]> git.ipfire.org Git - thirdparty/gcc.git/blob - gcc/ada/exp_aggr.adb
ada: Further cleanup in finalization machinery
[thirdparty/gcc.git] / gcc / ada / exp_aggr.adb
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) 1992-2023, 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 Aspects; use Aspects;
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Debug; use Debug;
30 with Einfo; use Einfo;
31 with Einfo.Entities; use Einfo.Entities;
32 with Einfo.Utils; use Einfo.Utils;
33 with Elists; use Elists;
34 with Errout; use Errout;
35 with Expander; use Expander;
36 with Exp_Util; use Exp_Util;
37 with Exp_Ch3; use Exp_Ch3;
38 with Exp_Ch6; use Exp_Ch6;
39 with Exp_Ch7; use Exp_Ch7;
40 with Exp_Ch9; use Exp_Ch9;
41 with Exp_Disp; use Exp_Disp;
42 with Exp_Tss; use Exp_Tss;
43 with Freeze; use Freeze;
44 with Itypes; use Itypes;
45 with Lib; use Lib;
46 with Namet; use Namet;
47 with Nmake; use Nmake;
48 with Nlists; use Nlists;
49 with Opt; use Opt;
50 with Restrict; use Restrict;
51 with Rident; use Rident;
52 with Rtsfind; use Rtsfind;
53 with Ttypes; use Ttypes;
54 with Sem; use Sem;
55 with Sem_Aggr; use Sem_Aggr;
56 with Sem_Aux; use Sem_Aux;
57 with Sem_Case; use Sem_Case;
58 with Sem_Ch3; use Sem_Ch3;
59 with Sem_Ch8; use Sem_Ch8;
60 with Sem_Ch13; use Sem_Ch13;
61 with Sem_Eval; use Sem_Eval;
62 with Sem_Mech; use Sem_Mech;
63 with Sem_Res; use Sem_Res;
64 with Sem_Type; use Sem_Type;
65 with Sem_Util; use Sem_Util;
66 use Sem_Util.Storage_Model_Support;
67 with Sinfo; use Sinfo;
68 with Sinfo.Nodes; use Sinfo.Nodes;
69 with Sinfo.Utils; use Sinfo.Utils;
70 with Snames; use Snames;
71 with Stand; use Stand;
72 with Stringt; use Stringt;
73 with Tbuild; use Tbuild;
74 with Uintp; use Uintp;
75 with Urealp; use Urealp;
76 with Warnsw; use Warnsw;
77
78 package body Exp_Aggr is
79
80 function Build_Assignment_With_Temporary
81 (Target : Node_Id;
82 Typ : Entity_Id;
83 Source : Node_Id) return List_Id;
84 -- Returns a list of actions to assign Source to Target of type Typ using
85 -- an extra temporary, which can potentially be large.
86
87 type Case_Bounds is record
88 Choice_Lo : Node_Id;
89 Choice_Hi : Node_Id;
90 Choice_Node : Node_Id;
91 end record;
92
93 type Case_Table_Type is array (Nat range <>) of Case_Bounds;
94 -- Table type used by Check_Case_Choices procedure
95
96 procedure Expand_Delta_Array_Aggregate (N : Node_Id; Deltas : List_Id);
97 procedure Expand_Delta_Record_Aggregate (N : Node_Id; Deltas : List_Id);
98 procedure Expand_Container_Aggregate (N : Node_Id);
99
100 function Get_Base_Object (N : Node_Id) return Entity_Id;
101 -- Return the base object, i.e. the outermost prefix object, that N refers
102 -- to statically, or Empty if it cannot be determined. The assumption is
103 -- that all dereferences are explicit in the tree rooted at N.
104
105 function Has_Default_Init_Comps (N : Node_Id) return Boolean;
106 -- N is an aggregate (record or array). Checks the presence of default
107 -- initialization (<>) in any component (Ada 2005: AI-287).
108
109 procedure Initialize_Component
110 (N : Node_Id;
111 Comp : Node_Id;
112 Comp_Typ : Node_Id;
113 Init_Expr : Node_Id;
114 Stmts : List_Id);
115 -- Perform the initialization of component Comp with expected type
116 -- Comp_Typ of aggregate N. Init_Expr denotes the initialization
117 -- expression of the component. All generated code is added to Stmts.
118
119 function Is_CCG_Supported_Aggregate (N : Node_Id) return Boolean;
120 -- Return True if aggregate N is located in a context supported by the
121 -- CCG backend; False otherwise.
122
123 function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean;
124 -- Returns true if N is an aggregate used to initialize the components
125 -- of a statically allocated dispatch table.
126
127 function Late_Expansion
128 (N : Node_Id;
129 Typ : Entity_Id;
130 Target : Node_Id) return List_Id;
131 -- This routine implements top-down expansion of nested aggregates. In
132 -- doing so, it avoids the generation of temporaries at each level. N is
133 -- a nested record or array aggregate with the Expansion_Delayed flag.
134 -- Typ is the expected type of the aggregate. Target is a (duplicatable)
135 -- expression that will hold the result of the aggregate expansion.
136
137 function Make_OK_Assignment_Statement
138 (Sloc : Source_Ptr;
139 Name : Node_Id;
140 Expression : Node_Id) return Node_Id;
141 -- This is like Make_Assignment_Statement, except that Assignment_OK
142 -- is set in the left operand. All assignments built by this unit use
143 -- this routine. This is needed to deal with assignments to initialized
144 -- constants that are done in place.
145
146 function Must_Slide
147 (Aggr : Node_Id;
148 Obj_Type : Entity_Id;
149 Typ : Entity_Id) return Boolean;
150 -- A static array aggregate in an object declaration can in most cases be
151 -- expanded in place. The one exception is when the aggregate is given
152 -- with component associations that specify different bounds from those of
153 -- the type definition in the object declaration. In this pathological
154 -- case the aggregate must slide, and we must introduce an intermediate
155 -- temporary to hold it.
156 --
157 -- The same holds in an assignment to one-dimensional array of arrays,
158 -- when a component may be given with bounds that differ from those of the
159 -- component type.
160
161 function Number_Of_Choices (N : Node_Id) return Nat;
162 -- Returns the number of discrete choices (not including the others choice
163 -- if present) contained in (sub-)aggregate N.
164
165 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
166 -- Sort the Case Table using the Lower Bound of each Choice as the key.
167 -- A simple insertion sort is used since the number of choices in a case
168 -- statement of variant part will usually be small and probably in near
169 -- sorted order.
170
171 ------------------------------------------------------
172 -- Local subprograms for Record Aggregate Expansion --
173 ------------------------------------------------------
174
175 function Is_Build_In_Place_Aggregate_Return (N : Node_Id) return Boolean;
176 -- True if N is an aggregate (possibly qualified or a dependent expression
177 -- of a conditional expression, and possibly recursively so) that is being
178 -- returned from a build-in-place function. Such qualified and conditional
179 -- expressions are transparent for this purpose because an enclosing return
180 -- is propagated resp. distributed into these expressions by the expander.
181
182 function Build_Record_Aggr_Code
183 (N : Node_Id;
184 Typ : Entity_Id;
185 Lhs : Node_Id) return List_Id;
186 -- N is an N_Aggregate or an N_Extension_Aggregate. Typ is the type of the
187 -- aggregate. Target is an expression containing the location on which the
188 -- component by component assignments will take place. Returns the list of
189 -- assignments plus all other adjustments needed for tagged and controlled
190 -- types.
191
192 procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id);
193 -- Transform a record aggregate into a sequence of assignments performed
194 -- component by component. N is an N_Aggregate or N_Extension_Aggregate.
195 -- Typ is the type of the record aggregate.
196
197 procedure Expand_Record_Aggregate
198 (N : Node_Id;
199 Orig_Tag : Node_Id := Empty;
200 Parent_Expr : Node_Id := Empty);
201 -- This is the top level procedure for record aggregate expansion.
202 -- Expansion for record aggregates needs expand aggregates for tagged
203 -- record types. Specifically Expand_Record_Aggregate adds the Tag
204 -- field in front of the Component_Association list that was created
205 -- during resolution by Resolve_Record_Aggregate.
206 --
207 -- N is the record aggregate node.
208 -- Orig_Tag is the value of the Tag that has to be provided for this
209 -- specific aggregate. It carries the tag corresponding to the type
210 -- of the outermost aggregate during the recursive expansion
211 -- Parent_Expr is the ancestor part of the original extension
212 -- aggregate
213
214 function Has_Mutable_Components (Typ : Entity_Id) return Boolean;
215 -- Return true if one of the components is of a discriminated type with
216 -- defaults. An aggregate for a type with mutable components must be
217 -- expanded into individual assignments.
218
219 function In_Place_Assign_OK
220 (N : Node_Id;
221 Target_Object : Entity_Id := Empty) return Boolean;
222 -- Predicate to determine whether an aggregate assignment can be done in
223 -- place, because none of the new values can depend on the components of
224 -- the target of the assignment.
225
226 procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id);
227 -- If the type of the aggregate is a type extension with renamed discrimi-
228 -- nants, we must initialize the hidden discriminants of the parent.
229 -- Otherwise, the target object must not be initialized. The discriminants
230 -- are initialized by calling the initialization procedure for the type.
231 -- This is incorrect if the initialization of other components has any
232 -- side effects. We restrict this call to the case where the parent type
233 -- has a variant part, because this is the only case where the hidden
234 -- discriminants are accessed, namely when calling discriminant checking
235 -- functions of the parent type, and when applying a stream attribute to
236 -- an object of the derived type.
237
238 -----------------------------------------------------
239 -- Local Subprograms for Array Aggregate Expansion --
240 -----------------------------------------------------
241
242 function Aggr_Assignment_OK_For_Backend (N : Node_Id) return Boolean;
243 -- Returns true if an aggregate assignment can be done by the back end
244
245 function Aggr_Size_OK (N : Node_Id) return Boolean;
246 -- Very large static aggregates present problems to the back-end, and are
247 -- transformed into assignments and loops. This function verifies that the
248 -- total number of components of an aggregate is acceptable for rewriting
249 -- into a purely positional static form. Aggr_Size_OK must be called before
250 -- calling Flatten.
251 --
252 -- This function also detects and warns about one-component aggregates that
253 -- appear in a nonstatic context. Even if the component value is static,
254 -- such an aggregate must be expanded into an assignment.
255
256 function Backend_Processing_Possible (N : Node_Id) return Boolean;
257 -- This function checks if array aggregate N can be processed directly
258 -- by the backend. If this is the case, True is returned.
259
260 function Build_Array_Aggr_Code
261 (N : Node_Id;
262 Ctype : Entity_Id;
263 Index : Node_Id;
264 Into : Node_Id;
265 Scalar_Comp : Boolean;
266 Indexes : List_Id := No_List) return List_Id;
267 -- This recursive routine returns a list of statements containing the
268 -- loops and assignments that are needed for the expansion of the array
269 -- aggregate N.
270 --
271 -- N is the (sub-)aggregate node to be expanded into code. This node has
272 -- been fully analyzed, and its Etype is properly set.
273 --
274 -- Index is the index node corresponding to the array subaggregate N
275 --
276 -- Into is the target expression into which we are copying the aggregate.
277 -- Note that this node may not have been analyzed yet, and so the Etype
278 -- field may not be set.
279 --
280 -- Scalar_Comp is True if the component type of the aggregate is scalar
281 --
282 -- Indexes is the current list of expressions used to index the object we
283 -- are writing into.
284
285 procedure Convert_Array_Aggr_In_Allocator
286 (Decl : Node_Id;
287 Aggr : Node_Id;
288 Target : Node_Id);
289 -- If the aggregate appears within an allocator and can be expanded in
290 -- place, this routine generates the individual assignments to components
291 -- of the designated object. This is an optimization over the general
292 -- case, where a temporary is first created on the stack and then used to
293 -- construct the allocated object on the heap.
294
295 procedure Convert_To_Positional
296 (N : Node_Id;
297 Handle_Bit_Packed : Boolean := False);
298 -- If possible, convert named notation to positional notation. This
299 -- conversion is possible only in some static cases. If the conversion is
300 -- possible, then N is rewritten with the analyzed converted aggregate.
301 -- The parameter Handle_Bit_Packed is usually set False (since we do
302 -- not expect the back end to handle bit packed arrays, so the normal case
303 -- of conversion is pointless), but in the special case of a call from
304 -- Packed_Array_Aggregate_Handled, we set this parameter to True, since
305 -- these are cases we handle in there.
306
307 procedure Expand_Array_Aggregate (N : Node_Id);
308 -- This is the top-level routine to perform array aggregate expansion.
309 -- N is the N_Aggregate node to be expanded.
310
311 function Is_Two_Dim_Packed_Array (Typ : Entity_Id) return Boolean;
312 -- For 2D packed array aggregates with constant bounds and constant scalar
313 -- components, it is preferable to pack the inner aggregates because the
314 -- whole matrix can then be presented to the back-end as a one-dimensional
315 -- list of literals. This is much more efficient than expanding into single
316 -- component assignments. This function determines if the type Typ is for
317 -- an array that is suitable for this optimization: it returns True if Typ
318 -- is a two dimensional bit packed array with component size 1, 2, or 4.
319
320 function Max_Aggregate_Size
321 (N : Node_Id;
322 Default_Size : Nat := 5000) return Nat;
323 -- Return the max size for a static aggregate N. Return Default_Size if no
324 -- other special criteria trigger.
325
326 function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean;
327 -- Given an array aggregate, this function handles the case of a packed
328 -- array aggregate with all constant values, where the aggregate can be
329 -- evaluated at compile time. If this is possible, then N is rewritten
330 -- to be its proper compile time value with all the components properly
331 -- assembled. The expression is analyzed and resolved and True is returned.
332 -- If this transformation is not possible, N is unchanged and False is
333 -- returned.
334
335 function Two_Dim_Packed_Array_Handled (N : Node_Id) return Boolean;
336 -- If the type of the aggregate is a two-dimensional bit_packed array
337 -- it may be transformed into an array of bytes with constant values,
338 -- and presented to the back-end as a static value. The function returns
339 -- false if this transformation cannot be performed. THis is similar to,
340 -- and reuses part of the machinery in Packed_Array_Aggregate_Handled.
341
342 ------------------------------------
343 -- Aggr_Assignment_OK_For_Backend --
344 ------------------------------------
345
346 -- Back-end processing by Gigi/gcc is possible only if all the following
347 -- conditions are met:
348
349 -- 1. N consists of a single OTHERS choice, possibly recursively, or
350 -- of a single choice, possibly recursively, if it is surrounded by
351 -- a qualified expression whose subtype mark is unconstrained.
352
353 -- 2. The array type has no null ranges (the purpose of this is to
354 -- avoid a bogus warning for an out-of-range value).
355
356 -- 3. The array type has no atomic components
357
358 -- 4. The component type is elementary
359
360 -- 5. The component size is a multiple of Storage_Unit
361
362 -- 6. The component size is Storage_Unit or the value is of the form
363 -- M * (1 + A**1 + A**2 + .. A**(K-1)) where A = 2**(Storage_Unit)
364 -- and M in 0 .. A-1. This can also be viewed as K occurrences of
365 -- the Storage_Unit value M, concatenated together.
366
367 -- The ultimate goal is to generate a call to a fast memset routine
368 -- specifically optimized for the target.
369
370 function Aggr_Assignment_OK_For_Backend (N : Node_Id) return Boolean is
371
372 function Is_OK_Aggregate (Aggr : Node_Id) return Boolean;
373 -- Return true if Aggr is suitable for back-end assignment
374
375 ---------------------
376 -- Is_OK_Aggregate --
377 ---------------------
378
379 function Is_OK_Aggregate (Aggr : Node_Id) return Boolean is
380 Assoc : constant List_Id := Component_Associations (Aggr);
381
382 begin
383 -- An "others" aggregate is most likely OK, but see below
384
385 if Is_Others_Aggregate (Aggr) then
386 null;
387
388 -- An aggregate with a single choice requires a qualified expression
389 -- whose subtype mark is an unconstrained type because we need it to
390 -- have the semantics of an "others" aggregate.
391
392 elsif Nkind (Parent (N)) = N_Qualified_Expression
393 and then not Is_Constrained (Entity (Subtype_Mark (Parent (N))))
394 and then Is_Single_Aggregate (Aggr)
395 then
396 null;
397
398 -- The other cases are not OK
399
400 else
401 return False;
402 end if;
403
404 -- In any case we do not support an iterated association
405
406 return Nkind (First (Assoc)) /= N_Iterated_Component_Association;
407 end Is_OK_Aggregate;
408
409 Bounds : Range_Nodes;
410 Csiz : Uint := No_Uint;
411 Ctyp : Entity_Id;
412 Expr : Node_Id;
413 Index : Entity_Id;
414 Nunits : Int;
415 Remainder : Uint;
416 Value : Uint;
417
418 -- Start of processing for Aggr_Assignment_OK_For_Backend
419
420 begin
421 -- Back end doesn't know about <>
422
423 if Has_Default_Init_Comps (N) then
424 return False;
425 end if;
426
427 -- Recurse as far as possible to find the innermost component type
428
429 Ctyp := Etype (N);
430 Expr := N;
431 while Is_Array_Type (Ctyp) loop
432 if Nkind (Expr) /= N_Aggregate
433 or else not Is_OK_Aggregate (Expr)
434 then
435 return False;
436 end if;
437
438 Index := First_Index (Ctyp);
439 while Present (Index) loop
440 Bounds := Get_Index_Bounds (Index);
441
442 if Is_Null_Range (Bounds.First, Bounds.Last) then
443 return False;
444 end if;
445
446 Next_Index (Index);
447 end loop;
448
449 Expr := Expression (First (Component_Associations (Expr)));
450
451 for J in 1 .. Number_Dimensions (Ctyp) - 1 loop
452 if Nkind (Expr) /= N_Aggregate
453 or else not Is_OK_Aggregate (Expr)
454 then
455 return False;
456 end if;
457
458 Expr := Expression (First (Component_Associations (Expr)));
459 end loop;
460
461 if Has_Atomic_Components (Ctyp) then
462 return False;
463 end if;
464
465 Csiz := Component_Size (Ctyp);
466 Ctyp := Component_Type (Ctyp);
467
468 if Is_Full_Access (Ctyp) then
469 return False;
470 end if;
471 end loop;
472
473 -- Access types need to be dealt with specially
474
475 if Is_Access_Type (Ctyp) then
476
477 -- Component_Size is not set by Layout_Type if the component
478 -- type is an access type ???
479
480 Csiz := Esize (Ctyp);
481
482 -- Fat pointers are rejected as they are not really elementary
483 -- for the backend.
484
485 if No (Csiz) or else Csiz /= System_Address_Size then
486 return False;
487 end if;
488
489 -- The supported expressions are NULL and constants, others are
490 -- rejected upfront to avoid being analyzed below, which can be
491 -- problematic for some of them, for example allocators.
492
493 if Nkind (Expr) /= N_Null and then not Is_Entity_Name (Expr) then
494 return False;
495 end if;
496
497 -- Scalar types are OK if their size is a multiple of Storage_Unit
498
499 elsif Is_Scalar_Type (Ctyp) and then Present (Csiz) then
500
501 if Csiz mod System_Storage_Unit /= 0 then
502 return False;
503 end if;
504
505 -- Composite types are rejected
506
507 else
508 return False;
509 end if;
510
511 -- If the expression has side effects (e.g. contains calls with
512 -- potential side effects) reject as well. We only preanalyze the
513 -- expression to prevent the removal of intended side effects.
514
515 Preanalyze_And_Resolve (Expr, Ctyp);
516
517 if not Side_Effect_Free (Expr) then
518 return False;
519 end if;
520
521 -- The expression needs to be analyzed if True is returned
522
523 Analyze_And_Resolve (Expr, Ctyp);
524
525 -- Strip away any conversions from the expression as they simply
526 -- qualify the real expression.
527
528 while Nkind (Expr) in N_Unchecked_Type_Conversion | N_Type_Conversion
529 loop
530 Expr := Expression (Expr);
531 end loop;
532
533 Nunits := UI_To_Int (Csiz) / System_Storage_Unit;
534
535 if Nunits = 1 then
536 return True;
537 end if;
538
539 if not Compile_Time_Known_Value (Expr) then
540 return False;
541 end if;
542
543 -- The only supported value for floating point is 0.0
544
545 if Is_Floating_Point_Type (Ctyp) then
546 return Expr_Value_R (Expr) = Ureal_0;
547 end if;
548
549 -- For other types, we can look into the value as an integer, which
550 -- means the representation value for enumeration literals.
551
552 Value := Expr_Rep_Value (Expr);
553
554 if Has_Biased_Representation (Ctyp) then
555 Value := Value - Expr_Value (Type_Low_Bound (Ctyp));
556 end if;
557
558 -- Values 0 and -1 immediately satisfy the last check
559
560 if Value = Uint_0 or else Value = Uint_Minus_1 then
561 return True;
562 end if;
563
564 -- We need to work with an unsigned value
565
566 if Value < 0 then
567 Value := Value + 2**(System_Storage_Unit * Nunits);
568 end if;
569
570 Remainder := Value rem 2**System_Storage_Unit;
571
572 for J in 1 .. Nunits - 1 loop
573 Value := Value / 2**System_Storage_Unit;
574
575 if Value rem 2**System_Storage_Unit /= Remainder then
576 return False;
577 end if;
578 end loop;
579
580 return True;
581 end Aggr_Assignment_OK_For_Backend;
582
583 ------------------
584 -- Aggr_Size_OK --
585 ------------------
586
587 function Aggr_Size_OK (N : Node_Id) return Boolean is
588 Typ : constant Entity_Id := Etype (N);
589 Lo : Node_Id;
590 Hi : Node_Id;
591 Indx : Node_Id;
592 Size : Uint;
593 Lov : Uint;
594 Hiv : Uint;
595
596 Max_Aggr_Size : Nat;
597 -- Determines the maximum size of an array aggregate produced by
598 -- converting named to positional notation (e.g. from others clauses).
599 -- This avoids running away with attempts to convert huge aggregates,
600 -- which hit memory limits in the backend.
601
602 function Component_Count (T : Entity_Id) return Nat;
603 -- The limit is applied to the total number of subcomponents that the
604 -- aggregate will have, which is the number of static expressions
605 -- that will appear in the flattened array. This requires a recursive
606 -- computation of the number of scalar components of the structure.
607
608 ---------------------
609 -- Component_Count --
610 ---------------------
611
612 function Component_Count (T : Entity_Id) return Nat is
613 Res : Nat := 0;
614 Comp : Entity_Id;
615
616 begin
617 if Is_Scalar_Type (T) then
618 return 1;
619
620 elsif Is_Record_Type (T) then
621 Comp := First_Component (T);
622 while Present (Comp) loop
623 Res := Res + Component_Count (Etype (Comp));
624 Next_Component (Comp);
625 end loop;
626
627 return Res;
628
629 elsif Is_Array_Type (T) then
630 declare
631 Lo : constant Node_Id :=
632 Type_Low_Bound (Etype (First_Index (T)));
633 Hi : constant Node_Id :=
634 Type_High_Bound (Etype (First_Index (T)));
635
636 Siz : constant Nat := Component_Count (Component_Type (T));
637
638 begin
639 -- Check for superflat arrays, i.e. arrays with such bounds
640 -- as 4 .. 2, to insure that this function never returns a
641 -- meaningless negative value.
642
643 if not Compile_Time_Known_Value (Lo)
644 or else not Compile_Time_Known_Value (Hi)
645 or else Expr_Value (Hi) < Expr_Value (Lo)
646 then
647 return 0;
648
649 else
650 -- If the number of components is greater than Int'Last,
651 -- then return Int'Last, so caller will return False (Aggr
652 -- size is not OK). Otherwise, UI_To_Int will crash.
653
654 declare
655 UI : constant Uint :=
656 (Expr_Value (Hi) - Expr_Value (Lo) + 1) * Siz;
657 begin
658 if UI_Is_In_Int_Range (UI) then
659 return UI_To_Int (UI);
660 else
661 return Int'Last;
662 end if;
663 end;
664 end if;
665 end;
666
667 else
668 -- Can only be a null for an access type
669
670 return 1;
671 end if;
672 end Component_Count;
673
674 -- Start of processing for Aggr_Size_OK
675
676 begin
677 -- We bump the maximum size unless the aggregate has a single component
678 -- association, which will be more efficient if implemented with a loop.
679 -- The -gnatd_g switch disables this bumping.
680
681 if (No (Expressions (N))
682 and then No (Next (First (Component_Associations (N)))))
683 or else Debug_Flag_Underscore_G
684 then
685 Max_Aggr_Size := Max_Aggregate_Size (N);
686 else
687 Max_Aggr_Size := Max_Aggregate_Size (N, 500_000);
688 end if;
689
690 Size := UI_From_Int (Component_Count (Component_Type (Typ)));
691
692 Indx := First_Index (Typ);
693 while Present (Indx) loop
694 Lo := Type_Low_Bound (Etype (Indx));
695 Hi := Type_High_Bound (Etype (Indx));
696
697 -- Bounds need to be known at compile time
698
699 if not Compile_Time_Known_Value (Lo)
700 or else not Compile_Time_Known_Value (Hi)
701 then
702 return False;
703 end if;
704
705 Lov := Expr_Value (Lo);
706 Hiv := Expr_Value (Hi);
707
708 -- A flat array is always safe
709
710 if Hiv < Lov then
711 return True;
712 end if;
713
714 -- One-component aggregates are suspicious, and if the context type
715 -- is an object declaration with nonstatic bounds it will trip gcc;
716 -- such an aggregate must be expanded into a single assignment.
717
718 if Hiv = Lov and then Nkind (Parent (N)) = N_Object_Declaration then
719 declare
720 Index_Type : constant Entity_Id :=
721 Etype
722 (First_Index (Etype (Defining_Identifier (Parent (N)))));
723 Indx : Node_Id;
724
725 begin
726 if not Compile_Time_Known_Value (Type_Low_Bound (Index_Type))
727 or else not Compile_Time_Known_Value
728 (Type_High_Bound (Index_Type))
729 then
730 if Present (Component_Associations (N)) then
731 Indx :=
732 First
733 (Choice_List (First (Component_Associations (N))));
734
735 if Is_Entity_Name (Indx)
736 and then not Is_Type (Entity (Indx))
737 then
738 Error_Msg_N
739 ("single component aggregate in "
740 & "non-static context??", Indx);
741 Error_Msg_N ("\maybe subtype name was meant??", Indx);
742 end if;
743 end if;
744
745 return False;
746 end if;
747 end;
748 end if;
749
750 declare
751 Rng : constant Uint := Hiv - Lov + 1;
752
753 begin
754 -- Check if size is too large
755
756 if not UI_Is_In_Int_Range (Rng) then
757 return False;
758 end if;
759
760 -- Compute the size using universal arithmetic to avoid the
761 -- possibility of overflow on very large aggregates.
762
763 Size := Size * Rng;
764
765 if Size <= 0
766 or else Size > Max_Aggr_Size
767 then
768 return False;
769 end if;
770 end;
771
772 -- Bounds must be in integer range, for later array construction
773
774 if not UI_Is_In_Int_Range (Lov)
775 or else
776 not UI_Is_In_Int_Range (Hiv)
777 then
778 return False;
779 end if;
780
781 Next_Index (Indx);
782 end loop;
783
784 return True;
785 end Aggr_Size_OK;
786
787 ---------------------------------
788 -- Backend_Processing_Possible --
789 ---------------------------------
790
791 -- Backend processing by Gigi/gcc is possible only if all the following
792 -- conditions are met:
793
794 -- 1. N is fully positional
795
796 -- 2. N is not a bit-packed array aggregate;
797
798 -- 3. The size of N's array type must be known at compile time. Note
799 -- that this implies that the component size is also known
800
801 -- 4. The array type of N does not follow the Fortran layout convention
802 -- or if it does it must be 1 dimensional.
803
804 -- 5. The array component type may not be tagged (which could necessitate
805 -- reassignment of proper tags).
806
807 -- 6. The array component type must not have unaligned bit components
808
809 -- 7. None of the components of the aggregate may be bit unaligned
810 -- components.
811
812 -- 8. There cannot be delayed components, since we do not know enough
813 -- at this stage to know if back end processing is possible.
814
815 -- 9. There cannot be any discriminated record components, since the
816 -- back end cannot handle this complex case.
817
818 -- 10. No controlled actions need to be generated for components
819
820 -- 11. When generating C code, N must be part of a N_Object_Declaration
821
822 -- 12. When generating C code, N must not include function calls
823
824 function Backend_Processing_Possible (N : Node_Id) return Boolean is
825 Typ : constant Entity_Id := Etype (N);
826 -- Typ is the correct constrained array subtype of the aggregate
827
828 function Component_Check (N : Node_Id; Index : Node_Id) return Boolean;
829 -- This routine checks components of aggregate N, enforcing checks
830 -- 1, 7, 8, 9, 11, and 12. In the multidimensional case, these checks
831 -- are performed on subaggregates. The Index value is the current index
832 -- being checked in the multidimensional case.
833
834 ---------------------
835 -- Component_Check --
836 ---------------------
837
838 function Component_Check (N : Node_Id; Index : Node_Id) return Boolean is
839 function Ultimate_Original_Expression (N : Node_Id) return Node_Id;
840 -- Given a type conversion or an unchecked type conversion N, return
841 -- its innermost original expression.
842
843 ----------------------------------
844 -- Ultimate_Original_Expression --
845 ----------------------------------
846
847 function Ultimate_Original_Expression (N : Node_Id) return Node_Id is
848 Expr : Node_Id := Original_Node (N);
849
850 begin
851 while Nkind (Expr) in
852 N_Type_Conversion | N_Unchecked_Type_Conversion
853 loop
854 Expr := Original_Node (Expression (Expr));
855 end loop;
856
857 return Expr;
858 end Ultimate_Original_Expression;
859
860 -- Local variables
861
862 Expr : Node_Id;
863
864 -- Start of processing for Component_Check
865
866 begin
867 -- Checks 1: (no component associations)
868
869 if Present (Component_Associations (N)) then
870 return False;
871 end if;
872
873 -- Checks 11: The C code generator cannot handle aggregates that are
874 -- not part of an object declaration.
875
876 if Modify_Tree_For_C and then not Is_CCG_Supported_Aggregate (N) then
877 return False;
878 end if;
879
880 -- Checks on components
881
882 -- Recurse to check subaggregates, which may appear in qualified
883 -- expressions. If delayed, the front-end will have to expand.
884 -- If the component is a discriminated record, treat as nonstatic,
885 -- as the back-end cannot handle this properly.
886
887 Expr := First (Expressions (N));
888 while Present (Expr) loop
889
890 -- Checks 8: (no delayed components)
891
892 if Is_Delayed_Aggregate (Expr) then
893 return False;
894 end if;
895
896 -- Checks 9: (no discriminated records)
897
898 if Present (Etype (Expr))
899 and then Is_Record_Type (Etype (Expr))
900 and then Has_Discriminants (Etype (Expr))
901 then
902 return False;
903 end if;
904
905 -- Checks 7. Component must not be bit aligned component
906
907 if Possible_Bit_Aligned_Component (Expr) then
908 return False;
909 end if;
910
911 -- Checks 12: (no function call)
912
913 if Modify_Tree_For_C
914 and then
915 Nkind (Ultimate_Original_Expression (Expr)) = N_Function_Call
916 then
917 return False;
918 end if;
919
920 -- Recursion to following indexes for multiple dimension case
921
922 if Present (Next_Index (Index))
923 and then not Component_Check (Expr, Next_Index (Index))
924 then
925 return False;
926 end if;
927
928 -- All checks for that component finished, on to next
929
930 Next (Expr);
931 end loop;
932
933 return True;
934 end Component_Check;
935
936 -- Start of processing for Backend_Processing_Possible
937
938 begin
939 -- Checks 2 (array not bit packed) and 10 (no controlled actions)
940
941 if Is_Bit_Packed_Array (Typ) or else Needs_Finalization (Typ) then
942 return False;
943 end if;
944
945 -- If component is limited, aggregate must be expanded because each
946 -- component assignment must be built in place.
947
948 if Is_Inherently_Limited_Type (Component_Type (Typ)) then
949 return False;
950 end if;
951
952 -- Checks 4 (array must not be multidimensional Fortran case)
953
954 if Convention (Typ) = Convention_Fortran
955 and then Number_Dimensions (Typ) > 1
956 then
957 return False;
958 end if;
959
960 -- Checks 3 (size of array must be known at compile time)
961
962 if not Size_Known_At_Compile_Time (Typ) then
963 return False;
964 end if;
965
966 -- Checks on components
967
968 if not Component_Check (N, First_Index (Typ)) then
969 return False;
970 end if;
971
972 -- Checks 5 (if the component type is tagged, then we may need to do
973 -- tag adjustments. Perhaps this should be refined to check for any
974 -- component associations that actually need tag adjustment, similar
975 -- to the test in Component_OK_For_Backend for record aggregates with
976 -- tagged components, but not clear whether it's worthwhile ???; in the
977 -- case of virtual machines (no Tagged_Type_Expansion), object tags are
978 -- handled implicitly).
979
980 if Is_Tagged_Type (Component_Type (Typ))
981 and then Tagged_Type_Expansion
982 then
983 return False;
984 end if;
985
986 -- Checks 6 (component type must not have bit aligned components)
987
988 if Type_May_Have_Bit_Aligned_Components (Component_Type (Typ)) then
989 return False;
990 end if;
991
992 -- Backend processing is possible
993
994 return True;
995 end Backend_Processing_Possible;
996
997 ---------------------------
998 -- Build_Array_Aggr_Code --
999 ---------------------------
1000
1001 -- The code that we generate from a one dimensional aggregate is
1002
1003 -- 1. If the subaggregate contains discrete choices we
1004
1005 -- (a) Sort the discrete choices
1006
1007 -- (b) Otherwise for each discrete choice that specifies a range we
1008 -- emit a loop. If a range specifies a maximum of three values, or
1009 -- we are dealing with an expression we emit a sequence of
1010 -- assignments instead of a loop.
1011
1012 -- (c) Generate the remaining loops to cover the others choice if any
1013
1014 -- 2. If the aggregate contains positional elements we
1015
1016 -- (a) Translate the positional elements in a series of assignments
1017
1018 -- (b) Generate a final loop to cover the others choice if any.
1019 -- Note that this final loop has to be a while loop since the case
1020
1021 -- L : Integer := Integer'Last;
1022 -- H : Integer := Integer'Last;
1023 -- A : array (L .. H) := (1, others =>0);
1024
1025 -- cannot be handled by a for loop. Thus for the following
1026
1027 -- array (L .. H) := (.. positional elements.., others => E);
1028
1029 -- we always generate something like:
1030
1031 -- J : Index_Type := Index_Of_Last_Positional_Element;
1032 -- while J < H loop
1033 -- J := Index_Base'Succ (J)
1034 -- Tmp (J) := E;
1035 -- end loop;
1036
1037 function Build_Array_Aggr_Code
1038 (N : Node_Id;
1039 Ctype : Entity_Id;
1040 Index : Node_Id;
1041 Into : Node_Id;
1042 Scalar_Comp : Boolean;
1043 Indexes : List_Id := No_List) return List_Id
1044 is
1045 Loc : constant Source_Ptr := Sloc (N);
1046 Typ : constant Entity_Id := Etype (N);
1047 Index_Base : constant Entity_Id := Base_Type (Etype (Index));
1048 Index_Base_L : constant Node_Id := Type_Low_Bound (Index_Base);
1049 Index_Base_H : constant Node_Id := Type_High_Bound (Index_Base);
1050
1051 function Add (Val : Int; To : Node_Id) return Node_Id;
1052 -- Returns an expression where Val is added to expression To, unless
1053 -- To+Val is provably out of To's base type range. To must be an
1054 -- already analyzed expression.
