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1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- E X P _ A G G R --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2018, Free Software Foundation, Inc. --
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- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
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 --
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. --
20 -- --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
23 -- --
24 ------------------------------------------------------------------------------
25
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Debug; use Debug;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Expander; use Expander;
33 with Exp_Util; use Exp_Util;
34 with Exp_Ch3; use Exp_Ch3;
35 with Exp_Ch6; use Exp_Ch6;
36 with Exp_Ch7; use Exp_Ch7;
37 with Exp_Ch9; use Exp_Ch9;
38 with Exp_Disp; use Exp_Disp;
39 with Exp_Tss; use Exp_Tss;
40 with Freeze; use Freeze;
41 with Itypes; use Itypes;
42 with Lib; use Lib;
43 with Namet; use Namet;
44 with Nmake; use Nmake;
45 with Nlists; use Nlists;
46 with Opt; use Opt;
47 with Restrict; use Restrict;
48 with Rident; use Rident;
49 with Rtsfind; use Rtsfind;
50 with Ttypes; use Ttypes;
51 with Sem; use Sem;
52 with Sem_Aggr; use Sem_Aggr;
53 with Sem_Aux; use Sem_Aux;
54 with Sem_Ch3; use Sem_Ch3;
55 with Sem_Eval; use Sem_Eval;
56 with Sem_Res; use Sem_Res;
57 with Sem_Util; use Sem_Util;
58 with Sinfo; use Sinfo;
59 with Snames; use Snames;
60 with Stand; use Stand;
61 with Stringt; use Stringt;
62 with Tbuild; use Tbuild;
63 with Uintp; use Uintp;
64 with Urealp; use Urealp;
65
66 package body Exp_Aggr is
67
68 type Case_Bounds is record
69 Choice_Lo : Node_Id;
70 Choice_Hi : Node_Id;
71 Choice_Node : Node_Id;
72 end record;
73
74 type Case_Table_Type is array (Nat range <>) of Case_Bounds;
75 -- Table type used by Check_Case_Choices procedure
76
77 procedure Collect_Initialization_Statements
78 (Obj : Entity_Id;
79 N : Node_Id;
80 Node_After : Node_Id);
81 -- If Obj is not frozen, collect actions inserted after N until, but not
82 -- including, Node_After, for initialization of Obj, and move them to an
83 -- expression with actions, which becomes the Initialization_Statements for
84 -- Obj.
85
86 procedure Expand_Delta_Array_Aggregate (N : Node_Id; Deltas : List_Id);
87 procedure Expand_Delta_Record_Aggregate (N : Node_Id; Deltas : List_Id);
88
89 function Has_Default_Init_Comps (N : Node_Id) return Boolean;
90 -- N is an aggregate (record or array). Checks the presence of default
91 -- initialization (<>) in any component (Ada 2005: AI-287).
92
93 function Is_CCG_Supported_Aggregate (N : Node_Id) return Boolean;
94 -- Return True if aggregate N is located in a context supported by the
95 -- CCG backend; False otherwise.
96
97 function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean;
98 -- Returns true if N is an aggregate used to initialize the components
99 -- of a statically allocated dispatch table.
100
101 function Late_Expansion
102 (N : Node_Id;
103 Typ : Entity_Id;
104 Target : Node_Id) return List_Id;
105 -- This routine implements top-down expansion of nested aggregates. In
106 -- doing so, it avoids the generation of temporaries at each level. N is
107 -- a nested record or array aggregate with the Expansion_Delayed flag.
108 -- Typ is the expected type of the aggregate. Target is a (duplicatable)
109 -- expression that will hold the result of the aggregate expansion.
110
111 function Make_OK_Assignment_Statement
112 (Sloc : Source_Ptr;
113 Name : Node_Id;
114 Expression : Node_Id) return Node_Id;
115 -- This is like Make_Assignment_Statement, except that Assignment_OK
116 -- is set in the left operand. All assignments built by this unit use
117 -- this routine. This is needed to deal with assignments to initialized
118 -- constants that are done in place.
119
120 function Must_Slide
121 (Obj_Type : Entity_Id;
122 Typ : Entity_Id) return Boolean;
123 -- A static array aggregate in an object declaration can in most cases be
124 -- expanded in place. The one exception is when the aggregate is given
125 -- with component associations that specify different bounds from those of
126 -- the type definition in the object declaration. In this pathological
127 -- case the aggregate must slide, and we must introduce an intermediate
128 -- temporary to hold it.
129 --
130 -- The same holds in an assignment to one-dimensional array of arrays,
131 -- when a component may be given with bounds that differ from those of the
132 -- component type.
133
134 function Number_Of_Choices (N : Node_Id) return Nat;
135 -- Returns the number of discrete choices (not including the others choice
136 -- if present) contained in (sub-)aggregate N.
137
138 procedure Process_Transient_Component
139 (Loc : Source_Ptr;
140 Comp_Typ : Entity_Id;
141 Init_Expr : Node_Id;
142 Fin_Call : out Node_Id;
143 Hook_Clear : out Node_Id;
144 Aggr : Node_Id := Empty;
145 Stmts : List_Id := No_List);
146 -- Subsidiary to the expansion of array and record aggregates. Generate
147 -- part of the necessary code to finalize a transient component. Comp_Typ
148 -- is the component type. Init_Expr is the initialization expression of the
149 -- component which is always a function call. Fin_Call is the finalization
150 -- call used to clean up the transient function result. Hook_Clear is the
151 -- hook reset statement. Aggr and Stmts both control the placement of the
152 -- generated code. Aggr is the related aggregate. If present, all code is
153 -- inserted prior to Aggr using Insert_Action. Stmts is the initialization
154 -- statements of the component. If present, all code is added to Stmts.
155
156 procedure Process_Transient_Component_Completion
157 (Loc : Source_Ptr;
158 Aggr : Node_Id;
159 Fin_Call : Node_Id;
160 Hook_Clear : Node_Id;
161 Stmts : List_Id);
162 -- Subsidiary to the expansion of array and record aggregates. Generate
163 -- part of the necessary code to finalize a transient component. Aggr is
164 -- the related aggregate. Fin_Clear is the finalization call used to clean
165 -- up the transient component. Hook_Clear is the hook reset statment. Stmts
166 -- is the initialization statement list for the component. All generated
167 -- code is added to Stmts.
168
169 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
170 -- Sort the Case Table using the Lower Bound of each Choice as the key.
171 -- A simple insertion sort is used since the number of choices in a case
172 -- statement of variant part will usually be small and probably in near
173 -- sorted order.
174
175 ------------------------------------------------------
176 -- Local subprograms for Record Aggregate Expansion --
177 ------------------------------------------------------
178
179 function Is_Build_In_Place_Aggregate_Return (N : Node_Id) return Boolean;
180 -- True if N is an aggregate (possibly qualified or converted) that is
181 -- being returned from a build-in-place function.
182
183 function Build_Record_Aggr_Code
184 (N : Node_Id;
185 Typ : Entity_Id;
186 Lhs : Node_Id) return List_Id;
187 -- N is an N_Aggregate or an N_Extension_Aggregate. Typ is the type of the
188 -- aggregate. Target is an expression containing the location on which the
189 -- component by component assignments will take place. Returns the list of
190 -- assignments plus all other adjustments needed for tagged and controlled
191 -- types.
192
193 procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id);
194 -- Transform a record aggregate into a sequence of assignments performed
195 -- component by component. N is an N_Aggregate or N_Extension_Aggregate.
196 -- Typ is the type of the record aggregate.
197
198 procedure Expand_Record_Aggregate
199 (N : Node_Id;
200 Orig_Tag : Node_Id := Empty;
201 Parent_Expr : Node_Id := Empty);
202 -- This is the top level procedure for record aggregate expansion.
203 -- Expansion for record aggregates needs expand aggregates for tagged
204 -- record types. Specifically Expand_Record_Aggregate adds the Tag
205 -- field in front of the Component_Association list that was created
206 -- during resolution by Resolve_Record_Aggregate.
207 --
208 -- N is the record aggregate node.
209 -- Orig_Tag is the value of the Tag that has to be provided for this
210 -- specific aggregate. It carries the tag corresponding to the type
211 -- of the outermost aggregate during the recursive expansion
212 -- Parent_Expr is the ancestor part of the original extension
213 -- aggregate
214
215 function Has_Mutable_Components (Typ : Entity_Id) return Boolean;
216 -- Return true if one of the components is of a discriminated type with
217 -- defaults. An aggregate for a type with mutable components must be
218 -- expanded into individual assignments.
219
220 procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id);
221 -- If the type of the aggregate is a type extension with renamed discrimi-
222 -- nants, we must initialize the hidden discriminants of the parent.
223 -- Otherwise, the target object must not be initialized. The discriminants
224 -- are initialized by calling the initialization procedure for the type.
225 -- This is incorrect if the initialization of other components has any
226 -- side effects. We restrict this call to the case where the parent type
227 -- has a variant part, because this is the only case where the hidden
228 -- discriminants are accessed, namely when calling discriminant checking
229 -- functions of the parent type, and when applying a stream attribute to
230 -- an object of the derived type.
231
232 -----------------------------------------------------
233 -- Local Subprograms for Array Aggregate Expansion --
234 -----------------------------------------------------
235
236 function Aggr_Size_OK (N : Node_Id; Typ : Entity_Id) return Boolean;
237 -- Very large static aggregates present problems to the back-end, and are
238 -- transformed into assignments and loops. This function verifies that the
239 -- total number of components of an aggregate is acceptable for rewriting
240 -- into a purely positional static form. Aggr_Size_OK must be called before
241 -- calling Flatten.
242 --
243 -- This function also detects and warns about one-component aggregates that
244 -- appear in a nonstatic context. Even if the component value is static,
245 -- such an aggregate must be expanded into an assignment.
246
247 function Backend_Processing_Possible (N : Node_Id) return Boolean;
248 -- This function checks if array aggregate N can be processed directly
249 -- by the backend. If this is the case, True is returned.
250
251 function Build_Array_Aggr_Code
252 (N : Node_Id;
253 Ctype : Entity_Id;
254 Index : Node_Id;
255 Into : Node_Id;
256 Scalar_Comp : Boolean;
257 Indexes : List_Id := No_List) return List_Id;
258 -- This recursive routine returns a list of statements containing the
259 -- loops and assignments that are needed for the expansion of the array
260 -- aggregate N.
261 --
262 -- N is the (sub-)aggregate node to be expanded into code. This node has
263 -- been fully analyzed, and its Etype is properly set.
264 --
265 -- Index is the index node corresponding to the array subaggregate N
266 --
267 -- Into is the target expression into which we are copying the aggregate.
268 -- Note that this node may not have been analyzed yet, and so the Etype
269 -- field may not be set.
270 --
271 -- Scalar_Comp is True if the component type of the aggregate is scalar
272 --
273 -- Indexes is the current list of expressions used to index the object we
274 -- are writing into.
275
276 procedure Convert_Array_Aggr_In_Allocator
277 (Decl : Node_Id;
278 Aggr : Node_Id;
279 Target : Node_Id);
280 -- If the aggregate appears within an allocator and can be expanded in
281 -- place, this routine generates the individual assignments to components
282 -- of the designated object. This is an optimization over the general
283 -- case, where a temporary is first created on the stack and then used to
284 -- construct the allocated object on the heap.
285
286 procedure Convert_To_Positional
287 (N : Node_Id;
288 Max_Others_Replicate : Nat := 32;
289 Handle_Bit_Packed : Boolean := False);
290 -- If possible, convert named notation to positional notation. This
291 -- conversion is possible only in some static cases. If the conversion is
292 -- possible, then N is rewritten with the analyzed converted aggregate.
293 -- The parameter Max_Others_Replicate controls the maximum number of
294 -- values corresponding to an others choice that will be converted to
295 -- positional notation (the default of 32 is the normal limit, and reflects
296 -- the fact that normally the loop is better than a lot of separate
297 -- assignments). Note that this limit gets overridden in any case if
298 -- either of the restrictions No_Elaboration_Code or No_Implicit_Loops is
299 -- set. The parameter Handle_Bit_Packed is usually set False (since we do
300 -- not expect the back end to handle bit packed arrays, so the normal case
301 -- of conversion is pointless), but in the special case of a call from
302 -- Packed_Array_Aggregate_Handled, we set this parameter to True, since
303 -- these are cases we handle in there.
304
305 procedure Expand_Array_Aggregate (N : Node_Id);
306 -- This is the top-level routine to perform array aggregate expansion.
307 -- N is the N_Aggregate node to be expanded.
308
309 function Is_Two_Dim_Packed_Array (Typ : Entity_Id) return Boolean;
310 -- For two-dimensional packed aggregates with constant bounds and constant
311 -- components, it is preferable to pack the inner aggregates because the
312 -- whole matrix can then be presented to the back-end as a one-dimensional
313 -- list of literals. This is much more efficient than expanding into single
314 -- component assignments. This function determines if the type Typ is for
315 -- an array that is suitable for this optimization: it returns True if Typ
316 -- is a two dimensional bit packed array with component size 1, 2, or 4.
317
318 function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean;
319 -- Given an array aggregate, this function handles the case of a packed
320 -- array aggregate with all constant values, where the aggregate can be
321 -- evaluated at compile time. If this is possible, then N is rewritten
322 -- to be its proper compile time value with all the components properly
323 -- assembled. The expression is analyzed and resolved and True is returned.
324 -- If this transformation is not possible, N is unchanged and False is
325 -- returned.
326
327 function Two_Dim_Packed_Array_Handled (N : Node_Id) return Boolean;
328 -- If the type of the aggregate is a two-dimensional bit_packed array
329 -- it may be transformed into an array of bytes with constant values,
330 -- and presented to the back-end as a static value. The function returns
331 -- false if this transformation cannot be performed. THis is similar to,
332 -- and reuses part of the machinery in Packed_Array_Aggregate_Handled.
333
334 ------------------
335 -- Aggr_Size_OK --
336 ------------------
337
338 function Aggr_Size_OK (N : Node_Id; Typ : Entity_Id) return Boolean is
339 Lo : Node_Id;
340 Hi : Node_Id;
341 Indx : Node_Id;
342 Siz : Int;
343 Lov : Uint;
344 Hiv : Uint;
345
346 Max_Aggr_Size : Nat;
347 -- Determines the maximum size of an array aggregate produced by
348 -- converting named to positional notation (e.g. from others clauses).
349 -- This avoids running away with attempts to convert huge aggregates,
350 -- which hit memory limits in the backend.
351
352 function Component_Count (T : Entity_Id) return Nat;
353 -- The limit is applied to the total number of subcomponents that the
354 -- aggregate will have, which is the number of static expressions
355 -- that will appear in the flattened array. This requires a recursive
356 -- computation of the number of scalar components of the structure.
357
358 ---------------------
359 -- Component_Count --
360 ---------------------
361
362 function Component_Count (T : Entity_Id) return Nat is
363 Res : Nat := 0;
364 Comp : Entity_Id;
365
366 begin
367 if Is_Scalar_Type (T) then
368 return 1;
369
370 elsif Is_Record_Type (T) then
371 Comp := First_Component (T);
372 while Present (Comp) loop
373 Res := Res + Component_Count (Etype (Comp));
374 Next_Component (Comp);
375 end loop;
376
377 return Res;
378
379 elsif Is_Array_Type (T) then
380 declare
381 Lo : constant Node_Id :=
382 Type_Low_Bound (Etype (First_Index (T)));
383 Hi : constant Node_Id :=
384 Type_High_Bound (Etype (First_Index (T)));
385
386 Siz : constant Nat := Component_Count (Component_Type (T));
387
388 begin
389 -- Check for superflat arrays, i.e. arrays with such bounds
390 -- as 4 .. 2, to insure that this function never returns a
391 -- meaningless negative value.
392
393 if not Compile_Time_Known_Value (Lo)
394 or else not Compile_Time_Known_Value (Hi)
395 or else Expr_Value (Hi) < Expr_Value (Lo)
396 then
397 return 0;
398
399 else
400 -- If the number of components is greater than Int'Last,
401 -- then return Int'Last, so caller will return False (Aggr
402 -- size is not OK). Otherwise, UI_To_Int will crash.
403
404 declare
405 UI : constant Uint :=
406 Expr_Value (Hi) - Expr_Value (Lo) + 1;
407 begin
408 if UI_Is_In_Int_Range (UI) then
409 return Siz * UI_To_Int (UI);
410 else
411 return Int'Last;
412 end if;
413 end;
414 end if;
415 end;
416
417 else
418 -- Can only be a null for an access type
419
420 return 1;
421 end if;
422 end Component_Count;
423
424 -- Start of processing for Aggr_Size_OK
425
426 begin
427 -- The normal aggregate limit is 500000, but we increase this limit to
428 -- 2**24 (about 16 million) if Restrictions (No_Elaboration_Code) or
429 -- Restrictions (No_Implicit_Loops) is specified, since in either case
430 -- we are at risk of declaring the program illegal because of this
431 -- limit. We also increase the limit when Static_Elaboration_Desired,
432 -- given that this means that objects are intended to be placed in data
433 -- memory.
434
435 -- We also increase the limit if the aggregate is for a packed two-
436 -- dimensional array, because if components are static it is much more
437 -- efficient to construct a one-dimensional equivalent array with static
438 -- components.
439
440 -- Conversely, we decrease the maximum size if none of the above
441 -- requirements apply, and if the aggregate has a single component
442 -- association, which will be more efficient if implemented with a loop.
443
444 -- Finally, we use a small limit in CodePeer mode where we favor loops
445 -- instead of thousands of single assignments (from large aggregates).
446
447 Max_Aggr_Size := 500000;
448
449 if CodePeer_Mode then
450 Max_Aggr_Size := 100;
451
452 elsif Restriction_Active (No_Elaboration_Code)
453 or else Restriction_Active (No_Implicit_Loops)
454 or else Is_Two_Dim_Packed_Array (Typ)
455 or else (Ekind (Current_Scope) = E_Package
456 and then Static_Elaboration_Desired (Current_Scope))
457 then
458 Max_Aggr_Size := 2 ** 24;
459
460 elsif No (Expressions (N))
461 and then No (Next (First (Component_Associations (N))))
462 then
463 Max_Aggr_Size := 5000;
464 end if;
465
466 Siz := Component_Count (Component_Type (Typ));
467
468 Indx := First_Index (Typ);
469 while Present (Indx) loop
470 Lo := Type_Low_Bound (Etype (Indx));
471 Hi := Type_High_Bound (Etype (Indx));
472
473 -- Bounds need to be known at compile time
474
475 if not Compile_Time_Known_Value (Lo)
476 or else not Compile_Time_Known_Value (Hi)
477 then
478 return False;
479 end if;
480
481 Lov := Expr_Value (Lo);
482 Hiv := Expr_Value (Hi);
483
484 -- A flat array is always safe
485
486 if Hiv < Lov then
487 return True;
488 end if;
489
490 -- One-component aggregates are suspicious, and if the context type
491 -- is an object declaration with nonstatic bounds it will trip gcc;
492 -- such an aggregate must be expanded into a single assignment.
493
494 if Hiv = Lov and then Nkind (Parent (N)) = N_Object_Declaration then
495 declare
496 Index_Type : constant Entity_Id :=
497 Etype
498 (First_Index (Etype (Defining_Identifier (Parent (N)))));
499 Indx : Node_Id;
500
501 begin
502 if not Compile_Time_Known_Value (Type_Low_Bound (Index_Type))
503 or else not Compile_Time_Known_Value
504 (Type_High_Bound (Index_Type))
505 then
506 if Present (Component_Associations (N)) then
507 Indx :=
508 First
509 (Choice_List (First (Component_Associations (N))));
510
511 if Is_Entity_Name (Indx)
512 and then not Is_Type (Entity (Indx))
513 then
514 Error_Msg_N
515 ("single component aggregate in "
516 & "non-static context??", Indx);
517 Error_Msg_N ("\maybe subtype name was meant??", Indx);
518 end if;
519 end if;
520
521 return False;
522 end if;
523 end;
524 end if;
525
526 declare
527 Rng : constant Uint := Hiv - Lov + 1;
528
529 begin
530 -- Check if size is too large
531
532 if not UI_Is_In_Int_Range (Rng) then
533 return False;
534 end if;
535
536 Siz := Siz * UI_To_Int (Rng);
537 end;
538
539 if Siz <= 0
540 or else Siz > Max_Aggr_Size
541 then
542 return False;
543 end if;
544
545 -- Bounds must be in integer range, for later array construction
546
547 if not UI_Is_In_Int_Range (Lov)
548 or else
549 not UI_Is_In_Int_Range (Hiv)
550 then
551 return False;
552 end if;
553
554 Next_Index (Indx);
555 end loop;
556
557 return True;
558 end Aggr_Size_OK;
559
560 ---------------------------------
561 -- Backend_Processing_Possible --
562 ---------------------------------
563
564 -- Backend processing by Gigi/gcc is possible only if all the following
565 -- conditions are met:
566
567 -- 1. N is fully positional
568
569 -- 2. N is not a bit-packed array aggregate;
570
571 -- 3. The size of N's array type must be known at compile time. Note
572 -- that this implies that the component size is also known
573
574 -- 4. The array type of N does not follow the Fortran layout convention
575 -- or if it does it must be 1 dimensional.
576
577 -- 5. The array component type may not be tagged (which could necessitate
578 -- reassignment of proper tags).
579
580 -- 6. The array component type must not have unaligned bit components
581
582 -- 7. None of the components of the aggregate may be bit unaligned
583 -- components.
584
585 -- 8. There cannot be delayed components, since we do not know enough
586 -- at this stage to know if back end processing is possible.
587
588 -- 9. There cannot be any discriminated record components, since the
589 -- back end cannot handle this complex case.
590
591 -- 10. No controlled actions need to be generated for components
592
593 -- 11. When generating C code, N must be part of a N_Object_Declaration
594
595 -- 12. When generating C code, N must not include function calls
596
597 function Backend_Processing_Possible (N : Node_Id) return Boolean is
598 Typ : constant Entity_Id := Etype (N);
599 -- Typ is the correct constrained array subtype of the aggregate
600
601 function Component_Check (N : Node_Id; Index : Node_Id) return Boolean;
602 -- This routine checks components of aggregate N, enforcing checks
603 -- 1, 7, 8, 9, 11, and 12. In the multidimensional case, these checks
604 -- are performed on subaggregates. The Index value is the current index
605 -- being checked in the multidimensional case.
606
607 ---------------------
608 -- Component_Check --
609 ---------------------
610
611 function Component_Check (N : Node_Id; Index : Node_Id) return Boolean is
612 function Ultimate_Original_Expression (N : Node_Id) return Node_Id;
613 -- Given a type conversion or an unchecked type conversion N, return
614 -- its innermost original expression.
615
616 ----------------------------------
617 -- Ultimate_Original_Expression --
618 ----------------------------------
619
620 function Ultimate_Original_Expression (N : Node_Id) return Node_Id is
621 Expr : Node_Id := Original_Node (N);
622
623 begin
624 while Nkind_In (Expr, N_Type_Conversion,
625 N_Unchecked_Type_Conversion)
626 loop
627 Expr := Original_Node (Expression (Expr));
628 end loop;
629
630 return Expr;
631 end Ultimate_Original_Expression;
632
633 -- Local variables
634
635 Expr : Node_Id;
636
637 -- Start of processing for Component_Check
638
639 begin
640 -- Checks 1: (no component associations)
641
642 if Present (Component_Associations (N)) then
643 return False;
644 end if;
645
646 -- Checks 11: The C code generator cannot handle aggregates that are
647 -- not part of an object declaration.
648
649 if Modify_Tree_For_C then
650 declare
651 Par : Node_Id := Parent (N);
652
653 begin
654 -- Skip enclosing nested aggregates and their qualified
655 -- expressions.
656
657 while Nkind (Par) = N_Aggregate
658 or else Nkind (Par) = N_Qualified_Expression
659 loop
660 Par := Parent (Par);
661 end loop;
662
663 if Nkind (Par) /= N_Object_Declaration then
664 return False;
665 end if;
666 end;
667 end if;
668
669 -- Checks on components
670
671 -- Recurse to check subaggregates, which may appear in qualified
672 -- expressions. If delayed, the front-end will have to expand.
673 -- If the component is a discriminated record, treat as nonstatic,
674 -- as the back-end cannot handle this properly.
675
676 Expr := First (Expressions (N));
677 while Present (Expr) loop
678
679 -- Checks 8: (no delayed components)
680
681 if Is_Delayed_Aggregate (Expr) then
682 return False;
683 end if;
684
685 -- Checks 9: (no discriminated records)
686
687 if Present (Etype (Expr))
688 and then Is_Record_Type (Etype (Expr))
689 and then Has_Discriminants (Etype (Expr))
690 then
691 return False;
692 end if;
693
694 -- Checks 7. Component must not be bit aligned component
695
696 if Possible_Bit_Aligned_Component (Expr) then
697 return False;
698 end if;
699
700 -- Checks 12: (no function call)
701
702 if Modify_Tree_For_C
703 and then
704 Nkind (Ultimate_Original_Expression (Expr)) = N_Function_Call
705 then
706 return False;
707 end if;
708
709 -- Recursion to following indexes for multiple dimension case
710
711 if Present (Next_Index (Index))
712 and then not Component_Check (Expr, Next_Index (Index))
713 then
714 return False;
715 end if;
716
717 -- All checks for that component finished, on to next
718
719 Next (Expr);
720 end loop;
721
722 return True;
723 end Component_Check;
724
725 -- Start of processing for Backend_Processing_Possible
726
727 begin
728 -- Checks 2 (array not bit packed) and 10 (no controlled actions)
729
730 if Is_Bit_Packed_Array (Typ) or else Needs_Finalization (Typ) then
731 return False;
732 end if;
733
734 -- If component is limited, aggregate must be expanded because each
735 -- component assignment must be built in place.
736
737 if Is_Limited_View (Component_Type (Typ)) then
738 return False;
739 end if;
740
741 -- Checks 4 (array must not be multidimensional Fortran case)
742
743 if Convention (Typ) = Convention_Fortran
744 and then Number_Dimensions (Typ) > 1
745 then
746 return False;
747 end if;
748
749 -- Checks 3 (size of array must be known at compile time)
750
751 if not Size_Known_At_Compile_Time (Typ) then
752 return False;
753 end if;
754
755 -- Checks on components
756
757 if not Component_Check (N, First_Index (Typ)) then
758 return False;
759 end if;
760
761 -- Checks 5 (if the component type is tagged, then we may need to do
762 -- tag adjustments. Perhaps this should be refined to check for any
763 -- component associations that actually need tag adjustment, similar
764 -- to the test in Component_OK_For_Backend for record aggregates with
765 -- tagged components, but not clear whether it's worthwhile ???; in the
766 -- case of virtual machines (no Tagged_Type_Expansion), object tags are
767 -- handled implicitly).
768
769 if Is_Tagged_Type (Component_Type (Typ))
770 and then Tagged_Type_Expansion
771 then
772 return False;
773 end if;
774
775 -- Checks 6 (component type must not have bit aligned components)
776
777 if Type_May_Have_Bit_Aligned_Components (Component_Type (Typ)) then
778 return False;
779 end if;
780
781 -- Backend processing is possible
782
783 Set_Size_Known_At_Compile_Time (Etype (N), True);
784 return True;
785 end Backend_Processing_Possible;
786
787 ---------------------------
788 -- Build_Array_Aggr_Code --
789 ---------------------------
790
791 -- The code that we generate from a one dimensional aggregate is
792
793 -- 1. If the subaggregate contains discrete choices we
794
795 -- (a) Sort the discrete choices
796
797 -- (b) Otherwise for each discrete choice that specifies a range we
798 -- emit a loop. If a range specifies a maximum of three values, or
799 -- we are dealing with an expression we emit a sequence of
800 -- assignments instead of a loop.
801
802 -- (c) Generate the remaining loops to cover the others choice if any
803
804 -- 2. If the aggregate contains positional elements we
805
806 -- (a) translate the positional elements in a series of assignments
807
808 -- (b) Generate a final loop to cover the others choice if any.
809 -- Note that this final loop has to be a while loop since the case
810
811 -- L : Integer := Integer'Last;
812 -- H : Integer := Integer'Last;
813 -- A : array (L .. H) := (1, others =>0);
814
815 -- cannot be handled by a for loop. Thus for the following
816
817 -- array (L .. H) := (.. positional elements.., others =>E);
818
819 -- we always generate something like:
820
821 -- J : Index_Type := Index_Of_Last_Positional_Element;
822 -- while J < H loop
823 -- J := Index_Base'Succ (J)
824 -- Tmp (J) := E;
825 -- end loop;
826
827 function Build_Array_Aggr_Code
828 (N : Node_Id;
829 Ctype : Entity_Id;
830 Index : Node_Id;
831 Into : Node_Id;
832 Scalar_Comp : Boolean;
833 Indexes : List_Id := No_List) return List_Id
834 is
835 Loc : constant Source_Ptr := Sloc (N);
836 Index_Base : constant Entity_Id := Base_Type (Etype (Index));
837 Index_Base_L : constant Node_Id := Type_Low_Bound (Index_Base);
838 Index_Base_H : constant Node_Id := Type_High_Bound (Index_Base);
839
840 function Add (Val : Int; To : Node_Id) return Node_Id;
841 -- Returns an expression where Val is added to expression To, unless
842 -- To+Val is provably out of To's base type range. To must be an
843 -- already analyzed expression.
844
845 function Empty_Range (L, H : Node_Id) return Boolean;
846 -- Returns True if the range defined by L .. H is certainly empty
847
848 function Equal (L, H : Node_Id) return Boolean;
849 -- Returns True if L = H for sure
850
851 function Index_Base_Name return Node_Id;
852 -- Returns a new reference to the index type name
853
854 function Gen_Assign
855 (Ind : Node_Id;
856 Expr : Node_Id;
857 In_Loop : Boolean := False) return List_Id;
858 -- Ind must be a side-effect-free expression. If the input aggregate N
859 -- to Build_Loop contains no subaggregates, then this function returns
860 -- the assignment statement:
861 --
862 -- Into (Indexes, Ind) := Expr;
863 --
864 -- Otherwise we call Build_Code recursively. Flag In_Loop should be set
865 -- when the assignment appears within a generated loop.
866 --
867 -- Ada 2005 (AI-287): In case of default initialized component, Expr
868 -- is empty and we generate a call to the corresponding IP subprogram.
869
870 function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id;
871 -- Nodes L and H must be side-effect-free expressions. If the input
872 -- aggregate N to Build_Loop contains no subaggregates, this routine
873 -- returns the for loop statement:
874 --
875 -- for J in Index_Base'(L) .. Index_Base'(H) loop
876 -- Into (Indexes, J) := Expr;
877 -- end loop;
878 --
879 -- Otherwise we call Build_Code recursively. As an optimization if the
880 -- loop covers 3 or fewer scalar elements we generate a sequence of
881 -- assignments.
882 -- If the component association that generates the loop comes from an
883 -- Iterated_Component_Association, the loop parameter has the name of
884 -- the corresponding parameter in the original construct.
885
886 function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id;
887 -- Nodes L and H must be side-effect-free expressions. If the input
888 -- aggregate N to Build_Loop contains no subaggregates, this routine
889 -- returns the while loop statement:
890 --
891 -- J : Index_Base := L;
892 -- while J < H loop
893 -- J := Index_Base'Succ (J);
894 -- Into (Indexes, J) := Expr;
895 -- end loop;
896 --
897 -- Otherwise we call Build_Code recursively
898
899 function Get_Assoc_Expr (Assoc : Node_Id) return Node_Id;
900 -- For an association with a box, use value given by aspect
901 -- Default_Component_Value of array type if specified, else use
902 -- value given by aspect Default_Value for component type itself
903 -- if specified, else return Empty.
904
905 function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean;
906 function Local_Expr_Value (E : Node_Id) return Uint;
907 -- These two Local routines are used to replace the corresponding ones
908 -- in sem_eval because while processing the bounds of an aggregate with
909 -- discrete choices whose index type is an enumeration, we build static
910 -- expressions not recognized by Compile_Time_Known_Value as such since
911 -- they have not yet been analyzed and resolved. All the expressions in
912 -- question are things like Index_Base_Name'Val (Const) which we can
913 -- easily recognize as being constant.
914
915 ---------
916 -- Add --
917 ---------
918
919 function Add (Val : Int; To : Node_Id) return Node_Id is
920 Expr_Pos : Node_Id;
921 Expr : Node_Id;
922 To_Pos : Node_Id;
923 U_To : Uint;
924 U_Val : constant Uint := UI_From_Int (Val);
925
926 begin
927 -- Note: do not try to optimize the case of Val = 0, because
928 -- we need to build a new node with the proper Sloc value anyway.
929
930 -- First test if we can do constant folding
931
932 if Local_Compile_Time_Known_Value (To) then
933 U_To := Local_Expr_Value (To) + Val;
934
935 -- Determine if our constant is outside the range of the index.
936 -- If so return an Empty node. This empty node will be caught
937 -- by Empty_Range below.
938
939 if Compile_Time_Known_Value (Index_Base_L)
940 and then U_To < Expr_Value (Index_Base_L)
941 then
942 return Empty;
943
944 elsif Compile_Time_Known_Value (Index_Base_H)
945 and then U_To > Expr_Value (Index_Base_H)
946 then
947 return Empty;
948 end if;
949
950 Expr_Pos := Make_Integer_Literal (Loc, U_To);
951 Set_Is_Static_Expression (Expr_Pos);
952
953 if not Is_Enumeration_Type (Index_Base) then
954 Expr := Expr_Pos;
955
956 -- If we are dealing with enumeration return
957 -- Index_Base'Val (Expr_Pos)
958
959 else
960 Expr :=
961 Make_Attribute_Reference
962 (Loc,
963 Prefix => Index_Base_Name,
964 Attribute_Name => Name_Val,
965 Expressions => New_List (Expr_Pos));
966 end if;
967
968 return Expr;
969 end if;
970
971 -- If we are here no constant folding possible
972
973 if not Is_Enumeration_Type (Index_Base) then
974 Expr :=
975 Make_Op_Add (Loc,
976 Left_Opnd => Duplicate_Subexpr (To),
977 Right_Opnd => Make_Integer_Literal (Loc, U_Val));
978
979 -- If we are dealing with enumeration return
980 -- Index_Base'Val (Index_Base'Pos (To) + Val)
981
982 else
983 To_Pos :=
984 Make_Attribute_Reference
985 (Loc,
986 Prefix => Index_Base_Name,
987 Attribute_Name => Name_Pos,
988 Expressions => New_List (Duplicate_Subexpr (To)));
989
990 Expr_Pos :=
991 Make_Op_Add (Loc,
992 Left_Opnd => To_Pos,
993 Right_Opnd => Make_Integer_Literal (Loc, U_Val));
994
995 Expr :=
996 Make_Attribute_Reference
997 (Loc,
998 Prefix => Index_Base_Name,
999 Attribute_Name => Name_Val,
1000 Expressions => New_List (Expr_Pos));
1001 end if;
1002
1003 return Expr;
1004 end Add;
1005
1006 -----------------
1007 -- Empty_Range --
1008 -----------------
1009
1010 function Empty_Range (L, H : Node_Id) return Boolean is
1011 Is_Empty : Boolean := False;
1012 Low : Node_Id;
1013 High : Node_Id;
1014
1015 begin
1016 -- First check if L or H were already detected as overflowing the
1017 -- index base range type by function Add above. If this is so Add
1018 -- returns the empty node.
1019
1020 if No (L) or else No (H) then
1021 return True;
1022 end if;
1023
1024 for J in 1 .. 3 loop
1025 case J is
1026
1027 -- L > H range is empty
1028
1029 when 1 =>
1030 Low := L;
1031 High := H;
1032
1033 -- B_L > H range must be empty
1034
1035 when 2 =>
1036 Low := Index_Base_L;
1037 High := H;
1038
1039 -- L > B_H range must be empty
1040
1041 when 3 =>
1042 Low := L;
1043 High := Index_Base_H;
1044 end case;
1045
1046 if Local_Compile_Time_Known_Value (Low)
1047 and then
1048 Local_Compile_Time_Known_Value (High)
1049 then
1050 Is_Empty :=
1051 UI_Gt (Local_Expr_Value (Low), Local_Expr_Value (High));
1052 end if;
1053
1054 exit when Is_Empty;
1055 end loop;
1056
1057 return Is_Empty;
1058 end Empty_Range;
1059
1060 -----------
1061 -- Equal --
1062 -----------
1063
1064 function Equal (L, H : Node_Id) return Boolean is
1065 begin
1066 if L = H then
1067 return True;
1068
1069 elsif Local_Compile_Time_Known_Value (L)
1070 and then
1071 Local_Compile_Time_Known_Value (H)
1072 then
1073 return UI_Eq (Local_Expr_Value (L), Local_Expr_Value (H));
1074 end if;
1075
1076 return False;
1077 end Equal;
1078
1079 ----------------
1080 -- Gen_Assign --
1081 ----------------
1082
1083 function Gen_Assign
1084 (Ind : Node_Id;
1085 Expr : Node_Id;
1086 In_Loop : Boolean := False) return List_Id
1087 is
1088 function Add_Loop_Actions (Lis : List_Id) return List_Id;
1089 -- Collect insert_actions generated in the construction of a loop,
1090 -- and prepend them to the sequence of assignments to complete the
1091 -- eventual body of the loop.
1092
1093 procedure Initialize_Array_Component
1094 (Arr_Comp : Node_Id;
1095 Comp_Typ : Node_Id;
1096 Init_Expr : Node_Id;
1097 Stmts : List_Id);
1098 -- Perform the initialization of array component Arr_Comp with
1099 -- expected type Comp_Typ. Init_Expr denotes the initialization
1100 -- expression of the array component. All generated code is added
1101 -- to list Stmts.
1102
1103 procedure Initialize_Ctrl_Array_Component
1104 (Arr_Comp : Node_Id;
1105 Comp_Typ : Entity_Id;
1106 Init_Expr : Node_Id;
1107 Stmts : List_Id);
1108 -- Perform the initialization of array component Arr_Comp when its
1109 -- expected type Comp_Typ needs finalization actions. Init_Expr is
1110 -- the initialization expression of the array component. All hook-
1111 -- related declarations are inserted prior to aggregate N. Remaining
1112 -- code is added to list Stmts.
1113
1114 ----------------------
1115 -- Add_Loop_Actions --
1116 ----------------------
1117
1118 function Add_Loop_Actions (Lis : List_Id) return List_Id is
1119 Res : List_Id;
1120
1121 begin
1122 -- Ada 2005 (AI-287): Do nothing else in case of default
1123 -- initialized component.
