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996ae0b0
RK		 1------------------------------------------------------------------------------
2-- --
3-- GNAT COMPILER COMPONENTS --
4-- --
5-- S E M _ R E S --
6-- --
7-- B o d y --
8-- --
c28408b7 9-- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
996ae0b0
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- --
996ae0b0
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. --
996ae0b0
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. --
996ae0b0
RK		 23-- --
24------------------------------------------------------------------------------
25
26with Atree; use Atree;
27with Checks; use Checks;
28with Debug; use Debug;
29with Debug_A; use Debug_A;
30with Einfo; use Einfo;
b7d1f17f 31with Elists; use Elists;
996ae0b0
RK		 32with Errout; use Errout;
33with Expander; use Expander;
758c442c 34with Exp_Disp; use Exp_Disp;
0669bebe 35with Exp_Ch6; use Exp_Ch6;
996ae0b0 36with Exp_Ch7; use Exp_Ch7;
fbf5a39b 37with Exp_Tss; use Exp_Tss;
996ae0b0 38with Exp_Util; use Exp_Util;
dae2b8ea 39with Fname; use Fname;
996ae0b0
RK		 40with Freeze; use Freeze;
41with Itypes; use Itypes;
42with Lib; use Lib;
43with Lib.Xref; use Lib.Xref;
44with Namet; use Namet;
45with Nmake; use Nmake;
46with Nlists; use Nlists;
47with Opt; use Opt;
48with Output; use Output;
49with Restrict; use Restrict;
6e937c1c 50with Rident; use Rident;
996ae0b0
RK		 51with Rtsfind; use Rtsfind;
52with Sem; use Sem;
a4100e55 53with Sem_Aux; use Sem_Aux;
996ae0b0
RK		 54with Sem_Aggr; use Sem_Aggr;
55with Sem_Attr; use Sem_Attr;
56with Sem_Cat; use Sem_Cat;
57with Sem_Ch4; use Sem_Ch4;
58with Sem_Ch6; use Sem_Ch6;
59with Sem_Ch8; use Sem_Ch8;
4b92fd3c 60with Sem_Ch13; use Sem_Ch13;
996ae0b0
RK		 61with Sem_Disp; use Sem_Disp;
62with Sem_Dist; use Sem_Dist;
16212e89 63with Sem_Elim; use Sem_Elim;
996ae0b0
RK		 64with Sem_Elab; use Sem_Elab;
65with Sem_Eval; use Sem_Eval;
66with Sem_Intr; use Sem_Intr;
67with Sem_Util; use Sem_Util;
68with Sem_Type; use Sem_Type;
69with Sem_Warn; use Sem_Warn;
70with Sinfo; use Sinfo;
f4b049db 71with Sinfo.CN; use Sinfo.CN;
fbf5a39b 72with Snames; use Snames;
996ae0b0
RK		 73with Stand; use Stand;
74with Stringt; use Stringt;
45fc7ddb 75with Style; use Style;
996ae0b0
RK		 76with Tbuild; use Tbuild;
77with Uintp; use Uintp;
78with Urealp; use Urealp;
79
80package body Sem_Res is
81
82 -----------------------
83 -- Local Subprograms --
84 -----------------------
85
86 -- Second pass (top-down) type checking and overload resolution procedures
5cc9353d
RD		 87 -- Typ is the type required by context. These procedures propagate the type
88 -- information recursively to the descendants of N. If the node is not
89 -- overloaded, its Etype is established in the first pass. If overloaded,
90 -- the Resolve routines set the correct type. For arith. operators, the
91 -- Etype is the base type of the context.
996ae0b0
RK		 92
93 -- Note that Resolve_Attribute is separated off in Sem_Attr
94
bd29d519
AC		 95 function Bad_Unordered_Enumeration_Reference
96 (N : Node_Id;
97 T : Entity_Id) return Boolean;
98 -- Node N contains a potentially dubious reference to type T, either an
99 -- explicit comparison, or an explicit range. This function returns True
100 -- if the type T is an enumeration type for which No pragma Order has been
101 -- given, and the reference N is not in the same extended source unit as
102 -- the declaration of T.
103
996ae0b0
RK		 104 procedure Check_Discriminant_Use (N : Node_Id);
105 -- Enforce the restrictions on the use of discriminants when constraining
106 -- a component of a discriminated type (record or concurrent type).
107
108 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
109 -- Given a node for an operator associated with type T, check that
110 -- the operator is visible. Operators all of whose operands are
111 -- universal must be checked for visibility during resolution
112 -- because their type is not determinable based on their operands.
113
c8ef728f
ES		 114 procedure Check_Fully_Declared_Prefix
115 (Typ : Entity_Id;
116 Pref : Node_Id);
117 -- Check that the type of the prefix of a dereference is not incomplete
118
996ae0b0
RK		 119 function Check_Infinite_Recursion (N : Node_Id) return Boolean;
120 -- Given a call node, N, which is known to occur immediately within the
121 -- subprogram being called, determines whether it is a detectable case of
122 -- an infinite recursion, and if so, outputs appropriate messages. Returns
123 -- True if an infinite recursion is detected, and False otherwise.
124
125 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
126 -- If the type of the object being initialized uses the secondary stack
127 -- directly or indirectly, create a transient scope for the call to the
fbf5a39b
AC		 128 -- init proc. This is because we do not create transient scopes for the
129 -- initialization of individual components within the init proc itself.
996ae0b0
RK		 130 -- Could be optimized away perhaps?
131
f61580d4 132 procedure Check_No_Direct_Boolean_Operators (N : Node_Id);
6fb4cdde
AC		 133 -- N is the node for a logical operator. If the operator is predefined, and
134 -- the root type of the operands is Standard.Boolean, then a check is made
a36c1c3e
RD		 135 -- for restriction No_Direct_Boolean_Operators. This procedure also handles
136 -- the style check for Style_Check_Boolean_And_Or.
f61580d4 137
67ce0d7e 138 function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
5cc9353d
RD		 139 -- Determine whether E is an access type declared by an access declaration,
140 -- and not an (anonymous) allocator type.
67ce0d7e 141
996ae0b0 142 function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
6a497607
AC		 143 -- Utility to check whether the entity for an operator is a predefined
144 -- operator, in which case the expression is left as an operator in the
145 -- tree (else it is rewritten into a call). An instance of an intrinsic
146 -- conversion operation may be given an operator name, but is not treated
147 -- like an operator. Note that an operator that is an imported back-end
148 -- builtin has convention Intrinsic, but is expected to be rewritten into
149 -- a call, so such an operator is not treated as predefined by this
150 -- predicate.
996ae0b0
RK		 151
152 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
153 -- If a default expression in entry call N depends on the discriminants
154 -- of the task, it must be replaced with a reference to the discriminant
155 -- of the task being called.
156
10303118
BD		 157 procedure Resolve_Op_Concat_Arg
158 (N : Node_Id;
159 Arg : Node_Id;
160 Typ : Entity_Id;
161 Is_Comp : Boolean);
162 -- Internal procedure for Resolve_Op_Concat to resolve one operand of
163 -- concatenation operator. The operand is either of the array type or of
164 -- the component type. If the operand is an aggregate, and the component
165 -- type is composite, this is ambiguous if component type has aggregates.
166
167 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
168 -- Does the first part of the work of Resolve_Op_Concat
169
170 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
171 -- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
172 -- has been resolved. See Resolve_Op_Concat for details.
173
996ae0b0
RK		 174 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
175 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
176 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
19d846a0 177 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id);
996ae0b0
RK		 178 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
179 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
180 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id);
955871d3 181 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
996ae0b0
RK		 182 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
183 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
955871d3 184 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id);
996ae0b0
RK		 185 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
186 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
187 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
188 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
189 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
190 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
191 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
192 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
193 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
194 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
a961aa79 195 procedure Resolve_Quantified_Expression (N : Node_Id; Typ : Entity_Id);
996ae0b0
RK		 196 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
197 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
198 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
199 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
200 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
201 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
202 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
203 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
204 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id);
205 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
206 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
207 procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
208 procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
209
210 function Operator_Kind
211 (Op_Name : Name_Id;
0ab80019 212 Is_Binary : Boolean) return Node_Kind;
996ae0b0
RK		 213 -- Utility to map the name of an operator into the corresponding Node. Used
214 -- by other node rewriting procedures.
215
216 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
bc5f3720
RD		 217 -- Resolve actuals of call, and add default expressions for missing ones.
218 -- N is the Node_Id for the subprogram call, and Nam is the entity of the
219 -- called subprogram.
996ae0b0
RK		 220
221 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
222 -- Called from Resolve_Call, when the prefix denotes an entry or element
223 -- of entry family. Actuals are resolved as for subprograms, and the node
224 -- is rebuilt as an entry call. Also called for protected operations. Typ
225 -- is the context type, which is used when the operation is a protected
226 -- function with no arguments, and the return value is indexed.
227
228 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
5cc9353d
RD		 229 -- A call to a user-defined intrinsic operator is rewritten as a call to
230 -- the corresponding predefined operator, with suitable conversions. Note
231 -- that this applies only for intrinsic operators that denote predefined
232 -- operators, not ones that are intrinsic imports of back-end builtins.
996ae0b0 233
fbf5a39b 234 procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
305caf42
AC		 235 -- Ditto, for unary operators (arithmetic ones and "not" on signed
236 -- integer types for VMS).
fbf5a39b 237
996ae0b0
RK		 238 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
239 -- If an operator node resolves to a call to a user-defined operator,
240 -- rewrite the node as a function call.
241
242 procedure Make_Call_Into_Operator
243 (N : Node_Id;
244 Typ : Entity_Id;
245 Op_Id : Entity_Id);
246 -- Inverse transformation: if an operator is given in functional notation,
247 -- then after resolving the node, transform into an operator node, so
248 -- that operands are resolved properly. Recall that predefined operators
249 -- do not have a full signature and special resolution rules apply.
250
0ab80019
AC		 251 procedure Rewrite_Renamed_Operator
252 (N : Node_Id;
253 Op : Entity_Id;
254 Typ : Entity_Id);
996ae0b0 255 -- An operator can rename another, e.g. in an instantiation. In that
0ab80019 256 -- case, the proper operator node must be constructed and resolved.
996ae0b0
RK		 257
258 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
259 -- The String_Literal_Subtype is built for all strings that are not
07fc65c4
GB		 260 -- operands of a static concatenation operation. If the argument is
261 -- not a N_String_Literal node, then the call has no effect.
996ae0b0
RK		 262
263 procedure Set_Slice_Subtype (N : Node_Id);
fbf5a39b 264 -- Build subtype of array type, with the range specified by the slice
996ae0b0 265
0669bebe
GB		 266 procedure Simplify_Type_Conversion (N : Node_Id);
267 -- Called after N has been resolved and evaluated, but before range checks
268 -- have been applied. Currently simplifies a combination of floating-point
269 -- to integer conversion and Truncation attribute.
270
996ae0b0 271 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
5cc9353d
RD		 272 -- A universal_fixed expression in an universal context is unambiguous if
273 -- there is only one applicable fixed point type. Determining whether there
274 -- is only one requires a search over all visible entities, and happens
275 -- only in very pathological cases (see 6115-006).
996ae0b0
RK		 276
277 function Valid_Conversion
278 (N : Node_Id;
279 Target : Entity_Id;
0ab80019 280 Operand : Node_Id) return Boolean;
5cc9353d
RD		 281 -- Verify legality rules given in 4.6 (8-23). Target is the target type
282 -- of the conversion, which may be an implicit conversion of an actual
283 -- parameter to an anonymous access type (in which case N denotes the
284 -- actual parameter and N = Operand).
996ae0b0
RK		 285
286 -------------------------
287 -- Ambiguous_Character --
288 -------------------------
289
290 procedure Ambiguous_Character (C : Node_Id) is
291 E : Entity_Id;
292
293 begin
294 if Nkind (C) = N_Character_Literal then
ed2233dc 295 Error_Msg_N ("ambiguous character literal", C);
b7d1f17f
HK		 296
297 -- First the ones in Standard
298
ed2233dc
AC		 299 Error_Msg_N ("\\possible interpretation: Character!", C);
300 Error_Msg_N ("\\possible interpretation: Wide_Character!", C);
b7d1f17f
HK		 301
302 -- Include Wide_Wide_Character in Ada 2005 mode
303
0791fbe9 304 if Ada_Version >= Ada_2005 then
ed2233dc 305 Error_Msg_N ("\\possible interpretation: Wide_Wide_Character!", C);
b7d1f17f
HK		 306 end if;
307
308 -- Now any other types that match
996ae0b0
RK		 309
310 E := Current_Entity (C);
1420b484 311 while Present (E) loop
ed2233dc 312 Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
1420b484
JM		 313 E := Homonym (E);
314 end loop;
996ae0b0
RK		 315 end if;
316 end Ambiguous_Character;
317
318 -------------------------
319 -- Analyze_And_Resolve --
320 -------------------------
321
322 procedure Analyze_And_Resolve (N : Node_Id) is
323 begin
324 Analyze (N);
fbf5a39b 325 Resolve (N);
996ae0b0
RK		 326 end Analyze_And_Resolve;
327
328 procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
329 begin
330 Analyze (N);
331 Resolve (N, Typ);
332 end Analyze_And_Resolve;
333
334 -- Version withs check(s) suppressed
335
336 procedure Analyze_And_Resolve
337 (N : Node_Id;
338 Typ : Entity_Id;
339 Suppress : Check_Id)
340 is
fbf5a39b 341 Scop : constant Entity_Id := Current_Scope;
996ae0b0
RK		 342
343 begin
344 if Suppress = All_Checks then
345 declare
fbf5a39b 346 Svg : constant Suppress_Array := Scope_Suppress;
996ae0b0
RK		 347 begin
348 Scope_Suppress := (others => True);
349 Analyze_And_Resolve (N, Typ);
350 Scope_Suppress := Svg;
351 end;
352
353 else
354 declare
fbf5a39b 355 Svg : constant Boolean := Scope_Suppress (Suppress);
996ae0b0
RK		 356
357 begin
fbf5a39b 358 Scope_Suppress (Suppress) := True;
996ae0b0 359 Analyze_And_Resolve (N, Typ);
fbf5a39b 360 Scope_Suppress (Suppress) := Svg;
996ae0b0
RK		 361 end;
362 end if;
363
364 if Current_Scope /= Scop
365 and then Scope_Is_Transient
366 then
5cc9353d
RD		 367 -- This can only happen if a transient scope was created for an inner
368 -- expression, which will be removed upon completion of the analysis
369 -- of an enclosing construct. The transient scope must have the
370 -- suppress status of the enclosing environment, not of this Analyze
371 -- call.
996ae0b0
RK		 372
373 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
374 Scope_Suppress;
375 end if;
376 end Analyze_And_Resolve;
377
378 procedure Analyze_And_Resolve
379 (N : Node_Id;
380 Suppress : Check_Id)
381 is
fbf5a39b 382 Scop : constant Entity_Id := Current_Scope;
996ae0b0
RK		 383
384 begin
385 if Suppress = All_Checks then
386 declare
fbf5a39b 387 Svg : constant Suppress_Array := Scope_Suppress;
996ae0b0
RK		 388 begin
389 Scope_Suppress := (others => True);
390 Analyze_And_Resolve (N);
391 Scope_Suppress := Svg;
392 end;
393
394 else
395 declare
fbf5a39b 396 Svg : constant Boolean := Scope_Suppress (Suppress);
996ae0b0
RK		 397
398 begin
fbf5a39b 399 Scope_Suppress (Suppress) := True;
996ae0b0 400 Analyze_And_Resolve (N);
fbf5a39b 401 Scope_Suppress (Suppress) := Svg;
996ae0b0
RK		 402 end;
403 end if;
404
405 if Current_Scope /= Scop
406 and then Scope_Is_Transient
407 then
408 Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
409 Scope_Suppress;
410 end if;
411 end Analyze_And_Resolve;
412
bd29d519
AC		 413 ----------------------------------------
414 -- Bad_Unordered_Enumeration_Reference --
415 ----------------------------------------
416
417 function Bad_Unordered_Enumeration_Reference
418 (N : Node_Id;
419 T : Entity_Id) return Boolean
420 is
421 begin
422 return Is_Enumeration_Type (T)
423 and then Comes_From_Source (N)
424 and then Warn_On_Unordered_Enumeration_Type
425 and then not Has_Pragma_Ordered (T)
426 and then not In_Same_Extended_Unit (N, T);
427 end Bad_Unordered_Enumeration_Reference;
428
996ae0b0
RK		 429 ----------------------------
430 -- Check_Discriminant_Use --
431 ----------------------------
432
433 procedure Check_Discriminant_Use (N : Node_Id) is
434 PN : constant Node_Id := Parent (N);
435 Disc : constant Entity_Id := Entity (N);
436 P : Node_Id;
437 D : Node_Id;
438
439 begin
f3d0f304 440 -- Any use in a spec-expression is legal
996ae0b0 441
45fc7ddb 442 if In_Spec_Expression then
996ae0b0
RK		 443 null;
444
445 elsif Nkind (PN) = N_Range then
446
a77842bd 447 -- Discriminant cannot be used to constrain a scalar type
996ae0b0
RK		 448
449 P := Parent (PN);
450
451 if Nkind (P) = N_Range_Constraint
452 and then Nkind (Parent (P)) = N_Subtype_Indication
a397db96 453 and then Nkind (Parent (Parent (P))) = N_Component_Definition
996ae0b0
RK		 454 then
455 Error_Msg_N ("discriminant cannot constrain scalar type", N);
456
457 elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
458
5cc9353d
RD		 459 -- The following check catches the unusual case where a
460 -- discriminant appears within an index constraint that is part of
461 -- a larger expression within a constraint on a component, e.g. "C
462 -- : Int range 1 .. F (new A(1 .. D))". For now we only check case
463 -- of record components, and note that a similar check should also
464 -- apply in the case of discriminant constraints below. ???
996ae0b0
RK		 465
466 -- Note that the check for N_Subtype_Declaration below is to
467 -- detect the valid use of discriminants in the constraints of a
468 -- subtype declaration when this subtype declaration appears
469 -- inside the scope of a record type (which is syntactically
470 -- illegal, but which may be created as part of derived type
471 -- processing for records). See Sem_Ch3.Build_Derived_Record_Type
472 -- for more info.
473
474 if Ekind (Current_Scope) = E_Record_Type
475 and then Scope (Disc) = Current_Scope
476 and then not
477 (Nkind (Parent (P)) = N_Subtype_Indication
45fc7ddb
HK		 478 and then
479 Nkind_In (Parent (Parent (P)), N_Component_Definition,
480 N_Subtype_Declaration)
996ae0b0
RK		 481 and then Paren_Count (N) = 0)
482 then
483 Error_Msg_N
484 ("discriminant must appear alone in component constraint", N);
485 return;
486 end if;
487
a0ac3932 488 -- Detect a common error:
9bc43c53 489
996ae0b0 490 -- type R (D : Positive := 100) is record
9bc43c53 491 -- Name : String (1 .. D);
996ae0b0
RK		 492 -- end record;
493
a0ac3932
RD		 494 -- The default value causes an object of type R to be allocated
495 -- with room for Positive'Last characters. The RM does not mandate
496 -- the allocation of the maximum size, but that is what GNAT does
497 -- so we should warn the programmer that there is a problem.
996ae0b0 498
a0ac3932 499 Check_Large : declare
996ae0b0
RK		 500 SI : Node_Id;
501 T : Entity_Id;
502 TB : Node_Id;
503 CB : Entity_Id;
504
505 function Large_Storage_Type (T : Entity_Id) return Boolean;
5cc9353d
RD		 506 -- Return True if type T has a large enough range that any
507 -- array whose index type covered the whole range of the type
508 -- would likely raise Storage_Error.
996ae0b0 509
fbf5a39b
AC		 510 ------------------------
511 -- Large_Storage_Type --
512 ------------------------
513
996ae0b0
RK		 514 function Large_Storage_Type (T : Entity_Id) return Boolean is
515 begin
4b92fd3c
ST		 516 -- The type is considered large if its bounds are known at
517 -- compile time and if it requires at least as many bits as
518 -- a Positive to store the possible values.
519
520 return Compile_Time_Known_Value (Type_Low_Bound (T))
521 and then Compile_Time_Known_Value (Type_High_Bound (T))
522 and then
523 Minimum_Size (T, Biased => True) >=
a0ac3932 524 RM_Size (Standard_Positive);
996ae0b0
RK		 525 end Large_Storage_Type;
526
a0ac3932
RD		 527 -- Start of processing for Check_Large
528
996ae0b0
RK		 529 begin
530 -- Check that the Disc has a large range
531
532 if not Large_Storage_Type (Etype (Disc)) then
533 goto No_Danger;
534 end if;
535
536 -- If the enclosing type is limited, we allocate only the
537 -- default value, not the maximum, and there is no need for
538 -- a warning.
539
540 if Is_Limited_Type (Scope (Disc)) then
541 goto No_Danger;
542 end if;
543
544 -- Check that it is the high bound
545
546 if N /= High_Bound (PN)
c8ef728f 547 or else No (Discriminant_Default_Value (Disc))
996ae0b0
RK		 548 then
549 goto No_Danger;
550 end if;
551
5cc9353d
RD		 552 -- Check the array allows a large range at this bound. First
553 -- find the array
996ae0b0
RK		 554
555 SI := Parent (P);
556
557 if Nkind (SI) /= N_Subtype_Indication then
558 goto No_Danger;
559 end if;
560
561 T := Entity (Subtype_Mark (SI));
562
563 if not Is_Array_Type (T) then
564 goto No_Danger;
565 end if;
566
567 -- Next, find the dimension
568
569 TB := First_Index (T);
570 CB := First (Constraints (P));
571 while True
572 and then Present (TB)
573 and then Present (CB)
574 and then CB /= PN
575 loop
576 Next_Index (TB);
577 Next (CB);
578 end loop;
579
580 if CB /= PN then
581 goto No_Danger;
582 end if;
583
584 -- Now, check the dimension has a large range
585
586 if not Large_Storage_Type (Etype (TB)) then
587 goto No_Danger;
588 end if;
589
590 -- Warn about the danger
591
592 Error_Msg_N
aa5147f0 593 ("?creation of & object may raise Storage_Error!",
fbf5a39b 594 Scope (Disc));
996ae0b0
RK		 595
596 <<No_Danger>>
597 null;
598
a0ac3932 599 end Check_Large;
996ae0b0
RK		 600 end if;
601
602 -- Legal case is in index or discriminant constraint
603
45fc7ddb
HK		 604 elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint,
605 N_Discriminant_Association)
996ae0b0
RK		 606 then
607 if Paren_Count (N) > 0 then
608 Error_Msg_N
609 ("discriminant in constraint must appear alone", N);
758c442c
GD		 610
611 elsif Nkind (N) = N_Expanded_Name
612 and then Comes_From_Source (N)
613 then
614 Error_Msg_N
615 ("discriminant must appear alone as a direct name", N);
996ae0b0
RK		 616 end if;
617
618 return;
619
5cc9353d
RD		 620 -- Otherwise, context is an expression. It should not be within (i.e. a
621 -- subexpression of) a constraint for a component.
996ae0b0
RK		 622
623 else
624 D := PN;
625 P := Parent (PN);
45fc7ddb
HK		 626 while not Nkind_In (P, N_Component_Declaration,
627 N_Subtype_Indication,
628 N_Entry_Declaration)
996ae0b0
RK		 629 loop
630 D := P;
631 P := Parent (P);
632 exit when No (P);
633 end loop;
634
5cc9353d
RD		 635 -- If the discriminant is used in an expression that is a bound of a
636 -- scalar type, an Itype is created and the bounds are attached to
637 -- its range, not to the original subtype indication. Such use is of
638 -- course a double fault.
996ae0b0
RK		 639
640 if (Nkind (P) = N_Subtype_Indication
45fc7ddb
HK		 641 and then Nkind_In (Parent (P), N_Component_Definition,
642 N_Derived_Type_Definition)
996ae0b0
RK		 643 and then D = Constraint (P))
644
19fb051c
AC		 645 -- The constraint itself may be given by a subtype indication,
646 -- rather than by a more common discrete range.
996ae0b0
RK		 647
648 or else (Nkind (P) = N_Subtype_Indication
fbf5a39b
AC		 649 and then
650 Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
996ae0b0
RK		 651 or else Nkind (P) = N_Entry_Declaration
652 or else Nkind (D) = N_Defining_Identifier
653 then
654 Error_Msg_N
655 ("discriminant in constraint must appear alone", N);
656 end if;
657 end if;
658 end Check_Discriminant_Use;
659
660 --------------------------------
661 -- Check_For_Visible_Operator --
662 --------------------------------
663
664 procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
996ae0b0 665 begin
fbf5a39b 666 if Is_Invisible_Operator (N, T) then
305caf42 667 Error_Msg_NE -- CODEFIX
996ae0b0 668 ("operator for} is not directly visible!", N, First_Subtype (T));
305caf42
AC		 669 Error_Msg_N -- CODEFIX
670 ("use clause would make operation legal!", N);
996ae0b0
RK		 671 end if;
672 end Check_For_Visible_Operator;
673
c8ef728f
ES		 674 ----------------------------------
675 -- Check_Fully_Declared_Prefix --
676 ----------------------------------
677
678 procedure Check_Fully_Declared_Prefix
679 (Typ : Entity_Id;
680 Pref : Node_Id)
681 is
682 begin
683 -- Check that the designated type of the prefix of a dereference is
684 -- not an incomplete type. This cannot be done unconditionally, because
685 -- dereferences of private types are legal in default expressions. This
686 -- case is taken care of in Check_Fully_Declared, called below. There
687 -- are also 2005 cases where it is legal for the prefix to be unfrozen.
688
689 -- This consideration also applies to similar checks for allocators,
690 -- qualified expressions, and type conversions.
691
692 -- An additional exception concerns other per-object expressions that
693 -- are not directly related to component declarations, in particular
694 -- representation pragmas for tasks. These will be per-object
695 -- expressions if they depend on discriminants or some global entity.
696 -- If the task has access discriminants, the designated type may be
697 -- incomplete at the point the expression is resolved. This resolution
698 -- takes place within the body of the initialization procedure, where
699 -- the discriminant is replaced by its discriminal.
700
701 if Is_Entity_Name (Pref)
702 and then Ekind (Entity (Pref)) = E_In_Parameter
703 then
704 null;
705
706 -- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
707 -- are handled by Analyze_Access_Attribute, Analyze_Assignment,
708 -- Analyze_Object_Renaming, and Freeze_Entity.
709
0791fbe9 710 elsif Ada_Version >= Ada_2005
c8ef728f 711 and then Is_Entity_Name (Pref)
811c6a85 712 and then Is_Access_Type (Etype (Pref))
c8ef728f
ES		 713 and then Ekind (Directly_Designated_Type (Etype (Pref))) =
714 E_Incomplete_Type
715 and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
716 then
717 null;
718 else
719 Check_Fully_Declared (Typ, Parent (Pref));
720 end if;
721 end Check_Fully_Declared_Prefix;
722
996ae0b0
RK		 723 ------------------------------
724 -- Check_Infinite_Recursion --
725 ------------------------------
726
727 function Check_Infinite_Recursion (N : Node_Id) return Boolean is
728 P : Node_Id;
729 C : Node_Id;
730
07fc65c4 731 function Same_Argument_List return Boolean;
5cc9353d
RD		 732 -- Check whether list of actuals is identical to list of formals of
733 -- called function (which is also the enclosing scope).
07fc65c4
GB		 734
735 ------------------------
736 -- Same_Argument_List --
737 ------------------------
738
739 function Same_Argument_List return Boolean is
740 A : Node_Id;
741 F : Entity_Id;
742 Subp : Entity_Id;
743
744 begin
745 if not Is_Entity_Name (Name (N)) then
746 return False;
747 else
748 Subp := Entity (Name (N));
749 end if;
750
751 F := First_Formal (Subp);
752 A := First_Actual (N);
07fc65c4
GB		 753 while Present (F) and then Present (A) loop
754 if not Is_Entity_Name (A)
755 or else Entity (A) /= F
756 then
757 return False;
758 end if;
759
760 Next_Actual (A);
761 Next_Formal (F);
762 end loop;
763
764 return True;
765 end Same_Argument_List;
766
767 -- Start of processing for Check_Infinite_Recursion
768
996ae0b0 769 begin
26570b21
RD		 770 -- Special case, if this is a procedure call and is a call to the
771 -- current procedure with the same argument list, then this is for
772 -- sure an infinite recursion and we insert a call to raise SE.
773
774 if Is_List_Member (N)
775 and then List_Length (List_Containing (N)) = 1
776 and then Same_Argument_List
777 then
778 declare
779 P : constant Node_Id := Parent (N);
780 begin
781 if Nkind (P) = N_Handled_Sequence_Of_Statements
782 and then Nkind (Parent (P)) = N_Subprogram_Body
783 and then Is_Empty_List (Declarations (Parent (P)))
784 then
785 Error_Msg_N ("!?infinite recursion", N);
786 Error_Msg_N ("\!?Storage_Error will be raised at run time", N);
787 Insert_Action (N,
788 Make_Raise_Storage_Error (Sloc (N),
789 Reason => SE_Infinite_Recursion));
790 return True;
791 end if;
792 end;
793 end if;
794
795 -- If not that special case, search up tree, quitting if we reach a
796 -- construct (e.g. a conditional) that tells us that this is not a
797 -- case for an infinite recursion warning.
996ae0b0
RK		 798
799 C := N;
800 loop
801 P := Parent (C);
9a7da240
RD		 802
803 -- If no parent, then we were not inside a subprogram, this can for
804 -- example happen when processing certain pragmas in a spec. Just
805 -- return False in this case.
806
807 if No (P) then
808 return False;
809 end if;
810
811 -- Done if we get to subprogram body, this is definitely an infinite
812 -- recursion case if we did not find anything to stop us.
813
996ae0b0 814 exit when Nkind (P) = N_Subprogram_Body;
9a7da240
RD		 815
816 -- If appearing in conditional, result is false
817
45fc7ddb
HK		 818 if Nkind_In (P, N_Or_Else,
819 N_And_Then,
d347f572
AC		 820 N_Case_Expression,
821 N_Case_Statement,
822 N_Conditional_Expression,
823 N_If_Statement)
996ae0b0
RK		 824 then
825 return False;
826
827 elsif Nkind (P) = N_Handled_Sequence_Of_Statements
828 and then C /= First (Statements (P))
829 then
26570b21
RD		 830 -- If the call is the expression of a return statement and the
831 -- actuals are identical to the formals, it's worth a warning.
832 -- However, we skip this if there is an immediately preceding
833 -- raise statement, since the call is never executed.
07fc65c4
GB		 834
835 -- Furthermore, this corresponds to a common idiom:
836
837 -- function F (L : Thing) return Boolean is
838 -- begin
839 -- raise Program_Error;
840 -- return F (L);
841 -- end F;
842
843 -- for generating a stub function
844
aa5147f0 845 if Nkind (Parent (N)) = N_Simple_Return_Statement
07fc65c4
GB		 846 and then Same_Argument_List
847 then
9ebe3743
HK		 848 exit when not Is_List_Member (Parent (N));
849
850 -- OK, return statement is in a statement list, look for raise
851
852 declare
853 Nod : Node_Id;
854
855 begin
856 -- Skip past N_Freeze_Entity nodes generated by expansion
857
858 Nod := Prev (Parent (N));
859 while Present (Nod)
860 and then Nkind (Nod) = N_Freeze_Entity
861 loop
862 Prev (Nod);
863 end loop;
864
865 -- If no raise statement, give warning
866
867 exit when Nkind (Nod) /= N_Raise_Statement
868 and then
869 (Nkind (Nod) not in N_Raise_xxx_Error
19fb051c 870 or else Present (Condition (Nod)));
9ebe3743 871 end;
07fc65c4
GB		 872 end if;
873
996ae0b0
RK		 874 return False;
875
876 else
877 C := P;
878 end if;
879 end loop;
880
aa5147f0
ES		 881 Error_Msg_N ("!?possible infinite recursion", N);
882 Error_Msg_N ("\!?Storage_Error may be raised at run time", N);
996ae0b0
RK		 883
884 return True;
885 end Check_Infinite_Recursion;
886
887 -------------------------------
888 -- Check_Initialization_Call --
889 -------------------------------
890
891 procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
fbf5a39b 892 Typ : constant Entity_Id := Etype (First_Formal (Nam));
996ae0b0
RK		 893
894 function Uses_SS (T : Entity_Id) return Boolean;
07fc65c4
GB		 895 -- Check whether the creation of an object of the type will involve
896 -- use of the secondary stack. If T is a record type, this is true
f3d57416 897 -- if the expression for some component uses the secondary stack, e.g.
07fc65c4
GB		 898 -- through a call to a function that returns an unconstrained value.
899 -- False if T is controlled, because cleanups occur elsewhere.
900
901 -------------
902 -- Uses_SS --
903 -------------
996ae0b0
RK		 904
905 function Uses_SS (T : Entity_Id) return Boolean is
aa5147f0
ES		 906 Comp : Entity_Id;
907 Expr : Node_Id;
908 Full_Type : Entity_Id := Underlying_Type (T);
996ae0b0
RK		 909
910 begin
aa5147f0
ES		 911 -- Normally we want to use the underlying type, but if it's not set
912 -- then continue with T.
913
914 if not Present (Full_Type) then
915 Full_Type := T;
916 end if;
917
918 if Is_Controlled (Full_Type) then
996ae0b0
RK		 919 return False;
920
aa5147f0
ES		 921 elsif Is_Array_Type (Full_Type) then
922 return Uses_SS (Component_Type (Full_Type));
996ae0b0 923
aa5147f0
ES		 924 elsif Is_Record_Type (Full_Type) then
925 Comp := First_Component (Full_Type);
996ae0b0 926 while Present (Comp) loop
996ae0b0
RK		 927 if Ekind (Comp) = E_Component
928 and then Nkind (Parent (Comp)) = N_Component_Declaration
929 then
aa5147f0
ES		 930 -- The expression for a dynamic component may be rewritten
931 -- as a dereference, so retrieve original node.
932
933 Expr := Original_Node (Expression (Parent (Comp)));
996ae0b0 934
aa5147f0 935 -- Return True if the expression is a call to a function
1d57c04f
AC		 936 -- (including an attribute function such as Image, or a
937 -- user-defined operator) with a result that requires a
938 -- transient scope.
fbf5a39b 939
aa5147f0 940 if (Nkind (Expr) = N_Function_Call
1d57c04f 941 or else Nkind (Expr) in N_Op
aa5147f0
ES		 942 or else (Nkind (Expr) = N_Attribute_Reference
943 and then Present (Expressions (Expr))))
996ae0b0
RK		 944 and then Requires_Transient_Scope (Etype (Expr))
945 then
946 return True;
947
948 elsif Uses_SS (Etype (Comp)) then
949 return True;
950 end if;
951 end if;
952
953 Next_Component (Comp);
954 end loop;
955
956 return False;
957
958 else
959 return False;
960 end if;
961 end Uses_SS;
962
07fc65c4
GB		 963 -- Start of processing for Check_Initialization_Call
964
996ae0b0 965 begin
0669bebe 966 -- Establish a transient scope if the type needs it
07fc65c4 967
0669bebe 968 if Uses_SS (Typ) then
996ae0b0
RK		 969 Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
970 end if;
971 end Check_Initialization_Call;
972
f61580d4
AC		 973 ---------------------------------------
974 -- Check_No_Direct_Boolean_Operators --
975 ---------------------------------------
976
977 procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is
978 begin
979 if Scope (Entity (N)) = Standard_Standard
980 and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
981 then
6fb4cdde 982 -- Restriction only applies to original source code
f61580d4 983
6fb4cdde 984 if Comes_From_Source (N) then
f61580d4
AC		 985 Check_Restriction (No_Direct_Boolean_Operators, N);
986 end if;
987 end if;
a36c1c3e
RD		 988
989 if Style_Check then
990 Check_Boolean_Operator (N);
991 end if;
f61580d4
AC		 992 end Check_No_Direct_Boolean_Operators;
993
996ae0b0
RK		 994 ------------------------------
995 -- Check_Parameterless_Call --
996 ------------------------------
997
998 procedure Check_Parameterless_Call (N : Node_Id) is
999 Nam : Node_Id;
1000
bc5f3720
RD		 1001 function Prefix_Is_Access_Subp return Boolean;
1002 -- If the prefix is of an access_to_subprogram type, the node must be
1003 -- rewritten as a call. Ditto if the prefix is overloaded and all its
1004 -- interpretations are access to subprograms.
1005
1006 ---------------------------
1007 -- Prefix_Is_Access_Subp --
1008 ---------------------------
1009
1010 function Prefix_Is_Access_Subp return Boolean is
1011 I : Interp_Index;
1012 It : Interp;
1013
1014 begin
22b77f68 1015 -- If the context is an attribute reference that can apply to
b4a4936b 1016 -- functions, this is never a parameterless call (RM 4.1.4(6)).
96d2756f
AC		 1017
1018 if Nkind (Parent (N)) = N_Attribute_Reference
19fb051c
AC		 1019 and then (Attribute_Name (Parent (N)) = Name_Address or else
1020 Attribute_Name (Parent (N)) = Name_Code_Address or else
1021 Attribute_Name (Parent (N)) = Name_Access)
96d2756f
AC		 1022 then
1023 return False;
1024 end if;
1025
bc5f3720
RD		 1026 if not Is_Overloaded (N) then
1027 return
1028 Ekind (Etype (N)) = E_Subprogram_Type
1029 and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
1030 else
1031 Get_First_Interp (N, I, It);
1032 while Present (It.Typ) loop
1033 if Ekind (It.Typ) /= E_Subprogram_Type
1034 or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
1035 then
1036 return False;
1037 end if;
1038
1039 Get_Next_Interp (I, It);
1040 end loop;
1041
1042 return True;
1043 end if;
1044 end Prefix_Is_Access_Subp;
1045
1046 -- Start of processing for Check_Parameterless_Call
1047
996ae0b0 1048 begin
07fc65c4
GB		 1049 -- Defend against junk stuff if errors already detected
1050
1051 if Total_Errors_Detected /= 0 then
1052 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1053 return;
1054 elsif Nkind (N) in N_Has_Chars
1055 and then Chars (N) in Error_Name_Or_No_Name
1056 then
1057 return;
1058 end if;
fbf5a39b
AC		 1059
1060 Require_Entity (N);
996ae0b0
RK		 1061 end if;
1062
45fc7ddb
HK		 1063 -- If the context expects a value, and the name is a procedure, this is
1064 -- most likely a missing 'Access. Don't try to resolve the parameterless
1065 -- call, error will be caught when the outer call is analyzed.
18c0ecbe
AC		 1066
1067 if Is_Entity_Name (N)
1068 and then Ekind (Entity (N)) = E_Procedure
1069 and then not Is_Overloaded (N)
1070 and then
45fc7ddb
HK		 1071 Nkind_In (Parent (N), N_Parameter_Association,
1072 N_Function_Call,
1073 N_Procedure_Call_Statement)
18c0ecbe
AC		 1074 then
1075 return;
1076 end if;
1077
45fc7ddb
HK		 1078 -- Rewrite as call if overloadable entity that is (or could be, in the
1079 -- overloaded case) a function call. If we know for sure that the entity
1080 -- is an enumeration literal, we do not rewrite it.
f4b049db 1081
e1d9659d
AC		 1082 -- If the entity is the name of an operator, it cannot be a call because
1083 -- operators cannot have default parameters. In this case, this must be
1084 -- a string whose contents coincide with an operator name. Set the kind
96d2756f 1085 -- of the node appropriately.
996ae0b0
RK		 1086
1087 if (Is_Entity_Name (N)
e1d9659d 1088 and then Nkind (N) /= N_Operator_Symbol
996ae0b0
RK		 1089 and then Is_Overloadable (Entity (N))
1090 and then (Ekind (Entity (N)) /= E_Enumeration_Literal
964f13da 1091 or else Is_Overloaded (N)))
996ae0b0 1092
09494c32 1093 -- Rewrite as call if it is an explicit dereference of an expression of
f3d57416 1094 -- a subprogram access type, and the subprogram type is not that of a
996ae0b0
RK		 1095 -- procedure or entry.
1096
1097 or else
bc5f3720 1098 (Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
996ae0b0
RK		 1099
1100 -- Rewrite as call if it is a selected component which is a function,
1101 -- this is the case of a call to a protected function (which may be
1102 -- overloaded with other protected operations).
1103
1104 or else
1105 (Nkind (N) = N_Selected_Component
1106 and then (Ekind (Entity (Selector_Name (N))) = E_Function
964f13da
RD		 1107 or else
1108 (Ekind_In (Entity (Selector_Name (N)), E_Entry,
1109 E_Procedure)
1110 and then Is_Overloaded (Selector_Name (N)))))
996ae0b0 1111
5cc9353d
RD		 1112 -- If one of the above three conditions is met, rewrite as call. Apply
1113 -- the rewriting only once.
996ae0b0
RK		 1114
1115 then
1116 if Nkind (Parent (N)) /= N_Function_Call
1117 or else N /= Name (Parent (N))
1118 then
1119 Nam := New_Copy (N);
1120
bc5f3720 1121 -- If overloaded, overload set belongs to new copy
996ae0b0
RK		 1122
1123 Save_Interps (N, Nam);
1124
1125 -- Change node to parameterless function call (note that the
1126 -- Parameter_Associations associations field is left set to Empty,
1127 -- its normal default value since there are no parameters)
1128
1129 Change_Node (N, N_Function_Call);
1130 Set_Name (N, Nam);
1131 Set_Sloc (N, Sloc (Nam));
1132 Analyze_Call (N);
1133 end if;
1134
1135 elsif Nkind (N) = N_Parameter_Association then
1136 Check_Parameterless_Call (Explicit_Actual_Parameter (N));
e1d9659d
AC		 1137
1138 elsif Nkind (N) = N_Operator_Symbol then
1139 Change_Operator_Symbol_To_String_Literal (N);
1140 Set_Is_Overloaded (N, False);
1141 Set_Etype (N, Any_String);
996ae0b0
RK		 1142 end if;
1143 end Check_Parameterless_Call;
1144
67ce0d7e
RD		 1145 -----------------------------
1146 -- Is_Definite_Access_Type --
1147 -----------------------------
1148
1149 function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
1150 Btyp : constant Entity_Id := Base_Type (E);
1151 begin
1152 return Ekind (Btyp) = E_Access_Type
1153 or else (Ekind (Btyp) = E_Access_Subprogram_Type
72e9f2b9 1154 and then Comes_From_Source (Btyp));
67ce0d7e
RD		 1155 end Is_Definite_Access_Type;
1156
996ae0b0
RK		 1157 ----------------------
1158 -- Is_Predefined_Op --
1159 ----------------------
1160
1161 function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
1162 begin
6a497607
AC		 1163 -- Predefined operators are intrinsic subprograms
1164
1165 if not Is_Intrinsic_Subprogram (Nam) then
1166 return False;
1167 end if;
1168
1169 -- A call to a back-end builtin is never a predefined operator
1170
1171 if Is_Imported (Nam) and then Present (Interface_Name (Nam)) then
1172 return False;
1173 end if;
1174
1175 return not Is_Generic_Instance (Nam)
996ae0b0 1176 and then Chars (Nam) in Any_Operator_Name
6a497607 1177 and then (No (Alias (Nam)) or else Is_Predefined_Op (Alias (Nam)));
996ae0b0
RK		 1178 end Is_Predefined_Op;
1179
1180 -----------------------------
1181 -- Make_Call_Into_Operator --
1182 -----------------------------
1183
1184 procedure Make_Call_Into_Operator
1185 (N : Node_Id;
1186 Typ : Entity_Id;
1187 Op_Id : Entity_Id)
1188 is
1189 Op_Name : constant Name_Id := Chars (Op_Id);
1190 Act1 : Node_Id := First_Actual (N);
1191 Act2 : Node_Id := Next_Actual (Act1);
1192 Error : Boolean := False;
2820d220
AC		 1193 Func : constant Entity_Id := Entity (Name (N));
1194 Is_Binary : constant Boolean := Present (Act2);
996ae0b0
RK		 1195 Op_Node : Node_Id;
1196 Opnd_Type : Entity_Id;
1197 Orig_Type : Entity_Id := Empty;
1198 Pack : Entity_Id;
1199
1200 type Kind_Test is access function (E : Entity_Id) return Boolean;
1201
996ae0b0 1202 function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
b4a4936b
AC		 1203 -- If the operand is not universal, and the operator is given by an
1204 -- expanded name, verify that the operand has an interpretation with a
1205 -- type defined in the given scope of the operator.
996ae0b0
RK		 1206
1207 function Type_In_P (Test : Kind_Test) return Entity_Id;
b4a4936b
AC		 1208 -- Find a type of the given class in package Pack that contains the
1209 -- operator.
996ae0b0 1210
996ae0b0
RK		 1211 ---------------------------
1212 -- Operand_Type_In_Scope --
1213 ---------------------------
1214
1215 function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
1216 Nod : constant Node_Id := Right_Opnd (Op_Node);
1217 I : Interp_Index;
1218 It : Interp;
1219
1220 begin
1221 if not Is_Overloaded (Nod) then
1222 return Scope (Base_Type (Etype (Nod))) = S;
1223
1224 else
1225 Get_First_Interp (Nod, I, It);
996ae0b0 1226 while Present (It.Typ) loop
996ae0b0
RK		 1227 if Scope (Base_Type (It.Typ)) = S then
1228 return True;
1229 end if;
1230
1231 Get_Next_Interp (I, It);
1232 end loop;
1233
1234 return False;
1235 end if;
1236 end Operand_Type_In_Scope;
1237
1238 ---------------
1239 -- Type_In_P --
1240 ---------------
1241
1242 function Type_In_P (Test : Kind_Test) return Entity_Id is
1243 E : Entity_Id;
1244
1245 function In_Decl return Boolean;
1246 -- Verify that node is not part of the type declaration for the
1247 -- candidate type, which would otherwise be invisible.
1248
1249 -------------
1250 -- In_Decl --
1251 -------------
1252
1253 function In_Decl return Boolean is
1254 Decl_Node : constant Node_Id := Parent (E);
1255 N2 : Node_Id;
1256
1257 begin
1258 N2 := N;
1259
1260 if Etype (E) = Any_Type then
1261 return True;
1262
1263 elsif No (Decl_Node) then
1264 return False;
1265
1266 else
1267 while Present (N2)
1268 and then Nkind (N2) /= N_Compilation_Unit
1269 loop
1270 if N2 = Decl_Node then
1271 return True;
1272 else
1273 N2 := Parent (N2);
1274 end if;
1275 end loop;
1276
1277 return False;
1278 end if;
1279 end In_Decl;
1280
1281 -- Start of processing for Type_In_P
1282
1283 begin
b4a4936b
AC		 1284 -- If the context type is declared in the prefix package, this is the
1285 -- desired base type.
996ae0b0 1286
b4a4936b 1287 if Scope (Base_Type (Typ)) = Pack and then Test (Typ) then
996ae0b0
RK		 1288 return Base_Type (Typ);
1289
1290 else
1291 E := First_Entity (Pack);
996ae0b0 1292 while Present (E) loop
996ae0b0
RK		 1293 if Test (E)
1294 and then not In_Decl
1295 then
1296 return E;
1297 end if;
1298
1299 Next_Entity (E);
1300 end loop;
1301
1302 return Empty;
1303 end if;
1304 end Type_In_P;
1305
996ae0b0
RK		 1306 -- Start of processing for Make_Call_Into_Operator
1307
1308 begin
1309 Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
1310
1311 -- Binary operator
1312
1313 if Is_Binary then
1314 Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
1315 Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
1316 Save_Interps (Act1, Left_Opnd (Op_Node));
1317 Save_Interps (Act2, Right_Opnd (Op_Node));
1318 Act1 := Left_Opnd (Op_Node);
1319 Act2 := Right_Opnd (Op_Node);
1320
1321 -- Unary operator
1322
1323 else
1324 Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
1325 Save_Interps (Act1, Right_Opnd (Op_Node));
1326 Act1 := Right_Opnd (Op_Node);
1327 end if;
1328
1329 -- If the operator is denoted by an expanded name, and the prefix is
1330 -- not Standard, but the operator is a predefined one whose scope is
1331 -- Standard, then this is an implicit_operator, inserted as an
1332 -- interpretation by the procedure of the same name. This procedure
1333 -- overestimates the presence of implicit operators, because it does
1334 -- not examine the type of the operands. Verify now that the operand
1335 -- type appears in the given scope. If right operand is universal,
1336 -- check the other operand. In the case of concatenation, either
1337 -- argument can be the component type, so check the type of the result.
1338 -- If both arguments are literals, look for a type of the right kind
1339 -- defined in the given scope. This elaborate nonsense is brought to
1340 -- you courtesy of b33302a. The type itself must be frozen, so we must
1341 -- find the type of the proper class in the given scope.
1342
06f2efd7
TQ		 1343 -- A final wrinkle is the multiplication operator for fixed point types,
1344 -- which is defined in Standard only, and not in the scope of the
b4a4936b 1345 -- fixed point type itself.
996ae0b0
RK		 1346
1347 if Nkind (Name (N)) = N_Expanded_Name then
1348 Pack := Entity (Prefix (Name (N)));
1349
06f2efd7
TQ		 1350 -- If the entity being called is defined in the given package, it is
1351 -- a renaming of a predefined operator, and known to be legal.
996ae0b0
RK		 1352
1353 if Scope (Entity (Name (N))) = Pack
1354 and then Pack /= Standard_Standard
1355 then
1356 null;
1357
9ebe3743
HK		 1358 -- Visibility does not need to be checked in an instance: if the
1359 -- operator was not visible in the generic it has been diagnosed
1360 -- already, else there is an implicit copy of it in the instance.
1361
1362 elsif In_Instance then
1363 null;
1364
12577815 1365 elsif (Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide)
996ae0b0
RK		 1366 and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
1367 and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
1368 then
1369 if Pack /= Standard_Standard then
1370 Error := True;
1371 end if;
1372
b4a4936b 1373 -- Ada 2005 AI-420: Predefined equality on Universal_Access is
06f2efd7 1374 -- available.
c8ef728f 1375
0791fbe9 1376 elsif Ada_Version >= Ada_2005
c8ef728f
ES		 1377 and then (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1378 and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
1379 then
1380 null;
1381
996ae0b0
RK		 1382 else
1383 Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
1384
1385 if Op_Name = Name_Op_Concat then
1386 Opnd_Type := Base_Type (Typ);
1387
1388 elsif (Scope (Opnd_Type) = Standard_Standard
1389 and then Is_Binary)
1390 or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
1391 and then Is_Binary
1392 and then not Comes_From_Source (Opnd_Type))
1393 then
1394 Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
1395 end if;
1396
1397 if Scope (Opnd_Type) = Standard_Standard then
1398
1399 -- Verify that the scope contains a type that corresponds to
1400 -- the given literal. Optimize the case where Pack is Standard.
1401
1402 if Pack /= Standard_Standard then
1403
1404 if Opnd_Type = Universal_Integer then
06f2efd7 1405 Orig_Type := Type_In_P (Is_Integer_Type'Access);
996ae0b0
RK		 1406
1407 elsif Opnd_Type = Universal_Real then
1408 Orig_Type := Type_In_P (Is_Real_Type'Access);
1409
1410 elsif Opnd_Type = Any_String then
1411 Orig_Type := Type_In_P (Is_String_Type'Access);
1412
1413 elsif Opnd_Type = Any_Access then
06f2efd7 1414 Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
996ae0b0
RK		 1415
1416 elsif Opnd_Type = Any_Composite then
1417 Orig_Type := Type_In_P (Is_Composite_Type'Access);
1418
1419 if Present (Orig_Type) then
1420 if Has_Private_Component (Orig_Type) then
1421 Orig_Type := Empty;
1422 else
1423 Set_Etype (Act1, Orig_Type);
1424
1425 if Is_Binary then
1426 Set_Etype (Act2, Orig_Type);
1427 end if;
1428 end if;
1429 end if;
1430
1431 else
1432 Orig_Type := Empty;
1433 end if;
1434
1435 Error := No (Orig_Type);
1436 end if;
1437
1438 elsif Ekind (Opnd_Type) = E_Allocator_Type
1439 and then No (Type_In_P (Is_Definite_Access_Type'Access))
1440 then
1441 Error := True;
1442
1443 -- If the type is defined elsewhere, and the operator is not
1444 -- defined in the given scope (by a renaming declaration, e.g.)