1055
1056 function Empty_Range (L, H : Node_Id) return Boolean;
1057 -- Returns True if the range defined by L .. H is certainly empty
1058
1059 function Equal (L, H : Node_Id) return Boolean;
1060 -- Returns True if L = H for sure
1061
1062 function Index_Base_Name return Node_Id;
1063 -- Returns a new reference to the index type name
1064
1065 function Gen_Assign
1066 (Ind : Node_Id;
1067 Expr : Node_Id) return List_Id;
1068 -- Ind must be a side-effect-free expression. If the input aggregate N
1069 -- to Build_Loop contains no subaggregates, then this function returns
1070 -- the assignment statement:
1071 --
1072 -- Into (Indexes, Ind) := Expr;
1073 --
1074 -- Otherwise we call Build_Code recursively.
1075 --
1076 -- Ada 2005 (AI-287): In case of default initialized component, Expr
1077 -- is empty and we generate a call to the corresponding IP subprogram.
1078
1079 function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id;
1080 -- Nodes L and H must be side-effect-free expressions. If the input
1081 -- aggregate N to Build_Loop contains no subaggregates, this routine
1082 -- returns the for loop statement:
1083 --
1084 -- for J in Index_Base'(L) .. Index_Base'(H) loop
1085 -- Into (Indexes, J) := Expr;
1086 -- end loop;
1087 --
1088 -- Otherwise we call Build_Code recursively. As an optimization if the
1089 -- loop covers 3 or fewer scalar elements we generate a sequence of
1090 -- assignments.
1091 -- If the component association that generates the loop comes from an
1092 -- Iterated_Component_Association, the loop parameter has the name of
1093 -- the corresponding parameter in the original construct.
1094
1095 function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id;
1096 -- Nodes L and H must be side-effect-free expressions. If the input
1097 -- aggregate N to Build_Loop contains no subaggregates, this routine
1098 -- returns the while loop statement:
1099 --
1100 -- J : Index_Base := L;
1101 -- while J < H loop
1102 -- J := Index_Base'Succ (J);
1103 -- Into (Indexes, J) := Expr;
1104 -- end loop;
1105 --
1106 -- Otherwise we call Build_Code recursively
1107
1108 function Get_Assoc_Expr (Assoc : Node_Id) return Node_Id;
1109 -- For an association with a box, use value given by aspect
1110 -- Default_Component_Value of array type if specified, else use
1111 -- value given by aspect Default_Value for component type itself
1112 -- if specified, else return Empty.
1113
1114 function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean;
1115 function Local_Expr_Value (E : Node_Id) return Uint;
1116 -- These two Local routines are used to replace the corresponding ones
1117 -- in sem_eval because while processing the bounds of an aggregate with
1118 -- discrete choices whose index type is an enumeration, we build static
1119 -- expressions not recognized by Compile_Time_Known_Value as such since
1120 -- they have not yet been analyzed and resolved. All the expressions in
1121 -- question are things like Index_Base_Name'Val (Const) which we can
1122 -- easily recognize as being constant.
1123
1124 ---------
1125 -- Add --
1126 ---------
1127
1128 function Add (Val : Int; To : Node_Id) return Node_Id is
1129 Expr_Pos : Node_Id;
1130 Expr : Node_Id;
1131 To_Pos : Node_Id;
1132 U_To : Uint;
1133 U_Val : constant Uint := UI_From_Int (Val);
1134
1135 begin
1136 -- Note: do not try to optimize the case of Val = 0, because
1137 -- we need to build a new node with the proper Sloc value anyway.
1138
1139 -- First test if we can do constant folding
1140
1141 if Local_Compile_Time_Known_Value (To) then
1142 U_To := Local_Expr_Value (To) + Val;
1143
1144 -- Determine if our constant is outside the range of the index.
1145 -- If so return an Empty node. This empty node will be caught
1146 -- by Empty_Range below.
1147
1148 if Compile_Time_Known_Value (Index_Base_L)
1149 and then U_To < Expr_Value (Index_Base_L)
1150 then
1151 return Empty;
1152
1153 elsif Compile_Time_Known_Value (Index_Base_H)
1154 and then U_To > Expr_Value (Index_Base_H)
1155 then
1156 return Empty;
1157 end if;
1158
1159 Expr_Pos := Make_Integer_Literal (Loc, U_To);
1160 Set_Is_Static_Expression (Expr_Pos);
1161
1162 if not Is_Enumeration_Type (Index_Base) then
1163 Expr := Expr_Pos;
1164
1165 -- If we are dealing with enumeration return
1166 -- Index_Base'Val (Expr_Pos)
1167
1168 else
1169 Expr :=
1170 Make_Attribute_Reference
1171 (Loc,
1172 Prefix => Index_Base_Name,
1173 Attribute_Name => Name_Val,
1174 Expressions => New_List (Expr_Pos));
1175 end if;
1176
1177 return Expr;
1178 end if;
1179
1180 -- If we are here no constant folding possible
1181
1182 if not Is_Enumeration_Type (Index_Base) then
1183 Expr :=
1184 Make_Op_Add (Loc,
1185 Left_Opnd => Duplicate_Subexpr (To),
1186 Right_Opnd => Make_Integer_Literal (Loc, U_Val));
1187
1188 -- If we are dealing with enumeration return
1189 -- Index_Base'Val (Index_Base'Pos (To) + Val)
1190
1191 else
1192 To_Pos :=
1193 Make_Attribute_Reference
1194 (Loc,
1195 Prefix => Index_Base_Name,
1196 Attribute_Name => Name_Pos,
1197 Expressions => New_List (Duplicate_Subexpr (To)));
1198
1199 Expr_Pos :=
1200 Make_Op_Add (Loc,
1201 Left_Opnd => To_Pos,
1202 Right_Opnd => Make_Integer_Literal (Loc, U_Val));
1203
1204 Expr :=
1205 Make_Attribute_Reference
1206 (Loc,
1207 Prefix => Index_Base_Name,
1208 Attribute_Name => Name_Val,
1209 Expressions => New_List (Expr_Pos));
1210 end if;
1211
1212 return Expr;
1213 end Add;
1214
1215 -----------------
1216 -- Empty_Range --
1217 -----------------
1218
1219 function Empty_Range (L, H : Node_Id) return Boolean is
1220 Is_Empty : Boolean := False;
1221 Low : Node_Id;
1222 High : Node_Id;
1223
1224 begin
1225 -- First check if L or H were already detected as overflowing the
1226 -- index base range type by function Add above. If this is so Add
1227 -- returns the empty node.
1228
1229 if No (L) or else No (H) then
1230 return True;
1231 end if;
1232
1233 for J in 1 .. 3 loop
1234 case J is
1235
1236 -- L > H range is empty
1237
1238 when 1 =>
1239 Low := L;
1240 High := H;
1241
1242 -- B_L > H range must be empty
1243
1244 when 2 =>
1245 Low := Index_Base_L;
1246 High := H;
1247
1248 -- L > B_H range must be empty
1249
1250 when 3 =>
1251 Low := L;
1252 High := Index_Base_H;
1253 end case;
1254
1255 if Local_Compile_Time_Known_Value (Low)
1256 and then
1257 Local_Compile_Time_Known_Value (High)
1258 then
1259 Is_Empty :=
1260 UI_Gt (Local_Expr_Value (Low), Local_Expr_Value (High));
1261 end if;
1262
1263 exit when Is_Empty;
1264 end loop;
1265
1266 return Is_Empty;
1267 end Empty_Range;
1268
1269 -----------
1270 -- Equal --
1271 -----------
1272
1273 function Equal (L, H : Node_Id) return Boolean is
1274 begin
1275 if L = H then
1276 return True;
1277
1278 elsif Local_Compile_Time_Known_Value (L)
1279 and then
1280 Local_Compile_Time_Known_Value (H)
1281 then
1282 return UI_Eq (Local_Expr_Value (L), Local_Expr_Value (H));
1283 end if;
1284
1285 return False;
1286 end Equal;
1287
1288 ----------------
1289 -- Gen_Assign --
1290 ----------------
1291
1292 function Gen_Assign
1293 (Ind : Node_Id;
1294 Expr : Node_Id) return List_Id
1295 is
1296 function Add_Loop_Actions (Lis : List_Id) return List_Id;
1297 -- Collect insert_actions generated in the construction of a loop,
1298 -- and prepend them to the sequence of assignments to complete the
1299 -- eventual body of the loop.
1300
1301 ----------------------
1302 -- Add_Loop_Actions --
1303 ----------------------
1304
1305 function Add_Loop_Actions (Lis : List_Id) return List_Id is
1306 Res : List_Id;
1307
1308 begin
1309 -- Ada 2005 (AI-287): Do nothing else in case of default
1310 -- initialized component.
1311
1312 if No (Expr) then
1313 return Lis;
1314
1315 elsif Nkind (Parent (Expr)) = N_Component_Association
1316 and then Present (Loop_Actions (Parent (Expr)))
1317 then
1318 Append_List (Lis, Loop_Actions (Parent (Expr)));
1319 Res := Loop_Actions (Parent (Expr));
1320 Set_Loop_Actions (Parent (Expr), No_List);
1321 return Res;
1322
1323 else
1324 return Lis;
1325 end if;
1326 end Add_Loop_Actions;
1327
1328 -- Local variables
1329
1330 Stmts : constant List_Id := New_List;
1331
1332 Comp_Typ : Entity_Id := Empty;
1333 Expr_Q : Node_Id;
1334 Indexed_Comp : Node_Id;
1335 Init_Call : Node_Id;
1336 New_Indexes : List_Id;
1337
1338 -- Start of processing for Gen_Assign
1339
1340 begin
1341 if No (Indexes) then
1342 New_Indexes := New_List;
1343 else
1344 New_Indexes := New_Copy_List_Tree (Indexes);
1345 end if;
1346
1347 Append_To (New_Indexes, Ind);
1348
1349 if Present (Next_Index (Index)) then
1350 return
1351 Add_Loop_Actions (
1352 Build_Array_Aggr_Code
1353 (N => Expr,
1354 Ctype => Ctype,
1355 Index => Next_Index (Index),
1356 Into => Into,
1357 Scalar_Comp => Scalar_Comp,
1358 Indexes => New_Indexes));
1359 end if;
1360
1361 -- If we get here then we are at a bottom-level (sub-)aggregate
1362
1363 Indexed_Comp :=
1364 Checks_Off
1365 (Make_Indexed_Component (Loc,
1366 Prefix => New_Copy_Tree (Into),
1367 Expressions => New_Indexes));
1368
1369 Set_Assignment_OK (Indexed_Comp);
1370
1371 -- Ada 2005 (AI-287): In case of default initialized component, Expr
1372 -- is not present (and therefore we also initialize Expr_Q to empty).
1373
1374 Expr_Q := Unqualify (Expr);
1375
1376 if Present (Etype (N)) and then Etype (N) /= Any_Composite then
1377 Comp_Typ := Component_Type (Etype (N));
1378 pragma Assert (Comp_Typ = Ctype); -- AI-287
1379
1380 elsif Present (Next (First (New_Indexes))) then
1381
1382 -- Ada 2005 (AI-287): Do nothing in case of default initialized
1383 -- component because we have received the component type in
1384 -- the formal parameter Ctype.
1385
1386 -- ??? Some assert pragmas have been added to check if this new
1387 -- formal can be used to replace this code in all cases.
1388
1389 if Present (Expr) then
1390
1391 -- This is a multidimensional array. Recover the component type
1392 -- from the outermost aggregate, because subaggregates do not
1393 -- have an assigned type.
1394
1395 declare
1396 P : Node_Id;
1397
1398 begin
1399 P := Parent (Expr);
1400 while Present (P) loop
1401 if Nkind (P) = N_Aggregate
1402 and then Present (Etype (P))
1403 then
1404 Comp_Typ := Component_Type (Etype (P));
1405 exit;
1406
1407 else
1408 P := Parent (P);
1409 end if;
1410 end loop;
1411
1412 pragma Assert (Comp_Typ = Ctype); -- AI-287
1413 end;
1414 end if;
1415 end if;
1416
1417 -- Ada 2005 (AI-287): We only analyze the expression in case of non-
1418 -- default initialized components (otherwise Expr_Q is not present).
1419
1420 if Present (Expr_Q)
1421 and then Nkind (Expr_Q) in N_Aggregate | N_Extension_Aggregate
1422 then
1423 -- At this stage the Expression may not have been analyzed yet
1424 -- because the array aggregate code has not been updated to use
1425 -- the Expansion_Delayed flag and avoid analysis altogether to
1426 -- solve the same problem (see Resolve_Aggr_Expr). So let us do
1427 -- the analysis of non-array aggregates now in order to get the
1428 -- value of Expansion_Delayed flag for the inner aggregate ???
1429
1430 -- In the case of an iterated component association, the analysis
1431 -- of the generated loop will analyze the expression in the
1432 -- proper context, in which the loop parameter is visible.
1433
1434 if Present (Comp_Typ) and then not Is_Array_Type (Comp_Typ) then
1435 if Nkind (Parent (Expr_Q)) = N_Iterated_Component_Association
1436 or else Nkind (Parent (Parent ((Expr_Q)))) =
1437 N_Iterated_Component_Association
1438 then
1439 null;
1440 else
1441 Analyze_And_Resolve (Expr_Q, Comp_Typ);
1442 end if;
1443 end if;
1444
1445 if Is_Delayed_Aggregate (Expr_Q) then
1446
1447 -- This is either a subaggregate of a multidimensional array,
1448 -- or a component of an array type whose component type is
1449 -- also an array. In the latter case, the expression may have
1450 -- component associations that provide different bounds from
1451 -- those of the component type, and sliding must occur. Instead
1452 -- of decomposing the current aggregate assignment, force the
1453 -- reanalysis of the assignment, so that a temporary will be
1454 -- generated in the usual fashion, and sliding will take place.
1455
1456 if Nkind (Parent (N)) = N_Assignment_Statement
1457 and then Is_Array_Type (Comp_Typ)
1458 and then Present (Component_Associations (Expr_Q))
1459 and then Must_Slide (N, Comp_Typ, Etype (Expr_Q))
1460 then
1461 Set_Expansion_Delayed (Expr_Q, False);
1462 Set_Analyzed (Expr_Q, False);
1463
1464 else
1465 return
1466 Add_Loop_Actions (
1467 Late_Expansion (Expr_Q, Etype (Expr_Q), Indexed_Comp));
1468 end if;
1469 end if;
1470 end if;
1471
1472 if Present (Expr) then
1473 Initialize_Component
1474 (N => N,
1475 Comp => Indexed_Comp,
1476 Comp_Typ => Comp_Typ,
1477 Init_Expr => Expr,
1478 Stmts => Stmts);
1479
1480 -- Ada 2005 (AI-287): In case of default initialized component, call
1481 -- the initialization subprogram associated with the component type.
1482 -- If the component type is an access type, add an explicit null
1483 -- assignment, because for the back-end there is an initialization
1484 -- present for the whole aggregate, and no default initialization
1485 -- will take place.
1486
1487 -- In addition, if the component type is controlled, we must call
1488 -- its Initialize procedure explicitly, because there is no explicit
1489 -- object creation that will invoke it otherwise.
1490
1491 else
1492 if Present (Base_Init_Proc (Base_Type (Ctype)))
1493 or else Has_Task (Base_Type (Ctype))
1494 then
1495 Append_List_To (Stmts,
1496 Build_Initialization_Call (Loc,
1497 Id_Ref => Indexed_Comp,
1498 Typ => Ctype,
1499 With_Default_Init => True));
1500
1501 -- If the component type has invariants, add an invariant
1502 -- check after the component is default-initialized. It will
1503 -- be analyzed and resolved before the code for initialization
1504 -- of other components.
1505
1506 if Has_Invariants (Ctype) then
1507 Set_Etype (Indexed_Comp, Ctype);
1508 Append_To (Stmts, Make_Invariant_Call (Indexed_Comp));
1509 end if;
1510 end if;
1511
1512 if Needs_Finalization (Ctype) then
1513 Init_Call :=
1514 Make_Init_Call
1515 (Obj_Ref => New_Copy_Tree (Indexed_Comp),
1516 Typ => Ctype);
1517
1518 -- Guard against a missing [Deep_]Initialize when the component
1519 -- type was not properly frozen.
1520
1521 if Present (Init_Call) then
1522 Append_To (Stmts, Init_Call);
1523 end if;
1524 end if;
1525
1526 -- If Default_Initial_Condition applies to the component type,
1527 -- add a DIC check after the component is default-initialized,
1528 -- as well as after an Initialize procedure is called, in the
1529 -- case of components of a controlled type. It will be analyzed
1530 -- and resolved before the code for initialization of other
1531 -- components.
1532
1533 -- Theoretically this might also be needed for cases where Expr
1534 -- is not empty, but a default init still applies, such as for
1535 -- Default_Value cases, in which case we won't get here. ???
1536
1537 if Has_DIC (Ctype) and then Present (DIC_Procedure (Ctype)) then
1538 Append_To (Stmts,
1539 Build_DIC_Call (Loc, New_Copy_Tree (Indexed_Comp), Ctype));
1540 end if;
1541 end if;
1542
1543 return Add_Loop_Actions (Stmts);
1544 end Gen_Assign;
1545
1546 --------------
1547 -- Gen_Loop --
1548 --------------
1549
1550 function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id is
1551 Is_Iterated_Component : constant Boolean :=
1552 Parent_Kind (Expr) = N_Iterated_Component_Association;
1553
1554 Ent : Entity_Id;
1555
1556 L_J : Node_Id;
1557
1558 L_L : Node_Id;
1559 -- Index_Base'(L)
1560
1561 L_H : Node_Id;
1562 -- Index_Base'(H)
1563
1564 L_Range : Node_Id;
1565 -- Index_Base'(L) .. Index_Base'(H)
1566
1567 L_Iteration_Scheme : Node_Id;
1568 -- L_J in Index_Base'(L) .. Index_Base'(H)
1569
1570 L_Body : List_Id;
1571 -- The statements to execute in the loop
1572
1573 S : constant List_Id := New_List;
1574 -- List of statements
1575
1576 Tcopy : Node_Id;
1577 -- Copy of expression tree, used for checking purposes
1578
1579 begin
1580 -- If loop bounds define an empty range return the null statement
1581
1582 if Empty_Range (L, H) then
1583 Append_To (S, Make_Null_Statement (Loc));
1584
1585 -- Ada 2005 (AI-287): Nothing else need to be done in case of
1586 -- default initialized component.
1587
1588 if No (Expr) then
1589 null;
1590
1591 else
1592 -- The expression must be type-checked even though no component
1593 -- of the aggregate will have this value. This is done only for
1594 -- actual components of the array, not for subaggregates. Do
1595 -- the check on a copy, because the expression may be shared
1596 -- among several choices, some of which might be non-null.
1597
1598 if Present (Etype (N))
1599 and then Is_Array_Type (Etype (N))
1600 and then No (Next_Index (Index))
1601 then
1602 Expander_Mode_Save_And_Set (False);
1603 Tcopy := New_Copy_Tree (Expr);
1604 Set_Parent (Tcopy, N);
1605
1606 -- For iterated_component_association analyze and resolve
1607 -- the expression with name of the index parameter visible.
1608 -- To manipulate scopes, we use entity of the implicit loop.
1609
1610 if Is_Iterated_Component then
1611 declare
1612 Index_Parameter : constant Entity_Id :=
1613 Defining_Identifier (Parent (Expr));
1614 begin
1615 Push_Scope (Scope (Index_Parameter));
1616 Enter_Name (Index_Parameter);
1617 Analyze_And_Resolve
1618 (Tcopy, Component_Type (Etype (N)));
1619 End_Scope;
1620 end;
1621
1622 -- For ordinary component association, just analyze and
1623 -- resolve the expression.
1624
1625 else
1626 Analyze_And_Resolve (Tcopy, Component_Type (Etype (N)));
1627 end if;
1628
1629 Expander_Mode_Restore;
1630 end if;
1631 end if;
1632
1633 return S;
1634
1635 -- If loop bounds are the same then generate an assignment, unless
1636 -- the parent construct is an Iterated_Component_Association.
1637
1638 elsif Equal (L, H) and then not Is_Iterated_Component then
1639 return Gen_Assign (New_Copy_Tree (L), Expr);
1640
1641 -- If H - L <= 2 then generate a sequence of assignments when we are
1642 -- processing the bottom most aggregate and it contains scalar
1643 -- components.
1644
1645 elsif No (Next_Index (Index))
1646 and then Scalar_Comp
1647 and then Local_Compile_Time_Known_Value (L)
1648 and then Local_Compile_Time_Known_Value (H)
1649 and then Local_Expr_Value (H) - Local_Expr_Value (L) <= 2
1650 and then not Is_Iterated_Component
1651 then
1652 Append_List_To (S, Gen_Assign (New_Copy_Tree (L), Expr));
1653 Append_List_To (S, Gen_Assign (Add (1, To => L), Expr));
1654
1655 if Local_Expr_Value (H) - Local_Expr_Value (L) = 2 then
1656 Append_List_To (S, Gen_Assign (Add (2, To => L), Expr));
1657 end if;
1658
1659 return S;
1660 end if;
1661
1662 -- Otherwise construct the loop, starting with the loop index L_J
1663
1664 if Is_Iterated_Component then
1665
1666 -- Create a new scope for the loop variable so that the
1667 -- following Gen_Assign (that ends up calling
1668 -- Preanalyze_And_Resolve) can correctly find it.
1669
1670 Ent := New_Internal_Entity (E_Loop,
1671 Current_Scope, Loc, 'L');
1672 Set_Etype (Ent, Standard_Void_Type);
1673 Set_Parent (Ent, Parent (Parent (Expr)));
1674 Push_Scope (Ent);
1675
1676 L_J :=
1677 Make_Defining_Identifier (Loc,
1678 Chars => (Chars (Defining_Identifier (Parent (Expr)))));
1679
1680 Enter_Name (L_J);
1681
1682 -- The Etype will be set by a later Analyze call.
1683 Set_Etype (L_J, Any_Type);
1684
1685 Mutate_Ekind (L_J, E_Variable);
1686 Set_Is_Not_Self_Hidden (L_J);
1687 Set_Scope (L_J, Ent);
1688 else
1689 L_J := Make_Temporary (Loc, 'J', L);
1690 end if;
1691
1692 -- Construct "L .. H" in Index_Base. We use a qualified expression
1693 -- for the bound to convert to the index base, but we don't need
1694 -- to do that if we already have the base type at hand.
1695
1696 if Etype (L) = Index_Base then
1697 L_L := New_Copy_Tree (L);
1698 else
1699 L_L :=
1700 Make_Qualified_Expression (Loc,
1701 Subtype_Mark => Index_Base_Name,
1702 Expression => New_Copy_Tree (L));
1703 end if;
1704
1705 if Etype (H) = Index_Base then
1706 L_H := New_Copy_Tree (H);
1707 else
1708 L_H :=
1709 Make_Qualified_Expression (Loc,
1710 Subtype_Mark => Index_Base_Name,
1711 Expression => New_Copy_Tree (H));
1712 end if;
1713
1714 L_Range :=
1715 Make_Range (Loc,
1716 Low_Bound => L_L,
1717 High_Bound => L_H);
1718
1719 -- Construct "for L_J in Index_Base range L .. H"
1720
1721 L_Iteration_Scheme :=
1722 Make_Iteration_Scheme (Loc,
1723 Loop_Parameter_Specification =>
1724 Make_Loop_Parameter_Specification (Loc,
1725 Defining_Identifier => L_J,
1726 Discrete_Subtype_Definition => L_Range));
1727
1728 -- Construct the statements to execute in the loop body
1729
1730 L_Body := Gen_Assign (New_Occurrence_Of (L_J, Loc), Expr);
1731
1732 -- Construct the final loop
1733
1734 Append_To (S,
1735 Make_Implicit_Loop_Statement
1736 (Node => N,
1737 Identifier => Empty,
1738 Iteration_Scheme => L_Iteration_Scheme,
1739 Statements => L_Body));
1740
1741 if Is_Iterated_Component then
1742 End_Scope;
1743 end if;
1744
1745 -- A small optimization: if the aggregate is initialized with a box
1746 -- and the component type has no initialization procedure, remove the
1747 -- useless empty loop.
1748
1749 if Nkind (First (S)) = N_Loop_Statement
1750 and then Is_Empty_List (Statements (First (S)))
1751 then
1752 return New_List (Make_Null_Statement (Loc));
1753 else
1754 return S;
1755 end if;
1756 end Gen_Loop;
1757
1758 ---------------
1759 -- Gen_While --
1760 ---------------
1761
1762 -- The code built is
1763
1764 -- W_J : Index_Base := L;
1765 -- while W_J < H loop
1766 -- W_J := Index_Base'Succ (W);
1767 -- L_Body;
1768 -- end loop;
1769
1770 function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id is
1771 W_J : Node_Id;
1772
1773 W_Decl : Node_Id;
1774 -- W_J : Base_Type := L;
1775
1776 W_Iteration_Scheme : Node_Id;
1777 -- while W_J < H
1778
1779 W_Index_Succ : Node_Id;
1780 -- Index_Base'Succ (J)
1781
1782 W_Increment : Node_Id;
1783 -- W_J := Index_Base'Succ (W)
1784
1785 W_Body : constant List_Id := New_List;
1786 -- The statements to execute in the loop
1787
1788 S : constant List_Id := New_List;
1789 -- list of statement
1790
1791 begin
1792 -- If loop bounds define an empty range or are equal return null
1793
1794 if Empty_Range (L, H) or else Equal (L, H) then
1795 Append_To (S, Make_Null_Statement (Loc));
1796 return S;
1797 end if;
1798
1799 -- Build the decl of W_J
1800
1801 W_J := Make_Temporary (Loc, 'J', L);
1802 W_Decl :=
1803 Make_Object_Declaration
1804 (Loc,
1805 Defining_Identifier => W_J,
1806 Object_Definition => Index_Base_Name,
1807 Expression => L);
1808
1809 -- Theoretically we should do a New_Copy_Tree (L) here, but we know
1810 -- that in this particular case L is a fresh Expr generated by
1811 -- Add which we are the only ones to use.
1812
1813 Append_To (S, W_Decl);
1814
1815 -- Construct " while W_J < H"
1816
1817 W_Iteration_Scheme :=
1818 Make_Iteration_Scheme
1819 (Loc,
1820 Condition => Make_Op_Lt
1821 (Loc,
1822 Left_Opnd => New_Occurrence_Of (W_J, Loc),
1823 Right_Opnd => New_Copy_Tree (H)));
1824
1825 -- Construct the statements to execute in the loop body
1826
1827 W_Index_Succ :=
1828 Make_Attribute_Reference
1829 (Loc,
1830 Prefix => Index_Base_Name,
1831 Attribute_Name => Name_Succ,
1832 Expressions => New_List (New_Occurrence_Of (W_J, Loc)));
1833
1834 W_Increment :=
1835 Make_OK_Assignment_Statement
1836 (Loc,
1837 Name => New_Occurrence_Of (W_J, Loc),
1838 Expression => W_Index_Succ);
1839
1840 Append_To (W_Body, W_Increment);
1841
1842 Append_List_To (W_Body,
1843 Gen_Assign (New_Occurrence_Of (W_J, Loc), Expr));
1844
1845 -- Construct the final loop
1846
1847 Append_To (S,
1848 Make_Implicit_Loop_Statement
1849 (Node => N,
1850 Identifier => Empty,
1851 Iteration_Scheme => W_Iteration_Scheme,
1852 Statements => W_Body));
1853
1854 return S;
1855 end Gen_While;
1856
1857 --------------------
1858 -- Get_Assoc_Expr --
1859 --------------------
1860
1861 -- Duplicate the expression in case we will be generating several loops.
1862 -- As a result the expression is no longer shared between the loops and
1863 -- is reevaluated for each such loop.
1864
1865 function Get_Assoc_Expr (Assoc : Node_Id) return Node_Id is
1866 Typ : constant Entity_Id := Base_Type (Etype (N));
1867
1868 begin
1869 if Box_Present (Assoc) then
1870 if Present (Default_Aspect_Component_Value (Typ)) then
1871 return New_Copy_Tree (Default_Aspect_Component_Value (Typ));
1872 elsif Needs_Simple_Initialization (Ctype) then
1873 return New_Copy_Tree (Get_Simple_Init_Val (Ctype, N));
1874 else
1875 return Empty;
1876 end if;
1877
1878 else
1879 -- The expression will be passed to Gen_Loop, which immediately
1880 -- calls Parent_Kind on it, so we set Parent when it matters.
1881
1882 return
1883 Expr : constant Node_Id := New_Copy_Tree (Expression (Assoc))
1884 do
1885 Copy_Parent (To => Expr, From => Expression (Assoc));
1886 end return;
1887 end if;
1888 end Get_Assoc_Expr;
1889
1890 ---------------------
1891 -- Index_Base_Name --
1892 ---------------------
1893
1894 function Index_Base_Name return Node_Id is
1895 begin
1896 return New_Occurrence_Of (Index_Base, Sloc (N));
1897 end Index_Base_Name;
1898
1899 ------------------------------------
1900 -- Local_Compile_Time_Known_Value --
1901 ------------------------------------
1902
1903 function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean is
1904 begin
1905 return Compile_Time_Known_Value (E)
1906 or else
1907 (Nkind (E) = N_Attribute_Reference
1908 and then Attribute_Name (E) = Name_Val
1909 and then Compile_Time_Known_Value (First (Expressions (E))));
1910 end Local_Compile_Time_Known_Value;
1911
1912 ----------------------
1913 -- Local_Expr_Value --
1914 ----------------------
1915
1916 function Local_Expr_Value (E : Node_Id) return Uint is
1917 begin
1918 if Compile_Time_Known_Value (E) then
1919 return Expr_Value (E);
1920 else
1921 return Expr_Value (First (Expressions (E)));
1922 end if;
1923 end Local_Expr_Value;
1924
1925 -- Local variables
1926
1927 New_Code : constant List_Id := New_List;
1928
1929 Aggr_Bounds : constant Range_Nodes :=
1930 Get_Index_Bounds (Aggregate_Bounds (N));
1931 Aggr_L : Node_Id renames Aggr_Bounds.First;
1932 Aggr_H : Node_Id renames Aggr_Bounds.Last;
1933 -- The aggregate bounds of this specific subaggregate. Note that if the
1934 -- code generated by Build_Array_Aggr_Code is executed then these bounds
1935 -- are OK. Otherwise a Constraint_Error would have been raised.
1936
1937 Aggr_Low : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_L);
1938 Aggr_High : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_H);
1939 -- After Duplicate_Subexpr these are side-effect free
1940
1941 Assoc : Node_Id;
1942 Choice : Node_Id;
1943 Expr : Node_Id;
1944
1945 Bounds : Range_Nodes;
1946 Low : Node_Id renames Bounds.First;
1947 High : Node_Id renames Bounds.Last;
1948
1949 Nb_Choices : Nat := 0;
1950 Table : Case_Table_Type (1 .. Number_Of_Choices (N));
1951 -- Used to sort all the different choice values
1952
1953 Nb_Elements : Int;
1954 -- Number of elements in the positional aggregate
1955
1956 Others_Assoc : Node_Id := Empty;
1957
1958 -- Start of processing for Build_Array_Aggr_Code
1959
1960 begin
1961 -- First before we start, a special case. If we have a bit packed
1962 -- array represented as a modular type, then clear the value to
1963 -- zero first, to ensure that unused bits are properly cleared.
1964
1965 if Present (Typ)
1966 and then Is_Bit_Packed_Array (Typ)
1967 and then Is_Modular_Integer_Type (Packed_Array_Impl_Type (Typ))
1968 then
1969 declare
1970 Zero : constant Node_Id := Make_Integer_Literal (Loc, Uint_0);
1971 begin
1972 Analyze_And_Resolve (Zero, Packed_Array_Impl_Type (Typ));
1973 Append_To (New_Code,
1974 Make_Assignment_Statement (Loc,
1975 Name => New_Copy_Tree (Into),
1976 Expression => Unchecked_Convert_To (Typ, Zero)));
1977 end;
1978 end if;
1979
1980 -- If the component type contains tasks, we need to build a Master
1981 -- entity in the current scope, because it will be needed if build-
1982 -- in-place functions are called in the expanded code.
1983
1984 if Nkind (Parent (N)) = N_Object_Declaration and then Has_Task (Typ) then
1985 Build_Master_Entity (Defining_Identifier (Parent (N)));
1986 end if;
1987
1988 -- STEP 1: Process component associations
1989
1990 -- For those associations that may generate a loop, initialize
1991 -- Loop_Actions to collect inserted actions that may be crated.
1992
1993 -- Skip this if no component associations
1994
1995 if Is_Null_Aggregate (N) then
1996 null;
1997
1998 elsif No (Expressions (N)) then
1999
2000 -- STEP 1 (a): Sort the discrete choices
2001
2002 Assoc := First (Component_Associations (N));
2003 while Present (Assoc) loop
2004 Choice := First (Choice_List (Assoc));
2005 while Present (Choice) loop
2006 if Nkind (Choice) = N_Others_Choice then
2007 Others_Assoc := Assoc;
2008 exit;
2009 end if;
2010
2011 Bounds := Get_Index_Bounds (Choice);
2012
2013 if Low /= High then
2014 Set_Loop_Actions (Assoc, New_List);
2015 end if;
2016
2017 Nb_Choices := Nb_Choices + 1;
2018
2019 Table (Nb_Choices) :=
2020 (Choice_Lo => Low,
2021 Choice_Hi => High,
2022 Choice_Node => Get_Assoc_Expr (Assoc));
2023
2024 Next (Choice);
2025 end loop;
2026
2027 Next (Assoc);
2028 end loop;
2029
2030 -- If there is more than one set of choices these must be static
2031 -- and we can therefore sort them. Remember that Nb_Choices does not
2032 -- account for an others choice.
2033
2034 if Nb_Choices > 1 then
2035 Sort_Case_Table (Table);
2036 end if;
2037
2038 -- STEP 1 (b): take care of the whole set of discrete choices
2039
2040 for J in 1 .. Nb_Choices loop
2041 Low := Table (J).Choice_Lo;
2042 High := Table (J).Choice_Hi;
2043 Expr := Table (J).Choice_Node;
2044 Append_List (Gen_Loop (Low, High, Expr), To => New_Code);
2045 end loop;
2046
2047 -- STEP 1 (c): generate the remaining loops to cover others choice
2048 -- We don't need to generate loops over empty gaps, but if there is
2049 -- a single empty range we must analyze the expression for semantics
2050
2051 if Present (Others_Assoc) then
2052 declare
2053 First : Boolean := True;
2054
2055 begin
2056 for J in 0 .. Nb_Choices loop
2057 if J = 0 then
2058 Low := Aggr_Low;
2059 else
2060 Low := Add (1, To => Table (J).Choice_Hi);
2061 end if;
2062
2063 if J = Nb_Choices then
2064 High := Aggr_High;
2065 else
2066 High := Add (-1, To => Table (J + 1).Choice_Lo);
2067 end if;
2068
2069 -- If this is an expansion within an init proc, make
2070 -- sure that discriminant references are replaced by
2071 -- the corresponding discriminal.
2072
2073 if Inside_Init_Proc then
2074 if Is_Entity_Name (Low)
2075 and then Ekind (Entity (Low)) = E_Discriminant
2076 then
2077 Set_Entity (Low, Discriminal (Entity (Low)));
2078 end if;
2079
2080 if Is_Entity_Name (High)
2081 and then Ekind (Entity (High)) = E_Discriminant
2082 then
2083 Set_Entity (High, Discriminal (Entity (High)));
2084 end if;
2085 end if;
2086
2087 if First or else not Empty_Range (Low, High) then
2088 First := False;
2089 Set_Loop_Actions (Others_Assoc, New_List);
2090 Expr := Get_Assoc_Expr (Others_Assoc);
2091 Append_List (Gen_Loop (Low, High, Expr), To => New_Code);
2092 end if;
2093 end loop;
2094 end;
2095 end if;
2096
2097 -- STEP 2: Process positional components
2098
2099 else
2100 -- STEP 2 (a): Generate the assignments for each positional element
2101 -- Note that here we have to use Aggr_L rather than Aggr_Low because
2102 -- Aggr_L is analyzed and Add wants an analyzed expression.