1124
1125 if No (Expr) then
1126 return Lis;
1127
1128 elsif Nkind (Parent (Expr)) = N_Component_Association
1129 and then Present (Loop_Actions (Parent (Expr)))
1130 then
1131 Append_List (Lis, Loop_Actions (Parent (Expr)));
1132 Res := Loop_Actions (Parent (Expr));
1133 Set_Loop_Actions (Parent (Expr), No_List);
1134 return Res;
1135
1136 else
1137 return Lis;
1138 end if;
1139 end Add_Loop_Actions;
1140
1141 --------------------------------
1142 -- Initialize_Array_Component --
1143 --------------------------------
1144
1145 procedure Initialize_Array_Component
1146 (Arr_Comp : Node_Id;
1147 Comp_Typ : Node_Id;
1148 Init_Expr : Node_Id;
1149 Stmts : List_Id)
1150 is
1151 Exceptions_OK : constant Boolean :=
1152 not Restriction_Active
1153 (No_Exception_Propagation);
1154
1155 Finalization_OK : constant Boolean :=
1156 Present (Comp_Typ)
1157 and then Needs_Finalization (Comp_Typ);
1158
1159 Full_Typ : constant Entity_Id := Underlying_Type (Comp_Typ);
1160 Adj_Call : Node_Id;
1161 Blk_Stmts : List_Id;
1162 Init_Stmt : Node_Id;
1163
1164 begin
1165 -- Protect the initialization statements from aborts. Generate:
1166
1167 -- Abort_Defer;
1168
1169 if Finalization_OK and Abort_Allowed then
1170 if Exceptions_OK then
1171 Blk_Stmts := New_List;
1172 else
1173 Blk_Stmts := Stmts;
1174 end if;
1175
1176 Append_To (Blk_Stmts, Build_Runtime_Call (Loc, RE_Abort_Defer));
1177
1178 -- Otherwise aborts are not allowed. All generated code is added
1179 -- directly to the input list.
1180
1181 else
1182 Blk_Stmts := Stmts;
1183 end if;
1184
1185 -- Initialize the array element. Generate:
1186
1187 -- Arr_Comp := Init_Expr;
1188
1189 -- Note that the initialization expression is replicated because
1190 -- it has to be reevaluated within a generated loop.
1191
1192 Init_Stmt :=
1193 Make_OK_Assignment_Statement (Loc,
1194 Name => New_Copy_Tree (Arr_Comp),
1195 Expression => New_Copy_Tree (Init_Expr));
1196 Set_No_Ctrl_Actions (Init_Stmt);
1197
1198 -- If this is an aggregate for an array of arrays, each
1199 -- subaggregate will be expanded as well, and even with
1200 -- No_Ctrl_Actions the assignments of inner components will
1201 -- require attachment in their assignments to temporaries. These
1202 -- temporaries must be finalized for each subaggregate. Generate:
1203
1204 -- begin
1205 -- Arr_Comp := Init_Expr;
1206 -- end;
1207
1208 if Finalization_OK and then Is_Array_Type (Comp_Typ) then
1209 Init_Stmt :=
1210 Make_Block_Statement (Loc,
1211 Handled_Statement_Sequence =>
1212 Make_Handled_Sequence_Of_Statements (Loc,
1213 Statements => New_List (Init_Stmt)));
1214 end if;
1215
1216 Append_To (Blk_Stmts, Init_Stmt);
1217
1218 -- Adjust the tag due to a possible view conversion. Generate:
1219
1220 -- Arr_Comp._tag := Full_TypP;
1221
1222 if Tagged_Type_Expansion
1223 and then Present (Comp_Typ)
1224 and then Is_Tagged_Type (Comp_Typ)
1225 then
1226 Append_To (Blk_Stmts,
1227 Make_OK_Assignment_Statement (Loc,
1228 Name =>
1229 Make_Selected_Component (Loc,
1230 Prefix => New_Copy_Tree (Arr_Comp),
1231 Selector_Name =>
1232 New_Occurrence_Of
1233 (First_Tag_Component (Full_Typ), Loc)),
1234
1235 Expression =>
1236 Unchecked_Convert_To (RTE (RE_Tag),
1237 New_Occurrence_Of
1238 (Node (First_Elmt (Access_Disp_Table (Full_Typ))),
1239 Loc))));
1240 end if;
1241
1242 -- Adjust the array component. Controlled subaggregates are not
1243 -- considered because each of their individual elements will
1244 -- receive an adjustment of its own. Generate:
1245
1246 -- [Deep_]Adjust (Arr_Comp);
1247
1248 if Finalization_OK
1249 and then not Is_Limited_Type (Comp_Typ)
1250 and then not Is_Build_In_Place_Function_Call (Init_Expr)
1251 and then not
1252 (Is_Array_Type (Comp_Typ)
1253 and then Is_Controlled (Component_Type (Comp_Typ))
1254 and then Nkind (Expr) = N_Aggregate)
1255 then
1256 Adj_Call :=
1257 Make_Adjust_Call
1258 (Obj_Ref => New_Copy_Tree (Arr_Comp),
1259 Typ => Comp_Typ);
1260
1261 -- Guard against a missing [Deep_]Adjust when the component
1262 -- type was not frozen properly.
1263
1264 if Present (Adj_Call) then
1265 Append_To (Blk_Stmts, Adj_Call);
1266 end if;
1267 end if;
1268
1269 -- Complete the protection of the initialization statements
1270
1271 if Finalization_OK and Abort_Allowed then
1272
1273 -- Wrap the initialization statements in a block to catch a
1274 -- potential exception. Generate:
1275
1276 -- begin
1277 -- Abort_Defer;
1278 -- Arr_Comp := Init_Expr;
1279 -- Arr_Comp._tag := Full_TypP;
1280 -- [Deep_]Adjust (Arr_Comp);
1281 -- at end
1282 -- Abort_Undefer_Direct;
1283 -- end;
1284
1285 if Exceptions_OK then
1286 Append_To (Stmts,
1287 Build_Abort_Undefer_Block (Loc,
1288 Stmts => Blk_Stmts,
1289 Context => N));
1290
1291 -- Otherwise exceptions are not propagated. Generate:
1292
1293 -- Abort_Defer;
1294 -- Arr_Comp := Init_Expr;
1295 -- Arr_Comp._tag := Full_TypP;
1296 -- [Deep_]Adjust (Arr_Comp);
1297 -- Abort_Undefer;
1298
1299 else
1300 Append_To (Blk_Stmts,
1301 Build_Runtime_Call (Loc, RE_Abort_Undefer));
1302 end if;
1303 end if;
1304 end Initialize_Array_Component;
1305
1306 -------------------------------------
1307 -- Initialize_Ctrl_Array_Component --
1308 -------------------------------------
1309
1310 procedure Initialize_Ctrl_Array_Component
1311 (Arr_Comp : Node_Id;
1312 Comp_Typ : Entity_Id;
1313 Init_Expr : Node_Id;
1314 Stmts : List_Id)
1315 is
1316 Act_Aggr : Node_Id;
1317 Act_Stmts : List_Id;
1318 Expr : Node_Id;
1319 Fin_Call : Node_Id;
1320 Hook_Clear : Node_Id;
1321
1322 In_Place_Expansion : Boolean;
1323 -- Flag set when a nonlimited controlled function call requires
1324 -- in-place expansion.
1325
1326 begin
1327 -- Duplicate the initialization expression in case the context is
1328 -- a multi choice list or an "others" choice which plugs various
1329 -- holes in the aggregate. As a result the expression is no longer
1330 -- shared between the various components and is reevaluated for
1331 -- each such component.
1332
1333 Expr := New_Copy_Tree (Init_Expr);
1334 Set_Parent (Expr, Parent (Init_Expr));
1335
1336 -- Perform a preliminary analysis and resolution to determine what
1337 -- the initialization expression denotes. An unanalyzed function
1338 -- call may appear as an identifier or an indexed component.
1339
1340 if Nkind_In (Expr, N_Function_Call,
1341 N_Identifier,
1342 N_Indexed_Component)
1343 and then not Analyzed (Expr)
1344 then
1345 Preanalyze_And_Resolve (Expr, Comp_Typ);
1346 end if;
1347
1348 In_Place_Expansion :=
1349 Nkind (Expr) = N_Function_Call
1350 and then not Is_Build_In_Place_Result_Type (Comp_Typ);
1351
1352 -- The initialization expression is a controlled function call.
1353 -- Perform in-place removal of side effects to avoid creating a
1354 -- transient scope, which leads to premature finalization.
1355
1356 -- This in-place expansion is not performed for limited transient
1357 -- objects because the initialization is already done in-place.
1358
1359 if In_Place_Expansion then
1360
1361 -- Suppress the removal of side effects by general analysis
1362 -- because this behavior is emulated here. This avoids the
1363 -- generation of a transient scope, which leads to out-of-order
1364 -- adjustment and finalization.
1365
1366 Set_No_Side_Effect_Removal (Expr);
1367
1368 -- When the transient component initialization is related to a
1369 -- range or an "others", keep all generated statements within
1370 -- the enclosing loop. This way the controlled function call
1371 -- will be evaluated at each iteration, and its result will be
1372 -- finalized at the end of each iteration.
1373
1374 if In_Loop then
1375 Act_Aggr := Empty;
1376 Act_Stmts := Stmts;
1377
1378 -- Otherwise this is a single component initialization. Hook-
1379 -- related statements are inserted prior to the aggregate.
1380
1381 else
1382 Act_Aggr := N;
1383 Act_Stmts := No_List;
1384 end if;
1385
1386 -- Install all hook-related declarations and prepare the clean
1387 -- up statements.
1388
1389 Process_Transient_Component
1390 (Loc => Loc,
1391 Comp_Typ => Comp_Typ,
1392 Init_Expr => Expr,
1393 Fin_Call => Fin_Call,
1394 Hook_Clear => Hook_Clear,
1395 Aggr => Act_Aggr,
1396 Stmts => Act_Stmts);
1397 end if;
1398
1399 -- Use the noncontrolled component initialization circuitry to
1400 -- assign the result of the function call to the array element.
1401 -- This also performs subaggregate wrapping, tag adjustment, and
1402 -- [deep] adjustment of the array element.
1403
1404 Initialize_Array_Component
1405 (Arr_Comp => Arr_Comp,
1406 Comp_Typ => Comp_Typ,
1407 Init_Expr => Expr,
1408 Stmts => Stmts);
1409
1410 -- At this point the array element is fully initialized. Complete
1411 -- the processing of the controlled array component by finalizing
1412 -- the transient function result.
1413
1414 if In_Place_Expansion then
1415 Process_Transient_Component_Completion
1416 (Loc => Loc,
1417 Aggr => N,
1418 Fin_Call => Fin_Call,
1419 Hook_Clear => Hook_Clear,
1420 Stmts => Stmts);
1421 end if;
1422 end Initialize_Ctrl_Array_Component;
1423
1424 -- Local variables
1425
1426 Stmts : constant List_Id := New_List;
1427
1428 Comp_Typ : Entity_Id := Empty;
1429 Expr_Q : Node_Id;
1430 Indexed_Comp : Node_Id;
1431 Init_Call : Node_Id;
1432 New_Indexes : List_Id;
1433
1434 -- Start of processing for Gen_Assign
1435
1436 begin
1437 if No (Indexes) then
1438 New_Indexes := New_List;
1439 else
1440 New_Indexes := New_Copy_List_Tree (Indexes);
1441 end if;
1442
1443 Append_To (New_Indexes, Ind);
1444
1445 if Present (Next_Index (Index)) then
1446 return
1447 Add_Loop_Actions (
1448 Build_Array_Aggr_Code
1449 (N => Expr,
1450 Ctype => Ctype,
1451 Index => Next_Index (Index),
1452 Into => Into,
1453 Scalar_Comp => Scalar_Comp,
1454 Indexes => New_Indexes));
1455 end if;
1456
1457 -- If we get here then we are at a bottom-level (sub-)aggregate
1458
1459 Indexed_Comp :=
1460 Checks_Off
1461 (Make_Indexed_Component (Loc,
1462 Prefix => New_Copy_Tree (Into),
1463 Expressions => New_Indexes));
1464
1465 Set_Assignment_OK (Indexed_Comp);
1466
1467 -- Ada 2005 (AI-287): In case of default initialized component, Expr
1468 -- is not present (and therefore we also initialize Expr_Q to empty).
1469
1470 if No (Expr) then
1471 Expr_Q := Empty;
1472 elsif Nkind (Expr) = N_Qualified_Expression then
1473 Expr_Q := Expression (Expr);
1474 else
1475 Expr_Q := Expr;
1476 end if;
1477
1478 if Present (Etype (N)) and then Etype (N) /= Any_Composite then
1479 Comp_Typ := Component_Type (Etype (N));
1480 pragma Assert (Comp_Typ = Ctype); -- AI-287
1481
1482 elsif Present (Next (First (New_Indexes))) then
1483
1484 -- Ada 2005 (AI-287): Do nothing in case of default initialized
1485 -- component because we have received the component type in
1486 -- the formal parameter Ctype.
1487
1488 -- ??? Some assert pragmas have been added to check if this new
1489 -- formal can be used to replace this code in all cases.
1490
1491 if Present (Expr) then
1492
1493 -- This is a multidimensional array. Recover the component type
1494 -- from the outermost aggregate, because subaggregates do not
1495 -- have an assigned type.
1496
1497 declare
1498 P : Node_Id;
1499
1500 begin
1501 P := Parent (Expr);
1502 while Present (P) loop
1503 if Nkind (P) = N_Aggregate
1504 and then Present (Etype (P))
1505 then
1506 Comp_Typ := Component_Type (Etype (P));
1507 exit;
1508
1509 else
1510 P := Parent (P);
1511 end if;
1512 end loop;
1513
1514 pragma Assert (Comp_Typ = Ctype); -- AI-287
1515 end;
1516 end if;
1517 end if;
1518
1519 -- Ada 2005 (AI-287): We only analyze the expression in case of non-
1520 -- default initialized components (otherwise Expr_Q is not present).
1521
1522 if Present (Expr_Q)
1523 and then Nkind_In (Expr_Q, N_Aggregate, N_Extension_Aggregate)
1524 then
1525 -- At this stage the Expression may not have been analyzed yet
1526 -- because the array aggregate code has not been updated to use
1527 -- the Expansion_Delayed flag and avoid analysis altogether to
1528 -- solve the same problem (see Resolve_Aggr_Expr). So let us do
1529 -- the analysis of non-array aggregates now in order to get the
1530 -- value of Expansion_Delayed flag for the inner aggregate ???
1531
1532 -- In the case of an iterated component association, the analysis
1533 -- of the generated loop will analyze the expression in the
1534 -- proper context, in which the loop parameter is visible.
1535
1536 if Present (Comp_Typ) and then not Is_Array_Type (Comp_Typ) then
1537 if Nkind (Parent (Expr_Q)) = N_Iterated_Component_Association
1538 or else Nkind (Parent (Parent ((Expr_Q)))) =
1539 N_Iterated_Component_Association
1540 then
1541 null;
1542 else
1543 Analyze_And_Resolve (Expr_Q, Comp_Typ);
1544 end if;
1545 end if;
1546
1547 if Is_Delayed_Aggregate (Expr_Q) then
1548
1549 -- This is either a subaggregate of a multidimensional array,
1550 -- or a component of an array type whose component type is
1551 -- also an array. In the latter case, the expression may have
1552 -- component associations that provide different bounds from
1553 -- those of the component type, and sliding must occur. Instead
1554 -- of decomposing the current aggregate assignment, force the
1555 -- reanalysis of the assignment, so that a temporary will be
1556 -- generated in the usual fashion, and sliding will take place.
1557
1558 if Nkind (Parent (N)) = N_Assignment_Statement
1559 and then Is_Array_Type (Comp_Typ)
1560 and then Present (Component_Associations (Expr_Q))
1561 and then Must_Slide (Comp_Typ, Etype (Expr_Q))
1562 then
1563 Set_Expansion_Delayed (Expr_Q, False);
1564 Set_Analyzed (Expr_Q, False);
1565
1566 else
1567 return
1568 Add_Loop_Actions (
1569 Late_Expansion (Expr_Q, Etype (Expr_Q), Indexed_Comp));
1570 end if;
1571 end if;
1572 end if;
1573
1574 if Present (Expr) then
1575
1576 -- Handle an initialization expression of a controlled type in
1577 -- case it denotes a function call. In general such a scenario
1578 -- will produce a transient scope, but this will lead to wrong
1579 -- order of initialization, adjustment, and finalization in the
1580 -- context of aggregates.
1581
1582 -- Target (1) := Ctrl_Func_Call;
1583
1584 -- begin -- scope
1585 -- Trans_Obj : ... := Ctrl_Func_Call; -- object
1586 -- Target (1) := Trans_Obj;
1587 -- Finalize (Trans_Obj);
1588 -- end;
1589 -- Target (1)._tag := ...;
1590 -- Adjust (Target (1));
1591
1592 -- In the example above, the call to Finalize occurs too early
1593 -- and as a result it may leave the array component in a bad
1594 -- state. Finalization of the transient object should really
1595 -- happen after adjustment.
1596
1597 -- To avoid this scenario, perform in-place side-effect removal
1598 -- of the function call. This eliminates the transient property
1599 -- of the function result and ensures correct order of actions.
1600
1601 -- Res : ... := Ctrl_Func_Call;
1602 -- Target (1) := Res;
1603 -- Target (1)._tag := ...;
1604 -- Adjust (Target (1));
1605 -- Finalize (Res);
1606
1607 if Present (Comp_Typ)
1608 and then Needs_Finalization (Comp_Typ)
1609 and then Nkind (Expr) /= N_Aggregate
1610 then
1611 Initialize_Ctrl_Array_Component
1612 (Arr_Comp => Indexed_Comp,
1613 Comp_Typ => Comp_Typ,
1614 Init_Expr => Expr,
1615 Stmts => Stmts);
1616
1617 -- Otherwise perform simple component initialization
1618
1619 else
1620 Initialize_Array_Component
1621 (Arr_Comp => Indexed_Comp,
1622 Comp_Typ => Comp_Typ,
1623 Init_Expr => Expr,
1624 Stmts => Stmts);
1625 end if;
1626
1627 -- Ada 2005 (AI-287): In case of default initialized component, call
1628 -- the initialization subprogram associated with the component type.
1629 -- If the component type is an access type, add an explicit null
1630 -- assignment, because for the back-end there is an initialization
1631 -- present for the whole aggregate, and no default initialization
1632 -- will take place.
1633
1634 -- In addition, if the component type is controlled, we must call
1635 -- its Initialize procedure explicitly, because there is no explicit
1636 -- object creation that will invoke it otherwise.
1637
1638 else
1639 if Present (Base_Init_Proc (Base_Type (Ctype)))
1640 or else Has_Task (Base_Type (Ctype))
1641 then
1642 Append_List_To (Stmts,
1643 Build_Initialization_Call (Loc,
1644 Id_Ref => Indexed_Comp,
1645 Typ => Ctype,
1646 With_Default_Init => True));
1647
1648 -- If the component type has invariants, add an invariant
1649 -- check after the component is default-initialized. It will
1650 -- be analyzed and resolved before the code for initialization
1651 -- of other components.
1652
1653 if Has_Invariants (Ctype) then
1654 Set_Etype (Indexed_Comp, Ctype);
1655 Append_To (Stmts, Make_Invariant_Call (Indexed_Comp));
1656 end if;
1657
1658 elsif Is_Access_Type (Ctype) then
1659 Append_To (Stmts,
1660 Make_Assignment_Statement (Loc,
1661 Name => New_Copy_Tree (Indexed_Comp),
1662 Expression => Make_Null (Loc)));
1663 end if;
1664
1665 if Needs_Finalization (Ctype) then
1666 Init_Call :=
1667 Make_Init_Call
1668 (Obj_Ref => New_Copy_Tree (Indexed_Comp),
1669 Typ => Ctype);
1670
1671 -- Guard against a missing [Deep_]Initialize when the component
1672 -- type was not properly frozen.
1673
1674 if Present (Init_Call) then
1675 Append_To (Stmts, Init_Call);
1676 end if;
1677 end if;
1678 end if;
1679
1680 return Add_Loop_Actions (Stmts);
1681 end Gen_Assign;
1682
1683 --------------
1684 -- Gen_Loop --
1685 --------------
1686
1687 function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id is
1688 Is_Iterated_Component : constant Boolean :=
1689 Nkind (Parent (Expr)) = N_Iterated_Component_Association;
1690
1691 L_J : Node_Id;
1692
1693 L_L : Node_Id;
1694 -- Index_Base'(L)
1695
1696 L_H : Node_Id;
1697 -- Index_Base'(H)
1698
1699 L_Range : Node_Id;
1700 -- Index_Base'(L) .. Index_Base'(H)
1701
1702 L_Iteration_Scheme : Node_Id;
1703 -- L_J in Index_Base'(L) .. Index_Base'(H)
1704
1705 L_Body : List_Id;
1706 -- The statements to execute in the loop
1707
1708 S : constant List_Id := New_List;
1709 -- List of statements
1710
1711 Tcopy : Node_Id;
1712 -- Copy of expression tree, used for checking purposes
1713
1714 begin
1715 -- If loop bounds define an empty range return the null statement
1716
1717 if Empty_Range (L, H) then
1718 Append_To (S, Make_Null_Statement (Loc));
1719
1720 -- Ada 2005 (AI-287): Nothing else need to be done in case of
1721 -- default initialized component.
1722
1723 if No (Expr) then
1724 null;
1725
1726 else
1727 -- The expression must be type-checked even though no component
1728 -- of the aggregate will have this value. This is done only for
1729 -- actual components of the array, not for subaggregates. Do
1730 -- the check on a copy, because the expression may be shared
1731 -- among several choices, some of which might be non-null.
1732
1733 if Present (Etype (N))
1734 and then Is_Array_Type (Etype (N))
1735 and then No (Next_Index (Index))
1736 then
1737 Expander_Mode_Save_And_Set (False);
1738 Tcopy := New_Copy_Tree (Expr);
1739 Set_Parent (Tcopy, N);
1740 Analyze_And_Resolve (Tcopy, Component_Type (Etype (N)));
1741 Expander_Mode_Restore;
1742 end if;
1743 end if;
1744
1745 return S;
1746
1747 -- If loop bounds are the same then generate an assignment, unless
1748 -- the parent construct is an Iterated_Component_Association.
1749
1750 elsif Equal (L, H) and then not Is_Iterated_Component then
1751 return Gen_Assign (New_Copy_Tree (L), Expr);
1752
1753 -- If H - L <= 2 then generate a sequence of assignments when we are
1754 -- processing the bottom most aggregate and it contains scalar
1755 -- components.
1756
1757 elsif No (Next_Index (Index))
1758 and then Scalar_Comp
1759 and then Local_Compile_Time_Known_Value (L)
1760 and then Local_Compile_Time_Known_Value (H)
1761 and then Local_Expr_Value (H) - Local_Expr_Value (L) <= 2
1762 and then not Is_Iterated_Component
1763 then
1764 Append_List_To (S, Gen_Assign (New_Copy_Tree (L), Expr));
1765 Append_List_To (S, Gen_Assign (Add (1, To => L), Expr));
1766
1767 if Local_Expr_Value (H) - Local_Expr_Value (L) = 2 then
1768 Append_List_To (S, Gen_Assign (Add (2, To => L), Expr));
1769 end if;
1770
1771 return S;
1772 end if;
1773
1774 -- Otherwise construct the loop, starting with the loop index L_J
1775
1776 if Is_Iterated_Component then
1777 L_J :=
1778 Make_Defining_Identifier (Loc,
1779 Chars => (Chars (Defining_Identifier (Parent (Expr)))));
1780
1781 else
1782 L_J := Make_Temporary (Loc, 'J', L);
1783 end if;
1784
1785 -- Construct "L .. H" in Index_Base. We use a qualified expression
1786 -- for the bound to convert to the index base, but we don't need
1787 -- to do that if we already have the base type at hand.
1788
1789 if Etype (L) = Index_Base then
1790 L_L := L;
1791 else
1792 L_L :=
1793 Make_Qualified_Expression (Loc,
1794 Subtype_Mark => Index_Base_Name,
1795 Expression => New_Copy_Tree (L));
1796 end if;
1797
1798 if Etype (H) = Index_Base then
1799 L_H := H;
1800 else
1801 L_H :=
1802 Make_Qualified_Expression (Loc,
1803 Subtype_Mark => Index_Base_Name,
1804 Expression => New_Copy_Tree (H));
1805 end if;
1806
1807 L_Range :=
1808 Make_Range (Loc,
1809 Low_Bound => L_L,
1810 High_Bound => L_H);
1811
1812 -- Construct "for L_J in Index_Base range L .. H"
1813
1814 L_Iteration_Scheme :=
1815 Make_Iteration_Scheme
1816 (Loc,
1817 Loop_Parameter_Specification =>
1818 Make_Loop_Parameter_Specification
1819 (Loc,
1820 Defining_Identifier => L_J,
1821 Discrete_Subtype_Definition => L_Range));
1822
1823 -- Construct the statements to execute in the loop body
1824
1825 L_Body :=
1826 Gen_Assign (New_Occurrence_Of (L_J, Loc), Expr, In_Loop => True);
1827
1828 -- Construct the final loop
1829
1830 Append_To (S,
1831 Make_Implicit_Loop_Statement
1832 (Node => N,
1833 Identifier => Empty,
1834 Iteration_Scheme => L_Iteration_Scheme,
1835 Statements => L_Body));
1836
1837 -- A small optimization: if the aggregate is initialized with a box
1838 -- and the component type has no initialization procedure, remove the
1839 -- useless empty loop.
1840
1841 if Nkind (First (S)) = N_Loop_Statement
1842 and then Is_Empty_List (Statements (First (S)))
1843 then
1844 return New_List (Make_Null_Statement (Loc));
1845 else
1846 return S;
1847 end if;
1848 end Gen_Loop;
1849
1850 ---------------
1851 -- Gen_While --
1852 ---------------
1853
1854 -- The code built is
1855
1856 -- W_J : Index_Base := L;
1857 -- while W_J < H loop
1858 -- W_J := Index_Base'Succ (W);
1859 -- L_Body;
1860 -- end loop;
1861
1862 function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id is
1863 W_J : Node_Id;
1864
1865 W_Decl : Node_Id;
1866 -- W_J : Base_Type := L;
1867
1868 W_Iteration_Scheme : Node_Id;
1869 -- while W_J < H
1870
1871 W_Index_Succ : Node_Id;
1872 -- Index_Base'Succ (J)
1873
1874 W_Increment : Node_Id;
1875 -- W_J := Index_Base'Succ (W)
1876
1877 W_Body : constant List_Id := New_List;
1878 -- The statements to execute in the loop
1879
1880 S : constant List_Id := New_List;
1881 -- list of statement
1882
1883 begin
1884 -- If loop bounds define an empty range or are equal return null
1885
1886 if Empty_Range (L, H) or else Equal (L, H) then
1887 Append_To (S, Make_Null_Statement (Loc));
1888 return S;
1889 end if;
1890
1891 -- Build the decl of W_J
1892
1893 W_J := Make_Temporary (Loc, 'J', L);
1894 W_Decl :=
1895 Make_Object_Declaration
1896 (Loc,
1897 Defining_Identifier => W_J,
1898 Object_Definition => Index_Base_Name,
1899 Expression => L);
1900
1901 -- Theoretically we should do a New_Copy_Tree (L) here, but we know
1902 -- that in this particular case L is a fresh Expr generated by
1903 -- Add which we are the only ones to use.
1904
1905 Append_To (S, W_Decl);
1906
1907 -- Construct " while W_J < H"
1908
1909 W_Iteration_Scheme :=
1910 Make_Iteration_Scheme
1911 (Loc,
1912 Condition => Make_Op_Lt
1913 (Loc,
1914 Left_Opnd => New_Occurrence_Of (W_J, Loc),
1915 Right_Opnd => New_Copy_Tree (H)));
1916
1917 -- Construct the statements to execute in the loop body
1918
1919 W_Index_Succ :=
1920 Make_Attribute_Reference
1921 (Loc,
1922 Prefix => Index_Base_Name,
1923 Attribute_Name => Name_Succ,
1924 Expressions => New_List (New_Occurrence_Of (W_J, Loc)));
1925
1926 W_Increment :=
1927 Make_OK_Assignment_Statement
1928 (Loc,
1929 Name => New_Occurrence_Of (W_J, Loc),
1930 Expression => W_Index_Succ);
1931
1932 Append_To (W_Body, W_Increment);
1933
1934 Append_List_To (W_Body,
1935 Gen_Assign (New_Occurrence_Of (W_J, Loc), Expr, In_Loop => True));
1936
1937 -- Construct the final loop
1938
1939 Append_To (S,
1940 Make_Implicit_Loop_Statement
1941 (Node => N,
1942 Identifier => Empty,
1943 Iteration_Scheme => W_Iteration_Scheme,
1944 Statements => W_Body));
1945
1946 return S;
1947 end Gen_While;
1948
1949 --------------------
1950 -- Get_Assoc_Expr --
1951 --------------------
1952
1953 function Get_Assoc_Expr (Assoc : Node_Id) return Node_Id is
1954 Typ : constant Entity_Id := Base_Type (Etype (N));
1955
1956 begin
1957 if Box_Present (Assoc) then
1958 if Is_Scalar_Type (Ctype) then
1959 if Present (Default_Aspect_Component_Value (Typ)) then
1960 return Default_Aspect_Component_Value (Typ);
1961 elsif Present (Default_Aspect_Value (Ctype)) then
1962 return Default_Aspect_Value (Ctype);
1963 else
1964 return Empty;
1965 end if;
1966
1967 else
1968 return Empty;
1969 end if;
1970
1971 else
1972 return Expression (Assoc);
1973 end if;
1974 end Get_Assoc_Expr;
1975
1976 ---------------------
1977 -- Index_Base_Name --
1978 ---------------------
1979
1980 function Index_Base_Name return Node_Id is
1981 begin
1982 return New_Occurrence_Of (Index_Base, Sloc (N));
1983 end Index_Base_Name;
1984
1985 ------------------------------------
1986 -- Local_Compile_Time_Known_Value --
1987 ------------------------------------
1988
1989 function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean is
1990 begin
1991 return Compile_Time_Known_Value (E)
1992 or else
1993 (Nkind (E) = N_Attribute_Reference
1994 and then Attribute_Name (E) = Name_Val
1995 and then Compile_Time_Known_Value (First (Expressions (E))));
1996 end Local_Compile_Time_Known_Value;
1997
1998 ----------------------
1999 -- Local_Expr_Value --
2000 ----------------------
2001
2002 function Local_Expr_Value (E : Node_Id) return Uint is
2003 begin
2004 if Compile_Time_Known_Value (E) then
2005 return Expr_Value (E);
2006 else
2007 return Expr_Value (First (Expressions (E)));
2008 end if;
2009 end Local_Expr_Value;
2010
2011 -- Local variables
2012
2013 New_Code : constant List_Id := New_List;
2014
2015 Aggr_L : constant Node_Id := Low_Bound (Aggregate_Bounds (N));
2016 Aggr_H : constant Node_Id := High_Bound (Aggregate_Bounds (N));
2017 -- The aggregate bounds of this specific subaggregate. Note that if the
2018 -- code generated by Build_Array_Aggr_Code is executed then these bounds
2019 -- are OK. Otherwise a Constraint_Error would have been raised.
2020
2021 Aggr_Low : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_L);
2022 Aggr_High : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_H);
2023 -- After Duplicate_Subexpr these are side-effect free
2024
2025 Assoc : Node_Id;
2026 Choice : Node_Id;
2027 Expr : Node_Id;
2028 High : Node_Id;
2029 Low : Node_Id;
2030 Typ : Entity_Id;
2031
2032 Nb_Choices : Nat := 0;
2033 Table : Case_Table_Type (1 .. Number_Of_Choices (N));
2034 -- Used to sort all the different choice values
2035
2036 Nb_Elements : Int;
2037 -- Number of elements in the positional aggregate
2038
2039 Others_Assoc : Node_Id := Empty;
2040
2041 -- Start of processing for Build_Array_Aggr_Code
2042
2043 begin
2044 -- First before we start, a special case. if we have a bit packed
2045 -- array represented as a modular type, then clear the value to
2046 -- zero first, to ensure that unused bits are properly cleared.
2047
2048 Typ := Etype (N);
2049
2050 if Present (Typ)
2051 and then Is_Bit_Packed_Array (Typ)
2052 and then Is_Modular_Integer_Type (Packed_Array_Impl_Type (Typ))
2053 then
2054 Append_To (New_Code,
2055 Make_Assignment_Statement (Loc,
2056 Name => New_Copy_Tree (Into),
2057 Expression =>
2058 Unchecked_Convert_To (Typ,
2059 Make_Integer_Literal (Loc, Uint_0))));
2060 end if;
2061
2062 -- If the component type contains tasks, we need to build a Master
2063 -- entity in the current scope, because it will be needed if build-
2064 -- in-place functions are called in the expanded code.
2065
2066 if Nkind (Parent (N)) = N_Object_Declaration and then Has_Task (Typ) then
2067 Build_Master_Entity (Defining_Identifier (Parent (N)));
2068 end if;
2069
2070 -- STEP 1: Process component associations
2071
2072 -- For those associations that may generate a loop, initialize
2073 -- Loop_Actions to collect inserted actions that may be crated.
2074
2075 -- Skip this if no component associations
2076
2077 if No (Expressions (N)) then
2078
2079 -- STEP 1 (a): Sort the discrete choices
2080
2081 Assoc := First (Component_Associations (N));
2082 while Present (Assoc) loop
2083 Choice := First (Choice_List (Assoc));
2084 while Present (Choice) loop
2085 if Nkind (Choice) = N_Others_Choice then
2086 Set_Loop_Actions (Assoc, New_List);
2087 Others_Assoc := Assoc;
2088 exit;
2089 end if;
2090
2091 Get_Index_Bounds (Choice, Low, High);
2092
2093 if Low /= High then
2094 Set_Loop_Actions (Assoc, New_List);
2095 end if;
2096
2097 Nb_Choices := Nb_Choices + 1;
2098
2099 Table (Nb_Choices) :=
2100 (Choice_Lo => Low,
2101 Choice_Hi => High,
2102 Choice_Node => Get_Assoc_Expr (Assoc));
2103
2104 Next (Choice);
2105 end loop;
2106
2107 Next (Assoc);
2108 end loop;
2109
2110 -- If there is more than one set of choices these must be static
2111 -- and we can therefore sort them. Remember that Nb_Choices does not
2112 -- account for an others choice.
2113
2114 if Nb_Choices > 1 then
2115 Sort_Case_Table (Table);
2116 end if;
2117
2118 -- STEP 1 (b): take care of the whole set of discrete choices
2119
2120 for J in 1 .. Nb_Choices loop
2121 Low := Table (J).Choice_Lo;
2122 High := Table (J).Choice_Hi;
2123 Expr := Table (J).Choice_Node;
2124 Append_List (Gen_Loop (Low, High, Expr), To => New_Code);
2125 end loop;
2126
2127 -- STEP 1 (c): generate the remaining loops to cover others choice
2128 -- We don't need to generate loops over empty gaps, but if there is
2129 -- a single empty range we must analyze the expression for semantics
2130
2131 if Present (Others_Assoc) then
2132 declare
2133 First : Boolean := True;
2134
2135 begin
2136 for J in 0 .. Nb_Choices loop
2137 if J = 0 then
2138 Low := Aggr_Low;
2139 else
2140 Low := Add (1, To => Table (J).Choice_Hi);
2141 end if;
2142
2143 if J = Nb_Choices then
2144 High := Aggr_High;
2145 else
2146 High := Add (-1, To => Table (J + 1).Choice_Lo);
2147 end if;
2148
2149 -- If this is an expansion within an init proc, make
2150 -- sure that discriminant references are replaced by
2151 -- the corresponding discriminal.
2152
2153 if Inside_Init_Proc then
2154 if Is_Entity_Name (Low)
2155 and then Ekind (Entity (Low)) = E_Discriminant
2156 then
2157 Set_Entity (Low, Discriminal (Entity (Low)));
2158 end if;
2159
2160 if Is_Entity_Name (High)
2161 and then Ekind (Entity (High)) = E_Discriminant
2162 then
2163 Set_Entity (High, Discriminal (Entity (High)));
2164 end if;
2165 end if;
2166
2167 if First
2168 or else not Empty_Range (Low, High)
2169 then
2170 First := False;
2171 Append_List
2172 (Gen_Loop (Low, High,
2173 Get_Assoc_Expr (Others_Assoc)), To => New_Code);
2174 end if;
2175 end loop;
2176 end;
2177 end if;
2178
2179 -- STEP 2: Process positional components
2180
2181 else
2182 -- STEP 2 (a): Generate the assignments for each positional element
2183 -- Note that here we have to use Aggr_L rather than Aggr_Low because
2184 -- Aggr_L is analyzed and Add wants an analyzed expression.
2185
2186 Expr := First (Expressions (N));
2187 Nb_Elements := -1;
2188 while Present (Expr) loop
2189 Nb_Elements := Nb_Elements + 1;
2190 Append_List (Gen_Assign (Add (Nb_Elements, To => Aggr_L), Expr),
2191 To => New_Code);
2192 Next (Expr);
2193 end loop;
2194
2195 -- STEP 2 (b): Generate final loop if an others choice is present
2196 -- Here Nb_Elements gives the offset of the last positional element.
2197
2198 if Present (Component_Associations (N)) then
2199 Assoc := Last (Component_Associations (N));
2200
2201 -- Ada 2005 (AI-287)
2202
2203 Append_List (Gen_While (Add (Nb_Elements, To => Aggr_L),
2204 Aggr_High,
2205 Get_Assoc_Expr (Assoc)), -- AI-287
2206 To => New_Code);
2207 end if;
2208 end if;
2209
2210 return New_Code;
2211 end Build_Array_Aggr_Code;
2212
2213 ----------------------------
2214 -- Build_Record_Aggr_Code --
2215 ----------------------------
2216
2217 function Build_Record_Aggr_Code
2218 (N : Node_Id;
2219 Typ : Entity_Id;
2220 Lhs : Node_Id) return List_Id
2221 is
2222 Loc : constant Source_Ptr := Sloc (N);
2223 L : constant List_Id := New_List;
2224 N_Typ : constant Entity_Id := Etype (N);
2225
2226 Comp : Node_Id;
2227 Instr : Node_Id;
2228 Ref : Node_Id;
2229 Target : Entity_Id;
2230 Comp_Type : Entity_Id;
2231 Selector : Entity_Id;
2232 Comp_Expr : Node_Id;
2233 Expr_Q : Node_Id;
2234
2235 -- If this is an internal aggregate, the External_Final_List is an
2236 -- expression for the controller record of the enclosing type.