1445 -- then this is an error as well. If an extension of System is
1446 -- present, and the type may be defined there, Pack must be
1447 -- System itself.
1448
1449 elsif Scope (Opnd_Type) /= Pack
1450 and then Scope (Op_Id) /= Pack
1451 and then (No (System_Aux_Id)
1452 or else Scope (Opnd_Type) /= System_Aux_Id
1453 or else Pack /= Scope (System_Aux_Id))
1454 then
244e5a2c
AC		 1455 if not Is_Overloaded (Right_Opnd (Op_Node)) then
1456 Error := True;
1457 else
1458 Error := not Operand_Type_In_Scope (Pack);
1459 end if;
996ae0b0
RK		 1460
1461 elsif Pack = Standard_Standard
1462 and then not Operand_Type_In_Scope (Standard_Standard)
1463 then
1464 Error := True;
1465 end if;
1466 end if;
1467
1468 if Error then
1469 Error_Msg_Node_2 := Pack;
1470 Error_Msg_NE
1471 ("& not declared in&", N, Selector_Name (Name (N)));
1472 Set_Etype (N, Any_Type);
1473 return;
88b17d45
AC		 1474
1475 -- Detect a mismatch between the context type and the result type
1476 -- in the named package, which is otherwise not detected if the
1477 -- operands are universal. Check is only needed if source entity is
1478 -- an operator, not a function that renames an operator.
1479
1480 elsif Nkind (Parent (N)) /= N_Type_Conversion
1481 and then Ekind (Entity (Name (N))) = E_Operator
1482 and then Is_Numeric_Type (Typ)
1483 and then not Is_Universal_Numeric_Type (Typ)
1484 and then Scope (Base_Type (Typ)) /= Pack
1485 and then not In_Instance
1486 then
1487 if Is_Fixed_Point_Type (Typ)
1488 and then (Op_Name = Name_Op_Multiply
1489 or else
1490 Op_Name = Name_Op_Divide)
1491 then
1492 -- Already checked above
1493
1494 null;
1495
e86a3a7e 1496 -- Operator may be defined in an extension of System
80c3be7a
AC		 1497
1498 elsif Present (System_Aux_Id)
1499 and then Scope (Opnd_Type) = System_Aux_Id
1500 then
1501 null;
1502
88b17d45 1503 else
be5a1b93
TQ		 1504 -- Could we use Wrong_Type here??? (this would require setting
1505 -- Etype (N) to the actual type found where Typ was expected).
1506
e86a3a7e 1507 Error_Msg_NE ("expect }", N, Typ);
88b17d45 1508 end if;
996ae0b0
RK		 1509 end if;
1510 end if;
1511
1512 Set_Chars (Op_Node, Op_Name);
fbf5a39b
AC		 1513
1514 if not Is_Private_Type (Etype (N)) then
1515 Set_Etype (Op_Node, Base_Type (Etype (N)));
1516 else
1517 Set_Etype (Op_Node, Etype (N));
1518 end if;
1519
2820d220
AC		 1520 -- If this is a call to a function that renames a predefined equality,
1521 -- the renaming declaration provides a type that must be used to
1522 -- resolve the operands. This must be done now because resolution of
1523 -- the equality node will not resolve any remaining ambiguity, and it
1524 -- assumes that the first operand is not overloaded.
1525
1526 if (Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne)
1527 and then Ekind (Func) = E_Function
1528 and then Is_Overloaded (Act1)
1529 then
1530 Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
1531 Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
1532 end if;
1533
996ae0b0
RK		 1534 Set_Entity (Op_Node, Op_Id);
1535 Generate_Reference (Op_Id, N, ' ');
45fc7ddb
HK		 1536
1537 -- Do rewrite setting Comes_From_Source on the result if the original
1538 -- call came from source. Although it is not strictly the case that the
1539 -- operator as such comes from the source, logically it corresponds
1540 -- exactly to the function call in the source, so it should be marked
1541 -- this way (e.g. to make sure that validity checks work fine).
1542
1543 declare
1544 CS : constant Boolean := Comes_From_Source (N);
1545 begin
1546 Rewrite (N, Op_Node);
1547 Set_Comes_From_Source (N, CS);
1548 end;
fbf5a39b
AC		 1549
1550 -- If this is an arithmetic operator and the result type is private,
1551 -- the operands and the result must be wrapped in conversion to
1552 -- expose the underlying numeric type and expand the proper checks,
1553 -- e.g. on division.
1554
1555 if Is_Private_Type (Typ) then
1556 case Nkind (N) is
5cc9353d
RD		 1557 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
1558 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
fbf5a39b
AC		 1559 Resolve_Intrinsic_Operator (N, Typ);
1560
5cc9353d 1561 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
fbf5a39b
AC		 1562 Resolve_Intrinsic_Unary_Operator (N, Typ);
1563
1564 when others =>
1565 Resolve (N, Typ);
1566 end case;
1567 else
1568 Resolve (N, Typ);
1569 end if;
996ae0b0
RK		 1570 end Make_Call_Into_Operator;
1571
1572 -------------------
1573 -- Operator_Kind --
1574 -------------------
1575
1576 function Operator_Kind
1577 (Op_Name : Name_Id;
0ab80019 1578 Is_Binary : Boolean) return Node_Kind
996ae0b0
RK		 1579 is
1580 Kind : Node_Kind;
1581
1582 begin
b0186f71
AC		 1583 -- Use CASE statement or array???
1584
996ae0b0 1585 if Is_Binary then
aa5147f0
ES		 1586 if Op_Name = Name_Op_And then
1587 Kind := N_Op_And;
1588 elsif Op_Name = Name_Op_Or then
1589 Kind := N_Op_Or;
1590 elsif Op_Name = Name_Op_Xor then
1591 Kind := N_Op_Xor;
1592 elsif Op_Name = Name_Op_Eq then
1593 Kind := N_Op_Eq;
1594 elsif Op_Name = Name_Op_Ne then
1595 Kind := N_Op_Ne;
1596 elsif Op_Name = Name_Op_Lt then
1597 Kind := N_Op_Lt;
1598 elsif Op_Name = Name_Op_Le then
1599 Kind := N_Op_Le;
1600 elsif Op_Name = Name_Op_Gt then
1601 Kind := N_Op_Gt;
1602 elsif Op_Name = Name_Op_Ge then
1603 Kind := N_Op_Ge;
1604 elsif Op_Name = Name_Op_Add then
1605 Kind := N_Op_Add;
1606 elsif Op_Name = Name_Op_Subtract then
1607 Kind := N_Op_Subtract;
1608 elsif Op_Name = Name_Op_Concat then
1609 Kind := N_Op_Concat;
1610 elsif Op_Name = Name_Op_Multiply then
1611 Kind := N_Op_Multiply;
1612 elsif Op_Name = Name_Op_Divide then
1613 Kind := N_Op_Divide;
1614 elsif Op_Name = Name_Op_Mod then
1615 Kind := N_Op_Mod;
1616 elsif Op_Name = Name_Op_Rem then
1617 Kind := N_Op_Rem;
1618 elsif Op_Name = Name_Op_Expon then
1619 Kind := N_Op_Expon;
996ae0b0
RK		 1620 else
1621 raise Program_Error;
1622 end if;
1623
1624 -- Unary operators
1625
1626 else
aa5147f0
ES		 1627 if Op_Name = Name_Op_Add then
1628 Kind := N_Op_Plus;
1629 elsif Op_Name = Name_Op_Subtract then
1630 Kind := N_Op_Minus;
1631 elsif Op_Name = Name_Op_Abs then
1632 Kind := N_Op_Abs;
1633 elsif Op_Name = Name_Op_Not then
1634 Kind := N_Op_Not;
996ae0b0
RK		 1635 else
1636 raise Program_Error;
1637 end if;
1638 end if;
1639
1640 return Kind;
1641 end Operator_Kind;
1642
45fc7ddb
HK		 1643 ----------------------------
1644 -- Preanalyze_And_Resolve --
1645 ----------------------------
996ae0b0 1646
45fc7ddb 1647 procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
996ae0b0
RK		 1648 Save_Full_Analysis : constant Boolean := Full_Analysis;
1649
1650 begin
1651 Full_Analysis := False;
1652 Expander_Mode_Save_And_Set (False);
1653
1654 -- We suppress all checks for this analysis, since the checks will
1655 -- be applied properly, and in the right location, when the default
1656 -- expression is reanalyzed and reexpanded later on.
1657
1658 Analyze_And_Resolve (N, T, Suppress => All_Checks);
1659
1660 Expander_Mode_Restore;
1661 Full_Analysis := Save_Full_Analysis;
45fc7ddb 1662 end Preanalyze_And_Resolve;
996ae0b0 1663
a77842bd 1664 -- Version without context type
996ae0b0 1665
45fc7ddb 1666 procedure Preanalyze_And_Resolve (N : Node_Id) is
996ae0b0
RK		 1667 Save_Full_Analysis : constant Boolean := Full_Analysis;
1668
1669 begin
1670 Full_Analysis := False;
1671 Expander_Mode_Save_And_Set (False);
1672
1673 Analyze (N);
1674 Resolve (N, Etype (N), Suppress => All_Checks);
1675
1676 Expander_Mode_Restore;
1677 Full_Analysis := Save_Full_Analysis;
45fc7ddb 1678 end Preanalyze_And_Resolve;
996ae0b0
RK		 1679
1680 ----------------------------------
1681 -- Replace_Actual_Discriminants --
1682 ----------------------------------
1683
1684 procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
1685 Loc : constant Source_Ptr := Sloc (N);
1686 Tsk : Node_Id := Empty;
1687
1688 function Process_Discr (Nod : Node_Id) return Traverse_Result;
1689
1690 -------------------
1691 -- Process_Discr --
1692 -------------------
1693
1694 function Process_Discr (Nod : Node_Id) return Traverse_Result is
1695 Ent : Entity_Id;
1696
1697 begin
1698 if Nkind (Nod) = N_Identifier then
1699 Ent := Entity (Nod);
1700
1701 if Present (Ent)
1702 and then Ekind (Ent) = E_Discriminant
1703 then
1704 Rewrite (Nod,
1705 Make_Selected_Component (Loc,
1706 Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
1707 Selector_Name => Make_Identifier (Loc, Chars (Ent))));
1708
1709 Set_Etype (Nod, Etype (Ent));
1710 end if;
1711
1712 end if;
1713
1714 return OK;
1715 end Process_Discr;
1716
1717 procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
1718
1719 -- Start of processing for Replace_Actual_Discriminants
1720
1721 begin
1722 if not Expander_Active then
1723 return;
1724 end if;
1725
1726 if Nkind (Name (N)) = N_Selected_Component then
1727 Tsk := Prefix (Name (N));
1728
1729 elsif Nkind (Name (N)) = N_Indexed_Component then
1730 Tsk := Prefix (Prefix (Name (N)));
1731 end if;
1732
1733 if No (Tsk) then
1734 return;
1735 else
1736 Replace_Discrs (Default);
1737 end if;
1738 end Replace_Actual_Discriminants;
1739
1740 -------------
1741 -- Resolve --
1742 -------------
1743
1744 procedure Resolve (N : Node_Id; Typ : Entity_Id) is
dae2b8ea
HK		 1745 Ambiguous : Boolean := False;
1746 Ctx_Type : Entity_Id := Typ;
1747 Expr_Type : Entity_Id := Empty; -- prevent junk warning
1748 Err_Type : Entity_Id := Empty;
1749 Found : Boolean := False;
1750 From_Lib : Boolean;
996ae0b0 1751 I : Interp_Index;
dae2b8ea 1752 I1 : Interp_Index := 0; -- prevent junk warning
996ae0b0
RK		 1753 It : Interp;
1754 It1 : Interp;
996ae0b0 1755 Seen : Entity_Id := Empty; -- prevent junk warning
dae2b8ea
HK		 1756
1757 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
1758 -- Determine whether a node comes from a predefined library unit or
1759 -- Standard.
996ae0b0
RK		 1760
1761 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
1762 -- Try and fix up a literal so that it matches its expected type. New
1763 -- literals are manufactured if necessary to avoid cascaded errors.
1764
7415029d
AC		 1765 procedure Report_Ambiguous_Argument;
1766 -- Additional diagnostics when an ambiguous call has an ambiguous
1767 -- argument (typically a controlling actual).
1768
996ae0b0
RK		 1769 procedure Resolution_Failed;
1770 -- Called when attempt at resolving current expression fails
1771
dae2b8ea
HK		 1772 ------------------------------------
1773 -- Comes_From_Predefined_Lib_Unit --
1774 -------------------------------------
1775
1776 function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
1777 begin
1778 return
1779 Sloc (Nod) = Standard_Location
5cc9353d
RD		 1780 or else Is_Predefined_File_Name
1781 (Unit_File_Name (Get_Source_Unit (Sloc (Nod))));
dae2b8ea
HK		 1782 end Comes_From_Predefined_Lib_Unit;
1783
996ae0b0
RK		 1784 --------------------
1785 -- Patch_Up_Value --
1786 --------------------
1787
1788 procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
1789 begin
1790 if Nkind (N) = N_Integer_Literal
1791 and then Is_Real_Type (Typ)
1792 then
1793 Rewrite (N,
1794 Make_Real_Literal (Sloc (N),
1795 Realval => UR_From_Uint (Intval (N))));
1796 Set_Etype (N, Universal_Real);
1797 Set_Is_Static_Expression (N);
1798
1799 elsif Nkind (N) = N_Real_Literal
1800 and then Is_Integer_Type (Typ)
1801 then
1802 Rewrite (N,
1803 Make_Integer_Literal (Sloc (N),
1804 Intval => UR_To_Uint (Realval (N))));
1805 Set_Etype (N, Universal_Integer);
1806 Set_Is_Static_Expression (N);
45fc7ddb 1807
996ae0b0
RK		 1808 elsif Nkind (N) = N_String_Literal
1809 and then Is_Character_Type (Typ)
1810 then
1811 Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
1812 Rewrite (N,
1813 Make_Character_Literal (Sloc (N),
1814 Chars => Name_Find,
82c80734
RD		 1815 Char_Literal_Value =>
1816 UI_From_Int (Character'Pos ('A'))));
996ae0b0
RK		 1817 Set_Etype (N, Any_Character);
1818 Set_Is_Static_Expression (N);
1819
1820 elsif Nkind (N) /= N_String_Literal
1821 and then Is_String_Type (Typ)
1822 then
1823 Rewrite (N,
1824 Make_String_Literal (Sloc (N),
1825 Strval => End_String));
1826
1827 elsif Nkind (N) = N_Range then
1828 Patch_Up_Value (Low_Bound (N), Typ);
1829 Patch_Up_Value (High_Bound (N), Typ);
1830 end if;
1831 end Patch_Up_Value;
1832
7415029d
AC		 1833 -------------------------------
1834 -- Report_Ambiguous_Argument --
1835 -------------------------------
1836
1837 procedure Report_Ambiguous_Argument is
1838 Arg : constant Node_Id := First (Parameter_Associations (N));
1839 I : Interp_Index;
1840 It : Interp;
1841
1842 begin
1843 if Nkind (Arg) = N_Function_Call
1844 and then Is_Entity_Name (Name (Arg))
1845 and then Is_Overloaded (Name (Arg))
1846 then
ed2233dc 1847 Error_Msg_NE ("ambiguous call to&", Arg, Name (Arg));
7415029d 1848
bfc07071
AC		 1849 -- Could use comments on what is going on here ???
1850
7415029d
AC		 1851 Get_First_Interp (Name (Arg), I, It);
1852 while Present (It.Nam) loop
1853 Error_Msg_Sloc := Sloc (It.Nam);
1854
1855 if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then
ed2233dc 1856 Error_Msg_N ("interpretation (inherited) #!", Arg);
7415029d 1857 else
ed2233dc 1858 Error_Msg_N ("interpretation #!", Arg);
7415029d
AC		 1859 end if;
1860
1861 Get_Next_Interp (I, It);
1862 end loop;
1863 end if;
1864 end Report_Ambiguous_Argument;
1865
996ae0b0
RK		 1866 -----------------------
1867 -- Resolution_Failed --
1868 -----------------------
1869
1870 procedure Resolution_Failed is
1871 begin
1872 Patch_Up_Value (N, Typ);
1873 Set_Etype (N, Typ);
1874 Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
1875 Set_Is_Overloaded (N, False);
1876
1877 -- The caller will return without calling the expander, so we need
1878 -- to set the analyzed flag. Note that it is fine to set Analyzed
1879 -- to True even if we are in the middle of a shallow analysis,
1880 -- (see the spec of sem for more details) since this is an error
1881 -- situation anyway, and there is no point in repeating the
1882 -- analysis later (indeed it won't work to repeat it later, since
1883 -- we haven't got a clear resolution of which entity is being
1884 -- referenced.)
1885
1886 Set_Analyzed (N, True);
1887 return;
1888 end Resolution_Failed;
1889
1890 -- Start of processing for Resolve
1891
1892 begin
5c736541
RD		 1893 if N = Error then
1894 return;
1895 end if;
1896
996ae0b0
RK		 1897 -- Access attribute on remote subprogram cannot be used for
1898 -- a non-remote access-to-subprogram type.
1899
1900 if Nkind (N) = N_Attribute_Reference
19fb051c
AC		 1901 and then (Attribute_Name (N) = Name_Access or else
1902 Attribute_Name (N) = Name_Unrestricted_Access or else
1903 Attribute_Name (N) = Name_Unchecked_Access)
996ae0b0
RK		 1904 and then Comes_From_Source (N)
1905 and then Is_Entity_Name (Prefix (N))
1906 and then Is_Subprogram (Entity (Prefix (N)))
1907 and then Is_Remote_Call_Interface (Entity (Prefix (N)))
1908 and then not Is_Remote_Access_To_Subprogram_Type (Typ)
1909 then
1910 Error_Msg_N
1911 ("prefix must statically denote a non-remote subprogram", N);
1912 end if;
1913
dae2b8ea
HK		 1914 From_Lib := Comes_From_Predefined_Lib_Unit (N);
1915
996ae0b0
RK		 1916 -- If the context is a Remote_Access_To_Subprogram, access attributes
1917 -- must be resolved with the corresponding fat pointer. There is no need
1918 -- to check for the attribute name since the return type of an
1919 -- attribute is never a remote type.
1920
1921 if Nkind (N) = N_Attribute_Reference
1922 and then Comes_From_Source (N)
19fb051c 1923 and then (Is_Remote_Call_Interface (Typ) or else Is_Remote_Types (Typ))
996ae0b0
RK		 1924 then
1925 declare
1926 Attr : constant Attribute_Id :=
1927 Get_Attribute_Id (Attribute_Name (N));
1928 Pref : constant Node_Id := Prefix (N);
1929 Decl : Node_Id;
1930 Spec : Node_Id;
1931 Is_Remote : Boolean := True;
1932
1933 begin
a77842bd 1934 -- Check that Typ is a remote access-to-subprogram type
996ae0b0 1935
a77842bd 1936 if Is_Remote_Access_To_Subprogram_Type (Typ) then
955871d3 1937
996ae0b0
RK		 1938 -- Prefix (N) must statically denote a remote subprogram
1939 -- declared in a package specification.
1940
1941 if Attr = Attribute_Access then
1942 Decl := Unit_Declaration_Node (Entity (Pref));
1943
1944 if Nkind (Decl) = N_Subprogram_Body then
1945 Spec := Corresponding_Spec (Decl);
1946
1947 if not No (Spec) then
1948 Decl := Unit_Declaration_Node (Spec);
1949 end if;
1950 end if;
1951
1952 Spec := Parent (Decl);
1953
1954 if not Is_Entity_Name (Prefix (N))
1955 or else Nkind (Spec) /= N_Package_Specification
1956 or else
1957 not Is_Remote_Call_Interface (Defining_Entity (Spec))
1958 then
1959 Is_Remote := False;
1960 Error_Msg_N
1961 ("prefix must statically denote a remote subprogram ",
1962 N);
1963 end if;
1964 end if;
1965
fbf5a39b
AC		 1966 -- If we are generating code for a distributed program.
1967 -- perform semantic checks against the corresponding
1968 -- remote entities.
1969
19fb051c
AC		 1970 if (Attr = Attribute_Access or else
1971 Attr = Attribute_Unchecked_Access or else
1972 Attr = Attribute_Unrestricted_Access)
fbf5a39b 1973 and then Expander_Active
a77842bd 1974 and then Get_PCS_Name /= Name_No_DSA
996ae0b0
RK		 1975 then
1976 Check_Subtype_Conformant
1977 (New_Id => Entity (Prefix (N)),
1978 Old_Id => Designated_Type
19fb051c 1979 (Corresponding_Remote_Type (Typ)),
996ae0b0 1980 Err_Loc => N);
b7d1f17f 1981
996ae0b0
RK		 1982 if Is_Remote then
1983 Process_Remote_AST_Attribute (N, Typ);
1984 end if;
1985 end if;
1986 end if;
1987 end;
1988 end if;
1989
1990 Debug_A_Entry ("resolving ", N);
1991
07fc65c4
GB		 1992 if Comes_From_Source (N) then
1993 if Is_Fixed_Point_Type (Typ) then
1994 Check_Restriction (No_Fixed_Point, N);
996ae0b0 1995
07fc65c4
GB		 1996 elsif Is_Floating_Point_Type (Typ)
1997 and then Typ /= Universal_Real
1998 and then Typ /= Any_Real
1999 then
2000 Check_Restriction (No_Floating_Point, N);
2001 end if;
996ae0b0
RK		 2002 end if;
2003
2004 -- Return if already analyzed
2005
2006 if Analyzed (N) then
2007 Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
2008 return;
2009
2010 -- Return if type = Any_Type (previous error encountered)
2011
2012 elsif Etype (N) = Any_Type then
2013 Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
2014 return;
2015 end if;
2016
2017 Check_Parameterless_Call (N);
2018
2019 -- If not overloaded, then we know the type, and all that needs doing
2020 -- is to check that this type is compatible with the context.
2021
2022 if not Is_Overloaded (N) then
2023 Found := Covers (Typ, Etype (N));
2024 Expr_Type := Etype (N);
2025
2026 -- In the overloaded case, we must select the interpretation that
2027 -- is compatible with the context (i.e. the type passed to Resolve)
2028
2029 else
996ae0b0
RK		 2030 -- Loop through possible interpretations
2031
1420b484 2032 Get_First_Interp (N, I, It);
996ae0b0
RK		 2033 Interp_Loop : while Present (It.Typ) loop
2034
2035 -- We are only interested in interpretations that are compatible
aa5147f0 2036 -- with the expected type, any other interpretations are ignored.
996ae0b0 2037
fbf5a39b
AC		 2038 if not Covers (Typ, It.Typ) then
2039 if Debug_Flag_V then
2040 Write_Str (" interpretation incompatible with context");
2041 Write_Eol;
2042 end if;
996ae0b0 2043
fbf5a39b 2044 else
aa5147f0
ES		 2045 -- Skip the current interpretation if it is disabled by an
2046 -- abstract operator. This action is performed only when the
2047 -- type against which we are resolving is the same as the
2048 -- type of the interpretation.
2049
0791fbe9 2050 if Ada_Version >= Ada_2005
aa5147f0
ES		 2051 and then It.Typ = Typ
2052 and then Typ /= Universal_Integer
2053 and then Typ /= Universal_Real
2054 and then Present (It.Abstract_Op)
2055 then
2056 goto Continue;
2057 end if;
2058
996ae0b0
RK		 2059 -- First matching interpretation
2060
2061 if not Found then
2062 Found := True;
2063 I1 := I;
2064 Seen := It.Nam;
2065 Expr_Type := It.Typ;
2066
fbf5a39b 2067 -- Matching interpretation that is not the first, maybe an
996ae0b0
RK		 2068 -- error, but there are some cases where preference rules are
2069 -- used to choose between the two possibilities. These and
2070 -- some more obscure cases are handled in Disambiguate.
2071
2072 else
dae2b8ea
HK		 2073 -- If the current statement is part of a predefined library
2074 -- unit, then all interpretations which come from user level
2075 -- packages should not be considered.
2076
2077 if From_Lib
2078 and then not Comes_From_Predefined_Lib_Unit (It.Nam)
2079 then
2080 goto Continue;
2081 end if;
2082
996ae0b0
RK		 2083 Error_Msg_Sloc := Sloc (Seen);
2084 It1 := Disambiguate (N, I1, I, Typ);
2085
fbf5a39b
AC		 2086 -- Disambiguation has succeeded. Skip the remaining
2087 -- interpretations.
996ae0b0 2088
fbf5a39b
AC		 2089 if It1 /= No_Interp then
2090 Seen := It1.Nam;
2091 Expr_Type := It1.Typ;
2092
2093 while Present (It.Typ) loop
2094 Get_Next_Interp (I, It);
2095 end loop;
2096
2097 else
996ae0b0
RK		 2098 -- Before we issue an ambiguity complaint, check for
2099 -- the case of a subprogram call where at least one
2100 -- of the arguments is Any_Type, and if so, suppress
2101 -- the message, since it is a cascaded error.
2102
45fc7ddb
HK		 2103 if Nkind_In (N, N_Function_Call,
2104 N_Procedure_Call_Statement)
996ae0b0
RK		 2105 then
2106 declare
1420b484 2107 A : Node_Id;
996ae0b0
RK		 2108 E : Node_Id;
2109
2110 begin
1420b484 2111 A := First_Actual (N);
996ae0b0
RK		 2112 while Present (A) loop
2113 E := A;
2114
2115 if Nkind (E) = N_Parameter_Association then
2116 E := Explicit_Actual_Parameter (E);
2117 end if;
2118
2119 if Etype (E) = Any_Type then
2120 if Debug_Flag_V then
2121 Write_Str ("Any_Type in call");
2122 Write_Eol;
2123 end if;
2124
2125 exit Interp_Loop;
2126 end if;
2127
2128 Next_Actual (A);
2129 end loop;
2130 end;
2131
aa5147f0 2132 elsif Nkind (N) in N_Binary_Op
996ae0b0
RK		 2133 and then (Etype (Left_Opnd (N)) = Any_Type
2134 or else Etype (Right_Opnd (N)) = Any_Type)
2135 then
2136 exit Interp_Loop;
2137
2138 elsif Nkind (N) in N_Unary_Op
2139 and then Etype (Right_Opnd (N)) = Any_Type
2140 then
2141 exit Interp_Loop;
2142 end if;
2143
2144 -- Not that special case, so issue message using the
2145 -- flag Ambiguous to control printing of the header
2146 -- message only at the start of an ambiguous set.
2147
2148 if not Ambiguous then
aa180613
RD		 2149 if Nkind (N) = N_Function_Call
2150 and then Nkind (Name (N)) = N_Explicit_Dereference
2151 then
ed2233dc 2152 Error_Msg_N
aa180613
RD		 2153 ("ambiguous expression "
2154 & "(cannot resolve indirect call)!", N);
2155 else
483c78cb 2156 Error_Msg_NE -- CODEFIX
aa180613
RD		 2157 ("ambiguous expression (cannot resolve&)!",
2158 N, It.Nam);
2159 end if;
fbf5a39b 2160
996ae0b0 2161 Ambiguous := True;
0669bebe
GB		 2162
2163 if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
ed2233dc 2164 Error_Msg_N
0669bebe
GB		 2165 ("\\possible interpretation (inherited)#!", N);
2166 else
4e7a4f6e
AC		 2167 Error_Msg_N -- CODEFIX
2168 ("\\possible interpretation#!", N);
0669bebe 2169 end if;
7415029d
AC		 2170
2171 if Nkind_In
4519314c 2172 (N, N_Procedure_Call_Statement, N_Function_Call)
7415029d
AC		 2173 and then Present (Parameter_Associations (N))
2174 then
2175 Report_Ambiguous_Argument;
2176 end if;
996ae0b0
RK		 2177 end if;
2178
2179 Error_Msg_Sloc := Sloc (It.Nam);
996ae0b0 2180
fbf5a39b 2181 -- By default, the error message refers to the candidate
0669bebe
GB		 2182 -- interpretation. But if it is a predefined operator, it
2183 -- is implicitly declared at the declaration of the type
2184 -- of the operand. Recover the sloc of that declaration
2185 -- for the error message.
fbf5a39b
AC		 2186
2187 if Nkind (N) in N_Op
2188 and then Scope (It.Nam) = Standard_Standard
2189 and then not Is_Overloaded (Right_Opnd (N))
0669bebe
GB		 2190 and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
2191 Standard_Standard
fbf5a39b
AC		 2192 then
2193 Err_Type := First_Subtype (Etype (Right_Opnd (N)));
2194
2195 if Comes_From_Source (Err_Type)
2196 and then Present (Parent (Err_Type))
2197 then
2198 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2199 end if;
2200
2201 elsif Nkind (N) in N_Binary_Op
2202 and then Scope (It.Nam) = Standard_Standard
2203 and then not Is_Overloaded (Left_Opnd (N))
0669bebe
GB		 2204 and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
2205 Standard_Standard
fbf5a39b
AC		 2206 then
2207 Err_Type := First_Subtype (Etype (Left_Opnd (N)));
2208
2209 if Comes_From_Source (Err_Type)
2210 and then Present (Parent (Err_Type))
2211 then
2212 Error_Msg_Sloc := Sloc (Parent (Err_Type));
2213 end if;
aa180613
RD		 2214
2215 -- If this is an indirect call, use the subprogram_type
5cc9353d
RD		 2216 -- in the message, to have a meaningful location. Also
2217 -- indicate if this is an inherited operation, created
2218 -- by a type declaration.
aa180613
RD		 2219
2220 elsif Nkind (N) = N_Function_Call
2221 and then Nkind (Name (N)) = N_Explicit_Dereference
2222 and then Is_Type (It.Nam)
2223 then
2224 Err_Type := It.Nam;
2225 Error_Msg_Sloc :=
2226 Sloc (Associated_Node_For_Itype (Err_Type));
fbf5a39b
AC		 2227 else
2228 Err_Type := Empty;
2229 end if;
2230
2231 if Nkind (N) in N_Op
2232 and then Scope (It.Nam) = Standard_Standard
2233 and then Present (Err_Type)
2234 then
aa5147f0
ES		 2235 -- Special-case the message for universal_fixed
2236 -- operators, which are not declared with the type
2237 -- of the operand, but appear forever in Standard.
2238
2239 if It.Typ = Universal_Fixed
2240 and then Scope (It.Nam) = Standard_Standard
2241 then
ed2233dc 2242 Error_Msg_N
aa5147f0
ES		 2243 ("\\possible interpretation as " &
2244 "universal_fixed operation " &
2245 "(RM 4.5.5 (19))", N);
2246 else
ed2233dc 2247 Error_Msg_N
aa5147f0
ES		 2248 ("\\possible interpretation (predefined)#!", N);
2249 end if;
aa180613
RD		 2250
2251 elsif
2252 Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
2253 then
ed2233dc 2254 Error_Msg_N
aa180613 2255 ("\\possible interpretation (inherited)#!", N);
fbf5a39b 2256 else
4e7a4f6e
AC		 2257 Error_Msg_N -- CODEFIX
2258 ("\\possible interpretation#!", N);
fbf5a39b 2259 end if;
996ae0b0 2260
996ae0b0
RK		 2261 end if;
2262 end if;
2263
0669bebe
GB		 2264 -- We have a matching interpretation, Expr_Type is the type
2265 -- from this interpretation, and Seen is the entity.
996ae0b0 2266
0669bebe
GB		 2267 -- For an operator, just set the entity name. The type will be
2268 -- set by the specific operator resolution routine.
996ae0b0
RK		 2269
2270 if Nkind (N) in N_Op then
2271 Set_Entity (N, Seen);
2272 Generate_Reference (Seen, N);
2273
19d846a0
RD		 2274 elsif Nkind (N) = N_Case_Expression then
2275 Set_Etype (N, Expr_Type);
2276
996ae0b0
RK		 2277 elsif Nkind (N) = N_Character_Literal then
2278 Set_Etype (N, Expr_Type);
2279
e0ba1bfd
ES		 2280 elsif Nkind (N) = N_Conditional_Expression then
2281 Set_Etype (N, Expr_Type);
2282
996ae0b0 2283 -- For an explicit dereference, attribute reference, range,
0669bebe
GB		 2284 -- short-circuit form (which is not an operator node), or call
2285 -- with a name that is an explicit dereference, there is
2286 -- nothing to be done at this point.
996ae0b0 2287
45fc7ddb
HK		 2288 elsif Nkind_In (N, N_Explicit_Dereference,
2289 N_Attribute_Reference,
2290 N_And_Then,
2291 N_Indexed_Component,
2292 N_Or_Else,
2293 N_Range,
2294 N_Selected_Component,
2295 N_Slice)
996ae0b0
RK		 2296 or else Nkind (Name (N)) = N_Explicit_Dereference
2297 then
2298 null;
2299
0669bebe 2300 -- For procedure or function calls, set the type of the name,
4519314c 2301 -- and also the entity pointer for the prefix.
996ae0b0 2302
45fc7ddb 2303 elsif Nkind_In (N, N_Procedure_Call_Statement, N_Function_Call)
a3f2babd 2304 and then Is_Entity_Name (Name (N))
996ae0b0
RK		 2305 then
2306 Set_Etype (Name (N), Expr_Type);
2307 Set_Entity (Name (N), Seen);
2308 Generate_Reference (Seen, Name (N));
2309
2310 elsif Nkind (N) = N_Function_Call
2311 and then Nkind (Name (N)) = N_Selected_Component
2312 then
2313 Set_Etype (Name (N), Expr_Type);
2314 Set_Entity (Selector_Name (Name (N)), Seen);
2315 Generate_Reference (Seen, Selector_Name (Name (N)));
2316
2317 -- For all other cases, just set the type of the Name
2318
2319 else
2320 Set_Etype (Name (N), Expr_Type);
2321 end if;
2322
996ae0b0
RK		 2323 end if;
2324
aa5147f0
ES		 2325 <<Continue>>
2326
996ae0b0
RK		 2327 -- Move to next interpretation
2328
c8ef728f 2329 exit Interp_Loop when No (It.Typ);
996ae0b0
RK		 2330
2331 Get_Next_Interp (I, It);
2332 end loop Interp_Loop;
2333 end if;
2334
2335 -- At this stage Found indicates whether or not an acceptable
4519314c
AC		 2336 -- interpretation exists. If not, then we have an error, except that if
2337 -- the context is Any_Type as a result of some other error, then we
2338 -- suppress the error report.
996ae0b0
RK		 2339
2340 if not Found then
2341 if Typ /= Any_Type then
2342
0669bebe
GB		 2343 -- If type we are looking for is Void, then this is the procedure
2344 -- call case, and the error is simply that what we gave is not a
2345 -- procedure name (we think of procedure calls as expressions with
2346 -- types internally, but the user doesn't think of them this way!)
996ae0b0
RK		 2347
2348 if Typ = Standard_Void_Type then
91b1417d
AC		 2349
2350 -- Special case message if function used as a procedure
2351
2352 if Nkind (N) = N_Procedure_Call_Statement
2353 and then Is_Entity_Name (Name (N))
2354 and then Ekind (Entity (Name (N))) = E_Function
2355 then
2356 Error_Msg_NE
2357 ("cannot use function & in a procedure call",
2358 Name (N), Entity (Name (N)));
2359
0669bebe
GB		 2360 -- Otherwise give general message (not clear what cases this
2361 -- covers, but no harm in providing for them!)
91b1417d
AC		 2362
2363 else
2364 Error_Msg_N ("expect procedure name in procedure call", N);
2365 end if;
2366
996ae0b0
RK		 2367 Found := True;
2368
2369 -- Otherwise we do have a subexpression with the wrong type
2370
0669bebe
GB		 2371 -- Check for the case of an allocator which uses an access type
2372 -- instead of the designated type. This is a common error and we
2373 -- specialize the message, posting an error on the operand of the
2374 -- allocator, complaining that we expected the designated type of
2375 -- the allocator.
996ae0b0
RK		 2376
2377 elsif Nkind (N) = N_Allocator
2378 and then Ekind (Typ) in Access_Kind
2379 and then Ekind (Etype (N)) in Access_Kind
2380 and then Designated_Type (Etype (N)) = Typ
2381 then
2382 Wrong_Type (Expression (N), Designated_Type (Typ));
2383 Found := True;
2384
0669bebe
GB		 2385 -- Check for view mismatch on Null in instances, for which the
2386 -- view-swapping mechanism has no identifier.
17be0cdf
ES		 2387
2388 elsif (In_Instance or else In_Inlined_Body)
2389 and then (Nkind (N) = N_Null)
2390 and then Is_Private_Type (Typ)
2391 and then Is_Access_Type (Full_View (Typ))
2392 then
2393 Resolve (N, Full_View (Typ));
2394 Set_Etype (N, Typ);
2395 return;
2396
aa180613
RD		 2397 -- Check for an aggregate. Sometimes we can get bogus aggregates
2398 -- from misuse of parentheses, and we are about to complain about
2399 -- the aggregate without even looking inside it.
996ae0b0 2400
aa180613
RD		 2401 -- Instead, if we have an aggregate of type Any_Composite, then
2402 -- analyze and resolve the component fields, and then only issue
2403 -- another message if we get no errors doing this (otherwise
2404 -- assume that the errors in the aggregate caused the problem).
996ae0b0
RK		 2405
2406 elsif Nkind (N) = N_Aggregate
2407 and then Etype (N) = Any_Composite
2408 then
996ae0b0
RK		 2409 -- Disable expansion in any case. If there is a type mismatch
2410 -- it may be fatal to try to expand the aggregate. The flag
2411 -- would otherwise be set to false when the error is posted.
2412
2413 Expander_Active := False;
2414
2415 declare
2416 procedure Check_Aggr (Aggr : Node_Id);
aa180613
RD		 2417 -- Check one aggregate, and set Found to True if we have a
2418 -- definite error in any of its elements
996ae0b0
RK		 2419
2420 procedure Check_Elmt (Aelmt : Node_Id);
aa180613
RD		 2421 -- Check one element of aggregate and set Found to True if
2422 -- we definitely have an error in the element.
2423
2424 ----------------
2425 -- Check_Aggr --
2426 ----------------
996ae0b0
RK		 2427
2428 procedure Check_Aggr (Aggr : Node_Id) is
2429 Elmt : Node_Id;
2430
2431 begin
2432 if Present (Expressions (Aggr)) then
2433 Elmt := First (Expressions (Aggr));
2434 while Present (Elmt) loop
2435 Check_Elmt (Elmt);
2436 Next (Elmt);
2437 end loop;
2438 end if;
2439
2440 if Present (Component_Associations (Aggr)) then
2441 Elmt := First (Component_Associations (Aggr));
2442 while Present (Elmt) loop
aa180613 2443
0669bebe
GB		 2444 -- If this is a default-initialized component, then
2445 -- there is nothing to check. The box will be
2446 -- replaced by the appropriate call during late
2447 -- expansion.
aa180613
RD		 2448
2449 if not Box_Present (Elmt) then
2450 Check_Elmt (Expression (Elmt));
2451 end if;
2452
996ae0b0
RK		 2453 Next (Elmt);
2454 end loop;
2455 end if;
2456 end Check_Aggr;
2457
fbf5a39b
AC		 2458 ----------------
2459 -- Check_Elmt --
2460 ----------------
2461
996ae0b0
RK		 2462 procedure Check_Elmt (Aelmt : Node_Id) is
2463 begin
2464 -- If we have a nested aggregate, go inside it (to
5cc9353d
RD		 2465 -- attempt a naked analyze-resolve of the aggregate can
2466 -- cause undesirable cascaded errors). Do not resolve
2467 -- expression if it needs a type from context, as for
2468 -- integer * fixed expression.
996ae0b0
RK		 2469
2470 if Nkind (Aelmt) = N_Aggregate then
2471 Check_Aggr (Aelmt);
2472
2473 else
2474 Analyze (Aelmt);
2475
2476 if not Is_Overloaded (Aelmt)
2477 and then Etype (Aelmt) /= Any_Fixed
2478 then
fbf5a39b 2479 Resolve (Aelmt);
996ae0b0
RK		 2480 end if;
2481
2482 if Etype (Aelmt) = Any_Type then
2483 Found := True;
2484 end if;
2485 end if;
2486 end Check_Elmt;
2487
2488 begin
2489 Check_Aggr (N);
2490 end;
2491 end if;
2492
5cc9353d
RD		 2493 -- If an error message was issued already, Found got reset to
2494 -- True, so if it is still False, issue standard Wrong_Type msg.
996ae0b0
RK		 2495
2496 if not Found then
2497 if Is_Overloaded (N)
2498 and then Nkind (N) = N_Function_Call
2499 then
65356e64
AC		 2500 declare
2501 Subp_Name : Node_Id;
2502 begin
2503 if Is_Entity_Name (Name (N)) then
2504 Subp_Name := Name (N);
2505
2506 elsif Nkind (Name (N)) = N_Selected_Component then
2507
a77842bd 2508 -- Protected operation: retrieve operation name
65356e64
AC		 2509
2510 Subp_Name := Selector_Name (Name (N));
19fb051c 2511
65356e64
AC		 2512 else
2513 raise Program_Error;
2514 end if;
2515
2516 Error_Msg_Node_2 := Typ;
2517 Error_Msg_NE ("no visible interpretation of&" &
2518 " matches expected type&", N, Subp_Name);
2519 end;
996ae0b0
RK		 2520
2521 if All_Errors_Mode then
2522 declare
2523 Index : Interp_Index;
2524 It : Interp;
2525
2526 begin
aa180613 2527 Error_Msg_N ("\\possible interpretations:", N);
996ae0b0 2528
1420b484 2529 Get_First_Interp (Name (N), Index, It);
996ae0b0 2530 while Present (It.Nam) loop
ea985d95 2531 Error_Msg_Sloc := Sloc (It.Nam);
aa5147f0
ES		 2532 Error_Msg_Node_2 := It.Nam;
2533 Error_Msg_NE
2534 ("\\ type& for & declared#", N, It.Typ);
996ae0b0
RK		 2535 Get_Next_Interp (Index, It);
2536 end loop;
2537 end;
aa5147f0 2538
996ae0b0
RK		 2539 else
2540 Error_Msg_N ("\use -gnatf for details", N);
2541 end if;
19fb051c 2542
996ae0b0
RK		 2543 else
2544 Wrong_Type (N, Typ);
2545 end if;
2546 end if;
2547 end if;
2548
2549 Resolution_Failed;
2550 return;
2551
2552 -- Test if we have more than one interpretation for the context
2553
2554 elsif Ambiguous then
2555 Resolution_Failed;
2556 return;
2557
2558 -- Here we have an acceptable interpretation for the context
2559
2560 else
996ae0b0
RK		 2561 -- Propagate type information and normalize tree for various
2562 -- predefined operations. If the context only imposes a class of
2563 -- types, rather than a specific type, propagate the actual type
2564 -- downward.
2565
19fb051c
AC		 2566 if Typ = Any_Integer or else
2567 Typ = Any_Boolean or else
2568 Typ = Any_Modular or else
2569 Typ = Any_Real or else
2570 Typ = Any_Discrete
996ae0b0
RK		 2571 then
2572 Ctx_Type := Expr_Type;
2573
5cc9353d
RD		 2574 -- Any_Fixed is legal in a real context only if a specific fixed-
2575 -- point type is imposed. If Norman Cohen can be confused by this,
2576 -- it deserves a separate message.
996ae0b0
RK		 2577
2578 if Typ = Any_Real
2579 and then Expr_Type = Any_Fixed
2580 then
758c442c 2581 Error_Msg_N ("illegal context for mixed mode operation", N);
996ae0b0
RK		 2582 Set_Etype (N, Universal_Real);
2583 Ctx_Type := Universal_Real;
2584 end if;
2585 end if;
2586
f3d57416 2587 -- A user-defined operator is transformed into a function call at
0ab80019
AC		 2588 -- this point, so that further processing knows that operators are
2589 -- really operators (i.e. are predefined operators). User-defined
2590 -- operators that are intrinsic are just renamings of the predefined
2591 -- ones, and need not be turned into calls either, but if they rename
2592 -- a different operator, we must transform the node accordingly.
2593 -- Instantiations of Unchecked_Conversion are intrinsic but are
2594 -- treated as functions, even if given an operator designator.
2595
2596 if Nkind (N) in N_Op
2597 and then Present (Entity (N))
2598 and then Ekind (Entity (N)) /= E_Operator
2599 then
2600
2601 if not Is_Predefined_Op (Entity (N)) then
2602 Rewrite_Operator_As_Call (N, Entity (N));
2603
615cbd95
AC		 2604 elsif Present (Alias (Entity (N)))
2605 and then
45fc7ddb
HK		 2606 Nkind (Parent (Parent (Entity (N)))) =
2607 N_Subprogram_Renaming_Declaration
615cbd95 2608 then
0ab80019
AC		 2609 Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
2610
2611 -- If the node is rewritten, it will be fully resolved in
2612 -- Rewrite_Renamed_Operator.
2613
2614 if Analyzed (N) then
2615 return;
2616 end if;
2617 end if;
2618 end if;
2619
996ae0b0
RK		 2620 case N_Subexpr'(Nkind (N)) is
2621
2622 when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
2623
2624 when N_Allocator => Resolve_Allocator (N, Ctx_Type);
2625
514d0fc5 2626 when N_Short_Circuit
996ae0b0
RK		 2627 => Resolve_Short_Circuit (N, Ctx_Type);
2628
2629 when N_Attribute_Reference
2630 => Resolve_Attribute (N, Ctx_Type);
2631
19d846a0
RD		 2632 when N_Case_Expression
2633 => Resolve_Case_Expression (N, Ctx_Type);
2634
996ae0b0
RK		 2635 when N_Character_Literal
2636 => Resolve_Character_Literal (N, Ctx_Type);
2637
2638 when N_Conditional_Expression
2639 => Resolve_Conditional_Expression (N, Ctx_Type);
2640
2641 when N_Expanded_Name
2642 => Resolve_Entity_Name (N, Ctx_Type);
2643
996ae0b0
RK		 2644 when N_Explicit_Dereference
2645 => Resolve_Explicit_Dereference (N, Ctx_Type);
2646
955871d3
AC		 2647 when N_Expression_With_Actions
2648 => Resolve_Expression_With_Actions (N, Ctx_Type);
2649
2650 when N_Extension_Aggregate
2651 => Resolve_Extension_Aggregate (N, Ctx_Type);
2652
996ae0b0
RK		 2653 when N_Function_Call
2654 => Resolve_Call (N, Ctx_Type);
2655
2656 when N_Identifier
2657 => Resolve_Entity_Name (N, Ctx_Type);
2658
996ae0b0
RK		 2659 when N_Indexed_Component
2660 => Resolve_Indexed_Component (N, Ctx_Type);
2661
2662 when N_Integer_Literal
2663 => Resolve_Integer_Literal (N, Ctx_Type);
2664
0669bebe
GB		 2665 when N_Membership_Test
2666 => Resolve_Membership_Op (N, Ctx_Type);
2667
996ae0b0
RK		 2668 when N_Null => Resolve_Null (N, Ctx_Type);
2669
2670 when N_Op_And | N_Op_Or | N_Op_Xor
2671 => Resolve_Logical_Op (N, Ctx_Type);
2672
2673 when N_Op_Eq | N_Op_Ne
2674 => Resolve_Equality_Op (N, Ctx_Type);
2675
2676 when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
2677 => Resolve_Comparison_Op (N, Ctx_Type);
2678
2679 when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
2680
2681 when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
2682 N_Op_Divide | N_Op_Mod | N_Op_Rem
2683
2684 => Resolve_Arithmetic_Op (N, Ctx_Type);
2685
2686 when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
2687
2688 when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
2689
2690 when N_Op_Plus | N_Op_Minus | N_Op_Abs
2691 => Resolve_Unary_Op (N, Ctx_Type);
2692
2693 when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
2694
2695 when N_Procedure_Call_Statement
2696 => Resolve_Call (N, Ctx_Type);
2697
2698 when N_Operator_Symbol
2699 => Resolve_Operator_Symbol (N, Ctx_Type);
2700
2701 when N_Qualified_Expression
2702 => Resolve_Qualified_Expression (N, Ctx_Type);
2703
a961aa79
AC		 2704 when N_Quantified_Expression
2705 => Resolve_Quantified_Expression (N, Ctx_Type);
2706
996ae0b0
RK		 2707 when N_Raise_xxx_Error
2708 => Set_Etype (N, Ctx_Type);
2709
2710 when N_Range => Resolve_Range (N, Ctx_Type);
2711
2712 when N_Real_Literal
2713 => Resolve_Real_Literal (N, Ctx_Type);
2714
2715 when N_Reference => Resolve_Reference (N, Ctx_Type);
2716
2717 when N_Selected_Component
2718 => Resolve_Selected_Component (N, Ctx_Type);
2719
2720 when N_Slice => Resolve_Slice (N, Ctx_Type);
2721
2722 when N_String_Literal
2723 => Resolve_String_Literal (N, Ctx_Type);
2724
2725 when N_Subprogram_Info
2726 => Resolve_Subprogram_Info (N, Ctx_Type);
2727
2728 when N_Type_Conversion
2729 => Resolve_Type_Conversion (N, Ctx_Type);
2730
2731 when N_Unchecked_Expression =>
2732 Resolve_Unchecked_Expression (N, Ctx_Type);
2733
2734 when N_Unchecked_Type_Conversion =>
2735 Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
996ae0b0
RK		 2736 end case;
2737
2738 -- If the subexpression was replaced by a non-subexpression, then
2739 -- all we do is to expand it. The only legitimate case we know of
2740 -- is converting procedure call statement to entry call statements,
2741 -- but there may be others, so we are making this test general.
2742
2743 if Nkind (N) not in N_Subexpr then
2744 Debug_A_Exit ("resolving ", N, " (done)");
2745 Expand (N);
2746 return;
2747 end if;
2748
1e194575
AC		 2749 -- AI05-144-2: Check dangerous order dependence within an expression
2750 -- that is not a subexpression. Exclude RHS of an assignment, because
2751 -- both sides may have side-effects and the check must be performed
2752 -- over the statement.
2753
2754 if Nkind (Parent (N)) not in N_Subexpr
2755 and then Nkind (Parent (N)) /= N_Assignment_Statement
2756 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
2757 then
2758 Check_Order_Dependence;
2759 end if;
2760
996ae0b0
RK		 2761 -- The expression is definitely NOT overloaded at this point, so
2762 -- we reset the Is_Overloaded flag to avoid any confusion when
2763 -- reanalyzing the node.
2764
2765 Set_Is_Overloaded (N, False);
2766
2767 -- Freeze expression type, entity if it is a name, and designated
fbf5a39b 2768 -- type if it is an allocator (RM 13.14(10,11,13)).
996ae0b0 2769
5cc9353d
RD		 2770 -- Now that the resolution of the type of the node is complete, and
2771 -- we did not detect an error, we can expand this node. We skip the
2772 -- expand call if we are in a default expression, see section
2773 -- "Handling of Default Expressions" in Sem spec.
996ae0b0
RK		 2774
2775 Debug_A_Exit ("resolving ", N, " (done)");
2776
2777 -- We unconditionally freeze the expression, even if we are in
5cc9353d
RD		 2778 -- default expression mode (the Freeze_Expression routine tests this
2779 -- flag and only freezes static types if it is set).