2103
2104 Expr := First (Expressions (N));
2105 Nb_Elements := -1;
2106 while Present (Expr) loop
2107 Nb_Elements := Nb_Elements + 1;
2108 Append_List (Gen_Assign (Add (Nb_Elements, To => Aggr_L), Expr),
2109 To => New_Code);
2110 Next (Expr);
2111 end loop;
2112
2113 -- STEP 2 (b): Generate final loop if an others choice is present.
2114 -- Here Nb_Elements gives the offset of the last positional element.
2115
2116 if Present (Component_Associations (N)) then
2117 Assoc := Last (Component_Associations (N));
2118
2119 if Nkind (Assoc) = N_Iterated_Component_Association then
2120 -- Ada 2022: generate a loop to have a proper scope for
2121 -- the identifier that typically appears in the expression.
2122 -- The lower bound of the loop is the position after all
2123 -- previous positional components.
2124
2125 Append_List (Gen_Loop (Add (Nb_Elements + 1, To => Aggr_L),
2126 Aggr_High,
2127 Expression (Assoc)),
2128 To => New_Code);
2129 else
2130 -- Ada 2005 (AI-287)
2131
2132 Append_List (Gen_While (Add (Nb_Elements, To => Aggr_L),
2133 Aggr_High,
2134 Get_Assoc_Expr (Assoc)),
2135 To => New_Code);
2136 end if;
2137 end if;
2138 end if;
2139
2140 return New_Code;
2141 end Build_Array_Aggr_Code;
2142
2143 -------------------------------------
2144 -- Build_Assignment_With_Temporary --
2145 -------------------------------------
2146
2147 function Build_Assignment_With_Temporary
2148 (Target : Node_Id;
2149 Typ : Entity_Id;
2150 Source : Node_Id) return List_Id
2151 is
2152 Loc : constant Source_Ptr := Sloc (Source);
2153
2154 Aggr_Code : List_Id;
2155 Tmp : Entity_Id;
2156
2157 begin
2158 Aggr_Code := New_List;
2159
2160 Tmp := Build_Temporary_On_Secondary_Stack (Loc, Typ, Aggr_Code);
2161
2162 Append_To (Aggr_Code,
2163 Make_OK_Assignment_Statement (Loc,
2164 Name =>
2165 Make_Explicit_Dereference (Loc,
2166 Prefix => New_Occurrence_Of (Tmp, Loc)),
2167 Expression => Source));
2168
2169 Append_To (Aggr_Code,
2170 Make_OK_Assignment_Statement (Loc,
2171 Name => Target,
2172 Expression =>
2173 Make_Explicit_Dereference (Loc,
2174 Prefix => New_Occurrence_Of (Tmp, Loc))));
2175
2176 return Aggr_Code;
2177 end Build_Assignment_With_Temporary;
2178
2179 ----------------------------
2180 -- Build_Record_Aggr_Code --
2181 ----------------------------
2182
2183 function Build_Record_Aggr_Code
2184 (N : Node_Id;
2185 Typ : Entity_Id;
2186 Lhs : Node_Id) return List_Id
2187 is
2188 Loc : constant Source_Ptr := Sloc (N);
2189 L : constant List_Id := New_List;
2190 N_Typ : constant Entity_Id := Etype (N);
2191
2192 Comp : Node_Id;
2193 Instr : Node_Id;
2194 Ref : Node_Id;
2195 Target : Entity_Id;
2196 Comp_Type : Entity_Id;
2197 Selector : Entity_Id;
2198 Comp_Expr : Node_Id;
2199 Expr_Q : Node_Id;
2200
2201 Ancestor_Is_Subtype_Mark : Boolean := False;
2202
2203 Init_Typ : Entity_Id := Empty;
2204
2205 Finalization_Done : Boolean := False;
2206 -- True if Generate_Finalization_Actions has already been called; calls
2207 -- after the first do nothing.
2208
2209 function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id;
2210 -- Returns the value that the given discriminant of an ancestor type
2211 -- should receive (in the absence of a conflict with the value provided
2212 -- by an ancestor part of an extension aggregate).
2213
2214 procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id);
2215 -- Check that each of the discriminant values defined by the ancestor
2216 -- part of an extension aggregate match the corresponding values
2217 -- provided by either an association of the aggregate or by the
2218 -- constraint imposed by a parent type (RM95-4.3.2(8)).
2219
2220 function Compatible_Int_Bounds
2221 (Agg_Bounds : Node_Id;
2222 Typ_Bounds : Node_Id) return Boolean;
2223 -- Return true if Agg_Bounds are equal or within Typ_Bounds. It is
2224 -- assumed that both bounds are integer ranges.
2225
2226 procedure Generate_Finalization_Actions;
2227 -- Deal with the various controlled type data structure initializations
2228 -- (but only if it hasn't been done already).
2229
2230 function Get_Constraint_Association (T : Entity_Id) return Node_Id;
2231 -- Returns the first discriminant association in the constraint
2232 -- associated with T, if any, otherwise returns Empty.
2233
2234 function Get_Explicit_Discriminant_Value (D : Entity_Id) return Node_Id;
2235 -- If the ancestor part is an unconstrained type and further ancestors
2236 -- do not provide discriminants for it, check aggregate components for
2237 -- values of the discriminants.
2238
2239 procedure Init_Hidden_Discriminants (Typ : Entity_Id; List : List_Id);
2240 -- If Typ is derived, and constrains discriminants of the parent type,
2241 -- these discriminants are not components of the aggregate, and must be
2242 -- initialized. The assignments are appended to List. The same is done
2243 -- if Typ derives from an already constrained subtype of a discriminated
2244 -- parent type.
2245
2246 procedure Init_Stored_Discriminants;
2247 -- If the type is derived and has inherited discriminants, generate
2248 -- explicit assignments for each, using the store constraint of the
2249 -- type. Note that both visible and stored discriminants must be
2250 -- initialized in case the derived type has some renamed and some
2251 -- constrained discriminants.
2252
2253 procedure Init_Visible_Discriminants;
2254 -- If type has discriminants, retrieve their values from aggregate,
2255 -- and generate explicit assignments for each. This does not include
2256 -- discriminants inherited from ancestor, which are handled above.
2257 -- The type of the aggregate is a subtype created ealier using the
2258 -- given values of the discriminant components of the aggregate.
2259
2260 function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean;
2261 -- Check whether Bounds is a range node and its lower and higher bounds
2262 -- are integers literals.
2263
2264 function Replace_Type (Expr : Node_Id) return Traverse_Result;
2265 -- If the aggregate contains a self-reference, traverse each expression
2266 -- to replace a possible self-reference with a reference to the proper
2267 -- component of the target of the assignment.
2268
2269 function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result;
2270 -- If default expression of a component mentions a discriminant of the
2271 -- type, it must be rewritten as the discriminant of the target object.
2272
2273 ---------------------------------
2274 -- Ancestor_Discriminant_Value --
2275 ---------------------------------
2276
2277 function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id is
2278 Assoc : Node_Id;
2279 Assoc_Elmt : Elmt_Id;
2280 Aggr_Comp : Entity_Id;
2281 Corresp_Disc : Entity_Id;
2282 Current_Typ : Entity_Id := Base_Type (Typ);
2283 Parent_Typ : Entity_Id;
2284 Parent_Disc : Entity_Id;
2285 Save_Assoc : Node_Id := Empty;
2286
2287 begin
2288 -- First check any discriminant associations to see if any of them
2289 -- provide a value for the discriminant.
2290
2291 if Present (Discriminant_Specifications (Parent (Current_Typ))) then
2292 Assoc := First (Component_Associations (N));
2293 while Present (Assoc) loop
2294 Aggr_Comp := Entity (First (Choices (Assoc)));
2295
2296 if Ekind (Aggr_Comp) = E_Discriminant then
2297 Save_Assoc := Expression (Assoc);
2298
2299 Corresp_Disc := Corresponding_Discriminant (Aggr_Comp);
2300 while Present (Corresp_Disc) loop
2301
2302 -- If found a corresponding discriminant then return the
2303 -- value given in the aggregate. (Note: this is not
2304 -- correct in the presence of side effects. ???)
2305
2306 if Disc = Corresp_Disc then
2307 return Duplicate_Subexpr (Expression (Assoc));
2308 end if;
2309
2310 Corresp_Disc := Corresponding_Discriminant (Corresp_Disc);
2311 end loop;
2312 end if;
2313
2314 Next (Assoc);
2315 end loop;
2316 end if;
2317
2318 -- No match found in aggregate, so chain up parent types to find
2319 -- a constraint that defines the value of the discriminant.
2320
2321 Parent_Typ := Etype (Current_Typ);
2322 while Current_Typ /= Parent_Typ loop
2323 if Has_Discriminants (Parent_Typ)
2324 and then not Has_Unknown_Discriminants (Parent_Typ)
2325 then
2326 Parent_Disc := First_Discriminant (Parent_Typ);
2327
2328 -- We either get the association from the subtype indication
2329 -- of the type definition itself, or from the discriminant
2330 -- constraint associated with the type entity (which is
2331 -- preferable, but it's not always present ???)
2332
2333 if Is_Empty_Elmt_List (Discriminant_Constraint (Current_Typ))
2334 then
2335 Assoc := Get_Constraint_Association (Current_Typ);
2336 Assoc_Elmt := No_Elmt;
2337 else
2338 Assoc_Elmt :=
2339 First_Elmt (Discriminant_Constraint (Current_Typ));
2340 Assoc := Node (Assoc_Elmt);
2341 end if;
2342
2343 -- Traverse the discriminants of the parent type looking
2344 -- for one that corresponds.
2345
2346 while Present (Parent_Disc) and then Present (Assoc) loop
2347 Corresp_Disc := Parent_Disc;
2348 while Present (Corresp_Disc)
2349 and then Disc /= Corresp_Disc
2350 loop
2351 Corresp_Disc := Corresponding_Discriminant (Corresp_Disc);
2352 end loop;
2353
2354 if Disc = Corresp_Disc then
2355 if Nkind (Assoc) = N_Discriminant_Association then
2356 Assoc := Expression (Assoc);
2357 end if;
2358
2359 -- If the located association directly denotes
2360 -- a discriminant, then use the value of a saved
2361 -- association of the aggregate. This is an approach
2362 -- used to handle certain cases involving multiple
2363 -- discriminants mapped to a single discriminant of
2364 -- a descendant. It's not clear how to locate the
2365 -- appropriate discriminant value for such cases. ???
2366
2367 if Is_Entity_Name (Assoc)
2368 and then Ekind (Entity (Assoc)) = E_Discriminant
2369 then
2370 Assoc := Save_Assoc;
2371 end if;
2372
2373 return Duplicate_Subexpr (Assoc);
2374 end if;
2375
2376 Next_Discriminant (Parent_Disc);
2377
2378 if No (Assoc_Elmt) then
2379 Next (Assoc);
2380
2381 else
2382 Next_Elmt (Assoc_Elmt);
2383
2384 if Present (Assoc_Elmt) then
2385 Assoc := Node (Assoc_Elmt);
2386 else
2387 Assoc := Empty;
2388 end if;
2389 end if;
2390 end loop;
2391 end if;
2392
2393 Current_Typ := Parent_Typ;
2394 Parent_Typ := Etype (Current_Typ);
2395 end loop;
2396
2397 -- In some cases there's no ancestor value to locate (such as
2398 -- when an ancestor part given by an expression defines the
2399 -- discriminant value).
2400
2401 return Empty;
2402 end Ancestor_Discriminant_Value;
2403
2404 ----------------------------------
2405 -- Check_Ancestor_Discriminants --
2406 ----------------------------------
2407
2408 procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id) is
2409 Discr : Entity_Id;
2410 Disc_Value : Node_Id;
2411 Cond : Node_Id;
2412
2413 begin
2414 Discr := First_Discriminant (Base_Type (Anc_Typ));
2415 while Present (Discr) loop
2416 Disc_Value := Ancestor_Discriminant_Value (Discr);
2417
2418 if Present (Disc_Value) then
2419 Cond := Make_Op_Ne (Loc,
2420 Left_Opnd =>
2421 Make_Selected_Component (Loc,
2422 Prefix => New_Copy_Tree (Target),
2423 Selector_Name => New_Occurrence_Of (Discr, Loc)),
2424 Right_Opnd => Disc_Value);
2425
2426 Append_To (L,
2427 Make_Raise_Constraint_Error (Loc,
2428 Condition => Cond,
2429 Reason => CE_Discriminant_Check_Failed));
2430 end if;
2431
2432 Next_Discriminant (Discr);
2433 end loop;
2434 end Check_Ancestor_Discriminants;
2435
2436 ---------------------------
2437 -- Compatible_Int_Bounds --
2438 ---------------------------
2439
2440 function Compatible_Int_Bounds
2441 (Agg_Bounds : Node_Id;
2442 Typ_Bounds : Node_Id) return Boolean
2443 is
2444 Agg_Lo : constant Uint := Intval (Low_Bound (Agg_Bounds));
2445 Agg_Hi : constant Uint := Intval (High_Bound (Agg_Bounds));
2446 Typ_Lo : constant Uint := Intval (Low_Bound (Typ_Bounds));
2447 Typ_Hi : constant Uint := Intval (High_Bound (Typ_Bounds));
2448 begin
2449 return Typ_Lo <= Agg_Lo and then Agg_Hi <= Typ_Hi;
2450 end Compatible_Int_Bounds;
2451
2452 -----------------------------------
2453 -- Generate_Finalization_Actions --
2454 -----------------------------------
2455
2456 procedure Generate_Finalization_Actions is
2457 begin
2458 -- Do the work only the first time this is called
2459
2460 if Finalization_Done then
2461 return;
2462 end if;
2463
2464 Finalization_Done := True;
2465
2466 -- Determine the external finalization list. It is either the
2467 -- finalization list of the outer scope or the one coming from an
2468 -- outer aggregate. When the target is not a temporary, the proper
2469 -- scope is the scope of the target rather than the potentially
2470 -- transient current scope.
2471
2472 if Is_Controlled (Typ) and then Ancestor_Is_Subtype_Mark then
2473 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2474 Set_Assignment_OK (Ref);
2475
2476 Append_To (L,
2477 Make_Procedure_Call_Statement (Loc,
2478 Name =>
2479 New_Occurrence_Of
2480 (Find_Prim_Op (Init_Typ, Name_Initialize), Loc),
2481 Parameter_Associations => New_List (New_Copy_Tree (Ref))));
2482 end if;
2483 end Generate_Finalization_Actions;
2484
2485 --------------------------------
2486 -- Get_Constraint_Association --
2487 --------------------------------
2488
2489 function Get_Constraint_Association (T : Entity_Id) return Node_Id is
2490 Indic : Node_Id;
2491 Typ : Entity_Id;
2492
2493 begin
2494 Typ := T;
2495
2496 -- If type is private, get constraint from full view. This was
2497 -- previously done in an instance context, but is needed whenever
2498 -- the ancestor part has a discriminant, possibly inherited through
2499 -- multiple derivations.
2500
2501 if Is_Private_Type (Typ) and then Present (Full_View (Typ)) then
2502 Typ := Full_View (Typ);
2503 end if;
2504
2505 Indic := Subtype_Indication (Type_Definition (Parent (Typ)));
2506
2507 -- Verify that the subtype indication carries a constraint
2508
2509 if Nkind (Indic) = N_Subtype_Indication
2510 and then Present (Constraint (Indic))
2511 then
2512 return First (Constraints (Constraint (Indic)));
2513 end if;
2514
2515 return Empty;
2516 end Get_Constraint_Association;
2517
2518 -------------------------------------
2519 -- Get_Explicit_Discriminant_Value --
2520 -------------------------------------
2521
2522 function Get_Explicit_Discriminant_Value
2523 (D : Entity_Id) return Node_Id
2524 is
2525 Assoc : Node_Id;
2526 Choice : Node_Id;
2527 Val : Node_Id;
2528
2529 begin
2530 -- The aggregate has been normalized and all associations have a
2531 -- single choice.
2532
2533 Assoc := First (Component_Associations (N));
2534 while Present (Assoc) loop
2535 Choice := First (Choices (Assoc));
2536
2537 if Chars (Choice) = Chars (D) then
2538 Val := Expression (Assoc);
2539 Remove (Assoc);
2540 return Val;
2541 end if;
2542
2543 Next (Assoc);
2544 end loop;
2545
2546 return Empty;
2547 end Get_Explicit_Discriminant_Value;
2548
2549 -------------------------------
2550 -- Init_Hidden_Discriminants --
2551 -------------------------------
2552
2553 procedure Init_Hidden_Discriminants (Typ : Entity_Id; List : List_Id) is
2554 function Is_Completely_Hidden_Discriminant
2555 (Discr : Entity_Id) return Boolean;
2556 -- Determine whether Discr is a completely hidden discriminant of
2557 -- type Typ.
2558
2559 ---------------------------------------
2560 -- Is_Completely_Hidden_Discriminant --
2561 ---------------------------------------
2562
2563 function Is_Completely_Hidden_Discriminant
2564 (Discr : Entity_Id) return Boolean
2565 is
2566 Item : Entity_Id;
2567
2568 begin
2569 -- Use First/Next_Entity as First/Next_Discriminant do not yield
2570 -- completely hidden discriminants.
2571
2572 Item := First_Entity (Typ);
2573 while Present (Item) loop
2574 if Ekind (Item) = E_Discriminant
2575 and then Is_Completely_Hidden (Item)
2576 and then Chars (Original_Record_Component (Item)) =
2577 Chars (Discr)
2578 then
2579 return True;
2580 end if;
2581
2582 Next_Entity (Item);
2583 end loop;
2584
2585 return False;
2586 end Is_Completely_Hidden_Discriminant;
2587
2588 -- Local variables
2589
2590 Base_Typ : Entity_Id;
2591 Discr : Entity_Id;
2592 Discr_Constr : Elmt_Id;
2593 Discr_Init : Node_Id;
2594 Discr_Val : Node_Id;
2595 In_Aggr_Type : Boolean;
2596 Par_Typ : Entity_Id;
2597
2598 -- Start of processing for Init_Hidden_Discriminants
2599
2600 begin
2601 -- The constraints on the hidden discriminants, if present, are kept
2602 -- in the Stored_Constraint list of the type itself, or in that of
2603 -- the base type. If not in the constraints of the aggregate itself,
2604 -- we examine ancestors to find discriminants that are not renamed
2605 -- by other discriminants but constrained explicitly.
2606
2607 In_Aggr_Type := True;
2608
2609 Base_Typ := Base_Type (Typ);
2610 while Is_Derived_Type (Base_Typ)
2611 and then
2612 (Present (Stored_Constraint (Base_Typ))
2613 or else
2614 (In_Aggr_Type and then Present (Stored_Constraint (Typ))))
2615 loop
2616 Par_Typ := Etype (Base_Typ);
2617
2618 if not Has_Discriminants (Par_Typ) then
2619 return;
2620 end if;
2621
2622 Discr := First_Discriminant (Par_Typ);
2623
2624 -- We know that one of the stored-constraint lists is present
2625
2626 if Present (Stored_Constraint (Base_Typ)) then
2627 Discr_Constr := First_Elmt (Stored_Constraint (Base_Typ));
2628
2629 -- For private extension, stored constraint may be on full view
2630
2631 elsif Is_Private_Type (Base_Typ)
2632 and then Present (Full_View (Base_Typ))
2633 and then Present (Stored_Constraint (Full_View (Base_Typ)))
2634 then
2635 Discr_Constr :=
2636 First_Elmt (Stored_Constraint (Full_View (Base_Typ)));
2637
2638 -- Otherwise, no discriminant to process
2639
2640 else
2641 Discr_Constr := No_Elmt;
2642 end if;
2643
2644 while Present (Discr) and then Present (Discr_Constr) loop
2645 Discr_Val := Node (Discr_Constr);
2646
2647 -- The parent discriminant is renamed in the derived type,
2648 -- nothing to initialize.
2649
2650 -- type Deriv_Typ (Discr : ...)
2651 -- is new Parent_Typ (Discr => Discr);
2652
2653 if Is_Entity_Name (Discr_Val)
2654 and then Ekind (Entity (Discr_Val)) = E_Discriminant
2655 then
2656 null;
2657
2658 -- When the parent discriminant is constrained at the type
2659 -- extension level, it does not appear in the derived type.
2660
2661 -- type Deriv_Typ (Discr : ...)
2662 -- is new Parent_Typ (Discr => Discr,
2663 -- Hidden_Discr => Expression);
2664
2665 elsif Is_Completely_Hidden_Discriminant (Discr) then
2666 null;
2667
2668 -- Otherwise initialize the discriminant
2669
2670 else
2671 Discr_Init :=
2672 Make_OK_Assignment_Statement (Loc,
2673 Name =>
2674 Make_Selected_Component (Loc,
2675 Prefix => New_Copy_Tree (Target),
2676 Selector_Name => New_Occurrence_Of (Discr, Loc)),
2677 Expression => New_Copy_Tree (Discr_Val));
2678
2679 Append_To (List, Discr_Init);
2680 end if;
2681
2682 Next_Elmt (Discr_Constr);
2683 Next_Discriminant (Discr);
2684 end loop;
2685
2686 In_Aggr_Type := False;
2687 Base_Typ := Base_Type (Par_Typ);
2688 end loop;
2689 end Init_Hidden_Discriminants;
2690
2691 --------------------------------
2692 -- Init_Visible_Discriminants --
2693 --------------------------------
2694
2695 procedure Init_Visible_Discriminants is
2696 Discriminant : Entity_Id;
2697 Discriminant_Value : Node_Id;
2698
2699 begin
2700 Discriminant := First_Discriminant (Typ);
2701 while Present (Discriminant) loop
2702 Comp_Expr :=
2703 Make_Selected_Component (Loc,
2704 Prefix => New_Copy_Tree (Target),
2705 Selector_Name => New_Occurrence_Of (Discriminant, Loc));
2706
2707 Discriminant_Value :=
2708 Get_Discriminant_Value
2709 (Discriminant, Typ, Discriminant_Constraint (N_Typ));
2710
2711 Instr :=
2712 Make_OK_Assignment_Statement (Loc,
2713 Name => Comp_Expr,
2714 Expression => New_Copy_Tree (Discriminant_Value));
2715
2716 Append_To (L, Instr);
2717
2718 Next_Discriminant (Discriminant);
2719 end loop;
2720 end Init_Visible_Discriminants;
2721
2722 -------------------------------
2723 -- Init_Stored_Discriminants --
2724 -------------------------------
2725
2726 procedure Init_Stored_Discriminants is
2727 Discriminant : Entity_Id;
2728 Discriminant_Value : Node_Id;
2729
2730 begin
2731 Discriminant := First_Stored_Discriminant (Typ);
2732 while Present (Discriminant) loop
2733 Comp_Expr :=
2734 Make_Selected_Component (Loc,
2735 Prefix => New_Copy_Tree (Target),
2736 Selector_Name => New_Occurrence_Of (Discriminant, Loc));
2737
2738 Discriminant_Value :=
2739 Get_Discriminant_Value
2740 (Discriminant, N_Typ, Discriminant_Constraint (N_Typ));
2741
2742 Instr :=
2743 Make_OK_Assignment_Statement (Loc,
2744 Name => Comp_Expr,
2745 Expression => New_Copy_Tree (Discriminant_Value));
2746
2747 Append_To (L, Instr);
2748
2749 Next_Stored_Discriminant (Discriminant);
2750 end loop;
2751 end Init_Stored_Discriminants;
2752
2753 -------------------------
2754 -- Is_Int_Range_Bounds --
2755 -------------------------
2756
2757 function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean is
2758 begin
2759 return Nkind (Bounds) = N_Range
2760 and then Nkind (Low_Bound (Bounds)) = N_Integer_Literal
2761 and then Nkind (High_Bound (Bounds)) = N_Integer_Literal;
2762 end Is_Int_Range_Bounds;
2763
2764 ------------------
2765 -- Replace_Type --
2766 ------------------
2767
2768 function Replace_Type (Expr : Node_Id) return Traverse_Result is
2769 begin
2770 -- Note about the Is_Ancestor test below: aggregate components for
2771 -- self-referential types include attribute references to the current
2772 -- instance, of the form: Typ'access, etc. These references are
2773 -- rewritten as references to the target of the aggregate: the
2774 -- left-hand side of an assignment, the entity in a declaration,
2775 -- or a temporary. Without this test, we would improperly extend
2776 -- this rewriting to attribute references whose prefix is not the
2777 -- type of the aggregate.
2778
2779 if Nkind (Expr) = N_Attribute_Reference
2780 and then Is_Entity_Name (Prefix (Expr))
2781 and then Is_Type (Entity (Prefix (Expr)))
2782 and then
2783 Is_Ancestor
2784 (Entity (Prefix (Expr)), Etype (N), Use_Full_View => True)
2785 then
2786 if Is_Entity_Name (Lhs) then
2787 Rewrite (Prefix (Expr), New_Occurrence_Of (Entity (Lhs), Loc));
2788
2789 else
2790 Rewrite (Expr,
2791 Make_Attribute_Reference (Loc,
2792 Attribute_Name => Name_Unrestricted_Access,
2793 Prefix => New_Copy_Tree (Lhs)));
2794 Set_Analyzed (Parent (Expr), False);
2795 end if;
2796 end if;
2797
2798 return OK;
2799 end Replace_Type;
2800
2801 --------------------------
2802 -- Rewrite_Discriminant --
2803 --------------------------
2804
2805 function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result is
2806 begin
2807 if Is_Entity_Name (Expr)
2808 and then Present (Entity (Expr))
2809 and then Ekind (Entity (Expr)) = E_In_Parameter
2810 and then Present (Discriminal_Link (Entity (Expr)))
2811 and then Scope (Discriminal_Link (Entity (Expr))) =
2812 Base_Type (Etype (N))
2813 then
2814 Rewrite (Expr,
2815 Make_Selected_Component (Loc,
2816 Prefix => New_Copy_Tree (Lhs),
2817 Selector_Name => Make_Identifier (Loc, Chars (Expr))));
2818
2819 -- The generated code will be reanalyzed, but if the reference
2820 -- to the discriminant appears within an already analyzed
2821 -- expression (e.g. a conditional) we must set its proper entity
2822 -- now. Context is an initialization procedure.
2823
2824 Analyze (Expr);
2825 end if;
2826
2827 return OK;
2828 end Rewrite_Discriminant;
2829
2830 procedure Replace_Discriminants is
2831 new Traverse_Proc (Rewrite_Discriminant);
2832
2833 procedure Replace_Self_Reference is
2834 new Traverse_Proc (Replace_Type);
2835
2836 -- Start of processing for Build_Record_Aggr_Code
2837
2838 begin
2839 if Has_Self_Reference (N) then
2840 Replace_Self_Reference (N);
2841 end if;
2842
2843 -- If the target of the aggregate is class-wide, we must convert it
2844 -- to the actual type of the aggregate, so that the proper components
2845 -- are visible. We know already that the types are compatible.
2846
2847 if Present (Etype (Lhs)) and then Is_Class_Wide_Type (Etype (Lhs)) then
2848 Target := Unchecked_Convert_To (Typ, Lhs);
2849 else
2850 Target := Lhs;
2851 end if;
2852
2853 -- Deal with the ancestor part of extension aggregates or with the
2854 -- discriminants of the root type.
2855
2856 if Nkind (N) = N_Extension_Aggregate then
2857 declare
2858 Ancestor : constant Node_Id := Ancestor_Part (N);
2859 Ancestor_Q : constant Node_Id := Unqualify (Ancestor);
2860
2861 Assign : List_Id;
2862
2863 begin
2864 -- If the ancestor part is a subtype mark T, we generate
2865
2866 -- init-proc (T (tmp)); if T is constrained and
2867 -- init-proc (S (tmp)); where S applies an appropriate
2868 -- constraint if T is unconstrained
2869
2870 if Is_Entity_Name (Ancestor)
2871 and then Is_Type (Entity (Ancestor))
2872 then
2873 Ancestor_Is_Subtype_Mark := True;
2874
2875 if Is_Constrained (Entity (Ancestor)) then
2876 Init_Typ := Entity (Ancestor);
2877
2878 -- For an ancestor part given by an unconstrained type mark,
2879 -- create a subtype constrained by appropriate corresponding
2880 -- discriminant values coming from either associations of the
2881 -- aggregate or a constraint on a parent type. The subtype will
2882 -- be used to generate the correct default value for the
2883 -- ancestor part.
2884
2885 elsif Has_Discriminants (Entity (Ancestor)) then
2886 declare
2887 Anc_Typ : constant Entity_Id := Entity (Ancestor);
2888 Anc_Constr : constant List_Id := New_List;
2889 Discrim : Entity_Id;
2890 Disc_Value : Node_Id;
2891 New_Indic : Node_Id;
2892 Subt_Decl : Node_Id;
2893
2894 begin
2895 Discrim := First_Discriminant (Anc_Typ);
2896 while Present (Discrim) loop
2897 Disc_Value := Ancestor_Discriminant_Value (Discrim);
2898
2899 -- If no usable discriminant in ancestors, check
2900 -- whether aggregate has an explicit value for it.
2901
2902 if No (Disc_Value) then
2903 Disc_Value :=
2904 Get_Explicit_Discriminant_Value (Discrim);
2905 end if;
2906
2907 Append_To (Anc_Constr, Disc_Value);
2908 Next_Discriminant (Discrim);
2909 end loop;
2910
2911 New_Indic :=
2912 Make_Subtype_Indication (Loc,
2913 Subtype_Mark => New_Occurrence_Of (Anc_Typ, Loc),
2914 Constraint =>
2915 Make_Index_Or_Discriminant_Constraint (Loc,
2916 Constraints => Anc_Constr));
2917
2918 Init_Typ := Create_Itype (Ekind (Anc_Typ), N);
2919
2920 Subt_Decl :=
2921 Make_Subtype_Declaration (Loc,
2922 Defining_Identifier => Init_Typ,
2923 Subtype_Indication => New_Indic);
2924
2925 -- Itypes must be analyzed with checks off Declaration
2926 -- must have a parent for proper handling of subsidiary
2927 -- actions.
2928
2929 Set_Parent (Subt_Decl, N);
2930 Analyze (Subt_Decl, Suppress => All_Checks);
2931 end;
2932 end if;
2933
2934 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2935 Set_Assignment_OK (Ref);
2936
2937 if not Is_Interface (Init_Typ) then
2938 Append_List_To (L,
2939 Build_Initialization_Call (Loc,
2940 Id_Ref => Ref,
2941 Typ => Init_Typ,
2942 In_Init_Proc => Within_Init_Proc,
2943 With_Default_Init => Has_Default_Init_Comps (N)
2944 or else
2945 Has_Task (Base_Type (Init_Typ))));
2946
2947 if Is_Constrained (Entity (Ancestor))
2948 and then Has_Discriminants (Entity (Ancestor))
2949 then
2950 Check_Ancestor_Discriminants (Entity (Ancestor));
2951 end if;
2952
2953 -- If ancestor type has Default_Initialization_Condition,
2954 -- add a DIC check after the ancestor object is initialized
2955 -- by default.
2956
2957 if Has_DIC (Entity (Ancestor))
2958 and then Present (DIC_Procedure (Entity (Ancestor)))
2959 then
2960 Append_To (L,
2961 Build_DIC_Call
2962 (Loc, New_Copy_Tree (Ref), Entity (Ancestor)));
2963 end if;
2964 end if;
2965
2966 -- Handle calls to C++ constructors
2967
2968 elsif Is_CPP_Constructor_Call (Ancestor) then
2969 Init_Typ := Etype (Ancestor);
2970 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2971 Set_Assignment_OK (Ref);
2972
2973 Append_List_To (L,
2974 Build_Initialization_Call (Loc,
2975 Id_Ref => Ref,
2976 Typ => Init_Typ,
2977 In_Init_Proc => Within_Init_Proc,
2978 With_Default_Init => Has_Default_Init_Comps (N),
2979 Constructor_Ref => Ancestor));
2980
2981 -- Ada 2005 (AI-287): If the ancestor part is an aggregate of
2982 -- limited type, a recursive call expands the ancestor. Note that
2983 -- in the limited case, the ancestor part must be either a
2984 -- function call (possibly qualified) or aggregate (definitely
2985 -- qualified).
2986
2987 elsif Is_Limited_Type (Etype (Ancestor))
2988 and then Nkind (Ancestor_Q) in N_Aggregate
2989 | N_Extension_Aggregate
2990 then
2991 Append_List_To (L,
2992 Build_Record_Aggr_Code
2993 (N => Ancestor_Q,
2994 Typ => Etype (Ancestor_Q),
2995 Lhs => Target));
2996
2997 -- If the ancestor part is an expression E of type T, we generate
2998
2999 -- T (tmp) := E;
3000
3001 -- In Ada 2005, this includes the case of a (possibly qualified)
3002 -- limited function call. The assignment will later be turned into
3003 -- a build-in-place function call (for further details, see
3004 -- Make_Build_In_Place_Call_In_Assignment).
3005
3006 else
3007 Init_Typ := Etype (Ancestor);
3008
3009 -- If the ancestor part is an aggregate, force its full
3010 -- expansion, which was delayed.
3011
3012 if Nkind (Ancestor_Q) in N_Aggregate | N_Extension_Aggregate
3013 then
3014 Set_Analyzed (Ancestor, False);
3015 Set_Analyzed (Expression (Ancestor), False);
3016 end if;
3017
3018 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
3019
3020 Assign := New_List (
3021 Make_OK_Assignment_Statement (Loc,
3022 Name => Ref,
3023 Expression => Ancestor));
3024
3025 -- Arrange for the component to be adjusted if need be (the
3026 -- call will be generated by Make_Tag_Ctrl_Assignment).
3027
3028 if Needs_Finalization (Init_Typ)
3029 and then not Is_Inherently_Limited_Type (Init_Typ)
3030 then
3031 Set_No_Finalize_Actions (First (Assign));
3032 else
3033 Set_No_Ctrl_Actions (First (Assign));
3034 end if;
3035
3036 Append_To (L,
3037 Make_Suppress_Block (Loc, Name_Discriminant_Check, Assign));
3038
3039 if Has_Discriminants (Init_Typ) then
3040 Check_Ancestor_Discriminants (Init_Typ);
3041 end if;
3042 end if;
3043 end;
3044
3045 -- Generate assignments of hidden discriminants. If the base type is
3046 -- an unchecked union, the discriminants are unknown to the back-end
3047 -- and absent from a value of the type, so assignments for them are
3048 -- not emitted.
3049
3050 if Has_Discriminants (Typ)
3051 and then not Is_Unchecked_Union (Base_Type (Typ))
3052 then
3053 Init_Hidden_Discriminants (Typ, L);
3054 end if;
3055
3056 -- Normal case (not an extension aggregate)
3057
3058 else
3059 -- Generate the discriminant expressions, component by component.
3060 -- If the base type is an unchecked union, the discriminants are
3061 -- unknown to the back-end and absent from a value of the type, so
3062 -- assignments for them are not emitted.
3063
3064 if Has_Discriminants (Typ)
3065 and then not Is_Unchecked_Union (Base_Type (Typ))
3066 then
3067 Init_Hidden_Discriminants (Typ, L);
3068
3069 -- Generate discriminant init values for the visible discriminants
3070
3071 Init_Visible_Discriminants;
3072
3073 if Is_Derived_Type (N_Typ) then
3074 Init_Stored_Discriminants;
3075 end if;
3076 end if;
3077 end if;
3078
3079 -- For CPP types we generate an implicit call to the C++ default
3080 -- constructor to ensure the proper initialization of the _Tag
3081 -- component.
3082
3083 if Is_CPP_Class (Root_Type (Typ)) and then CPP_Num_Prims (Typ) > 0 then
3084 Invoke_Constructor : declare
3085 CPP_Parent : constant Entity_Id := Enclosing_CPP_Parent (Typ);
3086
3087 procedure Invoke_IC_Proc (T : Entity_Id);
3088 -- Recursive routine used to climb to parents. Required because
3089 -- parents must be initialized before descendants to ensure
3090 -- propagation of inherited C++ slots.
