 | |
a91e9ac7 AC |
213 | procedure Apply_Division_Check |
214 | (N : Node_Id; | |
215 | Rlo : Uint; | |
216 | Rhi : Uint; | |
217 | ROK : Boolean); | |
218 | -- N is an N_Op_Div, N_Op_Rem, or N_Op_Mod node. This routine applies | |
219 | -- division checks as required if the Do_Division_Check flag is set. | |
220 | -- Rlo and Rhi give the possible range of the right operand, these values | |
221 | -- can be referenced and trusted only if ROK is set True. | |
222 | ||
223 | procedure Apply_Float_Conversion_Check | |
224 | (Ck_Node : Node_Id; | |
225 | Target_Typ : Entity_Id); | |
226 | -- The checks on a conversion from a floating-point type to an integer | |
227 | -- type are delicate. They have to be performed before conversion, they | |
228 | -- have to raise an exception when the operand is a NaN, and rounding must | |
229 | -- be taken into account to determine the safe bounds of the operand. | |
230 | ||
70482933 RK |
231 | procedure Apply_Selected_Length_Checks |
232 | (Ck_Node : Node_Id; | |
233 | Target_Typ : Entity_Id; | |
234 | Source_Typ : Entity_Id; | |
235 | Do_Static : Boolean); | |
236 | -- This is the subprogram that does all the work for Apply_Length_Check | |
237 | -- and Apply_Static_Length_Check. Expr, Target_Typ and Source_Typ are as | |
238 | -- described for the above routines. The Do_Static flag indicates that | |
239 | -- only a static check is to be done. | |
240 | ||
241 | procedure Apply_Selected_Range_Checks | |
242 | (Ck_Node : Node_Id; | |
243 | Target_Typ : Entity_Id; | |
244 | Source_Typ : Entity_Id; | |
245 | Do_Static : Boolean); | |
246 | -- This is the subprogram that does all the work for Apply_Range_Check. | |
247 | -- Expr, Target_Typ and Source_Typ are as described for the above | |
248 | -- routine. The Do_Static flag indicates that only a static check is | |
249 | -- to be done. | |
250 | ||
939c12d2 | 251 | type Check_Type is new Check_Id range Access_Check .. Division_Check; |
2ede092b RD |
252 | function Check_Needed (Nod : Node_Id; Check : Check_Type) return Boolean; |
253 | -- This function is used to see if an access or division by zero check is | |
254 | -- needed. The check is to be applied to a single variable appearing in the | |
255 | -- source, and N is the node for the reference. If N is not of this form, | |
256 | -- True is returned with no further processing. If N is of the right form, | |
257 | -- then further processing determines if the given Check is needed. | |
258 | -- | |
259 | -- The particular circuit is to see if we have the case of a check that is | |
260 | -- not needed because it appears in the right operand of a short circuited | |
261 | -- conditional where the left operand guards the check. For example: | |
262 | -- | |
263 | -- if Var = 0 or else Q / Var > 12 then | |
264 | -- ... | |
265 | -- end if; | |
266 | -- | |
267 | -- In this example, the division check is not required. At the same time | |
268 | -- we can issue warnings for suspicious use of non-short-circuited forms, | |
269 | -- such as: | |
270 | -- | |
271 | -- if Var = 0 or Q / Var > 12 then | |
272 | -- ... | |
273 | -- end if; | |
274 | ||
fbf5a39b AC |
275 | procedure Find_Check |
276 | (Expr : Node_Id; | |
277 | Check_Type : Character; | |
278 | Target_Type : Entity_Id; | |
279 | Entry_OK : out Boolean; | |
280 | Check_Num : out Nat; | |
281 | Ent : out Entity_Id; | |
282 | Ofs : out Uint); | |
283 | -- This routine is used by Enable_Range_Check and Enable_Overflow_Check | |
284 | -- to see if a check is of the form for optimization, and if so, to see | |
285 | -- if it has already been performed. Expr is the expression to check, | |
286 | -- and Check_Type is 'R' for a range check, 'O' for an overflow check. | |
287 | -- Target_Type is the target type for a range check, and Empty for an | |
288 | -- overflow check. If the entry is not of the form for optimization, | |
289 | -- then Entry_OK is set to False, and the remaining out parameters | |
290 | -- are undefined. If the entry is OK, then Ent/Ofs are set to the | |
291 | -- entity and offset from the expression. Check_Num is the number of | |
292 | -- a matching saved entry in Saved_Checks, or zero if no such entry | |
293 | -- is located. | |
294 | ||
70482933 RK |
295 | function Get_Discriminal (E : Entity_Id; Bound : Node_Id) return Node_Id; |
296 | -- If a discriminal is used in constraining a prival, Return reference | |
297 | -- to the discriminal of the protected body (which renames the parameter | |
298 | -- of the enclosing protected operation). This clumsy transformation is | |
299 | -- needed because privals are created too late and their actual subtypes | |
300 | -- are not available when analysing the bodies of the protected operations. | |
c064e066 RD |
301 | -- This function is called whenever the bound is an entity and the scope |
302 | -- indicates a protected operation. If the bound is an in-parameter of | |
303 | -- a protected operation that is not a prival, the function returns the | |
304 | -- bound itself. | |
70482933 RK |
305 | -- To be cleaned up??? |
306 | ||
307 | function Guard_Access | |
308 | (Cond : Node_Id; | |
309 | Loc : Source_Ptr; | |
6b6fcd3e | 310 | Ck_Node : Node_Id) return Node_Id; |
70482933 RK |
311 | -- In the access type case, guard the test with a test to ensure |
312 | -- that the access value is non-null, since the checks do not | |
313 | -- not apply to null access values. | |
314 | ||
315 | procedure Install_Static_Check (R_Cno : Node_Id; Loc : Source_Ptr); | |
316 | -- Called by Apply_{Length,Range}_Checks to rewrite the tree with the | |
317 | -- Constraint_Error node. | |
318 | ||
acad3c0a AC |
319 | function Is_Signed_Integer_Arithmetic_Op (N : Node_Id) return Boolean; |
320 | -- Returns True if node N is for an arithmetic operation with signed | |
4b1c4f20 RD |
321 | -- integer operands. This includes unary and binary operators, and also |
322 | -- if and case expression nodes where the dependent expressions are of | |
323 | -- a signed integer type. These are the kinds of nodes for which special | |
3ada950b | 324 | -- handling applies in MINIMIZED or ELIMINATED overflow checking mode. |
acad3c0a | 325 | |
c064e066 RD |
326 | function Range_Or_Validity_Checks_Suppressed |
327 | (Expr : Node_Id) return Boolean; | |
328 | -- Returns True if either range or validity checks or both are suppressed | |
329 | -- for the type of the given expression, or, if the expression is the name | |
330 | -- of an entity, if these checks are suppressed for the entity. | |
331 | ||
70482933 RK |
332 | function Selected_Length_Checks |
333 | (Ck_Node : Node_Id; | |
334 | Target_Typ : Entity_Id; | |
335 | Source_Typ : Entity_Id; | |
6b6fcd3e | 336 | Warn_Node : Node_Id) return Check_Result; |
70482933 RK |
337 | -- Like Apply_Selected_Length_Checks, except it doesn't modify |
338 | -- anything, just returns a list of nodes as described in the spec of | |
339 | -- this package for the Range_Check function. | |
340 | ||
341 | function Selected_Range_Checks | |
342 | (Ck_Node : Node_Id; | |
343 | Target_Typ : Entity_Id; | |
344 | Source_Typ : Entity_Id; | |
6b6fcd3e | 345 | Warn_Node : Node_Id) return Check_Result; |
70482933 RK |
346 | -- Like Apply_Selected_Range_Checks, except it doesn't modify anything, |
347 | -- just returns a list of nodes as described in the spec of this package | |
348 | -- for the Range_Check function. | |
349 | ||
350 | ------------------------------ | |
351 | -- Access_Checks_Suppressed -- | |
352 | ------------------------------ | |
353 | ||
354 | function Access_Checks_Suppressed (E : Entity_Id) return Boolean is | |
355 | begin | |
fbf5a39b AC |
356 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
357 | return Is_Check_Suppressed (E, Access_Check); | |
358 | else | |
3217f71e | 359 | return Scope_Suppress.Suppress (Access_Check); |
fbf5a39b | 360 | end if; |
70482933 RK |
361 | end Access_Checks_Suppressed; |
362 | ||
363 | ------------------------------------- | |
364 | -- Accessibility_Checks_Suppressed -- | |
365 | ------------------------------------- | |
366 | ||
367 | function Accessibility_Checks_Suppressed (E : Entity_Id) return Boolean is | |
368 | begin | |
fbf5a39b AC |
369 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
370 | return Is_Check_Suppressed (E, Accessibility_Check); | |
371 | else | |
3217f71e | 372 | return Scope_Suppress.Suppress (Accessibility_Check); |
fbf5a39b | 373 | end if; |
70482933 RK |
374 | end Accessibility_Checks_Suppressed; |
375 | ||
11b4899f JM |
376 | ----------------------------- |
377 | -- Activate_Division_Check -- | |
378 | ----------------------------- | |
379 | ||
380 | procedure Activate_Division_Check (N : Node_Id) is | |
381 | begin | |
382 | Set_Do_Division_Check (N, True); | |
383 | Possible_Local_Raise (N, Standard_Constraint_Error); | |
384 | end Activate_Division_Check; | |
385 | ||
386 | ----------------------------- | |
387 | -- Activate_Overflow_Check -- | |
388 | ----------------------------- | |
389 | ||
390 | procedure Activate_Overflow_Check (N : Node_Id) is | |
391 | begin | |
396eb900 AC |
392 | -- Nothing to do for unconstrained floating-point types (the test for |
393 | -- Etype (N) being present seems necessary in some cases, should be | |
e943fe8a AC |
394 | -- tracked down, but for now just ignore the check in this case ???), |
395 | -- except if Check_Float_Overflow is set. | |
396eb900 AC |
396 | |
397 | if Present (Etype (N)) | |
398 | and then Is_Floating_Point_Type (Etype (N)) | |
399 | and then not Is_Constrained (Etype (N)) | |
e943fe8a | 400 | and then not Check_Float_Overflow |
396eb900 AC |
401 | then |
402 | return; | |
be4c5193 | 403 | end if; |
396eb900 AC |
404 | |
405 | -- Nothing to do for Rem/Mod/Plus (overflow not possible) | |
406 | ||
407 | if Nkind_In (N, N_Op_Rem, N_Op_Mod, N_Op_Plus) then | |
408 | return; | |
409 | end if; | |
410 | ||
411 | -- Otherwise set the flag | |
412 | ||
413 | Set_Do_Overflow_Check (N, True); | |
414 | Possible_Local_Raise (N, Standard_Constraint_Error); | |
11b4899f JM |
415 | end Activate_Overflow_Check; |
416 | ||
417 | -------------------------- | |
418 | -- Activate_Range_Check -- | |
419 | -------------------------- | |
420 | ||
421 | procedure Activate_Range_Check (N : Node_Id) is | |
422 | begin | |
423 | Set_Do_Range_Check (N, True); | |
424 | Possible_Local_Raise (N, Standard_Constraint_Error); | |
425 | end Activate_Range_Check; | |
426 | ||
c064e066 RD |
427 | --------------------------------- |
428 | -- Alignment_Checks_Suppressed -- | |
429 | --------------------------------- | |
430 | ||
431 | function Alignment_Checks_Suppressed (E : Entity_Id) return Boolean is | |
432 | begin | |
433 | if Present (E) and then Checks_May_Be_Suppressed (E) then | |
434 | return Is_Check_Suppressed (E, Alignment_Check); | |
435 | else | |
3217f71e | 436 | return Scope_Suppress.Suppress (Alignment_Check); |
c064e066 RD |
437 | end if; |
438 | end Alignment_Checks_Suppressed; | |
439 | ||
b07b7ace AC |
440 | ---------------------------------- |
441 | -- Allocation_Checks_Suppressed -- | |
442 | ---------------------------------- | |
443 | ||
59f4d038 RD |
444 | -- Note: at the current time there are no calls to this function, because |
445 | -- the relevant check is in the run-time, so it is not a check that the | |
446 | -- compiler can suppress anyway, but we still have to recognize the check | |
447 | -- name Allocation_Check since it is part of the standard. | |
448 | ||
b07b7ace AC |
449 | function Allocation_Checks_Suppressed (E : Entity_Id) return Boolean is |
450 | begin | |
451 | if Present (E) and then Checks_May_Be_Suppressed (E) then | |
452 | return Is_Check_Suppressed (E, Allocation_Check); | |
453 | else | |
454 | return Scope_Suppress.Suppress (Allocation_Check); | |
455 | end if; | |
456 | end Allocation_Checks_Suppressed; | |
457 | ||
70482933 RK |
458 | ------------------------- |
459 | -- Append_Range_Checks -- | |
460 | ------------------------- | |
461 | ||
462 | procedure Append_Range_Checks | |
463 | (Checks : Check_Result; | |
464 | Stmts : List_Id; | |
465 | Suppress_Typ : Entity_Id; | |
466 | Static_Sloc : Source_Ptr; | |
467 | Flag_Node : Node_Id) | |
468 | is | |
fbf5a39b AC |
469 | Internal_Flag_Node : constant Node_Id := Flag_Node; |
470 | Internal_Static_Sloc : constant Source_Ptr := Static_Sloc; | |
471 | ||
70482933 | 472 | Checks_On : constant Boolean := |
15f0f591 AC |
473 | (not Index_Checks_Suppressed (Suppress_Typ)) |
474 | or else (not Range_Checks_Suppressed (Suppress_Typ)); | |
70482933 RK |
475 | |
476 | begin | |
477 | -- For now we just return if Checks_On is false, however this should | |
478 | -- be enhanced to check for an always True value in the condition | |
479 | -- and to generate a compilation warning??? | |
480 | ||
481 | if not Checks_On then | |
482 | return; | |
483 | end if; | |
484 | ||
485 | for J in 1 .. 2 loop | |
486 | exit when No (Checks (J)); | |
487 | ||
488 | if Nkind (Checks (J)) = N_Raise_Constraint_Error | |
489 | and then Present (Condition (Checks (J))) | |
490 | then | |
491 | if not Has_Dynamic_Range_Check (Internal_Flag_Node) then | |
492 | Append_To (Stmts, Checks (J)); | |
493 | Set_Has_Dynamic_Range_Check (Internal_Flag_Node); | |
494 | end if; | |
495 | ||
496 | else | |
497 | Append_To | |
07fc65c4 GB |
498 | (Stmts, |
499 | Make_Raise_Constraint_Error (Internal_Static_Sloc, | |
500 | Reason => CE_Range_Check_Failed)); | |
70482933 RK |
501 | end if; |
502 | end loop; | |
503 | end Append_Range_Checks; | |
504 | ||
505 | ------------------------ | |
506 | -- Apply_Access_Check -- | |
507 | ------------------------ | |
508 | ||
509 | procedure Apply_Access_Check (N : Node_Id) is | |
510 | P : constant Node_Id := Prefix (N); | |
511 | ||
512 | begin | |
2ede092b RD |
513 | -- We do not need checks if we are not generating code (i.e. the |
514 | -- expander is not active). This is not just an optimization, there | |
515 | -- are cases (e.g. with pragma Debug) where generating the checks | |
516 | -- can cause real trouble). | |
6cdb2c6e | 517 | |
4460a9bc | 518 | if not Expander_Active then |
2ede092b | 519 | return; |
fbf5a39b | 520 | end if; |
70482933 | 521 | |
86ac5e79 | 522 | -- No check if short circuiting makes check unnecessary |
fbf5a39b | 523 | |
86ac5e79 ES |
524 | if not Check_Needed (P, Access_Check) then |
525 | return; | |
70482933 | 526 | end if; |
fbf5a39b | 527 | |
f2cbd970 JM |
528 | -- No check if accessing the Offset_To_Top component of a dispatch |
529 | -- table. They are safe by construction. | |
530 | ||
1be9633f AC |
531 | if Tagged_Type_Expansion |
532 | and then Present (Etype (P)) | |
f2cbd970 JM |
533 | and then RTU_Loaded (Ada_Tags) |
534 | and then RTE_Available (RE_Offset_To_Top_Ptr) | |
535 | and then Etype (P) = RTE (RE_Offset_To_Top_Ptr) | |
536 | then | |
537 | return; | |
538 | end if; | |
539 | ||
86ac5e79 | 540 | -- Otherwise go ahead and install the check |
fbf5a39b | 541 | |
2820d220 | 542 | Install_Null_Excluding_Check (P); |
70482933 RK |
543 | end Apply_Access_Check; |
544 | ||
545 | ------------------------------- | |
546 | -- Apply_Accessibility_Check -- | |
547 | ------------------------------- | |
548 | ||
e84e11ba GD |
549 | procedure Apply_Accessibility_Check |
550 | (N : Node_Id; | |
551 | Typ : Entity_Id; | |
552 | Insert_Node : Node_Id) | |
553 | is | |
70482933 | 554 | Loc : constant Source_Ptr := Sloc (N); |
996c8821 | 555 | Param_Ent : Entity_Id := Param_Entity (N); |
70482933 RK |
556 | Param_Level : Node_Id; |
557 | Type_Level : Node_Id; | |
558 | ||
559 | begin | |
d15f9422 AC |
560 | if Ada_Version >= Ada_2012 |
561 | and then not Present (Param_Ent) | |
562 | and then Is_Entity_Name (N) | |
563 | and then Ekind_In (Entity (N), E_Constant, E_Variable) | |
564 | and then Present (Effective_Extra_Accessibility (Entity (N))) | |
565 | then | |
566 | Param_Ent := Entity (N); | |
567 | while Present (Renamed_Object (Param_Ent)) loop | |
996c8821 | 568 | |
d15f9422 AC |
569 | -- Renamed_Object must return an Entity_Name here |
570 | -- because of preceding "Present (E_E_A (...))" test. | |
571 | ||
572 | Param_Ent := Entity (Renamed_Object (Param_Ent)); | |
573 | end loop; | |
574 | end if; | |
575 | ||
70482933 RK |
576 | if Inside_A_Generic then |
577 | return; | |
578 | ||
d175a2fa AC |
579 | -- Only apply the run-time check if the access parameter has an |
580 | -- associated extra access level parameter and when the level of the | |
581 | -- type is less deep than the level of the access parameter, and | |
582 | -- accessibility checks are not suppressed. | |
70482933 RK |
583 | |
584 | elsif Present (Param_Ent) | |
585 | and then Present (Extra_Accessibility (Param_Ent)) | |
d15f9422 | 586 | and then UI_Gt (Object_Access_Level (N), |
996c8821 | 587 | Deepest_Type_Access_Level (Typ)) |
70482933 RK |
588 | and then not Accessibility_Checks_Suppressed (Param_Ent) |
589 | and then not Accessibility_Checks_Suppressed (Typ) | |
590 | then | |
591 | Param_Level := | |
592 | New_Occurrence_Of (Extra_Accessibility (Param_Ent), Loc); | |
593 | ||
996c8821 RD |
594 | Type_Level := |
595 | Make_Integer_Literal (Loc, Deepest_Type_Access_Level (Typ)); | |
70482933 | 596 | |
16b05213 | 597 | -- Raise Program_Error if the accessibility level of the access |
86ac5e79 | 598 | -- parameter is deeper than the level of the target access type. |
70482933 | 599 | |
e84e11ba | 600 | Insert_Action (Insert_Node, |
70482933 RK |
601 | Make_Raise_Program_Error (Loc, |
602 | Condition => | |
603 | Make_Op_Gt (Loc, | |
604 | Left_Opnd => Param_Level, | |
07fc65c4 GB |
605 | Right_Opnd => Type_Level), |
606 | Reason => PE_Accessibility_Check_Failed)); | |
70482933 RK |
607 | |
608 | Analyze_And_Resolve (N); | |
609 | end if; | |
610 | end Apply_Accessibility_Check; | |
611 | ||
c064e066 RD |
612 | -------------------------------- |
613 | -- Apply_Address_Clause_Check -- | |
614 | -------------------------------- | |
615 | ||
616 | procedure Apply_Address_Clause_Check (E : Entity_Id; N : Node_Id) is | |
6f5c2c4b AC |
617 | pragma Assert (Nkind (N) = N_Freeze_Entity); |
618 | ||
c064e066 RD |
619 | AC : constant Node_Id := Address_Clause (E); |
620 | Loc : constant Source_Ptr := Sloc (AC); | |
621 | Typ : constant Entity_Id := Etype (E); | |
622 | Aexp : constant Node_Id := Expression (AC); | |
980f237d | 623 | |
980f237d | 624 | Expr : Node_Id; |
c064e066 RD |
625 | -- Address expression (not necessarily the same as Aexp, for example |
626 | -- when Aexp is a reference to a constant, in which case Expr gets | |
aca670a0 | 627 | -- reset to reference the value expression of the constant). |
c064e066 | 628 | |
c064e066 RD |
629 | procedure Compile_Time_Bad_Alignment; |
630 | -- Post error warnings when alignment is known to be incompatible. Note | |
631 | -- that we do not go as far as inserting a raise of Program_Error since | |
632 | -- this is an erroneous case, and it may happen that we are lucky and an | |
f4cd2542 | 633 | -- underaligned address turns out to be OK after all. |
c064e066 RD |
634 | |
635 | -------------------------------- | |
636 | -- Compile_Time_Bad_Alignment -- | |
637 | -------------------------------- | |
638 | ||
639 | procedure Compile_Time_Bad_Alignment is | |
640 | begin | |
f4cd2542 | 641 | if Address_Clause_Overlay_Warnings then |
c064e066 | 642 | Error_Msg_FE |
685bc70f | 643 | ("?o?specified address for& may be inconsistent with alignment", |
c064e066 RD |
644 | Aexp, E); |
645 | Error_Msg_FE | |
685bc70f | 646 | ("\?o?program execution may be erroneous (RM 13.3(27))", |
c064e066 | 647 | Aexp, E); |
2642f998 | 648 | Set_Address_Warning_Posted (AC); |
c064e066 RD |
649 | end if; |
650 | end Compile_Time_Bad_Alignment; | |
980f237d | 651 | |
939c12d2 | 652 | -- Start of processing for Apply_Address_Clause_Check |
91b1417d | 653 | |
980f237d | 654 | begin |
f4cd2542 EB |
655 | -- See if alignment check needed. Note that we never need a check if the |
656 | -- maximum alignment is one, since the check will always succeed. | |
657 | ||
658 | -- Note: we do not check for checks suppressed here, since that check | |
659 | -- was done in Sem_Ch13 when the address clause was processed. We are | |
660 | -- only called if checks were not suppressed. The reason for this is | |
661 | -- that we have to delay the call to Apply_Alignment_Check till freeze | |
662 | -- time (so that all types etc are elaborated), but we have to check | |
663 | -- the status of check suppressing at the point of the address clause. | |
664 | ||
665 | if No (AC) | |
666 | or else not Check_Address_Alignment (AC) | |
667 | or else Maximum_Alignment = 1 | |
668 | then | |
669 | return; | |
670 | end if; | |
671 | ||
672 | -- Obtain expression from address clause | |
fbf5a39b | 673 | |
c064e066 RD |
674 | Expr := Expression (AC); |
675 | ||
676 | -- The following loop digs for the real expression to use in the check | |
677 | ||
678 | loop | |
679 | -- For constant, get constant expression | |
680 | ||
681 | if Is_Entity_Name (Expr) | |
682 | and then Ekind (Entity (Expr)) = E_Constant | |
683 | then | |
684 | Expr := Constant_Value (Entity (Expr)); | |
685 | ||
686 | -- For unchecked conversion, get result to convert | |
687 | ||
688 | elsif Nkind (Expr) = N_Unchecked_Type_Conversion then | |
689 | Expr := Expression (Expr); | |
690 | ||
691 | -- For (common case) of To_Address call, get argument | |
692 | ||
693 | elsif Nkind (Expr) = N_Function_Call | |
694 | and then Is_Entity_Name (Name (Expr)) | |
695 | and then Is_RTE (Entity (Name (Expr)), RE_To_Address) | |
696 | then | |
697 | Expr := First (Parameter_Associations (Expr)); | |
698 | ||
699 | if Nkind (Expr) = N_Parameter_Association then | |
700 | Expr := Explicit_Actual_Parameter (Expr); | |
701 | end if; | |
702 | ||
703 | -- We finally have the real expression | |
704 | ||
705 | else | |
706 | exit; | |
707 | end if; | |
708 | end loop; | |
709 | ||
f4cd2542 | 710 | -- See if we know that Expr has a bad alignment at compile time |
980f237d GB |
711 | |
712 | if Compile_Time_Known_Value (Expr) | |
ddda9d0f | 713 | and then (Known_Alignment (E) or else Known_Alignment (Typ)) |
980f237d | 714 | then |
ddda9d0f AC |
715 | declare |
716 | AL : Uint := Alignment (Typ); | |
717 | ||
718 | begin | |
719 | -- The object alignment might be more restrictive than the | |
720 | -- type alignment. | |
721 | ||
722 | if Known_Alignment (E) then | |
723 | AL := Alignment (E); | |
724 | end if; | |
725 | ||
726 | if Expr_Value (Expr) mod AL /= 0 then | |
c064e066 RD |
727 | Compile_Time_Bad_Alignment; |
728 | else | |
729 | return; | |
ddda9d0f AC |
730 | end if; |
731 | end; | |
980f237d | 732 | |
c064e066 RD |
733 | -- If the expression has the form X'Address, then we can find out if |
734 | -- the object X has an alignment that is compatible with the object E. | |
f4cd2542 EB |
735 | -- If it hasn't or we don't know, we defer issuing the warning until |
736 | -- the end of the compilation to take into account back end annotations. | |
980f237d | 737 | |
c064e066 RD |
738 | elsif Nkind (Expr) = N_Attribute_Reference |
739 | and then Attribute_Name (Expr) = Name_Address | |
f4cd2542 | 740 | and then Has_Compatible_Alignment (E, Prefix (Expr)) = Known_Compatible |
c064e066 | 741 | then |
f4cd2542 | 742 | return; |
c064e066 | 743 | end if; |
980f237d | 744 | |
308e6f3a RW |
745 | -- Here we do not know if the value is acceptable. Strictly we don't |
746 | -- have to do anything, since if the alignment is bad, we have an | |
747 | -- erroneous program. However we are allowed to check for erroneous | |
748 | -- conditions and we decide to do this by default if the check is not | |
749 | -- suppressed. | |
c064e066 RD |
750 | |
751 | -- However, don't do the check if elaboration code is unwanted | |
752 | ||
753 | if Restriction_Active (No_Elaboration_Code) then | |
754 | return; | |
755 | ||
756 | -- Generate a check to raise PE if alignment may be inappropriate | |
757 | ||
758 | else | |
759 | -- If the original expression is a non-static constant, use the | |
760 | -- name of the constant itself rather than duplicating its | |
11b4899f | 761 | -- defining expression, which was extracted above. |
c064e066 | 762 | |
11b4899f JM |
763 | -- Note: Expr is empty if the address-clause is applied to in-mode |
764 | -- actuals (allowed by 13.1(22)). | |
765 | ||
766 | if not Present (Expr) | |
767 | or else | |
768 | (Is_Entity_Name (Expression (AC)) | |
769 | and then Ekind (Entity (Expression (AC))) = E_Constant | |
770 | and then Nkind (Parent (Entity (Expression (AC)))) | |
771 | = N_Object_Declaration) | |
c064e066 RD |
772 | then |
773 | Expr := New_Copy_Tree (Expression (AC)); | |
774 | else | |
775 | Remove_Side_Effects (Expr); | |
980f237d | 776 | end if; |
980f237d | 777 | |
6f5c2c4b AC |
778 | if No (Actions (N)) then |
779 | Set_Actions (N, New_List); | |
780 | end if; | |
781 | ||
782 | Prepend_To (Actions (N), | |
c064e066 RD |
783 | Make_Raise_Program_Error (Loc, |
784 | Condition => | |
785 | Make_Op_Ne (Loc, | |
786 | Left_Opnd => | |
787 | Make_Op_Mod (Loc, | |
788 | Left_Opnd => | |
789 | Unchecked_Convert_To | |
790 | (RTE (RE_Integer_Address), Expr), | |
791 | Right_Opnd => | |
792 | Make_Attribute_Reference (Loc, | |
6f5c2c4b | 793 | Prefix => New_Occurrence_Of (E, Loc), |
c064e066 RD |
794 | Attribute_Name => Name_Alignment)), |
795 | Right_Opnd => Make_Integer_Literal (Loc, Uint_0)), | |
aca670a0 AC |
796 | Reason => PE_Misaligned_Address_Value)); |
797 | ||
798 | Warning_Msg := No_Error_Msg; | |
6f5c2c4b | 799 | Analyze (First (Actions (N)), Suppress => All_Checks); |
3b4598a7 | 800 | |
aca670a0 AC |
801 | -- If the address clause generated a warning message (for example, |
802 | -- from Warn_On_Non_Local_Exception mode with the active restriction | |
803 | -- No_Exception_Propagation). | |
804 | ||
805 | if Warning_Msg /= No_Error_Msg then | |
806 | ||
807 | -- If the expression has a known at compile time value, then | |
808 | -- once we know the alignment of the type, we can check if the | |
809 | -- exception will be raised or not, and if not, we don't need | |
810 | -- the warning so we will kill the warning later on. | |
811 | ||
812 | if Compile_Time_Known_Value (Expr) then | |
813 | Alignment_Warnings.Append | |
814 | ((E => E, A => Expr_Value (Expr), W => Warning_Msg)); | |
815 | end if; | |
816 | ||
817 | -- Add explanation of the warning that is generated by the check | |
3b4598a7 | 818 | |
6fd0a72a | 819 | Error_Msg_N |
aca670a0 AC |
820 | ("\address value may be incompatible with alignment " |
821 | & "of object?X?", AC); | |
3b4598a7 | 822 | end if; |
6fd0a72a | 823 | |
c064e066 RD |
824 | return; |
825 | end if; | |
fbf5a39b AC |
826 | |
827 | exception | |
c064e066 RD |
828 | -- If we have some missing run time component in configurable run time |
829 | -- mode then just skip the check (it is not required in any case). | |
830 | ||
fbf5a39b AC |
831 | when RE_Not_Available => |
832 | return; | |
c064e066 | 833 | end Apply_Address_Clause_Check; |
980f237d | 834 | |
70482933 RK |
835 | ------------------------------------- |
836 | -- Apply_Arithmetic_Overflow_Check -- | |
837 | ------------------------------------- | |
838 | ||
acad3c0a AC |
839 | procedure Apply_Arithmetic_Overflow_Check (N : Node_Id) is |
840 | begin | |
841 | -- Use old routine in almost all cases (the only case we are treating | |
5707e389 | 842 | -- specially is the case of a signed integer arithmetic op with the |
a7f1b24f | 843 | -- overflow checking mode set to MINIMIZED or ELIMINATED). |
acad3c0a | 844 | |
a7f1b24f | 845 | if Overflow_Check_Mode = Strict |
acad3c0a AC |
846 | or else not Is_Signed_Integer_Arithmetic_Op (N) |
847 | then | |
a7f1b24f | 848 | Apply_Arithmetic_Overflow_Strict (N); |
acad3c0a | 849 | |
5707e389 AC |
850 | -- Otherwise use the new routine for the case of a signed integer |
851 | -- arithmetic op, with Do_Overflow_Check set to True, and the checking | |
852 | -- mode is MINIMIZED or ELIMINATED. | |
acad3c0a AC |
853 | |
854 | else | |
855 | Apply_Arithmetic_Overflow_Minimized_Eliminated (N); | |
856 | end if; | |
857 | end Apply_Arithmetic_Overflow_Check; | |
858 | ||
a7f1b24f RD |
859 | -------------------------------------- |
860 | -- Apply_Arithmetic_Overflow_Strict -- | |
861 | -------------------------------------- | |
acad3c0a | 862 | |
ec2dd67a RD |
863 | -- This routine is called only if the type is an integer type, and a |
864 | -- software arithmetic overflow check may be needed for op (add, subtract, | |
865 | -- or multiply). This check is performed only if Software_Overflow_Checking | |
866 | -- is enabled and Do_Overflow_Check is set. In this case we expand the | |
867 | -- operation into a more complex sequence of tests that ensures that | |
868 | -- overflow is properly caught. | |
70482933 | 869 | |
a7f1b24f RD |
870 | -- This is used in CHECKED modes. It is identical to the code for this |
871 | -- cases before the big overflow earthquake, thus ensuring that in this | |
872 | -- modes we have compatible behavior (and reliability) to what was there | |
873 | -- before. It is also called for types other than signed integers, and if | |
874 | -- the Do_Overflow_Check flag is off. | |
acad3c0a AC |
875 | |
876 | -- Note: we also call this routine if we decide in the MINIMIZED case | |
877 | -- to give up and just generate an overflow check without any fuss. | |
878 | ||
a7f1b24f | 879 | procedure Apply_Arithmetic_Overflow_Strict (N : Node_Id) is |
5707e389 AC |
880 | Loc : constant Source_Ptr := Sloc (N); |
881 | Typ : constant Entity_Id := Etype (N); | |
882 | Rtyp : constant Entity_Id := Root_Type (Typ); | |
70482933 RK |
883 | |
884 | begin | |
a7f1b24f RD |
885 | -- Nothing to do if Do_Overflow_Check not set or overflow checks |
886 | -- suppressed. | |
887 | ||
888 | if not Do_Overflow_Check (N) then | |
889 | return; | |
890 | end if; | |
891 | ||
ec2dd67a RD |
892 | -- An interesting special case. If the arithmetic operation appears as |
893 | -- the operand of a type conversion: | |
894 | ||
895 | -- type1 (x op y) | |
896 | ||
897 | -- and all the following conditions apply: | |
898 | ||
899 | -- arithmetic operation is for a signed integer type | |
900 | -- target type type1 is a static integer subtype | |
901 | -- range of x and y are both included in the range of type1 | |
902 | -- range of x op y is included in the range of type1 | |
903 | -- size of type1 is at least twice the result size of op | |
904 | ||
905 | -- then we don't do an overflow check in any case, instead we transform | |
906 | -- the operation so that we end up with: | |
907 | ||
908 | -- type1 (type1 (x) op type1 (y)) | |
909 | ||
910 | -- This avoids intermediate overflow before the conversion. It is | |
911 | -- explicitly permitted by RM 3.5.4(24): | |
912 | ||
913 | -- For the execution of a predefined operation of a signed integer | |
914 | -- type, the implementation need not raise Constraint_Error if the | |
915 | -- result is outside the base range of the type, so long as the | |
916 | -- correct result is produced. | |
917 | ||
918 | -- It's hard to imagine that any programmer counts on the exception | |
919 | -- being raised in this case, and in any case it's wrong coding to | |
920 | -- have this expectation, given the RM permission. Furthermore, other | |
921 | -- Ada compilers do allow such out of range results. | |
922 | ||
923 | -- Note that we do this transformation even if overflow checking is | |
924 | -- off, since this is precisely about giving the "right" result and | |
925 | -- avoiding the need for an overflow check. | |
926 | ||
eaa826f8 RD |
927 | -- Note: this circuit is partially redundant with respect to the similar |
928 | -- processing in Exp_Ch4.Expand_N_Type_Conversion, but the latter deals | |
929 | -- with cases that do not come through here. We still need the following | |
930 | -- processing even with the Exp_Ch4 code in place, since we want to be | |
931 | -- sure not to generate the arithmetic overflow check in these cases | |
932 | -- (Exp_Ch4 would have a hard time removing them once generated). | |
933 | ||
ec2dd67a RD |
934 | if Is_Signed_Integer_Type (Typ) |
935 | and then Nkind (Parent (N)) = N_Type_Conversion | |
70482933 | 936 | then |
b6b5cca8 | 937 | Conversion_Optimization : declare |
ec2dd67a | 938 | Target_Type : constant Entity_Id := |
15f0f591 | 939 | Base_Type (Entity (Subtype_Mark (Parent (N)))); |
ec2dd67a RD |
940 | |
941 | Llo, Lhi : Uint; | |
942 | Rlo, Rhi : Uint; | |
943 | LOK, ROK : Boolean; | |
944 | ||
945 | Vlo : Uint; | |
946 | Vhi : Uint; | |
947 | VOK : Boolean; | |
948 | ||
949 | Tlo : Uint; | |
950 | Thi : Uint; | |
951 | ||
952 | begin | |
953 | if Is_Integer_Type (Target_Type) | |
954 | and then RM_Size (Root_Type (Target_Type)) >= 2 * RM_Size (Rtyp) | |
955 | then | |
956 | Tlo := Expr_Value (Type_Low_Bound (Target_Type)); | |
957 | Thi := Expr_Value (Type_High_Bound (Target_Type)); | |
958 | ||
c800f862 RD |
959 | Determine_Range |
960 | (Left_Opnd (N), LOK, Llo, Lhi, Assume_Valid => True); | |
961 | Determine_Range | |
962 | (Right_Opnd (N), ROK, Rlo, Rhi, Assume_Valid => True); | |
ec2dd67a RD |
963 | |
964 | if (LOK and ROK) | |
965 | and then Tlo <= Llo and then Lhi <= Thi | |
966 | and then Tlo <= Rlo and then Rhi <= Thi | |
967 | then | |
c800f862 | 968 | Determine_Range (N, VOK, Vlo, Vhi, Assume_Valid => True); |
ec2dd67a RD |
969 | |
970 | if VOK and then Tlo <= Vlo and then Vhi <= Thi then | |
971 | Rewrite (Left_Opnd (N), | |
972 | Make_Type_Conversion (Loc, | |
973 | Subtype_Mark => New_Occurrence_Of (Target_Type, Loc), | |
974 | Expression => Relocate_Node (Left_Opnd (N)))); | |
975 | ||
976 | Rewrite (Right_Opnd (N), | |
977 | Make_Type_Conversion (Loc, | |
978 | Subtype_Mark => New_Occurrence_Of (Target_Type, Loc), | |
979 | Expression => Relocate_Node (Right_Opnd (N)))); | |
980 | ||
4fb0b3f0 AC |
981 | -- Rewrite the conversion operand so that the original |
982 | -- node is retained, in order to avoid the warning for | |
983 | -- redundant conversions in Resolve_Type_Conversion. | |
984 | ||
985 | Rewrite (N, Relocate_Node (N)); | |
986 | ||
ec2dd67a | 987 | Set_Etype (N, Target_Type); |
4fb0b3f0 | 988 | |
ec2dd67a RD |
989 | Analyze_And_Resolve (Left_Opnd (N), Target_Type); |
990 | Analyze_And_Resolve (Right_Opnd (N), Target_Type); | |
991 | ||
992 | -- Given that the target type is twice the size of the | |
993 | -- source type, overflow is now impossible, so we can | |
994 | -- safely kill the overflow check and return. | |
995 | ||
996 | Set_Do_Overflow_Check (N, False); | |
997 | return; | |
998 | end if; | |
999 | end if; | |
1000 | end if; | |
b6b5cca8 | 1001 | end Conversion_Optimization; |
70482933 RK |
1002 | end if; |
1003 | ||
ec2dd67a RD |
1004 | -- Now see if an overflow check is required |
1005 | ||
1006 | declare | |
1007 | Siz : constant Int := UI_To_Int (Esize (Rtyp)); | |
1008 | Dsiz : constant Int := Siz * 2; | |
1009 | Opnod : Node_Id; | |
1010 | Ctyp : Entity_Id; | |
1011 | Opnd : Node_Id; | |
1012 | Cent : RE_Id; | |
70482933 | 1013 | |
ec2dd67a RD |
1014 | begin |
1015 | -- Skip check if back end does overflow checks, or the overflow flag | |
fdfcc663 AC |
1016 | -- is not set anyway, or we are not doing code expansion, or the |
1017 | -- parent node is a type conversion whose operand is an arithmetic | |
1018 | -- operation on signed integers on which the expander can promote | |
0c0c6f49 | 1019 | -- later the operands to type Integer (see Expand_N_Type_Conversion). |
70482933 | 1020 | |
ec2dd67a RD |
1021 | -- Special case CLI target, where arithmetic overflow checks can be |
1022 | -- performed for integer and long_integer | |
70482933 | 1023 | |
ec2dd67a RD |
1024 | if Backend_Overflow_Checks_On_Target |
1025 | or else not Do_Overflow_Check (N) | |
4460a9bc | 1026 | or else not Expander_Active |
fdfcc663 AC |
1027 | or else (Present (Parent (N)) |
1028 | and then Nkind (Parent (N)) = N_Type_Conversion | |
1029 | and then Integer_Promotion_Possible (Parent (N))) | |
ec2dd67a RD |
1030 | or else |
1031 | (VM_Target = CLI_Target and then Siz >= Standard_Integer_Size) | |
1032 | then | |
1033 | return; | |
1034 | end if; | |
70482933 | 1035 | |
ec2dd67a RD |
1036 | -- Otherwise, generate the full general code for front end overflow |
1037 | -- detection, which works by doing arithmetic in a larger type: | |
70482933 | 1038 | |
ec2dd67a | 1039 | -- x op y |
70482933 | 1040 | |
ec2dd67a | 1041 | -- is expanded into |
70482933 | 1042 | |
ec2dd67a | 1043 | -- Typ (Checktyp (x) op Checktyp (y)); |
70482933 | 1044 | |
ec2dd67a RD |
1045 | -- where Typ is the type of the original expression, and Checktyp is |
1046 | -- an integer type of sufficient length to hold the largest possible | |
1047 | -- result. | |
70482933 | 1048 | |
ec2dd67a RD |
1049 | -- If the size of check type exceeds the size of Long_Long_Integer, |
1050 | -- we use a different approach, expanding to: | |
70482933 | 1051 | |
ec2dd67a | 1052 | -- typ (xxx_With_Ovflo_Check (Integer_64 (x), Integer (y))) |
70482933 | 1053 | |
ec2dd67a | 1054 | -- where xxx is Add, Multiply or Subtract as appropriate |
70482933 | 1055 | |
ec2dd67a RD |
1056 | -- Find check type if one exists |
1057 | ||
1058 | if Dsiz <= Standard_Integer_Size then | |
1059 | Ctyp := Standard_Integer; | |
70482933 | 1060 | |
ec2dd67a RD |
1061 | elsif Dsiz <= Standard_Long_Long_Integer_Size then |
1062 | Ctyp := Standard_Long_Long_Integer; | |
1063 | ||
ce532f42 | 1064 | -- No check type exists, use runtime call |
70482933 RK |
1065 | |
1066 | else | |
ec2dd67a RD |
1067 | if Nkind (N) = N_Op_Add then |
1068 | Cent := RE_Add_With_Ovflo_Check; | |
70482933 | 1069 | |
ec2dd67a RD |
1070 | elsif Nkind (N) = N_Op_Multiply then |
1071 | Cent := RE_Multiply_With_Ovflo_Check; | |
70482933 | 1072 | |
ec2dd67a RD |
1073 | else |
1074 | pragma Assert (Nkind (N) = N_Op_Subtract); | |
1075 | Cent := RE_Subtract_With_Ovflo_Check; | |
1076 | end if; | |
1077 | ||
1078 | Rewrite (N, | |
1079 | OK_Convert_To (Typ, | |
1080 | Make_Function_Call (Loc, | |
e4494292 | 1081 | Name => New_Occurrence_Of (RTE (Cent), Loc), |
ec2dd67a RD |
1082 | Parameter_Associations => New_List ( |
1083 | OK_Convert_To (RTE (RE_Integer_64), Left_Opnd (N)), | |
1084 | OK_Convert_To (RTE (RE_Integer_64), Right_Opnd (N)))))); | |
70482933 | 1085 | |
ec2dd67a RD |
1086 | Analyze_And_Resolve (N, Typ); |
1087 | return; | |
1088 | end if; | |
70482933 | 1089 | |
ec2dd67a RD |
1090 | -- If we fall through, we have the case where we do the arithmetic |
1091 | -- in the next higher type and get the check by conversion. In these | |
1092 | -- cases Ctyp is set to the type to be used as the check type. | |
70482933 | 1093 | |
ec2dd67a | 1094 | Opnod := Relocate_Node (N); |
70482933 | 1095 | |
ec2dd67a | 1096 | Opnd := OK_Convert_To (Ctyp, Left_Opnd (Opnod)); |
70482933 | 1097 | |
ec2dd67a RD |
1098 | Analyze (Opnd); |
1099 | Set_Etype (Opnd, Ctyp); | |
1100 | Set_Analyzed (Opnd, True); | |
1101 | Set_Left_Opnd (Opnod, Opnd); | |
70482933 | 1102 | |
ec2dd67a | 1103 | Opnd := OK_Convert_To (Ctyp, Right_Opnd (Opnod)); |
70482933 | 1104 | |
ec2dd67a RD |
1105 | Analyze (Opnd); |
1106 | Set_Etype (Opnd, Ctyp); | |
1107 | Set_Analyzed (Opnd, True); | |
1108 | Set_Right_Opnd (Opnod, Opnd); | |
70482933 | 1109 | |
ec2dd67a RD |
1110 | -- The type of the operation changes to the base type of the check |
1111 | -- type, and we reset the overflow check indication, since clearly no | |
1112 | -- overflow is possible now that we are using a double length type. | |
1113 | -- We also set the Analyzed flag to avoid a recursive attempt to | |
1114 | -- expand the node. | |
70482933 | 1115 | |
ec2dd67a RD |
1116 | Set_Etype (Opnod, Base_Type (Ctyp)); |
1117 | Set_Do_Overflow_Check (Opnod, False); | |
1118 | Set_Analyzed (Opnod, True); | |
70482933 | 1119 | |
ec2dd67a | 1120 | -- Now build the outer conversion |
70482933 | 1121 | |
ec2dd67a RD |
1122 | Opnd := OK_Convert_To (Typ, Opnod); |
1123 | Analyze (Opnd); | |
1124 | Set_Etype (Opnd, Typ); | |
fbf5a39b | 1125 | |
ec2dd67a RD |
1126 | -- In the discrete type case, we directly generate the range check |
1127 | -- for the outer operand. This range check will implement the | |
1128 | -- required overflow check. | |
fbf5a39b | 1129 | |
ec2dd67a RD |
1130 | if Is_Discrete_Type (Typ) then |
1131 | Rewrite (N, Opnd); | |
1132 | Generate_Range_Check | |
1133 | (Expression (N), Typ, CE_Overflow_Check_Failed); | |
fbf5a39b | 1134 | |
ec2dd67a RD |
1135 | -- For other types, we enable overflow checking on the conversion, |
1136 | -- after setting the node as analyzed to prevent recursive attempts | |
1137 | -- to expand the conversion node. | |
fbf5a39b | 1138 | |
ec2dd67a RD |
1139 | else |
1140 | Set_Analyzed (Opnd, True); | |
1141 | Enable_Overflow_Check (Opnd); | |
1142 | Rewrite (N, Opnd); | |
1143 | end if; | |
1144 | ||
1145 | exception | |
1146 | when RE_Not_Available => | |
1147 | return; | |
1148 | end; | |
a7f1b24f | 1149 | end Apply_Arithmetic_Overflow_Strict; |
acad3c0a AC |
1150 | |
1151 | ---------------------------------------------------- | |
1152 | -- Apply_Arithmetic_Overflow_Minimized_Eliminated -- | |
1153 | ---------------------------------------------------- | |
1154 | ||
1155 | procedure Apply_Arithmetic_Overflow_Minimized_Eliminated (Op : Node_Id) is | |
1156 | pragma Assert (Is_Signed_Integer_Arithmetic_Op (Op)); | |
acad3c0a AC |
1157 | |
1158 | Loc : constant Source_Ptr := Sloc (Op); | |
1159 | P : constant Node_Id := Parent (Op); | |
1160 | ||
d79059a3 AC |
1161 | LLIB : constant Entity_Id := Base_Type (Standard_Long_Long_Integer); |
1162 | -- Operands and results are of this type when we convert | |
1163 | ||
acad3c0a AC |
1164 | Result_Type : constant Entity_Id := Etype (Op); |
1165 | -- Original result type | |
1166 | ||
15c94a55 | 1167 | Check_Mode : constant Overflow_Mode_Type := Overflow_Check_Mode; |
acad3c0a AC |
1168 | pragma Assert (Check_Mode in Minimized_Or_Eliminated); |
1169 | ||
1170 | Lo, Hi : Uint; | |
1171 | -- Ranges of values for result | |
1172 | ||
1173 | begin | |
1174 | -- Nothing to do if our parent is one of the following: | |
1175 | ||
4b1c4f20 | 1176 | -- Another signed integer arithmetic op |
acad3c0a AC |
1177 | -- A membership operation |
1178 | -- A comparison operation | |
1179 | ||
1180 | -- In all these cases, we will process at the higher level (and then | |
1181 | -- this node will be processed during the downwards recursion that | |
a7f1b24f | 1182 | -- is part of the processing in Minimize_Eliminate_Overflows). |
acad3c0a AC |
1183 | |
1184 | if Is_Signed_Integer_Arithmetic_Op (P) | |
71fb4dc8 AC |
1185 | or else Nkind (P) in N_Membership_Test |
1186 | or else Nkind (P) in N_Op_Compare | |
f6194278 | 1187 | |
f6636994 AC |
1188 | -- This is also true for an alternative in a case expression |
1189 | ||
1190 | or else Nkind (P) = N_Case_Expression_Alternative | |
1191 | ||
1192 | -- This is also true for a range operand in a membership test | |
f6194278 | 1193 | |
71fb4dc8 AC |
1194 | or else (Nkind (P) = N_Range |
1195 | and then Nkind (Parent (P)) in N_Membership_Test) | |
acad3c0a AC |
1196 | then |
1197 | return; | |
1198 | end if; | |
1199 | ||
4b1c4f20 | 1200 | -- Otherwise, we have a top level arithmetic operation node, and this |
5707e389 AC |
1201 | -- is where we commence the special processing for MINIMIZED/ELIMINATED |
1202 | -- modes. This is the case where we tell the machinery not to move into | |
1203 | -- Bignum mode at this top level (of course the top level operation | |
1204 | -- will still be in Bignum mode if either of its operands are of type | |
1205 | -- Bignum). | |
acad3c0a | 1206 | |
a7f1b24f | 1207 | Minimize_Eliminate_Overflows (Op, Lo, Hi, Top_Level => True); |
acad3c0a AC |
1208 | |
1209 | -- That call may but does not necessarily change the result type of Op. | |
1210 | -- It is the job of this routine to undo such changes, so that at the | |
1211 | -- top level, we have the proper type. This "undoing" is a point at | |
1212 | -- which a final overflow check may be applied. | |
1213 | ||
b6b5cca8 AC |
1214 | -- If the result type was not fiddled we are all set. We go to base |
1215 | -- types here because things may have been rewritten to generate the | |
1216 | -- base type of the operand types. | |
acad3c0a | 1217 | |
b6b5cca8 | 1218 | if Base_Type (Etype (Op)) = Base_Type (Result_Type) then |
acad3c0a AC |
1219 | return; |
1220 | ||
1221 | -- Bignum case | |
1222 | ||
d79059a3 | 1223 | elsif Is_RTE (Etype (Op), RE_Bignum) then |
acad3c0a | 1224 | |
456cbfa5 | 1225 | -- We need a sequence that looks like: |
acad3c0a AC |
1226 | |
1227 | -- Rnn : Result_Type; | |
1228 | ||
1229 | -- declare | |
456cbfa5 | 1230 | -- M : Mark_Id := SS_Mark; |
acad3c0a | 1231 | -- begin |
d79059a3 | 1232 | -- Rnn := Long_Long_Integer'Base (From_Bignum (Op)); |
acad3c0a AC |
1233 | -- SS_Release (M); |
1234 | -- end; | |
1235 | ||
1236 | -- This block is inserted (using Insert_Actions), and then the node | |
1237 | -- is replaced with a reference to Rnn. | |
1238 | ||
1239 | -- A special case arises if our parent is a conversion node. In this | |
1240 | -- case no point in generating a conversion to Result_Type, we will | |
1241 | -- let the parent handle this. Note that this special case is not | |
1242 | -- just about optimization. Consider | |
1243 | ||
1244 | -- A,B,C : Integer; | |
1245 | -- ... | |
d79059a3 | 1246 | -- X := Long_Long_Integer'Base (A * (B ** C)); |
acad3c0a AC |
1247 | |
1248 | -- Now the product may fit in Long_Long_Integer but not in Integer. | |
5707e389 AC |
1249 | -- In MINIMIZED/ELIMINATED mode, we don't want to introduce an |
1250 | -- overflow exception for this intermediate value. | |
acad3c0a AC |
1251 | |
1252 | declare | |
d79059a3 | 1253 | Blk : constant Node_Id := Make_Bignum_Block (Loc); |
acad3c0a AC |
1254 | Rnn : constant Entity_Id := Make_Temporary (Loc, 'R', Op); |
1255 | RHS : Node_Id; | |
1256 | ||
1257 | Rtype : Entity_Id; | |
1258 | ||
1259 | begin | |
1260 | RHS := Convert_From_Bignum (Op); | |
1261 | ||
1262 | if Nkind (P) /= N_Type_Conversion then | |
d79059a3 | 1263 | Convert_To_And_Rewrite (Result_Type, RHS); |
acad3c0a AC |
1264 | Rtype := Result_Type; |
1265 | ||
1266 | -- Interesting question, do we need a check on that conversion | |
1267 | -- operation. Answer, not if we know the result is in range. | |
1268 | -- At the moment we are not taking advantage of this. To be | |
1269 | -- looked at later ??? | |
1270 | ||
1271 | else | |
d79059a3 | 1272 | Rtype := LLIB; |
acad3c0a AC |
1273 | end if; |
1274 | ||
1275 | Insert_Before | |
1276 | (First (Statements (Handled_Statement_Sequence (Blk))), | |
1277 | Make_Assignment_Statement (Loc, | |
1278 | Name => New_Occurrence_Of (Rnn, Loc), | |
1279 | Expression => RHS)); | |
1280 | ||
1281 | Insert_Actions (Op, New_List ( | |
1282 | Make_Object_Declaration (Loc, | |
1283 | Defining_Identifier => Rnn, | |
1284 | Object_Definition => New_Occurrence_Of (Rtype, Loc)), | |
1285 | Blk)); | |
1286 | ||
1287 | Rewrite (Op, New_Occurrence_Of (Rnn, Loc)); | |
1288 | Analyze_And_Resolve (Op); | |
1289 | end; | |
1290 | ||
60b68e56 RD |
1291 | -- Here we know the result is Long_Long_Integer'Base, of that it has |
1292 | -- been rewritten because the parent operation is a conversion. See | |
a7f1b24f | 1293 | -- Apply_Arithmetic_Overflow_Strict.Conversion_Optimization. |
acad3c0a AC |
1294 | |
1295 | else | |
b6b5cca8 AC |
1296 | pragma Assert |
1297 | (Etype (Op) = LLIB or else Nkind (Parent (Op)) = N_Type_Conversion); | |
acad3c0a AC |
1298 | |
1299 | -- All we need to do here is to convert the result to the proper | |
1300 | -- result type. As explained above for the Bignum case, we can | |
1301 | -- omit this if our parent is a type conversion. | |
1302 | ||
1303 | if Nkind (P) /= N_Type_Conversion then | |
1304 | Convert_To_And_Rewrite (Result_Type, Op); | |
1305 | end if; | |
1306 | ||
1307 | Analyze_And_Resolve (Op); | |
1308 | end if; | |
1309 | end Apply_Arithmetic_Overflow_Minimized_Eliminated; | |
70482933 | 1310 | |
70482933 RK |
1311 | ---------------------------- |
1312 | -- Apply_Constraint_Check -- | |
1313 | ---------------------------- | |
1314 | ||
1315 | procedure Apply_Constraint_Check | |
1316 | (N : Node_Id; | |
1317 | Typ : Entity_Id; | |
1318 | No_Sliding : Boolean := False) | |
1319 | is | |
1320 | Desig_Typ : Entity_Id; | |
1321 | ||
1322 | begin | |
48f91b44 RD |
1323 | -- No checks inside a generic (check the instantiations) |
1324 | ||
70482933 RK |
1325 | if Inside_A_Generic then |
1326 | return; | |
48f91b44 | 1327 | end if; |
70482933 | 1328 | |
308e6f3a | 1329 | -- Apply required constraint checks |
48f91b44 RD |
1330 | |
1331 | if Is_Scalar_Type (Typ) then | |
70482933 RK |
1332 | Apply_Scalar_Range_Check (N, Typ); |
1333 | ||