996ae0b0
RK		 2780
2781 Freeze_Expression (N);
2782
2783 -- Now we can do the expansion
2784
2785 Expand (N);
2786 end if;
996ae0b0
RK		 2787 end Resolve;
2788
fbf5a39b
AC		 2789 -------------
2790 -- Resolve --
2791 -------------
2792
996ae0b0
RK		 2793 -- Version with check(s) suppressed
2794
2795 procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
2796 begin
2797 if Suppress = All_Checks then
2798 declare
fbf5a39b 2799 Svg : constant Suppress_Array := Scope_Suppress;
996ae0b0
RK		 2800 begin
2801 Scope_Suppress := (others => True);
2802 Resolve (N, Typ);
2803 Scope_Suppress := Svg;
2804 end;
2805
2806 else
2807 declare
fbf5a39b 2808 Svg : constant Boolean := Scope_Suppress (Suppress);
996ae0b0 2809 begin
fbf5a39b 2810 Scope_Suppress (Suppress) := True;
996ae0b0 2811 Resolve (N, Typ);
fbf5a39b 2812 Scope_Suppress (Suppress) := Svg;
996ae0b0
RK		 2813 end;
2814 end if;
2815 end Resolve;
2816
fbf5a39b
AC		 2817 -------------
2818 -- Resolve --
2819 -------------
2820
2821 -- Version with implicit type
2822
2823 procedure Resolve (N : Node_Id) is
2824 begin
2825 Resolve (N, Etype (N));
2826 end Resolve;
2827
996ae0b0
RK		 2828 ---------------------
2829 -- Resolve_Actuals --
2830 ---------------------
2831
2832 procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
2833 Loc : constant Source_Ptr := Sloc (N);
2834 A : Node_Id;
2835 F : Entity_Id;
2836 A_Typ : Entity_Id;
2837 F_Typ : Entity_Id;
2838 Prev : Node_Id := Empty;
67ce0d7e 2839 Orig_A : Node_Id;
996ae0b0 2840
45fc7ddb
HK		 2841 procedure Check_Argument_Order;
2842 -- Performs a check for the case where the actuals are all simple
2843 -- identifiers that correspond to the formal names, but in the wrong
2844 -- order, which is considered suspicious and cause for a warning.
2845
b7d1f17f
HK		 2846 procedure Check_Prefixed_Call;
2847 -- If the original node is an overloaded call in prefix notation,
2848 -- insert an 'Access or a dereference as needed over the first actual.
2849 -- Try_Object_Operation has already verified that there is a valid
2850 -- interpretation, but the form of the actual can only be determined
2851 -- once the primitive operation is identified.
2852
996ae0b0
RK		 2853 procedure Insert_Default;
2854 -- If the actual is missing in a call, insert in the actuals list
2855 -- an instance of the default expression. The insertion is always
2856 -- a named association.
2857
fbf5a39b
AC		 2858 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
2859 -- Check whether T1 and T2, or their full views, are derived from a
2860 -- common type. Used to enforce the restrictions on array conversions
2861 -- of AI95-00246.
2862
a7a3cf5c
AC		 2863 function Static_Concatenation (N : Node_Id) return Boolean;
2864 -- Predicate to determine whether an actual that is a concatenation
2865 -- will be evaluated statically and does not need a transient scope.
2866 -- This must be determined before the actual is resolved and expanded
2867 -- because if needed the transient scope must be introduced earlier.
2868
45fc7ddb
HK		 2869 --------------------------
2870 -- Check_Argument_Order --
2871 --------------------------
2872
2873 procedure Check_Argument_Order is
2874 begin
2875 -- Nothing to do if no parameters, or original node is neither a
2876 -- function call nor a procedure call statement (happens in the
2877 -- operator-transformed-to-function call case), or the call does
2878 -- not come from source, or this warning is off.
2879
2880 if not Warn_On_Parameter_Order
19fb051c
AC		 2881 or else No (Parameter_Associations (N))
2882 or else not Nkind_In (Original_Node (N), N_Procedure_Call_Statement,
2883 N_Function_Call)
2884 or else not Comes_From_Source (N)
45fc7ddb
HK		 2885 then
2886 return;
2887 end if;
2888
2889 declare
2890 Nargs : constant Nat := List_Length (Parameter_Associations (N));
2891
2892 begin
2893 -- Nothing to do if only one parameter
2894
2895 if Nargs < 2 then
2896 return;
2897 end if;
2898
2899 -- Here if at least two arguments
2900
2901 declare
2902 Actuals : array (1 .. Nargs) of Node_Id;
2903 Actual : Node_Id;
2904 Formal : Node_Id;
2905
2906 Wrong_Order : Boolean := False;
2907 -- Set True if an out of order case is found
2908
2909 begin
2910 -- Collect identifier names of actuals, fail if any actual is
2911 -- not a simple identifier, and record max length of name.
2912
2913 Actual := First (Parameter_Associations (N));
2914 for J in Actuals'Range loop
2915 if Nkind (Actual) /= N_Identifier then
2916 return;
2917 else
2918 Actuals (J) := Actual;
2919 Next (Actual);
2920 end if;
2921 end loop;
2922
2923 -- If we got this far, all actuals are identifiers and the list
2924 -- of their names is stored in the Actuals array.
2925
2926 Formal := First_Formal (Nam);
2927 for J in Actuals'Range loop
2928
2929 -- If we ran out of formals, that's odd, probably an error
2930 -- which will be detected elsewhere, but abandon the search.
2931
2932 if No (Formal) then
2933 return;
2934 end if;
2935
2936 -- If name matches and is in order OK
2937
2938 if Chars (Formal) = Chars (Actuals (J)) then
2939 null;
2940
2941 else
2942 -- If no match, see if it is elsewhere in list and if so
2943 -- flag potential wrong order if type is compatible.
2944
2945 for K in Actuals'Range loop
2946 if Chars (Formal) = Chars (Actuals (K))
2947 and then
2948 Has_Compatible_Type (Actuals (K), Etype (Formal))
2949 then
2950 Wrong_Order := True;
2951 goto Continue;
2952 end if;
2953 end loop;
2954
2955 -- No match
2956
2957 return;
2958 end if;
2959
2960 <<Continue>> Next_Formal (Formal);
2961 end loop;
2962
2963 -- If Formals left over, also probably an error, skip warning
2964
2965 if Present (Formal) then
2966 return;
2967 end if;
2968
2969 -- Here we give the warning if something was out of order
2970
2971 if Wrong_Order then
2972 Error_Msg_N
2973 ("actuals for this call may be in wrong order?", N);
2974 end if;
2975 end;
2976 end;
2977 end Check_Argument_Order;
2978
b7d1f17f
HK		 2979 -------------------------
2980 -- Check_Prefixed_Call --
2981 -------------------------
2982
2983 procedure Check_Prefixed_Call is
2984 Act : constant Node_Id := First_Actual (N);
2985 A_Type : constant Entity_Id := Etype (Act);
2986 F_Type : constant Entity_Id := Etype (First_Formal (Nam));
2987 Orig : constant Node_Id := Original_Node (N);
2988 New_A : Node_Id;
2989
2990 begin
2991 -- Check whether the call is a prefixed call, with or without
2992 -- additional actuals.
2993
2994 if Nkind (Orig) = N_Selected_Component
2995 or else
2996 (Nkind (Orig) = N_Indexed_Component
2997 and then Nkind (Prefix (Orig)) = N_Selected_Component
2998 and then Is_Entity_Name (Prefix (Prefix (Orig)))
2999 and then Is_Entity_Name (Act)
3000 and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
3001 then
3002 if Is_Access_Type (A_Type)
3003 and then not Is_Access_Type (F_Type)
3004 then
3005 -- Introduce dereference on object in prefix
3006
3007 New_A :=
3008 Make_Explicit_Dereference (Sloc (Act),
3009 Prefix => Relocate_Node (Act));
3010 Rewrite (Act, New_A);
3011 Analyze (Act);
3012
3013 elsif Is_Access_Type (F_Type)
3014 and then not Is_Access_Type (A_Type)
3015 then
3016 -- Introduce an implicit 'Access in prefix
3017
3018 if not Is_Aliased_View (Act) then
ed2233dc 3019 Error_Msg_NE
b7d1f17f 3020 ("object in prefixed call to& must be aliased"
aa5147f0 3021 & " (RM-2005 4.3.1 (13))",
b7d1f17f
HK		 3022 Prefix (Act), Nam);
3023 end if;
3024
3025 Rewrite (Act,
3026 Make_Attribute_Reference (Loc,
3027 Attribute_Name => Name_Access,
3028 Prefix => Relocate_Node (Act)));
3029 end if;
3030
3031 Analyze (Act);
3032 end if;
3033 end Check_Prefixed_Call;
3034
996ae0b0
RK		 3035 --------------------
3036 -- Insert_Default --
3037 --------------------
3038
3039 procedure Insert_Default is
3040 Actval : Node_Id;
3041 Assoc : Node_Id;
3042
3043 begin
fbf5a39b 3044 -- Missing argument in call, nothing to insert
996ae0b0 3045
fbf5a39b
AC		 3046 if No (Default_Value (F)) then
3047 return;
3048
3049 else
3050 -- Note that we do a full New_Copy_Tree, so that any associated
3051 -- Itypes are properly copied. This may not be needed any more,
3052 -- but it does no harm as a safety measure! Defaults of a generic
3053 -- formal may be out of bounds of the corresponding actual (see
3054 -- cc1311b) and an additional check may be required.
996ae0b0 3055
b7d1f17f
HK		 3056 Actval :=
3057 New_Copy_Tree
3058 (Default_Value (F),
3059 New_Scope => Current_Scope,
3060 New_Sloc => Loc);
996ae0b0
RK		 3061
3062 if Is_Concurrent_Type (Scope (Nam))
3063 and then Has_Discriminants (Scope (Nam))
3064 then
3065 Replace_Actual_Discriminants (N, Actval);
3066 end if;
3067
3068 if Is_Overloadable (Nam)
3069 and then Present (Alias (Nam))
3070 then
3071 if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
3072 and then not Is_Tagged_Type (Etype (F))
3073 then
3074 -- If default is a real literal, do not introduce a
3075 -- conversion whose effect may depend on the run-time
3076 -- size of universal real.
3077
3078 if Nkind (Actval) = N_Real_Literal then
3079 Set_Etype (Actval, Base_Type (Etype (F)));
3080 else
3081 Actval := Unchecked_Convert_To (Etype (F), Actval);
3082 end if;
3083 end if;
3084
3085 if Is_Scalar_Type (Etype (F)) then
3086 Enable_Range_Check (Actval);
3087 end if;
3088
996ae0b0
RK		 3089 Set_Parent (Actval, N);
3090
3091 -- Resolve aggregates with their base type, to avoid scope
f3d57416 3092 -- anomalies: the subtype was first built in the subprogram
996ae0b0
RK		 3093 -- declaration, and the current call may be nested.
3094
76b84bf0
AC		 3095 if Nkind (Actval) = N_Aggregate then
3096 Analyze_And_Resolve (Actval, Etype (F));
996ae0b0
RK		 3097 else
3098 Analyze_And_Resolve (Actval, Etype (Actval));
3099 end if;
fbf5a39b
AC		 3100
3101 else
3102 Set_Parent (Actval, N);
3103
a77842bd 3104 -- See note above concerning aggregates
fbf5a39b
AC		 3105
3106 if Nkind (Actval) = N_Aggregate
3107 and then Has_Discriminants (Etype (Actval))
3108 then
3109 Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
3110
5cc9353d
RD		 3111 -- Resolve entities with their own type, which may differ from
3112 -- the type of a reference in a generic context (the view
3113 -- swapping mechanism did not anticipate the re-analysis of
3114 -- default values in calls).
fbf5a39b
AC		 3115
3116 elsif Is_Entity_Name (Actval) then
3117 Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
3118
3119 else
3120 Analyze_And_Resolve (Actval, Etype (Actval));
3121 end if;
996ae0b0
RK		 3122 end if;
3123
5cc9353d
RD		 3124 -- If default is a tag indeterminate function call, propagate tag
3125 -- to obtain proper dispatching.
996ae0b0
RK		 3126
3127 if Is_Controlling_Formal (F)
3128 and then Nkind (Default_Value (F)) = N_Function_Call
3129 then
3130 Set_Is_Controlling_Actual (Actval);
3131 end if;
3132
996ae0b0
RK		 3133 end if;
3134
3135 -- If the default expression raises constraint error, then just
5cc9353d
RD		 3136 -- silently replace it with an N_Raise_Constraint_Error node, since
3137 -- we already gave the warning on the subprogram spec. If node is
3138 -- already a Raise_Constraint_Error leave as is, to prevent loops in
3139 -- the warnings removal machinery.
996ae0b0 3140
2604ec03
AC		 3141 if Raises_Constraint_Error (Actval)
3142 and then Nkind (Actval) /= N_Raise_Constraint_Error
3143 then
996ae0b0 3144 Rewrite (Actval,
07fc65c4
GB		 3145 Make_Raise_Constraint_Error (Loc,
3146 Reason => CE_Range_Check_Failed));
996ae0b0
RK		 3147 Set_Raises_Constraint_Error (Actval);
3148 Set_Etype (Actval, Etype (F));
3149 end if;
3150
3151 Assoc :=
3152 Make_Parameter_Association (Loc,
3153 Explicit_Actual_Parameter => Actval,
3154 Selector_Name => Make_Identifier (Loc, Chars (F)));
3155
3156 -- Case of insertion is first named actual
3157
3158 if No (Prev) or else
3159 Nkind (Parent (Prev)) /= N_Parameter_Association
3160 then
3161 Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
3162 Set_First_Named_Actual (N, Actval);
3163
3164 if No (Prev) then
c8ef728f 3165 if No (Parameter_Associations (N)) then
996ae0b0
RK		 3166 Set_Parameter_Associations (N, New_List (Assoc));
3167 else
3168 Append (Assoc, Parameter_Associations (N));
3169 end if;
3170
3171 else
3172 Insert_After (Prev, Assoc);
3173 end if;
3174
3175 -- Case of insertion is not first named actual
3176
3177 else
3178 Set_Next_Named_Actual
3179 (Assoc, Next_Named_Actual (Parent (Prev)));
3180 Set_Next_Named_Actual (Parent (Prev), Actval);
3181 Append (Assoc, Parameter_Associations (N));
3182 end if;
3183
3184 Mark_Rewrite_Insertion (Assoc);
3185 Mark_Rewrite_Insertion (Actval);
3186
3187 Prev := Actval;
3188 end Insert_Default;
3189
fbf5a39b
AC		 3190 -------------------
3191 -- Same_Ancestor --
3192 -------------------
3193
3194 function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
3195 FT1 : Entity_Id := T1;
3196 FT2 : Entity_Id := T2;
3197
3198 begin
3199 if Is_Private_Type (T1)
3200 and then Present (Full_View (T1))
3201 then
3202 FT1 := Full_View (T1);
3203 end if;
3204
3205 if Is_Private_Type (T2)
3206 and then Present (Full_View (T2))
3207 then
3208 FT2 := Full_View (T2);
3209 end if;
3210
3211 return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
3212 end Same_Ancestor;
3213
a7a3cf5c
AC		 3214 --------------------------
3215 -- Static_Concatenation --
3216 --------------------------
3217
3218 function Static_Concatenation (N : Node_Id) return Boolean is
3219 begin
c72a85f2
TQ		 3220 case Nkind (N) is
3221 when N_String_Literal =>
3222 return True;
a7a3cf5c 3223
d81b4bfe
TQ		 3224 when N_Op_Concat =>
3225
5cc9353d
RD		 3226 -- Concatenation is static when both operands are static and
3227 -- the concatenation operator is a predefined one.
4342eda9
TQ		 3228
3229 return Scope (Entity (N)) = Standard_Standard
3230 and then
3231 Static_Concatenation (Left_Opnd (N))
c72a85f2
TQ		 3232 and then
3233 Static_Concatenation (Right_Opnd (N));
3234
3235 when others =>
3236 if Is_Entity_Name (N) then
3237 declare
3238 Ent : constant Entity_Id := Entity (N);
3239 begin
3240 return Ekind (Ent) = E_Constant
3241 and then Present (Constant_Value (Ent))
d81b4bfe
TQ		 3242 and then
3243 Is_Static_Expression (Constant_Value (Ent));
c72a85f2 3244 end;
a7a3cf5c 3245
a7a3cf5c
AC		 3246 else
3247 return False;
3248 end if;
c72a85f2 3249 end case;
a7a3cf5c
AC		 3250 end Static_Concatenation;
3251
996ae0b0
RK		 3252 -- Start of processing for Resolve_Actuals
3253
3254 begin
45fc7ddb
HK		 3255 Check_Argument_Order;
3256
b7d1f17f
HK		 3257 if Present (First_Actual (N)) then
3258 Check_Prefixed_Call;
3259 end if;
3260
996ae0b0
RK		 3261 A := First_Actual (N);
3262 F := First_Formal (Nam);
996ae0b0 3263 while Present (F) loop
fbf5a39b
AC		 3264 if No (A) and then Needs_No_Actuals (Nam) then
3265 null;
996ae0b0 3266
d81b4bfe
TQ		 3267 -- If we have an error in any actual or formal, indicated by a type
3268 -- of Any_Type, then abandon resolution attempt, and set result type
3269 -- to Any_Type.
07fc65c4 3270
fbf5a39b
AC		 3271 elsif (Present (A) and then Etype (A) = Any_Type)
3272 or else Etype (F) = Any_Type
07fc65c4
GB		 3273 then
3274 Set_Etype (N, Any_Type);
3275 return;
3276 end if;
3277
e65f50ec
ES		 3278 -- Case where actual is present
3279
45fc7ddb 3280 -- If the actual is an entity, generate a reference to it now. We
36fcf362
RD		 3281 -- do this before the actual is resolved, because a formal of some
3282 -- protected subprogram, or a task discriminant, will be rewritten
5cc9353d 3283 -- during expansion, and the source entity reference may be lost.
36fcf362
RD		 3284
3285 if Present (A)
3286 and then Is_Entity_Name (A)
3287 and then Comes_From_Source (N)
3288 then
3289 Orig_A := Entity (A);
3290
3291 if Present (Orig_A) then
3292 if Is_Formal (Orig_A)
3293 and then Ekind (F) /= E_In_Parameter
3294 then
3295 Generate_Reference (Orig_A, A, 'm');
19fb051c 3296
36fcf362
RD		 3297 elsif not Is_Overloaded (A) then
3298 Generate_Reference (Orig_A, A);
3299 end if;
3300 end if;
3301 end if;
3302
996ae0b0
RK		 3303 if Present (A)
3304 and then (Nkind (Parent (A)) /= N_Parameter_Association
19fb051c 3305 or else Chars (Selector_Name (Parent (A))) = Chars (F))
996ae0b0 3306 then
45fc7ddb
HK		 3307 -- If style checking mode on, check match of formal name
3308
3309 if Style_Check then
3310 if Nkind (Parent (A)) = N_Parameter_Association then
3311 Check_Identifier (Selector_Name (Parent (A)), F);
3312 end if;
3313 end if;
3314
996ae0b0
RK		 3315 -- If the formal is Out or In_Out, do not resolve and expand the
3316 -- conversion, because it is subsequently expanded into explicit
3317 -- temporaries and assignments. However, the object of the
ea985d95
RD		 3318 -- conversion can be resolved. An exception is the case of tagged
3319 -- type conversion with a class-wide actual. In that case we want
3320 -- the tag check to occur and no temporary will be needed (no
3321 -- representation change can occur) and the parameter is passed by
3322 -- reference, so we go ahead and resolve the type conversion.
c8ef728f 3323 -- Another exception is the case of reference to component or
ea985d95
RD		 3324 -- subcomponent of a bit-packed array, in which case we want to
3325 -- defer expansion to the point the in and out assignments are
3326 -- performed.
996ae0b0
RK		 3327
3328 if Ekind (F) /= E_In_Parameter
3329 and then Nkind (A) = N_Type_Conversion
3330 and then not Is_Class_Wide_Type (Etype (Expression (A)))
3331 then
07fc65c4
GB		 3332 if Ekind (F) = E_In_Out_Parameter
3333 and then Is_Array_Type (Etype (F))
07fc65c4 3334 then
038140ed
AC		 3335 -- In a view conversion, the conversion must be legal in
3336 -- both directions, and thus both component types must be
3337 -- aliased, or neither (4.6 (8)).
758c442c 3338
038140ed
AC		 3339 -- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
3340 -- the privacy requirement should not apply to generic
3341 -- types, and should be checked in an instance. ARG query
3342 -- is in order ???
45fc7ddb 3343
038140ed
AC		 3344 if Has_Aliased_Components (Etype (Expression (A))) /=
3345 Has_Aliased_Components (Etype (F))
3346 then
45fc7ddb
HK		 3347 Error_Msg_N
3348 ("both component types in a view conversion must be"
3349 & " aliased, or neither", A);
3350
038140ed
AC		 3351 -- Comment here??? what set of cases???
3352
45fc7ddb
HK		 3353 elsif
3354 not Same_Ancestor (Etype (F), Etype (Expression (A)))
3355 then
038140ed
AC		 3356 -- Check view conv between unrelated by ref array types
3357
45fc7ddb
HK		 3358 if Is_By_Reference_Type (Etype (F))
3359 or else Is_By_Reference_Type (Etype (Expression (A)))
758c442c
GD		 3360 then
3361 Error_Msg_N
45fc7ddb
HK		 3362 ("view conversion between unrelated by reference " &
3363 "array types not allowed (\'A'I-00246)", A);
038140ed
AC		 3364
3365 -- In Ada 2005 mode, check view conversion component
3366 -- type cannot be private, tagged, or volatile. Note
3367 -- that we only apply this to source conversions. The
3368 -- generated code can contain conversions which are
3369 -- not subject to this test, and we cannot extract the
3370 -- component type in such cases since it is not present.
3371
3372 elsif Comes_From_Source (A)
3373 and then Ada_Version >= Ada_2005
3374 then
45fc7ddb
HK		 3375 declare
3376 Comp_Type : constant Entity_Id :=
3377 Component_Type
3378 (Etype (Expression (A)));
3379 begin
038140ed
AC		 3380 if (Is_Private_Type (Comp_Type)
3381 and then not Is_Generic_Type (Comp_Type))
3382 or else Is_Tagged_Type (Comp_Type)
3383 or else Is_Volatile (Comp_Type)
45fc7ddb
HK		 3384 then
3385 Error_Msg_N
3386 ("component type of a view conversion cannot"
3387 & " be private, tagged, or volatile"
3388 & " (RM 4.6 (24))",
3389 Expression (A));
3390 end if;
3391 end;
758c442c 3392 end if;
fbf5a39b 3393 end if;
07fc65c4
GB		 3394 end if;
3395
038140ed
AC		 3396 -- Resolve expression if conversion is all OK
3397
16397eff 3398 if (Conversion_OK (A)
038140ed 3399 or else Valid_Conversion (A, Etype (A), Expression (A)))
16397eff 3400 and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
996ae0b0 3401 then
fbf5a39b 3402 Resolve (Expression (A));
996ae0b0
RK		 3403 end if;
3404
b7d1f17f
HK		 3405 -- If the actual is a function call that returns a limited
3406 -- unconstrained object that needs finalization, create a
3407 -- transient scope for it, so that it can receive the proper
3408 -- finalization list.
3409
3410 elsif Nkind (A) = N_Function_Call
3411 and then Is_Limited_Record (Etype (F))
3412 and then not Is_Constrained (Etype (F))
3413 and then Expander_Active
19fb051c 3414 and then (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
b7d1f17f
HK		 3415 then
3416 Establish_Transient_Scope (A, False);
3417
a52fefe6
AC		 3418 -- A small optimization: if one of the actuals is a concatenation
3419 -- create a block around a procedure call to recover stack space.
3420 -- This alleviates stack usage when several procedure calls in
76e776e5
AC		 3421 -- the same statement list use concatenation. We do not perform
3422 -- this wrapping for code statements, where the argument is a
3423 -- static string, and we want to preserve warnings involving
3424 -- sequences of such statements.
a52fefe6
AC		 3425
3426 elsif Nkind (A) = N_Op_Concat
3427 and then Nkind (N) = N_Procedure_Call_Statement
3428 and then Expander_Active
76e776e5
AC		 3429 and then
3430 not (Is_Intrinsic_Subprogram (Nam)
3431 and then Chars (Nam) = Name_Asm)
a7a3cf5c 3432 and then not Static_Concatenation (A)
a52fefe6
AC		 3433 then
3434 Establish_Transient_Scope (A, False);
3435 Resolve (A, Etype (F));
3436
996ae0b0 3437 else
fbf5a39b
AC		 3438 if Nkind (A) = N_Type_Conversion
3439 and then Is_Array_Type (Etype (F))
3440 and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
3441 and then
3442 (Is_Limited_Type (Etype (F))
3443 or else Is_Limited_Type (Etype (Expression (A))))
3444 then
3445 Error_Msg_N
758c442c
GD		 3446 ("conversion between unrelated limited array types " &
3447 "not allowed (\A\I-00246)", A);
fbf5a39b 3448
758c442c
GD		 3449 if Is_Limited_Type (Etype (F)) then
3450 Explain_Limited_Type (Etype (F), A);
3451 end if;
fbf5a39b 3452
758c442c
GD		 3453 if Is_Limited_Type (Etype (Expression (A))) then
3454 Explain_Limited_Type (Etype (Expression (A)), A);
3455 end if;
fbf5a39b
AC		 3456 end if;
3457
c8ef728f
ES		 3458 -- (Ada 2005: AI-251): If the actual is an allocator whose
3459 -- directly designated type is a class-wide interface, we build
3460 -- an anonymous access type to use it as the type of the
3461 -- allocator. Later, when the subprogram call is expanded, if
3462 -- the interface has a secondary dispatch table the expander
3463 -- will add a type conversion to force the correct displacement
3464 -- of the pointer.
3465
3466 if Nkind (A) = N_Allocator then
3467 declare
3468 DDT : constant Entity_Id :=
3469 Directly_Designated_Type (Base_Type (Etype (F)));
45fc7ddb 3470
c8ef728f 3471 New_Itype : Entity_Id;
45fc7ddb 3472
c8ef728f
ES		 3473 begin
3474 if Is_Class_Wide_Type (DDT)
3475 and then Is_Interface (DDT)
3476 then
3477 New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
45fc7ddb 3478 Set_Etype (New_Itype, Etype (A));
c8ef728f
ES		 3479 Set_Directly_Designated_Type (New_Itype,
3480 Directly_Designated_Type (Etype (A)));
3481 Set_Etype (A, New_Itype);
3482 end if;
0669bebe
GB		 3483
3484 -- Ada 2005, AI-162:If the actual is an allocator, the
3485 -- innermost enclosing statement is the master of the
b7d1f17f
HK		 3486 -- created object. This needs to be done with expansion
3487 -- enabled only, otherwise the transient scope will not
3488 -- be removed in the expansion of the wrapped construct.
0669bebe 3489
45fc7ddb 3490 if (Is_Controlled (DDT) or else Has_Task (DDT))
b7d1f17f 3491 and then Expander_Active
0669bebe
GB		 3492 then
3493 Establish_Transient_Scope (A, False);
3494 end if;
c8ef728f
ES		 3495 end;
3496 end if;
3497
b7d1f17f
HK		 3498 -- (Ada 2005): The call may be to a primitive operation of
3499 -- a tagged synchronized type, declared outside of the type.
3500 -- In this case the controlling actual must be converted to
3501 -- its corresponding record type, which is the formal type.
45fc7ddb
HK		 3502 -- The actual may be a subtype, either because of a constraint
3503 -- or because it is a generic actual, so use base type to
3504 -- locate concurrent type.
b7d1f17f 3505
15e4986c
JM		 3506 F_Typ := Base_Type (Etype (F));
3507
cb7fa356
AC		 3508 if Is_Tagged_Type (F_Typ)
3509 and then (Is_Concurrent_Type (F_Typ)
3510 or else Is_Concurrent_Record_Type (F_Typ))
3511 then
3512 -- If the actual is overloaded, look for an interpretation
3513 -- that has a synchronized type.
3514
3515 if not Is_Overloaded (A) then
3516 A_Typ := Base_Type (Etype (A));
15e4986c 3517
15e4986c 3518 else
cb7fa356
AC		 3519 declare
3520 Index : Interp_Index;
3521 It : Interp;
3522 begin
3523 Get_First_Interp (A, Index, It);
3524 while Present (It.Typ) loop
3525 if Is_Concurrent_Type (It.Typ)
3526 or else Is_Concurrent_Record_Type (It.Typ)
3527 then
3528 A_Typ := Base_Type (It.Typ);
3529 exit;
3530 end if;
3531
3532 Get_Next_Interp (Index, It);
3533 end loop;
3534 end;
15e4986c 3535 end if;
b7d1f17f 3536
cb7fa356
AC		 3537 declare
3538 Full_A_Typ : Entity_Id;
15e4986c 3539
cb7fa356
AC		 3540 begin
3541 if Present (Full_View (A_Typ)) then
3542 Full_A_Typ := Base_Type (Full_View (A_Typ));
3543 else
3544 Full_A_Typ := A_Typ;
3545 end if;
3546
3547 -- Tagged synchronized type (case 1): the actual is a
3548 -- concurrent type.
3549
3550 if Is_Concurrent_Type (A_Typ)
3551 and then Corresponding_Record_Type (A_Typ) = F_Typ
3552 then
3553 Rewrite (A,
3554 Unchecked_Convert_To
3555 (Corresponding_Record_Type (A_Typ), A));
3556 Resolve (A, Etype (F));
15e4986c 3557
cb7fa356
AC		 3558 -- Tagged synchronized type (case 2): the formal is a
3559 -- concurrent type.
15e4986c 3560
cb7fa356
AC		 3561 elsif Ekind (Full_A_Typ) = E_Record_Type
3562 and then Present
15e4986c 3563 (Corresponding_Concurrent_Type (Full_A_Typ))
cb7fa356
AC		 3564 and then Is_Concurrent_Type (F_Typ)
3565 and then Present (Corresponding_Record_Type (F_Typ))
3566 and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
3567 then
3568 Resolve (A, Corresponding_Record_Type (F_Typ));
15e4986c 3569
cb7fa356 3570 -- Common case
15e4986c 3571
cb7fa356
AC		 3572 else
3573 Resolve (A, Etype (F));
3574 end if;
3575 end;
3576 else
3577
3578 -- not a synchronized operation.
3579
3580 Resolve (A, Etype (F));
3581 end if;
996ae0b0
RK		 3582 end if;
3583
3584 A_Typ := Etype (A);
3585 F_Typ := Etype (F);
3586
b0186f71
AC		 3587 -- In SPARK or ALFA, the only view conversions are those involving
3588 -- ancestor conversion of an extended type.
3589
fe5d3068 3590 if Nkind (A) = N_Type_Conversion
b0186f71
AC		 3591 and then Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
3592 then
3593 declare
3594 Operand : constant Node_Id := Expression (A);
3595 Operand_Typ : constant Entity_Id := Etype (Operand);
3596 Target_Typ : constant Entity_Id := A_Typ;
780d052e 3597
b0186f71
AC		 3598 begin
3599 if not (Is_Tagged_Type (Target_Typ)
780d052e
RD		 3600 and then not Is_Class_Wide_Type (Target_Typ)
3601 and then Is_Tagged_Type (Operand_Typ)
3602 and then not Is_Class_Wide_Type (Operand_Typ)
3603 and then Is_Ancestor (Target_Typ, Operand_Typ))
b0186f71 3604 then
fe5d3068
YM		 3605 Check_Formal_Restriction
3606 ("ancestor conversion is the only permitted view "
3607 & "conversion", A);
b0186f71
AC		 3608 end if;
3609 end;
3610 end if;
3611
1e194575
AC		 3612 -- Save actual for subsequent check on order dependence, and
3613 -- indicate whether actual is modifiable. For AI05-0144-2.
bb481772 3614
1e194575 3615 Save_Actual (A, Ekind (F) /= E_In_Parameter);
bb481772 3616
26570b21
RD		 3617 -- For mode IN, if actual is an entity, and the type of the formal
3618 -- has warnings suppressed, then we reset Never_Set_In_Source for
3619 -- the calling entity. The reason for this is to catch cases like
3620 -- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
3621 -- uses trickery to modify an IN parameter.
3622
3623 if Ekind (F) = E_In_Parameter
3624 and then Is_Entity_Name (A)
3625 and then Present (Entity (A))
3626 and then Ekind (Entity (A)) = E_Variable
3627 and then Has_Warnings_Off (F_Typ)
3628 then
3629 Set_Never_Set_In_Source (Entity (A), False);
3630 end if;
3631
fbf5a39b
AC		 3632 -- Perform error checks for IN and IN OUT parameters
3633
3634 if Ekind (F) /= E_Out_Parameter then
3635
3636 -- Check unset reference. For scalar parameters, it is clearly
3637 -- wrong to pass an uninitialized value as either an IN or
3638 -- IN-OUT parameter. For composites, it is also clearly an
3639 -- error to pass a completely uninitialized value as an IN
3640 -- parameter, but the case of IN OUT is trickier. We prefer
3641 -- not to give a warning here. For example, suppose there is
3642 -- a routine that sets some component of a record to False.
3643 -- It is perfectly reasonable to make this IN-OUT and allow
3644 -- either initialized or uninitialized records to be passed
3645 -- in this case.
3646
3647 -- For partially initialized composite values, we also avoid
3648 -- warnings, since it is quite likely that we are passing a
3649 -- partially initialized value and only the initialized fields
3650 -- will in fact be read in the subprogram.
3651
3652 if Is_Scalar_Type (A_Typ)
3653 or else (Ekind (F) = E_In_Parameter
19fb051c 3654 and then not Is_Partially_Initialized_Type (A_Typ))
996ae0b0 3655 then
fbf5a39b 3656 Check_Unset_Reference (A);
996ae0b0 3657 end if;
996ae0b0 3658
758c442c
GD		 3659 -- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
3660 -- actual to a nested call, since this is case of reading an
3661 -- out parameter, which is not allowed.
996ae0b0 3662
0ab80019 3663 if Ada_Version = Ada_83
996ae0b0
RK		 3664 and then Is_Entity_Name (A)
3665 and then Ekind (Entity (A)) = E_Out_Parameter
3666 then
3667 Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
3668 end if;
3669 end if;
3670
67ce0d7e
RD		 3671 -- Case of OUT or IN OUT parameter
3672
36fcf362 3673 if Ekind (F) /= E_In_Parameter then
67ce0d7e
RD		 3674
3675 -- For an Out parameter, check for useless assignment. Note
45fc7ddb
HK		 3676 -- that we can't set Last_Assignment this early, because we may
3677 -- kill current values in Resolve_Call, and that call would
3678 -- clobber the Last_Assignment field.
67ce0d7e 3679
45fc7ddb
HK		 3680 -- Note: call Warn_On_Useless_Assignment before doing the check
3681 -- below for Is_OK_Variable_For_Out_Formal so that the setting
3682 -- of Referenced_As_LHS/Referenced_As_Out_Formal properly
3683 -- reflects the last assignment, not this one!
36fcf362 3684
67ce0d7e 3685 if Ekind (F) = E_Out_Parameter then
36fcf362 3686 if Warn_On_Modified_As_Out_Parameter (F)
67ce0d7e
RD		 3687 and then Is_Entity_Name (A)
3688 and then Present (Entity (A))
36fcf362 3689 and then Comes_From_Source (N)
67ce0d7e 3690 then
36fcf362 3691 Warn_On_Useless_Assignment (Entity (A), A);
67ce0d7e
RD		 3692 end if;
3693 end if;
3694
36fcf362
RD		 3695 -- Validate the form of the actual. Note that the call to
3696 -- Is_OK_Variable_For_Out_Formal generates the required
3697 -- reference in this case.
3698
3699 if not Is_OK_Variable_For_Out_Formal (A) then
3700 Error_Msg_NE ("actual for& must be a variable", A, F);
3701 end if;
3702
67ce0d7e 3703 -- What's the following about???
fbf5a39b
AC		 3704
3705 if Is_Entity_Name (A) then
3706 Kill_Checks (Entity (A));
3707 else
3708 Kill_All_Checks;
3709 end if;
3710 end if;
3711
3712 if Etype (A) = Any_Type then
3713 Set_Etype (N, Any_Type);
3714 return;
3715 end if;
3716
996ae0b0
RK		 3717 -- Apply appropriate range checks for in, out, and in-out
3718 -- parameters. Out and in-out parameters also need a separate
3719 -- check, if there is a type conversion, to make sure the return
3720 -- value meets the constraints of the variable before the
3721 -- conversion.
3722
3723 -- Gigi looks at the check flag and uses the appropriate types.
3724 -- For now since one flag is used there is an optimization which
3725 -- might not be done in the In Out case since Gigi does not do
3726 -- any analysis. More thought required about this ???
3727
8a95f4e8 3728 if Ekind_In (F, E_In_Parameter, E_In_Out_Parameter) then
48f91b44
RD		 3729
3730 -- Apply predicate checks, unless this is a call to the
3731 -- predicate check function itself, which would cause an
3732 -- infinite recursion.
3733
3734 if not (Ekind (Nam) = E_Function
3735 and then Has_Predicates (Nam))
3736 then
3737 Apply_Predicate_Check (A, F_Typ);
3738 end if;
3739
3740 -- Apply required constraint checks
3741
996ae0b0
RK		 3742 if Is_Scalar_Type (Etype (A)) then
3743 Apply_Scalar_Range_Check (A, F_Typ);
3744
3745 elsif Is_Array_Type (Etype (A)) then
3746 Apply_Length_Check (A, F_Typ);
3747
3748 elsif Is_Record_Type (F_Typ)
3749 and then Has_Discriminants (F_Typ)
3750 and then Is_Constrained (F_Typ)
3751 and then (not Is_Derived_Type (F_Typ)
19fb051c 3752 or else Comes_From_Source (Nam))
996ae0b0
RK		 3753 then
3754 Apply_Discriminant_Check (A, F_Typ);
3755
3756 elsif Is_Access_Type (F_Typ)
3757 and then Is_Array_Type (Designated_Type (F_Typ))
3758 and then Is_Constrained (Designated_Type (F_Typ))
3759 then
3760 Apply_Length_Check (A, F_Typ);
3761
3762 elsif Is_Access_Type (F_Typ)
3763 and then Has_Discriminants (Designated_Type (F_Typ))
3764 and then Is_Constrained (Designated_Type (F_Typ))
3765 then
3766 Apply_Discriminant_Check (A, F_Typ);
3767
3768 else
3769 Apply_Range_Check (A, F_Typ);
3770 end if;
2820d220 3771
0f1a6a0b
AC		 3772 -- Ada 2005 (AI-231): Note that the controlling parameter case
3773 -- already existed in Ada 95, which is partially checked
3774 -- elsewhere (see Checks), and we don't want the warning
3775 -- message to differ.
2820d220 3776
0f1a6a0b 3777 if Is_Access_Type (F_Typ)
1420b484 3778 and then Can_Never_Be_Null (F_Typ)
aa5147f0 3779 and then Known_Null (A)
2820d220 3780 then
0f1a6a0b
AC		 3781 if Is_Controlling_Formal (F) then
3782 Apply_Compile_Time_Constraint_Error
3783 (N => A,
3784 Msg => "null value not allowed here?",
3785 Reason => CE_Access_Check_Failed);
3786
3787 elsif Ada_Version >= Ada_2005 then
3788 Apply_Compile_Time_Constraint_Error
3789 (N => A,
3790 Msg => "(Ada 2005) null not allowed in "
3791 & "null-excluding formal?",
3792 Reason => CE_Null_Not_Allowed);
3793 end if;
2820d220 3794 end if;
996ae0b0
RK		 3795 end if;
3796
8a95f4e8 3797 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) then
996ae0b0
RK		 3798 if Nkind (A) = N_Type_Conversion then
3799 if Is_Scalar_Type (A_Typ) then
3800 Apply_Scalar_Range_Check
3801 (Expression (A), Etype (Expression (A)), A_Typ);
3802 else
3803 Apply_Range_Check
3804 (Expression (A), Etype (Expression (A)), A_Typ);
3805 end if;
3806
3807 else
3808 if Is_Scalar_Type (F_Typ) then
3809 Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
996ae0b0
RK		 3810 elsif Is_Array_Type (F_Typ)
3811 and then Ekind (F) = E_Out_Parameter
3812 then
3813 Apply_Length_Check (A, F_Typ);
996ae0b0
RK		 3814 else
3815 Apply_Range_Check (A, A_Typ, F_Typ);
3816 end if;
3817 end if;
3818 end if;
3819
3820 -- An actual associated with an access parameter is implicitly
45fc7ddb
HK		 3821 -- converted to the anonymous access type of the formal and must
3822 -- satisfy the legality checks for access conversions.
996ae0b0
RK		 3823
3824 if Ekind (F_Typ) = E_Anonymous_Access_Type then
3825 if not Valid_Conversion (A, F_Typ, A) then
3826 Error_Msg_N
3827 ("invalid implicit conversion for access parameter", A);
3828 end if;
3829 end if;
3830
3831 -- Check bad case of atomic/volatile argument (RM C.6(12))
3832
3833 if Is_By_Reference_Type (Etype (F))
3834 and then Comes_From_Source (N)
3835 then
3836 if Is_Atomic_Object (A)
3837 and then not Is_Atomic (Etype (F))
3838 then
3839 Error_Msg_N
3840 ("cannot pass atomic argument to non-atomic formal",
3841 N);
3842
3843 elsif Is_Volatile_Object (A)
3844 and then not Is_Volatile (Etype (F))
3845 then
3846 Error_Msg_N
3847 ("cannot pass volatile argument to non-volatile formal",
3848 N);
3849 end if;
3850 end if;
3851
3852 -- Check that subprograms don't have improper controlling
d81b4bfe 3853 -- arguments (RM 3.9.2 (9)).
996ae0b0 3854
0669bebe
GB		 3855 -- A primitive operation may have an access parameter of an
3856 -- incomplete tagged type, but a dispatching call is illegal
3857 -- if the type is still incomplete.
3858
996ae0b0
RK		 3859 if Is_Controlling_Formal (F) then
3860 Set_Is_Controlling_Actual (A);
0669bebe
GB		 3861
3862 if Ekind (Etype (F)) = E_Anonymous_Access_Type then
3863 declare
3864 Desig : constant Entity_Id := Designated_Type (Etype (F));
3865 begin
3866 if Ekind (Desig) = E_Incomplete_Type
3867 and then No (Full_View (Desig))
3868 and then No (Non_Limited_View (Desig))
3869 then
3870 Error_Msg_NE
3871 ("premature use of incomplete type& " &
3872 "in dispatching call", A, Desig);
3873 end if;
3874 end;
3875 end if;
3876
996ae0b0
RK		 3877 elsif Nkind (A) = N_Explicit_Dereference then
3878 Validate_Remote_Access_To_Class_Wide_Type (A);
3879 end if;
3880
3881 if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
3882 and then not Is_Class_Wide_Type (F_Typ)
3883 and then not Is_Controlling_Formal (F)
3884 then
3885 Error_Msg_N ("class-wide argument not allowed here!", A);
07fc65c4
GB		 3886
3887 if Is_Subprogram (Nam)
3888 and then Comes_From_Source (Nam)
3889 then
996ae0b0
RK		 3890 Error_Msg_Node_2 := F_Typ;
3891 Error_Msg_NE
82c80734 3892 ("& is not a dispatching operation of &!", A, Nam);
996ae0b0
RK		 3893 end if;
3894
3895 elsif Is_Access_Type (A_Typ)
3896 and then Is_Access_Type (F_Typ)
3897 and then Ekind (F_Typ) /= E_Access_Subprogram_Type
aa5147f0 3898 and then Ekind (F_Typ) /= E_Anonymous_Access_Subprogram_Type
996ae0b0 3899 and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
07fc65c4
GB		 3900 or else (Nkind (A) = N_Attribute_Reference
3901 and then
46fe0142 3902 Is_Class_Wide_Type (Etype (Prefix (A)))))
996ae0b0
RK		 3903 and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
3904 and then not Is_Controlling_Formal (F)
ae65d635 3905
46fe0142 3906 -- Disable these checks for call to imported C++ subprograms
ae65d635 3907
46fe0142
AC		 3908 and then not
3909 (Is_Entity_Name (Name (N))
3910 and then Is_Imported (Entity (Name (N)))
3911 and then Convention (Entity (Name (N))) = Convention_CPP)
996ae0b0
RK		 3912 then
3913 Error_Msg_N
3914 ("access to class-wide argument not allowed here!", A);
07fc65c4
GB		 3915
3916 if Is_Subprogram (Nam)
3917 and then Comes_From_Source (Nam)
3918 then
996ae0b0
RK		 3919 Error_Msg_Node_2 := Designated_Type (F_Typ);
3920 Error_Msg_NE
82c80734 3921 ("& is not a dispatching operation of &!", A, Nam);
996ae0b0
RK		 3922 end if;
3923 end if;
3924
3925 Eval_Actual (A);
3926
8e4dac80
TQ		 3927 -- If it is a named association, treat the selector_name as a
3928 -- proper identifier, and mark the corresponding entity.
996ae0b0
RK		 3929
3930 if Nkind (Parent (A)) = N_Parameter_Association then
3931 Set_Entity (Selector_Name (Parent (A)), F);
3932 Generate_Reference (F, Selector_Name (Parent (A)));
3933 Set_Etype (Selector_Name (Parent (A)), F_Typ);
3934 Generate_Reference (F_Typ, N, ' ');
3935 end if;
3936
3937 Prev := A;
fbf5a39b
AC		 3938
3939 if Ekind (F) /= E_Out_Parameter then
3940 Check_Unset_Reference (A);
3941 end if;
3942
996ae0b0
RK		 3943 Next_Actual (A);
3944
fbf5a39b
AC		 3945 -- Case where actual is not present
3946
996ae0b0
RK		 3947 else
3948 Insert_Default;
3949 end if;
3950
3951 Next_Formal (F);
3952 end loop;
996ae0b0
RK		 3953 end Resolve_Actuals;
3954
3955 -----------------------
3956 -- Resolve_Allocator --
3957 -----------------------
3958
3959 procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
3960 E : constant Node_Id := Expression (N);
3961 Subtyp : Entity_Id;
3962 Discrim : Entity_Id;
3963 Constr : Node_Id;
b7d1f17f
HK		 3964 Aggr : Node_Id;
3965 Assoc : Node_Id := Empty;
996ae0b0
RK		 3966 Disc_Exp : Node_Id;
3967
b7d1f17f
HK		 3968 procedure Check_Allocator_Discrim_Accessibility
3969 (Disc_Exp : Node_Id;
3970 Alloc_Typ : Entity_Id);
3971 -- Check that accessibility level associated with an access discriminant
3972 -- initialized in an allocator by the expression Disc_Exp is not deeper
3973 -- than the level of the allocator type Alloc_Typ. An error message is
3974 -- issued if this condition is violated. Specialized checks are done for
3975 -- the cases of a constraint expression which is an access attribute or
3976 -- an access discriminant.
3977
07fc65c4 3978 function In_Dispatching_Context return Boolean;
b7d1f17f
HK		 3979 -- If the allocator is an actual in a call, it is allowed to be class-
3980 -- wide when the context is not because it is a controlling actual.
3981
3982 procedure Propagate_Coextensions (Root : Node_Id);
3983 -- Propagate all nested coextensions which are located one nesting
3984 -- level down the tree to the node Root. Example:
3985 --
3986 -- Top_Record
3987 -- Level_1_Coextension
3988 -- Level_2_Coextension
3989 --
3990 -- The algorithm is paired with delay actions done by the Expander. In
3991 -- the above example, assume all coextensions are controlled types.
3992 -- The cycle of analysis, resolution and expansion will yield:
3993 --
3994 -- 1) Analyze Top_Record
3995 -- 2) Analyze Level_1_Coextension
3996 -- 3) Analyze Level_2_Coextension
f3d57416 3997 -- 4) Resolve Level_2_Coextension. The allocator is marked as a
b7d1f17f
HK		 3998 -- coextension.
3999 -- 5) Expand Level_2_Coextension. A temporary variable Temp_1 is
4000 -- generated to capture the allocated object. Temp_1 is attached
4001 -- to the coextension chain of Level_2_Coextension.
4002 -- 6) Resolve Level_1_Coextension. The allocator is marked as a
4003 -- coextension. A forward tree traversal is performed which finds
4004 -- Level_2_Coextension's list and copies its contents into its
4005 -- own list.
4006 -- 7) Expand Level_1_Coextension. A temporary variable Temp_2 is
4007 -- generated to capture the allocated object. Temp_2 is attached
4008 -- to the coextension chain of Level_1_Coextension. Currently, the
4009 -- contents of the list are [Temp_2, Temp_1].
4010 -- 8) Resolve Top_Record. A forward tree traversal is performed which
4011 -- finds Level_1_Coextension's list and copies its contents into
4012 -- its own list.
4013 -- 9) Expand Top_Record. Generate finalization calls for Temp_1 and
4014 -- Temp_2 and attach them to Top_Record's finalization list.
4015
4016 -------------------------------------------
4017 -- Check_Allocator_Discrim_Accessibility --
4018 -------------------------------------------
4019
4020 procedure Check_Allocator_Discrim_Accessibility
4021 (Disc_Exp : Node_Id;
4022 Alloc_Typ : Entity_Id)
4023 is
4024 begin
4025 if Type_Access_Level (Etype (Disc_Exp)) >
4026 Type_Access_Level (Alloc_Typ)
4027 then
4028 Error_Msg_N
4029 ("operand type has deeper level than allocator type", Disc_Exp);
4030
4031 -- When the expression is an Access attribute the level of the prefix
4032 -- object must not be deeper than that of the allocator's type.
4033
4034 elsif Nkind (Disc_Exp) = N_Attribute_Reference
4035 and then Get_Attribute_Id (Attribute_Name (Disc_Exp))
4036 = Attribute_Access
4037 and then Object_Access_Level (Prefix (Disc_Exp))
4038 > Type_Access_Level (Alloc_Typ)
4039 then
4040 Error_Msg_N
4041 ("prefix of attribute has deeper level than allocator type",
4042 Disc_Exp);
4043
4044 -- When the expression is an access discriminant the check is against
4045 -- the level of the prefix object.
4046
4047 elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
4048 and then Nkind (Disc_Exp) = N_Selected_Component
4049 and then Object_Access_Level (Prefix (Disc_Exp))
4050 > Type_Access_Level (Alloc_Typ)
4051 then
4052 Error_Msg_N
4053 ("access discriminant has deeper level than allocator type",
4054 Disc_Exp);
4055
4056 -- All other cases are legal
4057
4058 else
4059 null;
4060 end if;
4061 end Check_Allocator_Discrim_Accessibility;
07fc65c4
GB		 4062
4063 ----------------------------
4064 -- In_Dispatching_Context --
4065 ----------------------------
4066
4067 function In_Dispatching_Context return Boolean is
4068 Par : constant Node_Id := Parent (N);
07fc65c4 4069 begin
45fc7ddb 4070 return Nkind_In (Par, N_Function_Call, N_Procedure_Call_Statement)
07fc65c4
GB		 4071 and then Is_Entity_Name (Name (Par))
4072 and then Is_Dispatching_Operation (Entity (Name (Par)));
4073 end In_Dispatching_Context;
4074
b7d1f17f
HK		 4075 ----------------------------
4076 -- Propagate_Coextensions --
4077 ----------------------------
4078
4079 procedure Propagate_Coextensions (Root : Node_Id) is
4080
4081 procedure Copy_List (From : Elist_Id; To : Elist_Id);
4082 -- Copy the contents of list From into list To, preserving the
4083 -- order of elements.
4084
4085 function Process_Allocator (Nod : Node_Id) return Traverse_Result;
4086 -- Recognize an allocator or a rewritten allocator node and add it
f3d57416 4087 -- along with its nested coextensions to the list of Root.
b7d1f17f
HK		 4088
4089 ---------------
4090 -- Copy_List --
4091 ---------------
4092
4093 procedure Copy_List (From : Elist_Id; To : Elist_Id) is
4094 From_Elmt : Elmt_Id;
4095 begin
4096 From_Elmt := First_Elmt (From);
4097 while Present (From_Elmt) loop
4098 Append_Elmt (Node (From_Elmt), To);
4099 Next_Elmt (From_Elmt);
4100 end loop;
4101 end Copy_List;
4102
4103 -----------------------
4104 -- Process_Allocator --
4105 -----------------------
4106
4107 function Process_Allocator (Nod : Node_Id) return Traverse_Result is
4108 Orig_Nod : Node_Id := Nod;
4109
4110 begin
4111 -- This is a possible rewritten subtype indication allocator. Any
4112 -- nested coextensions will appear as discriminant constraints.