3091
3092 --------------------
3093 -- Invoke_IC_Proc --
3094 --------------------
3095
3096 procedure Invoke_IC_Proc (T : Entity_Id) is
3097 begin
3098 -- Avoid generating extra calls. Initialization required
3099 -- only for types defined from the level of derivation of
3100 -- type of the constructor and the type of the aggregate.
3101
3102 if T = CPP_Parent then
3103 return;
3104 end if;
3105
3106 Invoke_IC_Proc (Etype (T));
3107
3108 -- Generate call to the IC routine
3109
3110 if Present (CPP_Init_Proc (T)) then
3111 Append_To (L,
3112 Make_Procedure_Call_Statement (Loc,
3113 Name => New_Occurrence_Of (CPP_Init_Proc (T), Loc)));
3114 end if;
3115 end Invoke_IC_Proc;
3116
3117 -- Start of processing for Invoke_Constructor
3118
3119 begin
3120 -- Implicit invocation of the C++ constructor
3121
3122 if Nkind (N) = N_Aggregate then
3123 Append_To (L,
3124 Make_Procedure_Call_Statement (Loc,
3125 Name =>
3126 New_Occurrence_Of (Base_Init_Proc (CPP_Parent), Loc),
3127 Parameter_Associations => New_List (
3128 Unchecked_Convert_To (CPP_Parent,
3129 New_Copy_Tree (Lhs)))));
3130 end if;
3131
3132 Invoke_IC_Proc (Typ);
3133 end Invoke_Constructor;
3134 end if;
3135
3136 -- Generate the assignments, component by component
3137
3138 -- tmp.comp1 := Expr1_From_Aggr;
3139 -- tmp.comp2 := Expr2_From_Aggr;
3140 -- ....
3141
3142 Comp := First (Component_Associations (N));
3143 while Present (Comp) loop
3144 Selector := Entity (First (Choices (Comp)));
3145 pragma Assert (Present (Selector));
3146
3147 -- C++ constructors
3148
3149 if Is_CPP_Constructor_Call (Expression (Comp)) then
3150 Append_List_To (L,
3151 Build_Initialization_Call (Loc,
3152 Id_Ref =>
3153 Make_Selected_Component (Loc,
3154 Prefix => New_Copy_Tree (Target),
3155 Selector_Name => New_Occurrence_Of (Selector, Loc)),
3156 Typ => Etype (Selector),
3157 Enclos_Type => Typ,
3158 With_Default_Init => True,
3159 Constructor_Ref => Expression (Comp)));
3160
3161 elsif Box_Present (Comp)
3162 and then Needs_Simple_Initialization (Etype (Selector))
3163 then
3164 Comp_Expr :=
3165 Make_Selected_Component (Loc,
3166 Prefix => New_Copy_Tree (Target),
3167 Selector_Name => New_Occurrence_Of (Selector, Loc));
3168
3169 Initialize_Component
3170 (N => N,
3171 Comp => Comp_Expr,
3172 Comp_Typ => Etype (Selector),
3173 Init_Expr => Get_Simple_Init_Val
3174 (Typ => Etype (Selector),
3175 N => Comp,
3176 Size =>
3177 (if Known_Esize (Selector)
3178 then Esize (Selector)
3179 else Uint_0)),
3180 Stmts => L);
3181
3182 -- Ada 2005 (AI-287): For each default-initialized component generate
3183 -- a call to the corresponding IP subprogram if available.
3184
3185 elsif Box_Present (Comp)
3186 and then Has_Non_Null_Base_Init_Proc (Etype (Selector))
3187 then
3188 if Ekind (Selector) /= E_Discriminant then
3189 Generate_Finalization_Actions;
3190 end if;
3191
3192 -- Ada 2005 (AI-287): If the component type has tasks then
3193 -- generate the activation chain and master entities (except
3194 -- in case of an allocator because in that case these entities
3195 -- are generated by Build_Task_Allocate_Block_With_Init_Stmts).
3196
3197 declare
3198 Ctype : constant Entity_Id := Etype (Selector);
3199 Inside_Allocator : Boolean := False;
3200 P : Node_Id := Parent (N);
3201
3202 begin
3203 if Is_Task_Type (Ctype) or else Has_Task (Ctype) then
3204 while Present (P) loop
3205 if Nkind (P) = N_Allocator then
3206 Inside_Allocator := True;
3207 exit;
3208 end if;
3209
3210 P := Parent (P);
3211 end loop;
3212
3213 if not Inside_Init_Proc and not Inside_Allocator then
3214 Build_Activation_Chain_Entity (N);
3215 end if;
3216 end if;
3217 end;
3218
3219 Append_List_To (L,
3220 Build_Initialization_Call (Loc,
3221 Id_Ref => Make_Selected_Component (Loc,
3222 Prefix => New_Copy_Tree (Target),
3223 Selector_Name =>
3224 New_Occurrence_Of (Selector, Loc)),
3225 Typ => Etype (Selector),
3226 Enclos_Type => Typ,
3227 With_Default_Init => True));
3228
3229 -- Prepare for component assignment
3230
3231 elsif Ekind (Selector) /= E_Discriminant
3232 or else Nkind (N) = N_Extension_Aggregate
3233 then
3234 -- All the discriminants have now been assigned
3235
3236 -- This is now a good moment to initialize and attach all the
3237 -- controllers. Their position may depend on the discriminants.
3238
3239 if Ekind (Selector) /= E_Discriminant then
3240 Generate_Finalization_Actions;
3241 end if;
3242
3243 Comp_Type := Underlying_Type (Etype (Selector));
3244 Comp_Expr :=
3245 Make_Selected_Component (Loc,
3246 Prefix => New_Copy_Tree (Target),
3247 Selector_Name => New_Occurrence_Of (Selector, Loc));
3248
3249 Expr_Q := Unqualify (Expression (Comp));
3250
3251 -- Now either create the assignment or generate the code for the
3252 -- inner aggregate top-down.
3253
3254 if Is_Delayed_Aggregate (Expr_Q) then
3255
3256 -- We have the following case of aggregate nesting inside
3257 -- an object declaration:
3258
3259 -- type Arr_Typ is array (Integer range <>) of ...;
3260
3261 -- type Rec_Typ (...) is record
3262 -- Obj_Arr_Typ : Arr_Typ (A .. B);
3263 -- end record;
3264
3265 -- Obj_Rec_Typ : Rec_Typ := (...,
3266 -- Obj_Arr_Typ => (X => (...), Y => (...)));
3267
3268 -- The length of the ranges of the aggregate and Obj_Add_Typ
3269 -- are equal (B - A = Y - X), but they do not coincide (X /=
3270 -- A and B /= Y). This case requires array sliding which is
3271 -- performed in the following manner:
3272
3273 -- subtype Arr_Sub is Arr_Typ (X .. Y);
3274 -- Temp : Arr_Sub;
3275 -- Temp (X) := (...);
3276 -- ...
3277 -- Temp (Y) := (...);
3278 -- Obj_Rec_Typ.Obj_Arr_Typ := Temp;
3279
3280 if Ekind (Comp_Type) = E_Array_Subtype
3281 and then Is_Int_Range_Bounds (Aggregate_Bounds (Expr_Q))
3282 and then Is_Int_Range_Bounds (First_Index (Comp_Type))
3283 and then not
3284 Compatible_Int_Bounds
3285 (Agg_Bounds => Aggregate_Bounds (Expr_Q),
3286 Typ_Bounds => First_Index (Comp_Type))
3287 then
3288 -- Create the array subtype with bounds equal to those of
3289 -- the corresponding aggregate.
3290
3291 declare
3292 SubE : constant Entity_Id := Make_Temporary (Loc, 'T');
3293
3294 SubD : constant Node_Id :=
3295 Make_Subtype_Declaration (Loc,
3296 Defining_Identifier => SubE,
3297 Subtype_Indication =>
3298 Make_Subtype_Indication (Loc,
3299 Subtype_Mark =>
3300 New_Occurrence_Of (Etype (Comp_Type), Loc),
3301 Constraint =>
3302 Make_Index_Or_Discriminant_Constraint
3303 (Loc,
3304 Constraints => New_List (
3305 New_Copy_Tree
3306 (Aggregate_Bounds (Expr_Q))))));
3307
3308 -- Create a temporary array of the above subtype which
3309 -- will be used to capture the aggregate assignments.
3310
3311 TmpE : constant Entity_Id := Make_Temporary (Loc, 'A', N);
3312
3313 TmpD : constant Node_Id :=
3314 Make_Object_Declaration (Loc,
3315 Defining_Identifier => TmpE,
3316 Object_Definition => New_Occurrence_Of (SubE, Loc));
3317
3318 begin
3319 Set_No_Initialization (TmpD);
3320 Append_To (L, SubD);
3321 Append_To (L, TmpD);
3322
3323 -- Expand aggregate into assignments to the temp array
3324
3325 Append_List_To (L,
3326 Late_Expansion (Expr_Q, Comp_Type,
3327 New_Occurrence_Of (TmpE, Loc)));
3328
3329 -- Slide
3330
3331 Append_To (L,
3332 Make_Assignment_Statement (Loc,
3333 Name => New_Copy_Tree (Comp_Expr),
3334 Expression => New_Occurrence_Of (TmpE, Loc)));
3335 end;
3336
3337 -- Normal case (sliding not required)
3338
3339 else
3340 Append_List_To (L,
3341 Late_Expansion (Expr_Q, Comp_Type, Comp_Expr));
3342 end if;
3343
3344 -- Expr_Q is not delayed aggregate
3345
3346 else
3347 if Has_Discriminants (Typ) then
3348 Replace_Discriminants (Expr_Q);
3349
3350 -- If the component is an array type that depends on
3351 -- discriminants, and the expression is a single Others
3352 -- clause, create an explicit subtype for it because the
3353 -- backend has troubles recovering the actual bounds.
3354
3355 if Nkind (Expr_Q) = N_Aggregate
3356 and then Is_Array_Type (Comp_Type)
3357 and then Present (Component_Associations (Expr_Q))
3358 then
3359 declare
3360 Assoc : constant Node_Id :=
3361 First (Component_Associations (Expr_Q));
3362 Decl : Node_Id;
3363
3364 begin
3365 if Present (Assoc)
3366 and then
3367 Nkind (First (Choices (Assoc))) = N_Others_Choice
3368 then
3369 Decl :=
3370 Build_Actual_Subtype_Of_Component
3371 (Comp_Type, Comp_Expr);
3372
3373 -- If the component type does not in fact depend on
3374 -- discriminants, the subtype declaration is empty.
3375
3376 if Present (Decl) then
3377 Append_To (L, Decl);
3378 Set_Etype (Comp_Expr, Defining_Entity (Decl));
3379 end if;
3380 end if;
3381 end;
3382 end if;
3383 end if;
3384
3385 if Modify_Tree_For_C
3386 and then Nkind (Expr_Q) = N_Aggregate
3387 and then Is_Array_Type (Etype (Expr_Q))
3388 and then Present (First_Index (Etype (Expr_Q)))
3389 then
3390 declare
3391 Expr_Q_Type : constant Entity_Id := Etype (Expr_Q);
3392 begin
3393 Append_List_To (L,
3394 Build_Array_Aggr_Code
3395 (N => Expr_Q,
3396 Ctype => Component_Type (Expr_Q_Type),
3397 Index => First_Index (Expr_Q_Type),
3398 Into => Comp_Expr,
3399 Scalar_Comp =>
3400 Is_Scalar_Type (Component_Type (Expr_Q_Type))));
3401 end;
3402
3403 else
3404 Initialize_Component
3405 (N => N,
3406 Comp => Comp_Expr,
3407 Comp_Typ => Etype (Selector),
3408 Init_Expr => Expr_Q,
3409 Stmts => L);
3410 end if;
3411 end if;
3412
3413 -- comment would be good here ???
3414
3415 elsif Ekind (Selector) = E_Discriminant
3416 and then Nkind (N) /= N_Extension_Aggregate
3417 and then Nkind (Parent (N)) = N_Component_Association
3418 and then Is_Constrained (Typ)
3419 then
3420 -- We must check that the discriminant value imposed by the
3421 -- context is the same as the value given in the subaggregate,
3422 -- because after the expansion into assignments there is no
3423 -- record on which to perform a regular discriminant check.
3424
3425 declare
3426 D_Val : Elmt_Id;
3427 Disc : Entity_Id;
3428
3429 begin
3430 D_Val := First_Elmt (Discriminant_Constraint (Typ));
3431 Disc := First_Discriminant (Typ);
3432 while Chars (Disc) /= Chars (Selector) loop
3433 Next_Discriminant (Disc);
3434 Next_Elmt (D_Val);
3435 end loop;
3436
3437 pragma Assert (Present (D_Val));
3438
3439 -- This check cannot performed for components that are
3440 -- constrained by a current instance, because this is not a
3441 -- value that can be compared with the actual constraint.
3442
3443 if Nkind (Node (D_Val)) /= N_Attribute_Reference
3444 or else not Is_Entity_Name (Prefix (Node (D_Val)))
3445 or else not Is_Type (Entity (Prefix (Node (D_Val))))
3446 then
3447 Append_To (L,
3448 Make_Raise_Constraint_Error (Loc,
3449 Condition =>
3450 Make_Op_Ne (Loc,
3451 Left_Opnd => New_Copy_Tree (Node (D_Val)),
3452 Right_Opnd => Expression (Comp)),
3453 Reason => CE_Discriminant_Check_Failed));
3454
3455 else
3456 -- Find self-reference in previous discriminant assignment,
3457 -- and replace with proper expression.
3458
3459 declare
3460 Ass : Node_Id;
3461
3462 begin
3463 Ass := First (L);
3464 while Present (Ass) loop
3465 if Nkind (Ass) = N_Assignment_Statement
3466 and then Nkind (Name (Ass)) = N_Selected_Component
3467 and then Chars (Selector_Name (Name (Ass))) =
3468 Chars (Disc)
3469 then
3470 Set_Expression
3471 (Ass, New_Copy_Tree (Expression (Comp)));
3472 exit;
3473 end if;
3474 Next (Ass);
3475 end loop;
3476 end;
3477 end if;
3478 end;
3479 end if;
3480
3481 -- If the component association was specified with a box and the
3482 -- component type has a Default_Initial_Condition, then generate
3483 -- a call to the DIC procedure.
3484
3485 if Has_DIC (Etype (Selector))
3486 and then Was_Default_Init_Box_Association (Comp)
3487 and then Present (DIC_Procedure (Etype (Selector)))
3488 then
3489 Append_To (L,
3490 Build_DIC_Call (Loc,
3491 Make_Selected_Component (Loc,
3492 Prefix => New_Copy_Tree (Target),
3493 Selector_Name => New_Occurrence_Of (Selector, Loc)),
3494 Etype (Selector)));
3495 end if;
3496
3497 Next (Comp);
3498 end loop;
3499
3500 -- For CPP types we generated a call to the C++ default constructor
3501 -- before the components have been initialized to ensure the proper
3502 -- initialization of the _Tag component (see above).
3503
3504 if Is_CPP_Class (Typ) then
3505 null;
3506
3507 -- If the type is tagged, the tag needs to be initialized (unless we
3508 -- are in VM-mode where tags are implicit). It is done late in the
3509 -- initialization process because in some cases, we call the init
3510 -- proc of an ancestor which will not leave out the right tag.
3511
3512 elsif Is_Tagged_Type (Typ) and then Tagged_Type_Expansion then
3513 Instr :=
3514 Make_Tag_Assignment_From_Type
3515 (Loc, New_Copy_Tree (Target), Base_Type (Typ));
3516
3517 Append_To (L, Instr);
3518
3519 -- Ada 2005 (AI-251): If the tagged type has been derived from an
3520 -- abstract interfaces we must also initialize the tags of the
3521 -- secondary dispatch tables.
3522
3523 if Has_Interfaces (Base_Type (Typ)) then
3524 Init_Secondary_Tags
3525 (Typ => Base_Type (Typ),
3526 Target => Target,
3527 Stmts_List => L,
3528 Init_Tags_List => L);
3529 end if;
3530 end if;
3531
3532 -- If the controllers have not been initialized yet (by lack of non-
3533 -- discriminant components), let's do it now.
3534
3535 Generate_Finalization_Actions;
3536
3537 return L;
3538 end Build_Record_Aggr_Code;
3539
3540 -------------------------------
3541 -- Convert_Aggr_In_Allocator --
3542 -------------------------------
3543
3544 procedure Convert_Aggr_In_Allocator
3545 (Alloc : Node_Id;
3546 Decl : Node_Id;
3547 Aggr : Node_Id)
3548 is
3549 Loc : constant Source_Ptr := Sloc (Aggr);
3550 Typ : constant Entity_Id := Etype (Aggr);
3551 Temp : constant Entity_Id := Defining_Identifier (Decl);
3552
3553 Occ : constant Node_Id :=
3554 Unchecked_Convert_To (Typ,
3555 Make_Explicit_Dereference (Loc, New_Occurrence_Of (Temp, Loc)));
3556
3557 begin
3558 if Is_Array_Type (Typ) then
3559 Convert_Array_Aggr_In_Allocator (Decl, Aggr, Occ);
3560
3561 elsif Has_Default_Init_Comps (Aggr) then
3562 declare
3563 L : constant List_Id := New_List;
3564 Init_Stmts : List_Id;
3565
3566 begin
3567 Init_Stmts := Late_Expansion (Aggr, Typ, Occ);
3568
3569 if Has_Task (Typ) then
3570 Build_Task_Allocate_Block_With_Init_Stmts (L, Aggr, Init_Stmts);
3571 Insert_Actions (Alloc, L);
3572 else
3573 Insert_Actions (Alloc, Init_Stmts);
3574 end if;
3575 end;
3576
3577 else
3578 Insert_Actions (Alloc, Late_Expansion (Aggr, Typ, Occ));
3579 end if;
3580 end Convert_Aggr_In_Allocator;
3581
3582 --------------------------------
3583 -- Convert_Aggr_In_Assignment --
3584 --------------------------------
3585
3586 procedure Convert_Aggr_In_Assignment (N : Node_Id) is
3587 Aggr : constant Node_Id := Unqualify (Expression (N));
3588 Typ : constant Entity_Id := Etype (Aggr);
3589 Occ : constant Node_Id := New_Copy_Tree (Name (N));
3590
3591 begin
3592 Insert_Actions_After (N, Late_Expansion (Aggr, Typ, Occ));
3593 end Convert_Aggr_In_Assignment;
3594
3595 ---------------------------------
3596 -- Convert_Aggr_In_Object_Decl --
3597 ---------------------------------
3598
3599 procedure Convert_Aggr_In_Object_Decl (N : Node_Id) is
3600 Obj : constant Entity_Id := Defining_Identifier (N);
3601 Aggr : constant Node_Id := Unqualify (Expression (N));
3602 Loc : constant Source_Ptr := Sloc (Aggr);
3603 Typ : constant Entity_Id := Etype (Aggr);
3604 Occ : constant Node_Id := New_Occurrence_Of (Obj, Loc);
3605
3606 Has_Transient_Scope : Boolean := False;
3607
3608 function Discriminants_Ok return Boolean;
3609 -- If the object type is constrained, the discriminants in the
3610 -- aggregate must be checked against the discriminants of the subtype.
3611 -- This cannot be done using Apply_Discriminant_Checks because after
3612 -- expansion there is no aggregate left to check.
3613
3614 ----------------------
3615 -- Discriminants_Ok --
3616 ----------------------
3617
3618 function Discriminants_Ok return Boolean is
3619 Cond : Node_Id := Empty;
3620 Check : Node_Id;
3621 D : Entity_Id;
3622 Disc1 : Elmt_Id;
3623 Disc2 : Elmt_Id;
3624 Val1 : Node_Id;
3625 Val2 : Node_Id;
3626
3627 begin
3628 D := First_Discriminant (Typ);
3629 Disc1 := First_Elmt (Discriminant_Constraint (Typ));
3630 Disc2 := First_Elmt (Discriminant_Constraint (Etype (Obj)));
3631 while Present (Disc1) and then Present (Disc2) loop
3632 Val1 := Node (Disc1);
3633 Val2 := Node (Disc2);
3634
3635 if not Is_OK_Static_Expression (Val1)
3636 or else not Is_OK_Static_Expression (Val2)
3637 then
3638 Check := Make_Op_Ne (Loc,
3639 Left_Opnd => Duplicate_Subexpr (Val1),
3640 Right_Opnd => Duplicate_Subexpr (Val2));
3641
3642 if No (Cond) then
3643 Cond := Check;
3644
3645 else
3646 Cond := Make_Or_Else (Loc,
3647 Left_Opnd => Cond,
3648 Right_Opnd => Check);
3649 end if;
3650
3651 elsif Expr_Value (Val1) /= Expr_Value (Val2) then
3652 Apply_Compile_Time_Constraint_Error (Aggr,
3653 Msg => "incorrect value for discriminant&??",
3654 Reason => CE_Discriminant_Check_Failed,
3655 Ent => D);
3656 return False;
3657 end if;
3658
3659 Next_Discriminant (D);
3660 Next_Elmt (Disc1);
3661 Next_Elmt (Disc2);
3662 end loop;
3663
3664 -- If any discriminant constraint is nonstatic, emit a check
3665
3666 if Present (Cond) then
3667 Insert_Action (N,
3668 Make_Raise_Constraint_Error (Loc,
3669 Condition => Cond,
3670 Reason => CE_Discriminant_Check_Failed));
3671 end if;
3672
3673 return True;
3674 end Discriminants_Ok;
3675
3676 -- Start of processing for Convert_Aggr_In_Object_Decl
3677
3678 begin
3679 Set_Assignment_OK (Occ);
3680
3681 if Has_Discriminants (Typ)
3682 and then Typ /= Etype (Obj)
3683 and then Is_Constrained (Etype (Obj))
3684 and then not Discriminants_Ok
3685 then
3686 return;
3687 end if;
3688
3689 -- If the context is an extended return statement, it has its own
3690 -- finalization machinery (i.e. works like a transient scope) and
3691 -- we do not want to create an additional one, because objects on
3692 -- the finalization list of the return must be moved to the caller's
3693 -- finalization list to complete the return.
3694
3695 -- Similarly if the aggregate is limited, it is built in place, and the
3696 -- controlled components are not assigned to intermediate temporaries
3697 -- so there is no need for a transient scope in this case either.
3698
3699 if Requires_Transient_Scope (Typ)
3700 and then Ekind (Current_Scope) /= E_Return_Statement
3701 and then not Is_Limited_Type (Typ)
3702 then
3703 Establish_Transient_Scope (Aggr, Manage_Sec_Stack => False);
3704 Has_Transient_Scope := True;
3705 end if;
3706
3707 declare
3708 Stmts : constant List_Id := Late_Expansion (Aggr, Typ, Occ);
3709 Stmt : Node_Id;
3710 Param : Node_Id;
3711
3712 begin
3713 -- If Obj is already frozen or if N is wrapped in a transient scope,
3714 -- Stmts do not need to be saved in Initialization_Statements since
3715 -- there is no freezing issue.
3716
3717 if Is_Frozen (Obj) or else Has_Transient_Scope then
3718 Insert_Actions_After (N, Stmts);
3719 else
3720 Stmt := Make_Compound_Statement (Sloc (N), Actions => Stmts);
3721 Insert_Action_After (N, Stmt);
3722
3723 -- Insert_Action_After may freeze Obj in which case we should
3724 -- remove the compound statement just created and simply insert
3725 -- Stmts after N.
3726
3727 if Is_Frozen (Obj) then
3728 Remove (Stmt);
3729 Insert_Actions_After (N, Stmts);
3730 else
3731 Set_Initialization_Statements (Obj, Stmt);
3732 end if;
3733 end if;
3734
3735 -- If Typ has controlled components and a call to a Slice_Assign
3736 -- procedure is part of the initialization statements, then we
3737 -- need to initialize the array component since Slice_Assign will
3738 -- need to adjust it.
3739
3740 if Has_Controlled_Component (Typ) then
3741 Stmt := First (Stmts);
3742
3743 while Present (Stmt) loop
3744 if Nkind (Stmt) = N_Procedure_Call_Statement
3745 and then Is_TSS (Entity (Name (Stmt)), TSS_Slice_Assign)
3746 then
3747 Param := First (Parameter_Associations (Stmt));
3748 Insert_Actions
3749 (Stmt,
3750 Build_Initialization_Call
3751 (Sloc (N), New_Copy_Tree (Param), Etype (Param)));
3752 end if;
3753
3754 Next (Stmt);
3755 end loop;
3756 end if;
3757 end;
3758
3759 Set_No_Initialization (N);
3760
3761 -- After expansion the expression can be removed from the declaration
3762 -- except if the object is class-wide, in which case the aggregate
3763 -- provides the actual type.
3764
3765 if not Is_Class_Wide_Type (Etype (Obj)) then
3766 Set_Expression (N, Empty);
3767 end if;
3768
3769 Initialize_Discriminants (N, Typ);
3770 end Convert_Aggr_In_Object_Decl;
3771
3772 -------------------------------------
3773 -- Convert_Array_Aggr_In_Allocator --
3774 -------------------------------------
3775
3776 procedure Convert_Array_Aggr_In_Allocator
3777 (Decl : Node_Id;
3778 Aggr : Node_Id;
3779 Target : Node_Id)
3780 is
3781 Typ : constant Entity_Id := Etype (Aggr);
3782 Ctyp : constant Entity_Id := Component_Type (Typ);
3783 Aggr_Code : List_Id;
3784 New_Aggr : Node_Id;
3785
3786 begin
3787 -- The target is an explicit dereference of the allocated object
3788
3789 -- If the assignment can be done directly by the back end, then
3790 -- reset Set_Expansion_Delayed and do not expand further.
3791
3792 if not CodePeer_Mode
3793 and then not Modify_Tree_For_C
3794 and then Aggr_Assignment_OK_For_Backend (Aggr)
3795 then
3796 New_Aggr := New_Copy_Tree (Aggr);
3797 Set_Expansion_Delayed (New_Aggr, False);
3798
3799 -- In the case of Target's type using the Designated_Storage_Model
3800 -- aspect with a Copy_To procedure, insert a temporary and have the
3801 -- back end handle the assignment to it. Copy the result to the
3802 -- original target.
3803
3804 if Has_Designated_Storage_Model_Aspect
3805 (Etype (Prefix (Expression (Target))))
3806 and then Present (Storage_Model_Copy_To
3807 (Storage_Model_Object
3808 (Etype (Prefix (Expression (Target))))))
3809 then
3810 Aggr_Code :=
3811 Build_Assignment_With_Temporary (Target, Typ, New_Aggr);
3812
3813 else
3814 Aggr_Code :=
3815 New_List (
3816 Make_OK_Assignment_Statement (Sloc (New_Aggr),
3817 Name => Target,
3818 Expression => New_Aggr));
3819 end if;
3820
3821 -- Or else, generate component assignments to it, as for an aggregate
3822 -- that appears on the right-hand side of an assignment statement.
3823 else
3824 Aggr_Code :=
3825 Build_Array_Aggr_Code (Aggr,
3826 Ctype => Ctyp,
3827 Index => First_Index (Typ),
3828 Into => Target,
3829 Scalar_Comp => Is_Scalar_Type (Ctyp));
3830 end if;
3831
3832 Insert_Actions_After (Decl, Aggr_Code);
3833 end Convert_Array_Aggr_In_Allocator;
3834
3835 ------------------------
3836 -- In_Place_Assign_OK --
3837 ------------------------
3838
3839 function In_Place_Assign_OK
3840 (N : Node_Id;
3841 Target_Object : Entity_Id := Empty) return Boolean
3842 is
3843 Is_Array : constant Boolean := Is_Array_Type (Etype (N));
3844
3845 Aggr_In : Node_Id;
3846 Aggr_Bounds : Range_Nodes;
3847 Obj_In : Node_Id;
3848 Obj_Bounds : Range_Nodes;
3849 Parent_Kind : Node_Kind;
3850 Parent_Node : Node_Id;
3851
3852 function Safe_Aggregate (Aggr : Node_Id) return Boolean;
3853 -- Check recursively that each component of a (sub)aggregate does not
3854 -- depend on the variable being assigned to.
3855
3856 function Safe_Component (Expr : Node_Id) return Boolean;
3857 -- Verify that an expression cannot depend on the target being assigned
3858 -- to. Return true for compile-time known values, stand-alone objects,
3859 -- parameters passed by copy, calls to functions that return by copy,
3860 -- selected components thereof only if the aggregate's type is an array,
3861 -- indexed components and slices thereof only if the aggregate's type is
3862 -- a record, and simple expressions involving only these as operands.
3863 -- This is OK whatever the target because, for a component to overlap
3864 -- with the target, it must be either a direct reference to a component
3865 -- of the target, in which case there must be a matching selection or
3866 -- indexation or slicing, or an indirect reference to such a component,
3867 -- which is excluded by the above condition. Additionally, if the target
3868 -- is statically known, return true for arbitrarily nested selections,
3869 -- indexations or slicings, provided that their ultimate prefix is not
3870 -- the target itself.
3871
3872 --------------------
3873 -- Safe_Aggregate --
3874 --------------------
3875
3876 function Safe_Aggregate (Aggr : Node_Id) return Boolean is
3877 Expr : Node_Id;
3878
3879 begin
3880 if Nkind (Parent (Aggr)) = N_Iterated_Component_Association then
3881 return False;
3882 end if;
3883
3884 if Present (Expressions (Aggr)) then
3885 Expr := First (Expressions (Aggr));
3886 while Present (Expr) loop
3887 if Nkind (Expr) = N_Aggregate then
3888 if not Safe_Aggregate (Expr) then
3889 return False;
3890 end if;
3891
3892 elsif not Safe_Component (Expr) then
3893 return False;
3894 end if;
3895
3896 Next (Expr);
3897 end loop;
3898 end if;
3899
3900 if Present (Component_Associations (Aggr)) then
3901 Expr := First (Component_Associations (Aggr));
3902 while Present (Expr) loop
3903 if Nkind (Expression (Expr)) = N_Aggregate then
3904 if not Safe_Aggregate (Expression (Expr)) then
3905 return False;
3906 end if;
3907
3908 -- If association has a box, no way to determine yet whether
3909 -- default can be assigned in place.
3910
3911 elsif Box_Present (Expr) then
3912 return False;
3913
3914 elsif not Safe_Component (Expression (Expr)) then
3915 return False;
3916 end if;
3917
3918 Next (Expr);
3919 end loop;
3920 end if;
3921
3922 return True;
3923 end Safe_Aggregate;
3924
3925 --------------------
3926 -- Safe_Component --
3927 --------------------
3928
3929 function Safe_Component (Expr : Node_Id) return Boolean is
3930 Comp : Node_Id := Expr;
3931
3932 function Check_Component (C : Node_Id; T_OK : Boolean) return Boolean;
3933 -- Do the recursive traversal, after copy. If T_OK is True, return
3934 -- True for a stand-alone object only if the target is statically
3935 -- known and distinct from the object. At the top level, we start
3936 -- with T_OK set to False and set it to True at a deeper level only
3937 -- if we cannot disambiguate the component here without statically
3938 -- knowing the target. Note that this is not optimal, we should do
3939 -- something along the lines of Denotes_Same_Prefix for that.
3940
3941 ---------------------
3942 -- Check_Component --
3943 ---------------------
3944
3945 function Check_Component (C : Node_Id; T_OK : Boolean) return Boolean
3946 is
3947
3948 function SDO (E : Entity_Id) return Uint;
3949 -- Return the Scope Depth Of the enclosing dynamic scope of E
3950
3951 ---------
3952 -- SDO --
3953 ---------
3954
3955 function SDO (E : Entity_Id) return Uint is
3956 begin
3957 return Scope_Depth (Enclosing_Dynamic_Scope (E));
3958 end SDO;
3959
3960 -- Start of processing for Check_Component
3961
3962 begin
3963 if Is_Overloaded (C) then
3964 return False;
3965
3966 elsif Compile_Time_Known_Value (C) then
3967 return True;
3968 end if;
3969
3970 case Nkind (C) is
3971 when N_Attribute_Reference =>
3972 return Check_Component (Prefix (C), T_OK);
3973
3974 when N_Function_Call =>
3975 if Nkind (Name (C)) = N_Explicit_Dereference then
3976 return not Returns_By_Ref (Etype (Name (C)));
3977 else
3978 return not Returns_By_Ref (Entity (Name (C)));
3979 end if;
3980
3981 when N_Indexed_Component | N_Slice =>
3982 -- In a target record, these operations cannot determine
3983 -- alone a component so we can recurse whatever the target.
3984 return Check_Component (Prefix (C), T_OK or else Is_Array);
3985
3986 when N_Selected_Component =>
3987 -- In a target array, this operation cannot determine alone
3988 -- a component so we can recurse whatever the target.
3989 return
3990 Check_Component (Prefix (C), T_OK or else not Is_Array);
3991
3992 when N_Type_Conversion | N_Unchecked_Type_Conversion =>
3993 return Check_Component (Expression (C), T_OK);
3994
3995 when N_Binary_Op =>
3996 return Check_Component (Left_Opnd (C), T_OK)
3997 and then Check_Component (Right_Opnd (C), T_OK);
3998
3999 when N_Unary_Op =>
4000 return Check_Component (Right_Opnd (C), T_OK);
4001
4002 when others =>
4003 if Is_Entity_Name (C) and then Is_Object (Entity (C)) then
4004 -- Case of a formal parameter component. It's either
4005 -- trivial if passed by copy or very annoying if not,
4006 -- because in the latter case it's almost equivalent
4007 -- to a dereference, so the path-based disambiguation
4008 -- logic is totally off and we always need the target.
4009
4010 if Is_Formal (Entity (C)) then
4011
4012 -- If it is passed by copy, then this is safe
4013
4014 if Mechanism (Entity (C)) = By_Copy then
4015 return True;
4016
4017 -- Otherwise, this is safe if the target is present
4018 -- and is at least as deeply nested as the component.
4019
4020 else
4021 return Present (Target_Object)
4022 and then not Is_Formal (Target_Object)
4023 and then SDO (Target_Object) >= SDO (Entity (C));
4024 end if;
4025
4026 -- For a renamed object, recurse
4027
4028 elsif Present (Renamed_Object (Entity (C))) then
4029 return
4030 Check_Component (Renamed_Object (Entity (C)), T_OK);
4031
4032 -- If this is safe whatever the target, we are done
4033
4034 elsif not T_OK then
4035 return True;
4036
4037 -- If there is no target or the component is the target,
4038 -- this is not safe.
4039
4040 elsif No (Target_Object)
4041 or else Entity (C) = Target_Object
4042 then
4043 return False;
4044
4045 -- Case of a formal parameter target. This is safe if it
4046 -- is at most as deeply nested as the component.
4047
4048 elsif Is_Formal (Target_Object) then
4049 return SDO (Target_Object) <= SDO (Entity (C));
4050
4051 -- For distinct stand-alone objects, this is safe
4052
4053 else
4054 return True;
4055 end if;
4056
4057 -- For anything else than an object, this is not safe
4058
4059 else
4060 return False;
4061 end if;
4062 end case;
4063 end Check_Component;
4064
4065 -- Start of processing for Safe_Component
4066
4067 begin
4068 -- If the component appears in an association that may correspond
4069 -- to more than one element, it is not analyzed before expansion
4070 -- into assignments, to avoid side effects. We analyze, but do not
4071 -- resolve the copy, to obtain sufficient entity information for
4072 -- the checks that follow. If component is overloaded we assume
4073 -- an unsafe function call.
4074
4075 if not Analyzed (Comp) then
4076 if Is_Overloaded (Expr) then
4077 return False;
4078
4079 elsif Nkind (Expr) = N_Allocator then
4080
4081 -- For now, too complex to analyze
4082
4083 return False;
4084
4085 elsif Nkind (Parent (Expr)) = N_Iterated_Component_Association then
4086
4087 -- Ditto for iterated component associations, which in general
4088 -- require an enclosing loop and involve nonstatic expressions.