2237
2238 -- If the current aggregate has several controlled components, this
2239 -- expression will appear in several calls to attach to the finali-
2240 -- zation list, and it must not be shared.
2241
2242 Ancestor_Is_Expression : Boolean := False;
2243 Ancestor_Is_Subtype_Mark : Boolean := False;
2244
2245 Init_Typ : Entity_Id := Empty;
2246
2247 Finalization_Done : Boolean := False;
2248 -- True if Generate_Finalization_Actions has already been called; calls
2249 -- after the first do nothing.
2250
2251 function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id;
2252 -- Returns the value that the given discriminant of an ancestor type
2253 -- should receive (in the absence of a conflict with the value provided
2254 -- by an ancestor part of an extension aggregate).
2255
2256 procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id);
2257 -- Check that each of the discriminant values defined by the ancestor
2258 -- part of an extension aggregate match the corresponding values
2259 -- provided by either an association of the aggregate or by the
2260 -- constraint imposed by a parent type (RM95-4.3.2(8)).
2261
2262 function Compatible_Int_Bounds
2263 (Agg_Bounds : Node_Id;
2264 Typ_Bounds : Node_Id) return Boolean;
2265 -- Return true if Agg_Bounds are equal or within Typ_Bounds. It is
2266 -- assumed that both bounds are integer ranges.
2267
2268 procedure Generate_Finalization_Actions;
2269 -- Deal with the various controlled type data structure initializations
2270 -- (but only if it hasn't been done already).
2271
2272 function Get_Constraint_Association (T : Entity_Id) return Node_Id;
2273 -- Returns the first discriminant association in the constraint
2274 -- associated with T, if any, otherwise returns Empty.
2275
2276 function Get_Explicit_Discriminant_Value (D : Entity_Id) return Node_Id;
2277 -- If the ancestor part is an unconstrained type and further ancestors
2278 -- do not provide discriminants for it, check aggregate components for
2279 -- values of the discriminants.
2280
2281 procedure Init_Hidden_Discriminants (Typ : Entity_Id; List : List_Id);
2282 -- If Typ is derived, and constrains discriminants of the parent type,
2283 -- these discriminants are not components of the aggregate, and must be
2284 -- initialized. The assignments are appended to List. The same is done
2285 -- if Typ derives fron an already constrained subtype of a discriminated
2286 -- parent type.
2287
2288 procedure Init_Stored_Discriminants;
2289 -- If the type is derived and has inherited discriminants, generate
2290 -- explicit assignments for each, using the store constraint of the
2291 -- type. Note that both visible and stored discriminants must be
2292 -- initialized in case the derived type has some renamed and some
2293 -- constrained discriminants.
2294
2295 procedure Init_Visible_Discriminants;
2296 -- If type has discriminants, retrieve their values from aggregate,
2297 -- and generate explicit assignments for each. This does not include
2298 -- discriminants inherited from ancestor, which are handled above.
2299 -- The type of the aggregate is a subtype created ealier using the
2300 -- given values of the discriminant components of the aggregate.
2301
2302 procedure Initialize_Ctrl_Record_Component
2303 (Rec_Comp : Node_Id;
2304 Comp_Typ : Entity_Id;
2305 Init_Expr : Node_Id;
2306 Stmts : List_Id);
2307 -- Perform the initialization of controlled record component Rec_Comp.
2308 -- Comp_Typ is the component type. Init_Expr is the initialization
2309 -- expression for the record component. Hook-related declarations are
2310 -- inserted prior to aggregate N using Insert_Action. All remaining
2311 -- generated code is added to list Stmts.
2312
2313 procedure Initialize_Record_Component
2314 (Rec_Comp : Node_Id;
2315 Comp_Typ : Entity_Id;
2316 Init_Expr : Node_Id;
2317 Stmts : List_Id);
2318 -- Perform the initialization of record component Rec_Comp. Comp_Typ
2319 -- is the component type. Init_Expr is the initialization expression
2320 -- of the record component. All generated code is added to list Stmts.
2321
2322 function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean;
2323 -- Check whether Bounds is a range node and its lower and higher bounds
2324 -- are integers literals.
2325
2326 function Replace_Type (Expr : Node_Id) return Traverse_Result;
2327 -- If the aggregate contains a self-reference, traverse each expression
2328 -- to replace a possible self-reference with a reference to the proper
2329 -- component of the target of the assignment.
2330
2331 function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result;
2332 -- If default expression of a component mentions a discriminant of the
2333 -- type, it must be rewritten as the discriminant of the target object.
2334
2335 ---------------------------------
2336 -- Ancestor_Discriminant_Value --
2337 ---------------------------------
2338
2339 function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id is
2340 Assoc : Node_Id;
2341 Assoc_Elmt : Elmt_Id;
2342 Aggr_Comp : Entity_Id;
2343 Corresp_Disc : Entity_Id;
2344 Current_Typ : Entity_Id := Base_Type (Typ);
2345 Parent_Typ : Entity_Id;
2346 Parent_Disc : Entity_Id;
2347 Save_Assoc : Node_Id := Empty;
2348
2349 begin
2350 -- First check any discriminant associations to see if any of them
2351 -- provide a value for the discriminant.
2352
2353 if Present (Discriminant_Specifications (Parent (Current_Typ))) then
2354 Assoc := First (Component_Associations (N));
2355 while Present (Assoc) loop
2356 Aggr_Comp := Entity (First (Choices (Assoc)));
2357
2358 if Ekind (Aggr_Comp) = E_Discriminant then
2359 Save_Assoc := Expression (Assoc);
2360
2361 Corresp_Disc := Corresponding_Discriminant (Aggr_Comp);
2362 while Present (Corresp_Disc) loop
2363
2364 -- If found a corresponding discriminant then return the
2365 -- value given in the aggregate. (Note: this is not
2366 -- correct in the presence of side effects. ???)
2367
2368 if Disc = Corresp_Disc then
2369 return Duplicate_Subexpr (Expression (Assoc));
2370 end if;
2371
2372 Corresp_Disc := Corresponding_Discriminant (Corresp_Disc);
2373 end loop;
2374 end if;
2375
2376 Next (Assoc);
2377 end loop;
2378 end if;
2379
2380 -- No match found in aggregate, so chain up parent types to find
2381 -- a constraint that defines the value of the discriminant.
2382
2383 Parent_Typ := Etype (Current_Typ);
2384 while Current_Typ /= Parent_Typ loop
2385 if Has_Discriminants (Parent_Typ)
2386 and then not Has_Unknown_Discriminants (Parent_Typ)
2387 then
2388 Parent_Disc := First_Discriminant (Parent_Typ);
2389
2390 -- We either get the association from the subtype indication
2391 -- of the type definition itself, or from the discriminant
2392 -- constraint associated with the type entity (which is
2393 -- preferable, but it's not always present ???)
2394
2395 if Is_Empty_Elmt_List (Discriminant_Constraint (Current_Typ))
2396 then
2397 Assoc := Get_Constraint_Association (Current_Typ);
2398 Assoc_Elmt := No_Elmt;
2399 else
2400 Assoc_Elmt :=
2401 First_Elmt (Discriminant_Constraint (Current_Typ));
2402 Assoc := Node (Assoc_Elmt);
2403 end if;
2404
2405 -- Traverse the discriminants of the parent type looking
2406 -- for one that corresponds.
2407
2408 while Present (Parent_Disc) and then Present (Assoc) loop
2409 Corresp_Disc := Parent_Disc;
2410 while Present (Corresp_Disc)
2411 and then Disc /= Corresp_Disc
2412 loop
2413 Corresp_Disc := Corresponding_Discriminant (Corresp_Disc);
2414 end loop;
2415
2416 if Disc = Corresp_Disc then
2417 if Nkind (Assoc) = N_Discriminant_Association then
2418 Assoc := Expression (Assoc);
2419 end if;
2420
2421 -- If the located association directly denotes
2422 -- a discriminant, then use the value of a saved
2423 -- association of the aggregate. This is an approach
2424 -- used to handle certain cases involving multiple
2425 -- discriminants mapped to a single discriminant of
2426 -- a descendant. It's not clear how to locate the
2427 -- appropriate discriminant value for such cases. ???
2428
2429 if Is_Entity_Name (Assoc)
2430 and then Ekind (Entity (Assoc)) = E_Discriminant
2431 then
2432 Assoc := Save_Assoc;
2433 end if;
2434
2435 return Duplicate_Subexpr (Assoc);
2436 end if;
2437
2438 Next_Discriminant (Parent_Disc);
2439
2440 if No (Assoc_Elmt) then
2441 Next (Assoc);
2442
2443 else
2444 Next_Elmt (Assoc_Elmt);
2445
2446 if Present (Assoc_Elmt) then
2447 Assoc := Node (Assoc_Elmt);
2448 else
2449 Assoc := Empty;
2450 end if;
2451 end if;
2452 end loop;
2453 end if;
2454
2455 Current_Typ := Parent_Typ;
2456 Parent_Typ := Etype (Current_Typ);
2457 end loop;
2458
2459 -- In some cases there's no ancestor value to locate (such as
2460 -- when an ancestor part given by an expression defines the
2461 -- discriminant value).
2462
2463 return Empty;
2464 end Ancestor_Discriminant_Value;
2465
2466 ----------------------------------
2467 -- Check_Ancestor_Discriminants --
2468 ----------------------------------
2469
2470 procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id) is
2471 Discr : Entity_Id;
2472 Disc_Value : Node_Id;
2473 Cond : Node_Id;
2474
2475 begin
2476 Discr := First_Discriminant (Base_Type (Anc_Typ));
2477 while Present (Discr) loop
2478 Disc_Value := Ancestor_Discriminant_Value (Discr);
2479
2480 if Present (Disc_Value) then
2481 Cond := Make_Op_Ne (Loc,
2482 Left_Opnd =>
2483 Make_Selected_Component (Loc,
2484 Prefix => New_Copy_Tree (Target),
2485 Selector_Name => New_Occurrence_Of (Discr, Loc)),
2486 Right_Opnd => Disc_Value);
2487
2488 Append_To (L,
2489 Make_Raise_Constraint_Error (Loc,
2490 Condition => Cond,
2491 Reason => CE_Discriminant_Check_Failed));
2492 end if;
2493
2494 Next_Discriminant (Discr);
2495 end loop;
2496 end Check_Ancestor_Discriminants;
2497
2498 ---------------------------
2499 -- Compatible_Int_Bounds --
2500 ---------------------------
2501
2502 function Compatible_Int_Bounds
2503 (Agg_Bounds : Node_Id;
2504 Typ_Bounds : Node_Id) return Boolean
2505 is
2506 Agg_Lo : constant Uint := Intval (Low_Bound (Agg_Bounds));
2507 Agg_Hi : constant Uint := Intval (High_Bound (Agg_Bounds));
2508 Typ_Lo : constant Uint := Intval (Low_Bound (Typ_Bounds));
2509 Typ_Hi : constant Uint := Intval (High_Bound (Typ_Bounds));
2510 begin
2511 return Typ_Lo <= Agg_Lo and then Agg_Hi <= Typ_Hi;
2512 end Compatible_Int_Bounds;
2513
2514 -----------------------------------
2515 -- Generate_Finalization_Actions --
2516 -----------------------------------
2517
2518 procedure Generate_Finalization_Actions is
2519 begin
2520 -- Do the work only the first time this is called
2521
2522 if Finalization_Done then
2523 return;
2524 end if;
2525
2526 Finalization_Done := True;
2527
2528 -- Determine the external finalization list. It is either the
2529 -- finalization list of the outer scope or the one coming from an
2530 -- outer aggregate. When the target is not a temporary, the proper
2531 -- scope is the scope of the target rather than the potentially
2532 -- transient current scope.
2533
2534 if Is_Controlled (Typ) and then Ancestor_Is_Subtype_Mark then
2535 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2536 Set_Assignment_OK (Ref);
2537
2538 Append_To (L,
2539 Make_Procedure_Call_Statement (Loc,
2540 Name =>
2541 New_Occurrence_Of
2542 (Find_Prim_Op (Init_Typ, Name_Initialize), Loc),
2543 Parameter_Associations => New_List (New_Copy_Tree (Ref))));
2544 end if;
2545 end Generate_Finalization_Actions;
2546
2547 --------------------------------
2548 -- Get_Constraint_Association --
2549 --------------------------------
2550
2551 function Get_Constraint_Association (T : Entity_Id) return Node_Id is
2552 Indic : Node_Id;
2553 Typ : Entity_Id;
2554
2555 begin
2556 Typ := T;
2557
2558 -- If type is private, get constraint from full view. This was
2559 -- previously done in an instance context, but is needed whenever
2560 -- the ancestor part has a discriminant, possibly inherited through
2561 -- multiple derivations.
2562
2563 if Is_Private_Type (Typ) and then Present (Full_View (Typ)) then
2564 Typ := Full_View (Typ);
2565 end if;
2566
2567 Indic := Subtype_Indication (Type_Definition (Parent (Typ)));
2568
2569 -- Verify that the subtype indication carries a constraint
2570
2571 if Nkind (Indic) = N_Subtype_Indication
2572 and then Present (Constraint (Indic))
2573 then
2574 return First (Constraints (Constraint (Indic)));
2575 end if;
2576
2577 return Empty;
2578 end Get_Constraint_Association;
2579
2580 -------------------------------------
2581 -- Get_Explicit_Discriminant_Value --
2582 -------------------------------------
2583
2584 function Get_Explicit_Discriminant_Value
2585 (D : Entity_Id) return Node_Id
2586 is
2587 Assoc : Node_Id;
2588 Choice : Node_Id;
2589 Val : Node_Id;
2590
2591 begin
2592 -- The aggregate has been normalized and all associations have a
2593 -- single choice.
2594
2595 Assoc := First (Component_Associations (N));
2596 while Present (Assoc) loop
2597 Choice := First (Choices (Assoc));
2598
2599 if Chars (Choice) = Chars (D) then
2600 Val := Expression (Assoc);
2601 Remove (Assoc);
2602 return Val;
2603 end if;
2604
2605 Next (Assoc);
2606 end loop;
2607
2608 return Empty;
2609 end Get_Explicit_Discriminant_Value;
2610
2611 -------------------------------
2612 -- Init_Hidden_Discriminants --
2613 -------------------------------
2614
2615 procedure Init_Hidden_Discriminants (Typ : Entity_Id; List : List_Id) is
2616 function Is_Completely_Hidden_Discriminant
2617 (Discr : Entity_Id) return Boolean;
2618 -- Determine whether Discr is a completely hidden discriminant of
2619 -- type Typ.
2620
2621 ---------------------------------------
2622 -- Is_Completely_Hidden_Discriminant --
2623 ---------------------------------------
2624
2625 function Is_Completely_Hidden_Discriminant
2626 (Discr : Entity_Id) return Boolean
2627 is
2628 Item : Entity_Id;
2629
2630 begin
2631 -- Use First/Next_Entity as First/Next_Discriminant do not yield
2632 -- completely hidden discriminants.
2633
2634 Item := First_Entity (Typ);
2635 while Present (Item) loop
2636 if Ekind (Item) = E_Discriminant
2637 and then Is_Completely_Hidden (Item)
2638 and then Chars (Original_Record_Component (Item)) =
2639 Chars (Discr)
2640 then
2641 return True;
2642 end if;
2643
2644 Next_Entity (Item);
2645 end loop;
2646
2647 return False;
2648 end Is_Completely_Hidden_Discriminant;
2649
2650 -- Local variables
2651
2652 Base_Typ : Entity_Id;
2653 Discr : Entity_Id;
2654 Discr_Constr : Elmt_Id;
2655 Discr_Init : Node_Id;
2656 Discr_Val : Node_Id;
2657 In_Aggr_Type : Boolean;
2658 Par_Typ : Entity_Id;
2659
2660 -- Start of processing for Init_Hidden_Discriminants
2661
2662 begin
2663 -- The constraints on the hidden discriminants, if present, are kept
2664 -- in the Stored_Constraint list of the type itself, or in that of
2665 -- the base type. If not in the constraints of the aggregate itself,
2666 -- we examine ancestors to find discriminants that are not renamed
2667 -- by other discriminants but constrained explicitly.
2668
2669 In_Aggr_Type := True;
2670
2671 Base_Typ := Base_Type (Typ);
2672 while Is_Derived_Type (Base_Typ)
2673 and then
2674 (Present (Stored_Constraint (Base_Typ))
2675 or else
2676 (In_Aggr_Type and then Present (Stored_Constraint (Typ))))
2677 loop
2678 Par_Typ := Etype (Base_Typ);
2679
2680 if not Has_Discriminants (Par_Typ) then
2681 return;
2682 end if;
2683
2684 Discr := First_Discriminant (Par_Typ);
2685
2686 -- We know that one of the stored-constraint lists is present
2687
2688 if Present (Stored_Constraint (Base_Typ)) then
2689 Discr_Constr := First_Elmt (Stored_Constraint (Base_Typ));
2690
2691 -- For private extension, stored constraint may be on full view
2692
2693 elsif Is_Private_Type (Base_Typ)
2694 and then Present (Full_View (Base_Typ))
2695 and then Present (Stored_Constraint (Full_View (Base_Typ)))
2696 then
2697 Discr_Constr :=
2698 First_Elmt (Stored_Constraint (Full_View (Base_Typ)));
2699
2700 else
2701 Discr_Constr := First_Elmt (Stored_Constraint (Typ));
2702 end if;
2703
2704 while Present (Discr) and then Present (Discr_Constr) loop
2705 Discr_Val := Node (Discr_Constr);
2706
2707 -- The parent discriminant is renamed in the derived type,
2708 -- nothing to initialize.
2709
2710 -- type Deriv_Typ (Discr : ...)
2711 -- is new Parent_Typ (Discr => Discr);
2712
2713 if Is_Entity_Name (Discr_Val)
2714 and then Ekind (Entity (Discr_Val)) = E_Discriminant
2715 then
2716 null;
2717
2718 -- When the parent discriminant is constrained at the type
2719 -- extension level, it does not appear in the derived type.
2720
2721 -- type Deriv_Typ (Discr : ...)
2722 -- is new Parent_Typ (Discr => Discr,
2723 -- Hidden_Discr => Expression);
2724
2725 elsif Is_Completely_Hidden_Discriminant (Discr) then
2726 null;
2727
2728 -- Otherwise initialize the discriminant
2729
2730 else
2731 Discr_Init :=
2732 Make_OK_Assignment_Statement (Loc,
2733 Name =>
2734 Make_Selected_Component (Loc,
2735 Prefix => New_Copy_Tree (Target),
2736 Selector_Name => New_Occurrence_Of (Discr, Loc)),
2737 Expression => New_Copy_Tree (Discr_Val));
2738
2739 Append_To (List, Discr_Init);
2740 end if;
2741
2742 Next_Elmt (Discr_Constr);
2743 Next_Discriminant (Discr);
2744 end loop;
2745
2746 In_Aggr_Type := False;
2747 Base_Typ := Base_Type (Par_Typ);
2748 end loop;
2749 end Init_Hidden_Discriminants;
2750
2751 --------------------------------
2752 -- Init_Visible_Discriminants --
2753 --------------------------------
2754
2755 procedure Init_Visible_Discriminants is
2756 Discriminant : Entity_Id;
2757 Discriminant_Value : Node_Id;
2758
2759 begin
2760 Discriminant := First_Discriminant (Typ);
2761 while Present (Discriminant) loop
2762 Comp_Expr :=
2763 Make_Selected_Component (Loc,
2764 Prefix => New_Copy_Tree (Target),
2765 Selector_Name => New_Occurrence_Of (Discriminant, Loc));
2766
2767 Discriminant_Value :=
2768 Get_Discriminant_Value
2769 (Discriminant, Typ, Discriminant_Constraint (N_Typ));
2770
2771 Instr :=
2772 Make_OK_Assignment_Statement (Loc,
2773 Name => Comp_Expr,
2774 Expression => New_Copy_Tree (Discriminant_Value));
2775
2776 Append_To (L, Instr);
2777
2778 Next_Discriminant (Discriminant);
2779 end loop;
2780 end Init_Visible_Discriminants;
2781
2782 -------------------------------
2783 -- Init_Stored_Discriminants --
2784 -------------------------------
2785
2786 procedure Init_Stored_Discriminants is
2787 Discriminant : Entity_Id;
2788 Discriminant_Value : Node_Id;
2789
2790 begin
2791 Discriminant := First_Stored_Discriminant (Typ);
2792 while Present (Discriminant) loop
2793 Comp_Expr :=
2794 Make_Selected_Component (Loc,
2795 Prefix => New_Copy_Tree (Target),
2796 Selector_Name => New_Occurrence_Of (Discriminant, Loc));
2797
2798 Discriminant_Value :=
2799 Get_Discriminant_Value
2800 (Discriminant, N_Typ, Discriminant_Constraint (N_Typ));
2801
2802 Instr :=
2803 Make_OK_Assignment_Statement (Loc,
2804 Name => Comp_Expr,
2805 Expression => New_Copy_Tree (Discriminant_Value));
2806
2807 Append_To (L, Instr);
2808
2809 Next_Stored_Discriminant (Discriminant);
2810 end loop;
2811 end Init_Stored_Discriminants;
2812
2813 --------------------------------------
2814 -- Initialize_Ctrl_Record_Component --
2815 --------------------------------------
2816
2817 procedure Initialize_Ctrl_Record_Component
2818 (Rec_Comp : Node_Id;
2819 Comp_Typ : Entity_Id;
2820 Init_Expr : Node_Id;
2821 Stmts : List_Id)
2822 is
2823 Fin_Call : Node_Id;
2824 Hook_Clear : Node_Id;
2825
2826 In_Place_Expansion : Boolean;
2827 -- Flag set when a nonlimited controlled function call requires
2828 -- in-place expansion.
2829
2830 begin
2831 -- Perform a preliminary analysis and resolution to determine what
2832 -- the initialization expression denotes. Unanalyzed function calls
2833 -- may appear as identifiers or indexed components.
2834
2835 if Nkind_In (Init_Expr, N_Function_Call,
2836 N_Identifier,
2837 N_Indexed_Component)
2838 and then not Analyzed (Init_Expr)
2839 then
2840 Preanalyze_And_Resolve (Init_Expr, Comp_Typ);
2841 end if;
2842
2843 In_Place_Expansion :=
2844 Nkind (Init_Expr) = N_Function_Call
2845 and then not Is_Build_In_Place_Result_Type (Comp_Typ);
2846
2847 -- The initialization expression is a controlled function call.
2848 -- Perform in-place removal of side effects to avoid creating a
2849 -- transient scope.
2850
2851 -- This in-place expansion is not performed for limited transient
2852 -- objects because the initialization is already done in place.
2853
2854 if In_Place_Expansion then
2855
2856 -- Suppress the removal of side effects by general analysis
2857 -- because this behavior is emulated here. This avoids the
2858 -- generation of a transient scope, which leads to out-of-order
2859 -- adjustment and finalization.
2860
2861 Set_No_Side_Effect_Removal (Init_Expr);
2862
2863 -- Install all hook-related declarations and prepare the clean up
2864 -- statements. The generated code follows the initialization order
2865 -- of individual components and discriminants, rather than being
2866 -- inserted prior to the aggregate. This ensures that a transient
2867 -- component which mentions a discriminant has proper visibility
2868 -- of the discriminant.
2869
2870 Process_Transient_Component
2871 (Loc => Loc,
2872 Comp_Typ => Comp_Typ,
2873 Init_Expr => Init_Expr,
2874 Fin_Call => Fin_Call,
2875 Hook_Clear => Hook_Clear,
2876 Stmts => Stmts);
2877 end if;
2878
2879 -- Use the noncontrolled component initialization circuitry to
2880 -- assign the result of the function call to the record component.
2881 -- This also performs tag adjustment and [deep] adjustment of the
2882 -- record component.
2883
2884 Initialize_Record_Component
2885 (Rec_Comp => Rec_Comp,
2886 Comp_Typ => Comp_Typ,
2887 Init_Expr => Init_Expr,
2888 Stmts => Stmts);
2889
2890 -- At this point the record component is fully initialized. Complete
2891 -- the processing of the controlled record component by finalizing
2892 -- the transient function result.
2893
2894 if In_Place_Expansion then
2895 Process_Transient_Component_Completion
2896 (Loc => Loc,
2897 Aggr => N,
2898 Fin_Call => Fin_Call,
2899 Hook_Clear => Hook_Clear,
2900 Stmts => Stmts);
2901 end if;
2902 end Initialize_Ctrl_Record_Component;
2903
2904 ---------------------------------
2905 -- Initialize_Record_Component --
2906 ---------------------------------
2907
2908 procedure Initialize_Record_Component
2909 (Rec_Comp : Node_Id;
2910 Comp_Typ : Entity_Id;
2911 Init_Expr : Node_Id;
2912 Stmts : List_Id)
2913 is
2914 Exceptions_OK : constant Boolean :=
2915 not Restriction_Active (No_Exception_Propagation);
2916
2917 Finalization_OK : constant Boolean := Needs_Finalization (Comp_Typ);
2918
2919 Full_Typ : constant Entity_Id := Underlying_Type (Comp_Typ);
2920 Adj_Call : Node_Id;
2921 Blk_Stmts : List_Id;
2922 Init_Stmt : Node_Id;
2923
2924 begin
2925 -- Protect the initialization statements from aborts. Generate:
2926
2927 -- Abort_Defer;
2928
2929 if Finalization_OK and Abort_Allowed then
2930 if Exceptions_OK then
2931 Blk_Stmts := New_List;
2932 else
2933 Blk_Stmts := Stmts;
2934 end if;
2935
2936 Append_To (Blk_Stmts, Build_Runtime_Call (Loc, RE_Abort_Defer));
2937
2938 -- Otherwise aborts are not allowed. All generated code is added
2939 -- directly to the input list.
2940
2941 else
2942 Blk_Stmts := Stmts;
2943 end if;
2944
2945 -- Initialize the record component. Generate:
2946
2947 -- Rec_Comp := Init_Expr;
2948
2949 -- Note that the initialization expression is NOT replicated because
2950 -- only a single component may be initialized by it.
2951
2952 Init_Stmt :=
2953 Make_OK_Assignment_Statement (Loc,
2954 Name => New_Copy_Tree (Rec_Comp),
2955 Expression => Init_Expr);
2956 Set_No_Ctrl_Actions (Init_Stmt);
2957
2958 Append_To (Blk_Stmts, Init_Stmt);
2959
2960 -- Adjust the tag due to a possible view conversion. Generate:
2961
2962 -- Rec_Comp._tag := Full_TypeP;
2963
2964 if Tagged_Type_Expansion and then Is_Tagged_Type (Comp_Typ) then
2965 Append_To (Blk_Stmts,
2966 Make_OK_Assignment_Statement (Loc,
2967 Name =>
2968 Make_Selected_Component (Loc,
2969 Prefix => New_Copy_Tree (Rec_Comp),
2970 Selector_Name =>
2971 New_Occurrence_Of
2972 (First_Tag_Component (Full_Typ), Loc)),
2973
2974 Expression =>
2975 Unchecked_Convert_To (RTE (RE_Tag),
2976 New_Occurrence_Of
2977 (Node (First_Elmt (Access_Disp_Table (Full_Typ))),
2978 Loc))));
2979 end if;
2980
2981 -- Adjust the component. Generate:
2982
2983 -- [Deep_]Adjust (Rec_Comp);
2984
2985 if Finalization_OK
2986 and then not Is_Limited_Type (Comp_Typ)
2987 and then not Is_Build_In_Place_Function_Call (Init_Expr)
2988 then
2989 Adj_Call :=
2990 Make_Adjust_Call
2991 (Obj_Ref => New_Copy_Tree (Rec_Comp),
2992 Typ => Comp_Typ);
2993
2994 -- Guard against a missing [Deep_]Adjust when the component type
2995 -- was not properly frozen.
2996
2997 if Present (Adj_Call) then
2998 Append_To (Blk_Stmts, Adj_Call);
2999 end if;
3000 end if;
3001
3002 -- Complete the protection of the initialization statements
3003
3004 if Finalization_OK and Abort_Allowed then
3005
3006 -- Wrap the initialization statements in a block to catch a
3007 -- potential exception. Generate:
3008
3009 -- begin
3010 -- Abort_Defer;
3011 -- Rec_Comp := Init_Expr;
3012 -- Rec_Comp._tag := Full_TypP;
3013 -- [Deep_]Adjust (Rec_Comp);
3014 -- at end
3015 -- Abort_Undefer_Direct;
3016 -- end;
3017
3018 if Exceptions_OK then
3019 Append_To (Stmts,
3020 Build_Abort_Undefer_Block (Loc,
3021 Stmts => Blk_Stmts,
3022 Context => N));
3023
3024 -- Otherwise exceptions are not propagated. Generate:
3025
3026 -- Abort_Defer;
3027 -- Rec_Comp := Init_Expr;
3028 -- Rec_Comp._tag := Full_TypP;
3029 -- [Deep_]Adjust (Rec_Comp);
3030 -- Abort_Undefer;
3031
3032 else
3033 Append_To (Blk_Stmts,
3034 Build_Runtime_Call (Loc, RE_Abort_Undefer));
3035 end if;
3036 end if;
3037 end Initialize_Record_Component;
3038
3039 -------------------------
3040 -- Is_Int_Range_Bounds --
3041 -------------------------
3042
3043 function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean is
3044 begin
3045 return Nkind (Bounds) = N_Range
3046 and then Nkind (Low_Bound (Bounds)) = N_Integer_Literal
3047 and then Nkind (High_Bound (Bounds)) = N_Integer_Literal;
3048 end Is_Int_Range_Bounds;
3049
3050 ------------------
3051 -- Replace_Type --
3052 ------------------
3053
3054 function Replace_Type (Expr : Node_Id) return Traverse_Result is
3055 begin
3056 -- Note regarding the Root_Type test below: Aggregate components for
3057 -- self-referential types include attribute references to the current
3058 -- instance, of the form: Typ'access, etc.. These references are
3059 -- rewritten as references to the target of the aggregate: the
3060 -- left-hand side of an assignment, the entity in a declaration,
3061 -- or a temporary. Without this test, we would improperly extended
3062 -- this rewriting to attribute references whose prefix was not the
3063 -- type of the aggregate.
3064
3065 if Nkind (Expr) = N_Attribute_Reference
3066 and then Is_Entity_Name (Prefix (Expr))
3067 and then Is_Type (Entity (Prefix (Expr)))
3068 and then Root_Type (Etype (N)) = Root_Type (Entity (Prefix (Expr)))
3069 then
3070 if Is_Entity_Name (Lhs) then
3071 Rewrite (Prefix (Expr), New_Occurrence_Of (Entity (Lhs), Loc));
3072
3073 else
3074 Rewrite (Expr,
3075 Make_Attribute_Reference (Loc,
3076 Attribute_Name => Name_Unrestricted_Access,
3077 Prefix => New_Copy_Tree (Lhs)));
3078 Set_Analyzed (Parent (Expr), False);
3079 end if;
3080 end if;
3081
3082 return OK;
3083 end Replace_Type;
3084
3085 --------------------------
3086 -- Rewrite_Discriminant --
3087 --------------------------
3088
3089 function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result is
3090 begin
3091 if Is_Entity_Name (Expr)
3092 and then Present (Entity (Expr))
3093 and then Ekind (Entity (Expr)) = E_In_Parameter
3094 and then Present (Discriminal_Link (Entity (Expr)))
3095 and then Scope (Discriminal_Link (Entity (Expr))) =
3096 Base_Type (Etype (N))
3097 then
3098 Rewrite (Expr,
3099 Make_Selected_Component (Loc,
3100 Prefix => New_Copy_Tree (Lhs),
3101 Selector_Name => Make_Identifier (Loc, Chars (Expr))));
3102 end if;
3103
3104 return OK;
3105 end Rewrite_Discriminant;
3106
3107 procedure Replace_Discriminants is
3108 new Traverse_Proc (Rewrite_Discriminant);
3109
3110 procedure Replace_Self_Reference is
3111 new Traverse_Proc (Replace_Type);
3112
3113 -- Start of processing for Build_Record_Aggr_Code
3114
3115 begin
3116 if Has_Self_Reference (N) then
3117 Replace_Self_Reference (N);
3118 end if;
3119
3120 -- If the target of the aggregate is class-wide, we must convert it
3121 -- to the actual type of the aggregate, so that the proper components
3122 -- are visible. We know already that the types are compatible.
3123
3124 if Present (Etype (Lhs))
3125 and then Is_Class_Wide_Type (Etype (Lhs))
3126 then
3127 Target := Unchecked_Convert_To (Typ, Lhs);
3128 else
3129 Target := Lhs;
3130 end if;
3131
3132 -- Deal with the ancestor part of extension aggregates or with the
3133 -- discriminants of the root type.
3134
3135 if Nkind (N) = N_Extension_Aggregate then
3136 declare
3137 Ancestor : constant Node_Id := Ancestor_Part (N);
3138 Adj_Call : Node_Id;
3139 Assign : List_Id;
3140
3141 begin
3142 -- If the ancestor part is a subtype mark "T", we generate
3143
3144 -- init-proc (T (tmp)); if T is constrained and
3145 -- init-proc (S (tmp)); where S applies an appropriate
3146 -- constraint if T is unconstrained
3147
3148 if Is_Entity_Name (Ancestor)
3149 and then Is_Type (Entity (Ancestor))
3150 then
3151 Ancestor_Is_Subtype_Mark := True;
3152
3153 if Is_Constrained (Entity (Ancestor)) then
3154 Init_Typ := Entity (Ancestor);
3155
3156 -- For an ancestor part given by an unconstrained type mark,
3157 -- create a subtype constrained by appropriate corresponding
3158 -- discriminant values coming from either associations of the
3159 -- aggregate or a constraint on a parent type. The subtype will
3160 -- be used to generate the correct default value for the
3161 -- ancestor part.
3162
3163 elsif Has_Discriminants (Entity (Ancestor)) then
3164 declare
3165 Anc_Typ : constant Entity_Id := Entity (Ancestor);
3166 Anc_Constr : constant List_Id := New_List;
3167 Discrim : Entity_Id;
3168 Disc_Value : Node_Id;
3169 New_Indic : Node_Id;
3170 Subt_Decl : Node_Id;
3171
3172 begin
3173 Discrim := First_Discriminant (Anc_Typ);
3174 while Present (Discrim) loop
3175 Disc_Value := Ancestor_Discriminant_Value (Discrim);
3176
3177 -- If no usable discriminant in ancestors, check
3178 -- whether aggregate has an explicit value for it.
3179
3180 if No (Disc_Value) then
3181 Disc_Value :=
3182 Get_Explicit_Discriminant_Value (Discrim);
3183 end if;
3184
3185 Append_To (Anc_Constr, Disc_Value);
3186 Next_Discriminant (Discrim);
3187 end loop;
3188
3189 New_Indic :=
3190 Make_Subtype_Indication (Loc,
3191 Subtype_Mark => New_Occurrence_Of (Anc_Typ, Loc),
3192 Constraint =>
3193 Make_Index_Or_Discriminant_Constraint (Loc,
3194 Constraints => Anc_Constr));
3195
3196 Init_Typ := Create_Itype (Ekind (Anc_Typ), N);
3197
3198 Subt_Decl :=
3199 Make_Subtype_Declaration (Loc,
3200 Defining_Identifier => Init_Typ,
3201 Subtype_Indication => New_Indic);
3202
3203 -- Itypes must be analyzed with checks off Declaration
3204 -- must have a parent for proper handling of subsidiary
3205 -- actions.
3206
3207 Set_Parent (Subt_Decl, N);
3208 Analyze (Subt_Decl, Suppress => All_Checks);
3209 end;
3210 end if;
3211
3212 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
3213 Set_Assignment_OK (Ref);
3214
3215 if not Is_Interface (Init_Typ) then
3216 Append_List_To (L,
3217 Build_Initialization_Call (Loc,
3218 Id_Ref => Ref,
3219 Typ => Init_Typ,
3220 In_Init_Proc => Within_Init_Proc,
3221 With_Default_Init => Has_Default_Init_Comps (N)
3222 or else
3223 Has_Task (Base_Type (Init_Typ))));
3224
3225 if Is_Constrained (Entity (Ancestor))
3226 and then Has_Discriminants (Entity (Ancestor))
3227 then
3228 Check_Ancestor_Discriminants (Entity (Ancestor));
3229 end if;
3230 end if;
3231
3232 -- Handle calls to C++ constructors
3233
3234 elsif Is_CPP_Constructor_Call (Ancestor) then
3235 Init_Typ := Etype (Ancestor);
3236 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
3237 Set_Assignment_OK (Ref);
3238
3239 Append_List_To (L,
3240 Build_Initialization_Call (Loc,
3241 Id_Ref => Ref,
3242 Typ => Init_Typ,
3243 In_Init_Proc => Within_Init_Proc,
3244 With_Default_Init => Has_Default_Init_Comps (N),
3245 Constructor_Ref => Ancestor));
3246
3247 -- Ada 2005 (AI-287): If the ancestor part is an aggregate of
3248 -- limited type, a recursive call expands the ancestor. Note that
3249 -- in the limited case, the ancestor part must be either a
3250 -- function call (possibly qualified) or aggregate (definitely
3251 -- qualified).
3252
3253 elsif Is_Limited_Type (Etype (Ancestor))
3254 and then Nkind_In (Unqualify (Ancestor), N_Aggregate,
3255 N_Extension_Aggregate)
3256 then
3257 Ancestor_Is_Expression := True;
3258
3259 -- Set up finalization data for enclosing record, because
3260 -- controlled subcomponents of the ancestor part will be
3261 -- attached to it.
3262
3263 Generate_Finalization_Actions;
3264
3265 Append_List_To (L,
3266 Build_Record_Aggr_Code
3267 (N => Unqualify (Ancestor),
3268 Typ => Etype (Unqualify (Ancestor)),
3269 Lhs => Target));
3270
3271 -- If the ancestor part is an expression "E", we generate
3272
3273 -- T (tmp) := E;
3274
3275 -- In Ada 2005, this includes the case of a (possibly qualified)
3276 -- limited function call. The assignment will turn into a
3277 -- build-in-place function call (for further details, see
3278 -- Make_Build_In_Place_Call_In_Assignment).