4113
4114 if Nkind (Nod) = N_Identifier
4115 and then Present (Original_Node (Nod))
4116 and then Nkind (Original_Node (Nod)) = N_Subtype_Indication
4117 then
4118 declare
4119 Discr : Node_Id;
4120 Discr_Elmt : Elmt_Id;
4121
4122 begin
4123 if Is_Record_Type (Entity (Nod)) then
4124 Discr_Elmt :=
4125 First_Elmt (Discriminant_Constraint (Entity (Nod)));
4126 while Present (Discr_Elmt) loop
4127 Discr := Node (Discr_Elmt);
4128
4129 if Nkind (Discr) = N_Identifier
4130 and then Present (Original_Node (Discr))
4131 and then Nkind (Original_Node (Discr)) = N_Allocator
4132 and then Present (Coextensions (
4133 Original_Node (Discr)))
4134 then
4135 if No (Coextensions (Root)) then
4136 Set_Coextensions (Root, New_Elmt_List);
4137 end if;
4138
4139 Copy_List
4140 (From => Coextensions (Original_Node (Discr)),
4141 To => Coextensions (Root));
4142 end if;
4143
4144 Next_Elmt (Discr_Elmt);
4145 end loop;
4146
4147 -- There is no need to continue the traversal of this
4148 -- subtree since all the information has already been
4149 -- propagated.
4150
4151 return Skip;
4152 end if;
4153 end;
4154
4155 -- Case of either a stand alone allocator or a rewritten allocator
4156 -- with an aggregate.
4157
4158 else
4159 if Present (Original_Node (Nod)) then
4160 Orig_Nod := Original_Node (Nod);
4161 end if;
4162
4163 if Nkind (Orig_Nod) = N_Allocator then
4164
4165 -- Propagate the list of nested coextensions to the Root
4166 -- allocator. This is done through list copy since a single
4167 -- allocator may have multiple coextensions. Do not touch
4168 -- coextensions roots.
4169
4170 if not Is_Coextension_Root (Orig_Nod)
4171 and then Present (Coextensions (Orig_Nod))
4172 then
4173 if No (Coextensions (Root)) then
4174 Set_Coextensions (Root, New_Elmt_List);
4175 end if;
4176
4177 Copy_List
4178 (From => Coextensions (Orig_Nod),
4179 To => Coextensions (Root));
4180 end if;
4181
4182 -- There is no need to continue the traversal of this
4183 -- subtree since all the information has already been
4184 -- propagated.
4185
4186 return Skip;
4187 end if;
4188 end if;
4189
4190 -- Keep on traversing, looking for the next allocator
4191
4192 return OK;
4193 end Process_Allocator;
4194
4195 procedure Process_Allocators is
4196 new Traverse_Proc (Process_Allocator);
4197
4198 -- Start of processing for Propagate_Coextensions
4199
4200 begin
4201 Process_Allocators (Expression (Root));
4202 end Propagate_Coextensions;
4203
07fc65c4
GB		 4204 -- Start of processing for Resolve_Allocator
4205
996ae0b0
RK		 4206 begin
4207 -- Replace general access with specific type
4208
4209 if Ekind (Etype (N)) = E_Allocator_Type then
4210 Set_Etype (N, Base_Type (Typ));
4211 end if;
4212
0669bebe 4213 if Is_Abstract_Type (Typ) then
996ae0b0
RK		 4214 Error_Msg_N ("type of allocator cannot be abstract", N);
4215 end if;
4216
4217 -- For qualified expression, resolve the expression using the
4218 -- given subtype (nothing to do for type mark, subtype indication)
4219
4220 if Nkind (E) = N_Qualified_Expression then
4221 if Is_Class_Wide_Type (Etype (E))
4222 and then not Is_Class_Wide_Type (Designated_Type (Typ))
07fc65c4 4223 and then not In_Dispatching_Context
996ae0b0
RK		 4224 then
4225 Error_Msg_N
4226 ("class-wide allocator not allowed for this access type", N);
4227 end if;
4228
4229 Resolve (Expression (E), Etype (E));
4230 Check_Unset_Reference (Expression (E));
4231
fbf5a39b 4232 -- A qualified expression requires an exact match of the type,
7b4db06c 4233 -- class-wide matching is not allowed.
fbf5a39b 4234
7b4db06c 4235 if (Is_Class_Wide_Type (Etype (Expression (E)))
19fb051c 4236 or else Is_Class_Wide_Type (Etype (E)))
fbf5a39b
AC		 4237 and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
4238 then
4239 Wrong_Type (Expression (E), Etype (E));
4240 end if;
4241
b7d1f17f
HK		 4242 -- A special accessibility check is needed for allocators that
4243 -- constrain access discriminants. The level of the type of the
4244 -- expression used to constrain an access discriminant cannot be
f3d57416 4245 -- deeper than the type of the allocator (in contrast to access
b7d1f17f
HK		 4246 -- parameters, where the level of the actual can be arbitrary).
4247
4248 -- We can't use Valid_Conversion to perform this check because
4249 -- in general the type of the allocator is unrelated to the type
4250 -- of the access discriminant.
4251
4252 if Ekind (Typ) /= E_Anonymous_Access_Type
4253 or else Is_Local_Anonymous_Access (Typ)
4254 then
4255 Subtyp := Entity (Subtype_Mark (E));
4256
4257 Aggr := Original_Node (Expression (E));
4258
4259 if Has_Discriminants (Subtyp)
45fc7ddb 4260 and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
b7d1f17f
HK		 4261 then
4262 Discrim := First_Discriminant (Base_Type (Subtyp));
4263
4264 -- Get the first component expression of the aggregate
4265
4266 if Present (Expressions (Aggr)) then
4267 Disc_Exp := First (Expressions (Aggr));
4268
4269 elsif Present (Component_Associations (Aggr)) then
4270 Assoc := First (Component_Associations (Aggr));
4271
4272 if Present (Assoc) then
4273 Disc_Exp := Expression (Assoc);
4274 else
4275 Disc_Exp := Empty;
4276 end if;
4277
4278 else
4279 Disc_Exp := Empty;
4280 end if;
4281
4282 while Present (Discrim) and then Present (Disc_Exp) loop
4283 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4284 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
4285 end if;
4286
4287 Next_Discriminant (Discrim);
4288
4289 if Present (Discrim) then
4290 if Present (Assoc) then
4291 Next (Assoc);
4292 Disc_Exp := Expression (Assoc);
4293
4294 elsif Present (Next (Disc_Exp)) then
4295 Next (Disc_Exp);
4296
4297 else
4298 Assoc := First (Component_Associations (Aggr));
4299
4300 if Present (Assoc) then
4301 Disc_Exp := Expression (Assoc);
4302 else
4303 Disc_Exp := Empty;
4304 end if;
4305 end if;
4306 end if;
4307 end loop;
4308 end if;
4309 end if;
4310
996ae0b0
RK		 4311 -- For a subtype mark or subtype indication, freeze the subtype
4312
4313 else
4314 Freeze_Expression (E);
4315
4316 if Is_Access_Constant (Typ) and then not No_Initialization (N) then
4317 Error_Msg_N
4318 ("initialization required for access-to-constant allocator", N);
4319 end if;
4320
4321 -- A special accessibility check is needed for allocators that
4322 -- constrain access discriminants. The level of the type of the
b7d1f17f 4323 -- expression used to constrain an access discriminant cannot be
f3d57416 4324 -- deeper than the type of the allocator (in contrast to access
996ae0b0
RK		 4325 -- parameters, where the level of the actual can be arbitrary).
4326 -- We can't use Valid_Conversion to perform this check because
4327 -- in general the type of the allocator is unrelated to the type
b7d1f17f 4328 -- of the access discriminant.
996ae0b0
RK		 4329
4330 if Nkind (Original_Node (E)) = N_Subtype_Indication
b7d1f17f
HK		 4331 and then (Ekind (Typ) /= E_Anonymous_Access_Type
4332 or else Is_Local_Anonymous_Access (Typ))
996ae0b0
RK		 4333 then
4334 Subtyp := Entity (Subtype_Mark (Original_Node (E)));
4335
4336 if Has_Discriminants (Subtyp) then
4337 Discrim := First_Discriminant (Base_Type (Subtyp));
4338 Constr := First (Constraints (Constraint (Original_Node (E))));
996ae0b0
RK		 4339 while Present (Discrim) and then Present (Constr) loop
4340 if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
4341 if Nkind (Constr) = N_Discriminant_Association then
4342 Disc_Exp := Original_Node (Expression (Constr));
4343 else
4344 Disc_Exp := Original_Node (Constr);
4345 end if;
4346
b7d1f17f 4347 Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
996ae0b0 4348 end if;
b7d1f17f 4349
996ae0b0
RK		 4350 Next_Discriminant (Discrim);
4351 Next (Constr);
4352 end loop;
4353 end if;
4354 end if;
4355 end if;
4356
758c442c
GD		 4357 -- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
4358 -- check that the level of the type of the created object is not deeper
4359 -- than the level of the allocator's access type, since extensions can
4360 -- now occur at deeper levels than their ancestor types. This is a
4361 -- static accessibility level check; a run-time check is also needed in
4362 -- the case of an initialized allocator with a class-wide argument (see
4363 -- Expand_Allocator_Expression).
4364
0791fbe9 4365 if Ada_Version >= Ada_2005
758c442c
GD		 4366 and then Is_Class_Wide_Type (Designated_Type (Typ))
4367 then
4368 declare
b7d1f17f 4369 Exp_Typ : Entity_Id;
758c442c
GD		 4370
4371 begin
4372 if Nkind (E) = N_Qualified_Expression then
4373 Exp_Typ := Etype (E);
4374 elsif Nkind (E) = N_Subtype_Indication then
4375 Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
4376 else
4377 Exp_Typ := Entity (E);
4378 end if;
4379
4380 if Type_Access_Level (Exp_Typ) > Type_Access_Level (Typ) then
4381 if In_Instance_Body then
4382 Error_Msg_N ("?type in allocator has deeper level than" &
4383 " designated class-wide type", E);
c8ef728f
ES		 4384 Error_Msg_N ("\?Program_Error will be raised at run time",
4385 E);
758c442c
GD		 4386 Rewrite (N,
4387 Make_Raise_Program_Error (Sloc (N),
4388 Reason => PE_Accessibility_Check_Failed));
4389 Set_Etype (N, Typ);
aa180613
RD		 4390
4391 -- Do not apply Ada 2005 accessibility checks on a class-wide
4392 -- allocator if the type given in the allocator is a formal
4393 -- type. A run-time check will be performed in the instance.
4394
4395 elsif not Is_Generic_Type (Exp_Typ) then
758c442c
GD		 4396 Error_Msg_N ("type in allocator has deeper level than" &
4397 " designated class-wide type", E);
4398 end if;
4399 end if;
4400 end;
4401 end if;
4402
996ae0b0
RK		 4403 -- Check for allocation from an empty storage pool
4404
4405 if No_Pool_Assigned (Typ) then
8da337c5 4406 Error_Msg_N ("allocation from empty storage pool!", N);
1420b484 4407
5cc9353d
RD		 4408 -- If the context is an unchecked conversion, as may happen within an
4409 -- inlined subprogram, the allocator is being resolved with its own
4410 -- anonymous type. In that case, if the target type has a specific
1420b484
JM		 4411 -- storage pool, it must be inherited explicitly by the allocator type.
4412
4413 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
4414 and then No (Associated_Storage_Pool (Typ))
4415 then
4416 Set_Associated_Storage_Pool
4417 (Typ, Associated_Storage_Pool (Etype (Parent (N))));
996ae0b0 4418 end if;
b7d1f17f 4419
e57ab550
AC		 4420 if Ekind (Etype (N)) = E_Anonymous_Access_Type then
4421 Check_Restriction (No_Anonymous_Allocators, N);
4422 end if;
4423
b7d1f17f
HK		 4424 -- An erroneous allocator may be rewritten as a raise Program_Error
4425 -- statement.
4426
4427 if Nkind (N) = N_Allocator then
4428
4429 -- An anonymous access discriminant is the definition of a
aa5147f0 4430 -- coextension.
b7d1f17f
HK		 4431
4432 if Ekind (Typ) = E_Anonymous_Access_Type
4433 and then Nkind (Associated_Node_For_Itype (Typ)) =
4434 N_Discriminant_Specification
4435 then
4436 -- Avoid marking an allocator as a dynamic coextension if it is
aa5147f0 4437 -- within a static construct.
b7d1f17f
HK		 4438
4439 if not Is_Static_Coextension (N) then
aa5147f0 4440 Set_Is_Dynamic_Coextension (N);
b7d1f17f
HK		 4441 end if;
4442
4443 -- Cleanup for potential static coextensions
4444
4445 else
aa5147f0
ES		 4446 Set_Is_Dynamic_Coextension (N, False);
4447 Set_Is_Static_Coextension (N, False);
b7d1f17f
HK		 4448 end if;
4449
aa5147f0
ES		 4450 -- There is no need to propagate any nested coextensions if they
4451 -- are marked as static since they will be rewritten on the spot.
4452
4453 if not Is_Static_Coextension (N) then
4454 Propagate_Coextensions (N);
4455 end if;
b7d1f17f 4456 end if;
996ae0b0
RK		 4457 end Resolve_Allocator;
4458
4459 ---------------------------
4460 -- Resolve_Arithmetic_Op --
4461 ---------------------------
4462
4463 -- Used for resolving all arithmetic operators except exponentiation
4464
4465 procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
fbf5a39b
AC		 4466 L : constant Node_Id := Left_Opnd (N);
4467 R : constant Node_Id := Right_Opnd (N);
4468 TL : constant Entity_Id := Base_Type (Etype (L));
4469 TR : constant Entity_Id := Base_Type (Etype (R));
4470 T : Entity_Id;
4471 Rop : Node_Id;
996ae0b0
RK		 4472
4473 B_Typ : constant Entity_Id := Base_Type (Typ);
4474 -- We do the resolution using the base type, because intermediate values
4475 -- in expressions always are of the base type, not a subtype of it.
4476
aa180613
RD		 4477 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
4478 -- Returns True if N is in a context that expects "any real type"
4479
996ae0b0
RK		 4480 function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
4481 -- Return True iff given type is Integer or universal real/integer
4482
4483 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
4484 -- Choose type of integer literal in fixed-point operation to conform
4485 -- to available fixed-point type. T is the type of the other operand,
4486 -- which is needed to determine the expected type of N.
4487
4488 procedure Set_Operand_Type (N : Node_Id);
4489 -- Set operand type to T if universal
4490
aa180613
RD		 4491 -------------------------------
4492 -- Expected_Type_Is_Any_Real --
4493 -------------------------------
4494
4495 function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
4496 begin
4497 -- N is the expression after "delta" in a fixed_point_definition;
4498 -- see RM-3.5.9(6):
4499
45fc7ddb
HK		 4500 return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
4501 N_Decimal_Fixed_Point_Definition,
aa180613
RD		 4502
4503 -- N is one of the bounds in a real_range_specification;
4504 -- see RM-3.5.7(5):
4505
45fc7ddb 4506 N_Real_Range_Specification,
aa180613
RD		 4507
4508 -- N is the expression of a delta_constraint;
4509 -- see RM-J.3(3):
4510
45fc7ddb 4511 N_Delta_Constraint);
aa180613
RD		 4512 end Expected_Type_Is_Any_Real;
4513
996ae0b0
RK		 4514 -----------------------------
4515 -- Is_Integer_Or_Universal --
4516 -----------------------------
4517
4518 function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
4519 T : Entity_Id;
4520 Index : Interp_Index;
4521 It : Interp;
4522
4523 begin
4524 if not Is_Overloaded (N) then
4525 T := Etype (N);
4526 return Base_Type (T) = Base_Type (Standard_Integer)
4527 or else T = Universal_Integer
4528 or else T = Universal_Real;
4529 else
4530 Get_First_Interp (N, Index, It);
996ae0b0 4531 while Present (It.Typ) loop
996ae0b0
RK		 4532 if Base_Type (It.Typ) = Base_Type (Standard_Integer)
4533 or else It.Typ = Universal_Integer
4534 or else It.Typ = Universal_Real
4535 then
4536 return True;
4537 end if;
4538
4539 Get_Next_Interp (Index, It);
4540 end loop;
4541 end if;
4542
4543 return False;
4544 end Is_Integer_Or_Universal;
4545
4546 ----------------------------
4547 -- Set_Mixed_Mode_Operand --
4548 ----------------------------
4549
4550 procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
4551 Index : Interp_Index;
4552 It : Interp;
4553
4554 begin
4555 if Universal_Interpretation (N) = Universal_Integer then
4556
4557 -- A universal integer literal is resolved as standard integer
758c442c
GD		 4558 -- except in the case of a fixed-point result, where we leave it
4559 -- as universal (to be handled by Exp_Fixd later on)
996ae0b0
RK		 4560
4561 if Is_Fixed_Point_Type (T) then
4562 Resolve (N, Universal_Integer);
4563 else
4564 Resolve (N, Standard_Integer);
4565 end if;
4566
4567 elsif Universal_Interpretation (N) = Universal_Real
4568 and then (T = Base_Type (Standard_Integer)
4569 or else T = Universal_Integer
4570 or else T = Universal_Real)
4571 then
4572 -- A universal real can appear in a fixed-type context. We resolve
4573 -- the literal with that context, even though this might raise an
4574 -- exception prematurely (the other operand may be zero).
4575
4576 Resolve (N, B_Typ);
4577
4578 elsif Etype (N) = Base_Type (Standard_Integer)
4579 and then T = Universal_Real
4580 and then Is_Overloaded (N)
4581 then
4582 -- Integer arg in mixed-mode operation. Resolve with universal
4583 -- type, in case preference rule must be applied.
4584
4585 Resolve (N, Universal_Integer);
4586
4587 elsif Etype (N) = T
4588 and then B_Typ /= Universal_Fixed
4589 then
a77842bd 4590 -- Not a mixed-mode operation, resolve with context
996ae0b0
RK		 4591
4592 Resolve (N, B_Typ);
4593
4594 elsif Etype (N) = Any_Fixed then
4595
a77842bd 4596 -- N may itself be a mixed-mode operation, so use context type
996ae0b0
RK		 4597
4598 Resolve (N, B_Typ);
4599
4600 elsif Is_Fixed_Point_Type (T)
4601 and then B_Typ = Universal_Fixed
4602 and then Is_Overloaded (N)
4603 then
4604 -- Must be (fixed * fixed) operation, operand must have one
4605 -- compatible interpretation.
4606
4607 Resolve (N, Any_Fixed);
4608
4609 elsif Is_Fixed_Point_Type (B_Typ)
4610 and then (T = Universal_Real
4611 or else Is_Fixed_Point_Type (T))
4612 and then Is_Overloaded (N)
4613 then
4614 -- C * F(X) in a fixed context, where C is a real literal or a
4615 -- fixed-point expression. F must have either a fixed type
4616 -- interpretation or an integer interpretation, but not both.
4617
4618 Get_First_Interp (N, Index, It);
996ae0b0 4619 while Present (It.Typ) loop
996ae0b0 4620 if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
996ae0b0
RK		 4621 if Analyzed (N) then
4622 Error_Msg_N ("ambiguous operand in fixed operation", N);
4623 else
4624 Resolve (N, Standard_Integer);
4625 end if;
4626
4627 elsif Is_Fixed_Point_Type (It.Typ) then
996ae0b0
RK		 4628 if Analyzed (N) then
4629 Error_Msg_N ("ambiguous operand in fixed operation", N);
4630 else
4631 Resolve (N, It.Typ);
4632 end if;
4633 end if;
4634
4635 Get_Next_Interp (Index, It);
4636 end loop;
4637
758c442c
GD		 4638 -- Reanalyze the literal with the fixed type of the context. If
4639 -- context is Universal_Fixed, we are within a conversion, leave
4640 -- the literal as a universal real because there is no usable
4641 -- fixed type, and the target of the conversion plays no role in
4642 -- the resolution.
996ae0b0 4643
0ab80019
AC		 4644 declare
4645 Op2 : Node_Id;
4646 T2 : Entity_Id;
4647
4648 begin
4649 if N = L then
4650 Op2 := R;
4651 else
4652 Op2 := L;
4653 end if;
4654
4655 if B_Typ = Universal_Fixed
4656 and then Nkind (Op2) = N_Real_Literal
4657 then
4658 T2 := Universal_Real;
4659 else
4660 T2 := B_Typ;
4661 end if;
4662
4663 Set_Analyzed (Op2, False);
4664 Resolve (Op2, T2);
4665 end;
996ae0b0
RK		 4666
4667 else
fbf5a39b 4668 Resolve (N);
996ae0b0
RK		 4669 end if;
4670 end Set_Mixed_Mode_Operand;
4671
4672 ----------------------
4673 -- Set_Operand_Type --
4674 ----------------------
4675
4676 procedure Set_Operand_Type (N : Node_Id) is
4677 begin
4678 if Etype (N) = Universal_Integer
4679 or else Etype (N) = Universal_Real
4680 then
4681 Set_Etype (N, T);
4682 end if;
4683 end Set_Operand_Type;
4684
996ae0b0
RK		 4685 -- Start of processing for Resolve_Arithmetic_Op
4686
4687 begin
4688 if Comes_From_Source (N)
4689 and then Ekind (Entity (N)) = E_Function
4690 and then Is_Imported (Entity (N))
fbf5a39b 4691 and then Is_Intrinsic_Subprogram (Entity (N))
996ae0b0
RK		 4692 then
4693 Resolve_Intrinsic_Operator (N, Typ);
4694 return;
4695
5cc9353d
RD		 4696 -- Special-case for mixed-mode universal expressions or fixed point type
4697 -- operation: each argument is resolved separately. The same treatment
4698 -- is required if one of the operands of a fixed point operation is
4699 -- universal real, since in this case we don't do a conversion to a
4700 -- specific fixed-point type (instead the expander handles the case).
996ae0b0 4701
45fc7ddb 4702 elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
996ae0b0
RK		 4703 and then Present (Universal_Interpretation (L))
4704 and then Present (Universal_Interpretation (R))
4705 then
4706 Resolve (L, Universal_Interpretation (L));
4707 Resolve (R, Universal_Interpretation (R));
4708 Set_Etype (N, B_Typ);
4709
4710 elsif (B_Typ = Universal_Real
45fc7ddb
HK		 4711 or else Etype (N) = Universal_Fixed
4712 or else (Etype (N) = Any_Fixed
4713 and then Is_Fixed_Point_Type (B_Typ))
4714 or else (Is_Fixed_Point_Type (B_Typ)
4715 and then (Is_Integer_Or_Universal (L)
4716 or else
4717 Is_Integer_Or_Universal (R))))
4718 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
996ae0b0
RK		 4719 then
4720 if TL = Universal_Integer or else TR = Universal_Integer then
4721 Check_For_Visible_Operator (N, B_Typ);
4722 end if;
4723
5cc9353d
RD		 4724 -- If context is a fixed type and one operand is integer, the other
4725 -- is resolved with the type of the context.
996ae0b0
RK		 4726
4727 if Is_Fixed_Point_Type (B_Typ)
4728 and then (Base_Type (TL) = Base_Type (Standard_Integer)
4729 or else TL = Universal_Integer)
4730 then
4731 Resolve (R, B_Typ);
4732 Resolve (L, TL);
4733
4734 elsif Is_Fixed_Point_Type (B_Typ)
4735 and then (Base_Type (TR) = Base_Type (Standard_Integer)
4736 or else TR = Universal_Integer)
4737 then
4738 Resolve (L, B_Typ);
4739 Resolve (R, TR);
4740
4741 else
4742 Set_Mixed_Mode_Operand (L, TR);
4743 Set_Mixed_Mode_Operand (R, TL);
4744 end if;
4745
45fc7ddb
HK		 4746 -- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
4747 -- multiplying operators from being used when the expected type is
4748 -- also universal_fixed. Note that B_Typ will be Universal_Fixed in
4749 -- some cases where the expected type is actually Any_Real;
4750 -- Expected_Type_Is_Any_Real takes care of that case.
aa180613 4751
996ae0b0
RK		 4752 if Etype (N) = Universal_Fixed
4753 or else Etype (N) = Any_Fixed
4754 then
4755 if B_Typ = Universal_Fixed
aa180613 4756 and then not Expected_Type_Is_Any_Real (N)
45fc7ddb
HK		 4757 and then not Nkind_In (Parent (N), N_Type_Conversion,
4758 N_Unchecked_Type_Conversion)
996ae0b0 4759 then
45fc7ddb
HK		 4760 Error_Msg_N ("type cannot be determined from context!", N);
4761 Error_Msg_N ("\explicit conversion to result type required", N);
996ae0b0
RK		 4762
4763 Set_Etype (L, Any_Type);
4764 Set_Etype (R, Any_Type);
4765
4766 else
0ab80019 4767 if Ada_Version = Ada_83
45fc7ddb
HK		 4768 and then Etype (N) = Universal_Fixed
4769 and then not
4770 Nkind_In (Parent (N), N_Type_Conversion,
4771 N_Unchecked_Type_Conversion)
996ae0b0
RK		 4772 then
4773 Error_Msg_N
45fc7ddb
HK		 4774 ("(Ada 83) fixed-point operation "
4775 & "needs explicit conversion", N);
996ae0b0
RK		 4776 end if;
4777
aa180613 4778 -- The expected type is "any real type" in contexts like
5cc9353d 4779
aa180613 4780 -- type T is delta <universal_fixed-expression> ...
5cc9353d 4781
aa180613
RD		 4782 -- in which case we need to set the type to Universal_Real
4783 -- so that static expression evaluation will work properly.
4784
4785 if Expected_Type_Is_Any_Real (N) then
4786 Set_Etype (N, Universal_Real);
4787 else
4788 Set_Etype (N, B_Typ);
4789 end if;
996ae0b0
RK		 4790 end if;
4791
4792 elsif Is_Fixed_Point_Type (B_Typ)
4793 and then (Is_Integer_Or_Universal (L)
4794 or else Nkind (L) = N_Real_Literal
4795 or else Nkind (R) = N_Real_Literal
45fc7ddb 4796 or else Is_Integer_Or_Universal (R))
996ae0b0
RK		 4797 then
4798 Set_Etype (N, B_Typ);
4799
4800 elsif Etype (N) = Any_Fixed then
4801
5cc9353d
RD		 4802 -- If no previous errors, this is only possible if one operand is
4803 -- overloaded and the context is universal. Resolve as such.
996ae0b0
RK		 4804
4805 Set_Etype (N, B_Typ);
4806 end if;
4807
4808 else
4809 if (TL = Universal_Integer or else TL = Universal_Real)
45fc7ddb
HK		 4810 and then
4811 (TR = Universal_Integer or else TR = Universal_Real)
996ae0b0
RK		 4812 then
4813 Check_For_Visible_Operator (N, B_Typ);
4814 end if;
4815
4816 -- If the context is Universal_Fixed and the operands are also
4817 -- universal fixed, this is an error, unless there is only one
841dd0f5 4818 -- applicable fixed_point type (usually Duration).
996ae0b0 4819
45fc7ddb 4820 if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
996ae0b0
RK		 4821 T := Unique_Fixed_Point_Type (N);
4822
4823 if T = Any_Type then
4824 Set_Etype (N, T);
4825 return;
4826 else
4827 Resolve (L, T);
4828 Resolve (R, T);
4829 end if;
4830
4831 else
4832 Resolve (L, B_Typ);
4833 Resolve (R, B_Typ);
4834 end if;
4835
4836 -- If one of the arguments was resolved to a non-universal type.
4837 -- label the result of the operation itself with the same type.
4838 -- Do the same for the universal argument, if any.
4839
4840 T := Intersect_Types (L, R);
4841 Set_Etype (N, Base_Type (T));
4842 Set_Operand_Type (L);
4843 Set_Operand_Type (R);
4844 end if;
4845
fbf5a39b 4846 Generate_Operator_Reference (N, Typ);
996ae0b0
RK		 4847 Eval_Arithmetic_Op (N);
4848
b0186f71
AC		 4849 -- In SPARK and ALFA, a multiplication or division with operands of
4850 -- fixed point types shall be qualified or explicitly converted to
4851 -- identify the result type.
4852
fe5d3068
YM		 4853 if (Is_Fixed_Point_Type (Etype (L))
4854 or else Is_Fixed_Point_Type (Etype (R)))
b0186f71
AC		 4855 and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
4856 and then
4857 not Nkind_In (Parent (N), N_Qualified_Expression, N_Type_Conversion)
4858 then
fe5d3068
YM		 4859 Check_Formal_Restriction
4860 ("operation should be qualified or explicitly converted", N);
b0186f71
AC		 4861 end if;
4862
996ae0b0
RK		 4863 -- Set overflow and division checking bit. Much cleverer code needed
4864 -- here eventually and perhaps the Resolve routines should be separated
4865 -- for the various arithmetic operations, since they will need
4866 -- different processing. ???
4867
4868 if Nkind (N) in N_Op then
4869 if not Overflow_Checks_Suppressed (Etype (N)) then
fbf5a39b 4870 Enable_Overflow_Check (N);
996ae0b0
RK		 4871 end if;
4872
fbf5a39b
AC		 4873 -- Give warning if explicit division by zero
4874
45fc7ddb 4875 if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
996ae0b0
RK		 4876 and then not Division_Checks_Suppressed (Etype (N))
4877 then
fbf5a39b
AC		 4878 Rop := Right_Opnd (N);
4879
4880 if Compile_Time_Known_Value (Rop)
4881 and then ((Is_Integer_Type (Etype (Rop))
780d052e
RD		 4882 and then Expr_Value (Rop) = Uint_0)
4883 or else
4884 (Is_Real_Type (Etype (Rop))
4885 and then Expr_Value_R (Rop) = Ureal_0))
fbf5a39b 4886 then
aa180613
RD		 4887 -- Specialize the warning message according to the operation
4888
4889 case Nkind (N) is
4890 when N_Op_Divide =>
4891 Apply_Compile_Time_Constraint_Error
4892 (N, "division by zero?", CE_Divide_By_Zero,
4893 Loc => Sloc (Right_Opnd (N)));
4894
4895 when N_Op_Rem =>
4896 Apply_Compile_Time_Constraint_Error
4897 (N, "rem with zero divisor?", CE_Divide_By_Zero,
4898 Loc => Sloc (Right_Opnd (N)));
4899
4900 when N_Op_Mod =>
4901 Apply_Compile_Time_Constraint_Error
4902 (N, "mod with zero divisor?", CE_Divide_By_Zero,
4903 Loc => Sloc (Right_Opnd (N)));
4904
4905 -- Division by zero can only happen with division, rem,
4906 -- and mod operations.
4907
4908 when others =>
4909 raise Program_Error;
4910 end case;
fbf5a39b
AC		 4911
4912 -- Otherwise just set the flag to check at run time
4913
4914 else
b7d1f17f 4915 Activate_Division_Check (N);
fbf5a39b 4916 end if;
996ae0b0 4917 end if;
45fc7ddb
HK		 4918
4919 -- If Restriction No_Implicit_Conditionals is active, then it is
4920 -- violated if either operand can be negative for mod, or for rem
4921 -- if both operands can be negative.
4922
7a963087 4923 if Restriction_Check_Required (No_Implicit_Conditionals)
45fc7ddb
HK		 4924 and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
4925 then
4926 declare
4927 Lo : Uint;
4928 Hi : Uint;
4929 OK : Boolean;
4930
4931 LNeg : Boolean;
4932 RNeg : Boolean;
4933 -- Set if corresponding operand might be negative
4934
4935 begin
5d5e9775
AC		 4936 Determine_Range
4937 (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
45fc7ddb
HK		 4938 LNeg := (not OK) or else Lo < 0;
4939
5d5e9775
AC		 4940 Determine_Range
4941 (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
45fc7ddb
HK		 4942 RNeg := (not OK) or else Lo < 0;
4943
5d5e9775
AC		 4944 -- Check if we will be generating conditionals. There are two
4945 -- cases where that can happen, first for REM, the only case
4946 -- is largest negative integer mod -1, where the division can
4947 -- overflow, but we still have to give the right result. The
4948 -- front end generates a test for this annoying case. Here we
4949 -- just test if both operands can be negative (that's what the
4950 -- expander does, so we match its logic here).
4951
4952 -- The second case is mod where either operand can be negative.
308e6f3a 4953 -- In this case, the back end has to generate additional tests.
5d5e9775 4954
45fc7ddb
HK		 4955 if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
4956 or else
4957 (Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
4958 then
4959 Check_Restriction (No_Implicit_Conditionals, N);
4960 end if;
4961 end;
4962 end if;
996ae0b0
RK		 4963 end if;
4964
4965 Check_Unset_Reference (L);
4966 Check_Unset_Reference (R);
996ae0b0
RK		 4967 end Resolve_Arithmetic_Op;
4968
4969 ------------------
4970 -- Resolve_Call --
4971 ------------------
4972
4973 procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
4974 Loc : constant Source_Ptr := Sloc (N);
4975 Subp : constant Node_Id := Name (N);
4976 Nam : Entity_Id;
4977 I : Interp_Index;
4978 It : Interp;
4979 Norm_OK : Boolean;
4980 Scop : Entity_Id;
aa180613 4981 Rtype : Entity_Id;
996ae0b0 4982
ee81cbe9
AC		 4983 function Same_Or_Aliased_Subprograms
4984 (S : Entity_Id;
4985 E : Entity_Id) return Boolean;
4986 -- Returns True if the subprogram entity S is the same as E or else
4987 -- S is an alias of E.
4988
001c7783
AC		 4989 ---------------------------------
4990 -- Same_Or_Aliased_Subprograms --
4991 ---------------------------------
4992
ee81cbe9
AC		 4993 function Same_Or_Aliased_Subprograms
4994 (S : Entity_Id;
4995 E : Entity_Id) return Boolean
4996 is
4997 Subp_Alias : constant Entity_Id := Alias (S);
ee81cbe9
AC		 4998 begin
4999 return S = E
5000 or else (Present (Subp_Alias) and then Subp_Alias = E);
5001 end Same_Or_Aliased_Subprograms;
5002
5003 -- Start of processing for Resolve_Call
5004
996ae0b0 5005 begin
758c442c
GD		 5006 -- The context imposes a unique interpretation with type Typ on a
5007 -- procedure or function call. Find the entity of the subprogram that
5008 -- yields the expected type, and propagate the corresponding formal
5009 -- constraints on the actuals. The caller has established that an
5010 -- interpretation exists, and emitted an error if not unique.
996ae0b0
RK		 5011
5012 -- First deal with the case of a call to an access-to-subprogram,
5013 -- dereference made explicit in Analyze_Call.
5014
5015 if Ekind (Etype (Subp)) = E_Subprogram_Type then
996ae0b0
RK		 5016 if not Is_Overloaded (Subp) then
5017 Nam := Etype (Subp);
5018
5019 else
758c442c
GD		 5020 -- Find the interpretation whose type (a subprogram type) has a
5021 -- return type that is compatible with the context. Analysis of
5022 -- the node has established that one exists.
996ae0b0 5023
996ae0b0
RK		 5024 Nam := Empty;
5025
1420b484 5026 Get_First_Interp (Subp, I, It);
996ae0b0 5027 while Present (It.Typ) loop
996ae0b0
RK		 5028 if Covers (Typ, Etype (It.Typ)) then
5029 Nam := It.Typ;
5030 exit;
5031 end if;
5032
5033 Get_Next_Interp (I, It);
5034 end loop;
5035
5036 if No (Nam) then
5037 raise Program_Error;
5038 end if;
5039 end if;
5040
5041 -- If the prefix is not an entity, then resolve it
5042
5043 if not Is_Entity_Name (Subp) then
5044 Resolve (Subp, Nam);
5045 end if;
5046
758c442c
GD		 5047 -- For an indirect call, we always invalidate checks, since we do not
5048 -- know whether the subprogram is local or global. Yes we could do
5049 -- better here, e.g. by knowing that there are no local subprograms,
aa180613 5050 -- but it does not seem worth the effort. Similarly, we kill all
758c442c 5051 -- knowledge of current constant values.
fbf5a39b
AC		 5052
5053 Kill_Current_Values;
5054
b7d1f17f
HK		 5055 -- If this is a procedure call which is really an entry call, do
5056 -- the conversion of the procedure call to an entry call. Protected
5057 -- operations use the same circuitry because the name in the call
5058 -- can be an arbitrary expression with special resolution rules.
996ae0b0 5059
45fc7ddb 5060 elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
996ae0b0
RK		 5061 or else (Is_Entity_Name (Subp)
5062 and then Ekind (Entity (Subp)) = E_Entry)
5063 then
5064 Resolve_Entry_Call (N, Typ);
5065 Check_Elab_Call (N);
fbf5a39b
AC		 5066
5067 -- Kill checks and constant values, as above for indirect case
5068 -- Who knows what happens when another task is activated?
5069
5070 Kill_Current_Values;
996ae0b0
RK		 5071 return;
5072
5073 -- Normal subprogram call with name established in Resolve
5074
5075 elsif not (Is_Type (Entity (Subp))) then
5076 Nam := Entity (Subp);
5077 Set_Entity_With_Style_Check (Subp, Nam);
996ae0b0
RK		 5078
5079 -- Otherwise we must have the case of an overloaded call
5080
5081 else
5082 pragma Assert (Is_Overloaded (Subp));
d81b4bfe
TQ		 5083
5084 -- Initialize Nam to prevent warning (we know it will be assigned
5085 -- in the loop below, but the compiler does not know that).
5086
5087 Nam := Empty;
996ae0b0
RK		 5088
5089 Get_First_Interp (Subp, I, It);
996ae0b0
RK		 5090 while Present (It.Typ) loop
5091 if Covers (Typ, It.Typ) then
5092 Nam := It.Nam;
5093 Set_Entity_With_Style_Check (Subp, Nam);
996ae0b0
RK		 5094 exit;
5095 end if;
5096
5097 Get_Next_Interp (I, It);
5098 end loop;
5099 end if;
5100
c9b99571
ES		 5101 if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
5102 and then not Is_Access_Subprogram_Type (Base_Type (Typ))
53cf4600
ES		 5103 and then Nkind (Subp) /= N_Explicit_Dereference
5104 and then Present (Parameter_Associations (N))
5105 then
66aa7643
TQ		 5106 -- The prefix is a parameterless function call that returns an access
5107 -- to subprogram. If parameters are present in the current call, add
5108 -- add an explicit dereference. We use the base type here because
5109 -- within an instance these may be subtypes.
53cf4600
ES		 5110
5111 -- The dereference is added either in Analyze_Call or here. Should
5112 -- be consolidated ???
5113
5114 Set_Is_Overloaded (Subp, False);
5115 Set_Etype (Subp, Etype (Nam));
5116 Insert_Explicit_Dereference (Subp);
5117 Nam := Designated_Type (Etype (Nam));
5118 Resolve (Subp, Nam);
5119 end if;
5120
996ae0b0
RK		 5121 -- Check that a call to Current_Task does not occur in an entry body
5122
5123 if Is_RTE (Nam, RE_Current_Task) then
5124 declare
5125 P : Node_Id;
5126
5127 begin
5128 P := N;
5129 loop
5130 P := Parent (P);
45fc7ddb
HK		 5131
5132 -- Exclude calls that occur within the default of a formal
5133 -- parameter of the entry, since those are evaluated outside
5134 -- of the body.
5135
5136 exit when No (P) or else Nkind (P) = N_Parameter_Specification;
996ae0b0 5137
aa180613
RD		 5138 if Nkind (P) = N_Entry_Body
5139 or else (Nkind (P) = N_Subprogram_Body
45fc7ddb 5140 and then Is_Entry_Barrier_Function (P))
aa180613
RD		 5141 then
5142 Rtype := Etype (N);
996ae0b0 5143 Error_Msg_NE
aa5147f0 5144 ("?& should not be used in entry body (RM C.7(17))",
996ae0b0 5145 N, Nam);
aa180613
RD		 5146 Error_Msg_NE
5147 ("\Program_Error will be raised at run time?", N, Nam);
5148 Rewrite (N,
5149 Make_Raise_Program_Error (Loc,
5150 Reason => PE_Current_Task_In_Entry_Body));
5151 Set_Etype (N, Rtype);
e65f50ec 5152 return;
996ae0b0
RK		 5153 end if;
5154 end loop;
5155 end;
5156 end if;
5157
758c442c
GD		 5158 -- Check that a procedure call does not occur in the context of the
5159 -- entry call statement of a conditional or timed entry call. Note that
5160 -- the case of a call to a subprogram renaming of an entry will also be
5161 -- rejected. The test for N not being an N_Entry_Call_Statement is
5162 -- defensive, covering the possibility that the processing of entry
5163 -- calls might reach this point due to later modifications of the code
5164 -- above.
996ae0b0
RK		 5165
5166 if Nkind (Parent (N)) = N_Entry_Call_Alternative
5167 and then Nkind (N) /= N_Entry_Call_Statement
5168 and then Entry_Call_Statement (Parent (N)) = N
5169 then
0791fbe9 5170 if Ada_Version < Ada_2005 then
1420b484
JM		 5171 Error_Msg_N ("entry call required in select statement", N);
5172
5173 -- Ada 2005 (AI-345): If a procedure_call_statement is used
66aa7643
TQ		 5174 -- for a procedure_or_entry_call, the procedure_name or
5175 -- procedure_prefix of the procedure_call_statement shall denote
1420b484
JM		 5176 -- an entry renamed by a procedure, or (a view of) a primitive
5177 -- subprogram of a limited interface whose first parameter is
5178 -- a controlling parameter.
5179
5180 elsif Nkind (N) = N_Procedure_Call_Statement
5181 and then not Is_Renamed_Entry (Nam)
5182 and then not Is_Controlling_Limited_Procedure (Nam)
5183 then
5184 Error_Msg_N
c8ef728f 5185 ("entry call or dispatching primitive of interface required", N);
1420b484 5186 end if;
996ae0b0
RK		 5187 end if;
5188
66aa7643
TQ		 5189 -- Check that this is not a call to a protected procedure or entry from
5190 -- within a protected function.
fbf5a39b
AC		 5191
5192 if Ekind (Current_Scope) = E_Function
5193 and then Ekind (Scope (Current_Scope)) = E_Protected_Type
5194 and then Ekind (Nam) /= E_Function
5195 and then Scope (Nam) = Scope (Current_Scope)
5196 then
5197 Error_Msg_N ("within protected function, protected " &
5198 "object is constant", N);
5199 Error_Msg_N ("\cannot call operation that may modify it", N);
5200 end if;
5201
45fc7ddb 5202 -- Freeze the subprogram name if not in a spec-expression. Note that we
758c442c
GD		 5203 -- freeze procedure calls as well as function calls. Procedure calls are
5204 -- not frozen according to the rules (RM 13.14(14)) because it is
5205 -- impossible to have a procedure call to a non-frozen procedure in pure
5206 -- Ada, but in the code that we generate in the expander, this rule
5207 -- needs extending because we can generate procedure calls that need
5208 -- freezing.
996ae0b0 5209
45fc7ddb 5210 if Is_Entity_Name (Subp) and then not In_Spec_Expression then
996ae0b0
RK		 5211 Freeze_Expression (Subp);
5212 end if;
5213
758c442c
GD		 5214 -- For a predefined operator, the type of the result is the type imposed
5215 -- by context, except for a predefined operation on universal fixed.
5216 -- Otherwise The type of the call is the type returned by the subprogram
5217 -- being called.
996ae0b0
RK		 5218
5219 if Is_Predefined_Op (Nam) then
996ae0b0
RK		 5220 if Etype (N) /= Universal_Fixed then
5221 Set_Etype (N, Typ);
5222 end if;
5223
758c442c
GD		 5224 -- If the subprogram returns an array type, and the context requires the
5225 -- component type of that array type, the node is really an indexing of
5226 -- the parameterless call. Resolve as such. A pathological case occurs
5227 -- when the type of the component is an access to the array type. In
5228 -- this case the call is truly ambiguous.
996ae0b0 5229
0669bebe 5230 elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
996ae0b0
RK		 5231 and then
5232 ((Is_Array_Type (Etype (Nam))
19fb051c 5233 and then Covers (Typ, Component_Type (Etype (Nam))))
996ae0b0 5234 or else (Is_Access_Type (Etype (Nam))
19fb051c
AC		 5235 and then Is_Array_Type (Designated_Type (Etype (Nam)))
5236 and then
5237 Covers
5238 (Typ,
5239 Component_Type (Designated_Type (Etype (Nam))))))
996ae0b0
RK		 5240 then
5241 declare
5242 Index_Node : Node_Id;
fbf5a39b
AC		 5243 New_Subp : Node_Id;
5244 Ret_Type : constant Entity_Id := Etype (Nam);
996ae0b0
RK		 5245
5246 begin
fbf5a39b
AC		 5247 if Is_Access_Type (Ret_Type)
5248 and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
5249 then
5250 Error_Msg_N
5251 ("cannot disambiguate function call and indexing", N);
5252 else
5253 New_Subp := Relocate_Node (Subp);
5254 Set_Entity (Subp, Nam);
5255
7205254b 5256 if (Is_Array_Type (Ret_Type)
5d5e9775 5257 and then Component_Type (Ret_Type) /= Any_Type)
7205254b
JM		 5258 or else
5259 (Is_Access_Type (Ret_Type)
5d5e9775
AC		 5260 and then
5261 Component_Type (Designated_Type (Ret_Type)) /= Any_Type)
7205254b 5262 then
0669bebe
GB		 5263 if Needs_No_Actuals (Nam) then
5264
5265 -- Indexed call to a parameterless function
5266
5267 Index_Node :=
5268 Make_Indexed_Component (Loc,
5269 Prefix =>
5270 Make_Function_Call (Loc,
5271 Name => New_Subp),
5272 Expressions => Parameter_Associations (N));
5273 else
5274 -- An Ada 2005 prefixed call to a primitive operation
5275 -- whose first parameter is the prefix. This prefix was
5276 -- prepended to the parameter list, which is actually a
3b42c566 5277 -- list of indexes. Remove the prefix in order to build
0669bebe
GB		 5278 -- the proper indexed component.
5279
5280 Index_Node :=
5281 Make_Indexed_Component (Loc,
5282 Prefix =>
5283 Make_Function_Call (Loc,
5284 Name => New_Subp,
5285 Parameter_Associations =>
5286 New_List
5287 (Remove_Head (Parameter_Associations (N)))),
5288 Expressions => Parameter_Associations (N));
5289 end if;
fbf5a39b 5290
74e7891f
RD		 5291 -- Preserve the parenthesis count of the node
5292
5293 Set_Paren_Count (Index_Node, Paren_Count (N));
5294
fbf5a39b
AC		 5295 -- Since we are correcting a node classification error made
5296 -- by the parser, we call Replace rather than Rewrite.
5297
5298 Replace (N, Index_Node);
74e7891f 5299
fbf5a39b
AC		 5300 Set_Etype (Prefix (N), Ret_Type);
5301 Set_Etype (N, Typ);
5302 Resolve_Indexed_Component (N, Typ);
5303 Check_Elab_Call (Prefix (N));
5304 end if;
996ae0b0
RK		 5305 end if;
5306
5307 return;
5308 end;
5309
5310 else
5311 Set_Etype (N, Etype (Nam));
5312 end if;
5313
5314 -- In the case where the call is to an overloaded subprogram, Analyze
5315 -- calls Normalize_Actuals once per overloaded subprogram. Therefore in
5316 -- such a case Normalize_Actuals needs to be called once more to order
5317 -- the actuals correctly. Otherwise the call will have the ordering
5318 -- given by the last overloaded subprogram whether this is the correct
5319 -- one being called or not.
5320
5321 if Is_Overloaded (Subp) then
5322 Normalize_Actuals (N, Nam, False, Norm_OK);
5323 pragma Assert (Norm_OK);
5324 end if;
5325
5326 -- In any case, call is fully resolved now. Reset Overload flag, to
5327 -- prevent subsequent overload resolution if node is analyzed again
5328
5329 Set_Is_Overloaded (Subp, False);
5330 Set_Is_Overloaded (N, False);
5331
758c442c
GD		 5332 -- If we are calling the current subprogram from immediately within its
5333 -- body, then that is the case where we can sometimes detect cases of
5334 -- infinite recursion statically. Do not try this in case restriction
b7d1f17f 5335 -- No_Recursion is in effect anyway, and do it only for source calls.
996ae0b0 5336
b7d1f17f
HK		 5337 if Comes_From_Source (N) then
5338 Scop := Current_Scope;
996ae0b0 5339
26570b21
RD		 5340 -- Issue warning for possible infinite recursion in the absence
5341 -- of the No_Recursion restriction.
5342
ee81cbe9 5343 if Same_Or_Aliased_Subprograms (Nam, Scop)
b7d1f17f
HK		 5344 and then not Restriction_Active (No_Recursion)
5345 and then Check_Infinite_Recursion (N)
5346 then
5347 -- Here we detected and flagged an infinite recursion, so we do
da20aa43
RD		 5348 -- not need to test the case below for further warnings. Also we
5349 -- are all done if we now have a raise SE node.
996ae0b0 5350
26570b21
RD		 5351 if Nkind (N) = N_Raise_Storage_Error then
5352 return;
5353 end if;
996ae0b0 5354
26570b21
RD		 5355 -- If call is to immediately containing subprogram, then check for
5356 -- the case of a possible run-time detectable infinite recursion.
996ae0b0 5357
b7d1f17f
HK		 5358 else
5359 Scope_Loop : while Scop /= Standard_Standard loop
ee81cbe9 5360 if Same_Or_Aliased_Subprograms (Nam, Scop) then
b7d1f17f
HK		 5361
5362 -- Although in general case, recursion is not statically
5363 -- checkable, the case of calling an immediately containing
5364 -- subprogram is easy to catch.
5365
5366 Check_Restriction (No_Recursion, N);
5367
5368 -- If the recursive call is to a parameterless subprogram,
5369 -- then even if we can't statically detect infinite
5370 -- recursion, this is pretty suspicious, and we output a
5371 -- warning. Furthermore, we will try later to detect some
5372 -- cases here at run time by expanding checking code (see
5373 -- Detect_Infinite_Recursion in package Exp_Ch6).
5374
5375 -- If the recursive call is within a handler, do not emit a
5376 -- warning, because this is a common idiom: loop until input
5377 -- is correct, catch illegal input in handler and restart.
5378
5379 if No (First_Formal (Nam))
5380 and then Etype (Nam) = Standard_Void_Type
5381 and then not Error_Posted (N)
5382 and then Nkind (Parent (N)) /= N_Exception_Handler
aa180613 5383 then
b7d1f17f
HK		 5384 -- For the case of a procedure call. We give the message
5385 -- only if the call is the first statement in a sequence
5386 -- of statements, or if all previous statements are
5387 -- simple assignments. This is simply a heuristic to
5388 -- decrease false positives, without losing too many good
5389 -- warnings. The idea is that these previous statements
5390 -- may affect global variables the procedure depends on.