4089
4090 return False;
4091 end if;
4092
4093 Comp := New_Copy_Tree (Expr);
4094 Set_Parent (Comp, Parent (Expr));
4095 Analyze (Comp);
4096 end if;
4097
4098 if Nkind (Comp) = N_Aggregate then
4099 return Safe_Aggregate (Comp);
4100 else
4101 return Check_Component (Comp, False);
4102 end if;
4103 end Safe_Component;
4104
4105 -- Start of processing for In_Place_Assign_OK
4106
4107 begin
4108 -- By-copy semantic cannot be guaranteed for controlled objects
4109
4110 if Needs_Finalization (Etype (N)) then
4111 return False;
4112 end if;
4113
4114 Parent_Node := Parent (N);
4115 Parent_Kind := Nkind (Parent_Node);
4116
4117 if Parent_Kind = N_Qualified_Expression then
4118 Parent_Node := Parent (Parent_Node);
4119 Parent_Kind := Nkind (Parent_Node);
4120 end if;
4121
4122 -- On assignment, sliding can take place, so we cannot do the
4123 -- assignment in place unless the bounds of the aggregate are
4124 -- statically equal to those of the target.
4125
4126 -- If the aggregate is given by an others choice, the bounds are
4127 -- derived from the left-hand side, and the assignment is safe if
4128 -- the expression is.
4129
4130 if Is_Array
4131 and then Present (Component_Associations (N))
4132 and then not Is_Others_Aggregate (N)
4133 then
4134 Aggr_In := First_Index (Etype (N));
4135
4136 -- Context is an assignment
4137
4138 if Parent_Kind = N_Assignment_Statement then
4139 Obj_In := First_Index (Etype (Name (Parent_Node)));
4140
4141 -- Context is an allocator. Check the bounds of the aggregate against
4142 -- those of the designated type, except in the case where the type is
4143 -- unconstrained (and then we can directly return true, see below).
4144
4145 else pragma Assert (Parent_Kind = N_Allocator);
4146 declare
4147 Desig_Typ : constant Entity_Id :=
4148 Designated_Type (Etype (Parent_Node));
4149 begin
4150 if not Is_Constrained (Desig_Typ) then
4151 return True;
4152 end if;
4153
4154 Obj_In := First_Index (Desig_Typ);
4155 end;
4156 end if;
4157
4158 while Present (Aggr_In) loop
4159 Aggr_Bounds := Get_Index_Bounds (Aggr_In);
4160 Obj_Bounds := Get_Index_Bounds (Obj_In);
4161
4162 -- We require static bounds for the target and a static matching
4163 -- of low bound for the aggregate.
4164
4165 if not Compile_Time_Known_Value (Obj_Bounds.First)
4166 or else not Compile_Time_Known_Value (Obj_Bounds.Last)
4167 or else not Compile_Time_Known_Value (Aggr_Bounds.First)
4168 or else Expr_Value (Aggr_Bounds.First) /=
4169 Expr_Value (Obj_Bounds.First)
4170 then
4171 return False;
4172
4173 -- For an assignment statement we require static matching of
4174 -- bounds. Ditto for an allocator whose qualified expression
4175 -- is a constrained type. If the expression in the allocator
4176 -- is an unconstrained array, we accept an upper bound that
4177 -- is not static, to allow for nonstatic expressions of the
4178 -- base type. Clearly there are further possibilities (with
4179 -- diminishing returns) for safely building arrays in place
4180 -- here.
4181
4182 elsif Parent_Kind = N_Assignment_Statement
4183 or else Is_Constrained (Etype (Parent_Node))
4184 then
4185 if not Compile_Time_Known_Value (Aggr_Bounds.Last)
4186 or else Expr_Value (Aggr_Bounds.Last) /=
4187 Expr_Value (Obj_Bounds.Last)
4188 then
4189 return False;
4190 end if;
4191 end if;
4192
4193 Next_Index (Aggr_In);
4194 Next_Index (Obj_In);
4195 end loop;
4196 end if;
4197
4198 -- Now check the component values themselves, except for an allocator
4199 -- for which the target is newly allocated memory.
4200
4201 if Parent_Kind = N_Allocator then
4202 return True;
4203 else
4204 return Safe_Aggregate (N);
4205 end if;
4206 end In_Place_Assign_OK;
4207
4208 ----------------------------
4209 -- Convert_To_Assignments --
4210 ----------------------------
4211
4212 procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id) is
4213 Loc : constant Source_Ptr := Sloc (N);
4214 T : Entity_Id;
4215 Temp : Entity_Id;
4216
4217 Aggr_Code : List_Id;
4218 Instr : Node_Id;
4219 Target_Expr : Node_Id;
4220 Parent_Kind : Node_Kind;
4221 Unc_Decl : Boolean := False;
4222 Parent_Node : Node_Id;
4223
4224 begin
4225 pragma Assert (Nkind (N) in N_Aggregate | N_Extension_Aggregate);
4226 pragma Assert (not Is_Static_Dispatch_Table_Aggregate (N));
4227 pragma Assert (Is_Record_Type (Typ));
4228
4229 Parent_Node := Parent (N);
4230 Parent_Kind := Nkind (Parent_Node);
4231
4232 if Parent_Kind = N_Qualified_Expression then
4233 -- Check if we are in an unconstrained declaration because in this
4234 -- case the current delayed expansion mechanism doesn't work when
4235 -- the declared object size depends on the initializing expr.
4236
4237 Parent_Node := Parent (Parent_Node);
4238 Parent_Kind := Nkind (Parent_Node);
4239
4240 if Parent_Kind = N_Object_Declaration then
4241 Unc_Decl :=
4242 not Is_Entity_Name (Object_Definition (Parent_Node))
4243 or else (Nkind (N) = N_Aggregate
4244 and then
4245 Has_Discriminants
4246 (Entity (Object_Definition (Parent_Node))))
4247 or else Is_Class_Wide_Type
4248 (Entity (Object_Definition (Parent_Node)));
4249 end if;
4250 end if;
4251
4252 -- Just set the Delay flag in the cases where the transformation will be
4253 -- done top down from above.
4254
4255 if
4256 -- Internal aggregates (transformed when expanding the parent),
4257 -- excluding container aggregates as these are transformed into
4258 -- subprogram calls later.
4259
4260 (Parent_Kind = N_Component_Association
4261 and then not Is_Container_Aggregate (Parent (Parent_Node)))
4262
4263 or else (Parent_Kind in N_Aggregate | N_Extension_Aggregate
4264 and then not Is_Container_Aggregate (Parent_Node))
4265
4266 -- Allocator (see Convert_Aggr_In_Allocator)
4267
4268 or else Parent_Kind = N_Allocator
4269
4270 -- Object declaration (see Convert_Aggr_In_Object_Decl)
4271
4272 or else (Parent_Kind = N_Object_Declaration and then not Unc_Decl)
4273
4274 -- Safe assignment (see Convert_Aggr_Assignments). So far only the
4275 -- assignments in init procs are taken into account.
4276
4277 or else (Parent_Kind = N_Assignment_Statement
4278 and then Inside_Init_Proc)
4279
4280 -- (Ada 2005) An inherently limited type in a return statement, which
4281 -- will be handled in a build-in-place fashion, and may be rewritten
4282 -- as an extended return and have its own finalization machinery.
4283 -- In the case of a simple return, the aggregate needs to be delayed
4284 -- until the scope for the return statement has been created, so
4285 -- that any finalization chain will be associated with that scope.
4286 -- For extended returns, we delay expansion to avoid the creation
4287 -- of an unwanted transient scope that could result in premature
4288 -- finalization of the return object (which is built in place
4289 -- within the caller's scope).
4290
4291 or else Is_Build_In_Place_Aggregate_Return (N)
4292 then
4293 Set_Expansion_Delayed (N);
4294 return;
4295 end if;
4296
4297 -- Otherwise, if a transient scope is required, create it now
4298
4299 if Requires_Transient_Scope (Typ) then
4300 Establish_Transient_Scope (N, Manage_Sec_Stack => False);
4301 end if;
4302
4303 -- If the aggregate is nonlimited, create a temporary, since aggregates
4304 -- have "by copy" semantics. If it is limited and context is an
4305 -- assignment, this is a subaggregate for an enclosing aggregate being
4306 -- expanded. It must be built in place, so use target of the current
4307 -- assignment.
4308
4309 if Is_Limited_Type (Typ)
4310 and then Parent_Kind = N_Assignment_Statement
4311 then
4312 Target_Expr := New_Copy_Tree (Name (Parent_Node));
4313 Insert_Actions (Parent_Node,
4314 Build_Record_Aggr_Code (N, Typ, Target_Expr));
4315 Rewrite (Parent_Node, Make_Null_Statement (Loc));
4316
4317 -- Do not declare a temporary to initialize an aggregate assigned to
4318 -- a target when in-place assignment is possible, i.e. preserving the
4319 -- by-copy semantic of aggregates. This avoids large stack usage and
4320 -- generates more efficient code.
4321
4322 elsif Parent_Kind = N_Assignment_Statement
4323 and then In_Place_Assign_OK (N, Get_Base_Object (Name (Parent_Node)))
4324 then
4325 declare
4326 Lhs : constant Node_Id := Name (Parent_Node);
4327 begin
4328 -- Apply discriminant check if required
4329
4330 if Has_Discriminants (Etype (N)) then
4331 Apply_Discriminant_Check (N, Etype (Lhs), Lhs);
4332 end if;
4333
4334 -- The check just above may have replaced the aggregate with a CE
4335
4336 if Nkind (N) in N_Aggregate | N_Extension_Aggregate then
4337 Target_Expr := New_Copy_Tree (Lhs);
4338 Insert_Actions (Parent_Node,
4339 Build_Record_Aggr_Code (N, Typ, Target_Expr));
4340 Rewrite (Parent_Node, Make_Null_Statement (Loc));
4341 end if;
4342 end;
4343
4344 else
4345 Temp := Make_Temporary (Loc, 'A', N);
4346
4347 -- If the type inherits unknown discriminants, use the view with
4348 -- known discriminants if available.
4349
4350 if Has_Unknown_Discriminants (Typ)
4351 and then Present (Underlying_Record_View (Typ))
4352 then
4353 T := Underlying_Record_View (Typ);
4354 else
4355 T := Typ;
4356 end if;
4357
4358 Instr :=
4359 Make_Object_Declaration (Loc,
4360 Defining_Identifier => Temp,
4361 Object_Definition => New_Occurrence_Of (T, Loc));
4362
4363 Set_No_Initialization (Instr);
4364 Insert_Action (N, Instr);
4365 Initialize_Discriminants (Instr, T);
4366
4367 Target_Expr := New_Occurrence_Of (Temp, Loc);
4368 Aggr_Code := Build_Record_Aggr_Code (N, T, Target_Expr);
4369
4370 -- Save the last assignment statement associated with the aggregate
4371 -- when building a controlled object. This reference is utilized by
4372 -- the finalization machinery when marking an object as successfully
4373 -- initialized.
4374
4375 if Needs_Finalization (T) then
4376 Set_Last_Aggregate_Assignment (Temp, Last (Aggr_Code));
4377 end if;
4378
4379 Insert_Actions (N, Aggr_Code);
4380 Rewrite (N, New_Occurrence_Of (Temp, Loc));
4381 Analyze_And_Resolve (N, T);
4382 end if;
4383 end Convert_To_Assignments;
4384
4385 ---------------------------
4386 -- Convert_To_Positional --
4387 ---------------------------
4388
4389 procedure Convert_To_Positional
4390 (N : Node_Id;
4391 Handle_Bit_Packed : Boolean := False)
4392 is
4393 Typ : constant Entity_Id := Etype (N);
4394 Dims : constant Nat := Number_Dimensions (Typ);
4395 Max_Others_Replicate : constant Nat := Max_Aggregate_Size (N);
4396
4397 Static_Components : Boolean := True;
4398
4399 procedure Check_Static_Components;
4400 -- Check whether all components of the aggregate are compile-time known
4401 -- values, and can be passed as is to the back-end without further
4402 -- expansion.
4403
4404 function Flatten
4405 (N : Node_Id;
4406 Dims : Nat;
4407 Ix : Node_Id;
4408 Ixb : Node_Id) return Boolean;
4409 -- Convert the aggregate into a purely positional form if possible after
4410 -- checking that the bounds of all dimensions are known to be static.
4411
4412 function Is_Flat (N : Node_Id; Dims : Nat) return Boolean;
4413 -- Return True if the aggregate N is flat (which is not trivial in the
4414 -- case of multidimensional aggregates).
4415
4416 function Is_Static_Element (N : Node_Id; Dims : Nat) return Boolean;
4417 -- Return True if N, an element of a component association list, i.e.
4418 -- N_Component_Association or N_Iterated_Component_Association, has a
4419 -- compile-time known value and can be passed as is to the back-end
4420 -- without further expansion.
4421 -- An Iterated_Component_Association is treated as nonstatic in most
4422 -- cases for now, so there are possibilities for optimization.
4423
4424 -----------------------------
4425 -- Check_Static_Components --
4426 -----------------------------
4427
4428 -- Could use some comments in this body ???
4429
4430 procedure Check_Static_Components is
4431 Assoc : Node_Id;
4432 Expr : Node_Id;
4433
4434 begin
4435 Static_Components := True;
4436
4437 if Nkind (N) = N_String_Literal then
4438 null;
4439
4440 elsif Present (Expressions (N)) then
4441 Expr := First (Expressions (N));
4442 while Present (Expr) loop
4443 if Nkind (Expr) /= N_Aggregate
4444 or else not Compile_Time_Known_Aggregate (Expr)
4445 or else Expansion_Delayed (Expr)
4446 then
4447 Static_Components := False;
4448 exit;
4449 end if;
4450
4451 Next (Expr);
4452 end loop;
4453 end if;
4454
4455 if Nkind (N) = N_Aggregate
4456 and then Present (Component_Associations (N))
4457 then
4458 Assoc := First (Component_Associations (N));
4459 while Present (Assoc) loop
4460 if not Is_Static_Element (Assoc, Dims) then
4461 Static_Components := False;
4462 exit;
4463 end if;
4464
4465 Next (Assoc);
4466 end loop;
4467 end if;
4468 end Check_Static_Components;
4469
4470 -------------
4471 -- Flatten --
4472 -------------
4473
4474 function Flatten
4475 (N : Node_Id;
4476 Dims : Nat;
4477 Ix : Node_Id;
4478 Ixb : Node_Id) return Boolean
4479 is
4480 Loc : constant Source_Ptr := Sloc (N);
4481 Blo : constant Node_Id := Type_Low_Bound (Etype (Ixb));
4482 Lo : constant Node_Id := Type_Low_Bound (Etype (Ix));
4483 Hi : constant Node_Id := Type_High_Bound (Etype (Ix));
4484
4485 function Cannot_Flatten_Next_Aggr (Expr : Node_Id) return Boolean;
4486 -- Return true if Expr is an aggregate for the next dimension that
4487 -- cannot be recursively flattened.
4488
4489 ------------------------------
4490 -- Cannot_Flatten_Next_Aggr --
4491 ------------------------------
4492
4493 function Cannot_Flatten_Next_Aggr (Expr : Node_Id) return Boolean is
4494 begin
4495 return Nkind (Expr) = N_Aggregate
4496 and then Present (Next_Index (Ix))
4497 and then not
4498 Flatten (Expr, Dims - 1, Next_Index (Ix), Next_Index (Ixb));
4499 end Cannot_Flatten_Next_Aggr;
4500
4501 -- Local variables
4502
4503 Lov : Uint;
4504 Hiv : Uint;
4505 Others_Present : Boolean;
4506
4507 -- Start of processing for Flatten
4508
4509 begin
4510 if Nkind (Original_Node (N)) = N_String_Literal then
4511 return True;
4512 end if;
4513
4514 if not Compile_Time_Known_Value (Lo)
4515 or else not Compile_Time_Known_Value (Hi)
4516 then
4517 return False;
4518 end if;
4519
4520 Lov := Expr_Value (Lo);
4521 Hiv := Expr_Value (Hi);
4522
4523 -- Check if there is an others choice
4524
4525 Others_Present := False;
4526
4527 if Present (Component_Associations (N)) then
4528 if Is_Empty_List (Component_Associations (N)) then
4529 -- an expanded null array aggregate
4530 return False;
4531 end if;
4532
4533 declare
4534 Assoc : Node_Id;
4535 Choice : Node_Id;
4536
4537 begin
4538 Assoc := First (Component_Associations (N));
4539 while Present (Assoc) loop
4540
4541 -- If this is a box association, flattening is in general
4542 -- not possible because at this point we cannot tell if the
4543 -- default is static or even exists.
4544
4545 if Box_Present (Assoc) then
4546 return False;
4547
4548 elsif Nkind (Assoc) = N_Iterated_Component_Association then
4549 return False;
4550 end if;
4551
4552 Choice := First (Choice_List (Assoc));
4553
4554 while Present (Choice) loop
4555 if Nkind (Choice) = N_Others_Choice then
4556 Others_Present := True;
4557 end if;
4558
4559 Next (Choice);
4560 end loop;
4561
4562 Next (Assoc);
4563 end loop;
4564 end;
4565 end if;
4566
4567 -- If the low bound is not known at compile time and others is not
4568 -- present we can proceed since the bounds can be obtained from the
4569 -- aggregate.
4570
4571 if Hiv < Lov
4572 or else (not Compile_Time_Known_Value (Blo) and then Others_Present)
4573 then
4574 return False;
4575 end if;
4576
4577 -- Determine if set of alternatives is suitable for conversion and
4578 -- build an array containing the values in sequence.
4579
4580 declare
4581 Vals : array (UI_To_Int (Lov) .. UI_To_Int (Hiv))
4582 of Node_Id := (others => Empty);
4583 -- The values in the aggregate sorted appropriately
4584
4585 Vlist : List_Id;
4586 -- Same data as Vals in list form
4587
4588 Rep_Count : Nat;
4589 -- Used to validate Max_Others_Replicate limit
4590
4591 Elmt : Node_Id;
4592 Expr : Node_Id;
4593 Num : Int := UI_To_Int (Lov);
4594 Choice_Index : Int;
4595 Choice : Node_Id;
4596 Lo, Hi : Node_Id;
4597
4598 begin
4599 if Present (Expressions (N)) then
4600 Elmt := First (Expressions (N));
4601 while Present (Elmt) loop
4602 -- In the case of a multidimensional array, check that the
4603 -- aggregate can be recursively flattened.
4604
4605 if Cannot_Flatten_Next_Aggr (Elmt) then
4606 return False;
4607 end if;
4608
4609 -- Duplicate expression for each index it covers
4610
4611 Vals (Num) := New_Copy_Tree (Elmt);
4612 Num := Num + 1;
4613
4614 Next (Elmt);
4615 end loop;
4616 end if;
4617
4618 if No (Component_Associations (N)) then
4619 return True;
4620 end if;
4621
4622 Elmt := First (Component_Associations (N));
4623
4624 Component_Loop : while Present (Elmt) loop
4625 Expr := Expression (Elmt);
4626
4627 -- In the case of a multidimensional array, check that the
4628 -- aggregate can be recursively flattened.
4629
4630 if Cannot_Flatten_Next_Aggr (Expr) then
4631 return False;
4632 end if;
4633
4634 Choice := First (Choice_List (Elmt));
4635 Choice_Loop : while Present (Choice) loop
4636
4637 -- If we have an others choice, fill in the missing elements
4638 -- subject to the limit established by Max_Others_Replicate.
4639
4640 if Nkind (Choice) = N_Others_Choice then
4641 Rep_Count := 0;
4642
4643 -- If the expression involves a construct that generates
4644 -- a loop, we must generate individual assignments and
4645 -- no flattening is possible.
4646
4647 if Nkind (Expr) = N_Quantified_Expression then
4648 return False;
4649 end if;
4650
4651 for J in Vals'Range loop
4652 if No (Vals (J)) then
4653 Vals (J) := New_Copy_Tree (Expr);
4654 Rep_Count := Rep_Count + 1;
4655
4656 -- Check for maximum others replication. Note that
4657 -- we skip this test if either of the restrictions
4658 -- No_Implicit_Loops or No_Elaboration_Code is
4659 -- active, if this is a preelaborable unit or
4660 -- a predefined unit, or if the unit must be
4661 -- placed in data memory. This also ensures that
4662 -- predefined units get the same level of constant
4663 -- folding in Ada 95 and Ada 2005, where their
4664 -- categorization has changed.
4665
4666 declare
4667 P : constant Entity_Id :=
4668 Cunit_Entity (Current_Sem_Unit);
4669
4670 begin
4671 -- Check if duplication is always OK and, if so,
4672 -- continue processing.
4673
4674 if Restriction_Active (No_Implicit_Loops) then
4675 null;
4676
4677 -- If duplication is not always OK, continue
4678 -- only if either the element is static or is
4679 -- an aggregate (we already know it is OK).
4680
4681 elsif not Is_Static_Element (Elmt, Dims)
4682 and then Nkind (Expr) /= N_Aggregate
4683 then
4684 return False;
4685
4686 -- Check if duplication is OK for elaboration
4687 -- purposes and, if so, continue processing.
4688
4689 elsif Restriction_Active (No_Elaboration_Code)
4690 or else
4691 (Ekind (Current_Scope) = E_Package
4692 and then
4693 Static_Elaboration_Desired (Current_Scope))
4694 or else Is_Preelaborated (P)
4695 or else (Ekind (P) = E_Package_Body
4696 and then
4697 Is_Preelaborated (Spec_Entity (P)))
4698 or else
4699 Is_Predefined_Unit (Get_Source_Unit (P))
4700 then
4701 null;
4702
4703 -- Otherwise, check that the replication count
4704 -- is not too high.
4705
4706 elsif Rep_Count > Max_Others_Replicate then
4707 return False;
4708 end if;
4709 end;
4710 end if;
4711 end loop;
4712
4713 if Rep_Count = 0
4714 and then Warn_On_Redundant_Constructs
4715 then
4716 Error_Msg_N ("there are no others?r?", Elmt);
4717 end if;
4718
4719 exit Component_Loop;
4720
4721 -- Case of a subtype mark, identifier or expanded name
4722
4723 elsif Is_Entity_Name (Choice)
4724 and then Is_Type (Entity (Choice))
4725 then
4726 Lo := Type_Low_Bound (Etype (Choice));
4727 Hi := Type_High_Bound (Etype (Choice));
4728
4729 -- Case of subtype indication
4730
4731 elsif Nkind (Choice) = N_Subtype_Indication then
4732 Lo := Low_Bound (Range_Expression (Constraint (Choice)));
4733 Hi := High_Bound (Range_Expression (Constraint (Choice)));
4734
4735 -- Case of a range
4736
4737 elsif Nkind (Choice) = N_Range then
4738 Lo := Low_Bound (Choice);
4739 Hi := High_Bound (Choice);
4740
4741 -- Normal subexpression case
4742
4743 else pragma Assert (Nkind (Choice) in N_Subexpr);
4744 if not Compile_Time_Known_Value (Choice) then
4745 return False;
4746
4747 else
4748 Choice_Index := UI_To_Int (Expr_Value (Choice));
4749
4750 if Choice_Index in Vals'Range then
4751 Vals (Choice_Index) := New_Copy_Tree (Expr);
4752 goto Continue;
4753
4754 -- Choice is statically out-of-range, will be
4755 -- rewritten to raise Constraint_Error.
4756
4757 else
4758 return False;
4759 end if;
4760 end if;
4761 end if;
4762
4763 -- Range cases merge with Lo,Hi set
4764
4765 if not Compile_Time_Known_Value (Lo)
4766 or else
4767 not Compile_Time_Known_Value (Hi)
4768 then
4769 return False;
4770
4771 else
4772 for J in UI_To_Int (Expr_Value (Lo)) ..
4773 UI_To_Int (Expr_Value (Hi))
4774 loop
4775 Vals (J) := New_Copy_Tree (Expr);
4776 end loop;
4777 end if;
4778
4779 <<Continue>>
4780 Next (Choice);
4781 end loop Choice_Loop;
4782
4783 Next (Elmt);
4784 end loop Component_Loop;
4785
4786 -- If we get here the conversion is possible
4787
4788 Vlist := New_List;
4789 for J in Vals'Range loop
4790 Append (Vals (J), Vlist);
4791 end loop;
4792
4793 Rewrite (N, Make_Aggregate (Loc, Expressions => Vlist));
4794 Set_Aggregate_Bounds (N, Aggregate_Bounds (Original_Node (N)));
4795 return True;
4796 end;
4797 end Flatten;
4798
4799 -------------
4800 -- Is_Flat --
4801 -------------
4802
4803 function Is_Flat (N : Node_Id; Dims : Nat) return Boolean is
4804 Elmt : Node_Id;
4805
4806 begin
4807 if Dims = 0 then
4808 return True;
4809
4810 elsif Nkind (N) = N_Aggregate then
4811 if Present (Component_Associations (N)) then
4812 return False;
4813
4814 else
4815 Elmt := First (Expressions (N));
4816 while Present (Elmt) loop
4817 if not Is_Flat (Elmt, Dims - 1) then
4818 return False;
4819 end if;
4820
4821 Next (Elmt);
4822 end loop;
4823
4824 return True;
4825 end if;
4826 else
4827 return True;
4828 end if;
4829 end Is_Flat;
4830
4831 -------------------------
4832 -- Is_Static_Element --
4833 -------------------------
4834
4835 function Is_Static_Element (N : Node_Id; Dims : Nat) return Boolean is
4836 Expr : constant Node_Id := Expression (N);
4837
4838 begin
4839 -- In most cases the interesting expressions are unambiguously static
4840
4841 if Compile_Time_Known_Value (Expr) then
4842 return True;
4843
4844 elsif Nkind (N) = N_Iterated_Component_Association then
4845 return False;
4846
4847 elsif Nkind (Expr) = N_Aggregate
4848 and then Compile_Time_Known_Aggregate (Expr)
4849 and then not Expansion_Delayed (Expr)
4850 then
4851 return True;
4852
4853 -- However, one may write static expressions that are syntactically
4854 -- ambiguous, so preanalyze the expression before checking it again,
4855 -- but only at the innermost level for a multidimensional array.
4856
4857 elsif Dims = 1 then
4858 Preanalyze_And_Resolve (Expr, Component_Type (Typ));
4859 return Compile_Time_Known_Value (Expr);
4860
4861 else
4862 return False;
4863 end if;
4864 end Is_Static_Element;
4865
4866 -- Start of processing for Convert_To_Positional
4867
4868 begin
4869 -- Only convert to positional when generating C in case of an
4870 -- object declaration, this is the only case where aggregates are
4871 -- supported in C.
4872
4873 if Modify_Tree_For_C and then not Is_CCG_Supported_Aggregate (N) then
4874 return;
4875 end if;
4876
4877 -- Ada 2005 (AI-287): Do not convert in case of default initialized
4878 -- components because in this case will need to call the corresponding
4879 -- IP procedure.
4880
4881 if Has_Default_Init_Comps (N) then
4882 return;
4883 end if;
4884
4885 -- A subaggregate may have been flattened but is not known to be
4886 -- Compile_Time_Known. Set that flag in cases that cannot require
4887 -- elaboration code, so that the aggregate can be used as the
4888 -- initial value of a thread-local variable.
4889
4890 if Is_Flat (N, Dims) then
4891 if Static_Array_Aggregate (N) then
4892 Set_Compile_Time_Known_Aggregate (N);
4893 end if;
4894
4895 return;
4896 end if;
4897
4898 if Is_Bit_Packed_Array (Typ) and then not Handle_Bit_Packed then
4899 return;
4900 end if;
4901
4902 -- Do not convert to positional if controlled components are involved
4903 -- since these require special processing
4904
4905 if Has_Controlled_Component (Typ) then
4906 return;
4907 end if;
4908
4909 Check_Static_Components;
4910
4911 -- If the size is known, or all the components are static, try to
4912 -- build a fully positional aggregate.
4913
4914 -- The size of the type may not be known for an aggregate with
4915 -- discriminated array components, but if the components are static
4916 -- it is still possible to verify statically that the length is
4917 -- compatible with the upper bound of the type, and therefore it is
4918 -- worth flattening such aggregates as well.
4919
4920 if Aggr_Size_OK (N)
4921 and then
4922 Flatten (N, Dims, First_Index (Typ), First_Index (Base_Type (Typ)))
4923 then
4924 if Static_Components then
4925 Set_Compile_Time_Known_Aggregate (N);
4926 Set_Expansion_Delayed (N, False);
4927 end if;
4928
4929 Analyze_And_Resolve (N, Typ);
4930 end if;
4931
4932 -- If Static_Elaboration_Desired has been specified, diagnose aggregates
4933 -- that will still require initialization code.
4934
4935 if (Ekind (Current_Scope) = E_Package
4936 and then Static_Elaboration_Desired (Current_Scope))
4937 and then Nkind (Parent (N)) = N_Object_Declaration
4938 then
4939 declare
4940 Expr : Node_Id;
4941
4942 begin
4943 if Nkind (N) = N_Aggregate and then Present (Expressions (N)) then
4944 Expr := First (Expressions (N));
4945 while Present (Expr) loop
4946 if not Compile_Time_Known_Value (Expr) then
4947 Error_Msg_N
4948 ("non-static object requires elaboration code??", N);
4949 exit;
4950 end if;
4951
4952 Next (Expr);
4953 end loop;
4954
4955 if Present (Component_Associations (N)) then
4956 Error_Msg_N ("object requires elaboration code??", N);
4957 end if;
4958 end if;
4959 end;
4960 end if;
4961 end Convert_To_Positional;
4962
4963 ----------------------------
4964 -- Expand_Array_Aggregate --
4965 ----------------------------
4966
4967 -- Array aggregate expansion proceeds as follows:
4968
4969 -- 1. If requested we generate code to perform all the array aggregate
4970 -- bound checks, specifically
4971
4972 -- (a) Check that the index range defined by aggregate bounds is
4973 -- compatible with corresponding index subtype.
4974
4975 -- (b) If an others choice is present check that no aggregate
4976 -- index is outside the bounds of the index constraint.
4977
4978 -- (c) For multidimensional arrays make sure that all subaggregates
4979 -- corresponding to the same dimension have the same bounds.
4980
4981 -- 2. Check for packed array aggregate which can be converted to a
4982 -- constant so that the aggregate disappears completely.
4983
4984 -- 3. Check case of nested aggregate. Generally nested aggregates are
4985 -- handled during the processing of the parent aggregate.
4986
4987 -- 4. Check if the aggregate can be statically processed. If this is the
4988 -- case pass it as is to Gigi. Note that a necessary condition for
4989 -- static processing is that the aggregate be fully positional.
4990
4991 -- 5. If in-place aggregate expansion is possible (i.e. no need to create
4992 -- a temporary) then mark the aggregate as such and return. Otherwise
4993 -- create a new temporary and generate the appropriate initialization
4994 -- code.
4995
4996 procedure Expand_Array_Aggregate (N : Node_Id) is
4997 Loc : constant Source_Ptr := Sloc (N);
4998
4999 Typ : constant Entity_Id := Etype (N);
5000 Ctyp : constant Entity_Id := Component_Type (Typ);
5001 -- Typ is the correct constrained array subtype of the aggregate
5002 -- Ctyp is the corresponding component type.
5003
5004 Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
5005 -- Number of aggregate index dimensions
5006
5007 Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id;
5008 Aggr_High : array (1 .. Aggr_Dimension) of Node_Id;
5009 -- Low and High bounds of the constraint for each aggregate index
5010
5011 Aggr_Index_Typ : array (1 .. Aggr_Dimension) of Entity_Id;
5012 -- The type of each index
5013
5014 In_Place_Assign_OK_For_Declaration : Boolean := False;
5015 -- True if we are to generate an in-place assignment for a declaration
5016
5017 Maybe_In_Place_OK : Boolean;
5018 -- If the type is neither controlled nor packed and the aggregate
5019 -- is the expression in an assignment, assignment in place may be
5020 -- possible, provided other conditions are met on the LHS.
5021
5022 Others_Present : array (1 .. Aggr_Dimension) of Boolean :=
5023 (others => False);
5024 -- If Others_Present (J) is True, then there is an others choice in one
5025 -- of the subaggregates of N at dimension J.
5026
5027 procedure Build_Constrained_Type (Positional : Boolean);
5028 -- If the subtype is not static or unconstrained, build a constrained
5029 -- type using the computable sizes of the aggregate and its sub-
5030 -- aggregates.
5031
5032 procedure Check_Bounds (Aggr_Bounds_Node, Index_Bounds_Node : Node_Id);
5033 -- Checks that the bounds of Aggr_Bounds are within the bounds defined
5034 -- by Index_Bounds. For null array aggregate (Ada 2022) check that the
5035 -- aggregate bounds define a null range.
5036
5037 procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos);
5038 -- Checks that in a multidimensional array aggregate all subaggregates
5039 -- corresponding to the same dimension have the same bounds. Sub_Aggr is
5040 -- an array subaggregate. Dim is the dimension corresponding to the
5041 -- subaggregate.
5042
5043 procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos);
5044 -- Computes the values of array Others_Present. Sub_Aggr is the array
5045 -- subaggregate we start the computation from. Dim is the dimension
5046 -- corresponding to the subaggregate.
5047
5048 procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos);
5049 -- Checks that if an others choice is present in any subaggregate, no
5050 -- aggregate index is outside the bounds of the index constraint.
5051 -- Sub_Aggr is an array subaggregate. Dim is the dimension corresponding
5052 -- to the subaggregate.
5053
5054 function Safe_Left_Hand_Side (N : Node_Id) return Boolean;
5055 -- In addition to Maybe_In_Place_OK, in order for an aggregate to be
5056 -- built directly into the target of the assignment it must be free
5057 -- of side effects. N is the LHS of an assignment.
5058
5059 procedure Two_Pass_Aggregate_Expansion (N : Node_Id);
5060 -- If the aggregate consists only of iterated associations then the
5061 -- aggregate is constructed in two steps:
5062 -- a) Build an expression to compute the number of elements
5063 -- generated by each iterator, and use the expression to allocate
5064 -- the destination aggregate.
5065 -- b) Generate the loops corresponding to each iterator to insert
5066 -- the elements in their proper positions.
5067
5068 ----------------------------
5069 -- Build_Constrained_Type --
5070 ----------------------------
5071
5072 procedure Build_Constrained_Type (Positional : Boolean) is
5073 Agg_Type : constant Entity_Id := Make_Temporary (Loc, 'A');
5074 Decl : Node_Id;
5075 Indexes : constant List_Id := New_List;
5076 Num : Nat;
5077 Sub_Agg : Node_Id;
5078
5079 begin
5080 -- If the aggregate is purely positional, all its subaggregates
5081 -- have the same size. We collect the dimensions from the first
5082 -- subaggregate at each level.
5083
5084 if Positional then
5085 Sub_Agg := N;
5086
5087 for D in 1 .. Aggr_Dimension loop
5088 Num := List_Length (Expressions (Sub_Agg));
5089
5090 Append_To (Indexes,
5091 Make_Range (Loc,
5092 Low_Bound => Make_Integer_Literal (Loc, Uint_1),
5093 High_Bound => Make_Integer_Literal (Loc, Num)));
5094
5095 Sub_Agg := First (Expressions (Sub_Agg));
5096 end loop;
5097
5098 else
5099 -- We know the aggregate type is unconstrained and the aggregate
5100 -- is not processable by the back end, therefore not necessarily
5101 -- positional. Retrieve each dimension bounds (computed earlier).
5102
5103 for D in 1 .. Aggr_Dimension loop
5104 Append_To (Indexes,
5105 Make_Range (Loc,
5106 Low_Bound => Aggr_Low (D),
5107 High_Bound => Aggr_High (D)));
5108 end loop;
5109 end if;
5110
5111 Decl :=
5112 Make_Full_Type_Declaration (Loc,
5113 Defining_Identifier => Agg_Type,
5114 Type_Definition =>
5115 Make_Constrained_Array_Definition (Loc,
5116 Discrete_Subtype_Definitions => Indexes,
5117 Component_Definition =>
5118 Make_Component_Definition (Loc,
5119 Subtype_Indication =>
5120 New_Occurrence_Of (Component_Type (Typ), Loc))));
5121
5122 Insert_Action (N, Decl);
5123 Analyze (Decl);
5124 Set_Etype (N, Agg_Type);
5125 Set_Is_Itype (Agg_Type);
5126 Freeze_Itype (Agg_Type, N);
5127 end Build_Constrained_Type;
5128
5129 ------------------
5130 -- Check_Bounds --
5131 ------------------
5132
5133 procedure Check_Bounds (Aggr_Bounds_Node, Index_Bounds_Node : Node_Id) is
5134 Aggr_Bounds : constant Range_Nodes :=
5135 Get_Index_Bounds (Aggr_Bounds_Node);
5136 Ind_Bounds : constant Range_Nodes :=
5137 Get_Index_Bounds (Index_Bounds_Node);
5138
5139 Cond : Node_Id;
5140
5141 begin
5142 -- For a null array aggregate check that high bound (i.e., low
5143 -- bound predecessor) exists. Fail if low bound is low bound of
5144 -- base subtype (in all cases, including modular).