3279
3280 else
3281 Ancestor_Is_Expression := True;
3282 Init_Typ := Etype (Ancestor);
3283
3284 -- If the ancestor part is an aggregate, force its full
3285 -- expansion, which was delayed.
3286
3287 if Nkind_In (Unqualify (Ancestor), N_Aggregate,
3288 N_Extension_Aggregate)
3289 then
3290 Set_Analyzed (Ancestor, False);
3291 Set_Analyzed (Expression (Ancestor), False);
3292 end if;
3293
3294 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
3295 Set_Assignment_OK (Ref);
3296
3297 -- Make the assignment without usual controlled actions, since
3298 -- we only want to Adjust afterwards, but not to Finalize
3299 -- beforehand. Add manual Adjust when necessary.
3300
3301 Assign := New_List (
3302 Make_OK_Assignment_Statement (Loc,
3303 Name => Ref,
3304 Expression => Ancestor));
3305 Set_No_Ctrl_Actions (First (Assign));
3306
3307 -- Assign the tag now to make sure that the dispatching call in
3308 -- the subsequent deep_adjust works properly (unless
3309 -- Tagged_Type_Expansion where tags are implicit).
3310
3311 if Tagged_Type_Expansion then
3312 Instr :=
3313 Make_OK_Assignment_Statement (Loc,
3314 Name =>
3315 Make_Selected_Component (Loc,
3316 Prefix => New_Copy_Tree (Target),
3317 Selector_Name =>
3318 New_Occurrence_Of
3319 (First_Tag_Component (Base_Type (Typ)), Loc)),
3320
3321 Expression =>
3322 Unchecked_Convert_To (RTE (RE_Tag),
3323 New_Occurrence_Of
3324 (Node (First_Elmt
3325 (Access_Disp_Table (Base_Type (Typ)))),
3326 Loc)));
3327
3328 Set_Assignment_OK (Name (Instr));
3329 Append_To (Assign, Instr);
3330
3331 -- Ada 2005 (AI-251): If tagged type has progenitors we must
3332 -- also initialize tags of the secondary dispatch tables.
3333
3334 if Has_Interfaces (Base_Type (Typ)) then
3335 Init_Secondary_Tags
3336 (Typ => Base_Type (Typ),
3337 Target => Target,
3338 Stmts_List => Assign,
3339 Init_Tags_List => Assign);
3340 end if;
3341 end if;
3342
3343 -- Call Adjust manually
3344
3345 if Needs_Finalization (Etype (Ancestor))
3346 and then not Is_Limited_Type (Etype (Ancestor))
3347 and then not Is_Build_In_Place_Function_Call (Ancestor)
3348 then
3349 Adj_Call :=
3350 Make_Adjust_Call
3351 (Obj_Ref => New_Copy_Tree (Ref),
3352 Typ => Etype (Ancestor));
3353
3354 -- Guard against a missing [Deep_]Adjust when the ancestor
3355 -- type was not properly frozen.
3356
3357 if Present (Adj_Call) then
3358 Append_To (Assign, Adj_Call);
3359 end if;
3360 end if;
3361
3362 Append_To (L,
3363 Make_Unsuppress_Block (Loc, Name_Discriminant_Check, Assign));
3364
3365 if Has_Discriminants (Init_Typ) then
3366 Check_Ancestor_Discriminants (Init_Typ);
3367 end if;
3368 end if;
3369
3370 pragma Assert (Nkind (N) = N_Extension_Aggregate);
3371 pragma Assert
3372 (not (Ancestor_Is_Expression and Ancestor_Is_Subtype_Mark));
3373 end;
3374
3375 -- Generate assignments of hidden discriminants. If the base type is
3376 -- an unchecked union, the discriminants are unknown to the back-end
3377 -- and absent from a value of the type, so assignments for them are
3378 -- not emitted.
3379
3380 if Has_Discriminants (Typ)
3381 and then not Is_Unchecked_Union (Base_Type (Typ))
3382 then
3383 Init_Hidden_Discriminants (Typ, L);
3384 end if;
3385
3386 -- Normal case (not an extension aggregate)
3387
3388 else
3389 -- Generate the discriminant expressions, component by component.
3390 -- If the base type is an unchecked union, the discriminants are
3391 -- unknown to the back-end and absent from a value of the type, so
3392 -- assignments for them are not emitted.
3393
3394 if Has_Discriminants (Typ)
3395 and then not Is_Unchecked_Union (Base_Type (Typ))
3396 then
3397 Init_Hidden_Discriminants (Typ, L);
3398
3399 -- Generate discriminant init values for the visible discriminants
3400
3401 Init_Visible_Discriminants;
3402
3403 if Is_Derived_Type (N_Typ) then
3404 Init_Stored_Discriminants;
3405 end if;
3406 end if;
3407 end if;
3408
3409 -- For CPP types we generate an implicit call to the C++ default
3410 -- constructor to ensure the proper initialization of the _Tag
3411 -- component.
3412
3413 if Is_CPP_Class (Root_Type (Typ)) and then CPP_Num_Prims (Typ) > 0 then
3414 Invoke_Constructor : declare
3415 CPP_Parent : constant Entity_Id := Enclosing_CPP_Parent (Typ);
3416
3417 procedure Invoke_IC_Proc (T : Entity_Id);
3418 -- Recursive routine used to climb to parents. Required because
3419 -- parents must be initialized before descendants to ensure
3420 -- propagation of inherited C++ slots.
3421
3422 --------------------
3423 -- Invoke_IC_Proc --
3424 --------------------
3425
3426 procedure Invoke_IC_Proc (T : Entity_Id) is
3427 begin
3428 -- Avoid generating extra calls. Initialization required
3429 -- only for types defined from the level of derivation of
3430 -- type of the constructor and the type of the aggregate.
3431
3432 if T = CPP_Parent then
3433 return;
3434 end if;
3435
3436 Invoke_IC_Proc (Etype (T));
3437
3438 -- Generate call to the IC routine
3439
3440 if Present (CPP_Init_Proc (T)) then
3441 Append_To (L,
3442 Make_Procedure_Call_Statement (Loc,
3443 Name => New_Occurrence_Of (CPP_Init_Proc (T), Loc)));
3444 end if;
3445 end Invoke_IC_Proc;
3446
3447 -- Start of processing for Invoke_Constructor
3448
3449 begin
3450 -- Implicit invocation of the C++ constructor
3451
3452 if Nkind (N) = N_Aggregate then
3453 Append_To (L,
3454 Make_Procedure_Call_Statement (Loc,
3455 Name =>
3456 New_Occurrence_Of (Base_Init_Proc (CPP_Parent), Loc),
3457 Parameter_Associations => New_List (
3458 Unchecked_Convert_To (CPP_Parent,
3459 New_Copy_Tree (Lhs)))));
3460 end if;
3461
3462 Invoke_IC_Proc (Typ);
3463 end Invoke_Constructor;
3464 end if;
3465
3466 -- Generate the assignments, component by component
3467
3468 -- tmp.comp1 := Expr1_From_Aggr;
3469 -- tmp.comp2 := Expr2_From_Aggr;
3470 -- ....
3471
3472 Comp := First (Component_Associations (N));
3473 while Present (Comp) loop
3474 Selector := Entity (First (Choices (Comp)));
3475
3476 -- C++ constructors
3477
3478 if Is_CPP_Constructor_Call (Expression (Comp)) then
3479 Append_List_To (L,
3480 Build_Initialization_Call (Loc,
3481 Id_Ref =>
3482 Make_Selected_Component (Loc,
3483 Prefix => New_Copy_Tree (Target),
3484 Selector_Name => New_Occurrence_Of (Selector, Loc)),
3485 Typ => Etype (Selector),
3486 Enclos_Type => Typ,
3487 With_Default_Init => True,
3488 Constructor_Ref => Expression (Comp)));
3489
3490 -- Ada 2005 (AI-287): For each default-initialized component generate
3491 -- a call to the corresponding IP subprogram if available.
3492
3493 elsif Box_Present (Comp)
3494 and then Has_Non_Null_Base_Init_Proc (Etype (Selector))
3495 then
3496 if Ekind (Selector) /= E_Discriminant then
3497 Generate_Finalization_Actions;
3498 end if;
3499
3500 -- Ada 2005 (AI-287): If the component type has tasks then
3501 -- generate the activation chain and master entities (except
3502 -- in case of an allocator because in that case these entities
3503 -- are generated by Build_Task_Allocate_Block_With_Init_Stmts).
3504
3505 declare
3506 Ctype : constant Entity_Id := Etype (Selector);
3507 Inside_Allocator : Boolean := False;
3508 P : Node_Id := Parent (N);
3509
3510 begin
3511 if Is_Task_Type (Ctype) or else Has_Task (Ctype) then
3512 while Present (P) loop
3513 if Nkind (P) = N_Allocator then
3514 Inside_Allocator := True;
3515 exit;
3516 end if;
3517
3518 P := Parent (P);
3519 end loop;
3520
3521 if not Inside_Init_Proc and not Inside_Allocator then
3522 Build_Activation_Chain_Entity (N);
3523 end if;
3524 end if;
3525 end;
3526
3527 Append_List_To (L,
3528 Build_Initialization_Call (Loc,
3529 Id_Ref => Make_Selected_Component (Loc,
3530 Prefix => New_Copy_Tree (Target),
3531 Selector_Name =>
3532 New_Occurrence_Of (Selector, Loc)),
3533 Typ => Etype (Selector),
3534 Enclos_Type => Typ,
3535 With_Default_Init => True));
3536
3537 -- Prepare for component assignment
3538
3539 elsif Ekind (Selector) /= E_Discriminant
3540 or else Nkind (N) = N_Extension_Aggregate
3541 then
3542 -- All the discriminants have now been assigned
3543
3544 -- This is now a good moment to initialize and attach all the
3545 -- controllers. Their position may depend on the discriminants.
3546
3547 if Ekind (Selector) /= E_Discriminant then
3548 Generate_Finalization_Actions;
3549 end if;
3550
3551 Comp_Type := Underlying_Type (Etype (Selector));
3552 Comp_Expr :=
3553 Make_Selected_Component (Loc,
3554 Prefix => New_Copy_Tree (Target),
3555 Selector_Name => New_Occurrence_Of (Selector, Loc));
3556
3557 if Nkind (Expression (Comp)) = N_Qualified_Expression then
3558 Expr_Q := Expression (Expression (Comp));
3559 else
3560 Expr_Q := Expression (Comp);
3561 end if;
3562
3563 -- Now either create the assignment or generate the code for the
3564 -- inner aggregate top-down.
3565
3566 if Is_Delayed_Aggregate (Expr_Q) then
3567
3568 -- We have the following case of aggregate nesting inside
3569 -- an object declaration:
3570
3571 -- type Arr_Typ is array (Integer range <>) of ...;
3572
3573 -- type Rec_Typ (...) is record
3574 -- Obj_Arr_Typ : Arr_Typ (A .. B);
3575 -- end record;
3576
3577 -- Obj_Rec_Typ : Rec_Typ := (...,
3578 -- Obj_Arr_Typ => (X => (...), Y => (...)));
3579
3580 -- The length of the ranges of the aggregate and Obj_Add_Typ
3581 -- are equal (B - A = Y - X), but they do not coincide (X /=
3582 -- A and B /= Y). This case requires array sliding which is
3583 -- performed in the following manner:
3584
3585 -- subtype Arr_Sub is Arr_Typ (X .. Y);
3586 -- Temp : Arr_Sub;
3587 -- Temp (X) := (...);
3588 -- ...
3589 -- Temp (Y) := (...);
3590 -- Obj_Rec_Typ.Obj_Arr_Typ := Temp;
3591
3592 if Ekind (Comp_Type) = E_Array_Subtype
3593 and then Is_Int_Range_Bounds (Aggregate_Bounds (Expr_Q))
3594 and then Is_Int_Range_Bounds (First_Index (Comp_Type))
3595 and then not
3596 Compatible_Int_Bounds
3597 (Agg_Bounds => Aggregate_Bounds (Expr_Q),
3598 Typ_Bounds => First_Index (Comp_Type))
3599 then
3600 -- Create the array subtype with bounds equal to those of
3601 -- the corresponding aggregate.
3602
3603 declare
3604 SubE : constant Entity_Id := Make_Temporary (Loc, 'T');
3605
3606 SubD : constant Node_Id :=
3607 Make_Subtype_Declaration (Loc,
3608 Defining_Identifier => SubE,
3609 Subtype_Indication =>
3610 Make_Subtype_Indication (Loc,
3611 Subtype_Mark =>
3612 New_Occurrence_Of (Etype (Comp_Type), Loc),
3613 Constraint =>
3614 Make_Index_Or_Discriminant_Constraint
3615 (Loc,
3616 Constraints => New_List (
3617 New_Copy_Tree
3618 (Aggregate_Bounds (Expr_Q))))));
3619
3620 -- Create a temporary array of the above subtype which
3621 -- will be used to capture the aggregate assignments.
3622
3623 TmpE : constant Entity_Id := Make_Temporary (Loc, 'A', N);
3624
3625 TmpD : constant Node_Id :=
3626 Make_Object_Declaration (Loc,
3627 Defining_Identifier => TmpE,
3628 Object_Definition => New_Occurrence_Of (SubE, Loc));
3629
3630 begin
3631 Set_No_Initialization (TmpD);
3632 Append_To (L, SubD);
3633 Append_To (L, TmpD);
3634
3635 -- Expand aggregate into assignments to the temp array
3636
3637 Append_List_To (L,
3638 Late_Expansion (Expr_Q, Comp_Type,
3639 New_Occurrence_Of (TmpE, Loc)));
3640
3641 -- Slide
3642
3643 Append_To (L,
3644 Make_Assignment_Statement (Loc,
3645 Name => New_Copy_Tree (Comp_Expr),
3646 Expression => New_Occurrence_Of (TmpE, Loc)));
3647 end;
3648
3649 -- Normal case (sliding not required)
3650
3651 else
3652 Append_List_To (L,
3653 Late_Expansion (Expr_Q, Comp_Type, Comp_Expr));
3654 end if;
3655
3656 -- Expr_Q is not delayed aggregate
3657
3658 else
3659 if Has_Discriminants (Typ) then
3660 Replace_Discriminants (Expr_Q);
3661
3662 -- If the component is an array type that depends on
3663 -- discriminants, and the expression is a single Others
3664 -- clause, create an explicit subtype for it because the
3665 -- backend has troubles recovering the actual bounds.
3666
3667 if Nkind (Expr_Q) = N_Aggregate
3668 and then Is_Array_Type (Comp_Type)
3669 and then Present (Component_Associations (Expr_Q))
3670 then
3671 declare
3672 Assoc : constant Node_Id :=
3673 First (Component_Associations (Expr_Q));
3674 Decl : Node_Id;
3675
3676 begin
3677 if Nkind (First (Choices (Assoc))) = N_Others_Choice
3678 then
3679 Decl :=
3680 Build_Actual_Subtype_Of_Component
3681 (Comp_Type, Comp_Expr);
3682
3683 -- If the component type does not in fact depend on
3684 -- discriminants, the subtype declaration is empty.
3685
3686 if Present (Decl) then
3687 Append_To (L, Decl);
3688 Set_Etype (Comp_Expr, Defining_Entity (Decl));
3689 end if;
3690 end if;
3691 end;
3692 end if;
3693 end if;
3694
3695 if Modify_Tree_For_C
3696 and then Nkind (Expr_Q) = N_Aggregate
3697 and then Is_Array_Type (Etype (Expr_Q))
3698 and then Present (First_Index (Etype (Expr_Q)))
3699 then
3700 declare
3701 Expr_Q_Type : constant Node_Id := Etype (Expr_Q);
3702 begin
3703 Append_List_To (L,
3704 Build_Array_Aggr_Code
3705 (N => Expr_Q,
3706 Ctype => Component_Type (Expr_Q_Type),
3707 Index => First_Index (Expr_Q_Type),
3708 Into => Comp_Expr,
3709 Scalar_Comp =>
3710 Is_Scalar_Type (Component_Type (Expr_Q_Type))));
3711 end;
3712
3713 else
3714 -- Handle an initialization expression of a controlled type
3715 -- in case it denotes a function call. In general such a
3716 -- scenario will produce a transient scope, but this will
3717 -- lead to wrong order of initialization, adjustment, and
3718 -- finalization in the context of aggregates.
3719
3720 -- Target.Comp := Ctrl_Func_Call;
3721
3722 -- begin -- scope
3723 -- Trans_Obj : ... := Ctrl_Func_Call; -- object
3724 -- Target.Comp := Trans_Obj;
3725 -- Finalize (Trans_Obj);
3726 -- end
3727 -- Target.Comp._tag := ...;
3728 -- Adjust (Target.Comp);
3729
3730 -- In the example above, the call to Finalize occurs too
3731 -- early and as a result it may leave the record component
3732 -- in a bad state. Finalization of the transient object
3733 -- should really happen after adjustment.
3734
3735 -- To avoid this scenario, perform in-place side-effect
3736 -- removal of the function call. This eliminates the
3737 -- transient property of the function result and ensures
3738 -- correct order of actions.
3739
3740 -- Res : ... := Ctrl_Func_Call;
3741 -- Target.Comp := Res;
3742 -- Target.Comp._tag := ...;
3743 -- Adjust (Target.Comp);
3744 -- Finalize (Res);
3745
3746 if Needs_Finalization (Comp_Type)
3747 and then Nkind (Expr_Q) /= N_Aggregate
3748 then
3749 Initialize_Ctrl_Record_Component
3750 (Rec_Comp => Comp_Expr,
3751 Comp_Typ => Etype (Selector),
3752 Init_Expr => Expr_Q,
3753 Stmts => L);
3754
3755 -- Otherwise perform single component initialization
3756
3757 else
3758 Initialize_Record_Component
3759 (Rec_Comp => Comp_Expr,
3760 Comp_Typ => Etype (Selector),
3761 Init_Expr => Expr_Q,
3762 Stmts => L);
3763 end if;
3764 end if;
3765 end if;
3766
3767 -- comment would be good here ???
3768
3769 elsif Ekind (Selector) = E_Discriminant
3770 and then Nkind (N) /= N_Extension_Aggregate
3771 and then Nkind (Parent (N)) = N_Component_Association
3772 and then Is_Constrained (Typ)
3773 then
3774 -- We must check that the discriminant value imposed by the
3775 -- context is the same as the value given in the subaggregate,
3776 -- because after the expansion into assignments there is no
3777 -- record on which to perform a regular discriminant check.
3778
3779 declare
3780 D_Val : Elmt_Id;
3781 Disc : Entity_Id;
3782
3783 begin
3784 D_Val := First_Elmt (Discriminant_Constraint (Typ));
3785 Disc := First_Discriminant (Typ);
3786 while Chars (Disc) /= Chars (Selector) loop
3787 Next_Discriminant (Disc);
3788 Next_Elmt (D_Val);
3789 end loop;
3790
3791 pragma Assert (Present (D_Val));
3792
3793 -- This check cannot performed for components that are
3794 -- constrained by a current instance, because this is not a
3795 -- value that can be compared with the actual constraint.
3796
3797 if Nkind (Node (D_Val)) /= N_Attribute_Reference
3798 or else not Is_Entity_Name (Prefix (Node (D_Val)))
3799 or else not Is_Type (Entity (Prefix (Node (D_Val))))
3800 then
3801 Append_To (L,
3802 Make_Raise_Constraint_Error (Loc,
3803 Condition =>
3804 Make_Op_Ne (Loc,
3805 Left_Opnd => New_Copy_Tree (Node (D_Val)),
3806 Right_Opnd => Expression (Comp)),
3807 Reason => CE_Discriminant_Check_Failed));
3808
3809 else
3810 -- Find self-reference in previous discriminant assignment,
3811 -- and replace with proper expression.
3812
3813 declare
3814 Ass : Node_Id;
3815
3816 begin
3817 Ass := First (L);
3818 while Present (Ass) loop
3819 if Nkind (Ass) = N_Assignment_Statement
3820 and then Nkind (Name (Ass)) = N_Selected_Component
3821 and then Chars (Selector_Name (Name (Ass))) =
3822 Chars (Disc)
3823 then
3824 Set_Expression
3825 (Ass, New_Copy_Tree (Expression (Comp)));
3826 exit;
3827 end if;
3828 Next (Ass);
3829 end loop;
3830 end;
3831 end if;
3832 end;
3833 end if;
3834
3835 Next (Comp);
3836 end loop;
3837
3838 -- If the type is tagged, the tag needs to be initialized (unless we
3839 -- are in VM-mode where tags are implicit). It is done late in the
3840 -- initialization process because in some cases, we call the init
3841 -- proc of an ancestor which will not leave out the right tag.
3842
3843 if Ancestor_Is_Expression then
3844 null;
3845
3846 -- For CPP types we generated a call to the C++ default constructor
3847 -- before the components have been initialized to ensure the proper
3848 -- initialization of the _Tag component (see above).
3849
3850 elsif Is_CPP_Class (Typ) then
3851 null;
3852
3853 elsif Is_Tagged_Type (Typ) and then Tagged_Type_Expansion then
3854 Instr :=
3855 Make_OK_Assignment_Statement (Loc,
3856 Name =>
3857 Make_Selected_Component (Loc,
3858 Prefix => New_Copy_Tree (Target),
3859 Selector_Name =>
3860 New_Occurrence_Of
3861 (First_Tag_Component (Base_Type (Typ)), Loc)),
3862
3863 Expression =>
3864 Unchecked_Convert_To (RTE (RE_Tag),
3865 New_Occurrence_Of
3866 (Node (First_Elmt (Access_Disp_Table (Base_Type (Typ)))),
3867 Loc)));
3868
3869 Append_To (L, Instr);
3870
3871 -- Ada 2005 (AI-251): If the tagged type has been derived from an
3872 -- abstract interfaces we must also initialize the tags of the
3873 -- secondary dispatch tables.
3874
3875 if Has_Interfaces (Base_Type (Typ)) then
3876 Init_Secondary_Tags
3877 (Typ => Base_Type (Typ),
3878 Target => Target,
3879 Stmts_List => L,
3880 Init_Tags_List => L);
3881 end if;
3882 end if;
3883
3884 -- If the controllers have not been initialized yet (by lack of non-
3885 -- discriminant components), let's do it now.
3886
3887 Generate_Finalization_Actions;
3888
3889 return L;
3890 end Build_Record_Aggr_Code;
3891
3892 ---------------------------------------
3893 -- Collect_Initialization_Statements --
3894 ---------------------------------------
3895
3896 procedure Collect_Initialization_Statements
3897 (Obj : Entity_Id;
3898 N : Node_Id;
3899 Node_After : Node_Id)
3900 is
3901 Loc : constant Source_Ptr := Sloc (N);
3902 Init_Actions : constant List_Id := New_List;
3903 Init_Node : Node_Id;
3904 Comp_Stmt : Node_Id;
3905
3906 begin
3907 -- Nothing to do if Obj is already frozen, as in this case we known we
3908 -- won't need to move the initialization statements about later on.
3909
3910 if Is_Frozen (Obj) then
3911 return;
3912 end if;
3913
3914 Init_Node := N;
3915 while Next (Init_Node) /= Node_After loop
3916 Append_To (Init_Actions, Remove_Next (Init_Node));
3917 end loop;
3918
3919 if not Is_Empty_List (Init_Actions) then
3920 Comp_Stmt := Make_Compound_Statement (Loc, Actions => Init_Actions);
3921 Insert_Action_After (Init_Node, Comp_Stmt);
3922 Set_Initialization_Statements (Obj, Comp_Stmt);
3923 end if;
3924 end Collect_Initialization_Statements;
3925
3926 -------------------------------
3927 -- Convert_Aggr_In_Allocator --
3928 -------------------------------
3929
3930 procedure Convert_Aggr_In_Allocator
3931 (Alloc : Node_Id;
3932 Decl : Node_Id;
3933 Aggr : Node_Id)
3934 is
3935 Loc : constant Source_Ptr := Sloc (Aggr);
3936 Typ : constant Entity_Id := Etype (Aggr);
3937 Temp : constant Entity_Id := Defining_Identifier (Decl);
3938
3939 Occ : constant Node_Id :=
3940 Unchecked_Convert_To (Typ,
3941 Make_Explicit_Dereference (Loc, New_Occurrence_Of (Temp, Loc)));
3942
3943 begin
3944 if Is_Array_Type (Typ) then
3945 Convert_Array_Aggr_In_Allocator (Decl, Aggr, Occ);
3946
3947 elsif Has_Default_Init_Comps (Aggr) then
3948 declare
3949 L : constant List_Id := New_List;
3950 Init_Stmts : List_Id;
3951
3952 begin
3953 Init_Stmts := Late_Expansion (Aggr, Typ, Occ);
3954
3955 if Has_Task (Typ) then
3956 Build_Task_Allocate_Block_With_Init_Stmts (L, Aggr, Init_Stmts);
3957 Insert_Actions (Alloc, L);
3958 else
3959 Insert_Actions (Alloc, Init_Stmts);
3960 end if;
3961 end;
3962
3963 else
3964 Insert_Actions (Alloc, Late_Expansion (Aggr, Typ, Occ));
3965 end if;
3966 end Convert_Aggr_In_Allocator;
3967
3968 --------------------------------
3969 -- Convert_Aggr_In_Assignment --
3970 --------------------------------
3971
3972 procedure Convert_Aggr_In_Assignment (N : Node_Id) is
3973 Aggr : Node_Id := Expression (N);
3974 Typ : constant Entity_Id := Etype (Aggr);
3975 Occ : constant Node_Id := New_Copy_Tree (Name (N));
3976
3977 begin
3978 if Nkind (Aggr) = N_Qualified_Expression then
3979 Aggr := Expression (Aggr);
3980 end if;
3981
3982 Insert_Actions_After (N, Late_Expansion (Aggr, Typ, Occ));
3983 end Convert_Aggr_In_Assignment;
3984
3985 ---------------------------------
3986 -- Convert_Aggr_In_Object_Decl --
3987 ---------------------------------
3988
3989 procedure Convert_Aggr_In_Object_Decl (N : Node_Id) is
3990 Obj : constant Entity_Id := Defining_Identifier (N);
3991 Aggr : Node_Id := Expression (N);
3992 Loc : constant Source_Ptr := Sloc (Aggr);
3993 Typ : constant Entity_Id := Etype (Aggr);
3994 Occ : constant Node_Id := New_Occurrence_Of (Obj, Loc);
3995
3996 function Discriminants_Ok return Boolean;
3997 -- If the object type is constrained, the discriminants in the
3998 -- aggregate must be checked against the discriminants of the subtype.
3999 -- This cannot be done using Apply_Discriminant_Checks because after
4000 -- expansion there is no aggregate left to check.
4001
4002 ----------------------
4003 -- Discriminants_Ok --
4004 ----------------------
4005
4006 function Discriminants_Ok return Boolean is
4007 Cond : Node_Id := Empty;
4008 Check : Node_Id;
4009 D : Entity_Id;
4010 Disc1 : Elmt_Id;
4011 Disc2 : Elmt_Id;
4012 Val1 : Node_Id;
4013 Val2 : Node_Id;
4014
4015 begin
4016 D := First_Discriminant (Typ);
4017 Disc1 := First_Elmt (Discriminant_Constraint (Typ));
4018 Disc2 := First_Elmt (Discriminant_Constraint (Etype (Obj)));
4019 while Present (Disc1) and then Present (Disc2) loop
4020 Val1 := Node (Disc1);
4021 Val2 := Node (Disc2);
4022
4023 if not Is_OK_Static_Expression (Val1)
4024 or else not Is_OK_Static_Expression (Val2)
4025 then
4026 Check := Make_Op_Ne (Loc,
4027 Left_Opnd => Duplicate_Subexpr (Val1),
4028 Right_Opnd => Duplicate_Subexpr (Val2));
4029
4030 if No (Cond) then
4031 Cond := Check;
4032
4033 else
4034 Cond := Make_Or_Else (Loc,
4035 Left_Opnd => Cond,
4036 Right_Opnd => Check);
4037 end if;
4038
4039 elsif Expr_Value (Val1) /= Expr_Value (Val2) then
4040 Apply_Compile_Time_Constraint_Error (Aggr,
4041 Msg => "incorrect value for discriminant&??",
4042 Reason => CE_Discriminant_Check_Failed,
4043 Ent => D);
4044 return False;
4045 end if;
4046
4047 Next_Discriminant (D);
4048 Next_Elmt (Disc1);
4049 Next_Elmt (Disc2);
4050 end loop;
4051
4052 -- If any discriminant constraint is nonstatic, emit a check
4053
4054 if Present (Cond) then
4055 Insert_Action (N,
4056 Make_Raise_Constraint_Error (Loc,
4057 Condition => Cond,
4058 Reason => CE_Discriminant_Check_Failed));
4059 end if;
4060
4061 return True;
4062 end Discriminants_Ok;
4063
4064 -- Start of processing for Convert_Aggr_In_Object_Decl
4065
4066 begin
4067 Set_Assignment_OK (Occ);
4068
4069 if Nkind (Aggr) = N_Qualified_Expression then
4070 Aggr := Expression (Aggr);
4071 end if;
4072
4073 if Has_Discriminants (Typ)
4074 and then Typ /= Etype (Obj)
4075 and then Is_Constrained (Etype (Obj))
4076 and then not Discriminants_Ok
4077 then
4078 return;
4079 end if;
4080
4081 -- If the context is an extended return statement, it has its own
4082 -- finalization machinery (i.e. works like a transient scope) and
4083 -- we do not want to create an additional one, because objects on
4084 -- the finalization list of the return must be moved to the caller's
4085 -- finalization list to complete the return.
4086
4087 -- However, if the aggregate is limited, it is built in place, and the
4088 -- controlled components are not assigned to intermediate temporaries
4089 -- so there is no need for a transient scope in this case either.
4090
4091 if Requires_Transient_Scope (Typ)
4092 and then Ekind (Current_Scope) /= E_Return_Statement
4093 and then not Is_Limited_Type (Typ)
4094 then
4095 Establish_Transient_Scope (Aggr, Manage_Sec_Stack => False);
4096 end if;
4097
4098 declare
4099 Node_After : constant Node_Id := Next (N);
4100 begin
4101 Insert_Actions_After (N, Late_Expansion (Aggr, Typ, Occ));
4102 Collect_Initialization_Statements (Obj, N, Node_After);
4103 end;
4104
4105 Set_No_Initialization (N);
4106 Initialize_Discriminants (N, Typ);
4107 end Convert_Aggr_In_Object_Decl;
4108
4109 -------------------------------------
4110 -- Convert_Array_Aggr_In_Allocator --
4111 -------------------------------------
4112
4113 procedure Convert_Array_Aggr_In_Allocator
4114 (Decl : Node_Id;
4115 Aggr : Node_Id;
4116 Target : Node_Id)
4117 is
4118 Aggr_Code : List_Id;
4119 Typ : constant Entity_Id := Etype (Aggr);
4120 Ctyp : constant Entity_Id := Component_Type (Typ);
4121
4122 begin
4123 -- The target is an explicit dereference of the allocated object.
4124 -- Generate component assignments to it, as for an aggregate that
4125 -- appears on the right-hand side of an assignment statement.
4126
4127 Aggr_Code :=
4128 Build_Array_Aggr_Code (Aggr,
4129 Ctype => Ctyp,
4130 Index => First_Index (Typ),
4131 Into => Target,
4132 Scalar_Comp => Is_Scalar_Type (Ctyp));
4133
4134 Insert_Actions_After (Decl, Aggr_Code);
4135 end Convert_Array_Aggr_In_Allocator;
4136
4137 ----------------------------
4138 -- Convert_To_Assignments --
4139 ----------------------------
4140
4141 procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id) is
4142 Loc : constant Source_Ptr := Sloc (N);
4143 T : Entity_Id;
4144 Temp : Entity_Id;
4145
4146 Aggr_Code : List_Id;
4147 Instr : Node_Id;
4148 Target_Expr : Node_Id;
4149 Parent_Kind : Node_Kind;
4150 Unc_Decl : Boolean := False;
4151 Parent_Node : Node_Id;
4152
4153 begin
4154 pragma Assert (Nkind_In (N, N_Aggregate, N_Extension_Aggregate));
4155 pragma Assert (not Is_Static_Dispatch_Table_Aggregate (N));
4156 pragma Assert (Is_Record_Type (Typ));
4157
4158 Parent_Node := Parent (N);
4159 Parent_Kind := Nkind (Parent_Node);
4160
4161 if Parent_Kind = N_Qualified_Expression then
4162 -- Check if we are in an unconstrained declaration because in this
4163 -- case the current delayed expansion mechanism doesn't work when
4164 -- the declared object size depends on the initializing expr.
4165
4166 Parent_Node := Parent (Parent_Node);
4167 Parent_Kind := Nkind (Parent_Node);
4168
4169 if Parent_Kind = N_Object_Declaration then
4170 Unc_Decl :=
4171 not Is_Entity_Name (Object_Definition (Parent_Node))
4172 or else (Nkind (N) = N_Aggregate
4173 and then
4174 Has_Discriminants
4175 (Entity (Object_Definition (Parent_Node))))
4176 or else Is_Class_Wide_Type
4177 (Entity (Object_Definition (Parent_Node)));
4178 end if;
4179 end if;
4180
4181 -- Just set the Delay flag in the cases where the transformation will be
4182 -- done top down from above.
4183
4184 if False
4185
4186 -- Internal aggregate (transformed when expanding the parent)
4187
4188 or else Parent_Kind = N_Aggregate
4189 or else Parent_Kind = N_Extension_Aggregate
4190 or else Parent_Kind = N_Component_Association
4191
4192 -- Allocator (see Convert_Aggr_In_Allocator)
4193
4194 or else Parent_Kind = N_Allocator
4195
4196 -- Object declaration (see Convert_Aggr_In_Object_Decl)
4197
4198 or else (Parent_Kind = N_Object_Declaration and then not Unc_Decl)
4199
4200 -- Safe assignment (see Convert_Aggr_Assignments). So far only the
4201 -- assignments in init procs are taken into account.
4202
4203 or else (Parent_Kind = N_Assignment_Statement
4204 and then Inside_Init_Proc)
4205
4206 -- (Ada 2005) An inherently limited type in a return statement, which
4207 -- will be handled in a build-in-place fashion, and may be rewritten
4208 -- as an extended return and have its own finalization machinery.
4209 -- In the case of a simple return, the aggregate needs to be delayed
4210 -- until the scope for the return statement has been created, so
4211 -- that any finalization chain will be associated with that scope.
4212 -- For extended returns, we delay expansion to avoid the creation
4213 -- of an unwanted transient scope that could result in premature
4214 -- finalization of the return object (which is built in place
4215 -- within the caller's scope).
4216
4217 or else Is_Build_In_Place_Aggregate_Return (N)
4218 then
4219 Set_Expansion_Delayed (N);
4220 return;
4221 end if;
4222
4223 -- Otherwise, if a transient scope is required, create it now. If we
4224 -- are within an initialization procedure do not create such, because
4225 -- the target of the assignment must not be declared within a local
4226 -- block, and because cleanup will take place on return from the
4227 -- initialization procedure.
4228
4229 -- Should the condition be more restrictive ???
4230
4231 if Requires_Transient_Scope (Typ) and then not Inside_Init_Proc then
4232 Establish_Transient_Scope (N, Manage_Sec_Stack => False);
4233 end if;
4234
4235 -- If the aggregate is nonlimited, create a temporary. If it is limited
4236 -- and context is an assignment, this is a subaggregate for an enclosing
4237 -- aggregate being expanded. It must be built in place, so use target of
4238 -- the current assignment.
4239
4240 if Is_Limited_Type (Typ)
4241 and then Nkind (Parent (N)) = N_Assignment_Statement
4242 then
4243 Target_Expr := New_Copy_Tree (Name (Parent (N)));
4244 Insert_Actions (Parent (N),
4245 Build_Record_Aggr_Code (N, Typ, Target_Expr));
4246 Rewrite (Parent (N), Make_Null_Statement (Loc));
4247
4248 -- Generating C, do not declare a temporary to initialize an aggregate
4249 -- assigned to Out or In_Out parameters whose type has no discriminants.
4250 -- This avoids stack overflow errors at run time.
4251
4252 elsif Modify_Tree_For_C
4253 and then Nkind (Parent (N)) = N_Assignment_Statement
4254 and then Nkind (Name (Parent (N))) = N_Identifier
4255 and then Ekind_In (Entity (Name (Parent (N))), E_Out_Parameter,
4256 E_In_Out_Parameter)
4257 and then not Has_Discriminants (Etype (Entity (Name (Parent (N)))))
4258 then
4259 Target_Expr := New_Copy_Tree (Name (Parent (N)));
4260 Insert_Actions (Parent (N),
4261 Build_Record_Aggr_Code (N, Typ, Target_Expr));
4262 Rewrite (Parent (N), Make_Null_Statement (Loc));
4263
4264 else
4265 Temp := Make_Temporary (Loc, 'A', N);
4266
4267 -- If the type inherits unknown discriminants, use the view with
4268 -- known discriminants if available.
4269
4270 if Has_Unknown_Discriminants (Typ)
4271 and then Present (Underlying_Record_View (Typ))
4272 then
4273 T := Underlying_Record_View (Typ);
4274 else
4275 T := Typ;
4276 end if;
4277
4278 Instr :=
4279 Make_Object_Declaration (Loc,
4280 Defining_Identifier => Temp,
4281 Object_Definition => New_Occurrence_Of (T, Loc));
4282
4283 Set_No_Initialization (Instr);
4284 Insert_Action (N, Instr);
4285 Initialize_Discriminants (Instr, T);
4286
4287 Target_Expr := New_Occurrence_Of (Temp, Loc);
4288 Aggr_Code := Build_Record_Aggr_Code (N, T, Target_Expr);
4289
4290 -- Save the last assignment statement associated with the aggregate
4291 -- when building a controlled object. This reference is utilized by
4292 -- the finalization machinery when marking an object as successfully
4293 -- initialized.
4294
4295 if Needs_Finalization (T) then
4296 Set_Last_Aggregate_Assignment (Temp, Last (Aggr_Code));
4297 end if;
4298
4299 Insert_Actions (N, Aggr_Code);
4300 Rewrite (N, New_Occurrence_Of (Temp, Loc));
4301 Analyze_And_Resolve (N, T);
4302 end if;
4303 end Convert_To_Assignments;
4304
4305 ---------------------------
4306 -- Convert_To_Positional --
4307 ---------------------------
4308
4309 procedure Convert_To_Positional
4310 (N : Node_Id;
4311 Max_Others_Replicate : Nat := 32;
4312 Handle_Bit_Packed : Boolean := False)
4313 is
4314 Typ : constant Entity_Id := Etype (N);
4315
4316 Static_Components : Boolean := True;
4317
4318 procedure Check_Static_Components;
4319 -- Check whether all components of the aggregate are compile-time known
4320 -- values, and can be passed as is to the back-end without further
4321 -- expansion.