5391
5392 if Nkind (N) = N_Procedure_Call_Statement
5393 and then Is_List_Member (N)
5394 then
5395 declare
5396 P : Node_Id;
5397 begin
5398 P := Prev (N);
5399 while Present (P) loop
5400 if Nkind (P) /= N_Assignment_Statement then
5401 exit Scope_Loop;
5402 end if;
5403
5404 Prev (P);
5405 end loop;
5406 end;
5407 end if;
5408
5409 -- Do not give warning if we are in a conditional context
5410
aa180613 5411 declare
b7d1f17f 5412 K : constant Node_Kind := Nkind (Parent (N));
aa180613 5413 begin
b7d1f17f 5414 if (K = N_Loop_Statement
b5c739f9 5415 and then Present (Iteration_Scheme (Parent (N))))
b7d1f17f
HK		 5416 or else K = N_If_Statement
5417 or else K = N_Elsif_Part
5418 or else K = N_Case_Statement_Alternative
5419 then
5420 exit Scope_Loop;
5421 end if;
aa180613 5422 end;
aa180613 5423
b7d1f17f 5424 -- Here warning is to be issued
aa180613 5425
b7d1f17f
HK		 5426 Set_Has_Recursive_Call (Nam);
5427 Error_Msg_N
aa5147f0 5428 ("?possible infinite recursion!", N);
b7d1f17f 5429 Error_Msg_N
aa5147f0 5430 ("\?Storage_Error may be raised at run time!", N);
b7d1f17f 5431 end if;
aa180613 5432
b7d1f17f 5433 exit Scope_Loop;
996ae0b0
RK		 5434 end if;
5435
b7d1f17f
HK		 5436 Scop := Scope (Scop);
5437 end loop Scope_Loop;
5438 end if;
996ae0b0
RK		 5439 end if;
5440
b5c739f9
RD		 5441 -- Check obsolescent reference to Ada.Characters.Handling subprogram
5442
5443 Check_Obsolescent_2005_Entity (Nam, Subp);
5444
996ae0b0
RK		 5445 -- If subprogram name is a predefined operator, it was given in
5446 -- functional notation. Replace call node with operator node, so
5447 -- that actuals can be resolved appropriately.
5448
5449 if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
5450 Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
5451 return;
5452
5453 elsif Present (Alias (Nam))
5454 and then Is_Predefined_Op (Alias (Nam))
5455 then
5456 Resolve_Actuals (N, Nam);
5457 Make_Call_Into_Operator (N, Typ, Alias (Nam));
5458 return;
5459 end if;
5460
fbf5a39b
AC		 5461 -- Create a transient scope if the resulting type requires it
5462
4017021b
AC		 5463 -- There are several notable exceptions:
5464
4d2907fd 5465 -- a) In init procs, the transient scope overhead is not needed, and is
4017021b
AC		 5466 -- even incorrect when the call is a nested initialization call for a
5467 -- component whose expansion may generate adjust calls. However, if the
5468 -- call is some other procedure call within an initialization procedure
5469 -- (for example a call to Create_Task in the init_proc of the task
5470 -- run-time record) a transient scope must be created around this call.
5471
4d2907fd 5472 -- b) Enumeration literal pseudo-calls need no transient scope
4017021b 5473
4d2907fd 5474 -- c) Intrinsic subprograms (Unchecked_Conversion and source info
4017021b 5475 -- functions) do not use the secondary stack even though the return
4d2907fd 5476 -- type may be unconstrained.
4017021b 5477
4d2907fd 5478 -- d) Calls to a build-in-place function, since such functions may
4017021b
AC		 5479 -- allocate their result directly in a target object, and cases where
5480 -- the result does get allocated in the secondary stack are checked for
5481 -- within the specialized Exp_Ch6 procedures for expanding those
5482 -- build-in-place calls.
5483
5484 -- e) If the subprogram is marked Inline_Always, then even if it returns
c8ef728f 5485 -- an unconstrained type the call does not require use of the secondary
45fc7ddb
HK		 5486 -- stack. However, inlining will only take place if the body to inline
5487 -- is already present. It may not be available if e.g. the subprogram is
5488 -- declared in a child instance.
c8ef728f 5489
4017021b
AC		 5490 -- If this is an initialization call for a type whose construction
5491 -- uses the secondary stack, and it is not a nested call to initialize
5492 -- a component, we do need to create a transient scope for it. We
5493 -- check for this by traversing the type in Check_Initialization_Call.
5494
c8ef728f 5495 if Is_Inlined (Nam)
45fc7ddb
HK		 5496 and then Has_Pragma_Inline_Always (Nam)
5497 and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
5498 and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
c8ef728f
ES		 5499 then
5500 null;
5501
4017021b
AC		 5502 elsif Ekind (Nam) = E_Enumeration_Literal
5503 or else Is_Build_In_Place_Function (Nam)
5504 or else Is_Intrinsic_Subprogram (Nam)
5505 then
5506 null;
5507
c8ef728f 5508 elsif Expander_Active
996ae0b0
RK		 5509 and then Is_Type (Etype (Nam))
5510 and then Requires_Transient_Scope (Etype (Nam))
4017021b
AC		 5511 and then
5512 (not Within_Init_Proc
5513 or else
5514 (not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
996ae0b0 5515 then
0669bebe 5516 Establish_Transient_Scope (N, Sec_Stack => True);
996ae0b0 5517
a9f4e3d2
AC		 5518 -- If the call appears within the bounds of a loop, it will
5519 -- be rewritten and reanalyzed, nothing left to do here.
5520
5521 if Nkind (N) /= N_Function_Call then
5522 return;
5523 end if;
5524
fbf5a39b 5525 elsif Is_Init_Proc (Nam)
996ae0b0
RK		 5526 and then not Within_Init_Proc
5527 then
5528 Check_Initialization_Call (N, Nam);
5529 end if;
5530
5531 -- A protected function cannot be called within the definition of the
5532 -- enclosing protected type.
5533
5534 if Is_Protected_Type (Scope (Nam))
5535 and then In_Open_Scopes (Scope (Nam))
5536 and then not Has_Completion (Scope (Nam))
5537 then
5538 Error_Msg_NE
5539 ("& cannot be called before end of protected definition", N, Nam);
5540 end if;
5541
5542 -- Propagate interpretation to actuals, and add default expressions
5543 -- where needed.
5544
5545 if Present (First_Formal (Nam)) then
5546 Resolve_Actuals (N, Nam);
5547
d81b4bfe
TQ		 5548 -- Overloaded literals are rewritten as function calls, for purpose of
5549 -- resolution. After resolution, we can replace the call with the
5550 -- literal itself.
996ae0b0
RK		 5551
5552 elsif Ekind (Nam) = E_Enumeration_Literal then
5553 Copy_Node (Subp, N);
5554 Resolve_Entity_Name (N, Typ);
5555
fbf5a39b 5556 -- Avoid validation, since it is a static function call
996ae0b0 5557
e65f50ec 5558 Generate_Reference (Nam, Subp);
996ae0b0
RK		 5559 return;
5560 end if;
5561
b7d1f17f
HK		 5562 -- If the subprogram is not global, then kill all saved values and
5563 -- checks. This is a bit conservative, since in many cases we could do
5564 -- better, but it is not worth the effort. Similarly, we kill constant
5565 -- values. However we do not need to do this for internal entities
5566 -- (unless they are inherited user-defined subprograms), since they
5567 -- are not in the business of molesting local values.
5568
5569 -- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
5570 -- kill all checks and values for calls to global subprograms. This
5571 -- takes care of the case where an access to a local subprogram is
5572 -- taken, and could be passed directly or indirectly and then called
5573 -- from almost any context.
aa180613
RD		 5574
5575 -- Note: we do not do this step till after resolving the actuals. That
5576 -- way we still take advantage of the current value information while
5577 -- scanning the actuals.
5578
45fc7ddb
HK		 5579 -- We suppress killing values if we are processing the nodes associated
5580 -- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
5581 -- type kills all the values as part of analyzing the code that
5582 -- initializes the dispatch tables.
5583
5584 if Inside_Freezing_Actions = 0
5585 and then (not Is_Library_Level_Entity (Nam)
24357840
RD		 5586 or else Suppress_Value_Tracking_On_Call
5587 (Nearest_Dynamic_Scope (Current_Scope)))
aa180613
RD		 5588 and then (Comes_From_Source (Nam)
5589 or else (Present (Alias (Nam))
5590 and then Comes_From_Source (Alias (Nam))))
5591 then
5592 Kill_Current_Values;
5593 end if;
5594
36fcf362
RD		 5595 -- If we are warning about unread OUT parameters, this is the place to
5596 -- set Last_Assignment for OUT and IN OUT parameters. We have to do this
5597 -- after the above call to Kill_Current_Values (since that call clears
5598 -- the Last_Assignment field of all local variables).
67ce0d7e 5599
36fcf362 5600 if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
67ce0d7e
RD		 5601 and then Comes_From_Source (N)
5602 and then In_Extended_Main_Source_Unit (N)
5603 then
5604 declare
5605 F : Entity_Id;
5606 A : Node_Id;
5607
5608 begin
5609 F := First_Formal (Nam);
5610 A := First_Actual (N);
5611 while Present (F) and then Present (A) loop
964f13da 5612 if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
36fcf362 5613 and then Warn_On_Modified_As_Out_Parameter (F)
67ce0d7e
RD		 5614 and then Is_Entity_Name (A)
5615 and then Present (Entity (A))
36fcf362 5616 and then Comes_From_Source (N)
67ce0d7e
RD		 5617 and then Safe_To_Capture_Value (N, Entity (A))
5618 then
5619 Set_Last_Assignment (Entity (A), A);
5620 end if;
5621
5622 Next_Formal (F);
5623 Next_Actual (A);
5624 end loop;
5625 end;
5626 end if;
5627
996ae0b0
RK		 5628 -- If the subprogram is a primitive operation, check whether or not
5629 -- it is a correct dispatching call.
5630
5631 if Is_Overloadable (Nam)
5632 and then Is_Dispatching_Operation (Nam)
5633 then
5634 Check_Dispatching_Call (N);
5635
0669bebe
GB		 5636 elsif Ekind (Nam) /= E_Subprogram_Type
5637 and then Is_Abstract_Subprogram (Nam)
996ae0b0
RK		 5638 and then not In_Instance
5639 then
5640 Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
5641 end if;
5642
e65f50ec
ES		 5643 -- If this is a dispatching call, generate the appropriate reference,
5644 -- for better source navigation in GPS.
5645
5646 if Is_Overloadable (Nam)
5647 and then Present (Controlling_Argument (N))
5648 then
5649 Generate_Reference (Nam, Subp, 'R');
c5d91669 5650
5cc9353d 5651 -- Normal case, not a dispatching call: generate a call reference
c5d91669 5652
e65f50ec 5653 else
9c870c90 5654 Generate_Reference (Nam, Subp, 's');
e65f50ec
ES		 5655 end if;
5656
996ae0b0
RK		 5657 if Is_Intrinsic_Subprogram (Nam) then
5658 Check_Intrinsic_Call (N);
5659 end if;
5660
5b2217f8 5661 -- Check for violation of restriction No_Specific_Termination_Handlers
dce86910 5662 -- and warn on a potentially blocking call to Abort_Task.
5b2217f8
RD		 5663
5664 if Is_RTE (Nam, RE_Set_Specific_Handler)
5665 or else
5666 Is_RTE (Nam, RE_Specific_Handler)
5667 then
5668 Check_Restriction (No_Specific_Termination_Handlers, N);
dce86910
AC		 5669
5670 elsif Is_RTE (Nam, RE_Abort_Task) then
5671 Check_Potentially_Blocking_Operation (N);
5b2217f8
RD		 5672 end if;
5673
806f6d37
AC		 5674 -- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
5675 -- timing event violates restriction No_Relative_Delay (AI-0211). We
5676 -- need to check the second argument to determine whether it is an
5677 -- absolute or relative timing event.
afbcdf5e 5678
806f6d37
AC		 5679 if Is_RTE (Nam, RE_Set_Handler)
5680 and then Is_RTE (Etype (Next_Actual (First_Actual (N))), RE_Time_Span)
5681 then
afbcdf5e
AC		 5682 Check_Restriction (No_Relative_Delay, N);
5683 end if;
5684
9cbfc269
AC		 5685 -- Issue an error for a call to an eliminated subprogram. We skip this
5686 -- in a spec expression, e.g. a call in a default parameter value, since
5687 -- we are not really doing a call at this time. That's important because
5688 -- the spec expression may itself belong to an eliminated subprogram.
16212e89 5689
9cbfc269
AC		 5690 if not In_Spec_Expression then
5691 Check_For_Eliminated_Subprogram (Subp, Nam);
5692 end if;
16212e89 5693
67ce0d7e
RD		 5694 -- All done, evaluate call and deal with elaboration issues
5695
c01a9391 5696 Eval_Call (N);
996ae0b0 5697 Check_Elab_Call (N);
76b84bf0 5698 Warn_On_Overlapping_Actuals (Nam, N);
996ae0b0
RK		 5699 end Resolve_Call;
5700
19d846a0
RD		 5701 -----------------------------
5702 -- Resolve_Case_Expression --
5703 -----------------------------
5704
5705 procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id) is
5706 Alt : Node_Id;
5707
5708 begin
5709 Alt := First (Alternatives (N));
5710 while Present (Alt) loop
5711 Resolve (Expression (Alt), Typ);
5712 Next (Alt);
5713 end loop;
5714
5715 Set_Etype (N, Typ);
5716 Eval_Case_Expression (N);
5717 end Resolve_Case_Expression;
5718
996ae0b0
RK		 5719 -------------------------------
5720 -- Resolve_Character_Literal --
5721 -------------------------------
5722
5723 procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
5724 B_Typ : constant Entity_Id := Base_Type (Typ);
5725 C : Entity_Id;
5726
5727 begin
5728 -- Verify that the character does belong to the type of the context
5729
5730 Set_Etype (N, B_Typ);
5731 Eval_Character_Literal (N);
5732
82c80734
RD		 5733 -- Wide_Wide_Character literals must always be defined, since the set
5734 -- of wide wide character literals is complete, i.e. if a character
5735 -- literal is accepted by the parser, then it is OK for wide wide
5736 -- character (out of range character literals are rejected).
996ae0b0 5737
82c80734 5738 if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
996ae0b0
RK		 5739 return;
5740
5741 -- Always accept character literal for type Any_Character, which
5742 -- occurs in error situations and in comparisons of literals, both
5743 -- of which should accept all literals.
5744
5745 elsif B_Typ = Any_Character then
5746 return;
5747
5cc9353d
RD		 5748 -- For Standard.Character or a type derived from it, check that the
5749 -- literal is in range.
996ae0b0
RK		 5750
5751 elsif Root_Type (B_Typ) = Standard_Character then
82c80734
RD		 5752 if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
5753 return;
5754 end if;
5755
5cc9353d
RD		 5756 -- For Standard.Wide_Character or a type derived from it, check that the
5757 -- literal is in range.
82c80734
RD		 5758
5759 elsif Root_Type (B_Typ) = Standard_Wide_Character then
5760 if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
996ae0b0
RK		 5761 return;
5762 end if;
5763
82c80734
RD		 5764 -- For Standard.Wide_Wide_Character or a type derived from it, we
5765 -- know the literal is in range, since the parser checked!
5766
5767 elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
5768 return;
5769
d81b4bfe
TQ		 5770 -- If the entity is already set, this has already been resolved in a
5771 -- generic context, or comes from expansion. Nothing else to do.
996ae0b0
RK		 5772
5773 elsif Present (Entity (N)) then
5774 return;
5775
d81b4bfe
TQ		 5776 -- Otherwise we have a user defined character type, and we can use the
5777 -- standard visibility mechanisms to locate the referenced entity.
996ae0b0
RK		 5778
5779 else
5780 C := Current_Entity (N);
996ae0b0
RK		 5781 while Present (C) loop
5782 if Etype (C) = B_Typ then
5783 Set_Entity_With_Style_Check (N, C);
5784 Generate_Reference (C, N);
5785 return;
5786 end if;
5787
5788 C := Homonym (C);
5789 end loop;
5790 end if;
5791
5792 -- If we fall through, then the literal does not match any of the
5cc9353d
RD		 5793 -- entries of the enumeration type. This isn't just a constraint error
5794 -- situation, it is an illegality (see RM 4.2).
996ae0b0
RK		 5795
5796 Error_Msg_NE
5797 ("character not defined for }", N, First_Subtype (B_Typ));
996ae0b0
RK		 5798 end Resolve_Character_Literal;
5799
5800 ---------------------------
5801 -- Resolve_Comparison_Op --
5802 ---------------------------
5803
5804 -- Context requires a boolean type, and plays no role in resolution.
5cc9353d
RD		 5805 -- Processing identical to that for equality operators. The result type is
5806 -- the base type, which matters when pathological subtypes of booleans with
5807 -- limited ranges are used.
996ae0b0
RK		 5808
5809 procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
5810 L : constant Node_Id := Left_Opnd (N);
5811 R : constant Node_Id := Right_Opnd (N);
5812 T : Entity_Id;
5813
5814 begin
d81b4bfe
TQ		 5815 -- If this is an intrinsic operation which is not predefined, use the
5816 -- types of its declared arguments to resolve the possibly overloaded
5817 -- operands. Otherwise the operands are unambiguous and specify the
5818 -- expected type.
996ae0b0
RK		 5819
5820 if Scope (Entity (N)) /= Standard_Standard then
5821 T := Etype (First_Entity (Entity (N)));
1420b484 5822
996ae0b0
RK		 5823 else
5824 T := Find_Unique_Type (L, R);
5825
5826 if T = Any_Fixed then
5827 T := Unique_Fixed_Point_Type (L);
5828 end if;
5829 end if;
5830
fbf5a39b 5831 Set_Etype (N, Base_Type (Typ));
996ae0b0
RK		 5832 Generate_Reference (T, N, ' ');
5833
bd29d519 5834 -- Skip remaining processing if already set to Any_Type
996ae0b0 5835
bd29d519
AC		 5836 if T = Any_Type then
5837 return;
5838 end if;
5839
5840 -- Deal with other error cases
996ae0b0 5841
bd29d519
AC		 5842 if T = Any_String or else
5843 T = Any_Composite or else
5844 T = Any_Character
5845 then
5846 if T = Any_Character then
5847 Ambiguous_Character (L);
996ae0b0 5848 else
bd29d519 5849 Error_Msg_N ("ambiguous operands for comparison", N);
996ae0b0 5850 end if;
bd29d519
AC		 5851
5852 Set_Etype (N, Any_Type);
5853 return;
996ae0b0 5854 end if;
bd29d519
AC		 5855
5856 -- Resolve the operands if types OK
5857
5858 Resolve (L, T);
5859 Resolve (R, T);
5860 Check_Unset_Reference (L);
5861 Check_Unset_Reference (R);
5862 Generate_Operator_Reference (N, T);
5863 Check_Low_Bound_Tested (N);
5864
b0186f71
AC		 5865 -- In SPARK or ALFA, ordering operators <, <=, >, >= are not defined
5866 -- for Boolean types or array types except String.
5867
fe5d3068
YM		 5868 if Is_Boolean_Type (T) then
5869 Check_Formal_Restriction
5870 ("comparison is not defined on Boolean type", N);
5871 elsif Is_Array_Type (T)
5872 and then Base_Type (T) /= Standard_String
b0186f71 5873 then
fe5d3068
YM		 5874 Check_Formal_Restriction
5875 ("comparison is not defined on array types other than String", N);
5876 else
5877 null;
b0186f71
AC		 5878 end if;
5879
bd29d519
AC		 5880 -- Check comparison on unordered enumeration
5881
5882 if Comes_From_Source (N)
5883 and then Bad_Unordered_Enumeration_Reference (N, Etype (L))
5884 then
5885 Error_Msg_N ("comparison on unordered enumeration type?", N);
5886 end if;
5887
5cc9353d
RD		 5888 -- Evaluate the relation (note we do this after the above check since
5889 -- this Eval call may change N to True/False.
bd29d519
AC		 5890
5891 Eval_Relational_Op (N);
996ae0b0
RK		 5892 end Resolve_Comparison_Op;
5893
5894 ------------------------------------
5895 -- Resolve_Conditional_Expression --
5896 ------------------------------------
5897
5898 procedure Resolve_Conditional_Expression (N : Node_Id; Typ : Entity_Id) is
5899 Condition : constant Node_Id := First (Expressions (N));
5900 Then_Expr : constant Node_Id := Next (Condition);
19fb051c 5901 Else_Expr : Node_Id := Next (Then_Expr);
b46be8a2 5902
996ae0b0 5903 begin
b46be8a2 5904 Resolve (Condition, Any_Boolean);
996ae0b0 5905 Resolve (Then_Expr, Typ);
b46be8a2
RD		 5906
5907 -- If ELSE expression present, just resolve using the determined type
5908
5909 if Present (Else_Expr) then
5910 Resolve (Else_Expr, Typ);
5911
5912 -- If no ELSE expression is present, root type must be Standard.Boolean
5913 -- and we provide a Standard.True result converted to the appropriate
5914 -- Boolean type (in case it is a derived boolean type).
5915
5916 elsif Root_Type (Typ) = Standard_Boolean then
5917 Else_Expr :=
5918 Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
5919 Analyze_And_Resolve (Else_Expr, Typ);
5920 Append_To (Expressions (N), Else_Expr);
5921
5922 else
5923 Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
5924 Append_To (Expressions (N), Error);
5925 end if;
5926
996ae0b0
RK		 5927 Set_Etype (N, Typ);
5928 Eval_Conditional_Expression (N);
5929 end Resolve_Conditional_Expression;
5930
5931 -----------------------------------------
5932 -- Resolve_Discrete_Subtype_Indication --
5933 -----------------------------------------
5934
5935 procedure Resolve_Discrete_Subtype_Indication
5936 (N : Node_Id;
5937 Typ : Entity_Id)
5938 is
5939 R : Node_Id;
5940 S : Entity_Id;
5941
5942 begin
5943 Analyze (Subtype_Mark (N));
5944 S := Entity (Subtype_Mark (N));
5945
5946 if Nkind (Constraint (N)) /= N_Range_Constraint then
5947 Error_Msg_N ("expect range constraint for discrete type", N);
5948 Set_Etype (N, Any_Type);
5949
5950 else
5951 R := Range_Expression (Constraint (N));
5c736541
RD		 5952
5953 if R = Error then
5954 return;
5955 end if;
5956
996ae0b0
RK		 5957 Analyze (R);
5958
5959 if Base_Type (S) /= Base_Type (Typ) then
5960 Error_Msg_NE
5961 ("expect subtype of }", N, First_Subtype (Typ));
5962
5963 -- Rewrite the constraint as a range of Typ
5964 -- to allow compilation to proceed further.
5965
5966 Set_Etype (N, Typ);
5967 Rewrite (Low_Bound (R),
5968 Make_Attribute_Reference (Sloc (Low_Bound (R)),
5cc9353d 5969 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
996ae0b0
RK		 5970 Attribute_Name => Name_First));
5971 Rewrite (High_Bound (R),
5972 Make_Attribute_Reference (Sloc (High_Bound (R)),
5cc9353d 5973 Prefix => New_Occurrence_Of (Typ, Sloc (R)),
996ae0b0
RK		 5974 Attribute_Name => Name_First));
5975
5976 else
5977 Resolve (R, Typ);
5978 Set_Etype (N, Etype (R));
5979
5980 -- Additionally, we must check that the bounds are compatible
5981 -- with the given subtype, which might be different from the
5982 -- type of the context.
5983
5984 Apply_Range_Check (R, S);
5985
5986 -- ??? If the above check statically detects a Constraint_Error
5987 -- it replaces the offending bound(s) of the range R with a
5988 -- Constraint_Error node. When the itype which uses these bounds
5989 -- is frozen the resulting call to Duplicate_Subexpr generates
5990 -- a new temporary for the bounds.
5991
5992 -- Unfortunately there are other itypes that are also made depend
5993 -- on these bounds, so when Duplicate_Subexpr is called they get
5994 -- a forward reference to the newly created temporaries and Gigi
5995 -- aborts on such forward references. This is probably sign of a
5996 -- more fundamental problem somewhere else in either the order of
5997 -- itype freezing or the way certain itypes are constructed.
5998
5999 -- To get around this problem we call Remove_Side_Effects right
6000 -- away if either bounds of R are a Constraint_Error.
6001
6002 declare
fbf5a39b
AC		 6003 L : constant Node_Id := Low_Bound (R);
6004 H : constant Node_Id := High_Bound (R);
996ae0b0
RK		 6005
6006 begin
6007 if Nkind (L) = N_Raise_Constraint_Error then
6008 Remove_Side_Effects (L);
6009 end if;
6010
6011 if Nkind (H) = N_Raise_Constraint_Error then
6012 Remove_Side_Effects (H);
6013 end if;
6014 end;
6015
6016 Check_Unset_Reference (Low_Bound (R));
6017 Check_Unset_Reference (High_Bound (R));
6018 end if;
6019 end if;
6020 end Resolve_Discrete_Subtype_Indication;
6021
6022 -------------------------
6023 -- Resolve_Entity_Name --
6024 -------------------------
6025
6026 -- Used to resolve identifiers and expanded names
6027
6028 procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
6029 E : constant Entity_Id := Entity (N);
6030
6031 begin
07fc65c4
GB		 6032 -- If garbage from errors, set to Any_Type and return
6033
6034 if No (E) and then Total_Errors_Detected /= 0 then
6035 Set_Etype (N, Any_Type);
6036 return;
6037 end if;
6038
996ae0b0
RK		 6039 -- Replace named numbers by corresponding literals. Note that this is
6040 -- the one case where Resolve_Entity_Name must reset the Etype, since
6041 -- it is currently marked as universal.
6042
6043 if Ekind (E) = E_Named_Integer then
6044 Set_Etype (N, Typ);
6045 Eval_Named_Integer (N);
6046
6047 elsif Ekind (E) = E_Named_Real then
6048 Set_Etype (N, Typ);
6049 Eval_Named_Real (N);
6050
6989bc1f
AC		 6051 -- For enumeration literals, we need to make sure that a proper style
6052 -- check is done, since such literals are overloaded, and thus we did
6053 -- not do a style check during the first phase of analysis.
6054
6055 elsif Ekind (E) = E_Enumeration_Literal then
6056 Set_Entity_With_Style_Check (N, E);
6057 Eval_Entity_Name (N);
6058
e606088a 6059 -- Case of subtype name appearing as an operand in expression
996ae0b0
RK		 6060
6061 elsif Is_Type (E) then
e606088a
AC		 6062
6063 -- Allow use of subtype if it is a concurrent type where we are
6064 -- currently inside the body. This will eventually be expanded into a
6065 -- call to Self (for tasks) or _object (for protected objects). Any
6066 -- other use of a subtype is invalid.
6067
996ae0b0
RK		 6068 if Is_Concurrent_Type (E)
6069 and then In_Open_Scopes (E)
6070 then
6071 null;
e606088a 6072
308e6f3a 6073 -- Any other use is an error
e606088a 6074
996ae0b0
RK		 6075 else
6076 Error_Msg_N
758c442c 6077 ("invalid use of subtype mark in expression or call", N);
996ae0b0
RK		 6078 end if;
6079
6080 -- Check discriminant use if entity is discriminant in current scope,
6081 -- i.e. discriminant of record or concurrent type currently being
6082 -- analyzed. Uses in corresponding body are unrestricted.
6083
6084 elsif Ekind (E) = E_Discriminant
6085 and then Scope (E) = Current_Scope
6086 and then not Has_Completion (Current_Scope)
6087 then
6088 Check_Discriminant_Use (N);
6089
6090 -- A parameterless generic function cannot appear in a context that
6091 -- requires resolution.
6092
6093 elsif Ekind (E) = E_Generic_Function then
6094 Error_Msg_N ("illegal use of generic function", N);
6095
6096 elsif Ekind (E) = E_Out_Parameter
0ab80019 6097 and then Ada_Version = Ada_83
996ae0b0 6098 and then (Nkind (Parent (N)) in N_Op
19fb051c
AC		 6099 or else (Nkind (Parent (N)) = N_Assignment_Statement
6100 and then N = Expression (Parent (N)))
6101 or else Nkind (Parent (N)) = N_Explicit_Dereference)
996ae0b0
RK		 6102 then
6103 Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
6104
6105 -- In all other cases, just do the possible static evaluation
6106
6107 else
d81b4bfe
TQ		 6108 -- A deferred constant that appears in an expression must have a
6109 -- completion, unless it has been removed by in-place expansion of
6110 -- an aggregate.
996ae0b0
RK		 6111
6112 if Ekind (E) = E_Constant
6113 and then Comes_From_Source (E)
6114 and then No (Constant_Value (E))
6115 and then Is_Frozen (Etype (E))
45fc7ddb 6116 and then not In_Spec_Expression
996ae0b0
RK		 6117 and then not Is_Imported (E)
6118 then
996ae0b0
RK		 6119 if No_Initialization (Parent (E))
6120 or else (Present (Full_View (E))
6121 and then No_Initialization (Parent (Full_View (E))))
6122 then
6123 null;
6124 else
6125 Error_Msg_N (
6126 "deferred constant is frozen before completion", N);
6127 end if;
6128 end if;
6129
6130 Eval_Entity_Name (N);
6131 end if;
6132 end Resolve_Entity_Name;
6133
6134 -------------------
6135 -- Resolve_Entry --
6136 -------------------
6137
6138 procedure Resolve_Entry (Entry_Name : Node_Id) is
6139 Loc : constant Source_Ptr := Sloc (Entry_Name);
6140 Nam : Entity_Id;
6141 New_N : Node_Id;
6142 S : Entity_Id;
6143 Tsk : Entity_Id;
6144 E_Name : Node_Id;
6145 Index : Node_Id;
6146
6147 function Actual_Index_Type (E : Entity_Id) return Entity_Id;
6148 -- If the bounds of the entry family being called depend on task
6149 -- discriminants, build a new index subtype where a discriminant is
6150 -- replaced with the value of the discriminant of the target task.
6151 -- The target task is the prefix of the entry name in the call.
6152
6153 -----------------------
6154 -- Actual_Index_Type --
6155 -----------------------
6156
6157 function Actual_Index_Type (E : Entity_Id) return Entity_Id is
fbf5a39b
AC		 6158 Typ : constant Entity_Id := Entry_Index_Type (E);
6159 Tsk : constant Entity_Id := Scope (E);
6160 Lo : constant Node_Id := Type_Low_Bound (Typ);
6161 Hi : constant Node_Id := Type_High_Bound (Typ);
996ae0b0
RK		 6162 New_T : Entity_Id;
6163
6164 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
6165 -- If the bound is given by a discriminant, replace with a reference
d81b4bfe
TQ		 6166 -- to the discriminant of the same name in the target task. If the
6167 -- entry name is the target of a requeue statement and the entry is
6168 -- in the current protected object, the bound to be used is the
008f6fd3 6169 -- discriminal of the object (see Apply_Range_Checks for details of
d81b4bfe 6170 -- the transformation).
996ae0b0
RK		 6171
6172 -----------------------------
6173 -- Actual_Discriminant_Ref --
6174 -----------------------------
6175
6176 function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
fbf5a39b 6177 Typ : constant Entity_Id := Etype (Bound);
996ae0b0
RK		 6178 Ref : Node_Id;
6179
6180 begin
6181 Remove_Side_Effects (Bound);
6182
6183 if not Is_Entity_Name (Bound)
6184 or else Ekind (Entity (Bound)) /= E_Discriminant
6185 then
6186 return Bound;
6187
6188 elsif Is_Protected_Type (Tsk)
6189 and then In_Open_Scopes (Tsk)
6190 and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
6191 then
6ca9ec9c
AC		 6192 -- Note: here Bound denotes a discriminant of the corresponding
6193 -- record type tskV, whose discriminal is a formal of the
6194 -- init-proc tskVIP. What we want is the body discriminal,
6195 -- which is associated to the discriminant of the original
6196 -- concurrent type tsk.
6197
5a153b27
AC		 6198 return New_Occurrence_Of
6199 (Find_Body_Discriminal (Entity (Bound)), Loc);
996ae0b0
RK		 6200
6201 else
6202 Ref :=
6203 Make_Selected_Component (Loc,
6204 Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
6205 Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
6206 Analyze (Ref);
6207 Resolve (Ref, Typ);
6208 return Ref;
6209 end if;
6210 end Actual_Discriminant_Ref;
6211
6212 -- Start of processing for Actual_Index_Type
6213
6214 begin
6215 if not Has_Discriminants (Tsk)
19fb051c 6216 or else (not Is_Entity_Name (Lo) and then not Is_Entity_Name (Hi))
996ae0b0
RK		 6217 then
6218 return Entry_Index_Type (E);
6219
6220 else
6221 New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
6222 Set_Etype (New_T, Base_Type (Typ));
6223 Set_Size_Info (New_T, Typ);
6224 Set_RM_Size (New_T, RM_Size (Typ));
6225 Set_Scalar_Range (New_T,
6226 Make_Range (Sloc (Entry_Name),
6227 Low_Bound => Actual_Discriminant_Ref (Lo),
6228 High_Bound => Actual_Discriminant_Ref (Hi)));
6229
6230 return New_T;
6231 end if;
6232 end Actual_Index_Type;
6233
6234 -- Start of processing of Resolve_Entry
6235
6236 begin
5cc9353d
RD		 6237 -- Find name of entry being called, and resolve prefix of name with its
6238 -- own type. The prefix can be overloaded, and the name and signature of
6239 -- the entry must be taken into account.
996ae0b0
RK		 6240
6241 if Nkind (Entry_Name) = N_Indexed_Component then
6242
6243 -- Case of dealing with entry family within the current tasks
6244
6245 E_Name := Prefix (Entry_Name);
6246
6247 else
6248 E_Name := Entry_Name;
6249 end if;
6250
6251 if Is_Entity_Name (E_Name) then
996ae0b0 6252
d81b4bfe
TQ		 6253 -- Entry call to an entry (or entry family) in the current task. This
6254 -- is legal even though the task will deadlock. Rewrite as call to
6255 -- current task.
996ae0b0 6256
d81b4bfe
TQ		 6257 -- This can also be a call to an entry in an enclosing task. If this
6258 -- is a single task, we have to retrieve its name, because the scope
6259 -- of the entry is the task type, not the object. If the enclosing
6260 -- task is a task type, the identity of the task is given by its own
6261 -- self variable.
6262
6263 -- Finally this can be a requeue on an entry of the same task or
6264 -- protected object.
996ae0b0
RK		 6265
6266 S := Scope (Entity (E_Name));
6267
6268 for J in reverse 0 .. Scope_Stack.Last loop
996ae0b0
RK		 6269 if Is_Task_Type (Scope_Stack.Table (J).Entity)
6270 and then not Comes_From_Source (S)
6271 then
6272 -- S is an enclosing task or protected object. The concurrent
6273 -- declaration has been converted into a type declaration, and
6274 -- the object itself has an object declaration that follows
6275 -- the type in the same declarative part.
6276
6277 Tsk := Next_Entity (S);
996ae0b0
RK		 6278 while Etype (Tsk) /= S loop
6279 Next_Entity (Tsk);
6280 end loop;
6281
6282 S := Tsk;
6283 exit;
6284
6285 elsif S = Scope_Stack.Table (J).Entity then
6286
6287 -- Call to current task. Will be transformed into call to Self
6288
6289 exit;
6290
6291 end if;
6292 end loop;
6293
6294 New_N :=
6295 Make_Selected_Component (Loc,
6296 Prefix => New_Occurrence_Of (S, Loc),
6297 Selector_Name =>
6298 New_Occurrence_Of (Entity (E_Name), Loc));
6299 Rewrite (E_Name, New_N);
6300 Analyze (E_Name);
6301
6302 elsif Nkind (Entry_Name) = N_Selected_Component
6303 and then Is_Overloaded (Prefix (Entry_Name))
6304 then
d81b4bfe 6305 -- Use the entry name (which must be unique at this point) to find
5cc9353d 6306 -- the prefix that returns the corresponding task/protected type.
996ae0b0
RK		 6307
6308 declare
fbf5a39b
AC		 6309 Pref : constant Node_Id := Prefix (Entry_Name);
6310 Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
996ae0b0
RK		 6311 I : Interp_Index;
6312 It : Interp;
996ae0b0
RK		 6313
6314 begin
6315 Get_First_Interp (Pref, I, It);
996ae0b0 6316 while Present (It.Typ) loop
996ae0b0
RK		 6317 if Scope (Ent) = It.Typ then
6318 Set_Etype (Pref, It.Typ);
6319 exit;
6320 end if;
6321
6322 Get_Next_Interp (I, It);
6323 end loop;
6324 end;
6325 end if;
6326
6327 if Nkind (Entry_Name) = N_Selected_Component then
fbf5a39b 6328 Resolve (Prefix (Entry_Name));
996ae0b0
RK		 6329
6330 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
6331 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
fbf5a39b 6332 Resolve (Prefix (Prefix (Entry_Name)));
996ae0b0
RK		 6333 Index := First (Expressions (Entry_Name));
6334 Resolve (Index, Entry_Index_Type (Nam));
6335
d81b4bfe
TQ		 6336 -- Up to this point the expression could have been the actual in a
6337 -- simple entry call, and be given by a named association.
996ae0b0
RK		 6338
6339 if Nkind (Index) = N_Parameter_Association then
6340 Error_Msg_N ("expect expression for entry index", Index);
6341 else
6342 Apply_Range_Check (Index, Actual_Index_Type (Nam));
6343 end if;
6344 end if;
996ae0b0
RK		 6345 end Resolve_Entry;
6346
6347 ------------------------
6348 -- Resolve_Entry_Call --
6349 ------------------------
6350
6351 procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
6352 Entry_Name : constant Node_Id := Name (N);
6353 Loc : constant Source_Ptr := Sloc (Entry_Name);
6354 Actuals : List_Id;
6355 First_Named : Node_Id;
6356 Nam : Entity_Id;
6357 Norm_OK : Boolean;
6358 Obj : Node_Id;
6359 Was_Over : Boolean;
6360
6361 begin
d81b4bfe
TQ		 6362 -- We kill all checks here, because it does not seem worth the effort to
6363 -- do anything better, an entry call is a big operation.
fbf5a39b
AC		 6364
6365 Kill_All_Checks;
6366
996ae0b0
RK		 6367 -- Processing of the name is similar for entry calls and protected
6368 -- operation calls. Once the entity is determined, we can complete
6369 -- the resolution of the actuals.
6370
6371 -- The selector may be overloaded, in the case of a protected object
6372 -- with overloaded functions. The type of the context is used for
6373 -- resolution.
6374
6375 if Nkind (Entry_Name) = N_Selected_Component
6376 and then Is_Overloaded (Selector_Name (Entry_Name))
6377 and then Typ /= Standard_Void_Type
6378 then
6379 declare
6380 I : Interp_Index;
6381 It : Interp;
6382
6383 begin
6384 Get_First_Interp (Selector_Name (Entry_Name), I, It);
996ae0b0 6385 while Present (It.Typ) loop
996ae0b0
RK		 6386 if Covers (Typ, It.Typ) then
6387 Set_Entity (Selector_Name (Entry_Name), It.Nam);
6388 Set_Etype (Entry_Name, It.Typ);
6389
6390 Generate_Reference (It.Typ, N, ' ');
6391 end if;
6392
6393 Get_Next_Interp (I, It);
6394 end loop;
6395 end;
6396 end if;
6397
6398 Resolve_Entry (Entry_Name);
6399
6400 if Nkind (Entry_Name) = N_Selected_Component then
6401
a77842bd 6402 -- Simple entry call
996ae0b0
RK		 6403
6404 Nam := Entity (Selector_Name (Entry_Name));
6405 Obj := Prefix (Entry_Name);
6406 Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
6407
6408 else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
6409
a77842bd 6410 -- Call to member of entry family
996ae0b0
RK		 6411
6412 Nam := Entity (Selector_Name (Prefix (Entry_Name)));
6413 Obj := Prefix (Prefix (Entry_Name));
6414 Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
6415 end if;
6416
5cc9353d
RD		 6417 -- We cannot in general check the maximum depth of protected entry calls
6418 -- at compile time. But we can tell that any protected entry call at all
6419 -- violates a specified nesting depth of zero.
fbf5a39b
AC		 6420
6421 if Is_Protected_Type (Scope (Nam)) then
9f4fd324 6422 Check_Restriction (Max_Entry_Queue_Length, N);
fbf5a39b
AC		 6423 end if;
6424
996ae0b0 6425 -- Use context type to disambiguate a protected function that can be
5cc9353d
RD		 6426 -- called without actuals and that returns an array type, and where the
6427 -- argument list may be an indexing of the returned value.
996ae0b0
RK		 6428
6429 if Ekind (Nam) = E_Function
6430 and then Needs_No_Actuals (Nam)
6431 and then Present (Parameter_Associations (N))
6432 and then
6433 ((Is_Array_Type (Etype (Nam))
6434 and then Covers (Typ, Component_Type (Etype (Nam))))
6435
6436 or else (Is_Access_Type (Etype (Nam))
6437 and then Is_Array_Type (Designated_Type (Etype (Nam)))
19fb051c
AC		 6438 and then
6439 Covers
6440 (Typ,
6441 Component_Type (Designated_Type (Etype (Nam))))))
996ae0b0
RK		 6442 then
6443 declare
6444 Index_Node : Node_Id;
6445
6446 begin
6447 Index_Node :=
6448 Make_Indexed_Component (Loc,
6449 Prefix =>
19fb051c 6450 Make_Function_Call (Loc, Name => Relocate_Node (Entry_Name)),
996ae0b0
RK		 6451 Expressions => Parameter_Associations (N));
6452
5cc9353d
RD		 6453 -- Since we are correcting a node classification error made by the
6454 -- parser, we call Replace rather than Rewrite.
996ae0b0
RK		 6455
6456 Replace (N, Index_Node);
6457 Set_Etype (Prefix (N), Etype (Nam));
6458 Set_Etype (N, Typ);
6459 Resolve_Indexed_Component (N, Typ);
6460 return;
6461 end;
6462 end if;
6463
b7f17b20
ES		 6464 if Ekind_In (Nam, E_Entry, E_Entry_Family)
6465 and then Present (PPC_Wrapper (Nam))
6466 and then Current_Scope /= PPC_Wrapper (Nam)
6467 then
468ee96a 6468 -- Rewrite as call to the precondition wrapper, adding the task
5cc9353d
RD		 6469 -- object to the list of actuals. If the call is to a member of an
6470 -- entry family, include the index as well.
b7f17b20
ES		 6471
6472 declare
468ee96a 6473 New_Call : Node_Id;
b7f17b20 6474 New_Actuals : List_Id;
19fb051c 6475
b7f17b20
ES		 6476 begin
6477 New_Actuals := New_List (Obj);
3fd9f17c
AC		 6478
6479 if Nkind (Entry_Name) = N_Indexed_Component then
6480 Append_To (New_Actuals,
6481 New_Copy_Tree (First (Expressions (Entry_Name))));
6482 end if;
6483
b7f17b20 6484 Append_List (Parameter_Associations (N), New_Actuals);
468ee96a
AC		 6485 New_Call :=
6486 Make_Procedure_Call_Statement (Loc,
6487 Name =>
6488 New_Occurrence_Of (PPC_Wrapper (Nam), Loc),
6489 Parameter_Associations => New_Actuals);
b7f17b20
ES		 6490 Rewrite (N, New_Call);
6491 Analyze_And_Resolve (N);
6492 return;
6493 end;
6494 end if;
6495
996ae0b0 6496 -- The operation name may have been overloaded. Order the actuals
5cc9353d
RD		 6497 -- according to the formals of the resolved entity, and set the return
6498 -- type to that of the operation.
996ae0b0
RK		 6499
6500 if Was_Over then
6501 Normalize_Actuals (N, Nam, False, Norm_OK);
6502 pragma Assert (Norm_OK);
fbf5a39b 6503 Set_Etype (N, Etype (Nam));
996ae0b0
RK		 6504 end if;
6505
6506 Resolve_Actuals (N, Nam);
ae6ede77
AC		 6507
6508 -- Create a call reference to the entry
6509
6510 Generate_Reference (Nam, Entry_Name, 's');
996ae0b0 6511
8a95f4e8 6512 if Ekind_In (Nam, E_Entry, E_Entry_Family) then
996ae0b0
RK		 6513 Check_Potentially_Blocking_Operation (N);
6514 end if;
6515
6516 -- Verify that a procedure call cannot masquerade as an entry
6517 -- call where an entry call is expected.
6518
6519 if Ekind (Nam) = E_Procedure then
996ae0b0
RK		 6520 if Nkind (Parent (N)) = N_Entry_Call_Alternative
6521 and then N = Entry_Call_Statement (Parent (N))
6522 then
6523 Error_Msg_N ("entry call required in select statement", N);
6524
6525 elsif Nkind (Parent (N)) = N_Triggering_Alternative
6526 and then N = Triggering_Statement (Parent (N))
6527 then
6528 Error_Msg_N ("triggering statement cannot be procedure call", N);
6529
6530 elsif Ekind (Scope (Nam)) = E_Task_Type
6531 and then not In_Open_Scopes (Scope (Nam))
6532 then
758c442c 6533 Error_Msg_N ("task has no entry with this name", Entry_Name);
996ae0b0
RK		 6534 end if;
6535 end if;
6536
d81b4bfe
TQ		 6537 -- After resolution, entry calls and protected procedure calls are
6538 -- changed into entry calls, for expansion. The structure of the node
6539 -- does not change, so it can safely be done in place. Protected
6540 -- function calls must keep their structure because they are
6541 -- subexpressions.
996ae0b0
RK		 6542
6543 if Ekind (Nam) /= E_Function then
6544
6545 -- A protected operation that is not a function may modify the
d81b4bfe
TQ		 6546 -- corresponding object, and cannot apply to a constant. If this
6547 -- is an internal call, the prefix is the type itself.
996ae0b0
RK		 6548
6549 if Is_Protected_Type (Scope (Nam))
6550 and then not Is_Variable (Obj)
6551 and then (not Is_Entity_Name (Obj)
6552 or else not Is_Type (Entity (Obj)))
6553 then
6554 Error_Msg_N
6555 ("prefix of protected procedure or entry call must be variable",
6556 Entry_Name);
6557 end if;
6558
6559 Actuals := Parameter_Associations (N);
6560 First_Named := First_Named_Actual (N);
6561
6562 Rewrite (N,
6563 Make_Entry_Call_Statement (Loc,
6564 Name => Entry_Name,
6565 Parameter_Associations => Actuals));
6566
6567 Set_First_Named_Actual (N, First_Named);
6568 Set_Analyzed (N, True);
6569
6570 -- Protected functions can return on the secondary stack, in which
1420b484 6571 -- case we must trigger the transient scope mechanism.
996ae0b0
RK		 6572
6573 elsif Expander_Active
6574 and then Requires_Transient_Scope (Etype (Nam))
6575 then
0669bebe 6576 Establish_Transient_Scope (N, Sec_Stack => True);
996ae0b0 6577 end if;
996ae0b0
RK		 6578 end Resolve_Entry_Call;
6579
6580 -------------------------
6581 -- Resolve_Equality_Op --
6582 -------------------------
6583
d81b4bfe
TQ		 6584 -- Both arguments must have the same type, and the boolean context does
6585 -- not participate in the resolution. The first pass verifies that the
6586 -- interpretation is not ambiguous, and the type of the left argument is
6587 -- correctly set, or is Any_Type in case of ambiguity. If both arguments
6588 -- are strings or aggregates, allocators, or Null, they are ambiguous even
6589 -- though they carry a single (universal) type. Diagnose this case here.
996ae0b0
RK		 6590
6591 procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
6592 L : constant Node_Id := Left_Opnd (N);
6593 R : constant Node_Id := Right_Opnd (N);
6594 T : Entity_Id := Find_Unique_Type (L, R);
6595
a8930b80
AC		 6596 procedure Check_Conditional_Expression (Cond : Node_Id);
6597 -- The resolution rule for conditional expressions requires that each
6598 -- such must have a unique type. This means that if several dependent
6599 -- expressions are of a non-null anonymous access type, and the context
6600 -- does not impose an expected type (as can be the case in an equality
6601 -- operation) the expression must be rejected.
6602
996ae0b0
RK		 6603 function Find_Unique_Access_Type return Entity_Id;
6604 -- In the case of allocators, make a last-ditch attempt to find a single
6605 -- access type with the right designated type. This is semantically
6606 -- dubious, and of no interest to any real code, but c48008a makes it
6607 -- all worthwhile.
6608
a8930b80
AC		 6609 ----------------------------------
6610 -- Check_Conditional_Expression --
6611 ----------------------------------
6612
6613 procedure Check_Conditional_Expression (Cond : Node_Id) is
6614 Then_Expr : Node_Id;
6615 Else_Expr : Node_Id;
6616
6617 begin
6618 if Nkind (Cond) = N_Conditional_Expression then
6619 Then_Expr := Next (First (Expressions (Cond)));
6620 Else_Expr := Next (Then_Expr);
6621
6622 if Nkind (Then_Expr) /= N_Null
6623 and then Nkind (Else_Expr) /= N_Null
6624 then
6625 Error_Msg_N
6626 ("cannot determine type of conditional expression", Cond);
6627 end if;
6628 end if;
6629 end Check_Conditional_Expression;
6630
996ae0b0
RK		 6631 -----------------------------
6632 -- Find_Unique_Access_Type --
6633 -----------------------------
6634
6635 function Find_Unique_Access_Type return Entity_Id is
6636 Acc : Entity_Id;
6637 E : Entity_Id;
1420b484 6638 S : Entity_Id;
996ae0b0
RK		 6639
6640 begin
6641 if Ekind (Etype (R)) = E_Allocator_Type then
6642 Acc := Designated_Type (Etype (R));
996ae0b0
RK		 6643 elsif Ekind (Etype (L)) = E_Allocator_Type then
6644 Acc := Designated_Type (Etype (L));
996ae0b0
RK		 6645 else
6646 return Empty;
6647 end if;
6648
1420b484 6649 S := Current_Scope;
996ae0b0
RK		 6650 while S /= Standard_Standard loop
6651 E := First_Entity (S);
996ae0b0 6652 while Present (E) loop
996ae0b0
RK		 6653 if Is_Type (E)
6654 and then Is_Access_Type (E)
6655 and then Ekind (E) /= E_Allocator_Type
6656 and then Designated_Type (E) = Base_Type (Acc)
6657 then
6658 return E;
6659 end if;
6660
6661 Next_Entity (E);
6662 end loop;
6663
6664 S := Scope (S);
6665 end loop;
6666
6667 return Empty;
6668 end Find_Unique_Access_Type;
6669
6670 -- Start of processing for Resolve_Equality_Op
6671
6672 begin
6673 Set_Etype (N, Base_Type (Typ));
6674 Generate_Reference (T, N, ' ');
6675
6676 if T = Any_Fixed then
6677 T := Unique_Fixed_Point_Type (L);
6678 end if;
6679
6680 if T /= Any_Type then
19fb051c
AC		 6681 if T = Any_String or else
6682 T = Any_Composite or else
6683 T = Any_Character
996ae0b0 6684 then
996ae0b0
RK		 6685 if T = Any_Character then
6686 Ambiguous_Character (L);
6687 else
6688 Error_Msg_N ("ambiguous operands for equality", N);
6689 end if;
6690
6691 Set_Etype (N, Any_Type);
6692 return;
6693
6694 elsif T = Any_Access
964f13da 6695 or else Ekind_In (T, E_Allocator_Type, E_Access_Attribute_Type)
996ae0b0
RK		 6696 then
6697 T := Find_Unique_Access_Type;
6698
6699 if No (T) then
6700 Error_Msg_N ("ambiguous operands for equality", N);
6701 Set_Etype (N, Any_Type);
6702 return;
6703 end if;
a8930b80
AC		 6704
6705 -- Conditional expressions must have a single type, and if the
6706 -- context does not impose one the dependent expressions cannot
6707 -- be anonymous access types.
6708
6709 elsif Ada_Version >= Ada_2012
ae2aa109
AC		 6710 and then Ekind_In (Etype (L), E_Anonymous_Access_Type,
6711 E_Anonymous_Access_Subprogram_Type)
6712 and then Ekind_In (Etype (R), E_Anonymous_Access_Type,
6713 E_Anonymous_Access_Subprogram_Type)
a8930b80
AC		 6714 then
6715 Check_Conditional_Expression (L);
6716 Check_Conditional_Expression (R);
996ae0b0
RK		 6717 end if;
6718
996ae0b0
RK		 6719 Resolve (L, T);
6720 Resolve (R, T);
fbf5a39b 6721
b0186f71
AC		 6722 -- In SPARK or ALFA, equality operators = and /= for array types
6723 -- other than String are only defined when, for each index position,
6724 -- the operands have equal static bounds.