5145
5146 if Is_Null_Aggregate (N) then
5147 Insert_Action (N,
5148 Make_Raise_Constraint_Error (Loc,
5149 Condition =>
5150 Make_Op_Eq (Loc,
5151 New_Copy_Tree (Aggr_Bounds.First),
5152 New_Copy_Tree
5153 (Type_Low_Bound (Base_Type (Etype (Ind_Bounds.First))))),
5154 Reason => CE_Range_Check_Failed));
5155 return;
5156 end if;
5157
5158 -- Generate the following test:
5159
5160 -- [constraint_error when
5161 -- Aggr_Bounds.First <= Aggr_Bounds.Last and then
5162 -- (Aggr_Bounds.First < Ind_Bounds.First
5163 -- or else Aggr_Bounds.Last > Ind_Bounds.Last)]
5164
5165 -- As an optimization try to see if some tests are trivially vacuous
5166 -- because we are comparing an expression against itself.
5167
5168 if Aggr_Bounds.First = Ind_Bounds.First
5169 and then Aggr_Bounds.Last = Ind_Bounds.Last
5170 then
5171 Cond := Empty;
5172
5173 elsif Aggr_Bounds.Last = Ind_Bounds.Last then
5174 Cond :=
5175 Make_Op_Lt (Loc,
5176 Left_Opnd =>
5177 Duplicate_Subexpr_Move_Checks (Aggr_Bounds.First),
5178 Right_Opnd =>
5179 Duplicate_Subexpr_Move_Checks (Ind_Bounds.First));
5180
5181 elsif Aggr_Bounds.First = Ind_Bounds.First then
5182 Cond :=
5183 Make_Op_Gt (Loc,
5184 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Bounds.Last),
5185 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Bounds.Last));
5186
5187 else
5188 Cond :=
5189 Make_Or_Else (Loc,
5190 Left_Opnd =>
5191 Make_Op_Lt (Loc,
5192 Left_Opnd =>
5193 Duplicate_Subexpr_Move_Checks (Aggr_Bounds.First),
5194 Right_Opnd =>
5195 Duplicate_Subexpr_Move_Checks (Ind_Bounds.First)),
5196
5197 Right_Opnd =>
5198 Make_Op_Gt (Loc,
5199 Left_Opnd => Duplicate_Subexpr (Aggr_Bounds.Last),
5200 Right_Opnd => Duplicate_Subexpr (Ind_Bounds.Last)));
5201 end if;
5202
5203 if Present (Cond) then
5204 Cond :=
5205 Make_And_Then (Loc,
5206 Left_Opnd =>
5207 Make_Op_Le (Loc,
5208 Left_Opnd =>
5209 Duplicate_Subexpr_Move_Checks (Aggr_Bounds.First),
5210 Right_Opnd =>
5211 Duplicate_Subexpr_Move_Checks (Aggr_Bounds.Last)),
5212
5213 Right_Opnd => Cond);
5214
5215 Set_Analyzed (Left_Opnd (Left_Opnd (Cond)), False);
5216 Set_Analyzed (Right_Opnd (Left_Opnd (Cond)), False);
5217 Insert_Action (N,
5218 Make_Raise_Constraint_Error (Loc,
5219 Condition => Cond,
5220 Reason => CE_Range_Check_Failed));
5221 end if;
5222 end Check_Bounds;
5223
5224 ----------------------------
5225 -- Check_Same_Aggr_Bounds --
5226 ----------------------------
5227
5228 procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos) is
5229 Sub_Bounds : constant Range_Nodes :=
5230 Get_Index_Bounds (Aggregate_Bounds (Sub_Aggr));
5231 Sub_Lo : Node_Id renames Sub_Bounds.First;
5232 Sub_Hi : Node_Id renames Sub_Bounds.Last;
5233 -- The bounds of this specific subaggregate
5234
5235 Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
5236 Aggr_Hi : constant Node_Id := Aggr_High (Dim);
5237 -- The bounds of the aggregate for this dimension
5238
5239 Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
5240 -- The index type for this dimension.
5241
5242 Cond : Node_Id;
5243 Assoc : Node_Id;
5244 Expr : Node_Id;
5245
5246 begin
5247 -- If index checks are on generate the test
5248
5249 -- [constraint_error when
5250 -- Aggr_Lo /= Sub_Lo or else Aggr_Hi /= Sub_Hi]
5251
5252 -- As an optimization try to see if some tests are trivially vacuos
5253 -- because we are comparing an expression against itself. Also for
5254 -- the first dimension the test is trivially vacuous because there
5255 -- is just one aggregate for dimension 1.
5256
5257 if Index_Checks_Suppressed (Ind_Typ) then
5258 Cond := Empty;
5259
5260 elsif Dim = 1 or else (Aggr_Lo = Sub_Lo and then Aggr_Hi = Sub_Hi)
5261 then
5262 Cond := Empty;
5263
5264 elsif Aggr_Hi = Sub_Hi then
5265 Cond :=
5266 Make_Op_Ne (Loc,
5267 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
5268 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo));
5269
5270 elsif Aggr_Lo = Sub_Lo then
5271 Cond :=
5272 Make_Op_Ne (Loc,
5273 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi),
5274 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Hi));
5275
5276 else
5277 Cond :=
5278 Make_Or_Else (Loc,
5279 Left_Opnd =>
5280 Make_Op_Ne (Loc,
5281 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
5282 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo)),
5283
5284 Right_Opnd =>
5285 Make_Op_Ne (Loc,
5286 Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
5287 Right_Opnd => Duplicate_Subexpr (Sub_Hi)));
5288 end if;
5289
5290 if Present (Cond) then
5291 Insert_Action (N,
5292 Make_Raise_Constraint_Error (Loc,
5293 Condition => Cond,
5294 Reason => CE_Length_Check_Failed));
5295 end if;
5296
5297 -- Now look inside the subaggregate to see if there is more work
5298
5299 if Dim < Aggr_Dimension then
5300
5301 -- Process positional components
5302
5303 if Present (Expressions (Sub_Aggr)) then
5304 Expr := First (Expressions (Sub_Aggr));
5305 while Present (Expr) loop
5306 Check_Same_Aggr_Bounds (Expr, Dim + 1);
5307 Next (Expr);
5308 end loop;
5309 end if;
5310
5311 -- Process component associations
5312
5313 if Present (Component_Associations (Sub_Aggr)) then
5314 Assoc := First (Component_Associations (Sub_Aggr));
5315 while Present (Assoc) loop
5316 Expr := Expression (Assoc);
5317 Check_Same_Aggr_Bounds (Expr, Dim + 1);
5318 Next (Assoc);
5319 end loop;
5320 end if;
5321 end if;
5322 end Check_Same_Aggr_Bounds;
5323
5324 ----------------------------
5325 -- Compute_Others_Present --
5326 ----------------------------
5327
5328 procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos) is
5329 Assoc : Node_Id;
5330 Expr : Node_Id;
5331
5332 begin
5333 if Present (Component_Associations (Sub_Aggr)) then
5334 Assoc := Last (Component_Associations (Sub_Aggr));
5335
5336 if Present (Assoc)
5337 and then Nkind (First (Choice_List (Assoc))) = N_Others_Choice
5338 then
5339 Others_Present (Dim) := True;
5340
5341 -- An others_clause may be superfluous if previous components
5342 -- cover the full given range of a constrained array. In such
5343 -- a case an others_clause does not contribute any additional
5344 -- components and has not been analyzed. We analyze it now to
5345 -- detect type errors in the expression, even though no code
5346 -- will be generated for it.
5347
5348 if Dim = Aggr_Dimension
5349 and then Nkind (Assoc) /= N_Iterated_Component_Association
5350 and then not Analyzed (Expression (Assoc))
5351 and then not Box_Present (Assoc)
5352 then
5353 Preanalyze_And_Resolve (Expression (Assoc), Ctyp);
5354 end if;
5355 end if;
5356 end if;
5357
5358 -- Now look inside the subaggregate to see if there is more work
5359
5360 if Dim < Aggr_Dimension then
5361
5362 -- Process positional components
5363
5364 if Present (Expressions (Sub_Aggr)) then
5365 Expr := First (Expressions (Sub_Aggr));
5366 while Present (Expr) loop
5367 Compute_Others_Present (Expr, Dim + 1);
5368 Next (Expr);
5369 end loop;
5370 end if;
5371
5372 -- Process component associations
5373
5374 if Present (Component_Associations (Sub_Aggr)) then
5375 Assoc := First (Component_Associations (Sub_Aggr));
5376 while Present (Assoc) loop
5377 Expr := Expression (Assoc);
5378 Compute_Others_Present (Expr, Dim + 1);
5379 Next (Assoc);
5380 end loop;
5381 end if;
5382 end if;
5383 end Compute_Others_Present;
5384
5385 ------------------
5386 -- Others_Check --
5387 ------------------
5388
5389 procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos) is
5390 Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
5391 Aggr_Hi : constant Node_Id := Aggr_High (Dim);
5392 -- The bounds of the aggregate for this dimension
5393
5394 Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
5395 -- The index type for this dimension
5396
5397 Need_To_Check : Boolean := False;
5398
5399 Choices_Lo : Node_Id := Empty;
5400 Choices_Hi : Node_Id := Empty;
5401 -- The lowest and highest discrete choices for a named subaggregate
5402
5403 Nb_Choices : Int := -1;
5404 -- The number of discrete non-others choices in this subaggregate
5405
5406 Nb_Elements : Uint := Uint_0;
5407 -- The number of elements in a positional aggregate
5408
5409 Cond : Node_Id := Empty;
5410
5411 Assoc : Node_Id;
5412 Choice : Node_Id;
5413 Expr : Node_Id;
5414
5415 begin
5416 -- Check if we have an others choice. If we do make sure that this
5417 -- subaggregate contains at least one element in addition to the
5418 -- others choice.
5419
5420 if Range_Checks_Suppressed (Ind_Typ) then
5421 Need_To_Check := False;
5422
5423 elsif Present (Expressions (Sub_Aggr))
5424 and then Present (Component_Associations (Sub_Aggr))
5425 then
5426 Need_To_Check :=
5427 not (Is_Empty_List (Expressions (Sub_Aggr))
5428 and then Is_Empty_List
5429 (Component_Associations (Sub_Aggr)));
5430
5431 elsif Present (Component_Associations (Sub_Aggr)) then
5432 Assoc := Last (Component_Associations (Sub_Aggr));
5433
5434 if Nkind (First (Choice_List (Assoc))) /= N_Others_Choice then
5435 Need_To_Check := False;
5436
5437 else
5438 -- Count the number of discrete choices. Start with -1 because
5439 -- the others choice does not count.
5440
5441 -- Is there some reason we do not use List_Length here ???
5442
5443 Nb_Choices := -1;
5444 Assoc := First (Component_Associations (Sub_Aggr));
5445 while Present (Assoc) loop
5446 Choice := First (Choice_List (Assoc));
5447 while Present (Choice) loop
5448 Nb_Choices := Nb_Choices + 1;
5449 Next (Choice);
5450 end loop;
5451
5452 Next (Assoc);
5453 end loop;
5454
5455 -- If there is only an others choice nothing to do
5456
5457 Need_To_Check := (Nb_Choices > 0);
5458 end if;
5459
5460 else
5461 Need_To_Check := False;
5462 end if;
5463
5464 -- If we are dealing with a positional subaggregate with an others
5465 -- choice then compute the number or positional elements.
5466
5467 if Need_To_Check and then Present (Expressions (Sub_Aggr)) then
5468 Expr := First (Expressions (Sub_Aggr));
5469 Nb_Elements := Uint_0;
5470 while Present (Expr) loop
5471 Nb_Elements := Nb_Elements + 1;
5472 Next (Expr);
5473 end loop;
5474
5475 -- If the aggregate contains discrete choices and an others choice
5476 -- compute the smallest and largest discrete choice values.
5477
5478 elsif Need_To_Check then
5479 Compute_Choices_Lo_And_Choices_Hi : declare
5480
5481 Table : Case_Table_Type (1 .. Nb_Choices);
5482 -- Used to sort all the different choice values
5483
5484 J : Pos := 1;
5485
5486 begin
5487 Assoc := First (Component_Associations (Sub_Aggr));
5488 while Present (Assoc) loop
5489 Choice := First (Choice_List (Assoc));
5490 while Present (Choice) loop
5491 if Nkind (Choice) = N_Others_Choice then
5492 exit;
5493 end if;
5494
5495 declare
5496 Bounds : constant Range_Nodes :=
5497 Get_Index_Bounds (Choice);
5498 begin
5499 Table (J).Choice_Lo := Bounds.First;
5500 Table (J).Choice_Hi := Bounds.Last;
5501 end;
5502
5503 J := J + 1;
5504 Next (Choice);
5505 end loop;
5506
5507 Next (Assoc);
5508 end loop;
5509
5510 -- Sort the discrete choices
5511
5512 Sort_Case_Table (Table);
5513
5514 Choices_Lo := Table (1).Choice_Lo;
5515 Choices_Hi := Table (Nb_Choices).Choice_Hi;
5516 end Compute_Choices_Lo_And_Choices_Hi;
5517 end if;
5518
5519 -- If no others choice in this subaggregate, or the aggregate
5520 -- comprises only an others choice, nothing to do.
5521
5522 if not Need_To_Check then
5523 Cond := Empty;
5524
5525 -- If we are dealing with an aggregate containing an others choice
5526 -- and positional components, we generate the following test:
5527
5528 -- if Ind_Typ'Pos (Aggr_Lo) + (Nb_Elements - 1) >
5529 -- Ind_Typ'Pos (Aggr_Hi)
5530 -- then
5531 -- raise Constraint_Error;
5532 -- end if;
5533
5534 -- in the general case, but the following simpler test:
5535
5536 -- [constraint_error when
5537 -- Aggr_Lo + (Nb_Elements - 1) > Aggr_Hi];
5538
5539 -- instead if the index type is a signed integer.
5540
5541 elsif Nb_Elements > Uint_0 then
5542 if Nb_Elements = Uint_1 then
5543 Cond :=
5544 Make_Op_Gt (Loc,
5545 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
5546 Right_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi));
5547
5548 elsif Is_Signed_Integer_Type (Ind_Typ) then
5549 Cond :=
5550 Make_Op_Gt (Loc,
5551 Left_Opnd =>
5552 Make_Op_Add (Loc,
5553 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
5554 Right_Opnd =>
5555 Make_Integer_Literal (Loc, Nb_Elements - 1)),
5556 Right_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi));
5557
5558 else
5559 Cond :=
5560 Make_Op_Gt (Loc,
5561 Left_Opnd =>
5562 Make_Op_Add (Loc,
5563 Left_Opnd =>
5564 Make_Attribute_Reference (Loc,
5565 Prefix => New_Occurrence_Of (Ind_Typ, Loc),
5566 Attribute_Name => Name_Pos,
5567 Expressions =>
5568 New_List
5569 (Duplicate_Subexpr_Move_Checks (Aggr_Lo))),
5570 Right_Opnd => Make_Integer_Literal (Loc, Nb_Elements - 1)),
5571
5572 Right_Opnd =>
5573 Make_Attribute_Reference (Loc,
5574 Prefix => New_Occurrence_Of (Ind_Typ, Loc),
5575 Attribute_Name => Name_Pos,
5576 Expressions => New_List (
5577 Duplicate_Subexpr_Move_Checks (Aggr_Hi))));
5578 end if;
5579
5580 -- If we are dealing with an aggregate containing an others choice
5581 -- and discrete choices we generate the following test:
5582
5583 -- [constraint_error when
5584 -- Choices_Lo < Aggr_Lo or else Choices_Hi > Aggr_Hi];
5585
5586 else
5587 Cond :=
5588 Make_Or_Else (Loc,
5589 Left_Opnd =>
5590 Make_Op_Lt (Loc,
5591 Left_Opnd => Duplicate_Subexpr_Move_Checks (Choices_Lo),
5592 Right_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo)),
5593
5594 Right_Opnd =>
5595 Make_Op_Gt (Loc,
5596 Left_Opnd => Duplicate_Subexpr (Choices_Hi),
5597 Right_Opnd => Duplicate_Subexpr (Aggr_Hi)));
5598 end if;
5599
5600 if Present (Cond) then
5601 Insert_Action (N,
5602 Make_Raise_Constraint_Error (Loc,
5603 Condition => Cond,
5604 Reason => CE_Length_Check_Failed));
5605 -- Questionable reason code, shouldn't that be a
5606 -- CE_Range_Check_Failed ???
5607 end if;
5608
5609 -- Now look inside the subaggregate to see if there is more work
5610
5611 if Dim < Aggr_Dimension then
5612
5613 -- Process positional components
5614
5615 if Present (Expressions (Sub_Aggr)) then
5616 Expr := First (Expressions (Sub_Aggr));
5617 while Present (Expr) loop
5618 Others_Check (Expr, Dim + 1);
5619 Next (Expr);
5620 end loop;
5621 end if;
5622
5623 -- Process component associations
5624
5625 if Present (Component_Associations (Sub_Aggr)) then
5626 Assoc := First (Component_Associations (Sub_Aggr));
5627 while Present (Assoc) loop
5628 Expr := Expression (Assoc);
5629 Others_Check (Expr, Dim + 1);
5630 Next (Assoc);
5631 end loop;
5632 end if;
5633 end if;
5634 end Others_Check;
5635
5636 -------------------------
5637 -- Safe_Left_Hand_Side --
5638 -------------------------
5639
5640 function Safe_Left_Hand_Side (N : Node_Id) return Boolean is
5641 function Is_Safe_Index (Indx : Node_Id) return Boolean;
5642 -- If the left-hand side includes an indexed component, check that
5643 -- the indexes are free of side effects.
5644
5645 -------------------
5646 -- Is_Safe_Index --
5647 -------------------
5648
5649 function Is_Safe_Index (Indx : Node_Id) return Boolean is
5650 begin
5651 if Is_Entity_Name (Indx) then
5652 return True;
5653
5654 elsif Nkind (Indx) = N_Integer_Literal then
5655 return True;
5656
5657 elsif Nkind (Indx) = N_Function_Call
5658 and then Is_Entity_Name (Name (Indx))
5659 and then Has_Pragma_Pure_Function (Entity (Name (Indx)))
5660 then
5661 return True;
5662
5663 elsif Nkind (Indx) = N_Type_Conversion
5664 and then Is_Safe_Index (Expression (Indx))
5665 then
5666 return True;
5667
5668 else
5669 return False;
5670 end if;
5671 end Is_Safe_Index;
5672
5673 -- Start of processing for Safe_Left_Hand_Side
5674
5675 begin
5676 if Is_Entity_Name (N) then
5677 return True;
5678
5679 elsif Nkind (N) in N_Explicit_Dereference | N_Selected_Component
5680 and then Safe_Left_Hand_Side (Prefix (N))
5681 then
5682 return True;
5683
5684 elsif Nkind (N) = N_Indexed_Component
5685 and then Safe_Left_Hand_Side (Prefix (N))
5686 and then Is_Safe_Index (First (Expressions (N)))
5687 then
5688 return True;
5689
5690 elsif Nkind (N) = N_Unchecked_Type_Conversion then
5691 return Safe_Left_Hand_Side (Expression (N));
5692
5693 else
5694 return False;
5695 end if;
5696 end Safe_Left_Hand_Side;
5697
5698 ----------------------------------
5699 -- Two_Pass_Aggregate_Expansion --
5700 ----------------------------------
5701
5702 procedure Two_Pass_Aggregate_Expansion (N : Node_Id) is
5703 Loc : constant Source_Ptr := Sloc (N);
5704 Comp_Type : constant Entity_Id := Etype (N);
5705 Index_Id : constant Entity_Id := Make_Temporary (Loc, 'I', N);
5706 Index_Type : constant Entity_Id := Etype (First_Index (Etype (N)));
5707 Size_Id : constant Entity_Id := Make_Temporary (Loc, 'I', N);
5708 TmpE : constant Entity_Id := Make_Temporary (Loc, 'A', N);
5709
5710 Assoc : Node_Id := First (Component_Associations (N));
5711 Incr : Node_Id;
5712 Iter : Node_Id;
5713 New_Comp : Node_Id;
5714 One_Loop : Node_Id;
5715
5716 Size_Expr_Code : List_Id;
5717 Insertion_Code : List_Id := New_List;
5718
5719 begin
5720 Size_Expr_Code := New_List (
5721 Make_Object_Declaration (Loc,
5722 Defining_Identifier => Size_Id,
5723 Object_Definition => New_Occurrence_Of (Standard_Integer, Loc),
5724 Expression => Make_Integer_Literal (Loc, 0)));
5725
5726 -- First pass: execute the iterators to count the number of elements
5727 -- that will be generated.
5728
5729 while Present (Assoc) loop
5730 Iter := Iterator_Specification (Assoc);
5731 Incr := Make_Assignment_Statement (Loc,
5732 Name => New_Occurrence_Of (Size_Id, Loc),
5733 Expression =>
5734 Make_Op_Add (Loc,
5735 Left_Opnd => New_Occurrence_Of (Size_Id, Loc),
5736 Right_Opnd => Make_Integer_Literal (Loc, 1)));
5737
5738 One_Loop := Make_Implicit_Loop_Statement (N,
5739 Iteration_Scheme =>
5740 Make_Iteration_Scheme (Loc,
5741 Iterator_Specification => New_Copy_Tree (Iter)),
5742 Statements => New_List (Incr));
5743
5744 Append (One_Loop, Size_Expr_Code);
5745 Next (Assoc);
5746 end loop;
5747
5748 Insert_Actions (N, Size_Expr_Code);
5749
5750 -- Build a constrained subtype with the calculated length
5751 -- and declare the proper bounded aggregate object.
5752 -- The index type is some discrete type, so the bounds of the
5753 -- constructed array are computed as T'Val (T'Pos (ineger bound));
5754
5755 declare
5756 Pos_Lo : constant Node_Id :=
5757 Make_Attribute_Reference (Loc,
5758 Prefix => New_Occurrence_Of (Index_Type, Loc),
5759 Attribute_Name => Name_Pos,
5760 Expressions => New_List (
5761 Make_Attribute_Reference (Loc,
5762 Prefix => New_Occurrence_Of (Index_Type, Loc),
5763 Attribute_Name => Name_First)));
5764
5765 Aggr_Lo : constant Node_Id :=
5766 Make_Attribute_Reference (Loc,
5767 Prefix => New_Occurrence_Of (Index_Type, Loc),
5768 Attribute_Name => Name_Val,
5769 Expressions => New_List (New_Copy_Tree (Pos_Lo)));
5770
5771 -- Hi = Index_type'Pos (Lo + Size -1).
5772
5773 Pos_Hi : constant Node_Id :=
5774 Make_Op_Add (Loc,
5775 Left_Opnd => New_Copy_Tree (Pos_Lo),
5776 Right_Opnd =>
5777 Make_Op_Subtract (Loc,
5778 Left_Opnd => New_Occurrence_Of (Size_Id, Loc),
5779 Right_Opnd => Make_Integer_Literal (Loc, 1)));
5780
5781 -- Corresponding index value
5782
5783 Aggr_Hi : constant Node_Id :=
5784 Make_Attribute_Reference (Loc,
5785 Prefix => New_Occurrence_Of (Index_Type, Loc),
5786 Attribute_Name => Name_Val,
5787 Expressions => New_List (New_Copy_Tree (Pos_Hi)));
5788
5789 SubE : constant Entity_Id := Make_Temporary (Loc, 'T');
5790 SubD : constant Node_Id :=
5791 Make_Subtype_Declaration (Loc,
5792 Defining_Identifier => SubE,
5793 Subtype_Indication =>
5794 Make_Subtype_Indication (Loc,
5795 Subtype_Mark =>
5796 New_Occurrence_Of (Etype (Comp_Type), Loc),
5797 Constraint =>
5798 Make_Index_Or_Discriminant_Constraint
5799 (Loc,
5800 Constraints =>
5801 New_List (Make_Range (Loc, Aggr_Lo, Aggr_Hi)))));
5802
5803 -- Create a temporary array of the above subtype which
5804 -- will be used to capture the aggregate assignments.
5805
5806 TmpD : constant Node_Id :=
5807 Make_Object_Declaration (Loc,
5808 Defining_Identifier => TmpE,
5809 Object_Definition => New_Occurrence_Of (SubE, Loc));
5810 begin
5811 Insert_Actions (N, New_List (SubD, TmpD));
5812 end;
5813
5814 -- Second pass: use the iterators to generate the elements of the
5815 -- aggregate. Insertion index starts at Index_Type'First. We
5816 -- assume that the second evaluation of each iterator generates
5817 -- the same number of elements as the first pass, and consider
5818 -- that the execution is erroneous (even if the RM does not state
5819 -- this explicitly) if the number of elements generated differs
5820 -- between first and second pass.
5821
5822 Assoc := First (Component_Associations (N));
5823
5824 -- Initialize insertion position to first array component.
5825
5826 Insertion_Code := New_List (
5827 Make_Object_Declaration (Loc,
5828 Defining_Identifier => Index_Id,
5829 Object_Definition =>
5830 New_Occurrence_Of (Index_Type, Loc),
5831 Expression =>
5832 Make_Attribute_Reference (Loc,
5833 Prefix => New_Occurrence_Of (Index_Type, Loc),
5834 Attribute_Name => Name_First)));
5835
5836 while Present (Assoc) loop
5837 Iter := Iterator_Specification (Assoc);
5838 New_Comp := Make_Assignment_Statement (Loc,
5839 Name =>
5840 Make_Indexed_Component (Loc,
5841 Prefix => New_Occurrence_Of (TmpE, Loc),
5842 Expressions =>
5843 New_List (New_Occurrence_Of (Index_Id, Loc))),
5844 Expression => Copy_Separate_Tree (Expression (Assoc)));
5845
5846 -- Advance index position for insertion.
5847
5848 Incr := Make_Assignment_Statement (Loc,
5849 Name => New_Occurrence_Of (Index_Id, Loc),
5850 Expression =>
5851 Make_Attribute_Reference (Loc,
5852 Prefix =>
5853 New_Occurrence_Of (Index_Type, Loc),
5854 Attribute_Name => Name_Succ,
5855 Expressions =>
5856 New_List (New_Occurrence_Of (Index_Id, Loc))));
5857
5858 -- Add guard to skip last increment when upper bound is reached.
5859
5860 Incr := Make_If_Statement (Loc,
5861 Condition =>
5862 Make_Op_Ne (Loc,
5863 Left_Opnd => New_Occurrence_Of (Index_Id, Loc),
5864 Right_Opnd =>
5865 Make_Attribute_Reference (Loc,
5866 Prefix => New_Occurrence_Of (Index_Type, Loc),
5867 Attribute_Name => Name_Last)),
5868 Then_Statements => New_List (Incr));
5869
5870 One_Loop := Make_Implicit_Loop_Statement (N,
5871 Iteration_Scheme =>
5872 Make_Iteration_Scheme (Loc,
5873 Iterator_Specification => Copy_Separate_Tree (Iter)),
5874 Statements => New_List (New_Comp, Incr));
5875
5876 Append (One_Loop, Insertion_Code);
5877 Next (Assoc);
5878 end loop;
5879
5880 Insert_Actions (N, Insertion_Code);
5881
5882 -- Depending on context this may not work for build-in-place
5883 -- arrays ???
5884
5885 Rewrite (N, New_Occurrence_Of (TmpE, Loc));
5886
5887 end Two_Pass_Aggregate_Expansion;
5888
5889 -- Local variables
5890
5891 Tmp : Entity_Id;
5892 -- Holds the temporary aggregate value
5893
5894 Tmp_Decl : Node_Id;
5895 -- Holds the declaration of Tmp
5896
5897 Aggr_Code : List_Id;
5898 Parent_Node : Node_Id;
5899 Parent_Kind : Node_Kind;
5900
5901 -- Start of processing for Expand_Array_Aggregate
5902
5903 begin
5904 -- Do not touch the special aggregates of attributes used for Asm calls
5905
5906 if Is_RTE (Ctyp, RE_Asm_Input_Operand)
5907 or else Is_RTE (Ctyp, RE_Asm_Output_Operand)
5908 then
5909 return;
5910
5911 elsif Present (Component_Associations (N))
5912 and then Nkind (First (Component_Associations (N))) =
5913 N_Iterated_Component_Association
5914 and then
5915 Present (Iterator_Specification (First (Component_Associations (N))))
5916 then
5917 Two_Pass_Aggregate_Expansion (N);
5918 return;
5919
5920 -- Do not attempt expansion if error already detected. We may reach this
5921 -- point in spite of previous errors when compiling with -gnatq, to
5922 -- force all possible errors (this is the usual ACATS mode).
5923
5924 elsif Error_Posted (N) then
5925 return;
5926 end if;
5927
5928 -- If the semantic analyzer has determined that aggregate N will raise
5929 -- Constraint_Error at run time, then the aggregate node has been
5930 -- replaced with an N_Raise_Constraint_Error node and we should
5931 -- never get here.
5932
5933 pragma Assert (not Raises_Constraint_Error (N));
5934
5935 -- STEP 1a
5936
5937 -- Check that the index range defined by aggregate bounds is
5938 -- compatible with corresponding index subtype.
5939
5940 Index_Compatibility_Check : declare
5941 Aggr_Index_Range : Node_Id := First_Index (Typ);
5942 -- The current aggregate index range
5943
5944 Index_Constraint : Node_Id := First_Index (Etype (Typ));
5945 -- The corresponding index constraint against which we have to
5946 -- check the above aggregate index range.
5947
5948 begin
5949 Compute_Others_Present (N, 1);
5950
5951 for J in 1 .. Aggr_Dimension loop
5952 -- There is no need to emit a check if an others choice is present
5953 -- for this array aggregate dimension since in this case one of
5954 -- N's subaggregates has taken its bounds from the context and
5955 -- these bounds must have been checked already. In addition all
5956 -- subaggregates corresponding to the same dimension must all have
5957 -- the same bounds (checked in (c) below).
5958
5959 if not Range_Checks_Suppressed (Etype (Index_Constraint))
5960 and then not Others_Present (J)
5961 then
5962 -- We don't use Checks.Apply_Range_Check here because it emits
5963 -- a spurious check. Namely it checks that the range defined by
5964 -- the aggregate bounds is nonempty. But we know this already
5965 -- if we get here.
5966
5967 Check_Bounds (Aggr_Index_Range, Index_Constraint);
5968 end if;
5969
5970 -- Save the low and high bounds of the aggregate index as well as
5971 -- the index type for later use in checks (b) and (c) below.
5972
5973 Get_Index_Bounds
5974 (Aggr_Index_Range, L => Aggr_Low (J), H => Aggr_High (J));
5975
5976 Aggr_Index_Typ (J) := Etype (Index_Constraint);
5977
5978 Next_Index (Aggr_Index_Range);
5979 Next_Index (Index_Constraint);
5980 end loop;
5981 end Index_Compatibility_Check;
5982
5983 -- STEP 1b
5984
5985 -- If an others choice is present check that no aggregate index is
5986 -- outside the bounds of the index constraint.
5987
5988 Others_Check (N, 1);
5989
5990 -- STEP 1c
5991
5992 -- For multidimensional arrays make sure that all subaggregates
5993 -- corresponding to the same dimension have the same bounds.
5994
5995 if Aggr_Dimension > 1 then
5996 Check_Same_Aggr_Bounds (N, 1);
5997 end if;
5998
5999 -- STEP 1d
6000
6001 -- If we have a default component value, or simple initialization is
6002 -- required for the component type, then we replace <> in component
6003 -- associations by the required default value.
6004
6005 declare
6006 Default_Val : Node_Id;
6007 Assoc : Node_Id;
6008
6009 begin
6010 if (Present (Default_Aspect_Component_Value (Typ))
6011 or else Needs_Simple_Initialization (Ctyp))
6012 and then Present (Component_Associations (N))
6013 then
6014 Assoc := First (Component_Associations (N));
6015 while Present (Assoc) loop
6016 if Nkind (Assoc) = N_Component_Association
6017 and then Box_Present (Assoc)
6018 then
6019 Set_Box_Present (Assoc, False);
6020
6021 if Present (Default_Aspect_Component_Value (Typ)) then
6022 Default_Val := Default_Aspect_Component_Value (Typ);
6023 else
6024 Default_Val := Get_Simple_Init_Val (Ctyp, N);
6025 end if;
6026
6027 Set_Expression (Assoc, New_Copy_Tree (Default_Val));
6028 Analyze_And_Resolve (Expression (Assoc), Ctyp);
6029 end if;
6030
6031 Next (Assoc);
6032 end loop;
6033 end if;
6034 end;
6035
6036 -- STEP 2
6037
6038 -- Here we test for is packed array aggregate that we can handle at
6039 -- compile time. If so, return with transformation done. Note that we do
6040 -- this even if the aggregate is nested, because once we have done this
6041 -- processing, there is no more nested aggregate.
6042
6043 if Packed_Array_Aggregate_Handled (N) then
6044 return;
6045 end if;
6046
6047 -- At this point we try to convert to positional form
6048
6049 Convert_To_Positional (N);
6050
6051 -- If the result is no longer an aggregate (e.g. it may be a string
6052 -- literal, or a temporary which has the needed value), then we are
6053 -- done, since there is no longer a nested aggregate.
6054
6055 if Nkind (N) /= N_Aggregate then
6056 return;
6057
6058 -- We are also done if the result is an analyzed aggregate, indicating
6059 -- that Convert_To_Positional succeeded and reanalyzed the rewritten
6060 -- aggregate.
6061
6062 elsif Analyzed (N) and then Is_Rewrite_Substitution (N) then
6063 return;
6064 end if;
6065
6066 -- If all aggregate components are compile-time known and the aggregate
6067 -- has been flattened, nothing left to do. The same occurs if the
6068 -- aggregate is used to initialize the components of a statically
6069 -- allocated dispatch table.
6070
6071 if Compile_Time_Known_Aggregate (N)
6072 or else Is_Static_Dispatch_Table_Aggregate (N)
6073 then
6074 Set_Expansion_Delayed (N, False);
6075 return;
6076 end if;
6077
6078 -- Now see if back end processing is possible
6079
6080 if Backend_Processing_Possible (N) then
6081
6082 -- If the aggregate is static but the constraints are not, build
6083 -- a static subtype for the aggregate, so that Gigi can place it
6084 -- in static memory. Perform an unchecked_conversion to the non-
6085 -- static type imposed by the context.
6086
6087 declare
6088 Itype : constant Entity_Id := Etype (N);
6089 Index : Node_Id;
6090 Needs_Type : Boolean := False;
6091
6092 begin
6093 Index := First_Index (Itype);
6094 while Present (Index) loop
6095 if not Is_OK_Static_Subtype (Etype (Index)) then
6096 Needs_Type := True;
6097 exit;
6098 else
6099 Next_Index (Index);
6100 end if;
6101 end loop;
6102
6103 if Needs_Type then
6104 Build_Constrained_Type (Positional => True);
6105 Rewrite (N, Unchecked_Convert_To (Itype, N));
6106 Analyze (N);
6107 end if;
6108 end;
6109
6110 return;
6111 end if;
6112
6113 -- STEP 3
6114
6115 -- Delay expansion for nested aggregates: it will be taken care of when
6116 -- the parent aggregate is expanded, excluding container aggregates as
6117 -- these are transformed into subprogram calls later.