4322
4323 function Flatten
4324 (N : Node_Id;
4325 Ix : Node_Id;
4326 Ixb : Node_Id) return Boolean;
4327 -- Convert the aggregate into a purely positional form if possible. On
4328 -- entry the bounds of all dimensions are known to be static, and the
4329 -- total number of components is safe enough to expand.
4330
4331 function Is_Flat (N : Node_Id; Dims : Int) return Boolean;
4332 -- Return True iff the array N is flat (which is not trivial in the case
4333 -- of multidimensional aggregates).
4334
4335 function Is_Static_Element (N : Node_Id) return Boolean;
4336 -- Return True if N, an element of a component association list, i.e.
4337 -- N_Component_Association or N_Iterated_Component_Association, has a
4338 -- compile-time known value and can be passed as is to the back-end
4339 -- without further expansion.
4340 -- An Iterated_Component_Association is treated as nonstatic in most
4341 -- cases for now, so there are possibilities for optimization.
4342
4343 -----------------------------
4344 -- Check_Static_Components --
4345 -----------------------------
4346
4347 -- Could use some comments in this body ???
4348
4349 procedure Check_Static_Components is
4350 Assoc : Node_Id;
4351 Expr : Node_Id;
4352
4353 begin
4354 Static_Components := True;
4355
4356 if Nkind (N) = N_String_Literal then
4357 null;
4358
4359 elsif Present (Expressions (N)) then
4360 Expr := First (Expressions (N));
4361 while Present (Expr) loop
4362 if Nkind (Expr) /= N_Aggregate
4363 or else not Compile_Time_Known_Aggregate (Expr)
4364 or else Expansion_Delayed (Expr)
4365 then
4366 Static_Components := False;
4367 exit;
4368 end if;
4369
4370 Next (Expr);
4371 end loop;
4372 end if;
4373
4374 if Nkind (N) = N_Aggregate
4375 and then Present (Component_Associations (N))
4376 then
4377 Assoc := First (Component_Associations (N));
4378 while Present (Assoc) loop
4379 if not Is_Static_Element (Assoc) then
4380 Static_Components := False;
4381 exit;
4382 end if;
4383
4384 Next (Assoc);
4385 end loop;
4386 end if;
4387 end Check_Static_Components;
4388
4389 -------------
4390 -- Flatten --
4391 -------------
4392
4393 function Flatten
4394 (N : Node_Id;
4395 Ix : Node_Id;
4396 Ixb : Node_Id) return Boolean
4397 is
4398 Loc : constant Source_Ptr := Sloc (N);
4399 Blo : constant Node_Id := Type_Low_Bound (Etype (Ixb));
4400 Lo : constant Node_Id := Type_Low_Bound (Etype (Ix));
4401 Hi : constant Node_Id := Type_High_Bound (Etype (Ix));
4402 Lov : Uint;
4403 Hiv : Uint;
4404
4405 Others_Present : Boolean := False;
4406
4407 begin
4408 if Nkind (Original_Node (N)) = N_String_Literal then
4409 return True;
4410 end if;
4411
4412 if not Compile_Time_Known_Value (Lo)
4413 or else not Compile_Time_Known_Value (Hi)
4414 then
4415 return False;
4416 end if;
4417
4418 Lov := Expr_Value (Lo);
4419 Hiv := Expr_Value (Hi);
4420
4421 -- Check if there is an others choice
4422
4423 if Present (Component_Associations (N)) then
4424 declare
4425 Assoc : Node_Id;
4426 Choice : Node_Id;
4427
4428 begin
4429 Assoc := First (Component_Associations (N));
4430 while Present (Assoc) loop
4431
4432 -- If this is a box association, flattening is in general
4433 -- not possible because at this point we cannot tell if the
4434 -- default is static or even exists.
4435
4436 if Box_Present (Assoc) then
4437 return False;
4438
4439 elsif Nkind (Assoc) = N_Iterated_Component_Association then
4440 return False;
4441 end if;
4442
4443 Choice := First (Choice_List (Assoc));
4444
4445 while Present (Choice) loop
4446 if Nkind (Choice) = N_Others_Choice then
4447 Others_Present := True;
4448 end if;
4449
4450 Next (Choice);
4451 end loop;
4452
4453 Next (Assoc);
4454 end loop;
4455 end;
4456 end if;
4457
4458 -- If the low bound is not known at compile time and others is not
4459 -- present we can proceed since the bounds can be obtained from the
4460 -- aggregate.
4461
4462 if Hiv < Lov
4463 or else (not Compile_Time_Known_Value (Blo) and then Others_Present)
4464 then
4465 return False;
4466 end if;
4467
4468 -- Determine if set of alternatives is suitable for conversion and
4469 -- build an array containing the values in sequence.
4470
4471 declare
4472 Vals : array (UI_To_Int (Lov) .. UI_To_Int (Hiv))
4473 of Node_Id := (others => Empty);
4474 -- The values in the aggregate sorted appropriately
4475
4476 Vlist : List_Id;
4477 -- Same data as Vals in list form
4478
4479 Rep_Count : Nat;
4480 -- Used to validate Max_Others_Replicate limit
4481
4482 Elmt : Node_Id;
4483 Num : Int := UI_To_Int (Lov);
4484 Choice_Index : Int;
4485 Choice : Node_Id;
4486 Lo, Hi : Node_Id;
4487
4488 begin
4489 if Present (Expressions (N)) then
4490 Elmt := First (Expressions (N));
4491 while Present (Elmt) loop
4492 if Nkind (Elmt) = N_Aggregate
4493 and then Present (Next_Index (Ix))
4494 and then
4495 not Flatten (Elmt, Next_Index (Ix), Next_Index (Ixb))
4496 then
4497 return False;
4498 end if;
4499
4500 -- Duplicate expression for each index it covers
4501
4502 Vals (Num) := New_Copy_Tree (Elmt);
4503 Num := Num + 1;
4504
4505 Next (Elmt);
4506 end loop;
4507 end if;
4508
4509 if No (Component_Associations (N)) then
4510 return True;
4511 end if;
4512
4513 Elmt := First (Component_Associations (N));
4514
4515 if Nkind (Expression (Elmt)) = N_Aggregate then
4516 if Present (Next_Index (Ix))
4517 and then
4518 not Flatten
4519 (Expression (Elmt), Next_Index (Ix), Next_Index (Ixb))
4520 then
4521 return False;
4522 end if;
4523 end if;
4524
4525 Component_Loop : while Present (Elmt) loop
4526 Choice := First (Choice_List (Elmt));
4527 Choice_Loop : while Present (Choice) loop
4528
4529 -- If we have an others choice, fill in the missing elements
4530 -- subject to the limit established by Max_Others_Replicate.
4531
4532 if Nkind (Choice) = N_Others_Choice then
4533 Rep_Count := 0;
4534
4535 -- If the expression involves a construct that generates
4536 -- a loop, we must generate individual assignments and
4537 -- no flattening is possible.
4538
4539 if Nkind (Expression (Elmt)) = N_Quantified_Expression
4540 then
4541 return False;
4542 end if;
4543
4544 for J in Vals'Range loop
4545 if No (Vals (J)) then
4546 Vals (J) := New_Copy_Tree (Expression (Elmt));
4547 Rep_Count := Rep_Count + 1;
4548
4549 -- Check for maximum others replication. Note that
4550 -- we skip this test if either of the restrictions
4551 -- No_Elaboration_Code or No_Implicit_Loops is
4552 -- active, if this is a preelaborable unit or
4553 -- a predefined unit, or if the unit must be
4554 -- placed in data memory. This also ensures that
4555 -- predefined units get the same level of constant
4556 -- folding in Ada 95 and Ada 2005, where their
4557 -- categorization has changed.
4558
4559 declare
4560 P : constant Entity_Id :=
4561 Cunit_Entity (Current_Sem_Unit);
4562
4563 begin
4564 -- Check if duplication is always OK and, if so,
4565 -- continue processing.
4566
4567 if Restriction_Active (No_Elaboration_Code)
4568 or else Restriction_Active (No_Implicit_Loops)
4569 or else
4570 (Ekind (Current_Scope) = E_Package
4571 and then Static_Elaboration_Desired
4572 (Current_Scope))
4573 or else Is_Preelaborated (P)
4574 or else (Ekind (P) = E_Package_Body
4575 and then
4576 Is_Preelaborated (Spec_Entity (P)))
4577 or else
4578 Is_Predefined_Unit (Get_Source_Unit (P))
4579 then
4580 null;
4581
4582 -- If duplication is not always OK, continue
4583 -- only if either the element is static or is
4584 -- an aggregate which can itself be flattened,
4585 -- and the replication count is not too high.
4586
4587 elsif (Is_Static_Element (Elmt)
4588 or else
4589 (Nkind (Expression (Elmt)) = N_Aggregate
4590 and then Present (Next_Index (Ix))))
4591 and then Rep_Count <= Max_Others_Replicate
4592 then
4593 null;
4594
4595 -- Return False in all the other cases
4596
4597 else
4598 return False;
4599 end if;
4600 end;
4601 end if;
4602 end loop;
4603
4604 if Rep_Count = 0
4605 and then Warn_On_Redundant_Constructs
4606 then
4607 Error_Msg_N ("there are no others?r?", Elmt);
4608 end if;
4609
4610 exit Component_Loop;
4611
4612 -- Case of a subtype mark, identifier or expanded name
4613
4614 elsif Is_Entity_Name (Choice)
4615 and then Is_Type (Entity (Choice))
4616 then
4617 Lo := Type_Low_Bound (Etype (Choice));
4618 Hi := Type_High_Bound (Etype (Choice));
4619
4620 -- Case of subtype indication
4621
4622 elsif Nkind (Choice) = N_Subtype_Indication then
4623 Lo := Low_Bound (Range_Expression (Constraint (Choice)));
4624 Hi := High_Bound (Range_Expression (Constraint (Choice)));
4625
4626 -- Case of a range
4627
4628 elsif Nkind (Choice) = N_Range then
4629 Lo := Low_Bound (Choice);
4630 Hi := High_Bound (Choice);
4631
4632 -- Normal subexpression case
4633
4634 else pragma Assert (Nkind (Choice) in N_Subexpr);
4635 if not Compile_Time_Known_Value (Choice) then
4636 return False;
4637
4638 else
4639 Choice_Index := UI_To_Int (Expr_Value (Choice));
4640
4641 if Choice_Index in Vals'Range then
4642 Vals (Choice_Index) :=
4643 New_Copy_Tree (Expression (Elmt));
4644 goto Continue;
4645
4646 -- Choice is statically out-of-range, will be
4647 -- rewritten to raise Constraint_Error.
4648
4649 else
4650 return False;
4651 end if;
4652 end if;
4653 end if;
4654
4655 -- Range cases merge with Lo,Hi set
4656
4657 if not Compile_Time_Known_Value (Lo)
4658 or else
4659 not Compile_Time_Known_Value (Hi)
4660 then
4661 return False;
4662
4663 else
4664 for J in UI_To_Int (Expr_Value (Lo)) ..
4665 UI_To_Int (Expr_Value (Hi))
4666 loop
4667 Vals (J) := New_Copy_Tree (Expression (Elmt));
4668 end loop;
4669 end if;
4670
4671 <<Continue>>
4672 Next (Choice);
4673 end loop Choice_Loop;
4674
4675 Next (Elmt);
4676 end loop Component_Loop;
4677
4678 -- If we get here the conversion is possible
4679
4680 Vlist := New_List;
4681 for J in Vals'Range loop
4682 Append (Vals (J), Vlist);
4683 end loop;
4684
4685 Rewrite (N, Make_Aggregate (Loc, Expressions => Vlist));
4686 Set_Aggregate_Bounds (N, Aggregate_Bounds (Original_Node (N)));
4687 return True;
4688 end;
4689 end Flatten;
4690
4691 -------------
4692 -- Is_Flat --
4693 -------------
4694
4695 function Is_Flat (N : Node_Id; Dims : Int) return Boolean is
4696 Elmt : Node_Id;
4697
4698 begin
4699 if Dims = 0 then
4700 return True;
4701
4702 elsif Nkind (N) = N_Aggregate then
4703 if Present (Component_Associations (N)) then
4704 return False;
4705
4706 else
4707 Elmt := First (Expressions (N));
4708 while Present (Elmt) loop
4709 if not Is_Flat (Elmt, Dims - 1) then
4710 return False;
4711 end if;
4712
4713 Next (Elmt);
4714 end loop;
4715
4716 return True;
4717 end if;
4718 else
4719 return True;
4720 end if;
4721 end Is_Flat;
4722
4723 -------------------------
4724 -- Is_Static_Element --
4725 -------------------------
4726
4727 function Is_Static_Element (N : Node_Id) return Boolean is
4728 Expr : constant Node_Id := Expression (N);
4729
4730 begin
4731 if Nkind_In (Expr, N_Integer_Literal, N_Real_Literal) then
4732 return True;
4733
4734 elsif Is_Entity_Name (Expr)
4735 and then Present (Entity (Expr))
4736 and then Ekind (Entity (Expr)) = E_Enumeration_Literal
4737 then
4738 return True;
4739
4740 elsif Nkind (N) = N_Iterated_Component_Association then
4741 return False;
4742
4743 elsif Nkind (Expr) = N_Aggregate
4744 and then Compile_Time_Known_Aggregate (Expr)
4745 and then not Expansion_Delayed (Expr)
4746 then
4747 return True;
4748
4749 else
4750 return False;
4751 end if;
4752 end Is_Static_Element;
4753
4754 -- Start of processing for Convert_To_Positional
4755
4756 begin
4757 -- Only convert to positional when generating C in case of an
4758 -- object declaration, this is the only case where aggregates are
4759 -- supported in C.
4760
4761 if Modify_Tree_For_C and then not Is_CCG_Supported_Aggregate (N) then
4762 return;
4763 end if;
4764
4765 -- Ada 2005 (AI-287): Do not convert in case of default initialized
4766 -- components because in this case will need to call the corresponding
4767 -- IP procedure.
4768
4769 if Has_Default_Init_Comps (N) then
4770 return;
4771 end if;
4772
4773 -- A subaggregate may have been flattened but is not known to be
4774 -- Compile_Time_Known. Set that flag in cases that cannot require
4775 -- elaboration code, so that the aggregate can be used as the
4776 -- initial value of a thread-local variable.
4777
4778 if Is_Flat (N, Number_Dimensions (Typ)) then
4779 if Static_Array_Aggregate (N) then
4780 Set_Compile_Time_Known_Aggregate (N);
4781 end if;
4782
4783 return;
4784 end if;
4785
4786 if Is_Bit_Packed_Array (Typ) and then not Handle_Bit_Packed then
4787 return;
4788 end if;
4789
4790 -- Do not convert to positional if controlled components are involved
4791 -- since these require special processing
4792
4793 if Has_Controlled_Component (Typ) then
4794 return;
4795 end if;
4796
4797 Check_Static_Components;
4798
4799 -- If the size is known, or all the components are static, try to
4800 -- build a fully positional aggregate.
4801
4802 -- The size of the type may not be known for an aggregate with
4803 -- discriminated array components, but if the components are static
4804 -- it is still possible to verify statically that the length is
4805 -- compatible with the upper bound of the type, and therefore it is
4806 -- worth flattening such aggregates as well.
4807
4808 -- For now the back-end expands these aggregates into individual
4809 -- assignments to the target anyway, but it is conceivable that
4810 -- it will eventually be able to treat such aggregates statically???
4811
4812 if Aggr_Size_OK (N, Typ)
4813 and then Flatten (N, First_Index (Typ), First_Index (Base_Type (Typ)))
4814 then
4815 if Static_Components then
4816 Set_Compile_Time_Known_Aggregate (N);
4817 Set_Expansion_Delayed (N, False);
4818 end if;
4819
4820 Analyze_And_Resolve (N, Typ);
4821 end if;
4822
4823 -- If Static_Elaboration_Desired has been specified, diagnose aggregates
4824 -- that will still require initialization code.
4825
4826 if (Ekind (Current_Scope) = E_Package
4827 and then Static_Elaboration_Desired (Current_Scope))
4828 and then Nkind (Parent (N)) = N_Object_Declaration
4829 then
4830 declare
4831 Expr : Node_Id;
4832
4833 begin
4834 if Nkind (N) = N_Aggregate and then Present (Expressions (N)) then
4835 Expr := First (Expressions (N));
4836 while Present (Expr) loop
4837 if Nkind_In (Expr, N_Integer_Literal, N_Real_Literal)
4838 or else
4839 (Is_Entity_Name (Expr)
4840 and then Ekind (Entity (Expr)) = E_Enumeration_Literal)
4841 then
4842 null;
4843
4844 else
4845 Error_Msg_N
4846 ("non-static object requires elaboration code??", N);
4847 exit;
4848 end if;
4849
4850 Next (Expr);
4851 end loop;
4852
4853 if Present (Component_Associations (N)) then
4854 Error_Msg_N ("object requires elaboration code??", N);
4855 end if;
4856 end if;
4857 end;
4858 end if;
4859 end Convert_To_Positional;
4860
4861 ----------------------------
4862 -- Expand_Array_Aggregate --
4863 ----------------------------
4864
4865 -- Array aggregate expansion proceeds as follows:
4866
4867 -- 1. If requested we generate code to perform all the array aggregate
4868 -- bound checks, specifically
4869
4870 -- (a) Check that the index range defined by aggregate bounds is
4871 -- compatible with corresponding index subtype.
4872
4873 -- (b) If an others choice is present check that no aggregate
4874 -- index is outside the bounds of the index constraint.
4875
4876 -- (c) For multidimensional arrays make sure that all subaggregates
4877 -- corresponding to the same dimension have the same bounds.
4878
4879 -- 2. Check for packed array aggregate which can be converted to a
4880 -- constant so that the aggregate disappears completely.
4881
4882 -- 3. Check case of nested aggregate. Generally nested aggregates are
4883 -- handled during the processing of the parent aggregate.
4884
4885 -- 4. Check if the aggregate can be statically processed. If this is the
4886 -- case pass it as is to Gigi. Note that a necessary condition for
4887 -- static processing is that the aggregate be fully positional.
4888
4889 -- 5. If in place aggregate expansion is possible (i.e. no need to create
4890 -- a temporary) then mark the aggregate as such and return. Otherwise
4891 -- create a new temporary and generate the appropriate initialization
4892 -- code.
4893
4894 procedure Expand_Array_Aggregate (N : Node_Id) is
4895 Loc : constant Source_Ptr := Sloc (N);
4896
4897 Typ : constant Entity_Id := Etype (N);
4898 Ctyp : constant Entity_Id := Component_Type (Typ);
4899 -- Typ is the correct constrained array subtype of the aggregate
4900 -- Ctyp is the corresponding component type.
4901
4902 Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
4903 -- Number of aggregate index dimensions
4904
4905 Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id;
4906 Aggr_High : array (1 .. Aggr_Dimension) of Node_Id;
4907 -- Low and High bounds of the constraint for each aggregate index
4908
4909 Aggr_Index_Typ : array (1 .. Aggr_Dimension) of Entity_Id;
4910 -- The type of each index
4911
4912 In_Place_Assign_OK_For_Declaration : Boolean := False;
4913 -- True if we are to generate an in place assignment for a declaration
4914
4915 Maybe_In_Place_OK : Boolean;
4916 -- If the type is neither controlled nor packed and the aggregate
4917 -- is the expression in an assignment, assignment in place may be
4918 -- possible, provided other conditions are met on the LHS.
4919
4920 Others_Present : array (1 .. Aggr_Dimension) of Boolean :=
4921 (others => False);
4922 -- If Others_Present (J) is True, then there is an others choice in one
4923 -- of the subaggregates of N at dimension J.
4924
4925 function Aggr_Assignment_OK_For_Backend (N : Node_Id) return Boolean;
4926 -- Returns true if an aggregate assignment can be done by the back end
4927
4928 procedure Build_Constrained_Type (Positional : Boolean);
4929 -- If the subtype is not static or unconstrained, build a constrained
4930 -- type using the computable sizes of the aggregate and its sub-
4931 -- aggregates.
4932
4933 procedure Check_Bounds (Aggr_Bounds : Node_Id; Index_Bounds : Node_Id);
4934 -- Checks that the bounds of Aggr_Bounds are within the bounds defined
4935 -- by Index_Bounds.
4936
4937 procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos);
4938 -- Checks that in a multidimensional array aggregate all subaggregates
4939 -- corresponding to the same dimension have the same bounds. Sub_Aggr is
4940 -- an array subaggregate. Dim is the dimension corresponding to the
4941 -- subaggregate.
4942
4943 procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos);
4944 -- Computes the values of array Others_Present. Sub_Aggr is the array
4945 -- subaggregate we start the computation from. Dim is the dimension
4946 -- corresponding to the subaggregate.
4947
4948 function In_Place_Assign_OK return Boolean;
4949 -- Simple predicate to determine whether an aggregate assignment can
4950 -- be done in place, because none of the new values can depend on the
4951 -- components of the target of the assignment.
4952
4953 procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos);
4954 -- Checks that if an others choice is present in any subaggregate, no
4955 -- aggregate index is outside the bounds of the index constraint.
4956 -- Sub_Aggr is an array subaggregate. Dim is the dimension corresponding
4957 -- to the subaggregate.
4958
4959 function Safe_Left_Hand_Side (N : Node_Id) return Boolean;
4960 -- In addition to Maybe_In_Place_OK, in order for an aggregate to be
4961 -- built directly into the target of the assignment it must be free
4962 -- of side effects.
4963
4964 ------------------------------------
4965 -- Aggr_Assignment_OK_For_Backend --
4966 ------------------------------------
4967
4968 -- Backend processing by Gigi/gcc is possible only if all the following
4969 -- conditions are met:
4970
4971 -- 1. N consists of a single OTHERS choice, possibly recursively
4972
4973 -- 2. The array type has no null ranges (the purpose of this is to
4974 -- avoid a bogus warning for an out-of-range value).
4975
4976 -- 3. The array type has no atomic components
4977
4978 -- 4. The component type is elementary
4979
4980 -- 5. The component size is a multiple of Storage_Unit
4981
4982 -- 6. The component size is Storage_Unit or the value is of the form
4983 -- M * (1 + A**1 + A**2 + .. A**(K-1)) where A = 2**(Storage_Unit)
4984 -- and M in 1 .. A-1. This can also be viewed as K occurrences of
4985 -- the 8-bit value M, concatenated together.
4986
4987 -- The ultimate goal is to generate a call to a fast memset routine
4988 -- specifically optimized for the target.
4989
4990 function Aggr_Assignment_OK_For_Backend (N : Node_Id) return Boolean is
4991 Csiz : Uint;
4992 Ctyp : Entity_Id;
4993 Expr : Node_Id;
4994 High : Node_Id;
4995 Index : Entity_Id;
4996 Low : Node_Id;
4997 Nunits : Int;
4998 Remainder : Uint;
4999 Value : Uint;
5000
5001 begin
5002 -- Recurse as far as possible to find the innermost component type
5003
5004 Ctyp := Etype (N);
5005 Expr := N;
5006 while Is_Array_Type (Ctyp) loop
5007 if Nkind (Expr) /= N_Aggregate
5008 or else not Is_Others_Aggregate (Expr)
5009 then
5010 return False;
5011 end if;
5012
5013 Index := First_Index (Ctyp);
5014 while Present (Index) loop
5015 Get_Index_Bounds (Index, Low, High);
5016
5017 if Is_Null_Range (Low, High) then
5018 return False;
5019 end if;
5020
5021 Next_Index (Index);
5022 end loop;
5023
5024 Expr := Expression (First (Component_Associations (Expr)));
5025
5026 for J in 1 .. Number_Dimensions (Ctyp) - 1 loop
5027 if Nkind (Expr) /= N_Aggregate
5028 or else not Is_Others_Aggregate (Expr)
5029 then
5030 return False;
5031 end if;
5032
5033 Expr := Expression (First (Component_Associations (Expr)));
5034 end loop;
5035
5036 if Has_Atomic_Components (Ctyp) then
5037 return False;
5038 end if;
5039
5040 Csiz := Component_Size (Ctyp);
5041 Ctyp := Component_Type (Ctyp);
5042
5043 if Is_Atomic_Or_VFA (Ctyp) then
5044 return False;
5045 end if;
5046 end loop;
5047
5048 -- An Iterated_Component_Association involves a loop (in most cases)
5049 -- and is never static.
5050
5051 if Nkind (Parent (Expr)) = N_Iterated_Component_Association then
5052 return False;
5053 end if;
5054
5055 -- Access types need to be dealt with specially
5056
5057 if Is_Access_Type (Ctyp) then
5058
5059 -- Component_Size is not set by Layout_Type if the component
5060 -- type is an access type ???
5061
5062 Csiz := Esize (Ctyp);
5063
5064 -- Fat pointers are rejected as they are not really elementary
5065 -- for the backend.
5066
5067 if Csiz /= System_Address_Size then
5068 return False;
5069 end if;
5070
5071 -- The supported expressions are NULL and constants, others are
5072 -- rejected upfront to avoid being analyzed below, which can be
5073 -- problematic for some of them, for example allocators.
5074
5075 if Nkind (Expr) /= N_Null and then not Is_Entity_Name (Expr) then
5076 return False;
5077 end if;
5078
5079 -- Scalar types are OK if their size is a multiple of Storage_Unit
5080
5081 elsif Is_Scalar_Type (Ctyp) then
5082 if Csiz mod System_Storage_Unit /= 0 then
5083 return False;
5084 end if;
5085
5086 -- Composite types are rejected
5087
5088 else
5089 return False;
5090 end if;
5091
5092 -- The expression needs to be analyzed if True is returned
5093
5094 Analyze_And_Resolve (Expr, Ctyp);
5095
5096 -- Strip away any conversions from the expression as they simply
5097 -- qualify the real expression.
5098
5099 while Nkind_In (Expr, N_Unchecked_Type_Conversion,
5100 N_Type_Conversion)
5101 loop
5102 Expr := Expression (Expr);
5103 end loop;
5104
5105 Nunits := UI_To_Int (Csiz) / System_Storage_Unit;
5106
5107 if Nunits = 1 then
5108 return True;
5109 end if;
5110
5111 if not Compile_Time_Known_Value (Expr) then
5112 return False;
5113 end if;
5114
5115 -- The only supported value for floating point is 0.0
5116
5117 if Is_Floating_Point_Type (Ctyp) then
5118 return Expr_Value_R (Expr) = Ureal_0;
5119 end if;
5120
5121 -- For other types, we can look into the value as an integer
5122
5123 Value := Expr_Value (Expr);
5124
5125 if Has_Biased_Representation (Ctyp) then
5126 Value := Value - Expr_Value (Type_Low_Bound (Ctyp));
5127 end if;
5128
5129 -- Values 0 and -1 immediately satisfy the last check
5130
5131 if Value = Uint_0 or else Value = Uint_Minus_1 then
5132 return True;
5133 end if;
5134
5135 -- We need to work with an unsigned value
5136
5137 if Value < 0 then
5138 Value := Value + 2**(System_Storage_Unit * Nunits);
5139 end if;
5140
5141 Remainder := Value rem 2**System_Storage_Unit;
5142
5143 for J in 1 .. Nunits - 1 loop
5144 Value := Value / 2**System_Storage_Unit;
5145
5146 if Value rem 2**System_Storage_Unit /= Remainder then
5147 return False;
5148 end if;
5149 end loop;
5150
5151 return True;
5152 end Aggr_Assignment_OK_For_Backend;
5153
5154 ----------------------------
5155 -- Build_Constrained_Type --
5156 ----------------------------
5157
5158 procedure Build_Constrained_Type (Positional : Boolean) is
5159 Loc : constant Source_Ptr := Sloc (N);
5160 Agg_Type : constant Entity_Id := Make_Temporary (Loc, 'A');
5161 Comp : Node_Id;
5162 Decl : Node_Id;
5163 Typ : constant Entity_Id := Etype (N);
5164 Indexes : constant List_Id := New_List;
5165 Num : Nat;
5166 Sub_Agg : Node_Id;
5167
5168 begin
5169 -- If the aggregate is purely positional, all its subaggregates
5170 -- have the same size. We collect the dimensions from the first
5171 -- subaggregate at each level.
5172
5173 if Positional then
5174 Sub_Agg := N;
5175
5176 for D in 1 .. Number_Dimensions (Typ) loop
5177 Sub_Agg := First (Expressions (Sub_Agg));
5178
5179 Comp := Sub_Agg;
5180 Num := 0;
5181 while Present (Comp) loop
5182 Num := Num + 1;
5183 Next (Comp);
5184 end loop;
5185
5186 Append_To (Indexes,
5187 Make_Range (Loc,
5188 Low_Bound => Make_Integer_Literal (Loc, 1),
5189 High_Bound => Make_Integer_Literal (Loc, Num)));
5190 end loop;
5191
5192 else
5193 -- We know the aggregate type is unconstrained and the aggregate
5194 -- is not processable by the back end, therefore not necessarily
5195 -- positional. Retrieve each dimension bounds (computed earlier).
5196
5197 for D in 1 .. Number_Dimensions (Typ) loop
5198 Append_To (Indexes,
5199 Make_Range (Loc,
5200 Low_Bound => Aggr_Low (D),
5201 High_Bound => Aggr_High (D)));
5202 end loop;
5203 end if;
5204
5205 Decl :=
5206 Make_Full_Type_Declaration (Loc,
5207 Defining_Identifier => Agg_Type,
5208 Type_Definition =>
5209 Make_Constrained_Array_Definition (Loc,
5210 Discrete_Subtype_Definitions => Indexes,
5211 Component_Definition =>
5212 Make_Component_Definition (Loc,
5213 Aliased_Present => False,
5214 Subtype_Indication =>
5215 New_Occurrence_Of (Component_Type (Typ), Loc))));
5216
5217 Insert_Action (N, Decl);
5218 Analyze (Decl);
5219 Set_Etype (N, Agg_Type);
5220 Set_Is_Itype (Agg_Type);
5221 Freeze_Itype (Agg_Type, N);
5222 end Build_Constrained_Type;
5223
5224 ------------------
5225 -- Check_Bounds --
5226 ------------------
5227
5228 procedure Check_Bounds (Aggr_Bounds : Node_Id; Index_Bounds : Node_Id) is
5229 Aggr_Lo : Node_Id;
5230 Aggr_Hi : Node_Id;
5231
5232 Ind_Lo : Node_Id;
5233 Ind_Hi : Node_Id;
5234
5235 Cond : Node_Id := Empty;
5236
5237 begin
5238 Get_Index_Bounds (Aggr_Bounds, Aggr_Lo, Aggr_Hi);
5239 Get_Index_Bounds (Index_Bounds, Ind_Lo, Ind_Hi);
5240
5241 -- Generate the following test:
5242
5243 -- [constraint_error when
5244 -- Aggr_Lo <= Aggr_Hi and then
5245 -- (Aggr_Lo < Ind_Lo or else Aggr_Hi > Ind_Hi)]
5246
5247 -- As an optimization try to see if some tests are trivially vacuous
5248 -- because we are comparing an expression against itself.
5249
5250 if Aggr_Lo = Ind_Lo and then Aggr_Hi = Ind_Hi then
5251 Cond := Empty;
5252
5253 elsif Aggr_Hi = Ind_Hi then
5254 Cond :=
5255 Make_Op_Lt (Loc,
5256 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
5257 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Lo));
5258
5259 elsif Aggr_Lo = Ind_Lo then
5260 Cond :=
5261 Make_Op_Gt (Loc,
5262 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi),
5263 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Hi));
5264
5265 else
5266 Cond :=
5267 Make_Or_Else (Loc,
5268 Left_Opnd =>
5269 Make_Op_Lt (Loc,
5270 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
5271 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Lo)),
5272
5273 Right_Opnd =>
5274 Make_Op_Gt (Loc,
5275 Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
5276 Right_Opnd => Duplicate_Subexpr (Ind_Hi)));
5277 end if;
5278
5279 if Present (Cond) then
5280 Cond :=
5281 Make_And_Then (Loc,
5282 Left_Opnd =>
5283 Make_Op_Le (Loc,
5284 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
5285 Right_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi)),
5286
5287 Right_Opnd => Cond);
5288
5289 Set_Analyzed (Left_Opnd (Left_Opnd (Cond)), False);
5290 Set_Analyzed (Right_Opnd (Left_Opnd (Cond)), False);
5291 Insert_Action (N,
5292 Make_Raise_Constraint_Error (Loc,
5293 Condition => Cond,
5294 Reason => CE_Range_Check_Failed));
5295 end if;
5296 end Check_Bounds;
5297
5298 ----------------------------
5299 -- Check_Same_Aggr_Bounds --
5300 ----------------------------
5301
5302 procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos) is
5303 Sub_Lo : constant Node_Id := Low_Bound (Aggregate_Bounds (Sub_Aggr));
5304 Sub_Hi : constant Node_Id := High_Bound (Aggregate_Bounds (Sub_Aggr));
5305 -- The bounds of this specific subaggregate
5306
5307 Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
5308 Aggr_Hi : constant Node_Id := Aggr_High (Dim);
5309 -- The bounds of the aggregate for this dimension
5310
5311 Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
5312 -- The index type for this dimension.xxx
5313
5314 Cond : Node_Id := Empty;
5315 Assoc : Node_Id;
5316 Expr : Node_Id;
5317
5318 begin
5319 -- If index checks are on generate the test
5320
5321 -- [constraint_error when
5322 -- Aggr_Lo /= Sub_Lo or else Aggr_Hi /= Sub_Hi]
5323
5324 -- As an optimization try to see if some tests are trivially vacuos
5325 -- because we are comparing an expression against itself. Also for
5326 -- the first dimension the test is trivially vacuous because there
5327 -- is just one aggregate for dimension 1.
5328
5329 if Index_Checks_Suppressed (Ind_Typ) then
5330 Cond := Empty;
5331
5332 elsif Dim = 1 or else (Aggr_Lo = Sub_Lo and then Aggr_Hi = Sub_Hi)
5333 then
5334 Cond := Empty;
5335
5336 elsif Aggr_Hi = Sub_Hi then
5337 Cond :=
5338 Make_Op_Ne (Loc,
5339 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
5340 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo));
5341
5342 elsif Aggr_Lo = Sub_Lo then
5343 Cond :=
5344 Make_Op_Ne (Loc,
5345 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi),
5346 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Hi));
5347
5348 else
5349 Cond :=
5350 Make_Or_Else (Loc,
5351 Left_Opnd =>
5352 Make_Op_Ne (Loc,
5353 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
5354 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo)),
5355
5356 Right_Opnd =>
5357 Make_Op_Ne (Loc,
5358 Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
5359 Right_Opnd => Duplicate_Subexpr (Sub_Hi)));
5360 end if;
5361
5362 if Present (Cond) then
5363 Insert_Action (N,
5364 Make_Raise_Constraint_Error (Loc,
5365 Condition => Cond,
5366 Reason => CE_Length_Check_Failed));
5367 end if;
5368
5369 -- Now look inside the subaggregate to see if there is more work
5370
5371 if Dim < Aggr_Dimension then
5372
5373 -- Process positional components
5374
5375 if Present (Expressions (Sub_Aggr)) then
5376 Expr := First (Expressions (Sub_Aggr));
5377 while Present (Expr) loop
5378 Check_Same_Aggr_Bounds (Expr, Dim + 1);
5379 Next (Expr);
5380 end loop;
5381 end if;
5382
5383 -- Process component associations
5384
5385 if Present (Component_Associations (Sub_Aggr)) then
5386 Assoc := First (Component_Associations (Sub_Aggr));
5387 while Present (Assoc) loop
5388 Expr := Expression (Assoc);
5389 Check_Same_Aggr_Bounds (Expr, Dim + 1);
5390 Next (Assoc);
5391 end loop;
5392 end if;
5393 end if;
5394 end Check_Same_Aggr_Bounds;
5395
5396 ----------------------------
5397 -- Compute_Others_Present --
5398 ----------------------------
5399
5400 procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos) is
5401 Assoc : Node_Id;
5402 Expr : Node_Id;
5403
5404 begin
5405 if Present (Component_Associations (Sub_Aggr)) then
5406 Assoc := Last (Component_Associations (Sub_Aggr));
5407
5408 if Nkind (First (Choice_List (Assoc))) = N_Others_Choice then
5409 Others_Present (Dim) := True;
5410 end if;
5411 end if;
5412
5413 -- Now look inside the subaggregate to see if there is more work
5414
5415 if Dim < Aggr_Dimension then
5416
5417 -- Process positional components
5418
5419 if Present (Expressions (Sub_Aggr)) then
5420 Expr := First (Expressions (Sub_Aggr));
5421 while Present (Expr) loop
5422 Compute_Others_Present (Expr, Dim + 1);
5423 Next (Expr);
5424 end loop;
5425 end if;
5426
5427 -- Process component associations
5428
5429 if Present (Component_Associations (Sub_Aggr)) then
5430 Assoc := First (Component_Associations (Sub_Aggr));
5431 while Present (Assoc) loop
5432 Expr := Expression (Assoc);
5433 Compute_Others_Present (Expr, Dim + 1);
5434 Next (Assoc);
5435 end loop;
5436 end if;
5437 end if;
5438 end Compute_Others_Present;
5439
5440 ------------------------
5441 -- In_Place_Assign_OK --
5442 ------------------------
5443
5444 function In_Place_Assign_OK return Boolean is
5445 Aggr_In : Node_Id;
5446 Aggr_Lo : Node_Id;
5447 Aggr_Hi : Node_Id;
5448 Obj_In : Node_Id;
5449 Obj_Lo : Node_Id;
5450 Obj_Hi : Node_Id;
5451
5452 function Safe_Aggregate (Aggr : Node_Id) return Boolean;
5453 -- Check recursively that each component of a (sub)aggregate does not
5454 -- depend on the variable being assigned to.
5455
5456 function Safe_Component (Expr : Node_Id) return Boolean;
5457 -- Verify that an expression cannot depend on the variable being
5458 -- assigned to. Room for improvement here (but less than before).