1334 | elsif Is_Array_Type (Typ) then | |
1335 | ||
d8b9660d | 1336 | -- A useful optimization: an aggregate with only an others clause |
c84700e7 ES |
1337 | -- always has the right bounds. |
1338 | ||
1339 | if Nkind (N) = N_Aggregate | |
1340 | and then No (Expressions (N)) | |
1341 | and then Nkind | |
1342 | (First (Choices (First (Component_Associations (N))))) | |
1343 | = N_Others_Choice | |
1344 | then | |
1345 | return; | |
1346 | end if; | |
1347 | ||
70482933 RK |
1348 | if Is_Constrained (Typ) then |
1349 | Apply_Length_Check (N, Typ); | |
1350 | ||
1351 | if No_Sliding then | |
1352 | Apply_Range_Check (N, Typ); | |
1353 | end if; | |
1354 | else | |
1355 | Apply_Range_Check (N, Typ); | |
1356 | end if; | |
1357 | ||
a40ada7e | 1358 | elsif (Is_Record_Type (Typ) or else Is_Private_Type (Typ)) |
70482933 RK |
1359 | and then Has_Discriminants (Base_Type (Typ)) |
1360 | and then Is_Constrained (Typ) | |
1361 | then | |
1362 | Apply_Discriminant_Check (N, Typ); | |
1363 | ||
1364 | elsif Is_Access_Type (Typ) then | |
1365 | ||
1366 | Desig_Typ := Designated_Type (Typ); | |
1367 | ||
1368 | -- No checks necessary if expression statically null | |
1369 | ||
939c12d2 | 1370 | if Known_Null (N) then |
11b4899f JM |
1371 | if Can_Never_Be_Null (Typ) then |
1372 | Install_Null_Excluding_Check (N); | |
1373 | end if; | |
70482933 RK |
1374 | |
1375 | -- No sliding possible on access to arrays | |
1376 | ||
1377 | elsif Is_Array_Type (Desig_Typ) then | |
1378 | if Is_Constrained (Desig_Typ) then | |
1379 | Apply_Length_Check (N, Typ); | |
1380 | end if; | |
1381 | ||
1382 | Apply_Range_Check (N, Typ); | |
1383 | ||
1384 | elsif Has_Discriminants (Base_Type (Desig_Typ)) | |
1385 | and then Is_Constrained (Desig_Typ) | |
1386 | then | |
1387 | Apply_Discriminant_Check (N, Typ); | |
1388 | end if; | |
2820d220 | 1389 | |
16b05213 | 1390 | -- Apply the 2005 Null_Excluding check. Note that we do not apply |
11b4899f JM |
1391 | -- this check if the constraint node is illegal, as shown by having |
1392 | -- an error posted. This additional guard prevents cascaded errors | |
1393 | -- and compiler aborts on illegal programs involving Ada 2005 checks. | |
1394 | ||
2820d220 AC |
1395 | if Can_Never_Be_Null (Typ) |
1396 | and then not Can_Never_Be_Null (Etype (N)) | |
11b4899f | 1397 | and then not Error_Posted (N) |
2820d220 AC |
1398 | then |
1399 | Install_Null_Excluding_Check (N); | |
1400 | end if; | |
70482933 RK |
1401 | end if; |
1402 | end Apply_Constraint_Check; | |
1403 | ||
1404 | ------------------------------ | |
1405 | -- Apply_Discriminant_Check -- | |
1406 | ------------------------------ | |
1407 | ||
1408 | procedure Apply_Discriminant_Check | |
1409 | (N : Node_Id; | |
1410 | Typ : Entity_Id; | |
1411 | Lhs : Node_Id := Empty) | |
1412 | is | |
1413 | Loc : constant Source_Ptr := Sloc (N); | |
1414 | Do_Access : constant Boolean := Is_Access_Type (Typ); | |
1415 | S_Typ : Entity_Id := Etype (N); | |
1416 | Cond : Node_Id; | |
1417 | T_Typ : Entity_Id; | |
1418 | ||
438ff97c ES |
1419 | function Denotes_Explicit_Dereference (Obj : Node_Id) return Boolean; |
1420 | -- A heap object with an indefinite subtype is constrained by its | |
1421 | -- initial value, and assigning to it requires a constraint_check. | |
1422 | -- The target may be an explicit dereference, or a renaming of one. | |
1423 | ||
70482933 RK |
1424 | function Is_Aliased_Unconstrained_Component return Boolean; |
1425 | -- It is possible for an aliased component to have a nominal | |
1426 | -- unconstrained subtype (through instantiation). If this is a | |
1427 | -- discriminated component assigned in the expansion of an aggregate | |
1428 | -- in an initialization, the check must be suppressed. This unusual | |
939c12d2 | 1429 | -- situation requires a predicate of its own. |
70482933 | 1430 | |
438ff97c ES |
1431 | ---------------------------------- |
1432 | -- Denotes_Explicit_Dereference -- | |
1433 | ---------------------------------- | |
1434 | ||
1435 | function Denotes_Explicit_Dereference (Obj : Node_Id) return Boolean is | |
1436 | begin | |
1437 | return | |
1438 | Nkind (Obj) = N_Explicit_Dereference | |
1439 | or else | |
1440 | (Is_Entity_Name (Obj) | |
1441 | and then Present (Renamed_Object (Entity (Obj))) | |
e074d476 AC |
1442 | and then Nkind (Renamed_Object (Entity (Obj))) = |
1443 | N_Explicit_Dereference); | |
438ff97c ES |
1444 | end Denotes_Explicit_Dereference; |
1445 | ||
70482933 RK |
1446 | ---------------------------------------- |
1447 | -- Is_Aliased_Unconstrained_Component -- | |
1448 | ---------------------------------------- | |
1449 | ||
1450 | function Is_Aliased_Unconstrained_Component return Boolean is | |
1451 | Comp : Entity_Id; | |
1452 | Pref : Node_Id; | |
1453 | ||
1454 | begin | |
1455 | if Nkind (Lhs) /= N_Selected_Component then | |
1456 | return False; | |
1457 | else | |
1458 | Comp := Entity (Selector_Name (Lhs)); | |
1459 | Pref := Prefix (Lhs); | |
1460 | end if; | |
1461 | ||
1462 | if Ekind (Comp) /= E_Component | |
1463 | or else not Is_Aliased (Comp) | |
1464 | then | |
1465 | return False; | |
1466 | end if; | |
1467 | ||
1468 | return not Comes_From_Source (Pref) | |
1469 | and then In_Instance | |
1470 | and then not Is_Constrained (Etype (Comp)); | |
1471 | end Is_Aliased_Unconstrained_Component; | |
1472 | ||
1473 | -- Start of processing for Apply_Discriminant_Check | |
1474 | ||
1475 | begin | |
1476 | if Do_Access then | |
1477 | T_Typ := Designated_Type (Typ); | |
1478 | else | |
1479 | T_Typ := Typ; | |
1480 | end if; | |
1481 | ||
1482 | -- Nothing to do if discriminant checks are suppressed or else no code | |
1483 | -- is to be generated | |
1484 | ||
4460a9bc | 1485 | if not Expander_Active |
70482933 RK |
1486 | or else Discriminant_Checks_Suppressed (T_Typ) |
1487 | then | |
1488 | return; | |
1489 | end if; | |
1490 | ||
675d6070 TQ |
1491 | -- No discriminant checks necessary for an access when expression is |
1492 | -- statically Null. This is not only an optimization, it is fundamental | |
1493 | -- because otherwise discriminant checks may be generated in init procs | |
1494 | -- for types containing an access to a not-yet-frozen record, causing a | |
1495 | -- deadly forward reference. | |
70482933 | 1496 | |
675d6070 TQ |
1497 | -- Also, if the expression is of an access type whose designated type is |
1498 | -- incomplete, then the access value must be null and we suppress the | |
1499 | -- check. | |
70482933 | 1500 | |
939c12d2 | 1501 | if Known_Null (N) then |
70482933 RK |
1502 | return; |
1503 | ||
1504 | elsif Is_Access_Type (S_Typ) then | |
1505 | S_Typ := Designated_Type (S_Typ); | |
1506 | ||
1507 | if Ekind (S_Typ) = E_Incomplete_Type then | |
1508 | return; | |
1509 | end if; | |
1510 | end if; | |
1511 | ||
c064e066 RD |
1512 | -- If an assignment target is present, then we need to generate the |
1513 | -- actual subtype if the target is a parameter or aliased object with | |
1514 | -- an unconstrained nominal subtype. | |
1515 | ||
1516 | -- Ada 2005 (AI-363): For Ada 2005, we limit the building of the actual | |
1517 | -- subtype to the parameter and dereference cases, since other aliased | |
1518 | -- objects are unconstrained (unless the nominal subtype is explicitly | |
438ff97c | 1519 | -- constrained). |
70482933 RK |
1520 | |
1521 | if Present (Lhs) | |
1522 | and then (Present (Param_Entity (Lhs)) | |
0791fbe9 | 1523 | or else (Ada_Version < Ada_2005 |
c064e066 | 1524 | and then not Is_Constrained (T_Typ) |
70482933 | 1525 | and then Is_Aliased_View (Lhs) |
c064e066 | 1526 | and then not Is_Aliased_Unconstrained_Component) |
0791fbe9 | 1527 | or else (Ada_Version >= Ada_2005 |
c064e066 | 1528 | and then not Is_Constrained (T_Typ) |
438ff97c | 1529 | and then Denotes_Explicit_Dereference (Lhs) |
c064e066 RD |
1530 | and then Nkind (Original_Node (Lhs)) /= |
1531 | N_Function_Call)) | |
70482933 RK |
1532 | then |
1533 | T_Typ := Get_Actual_Subtype (Lhs); | |
1534 | end if; | |
1535 | ||
675d6070 TQ |
1536 | -- Nothing to do if the type is unconstrained (this is the case where |
1537 | -- the actual subtype in the RM sense of N is unconstrained and no check | |
1538 | -- is required). | |
70482933 RK |
1539 | |
1540 | if not Is_Constrained (T_Typ) then | |
1541 | return; | |
d8b9660d ES |
1542 | |
1543 | -- Ada 2005: nothing to do if the type is one for which there is a | |
1544 | -- partial view that is constrained. | |
1545 | ||
0791fbe9 | 1546 | elsif Ada_Version >= Ada_2005 |
0fbcb11c | 1547 | and then Object_Type_Has_Constrained_Partial_View |
414b312e AC |
1548 | (Typ => Base_Type (T_Typ), |
1549 | Scop => Current_Scope) | |
d8b9660d ES |
1550 | then |
1551 | return; | |
70482933 RK |
1552 | end if; |
1553 | ||
5d09245e AC |
1554 | -- Nothing to do if the type is an Unchecked_Union |
1555 | ||
1556 | if Is_Unchecked_Union (Base_Type (T_Typ)) then | |
1557 | return; | |
1558 | end if; | |
1559 | ||
6b6041ec | 1560 | -- Suppress checks if the subtypes are the same. The check must be |
675d6070 TQ |
1561 | -- preserved in an assignment to a formal, because the constraint is |
1562 | -- given by the actual. | |
70482933 RK |
1563 | |
1564 | if Nkind (Original_Node (N)) /= N_Allocator | |
1565 | and then (No (Lhs) | |
9972d439 RD |
1566 | or else not Is_Entity_Name (Lhs) |
1567 | or else No (Param_Entity (Lhs))) | |
70482933 RK |
1568 | then |
1569 | if (Etype (N) = Typ | |
1570 | or else (Do_Access and then Designated_Type (Typ) = S_Typ)) | |
1571 | and then not Is_Aliased_View (Lhs) | |
1572 | then | |
1573 | return; | |
1574 | end if; | |
1575 | ||
675d6070 TQ |
1576 | -- We can also eliminate checks on allocators with a subtype mark that |
1577 | -- coincides with the context type. The context type may be a subtype | |
1578 | -- without a constraint (common case, a generic actual). | |
70482933 RK |
1579 | |
1580 | elsif Nkind (Original_Node (N)) = N_Allocator | |
1581 | and then Is_Entity_Name (Expression (Original_Node (N))) | |
1582 | then | |
1583 | declare | |
fbf5a39b | 1584 | Alloc_Typ : constant Entity_Id := |
15f0f591 | 1585 | Entity (Expression (Original_Node (N))); |
70482933 RK |
1586 | |
1587 | begin | |
1588 | if Alloc_Typ = T_Typ | |
1589 | or else (Nkind (Parent (T_Typ)) = N_Subtype_Declaration | |
1590 | and then Is_Entity_Name ( | |
1591 | Subtype_Indication (Parent (T_Typ))) | |
1592 | and then Alloc_Typ = Base_Type (T_Typ)) | |
1593 | ||
1594 | then | |
1595 | return; | |
1596 | end if; | |
1597 | end; | |
1598 | end if; | |
1599 | ||
675d6070 TQ |
1600 | -- See if we have a case where the types are both constrained, and all |
1601 | -- the constraints are constants. In this case, we can do the check | |
1602 | -- successfully at compile time. | |
70482933 | 1603 | |
6b6041ec | 1604 | -- We skip this check for the case where the node is rewritten as |
c91dbd18 AC |
1605 | -- an allocator, because it already carries the context subtype, |
1606 | -- and extracting the discriminants from the aggregate is messy. | |
70482933 RK |
1607 | |
1608 | if Is_Constrained (S_Typ) | |
1609 | and then Nkind (Original_Node (N)) /= N_Allocator | |
1610 | then | |
1611 | declare | |
1612 | DconT : Elmt_Id; | |
1613 | Discr : Entity_Id; | |
1614 | DconS : Elmt_Id; | |
1615 | ItemS : Node_Id; | |
1616 | ItemT : Node_Id; | |
1617 | ||
1618 | begin | |
1619 | -- S_Typ may not have discriminants in the case where it is a | |
675d6070 | 1620 | -- private type completed by a default discriminated type. In that |
6b6041ec | 1621 | -- case, we need to get the constraints from the underlying type. |
675d6070 TQ |
1622 | -- If the underlying type is unconstrained (i.e. has no default |
1623 | -- discriminants) no check is needed. | |
70482933 RK |
1624 | |
1625 | if Has_Discriminants (S_Typ) then | |
1626 | Discr := First_Discriminant (S_Typ); | |
1627 | DconS := First_Elmt (Discriminant_Constraint (S_Typ)); | |
1628 | ||
1629 | else | |
1630 | Discr := First_Discriminant (Underlying_Type (S_Typ)); | |
1631 | DconS := | |
1632 | First_Elmt | |
1633 | (Discriminant_Constraint (Underlying_Type (S_Typ))); | |
1634 | ||
1635 | if No (DconS) then | |
1636 | return; | |
1637 | end if; | |
65356e64 AC |
1638 | |
1639 | -- A further optimization: if T_Typ is derived from S_Typ | |
1640 | -- without imposing a constraint, no check is needed. | |
1641 | ||
1642 | if Nkind (Original_Node (Parent (T_Typ))) = | |
1643 | N_Full_Type_Declaration | |
1644 | then | |
1645 | declare | |
91b1417d | 1646 | Type_Def : constant Node_Id := |
15f0f591 | 1647 | Type_Definition (Original_Node (Parent (T_Typ))); |
65356e64 AC |
1648 | begin |
1649 | if Nkind (Type_Def) = N_Derived_Type_Definition | |
1650 | and then Is_Entity_Name (Subtype_Indication (Type_Def)) | |
1651 | and then Entity (Subtype_Indication (Type_Def)) = S_Typ | |
1652 | then | |
1653 | return; | |
1654 | end if; | |
1655 | end; | |
1656 | end if; | |
70482933 RK |
1657 | end if; |
1658 | ||
d2a6bd6b AC |
1659 | -- Constraint may appear in full view of type |
1660 | ||
1661 | if Ekind (T_Typ) = E_Private_Subtype | |
1662 | and then Present (Full_View (T_Typ)) | |
1663 | then | |
c91dbd18 | 1664 | DconT := |
d2a6bd6b | 1665 | First_Elmt (Discriminant_Constraint (Full_View (T_Typ))); |
d2a6bd6b | 1666 | else |
c91dbd18 AC |
1667 | DconT := |
1668 | First_Elmt (Discriminant_Constraint (T_Typ)); | |
d2a6bd6b | 1669 | end if; |
70482933 RK |
1670 | |
1671 | while Present (Discr) loop | |
1672 | ItemS := Node (DconS); | |
1673 | ItemT := Node (DconT); | |
1674 | ||
11b4899f JM |
1675 | -- For a discriminated component type constrained by the |
1676 | -- current instance of an enclosing type, there is no | |
1677 | -- applicable discriminant check. | |
1678 | ||
1679 | if Nkind (ItemT) = N_Attribute_Reference | |
1680 | and then Is_Access_Type (Etype (ItemT)) | |
1681 | and then Is_Entity_Name (Prefix (ItemT)) | |
1682 | and then Is_Type (Entity (Prefix (ItemT))) | |
1683 | then | |
1684 | return; | |
1685 | end if; | |
1686 | ||
f2cbd970 JM |
1687 | -- If the expressions for the discriminants are identical |
1688 | -- and it is side-effect free (for now just an entity), | |
1689 | -- this may be a shared constraint, e.g. from a subtype | |
1690 | -- without a constraint introduced as a generic actual. | |
1691 | -- Examine other discriminants if any. | |
1692 | ||
1693 | if ItemS = ItemT | |
1694 | and then Is_Entity_Name (ItemS) | |
1695 | then | |
1696 | null; | |
1697 | ||
1698 | elsif not Is_OK_Static_Expression (ItemS) | |
1699 | or else not Is_OK_Static_Expression (ItemT) | |
1700 | then | |
1701 | exit; | |
70482933 | 1702 | |
f2cbd970 | 1703 | elsif Expr_Value (ItemS) /= Expr_Value (ItemT) then |
70482933 RK |
1704 | if Do_Access then -- needs run-time check. |
1705 | exit; | |
1706 | else | |
1707 | Apply_Compile_Time_Constraint_Error | |
685bc70f | 1708 | (N, "incorrect value for discriminant&??", |
07fc65c4 | 1709 | CE_Discriminant_Check_Failed, Ent => Discr); |
70482933 RK |
1710 | return; |
1711 | end if; | |
1712 | end if; | |
1713 | ||
1714 | Next_Elmt (DconS); | |
1715 | Next_Elmt (DconT); | |
1716 | Next_Discriminant (Discr); | |
1717 | end loop; | |
1718 | ||
1719 | if No (Discr) then | |
1720 | return; | |
1721 | end if; | |
1722 | end; | |
1723 | end if; | |
1724 | ||
1725 | -- Here we need a discriminant check. First build the expression | |
1726 | -- for the comparisons of the discriminants: | |
1727 | ||
1728 | -- (n.disc1 /= typ.disc1) or else | |
1729 | -- (n.disc2 /= typ.disc2) or else | |
1730 | -- ... | |
1731 | -- (n.discn /= typ.discn) | |
1732 | ||
1733 | Cond := Build_Discriminant_Checks (N, T_Typ); | |
1734 | ||
acad3c0a AC |
1735 | -- If Lhs is set and is a parameter, then the condition is guarded by: |
1736 | -- lhs'constrained and then (condition built above) | |
70482933 RK |
1737 | |
1738 | if Present (Param_Entity (Lhs)) then | |
1739 | Cond := | |
1740 | Make_And_Then (Loc, | |
1741 | Left_Opnd => | |
1742 | Make_Attribute_Reference (Loc, | |
1743 | Prefix => New_Occurrence_Of (Param_Entity (Lhs), Loc), | |
1744 | Attribute_Name => Name_Constrained), | |
1745 | Right_Opnd => Cond); | |
1746 | end if; | |
1747 | ||
1748 | if Do_Access then | |
1749 | Cond := Guard_Access (Cond, Loc, N); | |
1750 | end if; | |
1751 | ||
1752 | Insert_Action (N, | |
07fc65c4 GB |
1753 | Make_Raise_Constraint_Error (Loc, |
1754 | Condition => Cond, | |
1755 | Reason => CE_Discriminant_Check_Failed)); | |
70482933 RK |
1756 | end Apply_Discriminant_Check; |
1757 | ||
a91e9ac7 AC |
1758 | ------------------------- |
1759 | -- Apply_Divide_Checks -- | |
1760 | ------------------------- | |
70482933 | 1761 | |
a91e9ac7 | 1762 | procedure Apply_Divide_Checks (N : Node_Id) is |
70482933 RK |
1763 | Loc : constant Source_Ptr := Sloc (N); |
1764 | Typ : constant Entity_Id := Etype (N); | |
1765 | Left : constant Node_Id := Left_Opnd (N); | |
1766 | Right : constant Node_Id := Right_Opnd (N); | |
1767 | ||
15c94a55 | 1768 | Mode : constant Overflow_Mode_Type := Overflow_Check_Mode; |
a91e9ac7 AC |
1769 | -- Current overflow checking mode |
1770 | ||
70482933 RK |
1771 | LLB : Uint; |
1772 | Llo : Uint; | |
1773 | Lhi : Uint; | |
1774 | LOK : Boolean; | |
1775 | Rlo : Uint; | |
1776 | Rhi : Uint; | |
a91e9ac7 | 1777 | ROK : Boolean; |
67ce0d7e RD |
1778 | |
1779 | pragma Warnings (Off, Lhi); | |
1780 | -- Don't actually use this value | |
70482933 RK |
1781 | |
1782 | begin | |
a7f1b24f RD |
1783 | -- If we are operating in MINIMIZED or ELIMINATED mode, and we are |
1784 | -- operating on signed integer types, then the only thing this routine | |
1785 | -- does is to call Apply_Arithmetic_Overflow_Minimized_Eliminated. That | |
1786 | -- procedure will (possibly later on during recursive downward calls), | |
1787 | -- ensure that any needed overflow/division checks are properly applied. | |
a91e9ac7 AC |
1788 | |
1789 | if Mode in Minimized_Or_Eliminated | |
a91e9ac7 AC |
1790 | and then Is_Signed_Integer_Type (Typ) |
1791 | then | |
1792 | Apply_Arithmetic_Overflow_Minimized_Eliminated (N); | |
1793 | return; | |
1794 | end if; | |
1795 | ||
1796 | -- Proceed here in SUPPRESSED or CHECKED modes | |
1797 | ||
4460a9bc | 1798 | if Expander_Active |
2ede092b RD |
1799 | and then not Backend_Divide_Checks_On_Target |
1800 | and then Check_Needed (Right, Division_Check) | |
70482933 | 1801 | then |
c800f862 | 1802 | Determine_Range (Right, ROK, Rlo, Rhi, Assume_Valid => True); |
70482933 | 1803 | |
a91e9ac7 | 1804 | -- Deal with division check |
70482933 | 1805 | |
a91e9ac7 AC |
1806 | if Do_Division_Check (N) |
1807 | and then not Division_Checks_Suppressed (Typ) | |
1808 | then | |
1809 | Apply_Division_Check (N, Rlo, Rhi, ROK); | |
70482933 RK |
1810 | end if; |
1811 | ||
a91e9ac7 AC |
1812 | -- Deal with overflow check |
1813 | ||
a7f1b24f RD |
1814 | if Do_Overflow_Check (N) |
1815 | and then not Overflow_Checks_Suppressed (Etype (N)) | |
1816 | then | |
b7c874a7 AC |
1817 | Set_Do_Overflow_Check (N, False); |
1818 | ||
a91e9ac7 AC |
1819 | -- Test for extremely annoying case of xxx'First divided by -1 |
1820 | -- for division of signed integer types (only overflow case). | |
70482933 | 1821 | |
70482933 RK |
1822 | if Nkind (N) = N_Op_Divide |
1823 | and then Is_Signed_Integer_Type (Typ) | |
1824 | then | |
c800f862 | 1825 | Determine_Range (Left, LOK, Llo, Lhi, Assume_Valid => True); |
70482933 RK |
1826 | LLB := Expr_Value (Type_Low_Bound (Base_Type (Typ))); |
1827 | ||
1828 | if ((not ROK) or else (Rlo <= (-1) and then (-1) <= Rhi)) | |
a91e9ac7 AC |
1829 | and then |
1830 | ((not LOK) or else (Llo = LLB)) | |
70482933 RK |
1831 | then |
1832 | Insert_Action (N, | |
1833 | Make_Raise_Constraint_Error (Loc, | |
1834 | Condition => | |
1835 | Make_And_Then (Loc, | |
a91e9ac7 AC |
1836 | Left_Opnd => |
1837 | Make_Op_Eq (Loc, | |
1838 | Left_Opnd => | |
1839 | Duplicate_Subexpr_Move_Checks (Left), | |
1840 | Right_Opnd => Make_Integer_Literal (Loc, LLB)), | |
70482933 | 1841 | |
a91e9ac7 AC |
1842 | Right_Opnd => |
1843 | Make_Op_Eq (Loc, | |
1844 | Left_Opnd => Duplicate_Subexpr (Right), | |
1845 | Right_Opnd => Make_Integer_Literal (Loc, -1))), | |
70482933 | 1846 | |
07fc65c4 | 1847 | Reason => CE_Overflow_Check_Failed)); |
70482933 RK |
1848 | end if; |
1849 | end if; | |
1850 | end if; | |
1851 | end if; | |
a91e9ac7 AC |
1852 | end Apply_Divide_Checks; |
1853 | ||
1854 | -------------------------- | |
1855 | -- Apply_Division_Check -- | |
1856 | -------------------------- | |
1857 | ||
1858 | procedure Apply_Division_Check | |
1859 | (N : Node_Id; | |
1860 | Rlo : Uint; | |
1861 | Rhi : Uint; | |
1862 | ROK : Boolean) | |
1863 | is | |
1864 | pragma Assert (Do_Division_Check (N)); | |
1865 | ||
1866 | Loc : constant Source_Ptr := Sloc (N); | |
1867 | Right : constant Node_Id := Right_Opnd (N); | |
1868 | ||
1869 | begin | |
4460a9bc | 1870 | if Expander_Active |
a91e9ac7 AC |
1871 | and then not Backend_Divide_Checks_On_Target |
1872 | and then Check_Needed (Right, Division_Check) | |
1873 | then | |
1874 | -- See if division by zero possible, and if so generate test. This | |
1875 | -- part of the test is not controlled by the -gnato switch, since | |
1876 | -- it is a Division_Check and not an Overflow_Check. | |
1877 | ||
1878 | if Do_Division_Check (N) then | |
b7c874a7 AC |
1879 | Set_Do_Division_Check (N, False); |
1880 | ||
a91e9ac7 AC |
1881 | if (not ROK) or else (Rlo <= 0 and then 0 <= Rhi) then |
1882 | Insert_Action (N, | |
1883 | Make_Raise_Constraint_Error (Loc, | |
1884 | Condition => | |
1885 | Make_Op_Eq (Loc, | |
1886 | Left_Opnd => Duplicate_Subexpr_Move_Checks (Right), | |
1887 | Right_Opnd => Make_Integer_Literal (Loc, 0)), | |
1888 | Reason => CE_Divide_By_Zero)); | |
1889 | end if; | |
1890 | end if; | |
1891 | end if; | |
1892 | end Apply_Division_Check; | |
70482933 | 1893 | |
7324bf49 AC |
1894 | ---------------------------------- |
1895 | -- Apply_Float_Conversion_Check -- | |
1896 | ---------------------------------- | |
1897 | ||
675d6070 TQ |
1898 | -- Let F and I be the source and target types of the conversion. The RM |
1899 | -- specifies that a floating-point value X is rounded to the nearest | |
1900 | -- integer, with halfway cases being rounded away from zero. The rounded | |
1901 | -- value of X is checked against I'Range. | |
1902 | ||
1903 | -- The catch in the above paragraph is that there is no good way to know | |
1904 | -- whether the round-to-integer operation resulted in overflow. A remedy is | |
1905 | -- to perform a range check in the floating-point domain instead, however: | |
7324bf49 | 1906 | |
7324bf49 | 1907 | -- (1) The bounds may not be known at compile time |
939c12d2 | 1908 | -- (2) The check must take into account rounding or truncation. |
7324bf49 | 1909 | -- (3) The range of type I may not be exactly representable in F. |
939c12d2 RD |
1910 | -- (4) For the rounding case, The end-points I'First - 0.5 and |
1911 | -- I'Last + 0.5 may or may not be in range, depending on the | |
1912 | -- sign of I'First and I'Last. | |
7324bf49 AC |
1913 | -- (5) X may be a NaN, which will fail any comparison |
1914 | ||
939c12d2 | 1915 | -- The following steps correctly convert X with rounding: |
675d6070 | 1916 | |
7324bf49 AC |
1917 | -- (1) If either I'First or I'Last is not known at compile time, use |
1918 | -- I'Base instead of I in the next three steps and perform a | |
1919 | -- regular range check against I'Range after conversion. | |
1920 | -- (2) If I'First - 0.5 is representable in F then let Lo be that | |
1921 | -- value and define Lo_OK as (I'First > 0). Otherwise, let Lo be | |
939c12d2 RD |
1922 | -- F'Machine (I'First) and let Lo_OK be (Lo >= I'First). |
1923 | -- In other words, take one of the closest floating-point numbers | |
1924 | -- (which is an integer value) to I'First, and see if it is in | |
1925 | -- range or not. | |
7324bf49 AC |
1926 | -- (3) If I'Last + 0.5 is representable in F then let Hi be that value |
1927 | -- and define Hi_OK as (I'Last < 0). Otherwise, let Hi be | |
939c12d2 | 1928 | -- F'Machine (I'Last) and let Hi_OK be (Hi <= I'Last). |
7324bf49 AC |
1929 | -- (4) Raise CE when (Lo_OK and X < Lo) or (not Lo_OK and X <= Lo) |
1930 | -- or (Hi_OK and X > Hi) or (not Hi_OK and X >= Hi) | |
1931 | ||
939c12d2 RD |
1932 | -- For the truncating case, replace steps (2) and (3) as follows: |
1933 | -- (2) If I'First > 0, then let Lo be F'Pred (I'First) and let Lo_OK | |
1934 | -- be False. Otherwise, let Lo be F'Succ (I'First - 1) and let | |
1935 | -- Lo_OK be True. | |
1936 | -- (3) If I'Last < 0, then let Hi be F'Succ (I'Last) and let Hi_OK | |
1937 | -- be False. Otherwise let Hi be F'Pred (I'Last + 1) and let | |
1197ddb1 | 1938 | -- Hi_OK be True. |
939c12d2 | 1939 | |
7324bf49 AC |
1940 | procedure Apply_Float_Conversion_Check |
1941 | (Ck_Node : Node_Id; | |
1942 | Target_Typ : Entity_Id) | |
1943 | is | |
675d6070 TQ |
1944 | LB : constant Node_Id := Type_Low_Bound (Target_Typ); |
1945 | HB : constant Node_Id := Type_High_Bound (Target_Typ); | |
7324bf49 AC |
1946 | Loc : constant Source_Ptr := Sloc (Ck_Node); |
1947 | Expr_Type : constant Entity_Id := Base_Type (Etype (Ck_Node)); | |
675d6070 | 1948 | Target_Base : constant Entity_Id := |
15f0f591 | 1949 | Implementation_Base_Type (Target_Typ); |
675d6070 | 1950 | |
939c12d2 RD |
1951 | Par : constant Node_Id := Parent (Ck_Node); |
1952 | pragma Assert (Nkind (Par) = N_Type_Conversion); | |
1953 | -- Parent of check node, must be a type conversion | |
1954 | ||
1955 | Truncate : constant Boolean := Float_Truncate (Par); | |
1956 | Max_Bound : constant Uint := | |
15f0f591 AC |
1957 | UI_Expon |
1958 | (Machine_Radix_Value (Expr_Type), | |
1959 | Machine_Mantissa_Value (Expr_Type) - 1) - 1; | |
939c12d2 | 1960 | |
7324bf49 AC |
1961 | -- Largest bound, so bound plus or minus half is a machine number of F |
1962 | ||
675d6070 TQ |
1963 | Ifirst, Ilast : Uint; |
1964 | -- Bounds of integer type | |
1965 | ||
1966 | Lo, Hi : Ureal; | |
1967 | -- Bounds to check in floating-point domain | |
7324bf49 | 1968 | |
675d6070 TQ |
1969 | Lo_OK, Hi_OK : Boolean; |
1970 | -- True iff Lo resp. Hi belongs to I'Range | |
7324bf49 | 1971 | |
675d6070 TQ |
1972 | Lo_Chk, Hi_Chk : Node_Id; |
1973 | -- Expressions that are False iff check fails | |
1974 | ||
1975 | Reason : RT_Exception_Code; | |
7324bf49 AC |
1976 | |
1977 | begin | |
b5bdffcc AC |
1978 | -- We do not need checks if we are not generating code (i.e. the full |
1979 | -- expander is not active). In SPARK mode, we specifically don't want | |
1980 | -- the frontend to expand these checks, which are dealt with directly | |
1981 | -- in the formal verification backend. | |
1982 | ||
4460a9bc | 1983 | if not Expander_Active then |
b5bdffcc AC |
1984 | return; |
1985 | end if; | |
1986 | ||
7324bf49 AC |
1987 | if not Compile_Time_Known_Value (LB) |
1988 | or not Compile_Time_Known_Value (HB) | |
1989 | then | |
1990 | declare | |
675d6070 TQ |
1991 | -- First check that the value falls in the range of the base type, |
1992 | -- to prevent overflow during conversion and then perform a | |
1993 | -- regular range check against the (dynamic) bounds. | |
7324bf49 | 1994 | |
7324bf49 | 1995 | pragma Assert (Target_Base /= Target_Typ); |
7324bf49 | 1996 | |
191fcb3a | 1997 | Temp : constant Entity_Id := Make_Temporary (Loc, 'T', Par); |
7324bf49 AC |
1998 | |
1999 | begin | |
2000 | Apply_Float_Conversion_Check (Ck_Node, Target_Base); | |
2001 | Set_Etype (Temp, Target_Base); | |
2002 | ||
2003 | Insert_Action (Parent (Par), | |
2004 | Make_Object_Declaration (Loc, | |
2005 | Defining_Identifier => Temp, | |
2006 | Object_Definition => New_Occurrence_Of (Target_Typ, Loc), | |
2007 | Expression => New_Copy_Tree (Par)), | |
2008 | Suppress => All_Checks); | |
2009 | ||
2010 | Insert_Action (Par, | |
2011 | Make_Raise_Constraint_Error (Loc, | |
2012 | Condition => | |
2013 | Make_Not_In (Loc, | |
2014 | Left_Opnd => New_Occurrence_Of (Temp, Loc), | |
2015 | Right_Opnd => New_Occurrence_Of (Target_Typ, Loc)), | |
2016 | Reason => CE_Range_Check_Failed)); | |
2017 | Rewrite (Par, New_Occurrence_Of (Temp, Loc)); | |
2018 | ||
2019 | return; | |
2020 | end; | |
2021 | end if; | |
2022 | ||
44114dff | 2023 | -- Get the (static) bounds of the target type |
7324bf49 AC |
2024 | |
2025 | Ifirst := Expr_Value (LB); | |
2026 | Ilast := Expr_Value (HB); | |
2027 | ||
44114dff ES |
2028 | -- A simple optimization: if the expression is a universal literal, |
2029 | -- we can do the comparison with the bounds and the conversion to | |
2030 | -- an integer type statically. The range checks are unchanged. | |
2031 | ||
2032 | if Nkind (Ck_Node) = N_Real_Literal | |
2033 | and then Etype (Ck_Node) = Universal_Real | |
2034 | and then Is_Integer_Type (Target_Typ) | |
2035 | and then Nkind (Parent (Ck_Node)) = N_Type_Conversion | |
2036 | then | |
2037 | declare | |
2038 | Int_Val : constant Uint := UR_To_Uint (Realval (Ck_Node)); | |
2039 | ||
2040 | begin | |
2041 | if Int_Val <= Ilast and then Int_Val >= Ifirst then | |
2042 | ||
6f2b033b | 2043 | -- Conversion is safe |
44114dff ES |
2044 | |
2045 | Rewrite (Parent (Ck_Node), | |
2046 | Make_Integer_Literal (Loc, UI_To_Int (Int_Val))); | |
2047 | Analyze_And_Resolve (Parent (Ck_Node), Target_Typ); | |
2048 | return; | |
2049 | end if; | |
2050 | end; | |
2051 | end if; | |
2052 | ||
7324bf49 AC |
2053 | -- Check against lower bound |
2054 | ||
939c12d2 RD |
2055 | if Truncate and then Ifirst > 0 then |
2056 | Lo := Pred (Expr_Type, UR_From_Uint (Ifirst)); | |
2057 | Lo_OK := False; | |
2058 | ||
2059 | elsif Truncate then | |
2060 | Lo := Succ (Expr_Type, UR_From_Uint (Ifirst - 1)); | |
2061 | Lo_OK := True; | |
2062 | ||
2063 | elsif abs (Ifirst) < Max_Bound then | |
7324bf49 AC |
2064 | Lo := UR_From_Uint (Ifirst) - Ureal_Half; |
2065 | Lo_OK := (Ifirst > 0); | |
939c12d2 | 2066 | |
7324bf49 AC |
2067 | else |
2068 | Lo := Machine (Expr_Type, UR_From_Uint (Ifirst), Round_Even, Ck_Node); | |
2069 | Lo_OK := (Lo >= UR_From_Uint (Ifirst)); | |
2070 | end if; | |
2071 | ||
2072 | if Lo_OK then | |
2073 | ||
2074 | -- Lo_Chk := (X >= Lo) | |
2075 | ||
2076 | Lo_Chk := Make_Op_Ge (Loc, | |
2077 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), | |
2078 | Right_Opnd => Make_Real_Literal (Loc, Lo)); | |
2079 | ||
2080 | else | |
2081 | -- Lo_Chk := (X > Lo) | |
2082 | ||
2083 | Lo_Chk := Make_Op_Gt (Loc, | |
2084 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), | |
2085 | Right_Opnd => Make_Real_Literal (Loc, Lo)); | |
2086 | end if; | |
2087 | ||
2088 | -- Check against higher bound | |
2089 | ||
939c12d2 RD |
2090 | if Truncate and then Ilast < 0 then |
2091 | Hi := Succ (Expr_Type, UR_From_Uint (Ilast)); | |
c2db4b32 | 2092 | Hi_OK := False; |
939c12d2 RD |
2093 | |
2094 | elsif Truncate then | |
2095 | Hi := Pred (Expr_Type, UR_From_Uint (Ilast + 1)); | |
2096 | Hi_OK := True; | |
2097 | ||
2098 | elsif abs (Ilast) < Max_Bound then | |
7324bf49 AC |
2099 | Hi := UR_From_Uint (Ilast) + Ureal_Half; |
2100 | Hi_OK := (Ilast < 0); | |
2101 | else | |
2102 | Hi := Machine (Expr_Type, UR_From_Uint (Ilast), Round_Even, Ck_Node); | |
2103 | Hi_OK := (Hi <= UR_From_Uint (Ilast)); | |
2104 | end if; | |
2105 | ||
2106 | if Hi_OK then | |
2107 | ||
2108 | -- Hi_Chk := (X <= Hi) | |
2109 | ||
2110 | Hi_Chk := Make_Op_Le (Loc, | |
2111 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), | |
2112 | Right_Opnd => Make_Real_Literal (Loc, Hi)); | |
2113 | ||
2114 | else | |
2115 | -- Hi_Chk := (X < Hi) | |
2116 | ||
2117 | Hi_Chk := Make_Op_Lt (Loc, | |
2118 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), | |
2119 | Right_Opnd => Make_Real_Literal (Loc, Hi)); | |
2120 | end if; | |
2121 | ||
675d6070 TQ |
2122 | -- If the bounds of the target type are the same as those of the base |
2123 | -- type, the check is an overflow check as a range check is not | |
2124 | -- performed in these cases. | |
7324bf49 AC |
2125 | |
2126 | if Expr_Value (Type_Low_Bound (Target_Base)) = Ifirst | |
2127 | and then Expr_Value (Type_High_Bound (Target_Base)) = Ilast | |
2128 | then | |
2129 | Reason := CE_Overflow_Check_Failed; | |
2130 | else | |
2131 | Reason := CE_Range_Check_Failed; | |
2132 | end if; | |
2133 | ||
2134 | -- Raise CE if either conditions does not hold | |
2135 | ||
2136 | Insert_Action (Ck_Node, | |
2137 | Make_Raise_Constraint_Error (Loc, | |
d8b9660d | 2138 | Condition => Make_Op_Not (Loc, Make_And_Then (Loc, Lo_Chk, Hi_Chk)), |
7324bf49 AC |
2139 | Reason => Reason)); |
2140 | end Apply_Float_Conversion_Check; | |
2141 | ||
70482933 RK |
2142 | ------------------------ |
2143 | -- Apply_Length_Check -- | |
2144 | ------------------------ | |
2145 | ||
2146 | procedure Apply_Length_Check | |
2147 | (Ck_Node : Node_Id; | |
2148 | Target_Typ : Entity_Id; | |
2149 | Source_Typ : Entity_Id := Empty) | |
2150 | is | |
2151 | begin | |
2152 | Apply_Selected_Length_Checks | |
2153 | (Ck_Node, Target_Typ, Source_Typ, Do_Static => False); | |
2154 | end Apply_Length_Check; | |
2155 | ||
5f49133f AC |
2156 | ------------------------------------- |
2157 | -- Apply_Parameter_Aliasing_Checks -- | |
2158 | ------------------------------------- | |
0ea55619 | 2159 | |
5f49133f AC |
2160 | procedure Apply_Parameter_Aliasing_Checks |
2161 | (Call : Node_Id; | |
2162 | Subp : Entity_Id) | |
2163 | is | |
baed70ac AC |
2164 | Loc : constant Source_Ptr := Sloc (Call); |
2165 | ||
5f49133f AC |
2166 | function May_Cause_Aliasing |
2167 | (Formal_1 : Entity_Id; | |
2168 | Formal_2 : Entity_Id) return Boolean; | |
2169 | -- Determine whether two formal parameters can alias each other | |
2170 | -- depending on their modes. | |
2171 | ||
2172 | function Original_Actual (N : Node_Id) return Node_Id; | |
2173 | -- The expander may replace an actual with a temporary for the sake of | |
2174 | -- side effect removal. The temporary may hide a potential aliasing as | |
2175 | -- it does not share the address of the actual. This routine attempts | |
2176 | -- to retrieve the original actual. | |
2177 | ||
baed70ac AC |
2178 | procedure Overlap_Check |
2179 | (Actual_1 : Node_Id; | |
2180 | Actual_2 : Node_Id; | |
2181 | Formal_1 : Entity_Id; | |
2182 | Formal_2 : Entity_Id; | |
2183 | Check : in out Node_Id); | |
2184 | -- Create a check to determine whether Actual_1 overlaps with Actual_2. | |
2185 | -- If detailed exception messages are enabled, the check is augmented to | |
2186 | -- provide information about the names of the corresponding formals. See | |
2187 | -- the body for details. Actual_1 and Actual_2 denote the two actuals to | |
2188 | -- be tested. Formal_1 and Formal_2 denote the corresponding formals. | |
2189 | -- Check contains all and-ed simple tests generated so far or remains | |
2190 | -- unchanged in the case of detailed exception messaged. | |
2191 | ||
5f49133f AC |
2192 | ------------------------ |
2193 | -- May_Cause_Aliasing -- | |
2194 | ------------------------ | |
0ea55619 | 2195 | |
5f49133f | 2196 | function May_Cause_Aliasing |
e8dde875 | 2197 | (Formal_1 : Entity_Id; |
5f49133f AC |
2198 | Formal_2 : Entity_Id) return Boolean |
2199 | is | |
2200 | begin | |
2201 | -- The following combination cannot lead to aliasing | |
2202 | ||
2203 | -- Formal 1 Formal 2 | |
2204 | -- IN IN | |
2205 | ||
2206 | if Ekind (Formal_1) = E_In_Parameter | |
9a6dc470 RD |
2207 | and then |
2208 | Ekind (Formal_2) = E_In_Parameter | |
5f49133f AC |
2209 | then |
2210 | return False; | |
2211 | ||
2212 | -- The following combinations may lead to aliasing | |
2213 | ||
2214 | -- Formal 1 Formal 2 | |
2215 | -- IN OUT | |
2216 | -- IN IN OUT | |
2217 | -- OUT IN | |
2218 | -- OUT IN OUT | |
2219 | -- OUT OUT | |
2220 | ||
2221 | else | |
2222 | return True; | |
2223 | end if; | |
2224 | end May_Cause_Aliasing; | |
2225 | ||
2226 | --------------------- | |
2227 | -- Original_Actual -- | |
2228 | --------------------- | |
2229 | ||
2230 | function Original_Actual (N : Node_Id) return Node_Id is | |
2231 | begin | |
2232 | if Nkind (N) = N_Type_Conversion then | |
2233 | return Expression (N); | |
2234 | ||
2235 | -- The expander created a temporary to capture the result of a type | |
2236 | -- conversion where the expression is the real actual. | |
2237 | ||
2238 | elsif Nkind (N) = N_Identifier | |
2239 | and then Present (Original_Node (N)) | |
2240 | and then Nkind (Original_Node (N)) = N_Type_Conversion | |
2241 | then | |
2242 | return Expression (Original_Node (N)); | |
2243 | end if; | |
2244 | ||
2245 | return N; | |
2246 | end Original_Actual; | |
2247 | ||
baed70ac AC |
2248 | ------------------- |
2249 | -- Overlap_Check -- | |
2250 | ------------------- | |
2251 | ||
2252 | procedure Overlap_Check | |
2253 | (Actual_1 : Node_Id; | |
2254 | Actual_2 : Node_Id; | |
2255 | Formal_1 : Entity_Id; | |
2256 | Formal_2 : Entity_Id; | |
2257 | Check : in out Node_Id) | |
2258 | is | |
f7ea2603 RD |
2259 | Cond : Node_Id; |
2260 | ID_Casing : constant Casing_Type := | |
2261 | Identifier_Casing (Source_Index (Current_Sem_Unit)); | |
baed70ac AC |
2262 | |
2263 | begin | |
2264 | -- Generate: | |
2265 | -- Actual_1'Overlaps_Storage (Actual_2) | |
2266 | ||
2267 | Cond := | |
2268 | Make_Attribute_Reference (Loc, | |
2269 | Prefix => New_Copy_Tree (Original_Actual (Actual_1)), | |
2270 | Attribute_Name => Name_Overlaps_Storage, | |
2271 | Expressions => | |
2272 | New_List (New_Copy_Tree (Original_Actual (Actual_2)))); | |
2273 | ||
2274 | -- Generate the following check when detailed exception messages are | |
2275 | -- enabled: | |
2276 | ||
2277 | -- if Actual_1'Overlaps_Storage (Actual_2) then | |
2278 | -- raise Program_Error with <detailed message>; | |
2279 | -- end if; | |
2280 | ||
2281 | if Exception_Extra_Info then | |
2282 | Start_String; | |
2283 | ||
2284 | -- Do not generate location information for internal calls | |
2285 | ||
2286 | if Comes_From_Source (Call) then | |
2287 | Store_String_Chars (Build_Location_String (Loc)); | |
2288 | Store_String_Char (' '); | |
2289 | end if; | |
2290 | ||
2291 | Store_String_Chars ("aliased parameters, actuals for """); | |
f7ea2603 RD |
2292 | |
2293 | Get_Name_String (Chars (Formal_1)); | |
2294 | Set_Casing (ID_Casing); | |
2295 | Store_String_Chars (Name_Buffer (1 .. Name_Len)); | |
2296 | ||
baed70ac | 2297 | Store_String_Chars (""" and """); |
f7ea2603 RD |
2298 | |
2299 | Get_Name_String (Chars (Formal_2)); | |
2300 | Set_Casing (ID_Casing); | |
2301 | Store_String_Chars (Name_Buffer (1 .. Name_Len)); | |
2302 | ||
baed70ac AC |
2303 | Store_String_Chars (""" overlap"); |
2304 | ||
2305 | Insert_Action (Call, | |
2306 | Make_If_Statement (Loc, | |
2307 | Condition => Cond, | |
2308 | Then_Statements => New_List ( | |
2309 | Make_Raise_Statement (Loc, | |
2310 | Name => | |
e4494292 | 2311 | New_Occurrence_Of (Standard_Program_Error, Loc), |
baed70ac AC |
2312 | Expression => Make_String_Literal (Loc, End_String))))); |
2313 | ||
2314 | -- Create a sequence of overlapping checks by and-ing them all | |
2315 | -- together. | |
2316 | ||
2317 | else | |
2318 | if No (Check) then | |
2319 | Check := Cond; | |
2320 | else | |
2321 | Check := | |
2322 | Make_And_Then (Loc, | |
2323 | Left_Opnd => Check, | |
2324 | Right_Opnd => Cond); | |
2325 | end if; | |
2326 | end if; | |
2327 | end Overlap_Check; | |
2328 | ||
5f49133f AC |
2329 | -- Local variables |
2330 | ||
5f49133f AC |
2331 | Actual_1 : Node_Id; |
2332 | Actual_2 : Node_Id; | |
2333 | Check : Node_Id; | |
5f49133f AC |
2334 | Formal_1 : Entity_Id; |
2335 | Formal_2 : Entity_Id; | |
2336 | ||
2337 | -- Start of processing for Apply_Parameter_Aliasing_Checks | |
2338 | ||
2339 | begin | |
baed70ac | 2340 | Check := Empty; |
5f49133f AC |
2341 | |
2342 | Actual_1 := First_Actual (Call); | |
2343 | Formal_1 := First_Formal (Subp); | |
2344 | while Present (Actual_1) and then Present (Formal_1) loop | |
2345 | ||
2346 | -- Ensure that the actual is an object that is not passed by value. | |
2347 | -- Elementary types are always passed by value, therefore actuals of | |
2348 | -- such types cannot lead to aliasing. | |
2349 | ||
2350 | if Is_Object_Reference (Original_Actual (Actual_1)) | |
2351 | and then not Is_Elementary_Type (Etype (Original_Actual (Actual_1))) | |
2352 | then | |
2353 | Actual_2 := Next_Actual (Actual_1); | |
2354 | Formal_2 := Next_Formal (Formal_1); | |
2355 | while Present (Actual_2) and then Present (Formal_2) loop | |
2356 | ||
2357 | -- The other actual we are testing against must also denote | |
2358 | -- a non pass-by-value object. Generate the check only when | |
2359 | -- the mode of the two formals may lead to aliasing. | |
2360 | ||
2361 | if Is_Object_Reference (Original_Actual (Actual_2)) | |
2362 | and then not | |
2363 | Is_Elementary_Type (Etype (Original_Actual (Actual_2))) | |
2364 | and then May_Cause_Aliasing (Formal_1, Formal_2) | |
2365 | then | |
baed70ac AC |
2366 | Overlap_Check |
2367 | (Actual_1 => Actual_1, | |
2368 | Actual_2 => Actual_2, | |
2369 | Formal_1 => Formal_1, | |
2370 | Formal_2 => Formal_2, | |
2371 | Check => Check); | |
5f49133f AC |
2372 | end if; |
2373 | ||
2374 | Next_Actual (Actual_2); | |
2375 | Next_Formal (Formal_2); | |
2376 | end loop; | |
2377 | end if; | |
2378 | ||
2379 | Next_Actual (Actual_1); | |
2380 | Next_Formal (Formal_1); | |
2381 | end loop; | |
2382 | ||
baed70ac | 2383 | -- Place a simple check right before the call |
5f49133f | 2384 | |
baed70ac | 2385 | if Present (Check) and then not Exception_Extra_Info then |
5f49133f AC |
2386 | Insert_Action (Call, |
2387 | Make_Raise_Program_Error (Loc, | |
baed70ac AC |
2388 | Condition => Check, |
2389 | Reason => PE_Aliased_Parameters)); | |
5f49133f AC |
2390 | end if; |
2391 | end Apply_Parameter_Aliasing_Checks; | |
2392 | ||
2393 | ------------------------------------- | |
2394 | -- Apply_Parameter_Validity_Checks -- | |
2395 | ------------------------------------- | |
2396 | ||
2397 | procedure Apply_Parameter_Validity_Checks (Subp : Entity_Id) is | |
2398 | Subp_Decl : Node_Id; | |
0ea55619 | 2399 | |
e8dde875 AC |
2400 | procedure Add_Validity_Check |
2401 | (Context : Entity_Id; | |
2402 | PPC_Nam : Name_Id; | |
2403 | For_Result : Boolean := False); | |
2404 | -- Add a single 'Valid[_Scalar] check which verifies the initialization | |
2405 | -- of Context. PPC_Nam denotes the pre or post condition pragma name. | |
2406 | -- Set flag For_Result when to verify the result of a function. | |
0ea55619 | 2407 | |
e8dde875 AC |
2408 | procedure Build_PPC_Pragma (PPC_Nam : Name_Id; Check : Node_Id); |
2409 | -- Create a pre or post condition pragma with name PPC_Nam which | |
2410 | -- tests expression Check. | |
0ea55619 | 2411 | |
0ea55619 AC |
2412 | ------------------------ |
2413 | -- Add_Validity_Check -- | |
2414 | ------------------------ | |
2415 | ||
2416 | procedure Add_Validity_Check | |
2417 | (Context : Entity_Id; | |
e8dde875 | 2418 | PPC_Nam : Name_Id; |
0ea55619 AC |
2419 | For_Result : Boolean := False) |
2420 | is | |
e8dde875 AC |
2421 | Loc : constant Source_Ptr := Sloc (Subp); |
2422 | Typ : constant Entity_Id := Etype (Context); | |
0ea55619 AC |
2423 | Check : Node_Id; |
2424 | Nam : Name_Id; | |
2425 | ||
2426 | begin | |
e5c4e2bc | 2427 | -- For scalars, generate 'Valid test |
0ea55619 AC |
2428 | |
2429 | if Is_Scalar_Type (Typ) then | |
2430 | Nam := Name_Valid; | |
e5c4e2bc AC |
2431 | |
2432 | -- For any non-scalar with scalar parts, generate 'Valid_Scalars test | |
2433 | ||
2434 | elsif Scalar_Part_Present (Typ) then | |
0ea55619 | 2435 | Nam := Name_Valid_Scalars; |
e5c4e2bc AC |
2436 | |
2437 | -- No test needed for other cases (no scalars to test) | |
2438 | ||
0ea55619 AC |
2439 | else |
2440 | return; | |
2441 | end if; | |
2442 | ||
2443 | -- Step 1: Create the expression to verify the validity of the | |
2444 | -- context. | |
2445 | ||
e4494292 | 2446 | Check := New_Occurrence_Of (Context, Loc); |
0ea55619 AC |
2447 | |
2448 | -- When processing a function result, use 'Result. Generate | |
2449 | -- Context'Result | |
2450 | ||
2451 | if For_Result then | |
2452 | Check := | |
2453 | Make_Attribute_Reference (Loc, | |
2454 | Prefix => Check, | |
2455 | Attribute_Name => Name_Result); | |
2456 | end if; | |
2457 | ||
2458 | -- Generate: | |
2459 | -- Context['Result]'Valid[_Scalars] | |
2460 | ||
2461 | Check := | |
2462 | Make_Attribute_Reference (Loc, | |
2463 | Prefix => Check, | |
2464 | Attribute_Name => Nam); | |
2465 | ||
e8dde875 AC |
2466 | -- Step 2: Create a pre or post condition pragma |
2467 | ||
2468 | Build_PPC_Pragma (PPC_Nam, Check); | |
2469 | end Add_Validity_Check; | |
2470 | ||
2471 | ---------------------- | |
2472 | -- Build_PPC_Pragma -- | |
2473 | ---------------------- | |
0ea55619 | 2474 | |
e8dde875 | 2475 | procedure Build_PPC_Pragma (PPC_Nam : Name_Id; Check : Node_Id) is |
c5a26133 AC |
2476 | Loc : constant Source_Ptr := Sloc (Subp); |
2477 | Decls : List_Id; | |
2478 | Prag : Node_Id; | |
e8dde875 AC |
2479 | |
2480 | begin | |
2481 | Prag := | |
2482 | Make_Pragma (Loc, | |
2483 | Pragma_Identifier => Make_Identifier (Loc, PPC_Nam), | |
2484 | Pragma_Argument_Associations => New_List ( | |
2485 | Make_Pragma_Argument_Association (Loc, | |
2486 | Chars => Name_Check, | |
2487 | Expression => Check))); | |
2488 | ||
2489 | -- Add a message unless exception messages are suppressed | |
2490 | ||
2491 | if not Exception_Locations_Suppressed then | |
2492 | Append_To (Pragma_Argument_Associations (Prag), | |
2493 | Make_Pragma_Argument_Association (Loc, | |
2494 | Chars => Name_Message, | |
2495 | Expression => | |
2496 | Make_String_Literal (Loc, | |
2497 | Strval => "failed " & Get_Name_String (PPC_Nam) & | |
2498 | " from " & Build_Location_String (Loc)))); | |
2499 | end if; | |
2500 | ||
2501 | -- Insert the pragma in the tree | |
2502 | ||
2503 | if Nkind (Parent (Subp_Decl)) = N_Compilation_Unit then | |
2504 | Add_Global_Declaration (Prag); | |
c5a26133 AC |
2505 | Analyze (Prag); |
2506 | ||
2507 | -- PPC pragmas associated with subprogram bodies must be inserted in | |
2508 | -- the declarative part of the body. | |
2509 | ||
2510 | elsif Nkind (Subp_Decl) = N_Subprogram_Body then | |
2511 | Decls := Declarations (Subp_Decl); | |
2512 | ||
2513 | if No (Decls) then | |
2514 | Decls := New_List; | |
2515 | Set_Declarations (Subp_Decl, Decls); | |
2516 | end if; | |
2517 | ||
d85be3ba | 2518 | Prepend_To (Decls, Prag); |
c5a26133 AC |
2519 | |
2520 | -- Ensure the proper visibility of the subprogram body and its | |
2521 | -- parameters. | |
2522 | ||
2523 | Push_Scope (Subp); | |
2524 | Analyze (Prag); | |
2525 | Pop_Scope; | |
2526 | ||
2527 | -- For subprogram declarations insert the PPC pragma right after the | |
2528 | -- declarative node. | |
2529 | ||
0ea55619 | 2530 | else |
c5a26133 | 2531 | Insert_After_And_Analyze (Subp_Decl, Prag); |
0ea55619 | 2532 | end if; |
e8dde875 AC |
2533 | end Build_PPC_Pragma; |
2534 | ||
2535 | -- Local variables | |
2536 | ||
2537 | Formal : Entity_Id; | |
e8dde875 AC |
2538 | Subp_Spec : Node_Id; |
2539 | ||
5f49133f | 2540 | -- Start of processing for Apply_Parameter_Validity_Checks |
0ea55619 AC |
2541 | |
2542 | begin | |
e8dde875 | 2543 | -- Extract the subprogram specification and declaration nodes |
0ea55619 | 2544 | |
e8dde875 | 2545 | Subp_Spec := Parent (Subp); |
9a6dc470 | 2546 | |
e8dde875 AC |
2547 | if Nkind (Subp_Spec) = N_Defining_Program_Unit_Name then |
2548 | Subp_Spec := Parent (Subp_Spec); | |
2549 | end if; | |
9a6dc470 | 2550 | |
e8dde875 | 2551 | Subp_Decl := Parent (Subp_Spec); |
8e983d80 | 2552 | |
0ea55619 | 2553 | if not Comes_From_Source (Subp) |
e8dde875 AC |
2554 | |
2555 | -- Do not process formal subprograms because the corresponding actual | |
2556 | -- will receive the proper checks when the instance is analyzed. | |
2557 | ||
2558 | or else Is_Formal_Subprogram (Subp) | |
2559 | ||
9a6dc470 RD |
2560 | -- Do not process imported subprograms since pre and post conditions |
2561 | -- are never verified on routines coming from a different language. | |
e8dde875 | 2562 | |
0ea55619 AC |
2563 | or else Is_Imported (Subp) |
2564 | or else Is_Intrinsic_Subprogram (Subp) | |
e8dde875 | 2565 | |
9a6dc470 RD |
2566 | -- The PPC pragmas generated by this routine do not correspond to |
2567 | -- source aspects, therefore they cannot be applied to abstract | |
2568 | -- subprograms. | |
e8dde875 | 2569 | |
c5a26133 | 2570 | or else Nkind (Subp_Decl) = N_Abstract_Subprogram_Declaration |
e8dde875 | 2571 | |
9a6dc470 RD |
2572 | -- Do not consider subprogram renaminds because the renamed entity |
2573 | -- already has the proper PPC pragmas. | |
d85be3ba AC |
2574 | |
2575 | or else Nkind (Subp_Decl) = N_Subprogram_Renaming_Declaration | |
2576 | ||
9a6dc470 RD |
2577 | -- Do not process null procedures because there is no benefit of |