6118
6119 Parent_Node := Parent (N);
6120 Parent_Kind := Nkind (Parent_Node);
6121
6122 if Parent_Kind = N_Qualified_Expression then
6123 Parent_Node := Parent (Parent_Node);
6124 Parent_Kind := Nkind (Parent_Node);
6125 end if;
6126
6127 if (Parent_Kind = N_Component_Association
6128 and then not Is_Container_Aggregate (Parent (Parent_Node)))
6129 or else (Parent_Kind in N_Aggregate | N_Extension_Aggregate
6130 and then not Is_Container_Aggregate (Parent_Node))
6131 or else (Parent_Kind = N_Object_Declaration
6132 and then (Needs_Finalization (Typ)
6133 or else Is_Special_Return_Object
6134 (Defining_Identifier (Parent_Node))))
6135 or else (Parent_Kind = N_Assignment_Statement
6136 and then Inside_Init_Proc)
6137 then
6138 Set_Expansion_Delayed (N, not Static_Array_Aggregate (N));
6139 return;
6140 end if;
6141
6142 -- STEP 4
6143
6144 -- Check whether in-place aggregate expansion is possible
6145
6146 -- For object declarations we build the aggregate in place, unless
6147 -- the array is bit-packed.
6148
6149 -- For assignments we do the assignment in place if all the component
6150 -- associations have compile-time known values, or are default-
6151 -- initialized limited components, e.g. tasks. For other cases we
6152 -- create a temporary. A full analysis for safety of in-place assignment
6153 -- is delicate.
6154
6155 -- For allocators we assign to the designated object in place if the
6156 -- aggregate meets the same conditions as other in-place assignments.
6157 -- In this case the aggregate may not come from source but was created
6158 -- for default initialization, e.g. with Initialize_Scalars.
6159
6160 if Requires_Transient_Scope (Typ) then
6161 Establish_Transient_Scope (N, Manage_Sec_Stack => False);
6162 end if;
6163
6164 -- An array of limited components is built in place
6165
6166 if Is_Limited_Type (Typ) then
6167 Maybe_In_Place_OK := True;
6168
6169 elsif Has_Default_Init_Comps (N) then
6170 Maybe_In_Place_OK := False;
6171
6172 elsif Is_Bit_Packed_Array (Typ)
6173 or else Has_Controlled_Component (Typ)
6174 then
6175 Maybe_In_Place_OK := False;
6176
6177 elsif Parent_Kind = N_Assignment_Statement then
6178 Maybe_In_Place_OK :=
6179 In_Place_Assign_OK (N, Get_Base_Object (Name (Parent_Node)));
6180
6181 elsif Parent_Kind = N_Allocator then
6182 Maybe_In_Place_OK := In_Place_Assign_OK (N);
6183
6184 else
6185 Maybe_In_Place_OK := False;
6186 end if;
6187
6188 -- If this is an array of tasks, it will be expanded into build-in-place
6189 -- assignments. Build an activation chain for the tasks now.
6190
6191 if Has_Task (Typ) then
6192 Build_Activation_Chain_Entity (N);
6193 end if;
6194
6195 -- Perform in-place expansion of aggregate in an object declaration.
6196 -- Note: actions generated for the aggregate will be captured in an
6197 -- expression-with-actions statement so that they can be transferred
6198 -- to freeze actions later if there is an address clause for the
6199 -- object. (Note: we don't use a block statement because this would
6200 -- cause generated freeze nodes to be elaborated in the wrong scope).
6201
6202 -- Arrays of limited components must be built in place. The code
6203 -- previously excluded controlled components but this is an old
6204 -- oversight: the rules in 7.6 (17) are clear.
6205
6206 if Comes_From_Source (Parent_Node)
6207 and then Parent_Kind = N_Object_Declaration
6208 and then Present (Expression (Parent_Node))
6209 and then not
6210 Must_Slide (N, Etype (Defining_Identifier (Parent_Node)), Typ)
6211 and then not Is_Bit_Packed_Array (Typ)
6212 then
6213 In_Place_Assign_OK_For_Declaration := True;
6214 Tmp := Defining_Identifier (Parent_Node);
6215 Set_No_Initialization (Parent_Node);
6216 Set_Expression (Parent_Node, Empty);
6217
6218 -- Set kind and type of the entity, for use in the analysis
6219 -- of the subsequent assignments. If the nominal type is not
6220 -- constrained, build a subtype from the known bounds of the
6221 -- aggregate. If the declaration has a subtype mark, use it,
6222 -- otherwise use the itype of the aggregate.
6223
6224 Mutate_Ekind (Tmp, E_Variable);
6225
6226 if not Is_Constrained (Typ) then
6227 Build_Constrained_Type (Positional => False);
6228
6229 elsif Is_Entity_Name (Object_Definition (Parent_Node))
6230 and then Is_Constrained (Entity (Object_Definition (Parent_Node)))
6231 then
6232 Set_Etype (Tmp, Entity (Object_Definition (Parent_Node)));
6233
6234 else
6235 Set_Size_Known_At_Compile_Time (Typ, False);
6236 Set_Etype (Tmp, Typ);
6237 end if;
6238
6239 elsif Maybe_In_Place_OK and then Parent_Kind = N_Allocator then
6240 Set_Expansion_Delayed (N);
6241 return;
6242
6243 -- Limited arrays in return statements are expanded when
6244 -- enclosing construct is expanded.
6245
6246 elsif Maybe_In_Place_OK
6247 and then Parent_Kind = N_Simple_Return_Statement
6248 then
6249 Set_Expansion_Delayed (N);
6250 return;
6251
6252 -- In the remaining cases the aggregate appears in the RHS of an
6253 -- assignment, which may be part of the expansion of an object
6254 -- declaration. If the aggregate is an actual in a call, itself
6255 -- possibly in a RHS, building it in the target is not possible.
6256
6257 elsif Maybe_In_Place_OK
6258 and then Nkind (Parent_Node) not in N_Subprogram_Call
6259 and then Safe_Left_Hand_Side (Name (Parent_Node))
6260 then
6261 Tmp := Name (Parent_Node);
6262
6263 if Etype (Tmp) /= Etype (N) then
6264 Apply_Length_Check (N, Etype (Tmp));
6265
6266 if Nkind (N) = N_Raise_Constraint_Error then
6267
6268 -- Static error, nothing further to expand
6269
6270 return;
6271 end if;
6272 end if;
6273
6274 -- If a slice assignment has an aggregate with a single others_choice,
6275 -- the assignment can be done in place even if bounds are not static,
6276 -- by converting it into a loop over the discrete range of the slice.
6277
6278 elsif Maybe_In_Place_OK
6279 and then Nkind (Name (Parent_Node)) = N_Slice
6280 and then Is_Others_Aggregate (N)
6281 then
6282 Tmp := Name (Parent_Node);
6283
6284 -- Set type of aggregate to be type of lhs in assignment, in order
6285 -- to suppress redundant length checks.
6286
6287 Set_Etype (N, Etype (Tmp));
6288
6289 -- Step 5
6290
6291 -- In-place aggregate expansion is not possible
6292
6293 else
6294 Maybe_In_Place_OK := False;
6295 Tmp := Make_Temporary (Loc, 'A', N);
6296 Tmp_Decl :=
6297 Make_Object_Declaration (Loc,
6298 Defining_Identifier => Tmp,
6299 Object_Definition => New_Occurrence_Of (Typ, Loc));
6300 Set_No_Initialization (Tmp_Decl, True);
6301
6302 -- If we are within a loop, the temporary will be pushed on the
6303 -- stack at each iteration. If the aggregate is the expression
6304 -- for an allocator, it will be immediately copied to the heap
6305 -- and can be reclaimed at once. We create a transient scope
6306 -- around the aggregate for this purpose.
6307
6308 if Ekind (Current_Scope) = E_Loop
6309 and then Parent_Kind = N_Allocator
6310 then
6311 Establish_Transient_Scope (N, Manage_Sec_Stack => False);
6312
6313 -- If the parent is an assignment for which no controlled actions
6314 -- should take place, prevent the temporary from being finalized.
6315
6316 elsif Parent_Kind = N_Assignment_Statement
6317 and then No_Ctrl_Actions (Parent_Node)
6318 then
6319 Mutate_Ekind (Tmp, E_Variable);
6320 Set_Is_Ignored_Transient (Tmp);
6321 end if;
6322
6323 Insert_Action (N, Tmp_Decl);
6324 end if;
6325
6326 -- Construct and insert the aggregate code. We can safely suppress index
6327 -- checks because this code is guaranteed not to raise CE on index
6328 -- checks. However we should *not* suppress all checks.
6329
6330 declare
6331 Target : Node_Id;
6332
6333 begin
6334 if Nkind (Tmp) = N_Defining_Identifier then
6335 Target := New_Occurrence_Of (Tmp, Loc);
6336
6337 else
6338 if Has_Default_Init_Comps (N)
6339 and then not Maybe_In_Place_OK
6340 then
6341 -- Ada 2005 (AI-287): This case has not been analyzed???
6342
6343 raise Program_Error;
6344 end if;
6345
6346 -- Name in assignment is explicit dereference
6347
6348 Target := New_Copy (Tmp);
6349 end if;
6350
6351 -- If we are to generate an in-place assignment for a declaration or
6352 -- an assignment statement, and the assignment can be done directly
6353 -- by the back end, then do not expand further.
6354
6355 -- ??? We can also do that if in-place expansion is not possible but
6356 -- then we could go into an infinite recursion.
6357
6358 if (In_Place_Assign_OK_For_Declaration or else Maybe_In_Place_OK)
6359 and then not CodePeer_Mode
6360 and then not Modify_Tree_For_C
6361 and then not Possible_Bit_Aligned_Component (Target)
6362 and then not Is_Possibly_Unaligned_Slice (Target)
6363 and then Aggr_Assignment_OK_For_Backend (N)
6364 then
6365
6366 -- In the case of an assignment using an access with the
6367 -- Designated_Storage_Model aspect with a Copy_To procedure,
6368 -- insert a temporary and have the back end handle the assignment
6369 -- to it. Copy the result to the original target.
6370
6371 if Parent_Kind = N_Assignment_Statement
6372 and then Nkind (Name (Parent_Node)) = N_Explicit_Dereference
6373 and then Has_Designated_Storage_Model_Aspect
6374 (Etype (Prefix (Name (Parent_Node))))
6375 and then Present (Storage_Model_Copy_To
6376 (Storage_Model_Object
6377 (Etype (Prefix (Name (Parent_Node))))))
6378 then
6379 Aggr_Code := Build_Assignment_With_Temporary
6380 (Target, Typ, New_Copy_Tree (N));
6381
6382 else
6383 if Maybe_In_Place_OK then
6384 return;
6385 end if;
6386
6387 Aggr_Code := New_List (
6388 Make_Assignment_Statement (Loc,
6389 Name => Target,
6390 Expression => New_Copy_Tree (N)));
6391 end if;
6392
6393 else
6394 Aggr_Code :=
6395 Build_Array_Aggr_Code (N,
6396 Ctype => Ctyp,
6397 Index => First_Index (Typ),
6398 Into => Target,
6399 Scalar_Comp => Is_Scalar_Type (Ctyp));
6400 end if;
6401
6402 -- Save the last assignment statement associated with the aggregate
6403 -- when building a controlled object. This reference is utilized by
6404 -- the finalization machinery when marking an object as successfully
6405 -- initialized.
6406
6407 if Needs_Finalization (Typ)
6408 and then Is_Entity_Name (Target)
6409 and then Present (Entity (Target))
6410 and then Ekind (Entity (Target)) in E_Constant | E_Variable
6411 then
6412 Set_Last_Aggregate_Assignment (Entity (Target), Last (Aggr_Code));
6413 end if;
6414 end;
6415
6416 -- If the aggregate is the expression in a declaration, the expanded
6417 -- code must be inserted after it. The defining entity might not come
6418 -- from source if this is part of an inlined body, but the declaration
6419 -- itself will.
6420 -- The test below looks very specialized and kludgy???
6421
6422 if Comes_From_Source (Tmp)
6423 or else
6424 (Nkind (Parent (N)) = N_Object_Declaration
6425 and then Comes_From_Source (Parent (N))
6426 and then Tmp = Defining_Entity (Parent (N)))
6427 then
6428 if Parent_Kind /= N_Object_Declaration or else Is_Frozen (Tmp) then
6429 Insert_Actions_After (Parent_Node, Aggr_Code);
6430 else
6431 declare
6432 Comp_Stmt : constant Node_Id :=
6433 Make_Compound_Statement
6434 (Sloc (Parent_Node), Actions => Aggr_Code);
6435 begin
6436 Insert_Action_After (Parent_Node, Comp_Stmt);
6437 Set_Initialization_Statements (Tmp, Comp_Stmt);
6438 end;
6439 end if;
6440 else
6441 Insert_Actions (N, Aggr_Code);
6442 end if;
6443
6444 -- If the aggregate has been assigned in place, remove the original
6445 -- assignment.
6446
6447 if Parent_Kind = N_Assignment_Statement and then Maybe_In_Place_OK then
6448 Rewrite (Parent_Node, Make_Null_Statement (Loc));
6449
6450 -- Or else, if a temporary was created, replace the aggregate with it
6451
6452 elsif Parent_Kind /= N_Object_Declaration
6453 or else Tmp /= Defining_Identifier (Parent_Node)
6454 then
6455 Rewrite (N, New_Occurrence_Of (Tmp, Loc));
6456 Analyze_And_Resolve (N, Typ);
6457 end if;
6458 end Expand_Array_Aggregate;
6459
6460 ------------------------
6461 -- Expand_N_Aggregate --
6462 ------------------------
6463
6464 procedure Expand_N_Aggregate (N : Node_Id) is
6465 T : constant Entity_Id := Etype (N);
6466 begin
6467 -- Record aggregate case
6468
6469 if Is_Record_Type (T)
6470 and then not Is_Private_Type (T)
6471 and then not Is_Homogeneous_Aggregate (N)
6472 then
6473 Expand_Record_Aggregate (N);
6474
6475 elsif Has_Aspect (T, Aspect_Aggregate) then
6476 Expand_Container_Aggregate (N);
6477
6478 -- Array aggregate case
6479
6480 else
6481 -- A special case, if we have a string subtype with bounds 1 .. N,
6482 -- where N is known at compile time, and the aggregate is of the
6483 -- form (others => 'x'), with a single choice and no expressions,
6484 -- and N is less than 80 (an arbitrary limit for now), then replace
6485 -- the aggregate by the equivalent string literal (but do not mark
6486 -- it as static since it is not).
6487
6488 -- Note: this entire circuit is redundant with respect to code in
6489 -- Expand_Array_Aggregate that collapses others choices to positional
6490 -- form, but there are two problems with that circuit:
6491
6492 -- a) It is limited to very small cases due to ill-understood
6493 -- interactions with bootstrapping. That limit is removed by
6494 -- use of the No_Implicit_Loops restriction.
6495
6496 -- b) It incorrectly ends up with the resulting expressions being
6497 -- considered static when they are not. For example, the
6498 -- following test should fail:
6499
6500 -- pragma Restrictions (No_Implicit_Loops);
6501 -- package NonSOthers4 is
6502 -- B : constant String (1 .. 6) := (others => 'A');
6503 -- DH : constant String (1 .. 8) := B & "BB";
6504 -- X : Integer;
6505 -- pragma Export (C, X, Link_Name => DH);
6506 -- end;
6507
6508 -- But it succeeds (DH looks static to pragma Export)
6509
6510 -- To be sorted out ???
6511
6512 if Present (Component_Associations (N)) then
6513 declare
6514 CA : constant Node_Id := First (Component_Associations (N));
6515 MX : constant := 80;
6516
6517 begin
6518 if Present (CA)
6519 and then Nkind (First (Choice_List (CA))) = N_Others_Choice
6520 and then Nkind (Expression (CA)) = N_Character_Literal
6521 and then No (Expressions (N))
6522 then
6523 declare
6524 X : constant Node_Id := First_Index (T);
6525 EC : constant Node_Id := Expression (CA);
6526 CV : constant Uint := Char_Literal_Value (EC);
6527 CC : constant Char_Code := UI_To_CC (CV);
6528
6529 begin
6530 if Nkind (X) = N_Range
6531 and then Compile_Time_Known_Value (Low_Bound (X))
6532 and then Expr_Value (Low_Bound (X)) = 1
6533 and then Compile_Time_Known_Value (High_Bound (X))
6534 then
6535 declare
6536 Hi : constant Uint := Expr_Value (High_Bound (X));
6537
6538 begin
6539 if Hi <= MX then
6540 Start_String;
6541
6542 for J in 1 .. UI_To_Int (Hi) loop
6543 Store_String_Char (CC);
6544 end loop;
6545
6546 Rewrite (N,
6547 Make_String_Literal (Sloc (N),
6548 Strval => End_String));
6549
6550 if In_Character_Range (CC) then
6551 null;
6552 elsif In_Wide_Character_Range (CC) then
6553 Set_Has_Wide_Character (N);
6554 else
6555 Set_Has_Wide_Wide_Character (N);
6556 end if;
6557
6558 Analyze_And_Resolve (N, T);
6559 Set_Is_Static_Expression (N, False);
6560 return;
6561 end if;
6562 end;
6563 end if;
6564 end;
6565 end if;
6566 end;
6567 end if;
6568
6569 -- Not that special case, so normal expansion of array aggregate
6570
6571 Expand_Array_Aggregate (N);
6572 end if;
6573
6574 exception
6575 when RE_Not_Available =>
6576 return;
6577 end Expand_N_Aggregate;
6578
6579 --------------------------------
6580 -- Expand_Container_Aggregate --
6581 --------------------------------
6582
6583 procedure Expand_Container_Aggregate (N : Node_Id) is
6584 Loc : constant Source_Ptr := Sloc (N);
6585 Typ : constant Entity_Id := Etype (N);
6586 Asp : constant Node_Id := Find_Value_Of_Aspect (Typ, Aspect_Aggregate);
6587
6588 Empty_Subp : Node_Id := Empty;
6589 Add_Named_Subp : Node_Id := Empty;
6590 Add_Unnamed_Subp : Node_Id := Empty;
6591 New_Indexed_Subp : Node_Id := Empty;
6592 Assign_Indexed_Subp : Node_Id := Empty;
6593
6594 Aggr_Code : constant List_Id := New_List;
6595 Temp : constant Entity_Id := Make_Temporary (Loc, 'C', N);
6596
6597 Comp : Node_Id;
6598 Decl : Node_Id;
6599 Default : Node_Id;
6600 Init_Stat : Node_Id;
6601 Siz : Int;
6602
6603 -- The following are used when the size of the aggregate is not
6604 -- static and requires a dynamic evaluation.
6605 Siz_Decl : Node_Id;
6606 Siz_Exp : Node_Id := Empty;
6607 Count_Type : Entity_Id;
6608
6609 function Aggregate_Size return Int;
6610 -- Compute number of entries in aggregate, including choices
6611 -- that cover a range or subtype, as well as iterated constructs.
6612 -- Return -1 if the size is not known statically, in which case
6613 -- allocate a default size for the aggregate, or build an expression
6614 -- to estimate the size dynamically.
6615
6616 function Build_Siz_Exp (Comp : Node_Id) return Int;
6617 -- When the aggregate contains a single Iterated_Component_Association
6618 -- or Element_Association with non-static bounds, build an expression
6619 -- to be used as the allocated size of the container. This may be an
6620 -- overestimate if a filter is present, but is a safe approximation.
6621 -- If bounds are dynamic the aggregate is created in two passes, and
6622 -- the first generates a loop for the sole purpose of computing the
6623 -- number of elements that will be generated on the second pass.
6624
6625 procedure Expand_Iterated_Component (Comp : Node_Id);
6626 -- Handle iterated_component_association and iterated_Element
6627 -- association by generating a loop over the specified range,
6628 -- given either by a loop parameter specification or an iterator
6629 -- specification.
6630
6631 --------------------
6632 -- Aggregate_Size --
6633 --------------------
6634
6635 function Aggregate_Size return Int is
6636 Comp : Node_Id;
6637 Choice : Node_Id;
6638 Lo, Hi : Node_Id;
6639 Siz : Int;
6640
6641 procedure Add_Range_Size;
6642 -- Compute number of components specified by a component association
6643 -- given by a range or subtype name.
6644
6645 --------------------
6646 -- Add_Range_Size --
6647 --------------------
6648
6649 procedure Add_Range_Size is
6650 begin
6651 -- The bounds of the discrete range are integers or enumeration
6652 -- literals
6653
6654 if Nkind (Lo) = N_Integer_Literal then
6655 Siz := Siz + UI_To_Int (Intval (Hi))
6656 - UI_To_Int (Intval (Lo)) + 1;
6657 else
6658 Siz := Siz + UI_To_Int (Enumeration_Pos (Hi))
6659 - UI_To_Int (Enumeration_Pos (Lo)) + 1;
6660 end if;
6661 end Add_Range_Size;
6662
6663 begin
6664 -- Aggregate is either all positional or all named
6665
6666 Siz := List_Length (Expressions (N));
6667
6668 if Present (Component_Associations (N)) then
6669 Comp := First (Component_Associations (N));
6670 -- If there is a single component association it can be
6671 -- an iterated component with dynamic bounds or an element
6672 -- iterator over an iterable object. If it is an array
6673 -- we can use the attribute Length to get its size;
6674 -- for a predefined container the function Length plays
6675 -- the same role. There is no available mechanism for
6676 -- user-defined containers. For now we treat all of these
6677 -- as dynamic.
6678
6679 if List_Length (Component_Associations (N)) = 1
6680 and then Nkind (Comp) in N_Iterated_Component_Association |
6681 N_Iterated_Element_Association
6682 then
6683 return Build_Siz_Exp (Comp);
6684 end if;
6685
6686 -- Otherwise all associations must specify static sizes.
6687
6688 while Present (Comp) loop
6689 Choice := First (Choice_List (Comp));
6690
6691 while Present (Choice) loop
6692 Analyze (Choice);
6693
6694 if Nkind (Choice) = N_Range then
6695 Lo := Low_Bound (Choice);
6696 Hi := High_Bound (Choice);
6697 Add_Range_Size;
6698
6699 elsif Is_Entity_Name (Choice)
6700 and then Is_Type (Entity (Choice))
6701 then
6702 Lo := Type_Low_Bound (Entity (Choice));
6703 Hi := Type_High_Bound (Entity (Choice));
6704 Add_Range_Size;
6705
6706 Rewrite (Choice,
6707 Make_Range (Loc,
6708 New_Copy_Tree (Lo),
6709 New_Copy_Tree (Hi)));
6710
6711 else
6712 -- Single choice (syntax excludes a subtype
6713 -- indication).
6714
6715 Siz := Siz + 1;
6716 end if;
6717
6718 Next (Choice);
6719 end loop;
6720 Next (Comp);
6721 end loop;
6722 end if;
6723
6724 return Siz;
6725 end Aggregate_Size;
6726
6727 -------------------
6728 -- Build_Siz_Exp --
6729 -------------------
6730
6731 function Build_Siz_Exp (Comp : Node_Id) return Int is
6732 Lo, Hi : Node_Id;
6733 begin
6734 if Nkind (Comp) = N_Range then
6735 Lo := Low_Bound (Comp);
6736 Hi := High_Bound (Comp);
6737 Analyze (Lo);
6738 Analyze (Hi);
6739
6740 -- Compute static size when possible.
6741
6742 if Is_Static_Expression (Lo)
6743 and then Is_Static_Expression (Hi)
6744 then
6745 if Nkind (Lo) = N_Integer_Literal then
6746 Siz := UI_To_Int (Intval (Hi)) - UI_To_Int (Intval (Lo)) + 1;
6747 else
6748 Siz := UI_To_Int (Enumeration_Pos (Hi))
6749 - UI_To_Int (Enumeration_Pos (Lo)) + 1;
6750 end if;
6751 return Siz;
6752
6753 else
6754 Siz_Exp :=
6755 Make_Op_Add (Sloc (Comp),
6756 Left_Opnd =>
6757 Make_Op_Subtract (Sloc (Comp),
6758 Left_Opnd => New_Copy_Tree (Hi),
6759 Right_Opnd => New_Copy_Tree (Lo)),
6760 Right_Opnd =>
6761 Make_Integer_Literal (Loc, 1));
6762 return -1;
6763 end if;
6764
6765 elsif Nkind (Comp) = N_Iterated_Component_Association then
6766 return Build_Siz_Exp (First (Discrete_Choices (Comp)));
6767
6768 elsif Nkind (Comp) = N_Iterated_Element_Association then
6769 return -1;
6770
6771 -- ??? Need to create code for a loop and add to generated code,
6772 -- as is done for array aggregates with iterated element
6773 -- associations, instead of using Append operations.
6774
6775 else
6776 return -1;
6777 end if;
6778 end Build_Siz_Exp;
6779
6780 -------------------------------
6781 -- Expand_Iterated_Component --
6782 -------------------------------
6783
6784 procedure Expand_Iterated_Component (Comp : Node_Id) is
6785 Expr : constant Node_Id := Expression (Comp);
6786
6787 Key_Expr : Node_Id := Empty;
6788 Loop_Id : Entity_Id;
6789 L_Range : Node_Id;
6790 L_Iteration_Scheme : Node_Id;
6791 Loop_Stat : Node_Id;
6792 Params : List_Id;
6793 Stats : List_Id;
6794
6795 begin
6796 if Nkind (Comp) = N_Iterated_Element_Association then
6797 Key_Expr := Key_Expression (Comp);
6798
6799 -- We create a new entity as loop identifier in all cases,
6800 -- as is done for generated loops elsewhere, as the loop
6801 -- structure has been previously analyzed.
6802
6803 if Present (Iterator_Specification (Comp)) then
6804
6805 -- Either an Iterator_Specification or a Loop_Parameter_
6806 -- Specification is present.
6807
6808 L_Iteration_Scheme :=
6809 Make_Iteration_Scheme (Loc,
6810 Iterator_Specification => Iterator_Specification (Comp));
6811 Loop_Id :=
6812 Make_Defining_Identifier (Loc,
6813 Chars => Chars (Defining_Identifier
6814 (Iterator_Specification (Comp))));
6815 Set_Defining_Identifier
6816 (Iterator_Specification (L_Iteration_Scheme), Loop_Id);
6817
6818 else
6819 L_Iteration_Scheme :=
6820 Make_Iteration_Scheme (Loc,
6821 Loop_Parameter_Specification =>
6822 Loop_Parameter_Specification (Comp));
6823 Loop_Id :=
6824 Make_Defining_Identifier (Loc,
6825 Chars => Chars (Defining_Identifier
6826 (Loop_Parameter_Specification (Comp))));
6827 Set_Defining_Identifier
6828 (Loop_Parameter_Specification
6829 (L_Iteration_Scheme), Loop_Id);
6830 end if;
6831 else
6832
6833 -- Iterated_Component_Association.
6834
6835 if Present (Iterator_Specification (Comp)) then
6836 Loop_Id :=
6837 Make_Defining_Identifier (Loc,
6838 Chars => Chars (Defining_Identifier
6839 (Iterator_Specification (Comp))));
6840 L_Iteration_Scheme :=
6841 Make_Iteration_Scheme (Loc,
6842 Iterator_Specification => Iterator_Specification (Comp));
6843
6844 else
6845 -- Loop_Parameter_Specification is parsed with a choice list.
6846 -- where the range is the first (and only) choice.
6847
6848 Loop_Id :=
6849 Make_Defining_Identifier (Loc,
6850 Chars => Chars (Defining_Identifier (Comp)));
6851 L_Range := Relocate_Node (First (Discrete_Choices (Comp)));
6852
6853 L_Iteration_Scheme :=
6854 Make_Iteration_Scheme (Loc,
6855 Loop_Parameter_Specification =>
6856 Make_Loop_Parameter_Specification (Loc,
6857 Defining_Identifier => Loop_Id,
6858 Discrete_Subtype_Definition => L_Range));
6859 end if;
6860 end if;
6861
6862 -- Build insertion statement. For a positional aggregate, only the
6863 -- expression is needed. For a named aggregate, the loop variable,
6864 -- whose type is that of the key, is an additional parameter for
6865 -- the insertion operation.
6866 -- If a Key_Expression is present, it serves as the additional
6867 -- parameter. Otherwise the key is given by the loop parameter
6868 -- itself.
6869
6870 if Present (Add_Unnamed_Subp)
6871 and then No (Add_Named_Subp)
6872 then
6873 Stats := New_List
6874 (Make_Procedure_Call_Statement (Loc,
6875 Name => New_Occurrence_Of (Entity (Add_Unnamed_Subp), Loc),
6876 Parameter_Associations =>
6877 New_List (New_Occurrence_Of (Temp, Loc),
6878 New_Copy_Tree (Expr))));
6879 else
6880 -- Named or indexed aggregate, for which a key is present,
6881 -- possibly with a specified key_expression.
6882
6883 if Present (Key_Expr) then
6884 Params := New_List (New_Occurrence_Of (Temp, Loc),
6885 New_Copy_Tree (Key_Expr),
6886 New_Copy_Tree (Expr));
6887 else
6888 Params := New_List (New_Occurrence_Of (Temp, Loc),
6889 New_Occurrence_Of (Loop_Id, Loc),
6890 New_Copy_Tree (Expr));
6891 end if;
6892
6893 Stats := New_List
6894 (Make_Procedure_Call_Statement (Loc,
6895 Name => New_Occurrence_Of (Entity (Add_Named_Subp), Loc),
6896 Parameter_Associations => Params));
6897 end if;
6898
6899 Loop_Stat := Make_Implicit_Loop_Statement
6900 (Node => N,
6901 Identifier => Empty,
6902 Iteration_Scheme => L_Iteration_Scheme,
6903 Statements => Stats);
6904 Append (Loop_Stat, Aggr_Code);
6905
6906 end Expand_Iterated_Component;
6907
6908 -- Start of processing for Expand_Container_Aggregate
6909
6910 begin
6911 Parse_Aspect_Aggregate (Asp,
6912 Empty_Subp, Add_Named_Subp, Add_Unnamed_Subp,
6913 New_Indexed_Subp, Assign_Indexed_Subp);
6914
6915 -- The constructor for bounded containers is a function with
6916 -- a parameter that sets the size of the container. If the
6917 -- size cannot be determined statically we use a default value
6918 -- or a dynamic expression.
6919
6920 Siz := Aggregate_Size;
6921
6922 ---------------------
6923 -- Empty function --
6924 ---------------------
6925
6926 if Ekind (Entity (Empty_Subp)) = E_Function
6927 and then Present (First_Formal (Entity (Empty_Subp)))
6928 then
6929 Default := Default_Value (First_Formal (Entity (Empty_Subp)));
6930
6931 -- If aggregate size is not static, we can use default value
6932 -- of formal parameter for allocation. We assume that this
6933 -- (implementation-dependent) value is static, even though
6934 -- the AI does not require it.
6935
6936 -- Create declaration for size: a constant literal in the simple
6937 -- case, an expression if iterated component associations may be
6938 -- involved, the default otherwise.
6939
6940 Count_Type := Etype (First_Formal (Entity (Empty_Subp)));
6941 if Siz = -1 then
6942 if No (Siz_Exp) then
6943 Siz := UI_To_Int (Intval (Default));
6944 Siz_Exp := Make_Integer_Literal (Loc, Siz);
6945
6946 else
6947 Siz_Exp := Make_Type_Conversion (Loc,
6948 Subtype_Mark =>
6949 New_Occurrence_Of (Count_Type, Loc),
6950 Expression => Siz_Exp);
6951 end if;
6952
6953 else
6954 Siz_Exp := Make_Integer_Literal (Loc, Siz);
6955 end if;
6956
6957 Siz_Decl := Make_Object_Declaration (Loc,
6958 Defining_Identifier => Make_Temporary (Loc, 'S', N),
6959 Object_Definition =>
6960 New_Occurrence_Of (Count_Type, Loc),
6961 Expression => Siz_Exp);
6962 Append (Siz_Decl, Aggr_Code);
6963
6964 if Nkind (Siz_Exp) = N_Integer_Literal then
6965 Init_Stat :=
6966 Make_Object_Declaration (Loc,
6967 Defining_Identifier => Temp,
6968 Object_Definition => New_Occurrence_Of (Typ, Loc),
6969 Expression => Make_Function_Call (Loc,
6970 Name => New_Occurrence_Of (Entity (Empty_Subp), Loc),
6971 Parameter_Associations =>
6972 New_List
6973 (New_Occurrence_Of
6974 (Defining_Identifier (Siz_Decl), Loc))));
6975
6976 else
6977 Init_Stat :=
6978 Make_Object_Declaration (Loc,
6979 Defining_Identifier => Temp,
6980 Object_Definition => New_Occurrence_Of (Typ, Loc),
6981 Expression => Make_Function_Call (Loc,
6982 Name =>
6983 New_Occurrence_Of (Entity (New_Indexed_Subp), Loc),
6984 Parameter_Associations =>
6985 New_List (
6986 Make_Integer_Literal (Loc, 1),
6987 New_Occurrence_Of
6988 (Defining_Identifier (Siz_Decl), Loc))));
6989 end if;
6990
6991 Append (Init_Stat, Aggr_Code);
6992
6993 -- Size is dynamic: Create declaration for object, and initialize
6994 -- with a call to the null container, or an assignment to it.
6995
6996 else
6997 Decl :=
6998 Make_Object_Declaration (Loc,
6999 Defining_Identifier => Temp,
7000 Object_Definition => New_Occurrence_Of (Typ, Loc));
7001
7002 Insert_Action (N, Decl);
7003
7004 -- The Empty entity is either a parameterless function, or
7005 -- a constant.
7006
7007 if Ekind (Entity (Empty_Subp)) = E_Function then
7008 Init_Stat := Make_Assignment_Statement (Loc,
7009 Name => New_Occurrence_Of (Temp, Loc),
7010 Expression => Make_Function_Call (Loc,
7011 Name => New_Occurrence_Of (Entity (Empty_Subp), Loc)));
7012
7013 else
7014 Init_Stat := Make_Assignment_Statement (Loc,
7015 Name => New_Occurrence_Of (Temp, Loc),
7016 Expression => New_Occurrence_Of (Entity (Empty_Subp), Loc));
7017 end if;
7018
7019 Append (Init_Stat, Aggr_Code);
7020 end if;
7021
7022 -- Report warning on infinite recursion if an empty container aggregate
7023 -- appears in the return statement of its Empty function.
7024
7025 if Ekind (Entity (Empty_Subp)) = E_Function
7026 and then Nkind (Parent (N)) = N_Simple_Return_Statement
7027 and then Is_Empty_List (Expressions (N))
7028 and then Is_Empty_List (Component_Associations (N))
7029 and then Entity (Empty_Subp) = Current_Scope
7030 then
7031 Error_Msg_Warn := SPARK_Mode /= On;
7032 Error_Msg_N
7033 ("!empty aggregate returned by the empty function of a container"
7034 & " aggregate<<<", Parent (N));
7035 Error_Msg_N
7036 ("\this will result in infinite recursion??", Parent (N));
7037 end if;
7038
7039 ---------------------------
7040 -- Positional aggregate --
7041 ---------------------------
7042
7043 -- If the aggregate is positional the aspect must include
7044 -- an Add_Unnamed subprogram.
7045
7046 if Present (Add_Unnamed_Subp) then
7047 if Present (Expressions (N)) then
7048 declare
7049 Insert : constant Entity_Id := Entity (Add_Unnamed_Subp);
7050 Comp : Node_Id;
7051 Stat : Node_Id;
7052
7053 begin
7054 Comp := First (Expressions (N));
7055 while Present (Comp) loop
7056 Stat := Make_Procedure_Call_Statement (Loc,
7057 Name => New_Occurrence_Of (Insert, Loc),
7058 Parameter_Associations =>
7059 New_List (New_Occurrence_Of (Temp, Loc),
7060 New_Copy_Tree (Comp)));
7061 Append (Stat, Aggr_Code);
7062 Next (Comp);
7063 end loop;
7064 end;
7065 end if;
7066
7067 -- Indexed aggregates are handled below. Unnamed aggregates
7068 -- such as sets may include iterated component associations.