5459
5460 --------------------
5461 -- Safe_Aggregate --
5462 --------------------
5463
5464 function Safe_Aggregate (Aggr : Node_Id) return Boolean is
5465 Expr : Node_Id;
5466
5467 begin
5468 if Nkind (Parent (Aggr)) = N_Iterated_Component_Association then
5469 return False;
5470 end if;
5471
5472 if Present (Expressions (Aggr)) then
5473 Expr := First (Expressions (Aggr));
5474 while Present (Expr) loop
5475 if Nkind (Expr) = N_Aggregate then
5476 if not Safe_Aggregate (Expr) then
5477 return False;
5478 end if;
5479
5480 elsif not Safe_Component (Expr) then
5481 return False;
5482 end if;
5483
5484 Next (Expr);
5485 end loop;
5486 end if;
5487
5488 if Present (Component_Associations (Aggr)) then
5489 Expr := First (Component_Associations (Aggr));
5490 while Present (Expr) loop
5491 if Nkind (Expression (Expr)) = N_Aggregate then
5492 if not Safe_Aggregate (Expression (Expr)) then
5493 return False;
5494 end if;
5495
5496 -- If association has a box, no way to determine yet
5497 -- whether default can be assigned in place.
5498
5499 elsif Box_Present (Expr) then
5500 return False;
5501
5502 elsif not Safe_Component (Expression (Expr)) then
5503 return False;
5504 end if;
5505
5506 Next (Expr);
5507 end loop;
5508 end if;
5509
5510 return True;
5511 end Safe_Aggregate;
5512
5513 --------------------
5514 -- Safe_Component --
5515 --------------------
5516
5517 function Safe_Component (Expr : Node_Id) return Boolean is
5518 Comp : Node_Id := Expr;
5519
5520 function Check_Component (Comp : Node_Id) return Boolean;
5521 -- Do the recursive traversal, after copy
5522
5523 ---------------------
5524 -- Check_Component --
5525 ---------------------
5526
5527 function Check_Component (Comp : Node_Id) return Boolean is
5528 begin
5529 if Is_Overloaded (Comp) then
5530 return False;
5531 end if;
5532
5533 return Compile_Time_Known_Value (Comp)
5534
5535 or else (Is_Entity_Name (Comp)
5536 and then Present (Entity (Comp))
5537 and then No (Renamed_Object (Entity (Comp))))
5538
5539 or else (Nkind (Comp) = N_Attribute_Reference
5540 and then Check_Component (Prefix (Comp)))
5541
5542 or else (Nkind (Comp) in N_Binary_Op
5543 and then Check_Component (Left_Opnd (Comp))
5544 and then Check_Component (Right_Opnd (Comp)))
5545
5546 or else (Nkind (Comp) in N_Unary_Op
5547 and then Check_Component (Right_Opnd (Comp)))
5548
5549 or else (Nkind (Comp) = N_Selected_Component
5550 and then Check_Component (Prefix (Comp)))
5551
5552 or else (Nkind (Comp) = N_Unchecked_Type_Conversion
5553 and then Check_Component (Expression (Comp)));
5554 end Check_Component;
5555
5556 -- Start of processing for Safe_Component
5557
5558 begin
5559 -- If the component appears in an association that may correspond
5560 -- to more than one element, it is not analyzed before expansion
5561 -- into assignments, to avoid side effects. We analyze, but do not
5562 -- resolve the copy, to obtain sufficient entity information for
5563 -- the checks that follow. If component is overloaded we assume
5564 -- an unsafe function call.
5565
5566 if not Analyzed (Comp) then
5567 if Is_Overloaded (Expr) then
5568 return False;
5569
5570 elsif Nkind (Expr) = N_Aggregate
5571 and then not Is_Others_Aggregate (Expr)
5572 then
5573 return False;
5574
5575 elsif Nkind (Expr) = N_Allocator then
5576
5577 -- For now, too complex to analyze
5578
5579 return False;
5580
5581 elsif Nkind (Parent (Expr)) =
5582 N_Iterated_Component_Association
5583 then
5584 -- Ditto for iterated component associations, which in
5585 -- general require an enclosing loop and involve nonstatic
5586 -- expressions.
5587
5588 return False;
5589 end if;
5590
5591 Comp := New_Copy_Tree (Expr);
5592 Set_Parent (Comp, Parent (Expr));
5593 Analyze (Comp);
5594 end if;
5595
5596 if Nkind (Comp) = N_Aggregate then
5597 return Safe_Aggregate (Comp);
5598 else
5599 return Check_Component (Comp);
5600 end if;
5601 end Safe_Component;
5602
5603 -- Start of processing for In_Place_Assign_OK
5604
5605 begin
5606 if Present (Component_Associations (N)) then
5607
5608 -- On assignment, sliding can take place, so we cannot do the
5609 -- assignment in place unless the bounds of the aggregate are
5610 -- statically equal to those of the target.
5611
5612 -- If the aggregate is given by an others choice, the bounds are
5613 -- derived from the left-hand side, and the assignment is safe if
5614 -- the expression is.
5615
5616 if Is_Others_Aggregate (N) then
5617 return
5618 Safe_Component
5619 (Expression (First (Component_Associations (N))));
5620 end if;
5621
5622 Aggr_In := First_Index (Etype (N));
5623
5624 if Nkind (Parent (N)) = N_Assignment_Statement then
5625 Obj_In := First_Index (Etype (Name (Parent (N))));
5626
5627 else
5628 -- Context is an allocator. Check bounds of aggregate against
5629 -- given type in qualified expression.
5630
5631 pragma Assert (Nkind (Parent (Parent (N))) = N_Allocator);
5632 Obj_In :=
5633 First_Index (Etype (Entity (Subtype_Mark (Parent (N)))));
5634 end if;
5635
5636 while Present (Aggr_In) loop
5637 Get_Index_Bounds (Aggr_In, Aggr_Lo, Aggr_Hi);
5638 Get_Index_Bounds (Obj_In, Obj_Lo, Obj_Hi);
5639
5640 if not Compile_Time_Known_Value (Aggr_Lo)
5641 or else not Compile_Time_Known_Value (Obj_Lo)
5642 or else not Compile_Time_Known_Value (Obj_Hi)
5643 or else Expr_Value (Aggr_Lo) /= Expr_Value (Obj_Lo)
5644 then
5645 return False;
5646
5647 -- For an assignment statement we require static matching of
5648 -- bounds. Ditto for an allocator whose qualified expression
5649 -- is a constrained type. If the expression in the allocator
5650 -- is an unconstrained array, we accept an upper bound that
5651 -- is not static, to allow for nonstatic expressions of the
5652 -- base type. Clearly there are further possibilities (with
5653 -- diminishing returns) for safely building arrays in place
5654 -- here.
5655
5656 elsif Nkind (Parent (N)) = N_Assignment_Statement
5657 or else Is_Constrained (Etype (Parent (N)))
5658 then
5659 if not Compile_Time_Known_Value (Aggr_Hi)
5660 or else Expr_Value (Aggr_Hi) /= Expr_Value (Obj_Hi)
5661 then
5662 return False;
5663 end if;
5664 end if;
5665
5666 Next_Index (Aggr_In);
5667 Next_Index (Obj_In);
5668 end loop;
5669 end if;
5670
5671 -- Now check the component values themselves
5672
5673 return Safe_Aggregate (N);
5674 end In_Place_Assign_OK;
5675
5676 ------------------
5677 -- Others_Check --
5678 ------------------
5679
5680 procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos) is
5681 Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
5682 Aggr_Hi : constant Node_Id := Aggr_High (Dim);
5683 -- The bounds of the aggregate for this dimension
5684
5685 Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
5686 -- The index type for this dimension
5687
5688 Need_To_Check : Boolean := False;
5689
5690 Choices_Lo : Node_Id := Empty;
5691 Choices_Hi : Node_Id := Empty;
5692 -- The lowest and highest discrete choices for a named subaggregate
5693
5694 Nb_Choices : Int := -1;
5695 -- The number of discrete non-others choices in this subaggregate
5696
5697 Nb_Elements : Uint := Uint_0;
5698 -- The number of elements in a positional aggregate
5699
5700 Cond : Node_Id := Empty;
5701
5702 Assoc : Node_Id;
5703 Choice : Node_Id;
5704 Expr : Node_Id;
5705
5706 begin
5707 -- Check if we have an others choice. If we do make sure that this
5708 -- subaggregate contains at least one element in addition to the
5709 -- others choice.
5710
5711 if Range_Checks_Suppressed (Ind_Typ) then
5712 Need_To_Check := False;
5713
5714 elsif Present (Expressions (Sub_Aggr))
5715 and then Present (Component_Associations (Sub_Aggr))
5716 then
5717 Need_To_Check := True;
5718
5719 elsif Present (Component_Associations (Sub_Aggr)) then
5720 Assoc := Last (Component_Associations (Sub_Aggr));
5721
5722 if Nkind (First (Choice_List (Assoc))) /= N_Others_Choice then
5723 Need_To_Check := False;
5724
5725 else
5726 -- Count the number of discrete choices. Start with -1 because
5727 -- the others choice does not count.
5728
5729 -- Is there some reason we do not use List_Length here ???
5730
5731 Nb_Choices := -1;
5732 Assoc := First (Component_Associations (Sub_Aggr));
5733 while Present (Assoc) loop
5734 Choice := First (Choice_List (Assoc));
5735 while Present (Choice) loop
5736 Nb_Choices := Nb_Choices + 1;
5737 Next (Choice);
5738 end loop;
5739
5740 Next (Assoc);
5741 end loop;
5742
5743 -- If there is only an others choice nothing to do
5744
5745 Need_To_Check := (Nb_Choices > 0);
5746 end if;
5747
5748 else
5749 Need_To_Check := False;
5750 end if;
5751
5752 -- If we are dealing with a positional subaggregate with an others
5753 -- choice then compute the number or positional elements.
5754
5755 if Need_To_Check and then Present (Expressions (Sub_Aggr)) then
5756 Expr := First (Expressions (Sub_Aggr));
5757 Nb_Elements := Uint_0;
5758 while Present (Expr) loop
5759 Nb_Elements := Nb_Elements + 1;
5760 Next (Expr);
5761 end loop;
5762
5763 -- If the aggregate contains discrete choices and an others choice
5764 -- compute the smallest and largest discrete choice values.
5765
5766 elsif Need_To_Check then
5767 Compute_Choices_Lo_And_Choices_Hi : declare
5768
5769 Table : Case_Table_Type (1 .. Nb_Choices);
5770 -- Used to sort all the different choice values
5771
5772 J : Pos := 1;
5773 Low : Node_Id;
5774 High : Node_Id;
5775
5776 begin
5777 Assoc := First (Component_Associations (Sub_Aggr));
5778 while Present (Assoc) loop
5779 Choice := First (Choice_List (Assoc));
5780 while Present (Choice) loop
5781 if Nkind (Choice) = N_Others_Choice then
5782 exit;
5783 end if;
5784
5785 Get_Index_Bounds (Choice, Low, High);
5786 Table (J).Choice_Lo := Low;
5787 Table (J).Choice_Hi := High;
5788
5789 J := J + 1;
5790 Next (Choice);
5791 end loop;
5792
5793 Next (Assoc);
5794 end loop;
5795
5796 -- Sort the discrete choices
5797
5798 Sort_Case_Table (Table);
5799
5800 Choices_Lo := Table (1).Choice_Lo;
5801 Choices_Hi := Table (Nb_Choices).Choice_Hi;
5802 end Compute_Choices_Lo_And_Choices_Hi;
5803 end if;
5804
5805 -- If no others choice in this subaggregate, or the aggregate
5806 -- comprises only an others choice, nothing to do.
5807
5808 if not Need_To_Check then
5809 Cond := Empty;
5810
5811 -- If we are dealing with an aggregate containing an others choice
5812 -- and positional components, we generate the following test:
5813
5814 -- if Ind_Typ'Pos (Aggr_Lo) + (Nb_Elements - 1) >
5815 -- Ind_Typ'Pos (Aggr_Hi)
5816 -- then
5817 -- raise Constraint_Error;
5818 -- end if;
5819
5820 elsif Nb_Elements > Uint_0 then
5821 Cond :=
5822 Make_Op_Gt (Loc,
5823 Left_Opnd =>
5824 Make_Op_Add (Loc,
5825 Left_Opnd =>
5826 Make_Attribute_Reference (Loc,
5827 Prefix => New_Occurrence_Of (Ind_Typ, Loc),
5828 Attribute_Name => Name_Pos,
5829 Expressions =>
5830 New_List
5831 (Duplicate_Subexpr_Move_Checks (Aggr_Lo))),
5832 Right_Opnd => Make_Integer_Literal (Loc, Nb_Elements - 1)),
5833
5834 Right_Opnd =>
5835 Make_Attribute_Reference (Loc,
5836 Prefix => New_Occurrence_Of (Ind_Typ, Loc),
5837 Attribute_Name => Name_Pos,
5838 Expressions => New_List (
5839 Duplicate_Subexpr_Move_Checks (Aggr_Hi))));
5840
5841 -- If we are dealing with an aggregate containing an others choice
5842 -- and discrete choices we generate the following test:
5843
5844 -- [constraint_error when
5845 -- Choices_Lo < Aggr_Lo or else Choices_Hi > Aggr_Hi];
5846
5847 else
5848 Cond :=
5849 Make_Or_Else (Loc,
5850 Left_Opnd =>
5851 Make_Op_Lt (Loc,
5852 Left_Opnd => Duplicate_Subexpr_Move_Checks (Choices_Lo),
5853 Right_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo)),
5854
5855 Right_Opnd =>
5856 Make_Op_Gt (Loc,
5857 Left_Opnd => Duplicate_Subexpr (Choices_Hi),
5858 Right_Opnd => Duplicate_Subexpr (Aggr_Hi)));
5859 end if;
5860
5861 if Present (Cond) then
5862 Insert_Action (N,
5863 Make_Raise_Constraint_Error (Loc,
5864 Condition => Cond,
5865 Reason => CE_Length_Check_Failed));
5866 -- Questionable reason code, shouldn't that be a
5867 -- CE_Range_Check_Failed ???
5868 end if;
5869
5870 -- Now look inside the subaggregate to see if there is more work
5871
5872 if Dim < Aggr_Dimension then
5873
5874 -- Process positional components
5875
5876 if Present (Expressions (Sub_Aggr)) then
5877 Expr := First (Expressions (Sub_Aggr));
5878 while Present (Expr) loop
5879 Others_Check (Expr, Dim + 1);
5880 Next (Expr);
5881 end loop;
5882 end if;
5883
5884 -- Process component associations
5885
5886 if Present (Component_Associations (Sub_Aggr)) then
5887 Assoc := First (Component_Associations (Sub_Aggr));
5888 while Present (Assoc) loop
5889 Expr := Expression (Assoc);
5890 Others_Check (Expr, Dim + 1);
5891 Next (Assoc);
5892 end loop;
5893 end if;
5894 end if;
5895 end Others_Check;
5896
5897 -------------------------
5898 -- Safe_Left_Hand_Side --
5899 -------------------------
5900
5901 function Safe_Left_Hand_Side (N : Node_Id) return Boolean is
5902 function Is_Safe_Index (Indx : Node_Id) return Boolean;
5903 -- If the left-hand side includes an indexed component, check that
5904 -- the indexes are free of side effects.
5905
5906 -------------------
5907 -- Is_Safe_Index --
5908 -------------------
5909
5910 function Is_Safe_Index (Indx : Node_Id) return Boolean is
5911 begin
5912 if Is_Entity_Name (Indx) then
5913 return True;
5914
5915 elsif Nkind (Indx) = N_Integer_Literal then
5916 return True;
5917
5918 elsif Nkind (Indx) = N_Function_Call
5919 and then Is_Entity_Name (Name (Indx))
5920 and then Has_Pragma_Pure_Function (Entity (Name (Indx)))
5921 then
5922 return True;
5923
5924 elsif Nkind (Indx) = N_Type_Conversion
5925 and then Is_Safe_Index (Expression (Indx))
5926 then
5927 return True;
5928
5929 else
5930 return False;
5931 end if;
5932 end Is_Safe_Index;
5933
5934 -- Start of processing for Safe_Left_Hand_Side
5935
5936 begin
5937 if Is_Entity_Name (N) then
5938 return True;
5939
5940 elsif Nkind_In (N, N_Explicit_Dereference, N_Selected_Component)
5941 and then Safe_Left_Hand_Side (Prefix (N))
5942 then
5943 return True;
5944
5945 elsif Nkind (N) = N_Indexed_Component
5946 and then Safe_Left_Hand_Side (Prefix (N))
5947 and then Is_Safe_Index (First (Expressions (N)))
5948 then
5949 return True;
5950
5951 elsif Nkind (N) = N_Unchecked_Type_Conversion then
5952 return Safe_Left_Hand_Side (Expression (N));
5953
5954 else
5955 return False;
5956 end if;
5957 end Safe_Left_Hand_Side;
5958
5959 -- Local variables
5960
5961 Tmp : Entity_Id;
5962 -- Holds the temporary aggregate value
5963
5964 Tmp_Decl : Node_Id;
5965 -- Holds the declaration of Tmp
5966
5967 Aggr_Code : List_Id;
5968 Parent_Node : Node_Id;
5969 Parent_Kind : Node_Kind;
5970
5971 -- Start of processing for Expand_Array_Aggregate
5972
5973 begin
5974 -- Do not touch the special aggregates of attributes used for Asm calls
5975
5976 if Is_RTE (Ctyp, RE_Asm_Input_Operand)
5977 or else Is_RTE (Ctyp, RE_Asm_Output_Operand)
5978 then
5979 return;
5980
5981 -- Do not expand an aggregate for an array type which contains tasks if
5982 -- the aggregate is associated with an unexpanded return statement of a
5983 -- build-in-place function. The aggregate is expanded when the related
5984 -- return statement (rewritten into an extended return) is processed.
5985 -- This delay ensures that any temporaries and initialization code
5986 -- generated for the aggregate appear in the proper return block and
5987 -- use the correct _chain and _master.
5988
5989 elsif Has_Task (Base_Type (Etype (N)))
5990 and then Nkind (Parent (N)) = N_Simple_Return_Statement
5991 and then Is_Build_In_Place_Function
5992 (Return_Applies_To (Return_Statement_Entity (Parent (N))))
5993 then
5994 return;
5995
5996 -- Do not attempt expansion if error already detected. We may reach this
5997 -- point in spite of previous errors when compiling with -gnatq, to
5998 -- force all possible errors (this is the usual ACATS mode).
5999
6000 elsif Error_Posted (N) then
6001 return;
6002 end if;
6003
6004 -- If the semantic analyzer has determined that aggregate N will raise
6005 -- Constraint_Error at run time, then the aggregate node has been
6006 -- replaced with an N_Raise_Constraint_Error node and we should
6007 -- never get here.
6008
6009 pragma Assert (not Raises_Constraint_Error (N));
6010
6011 -- STEP 1a
6012
6013 -- Check that the index range defined by aggregate bounds is
6014 -- compatible with corresponding index subtype.
6015
6016 Index_Compatibility_Check : declare
6017 Aggr_Index_Range : Node_Id := First_Index (Typ);
6018 -- The current aggregate index range
6019
6020 Index_Constraint : Node_Id := First_Index (Etype (Typ));
6021 -- The corresponding index constraint against which we have to
6022 -- check the above aggregate index range.
6023
6024 begin
6025 Compute_Others_Present (N, 1);
6026
6027 for J in 1 .. Aggr_Dimension loop
6028 -- There is no need to emit a check if an others choice is present
6029 -- for this array aggregate dimension since in this case one of
6030 -- N's subaggregates has taken its bounds from the context and
6031 -- these bounds must have been checked already. In addition all
6032 -- subaggregates corresponding to the same dimension must all have
6033 -- the same bounds (checked in (c) below).
6034
6035 if not Range_Checks_Suppressed (Etype (Index_Constraint))
6036 and then not Others_Present (J)
6037 then
6038 -- We don't use Checks.Apply_Range_Check here because it emits
6039 -- a spurious check. Namely it checks that the range defined by
6040 -- the aggregate bounds is nonempty. But we know this already
6041 -- if we get here.
6042
6043 Check_Bounds (Aggr_Index_Range, Index_Constraint);
6044 end if;
6045
6046 -- Save the low and high bounds of the aggregate index as well as
6047 -- the index type for later use in checks (b) and (c) below.
6048
6049 Aggr_Low (J) := Low_Bound (Aggr_Index_Range);
6050 Aggr_High (J) := High_Bound (Aggr_Index_Range);
6051
6052 Aggr_Index_Typ (J) := Etype (Index_Constraint);
6053
6054 Next_Index (Aggr_Index_Range);
6055 Next_Index (Index_Constraint);
6056 end loop;
6057 end Index_Compatibility_Check;
6058
6059 -- STEP 1b
6060
6061 -- If an others choice is present check that no aggregate index is
6062 -- outside the bounds of the index constraint.
6063
6064 Others_Check (N, 1);
6065
6066 -- STEP 1c
6067
6068 -- For multidimensional arrays make sure that all subaggregates
6069 -- corresponding to the same dimension have the same bounds.
6070
6071 if Aggr_Dimension > 1 then
6072 Check_Same_Aggr_Bounds (N, 1);
6073 end if;
6074
6075 -- STEP 1d
6076
6077 -- If we have a default component value, or simple initialization is
6078 -- required for the component type, then we replace <> in component
6079 -- associations by the required default value.
6080
6081 declare
6082 Default_Val : Node_Id;
6083 Assoc : Node_Id;
6084
6085 begin
6086 if (Present (Default_Aspect_Component_Value (Typ))
6087 or else Needs_Simple_Initialization (Ctyp))
6088 and then Present (Component_Associations (N))
6089 then
6090 Assoc := First (Component_Associations (N));
6091 while Present (Assoc) loop
6092 if Nkind (Assoc) = N_Component_Association
6093 and then Box_Present (Assoc)
6094 then
6095 Set_Box_Present (Assoc, False);
6096
6097 if Present (Default_Aspect_Component_Value (Typ)) then
6098 Default_Val := Default_Aspect_Component_Value (Typ);
6099 else
6100 Default_Val := Get_Simple_Init_Val (Ctyp, N);
6101 end if;
6102
6103 Set_Expression (Assoc, New_Copy_Tree (Default_Val));
6104 Analyze_And_Resolve (Expression (Assoc), Ctyp);
6105 end if;
6106
6107 Next (Assoc);
6108 end loop;
6109 end if;
6110 end;
6111
6112 -- STEP 2
6113
6114 -- Here we test for is packed array aggregate that we can handle at
6115 -- compile time. If so, return with transformation done. Note that we do
6116 -- this even if the aggregate is nested, because once we have done this
6117 -- processing, there is no more nested aggregate.
6118
6119 if Packed_Array_Aggregate_Handled (N) then
6120 return;
6121 end if;
6122
6123 -- At this point we try to convert to positional form
6124
6125 if Ekind (Current_Scope) = E_Package
6126 and then Static_Elaboration_Desired (Current_Scope)
6127 then
6128 Convert_To_Positional (N, Max_Others_Replicate => 100);
6129 else
6130 Convert_To_Positional (N);
6131 end if;
6132
6133 -- if the result is no longer an aggregate (e.g. it may be a string
6134 -- literal, or a temporary which has the needed value), then we are
6135 -- done, since there is no longer a nested aggregate.
6136
6137 if Nkind (N) /= N_Aggregate then
6138 return;
6139
6140 -- We are also done if the result is an analyzed aggregate, indicating
6141 -- that Convert_To_Positional succeeded and reanalyzed the rewritten
6142 -- aggregate.
6143
6144 elsif Analyzed (N) and then Is_Rewrite_Substitution (N) then
6145 return;
6146 end if;
6147
6148 -- If all aggregate components are compile-time known and the aggregate
6149 -- has been flattened, nothing left to do. The same occurs if the
6150 -- aggregate is used to initialize the components of a statically
6151 -- allocated dispatch table.
6152
6153 if Compile_Time_Known_Aggregate (N)
6154 or else Is_Static_Dispatch_Table_Aggregate (N)
6155 then
6156 Set_Expansion_Delayed (N, False);
6157 return;
6158 end if;
6159
6160 -- Now see if back end processing is possible
6161
6162 if Backend_Processing_Possible (N) then
6163
6164 -- If the aggregate is static but the constraints are not, build
6165 -- a static subtype for the aggregate, so that Gigi can place it
6166 -- in static memory. Perform an unchecked_conversion to the non-
6167 -- static type imposed by the context.
6168
6169 declare
6170 Itype : constant Entity_Id := Etype (N);
6171 Index : Node_Id;
6172 Needs_Type : Boolean := False;
6173
6174 begin
6175 Index := First_Index (Itype);
6176 while Present (Index) loop
6177 if not Is_OK_Static_Subtype (Etype (Index)) then
6178 Needs_Type := True;
6179 exit;
6180 else
6181 Next_Index (Index);
6182 end if;
6183 end loop;
6184
6185 if Needs_Type then
6186 Build_Constrained_Type (Positional => True);
6187 Rewrite (N, Unchecked_Convert_To (Itype, N));
6188 Analyze (N);
6189 end if;
6190 end;
6191
6192 return;
6193 end if;
6194
6195 -- STEP 3
6196
6197 -- Delay expansion for nested aggregates: it will be taken care of when
6198 -- the parent aggregate is expanded.
6199
6200 Parent_Node := Parent (N);
6201 Parent_Kind := Nkind (Parent_Node);
6202
6203 if Parent_Kind = N_Qualified_Expression then
6204 Parent_Node := Parent (Parent_Node);
6205 Parent_Kind := Nkind (Parent_Node);
6206 end if;
6207
6208 if Parent_Kind = N_Aggregate
6209 or else Parent_Kind = N_Extension_Aggregate
6210 or else Parent_Kind = N_Component_Association
6211 or else (Parent_Kind = N_Object_Declaration
6212 and then Needs_Finalization (Typ))
6213 or else (Parent_Kind = N_Assignment_Statement
6214 and then Inside_Init_Proc)
6215 then
6216 Set_Expansion_Delayed (N, not Static_Array_Aggregate (N));
6217 return;
6218 end if;
6219
6220 -- STEP 4
6221
6222 -- Look if in place aggregate expansion is possible
6223
6224 -- For object declarations we build the aggregate in place, unless
6225 -- the array is bit-packed.
6226
6227 -- For assignments we do the assignment in place if all the component
6228 -- associations have compile-time known values, or are default-
6229 -- initialized limited components, e.g. tasks. For other cases we
6230 -- create a temporary. The analysis for safety of on-line assignment
6231 -- is delicate, i.e. we don't know how to do it fully yet ???
6232
6233 -- For allocators we assign to the designated object in place if the
6234 -- aggregate meets the same conditions as other in-place assignments.
6235 -- In this case the aggregate may not come from source but was created
6236 -- for default initialization, e.g. with Initialize_Scalars.
6237
6238 if Requires_Transient_Scope (Typ) then
6239 Establish_Transient_Scope (N, Manage_Sec_Stack => False);
6240 end if;
6241
6242 -- An array of limited components is built in place
6243
6244 if Is_Limited_Type (Typ) then
6245 Maybe_In_Place_OK := True;
6246
6247 elsif Has_Default_Init_Comps (N) then
6248 Maybe_In_Place_OK := False;
6249
6250 elsif Is_Bit_Packed_Array (Typ)
6251 or else Has_Controlled_Component (Typ)
6252 then
6253 Maybe_In_Place_OK := False;
6254
6255 else
6256 Maybe_In_Place_OK :=
6257 (Nkind (Parent (N)) = N_Assignment_Statement
6258 and then In_Place_Assign_OK)
6259
6260 or else
6261 (Nkind (Parent (Parent (N))) = N_Allocator
6262 and then In_Place_Assign_OK);
6263 end if;
6264
6265 -- If this is an array of tasks, it will be expanded into build-in-place
6266 -- assignments. Build an activation chain for the tasks now.
6267
6268 if Has_Task (Etype (N)) then
6269 Build_Activation_Chain_Entity (N);
6270 end if;
6271
6272 -- Perform in-place expansion of aggregate in an object declaration.
6273 -- Note: actions generated for the aggregate will be captured in an
6274 -- expression-with-actions statement so that they can be transferred
6275 -- to freeze actions later if there is an address clause for the
6276 -- object. (Note: we don't use a block statement because this would
6277 -- cause generated freeze nodes to be elaborated in the wrong scope).
6278
6279 -- Do not perform in-place expansion for SPARK 05 because aggregates are
6280 -- expected to appear in qualified form. In-place expansion eliminates
6281 -- the qualification and eventually violates this SPARK 05 restiction.
6282
6283 -- Arrays of limited components must be built in place. The code
6284 -- previously excluded controlled components but this is an old
6285 -- oversight: the rules in 7.6 (17) are clear.
6286
6287 if (not Has_Default_Init_Comps (N)
6288 or else Is_Limited_Type (Etype (N)))
6289 and then Comes_From_Source (Parent_Node)
6290 and then Parent_Kind = N_Object_Declaration
6291 and then Present (Expression (Parent_Node))
6292 and then not
6293 Must_Slide (Etype (Defining_Identifier (Parent_Node)), Typ)
6294 and then not Is_Bit_Packed_Array (Typ)
6295 and then not Restriction_Check_Required (SPARK_05)
6296 then
6297 In_Place_Assign_OK_For_Declaration := True;
6298 Tmp := Defining_Identifier (Parent_Node);
6299 Set_No_Initialization (Parent_Node);
6300 Set_Expression (Parent_Node, Empty);
6301
6302 -- Set kind and type of the entity, for use in the analysis
6303 -- of the subsequent assignments. If the nominal type is not
6304 -- constrained, build a subtype from the known bounds of the
6305 -- aggregate. If the declaration has a subtype mark, use it,
6306 -- otherwise use the itype of the aggregate.
6307
6308 Set_Ekind (Tmp, E_Variable);
6309
6310 if not Is_Constrained (Typ) then
6311 Build_Constrained_Type (Positional => False);
6312
6313 elsif Is_Entity_Name (Object_Definition (Parent_Node))
6314 and then Is_Constrained (Entity (Object_Definition (Parent_Node)))
6315 then
6316 Set_Etype (Tmp, Entity (Object_Definition (Parent_Node)));
6317
6318 else
6319 Set_Size_Known_At_Compile_Time (Typ, False);
6320 Set_Etype (Tmp, Typ);
6321 end if;
6322
6323 elsif Maybe_In_Place_OK
6324 and then Nkind (Parent (N)) = N_Qualified_Expression
6325 and then Nkind (Parent (Parent (N))) = N_Allocator
6326 then
6327 Set_Expansion_Delayed (N);
6328 return;
6329
6330 -- Limited arrays in return statements are expanded when
6331 -- enclosing construct is expanded.
6332
6333 elsif Maybe_In_Place_OK
6334 and then Nkind (Parent (N)) = N_Simple_Return_Statement
6335 then
6336 Set_Expansion_Delayed (N);
6337 return;
6338
6339 -- In the remaining cases the aggregate is the RHS of an assignment
6340
6341 elsif Maybe_In_Place_OK
6342 and then Safe_Left_Hand_Side (Name (Parent (N)))
6343 then
6344 Tmp := Name (Parent (N));
6345
6346 if Etype (Tmp) /= Etype (N) then
6347 Apply_Length_Check (N, Etype (Tmp));
6348
6349 if Nkind (N) = N_Raise_Constraint_Error then
6350
6351 -- Static error, nothing further to expand
6352
6353 return;
6354 end if;
6355 end if;
6356
6357 -- If a slice assignment has an aggregate with a single others_choice,
6358 -- the assignment can be done in place even if bounds are not static,
6359 -- by converting it into a loop over the discrete range of the slice.
6360
6361 elsif Maybe_In_Place_OK
6362 and then Nkind (Name (Parent (N))) = N_Slice
6363 and then Is_Others_Aggregate (N)
6364 then
6365 Tmp := Name (Parent (N));
6366
6367 -- Set type of aggregate to be type of lhs in assignment, in order
6368 -- to suppress redundant length checks.
6369
6370 Set_Etype (N, Etype (Tmp));
6371
6372 -- Step 5
6373
6374 -- In place aggregate expansion is not possible
6375
6376 else
6377 Maybe_In_Place_OK := False;
6378 Tmp := Make_Temporary (Loc, 'A', N);
6379 Tmp_Decl :=
6380 Make_Object_Declaration (Loc,
6381 Defining_Identifier => Tmp,
6382 Object_Definition => New_Occurrence_Of (Typ, Loc));
6383 Set_No_Initialization (Tmp_Decl, True);
6384 Set_Warnings_Off (Tmp);
6385
6386 -- If we are within a loop, the temporary will be pushed on the
6387 -- stack at each iteration. If the aggregate is the expression
6388 -- for an allocator, it will be immediately copied to the heap
6389 -- and can be reclaimed at once. We create a transient scope
6390 -- around the aggregate for this purpose.
6391
6392 if Ekind (Current_Scope) = E_Loop
6393 and then Nkind (Parent (Parent (N))) = N_Allocator
6394 then
6395 Establish_Transient_Scope (N, Manage_Sec_Stack => False);
6396 end if;
6397
6398 Insert_Action (N, Tmp_Decl);
6399 end if;
6400
6401 -- Construct and insert the aggregate code. We can safely suppress index
6402 -- checks because this code is guaranteed not to raise CE on index
6403 -- checks. However we should *not* suppress all checks.
6404
6405 declare
6406 Target : Node_Id;
6407
6408 begin
6409 if Nkind (Tmp) = N_Defining_Identifier then
6410 Target := New_Occurrence_Of (Tmp, Loc);
6411
6412 else
6413 if Has_Default_Init_Comps (N)
6414 and then not Maybe_In_Place_OK
6415 then
6416 -- Ada 2005 (AI-287): This case has not been analyzed???
6417
6418 raise Program_Error;
6419 end if;
6420
6421 -- Name in assignment is explicit dereference
6422
6423 Target := New_Copy (Tmp);
6424 end if;
6425
6426 -- If we are to generate an in place assignment for a declaration or
6427 -- an assignment statement, and the assignment can be done directly
6428 -- by the back end, then do not expand further.
6429
6430 -- ??? We can also do that if in place expansion is not possible but
6431 -- then we could go into an infinite recursion.
6432
6433 if (In_Place_Assign_OK_For_Declaration or else Maybe_In_Place_OK)
6434 and then not CodePeer_Mode
6435 and then not Modify_Tree_For_C
6436 and then not Possible_Bit_Aligned_Component (Target)
6437 and then not Is_Possibly_Unaligned_Slice (Target)
6438 and then Aggr_Assignment_OK_For_Backend (N)
6439 then
6440 if Maybe_In_Place_OK then
6441 return;
6442 end if;
6443
6444 Aggr_Code :=
6445 New_List (
6446 Make_Assignment_Statement (Loc,
6447 Name => Target,
6448 Expression => New_Copy_Tree (N)));
6449
6450 else
6451 Aggr_Code :=
6452 Build_Array_Aggr_Code (N,
6453 Ctype => Ctyp,
6454 Index => First_Index (Typ),
6455 Into => Target,
6456 Scalar_Comp => Is_Scalar_Type (Ctyp));
6457 end if;
6458
6459 -- Save the last assignment statement associated with the aggregate
6460 -- when building a controlled object. This reference is utilized by
6461 -- the finalization machinery when marking an object as successfully
6462 -- initialized.
6463
6464 if Needs_Finalization (Typ)
6465 and then Is_Entity_Name (Target)
6466 and then Present (Entity (Target))
6467 and then Ekind_In (Entity (Target), E_Constant, E_Variable)
6468 then
6469 Set_Last_Aggregate_Assignment (Entity (Target), Last (Aggr_Code));
6470 end if;
6471 end;
6472
6473 -- If the aggregate is the expression in a declaration, the expanded
6474 -- code must be inserted after it. The defining entity might not come
6475 -- from source if this is part of an inlined body, but the declaration
6476 -- itself will.
6477
6478 if Comes_From_Source (Tmp)
6479 or else
6480 (Nkind (Parent (N)) = N_Object_Declaration
6481 and then Comes_From_Source (Parent (N))
6482 and then Tmp = Defining_Entity (Parent (N)))
6483 then
6484 declare
6485 Node_After : constant Node_Id := Next (Parent_Node);
6486
6487 begin
6488 Insert_Actions_After (Parent_Node, Aggr_Code);
6489
6490 if Parent_Kind = N_Object_Declaration then
6491 Collect_Initialization_Statements
6492 (Obj => Tmp, N => Parent_Node, Node_After => Node_After);
6493 end if;
6494 end;
6495
6496 else
6497 Insert_Actions (N, Aggr_Code);
6498 end if;
6499
6500 -- If the aggregate has been assigned in place, remove the original
6501 -- assignment.
6502
6503 if Nkind (Parent (N)) = N_Assignment_Statement
6504 and then Maybe_In_Place_OK
6505 then
6506 Rewrite (Parent (N), Make_Null_Statement (Loc));
6507
6508 elsif Nkind (Parent (N)) /= N_Object_Declaration
6509 or else Tmp /= Defining_Identifier (Parent (N))
6510 then
6511 Rewrite (N, New_Occurrence_Of (Tmp, Loc));
6512 Analyze_And_Resolve (N, Typ);
6513 end if;
6514 end Expand_Array_Aggregate;
6515
6516 ------------------------
6517 -- Expand_N_Aggregate --
6518 ------------------------
6519
6520 procedure Expand_N_Aggregate (N : Node_Id) is
6521 begin
6522 -- Record aggregate case
6523
6524 if Is_Record_Type (Etype (N)) then
6525 Expand_Record_Aggregate (N);
6526
6527 -- Array aggregate case
6528
6529 else
6530 -- A special case, if we have a string subtype with bounds 1 .. N,
6531 -- where N is known at compile time, and the aggregate is of the
6532 -- form (others => 'x'), with a single choice and no expressions,
6533 -- and N is less than 80 (an arbitrary limit for now), then replace
6534 -- the aggregate by the equivalent string literal (but do not mark
6535 -- it as static since it is not).
6536
6537 -- Note: this entire circuit is redundant with respect to code in
6538 -- Expand_Array_Aggregate that collapses others choices to positional
6539 -- form, but there are two problems with that circuit:
6540
6541 -- a) It is limited to very small cases due to ill-understood
6542 -- interactions with bootstrapping. That limit is removed by
6543 -- use of the No_Implicit_Loops restriction.
6544
6545 -- b) It incorrectly ends up with the resulting expressions being
6546 -- considered static when they are not. For example, the
6547 -- following test should fail:
6548
6549 -- pragma Restrictions (No_Implicit_Loops);
6550 -- package NonSOthers4 is
6551 -- B : constant String (1 .. 6) := (others => 'A');
6552 -- DH : constant String (1 .. 8) := B & "BB";
6553 -- X : Integer;
6554 -- pragma Export (C, X, Link_Name => DH);
6555 -- end;
6556
6557 -- But it succeeds (DH looks static to pragma Export)
6558
6559 -- To be sorted out ???