2578 | -- adding the checks to a no action routine. | |
e8dde875 AC |
2579 | |
2580 | or else (Nkind (Subp_Spec) = N_Procedure_Specification | |
9a6dc470 | 2581 | and then Null_Present (Subp_Spec)) |
0ea55619 AC |
2582 | then |
2583 | return; | |
2584 | end if; | |
2585 | ||
e8dde875 AC |
2586 | -- Inspect all the formals applying aliasing and scalar initialization |
2587 | -- checks where applicable. | |
0ea55619 AC |
2588 | |
2589 | Formal := First_Formal (Subp); | |
2590 | while Present (Formal) loop | |
e8dde875 AC |
2591 | |
2592 | -- Generate the following scalar initialization checks for each | |
2593 | -- formal parameter: | |
2594 | ||
2595 | -- mode IN - Pre => Formal'Valid[_Scalars] | |
2596 | -- mode IN OUT - Pre, Post => Formal'Valid[_Scalars] | |
2597 | -- mode OUT - Post => Formal'Valid[_Scalars] | |
2598 | ||
2599 | if Check_Validity_Of_Parameters then | |
2600 | if Ekind_In (Formal, E_In_Parameter, E_In_Out_Parameter) then | |
2601 | Add_Validity_Check (Formal, Name_Precondition, False); | |
2602 | end if; | |
2603 | ||
2604 | if Ekind_In (Formal, E_In_Out_Parameter, E_Out_Parameter) then | |
2605 | Add_Validity_Check (Formal, Name_Postcondition, False); | |
2606 | end if; | |
0ea55619 AC |
2607 | end if; |
2608 | ||
0ea55619 AC |
2609 | Next_Formal (Formal); |
2610 | end loop; | |
2611 | ||
9a6dc470 | 2612 | -- Generate following scalar initialization check for function result: |
e8dde875 AC |
2613 | |
2614 | -- Post => Subp'Result'Valid[_Scalars] | |
0ea55619 | 2615 | |
9a6dc470 | 2616 | if Check_Validity_Of_Parameters and then Ekind (Subp) = E_Function then |
e8dde875 | 2617 | Add_Validity_Check (Subp, Name_Postcondition, True); |
0ea55619 | 2618 | end if; |
5f49133f | 2619 | end Apply_Parameter_Validity_Checks; |
0ea55619 | 2620 | |
48f91b44 RD |
2621 | --------------------------- |
2622 | -- Apply_Predicate_Check -- | |
2623 | --------------------------- | |
2624 | ||
2625 | procedure Apply_Predicate_Check (N : Node_Id; Typ : Entity_Id) is | |
62db841a | 2626 | S : Entity_Id; |
8e983d80 | 2627 | |
48f91b44 | 2628 | begin |
8110ee3b | 2629 | if Present (Predicate_Function (Typ)) then |
62db841a | 2630 | |
62db841a | 2631 | S := Current_Scope; |
8e983d80 | 2632 | while Present (S) and then not Is_Subprogram (S) loop |
62db841a AC |
2633 | S := Scope (S); |
2634 | end loop; | |
2635 | ||
8e1e62e3 AC |
2636 | -- A predicate check does not apply within internally generated |
2637 | -- subprograms, such as TSS functions. | |
2638 | ||
2639 | if Within_Internal_Subprogram then | |
62db841a | 2640 | return; |
0929eaeb | 2641 | |
3a0919e2 ES |
2642 | -- If the check appears within the predicate function itself, it |
2643 | -- means that the user specified a check whose formal is the | |
2644 | -- predicated subtype itself, rather than some covering type. This | |
2645 | -- is likely to be a common error, and thus deserves a warning. | |
0929eaeb | 2646 | |
155b4fcc | 2647 | elsif Present (S) and then S = Predicate_Function (Typ) then |
3a0919e2 ES |
2648 | Error_Msg_N |
2649 | ("predicate check includes a function call that " | |
685bc70f | 2650 | & "requires a predicate check??", Parent (N)); |
3a0919e2 | 2651 | Error_Msg_N |
685bc70f | 2652 | ("\this will result in infinite recursion??", Parent (N)); |
3a0919e2 | 2653 | Insert_Action (N, |
c7e152b5 AC |
2654 | Make_Raise_Storage_Error (Sloc (N), |
2655 | Reason => SE_Infinite_Recursion)); | |
0929eaeb | 2656 | |
0d5fbf52 | 2657 | -- Here for normal case of predicate active |
804fc056 | 2658 | |
c7e152b5 | 2659 | else |
fd8b8c01 AC |
2660 | -- If the type has a static predicate and the expression is known |
2661 | -- at compile time, see if the expression satisfies the predicate. | |
f197d2f2 AC |
2662 | |
2663 | Check_Expression_Against_Static_Predicate (N, Typ); | |
804fc056 | 2664 | |
62db841a AC |
2665 | Insert_Action (N, |
2666 | Make_Predicate_Check (Typ, Duplicate_Subexpr (N))); | |
2667 | end if; | |
48f91b44 RD |
2668 | end if; |
2669 | end Apply_Predicate_Check; | |
2670 | ||
70482933 RK |
2671 | ----------------------- |
2672 | -- Apply_Range_Check -- | |
2673 | ----------------------- | |
2674 | ||
2675 | procedure Apply_Range_Check | |
2676 | (Ck_Node : Node_Id; | |
2677 | Target_Typ : Entity_Id; | |
2678 | Source_Typ : Entity_Id := Empty) | |
2679 | is | |
2680 | begin | |
2681 | Apply_Selected_Range_Checks | |
2682 | (Ck_Node, Target_Typ, Source_Typ, Do_Static => False); | |
2683 | end Apply_Range_Check; | |
2684 | ||
2685 | ------------------------------ | |
2686 | -- Apply_Scalar_Range_Check -- | |
2687 | ------------------------------ | |
2688 | ||
675d6070 TQ |
2689 | -- Note that Apply_Scalar_Range_Check never turns the Do_Range_Check flag |
2690 | -- off if it is already set on. | |
70482933 RK |
2691 | |
2692 | procedure Apply_Scalar_Range_Check | |
2693 | (Expr : Node_Id; | |
2694 | Target_Typ : Entity_Id; | |
2695 | Source_Typ : Entity_Id := Empty; | |
2696 | Fixed_Int : Boolean := False) | |
2697 | is | |
2698 | Parnt : constant Node_Id := Parent (Expr); | |
2699 | S_Typ : Entity_Id; | |
2700 | Arr : Node_Id := Empty; -- initialize to prevent warning | |
2701 | Arr_Typ : Entity_Id := Empty; -- initialize to prevent warning | |
2702 | OK : Boolean; | |
2703 | ||
2704 | Is_Subscr_Ref : Boolean; | |
2705 | -- Set true if Expr is a subscript | |
2706 | ||
2707 | Is_Unconstrained_Subscr_Ref : Boolean; | |
2708 | -- Set true if Expr is a subscript of an unconstrained array. In this | |
2709 | -- case we do not attempt to do an analysis of the value against the | |
2710 | -- range of the subscript, since we don't know the actual subtype. | |
2711 | ||
2712 | Int_Real : Boolean; | |
675d6070 TQ |
2713 | -- Set to True if Expr should be regarded as a real value even though |
2714 | -- the type of Expr might be discrete. | |
70482933 RK |
2715 | |
2716 | procedure Bad_Value; | |
2717 | -- Procedure called if value is determined to be out of range | |
2718 | ||
fbf5a39b AC |
2719 | --------------- |
2720 | -- Bad_Value -- | |
2721 | --------------- | |
2722 | ||
70482933 RK |
2723 | procedure Bad_Value is |
2724 | begin | |
2725 | Apply_Compile_Time_Constraint_Error | |
685bc70f | 2726 | (Expr, "value not in range of}??", CE_Range_Check_Failed, |
70482933 RK |
2727 | Ent => Target_Typ, |
2728 | Typ => Target_Typ); | |
2729 | end Bad_Value; | |
2730 | ||
fbf5a39b AC |
2731 | -- Start of processing for Apply_Scalar_Range_Check |
2732 | ||
70482933 | 2733 | begin |
939c12d2 | 2734 | -- Return if check obviously not needed |
70482933 | 2735 | |
939c12d2 RD |
2736 | if |
2737 | -- Not needed inside generic | |
70482933 | 2738 | |
939c12d2 RD |
2739 | Inside_A_Generic |
2740 | ||
2741 | -- Not needed if previous error | |
2742 | ||
2743 | or else Target_Typ = Any_Type | |
2744 | or else Nkind (Expr) = N_Error | |
2745 | ||
2746 | -- Not needed for non-scalar type | |
2747 | ||
2748 | or else not Is_Scalar_Type (Target_Typ) | |
2749 | ||
2750 | -- Not needed if we know node raises CE already | |
2751 | ||
2752 | or else Raises_Constraint_Error (Expr) | |
70482933 RK |
2753 | then |
2754 | return; | |
2755 | end if; | |
2756 | ||
2757 | -- Now, see if checks are suppressed | |
2758 | ||
2759 | Is_Subscr_Ref := | |
2760 | Is_List_Member (Expr) and then Nkind (Parnt) = N_Indexed_Component; | |
2761 | ||
2762 | if Is_Subscr_Ref then | |
2763 | Arr := Prefix (Parnt); | |
2764 | Arr_Typ := Get_Actual_Subtype_If_Available (Arr); | |
ba759acd | 2765 | |
f4f92d9d | 2766 | if Is_Access_Type (Arr_Typ) then |
05c1e7d2 | 2767 | Arr_Typ := Designated_Type (Arr_Typ); |
f4f92d9d | 2768 | end if; |
70482933 RK |
2769 | end if; |
2770 | ||
2771 | if not Do_Range_Check (Expr) then | |
2772 | ||
2773 | -- Subscript reference. Check for Index_Checks suppressed | |
2774 | ||
2775 | if Is_Subscr_Ref then | |
2776 | ||
2777 | -- Check array type and its base type | |
2778 | ||
2779 | if Index_Checks_Suppressed (Arr_Typ) | |
fbf5a39b | 2780 | or else Index_Checks_Suppressed (Base_Type (Arr_Typ)) |
70482933 RK |
2781 | then |
2782 | return; | |
2783 | ||
2784 | -- Check array itself if it is an entity name | |
2785 | ||
2786 | elsif Is_Entity_Name (Arr) | |
fbf5a39b | 2787 | and then Index_Checks_Suppressed (Entity (Arr)) |
70482933 RK |
2788 | then |
2789 | return; | |
2790 | ||
2791 | -- Check expression itself if it is an entity name | |
2792 | ||
2793 | elsif Is_Entity_Name (Expr) | |
fbf5a39b | 2794 | and then Index_Checks_Suppressed (Entity (Expr)) |
70482933 RK |
2795 | then |
2796 | return; | |
2797 | end if; | |
2798 | ||
2799 | -- All other cases, check for Range_Checks suppressed | |
2800 | ||
2801 | else | |
2802 | -- Check target type and its base type | |
2803 | ||
2804 | if Range_Checks_Suppressed (Target_Typ) | |
fbf5a39b | 2805 | or else Range_Checks_Suppressed (Base_Type (Target_Typ)) |
70482933 RK |
2806 | then |
2807 | return; | |
2808 | ||
2809 | -- Check expression itself if it is an entity name | |
2810 | ||
2811 | elsif Is_Entity_Name (Expr) | |
fbf5a39b | 2812 | and then Range_Checks_Suppressed (Entity (Expr)) |
70482933 RK |
2813 | then |
2814 | return; | |
2815 | ||
675d6070 TQ |
2816 | -- If Expr is part of an assignment statement, then check left |
2817 | -- side of assignment if it is an entity name. | |
70482933 RK |
2818 | |
2819 | elsif Nkind (Parnt) = N_Assignment_Statement | |
2820 | and then Is_Entity_Name (Name (Parnt)) | |
fbf5a39b | 2821 | and then Range_Checks_Suppressed (Entity (Name (Parnt))) |
70482933 RK |
2822 | then |
2823 | return; | |
2824 | end if; | |
2825 | end if; | |
2826 | end if; | |
2827 | ||
fbf5a39b AC |
2828 | -- Do not set range checks if they are killed |
2829 | ||
2830 | if Nkind (Expr) = N_Unchecked_Type_Conversion | |
2831 | and then Kill_Range_Check (Expr) | |
2832 | then | |
2833 | return; | |
2834 | end if; | |
2835 | ||
2836 | -- Do not set range checks for any values from System.Scalar_Values | |
a90bd866 | 2837 | -- since the whole idea of such values is to avoid checking them. |
fbf5a39b AC |
2838 | |
2839 | if Is_Entity_Name (Expr) | |
2840 | and then Is_RTU (Scope (Entity (Expr)), System_Scalar_Values) | |
2841 | then | |
2842 | return; | |
2843 | end if; | |
2844 | ||
70482933 RK |
2845 | -- Now see if we need a check |
2846 | ||
2847 | if No (Source_Typ) then | |
2848 | S_Typ := Etype (Expr); | |
2849 | else | |
2850 | S_Typ := Source_Typ; | |
2851 | end if; | |
2852 | ||
2853 | if not Is_Scalar_Type (S_Typ) or else S_Typ = Any_Type then | |
2854 | return; | |
2855 | end if; | |
2856 | ||
2857 | Is_Unconstrained_Subscr_Ref := | |
2858 | Is_Subscr_Ref and then not Is_Constrained (Arr_Typ); | |
2859 | ||
347c766a | 2860 | -- Special checks for floating-point type |
70482933 | 2861 | |
347c766a RD |
2862 | if Is_Floating_Point_Type (S_Typ) then |
2863 | ||
2864 | -- Always do a range check if the source type includes infinities and | |
2865 | -- the target type does not include infinities. We do not do this if | |
2866 | -- range checks are killed. | |
2867 | ||
2868 | if Has_Infinities (S_Typ) | |
2869 | and then not Has_Infinities (Target_Typ) | |
2870 | then | |
2871 | Enable_Range_Check (Expr); | |
347c766a | 2872 | end if; |
70482933 RK |
2873 | end if; |
2874 | ||
675d6070 TQ |
2875 | -- Return if we know expression is definitely in the range of the target |
2876 | -- type as determined by Determine_Range. Right now we only do this for | |
2877 | -- discrete types, and not fixed-point or floating-point types. | |
70482933 | 2878 | |
ddda9d0f | 2879 | -- The additional less-precise tests below catch these cases |
70482933 | 2880 | |
675d6070 TQ |
2881 | -- Note: skip this if we are given a source_typ, since the point of |
2882 | -- supplying a Source_Typ is to stop us looking at the expression. | |
2883 | -- We could sharpen this test to be out parameters only ??? | |
70482933 RK |
2884 | |
2885 | if Is_Discrete_Type (Target_Typ) | |
2886 | and then Is_Discrete_Type (Etype (Expr)) | |
2887 | and then not Is_Unconstrained_Subscr_Ref | |
2888 | and then No (Source_Typ) | |
2889 | then | |
2890 | declare | |
2891 | Tlo : constant Node_Id := Type_Low_Bound (Target_Typ); | |
2892 | Thi : constant Node_Id := Type_High_Bound (Target_Typ); | |
2893 | Lo : Uint; | |
2894 | Hi : Uint; | |
2895 | ||
2896 | begin | |
2897 | if Compile_Time_Known_Value (Tlo) | |
2898 | and then Compile_Time_Known_Value (Thi) | |
2899 | then | |
fbf5a39b AC |
2900 | declare |
2901 | Lov : constant Uint := Expr_Value (Tlo); | |
2902 | Hiv : constant Uint := Expr_Value (Thi); | |
70482933 | 2903 | |
fbf5a39b AC |
2904 | begin |
2905 | -- If range is null, we for sure have a constraint error | |
2906 | -- (we don't even need to look at the value involved, | |
2907 | -- since all possible values will raise CE). | |
2908 | ||
2909 | if Lov > Hiv then | |
2910 | Bad_Value; | |
2911 | return; | |
2912 | end if; | |
2913 | ||
2914 | -- Otherwise determine range of value | |
2915 | ||
c800f862 | 2916 | Determine_Range (Expr, OK, Lo, Hi, Assume_Valid => True); |
fbf5a39b AC |
2917 | |
2918 | if OK then | |
2919 | ||
2920 | -- If definitely in range, all OK | |
70482933 | 2921 | |
70482933 RK |
2922 | if Lo >= Lov and then Hi <= Hiv then |
2923 | return; | |
2924 | ||
fbf5a39b AC |
2925 | -- If definitely not in range, warn |
2926 | ||
70482933 RK |
2927 | elsif Lov > Hi or else Hiv < Lo then |
2928 | Bad_Value; | |
2929 | return; | |
fbf5a39b AC |
2930 | |
2931 | -- Otherwise we don't know | |
2932 | ||
2933 | else | |
2934 | null; | |
70482933 | 2935 | end if; |
fbf5a39b AC |
2936 | end if; |
2937 | end; | |
70482933 RK |
2938 | end if; |
2939 | end; | |
2940 | end if; | |
2941 | ||
2942 | Int_Real := | |
2943 | Is_Floating_Point_Type (S_Typ) | |
2944 | or else (Is_Fixed_Point_Type (S_Typ) and then not Fixed_Int); | |
2945 | ||
2946 | -- Check if we can determine at compile time whether Expr is in the | |
fbf5a39b AC |
2947 | -- range of the target type. Note that if S_Typ is within the bounds |
2948 | -- of Target_Typ then this must be the case. This check is meaningful | |
2949 | -- only if this is not a conversion between integer and real types. | |
70482933 RK |
2950 | |
2951 | if not Is_Unconstrained_Subscr_Ref | |
347c766a | 2952 | and then Is_Discrete_Type (S_Typ) = Is_Discrete_Type (Target_Typ) |
70482933 | 2953 | and then |
c27f2f15 | 2954 | (In_Subrange_Of (S_Typ, Target_Typ, Fixed_Int) |
70482933 | 2955 | or else |
c800f862 RD |
2956 | Is_In_Range (Expr, Target_Typ, |
2957 | Assume_Valid => True, | |
347c766a RD |
2958 | Fixed_Int => Fixed_Int, |
2959 | Int_Real => Int_Real)) | |
70482933 RK |
2960 | then |
2961 | return; | |
2962 | ||
c800f862 RD |
2963 | elsif Is_Out_Of_Range (Expr, Target_Typ, |
2964 | Assume_Valid => True, | |
2965 | Fixed_Int => Fixed_Int, | |
2966 | Int_Real => Int_Real) | |
2967 | then | |
70482933 RK |
2968 | Bad_Value; |
2969 | return; | |
2970 | ||
347c766a | 2971 | -- Floating-point case |
675d6070 TQ |
2972 | -- In the floating-point case, we only do range checks if the type is |
2973 | -- constrained. We definitely do NOT want range checks for unconstrained | |
2974 | -- types, since we want to have infinities | |
70482933 | 2975 | |
fbf5a39b | 2976 | elsif Is_Floating_Point_Type (S_Typ) then |
347c766a RD |
2977 | |
2978 | -- Normally, we only do range checks if the type is constrained. We do | |
2979 | -- NOT want range checks for unconstrained types, since we want to have | |
d26d790d | 2980 | -- infinities. |
347c766a | 2981 | |
d26d790d | 2982 | if Is_Constrained (S_Typ) then |
fbf5a39b AC |
2983 | Enable_Range_Check (Expr); |
2984 | end if; | |
70482933 | 2985 | |
fbf5a39b | 2986 | -- For all other cases we enable a range check unconditionally |
70482933 RK |
2987 | |
2988 | else | |
2989 | Enable_Range_Check (Expr); | |
2990 | return; | |
2991 | end if; | |
70482933 RK |
2992 | end Apply_Scalar_Range_Check; |
2993 | ||
2994 | ---------------------------------- | |
2995 | -- Apply_Selected_Length_Checks -- | |
2996 | ---------------------------------- | |
2997 | ||
2998 | procedure Apply_Selected_Length_Checks | |
2999 | (Ck_Node : Node_Id; | |
3000 | Target_Typ : Entity_Id; | |
3001 | Source_Typ : Entity_Id; | |
3002 | Do_Static : Boolean) | |
3003 | is | |
3004 | Cond : Node_Id; | |
3005 | R_Result : Check_Result; | |
3006 | R_Cno : Node_Id; | |
3007 | ||
3008 | Loc : constant Source_Ptr := Sloc (Ck_Node); | |
3009 | Checks_On : constant Boolean := | |
15f0f591 | 3010 | (not Index_Checks_Suppressed (Target_Typ)) |
4a28b181 | 3011 | or else (not Length_Checks_Suppressed (Target_Typ)); |
70482933 RK |
3012 | |
3013 | begin | |
4a28b181 AC |
3014 | -- Note: this means that we lose some useful warnings if the expander |
3015 | -- is not active, and we also lose these warnings in SPARK mode ??? | |
3016 | ||
4460a9bc | 3017 | if not Expander_Active then |
70482933 RK |
3018 | return; |
3019 | end if; | |
3020 | ||
3021 | R_Result := | |
3022 | Selected_Length_Checks (Ck_Node, Target_Typ, Source_Typ, Empty); | |
3023 | ||
3024 | for J in 1 .. 2 loop | |
70482933 RK |
3025 | R_Cno := R_Result (J); |
3026 | exit when No (R_Cno); | |
3027 | ||
3028 | -- A length check may mention an Itype which is attached to a | |
3029 | -- subsequent node. At the top level in a package this can cause | |
3030 | -- an order-of-elaboration problem, so we make sure that the itype | |
3031 | -- is referenced now. | |
3032 | ||
3033 | if Ekind (Current_Scope) = E_Package | |
3034 | and then Is_Compilation_Unit (Current_Scope) | |
3035 | then | |
3036 | Ensure_Defined (Target_Typ, Ck_Node); | |
3037 | ||
3038 | if Present (Source_Typ) then | |
3039 | Ensure_Defined (Source_Typ, Ck_Node); | |
3040 | ||
3041 | elsif Is_Itype (Etype (Ck_Node)) then | |
3042 | Ensure_Defined (Etype (Ck_Node), Ck_Node); | |
3043 | end if; | |
3044 | end if; | |
3045 | ||
675d6070 TQ |
3046 | -- If the item is a conditional raise of constraint error, then have |
3047 | -- a look at what check is being performed and ??? | |
70482933 RK |
3048 | |
3049 | if Nkind (R_Cno) = N_Raise_Constraint_Error | |
3050 | and then Present (Condition (R_Cno)) | |
3051 | then | |
3052 | Cond := Condition (R_Cno); | |
3053 | ||
c064e066 | 3054 | -- Case where node does not now have a dynamic check |
70482933 | 3055 | |
c064e066 RD |
3056 | if not Has_Dynamic_Length_Check (Ck_Node) then |
3057 | ||
3058 | -- If checks are on, just insert the check | |
3059 | ||
3060 | if Checks_On then | |
3061 | Insert_Action (Ck_Node, R_Cno); | |
3062 | ||
3063 | if not Do_Static then | |
3064 | Set_Has_Dynamic_Length_Check (Ck_Node); | |
3065 | end if; | |
3066 | ||
3067 | -- If checks are off, then analyze the length check after | |
3068 | -- temporarily attaching it to the tree in case the relevant | |
308e6f3a | 3069 | -- condition can be evaluated at compile time. We still want a |
c064e066 RD |
3070 | -- compile time warning in this case. |
3071 | ||
3072 | else | |
3073 | Set_Parent (R_Cno, Ck_Node); | |
3074 | Analyze (R_Cno); | |
70482933 | 3075 | end if; |
70482933 RK |
3076 | end if; |
3077 | ||
3078 | -- Output a warning if the condition is known to be True | |
3079 | ||
3080 | if Is_Entity_Name (Cond) | |
3081 | and then Entity (Cond) = Standard_True | |
3082 | then | |
3083 | Apply_Compile_Time_Constraint_Error | |
685bc70f | 3084 | (Ck_Node, "wrong length for array of}??", |
07fc65c4 | 3085 | CE_Length_Check_Failed, |
70482933 RK |
3086 | Ent => Target_Typ, |
3087 | Typ => Target_Typ); | |
3088 | ||
3089 | -- If we were only doing a static check, or if checks are not | |
3090 | -- on, then we want to delete the check, since it is not needed. | |
3091 | -- We do this by replacing the if statement by a null statement | |
3092 | ||
3093 | elsif Do_Static or else not Checks_On then | |
11b4899f | 3094 | Remove_Warning_Messages (R_Cno); |
70482933 RK |
3095 | Rewrite (R_Cno, Make_Null_Statement (Loc)); |
3096 | end if; | |
3097 | ||
3098 | else | |
3099 | Install_Static_Check (R_Cno, Loc); | |
3100 | end if; | |
70482933 | 3101 | end loop; |
70482933 RK |
3102 | end Apply_Selected_Length_Checks; |
3103 | ||
3104 | --------------------------------- | |
3105 | -- Apply_Selected_Range_Checks -- | |
3106 | --------------------------------- | |
3107 | ||
3108 | procedure Apply_Selected_Range_Checks | |
3109 | (Ck_Node : Node_Id; | |
3110 | Target_Typ : Entity_Id; | |
3111 | Source_Typ : Entity_Id; | |
3112 | Do_Static : Boolean) | |
3113 | is | |
70482933 RK |
3114 | Loc : constant Source_Ptr := Sloc (Ck_Node); |
3115 | Checks_On : constant Boolean := | |
f9966234 | 3116 | not Index_Checks_Suppressed (Target_Typ) |
6e32b1ab AC |
3117 | or else |
3118 | not Range_Checks_Suppressed (Target_Typ); | |
f9966234 AC |
3119 | |
3120 | Cond : Node_Id; | |
3121 | R_Cno : Node_Id; | |
3122 | R_Result : Check_Result; | |
70482933 RK |
3123 | |
3124 | begin | |
6e32b1ab | 3125 | if not Expander_Active or not Checks_On then |
70482933 RK |
3126 | return; |
3127 | end if; | |
3128 | ||
3129 | R_Result := | |
3130 | Selected_Range_Checks (Ck_Node, Target_Typ, Source_Typ, Empty); | |
3131 | ||
3132 | for J in 1 .. 2 loop | |
70482933 RK |
3133 | R_Cno := R_Result (J); |
3134 | exit when No (R_Cno); | |
3135 | ||
f9966234 AC |
3136 | -- The range check requires runtime evaluation. Depending on what its |
3137 | -- triggering condition is, the check may be converted into a compile | |
3138 | -- time constraint check. | |
70482933 RK |
3139 | |
3140 | if Nkind (R_Cno) = N_Raise_Constraint_Error | |
3141 | and then Present (Condition (R_Cno)) | |
3142 | then | |
3143 | Cond := Condition (R_Cno); | |
3144 | ||
f9966234 AC |
3145 | -- Insert the range check before the related context. Note that |
3146 | -- this action analyses the triggering condition. | |
70482933 | 3147 | |
f9966234 AC |
3148 | Insert_Action (Ck_Node, R_Cno); |
3149 | ||
3150 | -- This old code doesn't make sense, why is the context flagged as | |
3151 | -- requiring dynamic range checks now in the middle of generating | |
3152 | -- them ??? | |
3153 | ||
3154 | if not Do_Static then | |
3155 | Set_Has_Dynamic_Range_Check (Ck_Node); | |
70482933 RK |
3156 | end if; |
3157 | ||
f9966234 AC |
3158 | -- The triggering condition evaluates to True, the range check |
3159 | -- can be converted into a compile time constraint check. | |
70482933 RK |
3160 | |
3161 | if Is_Entity_Name (Cond) | |
3162 | and then Entity (Cond) = Standard_True | |
3163 | then | |
675d6070 TQ |
3164 | -- Since an N_Range is technically not an expression, we have |
3165 | -- to set one of the bounds to C_E and then just flag the | |
3166 | -- N_Range. The warning message will point to the lower bound | |
3167 | -- and complain about a range, which seems OK. | |
70482933 RK |
3168 | |
3169 | if Nkind (Ck_Node) = N_Range then | |
3170 | Apply_Compile_Time_Constraint_Error | |
6e32b1ab AC |
3171 | (Low_Bound (Ck_Node), |
3172 | "static range out of bounds of}??", | |
07fc65c4 | 3173 | CE_Range_Check_Failed, |
70482933 RK |
3174 | Ent => Target_Typ, |
3175 | Typ => Target_Typ); | |
3176 | ||
3177 | Set_Raises_Constraint_Error (Ck_Node); | |
3178 | ||
3179 | else | |
3180 | Apply_Compile_Time_Constraint_Error | |
6e32b1ab | 3181 | (Ck_Node, |
b785e0b8 | 3182 | "static value out of range of}??", |
07fc65c4 | 3183 | CE_Range_Check_Failed, |
70482933 RK |
3184 | Ent => Target_Typ, |
3185 | Typ => Target_Typ); | |
3186 | end if; | |
3187 | ||
3188 | -- If we were only doing a static check, or if checks are not | |
3189 | -- on, then we want to delete the check, since it is not needed. | |
3190 | -- We do this by replacing the if statement by a null statement | |
3191 | ||
f9966234 AC |
3192 | -- Why are we even generating checks if checks are turned off ??? |
3193 | ||
70482933 | 3194 | elsif Do_Static or else not Checks_On then |
11b4899f | 3195 | Remove_Warning_Messages (R_Cno); |
70482933 RK |
3196 | Rewrite (R_Cno, Make_Null_Statement (Loc)); |
3197 | end if; | |
3198 | ||
f9966234 AC |
3199 | -- The range check raises Constrant_Error explicitly |
3200 | ||
70482933 RK |
3201 | else |
3202 | Install_Static_Check (R_Cno, Loc); | |
3203 | end if; | |
70482933 | 3204 | end loop; |
70482933 RK |
3205 | end Apply_Selected_Range_Checks; |
3206 | ||
3207 | ------------------------------- | |
3208 | -- Apply_Static_Length_Check -- | |
3209 | ------------------------------- | |
3210 | ||
3211 | procedure Apply_Static_Length_Check | |
3212 | (Expr : Node_Id; | |
3213 | Target_Typ : Entity_Id; | |
3214 | Source_Typ : Entity_Id := Empty) | |
3215 | is | |
3216 | begin | |
3217 | Apply_Selected_Length_Checks | |
3218 | (Expr, Target_Typ, Source_Typ, Do_Static => True); | |
3219 | end Apply_Static_Length_Check; | |
3220 | ||
3221 | ------------------------------------- | |
3222 | -- Apply_Subscript_Validity_Checks -- | |
3223 | ------------------------------------- | |
3224 | ||
3225 | procedure Apply_Subscript_Validity_Checks (Expr : Node_Id) is | |
3226 | Sub : Node_Id; | |
3227 | ||
3228 | begin | |
3229 | pragma Assert (Nkind (Expr) = N_Indexed_Component); | |
3230 | ||
3231 | -- Loop through subscripts | |
3232 | ||
3233 | Sub := First (Expressions (Expr)); | |
3234 | while Present (Sub) loop | |
3235 | ||
675d6070 TQ |
3236 | -- Check one subscript. Note that we do not worry about enumeration |
3237 | -- type with holes, since we will convert the value to a Pos value | |
3238 | -- for the subscript, and that convert will do the necessary validity | |
3239 | -- check. | |
70482933 RK |
3240 | |
3241 | Ensure_Valid (Sub, Holes_OK => True); | |
3242 | ||
3243 | -- Move to next subscript | |
3244 | ||
3245 | Sub := Next (Sub); | |
3246 | end loop; | |
3247 | end Apply_Subscript_Validity_Checks; | |
3248 | ||
3249 | ---------------------------------- | |
3250 | -- Apply_Type_Conversion_Checks -- | |
3251 | ---------------------------------- | |
3252 | ||
3253 | procedure Apply_Type_Conversion_Checks (N : Node_Id) is | |
3254 | Target_Type : constant Entity_Id := Etype (N); | |
3255 | Target_Base : constant Entity_Id := Base_Type (Target_Type); | |
fbf5a39b | 3256 | Expr : constant Node_Id := Expression (N); |
2c1a2cf3 RD |
3257 | |
3258 | Expr_Type : constant Entity_Id := Underlying_Type (Etype (Expr)); | |
1197ddb1 AC |
3259 | -- Note: if Etype (Expr) is a private type without discriminants, its |
3260 | -- full view might have discriminants with defaults, so we need the | |
3261 | -- full view here to retrieve the constraints. | |
70482933 RK |
3262 | |
3263 | begin | |
3264 | if Inside_A_Generic then | |
3265 | return; | |
3266 | ||
07fc65c4 | 3267 | -- Skip these checks if serious errors detected, there are some nasty |
70482933 RK |
3268 | -- situations of incomplete trees that blow things up. |
3269 | ||
07fc65c4 | 3270 | elsif Serious_Errors_Detected > 0 then |
70482933 RK |
3271 | return; |
3272 | ||
8e1e62e3 AC |
3273 | -- Never generate discriminant checks for Unchecked_Union types |
3274 | ||
3275 | elsif Present (Expr_Type) | |
3276 | and then Is_Unchecked_Union (Expr_Type) | |
3277 | then | |
3278 | return; | |
3279 | ||
675d6070 TQ |
3280 | -- Scalar type conversions of the form Target_Type (Expr) require a |
3281 | -- range check if we cannot be sure that Expr is in the base type of | |
3282 | -- Target_Typ and also that Expr is in the range of Target_Typ. These | |
3283 | -- are not quite the same condition from an implementation point of | |
3284 | -- view, but clearly the second includes the first. | |
70482933 RK |
3285 | |
3286 | elsif Is_Scalar_Type (Target_Type) then | |
3287 | declare | |
3288 | Conv_OK : constant Boolean := Conversion_OK (N); | |
675d6070 | 3289 | -- If the Conversion_OK flag on the type conversion is set and no |
8e1e62e3 AC |
3290 | -- floating-point type is involved in the type conversion then |
3291 | -- fixed-point values must be read as integral values. | |
70482933 | 3292 | |
7324bf49 | 3293 | Float_To_Int : constant Boolean := |
15f0f591 AC |
3294 | Is_Floating_Point_Type (Expr_Type) |
3295 | and then Is_Integer_Type (Target_Type); | |
7324bf49 | 3296 | |
70482933 | 3297 | begin |
70482933 | 3298 | if not Overflow_Checks_Suppressed (Target_Base) |
a7f1b24f | 3299 | and then not Overflow_Checks_Suppressed (Target_Type) |
1c7717c3 | 3300 | and then not |
c27f2f15 | 3301 | In_Subrange_Of (Expr_Type, Target_Base, Fixed_Int => Conv_OK) |
7324bf49 | 3302 | and then not Float_To_Int |
70482933 | 3303 | then |
11b4899f | 3304 | Activate_Overflow_Check (N); |
70482933 RK |
3305 | end if; |
3306 | ||
3307 | if not Range_Checks_Suppressed (Target_Type) | |
3308 | and then not Range_Checks_Suppressed (Expr_Type) | |
3309 | then | |
7324bf49 AC |
3310 | if Float_To_Int then |
3311 | Apply_Float_Conversion_Check (Expr, Target_Type); | |
3312 | else | |
3313 | Apply_Scalar_Range_Check | |
3314 | (Expr, Target_Type, Fixed_Int => Conv_OK); | |
b2009d46 AC |
3315 | |
3316 | -- If the target type has predicates, we need to indicate | |
8e1e62e3 AC |
3317 | -- the need for a check, even if Determine_Range finds that |
3318 | -- the value is within bounds. This may be the case e.g for | |
3319 | -- a division with a constant denominator. | |
b2009d46 AC |
3320 | |
3321 | if Has_Predicates (Target_Type) then | |
3322 | Enable_Range_Check (Expr); | |
3323 | end if; | |
7324bf49 | 3324 | end if; |
70482933 RK |
3325 | end if; |
3326 | end; | |
3327 | ||
3328 | elsif Comes_From_Source (N) | |
ec2dd67a | 3329 | and then not Discriminant_Checks_Suppressed (Target_Type) |
70482933 RK |
3330 | and then Is_Record_Type (Target_Type) |
3331 | and then Is_Derived_Type (Target_Type) | |
3332 | and then not Is_Tagged_Type (Target_Type) | |
3333 | and then not Is_Constrained (Target_Type) | |
fbf5a39b | 3334 | and then Present (Stored_Constraint (Target_Type)) |
70482933 | 3335 | then |
1197ddb1 | 3336 | -- An unconstrained derived type may have inherited discriminant. |
fbf5a39b | 3337 | -- Build an actual discriminant constraint list using the stored |
70482933 | 3338 | -- constraint, to verify that the expression of the parent type |
8e1e62e3 AC |
3339 | -- satisfies the constraints imposed by the (unconstrained) derived |
3340 | -- type. This applies to value conversions, not to view conversions | |
3341 | -- of tagged types. | |
70482933 RK |
3342 | |
3343 | declare | |
fbf5a39b AC |
3344 | Loc : constant Source_Ptr := Sloc (N); |
3345 | Cond : Node_Id; | |
3346 | Constraint : Elmt_Id; | |
3347 | Discr_Value : Node_Id; | |
3348 | Discr : Entity_Id; | |
3349 | ||
3350 | New_Constraints : constant Elist_Id := New_Elmt_List; | |
3351 | Old_Constraints : constant Elist_Id := | |
15f0f591 | 3352 | Discriminant_Constraint (Expr_Type); |
70482933 RK |
3353 | |
3354 | begin | |
fbf5a39b | 3355 | Constraint := First_Elmt (Stored_Constraint (Target_Type)); |
70482933 RK |
3356 | while Present (Constraint) loop |
3357 | Discr_Value := Node (Constraint); | |
3358 | ||
3359 | if Is_Entity_Name (Discr_Value) | |
3360 | and then Ekind (Entity (Discr_Value)) = E_Discriminant | |
3361 | then | |
3362 | Discr := Corresponding_Discriminant (Entity (Discr_Value)); | |
3363 | ||
3364 | if Present (Discr) | |
3365 | and then Scope (Discr) = Base_Type (Expr_Type) | |
3366 | then | |
3367 | -- Parent is constrained by new discriminant. Obtain | |
675d6070 TQ |
3368 | -- Value of original discriminant in expression. If the |
3369 | -- new discriminant has been used to constrain more than | |
3370 | -- one of the stored discriminants, this will provide the | |
3371 | -- required consistency check. | |
70482933 | 3372 | |
7675ad4f AC |
3373 | Append_Elmt |
3374 | (Make_Selected_Component (Loc, | |
3375 | Prefix => | |
fbf5a39b AC |
3376 | Duplicate_Subexpr_No_Checks |
3377 | (Expr, Name_Req => True), | |
70482933 RK |
3378 | Selector_Name => |
3379 | Make_Identifier (Loc, Chars (Discr))), | |
7675ad4f | 3380 | New_Constraints); |
70482933 RK |
3381 | |
3382 | else | |
3383 | -- Discriminant of more remote ancestor ??? | |
3384 | ||
3385 | return; | |
3386 | end if; | |
3387 | ||
675d6070 TQ |
3388 | -- Derived type definition has an explicit value for this |
3389 | -- stored discriminant. | |
70482933 RK |
3390 | |
3391 | else | |
3392 | Append_Elmt | |
fbf5a39b AC |
3393 | (Duplicate_Subexpr_No_Checks (Discr_Value), |
3394 | New_Constraints); | |
70482933 RK |
3395 | end if; |
3396 | ||
3397 | Next_Elmt (Constraint); | |
3398 | end loop; | |
3399 | ||
3400 | -- Use the unconstrained expression type to retrieve the | |
3401 | -- discriminants of the parent, and apply momentarily the | |
3402 | -- discriminant constraint synthesized above. | |
3403 | ||
3404 | Set_Discriminant_Constraint (Expr_Type, New_Constraints); | |
3405 | Cond := Build_Discriminant_Checks (Expr, Expr_Type); | |
3406 | Set_Discriminant_Constraint (Expr_Type, Old_Constraints); | |
3407 | ||
3408 | Insert_Action (N, | |
07fc65c4 GB |
3409 | Make_Raise_Constraint_Error (Loc, |
3410 | Condition => Cond, | |
3411 | Reason => CE_Discriminant_Check_Failed)); | |
70482933 RK |
3412 | end; |
3413 | ||
8bfbd380 AC |
3414 | -- For arrays, checks are set now, but conversions are applied during |
3415 | -- expansion, to take into accounts changes of representation. The | |
3416 | -- checks become range checks on the base type or length checks on the | |
3417 | -- subtype, depending on whether the target type is unconstrained or | |
83851b23 AC |
3418 | -- constrained. Note that the range check is put on the expression of a |
3419 | -- type conversion, while the length check is put on the type conversion | |
3420 | -- itself. | |
8bfbd380 AC |
3421 | |
3422 | elsif Is_Array_Type (Target_Type) then | |
3423 | if Is_Constrained (Target_Type) then | |
3424 | Set_Do_Length_Check (N); | |
3425 | else | |
3426 | Set_Do_Range_Check (Expr); | |
3427 | end if; | |
70482933 | 3428 | end if; |
70482933 RK |
3429 | end Apply_Type_Conversion_Checks; |
3430 | ||
3431 | ---------------------------------------------- | |
3432 | -- Apply_Universal_Integer_Attribute_Checks -- | |
3433 | ---------------------------------------------- | |
3434 | ||
3435 | procedure Apply_Universal_Integer_Attribute_Checks (N : Node_Id) is | |
3436 | Loc : constant Source_Ptr := Sloc (N); | |
3437 | Typ : constant Entity_Id := Etype (N); | |
3438 | ||
3439 | begin | |
3440 | if Inside_A_Generic then | |
3441 | return; | |
3442 | ||
3443 | -- Nothing to do if checks are suppressed | |
3444 | ||
3445 | elsif Range_Checks_Suppressed (Typ) | |
3446 | and then Overflow_Checks_Suppressed (Typ) | |
3447 | then | |
3448 | return; | |
3449 | ||
3450 | -- Nothing to do if the attribute does not come from source. The | |
3451 | -- internal attributes we generate of this type do not need checks, | |
3452 | -- and furthermore the attempt to check them causes some circular | |
3453 | -- elaboration orders when dealing with packed types. | |
3454 | ||
3455 | elsif not Comes_From_Source (N) then | |
3456 | return; | |
3457 | ||
fbf5a39b AC |
3458 | -- If the prefix is a selected component that depends on a discriminant |
3459 | -- the check may improperly expose a discriminant instead of using | |
3460 | -- the bounds of the object itself. Set the type of the attribute to | |
3461 | -- the base type of the context, so that a check will be imposed when | |
3462 | -- needed (e.g. if the node appears as an index). | |
3463 | ||
3464 | elsif Nkind (Prefix (N)) = N_Selected_Component | |
3465 | and then Ekind (Typ) = E_Signed_Integer_Subtype | |
3466 | and then Depends_On_Discriminant (Scalar_Range (Typ)) | |
3467 | then | |
3468 | Set_Etype (N, Base_Type (Typ)); | |
3469 | ||
675d6070 TQ |
3470 | -- Otherwise, replace the attribute node with a type conversion node |
3471 | -- whose expression is the attribute, retyped to universal integer, and | |
3472 | -- whose subtype mark is the target type. The call to analyze this | |
3473 | -- conversion will set range and overflow checks as required for proper | |
3474 | -- detection of an out of range value. | |
70482933 RK |
3475 | |
3476 | else | |
3477 | Set_Etype (N, Universal_Integer); | |
3478 | Set_Analyzed (N, True); | |
3479 | ||
3480 | Rewrite (N, | |
3481 | Make_Type_Conversion (Loc, | |
3482 | Subtype_Mark => New_Occurrence_Of (Typ, Loc), | |
3483 | Expression => Relocate_Node (N))); | |
3484 | ||
3485 | Analyze_And_Resolve (N, Typ); | |
3486 | return; | |
3487 | end if; | |
70482933 RK |
3488 | end Apply_Universal_Integer_Attribute_Checks; |
3489 | ||
12b4d338 AC |
3490 | ------------------------------------- |
3491 | -- Atomic_Synchronization_Disabled -- | |
3492 | ------------------------------------- | |
3493 | ||
3494 | -- Note: internally Disable/Enable_Atomic_Synchronization is implemented | |
3495 | -- using a bogus check called Atomic_Synchronization. This is to make it | |
3496 | -- more convenient to get exactly the same semantics as [Un]Suppress. | |
3497 | ||
3498 | function Atomic_Synchronization_Disabled (E : Entity_Id) return Boolean is | |
3499 | begin | |
4c318253 AC |
3500 | -- If debug flag d.e is set, always return False, i.e. all atomic sync |
3501 | -- looks enabled, since it is never disabled. | |
3502 | ||
3503 | if Debug_Flag_Dot_E then | |
3504 | return False; | |
3505 | ||
3506 | -- If debug flag d.d is set then always return True, i.e. all atomic | |
3507 | -- sync looks disabled, since it always tests True. | |
3508 | ||
3509 | elsif Debug_Flag_Dot_D then | |
3510 | return True; | |
3511 | ||
3512 | -- If entity present, then check result for that entity | |
3513 | ||
3514 | elsif Present (E) and then Checks_May_Be_Suppressed (E) then | |
12b4d338 | 3515 | return Is_Check_Suppressed (E, Atomic_Synchronization); |
4c318253 AC |
3516 | |
3517 | -- Otherwise result depends on current scope setting | |
3518 | ||
12b4d338 | 3519 | else |
3217f71e | 3520 | return Scope_Suppress.Suppress (Atomic_Synchronization); |
12b4d338 AC |
3521 | end if; |
3522 | end Atomic_Synchronization_Disabled; | |
3523 | ||
70482933 RK |
3524 | ------------------------------- |
3525 | -- Build_Discriminant_Checks -- | |
3526 | ------------------------------- | |
3527 | ||
3528 | function Build_Discriminant_Checks | |
3529 | (N : Node_Id; | |
6b6fcd3e | 3530 | T_Typ : Entity_Id) return Node_Id |
70482933 RK |
3531 | is |
3532 | Loc : constant Source_Ptr := Sloc (N); | |
3533 | Cond : Node_Id; | |
3534 | Disc : Elmt_Id; | |
3535 | Disc_Ent : Entity_Id; | |
fbf5a39b | 3536 | Dref : Node_Id; |
70482933 RK |
3537 | Dval : Node_Id; |
3538 | ||
86ac5e79 ES |
3539 | function Aggregate_Discriminant_Val (Disc : Entity_Id) return Node_Id; |
3540 | ||
3541 | ---------------------------------- | |
3542 | -- Aggregate_Discriminant_Value -- | |
3543 | ---------------------------------- | |
3544 | ||
3545 | function Aggregate_Discriminant_Val (Disc : Entity_Id) return Node_Id is | |
3546 | Assoc : Node_Id; | |
3547 | ||
3548 | begin | |
675d6070 TQ |
3549 | -- The aggregate has been normalized with named associations. We use |
3550 | -- the Chars field to locate the discriminant to take into account | |
3551 | -- discriminants in derived types, which carry the same name as those | |
3552 | -- in the parent. | |
86ac5e79 ES |
3553 | |
3554 | Assoc := First (Component_Associations (N)); | |
3555 | while Present (Assoc) loop | |
3556 | if Chars (First (Choices (Assoc))) = Chars (Disc) then | |
3557 | return Expression (Assoc); | |
3558 | else | |
3559 | Next (Assoc); | |
3560 | end if; | |
3561 | end loop; | |
3562 | ||
3563 | -- Discriminant must have been found in the loop above | |
3564 | ||
3565 | raise Program_Error; | |
3566 | end Aggregate_Discriminant_Val; | |
3567 | ||
3568 | -- Start of processing for Build_Discriminant_Checks | |
3569 | ||
70482933 | 3570 | begin |
86ac5e79 ES |
3571 | -- Loop through discriminants evolving the condition |
3572 | ||
70482933 RK |
3573 | Cond := Empty; |
3574 | Disc := First_Elmt (Discriminant_Constraint (T_Typ)); | |
3575 | ||
fbf5a39b | 3576 | -- For a fully private type, use the discriminants of the parent type |
70482933 RK |
3577 | |
3578 | if Is_Private_Type (T_Typ) | |
3579 | and then No (Full_View (T_Typ)) | |
3580 | then | |
3581 | Disc_Ent := First_Discriminant (Etype (Base_Type (T_Typ))); | |
3582 | else | |
3583 | Disc_Ent := First_Discriminant (T_Typ); | |
3584 | end if; | |
3585 | ||
3586 | while Present (Disc) loop | |
70482933 RK |
3587 | Dval := Node (Disc); |
3588 | ||
3589 | if Nkind (Dval) = N_Identifier | |
3590 | and then Ekind (Entity (Dval)) = E_Discriminant | |
3591 | then | |
3592 | Dval := New_Occurrence_Of (Discriminal (Entity (Dval)), Loc); | |
3593 | else | |
fbf5a39b | 3594 | Dval := Duplicate_Subexpr_No_Checks (Dval); |
70482933 RK |
3595 | end if; |
3596 | ||
5d09245e AC |
3597 | -- If we have an Unchecked_Union node, we can infer the discriminants |
3598 | -- of the node. | |
fbf5a39b | 3599 | |
5d09245e AC |
3600 | if Is_Unchecked_Union (Base_Type (T_Typ)) then |
3601 | Dref := New_Copy ( | |
3602 | Get_Discriminant_Value ( | |
3603 | First_Discriminant (T_Typ), | |
3604 | T_Typ, | |
3605 | Stored_Constraint (T_Typ))); | |
3606 | ||
86ac5e79 ES |
3607 | elsif Nkind (N) = N_Aggregate then |
3608 | Dref := | |
3609 | Duplicate_Subexpr_No_Checks | |
3610 | (Aggregate_Discriminant_Val (Disc_Ent)); | |
3611 | ||
5d09245e AC |
3612 | else |
3613 | Dref := | |
3614 | Make_Selected_Component (Loc, | |
637a41a5 | 3615 | Prefix => |
5d09245e | 3616 | Duplicate_Subexpr_No_Checks (N, Name_Req => True), |
637a41a5 | 3617 | Selector_Name => Make_Identifier (Loc, Chars (Disc_Ent))); |
5d09245e AC |
3618 | |
3619 | Set_Is_In_Discriminant_Check (Dref); | |
3620 | end if; | |
fbf5a39b | 3621 | |
70482933 RK |
3622 | Evolve_Or_Else (Cond, |
3623 | Make_Op_Ne (Loc, | |
637a41a5 | 3624 | Left_Opnd => Dref, |
70482933 RK |
3625 | Right_Opnd => Dval)); |
3626 | ||
3627 | Next_Elmt (Disc); | |
3628 | Next_Discriminant (Disc_Ent); | |
3629 | end loop; | |
3630 | ||
3631 | return Cond; | |
3632 | end Build_Discriminant_Checks; | |
3633 | ||
2ede092b RD |
3634 | ------------------ |
3635 | -- Check_Needed -- | |
3636 | ------------------ | |
3637 | ||
3638 | function Check_Needed (Nod : Node_Id; Check : Check_Type) return Boolean is | |
3639 | N : Node_Id; | |
3640 | P : Node_Id; | |
3641 | K : Node_Kind; | |
3642 | L : Node_Id; | |
3643 | R : Node_Id; | |
3644 | ||
ef163a0a AC |
3645 | function Left_Expression (Op : Node_Id) return Node_Id; |
3646 | -- Return the relevant expression from the left operand of the given | |
3647 | -- short circuit form: this is LO itself, except if LO is a qualified | |
3648 | -- expression, a type conversion, or an expression with actions, in | |
3649 | -- which case this is Left_Expression (Expression (LO)). | |
3650 | ||
3651 | --------------------- | |
3652 | -- Left_Expression -- | |
3653 | --------------------- | |
3654 | ||
3655 | function Left_Expression (Op : Node_Id) return Node_Id is | |
3656 | LE : Node_Id := Left_Opnd (Op); | |
3657 | begin | |
637a41a5 AC |
3658 | while Nkind_In (LE, N_Qualified_Expression, |
3659 | N_Type_Conversion, | |
3660 | N_Expression_With_Actions) | |
ef163a0a AC |
3661 | loop |
3662 | LE := Expression (LE); | |
3663 | end loop; | |
3664 | ||
3665 | return LE; | |
3666 | end Left_Expression; | |
3667 | ||
3668 | -- Start of processing for Check_Needed | |
3669 | ||
2ede092b RD |
3670 | begin |
3671 | -- Always check if not simple entity | |
3672 | ||
3673 | if Nkind (Nod) not in N_Has_Entity | |
3674 | or else not Comes_From_Source (Nod) | |
3675 | then | |
3676 | return True; | |
3677 | end if; | |
3678 | ||
3679 | -- Look up tree for short circuit | |
3680 | ||
3681 | N := Nod; | |
3682 | loop | |
3683 | P := Parent (N); | |
3684 | K := Nkind (P); | |
3685 | ||
16a55e63 RD |
3686 | -- Done if out of subexpression (note that we allow generated stuff |
3687 | -- such as itype declarations in this context, to keep the loop going | |
3688 | -- since we may well have generated such stuff in complex situations. | |
3689 | -- Also done if no parent (probably an error condition, but no point | |
a90bd866 | 3690 | -- in behaving nasty if we find it). |
16a55e63 RD |
3691 | |
3692 | if No (P) | |
3693 | or else (K not in N_Subexpr and then Comes_From_Source (P)) | |
3694 | then | |
2ede092b RD |
3695 | return True; |
3696 | ||
16a55e63 RD |
3697 | -- Or/Or Else case, where test is part of the right operand, or is |
3698 | -- part of one of the actions associated with the right operand, and | |
3699 | -- the left operand is an equality test. | |
2ede092b | 3700 | |
16a55e63 | 3701 | elsif K = N_Op_Or then |
2ede092b | 3702 | exit when N = Right_Opnd (P) |
ef163a0a | 3703 | and then Nkind (Left_Expression (P)) = N_Op_Eq; |
2ede092b | 3704 | |
16a55e63 RD |
3705 | elsif K = N_Or_Else then |
3706 | exit when (N = Right_Opnd (P) | |
3707 | or else | |
3708 | (Is_List_Member (N) | |
3709 | and then List_Containing (N) = Actions (P))) | |
ef163a0a | 3710 | and then Nkind (Left_Expression (P)) = N_Op_Eq; |
2ede092b | 3711 | |
16a55e63 RD |
3712 | -- Similar test for the And/And then case, where the left operand |
3713 | -- is an inequality test. | |
3714 | ||
3715 | elsif K = N_Op_And then | |
2ede092b | 3716 | exit when N = Right_Opnd (P) |
ef163a0a | 3717 | and then Nkind (Left_Expression (P)) = N_Op_Ne; |
16a55e63 RD |
3718 | |
3719 | elsif K = N_And_Then then | |
3720 | exit when (N = Right_Opnd (P) | |
3721 | or else | |
3722 | (Is_List_Member (N) | |
637a41a5 | 3723 | and then List_Containing (N) = Actions (P))) |
ef163a0a | 3724 | and then Nkind (Left_Expression (P)) = N_Op_Ne; |
2ede092b RD |
3725 | end if; |
3726 | ||
3727 | N := P; | |
3728 | end loop; | |
3729 | ||
3730 | -- If we fall through the loop, then we have a conditional with an | |
ef163a0a AC |
3731 | -- appropriate test as its left operand, so look further. |
3732 | ||
3733 | L := Left_Expression (P); | |
3734 | ||
3735 | -- L is an "=" or "/=" operator: extract its operands | |
2ede092b | 3736 | |
2ede092b RD |
3737 | R := Right_Opnd (L); |
3738 | L := Left_Opnd (L); | |
3739 | ||
3740 | -- Left operand of test must match original variable | |
3741 | ||
637a41a5 | 3742 | if Nkind (L) not in N_Has_Entity or else Entity (L) /= Entity (Nod) then |
2ede092b RD |
3743 | return True; |
3744 | end if; | |
3745 | ||
939c12d2 | 3746 | -- Right operand of test must be key value (zero or null) |
2ede092b RD |
3747 | |
3748 | case Check is | |
3749 | when Access_Check => | |
939c12d2 | 3750 | if not Known_Null (R) then |
2ede092b RD |
3751 | return True; |
3752 | end if; | |
3753 | ||
3754 | when Division_Check => | |
3755 | if not Compile_Time_Known_Value (R) | |
3756 | or else Expr_Value (R) /= Uint_0 | |
3757 | then | |
3758 | return True; | |
3759 | end if; | |
939c12d2 RD |
3760 | |
3761 | when others => | |
3762 | raise Program_Error; | |
2ede092b RD |
3763 | end case; |
3764 | ||
3765 | -- Here we have the optimizable case, warn if not short-circuited | |
3766 | ||
3767 | if K = N_Op_And or else K = N_Op_Or then | |
43417b90 | 3768 | Error_Msg_Warn := SPARK_Mode /= On; |
4a28b181 | 3769 | |
2ede092b RD |
3770 | case Check is |
3771 | when Access_Check => | |
4a28b181 AC |
3772 | if GNATprove_Mode then |
3773 | Error_Msg_N | |
3774 | ("Constraint_Error might have been raised (access check)", | |
3775 | Parent (Nod)); | |
3776 | else | |
3777 | Error_Msg_N | |
3778 | ("Constraint_Error may be raised (access check)??", | |
3779 | Parent (Nod)); | |
3780 | end if; | |
3781 | ||
2ede092b | 3782 | when Division_Check => |
4a28b181 AC |
3783 | if GNATprove_Mode then |
3784 | Error_Msg_N | |
3785 | ("Constraint_Error might have been raised (zero divide)", | |
3786 | Parent (Nod)); | |
3787 | else | |
3788 | Error_Msg_N | |
3789 | ("Constraint_Error may be raised (zero divide)??", | |
3790 | Parent (Nod)); | |
3791 | end if; | |
939c12d2 RD |
3792 | |
3793 | when others => | |
3794 | raise Program_Error; | |
2ede092b RD |
3795 | end case; |
3796 | ||
3797 | if K = N_Op_And then | |
19d846a0 | 3798 | Error_Msg_N -- CODEFIX |
685bc70f | 3799 | ("use `AND THEN` instead of AND??", P); |
2ede092b | 3800 | else |
19d846a0 | 3801 | Error_Msg_N -- CODEFIX |
685bc70f | 3802 | ("use `OR ELSE` instead of OR??", P); |
2ede092b RD |
3803 | end if; |
3804 | ||
308e6f3a | 3805 | -- If not short-circuited, we need the check |
2ede092b RD |
3806 | |
3807 | return True; | |
3808 | ||
3809 | -- If short-circuited, we can omit the check | |
3810 | ||
3811 | else | |
3812 | return False; | |
3813 | end if; | |
3814 | end Check_Needed; | |
3815 | ||
70482933 RK |
3816 | ----------------------------------- |
3817 | -- Check_Valid_Lvalue_Subscripts -- | |
3818 | ----------------------------------- | |
3819 | ||
3820 | procedure Check_Valid_Lvalue_Subscripts (Expr : Node_Id) is | |
3821 | begin | |
3822 | -- Skip this if range checks are suppressed | |
3823 | ||
3824 | if Range_Checks_Suppressed (Etype (Expr)) then | |
3825 | return; | |
3826 | ||
675d6070 TQ |