6725
fe5d3068 6726 if Is_Array_Type (T)
b0186f71 6727 and then Base_Type (T) /= Standard_String
19fb051c 6728 and then Base_Type (Etype (L)) = Base_Type (Etype (R))
b0186f71
AC		 6729 and then not Matching_Static_Array_Bounds (Etype (L), Etype (R))
6730 then
fe5d3068
YM		 6731 Check_Formal_Restriction
6732 ("array types should have matching static bounds", N);
b0186f71
AC		 6733 end if;
6734
0669bebe
GB		 6735 -- If the unique type is a class-wide type then it will be expanded
6736 -- into a dispatching call to the predefined primitive. Therefore we
6737 -- check here for potential violation of such restriction.
6738
6739 if Is_Class_Wide_Type (T) then
6740 Check_Restriction (No_Dispatching_Calls, N);
6741 end if;
6742
fbf5a39b
AC		 6743 if Warn_On_Redundant_Constructs
6744 and then Comes_From_Source (N)
6745 and then Is_Entity_Name (R)
6746 and then Entity (R) = Standard_True
6747 and then Comes_From_Source (R)
6748 then
305caf42
AC		 6749 Error_Msg_N -- CODEFIX
6750 ("?comparison with True is redundant!", R);
fbf5a39b
AC		 6751 end if;
6752
996ae0b0
RK		 6753 Check_Unset_Reference (L);
6754 Check_Unset_Reference (R);
fbf5a39b 6755 Generate_Operator_Reference (N, T);
fad0600d 6756 Check_Low_Bound_Tested (N);
996ae0b0
RK		 6757
6758 -- If this is an inequality, it may be the implicit inequality
6759 -- created for a user-defined operation, in which case the corres-
6760 -- ponding equality operation is not intrinsic, and the operation
6761 -- cannot be constant-folded. Else fold.
6762
6763 if Nkind (N) = N_Op_Eq
6764 or else Comes_From_Source (Entity (N))
6765 or else Ekind (Entity (N)) = E_Operator
6766 or else Is_Intrinsic_Subprogram
19fb051c 6767 (Corresponding_Equality (Entity (N)))
996ae0b0
RK		 6768 then
6769 Eval_Relational_Op (N);
45fc7ddb 6770
996ae0b0 6771 elsif Nkind (N) = N_Op_Ne
0669bebe 6772 and then Is_Abstract_Subprogram (Entity (N))
996ae0b0
RK		 6773 then
6774 Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
6775 end if;
758c442c 6776
d81b4bfe
TQ		 6777 -- Ada 2005: If one operand is an anonymous access type, convert the
6778 -- other operand to it, to ensure that the underlying types match in
6779 -- the back-end. Same for access_to_subprogram, and the conversion
6780 -- verifies that the types are subtype conformant.
b7d1f17f 6781
d81b4bfe
TQ		 6782 -- We apply the same conversion in the case one of the operands is a
6783 -- private subtype of the type of the other.
c8ef728f 6784
b7d1f17f
HK		 6785 -- Why the Expander_Active test here ???
6786
4197ae1e 6787 if Expander_Active
b7d1f17f 6788 and then
964f13da
RD		 6789 (Ekind_In (T, E_Anonymous_Access_Type,
6790 E_Anonymous_Access_Subprogram_Type)
b7d1f17f 6791 or else Is_Private_Type (T))
c8ef728f
ES		 6792 then
6793 if Etype (L) /= T then
6794 Rewrite (L,
6795 Make_Unchecked_Type_Conversion (Sloc (L),
6796 Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
6797 Expression => Relocate_Node (L)));
6798 Analyze_And_Resolve (L, T);
6799 end if;
6800
6801 if (Etype (R)) /= T then
6802 Rewrite (R,
6803 Make_Unchecked_Type_Conversion (Sloc (R),
6804 Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
6805 Expression => Relocate_Node (R)));
6806 Analyze_And_Resolve (R, T);
6807 end if;
6808 end if;
996ae0b0
RK		 6809 end if;
6810 end Resolve_Equality_Op;
6811
6812 ----------------------------------
6813 -- Resolve_Explicit_Dereference --
6814 ----------------------------------
6815
6816 procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
bc5f3720
RD		 6817 Loc : constant Source_Ptr := Sloc (N);
6818 New_N : Node_Id;
6819 P : constant Node_Id := Prefix (N);
6820 I : Interp_Index;
6821 It : Interp;
996ae0b0
RK		 6822
6823 begin
c8ef728f 6824 Check_Fully_Declared_Prefix (Typ, P);
996ae0b0
RK		 6825
6826 if Is_Overloaded (P) then
6827
758c442c
GD		 6828 -- Use the context type to select the prefix that has the correct
6829 -- designated type.
996ae0b0
RK		 6830
6831 Get_First_Interp (P, I, It);
6832 while Present (It.Typ) loop
6833 exit when Is_Access_Type (It.Typ)
6834 and then Covers (Typ, Designated_Type (It.Typ));
996ae0b0
RK		 6835 Get_Next_Interp (I, It);
6836 end loop;
6837
bc5f3720
RD		 6838 if Present (It.Typ) then
6839 Resolve (P, It.Typ);
6840 else
758c442c
GD		 6841 -- If no interpretation covers the designated type of the prefix,
6842 -- this is the pathological case where not all implementations of
6843 -- the prefix allow the interpretation of the node as a call. Now
6844 -- that the expected type is known, Remove other interpretations
6845 -- from prefix, rewrite it as a call, and resolve again, so that
6846 -- the proper call node is generated.
bc5f3720
RD		 6847
6848 Get_First_Interp (P, I, It);
6849 while Present (It.Typ) loop
6850 if Ekind (It.Typ) /= E_Access_Subprogram_Type then
6851 Remove_Interp (I);
6852 end if;
6853
6854 Get_Next_Interp (I, It);
6855 end loop;
6856
6857 New_N :=
6858 Make_Function_Call (Loc,
6859 Name =>
6860 Make_Explicit_Dereference (Loc,
6861 Prefix => P),
6862 Parameter_Associations => New_List);
6863
6864 Save_Interps (N, New_N);
6865 Rewrite (N, New_N);
6866 Analyze_And_Resolve (N, Typ);
6867 return;
6868 end if;
6869
996ae0b0
RK		 6870 Set_Etype (N, Designated_Type (It.Typ));
6871
6872 else
fbf5a39b 6873 Resolve (P);
996ae0b0
RK		 6874 end if;
6875
6876 if Is_Access_Type (Etype (P)) then
6877 Apply_Access_Check (N);
6878 end if;
6879
758c442c
GD		 6880 -- If the designated type is a packed unconstrained array type, and the
6881 -- explicit dereference is not in the context of an attribute reference,
6882 -- then we must compute and set the actual subtype, since it is needed
6883 -- by Gigi. The reason we exclude the attribute case is that this is
6884 -- handled fine by Gigi, and in fact we use such attributes to build the
6885 -- actual subtype. We also exclude generated code (which builds actual
6886 -- subtypes directly if they are needed).
996ae0b0
RK		 6887
6888 if Is_Array_Type (Etype (N))
6889 and then Is_Packed (Etype (N))
6890 and then not Is_Constrained (Etype (N))
6891 and then Nkind (Parent (N)) /= N_Attribute_Reference
6892 and then Comes_From_Source (N)
6893 then
6894 Set_Etype (N, Get_Actual_Subtype (N));
6895 end if;
6896
09494c32
AC		 6897 -- Note: No Eval processing is required for an explicit dereference,
6898 -- because such a name can never be static.
996ae0b0
RK		 6899
6900 end Resolve_Explicit_Dereference;
6901
955871d3
AC		 6902 -------------------------------------
6903 -- Resolve_Expression_With_Actions --
6904 -------------------------------------
6905
6906 procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id) is
6907 begin
6908 Set_Etype (N, Typ);
6909 end Resolve_Expression_With_Actions;
6910
996ae0b0
RK		 6911 -------------------------------
6912 -- Resolve_Indexed_Component --
6913 -------------------------------
6914
6915 procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
6916 Name : constant Node_Id := Prefix (N);
6917 Expr : Node_Id;
6918 Array_Type : Entity_Id := Empty; -- to prevent junk warning
6919 Index : Node_Id;
6920
6921 begin
6922 if Is_Overloaded (Name) then
6923
758c442c
GD		 6924 -- Use the context type to select the prefix that yields the correct
6925 -- component type.
996ae0b0
RK		 6926
6927 declare
6928 I : Interp_Index;
6929 It : Interp;
6930 I1 : Interp_Index := 0;
6931 P : constant Node_Id := Prefix (N);
6932 Found : Boolean := False;
6933
6934 begin
6935 Get_First_Interp (P, I, It);
996ae0b0 6936 while Present (It.Typ) loop
996ae0b0
RK		 6937 if (Is_Array_Type (It.Typ)
6938 and then Covers (Typ, Component_Type (It.Typ)))
6939 or else (Is_Access_Type (It.Typ)
6940 and then Is_Array_Type (Designated_Type (It.Typ))
19fb051c
AC		 6941 and then
6942 Covers
6943 (Typ,
6944 Component_Type (Designated_Type (It.Typ))))
996ae0b0
RK		 6945 then
6946 if Found then
6947 It := Disambiguate (P, I1, I, Any_Type);
6948
6949 if It = No_Interp then
6950 Error_Msg_N ("ambiguous prefix for indexing", N);
6951 Set_Etype (N, Typ);
6952 return;
6953
6954 else
6955 Found := True;
6956 Array_Type := It.Typ;
6957 I1 := I;
6958 end if;
6959
6960 else
6961 Found := True;
6962 Array_Type := It.Typ;
6963 I1 := I;
6964 end if;
6965 end if;
6966
6967 Get_Next_Interp (I, It);
6968 end loop;
6969 end;
6970
6971 else
6972 Array_Type := Etype (Name);
6973 end if;
6974
6975 Resolve (Name, Array_Type);
6976 Array_Type := Get_Actual_Subtype_If_Available (Name);
6977
6978 -- If prefix is access type, dereference to get real array type.
6979 -- Note: we do not apply an access check because the expander always
6980 -- introduces an explicit dereference, and the check will happen there.
6981
6982 if Is_Access_Type (Array_Type) then
6983 Array_Type := Designated_Type (Array_Type);
6984 end if;
6985
a77842bd 6986 -- If name was overloaded, set component type correctly now
f3d57416 6987 -- If a misplaced call to an entry family (which has no index types)
b7d1f17f 6988 -- return. Error will be diagnosed from calling context.
996ae0b0 6989
b7d1f17f
HK		 6990 if Is_Array_Type (Array_Type) then
6991 Set_Etype (N, Component_Type (Array_Type));
6992 else
6993 return;
6994 end if;
996ae0b0
RK		 6995
6996 Index := First_Index (Array_Type);
6997 Expr := First (Expressions (N));
6998
758c442c
GD		 6999 -- The prefix may have resolved to a string literal, in which case its
7000 -- etype has a special representation. This is only possible currently
7001 -- if the prefix is a static concatenation, written in functional
7002 -- notation.
996ae0b0
RK		 7003
7004 if Ekind (Array_Type) = E_String_Literal_Subtype then
7005 Resolve (Expr, Standard_Positive);
7006
7007 else
7008 while Present (Index) and Present (Expr) loop
7009 Resolve (Expr, Etype (Index));
7010 Check_Unset_Reference (Expr);
7011
7012 if Is_Scalar_Type (Etype (Expr)) then
7013 Apply_Scalar_Range_Check (Expr, Etype (Index));
7014 else
7015 Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
7016 end if;
7017
7018 Next_Index (Index);
7019 Next (Expr);
7020 end loop;
7021 end if;
7022
0669bebe
GB		 7023 -- Do not generate the warning on suspicious index if we are analyzing
7024 -- package Ada.Tags; otherwise we will report the warning with the
7025 -- Prims_Ptr field of the dispatch table.
7026
7027 if Scope (Etype (Prefix (N))) = Standard_Standard
7028 or else not
7029 Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
7030 Ada_Tags)
7031 then
7032 Warn_On_Suspicious_Index (Name, First (Expressions (N)));
7033 Eval_Indexed_Component (N);
7034 end if;
c28408b7
RD		 7035
7036 -- If the array type is atomic, and is packed, and we are in a left side
7037 -- context, then this is worth a warning, since we have a situation
7038 -- where the access to the component may cause extra read/writes of
7039 -- the atomic array object, which could be considered unexpected.
7040
7041 if Nkind (N) = N_Indexed_Component
7042 and then (Is_Atomic (Array_Type)
7043 or else (Is_Entity_Name (Prefix (N))
7044 and then Is_Atomic (Entity (Prefix (N)))))
7045 and then Is_Bit_Packed_Array (Array_Type)
7046 and then Is_LHS (N)
7047 then
7048 Error_Msg_N ("?assignment to component of packed atomic array",
7049 Prefix (N));
7050 Error_Msg_N ("?\may cause unexpected accesses to atomic object",
7051 Prefix (N));
7052 end if;
996ae0b0
RK		 7053 end Resolve_Indexed_Component;
7054
7055 -----------------------------
7056 -- Resolve_Integer_Literal --
7057 -----------------------------
7058
7059 procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
7060 begin
7061 Set_Etype (N, Typ);
7062 Eval_Integer_Literal (N);
7063 end Resolve_Integer_Literal;
7064
15ce9ca2
AC		 7065 --------------------------------
7066 -- Resolve_Intrinsic_Operator --
7067 --------------------------------
996ae0b0
RK		 7068
7069 procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
bb481772
AC		 7070 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
7071 Op : Entity_Id;
7072 Orig_Op : constant Entity_Id := Entity (N);
7073 Arg1 : Node_Id;
7074 Arg2 : Node_Id;
996ae0b0
RK		 7075
7076 begin
305caf42
AC		 7077 -- We must preserve the original entity in a generic setting, so that
7078 -- the legality of the operation can be verified in an instance.
7079
7080 if not Expander_Active then
7081 return;
7082 end if;
7083
996ae0b0 7084 Op := Entity (N);
996ae0b0
RK		 7085 while Scope (Op) /= Standard_Standard loop
7086 Op := Homonym (Op);
7087 pragma Assert (Present (Op));
7088 end loop;
7089
7090 Set_Entity (N, Op);
af152989 7091 Set_Is_Overloaded (N, False);
996ae0b0 7092
758c442c
GD		 7093 -- If the operand type is private, rewrite with suitable conversions on
7094 -- the operands and the result, to expose the proper underlying numeric
7095 -- type.
996ae0b0 7096
fbf5a39b
AC		 7097 if Is_Private_Type (Typ) then
7098 Arg1 := Unchecked_Convert_To (Btyp, Left_Opnd (N));
7099
7100 if Nkind (N) = N_Op_Expon then
7101 Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
7102 else
7103 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
7104 end if;
7105
bb481772
AC		 7106 if Nkind (Arg1) = N_Type_Conversion then
7107 Save_Interps (Left_Opnd (N), Expression (Arg1));
7108 end if;
7109
7110 if Nkind (Arg2) = N_Type_Conversion then
7111 Save_Interps (Right_Opnd (N), Expression (Arg2));
7112 end if;
996ae0b0 7113
fbf5a39b
AC		 7114 Set_Left_Opnd (N, Arg1);
7115 Set_Right_Opnd (N, Arg2);
7116
7117 Set_Etype (N, Btyp);
7118 Rewrite (N, Unchecked_Convert_To (Typ, N));
7119 Resolve (N, Typ);
7120
7121 elsif Typ /= Etype (Left_Opnd (N))
7122 or else Typ /= Etype (Right_Opnd (N))
7123 then
d81b4bfe 7124 -- Add explicit conversion where needed, and save interpretations in
bb481772
AC		 7125 -- case operands are overloaded. If the context is a VMS operation,
7126 -- assert that the conversion is legal (the operands have the proper
7127 -- types to select the VMS intrinsic). Note that in rare cases the
7128 -- VMS operators may be visible, but the default System is being used
7129 -- and Address is a private type.
fbf5a39b 7130
af152989 7131 Arg1 := Convert_To (Typ, Left_Opnd (N));
fbf5a39b
AC		 7132 Arg2 := Convert_To (Typ, Right_Opnd (N));
7133
7134 if Nkind (Arg1) = N_Type_Conversion then
7135 Save_Interps (Left_Opnd (N), Expression (Arg1));
bb481772
AC		 7136
7137 if Is_VMS_Operator (Orig_Op) then
7138 Set_Conversion_OK (Arg1);
7139 end if;
af152989
AC		 7140 else
7141 Save_Interps (Left_Opnd (N), Arg1);
fbf5a39b
AC		 7142 end if;
7143
7144 if Nkind (Arg2) = N_Type_Conversion then
7145 Save_Interps (Right_Opnd (N), Expression (Arg2));
bb481772
AC		 7146
7147 if Is_VMS_Operator (Orig_Op) then
7148 Set_Conversion_OK (Arg2);
7149 end if;
af152989 7150 else
0ab80019 7151 Save_Interps (Right_Opnd (N), Arg2);
fbf5a39b
AC		 7152 end if;
7153
7154 Rewrite (Left_Opnd (N), Arg1);
7155 Rewrite (Right_Opnd (N), Arg2);
7156 Analyze (Arg1);
7157 Analyze (Arg2);
7158 Resolve_Arithmetic_Op (N, Typ);
7159
7160 else
7161 Resolve_Arithmetic_Op (N, Typ);
7162 end if;
996ae0b0
RK		 7163 end Resolve_Intrinsic_Operator;
7164
fbf5a39b
AC		 7165 --------------------------------------
7166 -- Resolve_Intrinsic_Unary_Operator --
7167 --------------------------------------
7168
7169 procedure Resolve_Intrinsic_Unary_Operator
7170 (N : Node_Id;
7171 Typ : Entity_Id)
7172 is
7173 Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
7174 Op : Entity_Id;
7175 Arg2 : Node_Id;
7176
7177 begin
7178 Op := Entity (N);
fbf5a39b
AC		 7179 while Scope (Op) /= Standard_Standard loop
7180 Op := Homonym (Op);
7181 pragma Assert (Present (Op));
7182 end loop;
7183
7184 Set_Entity (N, Op);
7185
7186 if Is_Private_Type (Typ) then
7187 Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
7188 Save_Interps (Right_Opnd (N), Expression (Arg2));
7189
7190 Set_Right_Opnd (N, Arg2);
7191
7192 Set_Etype (N, Btyp);
7193 Rewrite (N, Unchecked_Convert_To (Typ, N));
7194 Resolve (N, Typ);
7195
7196 else
7197 Resolve_Unary_Op (N, Typ);
7198 end if;
7199 end Resolve_Intrinsic_Unary_Operator;
7200
996ae0b0
RK		 7201 ------------------------
7202 -- Resolve_Logical_Op --
7203 ------------------------
7204
7205 procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
7206 B_Typ : Entity_Id;
7207
7208 begin
f61580d4
AC		 7209 Check_No_Direct_Boolean_Operators (N);
7210
758c442c
GD		 7211 -- Predefined operations on scalar types yield the base type. On the
7212 -- other hand, logical operations on arrays yield the type of the
7213 -- arguments (and the context).
996ae0b0
RK		 7214
7215 if Is_Array_Type (Typ) then
7216 B_Typ := Typ;
7217 else
7218 B_Typ := Base_Type (Typ);
7219 end if;
7220
001c7783
AC		 7221 -- OK if this is a VMS-specific intrinsic operation
7222
7223 if Is_VMS_Operator (Entity (N)) then
7224 null;
7225
996ae0b0
RK		 7226 -- The following test is required because the operands of the operation
7227 -- may be literals, in which case the resulting type appears to be
7228 -- compatible with a signed integer type, when in fact it is compatible
7229 -- only with modular types. If the context itself is universal, the
7230 -- operation is illegal.
7231
001c7783 7232 elsif not Valid_Boolean_Arg (Typ) then
996ae0b0
RK		 7233 Error_Msg_N ("invalid context for logical operation", N);
7234 Set_Etype (N, Any_Type);
7235 return;
7236
7237 elsif Typ = Any_Modular then
7238 Error_Msg_N
7239 ("no modular type available in this context", N);
7240 Set_Etype (N, Any_Type);
7241 return;
19fb051c 7242
07fc65c4
GB		 7243 elsif Is_Modular_Integer_Type (Typ)
7244 and then Etype (Left_Opnd (N)) = Universal_Integer
7245 and then Etype (Right_Opnd (N)) = Universal_Integer
7246 then
7247 Check_For_Visible_Operator (N, B_Typ);
996ae0b0
RK		 7248 end if;
7249
7250 Resolve (Left_Opnd (N), B_Typ);
7251 Resolve (Right_Opnd (N), B_Typ);
7252
7253 Check_Unset_Reference (Left_Opnd (N));
7254 Check_Unset_Reference (Right_Opnd (N));
7255
7256 Set_Etype (N, B_Typ);
fbf5a39b 7257 Generate_Operator_Reference (N, B_Typ);
996ae0b0 7258 Eval_Logical_Op (N);
9f90d123
AC		 7259
7260 -- In SPARK or ALFA, logical operations AND, OR and XOR for arrays are
7261 -- defined only when both operands have same static lower and higher
19fb051c
AC		 7262 -- bounds. Of course the types have to match, so only check if operands
7263 -- are compatible and the node itself has no errors.
9f90d123 7264
fe5d3068 7265 if Is_Array_Type (B_Typ)
19fb051c
AC		 7266 and then Nkind (N) in N_Binary_Op
7267 and then
7268 Base_Type (Etype (Left_Opnd (N)))
7269 = Base_Type (Etype (Right_Opnd (N)))
b0186f71
AC		 7270 and then not Matching_Static_Array_Bounds (Etype (Left_Opnd (N)),
7271 Etype (Right_Opnd (N)))
9f90d123 7272 then
fe5d3068
YM		 7273 Check_Formal_Restriction
7274 ("array types should have matching static bounds", N);
9f90d123
AC		 7275 end if;
7276
996ae0b0
RK		 7277 end Resolve_Logical_Op;
7278
7279 ---------------------------
7280 -- Resolve_Membership_Op --
7281 ---------------------------
7282
5cc9353d
RD		 7283 -- The context can only be a boolean type, and does not determine the
7284 -- arguments. Arguments should be unambiguous, but the preference rule for
7285 -- universal types applies.
996ae0b0
RK		 7286
7287 procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
07fc65c4
GB		 7288 pragma Warnings (Off, Typ);
7289
197e4514 7290 L : constant Node_Id := Left_Opnd (N);
b1c11e0e 7291 R : constant Node_Id := Right_Opnd (N);
996ae0b0
RK		 7292 T : Entity_Id;
7293
197e4514 7294 procedure Resolve_Set_Membership;
5cc9353d
RD		 7295 -- Analysis has determined a unique type for the left operand. Use it to
7296 -- resolve the disjuncts.
197e4514
AC		 7297
7298 ----------------------------
7299 -- Resolve_Set_Membership --
7300 ----------------------------
7301
7302 procedure Resolve_Set_Membership is
7303 Alt : Node_Id;
7304
7305 begin
7306 Resolve (L, Etype (L));
7307
7308 Alt := First (Alternatives (N));
7309 while Present (Alt) loop
7310
7311 -- Alternative is an expression, a range
7312 -- or a subtype mark.
7313
7314 if not Is_Entity_Name (Alt)
7315 or else not Is_Type (Entity (Alt))
7316 then
7317 Resolve (Alt, Etype (L));
7318 end if;
7319
7320 Next (Alt);
7321 end loop;
7322 end Resolve_Set_Membership;
7323
442c0581 7324 -- Start of processing for Resolve_Membership_Op
197e4514 7325
996ae0b0
RK		 7326 begin
7327 if L = Error or else R = Error then
7328 return;
7329 end if;
7330
197e4514
AC		 7331 if Present (Alternatives (N)) then
7332 Resolve_Set_Membership;
7333 return;
7334
7335 elsif not Is_Overloaded (R)
996ae0b0 7336 and then
19fb051c
AC		 7337 (Etype (R) = Universal_Integer
7338 or else
996ae0b0
RK		 7339 Etype (R) = Universal_Real)
7340 and then Is_Overloaded (L)
7341 then
7342 T := Etype (R);
1420b484 7343
d81b4bfe 7344 -- Ada 2005 (AI-251): Support the following case:
1420b484
JM		 7345
7346 -- type I is interface;
7347 -- type T is tagged ...
7348
c8ef728f 7349 -- function Test (O : I'Class) is
1420b484
JM		 7350 -- begin
7351 -- return O in T'Class.
7352 -- end Test;
7353
d81b4bfe 7354 -- In this case we have nothing else to do. The membership test will be
e7c0dd39 7355 -- done at run time.
1420b484 7356
0791fbe9 7357 elsif Ada_Version >= Ada_2005
1420b484
JM		 7358 and then Is_Class_Wide_Type (Etype (L))
7359 and then Is_Interface (Etype (L))
7360 and then Is_Class_Wide_Type (Etype (R))
7361 and then not Is_Interface (Etype (R))
7362 then
7363 return;
996ae0b0
RK		 7364 else
7365 T := Intersect_Types (L, R);
7366 end if;
7367
9a0ddeee
AC		 7368 -- If mixed-mode operations are present and operands are all literal,
7369 -- the only interpretation involves Duration, which is probably not
7370 -- the intention of the programmer.
7371
7372 if T = Any_Fixed then
7373 T := Unique_Fixed_Point_Type (N);
7374
7375 if T = Any_Type then
7376 return;
7377 end if;
7378 end if;
7379
996ae0b0
RK		 7380 Resolve (L, T);
7381 Check_Unset_Reference (L);
7382
7383 if Nkind (R) = N_Range
7384 and then not Is_Scalar_Type (T)
7385 then
7386 Error_Msg_N ("scalar type required for range", R);
7387 end if;
7388
7389 if Is_Entity_Name (R) then
7390 Freeze_Expression (R);
7391 else
7392 Resolve (R, T);
7393 Check_Unset_Reference (R);
7394 end if;
7395
7396 Eval_Membership_Op (N);
7397 end Resolve_Membership_Op;
7398
7399 ------------------
7400 -- Resolve_Null --
7401 ------------------
7402
7403 procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
b1c11e0e
JM		 7404 Loc : constant Source_Ptr := Sloc (N);
7405
996ae0b0 7406 begin
758c442c 7407 -- Handle restriction against anonymous null access values This
6ba6b1e3 7408 -- restriction can be turned off using -gnatdj.
996ae0b0 7409
0ab80019 7410 -- Ada 2005 (AI-231): Remove restriction
2820d220 7411
0791fbe9 7412 if Ada_Version < Ada_2005
2820d220 7413 and then not Debug_Flag_J
996ae0b0
RK		 7414 and then Ekind (Typ) = E_Anonymous_Access_Type
7415 and then Comes_From_Source (N)
7416 then
d81b4bfe
TQ		 7417 -- In the common case of a call which uses an explicitly null value
7418 -- for an access parameter, give specialized error message.
996ae0b0 7419
45fc7ddb
HK		 7420 if Nkind_In (Parent (N), N_Procedure_Call_Statement,
7421 N_Function_Call)
996ae0b0
RK		 7422 then
7423 Error_Msg_N
7424 ("null is not allowed as argument for an access parameter", N);
7425
7426 -- Standard message for all other cases (are there any?)
7427
7428 else
7429 Error_Msg_N
7430 ("null cannot be of an anonymous access type", N);
7431 end if;
7432 end if;
7433
b1c11e0e
JM		 7434 -- Ada 2005 (AI-231): Generate the null-excluding check in case of
7435 -- assignment to a null-excluding object
7436
0791fbe9 7437 if Ada_Version >= Ada_2005
b1c11e0e
JM		 7438 and then Can_Never_Be_Null (Typ)
7439 and then Nkind (Parent (N)) = N_Assignment_Statement
7440 then
7441 if not Inside_Init_Proc then
7442 Insert_Action
7443 (Compile_Time_Constraint_Error (N,
7444 "(Ada 2005) null not allowed in null-excluding objects?"),
7445 Make_Raise_Constraint_Error (Loc,
7446 Reason => CE_Access_Check_Failed));
7447 else
7448 Insert_Action (N,
7449 Make_Raise_Constraint_Error (Loc,
7450 Reason => CE_Access_Check_Failed));
7451 end if;
7452 end if;
7453
d81b4bfe
TQ		 7454 -- In a distributed context, null for a remote access to subprogram may
7455 -- need to be replaced with a special record aggregate. In this case,
7456 -- return after having done the transformation.
996ae0b0
RK		 7457
7458 if (Ekind (Typ) = E_Record_Type
7459 or else Is_Remote_Access_To_Subprogram_Type (Typ))
7460 and then Remote_AST_Null_Value (N, Typ)
7461 then
7462 return;
7463 end if;
7464
a77842bd 7465 -- The null literal takes its type from the context
996ae0b0
RK		 7466
7467 Set_Etype (N, Typ);
7468 end Resolve_Null;
7469
7470 -----------------------
7471 -- Resolve_Op_Concat --
7472 -----------------------
7473
7474 procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
996ae0b0 7475
10303118
BD		 7476 -- We wish to avoid deep recursion, because concatenations are often
7477 -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
7478 -- operands nonrecursively until we find something that is not a simple
7479 -- concatenation (A in this case). We resolve that, and then walk back
7480 -- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
7481 -- to do the rest of the work at each level. The Parent pointers allow
7482 -- us to avoid recursion, and thus avoid running out of memory. See also
d81b4bfe 7483 -- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
996ae0b0 7484
10303118
BD		 7485 NN : Node_Id := N;
7486 Op1 : Node_Id;
996ae0b0 7487
10303118
BD		 7488 begin
7489 -- The following code is equivalent to:
996ae0b0 7490
10303118
BD		 7491 -- Resolve_Op_Concat_First (NN, Typ);
7492 -- Resolve_Op_Concat_Arg (N, ...);
7493 -- Resolve_Op_Concat_Rest (N, Typ);
996ae0b0 7494
10303118
BD		 7495 -- where the Resolve_Op_Concat_Arg call recurses back here if the left
7496 -- operand is a concatenation.
996ae0b0 7497
10303118 7498 -- Walk down left operands
996ae0b0 7499
10303118
BD		 7500 loop
7501 Resolve_Op_Concat_First (NN, Typ);
7502 Op1 := Left_Opnd (NN);
7503 exit when not (Nkind (Op1) = N_Op_Concat
7504 and then not Is_Array_Type (Component_Type (Typ))
7505 and then Entity (Op1) = Entity (NN));
7506 NN := Op1;
7507 end loop;
996ae0b0 7508
10303118 7509 -- Now (given the above example) NN is A&B and Op1 is A
996ae0b0 7510
10303118 7511 -- First resolve Op1 ...
9ebe3743 7512
10303118 7513 Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
9ebe3743 7514
10303118
BD		 7515 -- ... then walk NN back up until we reach N (where we started), calling
7516 -- Resolve_Op_Concat_Rest along the way.
9ebe3743 7517
10303118
BD		 7518 loop
7519 Resolve_Op_Concat_Rest (NN, Typ);
7520 exit when NN = N;
7521 NN := Parent (NN);
7522 end loop;
2933b16c 7523
fe5d3068
YM		 7524 if Base_Type (Etype (N)) /= Standard_String then
7525 Check_Formal_Restriction
7526 ("result of concatenation should have type String", N);
2933b16c 7527 end if;
10303118 7528 end Resolve_Op_Concat;
9ebe3743 7529
10303118
BD		 7530 ---------------------------
7531 -- Resolve_Op_Concat_Arg --
7532 ---------------------------
996ae0b0 7533
10303118
BD		 7534 procedure Resolve_Op_Concat_Arg
7535 (N : Node_Id;
7536 Arg : Node_Id;
7537 Typ : Entity_Id;
7538 Is_Comp : Boolean)
7539 is
7540 Btyp : constant Entity_Id := Base_Type (Typ);
996ae0b0 7541
10303118
BD		 7542 begin
7543 if In_Instance then
7544 if Is_Comp
7545 or else (not Is_Overloaded (Arg)
7546 and then Etype (Arg) /= Any_Composite
7547 and then Covers (Component_Type (Typ), Etype (Arg)))
7548 then
7549 Resolve (Arg, Component_Type (Typ));
7550 else
7551 Resolve (Arg, Btyp);
7552 end if;
fbf5a39b 7553
10303118
BD		 7554 elsif Has_Compatible_Type (Arg, Component_Type (Typ)) then
7555 if Nkind (Arg) = N_Aggregate
7556 and then Is_Composite_Type (Component_Type (Typ))
7557 then
7558 if Is_Private_Type (Component_Type (Typ)) then
7559 Resolve (Arg, Btyp);
7560 else
7561 Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
7562 Set_Etype (Arg, Any_Type);
996ae0b0
RK		 7563 end if;
7564
7565 else
10303118
BD		 7566 if Is_Overloaded (Arg)
7567 and then Has_Compatible_Type (Arg, Typ)
7568 and then Etype (Arg) /= Any_Type
7569 then
7570 declare
7571 I : Interp_Index;
7572 It : Interp;
7573 Func : Entity_Id;
7574
7575 begin
7576 Get_First_Interp (Arg, I, It);
7577 Func := It.Nam;
7578 Get_Next_Interp (I, It);
7579
7580 -- Special-case the error message when the overloading is
7581 -- caused by a function that yields an array and can be
7582 -- called without parameters.
7583
7584 if It.Nam = Func then
7585 Error_Msg_Sloc := Sloc (Func);
7586 Error_Msg_N ("ambiguous call to function#", Arg);
7587 Error_Msg_NE
7588 ("\\interpretation as call yields&", Arg, Typ);
7589 Error_Msg_NE
7590 ("\\interpretation as indexing of call yields&",
7591 Arg, Component_Type (Typ));
7592
7593 else
7594 Error_Msg_N
7595 ("ambiguous operand for concatenation!", Arg);
19fb051c 7596
10303118
BD		 7597 Get_First_Interp (Arg, I, It);
7598 while Present (It.Nam) loop
7599 Error_Msg_Sloc := Sloc (It.Nam);
7600
7601 if Base_Type (It.Typ) = Base_Type (Typ)
7602 or else Base_Type (It.Typ) =
19fb051c 7603 Base_Type (Component_Type (Typ))
10303118 7604 then
4e7a4f6e
AC		 7605 Error_Msg_N -- CODEFIX
7606 ("\\possible interpretation#", Arg);
10303118
BD		 7607 end if;
7608
7609 Get_Next_Interp (I, It);
7610 end loop;
7611 end if;
7612 end;
7613 end if;
7614
7615 Resolve (Arg, Component_Type (Typ));
7616
7617 if Nkind (Arg) = N_String_Literal then
7618 Set_Etype (Arg, Component_Type (Typ));
7619 end if;
7620
7621 if Arg = Left_Opnd (N) then
7622 Set_Is_Component_Left_Opnd (N);
7623 else
7624 Set_Is_Component_Right_Opnd (N);
7625 end if;
996ae0b0
RK		 7626 end if;
7627
10303118
BD		 7628 else
7629 Resolve (Arg, Btyp);
7630 end if;
7631
2933b16c
RD		 7632 -- Concatenation is restricted in SPARK or ALFA: each operand must be
7633 -- either a string literal, a static character expression, or another
7634 -- concatenation. Arg cannot be a concatenation here as callers of
7635 -- Resolve_Op_Concat_Arg call it separately on each final operand, past
7636 -- concatenation operations.
7637
fe5d3068
YM		 7638 if Is_Character_Type (Etype (Arg)) then
7639 if not Is_Static_Expression (Arg) then
7640 Check_Formal_Restriction
7641 ("character operand for concatenation should be static", N);
7642 end if;
2933b16c 7643
fe5d3068
YM		 7644 elsif Is_String_Type (Etype (Arg)) then
7645 if Nkind (Arg) /= N_String_Literal then
7646 Check_Formal_Restriction
7647 ("string operand for concatenation should be a literal", N);
7648 end if;
2933b16c 7649
b9e48541
AC		 7650 -- Do not issue error on an operand that is neither a character nor a
7651 -- string, as the error is issued in Resolve_Op_Concat.
2933b16c 7652
fe5d3068
YM		 7653 else
7654 null;
2933b16c
RD		 7655 end if;
7656
10303118
BD		 7657 Check_Unset_Reference (Arg);
7658 end Resolve_Op_Concat_Arg;
996ae0b0 7659
10303118
BD		 7660 -----------------------------
7661 -- Resolve_Op_Concat_First --
7662 -----------------------------
7663
7664 procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
7665 Btyp : constant Entity_Id := Base_Type (Typ);
7666 Op1 : constant Node_Id := Left_Opnd (N);
7667 Op2 : constant Node_Id := Right_Opnd (N);
996ae0b0
RK		 7668
7669 begin
dae2b8ea
HK		 7670 -- The parser folds an enormous sequence of concatenations of string
7671 -- literals into "" & "...", where the Is_Folded_In_Parser flag is set
4fc26524 7672 -- in the right operand. If the expression resolves to a predefined "&"
dae2b8ea
HK		 7673 -- operator, all is well. Otherwise, the parser's folding is wrong, so
7674 -- we give an error. See P_Simple_Expression in Par.Ch4.
7675
7676 if Nkind (Op2) = N_String_Literal
7677 and then Is_Folded_In_Parser (Op2)
7678 and then Ekind (Entity (N)) = E_Function
7679 then
7680 pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
7681 and then String_Length (Strval (Op1)) = 0);
7682 Error_Msg_N ("too many user-defined concatenations", N);
7683 return;
7684 end if;
7685
996ae0b0
RK		 7686 Set_Etype (N, Btyp);
7687
7688 if Is_Limited_Composite (Btyp) then
7689 Error_Msg_N ("concatenation not available for limited array", N);
fbf5a39b 7690 Explain_Limited_Type (Btyp, N);
996ae0b0 7691 end if;
10303118 7692 end Resolve_Op_Concat_First;
996ae0b0 7693
10303118
BD		 7694 ----------------------------
7695 -- Resolve_Op_Concat_Rest --
7696 ----------------------------
996ae0b0 7697
10303118
BD		 7698 procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
7699 Op1 : constant Node_Id := Left_Opnd (N);
7700 Op2 : constant Node_Id := Right_Opnd (N);
996ae0b0 7701
10303118
BD		 7702 begin
7703 Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
996ae0b0 7704
fbf5a39b 7705 Generate_Operator_Reference (N, Typ);
996ae0b0
RK		 7706
7707 if Is_String_Type (Typ) then
7708 Eval_Concatenation (N);
7709 end if;
7710
d81b4bfe
TQ		 7711 -- If this is not a static concatenation, but the result is a string
7712 -- type (and not an array of strings) ensure that static string operands
7713 -- have their subtypes properly constructed.
996ae0b0
RK		 7714
7715 if Nkind (N) /= N_String_Literal
7716 and then Is_Character_Type (Component_Type (Typ))
7717 then
7718 Set_String_Literal_Subtype (Op1, Typ);
7719 Set_String_Literal_Subtype (Op2, Typ);
7720 end if;
10303118 7721 end Resolve_Op_Concat_Rest;
996ae0b0
RK		 7722
7723 ----------------------
7724 -- Resolve_Op_Expon --
7725 ----------------------
7726
7727 procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
7728 B_Typ : constant Entity_Id := Base_Type (Typ);
7729
7730 begin
f3d57416 7731 -- Catch attempts to do fixed-point exponentiation with universal
758c442c
GD		 7732 -- operands, which is a case where the illegality is not caught during
7733 -- normal operator analysis.
996ae0b0
RK		 7734
7735 if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
7736 Error_Msg_N ("exponentiation not available for fixed point", N);
7737 return;
7738 end if;
7739
fbf5a39b
AC		 7740 if Comes_From_Source (N)
7741 and then Ekind (Entity (N)) = E_Function
7742 and then Is_Imported (Entity (N))
7743 and then Is_Intrinsic_Subprogram (Entity (N))
7744 then
7745 Resolve_Intrinsic_Operator (N, Typ);
7746 return;
7747 end if;
7748
996ae0b0
RK		 7749 if Etype (Left_Opnd (N)) = Universal_Integer
7750 or else Etype (Left_Opnd (N)) = Universal_Real
7751 then
7752 Check_For_Visible_Operator (N, B_Typ);
7753 end if;
7754
7755 -- We do the resolution using the base type, because intermediate values
7756 -- in expressions always are of the base type, not a subtype of it.
7757
7758 Resolve (Left_Opnd (N), B_Typ);
7759 Resolve (Right_Opnd (N), Standard_Integer);
7760
7761 Check_Unset_Reference (Left_Opnd (N));
7762 Check_Unset_Reference (Right_Opnd (N));
7763
7764 Set_Etype (N, B_Typ);
fbf5a39b 7765 Generate_Operator_Reference (N, B_Typ);
996ae0b0
RK		 7766 Eval_Op_Expon (N);
7767
7768 -- Set overflow checking bit. Much cleverer code needed here eventually
7769 -- and perhaps the Resolve routines should be separated for the various
7770 -- arithmetic operations, since they will need different processing. ???
7771
7772 if Nkind (N) in N_Op then
7773 if not Overflow_Checks_Suppressed (Etype (N)) then
fbf5a39b 7774 Enable_Overflow_Check (N);
996ae0b0
RK		 7775 end if;
7776 end if;
996ae0b0
RK		 7777 end Resolve_Op_Expon;
7778
7779 --------------------
7780 -- Resolve_Op_Not --
7781 --------------------
7782
7783 procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
7784 B_Typ : Entity_Id;
7785
7786 function Parent_Is_Boolean return Boolean;
5cc9353d
RD		 7787 -- This function determines if the parent node is a boolean operator or
7788 -- operation (comparison op, membership test, or short circuit form) and
7789 -- the not in question is the left operand of this operation. Note that
7790 -- if the not is in parens, then false is returned.
996ae0b0 7791
aa180613
RD		 7792 -----------------------
7793 -- Parent_Is_Boolean --
7794 -----------------------
7795
996ae0b0
RK		 7796 function Parent_Is_Boolean return Boolean is
7797 begin
7798 if Paren_Count (N) /= 0 then
7799 return False;
7800
7801 else
7802 case Nkind (Parent (N)) is
7803 when N_Op_And |
7804 N_Op_Eq |
7805 N_Op_Ge |
7806 N_Op_Gt |
7807 N_Op_Le |
7808 N_Op_Lt |
7809 N_Op_Ne |
7810 N_Op_Or |
7811 N_Op_Xor |
7812 N_In |
7813 N_Not_In |
7814 N_And_Then |
aa180613 7815 N_Or_Else =>
996ae0b0
RK		 7816
7817 return Left_Opnd (Parent (N)) = N;
7818
7819 when others =>
7820 return False;
7821 end case;
7822 end if;
7823 end Parent_Is_Boolean;
7824
7825 -- Start of processing for Resolve_Op_Not
7826
7827 begin
758c442c
GD		 7828 -- Predefined operations on scalar types yield the base type. On the
7829 -- other hand, logical operations on arrays yield the type of the
7830 -- arguments (and the context).
996ae0b0
RK		 7831
7832 if Is_Array_Type (Typ) then
7833 B_Typ := Typ;
7834 else
7835 B_Typ := Base_Type (Typ);
7836 end if;
7837
001c7783
AC		 7838 if Is_VMS_Operator (Entity (N)) then
7839 null;
7840
f3d57416 7841 -- Straightforward case of incorrect arguments
aa180613 7842
001c7783 7843 elsif not Valid_Boolean_Arg (Typ) then
996ae0b0
RK		 7844 Error_Msg_N ("invalid operand type for operator&", N);
7845 Set_Etype (N, Any_Type);
7846 return;
7847
aa180613
RD		 7848 -- Special case of probable missing parens
7849
fbf5a39b 7850 elsif Typ = Universal_Integer or else Typ = Any_Modular then
996ae0b0 7851 if Parent_Is_Boolean then
ed2233dc 7852 Error_Msg_N
996ae0b0
RK		 7853 ("operand of not must be enclosed in parentheses",
7854 Right_Opnd (N));
7855 else
7856 Error_Msg_N
7857 ("no modular type available in this context", N);
7858 end if;
7859
7860 Set_Etype (N, Any_Type);
7861 return;
7862
5cc9353d 7863 -- OK resolution of NOT
aa180613 7864
996ae0b0 7865 else
aa180613
RD		 7866 -- Warn if non-boolean types involved. This is a case like not a < b
7867 -- where a and b are modular, where we will get (not a) < b and most
7868 -- likely not (a < b) was intended.
7869
7870 if Warn_On_Questionable_Missing_Parens
7871 and then not Is_Boolean_Type (Typ)
996ae0b0
RK		 7872 and then Parent_Is_Boolean
7873 then
ed2233dc 7874 Error_Msg_N ("?not expression should be parenthesized here!", N);
996ae0b0
RK		 7875 end if;
7876
09bc9ab6
RD		 7877 -- Warn on double negation if checking redundant constructs
7878
7879 if Warn_On_Redundant_Constructs
7880 and then Comes_From_Source (N)
7881 and then Comes_From_Source (Right_Opnd (N))
7882 and then Root_Type (Typ) = Standard_Boolean
7883 and then Nkind (Right_Opnd (N)) = N_Op_Not
7884 then
ed2233dc 7885 Error_Msg_N ("redundant double negation?", N);
09bc9ab6
RD		 7886 end if;
7887
7888 -- Complete resolution and evaluation of NOT
7889
996ae0b0
RK		 7890 Resolve (Right_Opnd (N), B_Typ);
7891 Check_Unset_Reference (Right_Opnd (N));
7892 Set_Etype (N, B_Typ);
fbf5a39b 7893 Generate_Operator_Reference (N, B_Typ);
996ae0b0
RK		 7894 Eval_Op_Not (N);
7895 end if;
7896 end Resolve_Op_Not;
7897
7898 -----------------------------
7899 -- Resolve_Operator_Symbol --
7900 -----------------------------
7901
7902 -- Nothing to be done, all resolved already
7903
7904 procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
07fc65c4
GB		 7905 pragma Warnings (Off, N);
7906 pragma Warnings (Off, Typ);
7907
996ae0b0
RK		 7908 begin
7909 null;
7910 end Resolve_Operator_Symbol;
7911
7912 ----------------------------------
7913 -- Resolve_Qualified_Expression --
7914 ----------------------------------
7915
7916 procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
07fc65c4
GB		 7917 pragma Warnings (Off, Typ);
7918
996ae0b0
RK		 7919 Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
7920 Expr : constant Node_Id := Expression (N);
7921
7922 begin
7923 Resolve (Expr, Target_Typ);
7924
fe5d3068 7925 if Is_Array_Type (Target_Typ)
b0186f71
AC		 7926 and then Is_Array_Type (Etype (Expr))
7927 and then not Matching_Static_Array_Bounds (Target_Typ, Etype (Expr))
7928 then
fe5d3068
YM		 7929 Check_Formal_Restriction
7930 ("array types should have matching static bounds", N);
b0186f71
AC		 7931 end if;
7932
5cc9353d
RD		 7933 -- A qualified expression requires an exact match of the type, class-
7934 -- wide matching is not allowed. However, if the qualifying type is
7935 -- specific and the expression has a class-wide type, it may still be
7936 -- okay, since it can be the result of the expansion of a call to a
7937 -- dispatching function, so we also have to check class-wideness of the
7938 -- type of the expression's original node.
1420b484
JM		 7939
7940 if (Is_Class_Wide_Type (Target_Typ)
7941 or else
7942 (Is_Class_Wide_Type (Etype (Expr))
7943 and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
996ae0b0
RK		 7944 and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
7945 then
7946 Wrong_Type (Expr, Target_Typ);
7947 end if;
7948
90c63b09
AC		 7949 -- If the target type is unconstrained, then we reset the type of the
7950 -- result from the type of the expression. For other cases, the actual
7951 -- subtype of the expression is the target type.
996ae0b0
RK		 7952
7953 if Is_Composite_Type (Target_Typ)
7954 and then not Is_Constrained (Target_Typ)
7955 then
7956 Set_Etype (N, Etype (Expr));
7957 end if;
7958
7959 Eval_Qualified_Expression (N);
7960 end Resolve_Qualified_Expression;
7961
a961aa79
AC		 7962 -----------------------------------
7963 -- Resolve_Quantified_Expression --
7964 -----------------------------------
7965
7966 procedure Resolve_Quantified_Expression (N : Node_Id; Typ : Entity_Id) is
7967 begin
7968 -- The loop structure is already resolved during its analysis, only the
0592046e
AC		 7969 -- resolution of the condition needs to be done. Expansion is disabled
7970 -- so that checks and other generated code are inserted in the tree
7971 -- after expression has been rewritten as a loop.
a961aa79 7972
0592046e 7973 Expander_Mode_Save_And_Set (False);
a961aa79 7974 Resolve (Condition (N), Typ);
0592046e 7975 Expander_Mode_Restore;
a961aa79
AC		 7976 end Resolve_Quantified_Expression;
7977
996ae0b0
RK		 7978 -------------------
7979 -- Resolve_Range --
7980 -------------------
7981
7982 procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
7983 L : constant Node_Id := Low_Bound (N);
7984 H : constant Node_Id := High_Bound (N);
7985
bd29d519
AC		 7986 function First_Last_Ref return Boolean;
7987 -- Returns True if N is of the form X'First .. X'Last where X is the
7988 -- same entity for both attributes.
7989
7990 --------------------
7991 -- First_Last_Ref --
7992 --------------------
7993
7994 function First_Last_Ref return Boolean is
7995 Lorig : constant Node_Id := Original_Node (L);
7996 Horig : constant Node_Id := Original_Node (H);
7997
7998 begin
7999 if Nkind (Lorig) = N_Attribute_Reference
8000 and then Nkind (Horig) = N_Attribute_Reference
8001 and then Attribute_Name (Lorig) = Name_First
8002 and then Attribute_Name (Horig) = Name_Last
8003 then
8004 declare
8005 PL : constant Node_Id := Prefix (Lorig);
8006 PH : constant Node_Id := Prefix (Horig);
8007 begin
8008 if Is_Entity_Name (PL)
8009 and then Is_Entity_Name (PH)
8010 and then Entity (PL) = Entity (PH)
8011 then
8012 return True;
8013 end if;
8014 end;
8015 end if;
8016
8017 return False;
8018 end First_Last_Ref;
8019
8020 -- Start of processing for Resolve_Range
8021
996ae0b0
RK		 8022 begin
8023 Set_Etype (N, Typ);
8024 Resolve (L, Typ);
8025 Resolve (H, Typ);
8026
bd29d519
AC		 8027 -- Check for inappropriate range on unordered enumeration type
8028
8029 if Bad_Unordered_Enumeration_Reference (N, Typ)
8030
8031 -- Exclude X'First .. X'Last if X is the same entity for both
8032
8033 and then not First_Last_Ref
8034 then
8035 Error_Msg ("subrange of unordered enumeration type?", Sloc (N));
498d1b80
AC		 8036 end if;
8037
996ae0b0
RK		 8038 Check_Unset_Reference (L);
8039 Check_Unset_Reference (H);
8040
8041 -- We have to check the bounds for being within the base range as
758c442c
GD		 8042 -- required for a non-static context. Normally this is automatic and
8043 -- done as part of evaluating expressions, but the N_Range node is an
8044 -- exception, since in GNAT we consider this node to be a subexpression,
8045 -- even though in Ada it is not. The circuit in Sem_Eval could check for
8046 -- this, but that would put the test on the main evaluation path for
8047 -- expressions.
996ae0b0
RK		 8048
8049 Check_Non_Static_Context (L);
8050 Check_Non_Static_Context (H);
8051
b7d1f17f
HK		 8052 -- Check for an ambiguous range over character literals. This will
8053 -- happen with a membership test involving only literals.