6560
6561 if Present (Component_Associations (N)) then
6562 declare
6563 CA : constant Node_Id := First (Component_Associations (N));
6564 MX : constant := 80;
6565
6566 begin
6567 if Nkind (First (Choice_List (CA))) = N_Others_Choice
6568 and then Nkind (Expression (CA)) = N_Character_Literal
6569 and then No (Expressions (N))
6570 then
6571 declare
6572 T : constant Entity_Id := Etype (N);
6573 X : constant Node_Id := First_Index (T);
6574 EC : constant Node_Id := Expression (CA);
6575 CV : constant Uint := Char_Literal_Value (EC);
6576 CC : constant Int := UI_To_Int (CV);
6577
6578 begin
6579 if Nkind (X) = N_Range
6580 and then Compile_Time_Known_Value (Low_Bound (X))
6581 and then Expr_Value (Low_Bound (X)) = 1
6582 and then Compile_Time_Known_Value (High_Bound (X))
6583 then
6584 declare
6585 Hi : constant Uint := Expr_Value (High_Bound (X));
6586
6587 begin
6588 if Hi <= MX then
6589 Start_String;
6590
6591 for J in 1 .. UI_To_Int (Hi) loop
6592 Store_String_Char (Char_Code (CC));
6593 end loop;
6594
6595 Rewrite (N,
6596 Make_String_Literal (Sloc (N),
6597 Strval => End_String));
6598
6599 if CC >= Int (2 ** 16) then
6600 Set_Has_Wide_Wide_Character (N);
6601 elsif CC >= Int (2 ** 8) then
6602 Set_Has_Wide_Character (N);
6603 end if;
6604
6605 Analyze_And_Resolve (N, T);
6606 Set_Is_Static_Expression (N, False);
6607 return;
6608 end if;
6609 end;
6610 end if;
6611 end;
6612 end if;
6613 end;
6614 end if;
6615
6616 -- Not that special case, so normal expansion of array aggregate
6617
6618 Expand_Array_Aggregate (N);
6619 end if;
6620
6621 exception
6622 when RE_Not_Available =>
6623 return;
6624 end Expand_N_Aggregate;
6625
6626 ------------------------------
6627 -- Expand_N_Delta_Aggregate --
6628 ------------------------------
6629
6630 procedure Expand_N_Delta_Aggregate (N : Node_Id) is
6631 Loc : constant Source_Ptr := Sloc (N);
6632 Typ : constant Entity_Id := Etype (N);
6633 Decl : Node_Id;
6634
6635 begin
6636 Decl :=
6637 Make_Object_Declaration (Loc,
6638 Defining_Identifier => Make_Temporary (Loc, 'T'),
6639 Object_Definition => New_Occurrence_Of (Typ, Loc),
6640 Expression => New_Copy_Tree (Expression (N)));
6641
6642 if Is_Array_Type (Etype (N)) then
6643 Expand_Delta_Array_Aggregate (N, New_List (Decl));
6644 else
6645 Expand_Delta_Record_Aggregate (N, New_List (Decl));
6646 end if;
6647 end Expand_N_Delta_Aggregate;
6648
6649 ----------------------------------
6650 -- Expand_Delta_Array_Aggregate --
6651 ----------------------------------
6652
6653 procedure Expand_Delta_Array_Aggregate (N : Node_Id; Deltas : List_Id) is
6654 Loc : constant Source_Ptr := Sloc (N);
6655 Temp : constant Entity_Id := Defining_Identifier (First (Deltas));
6656 Assoc : Node_Id;
6657
6658 function Generate_Loop (C : Node_Id) return Node_Id;
6659 -- Generate a loop containing individual component assignments for
6660 -- choices that are ranges, subtype indications, subtype names, and
6661 -- iterated component associations.
6662
6663 -------------------
6664 -- Generate_Loop --
6665 -------------------
6666
6667 function Generate_Loop (C : Node_Id) return Node_Id is
6668 Sl : constant Source_Ptr := Sloc (C);
6669 Ix : Entity_Id;
6670
6671 begin
6672 if Nkind (Parent (C)) = N_Iterated_Component_Association then
6673 Ix :=
6674 Make_Defining_Identifier (Loc,
6675 Chars => (Chars (Defining_Identifier (Parent (C)))));
6676 else
6677 Ix := Make_Temporary (Sl, 'I');
6678 end if;
6679
6680 return
6681 Make_Loop_Statement (Loc,
6682 Iteration_Scheme =>
6683 Make_Iteration_Scheme (Sl,
6684 Loop_Parameter_Specification =>
6685 Make_Loop_Parameter_Specification (Sl,
6686 Defining_Identifier => Ix,
6687 Discrete_Subtype_Definition => New_Copy_Tree (C))),
6688
6689 Statements => New_List (
6690 Make_Assignment_Statement (Sl,
6691 Name =>
6692 Make_Indexed_Component (Sl,
6693 Prefix => New_Occurrence_Of (Temp, Sl),
6694 Expressions => New_List (New_Occurrence_Of (Ix, Sl))),
6695 Expression => New_Copy_Tree (Expression (Assoc)))),
6696 End_Label => Empty);
6697 end Generate_Loop;
6698
6699 -- Local variables
6700
6701 Choice : Node_Id;
6702
6703 -- Start of processing for Expand_Delta_Array_Aggregate
6704
6705 begin
6706 Assoc := First (Component_Associations (N));
6707 while Present (Assoc) loop
6708 Choice := First (Choice_List (Assoc));
6709 if Nkind (Assoc) = N_Iterated_Component_Association then
6710 while Present (Choice) loop
6711 Append_To (Deltas, Generate_Loop (Choice));
6712 Next (Choice);
6713 end loop;
6714
6715 else
6716 while Present (Choice) loop
6717
6718 -- Choice can be given by a range, a subtype indication, a
6719 -- subtype name, a scalar value, or an entity.
6720
6721 if Nkind (Choice) = N_Range
6722 or else (Is_Entity_Name (Choice)
6723 and then Is_Type (Entity (Choice)))
6724 then
6725 Append_To (Deltas, Generate_Loop (Choice));
6726
6727 elsif Nkind (Choice) = N_Subtype_Indication then
6728 Append_To (Deltas,
6729 Generate_Loop (Range_Expression (Constraint (Choice))));
6730
6731 else
6732 Append_To (Deltas,
6733 Make_Assignment_Statement (Sloc (Choice),
6734 Name =>
6735 Make_Indexed_Component (Sloc (Choice),
6736 Prefix => New_Occurrence_Of (Temp, Loc),
6737 Expressions => New_List (New_Copy_Tree (Choice))),
6738 Expression => New_Copy_Tree (Expression (Assoc))));
6739 end if;
6740
6741 Next (Choice);
6742 end loop;
6743 end if;
6744
6745 Next (Assoc);
6746 end loop;
6747
6748 Insert_Actions (N, Deltas);
6749 Rewrite (N, New_Occurrence_Of (Temp, Loc));
6750 end Expand_Delta_Array_Aggregate;
6751
6752 -----------------------------------
6753 -- Expand_Delta_Record_Aggregate --
6754 -----------------------------------
6755
6756 procedure Expand_Delta_Record_Aggregate (N : Node_Id; Deltas : List_Id) is
6757 Loc : constant Source_Ptr := Sloc (N);
6758 Temp : constant Entity_Id := Defining_Identifier (First (Deltas));
6759 Assoc : Node_Id;
6760 Choice : Node_Id;
6761
6762 begin
6763 Assoc := First (Component_Associations (N));
6764
6765 while Present (Assoc) loop
6766 Choice := First (Choice_List (Assoc));
6767 while Present (Choice) loop
6768 Append_To (Deltas,
6769 Make_Assignment_Statement (Sloc (Choice),
6770 Name =>
6771 Make_Selected_Component (Sloc (Choice),
6772 Prefix => New_Occurrence_Of (Temp, Loc),
6773 Selector_Name => Make_Identifier (Loc, Chars (Choice))),
6774 Expression => New_Copy_Tree (Expression (Assoc))));
6775 Next (Choice);
6776 end loop;
6777
6778 Next (Assoc);
6779 end loop;
6780
6781 Insert_Actions (N, Deltas);
6782 Rewrite (N, New_Occurrence_Of (Temp, Loc));
6783 end Expand_Delta_Record_Aggregate;
6784
6785 ----------------------------------
6786 -- Expand_N_Extension_Aggregate --
6787 ----------------------------------
6788
6789 -- If the ancestor part is an expression, add a component association for
6790 -- the parent field. If the type of the ancestor part is not the direct
6791 -- parent of the expected type, build recursively the needed ancestors.
6792 -- If the ancestor part is a subtype_mark, replace aggregate with a
6793 -- declaration for a temporary of the expected type, followed by
6794 -- individual assignments to the given components.
6795
6796 procedure Expand_N_Extension_Aggregate (N : Node_Id) is
6797 A : constant Node_Id := Ancestor_Part (N);
6798 Loc : constant Source_Ptr := Sloc (N);
6799 Typ : constant Entity_Id := Etype (N);
6800
6801 begin
6802 -- If the ancestor is a subtype mark, an init proc must be called
6803 -- on the resulting object which thus has to be materialized in
6804 -- the front-end
6805
6806 if Is_Entity_Name (A) and then Is_Type (Entity (A)) then
6807 Convert_To_Assignments (N, Typ);
6808
6809 -- The extension aggregate is transformed into a record aggregate
6810 -- of the following form (c1 and c2 are inherited components)
6811
6812 -- (Exp with c3 => a, c4 => b)
6813 -- ==> (c1 => Exp.c1, c2 => Exp.c2, c3 => a, c4 => b)
6814
6815 else
6816 Set_Etype (N, Typ);
6817
6818 if Tagged_Type_Expansion then
6819 Expand_Record_Aggregate (N,
6820 Orig_Tag =>
6821 New_Occurrence_Of
6822 (Node (First_Elmt (Access_Disp_Table (Typ))), Loc),
6823 Parent_Expr => A);
6824
6825 -- No tag is needed in the case of a VM
6826
6827 else
6828 Expand_Record_Aggregate (N, Parent_Expr => A);
6829 end if;
6830 end if;
6831
6832 exception
6833 when RE_Not_Available =>
6834 return;
6835 end Expand_N_Extension_Aggregate;
6836
6837 -----------------------------
6838 -- Expand_Record_Aggregate --
6839 -----------------------------
6840
6841 procedure Expand_Record_Aggregate
6842 (N : Node_Id;
6843 Orig_Tag : Node_Id := Empty;
6844 Parent_Expr : Node_Id := Empty)
6845 is
6846 Loc : constant Source_Ptr := Sloc (N);
6847 Comps : constant List_Id := Component_Associations (N);
6848 Typ : constant Entity_Id := Etype (N);
6849 Base_Typ : constant Entity_Id := Base_Type (Typ);
6850
6851 Static_Components : Boolean := True;
6852 -- Flag to indicate whether all components are compile-time known,
6853 -- and the aggregate can be constructed statically and handled by
6854 -- the back-end. Set to False by Component_OK_For_Backend.
6855
6856 procedure Build_Back_End_Aggregate;
6857 -- Build a proper aggregate to be handled by the back-end
6858
6859 function Compile_Time_Known_Composite_Value (N : Node_Id) return Boolean;
6860 -- Returns true if N is an expression of composite type which can be
6861 -- fully evaluated at compile time without raising constraint error.
6862 -- Such expressions can be passed as is to Gigi without any expansion.
6863 --
6864 -- This returns true for N_Aggregate with Compile_Time_Known_Aggregate
6865 -- set and constants whose expression is such an aggregate, recursively.
6866
6867 function Component_OK_For_Backend return Boolean;
6868 -- Check for presence of a component which makes it impossible for the
6869 -- backend to process the aggregate, thus requiring the use of a series
6870 -- of assignment statements. Cases checked for are a nested aggregate
6871 -- needing Late_Expansion, the presence of a tagged component which may
6872 -- need tag adjustment, and a bit unaligned component reference.
6873 --
6874 -- We also force expansion into assignments if a component is of a
6875 -- mutable type (including a private type with discriminants) because
6876 -- in that case the size of the component to be copied may be smaller
6877 -- than the side of the target, and there is no simple way for gigi
6878 -- to compute the size of the object to be copied.
6879 --
6880 -- NOTE: This is part of the ongoing work to define precisely the
6881 -- interface between front-end and back-end handling of aggregates.
6882 -- In general it is desirable to pass aggregates as they are to gigi,
6883 -- in order to minimize elaboration code. This is one case where the
6884 -- semantics of Ada complicate the analysis and lead to anomalies in
6885 -- the gcc back-end if the aggregate is not expanded into assignments.
6886 --
6887 -- NOTE: This sets the global Static_Components to False in most, but
6888 -- not all, cases when it returns False.
6889
6890 function Has_Per_Object_Constraint (L : List_Id) return Boolean;
6891 -- Return True if any element of L has Has_Per_Object_Constraint set.
6892 -- L should be the Choices component of an N_Component_Association.
6893
6894 function Has_Visible_Private_Ancestor (Id : E) return Boolean;
6895 -- If any ancestor of the current type is private, the aggregate
6896 -- cannot be built in place. We cannot rely on Has_Private_Ancestor,
6897 -- because it will not be set when type and its parent are in the
6898 -- same scope, and the parent component needs expansion.
6899
6900 function Top_Level_Aggregate (N : Node_Id) return Node_Id;
6901 -- For nested aggregates return the ultimate enclosing aggregate; for
6902 -- non-nested aggregates return N.
6903
6904 ------------------------------
6905 -- Build_Back_End_Aggregate --
6906 ------------------------------
6907
6908 procedure Build_Back_End_Aggregate is
6909 Comp : Entity_Id;
6910 New_Comp : Node_Id;
6911 Tag_Value : Node_Id;
6912
6913 begin
6914 if Nkind (N) = N_Aggregate then
6915
6916 -- If the aggregate is static and can be handled by the back-end,
6917 -- nothing left to do.
6918
6919 if Static_Components then
6920 Set_Compile_Time_Known_Aggregate (N);
6921 Set_Expansion_Delayed (N, False);
6922 end if;
6923 end if;
6924
6925 -- If no discriminants, nothing special to do
6926
6927 if not Has_Discriminants (Typ) then
6928 null;
6929
6930 -- Case of discriminants present
6931
6932 elsif Is_Derived_Type (Typ) then
6933
6934 -- For untagged types, non-stored discriminants are replaced with
6935 -- stored discriminants, which are the ones that gigi uses to
6936 -- describe the type and its components.
6937
6938 Generate_Aggregate_For_Derived_Type : declare
6939 procedure Prepend_Stored_Values (T : Entity_Id);
6940 -- Scan the list of stored discriminants of the type, and add
6941 -- their values to the aggregate being built.
6942
6943 ---------------------------
6944 -- Prepend_Stored_Values --
6945 ---------------------------
6946
6947 procedure Prepend_Stored_Values (T : Entity_Id) is
6948 Discr : Entity_Id;
6949 First_Comp : Node_Id := Empty;
6950
6951 begin
6952 Discr := First_Stored_Discriminant (T);
6953 while Present (Discr) loop
6954 New_Comp :=
6955 Make_Component_Association (Loc,
6956 Choices => New_List (
6957 New_Occurrence_Of (Discr, Loc)),
6958 Expression =>
6959 New_Copy_Tree
6960 (Get_Discriminant_Value
6961 (Discr,
6962 Typ,
6963 Discriminant_Constraint (Typ))));
6964
6965 if No (First_Comp) then
6966 Prepend_To (Component_Associations (N), New_Comp);
6967 else
6968 Insert_After (First_Comp, New_Comp);
6969 end if;
6970
6971 First_Comp := New_Comp;
6972 Next_Stored_Discriminant (Discr);
6973 end loop;
6974 end Prepend_Stored_Values;
6975
6976 -- Local variables
6977
6978 Constraints : constant List_Id := New_List;
6979
6980 Discr : Entity_Id;
6981 Decl : Node_Id;
6982 Num_Disc : Nat := 0;
6983 Num_Gird : Nat := 0;
6984
6985 -- Start of processing for Generate_Aggregate_For_Derived_Type
6986
6987 begin
6988 -- Remove the associations for the discriminant of derived type
6989
6990 declare
6991 First_Comp : Node_Id;
6992
6993 begin
6994 First_Comp := First (Component_Associations (N));
6995 while Present (First_Comp) loop
6996 Comp := First_Comp;
6997 Next (First_Comp);
6998
6999 if Ekind (Entity (First (Choices (Comp)))) =
7000 E_Discriminant
7001 then
7002 Remove (Comp);
7003 Num_Disc := Num_Disc + 1;
7004 end if;
7005 end loop;
7006 end;
7007
7008 -- Insert stored discriminant associations in the correct
7009 -- order. If there are more stored discriminants than new
7010 -- discriminants, there is at least one new discriminant that
7011 -- constrains more than one of the stored discriminants. In
7012 -- this case we need to construct a proper subtype of the
7013 -- parent type, in order to supply values to all the
7014 -- components. Otherwise there is one-one correspondence
7015 -- between the constraints and the stored discriminants.
7016
7017 Discr := First_Stored_Discriminant (Base_Type (Typ));
7018 while Present (Discr) loop
7019 Num_Gird := Num_Gird + 1;
7020 Next_Stored_Discriminant (Discr);
7021 end loop;
7022
7023 -- Case of more stored discriminants than new discriminants
7024
7025 if Num_Gird > Num_Disc then
7026
7027 -- Create a proper subtype of the parent type, which is the
7028 -- proper implementation type for the aggregate, and convert
7029 -- it to the intended target type.
7030
7031 Discr := First_Stored_Discriminant (Base_Type (Typ));
7032 while Present (Discr) loop
7033 New_Comp :=
7034 New_Copy_Tree
7035 (Get_Discriminant_Value
7036 (Discr,
7037 Typ,
7038 Discriminant_Constraint (Typ)));
7039
7040 Append (New_Comp, Constraints);
7041 Next_Stored_Discriminant (Discr);
7042 end loop;
7043
7044 Decl :=
7045 Make_Subtype_Declaration (Loc,
7046 Defining_Identifier => Make_Temporary (Loc, 'T'),
7047 Subtype_Indication =>
7048 Make_Subtype_Indication (Loc,
7049 Subtype_Mark =>
7050 New_Occurrence_Of (Etype (Base_Type (Typ)), Loc),
7051 Constraint =>
7052 Make_Index_Or_Discriminant_Constraint
7053 (Loc, Constraints)));
7054
7055 Insert_Action (N, Decl);
7056 Prepend_Stored_Values (Base_Type (Typ));
7057
7058 Set_Etype (N, Defining_Identifier (Decl));
7059 Set_Analyzed (N);
7060
7061 Rewrite (N, Unchecked_Convert_To (Typ, N));
7062 Analyze (N);
7063
7064 -- Case where we do not have fewer new discriminants than
7065 -- stored discriminants, so in this case we can simply use the
7066 -- stored discriminants of the subtype.
7067
7068 else
7069 Prepend_Stored_Values (Typ);
7070 end if;
7071 end Generate_Aggregate_For_Derived_Type;
7072 end if;
7073
7074 if Is_Tagged_Type (Typ) then
7075
7076 -- In the tagged case, _parent and _tag component must be created
7077
7078 -- Reset Null_Present unconditionally. Tagged records always have
7079 -- at least one field (the tag or the parent).
7080
7081 Set_Null_Record_Present (N, False);
7082
7083 -- When the current aggregate comes from the expansion of an
7084 -- extension aggregate, the parent expr is replaced by an
7085 -- aggregate formed by selected components of this expr.
7086
7087 if Present (Parent_Expr) and then Is_Empty_List (Comps) then
7088 Comp := First_Component_Or_Discriminant (Typ);
7089 while Present (Comp) loop
7090
7091 -- Skip all expander-generated components
7092
7093 if not Comes_From_Source (Original_Record_Component (Comp))
7094 then
7095 null;
7096
7097 else
7098 New_Comp :=
7099 Make_Selected_Component (Loc,
7100 Prefix =>
7101 Unchecked_Convert_To (Typ,
7102 Duplicate_Subexpr (Parent_Expr, True)),
7103 Selector_Name => New_Occurrence_Of (Comp, Loc));
7104
7105 Append_To (Comps,
7106 Make_Component_Association (Loc,
7107 Choices => New_List (
7108 New_Occurrence_Of (Comp, Loc)),
7109 Expression => New_Comp));
7110
7111 Analyze_And_Resolve (New_Comp, Etype (Comp));
7112 end if;
7113
7114 Next_Component_Or_Discriminant (Comp);
7115 end loop;
7116 end if;
7117
7118 -- Compute the value for the Tag now, if the type is a root it
7119 -- will be included in the aggregate right away, otherwise it will
7120 -- be propagated to the parent aggregate.
7121
7122 if Present (Orig_Tag) then
7123 Tag_Value := Orig_Tag;
7124
7125 elsif not Tagged_Type_Expansion then
7126 Tag_Value := Empty;
7127
7128 else
7129 Tag_Value :=
7130 New_Occurrence_Of
7131 (Node (First_Elmt (Access_Disp_Table (Typ))), Loc);
7132 end if;
7133
7134 -- For a derived type, an aggregate for the parent is formed with
7135 -- all the inherited components.
7136
7137 if Is_Derived_Type (Typ) then
7138 declare
7139 First_Comp : Node_Id;
7140 Parent_Comps : List_Id;
7141 Parent_Aggr : Node_Id;
7142 Parent_Name : Node_Id;
7143
7144 begin
7145 -- Remove the inherited component association from the
7146 -- aggregate and store them in the parent aggregate
7147
7148 First_Comp := First (Component_Associations (N));
7149 Parent_Comps := New_List;
7150 while Present (First_Comp)
7151 and then
7152 Scope (Original_Record_Component
7153 (Entity (First (Choices (First_Comp))))) /=
7154 Base_Typ
7155 loop
7156 Comp := First_Comp;
7157 Next (First_Comp);
7158 Remove (Comp);
7159 Append (Comp, Parent_Comps);
7160 end loop;
7161
7162 Parent_Aggr :=
7163 Make_Aggregate (Loc,
7164 Component_Associations => Parent_Comps);
7165 Set_Etype (Parent_Aggr, Etype (Base_Type (Typ)));
7166
7167 -- Find the _parent component
7168
7169 Comp := First_Component (Typ);
7170 while Chars (Comp) /= Name_uParent loop
7171 Comp := Next_Component (Comp);
7172 end loop;
7173
7174 Parent_Name := New_Occurrence_Of (Comp, Loc);
7175
7176 -- Insert the parent aggregate
7177
7178 Prepend_To (Component_Associations (N),
7179 Make_Component_Association (Loc,
7180 Choices => New_List (Parent_Name),
7181 Expression => Parent_Aggr));
7182
7183 -- Expand recursively the parent propagating the right Tag
7184
7185 Expand_Record_Aggregate
7186 (Parent_Aggr, Tag_Value, Parent_Expr);
7187
7188 -- The ancestor part may be a nested aggregate that has
7189 -- delayed expansion: recheck now.
7190
7191 if not Component_OK_For_Backend then
7192 Convert_To_Assignments (N, Typ);
7193 end if;
7194 end;
7195
7196 -- For a root type, the tag component is added (unless compiling
7197 -- for the VMs, where tags are implicit).
7198
7199 elsif Tagged_Type_Expansion then
7200 declare
7201 Tag_Name : constant Node_Id :=
7202 New_Occurrence_Of
7203 (First_Tag_Component (Typ), Loc);
7204 Typ_Tag : constant Entity_Id := RTE (RE_Tag);
7205 Conv_Node : constant Node_Id :=
7206 Unchecked_Convert_To (Typ_Tag, Tag_Value);
7207
7208 begin
7209 Set_Etype (Conv_Node, Typ_Tag);
7210 Prepend_To (Component_Associations (N),
7211 Make_Component_Association (Loc,
7212 Choices => New_List (Tag_Name),
7213 Expression => Conv_Node));
7214 end;
7215 end if;
7216 end if;
7217 end Build_Back_End_Aggregate;
7218
7219 ----------------------------------------
7220 -- Compile_Time_Known_Composite_Value --
7221 ----------------------------------------
7222
7223 function Compile_Time_Known_Composite_Value
7224 (N : Node_Id) return Boolean
7225 is
7226 begin
7227 -- If we have an entity name, then see if it is the name of a
7228 -- constant and if so, test the corresponding constant value.
7229
7230 if Is_Entity_Name (N) then
7231 declare
7232 E : constant Entity_Id := Entity (N);
7233 V : Node_Id;
7234 begin
7235 if Ekind (E) /= E_Constant then
7236 return False;
7237 else
7238 V := Constant_Value (E);
7239 return Present (V)
7240 and then Compile_Time_Known_Composite_Value (V);
7241 end if;
7242 end;
7243
7244 -- We have a value, see if it is compile time known
7245
7246 else
7247 if Nkind (N) = N_Aggregate then
7248 return Compile_Time_Known_Aggregate (N);
7249 end if;
7250
7251 -- All other types of values are not known at compile time
7252
7253 return False;
7254 end if;
7255
7256 end Compile_Time_Known_Composite_Value;
7257
7258 ------------------------------
7259 -- Component_OK_For_Backend --
7260 ------------------------------
7261
7262 function Component_OK_For_Backend return Boolean is
7263 C : Node_Id;
7264 Expr_Q : Node_Id;
7265
7266 begin
7267 if No (Comps) then
7268 return True;
7269 end if;
7270
7271 C := First (Comps);
7272 while Present (C) loop
7273
7274 -- If the component has box initialization, expansion is needed
7275 -- and component is not ready for backend.
7276
7277 if Box_Present (C) then
7278 return False;
7279 end if;
7280
7281 if Nkind (Expression (C)) = N_Qualified_Expression then
7282 Expr_Q := Expression (Expression (C));
7283 else
7284 Expr_Q := Expression (C);
7285 end if;
7286
7287 -- Return False for array components whose bounds raise
7288 -- constraint error.
7289
7290 declare
7291 Comp : constant Entity_Id := First (Choices (C));
7292 Indx : Node_Id;
7293
7294 begin
7295 if Present (Etype (Comp))
7296 and then Is_Array_Type (Etype (Comp))
7297 then
7298 Indx := First_Index (Etype (Comp));
7299 while Present (Indx) loop
7300 if Nkind (Type_Low_Bound (Etype (Indx))) =
7301 N_Raise_Constraint_Error
7302 or else Nkind (Type_High_Bound (Etype (Indx))) =
7303 N_Raise_Constraint_Error
7304 then
7305 return False;
7306 end if;
7307
7308 Indx := Next_Index (Indx);
7309 end loop;
7310 end if;
7311 end;
7312
7313 -- Return False if the aggregate has any associations for tagged
7314 -- components that may require tag adjustment.
7315
7316 -- These are cases where the source expression may have a tag that
7317 -- could differ from the component tag (e.g., can occur for type
7318 -- conversions and formal parameters). (Tag adjustment not needed
7319 -- if Tagged_Type_Expansion because object tags are implicit in
7320 -- the machine.)
7321
7322 if Is_Tagged_Type (Etype (Expr_Q))
7323 and then
7324 (Nkind (Expr_Q) = N_Type_Conversion
7325 or else
7326 (Is_Entity_Name (Expr_Q)
7327 and then Is_Formal (Entity (Expr_Q))))
7328 and then Tagged_Type_Expansion
7329 then
7330 Static_Components := False;
7331 return False;
7332
7333 elsif Is_Delayed_Aggregate (Expr_Q) then
7334 Static_Components := False;
7335 return False;
7336
7337 elsif Nkind (Expr_Q) = N_Quantified_Expression then
7338 Static_Components := False;
7339 return False;
7340
7341 elsif Possible_Bit_Aligned_Component (Expr_Q) then
7342 Static_Components := False;
7343 return False;
7344
7345 elsif Modify_Tree_For_C
7346 and then Nkind (C) = N_Component_Association
7347 and then Has_Per_Object_Constraint (Choices (C))
7348 then
7349 Static_Components := False;
7350 return False;
7351
7352 elsif Modify_Tree_For_C
7353 and then Nkind (Expr_Q) = N_Identifier
7354 and then Is_Array_Type (Etype (Expr_Q))
7355 then
7356 Static_Components := False;
7357 return False;
7358
7359 elsif Modify_Tree_For_C
7360 and then Nkind (Expr_Q) = N_Type_Conversion
7361 and then Is_Array_Type (Etype (Expr_Q))
7362 then
7363 Static_Components := False;
7364 return False;
7365 end if;
7366
7367 if Is_Elementary_Type (Etype (Expr_Q)) then
7368 if not Compile_Time_Known_Value (Expr_Q) then
7369 Static_Components := False;
7370 end if;
7371
7372 elsif not Compile_Time_Known_Composite_Value (Expr_Q) then
7373 Static_Components := False;
7374
7375 if Is_Private_Type (Etype (Expr_Q))
7376 and then Has_Discriminants (Etype (Expr_Q))
7377 then
7378 return False;
7379 end if;
7380 end if;
7381
7382 Next (C);
7383 end loop;
7384
7385 return True;
7386 end Component_OK_For_Backend;
7387
7388 -------------------------------
7389 -- Has_Per_Object_Constraint --
7390 -------------------------------
7391
7392 function Has_Per_Object_Constraint (L : List_Id) return Boolean is
7393 N : Node_Id := First (L);
7394 begin
7395 while Present (N) loop
7396 if Is_Entity_Name (N)
7397 and then Present (Entity (N))
7398 and then Has_Per_Object_Constraint (Entity (N))
7399 then
7400 return True;
7401 end if;
7402
7403 Next (N);
7404 end loop;
7405
7406 return False;
7407 end Has_Per_Object_Constraint;
7408
7409 -----------------------------------
7410 -- Has_Visible_Private_Ancestor --
7411 -----------------------------------
7412
7413 function Has_Visible_Private_Ancestor (Id : E) return Boolean is
7414 R : constant Entity_Id := Root_Type (Id);
7415 T1 : Entity_Id := Id;
7416
7417 begin
7418 loop
7419 if Is_Private_Type (T1) then
7420 return True;
7421
7422 elsif T1 = R then
7423 return False;
7424
7425 else
7426 T1 := Etype (T1);
7427 end if;
7428 end loop;
7429 end Has_Visible_Private_Ancestor;
7430
7431 -------------------------
7432 -- Top_Level_Aggregate --
7433 -------------------------
7434
7435 function Top_Level_Aggregate (N : Node_Id) return Node_Id is
7436 Aggr : Node_Id;
7437
7438 begin
7439 Aggr := N;
7440 while Present (Parent (Aggr))
7441 and then Nkind_In (Parent (Aggr), N_Aggregate,
7442 N_Component_Association)
7443 loop
7444 Aggr := Parent (Aggr);
7445 end loop;
7446
7447 return Aggr;
7448 end Top_Level_Aggregate;
7449
7450 -- Local variables
7451
7452 Top_Level_Aggr : constant Node_Id := Top_Level_Aggregate (N);
7453
7454 -- Start of processing for Expand_Record_Aggregate
7455
7456 begin
7457 -- If the aggregate is to be assigned to an atomic/VFA variable, we have
7458 -- to prevent a piecemeal assignment even if the aggregate is to be
7459 -- expanded. We create a temporary for the aggregate, and assign the
7460 -- temporary instead, so that the back end can generate an atomic move
7461 -- for it.
7462
7463 if Is_Atomic_VFA_Aggregate (N) then
7464 return;
7465
7466 -- No special management required for aggregates used to initialize
7467 -- statically allocated dispatch tables
7468
7469 elsif Is_Static_Dispatch_Table_Aggregate (N) then
7470 return;
7471 end if;
7472
7473 -- Ada 2005 (AI-318-2): We need to convert to assignments if components
7474 -- are build-in-place function calls. The assignments will each turn
7475 -- into a build-in-place function call. If components are all static,
7476 -- we can pass the aggregate to the back end regardless of limitedness.
7477
7478 -- Extension aggregates, aggregates in extended return statements, and
7479 -- aggregates for C++ imported types must be expanded.
7480
7481 if Ada_Version >= Ada_2005 and then Is_Limited_View (Typ) then
7482 if not Nkind_In (Parent (N), N_Component_Association,
7483 N_Object_Declaration)
7484 then
7485 Convert_To_Assignments (N, Typ);
7486
7487 elsif Nkind (N) = N_Extension_Aggregate
7488 or else Convention (Typ) = Convention_CPP
7489 then
7490 Convert_To_Assignments (N, Typ);
7491
7492 elsif not Size_Known_At_Compile_Time (Typ)
7493 or else not Component_OK_For_Backend
7494 or else not Static_Components
7495 then
7496 Convert_To_Assignments (N, Typ);
7497
7498 -- In all other cases, build a proper aggregate to be handled by
7499 -- the back-end
7500
7501 else
7502 Build_Back_End_Aggregate;
7503 end if;
7504
7505 -- Gigi doesn't properly handle temporaries of variable size so we
7506 -- generate it in the front-end
7507
7508 elsif not Size_Known_At_Compile_Time (Typ)
7509 and then Tagged_Type_Expansion
7510 then
7511 Convert_To_Assignments (N, Typ);
7512
7513 -- An aggregate used to initialize a controlled object must be turned
7514 -- into component assignments as the components themselves may require
7515 -- finalization actions such as adjustment.
7516
7517 elsif Needs_Finalization (Typ) then
7518 Convert_To_Assignments (N, Typ);
7519
7520 -- Ada 2005 (AI-287): In case of default initialized components we
7521 -- convert the aggregate into assignments.
7522
7523 elsif Has_Default_Init_Comps (N) then
7524 Convert_To_Assignments (N, Typ);
7525
7526 -- Check components
7527
7528 elsif not Component_OK_For_Backend then
7529 Convert_To_Assignments (N, Typ);
7530
7531 -- If an ancestor is private, some components are not inherited and we
7532 -- cannot expand into a record aggregate.
7533
7534 elsif Has_Visible_Private_Ancestor (Typ) then
7535 Convert_To_Assignments (N, Typ);
7536
7537 -- ??? The following was done to compile fxacc00.ads in the ACVCs. Gigi
7538 -- is not able to handle the aggregate for Late_Request.
7539
7540 elsif Is_Tagged_Type (Typ) and then Has_Discriminants (Typ) then
7541 Convert_To_Assignments (N, Typ);
7542
7543 -- If the tagged types covers interface types we need to initialize all
7544 -- hidden components containing pointers to secondary dispatch tables.
7545
7546 elsif Is_Tagged_Type (Typ) and then Has_Interfaces (Typ) then
7547 Convert_To_Assignments (N, Typ);
7548
7549 -- If some components are mutable, the size of the aggregate component
7550 -- may be distinct from the default size of the type component, so
7551 -- we need to expand to insure that the back-end copies the proper
7552 -- size of the data. However, if the aggregate is the initial value of
7553 -- a constant, the target is immutable and might be built statically
7554 -- if components are appropriate.
7555
7556 elsif Has_Mutable_Components (Typ)
7557 and then
7558 (Nkind (Parent (Top_Level_Aggr)) /= N_Object_Declaration
7559 or else not Constant_Present (Parent (Top_Level_Aggr))
7560 or else not Static_Components)
7561 then
7562 Convert_To_Assignments (N, Typ);
7563
7564 -- If the type involved has bit aligned components, then we are not sure
7565 -- that the back end can handle this case correctly.
7566
7567 elsif Type_May_Have_Bit_Aligned_Components (Typ) then
7568 Convert_To_Assignments (N, Typ);
7569
7570 -- When generating C, only generate an aggregate when declaring objects
7571 -- since C does not support aggregates in e.g. assignment statements.