3827 | -- Only do this check for expressions that come from source. We assume |
3828 | -- that expander generated assignments explicitly include any necessary | |
3829 | -- checks. Note that this is not just an optimization, it avoids | |
a90bd866 | 3830 | -- infinite recursions. |
70482933 RK |
3831 | |
3832 | elsif not Comes_From_Source (Expr) then | |
3833 | return; | |
3834 | ||
3835 | -- For a selected component, check the prefix | |
3836 | ||
3837 | elsif Nkind (Expr) = N_Selected_Component then | |
3838 | Check_Valid_Lvalue_Subscripts (Prefix (Expr)); | |
3839 | return; | |
3840 | ||
3841 | -- Case of indexed component | |
3842 | ||
3843 | elsif Nkind (Expr) = N_Indexed_Component then | |
3844 | Apply_Subscript_Validity_Checks (Expr); | |
3845 | ||
675d6070 TQ |
3846 | -- Prefix may itself be or contain an indexed component, and these |
3847 | -- subscripts need checking as well. | |
70482933 RK |
3848 | |
3849 | Check_Valid_Lvalue_Subscripts (Prefix (Expr)); | |
3850 | end if; | |
3851 | end Check_Valid_Lvalue_Subscripts; | |
3852 | ||
2820d220 AC |
3853 | ---------------------------------- |
3854 | -- Null_Exclusion_Static_Checks -- | |
3855 | ---------------------------------- | |
3856 | ||
3857 | procedure Null_Exclusion_Static_Checks (N : Node_Id) is | |
c064e066 RD |
3858 | Error_Node : Node_Id; |
3859 | Expr : Node_Id; | |
3860 | Has_Null : constant Boolean := Has_Null_Exclusion (N); | |
3861 | K : constant Node_Kind := Nkind (N); | |
3862 | Typ : Entity_Id; | |
2820d220 | 3863 | |
2ede092b | 3864 | begin |
c064e066 | 3865 | pragma Assert |
8e1e62e3 AC |
3866 | (Nkind_In (K, N_Component_Declaration, |
3867 | N_Discriminant_Specification, | |
3868 | N_Function_Specification, | |
3869 | N_Object_Declaration, | |
3870 | N_Parameter_Specification)); | |
c064e066 RD |
3871 | |
3872 | if K = N_Function_Specification then | |
3873 | Typ := Etype (Defining_Entity (N)); | |
3874 | else | |
3875 | Typ := Etype (Defining_Identifier (N)); | |
3876 | end if; | |
2820d220 | 3877 | |
2ede092b | 3878 | case K is |
2ede092b RD |
3879 | when N_Component_Declaration => |
3880 | if Present (Access_Definition (Component_Definition (N))) then | |
c064e066 | 3881 | Error_Node := Component_Definition (N); |
2ede092b | 3882 | else |
c064e066 | 3883 | Error_Node := Subtype_Indication (Component_Definition (N)); |
2ede092b | 3884 | end if; |
7324bf49 | 3885 | |
c064e066 RD |
3886 | when N_Discriminant_Specification => |
3887 | Error_Node := Discriminant_Type (N); | |
3888 | ||
3889 | when N_Function_Specification => | |
3890 | Error_Node := Result_Definition (N); | |
3891 | ||
3892 | when N_Object_Declaration => | |
3893 | Error_Node := Object_Definition (N); | |
3894 | ||
3895 | when N_Parameter_Specification => | |
3896 | Error_Node := Parameter_Type (N); | |
3897 | ||
2ede092b RD |
3898 | when others => |
3899 | raise Program_Error; | |
3900 | end case; | |
7324bf49 | 3901 | |
c064e066 | 3902 | if Has_Null then |
7324bf49 | 3903 | |
c064e066 RD |
3904 | -- Enforce legality rule 3.10 (13): A null exclusion can only be |
3905 | -- applied to an access [sub]type. | |
7324bf49 | 3906 | |
c064e066 | 3907 | if not Is_Access_Type (Typ) then |
ed2233dc | 3908 | Error_Msg_N |
11b4899f | 3909 | ("`NOT NULL` allowed only for an access type", Error_Node); |
7324bf49 | 3910 | |
675d6070 | 3911 | -- Enforce legality rule RM 3.10(14/1): A null exclusion can only |
c064e066 RD |
3912 | -- be applied to a [sub]type that does not exclude null already. |
3913 | ||
3914 | elsif Can_Never_Be_Null (Typ) | |
b1c11e0e | 3915 | and then Comes_From_Source (Typ) |
c064e066 | 3916 | then |
ed2233dc | 3917 | Error_Msg_NE |
11b4899f JM |
3918 | ("`NOT NULL` not allowed (& already excludes null)", |
3919 | Error_Node, Typ); | |
c064e066 | 3920 | end if; |
2ede092b | 3921 | end if; |
7324bf49 | 3922 | |
f2cbd970 JM |
3923 | -- Check that null-excluding objects are always initialized, except for |
3924 | -- deferred constants, for which the expression will appear in the full | |
3925 | -- declaration. | |
2ede092b RD |
3926 | |
3927 | if K = N_Object_Declaration | |
86ac5e79 | 3928 | and then No (Expression (N)) |
f2cbd970 | 3929 | and then not Constant_Present (N) |
675d6070 | 3930 | and then not No_Initialization (N) |
2ede092b | 3931 | then |
675d6070 TQ |
3932 | -- Add an expression that assigns null. This node is needed by |
3933 | -- Apply_Compile_Time_Constraint_Error, which will replace this with | |
3934 | -- a Constraint_Error node. | |
2ede092b RD |
3935 | |
3936 | Set_Expression (N, Make_Null (Sloc (N))); | |
3937 | Set_Etype (Expression (N), Etype (Defining_Identifier (N))); | |
7324bf49 | 3938 | |
2ede092b RD |
3939 | Apply_Compile_Time_Constraint_Error |
3940 | (N => Expression (N), | |
685bc70f AC |
3941 | Msg => |
3942 | "(Ada 2005) null-excluding objects must be initialized??", | |
2ede092b RD |
3943 | Reason => CE_Null_Not_Allowed); |
3944 | end if; | |
7324bf49 | 3945 | |
f2cbd970 JM |
3946 | -- Check that a null-excluding component, formal or object is not being |
3947 | -- assigned a null value. Otherwise generate a warning message and | |
f3d0f304 | 3948 | -- replace Expression (N) by an N_Constraint_Error node. |
2ede092b | 3949 | |
c064e066 RD |
3950 | if K /= N_Function_Specification then |
3951 | Expr := Expression (N); | |
7324bf49 | 3952 | |
939c12d2 | 3953 | if Present (Expr) and then Known_Null (Expr) then |
2ede092b | 3954 | case K is |
c064e066 RD |
3955 | when N_Component_Declaration | |
3956 | N_Discriminant_Specification => | |
82c80734 | 3957 | Apply_Compile_Time_Constraint_Error |
c064e066 | 3958 | (N => Expr, |
4a28b181 AC |
3959 | Msg => "(Ada 2005) null not allowed " |
3960 | & "in null-excluding components??", | |
c064e066 | 3961 | Reason => CE_Null_Not_Allowed); |
7324bf49 | 3962 | |
c064e066 | 3963 | when N_Object_Declaration => |
82c80734 | 3964 | Apply_Compile_Time_Constraint_Error |
c064e066 | 3965 | (N => Expr, |
4a28b181 | 3966 | Msg => "(Ada 2005) null not allowed " |
b785e0b8 | 3967 | & "in null-excluding objects??", |
c064e066 | 3968 | Reason => CE_Null_Not_Allowed); |
7324bf49 | 3969 | |
c064e066 | 3970 | when N_Parameter_Specification => |
82c80734 | 3971 | Apply_Compile_Time_Constraint_Error |
c064e066 | 3972 | (N => Expr, |
4a28b181 AC |
3973 | Msg => "(Ada 2005) null not allowed " |
3974 | & "in null-excluding formals??", | |
c064e066 | 3975 | Reason => CE_Null_Not_Allowed); |
2ede092b RD |
3976 | |
3977 | when others => | |
3978 | null; | |
7324bf49 AC |
3979 | end case; |
3980 | end if; | |
c064e066 | 3981 | end if; |
2820d220 AC |
3982 | end Null_Exclusion_Static_Checks; |
3983 | ||
fbf5a39b AC |
3984 | ---------------------------------- |
3985 | -- Conditional_Statements_Begin -- | |
3986 | ---------------------------------- | |
3987 | ||
3988 | procedure Conditional_Statements_Begin is | |
3989 | begin | |
3990 | Saved_Checks_TOS := Saved_Checks_TOS + 1; | |
3991 | ||
675d6070 TQ |
3992 | -- If stack overflows, kill all checks, that way we know to simply reset |
3993 | -- the number of saved checks to zero on return. This should never occur | |
3994 | -- in practice. | |
fbf5a39b AC |
3995 | |
3996 | if Saved_Checks_TOS > Saved_Checks_Stack'Last then | |
3997 | Kill_All_Checks; | |
3998 | ||
675d6070 TQ |
3999 | -- In the normal case, we just make a new stack entry saving the current |
4000 | -- number of saved checks for a later restore. | |
fbf5a39b AC |
4001 | |
4002 | else | |
4003 | Saved_Checks_Stack (Saved_Checks_TOS) := Num_Saved_Checks; | |
4004 | ||
4005 | if Debug_Flag_CC then | |
4006 | w ("Conditional_Statements_Begin: Num_Saved_Checks = ", | |
4007 | Num_Saved_Checks); | |
4008 | end if; | |
4009 | end if; | |
4010 | end Conditional_Statements_Begin; | |
4011 | ||
4012 | -------------------------------- | |
4013 | -- Conditional_Statements_End -- | |
4014 | -------------------------------- | |
4015 | ||
4016 | procedure Conditional_Statements_End is | |
4017 | begin | |
4018 | pragma Assert (Saved_Checks_TOS > 0); | |
4019 | ||
675d6070 TQ |
4020 | -- If the saved checks stack overflowed, then we killed all checks, so |
4021 | -- setting the number of saved checks back to zero is correct. This | |
4022 | -- should never occur in practice. | |
fbf5a39b AC |
4023 | |
4024 | if Saved_Checks_TOS > Saved_Checks_Stack'Last then | |
4025 | Num_Saved_Checks := 0; | |
4026 | ||
675d6070 TQ |
4027 | -- In the normal case, restore the number of saved checks from the top |
4028 | -- stack entry. | |
fbf5a39b AC |
4029 | |
4030 | else | |
4031 | Num_Saved_Checks := Saved_Checks_Stack (Saved_Checks_TOS); | |
637a41a5 | 4032 | |
fbf5a39b AC |
4033 | if Debug_Flag_CC then |
4034 | w ("Conditional_Statements_End: Num_Saved_Checks = ", | |
4035 | Num_Saved_Checks); | |
4036 | end if; | |
4037 | end if; | |
4038 | ||
4039 | Saved_Checks_TOS := Saved_Checks_TOS - 1; | |
4040 | end Conditional_Statements_End; | |
4041 | ||
acad3c0a AC |
4042 | ------------------------- |
4043 | -- Convert_From_Bignum -- | |
4044 | ------------------------- | |
4045 | ||
4046 | function Convert_From_Bignum (N : Node_Id) return Node_Id is | |
4047 | Loc : constant Source_Ptr := Sloc (N); | |
4048 | ||
4049 | begin | |
4050 | pragma Assert (Is_RTE (Etype (N), RE_Bignum)); | |
4051 | ||
4052 | -- Construct call From Bignum | |
4053 | ||
4054 | return | |
4055 | Make_Function_Call (Loc, | |
4056 | Name => | |
4057 | New_Occurrence_Of (RTE (RE_From_Bignum), Loc), | |
4058 | Parameter_Associations => New_List (Relocate_Node (N))); | |
4059 | end Convert_From_Bignum; | |
4060 | ||
4061 | ----------------------- | |
4062 | -- Convert_To_Bignum -- | |
4063 | ----------------------- | |
4064 | ||
4065 | function Convert_To_Bignum (N : Node_Id) return Node_Id is | |
4066 | Loc : constant Source_Ptr := Sloc (N); | |
4067 | ||
4068 | begin | |
4b1c4f20 | 4069 | -- Nothing to do if Bignum already except call Relocate_Node |
acad3c0a AC |
4070 | |
4071 | if Is_RTE (Etype (N), RE_Bignum) then | |
4072 | return Relocate_Node (N); | |
4073 | ||
5707e389 AC |
4074 | -- Otherwise construct call to To_Bignum, converting the operand to the |
4075 | -- required Long_Long_Integer form. | |
acad3c0a AC |
4076 | |
4077 | else | |
4078 | pragma Assert (Is_Signed_Integer_Type (Etype (N))); | |
4079 | return | |
4080 | Make_Function_Call (Loc, | |
4081 | Name => | |
4082 | New_Occurrence_Of (RTE (RE_To_Bignum), Loc), | |
4083 | Parameter_Associations => New_List ( | |
4084 | Convert_To (Standard_Long_Long_Integer, Relocate_Node (N)))); | |
4085 | end if; | |
4086 | end Convert_To_Bignum; | |
4087 | ||
70482933 RK |
4088 | --------------------- |
4089 | -- Determine_Range -- | |
4090 | --------------------- | |
4091 | ||
c9a4817d | 4092 | Cache_Size : constant := 2 ** 10; |
70482933 | 4093 | type Cache_Index is range 0 .. Cache_Size - 1; |
a90bd866 | 4094 | -- Determine size of below cache (power of 2 is more efficient) |
70482933 | 4095 | |
6b6bce61 AC |
4096 | Determine_Range_Cache_N : array (Cache_Index) of Node_Id; |
4097 | Determine_Range_Cache_V : array (Cache_Index) of Boolean; | |
4098 | Determine_Range_Cache_Lo : array (Cache_Index) of Uint; | |
4099 | Determine_Range_Cache_Hi : array (Cache_Index) of Uint; | |
4100 | Determine_Range_Cache_Lo_R : array (Cache_Index) of Ureal; | |
4101 | Determine_Range_Cache_Hi_R : array (Cache_Index) of Ureal; | |
675d6070 | 4102 | -- The above arrays are used to implement a small direct cache for |
6b6bce61 AC |
4103 | -- Determine_Range and Determine_Range_R calls. Because of the way these |
4104 | -- subprograms recursively traces subexpressions, and because overflow | |
4105 | -- checking calls the routine on the way up the tree, a quadratic behavior | |
4106 | -- can otherwise be encountered in large expressions. The cache entry for | |
4107 | -- node N is stored in the (N mod Cache_Size) entry, and can be validated | |
4108 | -- by checking the actual node value stored there. The Range_Cache_V array | |
4109 | -- records the setting of Assume_Valid for the cache entry. | |
70482933 RK |
4110 | |
4111 | procedure Determine_Range | |
c800f862 RD |
4112 | (N : Node_Id; |
4113 | OK : out Boolean; | |
4114 | Lo : out Uint; | |
4115 | Hi : out Uint; | |
4116 | Assume_Valid : Boolean := False) | |
70482933 | 4117 | is |
1c7717c3 AC |
4118 | Typ : Entity_Id := Etype (N); |
4119 | -- Type to use, may get reset to base type for possibly invalid entity | |
c1c22e7a GB |
4120 | |
4121 | Lo_Left : Uint; | |
4122 | Hi_Left : Uint; | |
4123 | -- Lo and Hi bounds of left operand | |
70482933 | 4124 | |
70482933 | 4125 | Lo_Right : Uint; |
70482933 | 4126 | Hi_Right : Uint; |
c1c22e7a GB |
4127 | -- Lo and Hi bounds of right (or only) operand |
4128 | ||
4129 | Bound : Node_Id; | |
4130 | -- Temp variable used to hold a bound node | |
4131 | ||
4132 | Hbound : Uint; | |
4133 | -- High bound of base type of expression | |
4134 | ||
4135 | Lor : Uint; | |
4136 | Hir : Uint; | |
4137 | -- Refined values for low and high bounds, after tightening | |
4138 | ||
4139 | OK1 : Boolean; | |
4140 | -- Used in lower level calls to indicate if call succeeded | |
4141 | ||
4142 | Cindex : Cache_Index; | |
4143 | -- Used to search cache | |
70482933 | 4144 | |
d7a44b14 AC |
4145 | Btyp : Entity_Id; |
4146 | -- Base type | |
4147 | ||
70482933 RK |
4148 | function OK_Operands return Boolean; |
4149 | -- Used for binary operators. Determines the ranges of the left and | |
4150 | -- right operands, and if they are both OK, returns True, and puts | |
93c3fca7 | 4151 | -- the results in Lo_Right, Hi_Right, Lo_Left, Hi_Left. |
70482933 RK |
4152 | |
4153 | ----------------- | |
4154 | -- OK_Operands -- | |
4155 | ----------------- | |
4156 | ||
4157 | function OK_Operands return Boolean is | |
4158 | begin | |
c800f862 RD |
4159 | Determine_Range |
4160 | (Left_Opnd (N), OK1, Lo_Left, Hi_Left, Assume_Valid); | |
70482933 RK |
4161 | |
4162 | if not OK1 then | |
4163 | return False; | |
4164 | end if; | |
4165 | ||
c800f862 RD |
4166 | Determine_Range |
4167 | (Right_Opnd (N), OK1, Lo_Right, Hi_Right, Assume_Valid); | |
70482933 RK |
4168 | return OK1; |
4169 | end OK_Operands; | |
4170 | ||
4171 | -- Start of processing for Determine_Range | |
4172 | ||
4173 | begin | |
3e65bfab AC |
4174 | -- Prevent junk warnings by initializing range variables |
4175 | ||
4176 | Lo := No_Uint; | |
4177 | Hi := No_Uint; | |
4178 | Lor := No_Uint; | |
4179 | Hir := No_Uint; | |
4180 | ||
62be5d0a JM |
4181 | -- For temporary constants internally generated to remove side effects |
4182 | -- we must use the corresponding expression to determine the range of | |
3e65bfab AC |
4183 | -- the expression. But note that the expander can also generate |
4184 | -- constants in other cases, including deferred constants. | |
62be5d0a JM |
4185 | |
4186 | if Is_Entity_Name (N) | |
4187 | and then Nkind (Parent (Entity (N))) = N_Object_Declaration | |
4188 | and then Ekind (Entity (N)) = E_Constant | |
4189 | and then Is_Internal_Name (Chars (Entity (N))) | |
4190 | then | |
3e65bfab AC |
4191 | if Present (Expression (Parent (Entity (N)))) then |
4192 | Determine_Range | |
4193 | (Expression (Parent (Entity (N))), OK, Lo, Hi, Assume_Valid); | |
62be5d0a | 4194 | |
3e65bfab AC |
4195 | elsif Present (Full_View (Entity (N))) then |
4196 | Determine_Range | |
4197 | (Expression (Parent (Full_View (Entity (N)))), | |
4198 | OK, Lo, Hi, Assume_Valid); | |
70482933 | 4199 | |
3e65bfab AC |
4200 | else |
4201 | OK := False; | |
4202 | end if; | |
4203 | return; | |
4204 | end if; | |
70482933 | 4205 | |
1abad480 | 4206 | -- If type is not defined, we can't determine its range |
70482933 | 4207 | |
1abad480 AC |
4208 | if No (Typ) |
4209 | ||
4210 | -- We don't deal with anything except discrete types | |
4211 | ||
4212 | or else not Is_Discrete_Type (Typ) | |
4213 | ||
4214 | -- Ignore type for which an error has been posted, since range in | |
4215 | -- this case may well be a bogosity deriving from the error. Also | |
4216 | -- ignore if error posted on the reference node. | |
4217 | ||
4218 | or else Error_Posted (N) or else Error_Posted (Typ) | |
70482933 RK |
4219 | then |
4220 | OK := False; | |
4221 | return; | |
4222 | end if; | |
4223 | ||
4224 | -- For all other cases, we can determine the range | |
4225 | ||
4226 | OK := True; | |
4227 | ||
675d6070 | 4228 | -- If value is compile time known, then the possible range is the one |
a90bd866 | 4229 | -- value that we know this expression definitely has. |
70482933 RK |
4230 | |
4231 | if Compile_Time_Known_Value (N) then | |
4232 | Lo := Expr_Value (N); | |
4233 | Hi := Lo; | |
4234 | return; | |
4235 | end if; | |
4236 | ||
4237 | -- Return if already in the cache | |
4238 | ||
4239 | Cindex := Cache_Index (N mod Cache_Size); | |
4240 | ||
c800f862 RD |
4241 | if Determine_Range_Cache_N (Cindex) = N |
4242 | and then | |
4243 | Determine_Range_Cache_V (Cindex) = Assume_Valid | |
4244 | then | |
70482933 RK |
4245 | Lo := Determine_Range_Cache_Lo (Cindex); |
4246 | Hi := Determine_Range_Cache_Hi (Cindex); | |
4247 | return; | |
4248 | end if; | |
4249 | ||
675d6070 TQ |
4250 | -- Otherwise, start by finding the bounds of the type of the expression, |
4251 | -- the value cannot be outside this range (if it is, then we have an | |
4252 | -- overflow situation, which is a separate check, we are talking here | |
4253 | -- only about the expression value). | |
70482933 | 4254 | |
93c3fca7 AC |
4255 | -- First a check, never try to find the bounds of a generic type, since |
4256 | -- these bounds are always junk values, and it is only valid to look at | |
4257 | -- the bounds in an instance. | |
4258 | ||
4259 | if Is_Generic_Type (Typ) then | |
4260 | OK := False; | |
4261 | return; | |
4262 | end if; | |
4263 | ||
c800f862 | 4264 | -- First step, change to use base type unless we know the value is valid |
1c7717c3 | 4265 | |
c800f862 RD |
4266 | if (Is_Entity_Name (N) and then Is_Known_Valid (Entity (N))) |
4267 | or else Assume_No_Invalid_Values | |
4268 | or else Assume_Valid | |
1c7717c3 | 4269 | then |
c800f862 RD |
4270 | null; |
4271 | else | |
4272 | Typ := Underlying_Type (Base_Type (Typ)); | |
1c7717c3 AC |
4273 | end if; |
4274 | ||
d7a44b14 AC |
4275 | -- Retrieve the base type. Handle the case where the base type is a |
4276 | -- private enumeration type. | |
4277 | ||
4278 | Btyp := Base_Type (Typ); | |
4279 | ||
4280 | if Is_Private_Type (Btyp) and then Present (Full_View (Btyp)) then | |
4281 | Btyp := Full_View (Btyp); | |
4282 | end if; | |
4283 | ||
675d6070 TQ |
4284 | -- We use the actual bound unless it is dynamic, in which case use the |
4285 | -- corresponding base type bound if possible. If we can't get a bound | |
4286 | -- then we figure we can't determine the range (a peculiar case, that | |
4287 | -- perhaps cannot happen, but there is no point in bombing in this | |
4288 | -- optimization circuit. | |
c1c22e7a GB |
4289 | |
4290 | -- First the low bound | |
70482933 RK |
4291 | |
4292 | Bound := Type_Low_Bound (Typ); | |
4293 | ||
4294 | if Compile_Time_Known_Value (Bound) then | |
4295 | Lo := Expr_Value (Bound); | |
4296 | ||
d7a44b14 AC |
4297 | elsif Compile_Time_Known_Value (Type_Low_Bound (Btyp)) then |
4298 | Lo := Expr_Value (Type_Low_Bound (Btyp)); | |
70482933 RK |
4299 | |
4300 | else | |
4301 | OK := False; | |
4302 | return; | |
4303 | end if; | |
4304 | ||
c1c22e7a GB |
4305 | -- Now the high bound |
4306 | ||
70482933 RK |
4307 | Bound := Type_High_Bound (Typ); |
4308 | ||
c1c22e7a GB |
4309 | -- We need the high bound of the base type later on, and this should |
4310 | -- always be compile time known. Again, it is not clear that this | |
4311 | -- can ever be false, but no point in bombing. | |
70482933 | 4312 | |
d7a44b14 AC |
4313 | if Compile_Time_Known_Value (Type_High_Bound (Btyp)) then |
4314 | Hbound := Expr_Value (Type_High_Bound (Btyp)); | |
70482933 RK |
4315 | Hi := Hbound; |
4316 | ||
4317 | else | |
4318 | OK := False; | |
4319 | return; | |
4320 | end if; | |
4321 | ||
675d6070 TQ |
4322 | -- If we have a static subtype, then that may have a tighter bound so |
4323 | -- use the upper bound of the subtype instead in this case. | |
c1c22e7a GB |
4324 | |
4325 | if Compile_Time_Known_Value (Bound) then | |
4326 | Hi := Expr_Value (Bound); | |
4327 | end if; | |
4328 | ||
675d6070 TQ |
4329 | -- We may be able to refine this value in certain situations. If any |
4330 | -- refinement is possible, then Lor and Hir are set to possibly tighter | |
4331 | -- bounds, and OK1 is set to True. | |
70482933 RK |
4332 | |
4333 | case Nkind (N) is | |
4334 | ||
4335 | -- For unary plus, result is limited by range of operand | |
4336 | ||
4337 | when N_Op_Plus => | |
c800f862 RD |
4338 | Determine_Range |
4339 | (Right_Opnd (N), OK1, Lor, Hir, Assume_Valid); | |
70482933 RK |
4340 | |
4341 | -- For unary minus, determine range of operand, and negate it | |
4342 | ||
4343 | when N_Op_Minus => | |
c800f862 RD |
4344 | Determine_Range |
4345 | (Right_Opnd (N), OK1, Lo_Right, Hi_Right, Assume_Valid); | |
70482933 RK |
4346 | |
4347 | if OK1 then | |
4348 | Lor := -Hi_Right; | |
4349 | Hir := -Lo_Right; | |
4350 | end if; | |
4351 | ||
4352 | -- For binary addition, get range of each operand and do the | |
4353 | -- addition to get the result range. | |
4354 | ||
4355 | when N_Op_Add => | |
4356 | if OK_Operands then | |
4357 | Lor := Lo_Left + Lo_Right; | |
4358 | Hir := Hi_Left + Hi_Right; | |
4359 | end if; | |
4360 | ||
675d6070 TQ |
4361 | -- Division is tricky. The only case we consider is where the right |
4362 | -- operand is a positive constant, and in this case we simply divide | |
4363 | -- the bounds of the left operand | |
70482933 RK |
4364 | |
4365 | when N_Op_Divide => | |
4366 | if OK_Operands then | |
4367 | if Lo_Right = Hi_Right | |
4368 | and then Lo_Right > 0 | |
4369 | then | |
4370 | Lor := Lo_Left / Lo_Right; | |
4371 | Hir := Hi_Left / Lo_Right; | |
70482933 RK |
4372 | else |
4373 | OK1 := False; | |
4374 | end if; | |
4375 | end if; | |
4376 | ||
675d6070 TQ |
4377 | -- For binary subtraction, get range of each operand and do the worst |
4378 | -- case subtraction to get the result range. | |
70482933 RK |
4379 | |
4380 | when N_Op_Subtract => | |
4381 | if OK_Operands then | |
4382 | Lor := Lo_Left - Hi_Right; | |
4383 | Hir := Hi_Left - Lo_Right; | |
4384 | end if; | |
4385 | ||
675d6070 TQ |
4386 | -- For MOD, if right operand is a positive constant, then result must |
4387 | -- be in the allowable range of mod results. | |
70482933 RK |
4388 | |
4389 | when N_Op_Mod => | |
4390 | if OK_Operands then | |
fbf5a39b AC |
4391 | if Lo_Right = Hi_Right |
4392 | and then Lo_Right /= 0 | |
4393 | then | |
70482933 RK |
4394 | if Lo_Right > 0 then |
4395 | Lor := Uint_0; | |
4396 | Hir := Lo_Right - 1; | |
4397 | ||
fbf5a39b | 4398 | else -- Lo_Right < 0 |
70482933 RK |
4399 | Lor := Lo_Right + 1; |
4400 | Hir := Uint_0; | |
4401 | end if; | |
4402 | ||
4403 | else | |
4404 | OK1 := False; | |
4405 | end if; | |
4406 | end if; | |
4407 | ||
675d6070 TQ |
4408 | -- For REM, if right operand is a positive constant, then result must |
4409 | -- be in the allowable range of mod results. | |
70482933 RK |
4410 | |
4411 | when N_Op_Rem => | |
4412 | if OK_Operands then | |
fbf5a39b AC |
4413 | if Lo_Right = Hi_Right |
4414 | and then Lo_Right /= 0 | |
4415 | then | |
70482933 RK |
4416 | declare |
4417 | Dval : constant Uint := (abs Lo_Right) - 1; | |
4418 | ||
4419 | begin | |
4420 | -- The sign of the result depends on the sign of the | |
4421 | -- dividend (but not on the sign of the divisor, hence | |
4422 | -- the abs operation above). | |
4423 | ||
4424 | if Lo_Left < 0 then | |
4425 | Lor := -Dval; | |
4426 | else | |
4427 | Lor := Uint_0; | |
4428 | end if; | |
4429 | ||
4430 | if Hi_Left < 0 then | |
4431 | Hir := Uint_0; | |
4432 | else | |
4433 | Hir := Dval; | |
4434 | end if; | |
4435 | end; | |
4436 | ||
4437 | else | |
4438 | OK1 := False; | |
4439 | end if; | |
4440 | end if; | |
4441 | ||
4442 | -- Attribute reference cases | |
4443 | ||
4444 | when N_Attribute_Reference => | |
4445 | case Attribute_Name (N) is | |
4446 | ||
4447 | -- For Pos/Val attributes, we can refine the range using the | |
f26d5cd3 | 4448 | -- possible range of values of the attribute expression. |
70482933 RK |
4449 | |
4450 | when Name_Pos | Name_Val => | |
c800f862 RD |
4451 | Determine_Range |
4452 | (First (Expressions (N)), OK1, Lor, Hir, Assume_Valid); | |
70482933 RK |
4453 | |
4454 | -- For Length attribute, use the bounds of the corresponding | |
4455 | -- index type to refine the range. | |
4456 | ||
4457 | when Name_Length => | |
4458 | declare | |
4459 | Atyp : Entity_Id := Etype (Prefix (N)); | |
4460 | Inum : Nat; | |
4461 | Indx : Node_Id; | |
4462 | ||
4463 | LL, LU : Uint; | |
4464 | UL, UU : Uint; | |
4465 | ||
4466 | begin | |
4467 | if Is_Access_Type (Atyp) then | |
4468 | Atyp := Designated_Type (Atyp); | |
4469 | end if; | |
4470 | ||
4471 | -- For string literal, we know exact value | |
4472 | ||
4473 | if Ekind (Atyp) = E_String_Literal_Subtype then | |
4474 | OK := True; | |
4475 | Lo := String_Literal_Length (Atyp); | |
4476 | Hi := String_Literal_Length (Atyp); | |
4477 | return; | |
4478 | end if; | |
4479 | ||
4480 | -- Otherwise check for expression given | |
4481 | ||
4482 | if No (Expressions (N)) then | |
4483 | Inum := 1; | |
4484 | else | |
4485 | Inum := | |
4486 | UI_To_Int (Expr_Value (First (Expressions (N)))); | |
4487 | end if; | |
4488 | ||
4489 | Indx := First_Index (Atyp); | |
4490 | for J in 2 .. Inum loop | |
4491 | Indx := Next_Index (Indx); | |
4492 | end loop; | |
4493 | ||
5b599df4 | 4494 | -- If the index type is a formal type or derived from |
b4d7b435 AC |
4495 | -- one, the bounds are not static. |
4496 | ||
4497 | if Is_Generic_Type (Root_Type (Etype (Indx))) then | |
4498 | OK := False; | |
4499 | return; | |
4500 | end if; | |
4501 | ||
70482933 | 4502 | Determine_Range |
c800f862 RD |
4503 | (Type_Low_Bound (Etype (Indx)), OK1, LL, LU, |
4504 | Assume_Valid); | |
70482933 RK |
4505 | |
4506 | if OK1 then | |
4507 | Determine_Range | |
c800f862 RD |
4508 | (Type_High_Bound (Etype (Indx)), OK1, UL, UU, |
4509 | Assume_Valid); | |
70482933 RK |
4510 | |
4511 | if OK1 then | |
4512 | ||
4513 | -- The maximum value for Length is the biggest | |
4514 | -- possible gap between the values of the bounds. | |
4515 | -- But of course, this value cannot be negative. | |
4516 | ||
c800f862 | 4517 | Hir := UI_Max (Uint_0, UU - LL + 1); |
70482933 RK |
4518 | |
4519 | -- For constrained arrays, the minimum value for | |
4520 | -- Length is taken from the actual value of the | |
5b599df4 AC |
4521 | -- bounds, since the index will be exactly of this |
4522 | -- subtype. | |
70482933 RK |
4523 | |
4524 | if Is_Constrained (Atyp) then | |
c800f862 | 4525 | Lor := UI_Max (Uint_0, UL - LU + 1); |
70482933 RK |
4526 | |
4527 | -- For an unconstrained array, the minimum value | |
4528 | -- for length is always zero. | |
4529 | ||
4530 | else | |
4531 | Lor := Uint_0; | |
4532 | end if; | |
4533 | end if; | |
4534 | end if; | |
4535 | end; | |
4536 | ||
4537 | -- No special handling for other attributes | |
5b599df4 | 4538 | -- Probably more opportunities exist here??? |
70482933 RK |
4539 | |
4540 | when others => | |
4541 | OK1 := False; | |
4542 | ||
4543 | end case; | |
4544 | ||
675d6070 TQ |
4545 | -- For type conversion from one discrete type to another, we can |
4546 | -- refine the range using the converted value. | |
70482933 RK |
4547 | |
4548 | when N_Type_Conversion => | |
c800f862 | 4549 | Determine_Range (Expression (N), OK1, Lor, Hir, Assume_Valid); |
70482933 RK |
4550 | |
4551 | -- Nothing special to do for all other expression kinds | |
4552 | ||
4553 | when others => | |
4554 | OK1 := False; | |
4555 | Lor := No_Uint; | |
4556 | Hir := No_Uint; | |
4557 | end case; | |
4558 | ||
5b599df4 AC |
4559 | -- At this stage, if OK1 is true, then we know that the actual result of |
4560 | -- the computed expression is in the range Lor .. Hir. We can use this | |
4561 | -- to restrict the possible range of results. | |
70482933 RK |
4562 | |
4563 | if OK1 then | |
4564 | ||
5b599df4 | 4565 | -- If the refined value of the low bound is greater than the type |
6b6bce61 | 4566 | -- low bound, then reset it to the more restrictive value. However, |
5b599df4 AC |
4567 | -- we do NOT do this for the case of a modular type where the |
4568 | -- possible upper bound on the value is above the base type high | |
4569 | -- bound, because that means the result could wrap. | |
70482933 RK |
4570 | |
4571 | if Lor > Lo | |
5b599df4 | 4572 | and then not (Is_Modular_Integer_Type (Typ) and then Hir > Hbound) |
70482933 RK |
4573 | then |
4574 | Lo := Lor; | |
4575 | end if; | |
4576 | ||
5b599df4 AC |
4577 | -- Similarly, if the refined value of the high bound is less than the |
4578 | -- value so far, then reset it to the more restrictive value. Again, | |
4579 | -- we do not do this if the refined low bound is negative for a | |
4580 | -- modular type, since this would wrap. | |
70482933 RK |
4581 | |
4582 | if Hir < Hi | |
5b599df4 | 4583 | and then not (Is_Modular_Integer_Type (Typ) and then Lor < Uint_0) |
70482933 RK |
4584 | then |
4585 | Hi := Hir; | |
4586 | end if; | |
4587 | end if; | |
4588 | ||
4589 | -- Set cache entry for future call and we are all done | |
4590 | ||
4591 | Determine_Range_Cache_N (Cindex) := N; | |
c800f862 | 4592 | Determine_Range_Cache_V (Cindex) := Assume_Valid; |
70482933 RK |
4593 | Determine_Range_Cache_Lo (Cindex) := Lo; |
4594 | Determine_Range_Cache_Hi (Cindex) := Hi; | |
4595 | return; | |
4596 | ||
5b599df4 AC |
4597 | -- If any exception occurs, it means that we have some bug in the compiler, |
4598 | -- possibly triggered by a previous error, or by some unforeseen peculiar | |
70482933 RK |
4599 | -- occurrence. However, this is only an optimization attempt, so there is |
4600 | -- really no point in crashing the compiler. Instead we just decide, too | |
4601 | -- bad, we can't figure out a range in this case after all. | |
4602 | ||
4603 | exception | |
4604 | when others => | |
4605 | ||
4606 | -- Debug flag K disables this behavior (useful for debugging) | |
4607 | ||
4608 | if Debug_Flag_K then | |
4609 | raise; | |
4610 | else | |
4611 | OK := False; | |
4612 | Lo := No_Uint; | |
4613 | Hi := No_Uint; | |
4614 | return; | |
4615 | end if; | |
70482933 RK |
4616 | end Determine_Range; |
4617 | ||
6b6bce61 AC |
4618 | ----------------------- |
4619 | -- Determine_Range_R -- | |
4620 | ----------------------- | |
4621 | ||
4622 | procedure Determine_Range_R | |
4623 | (N : Node_Id; | |
4624 | OK : out Boolean; | |
4625 | Lo : out Ureal; | |
4626 | Hi : out Ureal; | |
4627 | Assume_Valid : Boolean := False) | |
4628 | is | |
4629 | Typ : Entity_Id := Etype (N); | |
4630 | -- Type to use, may get reset to base type for possibly invalid entity | |
4631 | ||
4632 | Lo_Left : Ureal; | |
4633 | Hi_Left : Ureal; | |
4634 | -- Lo and Hi bounds of left operand | |
4635 | ||
4636 | Lo_Right : Ureal; | |
4637 | Hi_Right : Ureal; | |
4638 | -- Lo and Hi bounds of right (or only) operand | |
4639 | ||
4640 | Bound : Node_Id; | |
4641 | -- Temp variable used to hold a bound node | |
4642 | ||
4643 | Hbound : Ureal; | |
4644 | -- High bound of base type of expression | |
4645 | ||
4646 | Lor : Ureal; | |
4647 | Hir : Ureal; | |
4648 | -- Refined values for low and high bounds, after tightening | |
4649 | ||
4650 | OK1 : Boolean; | |
4651 | -- Used in lower level calls to indicate if call succeeded | |
4652 | ||
4653 | Cindex : Cache_Index; | |
4654 | -- Used to search cache | |
4655 | ||
4656 | Btyp : Entity_Id; | |
4657 | -- Base type | |
4658 | ||
4659 | function OK_Operands return Boolean; | |
4660 | -- Used for binary operators. Determines the ranges of the left and | |
4661 | -- right operands, and if they are both OK, returns True, and puts | |
4662 | -- the results in Lo_Right, Hi_Right, Lo_Left, Hi_Left. | |
4663 | ||
4664 | function Round_Machine (B : Ureal) return Ureal; | |
4665 | -- B is a real bound. Round it using mode Round_Even. | |
4666 | ||
4667 | ----------------- | |
4668 | -- OK_Operands -- | |
4669 | ----------------- | |
4670 | ||
4671 | function OK_Operands return Boolean is | |
4672 | begin | |
4673 | Determine_Range_R | |
4674 | (Left_Opnd (N), OK1, Lo_Left, Hi_Left, Assume_Valid); | |
4675 | ||
4676 | if not OK1 then | |
4677 | return False; | |
4678 | end if; | |
4679 | ||
4680 | Determine_Range_R | |
4681 | (Right_Opnd (N), OK1, Lo_Right, Hi_Right, Assume_Valid); | |
4682 | return OK1; | |
4683 | end OK_Operands; | |
4684 | ||
4685 | ------------------- | |
4686 | -- Round_Machine -- | |
4687 | ------------------- | |
4688 | ||
4689 | function Round_Machine (B : Ureal) return Ureal is | |
4690 | begin | |
4691 | return Machine (Typ, B, Round_Even, N); | |
4692 | end Round_Machine; | |
4693 | ||
4694 | -- Start of processing for Determine_Range_R | |
4695 | ||
4696 | begin | |
4697 | -- Prevent junk warnings by initializing range variables | |
4698 | ||
4699 | Lo := No_Ureal; | |
4700 | Hi := No_Ureal; | |
4701 | Lor := No_Ureal; | |
4702 | Hir := No_Ureal; | |
4703 | ||
4704 | -- For temporary constants internally generated to remove side effects | |
4705 | -- we must use the corresponding expression to determine the range of | |
4706 | -- the expression. But note that the expander can also generate | |
4707 | -- constants in other cases, including deferred constants. | |
4708 | ||
4709 | if Is_Entity_Name (N) | |
4710 | and then Nkind (Parent (Entity (N))) = N_Object_Declaration | |
4711 | and then Ekind (Entity (N)) = E_Constant | |
4712 | and then Is_Internal_Name (Chars (Entity (N))) | |
4713 | then | |
4714 | if Present (Expression (Parent (Entity (N)))) then | |
4715 | Determine_Range_R | |
4716 | (Expression (Parent (Entity (N))), OK, Lo, Hi, Assume_Valid); | |
4717 | ||
4718 | elsif Present (Full_View (Entity (N))) then | |
4719 | Determine_Range_R | |
4720 | (Expression (Parent (Full_View (Entity (N)))), | |
4721 | OK, Lo, Hi, Assume_Valid); | |
4722 | ||
4723 | else | |
4724 | OK := False; | |
4725 | end if; | |
d6e8719d | 4726 | |
6b6bce61 AC |
4727 | return; |
4728 | end if; | |
4729 | ||
4730 | -- If type is not defined, we can't determine its range | |
4731 | ||
4732 | if No (Typ) | |
4733 | ||
4734 | -- We don't deal with anything except IEEE floating-point types | |
4735 | ||
4736 | or else not Is_Floating_Point_Type (Typ) | |
4737 | or else Float_Rep (Typ) /= IEEE_Binary | |
4738 | ||
4739 | -- Ignore type for which an error has been posted, since range in | |
4740 | -- this case may well be a bogosity deriving from the error. Also | |
4741 | -- ignore if error posted on the reference node. | |
4742 | ||
4743 | or else Error_Posted (N) or else Error_Posted (Typ) | |
4744 | then | |
4745 | OK := False; | |
4746 | return; | |
4747 | end if; | |
4748 | ||
4749 | -- For all other cases, we can determine the range | |
4750 | ||
4751 | OK := True; | |
4752 | ||
4753 | -- If value is compile time known, then the possible range is the one | |
4754 | -- value that we know this expression definitely has. | |
4755 | ||
4756 | if Compile_Time_Known_Value (N) then | |
4757 | Lo := Expr_Value_R (N); | |
4758 | Hi := Lo; | |
4759 | return; | |
4760 | end if; | |
4761 | ||
4762 | -- Return if already in the cache | |
4763 | ||
4764 | Cindex := Cache_Index (N mod Cache_Size); | |
4765 | ||
4766 | if Determine_Range_Cache_N (Cindex) = N | |
4767 | and then | |
4768 | Determine_Range_Cache_V (Cindex) = Assume_Valid | |
4769 | then | |
4770 | Lo := Determine_Range_Cache_Lo_R (Cindex); | |
4771 | Hi := Determine_Range_Cache_Hi_R (Cindex); | |
4772 | return; | |
4773 | end if; | |
4774 | ||
4775 | -- Otherwise, start by finding the bounds of the type of the expression, | |
4776 | -- the value cannot be outside this range (if it is, then we have an | |
4777 | -- overflow situation, which is a separate check, we are talking here | |
4778 | -- only about the expression value). | |
4779 | ||
4780 | -- First a check, never try to find the bounds of a generic type, since | |
4781 | -- these bounds are always junk values, and it is only valid to look at | |
4782 | -- the bounds in an instance. | |
4783 | ||
4784 | if Is_Generic_Type (Typ) then | |
4785 | OK := False; | |
4786 | return; | |
4787 | end if; | |
4788 | ||
4789 | -- First step, change to use base type unless we know the value is valid | |
4790 | ||
4791 | if (Is_Entity_Name (N) and then Is_Known_Valid (Entity (N))) | |
4792 | or else Assume_No_Invalid_Values | |
4793 | or else Assume_Valid | |
4794 | then | |
4795 | null; | |
4796 | else | |
4797 | Typ := Underlying_Type (Base_Type (Typ)); | |
4798 | end if; | |
4799 | ||
4800 | -- Retrieve the base type. Handle the case where the base type is a | |
4801 | -- private type. | |
4802 | ||
4803 | Btyp := Base_Type (Typ); | |
4804 | ||
4805 | if Is_Private_Type (Btyp) and then Present (Full_View (Btyp)) then | |
4806 | Btyp := Full_View (Btyp); | |
4807 | end if; | |
4808 | ||
4809 | -- We use the actual bound unless it is dynamic, in which case use the | |
4810 | -- corresponding base type bound if possible. If we can't get a bound | |
4811 | -- then we figure we can't determine the range (a peculiar case, that | |
4812 | -- perhaps cannot happen, but there is no point in bombing in this | |
4813 | -- optimization circuit). | |
4814 | ||
4815 | -- First the low bound | |
4816 | ||
4817 | Bound := Type_Low_Bound (Typ); | |
4818 | ||
4819 | if Compile_Time_Known_Value (Bound) then | |
4820 | Lo := Expr_Value_R (Bound); | |
4821 | ||
4822 | elsif Compile_Time_Known_Value (Type_Low_Bound (Btyp)) then | |
4823 | Lo := Expr_Value_R (Type_Low_Bound (Btyp)); | |
4824 | ||
4825 | else | |
4826 | OK := False; | |
4827 | return; | |
4828 | end if; | |
4829 | ||
4830 | -- Now the high bound | |
4831 | ||
4832 | Bound := Type_High_Bound (Typ); | |
4833 | ||
4834 | -- We need the high bound of the base type later on, and this should | |
4835 | -- always be compile time known. Again, it is not clear that this | |
4836 | -- can ever be false, but no point in bombing. | |
4837 | ||
4838 | if Compile_Time_Known_Value (Type_High_Bound (Btyp)) then | |
4839 | Hbound := Expr_Value_R (Type_High_Bound (Btyp)); | |
4840 | Hi := Hbound; | |
4841 | ||
4842 | else | |
4843 | OK := False; | |
4844 | return; | |
4845 | end if; | |
4846 | ||
4847 | -- If we have a static subtype, then that may have a tighter bound so | |
4848 | -- use the upper bound of the subtype instead in this case. | |
4849 | ||
4850 | if Compile_Time_Known_Value (Bound) then | |
4851 | Hi := Expr_Value_R (Bound); | |
4852 | end if; | |
4853 | ||
4854 | -- We may be able to refine this value in certain situations. If any | |
4855 | -- refinement is possible, then Lor and Hir are set to possibly tighter | |
4856 | -- bounds, and OK1 is set to True. | |
4857 | ||
4858 | case Nkind (N) is | |
4859 | ||
4860 | -- For unary plus, result is limited by range of operand | |
4861 | ||
4862 | when N_Op_Plus => | |
4863 | Determine_Range_R | |
4864 | (Right_Opnd (N), OK1, Lor, Hir, Assume_Valid); | |
4865 | ||
4866 | -- For unary minus, determine range of operand, and negate it | |
4867 | ||
4868 | when N_Op_Minus => | |
4869 | Determine_Range_R | |
4870 | (Right_Opnd (N), OK1, Lo_Right, Hi_Right, Assume_Valid); | |
4871 | ||
4872 | if OK1 then | |
4873 | Lor := -Hi_Right; | |
4874 | Hir := -Lo_Right; | |
4875 | end if; | |
4876 | ||
4877 | -- For binary addition, get range of each operand and do the | |
4878 | -- addition to get the result range. | |
4879 | ||
4880 | when N_Op_Add => | |
4881 | if OK_Operands then | |
4882 | Lor := Round_Machine (Lo_Left + Lo_Right); | |
4883 | Hir := Round_Machine (Hi_Left + Hi_Right); | |
4884 | end if; | |
4885 | ||
4886 | -- For binary subtraction, get range of each operand and do the worst | |
4887 | -- case subtraction to get the result range. | |
4888 | ||
4889 | when N_Op_Subtract => | |
4890 | if OK_Operands then | |
4891 | Lor := Round_Machine (Lo_Left - Hi_Right); | |
4892 | Hir := Round_Machine (Hi_Left - Lo_Right); | |
4893 | end if; | |
4894 | ||
4895 | -- For multiplication, get range of each operand and do the | |
4896 | -- four multiplications to get the result range. | |
4897 | ||
4898 | when N_Op_Multiply => | |
4899 | if OK_Operands then | |
4900 | declare | |
4901 | M1 : constant Ureal := Round_Machine (Lo_Left * Lo_Right); | |
4902 | M2 : constant Ureal := Round_Machine (Lo_Left * Hi_Right); | |
4903 | M3 : constant Ureal := Round_Machine (Hi_Left * Lo_Right); | |
4904 | M4 : constant Ureal := Round_Machine (Hi_Left * Hi_Right); | |
4905 | begin | |
4906 | Lor := UR_Min (UR_Min (M1, M2), UR_Min (M3, M4)); | |
4907 | Hir := UR_Max (UR_Max (M1, M2), UR_Max (M3, M4)); | |
4908 | end; | |
4909 | end if; | |
4910 | ||
4911 | -- For division, consider separately the cases where the right | |
4912 | -- operand is positive or negative. Otherwise, the right operand | |
4913 | -- can be arbitrarily close to zero, so the result is likely to | |
4914 | -- be unbounded in one direction, do not attempt to compute it. | |
4915 | ||
4916 | when N_Op_Divide => | |
4917 | if OK_Operands then | |
4918 | ||
4919 | -- Right operand is positive | |
4920 | ||
4921 | if Lo_Right > Ureal_0 then | |
4922 | ||
4923 | -- If the low bound of the left operand is negative, obtain | |
4924 | -- the overall low bound by dividing it by the smallest | |
4925 | -- value of the right operand, and otherwise by the largest | |
4926 | -- value of the right operand. | |
4927 | ||
4928 | if Lo_Left < Ureal_0 then | |
4929 | Lor := Round_Machine (Lo_Left / Lo_Right); | |
4930 | else | |
4931 | Lor := Round_Machine (Lo_Left / Hi_Right); | |
4932 | end if; | |
4933 | ||
4934 | -- If the high bound of the left operand is negative, obtain | |
4935 | -- the overall high bound by dividing it by the largest | |
4936 | -- value of the right operand, and otherwise by the | |
4937 | -- smallest value of the right operand. | |
4938 | ||
4939 | if Hi_Left < Ureal_0 then | |
4940 | Hir := Round_Machine (Hi_Left / Hi_Right); | |
4941 | else | |
4942 | Hir := Round_Machine (Hi_Left / Lo_Right); | |
4943 | end if; | |
4944 | ||
4945 | -- Right operand is negative | |
4946 | ||
4947 | elsif Hi_Right < Ureal_0 then | |
4948 | ||
4949 | -- If the low bound of the left operand is negative, obtain | |
4950 | -- the overall low bound by dividing it by the largest | |
4951 | -- value of the right operand, and otherwise by the smallest | |
4952 | -- value of the right operand. | |
4953 | ||
4954 | if Lo_Left < Ureal_0 then | |
4955 | Lor := Round_Machine (Lo_Left / Hi_Right); | |
4956 | else | |
4957 | Lor := Round_Machine (Lo_Left / Lo_Right); | |
4958 | end if; | |
4959 | ||
4960 | -- If the high bound of the left operand is negative, obtain | |
4961 | -- the overall high bound by dividing it by the smallest | |
4962 | -- value of the right operand, and otherwise by the | |
4963 | -- largest value of the right operand. | |
4964 | ||
4965 | if Hi_Left < Ureal_0 then | |
4966 | Hir := Round_Machine (Hi_Left / Lo_Right); | |
4967 | else | |
4968 | Hir := Round_Machine (Hi_Left / Hi_Right); | |
4969 | end if; | |
4970 | ||
4971 | else | |
4972 | OK1 := False; | |
4973 | end if; | |
4974 | end if; | |
4975 | ||
4976 | -- For type conversion from one floating-point type to another, we | |
4977 | -- can refine the range using the converted value. | |
4978 | ||
4979 | when N_Type_Conversion => | |
4980 | Determine_Range_R (Expression (N), OK1, Lor, Hir, Assume_Valid); | |
4981 | ||
4982 | -- Nothing special to do for all other expression kinds | |
4983 | ||
4984 | when others => | |
4985 | OK1 := False; | |
4986 | Lor := No_Ureal; | |
4987 | Hir := No_Ureal; | |
4988 | end case; | |
4989 | ||
4990 | -- At this stage, if OK1 is true, then we know that the actual result of | |
4991 | -- the computed expression is in the range Lor .. Hir. We can use this | |
4992 | -- to restrict the possible range of results. | |
4993 | ||
4994 | if OK1 then | |
4995 | ||
4996 | -- If the refined value of the low bound is greater than the type | |
4997 | -- low bound, then reset it to the more restrictive value. | |
4998 | ||
4999 | if Lor > Lo then | |
5000 | Lo := Lor; | |
5001 | end if; | |
5002 | ||
5003 | -- Similarly, if the refined value of the high bound is less than the | |
5004 | -- value so far, then reset it to the more restrictive value. | |
5005 | ||
5006 | if Hir < Hi then | |
5007 | Hi := Hir; | |
5008 | end if; | |
5009 | end if; | |
5010 | ||
5011 | -- Set cache entry for future call and we are all done | |
5012 | ||
5013 | Determine_Range_Cache_N (Cindex) := N; | |
5014 | Determine_Range_Cache_V (Cindex) := Assume_Valid; | |
5015 | Determine_Range_Cache_Lo_R (Cindex) := Lo; | |
5016 | Determine_Range_Cache_Hi_R (Cindex) := Hi; | |
5017 | return; | |
5018 | ||
5019 | -- If any exception occurs, it means that we have some bug in the compiler, | |
5020 | -- possibly triggered by a previous error, or by some unforeseen peculiar | |
5021 | -- occurrence. However, this is only an optimization attempt, so there is | |
5022 | -- really no point in crashing the compiler. Instead we just decide, too | |
5023 | -- bad, we can't figure out a range in this case after all. | |
5024 | ||
5025 | exception | |
5026 | when others => | |
5027 | ||
5028 | -- Debug flag K disables this behavior (useful for debugging) | |
5029 | ||
5030 | if Debug_Flag_K then | |
5031 | raise; | |
5032 | else | |
5033 | OK := False; | |
5034 | Lo := No_Ureal; | |
5035 | Hi := No_Ureal; | |
5036 | return; | |
5037 | end if; | |
5038 | end Determine_Range_R; | |
5039 | ||
70482933 RK |
5040 | ------------------------------------ |
5041 | -- Discriminant_Checks_Suppressed -- | |
5042 | ------------------------------------ | |
5043 | ||
5044 | function Discriminant_Checks_Suppressed (E : Entity_Id) return Boolean is | |
5045 | begin | |
fbf5a39b AC |
5046 | if Present (E) then |
5047 | if Is_Unchecked_Union (E) then | |
5048 | return True; | |
5049 | elsif Checks_May_Be_Suppressed (E) then | |
5050 | return Is_Check_Suppressed (E, Discriminant_Check); | |
5051 | end if; | |
5052 | end if; | |
5053 | ||
3217f71e | 5054 | return Scope_Suppress.Suppress (Discriminant_Check); |
70482933 RK |
5055 | end Discriminant_Checks_Suppressed; |
5056 | ||
5057 | -------------------------------- | |
5058 | -- Division_Checks_Suppressed -- | |
5059 | -------------------------------- | |
5060 | ||
5061 | function Division_Checks_Suppressed (E : Entity_Id) return Boolean is | |
5062 | begin | |
fbf5a39b AC |
5063 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
5064 | return Is_Check_Suppressed (E, Division_Check); | |
5065 | else | |
3217f71e | 5066 | return Scope_Suppress.Suppress (Division_Check); |
fbf5a39b | 5067 | end if; |
70482933 RK |
5068 | end Division_Checks_Suppressed; |
5069 | ||
59f4d038 RD |
5070 | -------------------------------------- |
5071 | -- Duplicated_Tag_Checks_Suppressed -- | |
5072 | -------------------------------------- | |
5073 | ||
5074 | function Duplicated_Tag_Checks_Suppressed (E : Entity_Id) return Boolean is | |
5075 | begin | |
5076 | if Present (E) and then Checks_May_Be_Suppressed (E) then | |
5077 | return Is_Check_Suppressed (E, Duplicated_Tag_Check); | |
5078 | else | |
5079 | return Scope_Suppress.Suppress (Duplicated_Tag_Check); | |
5080 | end if; | |
5081 | end Duplicated_Tag_Checks_Suppressed; | |
5082 | ||
70482933 RK |
5083 | ----------------------------------- |
5084 | -- Elaboration_Checks_Suppressed -- | |
5085 | ----------------------------------- | |
5086 | ||
5087 | function Elaboration_Checks_Suppressed (E : Entity_Id) return Boolean is | |
5088 | begin | |
f02b8bb8 RD |
5089 | -- The complication in this routine is that if we are in the dynamic |
5090 | -- model of elaboration, we also check All_Checks, since All_Checks | |
5091 | -- does not set Elaboration_Check explicitly. | |
5092 | ||
fbf5a39b AC |
5093 | if Present (E) then |
5094 | if Kill_Elaboration_Checks (E) then | |
5095 | return True; | |
f02b8bb8 | 5096 | |
fbf5a39b | 5097 | elsif Checks_May_Be_Suppressed (E) then |
f02b8bb8 RD |
5098 | if Is_Check_Suppressed (E, Elaboration_Check) then |
5099 | return True; | |
5100 | elsif Dynamic_Elaboration_Checks then | |
5101 | return Is_Check_Suppressed (E, All_Checks); | |
5102 | else | |
5103 | return False; | |
5104 | end if; | |
fbf5a39b AC |
5105 | end if; |
5106 | end if; | |
5107 | ||
3217f71e | 5108 | if Scope_Suppress.Suppress (Elaboration_Check) then |
f02b8bb8 RD |
5109 | return True; |
5110 | elsif Dynamic_Elaboration_Checks then | |
3217f71e | 5111 | return Scope_Suppress.Suppress (All_Checks); |
f02b8bb8 RD |
5112 | else |
5113 | return False; | |
5114 | end if; | |
70482933 RK |