8054
8055 if Typ = Any_Character then
8056 Ambiguous_Character (L);
8057 Set_Etype (N, Any_Type);
8058 return;
8059 end if;
8060
5cc9353d
RD		 8061 -- If bounds are static, constant-fold them, so size computations are
8062 -- identical between front-end and back-end. Do not perform this
fbf5a39b 8063 -- transformation while analyzing generic units, as type information
5cc9353d 8064 -- would be lost when reanalyzing the constant node in the instance.
fbf5a39b
AC		 8065
8066 if Is_Discrete_Type (Typ) and then Expander_Active then
8067 if Is_OK_Static_Expression (L) then
8068 Fold_Uint (L, Expr_Value (L), Is_Static_Expression (L));
8069 end if;
8070
8071 if Is_OK_Static_Expression (H) then
8072 Fold_Uint (H, Expr_Value (H), Is_Static_Expression (H));
8073 end if;
8074 end if;
996ae0b0
RK		 8075 end Resolve_Range;
8076
8077 --------------------------
8078 -- Resolve_Real_Literal --
8079 --------------------------
8080
8081 procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
8082 Actual_Typ : constant Entity_Id := Etype (N);
8083
8084 begin
8085 -- Special processing for fixed-point literals to make sure that the
5cc9353d
RD		 8086 -- value is an exact multiple of small where this is required. We skip
8087 -- this for the universal real case, and also for generic types.
996ae0b0
RK		 8088
8089 if Is_Fixed_Point_Type (Typ)
8090 and then Typ /= Universal_Fixed
8091 and then Typ /= Any_Fixed
8092 and then not Is_Generic_Type (Typ)
8093 then
8094 declare
8095 Val : constant Ureal := Realval (N);
8096 Cintr : constant Ureal := Val / Small_Value (Typ);
8097 Cint : constant Uint := UR_Trunc (Cintr);
8098 Den : constant Uint := Norm_Den (Cintr);
8099 Stat : Boolean;
8100
8101 begin
8102 -- Case of literal is not an exact multiple of the Small
8103
8104 if Den /= 1 then
8105
5cc9353d
RD		 8106 -- For a source program literal for a decimal fixed-point type,
8107 -- this is statically illegal (RM 4.9(36)).
996ae0b0
RK		 8108
8109 if Is_Decimal_Fixed_Point_Type (Typ)
8110 and then Actual_Typ = Universal_Real
8111 and then Comes_From_Source (N)
8112 then
8113 Error_Msg_N ("value has extraneous low order digits", N);
8114 end if;
8115
bc5f3720
RD		 8116 -- Generate a warning if literal from source
8117
8118 if Is_Static_Expression (N)
8119 and then Warn_On_Bad_Fixed_Value
8120 then
8121 Error_Msg_N
aa5147f0 8122 ("?static fixed-point value is not a multiple of Small!",
bc5f3720
RD		 8123 N);
8124 end if;
8125
996ae0b0
RK		 8126 -- Replace literal by a value that is the exact representation
8127 -- of a value of the type, i.e. a multiple of the small value,
8128 -- by truncation, since Machine_Rounds is false for all GNAT
8129 -- fixed-point types (RM 4.9(38)).
8130
8131 Stat := Is_Static_Expression (N);
8132 Rewrite (N,
8133 Make_Real_Literal (Sloc (N),
8134 Realval => Small_Value (Typ) * Cint));
8135
8136 Set_Is_Static_Expression (N, Stat);
8137 end if;
8138
8139 -- In all cases, set the corresponding integer field
8140
8141 Set_Corresponding_Integer_Value (N, Cint);
8142 end;
8143 end if;
8144
8145 -- Now replace the actual type by the expected type as usual
8146
8147 Set_Etype (N, Typ);
8148 Eval_Real_Literal (N);
8149 end Resolve_Real_Literal;
8150
8151 -----------------------
8152 -- Resolve_Reference --
8153 -----------------------
8154
8155 procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
8156 P : constant Node_Id := Prefix (N);
8157
8158 begin
8159 -- Replace general access with specific type
8160
8161 if Ekind (Etype (N)) = E_Allocator_Type then
8162 Set_Etype (N, Base_Type (Typ));
8163 end if;
8164
8165 Resolve (P, Designated_Type (Etype (N)));
8166
5cc9353d
RD		 8167 -- If we are taking the reference of a volatile entity, then treat it as
8168 -- a potential modification of this entity. This is too conservative,
8169 -- but necessary because remove side effects can cause transformations
8170 -- of normal assignments into reference sequences that otherwise fail to
8171 -- notice the modification.
996ae0b0 8172
fbf5a39b 8173 if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
45fc7ddb 8174 Note_Possible_Modification (P, Sure => False);
996ae0b0
RK		 8175 end if;
8176 end Resolve_Reference;
8177
8178 --------------------------------
8179 -- Resolve_Selected_Component --
8180 --------------------------------
8181
8182 procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
8183 Comp : Entity_Id;
8184 Comp1 : Entity_Id := Empty; -- prevent junk warning
8185 P : constant Node_Id := Prefix (N);
8186 S : constant Node_Id := Selector_Name (N);
8187 T : Entity_Id := Etype (P);
8188 I : Interp_Index;
8189 I1 : Interp_Index := 0; -- prevent junk warning
8190 It : Interp;
8191 It1 : Interp;
8192 Found : Boolean;
8193
6510f4c9
GB		 8194 function Init_Component return Boolean;
8195 -- Check whether this is the initialization of a component within an
fbf5a39b 8196 -- init proc (by assignment or call to another init proc). If true,
6510f4c9
GB		 8197 -- there is no need for a discriminant check.
8198
8199 --------------------
8200 -- Init_Component --
8201 --------------------
8202
8203 function Init_Component return Boolean is
8204 begin
8205 return Inside_Init_Proc
8206 and then Nkind (Prefix (N)) = N_Identifier
8207 and then Chars (Prefix (N)) = Name_uInit
8208 and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
8209 end Init_Component;
8210
8211 -- Start of processing for Resolve_Selected_Component
8212
996ae0b0
RK		 8213 begin
8214 if Is_Overloaded (P) then
8215
8216 -- Use the context type to select the prefix that has a selector
8217 -- of the correct name and type.
8218
8219 Found := False;
8220 Get_First_Interp (P, I, It);
8221
8222 Search : while Present (It.Typ) loop
8223 if Is_Access_Type (It.Typ) then
8224 T := Designated_Type (It.Typ);
8225 else
8226 T := It.Typ;
8227 end if;
8228
8229 if Is_Record_Type (T) then
36fcf362
RD		 8230
8231 -- The visible components of a class-wide type are those of
8232 -- the root type.
8233
8234 if Is_Class_Wide_Type (T) then
8235 T := Etype (T);
8236 end if;
8237
996ae0b0 8238 Comp := First_Entity (T);
996ae0b0 8239 while Present (Comp) loop
996ae0b0
RK		 8240 if Chars (Comp) = Chars (S)
8241 and then Covers (Etype (Comp), Typ)
8242 then
8243 if not Found then
8244 Found := True;
8245 I1 := I;
8246 It1 := It;
8247 Comp1 := Comp;
8248
8249 else
8250 It := Disambiguate (P, I1, I, Any_Type);
8251
8252 if It = No_Interp then
8253 Error_Msg_N
8254 ("ambiguous prefix for selected component", N);
8255 Set_Etype (N, Typ);
8256 return;
8257
8258 else
8259 It1 := It;
8260
c8ef728f
ES		 8261 -- There may be an implicit dereference. Retrieve
8262 -- designated record type.
8263
8264 if Is_Access_Type (It1.Typ) then
8265 T := Designated_Type (It1.Typ);
8266 else
8267 T := It1.Typ;
8268 end if;
8269
8270 if Scope (Comp1) /= T then
996ae0b0
RK		 8271
8272 -- Resolution chooses the new interpretation.
8273 -- Find the component with the right name.
8274
c8ef728f 8275 Comp1 := First_Entity (T);
996ae0b0
RK		 8276 while Present (Comp1)
8277 and then Chars (Comp1) /= Chars (S)
8278 loop
8279 Comp1 := Next_Entity (Comp1);
8280 end loop;
8281 end if;
8282
8283 exit Search;
8284 end if;
8285 end if;
8286 end if;
8287
8288 Comp := Next_Entity (Comp);
8289 end loop;
996ae0b0
RK		 8290 end if;
8291
8292 Get_Next_Interp (I, It);
996ae0b0
RK		 8293 end loop Search;
8294
8295 Resolve (P, It1.Typ);
8296 Set_Etype (N, Typ);
aa180613 8297 Set_Entity_With_Style_Check (S, Comp1);
996ae0b0
RK		 8298
8299 else
fbf5a39b 8300 -- Resolve prefix with its type
996ae0b0
RK		 8301
8302 Resolve (P, T);
8303 end if;
8304
aa180613
RD		 8305 -- Generate cross-reference. We needed to wait until full overloading
8306 -- resolution was complete to do this, since otherwise we can't tell if
01e17342 8307 -- we are an lvalue or not.
aa180613
RD		 8308
8309 if May_Be_Lvalue (N) then
8310 Generate_Reference (Entity (S), S, 'm');
8311 else
8312 Generate_Reference (Entity (S), S, 'r');
8313 end if;
8314
c8ef728f
ES		 8315 -- If prefix is an access type, the node will be transformed into an
8316 -- explicit dereference during expansion. The type of the node is the
8317 -- designated type of that of the prefix.
996ae0b0
RK		 8318
8319 if Is_Access_Type (Etype (P)) then
996ae0b0 8320 T := Designated_Type (Etype (P));
c8ef728f 8321 Check_Fully_Declared_Prefix (T, P);
996ae0b0
RK		 8322 else
8323 T := Etype (P);
8324 end if;
8325
8326 if Has_Discriminants (T)
964f13da 8327 and then Ekind_In (Entity (S), E_Component, E_Discriminant)
996ae0b0
RK		 8328 and then Present (Original_Record_Component (Entity (S)))
8329 and then Ekind (Original_Record_Component (Entity (S))) = E_Component
8330 and then Present (Discriminant_Checking_Func
8331 (Original_Record_Component (Entity (S))))
8332 and then not Discriminant_Checks_Suppressed (T)
6510f4c9 8333 and then not Init_Component
996ae0b0
RK		 8334 then
8335 Set_Do_Discriminant_Check (N);
8336 end if;
8337
8338 if Ekind (Entity (S)) = E_Void then
8339 Error_Msg_N ("premature use of component", S);
8340 end if;
8341
8342 -- If the prefix is a record conversion, this may be a renamed
8343 -- discriminant whose bounds differ from those of the original
8344 -- one, so we must ensure that a range check is performed.
8345
8346 if Nkind (P) = N_Type_Conversion
8347 and then Ekind (Entity (S)) = E_Discriminant
fbf5a39b 8348 and then Is_Discrete_Type (Typ)
996ae0b0
RK		 8349 then
8350 Set_Etype (N, Base_Type (Typ));
8351 end if;
8352
8353 -- Note: No Eval processing is required, because the prefix is of a
8354 -- record type, or protected type, and neither can possibly be static.
8355
c28408b7
RD		 8356 -- If the array type is atomic, and is packed, and we are in a left side
8357 -- context, then this is worth a warning, since we have a situation
5cc9353d
RD		 8358 -- where the access to the component may cause extra read/writes of the
8359 -- atomic array object, which could be considered unexpected.
c28408b7
RD		 8360
8361 if Nkind (N) = N_Selected_Component
8362 and then (Is_Atomic (T)
8363 or else (Is_Entity_Name (Prefix (N))
8364 and then Is_Atomic (Entity (Prefix (N)))))
8365 and then Is_Packed (T)
8366 and then Is_LHS (N)
8367 then
8368 Error_Msg_N ("?assignment to component of packed atomic record",
8369 Prefix (N));
8370 Error_Msg_N ("?\may cause unexpected accesses to atomic object",
8371 Prefix (N));
8372 end if;
996ae0b0
RK		 8373 end Resolve_Selected_Component;
8374
8375 -------------------
8376 -- Resolve_Shift --
8377 -------------------
8378
8379 procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
8380 B_Typ : constant Entity_Id := Base_Type (Typ);
8381 L : constant Node_Id := Left_Opnd (N);
8382 R : constant Node_Id := Right_Opnd (N);
8383
8384 begin
8385 -- We do the resolution using the base type, because intermediate values
8386 -- in expressions always are of the base type, not a subtype of it.
8387
8388 Resolve (L, B_Typ);
8389 Resolve (R, Standard_Natural);
8390
8391 Check_Unset_Reference (L);
8392 Check_Unset_Reference (R);
8393
8394 Set_Etype (N, B_Typ);
fbf5a39b 8395 Generate_Operator_Reference (N, B_Typ);
996ae0b0
RK		 8396 Eval_Shift (N);
8397 end Resolve_Shift;
8398
8399 ---------------------------
8400 -- Resolve_Short_Circuit --
8401 ---------------------------
8402
8403 procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
8404 B_Typ : constant Entity_Id := Base_Type (Typ);
8405 L : constant Node_Id := Left_Opnd (N);
8406 R : constant Node_Id := Right_Opnd (N);
8407
8408 begin
8409 Resolve (L, B_Typ);
8410 Resolve (R, B_Typ);
8411
45fc7ddb
HK		 8412 -- Check for issuing warning for always False assert/check, this happens
8413 -- when assertions are turned off, in which case the pragma Assert/Check
36fcf362
RD		 8414 -- was transformed into:
8415
8416 -- if False and then <condition> then ...
8417
8418 -- and we detect this pattern
8419
8420 if Warn_On_Assertion_Failure
8421 and then Is_Entity_Name (R)
8422 and then Entity (R) = Standard_False
8423 and then Nkind (Parent (N)) = N_If_Statement
8424 and then Nkind (N) = N_And_Then
8425 and then Is_Entity_Name (L)
8426 and then Entity (L) = Standard_False
8427 then
8428 declare
8429 Orig : constant Node_Id := Original_Node (Parent (N));
45fc7ddb 8430
36fcf362
RD		 8431 begin
8432 if Nkind (Orig) = N_Pragma
26570b21 8433 and then Pragma_Name (Orig) = Name_Assert
36fcf362
RD		 8434 then
8435 -- Don't want to warn if original condition is explicit False
8436
8437 declare
8438 Expr : constant Node_Id :=
8439 Original_Node
8440 (Expression
8441 (First (Pragma_Argument_Associations (Orig))));
8442 begin
8443 if Is_Entity_Name (Expr)
8444 and then Entity (Expr) = Standard_False
8445 then
8446 null;
8447 else
51bf9bdf
AC		 8448 -- Issue warning. We do not want the deletion of the
8449 -- IF/AND-THEN to take this message with it. We achieve
8450 -- this by making sure that the expanded code points to
8451 -- the Sloc of the expression, not the original pragma.
8452
8453 Error_Msg_N
e7c0dd39 8454 ("?assertion would fail at run time!",
51bf9bdf
AC		 8455 Expression
8456 (First (Pragma_Argument_Associations (Orig))));
36fcf362
RD		 8457 end if;
8458 end;
45fc7ddb
HK		 8459
8460 -- Similar processing for Check pragma
8461
8462 elsif Nkind (Orig) = N_Pragma
8463 and then Pragma_Name (Orig) = Name_Check
8464 then
8465 -- Don't want to warn if original condition is explicit False
8466
8467 declare
8468 Expr : constant Node_Id :=
8469 Original_Node
8470 (Expression
8471 (Next (First
8472 (Pragma_Argument_Associations (Orig)))));
8473 begin
8474 if Is_Entity_Name (Expr)
8475 and then Entity (Expr) = Standard_False
8476 then
8477 null;
8478 else
51bf9bdf 8479 Error_Msg_N
e7c0dd39 8480 ("?check would fail at run time!",
51bf9bdf
AC		 8481 Expression
8482 (Last (Pragma_Argument_Associations (Orig))));
45fc7ddb
HK		 8483 end if;
8484 end;
36fcf362
RD		 8485 end if;
8486 end;
8487 end if;
8488
8489 -- Continue with processing of short circuit
8490
996ae0b0
RK		 8491 Check_Unset_Reference (L);
8492 Check_Unset_Reference (R);
8493
8494 Set_Etype (N, B_Typ);
8495 Eval_Short_Circuit (N);
8496 end Resolve_Short_Circuit;
8497
8498 -------------------
8499 -- Resolve_Slice --
8500 -------------------
8501
8502 procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
8503 Name : constant Node_Id := Prefix (N);
8504 Drange : constant Node_Id := Discrete_Range (N);
8505 Array_Type : Entity_Id := Empty;
8506 Index : Node_Id;
8507
8508 begin
8509 if Is_Overloaded (Name) then
8510
d81b4bfe
TQ		 8511 -- Use the context type to select the prefix that yields the correct
8512 -- array type.
996ae0b0
RK		 8513
8514 declare
8515 I : Interp_Index;
8516 I1 : Interp_Index := 0;
8517 It : Interp;
8518 P : constant Node_Id := Prefix (N);
8519 Found : Boolean := False;
8520
8521 begin
8522 Get_First_Interp (P, I, It);
996ae0b0 8523 while Present (It.Typ) loop
996ae0b0
RK		 8524 if (Is_Array_Type (It.Typ)
8525 and then Covers (Typ, It.Typ))
8526 or else (Is_Access_Type (It.Typ)
8527 and then Is_Array_Type (Designated_Type (It.Typ))
8528 and then Covers (Typ, Designated_Type (It.Typ)))
8529 then
8530 if Found then
8531 It := Disambiguate (P, I1, I, Any_Type);
8532
8533 if It = No_Interp then
8534 Error_Msg_N ("ambiguous prefix for slicing", N);
8535 Set_Etype (N, Typ);
8536 return;
8537 else
8538 Found := True;
8539 Array_Type := It.Typ;
8540 I1 := I;
8541 end if;
8542 else
8543 Found := True;
8544 Array_Type := It.Typ;
8545 I1 := I;
8546 end if;
8547 end if;
8548
8549 Get_Next_Interp (I, It);
8550 end loop;
8551 end;
8552
8553 else
8554 Array_Type := Etype (Name);
8555 end if;
8556
8557 Resolve (Name, Array_Type);
8558
8559 if Is_Access_Type (Array_Type) then
8560 Apply_Access_Check (N);
8561 Array_Type := Designated_Type (Array_Type);
8562
c8ef728f
ES		 8563 -- If the prefix is an access to an unconstrained array, we must use
8564 -- the actual subtype of the object to perform the index checks. The
8565 -- object denoted by the prefix is implicit in the node, so we build
8566 -- an explicit representation for it in order to compute the actual
8567 -- subtype.
82c80734
RD		 8568
8569 if not Is_Constrained (Array_Type) then
8570 Remove_Side_Effects (Prefix (N));
8571
8572 declare
8573 Obj : constant Node_Id :=
8574 Make_Explicit_Dereference (Sloc (N),
8575 Prefix => New_Copy_Tree (Prefix (N)));
8576 begin
8577 Set_Etype (Obj, Array_Type);
8578 Set_Parent (Obj, Parent (N));
8579 Array_Type := Get_Actual_Subtype (Obj);
8580 end;
8581 end if;
8582
996ae0b0 8583 elsif Is_Entity_Name (Name)
6c994759 8584 or else Nkind (Name) = N_Explicit_Dereference
996ae0b0
RK		 8585 or else (Nkind (Name) = N_Function_Call
8586 and then not Is_Constrained (Etype (Name)))
8587 then
8588 Array_Type := Get_Actual_Subtype (Name);
aa5147f0
ES		 8589
8590 -- If the name is a selected component that depends on discriminants,
8591 -- build an actual subtype for it. This can happen only when the name
8592 -- itself is overloaded; otherwise the actual subtype is created when
8593 -- the selected component is analyzed.
8594
8595 elsif Nkind (Name) = N_Selected_Component
8596 and then Full_Analysis
8597 and then Depends_On_Discriminant (First_Index (Array_Type))
8598 then
8599 declare
8600 Act_Decl : constant Node_Id :=
8601 Build_Actual_Subtype_Of_Component (Array_Type, Name);
8602 begin
8603 Insert_Action (N, Act_Decl);
8604 Array_Type := Defining_Identifier (Act_Decl);
8605 end;
d79e621a
GD		 8606
8607 -- Maybe this should just be "else", instead of checking for the
5cc9353d
RD		 8608 -- specific case of slice??? This is needed for the case where the
8609 -- prefix is an Image attribute, which gets expanded to a slice, and so
8610 -- has a constrained subtype which we want to use for the slice range
8611 -- check applied below (the range check won't get done if the
8612 -- unconstrained subtype of the 'Image is used).
d79e621a
GD		 8613
8614 elsif Nkind (Name) = N_Slice then
8615 Array_Type := Etype (Name);
996ae0b0
RK		 8616 end if;
8617
8618 -- If name was overloaded, set slice type correctly now
8619
8620 Set_Etype (N, Array_Type);
8621
c8ef728f
ES		 8622 -- If the range is specified by a subtype mark, no resolution is
8623 -- necessary. Else resolve the bounds, and apply needed checks.
996ae0b0
RK		 8624
8625 if not Is_Entity_Name (Drange) then
8626 Index := First_Index (Array_Type);
8627 Resolve (Drange, Base_Type (Etype (Index)));
8628
dbe945f1
AC		 8629 if Nkind (Drange) = N_Range then
8630
8631 -- Ensure that side effects in the bounds are properly handled
8632
8633 Remove_Side_Effects (Low_Bound (Drange), Variable_Ref => True);
8634 Remove_Side_Effects (High_Bound (Drange), Variable_Ref => True);
0669bebe
GB		 8635
8636 -- Do not apply the range check to nodes associated with the
8637 -- frontend expansion of the dispatch table. We first check
dbe945f1 8638 -- if Ada.Tags is already loaded to avoid the addition of an
0669bebe
GB		 8639 -- undesired dependence on such run-time unit.
8640
dbe945f1
AC		 8641 if not Tagged_Type_Expansion
8642 or else not
8643 (RTU_Loaded (Ada_Tags)
cead616d
AC		 8644 and then Nkind (Prefix (N)) = N_Selected_Component
8645 and then Present (Entity (Selector_Name (Prefix (N))))
8646 and then Entity (Selector_Name (Prefix (N))) =
dbe945f1
AC		 8647 RTE_Record_Component (RE_Prims_Ptr))
8648 then
8649 Apply_Range_Check (Drange, Etype (Index));
8650 end if;
996ae0b0
RK		 8651 end if;
8652 end if;
8653
8654 Set_Slice_Subtype (N);
aa180613 8655
ea034236
AC		 8656 -- Check bad use of type with predicates
8657
8658 if Has_Predicates (Etype (Drange)) then
ed00f472 8659 Bad_Predicated_Subtype_Use
ea034236
AC		 8660 ("subtype& has predicate, not allowed in slice",
8661 Drange, Etype (Drange));
8662
8663 -- Otherwise here is where we check suspicious indexes
8664
8665 elsif Nkind (Drange) = N_Range then
aa180613
RD		 8666 Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
8667 Warn_On_Suspicious_Index (Name, High_Bound (Drange));
8668 end if;
8669
996ae0b0 8670 Eval_Slice (N);
996ae0b0
RK		 8671 end Resolve_Slice;
8672
8673 ----------------------------
8674 -- Resolve_String_Literal --
8675 ----------------------------
8676
8677 procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
8678 C_Typ : constant Entity_Id := Component_Type (Typ);
8679 R_Typ : constant Entity_Id := Root_Type (C_Typ);
8680 Loc : constant Source_Ptr := Sloc (N);
8681 Str : constant String_Id := Strval (N);
8682 Strlen : constant Nat := String_Length (Str);
8683 Subtype_Id : Entity_Id;
8684 Need_Check : Boolean;
8685
8686 begin
8687 -- For a string appearing in a concatenation, defer creation of the
8688 -- string_literal_subtype until the end of the resolution of the
c8ef728f
ES		 8689 -- concatenation, because the literal may be constant-folded away. This
8690 -- is a useful optimization for long concatenation expressions.
996ae0b0 8691
c8ef728f 8692 -- If the string is an aggregate built for a single character (which
996ae0b0 8693 -- happens in a non-static context) or a is null string to which special
c8ef728f
ES		 8694 -- checks may apply, we build the subtype. Wide strings must also get a
8695 -- string subtype if they come from a one character aggregate. Strings
996ae0b0
RK		 8696 -- generated by attributes might be static, but it is often hard to
8697 -- determine whether the enclosing context is static, so we generate
8698 -- subtypes for them as well, thus losing some rarer optimizations ???
8699 -- Same for strings that come from a static conversion.
8700
8701 Need_Check :=
8702 (Strlen = 0 and then Typ /= Standard_String)
8703 or else Nkind (Parent (N)) /= N_Op_Concat
8704 or else (N /= Left_Opnd (Parent (N))
8705 and then N /= Right_Opnd (Parent (N)))
82c80734
RD		 8706 or else ((Typ = Standard_Wide_String
8707 or else Typ = Standard_Wide_Wide_String)
996ae0b0
RK		 8708 and then Nkind (Original_Node (N)) /= N_String_Literal);
8709
d81b4bfe
TQ		 8710 -- If the resolving type is itself a string literal subtype, we can just
8711 -- reuse it, since there is no point in creating another.
996ae0b0
RK		 8712
8713 if Ekind (Typ) = E_String_Literal_Subtype then
8714 Subtype_Id := Typ;
8715
8716 elsif Nkind (Parent (N)) = N_Op_Concat
8717 and then not Need_Check
45fc7ddb
HK		 8718 and then not Nkind_In (Original_Node (N), N_Character_Literal,
8719 N_Attribute_Reference,
8720 N_Qualified_Expression,
8721 N_Type_Conversion)
996ae0b0
RK		 8722 then
8723 Subtype_Id := Typ;
8724
8725 -- Otherwise we must create a string literal subtype. Note that the
8726 -- whole idea of string literal subtypes is simply to avoid the need
8727 -- for building a full fledged array subtype for each literal.
45fc7ddb 8728
996ae0b0
RK		 8729 else
8730 Set_String_Literal_Subtype (N, Typ);
8731 Subtype_Id := Etype (N);
8732 end if;
8733
8734 if Nkind (Parent (N)) /= N_Op_Concat
8735 or else Need_Check
8736 then
8737 Set_Etype (N, Subtype_Id);
8738 Eval_String_Literal (N);
8739 end if;
8740
8741 if Is_Limited_Composite (Typ)
8742 or else Is_Private_Composite (Typ)
8743 then
8744 Error_Msg_N ("string literal not available for private array", N);
8745 Set_Etype (N, Any_Type);
8746 return;
8747 end if;
8748
d81b4bfe
TQ		 8749 -- The validity of a null string has been checked in the call to
8750 -- Eval_String_Literal.
996ae0b0
RK		 8751
8752 if Strlen = 0 then
8753 return;
8754
c8ef728f
ES		 8755 -- Always accept string literal with component type Any_Character, which
8756 -- occurs in error situations and in comparisons of literals, both of
8757 -- which should accept all literals.
996ae0b0
RK		 8758
8759 elsif R_Typ = Any_Character then
8760 return;
8761
f3d57416
RW		 8762 -- If the type is bit-packed, then we always transform the string
8763 -- literal into a full fledged aggregate.
996ae0b0
RK		 8764
8765 elsif Is_Bit_Packed_Array (Typ) then
8766 null;
8767
82c80734 8768 -- Deal with cases of Wide_Wide_String, Wide_String, and String
996ae0b0
RK		 8769
8770 else
82c80734
RD		 8771 -- For Standard.Wide_Wide_String, or any other type whose component
8772 -- type is Standard.Wide_Wide_Character, we know that all the
996ae0b0
RK		 8773 -- characters in the string must be acceptable, since the parser
8774 -- accepted the characters as valid character literals.
8775
82c80734 8776 if R_Typ = Standard_Wide_Wide_Character then
996ae0b0
RK		 8777 null;
8778
c8ef728f
ES		 8779 -- For the case of Standard.String, or any other type whose component
8780 -- type is Standard.Character, we must make sure that there are no
8781 -- wide characters in the string, i.e. that it is entirely composed
8782 -- of characters in range of type Character.
996ae0b0 8783
c8ef728f
ES		 8784 -- If the string literal is the result of a static concatenation, the
8785 -- test has already been performed on the components, and need not be
8786 -- repeated.
996ae0b0
RK		 8787
8788 elsif R_Typ = Standard_Character
8789 and then Nkind (Original_Node (N)) /= N_Op_Concat
8790 then
8791 for J in 1 .. Strlen loop
8792 if not In_Character_Range (Get_String_Char (Str, J)) then
8793
8794 -- If we are out of range, post error. This is one of the
8795 -- very few places that we place the flag in the middle of
d81b4bfe
TQ		 8796 -- a token, right under the offending wide character. Not
8797 -- quite clear if this is right wrt wide character encoding
8798 -- sequences, but it's only an error message!
996ae0b0
RK		 8799
8800 Error_Msg
82c80734
RD		 8801 ("literal out of range of type Standard.Character",
8802 Source_Ptr (Int (Loc) + J));
8803 return;
8804 end if;
8805 end loop;
8806
8807 -- For the case of Standard.Wide_String, or any other type whose
8808 -- component type is Standard.Wide_Character, we must make sure that
8809 -- there are no wide characters in the string, i.e. that it is
8810 -- entirely composed of characters in range of type Wide_Character.
8811
8812 -- If the string literal is the result of a static concatenation,
8813 -- the test has already been performed on the components, and need
8814 -- not be repeated.
8815
8816 elsif R_Typ = Standard_Wide_Character
8817 and then Nkind (Original_Node (N)) /= N_Op_Concat
8818 then
8819 for J in 1 .. Strlen loop
8820 if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
8821
8822 -- If we are out of range, post error. This is one of the
8823 -- very few places that we place the flag in the middle of
8824 -- a token, right under the offending wide character.
8825
8826 -- This is not quite right, because characters in general
8827 -- will take more than one character position ???
8828
8829 Error_Msg
8830 ("literal out of range of type Standard.Wide_Character",
996ae0b0
RK		 8831 Source_Ptr (Int (Loc) + J));
8832 return;
8833 end if;
8834 end loop;
8835
8836 -- If the root type is not a standard character, then we will convert
8837 -- the string into an aggregate and will let the aggregate code do
82c80734 8838 -- the checking. Standard Wide_Wide_Character is also OK here.
996ae0b0
RK		 8839
8840 else
8841 null;
996ae0b0
RK		 8842 end if;
8843
c8ef728f
ES		 8844 -- See if the component type of the array corresponding to the string
8845 -- has compile time known bounds. If yes we can directly check
8846 -- whether the evaluation of the string will raise constraint error.
8847 -- Otherwise we need to transform the string literal into the
5cc9353d
RD		 8848 -- corresponding character aggregate and let the aggregate code do
8849 -- the checking.
996ae0b0 8850
45fc7ddb
HK		 8851 if Is_Standard_Character_Type (R_Typ) then
8852
996ae0b0
RK		 8853 -- Check for the case of full range, where we are definitely OK
8854
8855 if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
8856 return;
8857 end if;
8858
8859 -- Here the range is not the complete base type range, so check
8860
8861 declare
8862 Comp_Typ_Lo : constant Node_Id :=
8863 Type_Low_Bound (Component_Type (Typ));
8864 Comp_Typ_Hi : constant Node_Id :=
8865 Type_High_Bound (Component_Type (Typ));
8866
8867 Char_Val : Uint;
8868
8869 begin
8870 if Compile_Time_Known_Value (Comp_Typ_Lo)
8871 and then Compile_Time_Known_Value (Comp_Typ_Hi)
8872 then
8873 for J in 1 .. Strlen loop
8874 Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
8875
8876 if Char_Val < Expr_Value (Comp_Typ_Lo)
8877 or else Char_Val > Expr_Value (Comp_Typ_Hi)
8878 then
8879 Apply_Compile_Time_Constraint_Error
07fc65c4 8880 (N, "character out of range?", CE_Range_Check_Failed,
996ae0b0
RK		 8881 Loc => Source_Ptr (Int (Loc) + J));
8882 end if;
8883 end loop;
8884
8885 return;
8886 end if;
8887 end;
8888 end if;
8889 end if;
8890
8891 -- If we got here we meed to transform the string literal into the
8892 -- equivalent qualified positional array aggregate. This is rather
8893 -- heavy artillery for this situation, but it is hard work to avoid.
8894
8895 declare
fbf5a39b 8896 Lits : constant List_Id := New_List;
996ae0b0
RK		 8897 P : Source_Ptr := Loc + 1;
8898 C : Char_Code;
8899
8900 begin
c8ef728f
ES		 8901 -- Build the character literals, we give them source locations that
8902 -- correspond to the string positions, which is a bit tricky given
8903 -- the possible presence of wide character escape sequences.
996ae0b0
RK		 8904
8905 for J in 1 .. Strlen loop
8906 C := Get_String_Char (Str, J);
8907 Set_Character_Literal_Name (C);
8908
8909 Append_To (Lits,
82c80734
RD		 8910 Make_Character_Literal (P,
8911 Chars => Name_Find,
8912 Char_Literal_Value => UI_From_CC (C)));
996ae0b0
RK		 8913
8914 if In_Character_Range (C) then
8915 P := P + 1;
8916
8917 -- Should we have a call to Skip_Wide here ???
5cc9353d 8918
996ae0b0
RK		 8919 -- ??? else
8920 -- Skip_Wide (P);
8921
8922 end if;
8923 end loop;
8924
8925 Rewrite (N,
8926 Make_Qualified_Expression (Loc,
8927 Subtype_Mark => New_Reference_To (Typ, Loc),
8928 Expression =>
8929 Make_Aggregate (Loc, Expressions => Lits)));
8930
8931 Analyze_And_Resolve (N, Typ);
8932 end;
8933 end Resolve_String_Literal;
8934
8935 -----------------------------
8936 -- Resolve_Subprogram_Info --
8937 -----------------------------
8938
8939 procedure Resolve_Subprogram_Info (N : Node_Id; Typ : Entity_Id) is
8940 begin
8941 Set_Etype (N, Typ);
8942 end Resolve_Subprogram_Info;
8943
8944 -----------------------------
8945 -- Resolve_Type_Conversion --
8946 -----------------------------
8947
8948 procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
4b2d2c13
AC		 8949 Conv_OK : constant Boolean := Conversion_OK (N);
8950 Operand : constant Node_Id := Expression (N);
b7d1f17f
HK		 8951 Operand_Typ : constant Entity_Id := Etype (Operand);
8952 Target_Typ : constant Entity_Id := Etype (N);
996ae0b0 8953 Rop : Node_Id;
fbf5a39b
AC		 8954 Orig_N : Node_Id;
8955 Orig_T : Node_Id;
996ae0b0 8956
ae2aa109
AC		 8957 Test_Redundant : Boolean := Warn_On_Redundant_Constructs;
8958 -- Set to False to suppress cases where we want to suppress the test
8959 -- for redundancy to avoid possible false positives on this warning.
8960
996ae0b0 8961 begin
996ae0b0 8962 if not Conv_OK
b7d1f17f 8963 and then not Valid_Conversion (N, Target_Typ, Operand)
996ae0b0
RK		 8964 then
8965 return;
8966 end if;
8967
ae2aa109
AC		 8968 -- If the Operand Etype is Universal_Fixed, then the conversion is
8969 -- never redundant. We need this check because by the time we have
8970 -- finished the rather complex transformation, the conversion looks
8971 -- redundant when it is not.
8972
8973 if Operand_Typ = Universal_Fixed then
8974 Test_Redundant := False;
8975
8976 -- If the operand is marked as Any_Fixed, then special processing is
8977 -- required. This is also a case where we suppress the test for a
8978 -- redundant conversion, since most certainly it is not redundant.
8979
8980 elsif Operand_Typ = Any_Fixed then
8981 Test_Redundant := False;
996ae0b0
RK		 8982
8983 -- Mixed-mode operation involving a literal. Context must be a fixed
8984 -- type which is applied to the literal subsequently.
8985
8986 if Is_Fixed_Point_Type (Typ) then
8987 Set_Etype (Operand, Universal_Real);
8988
8989 elsif Is_Numeric_Type (Typ)
45fc7ddb 8990 and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
996ae0b0 8991 and then (Etype (Right_Opnd (Operand)) = Universal_Real
45fc7ddb
HK		 8992 or else
8993 Etype (Left_Opnd (Operand)) = Universal_Real)
996ae0b0 8994 then
a77842bd
TQ		 8995 -- Return if expression is ambiguous
8996
996ae0b0 8997 if Unique_Fixed_Point_Type (N) = Any_Type then
a77842bd 8998 return;
82c80734 8999
a77842bd
TQ		 9000 -- If nothing else, the available fixed type is Duration
9001
9002 else
996ae0b0
RK		 9003 Set_Etype (Operand, Standard_Duration);
9004 end if;
9005
bc5f3720 9006 -- Resolve the real operand with largest available precision
9ebe3743 9007
996ae0b0
RK		 9008 if Etype (Right_Opnd (Operand)) = Universal_Real then
9009 Rop := New_Copy_Tree (Right_Opnd (Operand));
9010 else
9011 Rop := New_Copy_Tree (Left_Opnd (Operand));
9012 end if;
9013
9ebe3743 9014 Resolve (Rop, Universal_Real);
996ae0b0 9015
82c80734
RD		 9016 -- If the operand is a literal (it could be a non-static and
9017 -- illegal exponentiation) check whether the use of Duration
9018 -- is potentially inaccurate.
9019
9020 if Nkind (Rop) = N_Real_Literal
9021 and then Realval (Rop) /= Ureal_0
996ae0b0
RK		 9022 and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
9023 then
aa180613 9024 Error_Msg_N
aa5147f0
ES		 9025 ("?universal real operand can only " &
9026 "be interpreted as Duration!",
aa180613
RD		 9027 Rop);
9028 Error_Msg_N
aa5147f0 9029 ("\?precision will be lost in the conversion!", Rop);
996ae0b0
RK		 9030 end if;
9031
891a6e79
AC		 9032 elsif Is_Numeric_Type (Typ)
9033 and then Nkind (Operand) in N_Op
9034 and then Unique_Fixed_Point_Type (N) /= Any_Type
9035 then
9036 Set_Etype (Operand, Standard_Duration);
9037
996ae0b0
RK		 9038 else
9039 Error_Msg_N ("invalid context for mixed mode operation", N);
9040 Set_Etype (Operand, Any_Type);
9041 return;
9042 end if;
9043 end if;
9044
fbf5a39b 9045 Resolve (Operand);
996ae0b0 9046
b0186f71
AC		 9047 -- In SPARK or ALFA, a type conversion between array types should be
9048 -- restricted to types which have matching static bounds.
9049
fe5d3068 9050 if Is_Array_Type (Target_Typ)
b0186f71
AC		 9051 and then Is_Array_Type (Operand_Typ)
9052 and then not Matching_Static_Array_Bounds (Target_Typ, Operand_Typ)
9053 then
fe5d3068
YM		 9054 Check_Formal_Restriction
9055 ("array types should have matching static bounds", N);
b0186f71
AC		 9056 end if;
9057
996ae0b0 9058 -- Note: we do the Eval_Type_Conversion call before applying the
d81b4bfe
TQ		 9059 -- required checks for a subtype conversion. This is important, since
9060 -- both are prepared under certain circumstances to change the type
9061 -- conversion to a constraint error node, but in the case of
9062 -- Eval_Type_Conversion this may reflect an illegality in the static
9063 -- case, and we would miss the illegality (getting only a warning
9064 -- message), if we applied the type conversion checks first.
996ae0b0
RK		 9065
9066 Eval_Type_Conversion (N);
9067
d81b4bfe
TQ		 9068 -- Even when evaluation is not possible, we may be able to simplify the
9069 -- conversion or its expression. This needs to be done before applying
9070 -- checks, since otherwise the checks may use the original expression
9071 -- and defeat the simplifications. This is specifically the case for
9072 -- elimination of the floating-point Truncation attribute in
9073 -- float-to-int conversions.
0669bebe
GB		 9074
9075 Simplify_Type_Conversion (N);
9076
d81b4bfe
TQ		 9077 -- If after evaluation we still have a type conversion, then we may need
9078 -- to apply checks required for a subtype conversion.
996ae0b0
RK		 9079
9080 -- Skip these type conversion checks if universal fixed operands
9081 -- operands involved, since range checks are handled separately for
9082 -- these cases (in the appropriate Expand routines in unit Exp_Fixd).
9083
9084 if Nkind (N) = N_Type_Conversion
b7d1f17f
HK		 9085 and then not Is_Generic_Type (Root_Type (Target_Typ))
9086 and then Target_Typ /= Universal_Fixed
9087 and then Operand_Typ /= Universal_Fixed
996ae0b0
RK		 9088 then
9089 Apply_Type_Conversion_Checks (N);
9090 end if;
9091
d81b4bfe
TQ		 9092 -- Issue warning for conversion of simple object to its own type. We
9093 -- have to test the original nodes, since they may have been rewritten
9094 -- by various optimizations.
fbf5a39b
AC		 9095
9096 Orig_N := Original_Node (N);
996ae0b0 9097
ae2aa109
AC		 9098 -- Here we test for a redundant conversion if the warning mode is
9099 -- active (and was not locally reset), and we have a type conversion
9100 -- from source not appearing in a generic instance.
9101
9102 if Test_Redundant
fbf5a39b 9103 and then Nkind (Orig_N) = N_Type_Conversion
ae2aa109 9104 and then Comes_From_Source (Orig_N)
5453d5bd 9105 and then not In_Instance
996ae0b0 9106 then
fbf5a39b 9107 Orig_N := Original_Node (Expression (Orig_N));
b7d1f17f 9108 Orig_T := Target_Typ;
fbf5a39b
AC		 9109
9110 -- If the node is part of a larger expression, the Target_Type
9111 -- may not be the original type of the node if the context is a
9112 -- condition. Recover original type to see if conversion is needed.
9113
9114 if Is_Boolean_Type (Orig_T)
9115 and then Nkind (Parent (N)) in N_Op
9116 then
9117 Orig_T := Etype (Parent (N));
9118 end if;
9119
4adf3c50 9120 -- If we have an entity name, then give the warning if the entity
ae2aa109
AC		 9121 -- is the right type, or if it is a loop parameter covered by the
9122 -- original type (that's needed because loop parameters have an
9123 -- odd subtype coming from the bounds).
9124
9125 if (Is_Entity_Name (Orig_N)
9126 and then
9127 (Etype (Entity (Orig_N)) = Orig_T
9128 or else
9129 (Ekind (Entity (Orig_N)) = E_Loop_Parameter
477bd732 9130 and then Covers (Orig_T, Etype (Entity (Orig_N))))))
ae2aa109 9131
477bd732 9132 -- If not an entity, then type of expression must match
ae2aa109
AC		 9133
9134 or else Etype (Orig_N) = Orig_T
fbf5a39b 9135 then
4b2d2c13
AC		 9136 -- One more check, do not give warning if the analyzed conversion
9137 -- has an expression with non-static bounds, and the bounds of the
9138 -- target are static. This avoids junk warnings in cases where the
9139 -- conversion is necessary to establish staticness, for example in
9140 -- a case statement.
9141
9142 if not Is_OK_Static_Subtype (Operand_Typ)
9143 and then Is_OK_Static_Subtype (Target_Typ)
9144 then
9145 null;
9146
5cc9353d
RD		 9147 -- Finally, if this type conversion occurs in a context requiring
9148 -- a prefix, and the expression is a qualified expression then the
9149 -- type conversion is not redundant, since a qualified expression
9150 -- is not a prefix, whereas a type conversion is. For example, "X
9151 -- := T'(Funx(...)).Y;" is illegal because a selected component
9152 -- requires a prefix, but a type conversion makes it legal: "X :=
9153 -- T(T'(Funx(...))).Y;"
4adf3c50 9154
9db0b232
AC		 9155 -- In Ada 2012, a qualified expression is a name, so this idiom is
9156 -- no longer needed, but we still suppress the warning because it
9157 -- seems unfriendly for warnings to pop up when you switch to the
9158 -- newer language version.
be257e99
AC		 9159
9160 elsif Nkind (Orig_N) = N_Qualified_Expression
f5d96d00
AC		 9161 and then Nkind_In (Parent (N), N_Attribute_Reference,
9162 N_Indexed_Component,
9163 N_Selected_Component,
9164 N_Slice,
9165 N_Explicit_Dereference)
be257e99
AC		 9166 then
9167 null;
9168
ae2aa109
AC		 9169 -- Here we give the redundant conversion warning. If it is an
9170 -- entity, give the name of the entity in the message. If not,
9171 -- just mention the expression.
4b2d2c13
AC		 9172
9173 else
ae2aa109
AC		 9174 if Is_Entity_Name (Orig_N) then
9175 Error_Msg_Node_2 := Orig_T;
9176 Error_Msg_NE -- CODEFIX
9177 ("?redundant conversion, & is of type &!",
9178 N, Entity (Orig_N));
9179 else
9180 Error_Msg_NE
9181 ("?redundant conversion, expression is of type&!",
9182 N, Orig_T);
9183 end if;
4b2d2c13 9184 end if;
fbf5a39b 9185 end if;
996ae0b0 9186 end if;
758c442c 9187
b7d1f17f 9188 -- Ada 2005 (AI-251): Handle class-wide interface type conversions.
0669bebe
GB		 9189 -- No need to perform any interface conversion if the type of the
9190 -- expression coincides with the target type.
758c442c 9191
0791fbe9 9192 if Ada_Version >= Ada_2005
0669bebe 9193 and then Expander_Active
b7d1f17f 9194 and then Operand_Typ /= Target_Typ
0669bebe 9195 then
b7d1f17f
HK		 9196 declare
9197 Opnd : Entity_Id := Operand_Typ;
9198 Target : Entity_Id := Target_Typ;
758c442c 9199
b7d1f17f
HK		 9200 begin
9201 if Is_Access_Type (Opnd) then
841dd0f5 9202 Opnd := Designated_Type (Opnd);
1420b484
JM		 9203 end if;
9204
b7d1f17f 9205 if Is_Access_Type (Target_Typ) then
841dd0f5 9206 Target := Designated_Type (Target);
4197ae1e 9207 end if;
c8ef728f 9208
b7d1f17f
HK		 9209 if Opnd = Target then
9210 null;
c8ef728f 9211
b7d1f17f 9212 -- Conversion from interface type
ea985d95 9213
b7d1f17f 9214 elsif Is_Interface (Opnd) then
ea985d95 9215
b7d1f17f 9216 -- Ada 2005 (AI-217): Handle entities from limited views
aa180613 9217
b7d1f17f
HK		 9218 if From_With_Type (Opnd) then
9219 Error_Msg_Qual_Level := 99;
305caf42
AC		 9220 Error_Msg_NE -- CODEFIX
9221 ("missing WITH clause on package &", N,
b7d1f17f
HK		 9222 Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
9223 Error_Msg_N
9224 ("type conversions require visibility of the full view",
9225 N);
aa180613 9226
aa5147f0
ES		 9227 elsif From_With_Type (Target)
9228 and then not
9229 (Is_Access_Type (Target_Typ)
9230 and then Present (Non_Limited_View (Etype (Target))))
9231 then
b7d1f17f 9232 Error_Msg_Qual_Level := 99;
305caf42
AC		 9233 Error_Msg_NE -- CODEFIX
9234 ("missing WITH clause on package &", N,
b7d1f17f
HK		 9235 Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
9236 Error_Msg_N
9237 ("type conversions require visibility of the full view",
9238 N);
aa180613 9239
b7d1f17f
HK		 9240 else
9241 Expand_Interface_Conversion (N, Is_Static => False);
9242 end if;
9243
9244 -- Conversion to interface type
9245
9246 elsif Is_Interface (Target) then
9247
9248 -- Handle subtypes
9249
8a95f4e8 9250 if Ekind_In (Opnd, E_Protected_Subtype, E_Task_Subtype) then
b7d1f17f
HK		 9251 Opnd := Etype (Opnd);
9252 end if;
9253
9254 if not Interface_Present_In_Ancestor
9255 (Typ => Opnd,
9256 Iface => Target)
9257 then
9258 if Is_Class_Wide_Type (Opnd) then
9259
9260 -- The static analysis is not enough to know if the
9261 -- interface is implemented or not. Hence we must pass
9262 -- the work to the expander to generate code to evaluate
e7c0dd39 9263 -- the conversion at run time.
b7d1f17f
HK		 9264
9265 Expand_Interface_Conversion (N, Is_Static => False);
9266
9267 else
9268 Error_Msg_Name_1 := Chars (Etype (Target));
9269 Error_Msg_Name_2 := Chars (Opnd);
9270 Error_Msg_N
9271 ("wrong interface conversion (% is not a progenitor " &
9272 "of %)", N);
9273 end if;
9274
9275 else
9276 Expand_Interface_Conversion (N);
9277 end if;
9278 end if;
9279 end;
758c442c 9280 end if;
996ae0b0
RK		 9281 end Resolve_Type_Conversion;
9282
9283 ----------------------
9284 -- Resolve_Unary_Op --
9285 ----------------------
9286
9287 procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
fbf5a39b
AC		 9288 B_Typ : constant Entity_Id := Base_Type (Typ);
9289 R : constant Node_Id := Right_Opnd (N);
9290 OK : Boolean;
9291 Lo : Uint;
9292 Hi : Uint;
996ae0b0
RK		 9293
9294 begin
7a489a2b
AC		 9295 if Is_Modular_Integer_Type (Typ) and then Nkind (N) /= N_Op_Not then
9296 Error_Msg_Name_1 := Chars (Typ);
9297 Check_Formal_Restriction
9298 ("unary operator not defined for modular type%", N);
9299 end if;
9300
b7d1f17f 9301 -- Deal with intrinsic unary operators
996ae0b0 9302
fbf5a39b
AC		 9303 if Comes_From_Source (N)
9304 and then Ekind (Entity (N)) = E_Function
9305 and then Is_Imported (Entity (N))
9306 and then Is_Intrinsic_Subprogram (Entity (N))
9307 then
9308 Resolve_Intrinsic_Unary_Operator (N, Typ);
9309 return;
9310 end if;
9311
0669bebe
GB		 9312 -- Deal with universal cases
9313
996ae0b0 9314 if Etype (R) = Universal_Integer
0669bebe
GB		 9315 or else
9316 Etype (R) = Universal_Real
996ae0b0
RK		 9317 then
9318 Check_For_Visible_Operator (N, B_Typ);
9319 end if;
9320
9321 Set_Etype (N, B_Typ);
9322 Resolve (R, B_Typ);
fbf5a39b 9323
9ebe3743
HK		 9324 -- Generate warning for expressions like abs (x mod 2)
9325
9326 if Warn_On_Redundant_Constructs
9327 and then Nkind (N) = N_Op_Abs
9328 then
9329 Determine_Range (Right_Opnd (N), OK, Lo, Hi);
9330
9331 if OK and then Hi >= Lo and then Lo >= 0 then
305caf42 9332 Error_Msg_N -- CODEFIX
9ebe3743
HK		 9333 ("?abs applied to known non-negative value has no effect", N);
9334 end if;
9335 end if;
9336
0669bebe
GB		 9337 -- Deal with reference generation
9338
996ae0b0 9339 Check_Unset_Reference (R);
fbf5a39b 9340 Generate_Operator_Reference (N, B_Typ);
996ae0b0
RK		 9341 Eval_Unary_Op (N);
9342
9343 -- Set overflow checking bit. Much cleverer code needed here eventually
9344 -- and perhaps the Resolve routines should be separated for the various
9345 -- arithmetic operations, since they will need different processing ???
9346
9347 if Nkind (N) in N_Op then
9348 if not Overflow_Checks_Suppressed (Etype (N)) then
fbf5a39b 9349 Enable_Overflow_Check (N);
996ae0b0
RK		 9350 end if;
9351 end if;
0669bebe 9352
d81b4bfe
TQ		 9353 -- Generate warning for expressions like -5 mod 3 for integers. No need
9354 -- to worry in the floating-point case, since parens do not affect the
9355 -- result so there is no point in giving in a warning.
0669bebe
GB		 9356
9357 declare
9358 Norig : constant Node_Id := Original_Node (N);
9359 Rorig : Node_Id;
9360 Val : Uint;
9361 HB : Uint;
9362 LB : Uint;
9363 Lval : Uint;
9364 Opnd : Node_Id;
9365
9366 begin
9367 if Warn_On_Questionable_Missing_Parens
9368 and then Comes_From_Source (Norig)
9369 and then Is_Integer_Type (Typ)
9370 and then Nkind (Norig) = N_Op_Minus
9371 then
9372 Rorig := Original_Node (Right_Opnd (Norig));
9373
9374 -- We are looking for cases where the right operand is not
f3d57416 9375 -- parenthesized, and is a binary operator, multiply, divide, or
0669bebe
GB		 9376 -- mod. These are the cases where the grouping can affect results.