7572
7573 elsif Modify_Tree_For_C and then not Is_CCG_Supported_Aggregate (N) then
7574 Convert_To_Assignments (N, Typ);
7575
7576 -- In all other cases, build a proper aggregate to be handled by gigi
7577
7578 else
7579 Build_Back_End_Aggregate;
7580 end if;
7581 end Expand_Record_Aggregate;
7582
7583 ----------------------------
7584 -- Has_Default_Init_Comps --
7585 ----------------------------
7586
7587 function Has_Default_Init_Comps (N : Node_Id) return Boolean is
7588 Comps : constant List_Id := Component_Associations (N);
7589 C : Node_Id;
7590 Expr : Node_Id;
7591
7592 begin
7593 pragma Assert (Nkind_In (N, N_Aggregate, N_Extension_Aggregate));
7594
7595 if No (Comps) then
7596 return False;
7597 end if;
7598
7599 if Has_Self_Reference (N) then
7600 return True;
7601 end if;
7602
7603 -- Check if any direct component has default initialized components
7604
7605 C := First (Comps);
7606 while Present (C) loop
7607 if Box_Present (C) then
7608 return True;
7609 end if;
7610
7611 Next (C);
7612 end loop;
7613
7614 -- Recursive call in case of aggregate expression
7615
7616 C := First (Comps);
7617 while Present (C) loop
7618 Expr := Expression (C);
7619
7620 if Present (Expr)
7621 and then Nkind_In (Expr, N_Aggregate, N_Extension_Aggregate)
7622 and then Has_Default_Init_Comps (Expr)
7623 then
7624 return True;
7625 end if;
7626
7627 Next (C);
7628 end loop;
7629
7630 return False;
7631 end Has_Default_Init_Comps;
7632
7633 ----------------------------------------
7634 -- Is_Build_In_Place_Aggregate_Return --
7635 ----------------------------------------
7636
7637 function Is_Build_In_Place_Aggregate_Return (N : Node_Id) return Boolean is
7638 P : Node_Id := Parent (N);
7639
7640 begin
7641 while Nkind (P) = N_Qualified_Expression loop
7642 P := Parent (P);
7643 end loop;
7644
7645 if Nkind (P) = N_Simple_Return_Statement then
7646 null;
7647
7648 elsif Nkind (Parent (P)) = N_Extended_Return_Statement then
7649 P := Parent (P);
7650
7651 else
7652 return False;
7653 end if;
7654
7655 return
7656 Is_Build_In_Place_Function
7657 (Return_Applies_To (Return_Statement_Entity (P)));
7658 end Is_Build_In_Place_Aggregate_Return;
7659
7660 --------------------------
7661 -- Is_Delayed_Aggregate --
7662 --------------------------
7663
7664 function Is_Delayed_Aggregate (N : Node_Id) return Boolean is
7665 Node : Node_Id := N;
7666 Kind : Node_Kind := Nkind (Node);
7667
7668 begin
7669 if Kind = N_Qualified_Expression then
7670 Node := Expression (Node);
7671 Kind := Nkind (Node);
7672 end if;
7673
7674 if not Nkind_In (Kind, N_Aggregate, N_Extension_Aggregate) then
7675 return False;
7676 else
7677 return Expansion_Delayed (Node);
7678 end if;
7679 end Is_Delayed_Aggregate;
7680
7681 --------------------------------
7682 -- Is_CCG_Supported_Aggregate --
7683 --------------------------------
7684
7685 function Is_CCG_Supported_Aggregate
7686 (N : Node_Id) return Boolean
7687 is
7688 In_Obj_Decl : Boolean := False;
7689 P : Node_Id := Parent (N);
7690 begin
7691 while Present (P) loop
7692 if Nkind (P) = N_Object_Declaration then
7693 In_Obj_Decl := True;
7694 end if;
7695
7696 P := Parent (P);
7697 end loop;
7698
7699 -- Cases where aggregates are supported by the CCG backend
7700
7701 if In_Obj_Decl then
7702 if Nkind (Parent (N)) = N_Object_Declaration then
7703 return True;
7704
7705 elsif Nkind (Parent (N)) = N_Qualified_Expression
7706 and then Nkind_In (Parent (Parent (N)), N_Allocator,
7707 N_Object_Declaration)
7708 then
7709 return True;
7710 end if;
7711 end if;
7712
7713 return False;
7714 end Is_CCG_Supported_Aggregate;
7715
7716 ----------------------------------------
7717 -- Is_Static_Dispatch_Table_Aggregate --
7718 ----------------------------------------
7719
7720 function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean is
7721 Typ : constant Entity_Id := Base_Type (Etype (N));
7722
7723 begin
7724 return Building_Static_Dispatch_Tables
7725 and then Tagged_Type_Expansion
7726 and then RTU_Loaded (Ada_Tags)
7727
7728 -- Avoid circularity when rebuilding the compiler
7729
7730 and then Cunit_Entity (Get_Source_Unit (N)) /= RTU_Entity (Ada_Tags)
7731 and then (Typ = RTE (RE_Dispatch_Table_Wrapper)
7732 or else
7733 Typ = RTE (RE_Address_Array)
7734 or else
7735 Typ = RTE (RE_Type_Specific_Data)
7736 or else
7737 Typ = RTE (RE_Tag_Table)
7738 or else
7739 (RTE_Available (RE_Interface_Data)
7740 and then Typ = RTE (RE_Interface_Data))
7741 or else
7742 (RTE_Available (RE_Interfaces_Array)
7743 and then Typ = RTE (RE_Interfaces_Array))
7744 or else
7745 (RTE_Available (RE_Interface_Data_Element)
7746 and then Typ = RTE (RE_Interface_Data_Element)));
7747 end Is_Static_Dispatch_Table_Aggregate;
7748
7749 -----------------------------
7750 -- Is_Two_Dim_Packed_Array --
7751 -----------------------------
7752
7753 function Is_Two_Dim_Packed_Array (Typ : Entity_Id) return Boolean is
7754 C : constant Int := UI_To_Int (Component_Size (Typ));
7755 begin
7756 return Number_Dimensions (Typ) = 2
7757 and then Is_Bit_Packed_Array (Typ)
7758 and then (C = 1 or else C = 2 or else C = 4);
7759 end Is_Two_Dim_Packed_Array;
7760
7761 --------------------
7762 -- Late_Expansion --
7763 --------------------
7764
7765 function Late_Expansion
7766 (N : Node_Id;
7767 Typ : Entity_Id;
7768 Target : Node_Id) return List_Id
7769 is
7770 Aggr_Code : List_Id;
7771
7772 begin
7773 if Is_Array_Type (Etype (N)) then
7774 Aggr_Code :=
7775 Build_Array_Aggr_Code
7776 (N => N,
7777 Ctype => Component_Type (Etype (N)),
7778 Index => First_Index (Typ),
7779 Into => Target,
7780 Scalar_Comp => Is_Scalar_Type (Component_Type (Typ)),
7781 Indexes => No_List);
7782
7783 -- Directly or indirectly (e.g. access protected procedure) a record
7784
7785 else
7786 Aggr_Code := Build_Record_Aggr_Code (N, Typ, Target);
7787 end if;
7788
7789 -- Save the last assignment statement associated with the aggregate
7790 -- when building a controlled object. This reference is utilized by
7791 -- the finalization machinery when marking an object as successfully
7792 -- initialized.
7793
7794 if Needs_Finalization (Typ)
7795 and then Is_Entity_Name (Target)
7796 and then Present (Entity (Target))
7797 and then Ekind_In (Entity (Target), E_Constant, E_Variable)
7798 then
7799 Set_Last_Aggregate_Assignment (Entity (Target), Last (Aggr_Code));
7800 end if;
7801
7802 return Aggr_Code;
7803 end Late_Expansion;
7804
7805 ----------------------------------
7806 -- Make_OK_Assignment_Statement --
7807 ----------------------------------
7808
7809 function Make_OK_Assignment_Statement
7810 (Sloc : Source_Ptr;
7811 Name : Node_Id;
7812 Expression : Node_Id) return Node_Id
7813 is
7814 begin
7815 Set_Assignment_OK (Name);
7816 return Make_Assignment_Statement (Sloc, Name, Expression);
7817 end Make_OK_Assignment_Statement;
7818
7819 -----------------------
7820 -- Number_Of_Choices --
7821 -----------------------
7822
7823 function Number_Of_Choices (N : Node_Id) return Nat is
7824 Assoc : Node_Id;
7825 Choice : Node_Id;
7826
7827 Nb_Choices : Nat := 0;
7828
7829 begin
7830 if Present (Expressions (N)) then
7831 return 0;
7832 end if;
7833
7834 Assoc := First (Component_Associations (N));
7835 while Present (Assoc) loop
7836 Choice := First (Choice_List (Assoc));
7837 while Present (Choice) loop
7838 if Nkind (Choice) /= N_Others_Choice then
7839 Nb_Choices := Nb_Choices + 1;
7840 end if;
7841
7842 Next (Choice);
7843 end loop;
7844
7845 Next (Assoc);
7846 end loop;
7847
7848 return Nb_Choices;
7849 end Number_Of_Choices;
7850
7851 ------------------------------------
7852 -- Packed_Array_Aggregate_Handled --
7853 ------------------------------------
7854
7855 -- The current version of this procedure will handle at compile time
7856 -- any array aggregate that meets these conditions:
7857
7858 -- One and two dimensional, bit packed
7859 -- Underlying packed type is modular type
7860 -- Bounds are within 32-bit Int range
7861 -- All bounds and values are static
7862
7863 -- Note: for now, in the 2-D case, we only handle component sizes of
7864 -- 1, 2, 4 (cases where an integral number of elements occupies a byte).
7865
7866 function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean is
7867 Loc : constant Source_Ptr := Sloc (N);
7868 Typ : constant Entity_Id := Etype (N);
7869 Ctyp : constant Entity_Id := Component_Type (Typ);
7870
7871 Not_Handled : exception;
7872 -- Exception raised if this aggregate cannot be handled
7873
7874 begin
7875 -- Handle one- or two dimensional bit packed array
7876
7877 if not Is_Bit_Packed_Array (Typ)
7878 or else Number_Dimensions (Typ) > 2
7879 then
7880 return False;
7881 end if;
7882
7883 -- If two-dimensional, check whether it can be folded, and transformed
7884 -- into a one-dimensional aggregate for the Packed_Array_Impl_Type of
7885 -- the original type.
7886
7887 if Number_Dimensions (Typ) = 2 then
7888 return Two_Dim_Packed_Array_Handled (N);
7889 end if;
7890
7891 if not Is_Modular_Integer_Type (Packed_Array_Impl_Type (Typ)) then
7892 return False;
7893 end if;
7894
7895 if not Is_Scalar_Type (Component_Type (Typ))
7896 and then Has_Non_Standard_Rep (Component_Type (Typ))
7897 then
7898 return False;
7899 end if;
7900
7901 declare
7902 Csiz : constant Nat := UI_To_Int (Component_Size (Typ));
7903
7904 Lo : Node_Id;
7905 Hi : Node_Id;
7906 -- Bounds of index type
7907
7908 Lob : Uint;
7909 Hib : Uint;
7910 -- Values of bounds if compile time known
7911
7912 function Get_Component_Val (N : Node_Id) return Uint;
7913 -- Given a expression value N of the component type Ctyp, returns a
7914 -- value of Csiz (component size) bits representing this value. If
7915 -- the value is nonstatic or any other reason exists why the value
7916 -- cannot be returned, then Not_Handled is raised.
7917
7918 -----------------------
7919 -- Get_Component_Val --
7920 -----------------------
7921
7922 function Get_Component_Val (N : Node_Id) return Uint is
7923 Val : Uint;
7924
7925 begin
7926 -- We have to analyze the expression here before doing any further
7927 -- processing here. The analysis of such expressions is deferred
7928 -- till expansion to prevent some problems of premature analysis.
7929
7930 Analyze_And_Resolve (N, Ctyp);
7931
7932 -- Must have a compile time value. String literals have to be
7933 -- converted into temporaries as well, because they cannot easily
7934 -- be converted into their bit representation.
7935
7936 if not Compile_Time_Known_Value (N)
7937 or else Nkind (N) = N_String_Literal
7938 then
7939 raise Not_Handled;
7940 end if;
7941
7942 Val := Expr_Rep_Value (N);
7943
7944 -- Adjust for bias, and strip proper number of bits
7945
7946 if Has_Biased_Representation (Ctyp) then
7947 Val := Val - Expr_Value (Type_Low_Bound (Ctyp));
7948 end if;
7949
7950 return Val mod Uint_2 ** Csiz;
7951 end Get_Component_Val;
7952
7953 -- Here we know we have a one dimensional bit packed array
7954
7955 begin
7956 Get_Index_Bounds (First_Index (Typ), Lo, Hi);
7957
7958 -- Cannot do anything if bounds are dynamic
7959
7960 if not Compile_Time_Known_Value (Lo)
7961 or else
7962 not Compile_Time_Known_Value (Hi)
7963 then
7964 return False;
7965 end if;
7966
7967 -- Or are silly out of range of int bounds
7968
7969 Lob := Expr_Value (Lo);
7970 Hib := Expr_Value (Hi);
7971
7972 if not UI_Is_In_Int_Range (Lob)
7973 or else
7974 not UI_Is_In_Int_Range (Hib)
7975 then
7976 return False;
7977 end if;
7978
7979 -- At this stage we have a suitable aggregate for handling at compile
7980 -- time. The only remaining checks are that the values of expressions
7981 -- in the aggregate are compile-time known (checks are performed by
7982 -- Get_Component_Val), and that any subtypes or ranges are statically
7983 -- known.
7984
7985 -- If the aggregate is not fully positional at this stage, then
7986 -- convert it to positional form. Either this will fail, in which
7987 -- case we can do nothing, or it will succeed, in which case we have
7988 -- succeeded in handling the aggregate and transforming it into a
7989 -- modular value, or it will stay an aggregate, in which case we
7990 -- have failed to create a packed value for it.
7991
7992 if Present (Component_Associations (N)) then
7993 Convert_To_Positional
7994 (N, Max_Others_Replicate => 64, Handle_Bit_Packed => True);
7995 return Nkind (N) /= N_Aggregate;
7996 end if;
7997
7998 -- Otherwise we are all positional, so convert to proper value
7999
8000 declare
8001 Lov : constant Int := UI_To_Int (Lob);
8002 Hiv : constant Int := UI_To_Int (Hib);
8003
8004 Len : constant Nat := Int'Max (0, Hiv - Lov + 1);
8005 -- The length of the array (number of elements)
8006
8007 Aggregate_Val : Uint;
8008 -- Value of aggregate. The value is set in the low order bits of
8009 -- this value. For the little-endian case, the values are stored
8010 -- from low-order to high-order and for the big-endian case the
8011 -- values are stored from high-order to low-order. Note that gigi
8012 -- will take care of the conversions to left justify the value in
8013 -- the big endian case (because of left justified modular type
8014 -- processing), so we do not have to worry about that here.
8015
8016 Lit : Node_Id;
8017 -- Integer literal for resulting constructed value
8018
8019 Shift : Nat;
8020 -- Shift count from low order for next value
8021
8022 Incr : Int;
8023 -- Shift increment for loop
8024
8025 Expr : Node_Id;
8026 -- Next expression from positional parameters of aggregate
8027
8028 Left_Justified : Boolean;
8029 -- Set True if we are filling the high order bits of the target
8030 -- value (i.e. the value is left justified).
8031
8032 begin
8033 -- For little endian, we fill up the low order bits of the target
8034 -- value. For big endian we fill up the high order bits of the
8035 -- target value (which is a left justified modular value).
8036
8037 Left_Justified := Bytes_Big_Endian;
8038
8039 -- Switch justification if using -gnatd8
8040
8041 if Debug_Flag_8 then
8042 Left_Justified := not Left_Justified;
8043 end if;
8044
8045 -- Switch justfification if reverse storage order
8046
8047 if Reverse_Storage_Order (Base_Type (Typ)) then
8048 Left_Justified := not Left_Justified;
8049 end if;
8050
8051 if Left_Justified then
8052 Shift := Csiz * (Len - 1);
8053 Incr := -Csiz;
8054 else
8055 Shift := 0;
8056 Incr := +Csiz;
8057 end if;
8058
8059 -- Loop to set the values
8060
8061 if Len = 0 then
8062 Aggregate_Val := Uint_0;
8063 else
8064 Expr := First (Expressions (N));
8065 Aggregate_Val := Get_Component_Val (Expr) * Uint_2 ** Shift;
8066
8067 for J in 2 .. Len loop
8068 Shift := Shift + Incr;
8069 Next (Expr);
8070 Aggregate_Val :=
8071 Aggregate_Val + Get_Component_Val (Expr) * Uint_2 ** Shift;
8072 end loop;
8073 end if;
8074
8075 -- Now we can rewrite with the proper value
8076
8077 Lit := Make_Integer_Literal (Loc, Intval => Aggregate_Val);
8078 Set_Print_In_Hex (Lit);
8079
8080 -- Construct the expression using this literal. Note that it is
8081 -- important to qualify the literal with its proper modular type
8082 -- since universal integer does not have the required range and
8083 -- also this is a left justified modular type, which is important
8084 -- in the big-endian case.
8085
8086 Rewrite (N,
8087 Unchecked_Convert_To (Typ,
8088 Make_Qualified_Expression (Loc,
8089 Subtype_Mark =>
8090 New_Occurrence_Of (Packed_Array_Impl_Type (Typ), Loc),
8091 Expression => Lit)));
8092
8093 Analyze_And_Resolve (N, Typ);
8094 return True;
8095 end;
8096 end;
8097
8098 exception
8099 when Not_Handled =>
8100 return False;
8101 end Packed_Array_Aggregate_Handled;
8102
8103 ----------------------------
8104 -- Has_Mutable_Components --
8105 ----------------------------
8106
8107 function Has_Mutable_Components (Typ : Entity_Id) return Boolean is
8108 Comp : Entity_Id;
8109
8110 begin
8111 Comp := First_Component (Typ);
8112 while Present (Comp) loop
8113 if Is_Record_Type (Etype (Comp))
8114 and then Has_Discriminants (Etype (Comp))
8115 and then not Is_Constrained (Etype (Comp))
8116 then
8117 return True;
8118 end if;
8119
8120 Next_Component (Comp);
8121 end loop;
8122
8123 return False;
8124 end Has_Mutable_Components;
8125
8126 ------------------------------
8127 -- Initialize_Discriminants --
8128 ------------------------------
8129
8130 procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id) is
8131 Loc : constant Source_Ptr := Sloc (N);
8132 Bas : constant Entity_Id := Base_Type (Typ);
8133 Par : constant Entity_Id := Etype (Bas);
8134 Decl : constant Node_Id := Parent (Par);
8135 Ref : Node_Id;
8136
8137 begin
8138 if Is_Tagged_Type (Bas)
8139 and then Is_Derived_Type (Bas)
8140 and then Has_Discriminants (Par)
8141 and then Has_Discriminants (Bas)
8142 and then Number_Discriminants (Bas) /= Number_Discriminants (Par)
8143 and then Nkind (Decl) = N_Full_Type_Declaration
8144 and then Nkind (Type_Definition (Decl)) = N_Record_Definition
8145 and then
8146 Present (Variant_Part (Component_List (Type_Definition (Decl))))
8147 and then Nkind (N) /= N_Extension_Aggregate
8148 then
8149
8150 -- Call init proc to set discriminants.
8151 -- There should eventually be a special procedure for this ???
8152
8153 Ref := New_Occurrence_Of (Defining_Identifier (N), Loc);
8154 Insert_Actions_After (N,
8155 Build_Initialization_Call (Sloc (N), Ref, Typ));
8156 end if;
8157 end Initialize_Discriminants;
8158
8159 ----------------
8160 -- Must_Slide --
8161 ----------------
8162
8163 function Must_Slide
8164 (Obj_Type : Entity_Id;
8165 Typ : Entity_Id) return Boolean
8166 is
8167 L1, L2, H1, H2 : Node_Id;
8168
8169 begin
8170 -- No sliding if the type of the object is not established yet, if it is
8171 -- an unconstrained type whose actual subtype comes from the aggregate,
8172 -- or if the two types are identical.
8173
8174 if not Is_Array_Type (Obj_Type) then
8175 return False;
8176
8177 elsif not Is_Constrained (Obj_Type) then
8178 return False;
8179
8180 elsif Typ = Obj_Type then
8181 return False;
8182
8183 else
8184 -- Sliding can only occur along the first dimension
8185
8186 Get_Index_Bounds (First_Index (Typ), L1, H1);
8187 Get_Index_Bounds (First_Index (Obj_Type), L2, H2);
8188
8189 if not Is_OK_Static_Expression (L1) or else
8190 not Is_OK_Static_Expression (L2) or else
8191 not Is_OK_Static_Expression (H1) or else
8192 not Is_OK_Static_Expression (H2)
8193 then
8194 return False;
8195 else
8196 return Expr_Value (L1) /= Expr_Value (L2)
8197 or else
8198 Expr_Value (H1) /= Expr_Value (H2);
8199 end if;
8200 end if;
8201 end Must_Slide;
8202
8203 ---------------------------------
8204 -- Process_Transient_Component --
8205 ---------------------------------
8206
8207 procedure Process_Transient_Component
8208 (Loc : Source_Ptr;
8209 Comp_Typ : Entity_Id;
8210 Init_Expr : Node_Id;
8211 Fin_Call : out Node_Id;
8212 Hook_Clear : out Node_Id;
8213 Aggr : Node_Id := Empty;
8214 Stmts : List_Id := No_List)
8215 is
8216 procedure Add_Item (Item : Node_Id);
8217 -- Insert arbitrary node Item into the tree depending on the values of
8218 -- Aggr and Stmts.
8219
8220 --------------
8221 -- Add_Item --
8222 --------------
8223
8224 procedure Add_Item (Item : Node_Id) is
8225 begin
8226 if Present (Aggr) then
8227 Insert_Action (Aggr, Item);
8228 else
8229 pragma Assert (Present (Stmts));
8230 Append_To (Stmts, Item);
8231 end if;
8232 end Add_Item;
8233
8234 -- Local variables
8235
8236 Hook_Assign : Node_Id;
8237 Hook_Decl : Node_Id;
8238 Ptr_Decl : Node_Id;
8239 Res_Decl : Node_Id;
8240 Res_Id : Entity_Id;
8241 Res_Typ : Entity_Id;
8242
8243 -- Start of processing for Process_Transient_Component
8244
8245 begin
8246 -- Add the access type, which provides a reference to the function
8247 -- result. Generate:
8248
8249 -- type Res_Typ is access all Comp_Typ;
8250
8251 Res_Typ := Make_Temporary (Loc, 'A');
8252 Set_Ekind (Res_Typ, E_General_Access_Type);
8253 Set_Directly_Designated_Type (Res_Typ, Comp_Typ);
8254
8255 Add_Item
8256 (Make_Full_Type_Declaration (Loc,
8257 Defining_Identifier => Res_Typ,
8258 Type_Definition =>
8259 Make_Access_To_Object_Definition (Loc,
8260 All_Present => True,
8261 Subtype_Indication => New_Occurrence_Of (Comp_Typ, Loc))));
8262
8263 -- Add the temporary which captures the result of the function call.
8264 -- Generate:
8265
8266 -- Res : constant Res_Typ := Init_Expr'Reference;
8267
8268 -- Note that this temporary is effectively a transient object because
8269 -- its lifetime is bounded by the current array or record component.
8270
8271 Res_Id := Make_Temporary (Loc, 'R');
8272 Set_Ekind (Res_Id, E_Constant);
8273 Set_Etype (Res_Id, Res_Typ);
8274
8275 -- Mark the transient object as successfully processed to avoid double
8276 -- finalization.
8277
8278 Set_Is_Finalized_Transient (Res_Id);
8279
8280 -- Signal the general finalization machinery that this transient object
8281 -- should not be considered for finalization actions because its cleanup
8282 -- will be performed by Process_Transient_Component_Completion.
8283
8284 Set_Is_Ignored_Transient (Res_Id);
8285
8286 Res_Decl :=
8287 Make_Object_Declaration (Loc,
8288 Defining_Identifier => Res_Id,
8289 Constant_Present => True,
8290 Object_Definition => New_Occurrence_Of (Res_Typ, Loc),
8291 Expression =>
8292 Make_Reference (Loc, New_Copy_Tree (Init_Expr)));
8293
8294 Add_Item (Res_Decl);
8295
8296 -- Construct all pieces necessary to hook and finalize the transient
8297 -- result.
8298
8299 Build_Transient_Object_Statements
8300 (Obj_Decl => Res_Decl,
8301 Fin_Call => Fin_Call,
8302 Hook_Assign => Hook_Assign,
8303 Hook_Clear => Hook_Clear,
8304 Hook_Decl => Hook_Decl,
8305 Ptr_Decl => Ptr_Decl);
8306
8307 -- Add the access type which provides a reference to the transient
8308 -- result. Generate:
8309
8310 -- type Ptr_Typ is access all Comp_Typ;
8311
8312 Add_Item (Ptr_Decl);
8313
8314 -- Add the temporary which acts as a hook to the transient result.
8315 -- Generate:
8316
8317 -- Hook : Ptr_Typ := null;
8318
8319 Add_Item (Hook_Decl);
8320
8321 -- Attach the transient result to the hook. Generate:
8322
8323 -- Hook := Ptr_Typ (Res);
8324
8325 Add_Item (Hook_Assign);
8326
8327 -- The original initialization expression now references the value of
8328 -- the temporary function result. Generate:
8329
8330 -- Res.all
8331
8332 Rewrite (Init_Expr,
8333 Make_Explicit_Dereference (Loc,
8334 Prefix => New_Occurrence_Of (Res_Id, Loc)));
8335 end Process_Transient_Component;
8336
8337 --------------------------------------------
8338 -- Process_Transient_Component_Completion --
8339 --------------------------------------------
8340
8341 procedure Process_Transient_Component_Completion
8342 (Loc : Source_Ptr;
8343 Aggr : Node_Id;
8344 Fin_Call : Node_Id;
8345 Hook_Clear : Node_Id;
8346 Stmts : List_Id)
8347 is
8348 Exceptions_OK : constant Boolean :=
8349 not Restriction_Active (No_Exception_Propagation);
8350
8351 begin
8352 pragma Assert (Present (Hook_Clear));
8353
8354 -- Generate the following code if exception propagation is allowed:
8355
8356 -- declare
8357 -- Abort : constant Boolean := Triggered_By_Abort;
8358 -- <or>
8359 -- Abort : constant Boolean := False; -- no abort
8360
8361 -- E : Exception_Occurrence;
8362 -- Raised : Boolean := False;
8363
8364 -- begin
8365 -- [Abort_Defer;]
8366
8367 -- begin
8368 -- Hook := null;
8369 -- [Deep_]Finalize (Res.all);
8370
8371 -- exception
8372 -- when others =>
8373 -- if not Raised then
8374 -- Raised := True;
8375 -- Save_Occurrence (E,
8376 -- Get_Curent_Excep.all.all);
8377 -- end if;
8378 -- end;
8379
8380 -- [Abort_Undefer;]
8381
8382 -- if Raised and then not Abort then
8383 -- Raise_From_Controlled_Operation (E);
8384 -- end if;
8385 -- end;
8386
8387 if Exceptions_OK then
8388 Abort_And_Exception : declare
8389 Blk_Decls : constant List_Id := New_List;
8390 Blk_Stmts : constant List_Id := New_List;
8391 Fin_Stmts : constant List_Id := New_List;
8392
8393 Fin_Data : Finalization_Exception_Data;
8394
8395 begin
8396 -- Create the declarations of the two flags and the exception
8397 -- occurrence.
8398
8399 Build_Object_Declarations (Fin_Data, Blk_Decls, Loc);
8400
8401 -- Generate:
8402 -- Abort_Defer;
8403
8404 if Abort_Allowed then
8405 Append_To (Blk_Stmts,
8406 Build_Runtime_Call (Loc, RE_Abort_Defer));
8407 end if;
8408
8409 -- Wrap the hook clear and the finalization call in order to trap
8410 -- a potential exception.
8411
8412 Append_To (Fin_Stmts, Hook_Clear);
8413
8414 if Present (Fin_Call) then
8415 Append_To (Fin_Stmts, Fin_Call);
8416 end if;
8417
8418 Append_To (Blk_Stmts,
8419 Make_Block_Statement (Loc,
8420 Handled_Statement_Sequence =>
8421 Make_Handled_Sequence_Of_Statements (Loc,
8422 Statements => Fin_Stmts,
8423 Exception_Handlers => New_List (
8424 Build_Exception_Handler (Fin_Data)))));
8425
8426 -- Generate:
8427 -- Abort_Undefer;
8428
8429 if Abort_Allowed then
8430 Append_To (Blk_Stmts,
8431 Build_Runtime_Call (Loc, RE_Abort_Undefer));
8432 end if;
8433
8434 -- Reraise the potential exception with a proper "upgrade" to
8435 -- Program_Error if needed.
8436
8437 Append_To (Blk_Stmts, Build_Raise_Statement (Fin_Data));
8438
8439 -- Wrap everything in a block
8440
8441 Append_To (Stmts,
8442 Make_Block_Statement (Loc,
8443 Declarations => Blk_Decls,
8444 Handled_Statement_Sequence =>
8445 Make_Handled_Sequence_Of_Statements (Loc,
8446 Statements => Blk_Stmts)));
8447 end Abort_And_Exception;
8448
8449 -- Generate the following code if exception propagation is not allowed
8450 -- and aborts are allowed:
8451
8452 -- begin
8453 -- Abort_Defer;
8454 -- Hook := null;
8455 -- [Deep_]Finalize (Res.all);
8456 -- at end
8457 -- Abort_Undefer_Direct;
8458 -- end;
8459
8460 elsif Abort_Allowed then
8461 Abort_Only : declare
8462 Blk_Stmts : constant List_Id := New_List;
8463
8464 begin
8465 Append_To (Blk_Stmts, Build_Runtime_Call (Loc, RE_Abort_Defer));
8466 Append_To (Blk_Stmts, Hook_Clear);
8467
8468 if Present (Fin_Call) then
8469 Append_To (Blk_Stmts, Fin_Call);
8470 end if;
8471
8472 Append_To (Stmts,
8473 Build_Abort_Undefer_Block (Loc,
8474 Stmts => Blk_Stmts,
8475 Context => Aggr));
8476 end Abort_Only;
8477
8478 -- Otherwise generate:
8479
8480 -- Hook := null;
8481 -- [Deep_]Finalize (Res.all);
8482
8483 else
8484 Append_To (Stmts, Hook_Clear);
8485
8486 if Present (Fin_Call) then
8487 Append_To (Stmts, Fin_Call);
8488 end if;
8489 end if;
8490 end Process_Transient_Component_Completion;
8491
8492 ---------------------
8493 -- Sort_Case_Table --
8494 ---------------------
8495
8496 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
8497 L : constant Int := Case_Table'First;
8498 U : constant Int := Case_Table'Last;
8499 K : Int;
8500 J : Int;
8501 T : Case_Bounds;
8502
8503 begin
8504 K := L;
8505 while K /= U loop
8506 T := Case_Table (K + 1);
8507
8508 J := K + 1;
8509 while J /= L
8510 and then Expr_Value (Case_Table (J - 1).Choice_Lo) >
8511 Expr_Value (T.Choice_Lo)
8512 loop
8513 Case_Table (J) := Case_Table (J - 1);
8514 J := J - 1;
8515 end loop;
8516
8517 Case_Table (J) := T;
8518 K := K + 1;
8519 end loop;
8520 end Sort_Case_Table;
8521
8522 ----------------------------
8523 -- Static_Array_Aggregate --
8524 ----------------------------
8525
8526 function Static_Array_Aggregate (N : Node_Id) return Boolean is
8527
8528 function Is_Static_Component (N : Node_Id) return Boolean;
8529 -- Return True if N has a compile-time known value and can be passed as
8530 -- is to the back-end without further expansion.
8531
8532 ---------------------------
8533 -- Is_Static_Component --
8534 ---------------------------
8535
8536 function Is_Static_Component (N : Node_Id) return Boolean is
8537 begin
8538 if Nkind_In (N, N_Integer_Literal, N_Real_Literal) then
8539 return True;
8540
8541 elsif Is_Entity_Name (N)
8542 and then Present (Entity (N))
8543 and then Ekind (Entity (N)) = E_Enumeration_Literal
8544 then
8545 return True;
8546
8547 elsif Nkind (N) = N_Aggregate
8548 and then Compile_Time_Known_Aggregate (N)
8549 then
8550 return True;
8551
8552 else
8553 return False;
8554 end if;
8555 end Is_Static_Component;
8556
8557 Bounds : constant Node_Id := Aggregate_Bounds (N);
8558
8559 Typ : constant Entity_Id := Etype (N);
8560 Agg : Node_Id;
8561 Expr : Node_Id;
8562 Lo : Node_Id;
8563 Hi : Node_Id;
8564
8565 -- Start of processing for Static_Array_Aggregate
8566
8567 begin
8568 if Is_Packed (Typ) or else Has_Discriminants (Component_Type (Typ)) then
8569 return False;
8570 end if;
8571
8572 if Present (Bounds)
8573 and then Nkind (Bounds) = N_Range
8574 and then Nkind (Low_Bound (Bounds)) = N_Integer_Literal
8575 and then Nkind (High_Bound (Bounds)) = N_Integer_Literal
8576 then
8577 Lo := Low_Bound (Bounds);
8578 Hi := High_Bound (Bounds);
8579
8580 if No (Component_Associations (N)) then
8581
8582 -- Verify that all components are static
8583
8584 Expr := First (Expressions (N));
8585 while Present (Expr) loop
8586 if not Is_Static_Component (Expr) then
8587 return False;
8588 end if;
8589
8590 Next (Expr);
8591 end loop;
8592
8593 return True;
8594
8595 else
8596 -- We allow only a single named association, either a static
8597 -- range or an others_clause, with a static expression.
8598
8599 Expr := First (Component_Associations (N));
8600
8601 if Present (Expressions (N)) then
8602 return False;
8603
8604 elsif Present (Next (Expr)) then
8605 return False;
8606
8607 elsif Present (Next (First (Choice_List (Expr)))) then
8608 return False;
8609
8610 else
8611 -- The aggregate is static if all components are literals,
8612 -- or else all its components are static aggregates for the
8613 -- component type. We also limit the size of a static aggregate
8614 -- to prevent runaway static expressions.
8615
8616 if not Is_Static_Component (Expression (Expr)) then
8617 return False;
8618 end if;
8619
8620 if not Aggr_Size_OK (N, Typ) then
8621 return False;
8622 end if;
8623
8624 -- Create a positional aggregate with the right number of
8625 -- copies of the expression.
8626
8627 Agg := Make_Aggregate (Sloc (N), New_List, No_List);
8628
8629 for I in UI_To_Int (Intval (Lo)) .. UI_To_Int (Intval (Hi))
8630 loop
8631 Append_To (Expressions (Agg), New_Copy (Expression (Expr)));
8632
8633 -- The copied expression must be analyzed and resolved.
8634 -- Besides setting the type, this ensures that static
8635 -- expressions are appropriately marked as such.
8636
8637 Analyze_And_Resolve
8638 (Last (Expressions (Agg)), Component_Type (Typ));
8639 end loop;
8640
8641 Set_Aggregate_Bounds (Agg, Bounds);
8642 Set_Etype (Agg, Typ);
8643 Set_Analyzed (Agg);
8644 Rewrite (N, Agg);
8645 Set_Compile_Time_Known_Aggregate (N);
8646
8647 return True;
8648 end if;
8649 end if;
8650
8651 else
8652 return False;
8653 end if;
8654 end Static_Array_Aggregate;
8655
8656 ----------------------------------
8657 -- Two_Dim_Packed_Array_Handled --
8658 ----------------------------------
8659
8660 function Two_Dim_Packed_Array_Handled (N : Node_Id) return Boolean is
8661 Loc : constant Source_Ptr := Sloc (N);
8662 Typ : constant Entity_Id := Etype (N);
8663 Ctyp : constant Entity_Id := Component_Type (Typ);
8664 Comp_Size : constant Int := UI_To_Int (Component_Size (Typ));
8665 Packed_Array : constant Entity_Id :=
8666 Packed_Array_Impl_Type (Base_Type (Typ));
8667
8668 One_Comp : Node_Id;
8669 -- Expression in original aggregate
8670
8671 One_Dim : Node_Id;
8672 -- One-dimensional subaggregate
8673
8674 begin
8675
8676 -- For now, only deal with cases where an integral number of elements
8677 -- fit in a single byte. This includes the most common boolean case.
8678
8679 if not (Comp_Size = 1 or else
8680 Comp_Size = 2 or else
8681 Comp_Size = 4)
8682 then
8683 return False;
8684 end if;
8685
8686 Convert_To_Positional
8687 (N, Max_Others_Replicate => 64, Handle_Bit_Packed => True);
8688
8689 -- Verify that all components are static
8690
8691 if Nkind (N) = N_Aggregate
8692 and then Compile_Time_Known_Aggregate (N)
8693 then
8694 null;
8695
8696 -- The aggregate may have been reanalyzed and converted already
8697
8698 elsif Nkind (N) /= N_Aggregate then
8699 return True;
8700
8701 -- If component associations remain, the aggregate is not static
8702
8703 elsif Present (Component_Associations (N)) then
8704 return False;
8705
8706 else
8707 One_Dim := First (Expressions (N));
8708 while Present (One_Dim) loop
8709 if Present (Component_Associations (One_Dim)) then
8710 return False;
8711 end if;
8712
8713 One_Comp := First (Expressions (One_Dim));
8714 while Present (One_Comp) loop
8715 if not Is_OK_Static_Expression (One_Comp) then
8716 return False;
8717 end if;
8718
8719 Next (One_Comp);
8720 end loop;
8721
8722 Next (One_Dim);
8723 end loop;
8724 end if;
8725
8726 -- Two-dimensional aggregate is now fully positional so pack one
8727 -- dimension to create a static one-dimensional array, and rewrite
8728 -- as an unchecked conversion to the original type.
8729
8730 declare
8731 Byte_Size : constant Int := UI_To_Int (Component_Size (Packed_Array));
8732 -- The packed array type is a byte array
8733
8734 Packed_Num : Nat;
8735 -- Number of components accumulated in current byte
8736
8737 Comps : List_Id;
8738 -- Assembled list of packed values for equivalent aggregate
8739
8740 Comp_Val : Uint;
8741 -- Integer value of component
8742
8743 Incr : Int;
8744 -- Step size for packing
8745
8746 Init_Shift : Int;
8747 -- Endian-dependent start position for packing
8748
8749 Shift : Int;
8750 -- Current insertion position
8751
8752 Val : Int;
8753 -- Component of packed array being assembled
8754
8755 begin
8756 Comps := New_List;
8757 Val := 0;
8758 Packed_Num := 0;
8759
8760 -- Account for endianness. See corresponding comment in
8761 -- Packed_Array_Aggregate_Handled concerning the following.
8762
8763 if Bytes_Big_Endian
8764 xor Debug_Flag_8
8765 xor Reverse_Storage_Order (Base_Type (Typ))
8766 then
8767 Init_Shift := Byte_Size - Comp_Size;
8768 Incr := -Comp_Size;
8769 else
8770 Init_Shift := 0;
8771 Incr := +Comp_Size;
8772 end if;
8773
8774 -- Iterate over each subaggregate
8775
8776 Shift := Init_Shift;
8777 One_Dim := First (Expressions (N));
8778 while Present (One_Dim) loop
8779 One_Comp := First (Expressions (One_Dim));
8780 while Present (One_Comp) loop
8781 if Packed_Num = Byte_Size / Comp_Size then
8782
8783 -- Byte is complete, add to list of expressions
8784
8785 Append (Make_Integer_Literal (Sloc (One_Dim), Val), Comps);
8786 Val := 0;
8787 Shift := Init_Shift;
8788 Packed_Num := 0;
8789
8790 else
8791 Comp_Val := Expr_Rep_Value (One_Comp);
8792
8793 -- Adjust for bias, and strip proper number of bits
8794
8795 if Has_Biased_Representation (Ctyp) then
8796 Comp_Val := Comp_Val - Expr_Value (Type_Low_Bound (Ctyp));
8797 end if;
8798
8799 Comp_Val := Comp_Val mod Uint_2 ** Comp_Size;
8800 Val := UI_To_Int (Val + Comp_Val * Uint_2 ** Shift);
8801 Shift := Shift + Incr;
8802 One_Comp := Next (One_Comp);
8803 Packed_Num := Packed_Num + 1;
8804 end if;
8805 end loop;
8806
8807 One_Dim := Next (One_Dim);
8808 end loop;
8809
8810 if Packed_Num > 0 then
8811
8812 -- Add final incomplete byte if present
8813
8814 Append (Make_Integer_Literal (Sloc (One_Dim), Val), Comps);
8815 end if;
8816
8817 Rewrite (N,
8818 Unchecked_Convert_To (Typ,
8819 Make_Qualified_Expression (Loc,
8820 Subtype_Mark => New_Occurrence_Of (Packed_Array, Loc),
8821 Expression => Make_Aggregate (Loc, Expressions => Comps))));
8822 Analyze_And_Resolve (N);
8823 return True;
8824 end;
8825 end Two_Dim_Packed_Array_Handled;
8826
8827 end Exp_Aggr;
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