5115 | end Elaboration_Checks_Suppressed; |
5116 | ||
fbf5a39b AC |
5117 | --------------------------- |
5118 | -- Enable_Overflow_Check -- | |
5119 | --------------------------- | |
5120 | ||
5121 | procedure Enable_Overflow_Check (N : Node_Id) is | |
d6e8719d | 5122 | Typ : constant Entity_Id := Base_Type (Etype (N)); |
15c94a55 | 5123 | Mode : constant Overflow_Mode_Type := Overflow_Check_Mode; |
acad3c0a AC |
5124 | Chk : Nat; |
5125 | OK : Boolean; | |
5126 | Ent : Entity_Id; | |
5127 | Ofs : Uint; | |
5128 | Lo : Uint; | |
5129 | Hi : Uint; | |
70482933 | 5130 | |
b7c874a7 AC |
5131 | Do_Ovflow_Check : Boolean; |
5132 | ||
70482933 | 5133 | begin |
fbf5a39b AC |
5134 | if Debug_Flag_CC then |
5135 | w ("Enable_Overflow_Check for node ", Int (N)); | |
5136 | Write_Str (" Source location = "); | |
5137 | wl (Sloc (N)); | |
11b4899f | 5138 | pg (Union_Id (N)); |
70482933 | 5139 | end if; |
70482933 | 5140 | |
3d5952be AC |
5141 | -- No check if overflow checks suppressed for type of node |
5142 | ||
a7f1b24f | 5143 | if Overflow_Checks_Suppressed (Etype (N)) then |
3d5952be AC |
5144 | return; |
5145 | ||
991395ab AC |
5146 | -- Nothing to do for unsigned integer types, which do not overflow |
5147 | ||
5148 | elsif Is_Modular_Integer_Type (Typ) then | |
5149 | return; | |
acad3c0a AC |
5150 | end if; |
5151 | ||
a7f1b24f | 5152 | -- This is the point at which processing for STRICT mode diverges |
5707e389 AC |
5153 | -- from processing for MINIMIZED/ELIMINATED modes. This divergence is |
5154 | -- probably more extreme that it needs to be, but what is going on here | |
5155 | -- is that when we introduced MINIMIZED/ELIMINATED modes, we wanted | |
a7f1b24f | 5156 | -- to leave the processing for STRICT mode untouched. There were |
5707e389 | 5157 | -- two reasons for this. First it avoided any incompatible change of |
a7f1b24f | 5158 | -- behavior. Second, it guaranteed that STRICT mode continued to be |
5707e389 | 5159 | -- legacy reliable. |
acad3c0a | 5160 | |
a7f1b24f | 5161 | -- The big difference is that in STRICT mode there is a fair amount of |
acad3c0a AC |
5162 | -- circuitry to try to avoid setting the Do_Overflow_Check flag if we |
5163 | -- know that no check is needed. We skip all that in the two new modes, | |
5164 | -- since really overflow checking happens over a whole subtree, and we | |
5165 | -- do the corresponding optimizations later on when applying the checks. | |
5166 | ||
5167 | if Mode in Minimized_Or_Eliminated then | |
a7f1b24f RD |
5168 | if not (Overflow_Checks_Suppressed (Etype (N))) |
5169 | and then not (Is_Entity_Name (N) | |
5170 | and then Overflow_Checks_Suppressed (Entity (N))) | |
5171 | then | |
5172 | Activate_Overflow_Check (N); | |
5173 | end if; | |
acad3c0a AC |
5174 | |
5175 | if Debug_Flag_CC then | |
5176 | w ("Minimized/Eliminated mode"); | |
5177 | end if; | |
5178 | ||
5179 | return; | |
5180 | end if; | |
5181 | ||
a7f1b24f | 5182 | -- Remainder of processing is for STRICT case, and is unchanged from |
3ada950b | 5183 | -- earlier versions preceding the addition of MINIMIZED/ELIMINATED. |
991395ab | 5184 | |
675d6070 TQ |
5185 | -- Nothing to do if the range of the result is known OK. We skip this |
5186 | -- for conversions, since the caller already did the check, and in any | |
5187 | -- case the condition for deleting the check for a type conversion is | |
f2cbd970 | 5188 | -- different. |
70482933 | 5189 | |
acad3c0a | 5190 | if Nkind (N) /= N_Type_Conversion then |
c800f862 | 5191 | Determine_Range (N, OK, Lo, Hi, Assume_Valid => True); |
70482933 | 5192 | |
f2cbd970 JM |
5193 | -- Note in the test below that we assume that the range is not OK |
5194 | -- if a bound of the range is equal to that of the type. That's not | |
5195 | -- quite accurate but we do this for the following reasons: | |
70482933 | 5196 | |
fbf5a39b AC |
5197 | -- a) The way that Determine_Range works, it will typically report |
5198 | -- the bounds of the value as being equal to the bounds of the | |
5199 | -- type, because it either can't tell anything more precise, or | |
5200 | -- does not think it is worth the effort to be more precise. | |
70482933 | 5201 | |
fbf5a39b AC |
5202 | -- b) It is very unusual to have a situation in which this would |
5203 | -- generate an unnecessary overflow check (an example would be | |
5204 | -- a subtype with a range 0 .. Integer'Last - 1 to which the | |
f2cbd970 | 5205 | -- literal value one is added). |
70482933 | 5206 | |
fbf5a39b AC |
5207 | -- c) The alternative is a lot of special casing in this routine |
5208 | -- which would partially duplicate Determine_Range processing. | |
70482933 | 5209 | |
b7c874a7 AC |
5210 | if OK then |
5211 | Do_Ovflow_Check := True; | |
5212 | ||
5213 | -- Note that the following checks are quite deliberately > and < | |
5214 | -- rather than >= and <= as explained above. | |
5215 | ||
5216 | if Lo > Expr_Value (Type_Low_Bound (Typ)) | |
5217 | and then | |
5218 | Hi < Expr_Value (Type_High_Bound (Typ)) | |
5219 | then | |
5220 | Do_Ovflow_Check := False; | |
5221 | ||
5222 | -- Despite the comments above, it is worth dealing specially with | |
5223 | -- division specially. The only case where integer division can | |
5224 | -- overflow is (largest negative number) / (-1). So we will do | |
5225 | -- an extra range analysis to see if this is possible. | |
5226 | ||
5227 | elsif Nkind (N) = N_Op_Divide then | |
5228 | Determine_Range | |
5229 | (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True); | |
5230 | ||
5231 | if OK and then Lo > Expr_Value (Type_Low_Bound (Typ)) then | |
5232 | Do_Ovflow_Check := False; | |
5233 | ||
5234 | else | |
5235 | Determine_Range | |
5236 | (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True); | |
5237 | ||
5238 | if OK and then (Lo > Uint_Minus_1 | |
5239 | or else | |
5240 | Hi < Uint_Minus_1) | |
5241 | then | |
5242 | Do_Ovflow_Check := False; | |
5243 | end if; | |
5244 | end if; | |
fbf5a39b AC |
5245 | end if; |
5246 | ||
b7c874a7 AC |
5247 | -- If no overflow check required, we are done |
5248 | ||
5249 | if not Do_Ovflow_Check then | |
5250 | if Debug_Flag_CC then | |
5251 | w ("No overflow check required"); | |
5252 | end if; | |
5253 | ||
5254 | return; | |
5255 | end if; | |
fbf5a39b AC |
5256 | end if; |
5257 | end if; | |
5258 | ||
675d6070 TQ |
5259 | -- If not in optimizing mode, set flag and we are done. We are also done |
5260 | -- (and just set the flag) if the type is not a discrete type, since it | |
5261 | -- is not worth the effort to eliminate checks for other than discrete | |
5262 | -- types. In addition, we take this same path if we have stored the | |
5263 | -- maximum number of checks possible already (a very unlikely situation, | |
a90bd866 | 5264 | -- but we do not want to blow up). |
fbf5a39b AC |
5265 | |
5266 | if Optimization_Level = 0 | |
5267 | or else not Is_Discrete_Type (Etype (N)) | |
5268 | or else Num_Saved_Checks = Saved_Checks'Last | |
70482933 | 5269 | then |
11b4899f | 5270 | Activate_Overflow_Check (N); |
fbf5a39b AC |
5271 | |
5272 | if Debug_Flag_CC then | |
5273 | w ("Optimization off"); | |
5274 | end if; | |
5275 | ||
70482933 | 5276 | return; |
fbf5a39b | 5277 | end if; |
70482933 | 5278 | |
fbf5a39b AC |
5279 | -- Otherwise evaluate and check the expression |
5280 | ||
5281 | Find_Check | |
5282 | (Expr => N, | |
5283 | Check_Type => 'O', | |
5284 | Target_Type => Empty, | |
5285 | Entry_OK => OK, | |
5286 | Check_Num => Chk, | |
5287 | Ent => Ent, | |
5288 | Ofs => Ofs); | |
5289 | ||
5290 | if Debug_Flag_CC then | |
5291 | w ("Called Find_Check"); | |
5292 | w (" OK = ", OK); | |
5293 | ||
5294 | if OK then | |
5295 | w (" Check_Num = ", Chk); | |
5296 | w (" Ent = ", Int (Ent)); | |
5297 | Write_Str (" Ofs = "); | |
5298 | pid (Ofs); | |
5299 | end if; | |
5300 | end if; | |
70482933 | 5301 | |
fbf5a39b AC |
5302 | -- If check is not of form to optimize, then set flag and we are done |
5303 | ||
5304 | if not OK then | |
11b4899f | 5305 | Activate_Overflow_Check (N); |
70482933 | 5306 | return; |
fbf5a39b | 5307 | end if; |
70482933 | 5308 | |
fbf5a39b AC |
5309 | -- If check is already performed, then return without setting flag |
5310 | ||
5311 | if Chk /= 0 then | |
5312 | if Debug_Flag_CC then | |
5313 | w ("Check suppressed!"); | |
5314 | end if; | |
70482933 | 5315 | |
70482933 | 5316 | return; |
fbf5a39b | 5317 | end if; |
70482933 | 5318 | |
fbf5a39b AC |
5319 | -- Here we will make a new entry for the new check |
5320 | ||
11b4899f | 5321 | Activate_Overflow_Check (N); |
fbf5a39b AC |
5322 | Num_Saved_Checks := Num_Saved_Checks + 1; |
5323 | Saved_Checks (Num_Saved_Checks) := | |
5324 | (Killed => False, | |
5325 | Entity => Ent, | |
5326 | Offset => Ofs, | |
5327 | Check_Type => 'O', | |
5328 | Target_Type => Empty); | |
5329 | ||
5330 | if Debug_Flag_CC then | |
5331 | w ("Make new entry, check number = ", Num_Saved_Checks); | |
5332 | w (" Entity = ", Int (Ent)); | |
5333 | Write_Str (" Offset = "); | |
5334 | pid (Ofs); | |
5335 | w (" Check_Type = O"); | |
5336 | w (" Target_Type = Empty"); | |
5337 | end if; | |
70482933 | 5338 | |
675d6070 | 5339 | -- If we get an exception, then something went wrong, probably because of |
637a41a5 AC |
5340 | -- an error in the structure of the tree due to an incorrect program. Or |
5341 | -- it may be a bug in the optimization circuit. In either case the safest | |
675d6070 | 5342 | -- thing is simply to set the check flag unconditionally. |
fbf5a39b AC |
5343 | |
5344 | exception | |
5345 | when others => | |
11b4899f | 5346 | Activate_Overflow_Check (N); |
fbf5a39b AC |
5347 | |
5348 | if Debug_Flag_CC then | |
5349 | w (" exception occurred, overflow flag set"); | |
5350 | end if; | |
5351 | ||
5352 | return; | |
5353 | end Enable_Overflow_Check; | |
5354 | ||
5355 | ------------------------ | |
5356 | -- Enable_Range_Check -- | |
5357 | ------------------------ | |
5358 | ||
5359 | procedure Enable_Range_Check (N : Node_Id) is | |
5360 | Chk : Nat; | |
5361 | OK : Boolean; | |
5362 | Ent : Entity_Id; | |
5363 | Ofs : Uint; | |
5364 | Ttyp : Entity_Id; | |
5365 | P : Node_Id; | |
5366 | ||
5367 | begin | |
675d6070 | 5368 | -- Return if unchecked type conversion with range check killed. In this |
a90bd866 | 5369 | -- case we never set the flag (that's what Kill_Range_Check is about). |
fbf5a39b AC |
5370 | |
5371 | if Nkind (N) = N_Unchecked_Type_Conversion | |
5372 | and then Kill_Range_Check (N) | |
70482933 RK |
5373 | then |
5374 | return; | |
fbf5a39b | 5375 | end if; |
70482933 | 5376 | |
c7532b2d AC |
5377 | -- Do not set range check flag if parent is assignment statement or |
5378 | -- object declaration with Suppress_Assignment_Checks flag set | |
5379 | ||
5380 | if Nkind_In (Parent (N), N_Assignment_Statement, N_Object_Declaration) | |
5381 | and then Suppress_Assignment_Checks (Parent (N)) | |
5382 | then | |
5383 | return; | |
5384 | end if; | |
5385 | ||
c064e066 RD |
5386 | -- Check for various cases where we should suppress the range check |
5387 | ||
5388 | -- No check if range checks suppressed for type of node | |
5389 | ||
637a41a5 | 5390 | if Present (Etype (N)) and then Range_Checks_Suppressed (Etype (N)) then |
c064e066 RD |
5391 | return; |
5392 | ||
5393 | -- No check if node is an entity name, and range checks are suppressed | |
5394 | -- for this entity, or for the type of this entity. | |
5395 | ||
5396 | elsif Is_Entity_Name (N) | |
5397 | and then (Range_Checks_Suppressed (Entity (N)) | |
637a41a5 | 5398 | or else Range_Checks_Suppressed (Etype (Entity (N)))) |
c064e066 RD |
5399 | then |
5400 | return; | |
5401 | ||
5402 | -- No checks if index of array, and index checks are suppressed for | |
5403 | -- the array object or the type of the array. | |
5404 | ||
5405 | elsif Nkind (Parent (N)) = N_Indexed_Component then | |
5406 | declare | |
5407 | Pref : constant Node_Id := Prefix (Parent (N)); | |
5408 | begin | |
5409 | if Is_Entity_Name (Pref) | |
5410 | and then Index_Checks_Suppressed (Entity (Pref)) | |
5411 | then | |
5412 | return; | |
5413 | elsif Index_Checks_Suppressed (Etype (Pref)) then | |
5414 | return; | |
5415 | end if; | |
5416 | end; | |
5417 | end if; | |
5418 | ||
fbf5a39b | 5419 | -- Debug trace output |
70482933 | 5420 | |
fbf5a39b AC |
5421 | if Debug_Flag_CC then |
5422 | w ("Enable_Range_Check for node ", Int (N)); | |
5423 | Write_Str (" Source location = "); | |
5424 | wl (Sloc (N)); | |
11b4899f | 5425 | pg (Union_Id (N)); |
fbf5a39b AC |
5426 | end if; |
5427 | ||
675d6070 TQ |
5428 | -- If not in optimizing mode, set flag and we are done. We are also done |
5429 | -- (and just set the flag) if the type is not a discrete type, since it | |
5430 | -- is not worth the effort to eliminate checks for other than discrete | |
5431 | -- types. In addition, we take this same path if we have stored the | |
5432 | -- maximum number of checks possible already (a very unlikely situation, | |
a90bd866 | 5433 | -- but we do not want to blow up). |
fbf5a39b AC |
5434 | |
5435 | if Optimization_Level = 0 | |
5436 | or else No (Etype (N)) | |
5437 | or else not Is_Discrete_Type (Etype (N)) | |
5438 | or else Num_Saved_Checks = Saved_Checks'Last | |
70482933 | 5439 | then |
11b4899f | 5440 | Activate_Range_Check (N); |
fbf5a39b AC |
5441 | |
5442 | if Debug_Flag_CC then | |
5443 | w ("Optimization off"); | |
5444 | end if; | |
5445 | ||
70482933 | 5446 | return; |
fbf5a39b | 5447 | end if; |
70482933 | 5448 | |
fbf5a39b | 5449 | -- Otherwise find out the target type |
70482933 | 5450 | |
fbf5a39b | 5451 | P := Parent (N); |
70482933 | 5452 | |
fbf5a39b AC |
5453 | -- For assignment, use left side subtype |
5454 | ||
5455 | if Nkind (P) = N_Assignment_Statement | |
5456 | and then Expression (P) = N | |
5457 | then | |
5458 | Ttyp := Etype (Name (P)); | |
5459 | ||
5460 | -- For indexed component, use subscript subtype | |
5461 | ||
5462 | elsif Nkind (P) = N_Indexed_Component then | |
5463 | declare | |
5464 | Atyp : Entity_Id; | |
5465 | Indx : Node_Id; | |
5466 | Subs : Node_Id; | |
5467 | ||
5468 | begin | |
5469 | Atyp := Etype (Prefix (P)); | |
5470 | ||
5471 | if Is_Access_Type (Atyp) then | |
5472 | Atyp := Designated_Type (Atyp); | |
d935a36e AC |
5473 | |
5474 | -- If the prefix is an access to an unconstrained array, | |
675d6070 TQ |
5475 | -- perform check unconditionally: it depends on the bounds of |
5476 | -- an object and we cannot currently recognize whether the test | |
5477 | -- may be redundant. | |
d935a36e AC |
5478 | |
5479 | if not Is_Constrained (Atyp) then | |
11b4899f | 5480 | Activate_Range_Check (N); |
d935a36e AC |
5481 | return; |
5482 | end if; | |
82c80734 | 5483 | |
675d6070 TQ |
5484 | -- Ditto if the prefix is an explicit dereference whose designated |
5485 | -- type is unconstrained. | |
82c80734 RD |
5486 | |
5487 | elsif Nkind (Prefix (P)) = N_Explicit_Dereference | |
5488 | and then not Is_Constrained (Atyp) | |
5489 | then | |
11b4899f | 5490 | Activate_Range_Check (N); |
82c80734 | 5491 | return; |
fbf5a39b AC |
5492 | end if; |
5493 | ||
5494 | Indx := First_Index (Atyp); | |
5495 | Subs := First (Expressions (P)); | |
5496 | loop | |
5497 | if Subs = N then | |
5498 | Ttyp := Etype (Indx); | |
5499 | exit; | |
5500 | end if; | |
5501 | ||
5502 | Next_Index (Indx); | |
5503 | Next (Subs); | |
5504 | end loop; | |
5505 | end; | |
5506 | ||
5507 | -- For now, ignore all other cases, they are not so interesting | |
5508 | ||
5509 | else | |
5510 | if Debug_Flag_CC then | |
5511 | w (" target type not found, flag set"); | |
5512 | end if; | |
5513 | ||
11b4899f | 5514 | Activate_Range_Check (N); |
fbf5a39b AC |
5515 | return; |
5516 | end if; | |
5517 | ||
5518 | -- Evaluate and check the expression | |
5519 | ||
5520 | Find_Check | |
5521 | (Expr => N, | |
5522 | Check_Type => 'R', | |
5523 | Target_Type => Ttyp, | |
5524 | Entry_OK => OK, | |
5525 | Check_Num => Chk, | |
5526 | Ent => Ent, | |
5527 | Ofs => Ofs); | |
5528 | ||
5529 | if Debug_Flag_CC then | |
5530 | w ("Called Find_Check"); | |
5531 | w ("Target_Typ = ", Int (Ttyp)); | |
5532 | w (" OK = ", OK); | |
5533 | ||
5534 | if OK then | |
5535 | w (" Check_Num = ", Chk); | |
5536 | w (" Ent = ", Int (Ent)); | |
5537 | Write_Str (" Ofs = "); | |
5538 | pid (Ofs); | |
5539 | end if; | |
5540 | end if; | |
5541 | ||
5542 | -- If check is not of form to optimize, then set flag and we are done | |
5543 | ||
5544 | if not OK then | |
5545 | if Debug_Flag_CC then | |
5546 | w (" expression not of optimizable type, flag set"); | |
5547 | end if; | |
5548 | ||
11b4899f | 5549 | Activate_Range_Check (N); |
fbf5a39b AC |
5550 | return; |
5551 | end if; | |
5552 | ||
5553 | -- If check is already performed, then return without setting flag | |
5554 | ||
5555 | if Chk /= 0 then | |
5556 | if Debug_Flag_CC then | |
5557 | w ("Check suppressed!"); | |
5558 | end if; | |
5559 | ||
5560 | return; | |
5561 | end if; | |
5562 | ||
5563 | -- Here we will make a new entry for the new check | |
5564 | ||
11b4899f | 5565 | Activate_Range_Check (N); |
fbf5a39b AC |
5566 | Num_Saved_Checks := Num_Saved_Checks + 1; |
5567 | Saved_Checks (Num_Saved_Checks) := | |
5568 | (Killed => False, | |
5569 | Entity => Ent, | |
5570 | Offset => Ofs, | |
5571 | Check_Type => 'R', | |
5572 | Target_Type => Ttyp); | |
5573 | ||
5574 | if Debug_Flag_CC then | |
5575 | w ("Make new entry, check number = ", Num_Saved_Checks); | |
5576 | w (" Entity = ", Int (Ent)); | |
5577 | Write_Str (" Offset = "); | |
5578 | pid (Ofs); | |
5579 | w (" Check_Type = R"); | |
5580 | w (" Target_Type = ", Int (Ttyp)); | |
11b4899f | 5581 | pg (Union_Id (Ttyp)); |
fbf5a39b AC |
5582 | end if; |
5583 | ||
675d6070 TQ |
5584 | -- If we get an exception, then something went wrong, probably because of |
5585 | -- an error in the structure of the tree due to an incorrect program. Or | |
5586 | -- it may be a bug in the optimization circuit. In either case the safest | |
5587 | -- thing is simply to set the check flag unconditionally. | |
fbf5a39b AC |
5588 | |
5589 | exception | |
5590 | when others => | |
11b4899f | 5591 | Activate_Range_Check (N); |
fbf5a39b AC |
5592 | |
5593 | if Debug_Flag_CC then | |
5594 | w (" exception occurred, range flag set"); | |
5595 | end if; | |
5596 | ||
5597 | return; | |
5598 | end Enable_Range_Check; | |
5599 | ||
5600 | ------------------ | |
5601 | -- Ensure_Valid -- | |
5602 | ------------------ | |
5603 | ||
5604 | procedure Ensure_Valid (Expr : Node_Id; Holes_OK : Boolean := False) is | |
5605 | Typ : constant Entity_Id := Etype (Expr); | |
5606 | ||
5607 | begin | |
5608 | -- Ignore call if we are not doing any validity checking | |
5609 | ||
5610 | if not Validity_Checks_On then | |
5611 | return; | |
5612 | ||
c064e066 | 5613 | -- Ignore call if range or validity checks suppressed on entity or type |
fbf5a39b | 5614 | |
c064e066 | 5615 | elsif Range_Or_Validity_Checks_Suppressed (Expr) then |
fbf5a39b AC |
5616 | return; |
5617 | ||
675d6070 TQ |
5618 | -- No check required if expression is from the expander, we assume the |
5619 | -- expander will generate whatever checks are needed. Note that this is | |
a90bd866 | 5620 | -- not just an optimization, it avoids infinite recursions. |
fbf5a39b AC |
5621 | |
5622 | -- Unchecked conversions must be checked, unless they are initialized | |
5623 | -- scalar values, as in a component assignment in an init proc. | |
5624 | ||
5625 | -- In addition, we force a check if Force_Validity_Checks is set | |
5626 | ||
5627 | elsif not Comes_From_Source (Expr) | |
5628 | and then not Force_Validity_Checks | |
5629 | and then (Nkind (Expr) /= N_Unchecked_Type_Conversion | |
5630 | or else Kill_Range_Check (Expr)) | |
5631 | then | |
5632 | return; | |
5633 | ||
5634 | -- No check required if expression is known to have valid value | |
5635 | ||
5636 | elsif Expr_Known_Valid (Expr) then | |
5637 | return; | |
5638 | ||
675d6070 TQ |
5639 | -- Ignore case of enumeration with holes where the flag is set not to |
5640 | -- worry about holes, since no special validity check is needed | |
fbf5a39b AC |
5641 | |
5642 | elsif Is_Enumeration_Type (Typ) | |
5643 | and then Has_Non_Standard_Rep (Typ) | |
5644 | and then Holes_OK | |
5645 | then | |
5646 | return; | |
5647 | ||
ddda9d0f | 5648 | -- No check required on the left-hand side of an assignment |
fbf5a39b AC |
5649 | |
5650 | elsif Nkind (Parent (Expr)) = N_Assignment_Statement | |
5651 | and then Expr = Name (Parent (Expr)) | |
5652 | then | |
5653 | return; | |
5654 | ||
308e6f3a | 5655 | -- No check on a universal real constant. The context will eventually |
f02b8bb8 RD |
5656 | -- convert it to a machine number for some target type, or report an |
5657 | -- illegality. | |
5658 | ||
5659 | elsif Nkind (Expr) = N_Real_Literal | |
5660 | and then Etype (Expr) = Universal_Real | |
5661 | then | |
5662 | return; | |
5663 | ||
308e6f3a | 5664 | -- If the expression denotes a component of a packed boolean array, |
c064e066 RD |
5665 | -- no possible check applies. We ignore the old ACATS chestnuts that |
5666 | -- involve Boolean range True..True. | |
5667 | ||
5668 | -- Note: validity checks are generated for expressions that yield a | |
5669 | -- scalar type, when it is possible to create a value that is outside of | |
5670 | -- the type. If this is a one-bit boolean no such value exists. This is | |
5671 | -- an optimization, and it also prevents compiler blowing up during the | |
5672 | -- elaboration of improperly expanded packed array references. | |
5673 | ||
5674 | elsif Nkind (Expr) = N_Indexed_Component | |
5675 | and then Is_Bit_Packed_Array (Etype (Prefix (Expr))) | |
5676 | and then Root_Type (Etype (Expr)) = Standard_Boolean | |
5677 | then | |
5678 | return; | |
5679 | ||
064f4527 TQ |
5680 | -- For an expression with actions, we want to insert the validity check |
5681 | -- on the final Expression. | |
5682 | ||
5683 | elsif Nkind (Expr) = N_Expression_With_Actions then | |
5684 | Ensure_Valid (Expression (Expr)); | |
5685 | return; | |
5686 | ||
fbf5a39b AC |
5687 | -- An annoying special case. If this is an out parameter of a scalar |
5688 | -- type, then the value is not going to be accessed, therefore it is | |
5689 | -- inappropriate to do any validity check at the call site. | |
5690 | ||
5691 | else | |
5692 | -- Only need to worry about scalar types | |
5693 | ||
5694 | if Is_Scalar_Type (Typ) then | |
70482933 RK |
5695 | declare |
5696 | P : Node_Id; | |
5697 | N : Node_Id; | |
5698 | E : Entity_Id; | |
5699 | F : Entity_Id; | |
5700 | A : Node_Id; | |
5701 | L : List_Id; | |
5702 | ||
5703 | begin | |
5704 | -- Find actual argument (which may be a parameter association) | |
5705 | -- and the parent of the actual argument (the call statement) | |
5706 | ||
5707 | N := Expr; | |
5708 | P := Parent (Expr); | |
5709 | ||
5710 | if Nkind (P) = N_Parameter_Association then | |
5711 | N := P; | |
5712 | P := Parent (N); | |
5713 | end if; | |
5714 | ||
675d6070 TQ |
5715 | -- Only need to worry if we are argument of a procedure call |
5716 | -- since functions don't have out parameters. If this is an | |
5717 | -- indirect or dispatching call, get signature from the | |
5718 | -- subprogram type. | |
70482933 RK |
5719 | |
5720 | if Nkind (P) = N_Procedure_Call_Statement then | |
5721 | L := Parameter_Associations (P); | |
fbf5a39b AC |
5722 | |
5723 | if Is_Entity_Name (Name (P)) then | |
5724 | E := Entity (Name (P)); | |
5725 | else | |
5726 | pragma Assert (Nkind (Name (P)) = N_Explicit_Dereference); | |
5727 | E := Etype (Name (P)); | |
5728 | end if; | |
70482933 | 5729 | |
675d6070 TQ |
5730 | -- Only need to worry if there are indeed actuals, and if |
5731 | -- this could be a procedure call, otherwise we cannot get a | |
5732 | -- match (either we are not an argument, or the mode of the | |
5733 | -- formal is not OUT). This test also filters out the | |
5734 | -- generic case. | |
70482933 | 5735 | |
637a41a5 AC |
5736 | if Is_Non_Empty_List (L) and then Is_Subprogram (E) then |
5737 | ||
675d6070 TQ |
5738 | -- This is the loop through parameters, looking for an |
5739 | -- OUT parameter for which we are the argument. | |
70482933 RK |
5740 | |
5741 | F := First_Formal (E); | |
5742 | A := First (L); | |
70482933 RK |
5743 | while Present (F) loop |
5744 | if Ekind (F) = E_Out_Parameter and then A = N then | |
5745 | return; | |
5746 | end if; | |
5747 | ||
5748 | Next_Formal (F); | |
5749 | Next (A); | |
5750 | end loop; | |
5751 | end if; | |
5752 | end if; | |
5753 | end; | |
5754 | end if; | |
5755 | end if; | |
5756 | ||
1c218ac3 | 5757 | -- If this is a boolean expression, only its elementary operands need |
46f52a47 AC |
5758 | -- checking: if they are valid, a boolean or short-circuit operation |
5759 | -- with them will be valid as well. | |
38afef28 AC |
5760 | |
5761 | if Base_Type (Typ) = Standard_Boolean | |
96d2756f | 5762 | and then |
1c218ac3 | 5763 | (Nkind (Expr) in N_Op or else Nkind (Expr) in N_Short_Circuit) |
38afef28 AC |
5764 | then |
5765 | return; | |
5766 | end if; | |
5767 | ||
c064e066 | 5768 | -- If we fall through, a validity check is required |
70482933 RK |
5769 | |
5770 | Insert_Valid_Check (Expr); | |
1c3340e6 RD |
5771 | |
5772 | if Is_Entity_Name (Expr) | |
5773 | and then Safe_To_Capture_Value (Expr, Entity (Expr)) | |
5774 | then | |
5775 | Set_Is_Known_Valid (Entity (Expr)); | |
5776 | end if; | |
70482933 RK |
5777 | end Ensure_Valid; |
5778 | ||
5779 | ---------------------- | |
5780 | -- Expr_Known_Valid -- | |
5781 | ---------------------- | |
5782 | ||
5783 | function Expr_Known_Valid (Expr : Node_Id) return Boolean is | |
5784 | Typ : constant Entity_Id := Etype (Expr); | |
5785 | ||
5786 | begin | |
675d6070 TQ |
5787 | -- Non-scalar types are always considered valid, since they never give |
5788 | -- rise to the issues of erroneous or bounded error behavior that are | |
5789 | -- the concern. In formal reference manual terms the notion of validity | |
5790 | -- only applies to scalar types. Note that even when packed arrays are | |
5791 | -- represented using modular types, they are still arrays semantically, | |
5792 | -- so they are also always valid (in particular, the unused bits can be | |
5793 | -- random rubbish without affecting the validity of the array value). | |
70482933 | 5794 | |
8ca597af | 5795 | if not Is_Scalar_Type (Typ) or else Is_Packed_Array_Impl_Type (Typ) then |
70482933 RK |
5796 | return True; |
5797 | ||
5798 | -- If no validity checking, then everything is considered valid | |
5799 | ||
5800 | elsif not Validity_Checks_On then | |
5801 | return True; | |
5802 | ||
5803 | -- Floating-point types are considered valid unless floating-point | |
5804 | -- validity checks have been specifically turned on. | |
5805 | ||
5806 | elsif Is_Floating_Point_Type (Typ) | |
5807 | and then not Validity_Check_Floating_Point | |
5808 | then | |
5809 | return True; | |
5810 | ||
675d6070 TQ |
5811 | -- If the expression is the value of an object that is known to be |
5812 | -- valid, then clearly the expression value itself is valid. | |
70482933 RK |
5813 | |
5814 | elsif Is_Entity_Name (Expr) | |
5815 | and then Is_Known_Valid (Entity (Expr)) | |
fba9ebfc AC |
5816 | |
5817 | -- Exclude volatile variables | |
5818 | ||
5819 | and then not Treat_As_Volatile (Entity (Expr)) | |
70482933 RK |
5820 | then |
5821 | return True; | |
5822 | ||
c064e066 RD |
5823 | -- References to discriminants are always considered valid. The value |
5824 | -- of a discriminant gets checked when the object is built. Within the | |
5825 | -- record, we consider it valid, and it is important to do so, since | |
5826 | -- otherwise we can try to generate bogus validity checks which | |
675d6070 TQ |
5827 | -- reference discriminants out of scope. Discriminants of concurrent |
5828 | -- types are excluded for the same reason. | |
c064e066 RD |
5829 | |
5830 | elsif Is_Entity_Name (Expr) | |
675d6070 | 5831 | and then Denotes_Discriminant (Expr, Check_Concurrent => True) |
c064e066 RD |
5832 | then |
5833 | return True; | |
5834 | ||
675d6070 TQ |
5835 | -- If the type is one for which all values are known valid, then we are |
5836 | -- sure that the value is valid except in the slightly odd case where | |
5837 | -- the expression is a reference to a variable whose size has been | |
5838 | -- explicitly set to a value greater than the object size. | |
70482933 RK |
5839 | |
5840 | elsif Is_Known_Valid (Typ) then | |
5841 | if Is_Entity_Name (Expr) | |
5842 | and then Ekind (Entity (Expr)) = E_Variable | |
5843 | and then Esize (Entity (Expr)) > Esize (Typ) | |
5844 | then | |
5845 | return False; | |
5846 | else | |
5847 | return True; | |
5848 | end if; | |
5849 | ||
5850 | -- Integer and character literals always have valid values, where | |
5851 | -- appropriate these will be range checked in any case. | |
5852 | ||
637a41a5 | 5853 | elsif Nkind_In (Expr, N_Integer_Literal, N_Character_Literal) then |
70482933 RK |
5854 | return True; |
5855 | ||
cf427f02 AC |
5856 | -- Real literals are assumed to be valid in VM targets |
5857 | ||
637a41a5 | 5858 | elsif VM_Target /= No_VM and then Nkind (Expr) = N_Real_Literal then |
cf427f02 AC |
5859 | return True; |
5860 | ||
70482933 RK |
5861 | -- If we have a type conversion or a qualification of a known valid |
5862 | -- value, then the result will always be valid. | |
5863 | ||
637a41a5 | 5864 | elsif Nkind_In (Expr, N_Type_Conversion, N_Qualified_Expression) then |
70482933 RK |
5865 | return Expr_Known_Valid (Expression (Expr)); |
5866 | ||
162c21d9 AC |
5867 | -- Case of expression is a non-floating-point operator. In this case we |
5868 | -- can assume the result is valid the generated code for the operator | |
5869 | -- will include whatever checks are needed (e.g. range checks) to ensure | |
5870 | -- validity. This assumption does not hold for the floating-point case, | |
5871 | -- since floating-point operators can generate Infinite or NaN results | |
5872 | -- which are considered invalid. | |
5873 | ||
5874 | -- Historical note: in older versions, the exemption of floating-point | |
5875 | -- types from this assumption was done only in cases where the parent | |
5876 | -- was an assignment, function call or parameter association. Presumably | |
5877 | -- the idea was that in other contexts, the result would be checked | |
5878 | -- elsewhere, but this list of cases was missing tests (at least the | |
5879 | -- N_Object_Declaration case, as shown by a reported missing validity | |
5880 | -- check), and it is not clear why function calls but not procedure | |
5881 | -- calls were tested for. It really seems more accurate and much | |
5882 | -- safer to recognize that expressions which are the result of a | |
5883 | -- floating-point operator can never be assumed to be valid. | |
5884 | ||
5885 | elsif Nkind (Expr) in N_Op and then not Is_Floating_Point_Type (Typ) then | |
5886 | return True; | |
28e4d64e | 5887 | |
675d6070 TQ |
5888 | -- The result of a membership test is always valid, since it is true or |
5889 | -- false, there are no other possibilities. | |
c064e066 RD |
5890 | |
5891 | elsif Nkind (Expr) in N_Membership_Test then | |
5892 | return True; | |
5893 | ||
70482933 RK |
5894 | -- For all other cases, we do not know the expression is valid |
5895 | ||
5896 | else | |
5897 | return False; | |
5898 | end if; | |
5899 | end Expr_Known_Valid; | |
5900 | ||
fbf5a39b AC |
5901 | ---------------- |
5902 | -- Find_Check -- | |
5903 | ---------------- | |
5904 | ||
5905 | procedure Find_Check | |
5906 | (Expr : Node_Id; | |
5907 | Check_Type : Character; | |
5908 | Target_Type : Entity_Id; | |
5909 | Entry_OK : out Boolean; | |
5910 | Check_Num : out Nat; | |
5911 | Ent : out Entity_Id; | |
5912 | Ofs : out Uint) | |
5913 | is | |
5914 | function Within_Range_Of | |
5915 | (Target_Type : Entity_Id; | |
6b6fcd3e | 5916 | Check_Type : Entity_Id) return Boolean; |
fbf5a39b AC |
5917 | -- Given a requirement for checking a range against Target_Type, and |
5918 | -- and a range Check_Type against which a check has already been made, | |
5919 | -- determines if the check against check type is sufficient to ensure | |
5920 | -- that no check against Target_Type is required. | |
5921 | ||
5922 | --------------------- | |
5923 | -- Within_Range_Of -- | |
5924 | --------------------- | |
5925 | ||
5926 | function Within_Range_Of | |
5927 | (Target_Type : Entity_Id; | |
6b6fcd3e | 5928 | Check_Type : Entity_Id) return Boolean |
fbf5a39b AC |
5929 | is |
5930 | begin | |
5931 | if Target_Type = Check_Type then | |
5932 | return True; | |
5933 | ||
5934 | else | |
5935 | declare | |
5936 | Tlo : constant Node_Id := Type_Low_Bound (Target_Type); | |
5937 | Thi : constant Node_Id := Type_High_Bound (Target_Type); | |
5938 | Clo : constant Node_Id := Type_Low_Bound (Check_Type); | |
5939 | Chi : constant Node_Id := Type_High_Bound (Check_Type); | |
5940 | ||
5941 | begin | |
5942 | if (Tlo = Clo | |
5943 | or else (Compile_Time_Known_Value (Tlo) | |
5944 | and then | |
5945 | Compile_Time_Known_Value (Clo) | |
5946 | and then | |
5947 | Expr_Value (Clo) >= Expr_Value (Tlo))) | |
5948 | and then | |
5949 | (Thi = Chi | |
5950 | or else (Compile_Time_Known_Value (Thi) | |
5951 | and then | |
5952 | Compile_Time_Known_Value (Chi) | |
5953 | and then | |
5954 | Expr_Value (Chi) <= Expr_Value (Clo))) | |
5955 | then | |
5956 | return True; | |
5957 | else | |
5958 | return False; | |
5959 | end if; | |
5960 | end; | |
5961 | end if; | |
5962 | end Within_Range_Of; | |
5963 | ||
5964 | -- Start of processing for Find_Check | |
5965 | ||
5966 | begin | |
75ba322d | 5967 | -- Establish default, in case no entry is found |
fbf5a39b AC |
5968 | |
5969 | Check_Num := 0; | |
5970 | ||
5971 | -- Case of expression is simple entity reference | |
5972 | ||
5973 | if Is_Entity_Name (Expr) then | |
5974 | Ent := Entity (Expr); | |
5975 | Ofs := Uint_0; | |
5976 | ||
5977 | -- Case of expression is entity + known constant | |
5978 | ||
5979 | elsif Nkind (Expr) = N_Op_Add | |
5980 | and then Compile_Time_Known_Value (Right_Opnd (Expr)) | |
5981 | and then Is_Entity_Name (Left_Opnd (Expr)) | |
5982 | then | |
5983 | Ent := Entity (Left_Opnd (Expr)); | |
5984 | Ofs := Expr_Value (Right_Opnd (Expr)); | |
5985 | ||
5986 | -- Case of expression is entity - known constant | |
5987 | ||
5988 | elsif Nkind (Expr) = N_Op_Subtract | |
5989 | and then Compile_Time_Known_Value (Right_Opnd (Expr)) | |
5990 | and then Is_Entity_Name (Left_Opnd (Expr)) | |
5991 | then | |
5992 | Ent := Entity (Left_Opnd (Expr)); | |
5993 | Ofs := UI_Negate (Expr_Value (Right_Opnd (Expr))); | |
5994 | ||
5995 | -- Any other expression is not of the right form | |
5996 | ||
5997 | else | |
5998 | Ent := Empty; | |
5999 | Ofs := Uint_0; | |
6000 | Entry_OK := False; | |
6001 | return; | |
6002 | end if; | |
6003 | ||
675d6070 TQ |
6004 | -- Come here with expression of appropriate form, check if entity is an |
6005 | -- appropriate one for our purposes. | |
fbf5a39b AC |
6006 | |
6007 | if (Ekind (Ent) = E_Variable | |
f2cbd970 | 6008 | or else Is_Constant_Object (Ent)) |
fbf5a39b AC |
6009 | and then not Is_Library_Level_Entity (Ent) |
6010 | then | |
6011 | Entry_OK := True; | |
6012 | else | |
6013 | Entry_OK := False; | |
6014 | return; | |
6015 | end if; | |
6016 | ||
6017 | -- See if there is matching check already | |
6018 | ||
6019 | for J in reverse 1 .. Num_Saved_Checks loop | |
6020 | declare | |
6021 | SC : Saved_Check renames Saved_Checks (J); | |
fbf5a39b AC |
6022 | begin |
6023 | if SC.Killed = False | |
6024 | and then SC.Entity = Ent | |
6025 | and then SC.Offset = Ofs | |
6026 | and then SC.Check_Type = Check_Type | |
6027 | and then Within_Range_Of (Target_Type, SC.Target_Type) | |
6028 | then | |
6029 | Check_Num := J; | |
6030 | return; | |
6031 | end if; | |
6032 | end; | |
6033 | end loop; | |
6034 | ||
6035 | -- If we fall through entry was not found | |
6036 | ||
fbf5a39b AC |
6037 | return; |
6038 | end Find_Check; | |
6039 | ||
6040 | --------------------------------- | |
6041 | -- Generate_Discriminant_Check -- | |
6042 | --------------------------------- | |
6043 | ||
6044 | -- Note: the code for this procedure is derived from the | |
675d6070 | 6045 | -- Emit_Discriminant_Check Routine in trans.c. |
fbf5a39b AC |
6046 | |
6047 | procedure Generate_Discriminant_Check (N : Node_Id) is | |
6048 | Loc : constant Source_Ptr := Sloc (N); | |
6049 | Pref : constant Node_Id := Prefix (N); | |
6050 | Sel : constant Node_Id := Selector_Name (N); | |
6051 | ||
6052 | Orig_Comp : constant Entity_Id := | |
15f0f591 | 6053 | Original_Record_Component (Entity (Sel)); |
fbf5a39b AC |
6054 | -- The original component to be checked |
6055 | ||
6056 | Discr_Fct : constant Entity_Id := | |
15f0f591 | 6057 | Discriminant_Checking_Func (Orig_Comp); |
fbf5a39b AC |
6058 | -- The discriminant checking function |
6059 | ||
6060 | Discr : Entity_Id; | |
6061 | -- One discriminant to be checked in the type | |
6062 | ||
6063 | Real_Discr : Entity_Id; | |
6064 | -- Actual discriminant in the call | |
6065 | ||
6066 | Pref_Type : Entity_Id; | |
6067 | -- Type of relevant prefix (ignoring private/access stuff) | |
6068 | ||
6069 | Args : List_Id; | |
6070 | -- List of arguments for function call | |
6071 | ||
6072 | Formal : Entity_Id; | |
675d6070 TQ |
6073 | -- Keep track of the formal corresponding to the actual we build for |
6074 | -- each discriminant, in order to be able to perform the necessary type | |
6075 | -- conversions. | |
fbf5a39b AC |
6076 | |
6077 | Scomp : Node_Id; | |
6078 | -- Selected component reference for checking function argument | |
6079 | ||
6080 | begin | |
6081 | Pref_Type := Etype (Pref); | |
6082 | ||
6083 | -- Force evaluation of the prefix, so that it does not get evaluated | |
6084 | -- twice (once for the check, once for the actual reference). Such a | |
637a41a5 AC |
6085 | -- double evaluation is always a potential source of inefficiency, and |
6086 | -- is functionally incorrect in the volatile case, or when the prefix | |
6087 | -- may have side-effects. A non-volatile entity or a component of a | |
6088 | -- non-volatile entity requires no evaluation. | |
fbf5a39b AC |
6089 | |
6090 | if Is_Entity_Name (Pref) then | |
6091 | if Treat_As_Volatile (Entity (Pref)) then | |
6092 | Force_Evaluation (Pref, Name_Req => True); | |
6093 | end if; | |
6094 | ||
6095 | elsif Treat_As_Volatile (Etype (Pref)) then | |
637a41a5 | 6096 | Force_Evaluation (Pref, Name_Req => True); |
fbf5a39b AC |
6097 | |
6098 | elsif Nkind (Pref) = N_Selected_Component | |
6099 | and then Is_Entity_Name (Prefix (Pref)) | |
6100 | then | |
6101 | null; | |
6102 | ||
6103 | else | |
6104 | Force_Evaluation (Pref, Name_Req => True); | |
6105 | end if; | |
6106 | ||
6107 | -- For a tagged type, use the scope of the original component to | |
6108 | -- obtain the type, because ??? | |
6109 | ||
6110 | if Is_Tagged_Type (Scope (Orig_Comp)) then | |
6111 | Pref_Type := Scope (Orig_Comp); | |
6112 | ||
675d6070 TQ |
6113 | -- For an untagged derived type, use the discriminants of the parent |
6114 | -- which have been renamed in the derivation, possibly by a one-to-many | |
1fb63e89 | 6115 | -- discriminant constraint. For untagged type, initially get the Etype |
675d6070 | 6116 | -- of the prefix |
fbf5a39b AC |
6117 | |
6118 | else | |
6119 | if Is_Derived_Type (Pref_Type) | |
6120 | and then Number_Discriminants (Pref_Type) /= | |
6121 | Number_Discriminants (Etype (Base_Type (Pref_Type))) | |
6122 | then | |
6123 | Pref_Type := Etype (Base_Type (Pref_Type)); | |
6124 | end if; | |
6125 | end if; | |
6126 | ||
6127 | -- We definitely should have a checking function, This routine should | |
6128 | -- not be called if no discriminant checking function is present. | |
6129 | ||
6130 | pragma Assert (Present (Discr_Fct)); | |
6131 | ||
6132 | -- Create the list of the actual parameters for the call. This list | |
6133 | -- is the list of the discriminant fields of the record expression to | |
6134 | -- be discriminant checked. | |
6135 | ||
6136 | Args := New_List; | |
6137 | Formal := First_Formal (Discr_Fct); | |
6138 | Discr := First_Discriminant (Pref_Type); | |
6139 | while Present (Discr) loop | |
6140 | ||
6141 | -- If we have a corresponding discriminant field, and a parent | |
6142 | -- subtype is present, then we want to use the corresponding | |
6143 | -- discriminant since this is the one with the useful value. | |
6144 | ||
6145 | if Present (Corresponding_Discriminant (Discr)) | |
6146 | and then Ekind (Pref_Type) = E_Record_Type | |
6147 | and then Present (Parent_Subtype (Pref_Type)) | |
6148 | then | |
6149 | Real_Discr := Corresponding_Discriminant (Discr); | |
6150 | else | |
6151 | Real_Discr := Discr; | |
6152 | end if; | |
6153 | ||
6154 | -- Construct the reference to the discriminant | |
6155 | ||
6156 | Scomp := | |
6157 | Make_Selected_Component (Loc, | |
6158 | Prefix => | |
6159 | Unchecked_Convert_To (Pref_Type, | |
6160 | Duplicate_Subexpr (Pref)), | |
6161 | Selector_Name => New_Occurrence_Of (Real_Discr, Loc)); | |
6162 | ||
6163 | -- Manually analyze and resolve this selected component. We really | |
6164 | -- want it just as it appears above, and do not want the expander | |
675d6070 TQ |
6165 | -- playing discriminal games etc with this reference. Then we append |
6166 | -- the argument to the list we are gathering. | |
fbf5a39b AC |
6167 | |
6168 | Set_Etype (Scomp, Etype (Real_Discr)); | |
6169 | Set_Analyzed (Scomp, True); | |
6170 | Append_To (Args, Convert_To (Etype (Formal), Scomp)); | |
6171 | ||
6172 | Next_Formal_With_Extras (Formal); | |
6173 | Next_Discriminant (Discr); | |
6174 | end loop; | |
6175 | ||
6176 | -- Now build and insert the call | |
6177 | ||
6178 | Insert_Action (N, | |
6179 | Make_Raise_Constraint_Error (Loc, | |
6180 | Condition => | |
6181 | Make_Function_Call (Loc, | |
637a41a5 | 6182 | Name => New_Occurrence_Of (Discr_Fct, Loc), |
fbf5a39b AC |
6183 | Parameter_Associations => Args), |
6184 | Reason => CE_Discriminant_Check_Failed)); | |
6185 | end Generate_Discriminant_Check; | |
6186 | ||
15ce9ca2 AC |
6187 | --------------------------- |
6188 | -- Generate_Index_Checks -- | |
6189 | --------------------------- | |
fbf5a39b AC |
6190 | |
6191 | procedure Generate_Index_Checks (N : Node_Id) is | |
4230bdb7 AC |
6192 | |
6193 | function Entity_Of_Prefix return Entity_Id; | |
6194 | -- Returns the entity of the prefix of N (or Empty if not found) | |
6195 | ||
8ed68165 AC |
6196 | ---------------------- |
6197 | -- Entity_Of_Prefix -- | |
6198 | ---------------------- | |
6199 | ||
4230bdb7 | 6200 | function Entity_Of_Prefix return Entity_Id is |
0d53d36b AC |
6201 | P : Node_Id; |
6202 | ||
4230bdb7 | 6203 | begin |
0d53d36b | 6204 | P := Prefix (N); |
4230bdb7 AC |
6205 | while not Is_Entity_Name (P) loop |
6206 | if not Nkind_In (P, N_Selected_Component, | |
6207 | N_Indexed_Component) | |
6208 | then | |
6209 | return Empty; | |
6210 | end if; | |
6211 | ||
6212 | P := Prefix (P); | |
6213 | end loop; | |
6214 | ||
6215 | return Entity (P); | |
6216 | end Entity_Of_Prefix; | |
6217 | ||
6218 | -- Local variables | |
6219 | ||
6220 | Loc : constant Source_Ptr := Sloc (N); | |
6221 | A : constant Node_Id := Prefix (N); | |
6222 | A_Ent : constant Entity_Id := Entity_Of_Prefix; | |
6223 | Sub : Node_Id; | |
fbf5a39b | 6224 | |
8ed68165 AC |
6225 | -- Start of processing for Generate_Index_Checks |
6226 | ||
fbf5a39b | 6227 | begin |
4230bdb7 AC |
6228 | -- Ignore call if the prefix is not an array since we have a serious |
6229 | -- error in the sources. Ignore it also if index checks are suppressed | |
6230 | -- for array object or type. | |
c064e066 | 6231 | |
4230bdb7 | 6232 | if not Is_Array_Type (Etype (A)) |
637a41a5 | 6233 | or else (Present (A_Ent) and then Index_Checks_Suppressed (A_Ent)) |
c064e066 RD |
6234 | or else Index_Checks_Suppressed (Etype (A)) |
6235 | then | |
6236 | return; | |
3a3af4c3 AC |
6237 | |
6238 | -- The indexed component we are dealing with contains 'Loop_Entry in its | |
6239 | -- prefix. This case arises when analysis has determined that constructs | |
6240 | -- such as | |
6241 | ||
6242 | -- Prefix'Loop_Entry (Expr) | |
6243 | -- Prefix'Loop_Entry (Expr1, Expr2, ... ExprN) | |
6244 | ||
6245 | -- require rewriting for error detection purposes. A side effect of this | |
6246 | -- action is the generation of index checks that mention 'Loop_Entry. | |
6247 | -- Delay the generation of the check until 'Loop_Entry has been properly | |
6248 | -- expanded. This is done in Expand_Loop_Entry_Attributes. | |
6249 | ||
6250 | elsif Nkind (Prefix (N)) = N_Attribute_Reference | |
6251 | and then Attribute_Name (Prefix (N)) = Name_Loop_Entry | |
6252 | then | |
6253 | return; | |
c064e066 RD |
6254 | end if; |
6255 | ||
4230bdb7 AC |
6256 | -- Generate a raise of constraint error with the appropriate reason and |
6257 | -- a condition of the form: | |
6258 | ||
8ed68165 | 6259 | -- Base_Type (Sub) not in Array'Range (Subscript) |
4230bdb7 AC |
6260 | |
6261 | -- Note that the reason we generate the conversion to the base type here | |
6262 | -- is that we definitely want the range check to take place, even if it | |
6263 | -- looks like the subtype is OK. Optimization considerations that allow | |
6264 | -- us to omit the check have already been taken into account in the | |
6265 | -- setting of the Do_Range_Check flag earlier on. | |
c064e066 | 6266 | |
fbf5a39b | 6267 | Sub := First (Expressions (N)); |
4230bdb7 AC |
6268 | |
6269 | -- Handle string literals | |
6270 | ||
6271 | if Ekind (Etype (A)) = E_String_Literal_Subtype then | |
fbf5a39b AC |
6272 | if Do_Range_Check (Sub) then |
6273 | Set_Do_Range_Check (Sub, False); | |
6274 | ||
4230bdb7 AC |
6275 | -- For string literals we obtain the bounds of the string from the |
6276 | -- associated subtype. | |
fbf5a39b | 6277 | |
4230bdb7 | 6278 | Insert_Action (N, |
d7a44b14 AC |
6279 | Make_Raise_Constraint_Error (Loc, |
6280 | Condition => | |
6281 | Make_Not_In (Loc, | |
6282 | Left_Opnd => | |
6283 | Convert_To (Base_Type (Etype (Sub)), | |
6284 | Duplicate_Subexpr_Move_Checks (Sub)), | |
6285 | Right_Opnd => | |
6286 | Make_Attribute_Reference (Loc, | |
e4494292 | 6287 | Prefix => New_Occurrence_Of (Etype (A), Loc), |
d7a44b14 AC |
6288 | Attribute_Name => Name_Range)), |
6289 | Reason => CE_Index_Check_Failed)); | |
4230bdb7 | 6290 | end if; |
fbf5a39b | 6291 | |
4230bdb7 | 6292 | -- General case |
fbf5a39b | 6293 | |
4230bdb7 AC |
6294 | else |
6295 | declare | |
6296 | A_Idx : Node_Id := Empty; | |
6297 | A_Range : Node_Id; | |
6298 | Ind : Nat; | |
6299 | Num : List_Id; | |
6300 | Range_N : Node_Id; | |
fbf5a39b | 6301 | |
4230bdb7 AC |
6302 | begin |
6303 | A_Idx := First_Index (Etype (A)); | |
6304 | Ind := 1; | |
6305 | while Present (Sub) loop | |
6306 | if Do_Range_Check (Sub) then | |
6307 | Set_Do_Range_Check (Sub, False); | |
fbf5a39b | 6308 | |
4230bdb7 AC |
6309 | -- Force evaluation except for the case of a simple name of |
6310 | -- a non-volatile entity. | |
fbf5a39b | 6311 | |
4230bdb7 AC |
6312 | if not Is_Entity_Name (Sub) |
6313 | or else Treat_As_Volatile (Entity (Sub)) | |
6314 | then | |
6315 | Force_Evaluation (Sub); | |
6316 | end if; | |
fbf5a39b | 6317 | |
4230bdb7 AC |
6318 | if Nkind (A_Idx) = N_Range then |
6319 | A_Range := A_Idx; | |
6320 | ||
6321 | elsif Nkind (A_Idx) = N_Identifier | |
6322 | or else Nkind (A_Idx) = N_Expanded_Name | |
6323 | then | |
6324 | A_Range := Scalar_Range (Entity (A_Idx)); | |
6325 | ||
6326 | else pragma Assert (Nkind (A_Idx) = N_Subtype_Indication); | |
6327 | A_Range := Range_Expression (Constraint (A_Idx)); | |
6328 | end if; | |
6329 | ||
6330 | -- For array objects with constant bounds we can generate | |
6331 | -- the index check using the bounds of the type of the index | |
6332 | ||
6333 | if Present (A_Ent) | |
6334 | and then Ekind (A_Ent) = E_Variable | |
6335 | and then Is_Constant_Bound (Low_Bound (A_Range)) | |
6336 | and then Is_Constant_Bound (High_Bound (A_Range)) | |
6337 | then | |
6338 | Range_N := | |
6339 | Make_Attribute_Reference (Loc, | |
8ed68165 | 6340 | Prefix => |
e4494292 | 6341 | New_Occurrence_Of (Etype (A_Idx), Loc), |
4230bdb7 AC |
6342 | Attribute_Name => Name_Range); |
6343 | ||
6344 | -- For arrays with non-constant bounds we cannot generate | |
6345 | -- the index check using the bounds of the type of the index | |
6346 | -- since it may reference discriminants of some enclosing | |
6347 | -- type. We obtain the bounds directly from the prefix | |
6348 | -- object. | |
6349 | ||
6350 | else | |
6351 | if Ind = 1 then | |
6352 | Num := No_List; | |
6353 | else | |
6354 | Num := New_List (Make_Integer_Literal (Loc, Ind)); | |
6355 | end if; | |