9377
9378 if Paren_Count (Rorig) = 0
45fc7ddb 9379 and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
0669bebe
GB		 9380 then
9381 -- For mod, we always give the warning, since the value is
9382 -- affected by the parenthesization (e.g. (-5) mod 315 /=
d81b4bfe 9383 -- -(5 mod 315)). But for the other cases, the only concern is
0669bebe
GB		 9384 -- overflow, e.g. for the case of 8 big signed (-(2 * 64)
9385 -- overflows, but (-2) * 64 does not). So we try to give the
9386 -- message only when overflow is possible.
9387
9388 if Nkind (Rorig) /= N_Op_Mod
9389 and then Compile_Time_Known_Value (R)
9390 then
9391 Val := Expr_Value (R);
9392
9393 if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
9394 HB := Expr_Value (Type_High_Bound (Typ));
9395 else
9396 HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
9397 end if;
9398
9399 if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
9400 LB := Expr_Value (Type_Low_Bound (Typ));
9401 else
9402 LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
9403 end if;
9404
d81b4bfe
TQ		 9405 -- Note that the test below is deliberately excluding the
9406 -- largest negative number, since that is a potentially
0669bebe
GB		 9407 -- troublesome case (e.g. -2 * x, where the result is the
9408 -- largest negative integer has an overflow with 2 * x).
9409
9410 if Val > LB and then Val <= HB then
9411 return;
9412 end if;
9413 end if;
9414
9415 -- For the multiplication case, the only case we have to worry
9416 -- about is when (-a)*b is exactly the largest negative number
9417 -- so that -(a*b) can cause overflow. This can only happen if
9418 -- a is a power of 2, and more generally if any operand is a
9419 -- constant that is not a power of 2, then the parentheses
9420 -- cannot affect whether overflow occurs. We only bother to
9421 -- test the left most operand
9422
9423 -- Loop looking at left operands for one that has known value
9424
9425 Opnd := Rorig;
9426 Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
9427 if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
9428 Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
9429
9430 -- Operand value of 0 or 1 skips warning
9431
9432 if Lval <= 1 then
9433 return;
9434
9435 -- Otherwise check power of 2, if power of 2, warn, if
9436 -- anything else, skip warning.
9437
9438 else
9439 while Lval /= 2 loop
9440 if Lval mod 2 = 1 then
9441 return;
9442 else
9443 Lval := Lval / 2;
9444 end if;
9445 end loop;
9446
9447 exit Opnd_Loop;
9448 end if;
9449 end if;
9450
9451 -- Keep looking at left operands
9452
9453 Opnd := Left_Opnd (Opnd);
9454 end loop Opnd_Loop;
9455
9456 -- For rem or "/" we can only have a problematic situation
9457 -- if the divisor has a value of minus one or one. Otherwise
9458 -- overflow is impossible (divisor > 1) or we have a case of
9459 -- division by zero in any case.
9460
45fc7ddb 9461 if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
0669bebe
GB		 9462 and then Compile_Time_Known_Value (Right_Opnd (Rorig))
9463 and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
9464 then
9465 return;
9466 end if;
9467
9468 -- If we fall through warning should be issued
9469
ed2233dc 9470 Error_Msg_N
aa5147f0 9471 ("?unary minus expression should be parenthesized here!", N);
0669bebe
GB		 9472 end if;
9473 end if;
9474 end;
996ae0b0
RK		 9475 end Resolve_Unary_Op;
9476
9477 ----------------------------------
9478 -- Resolve_Unchecked_Expression --
9479 ----------------------------------
9480
9481 procedure Resolve_Unchecked_Expression
9482 (N : Node_Id;
9483 Typ : Entity_Id)
9484 is
9485 begin
9486 Resolve (Expression (N), Typ, Suppress => All_Checks);
9487 Set_Etype (N, Typ);
9488 end Resolve_Unchecked_Expression;
9489
9490 ---------------------------------------
9491 -- Resolve_Unchecked_Type_Conversion --
9492 ---------------------------------------
9493
9494 procedure Resolve_Unchecked_Type_Conversion
9495 (N : Node_Id;
9496 Typ : Entity_Id)
9497 is
07fc65c4
GB		 9498 pragma Warnings (Off, Typ);
9499
996ae0b0
RK		 9500 Operand : constant Node_Id := Expression (N);
9501 Opnd_Type : constant Entity_Id := Etype (Operand);
9502
9503 begin
a77842bd 9504 -- Resolve operand using its own type
996ae0b0
RK		 9505
9506 Resolve (Operand, Opnd_Type);
9507 Eval_Unchecked_Conversion (N);
996ae0b0
RK		 9508 end Resolve_Unchecked_Type_Conversion;
9509
9510 ------------------------------
9511 -- Rewrite_Operator_As_Call --
9512 ------------------------------
9513
9514 procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
fbf5a39b
AC		 9515 Loc : constant Source_Ptr := Sloc (N);
9516 Actuals : constant List_Id := New_List;
996ae0b0
RK		 9517 New_N : Node_Id;
9518
9519 begin
9520 if Nkind (N) in N_Binary_Op then
9521 Append (Left_Opnd (N), Actuals);
9522 end if;
9523
9524 Append (Right_Opnd (N), Actuals);
9525
9526 New_N :=
9527 Make_Function_Call (Sloc => Loc,
9528 Name => New_Occurrence_Of (Nam, Loc),
9529 Parameter_Associations => Actuals);
9530
9531 Preserve_Comes_From_Source (New_N, N);
9532 Preserve_Comes_From_Source (Name (New_N), N);
9533 Rewrite (N, New_N);
9534 Set_Etype (N, Etype (Nam));
9535 end Rewrite_Operator_As_Call;
9536
9537 ------------------------------
9538 -- Rewrite_Renamed_Operator --
9539 ------------------------------
9540
0ab80019
AC		 9541 procedure Rewrite_Renamed_Operator
9542 (N : Node_Id;
9543 Op : Entity_Id;
9544 Typ : Entity_Id)
9545 is
996ae0b0
RK		 9546 Nam : constant Name_Id := Chars (Op);
9547 Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
9548 Op_Node : Node_Id;
9549
9550 begin
d81b4bfe
TQ		 9551 -- Rewrite the operator node using the real operator, not its renaming.
9552 -- Exclude user-defined intrinsic operations of the same name, which are
9553 -- treated separately and rewritten as calls.
996ae0b0 9554
964f13da 9555 if Ekind (Op) /= E_Function or else Chars (N) /= Nam then
996ae0b0
RK		 9556 Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
9557 Set_Chars (Op_Node, Nam);
9558 Set_Etype (Op_Node, Etype (N));
9559 Set_Entity (Op_Node, Op);
9560 Set_Right_Opnd (Op_Node, Right_Opnd (N));
9561
b7d1f17f
HK		 9562 -- Indicate that both the original entity and its renaming are
9563 -- referenced at this point.
fbf5a39b
AC		 9564
9565 Generate_Reference (Entity (N), N);
996ae0b0
RK		 9566 Generate_Reference (Op, N);
9567
9568 if Is_Binary then
9569 Set_Left_Opnd (Op_Node, Left_Opnd (N));
9570 end if;
9571
9572 Rewrite (N, Op_Node);
0ab80019 9573
1366997b
AC		 9574 -- If the context type is private, add the appropriate conversions so
9575 -- that the operator is applied to the full view. This is done in the
9576 -- routines that resolve intrinsic operators.
0ab80019
AC		 9577
9578 if Is_Intrinsic_Subprogram (Op)
9579 and then Is_Private_Type (Typ)
9580 then
9581 case Nkind (N) is
9582 when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
9583 N_Op_Expon | N_Op_Mod | N_Op_Rem =>
9584 Resolve_Intrinsic_Operator (N, Typ);
9585
d81b4bfe 9586 when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
0ab80019
AC		 9587 Resolve_Intrinsic_Unary_Operator (N, Typ);
9588
9589 when others =>
9590 Resolve (N, Typ);
9591 end case;
9592 end if;
9593
964f13da
RD		 9594 elsif Ekind (Op) = E_Function and then Is_Intrinsic_Subprogram (Op) then
9595
1366997b
AC		 9596 -- Operator renames a user-defined operator of the same name. Use the
9597 -- original operator in the node, which is the one Gigi knows about.
0ab80019
AC		 9598
9599 Set_Entity (N, Op);
9600 Set_Is_Overloaded (N, False);
996ae0b0
RK		 9601 end if;
9602 end Rewrite_Renamed_Operator;
9603
9604 -----------------------
9605 -- Set_Slice_Subtype --
9606 -----------------------
9607
1366997b
AC		 9608 -- Build an implicit subtype declaration to represent the type delivered by
9609 -- the slice. This is an abbreviated version of an array subtype. We define
9610 -- an index subtype for the slice, using either the subtype name or the
9611 -- discrete range of the slice. To be consistent with index usage elsewhere
9612 -- we create a list header to hold the single index. This list is not
9613 -- otherwise attached to the syntax tree.
996ae0b0
RK		 9614
9615 procedure Set_Slice_Subtype (N : Node_Id) is
9616 Loc : constant Source_Ptr := Sloc (N);
fbf5a39b 9617 Index_List : constant List_Id := New_List;
996ae0b0 9618 Index : Node_Id;
996ae0b0
RK		 9619 Index_Subtype : Entity_Id;
9620 Index_Type : Entity_Id;
9621 Slice_Subtype : Entity_Id;
9622 Drange : constant Node_Id := Discrete_Range (N);
9623
9624 begin
9625 if Is_Entity_Name (Drange) then
9626 Index_Subtype := Entity (Drange);
9627
9628 else
9629 -- We force the evaluation of a range. This is definitely needed in
9630 -- the renamed case, and seems safer to do unconditionally. Note in
9631 -- any case that since we will create and insert an Itype referring
9632 -- to this range, we must make sure any side effect removal actions
9633 -- are inserted before the Itype definition.
9634
9635 if Nkind (Drange) = N_Range then
9636 Force_Evaluation (Low_Bound (Drange));
9637 Force_Evaluation (High_Bound (Drange));
9638 end if;
9639
9640 Index_Type := Base_Type (Etype (Drange));
9641
9642 Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
9643
8a95f4e8 9644 -- Take a new copy of Drange (where bounds have been rewritten to
3c1ecd7e
AC		 9645 -- reference side-effect-free names). Using a separate tree ensures
9646 -- that further expansion (e.g. while rewriting a slice assignment
8a95f4e8
RD		 9647 -- into a FOR loop) does not attempt to remove side effects on the
9648 -- bounds again (which would cause the bounds in the index subtype
9649 -- definition to refer to temporaries before they are defined) (the
9650 -- reason is that some names are considered side effect free here
9651 -- for the subtype, but not in the context of a loop iteration
9652 -- scheme).
9653
9654 Set_Scalar_Range (Index_Subtype, New_Copy_Tree (Drange));
4230bdb7 9655 Set_Parent (Scalar_Range (Index_Subtype), Index_Subtype);
996ae0b0
RK		 9656 Set_Etype (Index_Subtype, Index_Type);
9657 Set_Size_Info (Index_Subtype, Index_Type);
9658 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
9659 end if;
9660
9661 Slice_Subtype := Create_Itype (E_Array_Subtype, N);
9662
9663 Index := New_Occurrence_Of (Index_Subtype, Loc);
9664 Set_Etype (Index, Index_Subtype);
9665 Append (Index, Index_List);
9666
996ae0b0
RK		 9667 Set_First_Index (Slice_Subtype, Index);
9668 Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
9669 Set_Is_Constrained (Slice_Subtype, True);
996ae0b0 9670
8a95f4e8
RD		 9671 Check_Compile_Time_Size (Slice_Subtype);
9672
b7d1f17f
HK		 9673 -- The Etype of the existing Slice node is reset to this slice subtype.
9674 -- Its bounds are obtained from its first index.
996ae0b0
RK		 9675
9676 Set_Etype (N, Slice_Subtype);
9677
5cc9353d
RD		 9678 -- For packed slice subtypes, freeze immediately (except in the case of
9679 -- being in a "spec expression" where we never freeze when we first see
9680 -- the expression).
8a95f4e8
RD		 9681
9682 if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
9683 Freeze_Itype (Slice_Subtype, N);
996ae0b0 9684
cfab0c49
AC		 9685 -- For all other cases insert an itype reference in the slice's actions
9686 -- so that the itype is frozen at the proper place in the tree (i.e. at
9687 -- the point where actions for the slice are analyzed). Note that this
9688 -- is different from freezing the itype immediately, which might be
9689 -- premature (e.g. if the slice is within a transient scope).
9690
8a95f4e8
RD		 9691 else
9692 Ensure_Defined (Typ => Slice_Subtype, N => N);
9693 end if;
996ae0b0
RK		 9694 end Set_Slice_Subtype;
9695
9696 --------------------------------
9697 -- Set_String_Literal_Subtype --
9698 --------------------------------
9699
9700 procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
c8ef728f
ES		 9701 Loc : constant Source_Ptr := Sloc (N);
9702 Low_Bound : constant Node_Id :=
d81b4bfe 9703 Type_Low_Bound (Etype (First_Index (Typ)));
996ae0b0
RK		 9704 Subtype_Id : Entity_Id;
9705
9706 begin
9707 if Nkind (N) /= N_String_Literal then
9708 return;
996ae0b0
RK		 9709 end if;
9710
c8ef728f 9711 Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
91b1417d
AC		 9712 Set_String_Literal_Length (Subtype_Id, UI_From_Int
9713 (String_Length (Strval (N))));
c8ef728f
ES		 9714 Set_Etype (Subtype_Id, Base_Type (Typ));
9715 Set_Is_Constrained (Subtype_Id);
9716 Set_Etype (N, Subtype_Id);
9717
9718 if Is_OK_Static_Expression (Low_Bound) then
996ae0b0 9719
1366997b
AC		 9720 -- The low bound is set from the low bound of the corresponding index
9721 -- type. Note that we do not store the high bound in the string literal
9722 -- subtype, but it can be deduced if necessary from the length and the
9723 -- low bound.
996ae0b0 9724
c8ef728f 9725 Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
996ae0b0 9726
c8ef728f
ES		 9727 else
9728 Set_String_Literal_Low_Bound
9729 (Subtype_Id, Make_Integer_Literal (Loc, 1));
9730 Set_Etype (String_Literal_Low_Bound (Subtype_Id), Standard_Positive);
9731
b7d1f17f
HK		 9732 -- Build bona fide subtype for the string, and wrap it in an
9733 -- unchecked conversion, because the backend expects the
c8ef728f
ES		 9734 -- String_Literal_Subtype to have a static lower bound.
9735
9736 declare
9737 Index_List : constant List_Id := New_List;
9738 Index_Type : constant Entity_Id := Etype (First_Index (Typ));
9739 High_Bound : constant Node_Id :=
9740 Make_Op_Add (Loc,
9741 Left_Opnd => New_Copy_Tree (Low_Bound),
9742 Right_Opnd =>
9743 Make_Integer_Literal (Loc,
9744 String_Length (Strval (N)) - 1));
9745 Array_Subtype : Entity_Id;
9746 Index_Subtype : Entity_Id;
9747 Drange : Node_Id;
9748 Index : Node_Id;
9749
9750 begin
9751 Index_Subtype :=
9752 Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
0669bebe 9753 Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
c8ef728f
ES		 9754 Set_Scalar_Range (Index_Subtype, Drange);
9755 Set_Parent (Drange, N);
9756 Analyze_And_Resolve (Drange, Index_Type);
9757
36fcf362
RD		 9758 -- In the context, the Index_Type may already have a constraint,
9759 -- so use common base type on string subtype. The base type may
9760 -- be used when generating attributes of the string, for example
9761 -- in the context of a slice assignment.
9762
4adf3c50
AC		 9763 Set_Etype (Index_Subtype, Base_Type (Index_Type));
9764 Set_Size_Info (Index_Subtype, Index_Type);
9765 Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
c8ef728f
ES		 9766
9767 Array_Subtype := Create_Itype (E_Array_Subtype, N);
9768
9769 Index := New_Occurrence_Of (Index_Subtype, Loc);
9770 Set_Etype (Index, Index_Subtype);
9771 Append (Index, Index_List);
9772
9773 Set_First_Index (Array_Subtype, Index);
9774 Set_Etype (Array_Subtype, Base_Type (Typ));
9775 Set_Is_Constrained (Array_Subtype, True);
c8ef728f
ES		 9776
9777 Rewrite (N,
9778 Make_Unchecked_Type_Conversion (Loc,
9779 Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
9780 Expression => Relocate_Node (N)));
9781 Set_Etype (N, Array_Subtype);
9782 end;
9783 end if;
996ae0b0
RK		 9784 end Set_String_Literal_Subtype;
9785
0669bebe
GB		 9786 ------------------------------
9787 -- Simplify_Type_Conversion --
9788 ------------------------------
9789
9790 procedure Simplify_Type_Conversion (N : Node_Id) is
9791 begin
9792 if Nkind (N) = N_Type_Conversion then
9793 declare
9794 Operand : constant Node_Id := Expression (N);
9795 Target_Typ : constant Entity_Id := Etype (N);
9796 Opnd_Typ : constant Entity_Id := Etype (Operand);
9797
9798 begin
9799 if Is_Floating_Point_Type (Opnd_Typ)
9800 and then
9801 (Is_Integer_Type (Target_Typ)
9802 or else (Is_Fixed_Point_Type (Target_Typ)
9803 and then Conversion_OK (N)))
9804 and then Nkind (Operand) = N_Attribute_Reference
9805 and then Attribute_Name (Operand) = Name_Truncation
9806
9807 -- Special processing required if the conversion is the expression
9808 -- of a Truncation attribute reference. In this case we replace:
9809
9810 -- ityp (ftyp'Truncation (x))
9811
9812 -- by
9813
9814 -- ityp (x)
9815
4adf3c50 9816 -- with the Float_Truncate flag set, which is more efficient.
0669bebe
GB		 9817
9818 then
9819 Rewrite (Operand,
9820 Relocate_Node (First (Expressions (Operand))));
9821 Set_Float_Truncate (N, True);
9822 end if;
9823 end;
9824 end if;
9825 end Simplify_Type_Conversion;
9826
996ae0b0
RK		 9827 -----------------------------
9828 -- Unique_Fixed_Point_Type --
9829 -----------------------------
9830
9831 function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
9832 T1 : Entity_Id := Empty;
9833 T2 : Entity_Id;
9834 Item : Node_Id;
9835 Scop : Entity_Id;
9836
9837 procedure Fixed_Point_Error;
d81b4bfe
TQ		 9838 -- Give error messages for true ambiguity. Messages are posted on node
9839 -- N, and entities T1, T2 are the possible interpretations.
a77842bd
TQ		 9840
9841 -----------------------
9842 -- Fixed_Point_Error --
9843 -----------------------
996ae0b0
RK		 9844
9845 procedure Fixed_Point_Error is
9846 begin
ed2233dc
AC		 9847 Error_Msg_N ("ambiguous universal_fixed_expression", N);
9848 Error_Msg_NE ("\\possible interpretation as}", N, T1);
9849 Error_Msg_NE ("\\possible interpretation as}", N, T2);
996ae0b0
RK		 9850 end Fixed_Point_Error;
9851
a77842bd
TQ		 9852 -- Start of processing for Unique_Fixed_Point_Type
9853
996ae0b0
RK		 9854 begin
9855 -- The operations on Duration are visible, so Duration is always a
9856 -- possible interpretation.
9857
9858 T1 := Standard_Duration;
9859
bc5f3720 9860 -- Look for fixed-point types in enclosing scopes
996ae0b0 9861
fbf5a39b 9862 Scop := Current_Scope;
996ae0b0
RK		 9863 while Scop /= Standard_Standard loop
9864 T2 := First_Entity (Scop);
996ae0b0
RK		 9865 while Present (T2) loop
9866 if Is_Fixed_Point_Type (T2)
9867 and then Current_Entity (T2) = T2
9868 and then Scope (Base_Type (T2)) = Scop
9869 then
9870 if Present (T1) then
9871 Fixed_Point_Error;
9872 return Any_Type;
9873 else
9874 T1 := T2;
9875 end if;
9876 end if;
9877
9878 Next_Entity (T2);
9879 end loop;
9880
9881 Scop := Scope (Scop);
9882 end loop;
9883
a77842bd 9884 -- Look for visible fixed type declarations in the context
996ae0b0
RK		 9885
9886 Item := First (Context_Items (Cunit (Current_Sem_Unit)));
996ae0b0 9887 while Present (Item) loop
996ae0b0
RK		 9888 if Nkind (Item) = N_With_Clause then
9889 Scop := Entity (Name (Item));
9890 T2 := First_Entity (Scop);
996ae0b0
RK		 9891 while Present (T2) loop
9892 if Is_Fixed_Point_Type (T2)
9893 and then Scope (Base_Type (T2)) = Scop
19fb051c 9894 and then (Is_Potentially_Use_Visible (T2) or else In_Use (T2))
996ae0b0
RK		 9895 then
9896 if Present (T1) then
9897 Fixed_Point_Error;
9898 return Any_Type;
9899 else
9900 T1 := T2;
9901 end if;
9902 end if;
9903
9904 Next_Entity (T2);
9905 end loop;
9906 end if;
9907
9908 Next (Item);
9909 end loop;
9910
9911 if Nkind (N) = N_Real_Literal then
aa5147f0 9912 Error_Msg_NE ("?real literal interpreted as }!", N, T1);
996ae0b0 9913 else
aa5147f0 9914 Error_Msg_NE ("?universal_fixed expression interpreted as }!", N, T1);
996ae0b0
RK		 9915 end if;
9916
9917 return T1;
9918 end Unique_Fixed_Point_Type;
9919
9920 ----------------------
9921 -- Valid_Conversion --
9922 ----------------------
9923
9924 function Valid_Conversion
9925 (N : Node_Id;
9926 Target : Entity_Id;
0ab80019 9927 Operand : Node_Id) return Boolean
996ae0b0 9928 is
fbf5a39b 9929 Target_Type : constant Entity_Id := Base_Type (Target);
996ae0b0
RK		 9930 Opnd_Type : Entity_Id := Etype (Operand);
9931
9932 function Conversion_Check
9933 (Valid : Boolean;
0ab80019 9934 Msg : String) return Boolean;
996ae0b0
RK		 9935 -- Little routine to post Msg if Valid is False, returns Valid value
9936
9937 function Valid_Tagged_Conversion
9938 (Target_Type : Entity_Id;
0ab80019 9939 Opnd_Type : Entity_Id) return Boolean;
996ae0b0
RK		 9940 -- Specifically test for validity of tagged conversions
9941
aa180613 9942 function Valid_Array_Conversion return Boolean;
4adf3c50
AC		 9943 -- Check index and component conformance, and accessibility levels if
9944 -- the component types are anonymous access types (Ada 2005).
aa180613 9945
996ae0b0
RK		 9946 ----------------------
9947 -- Conversion_Check --
9948 ----------------------
9949
9950 function Conversion_Check
9951 (Valid : Boolean;
0ab80019 9952 Msg : String) return Boolean
996ae0b0
RK		 9953 is
9954 begin
9955 if not Valid then
9956 Error_Msg_N (Msg, Operand);
9957 end if;
9958
9959 return Valid;
9960 end Conversion_Check;
9961
aa180613
RD		 9962 ----------------------------
9963 -- Valid_Array_Conversion --
9964 ----------------------------
9965
9966 function Valid_Array_Conversion return Boolean
9967 is
9968 Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
9969 Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
9970
9971 Opnd_Index : Node_Id;
9972 Opnd_Index_Type : Entity_Id;
9973
9974 Target_Comp_Type : constant Entity_Id :=
9975 Component_Type (Target_Type);
9976 Target_Comp_Base : constant Entity_Id :=
9977 Base_Type (Target_Comp_Type);
9978
9979 Target_Index : Node_Id;
9980 Target_Index_Type : Entity_Id;
9981
9982 begin
9983 -- Error if wrong number of dimensions
9984
9985 if
9986 Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
9987 then
9988 Error_Msg_N
9989 ("incompatible number of dimensions for conversion", Operand);
9990 return False;
9991
9992 -- Number of dimensions matches
9993
9994 else
9995 -- Loop through indexes of the two arrays
9996
9997 Target_Index := First_Index (Target_Type);
9998 Opnd_Index := First_Index (Opnd_Type);
9999 while Present (Target_Index) and then Present (Opnd_Index) loop
10000 Target_Index_Type := Etype (Target_Index);
10001 Opnd_Index_Type := Etype (Opnd_Index);
10002
10003 -- Error if index types are incompatible
10004
10005 if not (Is_Integer_Type (Target_Index_Type)
10006 and then Is_Integer_Type (Opnd_Index_Type))
10007 and then (Root_Type (Target_Index_Type)
10008 /= Root_Type (Opnd_Index_Type))
10009 then
10010 Error_Msg_N
10011 ("incompatible index types for array conversion",
10012 Operand);
10013 return False;
10014 end if;
10015
10016 Next_Index (Target_Index);
10017 Next_Index (Opnd_Index);
10018 end loop;
10019
10020 -- If component types have same base type, all set
10021
10022 if Target_Comp_Base = Opnd_Comp_Base then
10023 null;
10024
10025 -- Here if base types of components are not the same. The only
10026 -- time this is allowed is if we have anonymous access types.
10027
10028 -- The conversion of arrays of anonymous access types can lead
10029 -- to dangling pointers. AI-392 formalizes the accessibility
10030 -- checks that must be applied to such conversions to prevent
10031 -- out-of-scope references.
10032
19fb051c
AC		 10033 elsif Ekind_In
10034 (Target_Comp_Base, E_Anonymous_Access_Type,
10035 E_Anonymous_Access_Subprogram_Type)
aa180613
RD		 10036 and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
10037 and then
10038 Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
10039 then
10040 if Type_Access_Level (Target_Type) <
10041 Type_Access_Level (Opnd_Type)
10042 then
10043 if In_Instance_Body then
10044 Error_Msg_N ("?source array type " &
10045 "has deeper accessibility level than target", Operand);
10046 Error_Msg_N ("\?Program_Error will be raised at run time",
10047 Operand);
10048 Rewrite (N,
10049 Make_Raise_Program_Error (Sloc (N),
10050 Reason => PE_Accessibility_Check_Failed));
10051 Set_Etype (N, Target_Type);
10052 return False;
10053
10054 -- Conversion not allowed because of accessibility levels
10055
10056 else
10057 Error_Msg_N ("source array type " &
10058 "has deeper accessibility level than target", Operand);
10059 return False;
10060 end if;
19fb051c 10061
aa180613
RD		 10062 else
10063 null;
10064 end if;
10065
10066 -- All other cases where component base types do not match
10067
10068 else
10069 Error_Msg_N
10070 ("incompatible component types for array conversion",
10071 Operand);
10072 return False;
10073 end if;
10074
45fc7ddb
HK		 10075 -- Check that component subtypes statically match. For numeric
10076 -- types this means that both must be either constrained or
10077 -- unconstrained. For enumeration types the bounds must match.
10078 -- All of this is checked in Subtypes_Statically_Match.
aa180613 10079
45fc7ddb 10080 if not Subtypes_Statically_Match
aa180613
RD		 10081 (Target_Comp_Type, Opnd_Comp_Type)
10082 then
10083 Error_Msg_N
10084 ("component subtypes must statically match", Operand);
10085 return False;
10086 end if;
10087 end if;
10088
10089 return True;
10090 end Valid_Array_Conversion;
10091
996ae0b0
RK		 10092 -----------------------------
10093 -- Valid_Tagged_Conversion --
10094 -----------------------------
10095
10096 function Valid_Tagged_Conversion
10097 (Target_Type : Entity_Id;
0ab80019 10098 Opnd_Type : Entity_Id) return Boolean
996ae0b0
RK		 10099 is
10100 begin
a77842bd 10101 -- Upward conversions are allowed (RM 4.6(22))
996ae0b0
RK		 10102
10103 if Covers (Target_Type, Opnd_Type)
10104 or else Is_Ancestor (Target_Type, Opnd_Type)
10105 then
10106 return True;
10107
a77842bd
TQ		 10108 -- Downward conversion are allowed if the operand is class-wide
10109 -- (RM 4.6(23)).
996ae0b0
RK		 10110
10111 elsif Is_Class_Wide_Type (Opnd_Type)
b7d1f17f 10112 and then Covers (Opnd_Type, Target_Type)
996ae0b0
RK		 10113 then
10114 return True;
10115
10116 elsif Covers (Opnd_Type, Target_Type)
10117 or else Is_Ancestor (Opnd_Type, Target_Type)
10118 then
10119 return
10120 Conversion_Check (False,
10121 "downward conversion of tagged objects not allowed");
758c442c 10122
0669bebe
GB		 10123 -- Ada 2005 (AI-251): The conversion to/from interface types is
10124 -- always valid
758c442c 10125
0669bebe 10126 elsif Is_Interface (Target_Type) or else Is_Interface (Opnd_Type) then
758c442c
GD		 10127 return True;
10128
b7d1f17f
HK		 10129 -- If the operand is a class-wide type obtained through a limited_
10130 -- with clause, and the context includes the non-limited view, use
10131 -- it to determine whether the conversion is legal.
10132
10133 elsif Is_Class_Wide_Type (Opnd_Type)
10134 and then From_With_Type (Opnd_Type)
10135 and then Present (Non_Limited_View (Etype (Opnd_Type)))
10136 and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
10137 then
10138 return True;
10139
aa180613
RD		 10140 elsif Is_Access_Type (Opnd_Type)
10141 and then Is_Interface (Directly_Designated_Type (Opnd_Type))
10142 then
10143 return True;
10144
996ae0b0
RK		 10145 else
10146 Error_Msg_NE
10147 ("invalid tagged conversion, not compatible with}",
10148 N, First_Subtype (Opnd_Type));
10149 return False;
10150 end if;
10151 end Valid_Tagged_Conversion;
10152
10153 -- Start of processing for Valid_Conversion
10154
10155 begin
10156 Check_Parameterless_Call (Operand);
10157
10158 if Is_Overloaded (Operand) then
10159 declare
10160 I : Interp_Index;
10161 I1 : Interp_Index;
10162 It : Interp;
10163 It1 : Interp;
10164 N1 : Entity_Id;
f0d10385 10165 T1 : Entity_Id;
996ae0b0
RK		 10166
10167 begin
d81b4bfe
TQ		 10168 -- Remove procedure calls, which syntactically cannot appear in
10169 -- this context, but which cannot be removed by type checking,
996ae0b0
RK		 10170 -- because the context does not impose a type.
10171
1420b484
JM		 10172 -- When compiling for VMS, spurious ambiguities can be produced
10173 -- when arithmetic operations have a literal operand and return
10174 -- System.Address or a descendant of it. These ambiguities are
10175 -- otherwise resolved by the context, but for conversions there
10176 -- is no context type and the removal of the spurious operations
10177 -- must be done explicitly here.
10178
4adf3c50
AC		 10179 -- The node may be labelled overloaded, but still contain only one
10180 -- interpretation because others were discarded earlier. If this
10181 -- is the case, retain the single interpretation if legal.
9ebe3743 10182
996ae0b0 10183 Get_First_Interp (Operand, I, It);
9ebe3743
HK		 10184 Opnd_Type := It.Typ;
10185 Get_Next_Interp (I, It);
996ae0b0 10186
9ebe3743
HK		 10187 if Present (It.Typ)
10188 and then Opnd_Type /= Standard_Void_Type
10189 then
10190 -- More than one candidate interpretation is available
996ae0b0 10191
9ebe3743
HK		 10192 Get_First_Interp (Operand, I, It);
10193 while Present (It.Typ) loop
10194 if It.Typ = Standard_Void_Type then
10195 Remove_Interp (I);
10196 end if;
1420b484 10197
9ebe3743
HK		 10198 if Present (System_Aux_Id)
10199 and then Is_Descendent_Of_Address (It.Typ)
10200 then
10201 Remove_Interp (I);
10202 end if;
10203
10204 Get_Next_Interp (I, It);
10205 end loop;
10206 end if;
996ae0b0
RK		 10207
10208 Get_First_Interp (Operand, I, It);
10209 I1 := I;
10210 It1 := It;
10211
10212 if No (It.Typ) then
10213 Error_Msg_N ("illegal operand in conversion", Operand);
10214 return False;
10215 end if;
10216
10217 Get_Next_Interp (I, It);
10218
10219 if Present (It.Typ) then
10220 N1 := It1.Nam;
f0d10385 10221 T1 := It1.Typ;
996ae0b0
RK		 10222 It1 := Disambiguate (Operand, I1, I, Any_Type);
10223
10224 if It1 = No_Interp then
10225 Error_Msg_N ("ambiguous operand in conversion", Operand);
10226
f0d10385
AC		 10227 -- If the interpretation involves a standard operator, use
10228 -- the location of the type, which may be user-defined.
10229
10230 if Sloc (It.Nam) = Standard_Location then
10231 Error_Msg_Sloc := Sloc (It.Typ);
10232 else
10233 Error_Msg_Sloc := Sloc (It.Nam);
10234 end if;
10235
4e7a4f6e
AC		 10236 Error_Msg_N -- CODEFIX
10237 ("\\possible interpretation#!", Operand);
996ae0b0 10238
f0d10385
AC		 10239 if Sloc (N1) = Standard_Location then
10240 Error_Msg_Sloc := Sloc (T1);
10241 else
10242 Error_Msg_Sloc := Sloc (N1);
10243 end if;
10244
4e7a4f6e
AC		 10245 Error_Msg_N -- CODEFIX
10246 ("\\possible interpretation#!", Operand);
996ae0b0
RK		 10247
10248 return False;
10249 end if;
10250 end if;
10251
10252 Set_Etype (Operand, It1.Typ);
10253 Opnd_Type := It1.Typ;
10254 end;
10255 end if;
10256
aa180613 10257 -- Numeric types
996ae0b0 10258
aa180613 10259 if Is_Numeric_Type (Target_Type) then
996ae0b0 10260
aa180613 10261 -- A universal fixed expression can be converted to any numeric type
996ae0b0 10262
996ae0b0
RK		 10263 if Opnd_Type = Universal_Fixed then
10264 return True;
7324bf49 10265
aa180613
RD		 10266 -- Also no need to check when in an instance or inlined body, because
10267 -- the legality has been established when the template was analyzed.
10268 -- Furthermore, numeric conversions may occur where only a private
f3d57416 10269 -- view of the operand type is visible at the instantiation point.
aa180613
RD		 10270 -- This results in a spurious error if we check that the operand type
10271 -- is a numeric type.
10272
10273 -- Note: in a previous version of this unit, the following tests were
10274 -- applied only for generated code (Comes_From_Source set to False),
10275 -- but in fact the test is required for source code as well, since
10276 -- this situation can arise in source code.
10277
10278 elsif In_Instance or else In_Inlined_Body then
d347f572 10279 return True;
aa180613
RD		 10280
10281 -- Otherwise we need the conversion check
7324bf49 10282
996ae0b0 10283 else
aa180613
RD		 10284 return Conversion_Check
10285 (Is_Numeric_Type (Opnd_Type),
10286 "illegal operand for numeric conversion");
996ae0b0
RK		 10287 end if;
10288
aa180613
RD		 10289 -- Array types
10290
996ae0b0
RK		 10291 elsif Is_Array_Type (Target_Type) then
10292 if not Is_Array_Type (Opnd_Type)
10293 or else Opnd_Type = Any_Composite
10294 or else Opnd_Type = Any_String
10295 then
4adf3c50 10296 Error_Msg_N ("illegal operand for array conversion", Operand);
996ae0b0 10297 return False;
996ae0b0 10298 else
aa180613 10299 return Valid_Array_Conversion;
996ae0b0
RK		 10300 end if;
10301
e65f50ec
ES		 10302 -- Ada 2005 (AI-251): Anonymous access types where target references an
10303 -- interface type.
758c442c 10304
964f13da
RD		 10305 elsif Ekind_In (Target_Type, E_General_Access_Type,
10306 E_Anonymous_Access_Type)
758c442c
GD		 10307 and then Is_Interface (Directly_Designated_Type (Target_Type))
10308 then
10309 -- Check the static accessibility rule of 4.6(17). Note that the
d81b4bfe
TQ		 10310 -- check is not enforced when within an instance body, since the
10311 -- RM requires such cases to be caught at run time.
758c442c
GD		 10312
10313 if Ekind (Target_Type) /= E_Anonymous_Access_Type then
10314 if Type_Access_Level (Opnd_Type) >
10315 Type_Access_Level (Target_Type)
10316 then
10317 -- In an instance, this is a run-time check, but one we know
10318 -- will fail, so generate an appropriate warning. The raise
10319 -- will be generated by Expand_N_Type_Conversion.
10320
10321 if In_Instance_Body then
10322 Error_Msg_N
10323 ("?cannot convert local pointer to non-local access type",
10324 Operand);
10325 Error_Msg_N
c8ef728f 10326 ("\?Program_Error will be raised at run time", Operand);
758c442c
GD		 10327 else
10328 Error_Msg_N
10329 ("cannot convert local pointer to non-local access type",
10330 Operand);
10331 return False;
10332 end if;
10333
10334 -- Special accessibility checks are needed in the case of access
10335 -- discriminants declared for a limited type.
10336
10337 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
10338 and then not Is_Local_Anonymous_Access (Opnd_Type)
10339 then
10340 -- When the operand is a selected access discriminant the check
10341 -- needs to be made against the level of the object denoted by
d81b4bfe
TQ		 10342 -- the prefix of the selected name (Object_Access_Level handles
10343 -- checking the prefix of the operand for this case).
758c442c
GD		 10344
10345 if Nkind (Operand) = N_Selected_Component
c8ef728f 10346 and then Object_Access_Level (Operand) >
45fc7ddb 10347 Type_Access_Level (Target_Type)
758c442c 10348 then
d81b4bfe
TQ		 10349 -- In an instance, this is a run-time check, but one we know
10350 -- will fail, so generate an appropriate warning. The raise
10351 -- will be generated by Expand_N_Type_Conversion.
758c442c
GD		 10352
10353 if In_Instance_Body then
10354 Error_Msg_N
10355 ("?cannot convert access discriminant to non-local" &
10356 " access type", Operand);
10357 Error_Msg_N
c8ef728f 10358 ("\?Program_Error will be raised at run time", Operand);
758c442c
GD		 10359 else
10360 Error_Msg_N
10361 ("cannot convert access discriminant to non-local" &
10362 " access type", Operand);
10363 return False;
10364 end if;
10365 end if;
10366
10367 -- The case of a reference to an access discriminant from
10368 -- within a limited type declaration (which will appear as
10369 -- a discriminal) is always illegal because the level of the
f3d57416 10370 -- discriminant is considered to be deeper than any (nameable)
758c442c
GD		 10371 -- access type.
10372
10373 if Is_Entity_Name (Operand)
10374 and then not Is_Local_Anonymous_Access (Opnd_Type)
964f13da
RD		 10375 and then
10376 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
758c442c
GD		 10377 and then Present (Discriminal_Link (Entity (Operand)))
10378 then
10379 Error_Msg_N
10380 ("discriminant has deeper accessibility level than target",
10381 Operand);
10382 return False;
10383 end if;
10384 end if;
10385 end if;
10386
10387 return True;
10388
aa180613
RD		 10389 -- General and anonymous access types
10390
964f13da
RD		 10391 elsif Ekind_In (Target_Type, E_General_Access_Type,
10392 E_Anonymous_Access_Type)
996ae0b0
RK		 10393 and then
10394 Conversion_Check
10395 (Is_Access_Type (Opnd_Type)
964f13da
RD		 10396 and then not
10397 Ekind_In (Opnd_Type, E_Access_Subprogram_Type,
10398 E_Access_Protected_Subprogram_Type),
996ae0b0
RK		 10399 "must be an access-to-object type")
10400 then
10401 if Is_Access_Constant (Opnd_Type)
10402 and then not Is_Access_Constant (Target_Type)
10403 then
10404 Error_Msg_N
10405 ("access-to-constant operand type not allowed", Operand);
10406 return False;
10407 end if;
10408
758c442c
GD		 10409 -- Check the static accessibility rule of 4.6(17). Note that the
10410 -- check is not enforced when within an instance body, since the RM
10411 -- requires such cases to be caught at run time.
996ae0b0 10412
758c442c
GD		 10413 if Ekind (Target_Type) /= E_Anonymous_Access_Type
10414 or else Is_Local_Anonymous_Access (Target_Type)
10415 then
996ae0b0
RK		 10416 if Type_Access_Level (Opnd_Type)
10417 > Type_Access_Level (Target_Type)
10418 then
d81b4bfe
TQ		 10419 -- In an instance, this is a run-time check, but one we know
10420 -- will fail, so generate an appropriate warning. The raise
10421 -- will be generated by Expand_N_Type_Conversion.
996ae0b0
RK		 10422
10423 if In_Instance_Body then
10424 Error_Msg_N
10425 ("?cannot convert local pointer to non-local access type",
10426 Operand);
10427 Error_Msg_N
c8ef728f 10428 ("\?Program_Error will be raised at run time", Operand);
996ae0b0
RK		 10429
10430 else
b90cfacd
HK		 10431 -- Avoid generation of spurious error message
10432
10433 if not Error_Posted (N) then
10434 Error_Msg_N
10435 ("cannot convert local pointer to non-local access type",
10436 Operand);
10437 end if;
10438
996ae0b0
RK		 10439 return False;
10440 end if;
10441
758c442c
GD		 10442 -- Special accessibility checks are needed in the case of access
10443 -- discriminants declared for a limited type.
10444
10445 elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
10446 and then not Is_Local_Anonymous_Access (Opnd_Type)
10447 then
758c442c
GD		 10448 -- When the operand is a selected access discriminant the check
10449 -- needs to be made against the level of the object denoted by
d81b4bfe
TQ		 10450 -- the prefix of the selected name (Object_Access_Level handles
10451 -- checking the prefix of the operand for this case).
996ae0b0
RK		 10452
10453 if Nkind (Operand) = N_Selected_Component
45fc7ddb
HK		 10454 and then Object_Access_Level (Operand) >
10455 Type_Access_Level (Target_Type)
996ae0b0 10456 then
d81b4bfe
TQ		 10457 -- In an instance, this is a run-time check, but one we know
10458 -- will fail, so generate an appropriate warning. The raise
10459 -- will be generated by Expand_N_Type_Conversion.
996ae0b0
RK		 10460
10461 if In_Instance_Body then
10462 Error_Msg_N
10463 ("?cannot convert access discriminant to non-local" &
10464 " access type", Operand);
10465 Error_Msg_N
c8ef728f
ES		 10466 ("\?Program_Error will be raised at run time",
10467 Operand);
996ae0b0
RK		 10468
10469 else
10470 Error_Msg_N
10471 ("cannot convert access discriminant to non-local" &
10472 " access type", Operand);
10473 return False;
10474 end if;
10475 end if;
10476
758c442c
GD		 10477 -- The case of a reference to an access discriminant from
10478 -- within a limited type declaration (which will appear as
10479 -- a discriminal) is always illegal because the level of the
f3d57416 10480 -- discriminant is considered to be deeper than any (nameable)
758c442c 10481 -- access type.
996ae0b0
RK		 10482
10483 if Is_Entity_Name (Operand)
964f13da
RD		 10484 and then
10485 Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
996ae0b0
RK		 10486 and then Present (Discriminal_Link (Entity (Operand)))
10487 then
10488 Error_Msg_N
10489 ("discriminant has deeper accessibility level than target",
10490 Operand);
10491 return False;
10492 end if;
10493 end if;
10494 end if;
10495
14e33999
AC		 10496 -- In the presence of limited_with clauses we have to use non-limited
10497 -- views, if available.
d81b4bfe 10498
14e33999 10499 Check_Limited : declare
0669bebe
GB		 10500 function Full_Designated_Type (T : Entity_Id) return Entity_Id;
10501 -- Helper function to handle limited views
10502
10503 --------------------------
10504 -- Full_Designated_Type --
10505 --------------------------
10506
10507 function Full_Designated_Type (T : Entity_Id) return Entity_Id is
950d217a 10508 Desig : constant Entity_Id := Designated_Type (T);
c0985d4e 10509
0669bebe 10510 begin
950d217a
AC		 10511 -- Handle the limited view of a type
10512
c0985d4e
HK		 10513 if Is_Incomplete_Type (Desig)
10514 and then From_With_Type (Desig)
0669bebe
GB		 10515 and then Present (Non_Limited_View (Desig))
10516 then
950d217a
AC		 10517 return Available_View (Desig);
10518 else
10519 return Desig;
0669bebe
GB		 10520 end if;
10521 end Full_Designated_Type;
10522
d81b4bfe
TQ		 10523 -- Local Declarations
10524
0669bebe
GB		 10525 Target : constant Entity_Id := Full_Designated_Type (Target_Type);
10526 Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
10527
10528 Same_Base : constant Boolean :=
10529 Base_Type (Target) = Base_Type (Opnd);
996ae0b0 10530
14e33999 10531 -- Start of processing for Check_Limited
d81b4bfe 10532
996ae0b0
RK		 10533 begin
10534 if Is_Tagged_Type (Target) then
10535 return Valid_Tagged_Conversion (Target, Opnd);
10536
10537 else
0669bebe 10538 if not Same_Base then
996ae0b0
RK		 10539 Error_Msg_NE
10540 ("target designated type not compatible with }",
10541 N, Base_Type (Opnd));
10542 return False;
10543
da709d08
AC		 10544 -- Ada 2005 AI-384: legality rule is symmetric in both
10545 -- designated types. The conversion is legal (with possible
10546 -- constraint check) if either designated type is
10547 -- unconstrained.
10548
10549 elsif Subtypes_Statically_Match (Target, Opnd)
10550 or else
10551 (Has_Discriminants (Target)
10552 and then
10553 (not Is_Constrained (Opnd)
10554 or else not Is_Constrained (Target)))
996ae0b0 10555 then
9fa33291
RD		 10556 -- Special case, if Value_Size has been used to make the
10557 -- sizes different, the conversion is not allowed even
10558 -- though the subtypes statically match.
10559
10560 if Known_Static_RM_Size (Target)
10561 and then Known_Static_RM_Size (Opnd)
10562 and then RM_Size (Target) /= RM_Size (Opnd)
10563 then
10564 Error_Msg_NE
10565 ("target designated subtype not compatible with }",
10566 N, Opnd);
10567 Error_Msg_NE
10568 ("\because sizes of the two designated subtypes differ",
10569 N, Opnd);
10570 return False;
10571
10572 -- Normal case where conversion is allowed
10573
10574 else
10575 return True;
10576 end if;
da709d08
AC		 10577
10578 else
996ae0b0
RK		 10579 Error_Msg_NE
10580 ("target designated subtype not compatible with }",
10581 N, Opnd);
10582 return False;
996ae0b0
RK		 10583 end if;
10584 end if;
14e33999 10585 end Check_Limited;
996ae0b0 10586
cdbf04c0 10587 -- Access to subprogram types. If the operand is an access parameter,
4adf3c50
AC		 10588 -- the type has a deeper accessibility that any master, and cannot be
10589 -- assigned. We must make an exception if the conversion is part of an
10590 -- assignment and the target is the return object of an extended return
10591 -- statement, because in that case the accessibility check takes place
10592 -- after the return.
aa180613 10593
dce86910 10594 elsif Is_Access_Subprogram_Type (Target_Type)
bc5f3720 10595 and then No (Corresponding_Remote_Type (Opnd_Type))
996ae0b0 10596 then
cdbf04c0
AC		 10597 if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
10598 and then Is_Entity_Name (Operand)
10599 and then Ekind (Entity (Operand)) = E_In_Parameter
53cf4600
ES		 10600 and then
10601 (Nkind (Parent (N)) /= N_Assignment_Statement
10602 or else not Is_Entity_Name (Name (Parent (N)))
10603 or else not Is_Return_Object (Entity (Name (Parent (N)))))
0669bebe
GB		 10604 then
10605 Error_Msg_N
10606 ("illegal attempt to store anonymous access to subprogram",
10607 Operand);
10608 Error_Msg_N
10609 ("\value has deeper accessibility than any master " &
aa5147f0 10610 "(RM 3.10.2 (13))",
0669bebe
GB		 10611 Operand);
10612
c147ac26
ES		 10613 Error_Msg_NE
10614 ("\use named access type for& instead of access parameter",
10615 Operand, Entity (Operand));
0669bebe
GB		 10616 end if;
10617
996ae0b0
RK		 10618 -- Check that the designated types are subtype conformant
10619
bc5f3720
RD		 10620 Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
10621 Old_Id => Designated_Type (Opnd_Type),
10622 Err_Loc => N);
996ae0b0
RK		 10623
10624 -- Check the static accessibility rule of 4.6(20)
10625
10626 if Type_Access_Level (Opnd_Type) >
10627 Type_Access_Level (Target_Type)
10628 then
10629 Error_Msg_N
10630 ("operand type has deeper accessibility level than target",
10631 Operand);
10632
10633 -- Check that if the operand type is declared in a generic body,
10634 -- then the target type must be declared within that same body
10635 -- (enforces last sentence of 4.6(20)).
10636
10637 elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
10638 declare
10639 O_Gen : constant Node_Id :=
10640 Enclosing_Generic_Body (Opnd_Type);
10641
1420b484 10642 T_Gen : Node_Id;
996ae0b0
RK		 10643
10644 begin
1420b484 10645 T_Gen := Enclosing_Generic_Body (Target_Type);
996ae0b0
RK		 10646 while Present (T_Gen) and then T_Gen /= O_Gen loop
10647 T_Gen := Enclosing_Generic_Body (T_Gen);
10648 end loop;
10649
10650 if T_Gen /= O_Gen then
10651 Error_Msg_N
10652 ("target type must be declared in same generic body"
10653 & " as operand type", N);
10654 end if;
10655 end;
10656 end if;
10657
10658 return True;
10659
aa180613
RD		 10660 -- Remote subprogram access types
10661
996ae0b0
RK		 10662 elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
10663 and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
10664 then
10665 -- It is valid to convert from one RAS type to another provided
10666 -- that their specification statically match.
10667
10668 Check_Subtype_Conformant
10669 (New_Id =>
10670 Designated_Type (Corresponding_Remote_Type (Target_Type)),
10671 Old_Id =>
10672 Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
10673 Err_Loc =>
10674 N);
10675 return True;
aa180613 10676
e65f50ec 10677 -- If both are tagged types, check legality of view conversions
996ae0b0 10678
e65f50ec 10679 elsif Is_Tagged_Type (Target_Type)
4adf3c50
AC		 10680 and then
10681 Is_Tagged_Type (Opnd_Type)
e65f50ec 10682 then
996ae0b0
RK		 10683 return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
10684
a77842bd 10685 -- Types derived from the same root type are convertible
996ae0b0
RK		 10686
10687 elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
10688 return True;
10689
4adf3c50
AC		 10690 -- In an instance or an inlined body, there may be inconsistent views of
10691 -- the same type, or of types derived from a common root.
996ae0b0 10692
aa5147f0
ES		 10693 elsif (In_Instance or In_Inlined_Body)
10694 and then
d81b4bfe
TQ		 10695 Root_Type (Underlying_Type (Target_Type)) =
10696 Root_Type (Underlying_Type (Opnd_Type))
996ae0b0
RK		 10697 then
10698 return True;
10699
10700 -- Special check for common access type error case
10701
10702 elsif Ekind (Target_Type) = E_Access_Type
10703 and then Is_Access_Type (Opnd_Type)
10704 then
10705 Error_Msg_N ("target type must be general access type!", N);
305caf42
AC		 10706 Error_Msg_NE -- CODEFIX
10707 ("add ALL to }!", N, Target_Type);
996ae0b0
RK		 10708 return False;
10709
10710 else
10711 Error_Msg_NE ("invalid conversion, not compatible with }",
10712 N, Opnd_Type);
996ae0b0
RK		 10713 return False;
10714 end if;
10715 end Valid_Conversion;
10716
10717end Sem_Res;
GNU Compiler Collection
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