6356 | ||
6357 | Range_N := | |
6358 | Make_Attribute_Reference (Loc, | |
6359 | Prefix => | |
6360 | Duplicate_Subexpr_Move_Checks (A, Name_Req => True), | |
6361 | Attribute_Name => Name_Range, | |
6362 | Expressions => Num); | |
6363 | end if; | |
6364 | ||
6365 | Insert_Action (N, | |
d7a44b14 AC |
6366 | Make_Raise_Constraint_Error (Loc, |
6367 | Condition => | |
6368 | Make_Not_In (Loc, | |
6369 | Left_Opnd => | |
6370 | Convert_To (Base_Type (Etype (Sub)), | |
6371 | Duplicate_Subexpr_Move_Checks (Sub)), | |
6372 | Right_Opnd => Range_N), | |
6373 | Reason => CE_Index_Check_Failed)); | |
4230bdb7 AC |
6374 | end if; |
6375 | ||
6376 | A_Idx := Next_Index (A_Idx); | |
6377 | Ind := Ind + 1; | |
6378 | Next (Sub); | |
6379 | end loop; | |
6380 | end; | |
6381 | end if; | |
fbf5a39b AC |
6382 | end Generate_Index_Checks; |
6383 | ||
6384 | -------------------------- | |
6385 | -- Generate_Range_Check -- | |
6386 | -------------------------- | |
6387 | ||
6388 | procedure Generate_Range_Check | |
6389 | (N : Node_Id; | |
6390 | Target_Type : Entity_Id; | |
6391 | Reason : RT_Exception_Code) | |
6392 | is | |
6393 | Loc : constant Source_Ptr := Sloc (N); | |
6394 | Source_Type : constant Entity_Id := Etype (N); | |
6395 | Source_Base_Type : constant Entity_Id := Base_Type (Source_Type); | |
6396 | Target_Base_Type : constant Entity_Id := Base_Type (Target_Type); | |
6397 | ||
f5655e4a AC |
6398 | procedure Convert_And_Check_Range; |
6399 | -- Convert the conversion operand to the target base type and save in | |
6400 | -- a temporary. Then check the converted value against the range of the | |
6401 | -- target subtype. | |
6402 | ||
b6621d10 AC |
6403 | ----------------------------- |
6404 | -- Convert_And_Check_Range -- | |
6405 | ----------------------------- | |
f5655e4a | 6406 | |
b6621d10 | 6407 | procedure Convert_And_Check_Range is |
f5655e4a AC |
6408 | Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', N); |
6409 | ||
b6621d10 AC |
6410 | begin |
6411 | -- We make a temporary to hold the value of the converted value | |
6412 | -- (converted to the base type), and then do the test against this | |
6413 | -- temporary. The conversion itself is replaced by an occurrence of | |
6414 | -- Tnn and followed by the explicit range check. Note that checks | |
6415 | -- are suppressed for this code, since we don't want a recursive | |
f5655e4a AC |
6416 | -- range check popping up. |
6417 | ||
b6621d10 AC |
6418 | -- Tnn : constant Target_Base_Type := Target_Base_Type (N); |
6419 | -- [constraint_error when Tnn not in Target_Type] | |
6420 | ||
f5655e4a AC |
6421 | Insert_Actions (N, New_List ( |
6422 | Make_Object_Declaration (Loc, | |
6423 | Defining_Identifier => Tnn, | |
6424 | Object_Definition => New_Occurrence_Of (Target_Base_Type, Loc), | |
6425 | Constant_Present => True, | |
6426 | Expression => | |
6427 | Make_Type_Conversion (Loc, | |
6428 | Subtype_Mark => New_Occurrence_Of (Target_Base_Type, Loc), | |
6429 | Expression => Duplicate_Subexpr (N))), | |
6430 | ||
6431 | Make_Raise_Constraint_Error (Loc, | |
6432 | Condition => | |
6433 | Make_Not_In (Loc, | |
6434 | Left_Opnd => New_Occurrence_Of (Tnn, Loc), | |
6435 | Right_Opnd => New_Occurrence_Of (Target_Type, Loc)), | |
6436 | Reason => Reason)), | |
6437 | Suppress => All_Checks); | |
6438 | ||
6439 | Rewrite (N, New_Occurrence_Of (Tnn, Loc)); | |
6440 | ||
6441 | -- Set the type of N, because the declaration for Tnn might not | |
6442 | -- be analyzed yet, as is the case if N appears within a record | |
6443 | -- declaration, as a discriminant constraint or expression. | |
6444 | ||
6445 | Set_Etype (N, Target_Base_Type); | |
6446 | end Convert_And_Check_Range; | |
6447 | ||
6448 | -- Start of processing for Generate_Range_Check | |
6449 | ||
fbf5a39b | 6450 | begin |
675d6070 TQ |
6451 | -- First special case, if the source type is already within the range |
6452 | -- of the target type, then no check is needed (probably we should have | |
6453 | -- stopped Do_Range_Check from being set in the first place, but better | |
edab6088 | 6454 | -- late than never in preventing junk code and junk flag settings. |
fbf5a39b | 6455 | |
c27f2f15 | 6456 | if In_Subrange_Of (Source_Type, Target_Type) |
347c766a RD |
6457 | |
6458 | -- We do NOT apply this if the source node is a literal, since in this | |
6459 | -- case the literal has already been labeled as having the subtype of | |
6460 | -- the target. | |
6461 | ||
fbf5a39b | 6462 | and then not |
347c766a | 6463 | (Nkind_In (N, N_Integer_Literal, N_Real_Literal, N_Character_Literal) |
fbf5a39b | 6464 | or else |
347c766a RD |
6465 | (Is_Entity_Name (N) |
6466 | and then Ekind (Entity (N)) = E_Enumeration_Literal)) | |
fbf5a39b | 6467 | then |
edab6088 | 6468 | Set_Do_Range_Check (N, False); |
fbf5a39b AC |
6469 | return; |
6470 | end if; | |
6471 | ||
edab6088 RD |
6472 | -- Here a check is needed. If the expander is not active, or if we are |
6473 | -- in GNATProve mode, then simply set the Do_Range_Check flag and we | |
6474 | -- are done. In both these cases, we just want to see the range check | |
6475 | -- flag set, we do not want to generate the explicit range check code. | |
6476 | ||
6477 | if GNATprove_Mode or else not Expander_Active then | |
6478 | Set_Do_Range_Check (N, True); | |
6479 | return; | |
6480 | end if; | |
6481 | ||
6482 | -- Here we will generate an explicit range check, so we don't want to | |
6483 | -- set the Do_Range check flag, since the range check is taken care of | |
6484 | -- by the code we will generate. | |
6485 | ||
6486 | Set_Do_Range_Check (N, False); | |
6487 | ||
6488 | -- Force evaluation of the node, so that it does not get evaluated twice | |
6489 | -- (once for the check, once for the actual reference). Such a double | |
6490 | -- evaluation is always a potential source of inefficiency, and is | |
6491 | -- functionally incorrect in the volatile case. | |
fbf5a39b | 6492 | |
347c766a | 6493 | if not Is_Entity_Name (N) or else Treat_As_Volatile (Entity (N)) then |
fbf5a39b AC |
6494 | Force_Evaluation (N); |
6495 | end if; | |
6496 | ||
675d6070 TQ |
6497 | -- The easiest case is when Source_Base_Type and Target_Base_Type are |
6498 | -- the same since in this case we can simply do a direct check of the | |
6499 | -- value of N against the bounds of Target_Type. | |
fbf5a39b AC |
6500 | |
6501 | -- [constraint_error when N not in Target_Type] | |
6502 | ||
6503 | -- Note: this is by far the most common case, for example all cases of | |
6504 | -- checks on the RHS of assignments are in this category, but not all | |
6505 | -- cases are like this. Notably conversions can involve two types. | |
6506 | ||
6507 | if Source_Base_Type = Target_Base_Type then | |
96e90ac1 RD |
6508 | |
6509 | -- Insert the explicit range check. Note that we suppress checks for | |
6510 | -- this code, since we don't want a recursive range check popping up. | |
6511 | ||
fbf5a39b AC |
6512 | Insert_Action (N, |
6513 | Make_Raise_Constraint_Error (Loc, | |
6514 | Condition => | |
6515 | Make_Not_In (Loc, | |
6516 | Left_Opnd => Duplicate_Subexpr (N), | |
6517 | Right_Opnd => New_Occurrence_Of (Target_Type, Loc)), | |
96e90ac1 RD |
6518 | Reason => Reason), |
6519 | Suppress => All_Checks); | |
fbf5a39b AC |
6520 | |
6521 | -- Next test for the case where the target type is within the bounds | |
6522 | -- of the base type of the source type, since in this case we can | |
6523 | -- simply convert these bounds to the base type of T to do the test. | |
6524 | ||
6525 | -- [constraint_error when N not in | |
6526 | -- Source_Base_Type (Target_Type'First) | |
6527 | -- .. | |
6528 | -- Source_Base_Type(Target_Type'Last))] | |
6529 | ||
ddda9d0f | 6530 | -- The conversions will always work and need no check |
fbf5a39b | 6531 | |
d79e621a GD |
6532 | -- Unchecked_Convert_To is used instead of Convert_To to handle the case |
6533 | -- of converting from an enumeration value to an integer type, such as | |
6534 | -- occurs for the case of generating a range check on Enum'Val(Exp) | |
6535 | -- (which used to be handled by gigi). This is OK, since the conversion | |
6536 | -- itself does not require a check. | |
6537 | ||
c27f2f15 | 6538 | elsif In_Subrange_Of (Target_Type, Source_Base_Type) then |
96e90ac1 RD |
6539 | |
6540 | -- Insert the explicit range check. Note that we suppress checks for | |
6541 | -- this code, since we don't want a recursive range check popping up. | |
6542 | ||
f5655e4a AC |
6543 | if Is_Discrete_Type (Source_Base_Type) |
6544 | and then | |
6545 | Is_Discrete_Type (Target_Base_Type) | |
6546 | then | |
6547 | Insert_Action (N, | |
6548 | Make_Raise_Constraint_Error (Loc, | |
6549 | Condition => | |
6550 | Make_Not_In (Loc, | |
6551 | Left_Opnd => Duplicate_Subexpr (N), | |
6552 | ||
6553 | Right_Opnd => | |
6554 | Make_Range (Loc, | |
6555 | Low_Bound => | |
6556 | Unchecked_Convert_To (Source_Base_Type, | |
6557 | Make_Attribute_Reference (Loc, | |
6558 | Prefix => | |
6559 | New_Occurrence_Of (Target_Type, Loc), | |
6560 | Attribute_Name => Name_First)), | |
6561 | ||
6562 | High_Bound => | |
6563 | Unchecked_Convert_To (Source_Base_Type, | |
6564 | Make_Attribute_Reference (Loc, | |
6565 | Prefix => | |
6566 | New_Occurrence_Of (Target_Type, Loc), | |
6567 | Attribute_Name => Name_Last)))), | |
6568 | Reason => Reason), | |
6569 | Suppress => All_Checks); | |
fbf5a39b | 6570 | |
f5655e4a AC |
6571 | -- For conversions involving at least one type that is not discrete, |
6572 | -- first convert to target type and then generate the range check. | |
6573 | -- This avoids problems with values that are close to a bound of the | |
6574 | -- target type that would fail a range check when done in a larger | |
6575 | -- source type before converting but would pass if converted with | |
6576 | -- rounding and then checked (such as in float-to-float conversions). | |
6577 | ||
6578 | else | |
6579 | Convert_And_Check_Range; | |
6580 | end if; | |
fbf5a39b | 6581 | |
675d6070 TQ |
6582 | -- Note that at this stage we now that the Target_Base_Type is not in |
6583 | -- the range of the Source_Base_Type (since even the Target_Type itself | |
6584 | -- is not in this range). It could still be the case that Source_Type is | |
6585 | -- in range of the target base type since we have not checked that case. | |
fbf5a39b | 6586 | |
675d6070 TQ |
6587 | -- If that is the case, we can freely convert the source to the target, |
6588 | -- and then test the target result against the bounds. | |
fbf5a39b | 6589 | |
c27f2f15 | 6590 | elsif In_Subrange_Of (Source_Type, Target_Base_Type) then |
f5655e4a | 6591 | Convert_And_Check_Range; |
fbf5a39b AC |
6592 | |
6593 | -- At this stage, we know that we have two scalar types, which are | |
6594 | -- directly convertible, and where neither scalar type has a base | |
6595 | -- range that is in the range of the other scalar type. | |
6596 | ||
6597 | -- The only way this can happen is with a signed and unsigned type. | |
6598 | -- So test for these two cases: | |
6599 | ||
6600 | else | |
6601 | -- Case of the source is unsigned and the target is signed | |
6602 | ||
6603 | if Is_Unsigned_Type (Source_Base_Type) | |
6604 | and then not Is_Unsigned_Type (Target_Base_Type) | |
6605 | then | |
6606 | -- If the source is unsigned and the target is signed, then we | |
6607 | -- know that the source is not shorter than the target (otherwise | |
6608 | -- the source base type would be in the target base type range). | |
6609 | ||
675d6070 TQ |
6610 | -- In other words, the unsigned type is either the same size as |
6611 | -- the target, or it is larger. It cannot be smaller. | |
fbf5a39b AC |
6612 | |
6613 | pragma Assert | |
6614 | (Esize (Source_Base_Type) >= Esize (Target_Base_Type)); | |
6615 | ||
6616 | -- We only need to check the low bound if the low bound of the | |
6617 | -- target type is non-negative. If the low bound of the target | |
6618 | -- type is negative, then we know that we will fit fine. | |
6619 | ||
6620 | -- If the high bound of the target type is negative, then we | |
6621 | -- know we have a constraint error, since we can't possibly | |
6622 | -- have a negative source. | |
6623 | ||
6624 | -- With these two checks out of the way, we can do the check | |
6625 | -- using the source type safely | |
6626 | ||
a90bd866 | 6627 | -- This is definitely the most annoying case. |
fbf5a39b AC |
6628 | |
6629 | -- [constraint_error | |
6630 | -- when (Target_Type'First >= 0 | |
6631 | -- and then | |
6632 | -- N < Source_Base_Type (Target_Type'First)) | |
6633 | -- or else Target_Type'Last < 0 | |
6634 | -- or else N > Source_Base_Type (Target_Type'Last)]; | |
6635 | ||
6636 | -- We turn off all checks since we know that the conversions | |
6637 | -- will work fine, given the guards for negative values. | |
6638 | ||
6639 | Insert_Action (N, | |
6640 | Make_Raise_Constraint_Error (Loc, | |
6641 | Condition => | |
6642 | Make_Or_Else (Loc, | |
6643 | Make_Or_Else (Loc, | |
6644 | Left_Opnd => | |
6645 | Make_And_Then (Loc, | |
6646 | Left_Opnd => Make_Op_Ge (Loc, | |
6647 | Left_Opnd => | |
6648 | Make_Attribute_Reference (Loc, | |
6649 | Prefix => | |
6650 | New_Occurrence_Of (Target_Type, Loc), | |
6651 | Attribute_Name => Name_First), | |
6652 | Right_Opnd => Make_Integer_Literal (Loc, Uint_0)), | |
6653 | ||
6654 | Right_Opnd => | |
6655 | Make_Op_Lt (Loc, | |
6656 | Left_Opnd => Duplicate_Subexpr (N), | |
6657 | Right_Opnd => | |
6658 | Convert_To (Source_Base_Type, | |
6659 | Make_Attribute_Reference (Loc, | |
6660 | Prefix => | |
6661 | New_Occurrence_Of (Target_Type, Loc), | |
6662 | Attribute_Name => Name_First)))), | |
6663 | ||
6664 | Right_Opnd => | |
6665 | Make_Op_Lt (Loc, | |
6666 | Left_Opnd => | |
6667 | Make_Attribute_Reference (Loc, | |
6668 | Prefix => New_Occurrence_Of (Target_Type, Loc), | |
6669 | Attribute_Name => Name_Last), | |
6670 | Right_Opnd => Make_Integer_Literal (Loc, Uint_0))), | |
6671 | ||
6672 | Right_Opnd => | |
6673 | Make_Op_Gt (Loc, | |
6674 | Left_Opnd => Duplicate_Subexpr (N), | |
6675 | Right_Opnd => | |
6676 | Convert_To (Source_Base_Type, | |
6677 | Make_Attribute_Reference (Loc, | |
6678 | Prefix => New_Occurrence_Of (Target_Type, Loc), | |
6679 | Attribute_Name => Name_Last)))), | |
6680 | ||
6681 | Reason => Reason), | |
6682 | Suppress => All_Checks); | |
6683 | ||
6684 | -- Only remaining possibility is that the source is signed and | |
b568955d | 6685 | -- the target is unsigned. |
fbf5a39b AC |
6686 | |
6687 | else | |
6688 | pragma Assert (not Is_Unsigned_Type (Source_Base_Type) | |
637a41a5 | 6689 | and then Is_Unsigned_Type (Target_Base_Type)); |
fbf5a39b | 6690 | |
675d6070 TQ |
6691 | -- If the source is signed and the target is unsigned, then we |
6692 | -- know that the target is not shorter than the source (otherwise | |
6693 | -- the target base type would be in the source base type range). | |
fbf5a39b | 6694 | |
675d6070 TQ |
6695 | -- In other words, the unsigned type is either the same size as |
6696 | -- the target, or it is larger. It cannot be smaller. | |
fbf5a39b | 6697 | |
675d6070 TQ |
6698 | -- Clearly we have an error if the source value is negative since |
6699 | -- no unsigned type can have negative values. If the source type | |
6700 | -- is non-negative, then the check can be done using the target | |
6701 | -- type. | |
fbf5a39b AC |
6702 | |
6703 | -- Tnn : constant Target_Base_Type (N) := Target_Type; | |
6704 | ||
6705 | -- [constraint_error | |
6706 | -- when N < 0 or else Tnn not in Target_Type]; | |
6707 | ||
675d6070 TQ |
6708 | -- We turn off all checks for the conversion of N to the target |
6709 | -- base type, since we generate the explicit check to ensure that | |
6710 | -- the value is non-negative | |
fbf5a39b AC |
6711 | |
6712 | declare | |
191fcb3a | 6713 | Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', N); |
fbf5a39b AC |
6714 | |
6715 | begin | |
6716 | Insert_Actions (N, New_List ( | |
6717 | Make_Object_Declaration (Loc, | |
6718 | Defining_Identifier => Tnn, | |
6719 | Object_Definition => | |
6720 | New_Occurrence_Of (Target_Base_Type, Loc), | |
6721 | Constant_Present => True, | |
6722 | Expression => | |
d79e621a | 6723 | Make_Unchecked_Type_Conversion (Loc, |
fbf5a39b AC |
6724 | Subtype_Mark => |
6725 | New_Occurrence_Of (Target_Base_Type, Loc), | |
6726 | Expression => Duplicate_Subexpr (N))), | |
6727 | ||
6728 | Make_Raise_Constraint_Error (Loc, | |
6729 | Condition => | |
6730 | Make_Or_Else (Loc, | |
6731 | Left_Opnd => | |
6732 | Make_Op_Lt (Loc, | |
6733 | Left_Opnd => Duplicate_Subexpr (N), | |
6734 | Right_Opnd => Make_Integer_Literal (Loc, Uint_0)), | |
6735 | ||
6736 | Right_Opnd => | |
6737 | Make_Not_In (Loc, | |
6738 | Left_Opnd => New_Occurrence_Of (Tnn, Loc), | |
6739 | Right_Opnd => | |
6740 | New_Occurrence_Of (Target_Type, Loc))), | |
6741 | ||
637a41a5 | 6742 | Reason => Reason)), |
fbf5a39b AC |
6743 | Suppress => All_Checks); |
6744 | ||
675d6070 TQ |
6745 | -- Set the Etype explicitly, because Insert_Actions may have |
6746 | -- placed the declaration in the freeze list for an enclosing | |
6747 | -- construct, and thus it is not analyzed yet. | |
fbf5a39b AC |
6748 | |
6749 | Set_Etype (Tnn, Target_Base_Type); | |
6750 | Rewrite (N, New_Occurrence_Of (Tnn, Loc)); | |
6751 | end; | |
6752 | end if; | |
6753 | end if; | |
6754 | end Generate_Range_Check; | |
6755 | ||
939c12d2 RD |
6756 | ------------------ |
6757 | -- Get_Check_Id -- | |
6758 | ------------------ | |
6759 | ||
6760 | function Get_Check_Id (N : Name_Id) return Check_Id is | |
6761 | begin | |
6762 | -- For standard check name, we can do a direct computation | |
6763 | ||
6764 | if N in First_Check_Name .. Last_Check_Name then | |
6765 | return Check_Id (N - (First_Check_Name - 1)); | |
6766 | ||
6767 | -- For non-standard names added by pragma Check_Name, search table | |
6768 | ||
6769 | else | |
6770 | for J in All_Checks + 1 .. Check_Names.Last loop | |
6771 | if Check_Names.Table (J) = N then | |
6772 | return J; | |
6773 | end if; | |
6774 | end loop; | |
6775 | end if; | |
6776 | ||
6777 | -- No matching name found | |
6778 | ||
6779 | return No_Check_Id; | |
6780 | end Get_Check_Id; | |
6781 | ||
70482933 RK |
6782 | --------------------- |
6783 | -- Get_Discriminal -- | |
6784 | --------------------- | |
6785 | ||
6786 | function Get_Discriminal (E : Entity_Id; Bound : Node_Id) return Node_Id is | |
6787 | Loc : constant Source_Ptr := Sloc (E); | |
6788 | D : Entity_Id; | |
6789 | Sc : Entity_Id; | |
6790 | ||
6791 | begin | |
c064e066 RD |
6792 | -- The bound can be a bona fide parameter of a protected operation, |
6793 | -- rather than a prival encoded as an in-parameter. | |
6794 | ||
6795 | if No (Discriminal_Link (Entity (Bound))) then | |
6796 | return Bound; | |
6797 | end if; | |
6798 | ||
939c12d2 RD |
6799 | -- Climb the scope stack looking for an enclosing protected type. If |
6800 | -- we run out of scopes, return the bound itself. | |
6801 | ||
6802 | Sc := Scope (E); | |
6803 | while Present (Sc) loop | |
6804 | if Sc = Standard_Standard then | |
6805 | return Bound; | |
939c12d2 RD |
6806 | elsif Ekind (Sc) = E_Protected_Type then |
6807 | exit; | |
6808 | end if; | |
6809 | ||
6810 | Sc := Scope (Sc); | |
6811 | end loop; | |
6812 | ||
70482933 | 6813 | D := First_Discriminant (Sc); |
939c12d2 RD |
6814 | while Present (D) loop |
6815 | if Chars (D) = Chars (Bound) then | |
6816 | return New_Occurrence_Of (Discriminal (D), Loc); | |
6817 | end if; | |
70482933 | 6818 | |
70482933 RK |
6819 | Next_Discriminant (D); |
6820 | end loop; | |
6821 | ||
939c12d2 | 6822 | return Bound; |
70482933 RK |
6823 | end Get_Discriminal; |
6824 | ||
939c12d2 RD |
6825 | ---------------------- |
6826 | -- Get_Range_Checks -- | |
6827 | ---------------------- | |
6828 | ||
6829 | function Get_Range_Checks | |
6830 | (Ck_Node : Node_Id; | |
6831 | Target_Typ : Entity_Id; | |
6832 | Source_Typ : Entity_Id := Empty; | |
6833 | Warn_Node : Node_Id := Empty) return Check_Result | |
6834 | is | |
6835 | begin | |
637a41a5 AC |
6836 | return |
6837 | Selected_Range_Checks (Ck_Node, Target_Typ, Source_Typ, Warn_Node); | |
939c12d2 RD |
6838 | end Get_Range_Checks; |
6839 | ||
70482933 RK |
6840 | ------------------ |
6841 | -- Guard_Access -- | |
6842 | ------------------ | |
6843 | ||
6844 | function Guard_Access | |
6845 | (Cond : Node_Id; | |
6846 | Loc : Source_Ptr; | |
6b6fcd3e | 6847 | Ck_Node : Node_Id) return Node_Id |
70482933 RK |
6848 | is |
6849 | begin | |
6850 | if Nkind (Cond) = N_Or_Else then | |
6851 | Set_Paren_Count (Cond, 1); | |
6852 | end if; | |
6853 | ||
6854 | if Nkind (Ck_Node) = N_Allocator then | |
6855 | return Cond; | |
637a41a5 | 6856 | |
70482933 RK |
6857 | else |
6858 | return | |
6859 | Make_And_Then (Loc, | |
6860 | Left_Opnd => | |
6861 | Make_Op_Ne (Loc, | |
fbf5a39b | 6862 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), |
70482933 RK |
6863 | Right_Opnd => Make_Null (Loc)), |
6864 | Right_Opnd => Cond); | |
6865 | end if; | |
6866 | end Guard_Access; | |
6867 | ||
6868 | ----------------------------- | |
6869 | -- Index_Checks_Suppressed -- | |
6870 | ----------------------------- | |
6871 | ||
6872 | function Index_Checks_Suppressed (E : Entity_Id) return Boolean is | |
6873 | begin | |
fbf5a39b AC |
6874 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
6875 | return Is_Check_Suppressed (E, Index_Check); | |
6876 | else | |
3217f71e | 6877 | return Scope_Suppress.Suppress (Index_Check); |
fbf5a39b | 6878 | end if; |
70482933 RK |
6879 | end Index_Checks_Suppressed; |
6880 | ||
6881 | ---------------- | |
6882 | -- Initialize -- | |
6883 | ---------------- | |
6884 | ||
6885 | procedure Initialize is | |
6886 | begin | |
6887 | for J in Determine_Range_Cache_N'Range loop | |
6888 | Determine_Range_Cache_N (J) := Empty; | |
6889 | end loop; | |
939c12d2 RD |
6890 | |
6891 | Check_Names.Init; | |
6892 | ||
6893 | for J in Int range 1 .. All_Checks loop | |
6894 | Check_Names.Append (Name_Id (Int (First_Check_Name) + J - 1)); | |
6895 | end loop; | |
70482933 RK |
6896 | end Initialize; |
6897 | ||
6898 | ------------------------- | |
6899 | -- Insert_Range_Checks -- | |
6900 | ------------------------- | |
6901 | ||
6902 | procedure Insert_Range_Checks | |
6903 | (Checks : Check_Result; | |
6904 | Node : Node_Id; | |
6905 | Suppress_Typ : Entity_Id; | |
6906 | Static_Sloc : Source_Ptr := No_Location; | |
6907 | Flag_Node : Node_Id := Empty; | |
6908 | Do_Before : Boolean := False) | |
6909 | is | |
6910 | Internal_Flag_Node : Node_Id := Flag_Node; | |
6911 | Internal_Static_Sloc : Source_Ptr := Static_Sloc; | |
6912 | ||
6913 | Check_Node : Node_Id; | |
6914 | Checks_On : constant Boolean := | |
15f0f591 AC |
6915 | (not Index_Checks_Suppressed (Suppress_Typ)) |
6916 | or else (not Range_Checks_Suppressed (Suppress_Typ)); | |
70482933 RK |
6917 | |
6918 | begin | |
675d6070 TQ |
6919 | -- For now we just return if Checks_On is false, however this should be |
6920 | -- enhanced to check for an always True value in the condition and to | |
6921 | -- generate a compilation warning??? | |
70482933 | 6922 | |
1f0b1e48 | 6923 | if not Expander_Active or not Checks_On then |
70482933 RK |
6924 | return; |
6925 | end if; | |
6926 | ||
6927 | if Static_Sloc = No_Location then | |
6928 | Internal_Static_Sloc := Sloc (Node); | |
6929 | end if; | |
6930 | ||
6931 | if No (Flag_Node) then | |
6932 | Internal_Flag_Node := Node; | |
6933 | end if; | |
6934 | ||
6935 | for J in 1 .. 2 loop | |
6936 | exit when No (Checks (J)); | |
6937 | ||
6938 | if Nkind (Checks (J)) = N_Raise_Constraint_Error | |
6939 | and then Present (Condition (Checks (J))) | |
6940 | then | |
6941 | if not Has_Dynamic_Range_Check (Internal_Flag_Node) then | |
6942 | Check_Node := Checks (J); | |
6943 | Mark_Rewrite_Insertion (Check_Node); | |
6944 | ||
6945 | if Do_Before then | |
6946 | Insert_Before_And_Analyze (Node, Check_Node); | |
6947 | else | |
6948 | Insert_After_And_Analyze (Node, Check_Node); | |
6949 | end if; | |
6950 | ||
6951 | Set_Has_Dynamic_Range_Check (Internal_Flag_Node); | |
6952 | end if; | |
6953 | ||
6954 | else | |
6955 | Check_Node := | |
07fc65c4 GB |
6956 | Make_Raise_Constraint_Error (Internal_Static_Sloc, |
6957 | Reason => CE_Range_Check_Failed); | |
70482933 RK |
6958 | Mark_Rewrite_Insertion (Check_Node); |
6959 | ||
6960 | if Do_Before then | |
6961 | Insert_Before_And_Analyze (Node, Check_Node); | |
6962 | else | |
6963 | Insert_After_And_Analyze (Node, Check_Node); | |
6964 | end if; | |
6965 | end if; | |
6966 | end loop; | |
6967 | end Insert_Range_Checks; | |
6968 | ||
6969 | ------------------------ | |
6970 | -- Insert_Valid_Check -- | |
6971 | ------------------------ | |
6972 | ||
6973 | procedure Insert_Valid_Check (Expr : Node_Id) is | |
6974 | Loc : constant Source_Ptr := Sloc (Expr); | |
d515aef3 | 6975 | Typ : constant Entity_Id := Etype (Expr); |
84157f51 | 6976 | Exp : Node_Id; |
70482933 RK |
6977 | |
6978 | begin | |
8dc2ddaf RD |
6979 | -- Do not insert if checks off, or if not checking validity or |
6980 | -- if expression is known to be valid | |
70482933 | 6981 | |
c064e066 RD |
6982 | if not Validity_Checks_On |
6983 | or else Range_Or_Validity_Checks_Suppressed (Expr) | |
8dc2ddaf | 6984 | or else Expr_Known_Valid (Expr) |
70482933 | 6985 | then |
84157f51 GB |
6986 | return; |
6987 | end if; | |
70482933 | 6988 | |
489c6e19 AC |
6989 | -- Do not insert checks within a predicate function. This will arise |
6990 | -- if the current unit and the predicate function are being compiled | |
6991 | -- with validity checks enabled. | |
d515aef3 AC |
6992 | |
6993 | if Present (Predicate_Function (Typ)) | |
6994 | and then Current_Scope = Predicate_Function (Typ) | |
6995 | then | |
6996 | return; | |
6997 | end if; | |
6998 | ||
9dc30a5f AC |
6999 | -- If the expression is a packed component of a modular type of the |
7000 | -- right size, the data is always valid. | |
7001 | ||
7002 | if Nkind (Expr) = N_Selected_Component | |
7003 | and then Present (Component_Clause (Entity (Selector_Name (Expr)))) | |
7004 | and then Is_Modular_Integer_Type (Typ) | |
7005 | and then Modulus (Typ) = 2 ** Esize (Entity (Selector_Name (Expr))) | |
7006 | then | |
7007 | return; | |
7008 | end if; | |
7009 | ||
84157f51 GB |
7010 | -- If we have a checked conversion, then validity check applies to |
7011 | -- the expression inside the conversion, not the result, since if | |
7012 | -- the expression inside is valid, then so is the conversion result. | |
70482933 | 7013 | |
84157f51 GB |
7014 | Exp := Expr; |
7015 | while Nkind (Exp) = N_Type_Conversion loop | |
7016 | Exp := Expression (Exp); | |
7017 | end loop; | |
7018 | ||
c064e066 RD |
7019 | -- We are about to insert the validity check for Exp. We save and |
7020 | -- reset the Do_Range_Check flag over this validity check, and then | |
7021 | -- put it back for the final original reference (Exp may be rewritten). | |
7022 | ||
7023 | declare | |
7024 | DRC : constant Boolean := Do_Range_Check (Exp); | |
0e564ab4 AC |
7025 | PV : Node_Id; |
7026 | CE : Node_Id; | |
d8b9660d | 7027 | |
c064e066 RD |
7028 | begin |
7029 | Set_Do_Range_Check (Exp, False); | |
7030 | ||
8dc2ddaf RD |
7031 | -- Force evaluation to avoid multiple reads for atomic/volatile |
7032 | ||
59f4d038 RD |
7033 | -- Note: we set Name_Req to False. We used to set it to True, with |
7034 | -- the thinking that a name is required as the prefix of the 'Valid | |
7035 | -- call, but in fact the check that the prefix of an attribute is | |
7036 | -- a name is in the parser, and we just don't require it here. | |
7037 | -- Moreover, when we set Name_Req to True, that interfered with the | |
7038 | -- checking for Volatile, since we couldn't just capture the value. | |
7039 | ||
8dc2ddaf RD |
7040 | if Is_Entity_Name (Exp) |
7041 | and then Is_Volatile (Entity (Exp)) | |
7042 | then | |
59f4d038 RD |
7043 | -- Same reasoning as above for setting Name_Req to False |
7044 | ||
7045 | Force_Evaluation (Exp, Name_Req => False); | |
8dc2ddaf RD |
7046 | end if; |
7047 | ||
0e564ab4 AC |
7048 | -- Build the prefix for the 'Valid call |
7049 | ||
59f4d038 | 7050 | PV := Duplicate_Subexpr_No_Checks (Exp, Name_Req => False); |
c064e066 | 7051 | |
e80f0cb0 RD |
7052 | -- A rather specialized test. If PV is an analyzed expression which |
7053 | -- is an indexed component of a packed array that has not been | |
7054 | -- properly expanded, turn off its Analyzed flag to make sure it | |
4bd4bb7f AC |
7055 | -- gets properly reexpanded. If the prefix is an access value, |
7056 | -- the dereference will be added later. | |
0e564ab4 AC |
7057 | |
7058 | -- The reason this arises is that Duplicate_Subexpr_No_Checks did | |
7059 | -- an analyze with the old parent pointer. This may point e.g. to | |
7060 | -- a subprogram call, which deactivates this expansion. | |
7061 | ||
7062 | if Analyzed (PV) | |
7063 | and then Nkind (PV) = N_Indexed_Component | |
4bd4bb7f | 7064 | and then Is_Array_Type (Etype (Prefix (PV))) |
8ca597af | 7065 | and then Present (Packed_Array_Impl_Type (Etype (Prefix (PV)))) |
0e564ab4 AC |
7066 | then |
7067 | Set_Analyzed (PV, False); | |
7068 | end if; | |
7069 | ||
59f4d038 RD |
7070 | -- Build the raise CE node to check for validity. We build a type |
7071 | -- qualification for the prefix, since it may not be of the form of | |
7072 | -- a name, and we don't care in this context! | |
0e564ab4 AC |
7073 | |
7074 | CE := | |
c064e066 RD |
7075 | Make_Raise_Constraint_Error (Loc, |
7076 | Condition => | |
7077 | Make_Op_Not (Loc, | |
7078 | Right_Opnd => | |
7079 | Make_Attribute_Reference (Loc, | |
0e564ab4 | 7080 | Prefix => PV, |
c064e066 | 7081 | Attribute_Name => Name_Valid)), |
0e564ab4 AC |
7082 | Reason => CE_Invalid_Data); |
7083 | ||
7084 | -- Insert the validity check. Note that we do this with validity | |
7085 | -- checks turned off, to avoid recursion, we do not want validity | |
a90bd866 | 7086 | -- checks on the validity checking code itself. |
0e564ab4 AC |
7087 | |
7088 | Insert_Action (Expr, CE, Suppress => Validity_Check); | |
c064e066 | 7089 | |
308e6f3a | 7090 | -- If the expression is a reference to an element of a bit-packed |
c064e066 RD |
7091 | -- array, then it is rewritten as a renaming declaration. If the |
7092 | -- expression is an actual in a call, it has not been expanded, | |
7093 | -- waiting for the proper point at which to do it. The same happens | |
7094 | -- with renamings, so that we have to force the expansion now. This | |
7095 | -- non-local complication is due to code in exp_ch2,adb, exp_ch4.adb | |
7096 | -- and exp_ch6.adb. | |
7097 | ||
7098 | if Is_Entity_Name (Exp) | |
7099 | and then Nkind (Parent (Entity (Exp))) = | |
637a41a5 | 7100 | N_Object_Renaming_Declaration |
c064e066 RD |
7101 | then |
7102 | declare | |
7103 | Old_Exp : constant Node_Id := Name (Parent (Entity (Exp))); | |
7104 | begin | |
7105 | if Nkind (Old_Exp) = N_Indexed_Component | |
7106 | and then Is_Bit_Packed_Array (Etype (Prefix (Old_Exp))) | |
7107 | then | |
7108 | Expand_Packed_Element_Reference (Old_Exp); | |
7109 | end if; | |
7110 | end; | |
7111 | end if; | |
7112 | ||
7113 | -- Put back the Do_Range_Check flag on the resulting (possibly | |
7114 | -- rewritten) expression. | |
7115 | ||
7116 | -- Note: it might be thought that a validity check is not required | |
7117 | -- when a range check is present, but that's not the case, because | |
7118 | -- the back end is allowed to assume for the range check that the | |
7119 | -- operand is within its declared range (an assumption that validity | |
a90bd866 | 7120 | -- checking is all about NOT assuming). |
c064e066 | 7121 | |
11b4899f JM |
7122 | -- Note: no need to worry about Possible_Local_Raise here, it will |
7123 | -- already have been called if original node has Do_Range_Check set. | |
7124 | ||
c064e066 RD |
7125 | Set_Do_Range_Check (Exp, DRC); |
7126 | end; | |
70482933 RK |
7127 | end Insert_Valid_Check; |
7128 | ||
acad3c0a AC |
7129 | ------------------------------------- |
7130 | -- Is_Signed_Integer_Arithmetic_Op -- | |
7131 | ------------------------------------- | |
7132 | ||
7133 | function Is_Signed_Integer_Arithmetic_Op (N : Node_Id) return Boolean is | |
7134 | begin | |
7135 | case Nkind (N) is | |
7136 | when N_Op_Abs | N_Op_Add | N_Op_Divide | N_Op_Expon | | |
7137 | N_Op_Minus | N_Op_Mod | N_Op_Multiply | N_Op_Plus | | |
7138 | N_Op_Rem | N_Op_Subtract => | |
7139 | return Is_Signed_Integer_Type (Etype (N)); | |
7140 | ||
9b16cb57 | 7141 | when N_If_Expression | N_Case_Expression => |
4b1c4f20 RD |
7142 | return Is_Signed_Integer_Type (Etype (N)); |
7143 | ||
acad3c0a AC |
7144 | when others => |
7145 | return False; | |
7146 | end case; | |
7147 | end Is_Signed_Integer_Arithmetic_Op; | |
7148 | ||
2820d220 AC |
7149 | ---------------------------------- |
7150 | -- Install_Null_Excluding_Check -- | |
7151 | ---------------------------------- | |
7152 | ||
7153 | procedure Install_Null_Excluding_Check (N : Node_Id) is | |
437f8c1e | 7154 | Loc : constant Source_Ptr := Sloc (Parent (N)); |
86ac5e79 ES |
7155 | Typ : constant Entity_Id := Etype (N); |
7156 | ||
ac7120ce RD |
7157 | function Safe_To_Capture_In_Parameter_Value return Boolean; |
7158 | -- Determines if it is safe to capture Known_Non_Null status for an | |
7159 | -- the entity referenced by node N. The caller ensures that N is indeed | |
7160 | -- an entity name. It is safe to capture the non-null status for an IN | |
7161 | -- parameter when the reference occurs within a declaration that is sure | |
7162 | -- to be executed as part of the declarative region. | |
bb6e3d41 | 7163 | |
86ac5e79 | 7164 | procedure Mark_Non_Null; |
bb6e3d41 HK |
7165 | -- After installation of check, if the node in question is an entity |
7166 | -- name, then mark this entity as non-null if possible. | |
7167 | ||
ac7120ce | 7168 | function Safe_To_Capture_In_Parameter_Value return Boolean is |
bb6e3d41 HK |
7169 | E : constant Entity_Id := Entity (N); |
7170 | S : constant Entity_Id := Current_Scope; | |
7171 | S_Par : Node_Id; | |
7172 | ||
7173 | begin | |
ac7120ce RD |
7174 | if Ekind (E) /= E_In_Parameter then |
7175 | return False; | |
7176 | end if; | |
bb6e3d41 HK |
7177 | |
7178 | -- Two initial context checks. We must be inside a subprogram body | |
7179 | -- with declarations and reference must not appear in nested scopes. | |
7180 | ||
ac7120ce | 7181 | if (Ekind (S) /= E_Function and then Ekind (S) /= E_Procedure) |
bb6e3d41 HK |
7182 | or else Scope (E) /= S |
7183 | then | |
7184 | return False; | |
7185 | end if; | |
7186 | ||
7187 | S_Par := Parent (Parent (S)); | |
7188 | ||
7189 | if Nkind (S_Par) /= N_Subprogram_Body | |
7190 | or else No (Declarations (S_Par)) | |
7191 | then | |
7192 | return False; | |
7193 | end if; | |
7194 | ||
7195 | declare | |
7196 | N_Decl : Node_Id; | |
7197 | P : Node_Id; | |
7198 | ||
7199 | begin | |
7200 | -- Retrieve the declaration node of N (if any). Note that N | |
7201 | -- may be a part of a complex initialization expression. | |
7202 | ||
7203 | P := Parent (N); | |
7204 | N_Decl := Empty; | |
7205 | while Present (P) loop | |
7206 | ||
ac7120ce RD |
7207 | -- If we have a short circuit form, and we are within the right |
7208 | -- hand expression, we return false, since the right hand side | |
7209 | -- is not guaranteed to be elaborated. | |
7210 | ||
7211 | if Nkind (P) in N_Short_Circuit | |
7212 | and then N = Right_Opnd (P) | |
7213 | then | |
7214 | return False; | |
7215 | end if; | |
7216 | ||
9b16cb57 RD |
7217 | -- Similarly, if we are in an if expression and not part of the |
7218 | -- condition, then we return False, since neither the THEN or | |
7219 | -- ELSE dependent expressions will always be elaborated. | |
ac7120ce | 7220 | |
9b16cb57 | 7221 | if Nkind (P) = N_If_Expression |
ac7120ce RD |
7222 | and then N /= First (Expressions (P)) |
7223 | then | |
7224 | return False; | |
19d846a0 RD |
7225 | end if; |
7226 | ||
637a41a5 AC |
7227 | -- If within a case expression, and not part of the expression, |
7228 | -- then return False, since a particular dependent expression | |
7229 | -- may not always be elaborated | |
19d846a0 RD |
7230 | |
7231 | if Nkind (P) = N_Case_Expression | |
7232 | and then N /= Expression (P) | |
7233 | then | |
7234 | return False; | |
ac7120ce RD |
7235 | end if; |
7236 | ||
637a41a5 AC |
7237 | -- While traversing the parent chain, if node N belongs to a |
7238 | -- statement, then it may never appear in a declarative region. | |
bb6e3d41 HK |
7239 | |
7240 | if Nkind (P) in N_Statement_Other_Than_Procedure_Call | |
7241 | or else Nkind (P) = N_Procedure_Call_Statement | |
7242 | then | |
7243 | return False; | |
7244 | end if; | |
7245 | ||
ac7120ce RD |
7246 | -- If we are at a declaration, record it and exit |
7247 | ||
bb6e3d41 HK |
7248 | if Nkind (P) in N_Declaration |
7249 | and then Nkind (P) not in N_Subprogram_Specification | |
7250 | then | |
7251 | N_Decl := P; | |
7252 | exit; | |
7253 | end if; | |
7254 | ||
7255 | P := Parent (P); | |
7256 | end loop; | |
7257 | ||
7258 | if No (N_Decl) then | |
7259 | return False; | |
7260 | end if; | |
7261 | ||
7262 | return List_Containing (N_Decl) = Declarations (S_Par); | |
7263 | end; | |
ac7120ce | 7264 | end Safe_To_Capture_In_Parameter_Value; |
86ac5e79 ES |
7265 | |
7266 | ------------------- | |
7267 | -- Mark_Non_Null -- | |
7268 | ------------------- | |
7269 | ||
7270 | procedure Mark_Non_Null is | |
7271 | begin | |
bb6e3d41 HK |
7272 | -- Only case of interest is if node N is an entity name |
7273 | ||
86ac5e79 | 7274 | if Is_Entity_Name (N) then |
bb6e3d41 HK |
7275 | |
7276 | -- For sure, we want to clear an indication that this is known to | |
a90bd866 | 7277 | -- be null, since if we get past this check, it definitely is not. |
bb6e3d41 | 7278 | |
86ac5e79 ES |
7279 | Set_Is_Known_Null (Entity (N), False); |
7280 | ||
bb6e3d41 HK |
7281 | -- We can mark the entity as known to be non-null if either it is |
7282 | -- safe to capture the value, or in the case of an IN parameter, | |
7283 | -- which is a constant, if the check we just installed is in the | |
7284 | -- declarative region of the subprogram body. In this latter case, | |
ac7120ce RD |
7285 | -- a check is decisive for the rest of the body if the expression |
7286 | -- is sure to be elaborated, since we know we have to elaborate | |
7287 | -- all declarations before executing the body. | |
7288 | ||
7289 | -- Couldn't this always be part of Safe_To_Capture_Value ??? | |
bb6e3d41 HK |
7290 | |
7291 | if Safe_To_Capture_Value (N, Entity (N)) | |
ac7120ce | 7292 | or else Safe_To_Capture_In_Parameter_Value |
bb6e3d41 HK |
7293 | then |
7294 | Set_Is_Known_Non_Null (Entity (N)); | |
86ac5e79 ES |
7295 | end if; |
7296 | end if; | |
7297 | end Mark_Non_Null; | |
7298 | ||
7299 | -- Start of processing for Install_Null_Excluding_Check | |
2820d220 AC |
7300 | |
7301 | begin | |
86ac5e79 | 7302 | pragma Assert (Is_Access_Type (Typ)); |
2820d220 | 7303 | |
cca7f107 | 7304 | -- No check inside a generic, check will be emitted in instance |
2820d220 | 7305 | |
86ac5e79 | 7306 | if Inside_A_Generic then |
2820d220 | 7307 | return; |
86ac5e79 ES |
7308 | end if; |
7309 | ||
7310 | -- No check needed if known to be non-null | |
7311 | ||
7312 | if Known_Non_Null (N) then | |
d8b9660d | 7313 | return; |
86ac5e79 | 7314 | end if; |
2820d220 | 7315 | |
86ac5e79 ES |
7316 | -- If known to be null, here is where we generate a compile time check |
7317 | ||
7318 | if Known_Null (N) then | |
b1c11e0e | 7319 | |
637a41a5 AC |
7320 | -- Avoid generating warning message inside init procs. In SPARK mode |
7321 | -- we can go ahead and call Apply_Compile_Time_Constraint_Error | |
cca7f107 | 7322 | -- since it will be turned into an error in any case. |
b1c11e0e | 7323 | |
cca7f107 AC |
7324 | if (not Inside_Init_Proc or else SPARK_Mode = On) |
7325 | ||
1ae70618 ES |
7326 | -- Do not emit the warning within a conditional expression, |
7327 | -- where the expression might not be evaluated, and the warning | |
7328 | -- appear as extraneous noise. | |
cca7f107 AC |
7329 | |
7330 | and then not Within_Case_Or_If_Expression (N) | |
7331 | then | |
b1c11e0e | 7332 | Apply_Compile_Time_Constraint_Error |
4a28b181 | 7333 | (N, "null value not allowed here??", CE_Access_Check_Failed); |
cca7f107 AC |
7334 | |
7335 | -- Remaining cases, where we silently insert the raise | |
7336 | ||
b1c11e0e JM |
7337 | else |
7338 | Insert_Action (N, | |
7339 | Make_Raise_Constraint_Error (Loc, | |
7340 | Reason => CE_Access_Check_Failed)); | |
7341 | end if; | |
7342 | ||
86ac5e79 ES |
7343 | Mark_Non_Null; |
7344 | return; | |
7345 | end if; | |
7346 | ||
7347 | -- If entity is never assigned, for sure a warning is appropriate | |
7348 | ||
7349 | if Is_Entity_Name (N) then | |
7350 | Check_Unset_Reference (N); | |
2820d220 | 7351 | end if; |
86ac5e79 ES |
7352 | |
7353 | -- No check needed if checks are suppressed on the range. Note that we | |
7354 | -- don't set Is_Known_Non_Null in this case (we could legitimately do | |
7355 | -- so, since the program is erroneous, but we don't like to casually | |
7356 | -- propagate such conclusions from erroneosity). | |
7357 | ||
7358 | if Access_Checks_Suppressed (Typ) then | |
7359 | return; | |
7360 | end if; | |
7361 | ||
939c12d2 RD |
7362 | -- No check needed for access to concurrent record types generated by |
7363 | -- the expander. This is not just an optimization (though it does indeed | |
7364 | -- remove junk checks). It also avoids generation of junk warnings. | |
7365 | ||
7366 | if Nkind (N) in N_Has_Chars | |
7367 | and then Chars (N) = Name_uObject | |
7368 | and then Is_Concurrent_Record_Type | |
7369 | (Directly_Designated_Type (Etype (N))) | |
7370 | then | |
7371 | return; | |
7372 | end if; | |
7373 | ||
0a376301 JM |
7374 | -- No check needed in interface thunks since the runtime check is |
7375 | -- already performed at the caller side. | |
7376 | ||
7377 | if Is_Thunk (Current_Scope) then | |
7378 | return; | |
7379 | end if; | |
7380 | ||
74cab21a EB |
7381 | -- No check needed for the Get_Current_Excep.all.all idiom generated by |
7382 | -- the expander within exception handlers, since we know that the value | |
7383 | -- can never be null. | |
7384 | ||
7385 | -- Is this really the right way to do this? Normally we generate such | |
7386 | -- code in the expander with checks off, and that's how we suppress this | |
7387 | -- kind of junk check ??? | |
7388 | ||
7389 | if Nkind (N) = N_Function_Call | |
7390 | and then Nkind (Name (N)) = N_Explicit_Dereference | |
7391 | and then Nkind (Prefix (Name (N))) = N_Identifier | |
7392 | and then Is_RTE (Entity (Prefix (Name (N))), RE_Get_Current_Excep) | |
7393 | then | |
7394 | return; | |
7395 | end if; | |
7396 | ||
86ac5e79 ES |
7397 | -- Otherwise install access check |
7398 | ||
7399 | Insert_Action (N, | |
7400 | Make_Raise_Constraint_Error (Loc, | |
7401 | Condition => | |
7402 | Make_Op_Eq (Loc, | |
7403 | Left_Opnd => Duplicate_Subexpr_Move_Checks (N), | |
7404 | Right_Opnd => Make_Null (Loc)), | |
7405 | Reason => CE_Access_Check_Failed)); | |
7406 | ||
7407 | Mark_Non_Null; | |
2820d220 AC |
7408 | end Install_Null_Excluding_Check; |
7409 | ||
70482933 RK |
7410 | -------------------------- |
7411 | -- Install_Static_Check -- | |
7412 | -------------------------- | |
7413 | ||
7414 | procedure Install_Static_Check (R_Cno : Node_Id; Loc : Source_Ptr) is | |
edab6088 | 7415 | Stat : constant Boolean := Is_OK_Static_Expression (R_Cno); |
70482933 RK |
7416 | Typ : constant Entity_Id := Etype (R_Cno); |
7417 | ||
7418 | begin | |
07fc65c4 GB |
7419 | Rewrite (R_Cno, |
7420 | Make_Raise_Constraint_Error (Loc, | |
7421 | Reason => CE_Range_Check_Failed)); | |
70482933 RK |
7422 | Set_Analyzed (R_Cno); |
7423 | Set_Etype (R_Cno, Typ); | |
7424 | Set_Raises_Constraint_Error (R_Cno); | |
7425 | Set_Is_Static_Expression (R_Cno, Stat); | |
3f92c93b AC |
7426 | |
7427 | -- Now deal with possible local raise handling | |
7428 | ||
7429 | Possible_Local_Raise (R_Cno, Standard_Constraint_Error); | |
70482933 RK |
7430 | end Install_Static_Check; |
7431 | ||
acad3c0a AC |
7432 | ------------------------- |
7433 | -- Is_Check_Suppressed -- | |
7434 | ------------------------- | |
7435 | ||
7436 | function Is_Check_Suppressed (E : Entity_Id; C : Check_Id) return Boolean is | |
7437 | Ptr : Suppress_Stack_Entry_Ptr; | |
7438 | ||
7439 | begin | |
7440 | -- First search the local entity suppress stack. We search this from the | |
7441 | -- top of the stack down so that we get the innermost entry that applies | |
7442 | -- to this case if there are nested entries. | |
7443 | ||
7444 | Ptr := Local_Suppress_Stack_Top; | |
7445 | while Ptr /= null loop | |
7446 | if (Ptr.Entity = Empty or else Ptr.Entity = E) | |
7447 | and then (Ptr.Check = All_Checks or else Ptr.Check = C) | |
7448 | then | |
7449 | return Ptr.Suppress; | |
7450 | end if; | |
7451 | ||
7452 | Ptr := Ptr.Prev; | |
7453 | end loop; | |
7454 | ||
7455 | -- Now search the global entity suppress table for a matching entry. | |
7456 | -- We also search this from the top down so that if there are multiple | |
7457 | -- pragmas for the same entity, the last one applies (not clear what | |
7458 | -- or whether the RM specifies this handling, but it seems reasonable). | |
7459 | ||
7460 | Ptr := Global_Suppress_Stack_Top; | |
7461 | while Ptr /= null loop | |
7462 | if (Ptr.Entity = Empty or else Ptr.Entity = E) | |
7463 | and then (Ptr.Check = All_Checks or else Ptr.Check = C) | |
7464 | then | |
7465 | return Ptr.Suppress; | |
7466 | end if; | |
7467 | ||
7468 | Ptr := Ptr.Prev; | |
7469 | end loop; | |
7470 | ||
7471 | -- If we did not find a matching entry, then use the normal scope | |
7472 | -- suppress value after all (actually this will be the global setting | |
7473 | -- since it clearly was not overridden at any point). For a predefined | |
7474 | -- check, we test the specific flag. For a user defined check, we check | |
7475 | -- the All_Checks flag. The Overflow flag requires special handling to | |
7476 | -- deal with the General vs Assertion case | |
7477 | ||
7478 | if C = Overflow_Check then | |
7479 | return Overflow_Checks_Suppressed (Empty); | |
7480 | elsif C in Predefined_Check_Id then | |
7481 | return Scope_Suppress.Suppress (C); | |
7482 | else | |
7483 | return Scope_Suppress.Suppress (All_Checks); | |
7484 | end if; | |
7485 | end Is_Check_Suppressed; | |
7486 | ||
fbf5a39b AC |
7487 | --------------------- |
7488 | -- Kill_All_Checks -- | |
7489 | --------------------- | |
7490 | ||
7491 | procedure Kill_All_Checks is | |
7492 | begin | |
7493 | if Debug_Flag_CC then | |
7494 | w ("Kill_All_Checks"); | |
7495 | end if; | |
7496 | ||
675d6070 TQ |
7497 | -- We reset the number of saved checks to zero, and also modify all |
7498 | -- stack entries for statement ranges to indicate that the number of | |
7499 | -- checks at each level is now zero. | |
fbf5a39b AC |
7500 | |
7501 | Num_Saved_Checks := 0; | |
7502 | ||
67ce0d7e RD |
7503 | -- Note: the Int'Min here avoids any possibility of J being out of |
7504 | -- range when called from e.g. Conditional_Statements_Begin. | |
7505 | ||
7506 | for J in 1 .. Int'Min (Saved_Checks_TOS, Saved_Checks_Stack'Last) loop | |
fbf5a39b AC |
7507 | Saved_Checks_Stack (J) := 0; |
7508 | end loop; | |
7509 | end Kill_All_Checks; | |
7510 | ||
7511 | ----------------- | |
7512 | -- Kill_Checks -- | |
7513 | ----------------- | |
7514 | ||
7515 | procedure Kill_Checks (V : Entity_Id) is | |
7516 | begin | |
7517 | if Debug_Flag_CC then | |
7518 | w ("Kill_Checks for entity", Int (V)); | |
7519 | end if; | |
7520 | ||
7521 | for J in 1 .. Num_Saved_Checks loop | |
7522 | if Saved_Checks (J).Entity = V then | |
7523 | if Debug_Flag_CC then | |
7524 | w (" Checks killed for saved check ", J); | |
7525 | end if; | |
7526 | ||
7527 | Saved_Checks (J).Killed := True; | |
7528 | end if; | |
7529 | end loop; | |
7530 | end Kill_Checks; | |
7531 | ||
70482933 RK |
7532 | ------------------------------ |
7533 | -- Length_Checks_Suppressed -- | |
7534 | ------------------------------ | |
7535 | ||
7536 | function Length_Checks_Suppressed (E : Entity_Id) return Boolean is | |
7537 | begin | |
fbf5a39b AC |
7538 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
7539 | return Is_Check_Suppressed (E, Length_Check); | |
7540 | else | |
3217f71e | 7541 | return Scope_Suppress.Suppress (Length_Check); |
fbf5a39b | 7542 | end if; |
70482933 RK |
7543 | end Length_Checks_Suppressed; |
7544 | ||
acad3c0a AC |
7545 | ----------------------- |
7546 | -- Make_Bignum_Block -- | |
7547 | ----------------------- | |
7548 | ||
7549 | function Make_Bignum_Block (Loc : Source_Ptr) return Node_Id is | |
7550 | M : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uM); | |
acad3c0a AC |
7551 | begin |
7552 | return | |
7553 | Make_Block_Statement (Loc, | |
8e888920 AC |
7554 | Declarations => |
7555 | New_List (Build_SS_Mark_Call (Loc, M)), | |
acad3c0a AC |
7556 | Handled_Statement_Sequence => |
7557 | Make_Handled_Sequence_Of_Statements (Loc, | |
8e888920 | 7558 | Statements => New_List (Build_SS_Release_Call (Loc, M)))); |
acad3c0a AC |
7559 | end Make_Bignum_Block; |
7560 | ||
a7f1b24f RD |
7561 | ---------------------------------- |
7562 | -- Minimize_Eliminate_Overflows -- | |
7563 | ---------------------------------- | |
acad3c0a | 7564 | |
b6b5cca8 AC |
7565 | -- This is a recursive routine that is called at the top of an expression |
7566 | -- tree to properly process overflow checking for a whole subtree by making | |
7567 | -- recursive calls to process operands. This processing may involve the use | |
7568 | -- of bignum or long long integer arithmetic, which will change the types | |
7569 | -- of operands and results. That's why we can't do this bottom up (since | |
5707e389 | 7570 | -- it would interfere with semantic analysis). |
b6b5cca8 | 7571 | |
5707e389 | 7572 | -- What happens is that if MINIMIZED/ELIMINATED mode is in effect then |
a7f1b24f RD |
7573 | -- the operator expansion routines, as well as the expansion routines for |
7574 | -- if/case expression, do nothing (for the moment) except call the routine | |
7575 | -- to apply the overflow check (Apply_Arithmetic_Overflow_Check). That | |
7576 | -- routine does nothing for non top-level nodes, so at the point where the | |
7577 | -- call is made for the top level node, the entire expression subtree has | |
7578 | -- not been expanded, or processed for overflow. All that has to happen as | |
7579 | -- a result of the top level call to this routine. | |
b6b5cca8 AC |
7580 | |
7581 | -- As noted above, the overflow processing works by making recursive calls | |
7582 | -- for the operands, and figuring out what to do, based on the processing | |
7583 | -- of these operands (e.g. if a bignum operand appears, the parent op has | |
7584 | -- to be done in bignum mode), and the determined ranges of the operands. | |
7585 | ||
7586 | -- After possible rewriting of a constituent subexpression node, a call is | |
a40ada7e | 7587 | -- made to either reexpand the node (if nothing has changed) or reanalyze |
5707e389 AC |
7588 | -- the node (if it has been modified by the overflow check processing). The |
7589 | -- Analyzed_Flag is set to False before the reexpand/reanalyze. To avoid | |
7590 | -- a recursive call into the whole overflow apparatus, an important rule | |
a7f1b24f RD |
7591 | -- for this call is that the overflow handling mode must be temporarily set |
7592 | -- to STRICT. | |
b6b5cca8 | 7593 | |
a7f1b24f | 7594 | procedure Minimize_Eliminate_Overflows |
c7e152b5 AC |
7595 | (N : Node_Id; |
7596 | Lo : out Uint; | |
7597 | Hi : out Uint; | |
7598 | Top_Level : Boolean) | |
acad3c0a | 7599 | is |
4b1c4f20 RD |
7600 | Rtyp : constant Entity_Id := Etype (N); |
7601 | pragma Assert (Is_Signed_Integer_Type (Rtyp)); | |
7602 | -- Result type, must be a signed integer type | |
acad3c0a | 7603 | |
15c94a55 | 7604 | Check_Mode : constant Overflow_Mode_Type := Overflow_Check_Mode; |
acad3c0a AC |
7605 | pragma Assert (Check_Mode in Minimized_Or_Eliminated); |
7606 | ||
7607 | Loc : constant Source_Ptr := Sloc (N); | |
7608 | ||
7609 | Rlo, Rhi : Uint; | |
4b1c4f20 | 7610 | -- Ranges of values for right operand (operator case) |
acad3c0a AC |
7611 | |
7612 | Llo, Lhi : Uint; | |
4b1c4f20 | 7613 | -- Ranges of values for left operand (operator case) |
acad3c0a | 7614 | |
d79059a3 AC |
7615 | LLIB : constant Entity_Id := Base_Type (Standard_Long_Long_Integer); |
7616 | -- Operands and results are of this type when we convert | |
7617 | ||
4b1c4f20 RD |
7618 | LLLo : constant Uint := Intval (Type_Low_Bound (LLIB)); |
7619 | LLHi : constant Uint := Intval (Type_High_Bound (LLIB)); | |
acad3c0a AC |
7620 | -- Bounds of Long_Long_Integer |
7621 | ||
7622 | Binary : constant Boolean := Nkind (N) in N_Binary_Op; | |
7623 | -- Indicates binary operator case | |
7624 | ||
7625 | OK : Boolean; | |
7626 | -- Used in call to Determine_Range | |
7627 | ||
c7e152b5 AC |
7628 | Bignum_Operands : Boolean; |
7629 | -- Set True if one or more operands is already of type Bignum, meaning | |
7630 | -- that for sure (regardless of Top_Level setting) we are committed to | |
4b1c4f20 | 7631 | -- doing the operation in Bignum mode (or in the case of a case or if |
5707e389 | 7632 | -- expression, converting all the dependent expressions to Bignum). |
4b1c4f20 RD |
7633 | |
7634 | Long_Long_Integer_Operands : Boolean; | |
5707e389 | 7635 | -- Set True if one or more operands is already of type Long_Long_Integer |
4b1c4f20 RD |
7636 | -- which means that if the result is known to be in the result type |
7637 | -- range, then we must convert such operands back to the result type. | |
a7f1b24f RD |
7638 | |
7639 | procedure Reanalyze (Typ : Entity_Id; Suppress : Boolean := False); | |
7640 | -- This is called when we have modified the node and we therefore need | |
7641 | -- to reanalyze it. It is important that we reset the mode to STRICT for | |
7642 | -- this reanalysis, since if we leave it in MINIMIZED or ELIMINATED mode | |
a90bd866 | 7643 | -- we would reenter this routine recursively which would not be good. |
a7f1b24f RD |
7644 | -- The argument Suppress is set True if we also want to suppress |
7645 | -- overflow checking for the reexpansion (this is set when we know | |
7646 | -- overflow is not possible). Typ is the type for the reanalysis. | |
7647 | ||
7648 | procedure Reexpand (Suppress : Boolean := False); | |
7649 | -- This is like Reanalyze, but does not do the Analyze step, it only | |
7650 | -- does a reexpansion. We do this reexpansion in STRICT mode, so that | |
7651 | -- instead of reentering the MINIMIZED/ELIMINATED mode processing, we | |
7652 | -- follow the normal expansion path (e.g. converting A**4 to A**2**2). | |
7653 | -- Note that skipping reanalysis is not just an optimization, testing | |
7654 | -- has showed up several complex cases in which reanalyzing an already | |
7655 | -- analyzed node causes incorrect behavior. | |
a40ada7e | 7656 | |
4b1c4f20 RD |
7657 | function In_Result_Range return Boolean; |
7658 | -- Returns True iff Lo .. Hi are within range of the result type | |
c7e152b5 | 7659 | |
a91e9ac7 | 7660 | procedure Max (A : in out Uint; B : Uint); |
5707e389 | 7661 | -- If A is No_Uint, sets A to B, else to UI_Max (A, B) |
a91e9ac7 AC |
7662 | |
7663 | procedure Min (A : in out Uint; B : Uint); | |
5707e389 | 7664 | -- If A is No_Uint, sets A to B, else to UI_Min (A, B) |
a91e9ac7 | 7665 | |
4b1c4f20 RD |
7666 | --------------------- |
7667 | -- In_Result_Range -- | |
7668 | --------------------- | |
7669 | ||
7670 | function In_Result_Range return Boolean is | |
7671 | begin | |
b6b5cca8 AC |
7672 | if Lo = No_Uint or else Hi = No_Uint then |
7673 | return False; | |
7674 | ||
edab6088 | 7675 | elsif Is_OK_Static_Subtype (Etype (N)) then |
4b1c4f20 RD |
7676 | return Lo >= Expr_Value (Type_Low_Bound (Rtyp)) |
7677 | and then | |
7678 | Hi <= Expr_Value (Type_High_Bound (Rtyp)); | |
b6b5cca8 | 7679 | |
4b1c4f20 RD |
7680 | else |
7681 | return Lo >= Expr_Value (Type_Low_Bound (Base_Type (Rtyp))) | |
7682 | and then | |
7683 | Hi <= Expr_Value (Type_High_Bound (Base_Type (Rtyp))); | |
7684 | end if; | |
7685 | end In_Result_Range; | |
7686 | ||
a91e9ac7 AC |
7687 | --------- |
7688 | -- Max -- | |
7689 | --------- | |
7690 | ||
7691 | procedure Max (A : in out Uint; B : Uint) is | |
7692 | begin | |
7693 | if A = No_Uint or else B > A then | |
7694 | A := B; | |
7695 | end if; | |
7696 | end Max; | |
7697 | ||
7698 | --------- | |
7699 | -- Min -- | |
7700 | --------- | |
7701 | ||
7702 | procedure Min (A : in out Uint; B : Uint) is | |
7703 | begin | |
7704 | if A = No_Uint or else B < A then | |
7705 | A := B; | |
7706 | end if; | |
7707 | end Min; | |
7708 | ||
a7f1b24f RD |
7709 | --------------- |
7710 | -- Reanalyze -- | |
7711 | --------------- | |
7712 | ||
7713 | procedure Reanalyze (Typ : Entity_Id; Suppress : Boolean := False) is | |
15c94a55 RD |
7714 | Svg : constant Overflow_Mode_Type := |
7715 | Scope_Suppress.Overflow_Mode_General; | |
7716 | Sva : constant Overflow_Mode_Type := | |
7717 | Scope_Suppress.Overflow_Mode_Assertions; | |
a7f1b24f RD |
7718 | Svo : constant Boolean := |
7719 | Scope_Suppress.Suppress (Overflow_Check); | |
7720 | ||
7721 | begin | |
15c94a55 RD |
7722 | Scope_Suppress.Overflow_Mode_General := Strict; |
7723 | Scope_Suppress.Overflow_Mode_Assertions := Strict; | |
a7f1b24f RD |
7724 | |
7725 | if Suppress then | |
7726 | Scope_Suppress.Suppress (Overflow_Check) := True; | |
7727 | end if; | |
7728 | ||
7729 | Analyze_And_Resolve (N, Typ); | |
7730 | ||
7731 | Scope_Suppress.Suppress (Overflow_Check) := Svo; | |
15c94a55 RD |
7732 | Scope_Suppress.Overflow_Mode_General := Svg; |
7733 | Scope_Suppress.Overflow_Mode_Assertions := Sva; | |
a7f1b24f RD |
7734 | end Reanalyze; |
7735 | ||
a40ada7e RD |
7736 | -------------- |
7737 | -- Reexpand -- | |
7738 | -------------- | |
7739 | ||
a7f1b24f | 7740 | procedure Reexpand (Suppress : Boolean := False) is |
15c94a55 RD |
7741 | Svg : constant Overflow_Mode_Type := |
7742 | Scope_Suppress.Overflow_Mode_General; | |
7743 | Sva : constant Overflow_Mode_Type := | |
7744 | Scope_Suppress.Overflow_Mode_Assertions; | |
a7f1b24f RD |
7745 | Svo : constant Boolean := |
7746 | Scope_Suppress.Suppress (Overflow_Check); | |
7747 | ||
a40ada7e | 7748 | begin |
15c94a55 RD |
7749 | Scope_Suppress.Overflow_Mode_General := Strict; |
7750 | Scope_Suppress.Overflow_Mode_Assertions := Strict; | |
a40ada7e | 7751 | Set_Analyzed (N, False); |
a7f1b24f RD |
7752 | |
7753 | if Suppress then | |
7754 | Scope_Suppress.Suppress (Overflow_Check) := True; | |
7755 | end if; | |
7756 | ||
a40ada7e | 7757 | Expand (N); |
a7f1b24f RD |
7758 | |
7759 | Scope_Suppress.Suppress (Overflow_Check) := Svo; | |
15c94a55 RD |
7760 | Scope_Suppress.Overflow_Mode_General := Svg; |
7761 | Scope_Suppress.Overflow_Mode_Assertions := Sva; | |
a40ada7e RD |
7762 | end Reexpand; |
7763 | ||
a7f1b24f | 7764 | -- Start of processing for Minimize_Eliminate_Overflows |
a91e9ac7 | 7765 | |
acad3c0a | 7766 | begin |
4b1c4f20 | 7767 | -- Case where we do not have a signed integer arithmetic operation |
acad3c0a AC |
7768 | |
7769 | if not Is_Signed_Integer_Arithmetic_Op (N) then | |
7770 | ||
7771 | -- Use the normal Determine_Range routine to get the range. We | |
7772 | -- don't require operands to be valid, invalid values may result in | |
7773 | -- rubbish results where the result has not been properly checked for | |
a90bd866 | 7774 | -- overflow, that's fine. |
acad3c0a AC |
7775 | |
7776 | Determine_Range (N, OK, Lo, Hi, Assume_Valid => False); | |
7777 | ||
5707e389 | 7778 | -- If Determine_Range did not work (can this in fact happen? Not |
acad3c0a AC |
7779 | -- clear but might as well protect), use type bounds. |
7780 | ||
7781 | if not OK then | |
7782 | Lo := Intval (Type_Low_Bound (Base_Type (Etype (N)))); | |
7783 | Hi := Intval (Type_High_Bound (Base_Type (Etype (N)))); | |
7784 | end if; | |
7785 | ||
7786 | -- If we don't have a binary operator, all we have to do is to set | |
637a41a5 | 7787 | -- the Hi/Lo range, so we are done. |
acad3c0a AC |
7788 | |
7789 | return; | |
7790 | ||
4b1c4f20 RD |
7791 | -- Processing for if expression |
7792 | ||
9b16cb57 | 7793 | elsif Nkind (N) = N_If_Expression then |
4b1c4f20 RD |
7794 | declare |
7795 | Then_DE : constant Node_Id := Next (First (Expressions (N))); | |
7796 | Else_DE : constant Node_Id := Next (Then_DE); | |
7797 | ||
7798 | begin | |
7799 | Bignum_Operands := False; | |
7800 | ||
a7f1b24f | 7801 | Minimize_Eliminate_Overflows |
4b1c4f20 RD |
7802 | (Then_DE, Lo, Hi, Top_Level => False); |
7803 | ||
7804 | if Lo = No_Uint then | |
7805 | Bignum_Operands := True; | |
7806 | end if; | |
7807 | ||
a7f1b24f | 7808 | Minimize_Eliminate_Overflows |
4b1c4f20 RD |
7809 | (Else_DE, Rlo, Rhi, Top_Level => False); |
7810 | ||
7811 | if Rlo = No_Uint then | |
7812 | Bignum_Operands := True; | |
7813 | else | |
7814 | Long_Long_Integer_Operands := | |
7815 | Etype (Then_DE) = LLIB or else Etype (Else_DE) = LLIB; | |
7816 | ||
7817 | Min (Lo, Rlo); | |
7818 | Max (Hi, Rhi); | |
7819 | end if; | |
7820 | ||
5707e389 AC |
7821 | -- If at least one of our operands is now Bignum, we must rebuild |
7822 | -- the if expression to use Bignum operands. We will analyze the | |
4b1c4f20 | 7823 | -- rebuilt if expression with overflow checks off, since once we |
a90bd866 | 7824 | -- are in bignum mode, we are all done with overflow checks. |
4b1c4f20 RD |
7825 | |
7826 | if Bignum_Operands then | |
7827 | Rewrite (N, | |
9b16cb57 | 7828 | Make_If_Expression (Loc, |
4b1c4f20 RD |
7829 | Expressions => New_List ( |
7830 | Remove_Head (Expressions (N)), | |
7831 | Convert_To_Bignum (Then_DE), | |
7832 | Convert_To_Bignum (Else_DE)), | |
7833 | Is_Elsif => Is_Elsif (N))); | |
7834 | ||
a7f1b24f | 7835 | Reanalyze (RTE (RE_Bignum), Suppress => True); |
4b1c4f20 RD |
7836 | |
7837 | -- If we have no Long_Long_Integer operands, then we are in result | |
7838 | -- range, since it means that none of our operands felt the need | |
7839 | -- to worry about overflow (otherwise it would have already been | |
a40ada7e RD |
7840 | -- converted to long long integer or bignum). We reexpand to |
7841 | -- complete the expansion of the if expression (but we do not | |
7842 | -- need to reanalyze). | |
4b1c4f20 RD |
7843 | |
7844 | elsif not Long_Long_Integer_Operands then | |
7845 | Set_Do_Overflow_Check (N, False); | |
a7f1b24f | 7846 | Reexpand; |
4b1c4f20 RD |
7847 | |
7848 | -- Otherwise convert us to long long integer mode. Note that we | |
7849 | -- don't need any further overflow checking at this level. | |
7850 | ||
7851 | else | |
7852 | Convert_To_And_Rewrite (LLIB, Then_DE); | |
7853 | Convert_To_And_Rewrite (LLIB, Else_DE); | |
7854 | Set_Etype (N, LLIB); | |
b6b5cca8 AC |
7855 | |
7856 | -- Now reanalyze with overflow checks off | |
7857 | ||
4b1c4f20 | 7858 | Set_Do_Overflow_Check (N, False); |
a7f1b24f | 7859 | Reanalyze (LLIB, Suppress => True); |
4b1c4f20 RD |
7860 | end if; |
7861 | end; | |
7862 | ||
7863 | return; | |
7864 | ||
7865 | -- Here for case expression | |
7866 | ||
7867 | elsif Nkind (N) = N_Case_Expression then | |
7868 | Bignum_Operands := False; | |
7869 | Long_Long_Integer_Operands := False; | |
4b1c4f20 RD |
7870 | |
7871 | declare | |
b6b5cca8 | 7872 | Alt : Node_Id; |
4b1c4f20 RD |
7873 | |
7874 | begin | |
7875 | -- Loop through expressions applying recursive call | |
7876 | ||
7877 | Alt := First (Alternatives (N)); | |
7878 | while Present (Alt) loop | |
7879 | declare | |
7880 | Aexp : constant Node_Id := Expression (Alt); | |
7881 | ||
7882 | begin | |
a7f1b24f | 7883 | Minimize_Eliminate_Overflows |
4b1c4f20 RD |
7884 | (Aexp, Lo, Hi, Top_Level => False); |
7885 | ||
7886 | if Lo = No_Uint then | |
7887 | Bignum_Operands := True; | |
7888 | elsif Etype (Aexp) = LLIB then | |
7889 | Long_Long_Integer_Operands := True; | |
7890 | end if; | |
7891 | end; | |
7892 | ||
7893 | Next (Alt); | |
7894 | end loop; | |
7895 | ||
7896 | -- If we have no bignum or long long integer operands, it means | |
7897 | -- that none of our dependent expressions could raise overflow. | |
7898 | -- In this case, we simply return with no changes except for | |
7899 | -- resetting the overflow flag, since we are done with overflow | |
a40ada7e RD |
7900 | -- checks for this node. We will reexpand to get the needed |
7901 | -- expansion for the case expression, but we do not need to | |
5707e389 | 7902 | -- reanalyze, since nothing has changed. |
4b1c4f20 | 7903 | |
b6b5cca8 | 7904 | if not (Bignum_Operands or Long_Long_Integer_Operands) then |
4b1c4f20 | 7905 | Set_Do_Overflow_Check (N, False); |
a7f1b24f | 7906 | Reexpand (Suppress => True); |
4b1c4f20 RD |
7907 | |
7908 | -- Otherwise we are going to rebuild the case expression using | |
7909 | -- either bignum or long long integer operands throughout. | |
7910 | ||
7911 | else | |
b6b5cca8 AC |
7912 | declare |
7913 | Rtype : Entity_Id; | |
7914 | New_Alts : List_Id; | |
7915 | New_Exp : Node_Id; | |
7916 | ||
7917 | begin | |
7918 | New_Alts := New_List; | |
7919 | Alt := First (Alternatives (N)); | |
7920 | while Present (Alt) loop | |
7921 | if Bignum_Operands then | |
7922 | New_Exp := Convert_To_Bignum (Expression (Alt)); | |
7923 | Rtype := RTE (RE_Bignum); | |
7924 | else | |
7925 | New_Exp := Convert_To (LLIB, Expression (Alt)); | |
7926 | Rtype := LLIB; | |
7927 | end if; | |
4b1c4f20 | 7928 | |
b6b5cca8 AC |
7929 | Append_To (New_Alts, |
7930 | Make_Case_Expression_Alternative (Sloc (Alt), | |
7931 | Actions => No_List, | |
7932 | Discrete_Choices => Discrete_Choices (Alt), | |
7933 | Expression => New_Exp)); | |
4b1c4f20 | 7934 | |
b6b5cca8 AC |
7935 | Next (Alt); |
7936 | end loop; | |
4b1c4f20 | 7937 | |
b6b5cca8 AC |
7938 | Rewrite (N, |
7939 | Make_Case_Expression (Loc, | |
7940 | Expression => Expression (N), | |
7941 | Alternatives => New_Alts)); | |
4b1c4f20 | 7942 | |
a7f1b24f | 7943 | Reanalyze (Rtype, Suppress => True); |
b6b5cca8 | 7944 | end; |
4b1c4f20 RD |
7945 | end if; |
7946 | end; | |
7947 | ||
7948 | return; | |
7949 | end if; | |
7950 | ||
7951 | -- If we have an arithmetic operator we make recursive calls on the | |
acad3c0a | 7952 | -- operands to get the ranges (and to properly process the subtree |
637a41a5 | 7953 | -- that lies below us). |
acad3c0a | 7954 | |
a7f1b24f | 7955 | Minimize_Eliminate_Overflows |
4b1c4f20 | 7956 | (Right_Opnd (N), Rlo, Rhi, Top_Level => False); |
acad3c0a | 7957 | |
4b1c4f20 | 7958 | if Binary then |
a7f1b24f | 7959 | Minimize_Eliminate_Overflows |
4b1c4f20 | 7960 | (Left_Opnd (N), Llo, Lhi, Top_Level => False); |
acad3c0a AC |
7961 | end if; |
7962 | ||
b6b5cca8 AC |
7963 | -- Record if we have Long_Long_Integer operands |
7964 | ||
7965 | Long_Long_Integer_Operands := | |
7966 | Etype (Right_Opnd (N)) = LLIB | |
7967 | or else (Binary and then Etype (Left_Opnd (N)) = LLIB); | |
7968 | ||
7969 | -- If either operand is a bignum, then result will be a bignum and we | |
7970 | -- don't need to do any range analysis. As previously discussed we could | |
7971 | -- do range analysis in such cases, but it could mean working with giant | |
7972 | -- numbers at compile time for very little gain (the number of cases | |
5707e389 | 7973 | -- in which we could slip back from bignum mode is small). |
acad3c0a AC |
7974 | |
7975 | if Rlo = No_Uint or else (Binary and then Llo = No_Uint) then | |
7976 | Lo := No_Uint; | |
7977 | Hi := No_Uint; | |
c7e152b5 | 7978 | Bignum_Operands := True; |
acad3c0a AC |
7979 | |
7980 | -- Otherwise compute result range | |
7981 | ||
7982 | else | |
c7e152b5 AC |
7983 | Bignum_Operands := False; |
7984 | ||
acad3c0a AC |
7985 | case Nkind (N) is |
7986 | ||
7987 | -- Absolute value | |
7988 | ||
7989 | when N_Op_Abs => | |
7990 | Lo := Uint_0; | |
6cb3037c | 7991 | Hi := UI_Max (abs Rlo, abs Rhi); |
acad3c0a AC |
7992 | |
7993 | -- Addition | |
7994 | ||
7995 | when N_Op_Add => | |
7996 | Lo := Llo + Rlo; | |
7997 | Hi := Lhi + Rhi; | |
7998 | ||
7999 | -- Division | |
8000 | ||
8001 | when N_Op_Divide => | |
a91e9ac7 | 8002 | |
967fb65e | 8003 | -- If the right operand can only be zero, set 0..0 |
a91e9ac7 | 8004 | |
967fb65e AC |
8005 | if Rlo = 0 and then Rhi = 0 then |
8006 | Lo := Uint_0; | |
8007 | Hi := Uint_0; | |
a91e9ac7 | 8008 | |
967fb65e AC |
8009 | -- Possible bounds of division must come from dividing end |
8010 | -- values of the input ranges (four possibilities), provided | |
8011 | -- zero is not included in the possible values of the right | |
8012 | -- operand. | |
8013 | ||
8014 | -- Otherwise, we just consider two intervals of values for | |
8015 | -- the right operand: the interval of negative values (up to | |
8016 | -- -1) and the interval of positive values (starting at 1). | |
8017 | -- Since division by 1 is the identity, and division by -1 | |
8018 | -- is negation, we get all possible bounds of division in that | |
8019 | -- case by considering: | |
8020 | -- - all values from the division of end values of input | |
8021 | -- ranges; | |
8022 | -- - the end values of the left operand; | |
8023 | -- - the negation of the end values of the left operand. | |
a91e9ac7 | 8024 | |
967fb65e AC |
8025 | else |
8026 | declare | |
8027 | Mrk : constant Uintp.Save_Mark := Mark; | |
8028 | -- Mark so we can release the RR and Ev values | |
a91e9ac7 | 8029 | |
967fb65e AC |
8030 | Ev1 : Uint; |
8031 | Ev2 : Uint; | |
8032 | Ev3 : Uint; | |
8033 | Ev4 : Uint; | |
a91e9ac7 | 8034 | |
967fb65e AC |
8035 | begin |
8036 | -- Discard extreme values of zero for the divisor, since | |
8037 | -- they will simply result in an exception in any case. | |
a91e9ac7 | 8038 | |
967fb65e AC |
8039 | if Rlo = 0 then |
8040 | Rlo := Uint_1; | |
8041 | elsif Rhi = 0 then | |
8042 | Rhi := -Uint_1; | |
a91e9ac7 | 8043 | end if; |
a91e9ac7 | 8044 | |
967fb65e AC |
8045 | -- Compute possible bounds coming from dividing end |
8046 | -- values of the input ranges. | |
a91e9ac7 | 8047 | |
967fb65e AC |
8048 | Ev1 := Llo / Rlo; |
8049 | Ev2 := Llo / Rhi; | |
8050 | Ev3 := Lhi / Rlo; | |
8051 | Ev4 := Lhi / Rhi; | |
a91e9ac7 | 8052 | |
967fb65e AC |
8053 | Lo := UI_Min (UI_Min (Ev1, Ev2), UI_Min (Ev3, Ev4)); |
8054 | Hi := UI_Max (UI_Max (Ev1, Ev2), UI_Max (Ev3, Ev4)); | |
a91e9ac7 | 8055 | |
967fb65e AC |
8056 | -- If the right operand can be both negative or positive, |
8057 | -- include the end values of the left operand in the | |
8058 | -- extreme values, as well as their negation. | |
a91e9ac7 | 8059 | |
967fb65e AC |
8060 | if Rlo < 0 and then Rhi > 0 then |
8061 | Ev1 := Llo; | |
8062 | Ev2 := -Llo; | |
8063 | Ev3 := Lhi; | |
8064 | Ev4 := -Lhi; | |
a91e9ac7 | 8065 | |
967fb65e AC |
8066 | Min (Lo, |
8067 | UI_Min (UI_Min (Ev1, Ev2), UI_Min (Ev3, Ev4))); | |
8068 | Max (Hi, | |
8069 | UI_Max (UI_Max (Ev1, Ev2), UI_Max (Ev3, Ev4))); | |
a91e9ac7 | 8070 | end if; |
a91e9ac7 | 8071 | |
967fb65e | 8072 | -- Release the RR and Ev values |
a91e9ac7 | 8073 | |
967fb65e AC |
8074 | Release_And_Save (Mrk, Lo, Hi); |
8075 | end; | |
8076 | end if; | |
acad3c0a AC |
8077 | |
8078 | -- Exponentiation | |
8079 | ||
8080 | when N_Op_Expon => | |
6cb3037c AC |
8081 | |
8082 | -- Discard negative values for the exponent, since they will | |
8083 | -- simply result in an exception in any case. | |
8084 | ||
8085 | if Rhi < 0 then | |
8086 | Rhi := Uint_0; | |
8087 | elsif Rlo < 0 then | |
8088 | Rlo := Uint_0; | |
8089 | end if; | |
8090 | ||
8091 | -- Estimate number of bits in result before we go computing | |
8092 | -- giant useless bounds. Basically the number of bits in the | |
8093 | -- result is the number of bits in the base multiplied by the | |
8094 | -- value of the exponent. If this is big enough that the result | |
8095 | -- definitely won't fit in Long_Long_Integer, switch to bignum | |
8096 | -- mode immediately, and avoid computing giant bounds. | |
8097 | ||
8098 | -- The comparison here is approximate, but conservative, it | |
8099 | -- only clicks on cases that are sure to exceed the bounds. | |
8100 | ||
8101 | if Num_Bits (UI_Max (abs Llo, abs Lhi)) * Rhi + 1 > 100 then | |
8102 | Lo := No_Uint; | |
8103 | Hi := No_Uint; | |
8104 | ||
8105 | -- If right operand is zero then result is 1 | |
8106 | ||
8107 | elsif Rhi = 0 then | |
8108 | Lo := Uint_1; | |
8109 | Hi := Uint_1; | |
8110 | ||
8111 | else | |
8112 | -- High bound comes either from exponentiation of largest | |
967fb65e AC |
8113 | -- positive value to largest exponent value, or from |
8114 | -- the exponentiation of most negative value to an | |
8115 | -- even exponent. | |
6cb3037c AC |
8116 | |
8117 | declare | |
8118 | Hi1, Hi2 : Uint; | |
8119 | ||
8120 | begin | |
967fb65e | 8121 | if Lhi > 0 then |
6cb3037c AC |
8122 | Hi1 := Lhi ** Rhi; |
8123 | else | |
8124 | Hi1 := Uint_0; | |
8125 | end if; | |
8126 | ||
8127 | if Llo < 0 then | |
8128 | if Rhi mod 2 = 0 then | |
6cb3037c | 8129 | Hi2 := Llo ** Rhi; |
967fb65e AC |
8130 | else |
8131 | Hi2 := Llo ** (Rhi - 1); | |
6cb3037c AC |
8132 | end if; |
8133 | else | |
8134 | Hi2 := Uint_0; | |
8135 | end if; | |
8136 | ||
8137 | Hi := UI_Max (Hi1, Hi2); | |
8138 | end; | |
8139 | ||
8140 | -- Result can only be negative if base can be negative | |
8141 | ||
8142 | if Llo < 0 then | |
5707e389 | 8143 | if Rhi mod 2 = 0 then |
6cb3037c AC |
8144 | Lo := Llo ** (Rhi - 1); |
8145 | else | |
8146 | Lo := Llo ** Rhi; | |
8147 | end if; | |
8148 | ||
5707e389 | 8149 | -- Otherwise low bound is minimum ** minimum |
6cb3037c AC |
8150 | |
8151 | else | |
8152 | Lo := Llo ** Rlo; | |
8153 | end if; | |
8154 | end if; | |
acad3c0a AC |
8155 | |
8156 | -- Negation | |
8157 | ||
8158 | when N_Op_Minus => | |
8159 | Lo := -Rhi; | |
8160 | Hi := -Rlo; | |
8161 | ||
8162 | -- Mod | |
8163 | ||
8164 | when N_Op_Mod => | |
a91e9ac7 | 8165 | declare |
967fb65e | 8166 | Maxabs : constant Uint := UI_Max (abs Rlo, abs Rhi) - 1; |
a91e9ac7 AC |
8167 | -- This is the maximum absolute value of the result |
8168 | ||
8169 | begin | |
8170 | Lo := Uint_0; | |
8171 | Hi := Uint_0; | |
8172 | ||
8173 | -- The result depends only on the sign and magnitude of | |
8174 | -- the right operand, it does not depend on the sign or | |
8175 | -- magnitude of the left operand. | |
8176 | ||
8177 | if Rlo < 0 then | |
8178 | Lo := -Maxabs; | |
8179 | end if; | |
8180 | ||
8181 | if Rhi > 0 then | |
8182 | Hi := Maxabs; | |
8183 | end if; | |
8184 | end; | |
acad3c0a AC |
8185 | |
8186 | -- Multiplication | |
8187 | ||
8188 | when N_Op_Multiply => | |
d79059a3 AC |
8189 | |
8190 | -- Possible bounds of multiplication must come from multiplying | |
8191 | -- end values of the input ranges (four possibilities). | |
8192 | ||
8193 | declare | |
8194 | Mrk : constant Uintp.Save_Mark := Mark; | |
8195 | -- Mark so we can release the Ev values | |
8196 | ||
8197 | Ev1 : constant Uint := Llo * Rlo; | |
8198 | Ev2 : constant Uint := Llo * Rhi; | |
8199 | Ev3 : constant Uint := Lhi * Rlo; | |
8200 | Ev4 : constant Uint := Lhi * Rhi; | |
8201 | ||
8202 | begin | |
8203 | Lo := UI_Min (UI_Min (Ev1, Ev2), UI_Min (Ev3, Ev4)); | |
8204 | Hi := UI_Max (UI_Max (Ev1, Ev2), UI_Max (Ev3, Ev4)); | |
8205 | ||
8206 | -- Release the Ev values | |
8207 | ||
8208 | Release_And_Save (Mrk, Lo, Hi); | |
8209 | end; | |
acad3c0a AC |
8210 | |
8211 | -- Plus operator (affirmation) | |
8212 | ||
8213 | when N_Op_Plus => | |
8214 | Lo := Rlo; | |
8215 | Hi := Rhi; | |
8216 | ||
8217 | -- Remainder | |
8218 | ||
8219 | when N_Op_Rem => | |
a91e9ac7 | 8220 | declare |
967fb65e | 8221 | Maxabs : constant Uint := UI_Max (abs Rlo, abs Rhi) - 1; |
a91e9ac7 | 8222 | -- This is the maximum absolute value of the result. Note |
967fb65e AC |
8223 | -- that the result range does not depend on the sign of the |
8224 | -- right operand. | |
a91e9ac7 AC |
8225 | |
8226 | begin | |
8227 | Lo := Uint_0; | |
8228 | Hi := Uint_0; | |
8229 | ||
8230 | -- Case of left operand negative, which results in a range | |
8231 | -- of -Maxabs .. 0 for those negative values. If there are | |
8232 | -- no negative values then Lo value of result is always 0. | |
8233 | ||
8234 | if Llo < 0 then | |
8235 | Lo := -Maxabs; | |
8236 | end if; | |
8237 | ||
8238 | -- Case of left operand positive | |
8239 | ||
8240 | if Lhi > 0 then | |
8241 | Hi := Maxabs; | |
8242 | end if; | |
8243 | end; | |
acad3c0a AC |
8244 | |
8245 | -- Subtract | |
8246 | ||
8247 | when N_Op_Subtract => | |
8248 | Lo := Llo - Rhi; | |
8249 | Hi := Lhi - Rlo; | |
8250 | ||
8251 | -- Nothing else should be possible | |
8252 | ||
8253 | when others => | |
8254 | raise Program_Error; | |
acad3c0a AC |
8255 | end case; |
8256 | end if; | |
8257 | ||
a40ada7e | 8258 | -- Here for the case where we have not rewritten anything (no bignum |
5707e389 AC |
8259 | -- operands or long long integer operands), and we know the result. |
8260 | -- If we know we are in the result range, and we do not have Bignum | |
8261 | -- operands or Long_Long_Integer operands, we can just reexpand with | |
8262 | -- overflow checks turned off (since we know we cannot have overflow). | |
8263 | -- As always the reexpansion is required to complete expansion of the | |
8264 | -- operator, but we do not need to reanalyze, and we prevent recursion | |
8265 | -- by suppressing the check. | |
b6b5cca8 AC |
8266 | |
8267 | if not (Bignum_Operands or Long_Long_Integer_Operands) | |
8268 | and then In_Result_Range | |
8269 | then | |
8270 | Set_Do_Overflow_Check (N, False); | |
a7f1b24f | 8271 | Reexpand (Suppress => True); |
b6b5cca8 AC |
8272 | return; |
8273 | ||
8274 | -- Here we know that we are not in the result range, and in the general | |
5707e389 AC |
8275 | -- case we will move into either the Bignum or Long_Long_Integer domain |
8276 | -- to compute the result. However, there is one exception. If we are | |
8277 | -- at the top level, and we do not have Bignum or Long_Long_Integer | |
8278 | -- operands, we will have to immediately convert the result back to | |
8279 | -- the result type, so there is no point in Bignum/Long_Long_Integer | |
8280 | -- fiddling. | |
b6b5cca8 AC |
8281 | |
8282 | elsif Top_Level | |
8283 | and then not (Bignum_Operands or Long_Long_Integer_Operands) | |
2352eadb AC |
8284 | |
8285 | -- One further refinement. If we are at the top level, but our parent | |
8286 | -- is a type conversion, then go into bignum or long long integer node | |
8287 | -- since the result will be converted to that type directly without | |
8288 | -- going through the result type, and we may avoid an overflow. This | |
8289 | -- is the case for example of Long_Long_Integer (A ** 4), where A is | |
8290 | -- of type Integer, and the result A ** 4 fits in Long_Long_Integer | |
8291 | -- but does not fit in Integer. | |
8292 | ||
8293 | and then Nkind (Parent (N)) /= N_Type_Conversion | |
b6b5cca8 | 8294 | then |
a7f1b24f | 8295 | -- Here keep original types, but we need to complete analysis |
b6b5cca8 AC |
8296 | |
8297 | -- One subtlety. We can't just go ahead and do an analyze operation | |
5707e389 AC |
8298 | -- here because it will cause recursion into the whole MINIMIZED/ |
8299 | -- ELIMINATED overflow processing which is not what we want. Here | |
b6b5cca8 | 8300 | -- we are at the top level, and we need a check against the result |
a90bd866 | 8301 | -- mode (i.e. we want to use STRICT mode). So do exactly that. |
a40ada7e RD |
8302 | -- Also, we have not modified the node, so this is a case where |
8303 | -- we need to reexpand, but not reanalyze. | |
b6b5cca8 | 8304 | |
a7f1b24f | 8305 | Reexpand; |
b6b5cca8 AC |
8306 | return; |
8307 | ||
8308 | -- Cases where we do the operation in Bignum mode. This happens either | |
acad3c0a | 8309 | -- because one of our operands is in Bignum mode already, or because |
6cb3037c AC |
8310 | -- the computed bounds are outside the bounds of Long_Long_Integer, |
8311 | -- which in some cases can be indicated by Hi and Lo being No_Uint. | |
acad3c0a AC |
8312 | |
8313 | -- Note: we could do better here and in some cases switch back from | |
8314 | -- Bignum mode to normal mode, e.g. big mod 2 must be in the range | |
8315 | -- 0 .. 1, but the cases are rare and it is not worth the effort. | |
8316 | -- Failing to do this switching back is only an efficiency issue. | |
8317 | ||
b6b5cca8 | 8318 | elsif Lo = No_Uint or else Lo < LLLo or else Hi > LLHi then |
acad3c0a | 8319 | |
c7e152b5 | 8320 | -- OK, we are definitely outside the range of Long_Long_Integer. The |
b6b5cca8 | 8321 | -- question is whether to move to Bignum mode, or stay in the domain |
c7e152b5 AC |
8322 | -- of Long_Long_Integer, signalling that an overflow check is needed. |
8323 | ||
8324 | -- Obviously in MINIMIZED mode we stay with LLI, since we are not in | |
8325 | -- the Bignum business. In ELIMINATED mode, we will normally move | |
8326 | -- into Bignum mode, but there is an exception if neither of our | |
8327 | -- operands is Bignum now, and we are at the top level (Top_Level | |
8328 | -- set True). In this case, there is no point in moving into Bignum | |
8329 | -- mode to prevent overflow if the caller will immediately convert | |
8330 | -- the Bignum value back to LLI with an overflow check. It's more | |
a7f1b24f | 8331 | -- efficient to stay in LLI mode with an overflow check (if needed) |
c7e152b5 AC |
8332 | |
8333 | if Check_Mode = Minimized | |
8334 | or else (Top_Level and not Bignum_Operands) | |
8335 | then | |
a7f1b24f RD |
8336 | if Do_Overflow_Check (N) then |
8337 | Enable_Overflow_Check (N); | |
8338 | end if; | |
acad3c0a | 8339 | |
a7f1b24f RD |
8340 | -- The result now has to be in Long_Long_Integer mode, so adjust |
8341 | -- the possible range to reflect this. Note these calls also | |
8342 | -- change No_Uint values from the top level case to LLI bounds. | |
c7e152b5 AC |
8343 | |
8344 | Max (Lo, LLLo); | |
8345 | Min (Hi, LLHi); | |
8346 | ||
8347 | -- Otherwise we are in ELIMINATED mode and we switch to Bignum mode | |
acad3c0a AC |
8348 | |
8349 | else | |
8350 | pragma Assert (Check_Mode = Eliminated); | |
8351 | ||
8352 | declare | |
8353 | Fent : Entity_Id; | |
8354 | Args : List_Id; | |
8355 | ||
8356 | begin | |
8357 | case Nkind (N) is | |
8358 | when N_Op_Abs => | |
8359 | Fent := RTE (RE_Big_Abs); | |
8360 | ||
8361 | when N_Op_Add => | |
8362 | Fent := RTE (RE_Big_Add); | |
8363 | ||
8364 | when N_Op_Divide => | |
8365 | Fent := RTE (RE_Big_Div); | |
8366 | ||
8367 | when N_Op_Expon => | |
8368 | Fent := RTE (RE_Big_Exp); | |
8369 | ||
8370 | when N_Op_Minus => | |
8371 | Fent := RTE (RE_Big_Neg); | |
8372 | ||
8373 | when N_Op_Mod => | |
8374 | Fent := RTE (RE_Big_Mod); | |
8375 | ||
8376 | when N_Op_Multiply => | |
8377 | Fent := RTE (RE_Big_Mul); | |
8378 | ||
8379 | when N_Op_Rem => | |
8380 | Fent := RTE (RE_Big_Rem); | |
8381 | ||
8382 | when N_Op_Subtract => | |
8383 | Fent := RTE (RE_Big_Sub); | |
8384 | ||
8385 | -- Anything else is an internal error, this includes the | |
8386 | -- N_Op_Plus case, since how can plus cause the result | |
8387 | -- to be out of range if the operand is in range? | |
8388 | ||
8389 | when others => | |
8390 | raise Program_Error; | |
8391 | end case; | |
8392 | ||
8393 | -- Construct argument list for Bignum call, converting our | |
8394 | -- operands to Bignum form if they are not already there. | |
8395 | ||
8396 | Args := New_List; | |
8397 | ||
8398 | if Binary then | |
8399 | Append_To (Args, Convert_To_Bignum (Left_Opnd (N))); | |
8400 | end if; | |
8401 | ||
8402 | Append_To (Args, Convert_To_Bignum (Right_Opnd (N))); | |
8403 | ||
8404 | -- Now rewrite the arithmetic operator with a call to the | |
8405 | -- corresponding bignum function. | |
8406 | ||
8407 | Rewrite (N, | |
8408 | Make_Function_Call (Loc, | |
8409 | Name => New_Occurrence_Of (Fent, Loc), | |
8410 | Parameter_Associations => Args)); | |
a7f1b24f | 8411 | Reanalyze (RTE (RE_Bignum), Suppress => True); |
c7e152b5 AC |
8412 | |
8413 | -- Indicate result is Bignum mode | |
8414 | ||
8415 | Lo := No_Uint; | |
8416 | Hi := No_Uint; | |
6cb3037c | 8417 | return; |
acad3c0a AC |
8418 | end; |
8419 | end if; | |
8420 | ||
8421 | -- Otherwise we are in range of Long_Long_Integer, so no overflow | |
6cb3037c | 8422 | -- check is required, at least not yet. |
acad3c0a AC |
8423 | |
8424 | else | |
6cb3037c AC |
8425 | Set_Do_Overflow_Check (N, False); |
8426 | end if; | |
acad3c0a | 8427 | |
b6b5cca8 AC |
8428 | -- Here we are not in Bignum territory, but we may have long long |
8429 | -- integer operands that need special handling. First a special check: | |
8430 | -- If an exponentiation operator exponent is of type Long_Long_Integer, | |
8431 | -- it means we converted it to prevent overflow, but exponentiation | |
8432 | -- requires a Natural right operand, so convert it back to Natural. | |
8433 | -- This conversion may raise an exception which is fine. | |
4b1c4f20 | 8434 | |
b6b5cca8 AC |
8435 | if Nkind (N) = N_Op_Expon and then Etype (Right_Opnd (N)) = LLIB then |
8436 | Convert_To_And_Rewrite (Standard_Natural, Right_Opnd (N)); | |
4b1c4f20 RD |
8437 | end if; |
8438 | ||
6cb3037c AC |
8439 | -- Here we will do the operation in Long_Long_Integer. We do this even |
8440 | -- if we know an overflow check is required, better to do this in long | |
a90bd866 | 8441 | -- long integer mode, since we are less likely to overflow. |
acad3c0a | 8442 | |
6cb3037c AC |
8443 | -- Convert right or only operand to Long_Long_Integer, except that |
8444 | -- we do not touch the exponentiation right operand. | |
acad3c0a | 8445 | |
6cb3037c AC |
8446 | if Nkind (N) /= N_Op_Expon then |
8447 | Convert_To_And_Rewrite (LLIB, Right_Opnd (N)); | |
8448 | end if; | |
acad3c0a | 8449 | |
6cb3037c | 8450 | -- Convert left operand to Long_Long_Integer for binary case |
d79059a3 | 8451 | |
6cb3037c AC |
8452 | if Binary then |
8453 | Convert_To_And_Rewrite (LLIB, Left_Opnd (N)); | |
8454 | end if; | |
8455 | ||
8456 | -- Reset node to unanalyzed | |
8457 | ||
8458 | Set_Analyzed (N, False); | |
8459 | Set_Etype (N, Empty); | |
8460 | Set_Entity (N, Empty); | |
8461 | ||
a91e9ac7 AC |
8462 | -- Now analyze this new node. This reanalysis will complete processing |
8463 | -- for the node. In particular we will complete the expansion of an | |
8464 | -- exponentiation operator (e.g. changing A ** 2 to A * A), and also | |
8465 | -- we will complete any division checks (since we have not changed the | |
8466 | -- setting of the Do_Division_Check flag). | |
acad3c0a | 8467 | |
a7f1b24f | 8468 | -- We do this reanalysis in STRICT mode to avoid recursion into the |
a90bd866 | 8469 | -- MINIMIZED/ELIMINATED handling, since we are now done with that. |
acad3c0a | 8470 | |
a7f1b24f | 8471 | declare |
15c94a55 RD |
8472 | SG : constant Overflow_Mode_Type := |
8473 | Scope_Suppress.Overflow_Mode_General; | |
8474 | SA : constant Overflow_Mode_Type := | |
8475 | Scope_Suppress.Overflow_Mode_Assertions; | |
6cb3037c | 8476 | |
a7f1b24f | 8477 | begin |
15c94a55 RD |
8478 | Scope_Suppress.Overflow_Mode_General := Strict; |
8479 | Scope_Suppress.Overflow_Mode_Assertions := Strict; | |
6cb3037c | 8480 | |
a7f1b24f RD |
8481 | if not Do_Overflow_Check (N) then |
8482 | Reanalyze (LLIB, Suppress => True); | |
8483 | else | |
8484 | Reanalyze (LLIB); | |
8485 | end if; | |
8486 | ||
15c94a55 RD |
8487 | Scope_Suppress.Overflow_Mode_General := SG; |
8488 | Scope_Suppress.Overflow_Mode_Assertions := SA; | |
a7f1b24f RD |
8489 | end; |
8490 | end Minimize_Eliminate_Overflows; | |
acad3c0a AC |
8491 | |
8492 | ------------------------- | |
8493 | -- Overflow_Check_Mode -- | |
8494 | ------------------------- | |
8495 | ||
15c94a55 | 8496 | function Overflow_Check_Mode return Overflow_Mode_Type is |
70482933 | 8497 | begin |
05b34c18 | 8498 | if In_Assertion_Expr = 0 then |
15c94a55 | 8499 | return Scope_Suppress.Overflow_Mode_General; |
fbf5a39b | 8500 | else |
15c94a55 | 8501 | return Scope_Suppress.Overflow_Mode_Assertions; |
fbf5a39b | 8502 | end if; |
acad3c0a AC |
8503 | end Overflow_Check_Mode; |
8504 | ||
8505 | -------------------------------- | |
8506 | -- Overflow_Checks_Suppressed -- | |
8507 | -------------------------------- | |
8508 | ||
8509 | function Overflow_Checks_Suppressed (E : Entity_Id) return Boolean is | |
8510 | begin | |
a7f1b24f RD |
8511 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
8512 | return Is_Check_Suppressed (E, Overflow_Check); | |
8513 | else | |
8514 | return Scope_Suppress.Suppress (Overflow_Check); | |
8515 | end if; | |
70482933 | 8516 | end Overflow_Checks_Suppressed; |
b568955d | 8517 | |
f1c80977 AC |
8518 | --------------------------------- |
8519 | -- Predicate_Checks_Suppressed -- | |
8520 | --------------------------------- | |
8521 | ||
8522 | function Predicate_Checks_Suppressed (E : Entity_Id) return Boolean is | |
8523 | begin | |
8524 | if Present (E) and then Checks_May_Be_Suppressed (E) then | |
8525 | return Is_Check_Suppressed (E, Predicate_Check); | |
8526 | else | |
8527 | return Scope_Suppress.Suppress (Predicate_Check); | |
8528 | end if; | |
8529 | end Predicate_Checks_Suppressed; | |
8530 | ||
70482933 RK |
8531 | ----------------------------- |
8532 | -- Range_Checks_Suppressed -- | |
8533 | ----------------------------- | |
8534 | ||
8535 | function Range_Checks_Suppressed (E : Entity_Id) return Boolean is | |
8536 | begin | |
fbf5a39b | 8537 | if Present (E) then |
21c51f53 | 8538 | if Kill_Range_Checks (E) then |
fbf5a39b | 8539 | return True; |
4bd4bb7f | 8540 | |
fbf5a39b AC |
8541 | elsif Checks_May_Be_Suppressed (E) then |
8542 | return Is_Check_Suppressed (E, Range_Check); | |
8543 | end if; | |
8544 | end if; | |
70482933 | 8545 | |
3217f71e | 8546 | return Scope_Suppress.Suppress (Range_Check); |
70482933 RK |
8547 | end Range_Checks_Suppressed; |
8548 | ||
c064e066 RD |
8549 | ----------------------------------------- |
8550 | -- Range_Or_Validity_Checks_Suppressed -- | |
8551 | ----------------------------------------- | |
8552 | ||
8553 | -- Note: the coding would be simpler here if we simply made appropriate | |
8554 | -- calls to Range/Validity_Checks_Suppressed, but that would result in | |
8555 | -- duplicated checks which we prefer to avoid. | |
8556 | ||
8557 | function Range_Or_Validity_Checks_Suppressed | |
8558 | (Expr : Node_Id) return Boolean | |
8559 | is | |
8560 | begin | |
8561 | -- Immediate return if scope checks suppressed for either check | |
8562 | ||
3217f71e AC |
8563 | if Scope_Suppress.Suppress (Range_Check) |
8564 | or | |
8565 | Scope_Suppress.Suppress (Validity_Check) | |
8566 | then | |
c064e066 RD |
8567 | return True; |
8568 | end if; | |
8569 | ||
8570 | -- If no expression, that's odd, decide that checks are suppressed, | |
8571 | -- since we don't want anyone trying to do checks in this case, which | |
8572 | -- is most likely the result of some other error. | |
8573 | ||
8574 | if No (Expr) then | |
8575 | return True; | |
8576 | end if; | |
8577 | ||
8578 | -- Expression is present, so perform suppress checks on type | |
8579 | ||
8580 | declare | |
8581 | Typ : constant Entity_Id := Etype (Expr); | |
8582 | begin | |
21c51f53 | 8583 | if Checks_May_Be_Suppressed (Typ) |
c064e066 RD |
8584 | and then (Is_Check_Suppressed (Typ, Range_Check) |
8585 | or else | |
8586 | Is_Check_Suppressed (Typ, Validity_Check)) | |
8587 | then | |
8588 | return True; | |
8589 | end if; | |
8590 | end; | |
8591 | ||
8592 | -- If expression is an entity name, perform checks on this entity | |
8593 | ||
8594 | if Is_Entity_Name (Expr) then | |
8595 | declare | |
8596 | Ent : constant Entity_Id := Entity (Expr); | |
8597 | begin | |
8598 | if Checks_May_Be_Suppressed (Ent) then | |
8599 | return Is_Check_Suppressed (Ent, Range_Check) | |
8600 | or else Is_Check_Suppressed (Ent, Validity_Check); | |
8601 | end if; | |
8602 | end; | |
8603 | end if; | |
8604 | ||
8605 | -- If we fall through, no checks suppressed | |
8606 | ||
8607 | return False; | |
8608 | end Range_Or_Validity_Checks_Suppressed; | |
8609 | ||
8cbb664e MG |
8610 | ------------------- |
8611 | -- Remove_Checks -- | |
8612 | ------------------- | |
8613 | ||
8614 | procedure Remove_Checks (Expr : Node_Id) is | |
8cbb664e MG |
8615 | function Process (N : Node_Id) return Traverse_Result; |
8616 | -- Process a single node during the traversal | |
8617 | ||
10303118 BD |
8618 | procedure Traverse is new Traverse_Proc (Process); |
8619 | -- The traversal procedure itself | |
8cbb664e MG |
8620 | |
8621 | ------------- | |
8622 | -- Process -- | |
8623 | ------------- | |
8624 | ||
8625 | function Process (N : Node_Id) return Traverse_Result is | |
8626 | begin | |
8627 | if Nkind (N) not in N_Subexpr then | |
8628 | return Skip; | |
8629 | end if; | |
8630 | ||
8631 | Set_Do_Range_Check (N, False); | |
8632 | ||
8633 | case Nkind (N) is | |
8634 | when N_And_Then => | |
10303118 | 8635 | Traverse (Left_Opnd (N)); |
8cbb664e MG |
8636 | return Skip; |
8637 | ||
8638 | when N_Attribute_Reference => | |
8cbb664e MG |
8639 | Set_Do_Overflow_Check (N, False); |
8640 | ||
8cbb664e MG |
8641 | when N_Function_Call => |
8642 | Set_Do_Tag_Check (N, False); | |
8643 | ||
8cbb664e MG |
8644 | when N_Op => |
8645 | Set_Do_Overflow_Check (N, False); | |
8646 | ||
8647 | case Nkind (N) is | |
8648 | when N_Op_Divide => | |
8649 | Set_Do_Division_Check (N, False); | |
8650 | ||
8651 | when N_Op_And => | |
8652 | Set_Do_Length_Check (N, False); | |
8653 | ||
8654 | when N_Op_Mod => | |
8655 | Set_Do_Division_Check (N, False); | |
8656 | ||
8657 | when N_Op_Or => | |
8658 | Set_Do_Length_Check (N, False); | |
8659 | ||
8660 | when N_Op_Rem => | |
8661 | Set_Do_Division_Check (N, False); | |
8662 | ||
8663 | when N_Op_Xor => | |
8664 | Set_Do_Length_Check (N, False); | |
8665 | ||
8666 | when others => | |
8667 | null; | |
8668 | end case; | |
8669 | ||
8670 | when N_Or_Else => | |
10303118 | 8671 | Traverse (Left_Opnd (N)); |
8cbb664e MG |
8672 | return Skip; |
8673 | ||
8674 | when N_Selected_Component => | |
8cbb664e MG |
8675 | Set_Do_Discriminant_Check (N, False); |
8676 | ||
8cbb664e | 8677 | when N_Type_Conversion => |
fbf5a39b AC |
8678 | Set_Do_Length_Check (N, False); |
8679 | Set_Do_Tag_Check (N, False); | |
8cbb664e | 8680 | Set_Do_Overflow_Check (N, False); |
8cbb664e MG |
8681 | |
8682 | when others => | |
8683 | null; | |
8684 | end case; | |
8685 | ||
8686 | return OK; | |
8687 | end Process; | |
8688 | ||
8689 | -- Start of processing for Remove_Checks | |
8690 | ||
8691 | begin | |
10303118 | 8692 | Traverse (Expr); |
8cbb664e MG |
8693 | end Remove_Checks; |
8694 | ||
70482933 RK |
8695 | ---------------------------- |
8696 | -- Selected_Length_Checks -- | |
8697 | ---------------------------- | |
8698 | ||
8699 | function Selected_Length_Checks | |
8700 | (Ck_Node : Node_Id; | |
8701 | Target_Typ : Entity_Id; | |
8702 | Source_Typ : Entity_Id; | |
6b6fcd3e | 8703 | Warn_Node : Node_Id) return Check_Result |
70482933 RK |
8704 | is |
8705 | Loc : constant Source_Ptr := Sloc (Ck_Node); | |
8706 | S_Typ : Entity_Id; | |
8707 | T_Typ : Entity_Id; | |
8708 | Expr_Actual : Node_Id; | |
8709 | Exptyp : Entity_Id; | |
8710 | Cond : Node_Id := Empty; | |
8711 | Do_Access : Boolean := False; | |
8712 | Wnode : Node_Id := Warn_Node; | |
8713 | Ret_Result : Check_Result := (Empty, Empty); | |
8714 | Num_Checks : Natural := 0; | |
8715 | ||
8716 | procedure Add_Check (N : Node_Id); | |
8717 | -- Adds the action given to Ret_Result if N is non-Empty | |
8718 | ||
8719 | function Get_E_Length (E : Entity_Id; Indx : Nat) return Node_Id; | |
8720 | function Get_N_Length (N : Node_Id; Indx : Nat) return Node_Id; | |
6b6fcd3e | 8721 | -- Comments required ??? |
70482933 RK |
8722 | |
8723 | function Same_Bounds (L : Node_Id; R : Node_Id) return Boolean; | |
8724 | -- True for equal literals and for nodes that denote the same constant | |
c84700e7 | 8725 | -- entity, even if its value is not a static constant. This includes the |
fbf5a39b | 8726 | -- case of a discriminal reference within an init proc. Removes some |
c84700e7 | 8727 | -- obviously superfluous checks. |
70482933 RK |
8728 | |
8729 | function Length_E_Cond | |
8730 | (Exptyp : Entity_Id; | |
8731 | Typ : Entity_Id; | |
6b6fcd3e | 8732 | Indx : Nat) return Node_Id; |
70482933 RK |
8733 | -- Returns expression to compute: |
8734 | -- Typ'Length /= Exptyp'Length | |
8735 | ||
8736 | function Length_N_Cond | |
8737 | (Expr : Node_Id; | |
8738 | Typ : Entity_Id; | |
6b6fcd3e | 8739 | Indx : Nat) return Node_Id; |
70482933 RK |
8740 | -- Returns expression to compute: |
8741 | -- Typ'Length /= Expr'Length | |
8742 | ||
8743 | --------------- | |
8744 | -- Add_Check -- | |
8745 | --------------- | |
8746 | ||
8747 | procedure Add_Check (N : Node_Id) is | |
8748 | begin | |
8749 | if Present (N) then | |
8750 | ||
637a41a5 AC |
8751 | -- For now, ignore attempt to place more than two checks ??? |
8752 | -- This is really worrisome, are we really discarding checks ??? | |
70482933 RK |
8753 | |
8754 | if Num_Checks = 2 then | |
8755 | return; | |
8756 | end if; | |
8757 | ||
8758 | pragma Assert (Num_Checks <= 1); | |
8759 | Num_Checks := Num_Checks + 1; | |
8760 | Ret_Result (Num_Checks) := N; | |
8761 | end if; | |
8762 | end Add_Check; | |
8763 | ||
8764 | ------------------ | |
8765 | -- Get_E_Length -- | |
8766 | ------------------ | |
8767 | ||
8768 | function Get_E_Length (E : Entity_Id; Indx : Nat) return Node_Id is | |
11b4899f | 8769 | SE : constant Entity_Id := Scope (E); |
70482933 RK |
8770 | N : Node_Id; |
8771 | E1 : Entity_Id := E; | |
70482933 RK |
8772 | |
8773 | begin | |
8774 | if Ekind (Scope (E)) = E_Record_Type | |
8775 | and then Has_Discriminants (Scope (E)) | |
8776 | then | |
8777 | N := Build_Discriminal_Subtype_Of_Component (E); | |
8778 | ||
8779 | if Present (N) then | |
8780 | Insert_Action (Ck_Node, N); | |
8781 | E1 := Defining_Identifier (N); | |
8782 | end if; | |
8783 | end if; | |
8784 | ||
8785 | if Ekind (E1) = E_String_Literal_Subtype then | |
8786 | return | |
8787 | Make_Integer_Literal (Loc, | |
8788 | Intval => String_Literal_Length (E1)); | |
8789 | ||
11b4899f JM |
8790 | elsif SE /= Standard_Standard |
8791 | and then Ekind (Scope (SE)) = E_Protected_Type | |
8792 | and then Has_Discriminants (Scope (SE)) | |
8793 | and then Has_Completion (Scope (SE)) | |
70482933 RK |
8794 | and then not Inside_Init_Proc |
8795 | then | |
70482933 RK |
8796 | -- If the type whose length is needed is a private component |
8797 | -- constrained by a discriminant, we must expand the 'Length | |
8798 | -- attribute into an explicit computation, using the discriminal | |
8799 | -- of the current protected operation. This is because the actual | |
8800 | -- type of the prival is constructed after the protected opera- | |
8801 | -- tion has been fully expanded. | |
8802 | ||
8803 | declare | |
8804 | Indx_Type : Node_Id; | |
8805 | Lo : Node_Id; | |
8806 | Hi : Node_Id; | |
8807 | Do_Expand : Boolean := False; | |
8808 | ||
8809 | begin | |
8810 | Indx_Type := First_Index (E); | |
8811 | ||
8812 | for J in 1 .. Indx - 1 loop | |
8813 | Next_Index (Indx_Type); | |
8814 | end loop; | |
8815 | ||
939c12d2 | 8816 | Get_Index_Bounds (Indx_Type, Lo, Hi); |
70482933 RK |
8817 | |
8818 | if Nkind (Lo) = N_Identifier | |
8819 | and then Ekind (Entity (Lo)) = E_In_Parameter | |
8820 | then | |
8821 | Lo := Get_Discriminal (E, Lo); | |
8822 | Do_Expand := True; | |
8823 | end if; | |
8824 | ||
8825 | if Nkind (Hi) = N_Identifier | |
8826 | and then Ekind (Entity (Hi)) = E_In_Parameter | |
8827 | then | |
8828 | Hi := Get_Discriminal (E, Hi); | |
8829 | Do_Expand := True; | |
8830 | end if; | |
8831 | ||
8832 | if Do_Expand then | |
8833 | if not Is_Entity_Name (Lo) then | |
fbf5a39b | 8834 | Lo := Duplicate_Subexpr_No_Checks (Lo); |
70482933 RK |
8835 | end if; |
8836 | ||
8837 | if not Is_Entity_Name (Hi) then | |
fbf5a39b | 8838 | Lo := Duplicate_Subexpr_No_Checks (Hi); |
70482933 RK |
8839 | end if; |
8840 | ||
8841 | N := | |
8842 | Make_Op_Add (Loc, | |
8843 | Left_Opnd => | |
8844 | Make_Op_Subtract (Loc, | |
8845 | Left_Opnd => Hi, | |
8846 | Right_Opnd => Lo), | |
8847 | ||
8848 | Right_Opnd => Make_Integer_Literal (Loc, 1)); | |
8849 | return N; | |
8850 | ||
8851 | else | |
8852 | N := | |
8853 | Make_Attribute_Reference (Loc, | |
8854 | Attribute_Name => Name_Length, | |
8855 | Prefix => | |
8856 | New_Occurrence_Of (E1, Loc)); | |
8857 | ||
8858 | if Indx > 1 then | |
8859 | Set_Expressions (N, New_List ( | |
8860 | Make_Integer_Literal (Loc, Indx))); | |
8861 | end if; | |
8862 | ||
8863 | return N; | |
8864 | end if; | |
8865 | end; | |
8866 | ||
8867 | else | |
8868 | N := | |
8869 | Make_Attribute_Reference (Loc, | |
8870 | Attribute_Name => Name_Length, | |
8871 | Prefix => | |
8872 | New_Occurrence_Of (E1, Loc)); | |
8873 | ||
8874 | if Indx > 1 then | |
8875 | Set_Expressions (N, New_List ( | |
8876 | Make_Integer_Literal (Loc, Indx))); | |
8877 | end if; | |
8878 | ||
8879 | return N; | |
70482933 RK |
8880 | end if; |
8881 | end Get_E_Length; | |
8882 | ||
8883 | ------------------ | |
8884 | -- Get_N_Length -- | |
8885 | ------------------ | |
8886 | ||
8887 | function Get_N_Length (N : Node_Id; Indx : Nat) return Node_Id is | |
8888 | begin | |
8889 | return | |
8890 | Make_Attribute_Reference (Loc, | |
8891 | Attribute_Name => Name_Length, | |
8892 | Prefix => | |
fbf5a39b | 8893 | Duplicate_Subexpr_No_Checks (N, Name_Req => True), |
70482933 RK |
8894 | Expressions => New_List ( |
8895 | Make_Integer_Literal (Loc, Indx))); | |
70482933 RK |
8896 | end Get_N_Length; |
8897 | ||
8898 | ------------------- | |
8899 | -- Length_E_Cond -- | |
8900 | ------------------- | |
8901 | ||
8902 | function Length_E_Cond | |
8903 | (Exptyp : Entity_Id; | |
8904 | Typ : Entity_Id; | |
6b6fcd3e | 8905 | Indx : Nat) return Node_Id |
70482933 RK |
8906 | is |
8907 | begin | |
8908 | return | |
8909 | Make_Op_Ne (Loc, | |
8910 | Left_Opnd => Get_E_Length (Typ, Indx), | |
8911 | Right_Opnd => Get_E_Length (Exptyp, Indx)); | |
70482933 RK |
8912 | end Length_E_Cond; |
8913 | ||
8914 | ------------------- | |
8915 | -- Length_N_Cond -- | |
8916 | ------------------- | |
8917 | ||
8918 | function Length_N_Cond | |
8919 | (Expr : Node_Id; | |
8920 | Typ : Entity_Id; | |
6b6fcd3e | 8921 | Indx : Nat) return Node_Id |
70482933 RK |
8922 | is |
8923 | begin | |
8924 | return | |
8925 | Make_Op_Ne (Loc, | |
8926 | Left_Opnd => Get_E_Length (Typ, Indx), | |
8927 | Right_Opnd => Get_N_Length (Expr, Indx)); | |
70482933 RK |
8928 | end Length_N_Cond; |
8929 | ||
675d6070 TQ |
8930 | ----------------- |
8931 | -- Same_Bounds -- | |
8932 | ----------------- | |
8933 | ||
70482933 RK |
8934 | function Same_Bounds (L : Node_Id; R : Node_Id) return Boolean is |
8935 | begin | |
8936 | return | |
8937 | (Nkind (L) = N_Integer_Literal | |
8938 | and then Nkind (R) = N_Integer_Literal | |
8939 | and then Intval (L) = Intval (R)) | |
8940 | ||
8941 | or else | |
8942 | (Is_Entity_Name (L) | |
8943 | and then Ekind (Entity (L)) = E_Constant | |
8944 | and then ((Is_Entity_Name (R) | |
8945 | and then Entity (L) = Entity (R)) | |
8946 | or else | |
8947 | (Nkind (R) = N_Type_Conversion | |
8948 | and then Is_Entity_Name (Expression (R)) | |
8949 | and then Entity (L) = Entity (Expression (R))))) | |
8950 | ||
8951 | or else | |
8952 | (Is_Entity_Name (R) | |
8953 | and then Ekind (Entity (R)) = E_Constant | |
8954 | and then Nkind (L) = N_Type_Conversion | |
8955 | and then Is_Entity_Name (Expression (L)) | |
c84700e7 ES |
8956 | and then Entity (R) = Entity (Expression (L))) |
8957 | ||
8958 | or else | |
8959 | (Is_Entity_Name (L) | |
8960 | and then Is_Entity_Name (R) | |
8961 | and then Entity (L) = Entity (R) | |
8962 | and then Ekind (Entity (L)) = E_In_Parameter | |
8963 | and then Inside_Init_Proc); | |
70482933 RK |
8964 | end Same_Bounds; |
8965 | ||
8966 | -- Start of processing for Selected_Length_Checks | |
8967 | ||
8968 | begin | |
4460a9bc | 8969 | if not Expander_Active then |
70482933 RK |
8970 | return Ret_Result; |
8971 | end if; | |
8972 | ||
8973 | if Target_Typ = Any_Type | |
8974 | or else Target_Typ = Any_Composite | |
8975 | or else Raises_Constraint_Error (Ck_Node) | |
8976 | then | |
8977 | return Ret_Result; | |
8978 | end if; | |
8979 | ||
8980 | if No (Wnode) then | |
8981 | Wnode := Ck_Node; | |
8982 | end if; | |
8983 | ||
8984 | T_Typ := Target_Typ; | |
8985 | ||
8986 | if No (Source_Typ) then | |
8987 | S_Typ := Etype (Ck_Node); | |
8988 | else | |
8989 | S_Typ := Source_Typ; | |
8990 | end if; | |
8991 | ||
8992 | if S_Typ = Any_Type or else S_Typ = Any_Composite then | |
8993 | return Ret_Result; | |
8994 | end if; | |
8995 | ||
8996 | if Is_Access_Type (T_Typ) and then Is_Access_Type (S_Typ) then | |
8997 | S_Typ := Designated_Type (S_Typ); | |
8998 | T_Typ := Designated_Type (T_Typ); | |
8999 | Do_Access := True; | |
9000 | ||
939c12d2 | 9001 | -- A simple optimization for the null case |
70482933 | 9002 | |
939c12d2 | 9003 | if Known_Null (Ck_Node) then |
70482933 RK |
9004 | return Ret_Result; |
9005 | end if; | |
9006 | end if; | |
9007 | ||
9008 | if Is_Array_Type (T_Typ) and then Is_Array_Type (S_Typ) then | |
9009 | if Is_Constrained (T_Typ) then | |
9010 | ||
9b16cb57 RD |
9011 | -- The checking code to be generated will freeze the corresponding |
9012 | -- array type. However, we must freeze the type now, so that the | |
9013 | -- freeze node does not appear within the generated if expression, | |
9014 | -- but ahead of it. | |
70482933 RK |
9015 | |
9016 | Freeze_Before (Ck_Node, T_Typ); | |
9017 | ||
9018 | Expr_Actual := Get_Referenced_Object (Ck_Node); | |
86ac5e79 | 9019 | Exptyp := Get_Actual_Subtype (Ck_Node); |
70482933 RK |
9020 | |
9021 | if Is_Access_Type (Exptyp) then | |
9022 | Exptyp := Designated_Type (Exptyp); | |
9023 | end if; | |
9024 | ||
9025 | -- String_Literal case. This needs to be handled specially be- | |
9026 | -- cause no index types are available for string literals. The | |
9027 | -- condition is simply: | |
9028 | ||
9029 | -- T_Typ'Length = string-literal-length | |
9030 | ||
fbf5a39b AC |
9031 | if Nkind (Expr_Actual) = N_String_Literal |
9032 | and then Ekind (Etype (Expr_Actual)) = E_String_Literal_Subtype | |
9033 | then | |
70482933 RK |
9034 | Cond := |
9035 | Make_Op_Ne (Loc, | |
9036 | Left_Opnd => Get_E_Length (T_Typ, 1), | |
9037 | Right_Opnd => | |
9038 | Make_Integer_Literal (Loc, | |
9039 | Intval => | |
9040 | String_Literal_Length (Etype (Expr_Actual)))); | |
9041 | ||
9042 | -- General array case. Here we have a usable actual subtype for | |
9043 | -- the expression, and the condition is built from the two types | |
9044 | -- (Do_Length): | |
9045 | ||
9046 | -- T_Typ'Length /= Exptyp'Length or else | |
9047 | -- T_Typ'Length (2) /= Exptyp'Length (2) or else | |
9048 | -- T_Typ'Length (3) /= Exptyp'Length (3) or else | |
9049 | -- ... | |
9050 | ||
9051 | elsif Is_Constrained (Exptyp) then | |
9052 | declare | |
fbf5a39b AC |
9053 | Ndims : constant Nat := Number_Dimensions (T_Typ); |
9054 | ||
9055 | L_Index : Node_Id; | |
9056 | R_Index : Node_Id; | |
9057 | L_Low : Node_Id; | |
9058 | L_High : Node_Id; | |
9059 | R_Low : Node_Id; | |
9060 | R_High : Node_Id; | |
70482933 RK |
9061 | L_Length : Uint; |
9062 | R_Length : Uint; | |
fbf5a39b | 9063 | Ref_Node : Node_Id; |
70482933 RK |
9064 | |
9065 | begin | |
675d6070 TQ |
9066 | -- At the library level, we need to ensure that the type of |
9067 | -- the object is elaborated before the check itself is | |
9068 | -- emitted. This is only done if the object is in the | |
9069 | -- current compilation unit, otherwise the type is frozen | |
9070 | -- and elaborated in its unit. | |
fbf5a39b AC |
9071 | |
9072 | if Is_Itype (Exptyp) | |
9073 | and then | |
9074 | Ekind (Cunit_Entity (Current_Sem_Unit)) = E_Package | |
9075 | and then | |
9076 | not In_Package_Body (Cunit_Entity (Current_Sem_Unit)) | |
891a6e79 | 9077 | and then In_Open_Scopes (Scope (Exptyp)) |
fbf5a39b AC |
9078 | then |
9079 | Ref_Node := Make_Itype_Reference (Sloc (Ck_Node)); | |
9080 | Set_Itype (Ref_Node, Exptyp); | |
9081 | Insert_Action (Ck_Node, Ref_Node); | |
9082 | end if; | |
9083 | ||
70482933 RK |
9084 | L_Index := First_Index (T_Typ); |
9085 | R_Index := First_Index (Exptyp); | |
9086 | ||
9087 | for Indx in 1 .. Ndims loop | |
9088 | if not (Nkind (L_Index) = N_Raise_Constraint_Error | |
07fc65c4 GB |
9089 | or else |
9090 | Nkind (R_Index) = N_Raise_Constraint_Error) | |
70482933 RK |
9091 | then |
9092 | Get_Index_Bounds (L_Index, L_Low, L_High); | |
9093 | Get_Index_Bounds (R_Index, R_Low, R_High); | |
9094 | ||
9095 | -- Deal with compile time length check. Note that we | |
9096 | -- skip this in the access case, because the access | |
9097 | -- value may be null, so we cannot know statically. | |
9098 | ||
9099 | if not Do_Access | |
9100 | and then Compile_Time_Known_Value (L_Low) | |
9101 | and then Compile_Time_Known_Value (L_High) | |
9102 | and then Compile_Time_Known_Value (R_Low) | |
9103 | and then Compile_Time_Known_Value (R_High) | |
9104 | then | |
9105 | if Expr_Value (L_High) >= Expr_Value (L_Low) then | |
9106 | L_Length := Expr_Value (L_High) - | |
9107 | Expr_Value (L_Low) + 1; | |
9108 | else | |
9109 | L_Length := UI_From_Int (0); | |
9110 | end if; | |
9111 | ||
9112 | if Expr_Value (R_High) >= Expr_Value (R_Low) then | |
9113 | R_Length := Expr_Value (R_High) - | |
9114 | Expr_Value (R_Low) + 1; | |
9115 | else | |
9116 | R_Length := UI_From_Int (0); | |
9117 | end if; | |
9118 | ||
9119 | if L_Length > R_Length then | |
9120 | Add_Check | |
9121 | (Compile_Time_Constraint_Error | |
685bc70f | 9122 | (Wnode, "too few elements for}??", T_Typ)); |
70482933 RK |
9123 | |
9124 | elsif L_Length < R_Length then | |
9125 | Add_Check | |
9126 | (Compile_Time_Constraint_Error | |
685bc70f | 9127 | (Wnode, "too many elements for}??", T_Typ)); |
70482933 RK |
9128 | end if; |
9129 | ||
9130 | -- The comparison for an individual index subtype | |
9131 | -- is omitted if the corresponding index subtypes | |
9132 | -- statically match, since the result is known to | |
9133 | -- be true. Note that this test is worth while even | |
9134 | -- though we do static evaluation, because non-static | |
9135 | -- subtypes can statically match. | |
9136 | ||
9137 | elsif not | |
9138 | Subtypes_Statically_Match | |
9139 | (Etype (L_Index), Etype (R_Index)) | |
9140 | ||
9141 | and then not | |
9142 | (Same_Bounds (L_Low, R_Low) | |
9143 | and then Same_Bounds (L_High, R_High)) | |
9144 | then | |
9145 | Evolve_Or_Else | |
9146 | (Cond, Length_E_Cond (Exptyp, T_Typ, Indx)); | |
9147 | end if; | |
9148 | ||
9149 | Next (L_Index); | |
9150 | Next (R_Index); | |
9151 | end if; | |
9152 | end loop; | |
9153 | end; | |
9154 | ||
9155 | -- Handle cases where we do not get a usable actual subtype that | |
9156 | -- is constrained. This happens for example in the function call | |
9157 | -- and explicit dereference cases. In these cases, we have to get | |
9158 | -- the length or range from the expression itself, making sure we | |
9159 | -- do not evaluate it more than once. | |
9160 | ||
9161 | -- Here Ck_Node is the original expression, or more properly the | |
675d6070 TQ |
9162 | -- result of applying Duplicate_Expr to the original tree, forcing |
9163 | -- the result to be a name. | |
70482933 RK |
9164 | |
9165 | else | |
9166 | declare | |
fbf5a39b | 9167 | Ndims : constant Nat := Number_Dimensions (T_Typ); |
70482933 RK |
9168 | |
9169 | begin | |
9170 | -- Build the condition for the explicit dereference case | |
9171 | ||
9172 | for Indx in 1 .. Ndims loop | |
9173 | Evolve_Or_Else | |
9174 | (Cond, Length_N_Cond (Ck_Node, T_Typ, Indx)); | |
9175 | end loop; | |
9176 | end; | |
9177 | end if; | |
9178 | end if; | |
9179 | end if; | |
9180 | ||
9181 | -- Construct the test and insert into the tree | |
9182 | ||
9183 | if Present (Cond) then | |
9184 | if Do_Access then | |
9185 | Cond := Guard_Access (Cond, Loc, Ck_Node); | |
9186 | end if; | |
9187 | ||
07fc65c4 GB |
9188 | Add_Check |
9189 | (Make_Raise_Constraint_Error (Loc, | |
9190 | Condition => Cond, | |
9191 | Reason => CE_Length_Check_Failed)); | |
70482933 RK |
9192 | end if; |
9193 | ||
9194 | return Ret_Result; | |
70482933 RK |
9195 | end Selected_Length_Checks; |
9196 | ||
9197 | --------------------------- | |
9198 | -- Selected_Range_Checks -- | |
9199 | --------------------------- | |
9200 | ||
9201 | function Selected_Range_Checks | |
9202 | (Ck_Node : Node_Id; | |
9203 | Target_Typ : Entity_Id; | |
9204 | Source_Typ : Entity_Id; | |
6b6fcd3e | 9205 | Warn_Node : Node_Id) return Check_Result |
70482933 RK |
9206 | is |
9207 | Loc : constant Source_Ptr := Sloc (Ck_Node); | |
9208 | S_Typ : Entity_Id; | |
9209 | T_Typ : Entity_Id; | |
9210 | Expr_Actual : Node_Id; | |
9211 | Exptyp : Entity_Id; | |
9212 | Cond : Node_Id := Empty; | |
9213 | Do_Access : Boolean := False; | |
9214 | Wnode : Node_Id := Warn_Node; | |
9215 | Ret_Result : Check_Result := (Empty, Empty); | |
9216 | Num_Checks : Integer := 0; | |
e943fe8a | 9217 | Reason : RT_Exception_Code := CE_Range_Check_Failed; |
70482933 RK |
9218 | |
9219 | procedure Add_Check (N : Node_Id); | |
9220 | -- Adds the action given to Ret_Result if N is non-Empty | |
9221 | ||
9222 | function Discrete_Range_Cond | |
9223 | (Expr : Node_Id; | |
6b6fcd3e | 9224 | Typ : Entity_Id) return Node_Id; |
70482933 RK |
9225 | -- Returns expression to compute: |
9226 | -- Low_Bound (Expr) < Typ'First | |
9227 | -- or else | |
9228 | -- High_Bound (Expr) > Typ'Last | |
9229 | ||
9230 | function Discrete_Expr_Cond | |
9231 | (Expr : Node_Id; | |
6b6fcd3e | 9232 | Typ : Entity_Id) return Node_Id; |
70482933 RK |
9233 | -- Returns expression to compute: |
9234 | -- Expr < Typ'First | |
9235 | -- or else | |
9236 | -- Expr > Typ'Last | |
9237 | ||
9238 | function Get_E_First_Or_Last | |
5a153b27 AC |
9239 | (Loc : Source_Ptr; |
9240 | E : Entity_Id; | |
70482933 | 9241 | Indx : Nat; |
6b6fcd3e | 9242 | Nam : Name_Id) return Node_Id; |
a548f9ff | 9243 | -- Returns an attribute reference |
70482933 | 9244 | -- E'First or E'Last |
a548f9ff | 9245 | -- with a source location of Loc. |
6ca9ec9c | 9246 | -- |
a548f9ff TQ |
9247 | -- Nam is Name_First or Name_Last, according to which attribute is |
9248 | -- desired. If Indx is non-zero, it is passed as a literal in the | |
9249 | -- Expressions of the attribute reference (identifying the desired | |
9250 | -- array dimension). | |
70482933 RK |
9251 | |
9252 | function Get_N_First (N : Node_Id; Indx : Nat) return Node_Id; | |
9253 | function Get_N_Last (N : Node_Id; Indx : Nat) return Node_Id; | |
9254 | -- Returns expression to compute: | |
fbf5a39b | 9255 | -- N'First or N'Last using Duplicate_Subexpr_No_Checks |
70482933 RK |
9256 | |
9257 | function Range_E_Cond | |
9258 | (Exptyp : Entity_Id; | |
9259 | Typ : Entity_Id; | |
9260 | Indx : Nat) | |
9261 | return Node_Id; | |
9262 | -- Returns expression to compute: | |
9263 | -- Exptyp'First < Typ'First or else Exptyp'Last > Typ'Last | |
9264 | ||
9265 | function Range_Equal_E_Cond | |
9266 | (Exptyp : Entity_Id; | |
9267 | Typ : Entity_Id; | |
6b6fcd3e | 9268 | Indx : Nat) return Node_Id; |
70482933 RK |
9269 | -- Returns expression to compute: |
9270 | -- Exptyp'First /= Typ'First or else Exptyp'Last /= Typ'Last | |
9271 | ||
9272 | function Range_N_Cond | |
9273 | (Expr : Node_Id; | |
9274 | Typ : Entity_Id; | |
6b6fcd3e | 9275 | Indx : Nat) return Node_Id; |
70482933 RK |
9276 | -- Return expression to compute: |
9277 | -- Expr'First < Typ'First or else Expr'Last > Typ'Last | |
9278 | ||
9279 | --------------- | |
9280 | -- Add_Check -- | |
9281 | --------------- | |
9282 | ||
9283 | procedure Add_Check (N : Node_Id) is | |
9284 | begin | |
9285 | if Present (N) then | |
9286 | ||
9287 | -- For now, ignore attempt to place more than 2 checks ??? | |
9288 | ||
9289 | if Num_Checks = 2 then | |
9290 | return; | |
9291 | end if; | |
9292 | ||
9293 | pragma Assert (Num_Checks <= 1); | |
9294 | Num_Checks := Num_Checks + 1; | |
9295 | Ret_Result (Num_Checks) := N; | |
9296 | end if; | |
9297 | end Add_Check; | |
9298 | ||
9299 | ------------------------- | |
9300 | -- Discrete_Expr_Cond -- | |
9301 | ------------------------- | |
9302 | ||
9303 | function Discrete_Expr_Cond | |
9304 | (Expr : Node_Id; | |
6b6fcd3e | 9305 | Typ : Entity_Id) return Node_Id |
70482933 RK |
9306 | is |
9307 | begin | |
9308 | return | |
9309 | Make_Or_Else (Loc, | |
9310 | Left_Opnd => | |
9311 | Make_Op_Lt (Loc, | |
9312 | Left_Opnd => | |
fbf5a39b AC |
9313 | Convert_To (Base_Type (Typ), |
9314 | Duplicate_Subexpr_No_Checks (Expr)), | |
70482933 RK |
9315 | Right_Opnd => |
9316 | Convert_To (Base_Type (Typ), | |
5a153b27 | 9317 | Get_E_First_Or_Last (Loc, Typ, 0, Name_First))), |
70482933 RK |
9318 | |
9319 | Right_Opnd => | |
9320 | Make_Op_Gt (Loc, | |
9321 | Left_Opnd => | |
fbf5a39b AC |
9322 | Convert_To (Base_Type (Typ), |
9323 | Duplicate_Subexpr_No_Checks (Expr)), | |
70482933 RK |
9324 | Right_Opnd => |
9325 | Convert_To | |
9326 | (Base_Type (Typ), | |
5a153b27 | 9327 | Get_E_First_Or_Last (Loc, Typ, 0, Name_Last)))); |
70482933 RK |
9328 | end Discrete_Expr_Cond; |
9329 | ||
9330 | ------------------------- | |
9331 | -- Discrete_Range_Cond -- | |
9332 | ------------------------- | |
9333 | ||
9334 | function Discrete_Range_Cond | |
9335 | (Expr : Node_Id; | |
6b6fcd3e | 9336 | Typ : Entity_Id) return Node_Id |
70482933 RK |
9337 | is |
9338 | LB : Node_Id := Low_Bound (Expr); | |
9339 | HB : Node_Id := High_Bound (Expr); | |
9340 | ||
9341 | Left_Opnd : Node_Id; | |
9342 | Right_Opnd : Node_Id; | |
9343 | ||
9344 | begin | |
9345 | if Nkind (LB) = N_Identifier | |
675d6070 TQ |
9346 | and then Ekind (Entity (LB)) = E_Discriminant |
9347 | then | |
70482933 RK |
9348 | LB := New_Occurrence_Of (Discriminal (Entity (LB)), Loc); |
9349 | end if; | |
9350 | ||
70482933 RK |
9351 | Left_Opnd := |
9352 | Make_Op_Lt (Loc, | |
9353 | Left_Opnd => | |
9354 | Convert_To | |
fbf5a39b | 9355 | (Base_Type (Typ), Duplicate_Subexpr_No_Checks (LB)), |
70482933 RK |
9356 | |
9357 | Right_Opnd => | |
9358 | Convert_To | |
5a153b27 AC |
9359 | (Base_Type (Typ), |
9360 | Get_E_First_Or_Last (Loc, Typ, 0, Name_First))); | |
70482933 | 9361 | |
b3f96dc1 AC |
9362 | if Nkind (HB) = N_Identifier |
9363 | and then Ekind (Entity (HB)) = E_Discriminant | |
70482933 | 9364 | then |
b3f96dc1 | 9365 | HB := New_Occurrence_Of (Discriminal (Entity (HB)), Loc); |
70482933 RK |
9366 | end if; |
9367 | ||
9368 | Right_Opnd := | |
9369 | Make_Op_Gt (Loc, | |
9370 | Left_Opnd => | |
9371 | Convert_To | |
fbf5a39b | 9372 | (Base_Type (Typ), Duplicate_Subexpr_No_Checks (HB)), |
70482933 RK |
9373 | |
9374 | Right_Opnd => | |
9375 | Convert_To | |
9376 | (Base_Type (Typ), | |
5a153b27 | 9377 | Get_E_First_Or_Last (Loc, Typ, 0, Name_Last))); |
70482933 RK |
9378 | |
9379 | return Make_Or_Else (Loc, Left_Opnd, Right_Opnd); | |
9380 | end Discrete_Range_Cond; | |
9381 | ||
9382 | ------------------------- | |
9383 | -- Get_E_First_Or_Last -- | |
9384 | ------------------------- | |
9385 | ||
9386 | function Get_E_First_Or_Last | |
5a153b27 AC |
9387 | (Loc : Source_Ptr; |
9388 | E : Entity_Id; | |
70482933 | 9389 | Indx : Nat; |
6b6fcd3e | 9390 | Nam : Name_Id) return Node_Id |
70482933 | 9391 | is |
5a153b27 | 9392 | Exprs : List_Id; |
70482933 | 9393 | begin |
5a153b27 AC |
9394 | if Indx > 0 then |
9395 | Exprs := New_List (Make_Integer_Literal (Loc, UI_From_Int (Indx))); | |
70482933 | 9396 | else |
5a153b27 | 9397 | Exprs := No_List; |
70482933 RK |
9398 | end if; |
9399 | ||
5a153b27 AC |
9400 | return Make_Attribute_Reference (Loc, |
9401 | Prefix => New_Occurrence_Of (E, Loc), | |
9402 | Attribute_Name => Nam, | |
9403 | Expressions => Exprs); | |
70482933 RK |
9404 | end Get_E_First_Or_Last; |
9405 | ||
9406 | ----------------- | |
9407 | -- Get_N_First -- | |
9408 | ----------------- | |
9409 | ||
9410 | function Get_N_First (N : Node_Id; Indx : Nat) return Node_Id is | |
9411 | begin | |
9412 | return | |
9413 | Make_Attribute_Reference (Loc, | |
9414 | Attribute_Name => Name_First, | |
9415 | Prefix => | |
fbf5a39b | 9416 | Duplicate_Subexpr_No_Checks (N, Name_Req => True), |
70482933 RK |
9417 | Expressions => New_List ( |
9418 | Make_Integer_Literal (Loc, Indx))); | |
70482933 RK |
9419 | end Get_N_First; |
9420 | ||
9421 | ---------------- | |
9422 | -- Get_N_Last -- | |
9423 | ---------------- | |
9424 | ||
9425 | function Get_N_Last (N : Node_Id; Indx : Nat) return Node_Id is | |
9426 | begin | |
9427 | return | |
9428 | Make_Attribute_Reference (Loc, | |
9429 | Attribute_Name => Name_Last, | |
9430 | Prefix => | |
fbf5a39b | 9431 | Duplicate_Subexpr_No_Checks (N, Name_Req => True), |
70482933 RK |
9432 | Expressions => New_List ( |
9433 | Make_Integer_Literal (Loc, Indx))); | |
70482933 RK |
9434 | end Get_N_Last; |
9435 | ||
9436 | ------------------ | |
9437 | -- Range_E_Cond -- | |
9438 | ------------------ | |
9439 | ||
9440 | function Range_E_Cond | |
9441 | (Exptyp : Entity_Id; | |
9442 | Typ : Entity_Id; | |
6b6fcd3e | 9443 | Indx : Nat) return Node_Id |
70482933 RK |
9444 | is |
9445 | begin | |
9446 | return | |
9447 | Make_Or_Else (Loc, | |
9448 | Left_Opnd => | |
9449 | Make_Op_Lt (Loc, | |
5a153b27 AC |
9450 | Left_Opnd => |
9451 | Get_E_First_Or_Last (Loc, Exptyp, Indx, Name_First), | |
9452 | Right_Opnd => | |
9453 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_First)), | |
70482933 RK |
9454 | |
9455 | Right_Opnd => | |
9456 | Make_Op_Gt (Loc, | |
5a153b27 AC |
9457 | Left_Opnd => |
9458 | Get_E_First_Or_Last (Loc, Exptyp, Indx, Name_Last), | |
9459 | Right_Opnd => | |
9460 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_Last))); | |
70482933 RK |
9461 | end Range_E_Cond; |
9462 | ||
9463 | ------------------------ | |
9464 | -- Range_Equal_E_Cond -- | |
9465 | ------------------------ | |
9466 | ||
9467 | function Range_Equal_E_Cond | |
9468 | (Exptyp : Entity_Id; | |
9469 | Typ : Entity_Id; | |
6b6fcd3e | 9470 | Indx : Nat) return Node_Id |
70482933 RK |
9471 | is |
9472 | begin | |
9473 | return | |
9474 | Make_Or_Else (Loc, | |
9475 | Left_Opnd => | |
9476 | Make_Op_Ne (Loc, | |
5a153b27 AC |
9477 | Left_Opnd => |
9478 | Get_E_First_Or_Last (Loc, Exptyp, Indx, Name_First), | |
9479 | Right_Opnd => | |
9480 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_First)), | |
9481 | ||
70482933 RK |
9482 | Right_Opnd => |
9483 | Make_Op_Ne (Loc, | |
5a153b27 AC |
9484 | Left_Opnd => |
9485 | Get_E_First_Or_Last (Loc, Exptyp, Indx, Name_Last), | |
9486 | Right_Opnd => | |
9487 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_Last))); | |
70482933 RK |
9488 | end Range_Equal_E_Cond; |
9489 | ||
9490 | ------------------ | |
9491 | -- Range_N_Cond -- | |
9492 | ------------------ | |
9493 | ||
9494 | function Range_N_Cond | |
9495 | (Expr : Node_Id; | |
9496 | Typ : Entity_Id; | |
6b6fcd3e | 9497 | Indx : Nat) return Node_Id |
70482933 RK |
9498 | is |
9499 | begin | |
9500 | return | |
9501 | Make_Or_Else (Loc, | |
9502 | Left_Opnd => | |
9503 | Make_Op_Lt (Loc, | |
5a153b27 AC |
9504 | Left_Opnd => |
9505 | Get_N_First (Expr, Indx), | |
9506 | Right_Opnd => | |
9507 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_First)), | |
70482933 RK |
9508 | |
9509 | Right_Opnd => | |
9510 | Make_Op_Gt (Loc, | |
5a153b27 AC |
9511 | Left_Opnd => |
9512 | Get_N_Last (Expr, Indx), | |
9513 | Right_Opnd => | |
9514 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_Last))); | |
70482933 RK |
9515 | end Range_N_Cond; |
9516 | ||
9517 | -- Start of processing for Selected_Range_Checks | |
9518 | ||
9519 | begin | |
4460a9bc | 9520 | if not Expander_Active then |
70482933 RK |
9521 | return Ret_Result; |
9522 | end if; | |
9523 | ||
9524 | if Target_Typ = Any_Type | |
9525 | or else Target_Typ = Any_Composite | |
9526 | or else Raises_Constraint_Error (Ck_Node) | |
9527 | then | |
9528 | return Ret_Result; | |
9529 | end if; | |
9530 | ||
9531 | if No (Wnode) then | |
9532 | Wnode := Ck_Node; | |
9533 | end if; | |
9534 | ||
9535 | T_Typ := Target_Typ; | |
9536 | ||
9537 | if No (Source_Typ) then | |
9538 | S_Typ := Etype (Ck_Node); | |
9539 | else | |
9540 | S_Typ := Source_Typ; | |
9541 | end if; | |
9542 | ||
9543 | if S_Typ = Any_Type or else S_Typ = Any_Composite then | |
9544 | return Ret_Result; | |
9545 | end if; | |
9546 | ||
9547 | -- The order of evaluating T_Typ before S_Typ seems to be critical | |
9548 | -- because S_Typ can be derived from Etype (Ck_Node), if it's not passed | |
9549 | -- in, and since Node can be an N_Range node, it might be invalid. | |
9550 | -- Should there be an assert check somewhere for taking the Etype of | |
9551 | -- an N_Range node ??? | |
9552 | ||
9553 | if Is_Access_Type (T_Typ) and then Is_Access_Type (S_Typ) then | |
9554 | S_Typ := Designated_Type (S_Typ); | |
9555 | T_Typ := Designated_Type (T_Typ); | |
9556 | Do_Access := True; | |
9557 | ||
939c12d2 | 9558 | -- A simple optimization for the null case |
70482933 | 9559 | |
939c12d2 | 9560 | if Known_Null (Ck_Node) then |
70482933 RK |
9561 | return Ret_Result; |
9562 | end if; | |
9563 | end if; | |
9564 | ||
9565 | -- For an N_Range Node, check for a null range and then if not | |
9566 | -- null generate a range check action. | |
9567 | ||
9568 | if Nkind (Ck_Node) = N_Range then | |
9569 | ||
9570 | -- There's no point in checking a range against itself | |
9571 | ||
9572 | if Ck_Node = Scalar_Range (T_Typ) then | |
9573 | return Ret_Result; | |
9574 | end if; | |
9575 | ||
9576 | declare | |
9577 | T_LB : constant Node_Id := Type_Low_Bound (T_Typ); | |
9578 | T_HB : constant Node_Id := Type_High_Bound (T_Typ); | |
10475800 EB |
9579 | Known_T_LB : constant Boolean := Compile_Time_Known_Value (T_LB); |
9580 | Known_T_HB : constant Boolean := Compile_Time_Known_Value (T_HB); | |
70482933 | 9581 | |
10475800 EB |
9582 | LB : Node_Id := Low_Bound (Ck_Node); |
9583 | HB : Node_Id := High_Bound (Ck_Node); | |
9584 | Known_LB : Boolean; | |
9585 | Known_HB : Boolean; | |
9586 | ||
9587 | Null_Range : Boolean; | |
70482933 RK |
9588 | Out_Of_Range_L : Boolean; |
9589 | Out_Of_Range_H : Boolean; | |
9590 | ||
9591 | begin | |
10475800 EB |
9592 | -- Compute what is known at compile time |
9593 | ||
9594 | if Known_T_LB and Known_T_HB then | |
9595 | if Compile_Time_Known_Value (LB) then | |
9596 | Known_LB := True; | |
9597 | ||
9598 | -- There's no point in checking that a bound is within its | |
9599 | -- own range so pretend that it is known in this case. First | |
9600 | -- deal with low bound. | |
9601 | ||
9602 | elsif Ekind (Etype (LB)) = E_Signed_Integer_Subtype | |
9603 | and then Scalar_Range (Etype (LB)) = Scalar_Range (T_Typ) | |
9604 | then | |
9605 | LB := T_LB; | |
9606 | Known_LB := True; | |
9607 | ||
9608 | else | |
9609 | Known_LB := False; | |
9610 | end if; | |
9611 | ||
9612 | -- Likewise for the high bound | |
9613 | ||
9614 | if Compile_Time_Known_Value (HB) then | |
9615 | Known_HB := True; | |
9616 | ||
9617 | elsif Ekind (Etype (HB)) = E_Signed_Integer_Subtype | |
9618 | and then Scalar_Range (Etype (HB)) = Scalar_Range (T_Typ) | |
9619 | then | |
9620 | HB := T_HB; | |
9621 | Known_HB := True; | |
10475800 EB |
9622 | else |
9623 | Known_HB := False; | |
9624 | end if; | |
9625 | end if; | |
9626 | ||
9627 | -- Check for case where everything is static and we can do the | |
9628 | -- check at compile time. This is skipped if we have an access | |
9629 | -- type, since the access value may be null. | |
9630 | ||
9631 | -- ??? This code can be improved since you only need to know that | |
9632 | -- the two respective bounds (LB & T_LB or HB & T_HB) are known at | |
9633 | -- compile time to emit pertinent messages. | |
9634 | ||
9635 | if Known_T_LB and Known_T_HB and Known_LB and Known_HB | |
9636 | and not Do_Access | |
70482933 RK |
9637 | then |
9638 | -- Floating-point case | |
9639 | ||
9640 | if Is_Floating_Point_Type (S_Typ) then | |
9641 | Null_Range := Expr_Value_R (HB) < Expr_Value_R (LB); | |
9642 | Out_Of_Range_L := | |
9643 | (Expr_Value_R (LB) < Expr_Value_R (T_LB)) | |
10475800 | 9644 | or else |
70482933 RK |
9645 | (Expr_Value_R (LB) > Expr_Value_R (T_HB)); |
9646 | ||
9647 | Out_Of_Range_H := | |
9648 | (Expr_Value_R (HB) > Expr_Value_R (T_HB)) | |
10475800 | 9649 | or else |
70482933 RK |
9650 | (Expr_Value_R (HB) < Expr_Value_R (T_LB)); |
9651 | ||
9652 | -- Fixed or discrete type case | |
9653 | ||
9654 | else | |
9655 | Null_Range := Expr_Value (HB) < Expr_Value (LB); | |
9656 | Out_Of_Range_L := | |
9657 | (Expr_Value (LB) < Expr_Value (T_LB)) | |
10475800 | 9658 | or else |
70482933 RK |
9659 | (Expr_Value (LB) > Expr_Value (T_HB)); |
9660 | ||
9661 | Out_Of_Range_H := | |
9662 | (Expr_Value (HB) > Expr_Value (T_HB)) | |
10475800 | 9663 | or else |
70482933 RK |
9664 | (Expr_Value (HB) < Expr_Value (T_LB)); |
9665 | end if; | |
9666 | ||
9667 | if not Null_Range then | |
9668 | if Out_Of_Range_L then | |
9669 | if No (Warn_Node) then | |
9670 | Add_Check | |
9671 | (Compile_Time_Constraint_Error | |
9672 | (Low_Bound (Ck_Node), | |
685bc70f | 9673 | "static value out of range of}??", T_Typ)); |
70482933 RK |
9674 | |
9675 | else | |
9676 | Add_Check | |
9677 | (Compile_Time_Constraint_Error | |
9678 | (Wnode, | |
685bc70f | 9679 | "static range out of bounds of}??", T_Typ)); |
70482933 RK |
9680 | end if; |
9681 | end if; | |
9682 | ||
9683 | if Out_Of_Range_H then | |
9684 | if No (Warn_Node) then | |
9685 | Add_Check | |
9686 | (Compile_Time_Constraint_Error | |
9687 | (High_Bound (Ck_Node), | |
685bc70f | 9688 | "static value out of range of}??", T_Typ)); |
70482933 RK |
9689 | |
9690 | else | |
9691 | Add_Check | |
9692 | (Compile_Time_Constraint_Error | |
9693 | (Wnode, | |
685bc70f | 9694 | "static range out of bounds of}??", T_Typ)); |
70482933 RK |
9695 | end if; |
9696 | end if; | |
70482933 RK |
9697 | end if; |
9698 | ||
9699 | else | |
9700 | declare | |
9701 | LB : Node_Id := Low_Bound (Ck_Node); | |
9702 | HB : Node_Id := High_Bound (Ck_Node); | |
9703 | ||
9704 | begin | |
675d6070 TQ |
9705 | -- If either bound is a discriminant and we are within the |
9706 | -- record declaration, it is a use of the discriminant in a | |
9707 | -- constraint of a component, and nothing can be checked | |
9708 | -- here. The check will be emitted within the init proc. | |
9709 | -- Before then, the discriminal has no real meaning. | |
9710 | -- Similarly, if the entity is a discriminal, there is no | |
9711 | -- check to perform yet. | |
9712 | ||
9713 | -- The same holds within a discriminated synchronized type, | |
9714 | -- where the discriminant may constrain a component or an | |
9715 | -- entry family. | |
70482933 RK |
9716 | |
9717 | if Nkind (LB) = N_Identifier | |
c064e066 | 9718 | and then Denotes_Discriminant (LB, True) |
70482933 | 9719 | then |
c064e066 RD |
9720 | if Current_Scope = Scope (Entity (LB)) |
9721 | or else Is_Concurrent_Type (Current_Scope) | |
9722 | or else Ekind (Entity (LB)) /= E_Discriminant | |
9723 | then | |
70482933 RK |
9724 | return Ret_Result; |
9725 | else | |
9726 | LB := | |
9727 | New_Occurrence_Of (Discriminal (Entity (LB)), Loc); | |
9728 | end if; | |
9729 | end if; | |
9730 | ||
9731 | if Nkind (HB) = N_Identifier | |
c064e066 | 9732 | and then Denotes_Discriminant (HB, True) |
70482933 | 9733 | then |
c064e066 RD |
9734 | if Current_Scope = Scope (Entity (HB)) |
9735 | or else Is_Concurrent_Type (Current_Scope) | |
9736 | or else Ekind (Entity (HB)) /= E_Discriminant | |
9737 | then | |
70482933 RK |
9738 | return Ret_Result; |
9739 | else | |
9740 | HB := | |
9741 | New_Occurrence_Of (Discriminal (Entity (HB)), Loc); | |
9742 | end if; | |
9743 | end if; | |
9744 | ||
9745 | Cond := Discrete_Range_Cond (Ck_Node, T_Typ); | |
9746 | Set_Paren_Count (Cond, 1); | |
9747 | ||
9748 | Cond := | |
9749 | Make_And_Then (Loc, | |
9750 | Left_Opnd => | |
9751 | Make_Op_Ge (Loc, | |
4c51ff88 AC |
9752 | Left_Opnd => |
9753 | Convert_To (Base_Type (Etype (HB)), | |
9754 | Duplicate_Subexpr_No_Checks (HB)), | |
9755 | Right_Opnd => | |
9756 | Convert_To (Base_Type (Etype (LB)), | |
9757 | Duplicate_Subexpr_No_Checks (LB))), | |
70482933 RK |
9758 | Right_Opnd => Cond); |
9759 | end; | |
70482933 RK |
9760 | end if; |
9761 | end; | |
9762 | ||
9763 | elsif Is_Scalar_Type (S_Typ) then | |
9764 | ||
9765 | -- This somewhat duplicates what Apply_Scalar_Range_Check does, | |
9766 | -- except the above simply sets a flag in the node and lets | |
9767 | -- gigi generate the check base on the Etype of the expression. | |
9768 | -- Sometimes, however we want to do a dynamic check against an | |
9769 | -- arbitrary target type, so we do that here. | |
9770 | ||
9771 | if Ekind (Base_Type (S_Typ)) /= Ekind (Base_Type (T_Typ)) then | |
9772 | Cond := Discrete_Expr_Cond (Ck_Node, T_Typ); | |
9773 | ||
9774 | -- For literals, we can tell if the constraint error will be | |
9775 | -- raised at compile time, so we never need a dynamic check, but | |
9776 | -- if the exception will be raised, then post the usual warning, | |
9777 | -- and replace the literal with a raise constraint error | |
9778 | -- expression. As usual, skip this for access types | |
9779 | ||
637a41a5 | 9780 | elsif Compile_Time_Known_Value (Ck_Node) and then not Do_Access then |
70482933 RK |
9781 | declare |
9782 | LB : constant Node_Id := Type_Low_Bound (T_Typ); | |
9783 | UB : constant Node_Id := Type_High_Bound (T_Typ); | |
9784 | ||
9785 | Out_Of_Range : Boolean; | |
9786 | Static_Bounds : constant Boolean := | |
15f0f591 AC |
9787 | Compile_Time_Known_Value (LB) |
9788 | and Compile_Time_Known_Value (UB); | |
70482933 RK |
9789 | |
9790 | begin | |
9791 | -- Following range tests should use Sem_Eval routine ??? | |
9792 | ||
9793 | if Static_Bounds then | |
9794 | if Is_Floating_Point_Type (S_Typ) then | |
9795 | Out_Of_Range := | |
9796 | (Expr_Value_R (Ck_Node) < Expr_Value_R (LB)) | |
9797 | or else | |
9798 | (Expr_Value_R (Ck_Node) > Expr_Value_R (UB)); | |
9799 | ||
10475800 EB |
9800 | -- Fixed or discrete type |
9801 | ||
9802 | else | |
70482933 RK |
9803 | Out_Of_Range := |
9804 | Expr_Value (Ck_Node) < Expr_Value (LB) | |
9805 | or else | |
9806 | Expr_Value (Ck_Node) > Expr_Value (UB); | |
9807 | end if; | |
9808 | ||
10475800 EB |
9809 | -- Bounds of the type are static and the literal is out of |
9810 | -- range so output a warning message. | |
70482933 RK |
9811 | |
9812 | if Out_Of_Range then | |
9813 | if No (Warn_Node) then | |
9814 | Add_Check | |
9815 | (Compile_Time_Constraint_Error | |
9816 | (Ck_Node, | |
685bc70f | 9817 | "static value out of range of}??", T_Typ)); |
70482933 RK |
9818 | |
9819 | else | |
9820 | Add_Check | |
9821 | (Compile_Time_Constraint_Error | |
9822 | (Wnode, | |
685bc70f | 9823 | "static value out of range of}??", T_Typ)); |
70482933 RK |
9824 | end if; |
9825 | end if; | |
9826 | ||
9827 | else | |
9828 | Cond := Discrete_Expr_Cond (Ck_Node, T_Typ); | |
9829 | end if; | |
9830 | end; | |
9831 | ||
9832 | -- Here for the case of a non-static expression, we need a runtime | |
9833 | -- check unless the source type range is guaranteed to be in the | |
9834 | -- range of the target type. | |
9835 | ||
9836 | else | |
c27f2f15 | 9837 | if not In_Subrange_Of (S_Typ, T_Typ) then |
70482933 | 9838 | Cond := Discrete_Expr_Cond (Ck_Node, T_Typ); |
e943fe8a AC |
9839 | |
9840 | -- Special case CodePeer_Mode and apparently redundant checks on | |
9841 | -- floating point types: these are used as overflow checks, see | |
9842 | -- Exp_Util.Check_Float_Op_Overflow. | |
9843 | ||
9844 | elsif CodePeer_Mode and then Check_Float_Overflow | |
9845 | and then Is_Floating_Point_Type (S_Typ) | |
9846 | then | |
9847 | Cond := Discrete_Expr_Cond (Ck_Node, T_Typ); | |
9848 | Reason := CE_Overflow_Check_Failed; | |
70482933 RK |
9849 | end if; |
9850 | end if; | |
9851 | end if; | |
9852 | ||
9853 | if Is_Array_Type (T_Typ) and then Is_Array_Type (S_Typ) then | |
9854 | if Is_Constrained (T_Typ) then | |
9855 | ||
9856 | Expr_Actual := Get_Referenced_Object (Ck_Node); | |
9857 | Exptyp := Get_Actual_Subtype (Expr_Actual); | |
9858 | ||
9859 | if Is_Access_Type (Exptyp) then | |
9860 | Exptyp := Designated_Type (Exptyp); | |
9861 | end if; | |
9862 | ||
9863 | -- String_Literal case. This needs to be handled specially be- | |
9864 | -- cause no index types are available for string literals. The | |
9865 | -- condition is simply: | |
9866 | ||
9867 | -- T_Typ'Length = string-literal-length | |
9868 | ||
9869 | if Nkind (Expr_Actual) = N_String_Literal then | |
9870 | null; | |
9871 | ||
9872 | -- General array case. Here we have a usable actual subtype for | |
9873 | -- the expression, and the condition is built from the two types | |
9874 | ||
9875 | -- T_Typ'First < Exptyp'First or else | |
9876 | -- T_Typ'Last > Exptyp'Last or else | |
9877 | -- T_Typ'First(1) < Exptyp'First(1) or else | |
9878 | -- T_Typ'Last(1) > Exptyp'Last(1) or else | |
9879 | -- ... | |
9880 | ||
9881 | elsif Is_Constrained (Exptyp) then | |
9882 | declare | |
fbf5a39b AC |
9883 | Ndims : constant Nat := Number_Dimensions (T_Typ); |
9884 | ||
70482933 RK |
9885 | L_Index : Node_Id; |
9886 | R_Index : Node_Id; | |
70482933 RK |
9887 | |
9888 | begin | |
9889 | L_Index := First_Index (T_Typ); | |
9890 | R_Index := First_Index (Exptyp); | |
9891 | ||
9892 | for Indx in 1 .. Ndims loop | |
9893 | if not (Nkind (L_Index) = N_Raise_Constraint_Error | |
07fc65c4 GB |
9894 | or else |
9895 | Nkind (R_Index) = N_Raise_Constraint_Error) | |
70482933 | 9896 | then |
70482933 RK |
9897 | -- Deal with compile time length check. Note that we |
9898 | -- skip this in the access case, because the access | |
9899 | -- value may be null, so we cannot know statically. | |
9900 | ||
9901 | if not | |
9902 | Subtypes_Statically_Match | |
9903 | (Etype (L_Index), Etype (R_Index)) | |
9904 | then | |
9905 | -- If the target type is constrained then we | |
9906 | -- have to check for exact equality of bounds | |
9907 | -- (required for qualified expressions). | |
9908 | ||
9909 | if Is_Constrained (T_Typ) then | |
9910 | Evolve_Or_Else | |
9911 | (Cond, | |
9912 | Range_Equal_E_Cond (Exptyp, T_Typ, Indx)); | |
70482933 RK |
9913 | else |
9914 | Evolve_Or_Else | |
9915 | (Cond, Range_E_Cond (Exptyp, T_Typ, Indx)); | |
9916 | end if; | |
9917 | end if; | |
9918 | ||
9919 | Next (L_Index); | |
9920 | Next (R_Index); | |
70482933 RK |
9921 | end if; |
9922 | end loop; | |
9923 | end; | |
9924 | ||
9925 | -- Handle cases where we do not get a usable actual subtype that | |
9926 | -- is constrained. This happens for example in the function call | |
9927 | -- and explicit dereference cases. In these cases, we have to get | |
9928 | -- the length or range from the expression itself, making sure we | |
9929 | -- do not evaluate it more than once. | |
9930 | ||
9931 | -- Here Ck_Node is the original expression, or more properly the | |
9932 | -- result of applying Duplicate_Expr to the original tree, | |
9933 | -- forcing the result to be a name. | |
9934 | ||
9935 | else | |
9936 | declare | |
fbf5a39b | 9937 | Ndims : constant Nat := Number_Dimensions (T_Typ); |
70482933 RK |
9938 | |
9939 | begin | |
9940 | -- Build the condition for the explicit dereference case | |
9941 | ||
9942 | for Indx in 1 .. Ndims loop | |
9943 | Evolve_Or_Else | |
9944 | (Cond, Range_N_Cond (Ck_Node, T_Typ, Indx)); | |
9945 | end loop; | |
9946 | end; | |
70482933 RK |
9947 | end if; |
9948 | ||
9949 | else | |
675d6070 TQ |
9950 | -- For a conversion to an unconstrained array type, generate an |
9951 | -- Action to check that the bounds of the source value are within | |
9952 | -- the constraints imposed by the target type (RM 4.6(38)). No | |
9953 | -- check is needed for a conversion to an access to unconstrained | |
9954 | -- array type, as 4.6(24.15/2) requires the designated subtypes | |
9955 | -- of the two access types to statically match. | |
9956 | ||
9957 | if Nkind (Parent (Ck_Node)) = N_Type_Conversion | |
9958 | and then not Do_Access | |
9959 | then | |
70482933 RK |
9960 | declare |
9961 | Opnd_Index : Node_Id; | |
9962 | Targ_Index : Node_Id; | |
11b4899f | 9963 | Opnd_Range : Node_Id; |
70482933 RK |
9964 | |
9965 | begin | |
675d6070 | 9966 | Opnd_Index := First_Index (Get_Actual_Subtype (Ck_Node)); |
70482933 | 9967 | Targ_Index := First_Index (T_Typ); |
11b4899f JM |
9968 | while Present (Opnd_Index) loop |
9969 | ||
9970 | -- If the index is a range, use its bounds. If it is an | |
9971 | -- entity (as will be the case if it is a named subtype | |
9972 | -- or an itype created for a slice) retrieve its range. | |
9973 | ||
9974 | if Is_Entity_Name (Opnd_Index) | |
9975 | and then Is_Type (Entity (Opnd_Index)) | |
9976 | then | |
9977 | Opnd_Range := Scalar_Range (Entity (Opnd_Index)); | |
9978 | else | |
9979 | Opnd_Range := Opnd_Index; | |
9980 | end if; | |
9981 | ||
9982 | if Nkind (Opnd_Range) = N_Range then | |
c800f862 RD |
9983 | if Is_In_Range |
9984 | (Low_Bound (Opnd_Range), Etype (Targ_Index), | |
9985 | Assume_Valid => True) | |
70482933 RK |
9986 | and then |
9987 | Is_In_Range | |
c800f862 RD |
9988 | (High_Bound (Opnd_Range), Etype (Targ_Index), |
9989 | Assume_Valid => True) | |
70482933 RK |
9990 | then |
9991 | null; | |
9992 | ||
675d6070 | 9993 | -- If null range, no check needed |
ddda9d0f | 9994 | |
fbf5a39b | 9995 | elsif |
11b4899f | 9996 | Compile_Time_Known_Value (High_Bound (Opnd_Range)) |
fbf5a39b | 9997 | and then |
11b4899f | 9998 | Compile_Time_Known_Value (Low_Bound (Opnd_Range)) |
fbf5a39b | 9999 | and then |
11b4899f JM |
10000 | Expr_Value (High_Bound (Opnd_Range)) < |
10001 | Expr_Value (Low_Bound (Opnd_Range)) | |
fbf5a39b AC |
10002 | then |
10003 | null; | |
10004 | ||
70482933 | 10005 | elsif Is_Out_Of_Range |
c800f862 RD |
10006 | (Low_Bound (Opnd_Range), Etype (Targ_Index), |
10007 | Assume_Valid => True) | |
70482933 RK |
10008 | or else |
10009 | Is_Out_Of_Range | |
c800f862 RD |
10010 | (High_Bound (Opnd_Range), Etype (Targ_Index), |
10011 | Assume_Valid => True) | |
70482933 RK |
10012 | then |
10013 | Add_Check | |
10014 | (Compile_Time_Constraint_Error | |
685bc70f | 10015 | (Wnode, "value out of range of}??", T_Typ)); |
70482933 RK |
10016 | |
10017 | else | |
10018 | Evolve_Or_Else | |
10019 | (Cond, | |
10020 | Discrete_Range_Cond | |
11b4899f | 10021 | (Opnd_Range, Etype (Targ_Index))); |
70482933 RK |
10022 | end if; |
10023 | end if; | |
10024 | ||
10025 | Next_Index (Opnd_Index); | |
10026 | Next_Index (Targ_Index); | |
10027 | end loop; | |
10028 | end; | |
10029 | end if; | |
10030 | end if; | |
10031 | end if; | |
10032 | ||
10033 | -- Construct the test and insert into the tree | |
10034 | ||
10035 | if Present (Cond) then | |
10036 | if Do_Access then | |
10037 | Cond := Guard_Access (Cond, Loc, Ck_Node); | |
10038 | end if; | |
10039 | ||
07fc65c4 GB |
10040 | Add_Check |
10041 | (Make_Raise_Constraint_Error (Loc, | |
10475800 | 10042 | Condition => Cond, |
e943fe8a | 10043 | Reason => Reason)); |
70482933 RK |
10044 | end if; |
10045 | ||
10046 | return Ret_Result; | |
70482933 RK |
10047 | end Selected_Range_Checks; |
10048 | ||
10049 | ------------------------------- | |
10050 | -- Storage_Checks_Suppressed -- | |
10051 | ------------------------------- | |
10052 | ||
10053 | function Storage_Checks_Suppressed (E : Entity_Id) return Boolean is | |
10054 | begin | |
fbf5a39b AC |
10055 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
10056 | return Is_Check_Suppressed (E, Storage_Check); | |
10057 | else | |
3217f71e | 10058 | return Scope_Suppress.Suppress (Storage_Check); |
fbf5a39b | 10059 | end if; |
70482933 RK |
10060 | end Storage_Checks_Suppressed; |
10061 | ||
10062 | --------------------------- | |
10063 | -- Tag_Checks_Suppressed -- | |
10064 | --------------------------- | |
10065 | ||
10066 | function Tag_Checks_Suppressed (E : Entity_Id) return Boolean is | |
10067 | begin | |
b98e2969 AC |
10068 | if Present (E) |
10069 | and then Checks_May_Be_Suppressed (E) | |
10070 | then | |
10071 | return Is_Check_Suppressed (E, Tag_Check); | |
637a41a5 AC |
10072 | else |
10073 | return Scope_Suppress.Suppress (Tag_Check); | |
fbf5a39b | 10074 | end if; |
70482933 RK |
10075 | end Tag_Checks_Suppressed; |
10076 | ||
aca670a0 AC |
10077 | --------------------------------------- |
10078 | -- Validate_Alignment_Check_Warnings -- | |
10079 | --------------------------------------- | |
10080 | ||
10081 | procedure Validate_Alignment_Check_Warnings is | |
10082 | begin | |
10083 | for J in Alignment_Warnings.First .. Alignment_Warnings.Last loop | |
10084 | declare | |
10085 | AWR : Alignment_Warnings_Record | |
10086 | renames Alignment_Warnings.Table (J); | |
10087 | begin | |
10088 | if Known_Alignment (AWR.E) | |
10089 | and then AWR.A mod Alignment (AWR.E) = 0 | |
10090 | then | |
10091 | Delete_Warning_And_Continuations (AWR.W); | |
10092 | end if; | |
10093 | end; | |
10094 | end loop; | |
10095 | end Validate_Alignment_Check_Warnings; | |
10096 | ||
c064e066 RD |
10097 | -------------------------- |
10098 | -- Validity_Check_Range -- | |
10099 | -------------------------- | |
10100 | ||
10101 | procedure Validity_Check_Range (N : Node_Id) is | |
10102 | begin | |
10103 | if Validity_Checks_On and Validity_Check_Operands then | |
10104 | if Nkind (N) = N_Range then | |
10105 | Ensure_Valid (Low_Bound (N)); | |
10106 | Ensure_Valid (High_Bound (N)); | |
10107 | end if; | |
10108 | end if; | |
10109 | end Validity_Check_Range; | |
10110 | ||
10111 | -------------------------------- | |
10112 | -- Validity_Checks_Suppressed -- | |
10113 | -------------------------------- | |
10114 | ||
10115 | function Validity_Checks_Suppressed (E : Entity_Id) return Boolean is | |
10116 | begin | |
10117 | if Present (E) and then Checks_May_Be_Suppressed (E) then | |
10118 | return Is_Check_Suppressed (E, Validity_Check); | |
10119 | else | |
3217f71e | 10120 | return Scope_Suppress.Suppress (Validity_Check); |
c064e066 RD |
10121 | end if; |
10122 | end Validity_Checks_Suppressed; | |
10123 | ||
70482933 | 10124 | end Checks; |