7069
7070 if No (New_Indexed_Subp) then
7071 Comp := First (Component_Associations (N));
7072 while Present (Comp) loop
7073 if Nkind (Comp) = N_Iterated_Component_Association then
7074 Expand_Iterated_Component (Comp);
7075 end if;
7076 Next (Comp);
7077 end loop;
7078 end if;
7079
7080 ---------------------
7081 -- Named_Aggregate --
7082 ---------------------
7083
7084 elsif Present (Add_Named_Subp) then
7085 declare
7086 Insert : constant Entity_Id := Entity (Add_Named_Subp);
7087 Stat : Node_Id;
7088 Key : Node_Id;
7089 begin
7090 Comp := First (Component_Associations (N));
7091
7092 -- Each component association may contain several choices;
7093 -- generate an insertion statement for each.
7094
7095 while Present (Comp) loop
7096 if Nkind (Comp) in N_Iterated_Component_Association
7097 | N_Iterated_Element_Association
7098 then
7099 Expand_Iterated_Component (Comp);
7100 else
7101 Key := First (Choices (Comp));
7102
7103 while Present (Key) loop
7104 Stat := Make_Procedure_Call_Statement (Loc,
7105 Name => New_Occurrence_Of (Insert, Loc),
7106 Parameter_Associations =>
7107 New_List (New_Occurrence_Of (Temp, Loc),
7108 New_Copy_Tree (Key),
7109 New_Copy_Tree (Expression (Comp))));
7110 Append (Stat, Aggr_Code);
7111
7112 Next (Key);
7113 end loop;
7114 end if;
7115
7116 Next (Comp);
7117 end loop;
7118 end;
7119 end if;
7120
7121 -----------------------
7122 -- Indexed_Aggregate --
7123 -----------------------
7124
7125 -- For an indexed aggregate there must be an Assigned_Indexeed
7126 -- subprogram. Note that unlike array aggregates, a container
7127 -- aggregate must be fully positional or fully indexed. In the
7128 -- first case the expansion has already taken place.
7129 -- TBA: the keys for an indexed aggregate must provide a dense
7130 -- range with no repetitions.
7131
7132 if Present (Assign_Indexed_Subp)
7133 and then Present (Component_Associations (N))
7134 then
7135 declare
7136 Insert : constant Entity_Id := Entity (Assign_Indexed_Subp);
7137 Index_Type : constant Entity_Id :=
7138 Etype (Next_Formal (First_Formal (Insert)));
7139
7140 function Expand_Range_Component
7141 (Rng : Node_Id;
7142 Expr : Node_Id) return Node_Id;
7143 -- Transform a component assoication with a range into an
7144 -- explicit loop. If the choice is a subtype name, it is
7145 -- rewritten as a range with the corresponding bounds, which
7146 -- are known to be static.
7147
7148 Comp : Node_Id;
7149 Index : Node_Id;
7150 Pos : Int := 0;
7151 Stat : Node_Id;
7152 Key : Node_Id;
7153
7154 -----------------------------
7155 -- Expand_Raange_Component --
7156 -----------------------------
7157
7158 function Expand_Range_Component
7159 (Rng : Node_Id;
7160 Expr : Node_Id) return Node_Id
7161 is
7162 Loop_Id : constant Entity_Id :=
7163 Make_Temporary (Loc, 'T');
7164
7165 L_Iteration_Scheme : Node_Id;
7166 Stats : List_Id;
7167
7168 begin
7169 L_Iteration_Scheme :=
7170 Make_Iteration_Scheme (Loc,
7171 Loop_Parameter_Specification =>
7172 Make_Loop_Parameter_Specification (Loc,
7173 Defining_Identifier => Loop_Id,
7174 Discrete_Subtype_Definition => New_Copy_Tree (Rng)));
7175
7176 Stats := New_List
7177 (Make_Procedure_Call_Statement (Loc,
7178 Name =>
7179 New_Occurrence_Of (Entity (Assign_Indexed_Subp), Loc),
7180 Parameter_Associations =>
7181 New_List (New_Occurrence_Of (Temp, Loc),
7182 New_Occurrence_Of (Loop_Id, Loc),
7183 New_Copy_Tree (Expr))));
7184
7185 return Make_Implicit_Loop_Statement
7186 (Node => N,
7187 Identifier => Empty,
7188 Iteration_Scheme => L_Iteration_Scheme,
7189 Statements => Stats);
7190 end Expand_Range_Component;
7191
7192 begin
7193 if Siz > 0 then
7194
7195 -- Modify the call to the constructor to allocate the
7196 -- required size for the aggregwte : call the provided
7197 -- constructor rather than the Empty aggregate.
7198
7199 Index := Make_Op_Add (Loc,
7200 Left_Opnd => New_Copy_Tree (Type_Low_Bound (Index_Type)),
7201 Right_Opnd => Make_Integer_Literal (Loc, Siz - 1));
7202
7203 Set_Expression (Init_Stat,
7204 Make_Function_Call (Loc,
7205 Name =>
7206 New_Occurrence_Of (Entity (New_Indexed_Subp), Loc),
7207 Parameter_Associations =>
7208 New_List (
7209 New_Copy_Tree (Type_Low_Bound (Index_Type)),
7210 Index)));
7211 end if;
7212
7213 if Present (Expressions (N)) then
7214 Comp := First (Expressions (N));
7215
7216 while Present (Comp) loop
7217
7218 -- Compute index position for successive components
7219 -- in the list of expressions, and use the indexed
7220 -- assignment procedure for each.
7221
7222 Index := Make_Op_Add (Loc,
7223 Left_Opnd => Type_Low_Bound (Index_Type),
7224 Right_Opnd => Make_Integer_Literal (Loc, Pos));
7225
7226 Stat := Make_Procedure_Call_Statement (Loc,
7227 Name => New_Occurrence_Of (Insert, Loc),
7228 Parameter_Associations =>
7229 New_List (New_Occurrence_Of (Temp, Loc),
7230 Index,
7231 New_Copy_Tree (Comp)));
7232
7233 Pos := Pos + 1;
7234
7235 Append (Stat, Aggr_Code);
7236 Next (Comp);
7237 end loop;
7238 end if;
7239
7240 if Present (Component_Associations (N)) then
7241 Comp := First (Component_Associations (N));
7242
7243 -- The choice may be a static value, or a range with
7244 -- static bounds.
7245
7246 while Present (Comp) loop
7247 if Nkind (Comp) = N_Component_Association then
7248 Key := First (Choices (Comp));
7249 while Present (Key) loop
7250
7251 -- If the expression is a box, the corresponding
7252 -- component (s) is left uninitialized.
7253
7254 if Box_Present (Comp) then
7255 goto Next_Key;
7256
7257 elsif Nkind (Key) = N_Range then
7258
7259 -- Create loop for tne specified range,
7260 -- with copies of the expression.
7261
7262 Stat :=
7263 Expand_Range_Component (Key, Expression (Comp));
7264
7265 else
7266 Stat := Make_Procedure_Call_Statement (Loc,
7267 Name => New_Occurrence_Of
7268 (Entity (Assign_Indexed_Subp), Loc),
7269 Parameter_Associations =>
7270 New_List (New_Occurrence_Of (Temp, Loc),
7271 New_Copy_Tree (Key),
7272 New_Copy_Tree (Expression (Comp))));
7273 end if;
7274
7275 Append (Stat, Aggr_Code);
7276
7277 <<Next_Key>>
7278 Next (Key);
7279 end loop;
7280
7281 else
7282 -- Iterated component association. Discard
7283 -- positional insertion procedure.
7284
7285 if No (Iterator_Specification (Comp)) then
7286 Add_Named_Subp := Assign_Indexed_Subp;
7287 Add_Unnamed_Subp := Empty;
7288 end if;
7289
7290 Expand_Iterated_Component (Comp);
7291 end if;
7292
7293 Next (Comp);
7294 end loop;
7295 end if;
7296 end;
7297 end if;
7298
7299 Insert_Actions (N, Aggr_Code);
7300 Rewrite (N, New_Occurrence_Of (Temp, Loc));
7301 Analyze_And_Resolve (N, Typ);
7302 end Expand_Container_Aggregate;
7303
7304 ------------------------------
7305 -- Expand_N_Delta_Aggregate --
7306 ------------------------------
7307
7308 procedure Expand_N_Delta_Aggregate (N : Node_Id) is
7309 Loc : constant Source_Ptr := Sloc (N);
7310 Typ : constant Entity_Id := Etype (Expression (N));
7311 Decl : Node_Id;
7312
7313 begin
7314 Decl :=
7315 Make_Object_Declaration (Loc,
7316 Defining_Identifier => Make_Temporary (Loc, 'T'),
7317 Object_Definition => New_Occurrence_Of (Typ, Loc),
7318 Expression => New_Copy_Tree (Expression (N)));
7319
7320 if Is_Array_Type (Etype (N)) then
7321 Expand_Delta_Array_Aggregate (N, New_List (Decl));
7322 else
7323 Expand_Delta_Record_Aggregate (N, New_List (Decl));
7324 end if;
7325 end Expand_N_Delta_Aggregate;
7326
7327 ----------------------------------
7328 -- Expand_Delta_Array_Aggregate --
7329 ----------------------------------
7330
7331 procedure Expand_Delta_Array_Aggregate (N : Node_Id; Deltas : List_Id) is
7332 Loc : constant Source_Ptr := Sloc (N);
7333 Temp : constant Entity_Id := Defining_Identifier (First (Deltas));
7334 Assoc : Node_Id;
7335
7336 function Generate_Loop (C : Node_Id) return Node_Id;
7337 -- Generate a loop containing individual component assignments for
7338 -- choices that are ranges, subtype indications, subtype names, and
7339 -- iterated component associations.
7340
7341 function Make_Array_Delta_Assignment_LHS
7342 (Choice : Node_Id; Temp : Entity_Id) return Node_Id;
7343 -- Generate the LHS for the assignment associated with one
7344 -- component association. This can be more complex than just an
7345 -- indexed component in the case of a deep delta aggregate.
7346
7347 -------------------
7348 -- Generate_Loop --
7349 -------------------
7350
7351 function Generate_Loop (C : Node_Id) return Node_Id is
7352 Sl : constant Source_Ptr := Sloc (C);
7353 Ix : Entity_Id;
7354
7355 begin
7356 if Nkind (Parent (C)) = N_Iterated_Component_Association then
7357 Ix :=
7358 Make_Defining_Identifier (Loc,
7359 Chars => (Chars (Defining_Identifier (Parent (C)))));
7360 else
7361 Ix := Make_Temporary (Sl, 'I');
7362 end if;
7363
7364 return
7365 Make_Implicit_Loop_Statement (C,
7366 Iteration_Scheme =>
7367 Make_Iteration_Scheme (Sl,
7368 Loop_Parameter_Specification =>
7369 Make_Loop_Parameter_Specification (Sl,
7370 Defining_Identifier => Ix,
7371 Discrete_Subtype_Definition => New_Copy_Tree (C))),
7372
7373 Statements => New_List (
7374 Make_Assignment_Statement (Sl,
7375 Name =>
7376 Make_Indexed_Component (Sl,
7377 Prefix => New_Occurrence_Of (Temp, Sl),
7378 Expressions => New_List (New_Occurrence_Of (Ix, Sl))),
7379 Expression => New_Copy_Tree (Expression (Assoc)))),
7380 End_Label => Empty);
7381 end Generate_Loop;
7382
7383 function Make_Array_Delta_Assignment_LHS
7384 (Choice : Node_Id; Temp : Entity_Id) return Node_Id
7385 is
7386 function Make_Delta_Choice_LHS
7387 (Choice : Node_Id;
7388 Deep_Choice : Boolean) return Node_Id;
7389 -- Recursively (but recursion only in deep delta aggregate case)
7390 -- build up the LHS by successively applying selectors.
7391
7392 ---------------------------
7393 -- Make_Delta_Choice_LHS --
7394 ---------------------------
7395
7396 function Make_Delta_Choice_LHS
7397 (Choice : Node_Id;
7398 Deep_Choice : Boolean) return Node_Id
7399 is
7400 begin
7401 if not Deep_Choice
7402 or else Is_Root_Prefix_Of_Deep_Choice (Choice)
7403 then
7404 return Make_Indexed_Component (Sloc (Choice),
7405 Prefix => New_Occurrence_Of (Temp, Loc),
7406 Expressions => New_List (New_Copy_Tree (Choice)));
7407
7408 else
7409 -- a deep delta aggregate choice
7410 pragma Assert (All_Extensions_Allowed);
7411
7412 declare
7413 -- recursively get name for prefix
7414 LHS_Prefix : constant Node_Id
7415 := Make_Delta_Choice_LHS (Prefix (Choice), Deep_Choice);
7416 begin
7417 if Nkind (Choice) = N_Indexed_Component then
7418 return Make_Indexed_Component (Sloc (Choice),
7419 Prefix => LHS_Prefix,
7420 Expressions => New_Copy_List (Expressions (Choice)));
7421 else
7422 return Make_Selected_Component (Sloc (Choice),
7423 Prefix => LHS_Prefix,
7424 Selector_Name =>
7425 Make_Identifier
7426 (Sloc (Choice),
7427 Chars (Selector_Name (Choice))));
7428 end if;
7429 end;
7430 end if;
7431 end Make_Delta_Choice_LHS;
7432 begin
7433 return Make_Delta_Choice_LHS
7434 (Choice, Is_Deep_Choice (Choice, Etype (N)));
7435 end Make_Array_Delta_Assignment_LHS;
7436
7437 -- Local variables
7438
7439 Choice : Node_Id;
7440
7441 -- Start of processing for Expand_Delta_Array_Aggregate
7442
7443 begin
7444 Assoc := First (Component_Associations (N));
7445 while Present (Assoc) loop
7446 Choice := First (Choice_List (Assoc));
7447 if Nkind (Assoc) = N_Iterated_Component_Association then
7448 while Present (Choice) loop
7449 Append_To (Deltas, Generate_Loop (Choice));
7450 Next (Choice);
7451 end loop;
7452
7453 else
7454 while Present (Choice) loop
7455
7456 -- Choice can be given by a range, a subtype indication, a
7457 -- subtype name, a scalar value, or an entity.
7458
7459 if Nkind (Choice) = N_Range
7460 or else (Is_Entity_Name (Choice)
7461 and then Is_Type (Entity (Choice)))
7462 then
7463 Append_To (Deltas, Generate_Loop (Choice));
7464
7465 elsif Nkind (Choice) = N_Subtype_Indication then
7466 Append_To (Deltas,
7467 Generate_Loop (Range_Expression (Constraint (Choice))));
7468
7469 else
7470 Append_To (Deltas,
7471 Make_Assignment_Statement (Sloc (Choice),
7472 Name =>
7473 Make_Array_Delta_Assignment_LHS (Choice, Temp),
7474 Expression => New_Copy_Tree (Expression (Assoc))));
7475 end if;
7476
7477 Next (Choice);
7478 end loop;
7479 end if;
7480
7481 Next (Assoc);
7482 end loop;
7483
7484 Insert_Actions (N, Deltas);
7485 Rewrite (N, New_Occurrence_Of (Temp, Loc));
7486 end Expand_Delta_Array_Aggregate;
7487
7488 -----------------------------------
7489 -- Expand_Delta_Record_Aggregate --
7490 -----------------------------------
7491
7492 procedure Expand_Delta_Record_Aggregate (N : Node_Id; Deltas : List_Id) is
7493 Loc : constant Source_Ptr := Sloc (N);
7494 Temp : constant Entity_Id := Defining_Identifier (First (Deltas));
7495 Assoc : Node_Id;
7496 Choice : Node_Id;
7497
7498 function Make_Record_Delta_Assignment_LHS
7499 (Selector : Node_Id) return Node_Id;
7500 -- Generate the LHS for an assignment to a component (or subcomponent
7501 -- if -gnatX specified) of the result object.
7502
7503 --------------------------------------
7504 -- Make_Record_Delta_Assignment_LHS --
7505 --------------------------------------
7506
7507 function Make_Record_Delta_Assignment_LHS
7508 (Selector : Node_Id) return Node_Id
7509 is
7510 begin
7511 if Nkind (Selector) = N_Selected_Component then
7512 -- a deep delta aggregate, requires -gnatX0
7513 return
7514 Make_Selected_Component
7515 (Sloc (Choice),
7516 Prefix => Make_Record_Delta_Assignment_LHS
7517 (Prefix (Selector)),
7518 Selector_Name =>
7519 Make_Identifier (Loc, Chars (Selector_Name (Selector))));
7520 elsif Nkind (Selector) = N_Indexed_Component then
7521 -- a deep delta aggregate, requires -gnatX0
7522 return
7523 Make_Indexed_Component
7524 (Sloc (Choice),
7525 Prefix => Make_Record_Delta_Assignment_LHS
7526 (Prefix (Selector)),
7527 Expressions => Expressions (Selector));
7528 else
7529 return Make_Selected_Component
7530 (Sloc (Choice),
7531 Prefix => New_Occurrence_Of (Temp, Loc),
7532 Selector_Name => Make_Identifier (Loc, Chars (Selector)));
7533 end if;
7534 end Make_Record_Delta_Assignment_LHS;
7535 begin
7536 Assoc := First (Component_Associations (N));
7537
7538 while Present (Assoc) loop
7539 Choice := First (Choice_List (Assoc));
7540 while Present (Choice) loop
7541 Append_To (Deltas,
7542 Make_Assignment_Statement (Sloc (Choice),
7543 Name => Make_Record_Delta_Assignment_LHS (Choice),
7544 Expression => New_Copy_Tree (Expression (Assoc))));
7545 Next (Choice);
7546 end loop;
7547
7548 Next (Assoc);
7549 end loop;
7550
7551 Insert_Actions (N, Deltas);
7552 Rewrite (N, New_Occurrence_Of (Temp, Loc));
7553 end Expand_Delta_Record_Aggregate;
7554
7555 ----------------------------------
7556 -- Expand_N_Extension_Aggregate --
7557 ----------------------------------
7558
7559 -- If the ancestor part is an expression, add a component association for
7560 -- the parent field. If the type of the ancestor part is not the direct
7561 -- parent of the expected type, build recursively the needed ancestors.
7562 -- If the ancestor part is a subtype_mark, replace aggregate with a
7563 -- declaration for a temporary of the expected type, followed by
7564 -- individual assignments to the given components.
7565
7566 procedure Expand_N_Extension_Aggregate (N : Node_Id) is
7567 A : constant Node_Id := Ancestor_Part (N);
7568 Loc : constant Source_Ptr := Sloc (N);
7569 Typ : constant Entity_Id := Etype (N);
7570
7571 begin
7572 -- If the ancestor is a subtype mark, an init proc must be called
7573 -- on the resulting object which thus has to be materialized in
7574 -- the front-end
7575
7576 if Is_Entity_Name (A) and then Is_Type (Entity (A)) then
7577 Convert_To_Assignments (N, Typ);
7578
7579 -- The extension aggregate is transformed into a record aggregate
7580 -- of the following form (c1 and c2 are inherited components)
7581
7582 -- (Exp with c3 => a, c4 => b)
7583 -- ==> (c1 => Exp.c1, c2 => Exp.c2, c3 => a, c4 => b)
7584
7585 else
7586 Set_Etype (N, Typ);
7587
7588 if Tagged_Type_Expansion then
7589 Expand_Record_Aggregate (N,
7590 Orig_Tag =>
7591 New_Occurrence_Of
7592 (Node (First_Elmt (Access_Disp_Table (Typ))), Loc),
7593 Parent_Expr => A);
7594
7595 -- No tag is needed in the case of a VM
7596
7597 else
7598 Expand_Record_Aggregate (N, Parent_Expr => A);
7599 end if;
7600 end if;
7601
7602 exception
7603 when RE_Not_Available =>
7604 return;
7605 end Expand_N_Extension_Aggregate;
7606
7607 -----------------------------
7608 -- Expand_Record_Aggregate --
7609 -----------------------------
7610
7611 procedure Expand_Record_Aggregate
7612 (N : Node_Id;
7613 Orig_Tag : Node_Id := Empty;
7614 Parent_Expr : Node_Id := Empty)
7615 is
7616 Loc : constant Source_Ptr := Sloc (N);
7617 Comps : constant List_Id := Component_Associations (N);
7618 Typ : constant Entity_Id := Etype (N);
7619 Base_Typ : constant Entity_Id := Base_Type (Typ);
7620
7621 Static_Components : Boolean := True;
7622 -- Flag to indicate whether all components are compile-time known,
7623 -- and the aggregate can be constructed statically and handled by
7624 -- the back-end. Set to False by Component_OK_For_Backend.
7625
7626 procedure Build_Back_End_Aggregate;
7627 -- Build a proper aggregate to be handled by the back-end
7628
7629 function Compile_Time_Known_Composite_Value (N : Node_Id) return Boolean;
7630 -- Returns true if N is an expression of composite type which can be
7631 -- fully evaluated at compile time without raising constraint error.
7632 -- Such expressions can be passed as is to Gigi without any expansion.
7633 --
7634 -- This returns true for N_Aggregate with Compile_Time_Known_Aggregate
7635 -- set and constants whose expression is such an aggregate, recursively.
7636
7637 function Component_OK_For_Backend return Boolean;
7638 -- Check for presence of a component which makes it impossible for the
7639 -- backend to process the aggregate, thus requiring the use of a series
7640 -- of assignment statements. Cases checked for are a nested aggregate
7641 -- needing Late_Expansion, the presence of a tagged component which may
7642 -- need tag adjustment, and a bit unaligned component reference.
7643 --
7644 -- We also force expansion into assignments if a component is of a
7645 -- mutable type (including a private type with discriminants) because
7646 -- in that case the size of the component to be copied may be smaller
7647 -- than the side of the target, and there is no simple way for gigi
7648 -- to compute the size of the object to be copied.
7649 --
7650 -- NOTE: This is part of the ongoing work to define precisely the
7651 -- interface between front-end and back-end handling of aggregates.
7652 -- In general it is desirable to pass aggregates as they are to gigi,
7653 -- in order to minimize elaboration code. This is one case where the
7654 -- semantics of Ada complicate the analysis and lead to anomalies in
7655 -- the gcc back-end if the aggregate is not expanded into assignments.
7656 --
7657 -- NOTE: This sets the global Static_Components to False in most, but
7658 -- not all, cases when it returns False.
7659
7660 function Has_Per_Object_Constraint (L : List_Id) return Boolean;
7661 -- Return True if any element of L has Has_Per_Object_Constraint set.
7662 -- L should be the Choices component of an N_Component_Association.
7663
7664 function Has_Visible_Private_Ancestor (Id : E) return Boolean;
7665 -- If any ancestor of the current type is private, the aggregate
7666 -- cannot be built in place. We cannot rely on Has_Private_Ancestor,
7667 -- because it will not be set when type and its parent are in the
7668 -- same scope, and the parent component needs expansion.
7669
7670 function Top_Level_Aggregate (N : Node_Id) return Node_Id;
7671 -- For nested aggregates return the ultimate enclosing aggregate; for
7672 -- non-nested aggregates return N.
7673
7674 ------------------------------
7675 -- Build_Back_End_Aggregate --
7676 ------------------------------
7677
7678 procedure Build_Back_End_Aggregate is
7679 Comp : Entity_Id;
7680 New_Comp : Node_Id;
7681 Tag_Value : Node_Id;
7682
7683 begin
7684 if Nkind (N) = N_Aggregate then
7685
7686 -- If the aggregate is static and can be handled by the back-end,
7687 -- nothing left to do.
7688
7689 if Static_Components then
7690 Set_Compile_Time_Known_Aggregate (N);
7691 Set_Expansion_Delayed (N, False);
7692 end if;
7693 end if;
7694
7695 -- If no discriminants, nothing special to do
7696
7697 if not Has_Discriminants (Typ) then
7698 null;
7699
7700 -- Case of discriminants present
7701
7702 elsif Is_Derived_Type (Typ) then
7703
7704 -- For untagged types, non-stored discriminants are replaced with
7705 -- stored discriminants, which are the ones that gigi uses to
7706 -- describe the type and its components.
7707
7708 Generate_Aggregate_For_Derived_Type : declare
7709 procedure Prepend_Stored_Values (T : Entity_Id);
7710 -- Scan the list of stored discriminants of the type, and add
7711 -- their values to the aggregate being built.
7712
7713 ---------------------------
7714 -- Prepend_Stored_Values --
7715 ---------------------------
7716
7717 procedure Prepend_Stored_Values (T : Entity_Id) is
7718 Discr : Entity_Id;
7719 First_Comp : Node_Id := Empty;
7720
7721 begin
7722 Discr := First_Stored_Discriminant (T);
7723 while Present (Discr) loop
7724 New_Comp :=
7725 Make_Component_Association (Loc,
7726 Choices => New_List (
7727 New_Occurrence_Of (Discr, Loc)),
7728 Expression =>
7729 New_Copy_Tree
7730 (Get_Discriminant_Value
7731 (Discr,
7732 Typ,
7733 Discriminant_Constraint (Typ))));
7734
7735 if No (First_Comp) then
7736 Prepend_To (Component_Associations (N), New_Comp);
7737 else
7738 Insert_After (First_Comp, New_Comp);
7739 end if;
7740
7741 First_Comp := New_Comp;
7742 Next_Stored_Discriminant (Discr);
7743 end loop;
7744 end Prepend_Stored_Values;
7745
7746 -- Local variables
7747
7748 Constraints : constant List_Id := New_List;
7749
7750 Discr : Entity_Id;
7751 Decl : Node_Id;
7752 Num_Disc : Nat := 0;
7753 Num_Stor : Nat := 0;
7754
7755 -- Start of processing for Generate_Aggregate_For_Derived_Type
7756
7757 begin
7758 -- Remove the associations for the discriminant of derived type
7759
7760 declare
7761 First_Comp : Node_Id;
7762
7763 begin
7764 First_Comp := First (Component_Associations (N));
7765 while Present (First_Comp) loop
7766 Comp := First_Comp;
7767 Next (First_Comp);
7768
7769 if Ekind (Entity (First (Choices (Comp)))) =
7770 E_Discriminant
7771 then
7772 Remove (Comp);
7773 Num_Disc := Num_Disc + 1;
7774 end if;
7775 end loop;
7776 end;
7777
7778 -- Insert stored discriminant associations in the correct
7779 -- order. If there are more stored discriminants than new
7780 -- discriminants, there is at least one new discriminant that
7781 -- constrains more than one of the stored discriminants. In
7782 -- this case we need to construct a proper subtype of the
7783 -- parent type, in order to supply values to all the
7784 -- components. Otherwise there is one-one correspondence
7785 -- between the constraints and the stored discriminants.
7786
7787 Discr := First_Stored_Discriminant (Base_Type (Typ));
7788 while Present (Discr) loop
7789 Num_Stor := Num_Stor + 1;
7790 Next_Stored_Discriminant (Discr);
7791 end loop;
7792
7793 -- Case of more stored discriminants than new discriminants
7794
7795 if Num_Stor > Num_Disc then
7796
7797 -- Create a proper subtype of the parent type, which is the
7798 -- proper implementation type for the aggregate, and convert
7799 -- it to the intended target type.
7800
7801 Discr := First_Stored_Discriminant (Base_Type (Typ));
7802 while Present (Discr) loop
7803 New_Comp :=
7804 New_Copy_Tree
7805 (Get_Discriminant_Value
7806 (Discr,
7807 Typ,
7808 Discriminant_Constraint (Typ)));
7809
7810 Append (New_Comp, Constraints);
7811 Next_Stored_Discriminant (Discr);
7812 end loop;
7813
7814 Decl :=
7815 Make_Subtype_Declaration (Loc,
7816 Defining_Identifier => Make_Temporary (Loc, 'T'),
7817 Subtype_Indication =>
7818 Make_Subtype_Indication (Loc,
7819 Subtype_Mark =>
7820 New_Occurrence_Of (Etype (Base_Type (Typ)), Loc),
7821 Constraint =>
7822 Make_Index_Or_Discriminant_Constraint
7823 (Loc, Constraints)));
7824
7825 Insert_Action (N, Decl);
7826 Prepend_Stored_Values (Base_Type (Typ));
7827
7828 Set_Etype (N, Defining_Identifier (Decl));
7829 Set_Analyzed (N);
7830
7831 Rewrite (N, Unchecked_Convert_To (Typ, N));
7832 Analyze (N);
7833
7834 -- Case where we do not have fewer new discriminants than
7835 -- stored discriminants, so in this case we can simply use the
7836 -- stored discriminants of the subtype.
7837
7838 else
7839 Prepend_Stored_Values (Typ);
7840 end if;
7841 end Generate_Aggregate_For_Derived_Type;
7842 end if;
7843
7844 if Is_Tagged_Type (Typ) then
7845
7846 -- In the tagged case, _parent and _tag component must be created
7847
7848 -- Reset Null_Present unconditionally. Tagged records always have
7849 -- at least one field (the tag or the parent).
7850
7851 Set_Null_Record_Present (N, False);
7852
7853 -- When the current aggregate comes from the expansion of an
7854 -- extension aggregate, the parent expr is replaced by an
7855 -- aggregate formed by selected components of this expr.
7856
7857 if Present (Parent_Expr) and then Is_Empty_List (Comps) then
7858 Comp := First_Component_Or_Discriminant (Typ);
7859 while Present (Comp) loop
7860
7861 -- Skip all expander-generated components
7862
7863 if not Comes_From_Source (Original_Record_Component (Comp))
7864 then
7865 null;
7866
7867 else
7868 New_Comp :=
7869 Make_Selected_Component (Loc,
7870 Prefix =>
7871 Unchecked_Convert_To (Typ,
7872 Duplicate_Subexpr (Parent_Expr, True)),
7873 Selector_Name => New_Occurrence_Of (Comp, Loc));
7874
7875 Append_To (Comps,
7876 Make_Component_Association (Loc,
7877 Choices => New_List (
7878 New_Occurrence_Of (Comp, Loc)),
7879 Expression => New_Comp));
7880
7881 Analyze_And_Resolve (New_Comp, Etype (Comp));
7882 end if;
7883
7884 Next_Component_Or_Discriminant (Comp);
7885 end loop;
7886 end if;
7887
7888 -- Compute the value for the Tag now, if the type is a root it
7889 -- will be included in the aggregate right away, otherwise it will
7890 -- be propagated to the parent aggregate.
7891
7892 if Present (Orig_Tag) then
7893 Tag_Value := Orig_Tag;
7894
7895 elsif not Tagged_Type_Expansion then
7896 Tag_Value := Empty;
7897
7898 else
7899 Tag_Value :=
7900 New_Occurrence_Of
7901 (Node (First_Elmt (Access_Disp_Table (Typ))), Loc);
7902 end if;
7903
7904 -- For a derived type, an aggregate for the parent is formed with
7905 -- all the inherited components.
7906
7907 if Is_Derived_Type (Typ) then
7908 declare
7909 First_Comp : Node_Id;
7910 Parent_Comps : List_Id;
7911 Parent_Aggr : Node_Id;
7912 Parent_Name : Node_Id;
7913
7914 begin
7915 First_Comp := First (Component_Associations (N));
7916 Parent_Comps := New_List;
7917
7918 -- First skip the discriminants
7919
7920 while Present (First_Comp)
7921 and then Ekind (Entity (First (Choices (First_Comp))))
7922 = E_Discriminant
7923 loop
7924 Next (First_Comp);
7925 end loop;
7926
7927 -- Then remove the inherited component association from the
7928 -- aggregate and store them in the parent aggregate
7929
7930 while Present (First_Comp)
7931 and then
7932 Scope (Original_Record_Component
7933 (Entity (First (Choices (First_Comp))))) /=
7934 Base_Typ
7935 loop
7936 Comp := First_Comp;
7937 Next (First_Comp);
7938 Remove (Comp);
7939 Append (Comp, Parent_Comps);
7940 end loop;
7941
7942 Parent_Aggr :=
7943 Make_Aggregate (Loc,
7944 Component_Associations => Parent_Comps);
7945 Set_Etype (Parent_Aggr, Etype (Base_Type (Typ)));
7946
7947 -- Find the _parent component
7948
7949 Comp := First_Component (Typ);
7950 while Chars (Comp) /= Name_uParent loop
7951 Next_Component (Comp);
7952 end loop;
7953
7954 Parent_Name := New_Occurrence_Of (Comp, Loc);
7955
7956 -- Insert the parent aggregate
7957
7958 Prepend_To (Component_Associations (N),
7959 Make_Component_Association (Loc,
7960 Choices => New_List (Parent_Name),
7961 Expression => Parent_Aggr));
7962
7963 -- Expand recursively the parent propagating the right Tag
7964
7965 Expand_Record_Aggregate
7966 (Parent_Aggr, Tag_Value, Parent_Expr);
7967
7968 -- The ancestor part may be a nested aggregate that has
7969 -- delayed expansion: recheck now.
7970
7971 if not Component_OK_For_Backend then
7972 Convert_To_Assignments (N, Typ);
7973 end if;
7974 end;
7975
7976 -- For a root type, the tag component is added (unless compiling
7977 -- for the VMs, where tags are implicit).
7978
7979 elsif Tagged_Type_Expansion then
7980 declare
7981 Tag_Name : constant Node_Id :=
7982 New_Occurrence_Of
7983 (First_Tag_Component (Typ), Loc);
7984 Typ_Tag : constant Entity_Id := RTE (RE_Tag);
7985 Conv_Node : constant Node_Id :=
7986 Unchecked_Convert_To (Typ_Tag, Tag_Value);
7987
7988 begin
7989 Set_Etype (Conv_Node, Typ_Tag);
7990 Prepend_To (Component_Associations (N),
7991 Make_Component_Association (Loc,
7992 Choices => New_List (Tag_Name),
7993 Expression => Conv_Node));
7994 end;
7995 end if;
7996 end if;
7997 end Build_Back_End_Aggregate;
7998
7999 ----------------------------------------
8000 -- Compile_Time_Known_Composite_Value --
8001 ----------------------------------------
8002
8003 function Compile_Time_Known_Composite_Value
8004 (N : Node_Id) return Boolean
8005 is
8006 begin
8007 -- If we have an entity name, then see if it is the name of a
8008 -- constant and if so, test the corresponding constant value.
8009
8010 if Is_Entity_Name (N) then
8011 declare
8012 E : constant Entity_Id := Entity (N);
8013 V : Node_Id;
8014 begin
8015 if Ekind (E) /= E_Constant then
8016 return False;
8017 else
8018 V := Constant_Value (E);
8019 return Present (V)
8020 and then Compile_Time_Known_Composite_Value (V);
8021 end if;
8022 end;
8023
8024 -- We have a value, see if it is compile time known
8025
8026 else
8027 if Nkind (N) = N_Aggregate then
8028 return Compile_Time_Known_Aggregate (N);
8029 end if;
8030
8031 -- All other types of values are not known at compile time
8032
8033 return False;
8034 end if;
8035
8036 end Compile_Time_Known_Composite_Value;
8037
8038 ------------------------------
8039 -- Component_OK_For_Backend --
8040 ------------------------------
8041
8042 function Component_OK_For_Backend return Boolean is
8043 C : Node_Id;
8044 Expr_Q : Node_Id;
8045
8046 begin
8047 C := First (Comps);
8048 while Present (C) loop
8049
8050 -- If the component has box initialization, expansion is needed
8051 -- and component is not ready for backend.
8052
8053 if Box_Present (C) then
8054 return False;
8055 end if;
8056
8057 Expr_Q := Unqualify (Expression (C));
8058
8059 -- Return False for array components whose bounds raise
8060 -- constraint error.
8061
8062 declare
8063 Comp : constant Entity_Id := First (Choices (C));
8064 Indx : Node_Id;
8065
8066 begin
8067 if Present (Etype (Comp))
8068 and then Is_Array_Type (Etype (Comp))
8069 then
8070 Indx := First_Index (Etype (Comp));
8071 while Present (Indx) loop
8072 if Nkind (Type_Low_Bound (Etype (Indx))) =
8073 N_Raise_Constraint_Error
8074 or else Nkind (Type_High_Bound (Etype (Indx))) =
8075 N_Raise_Constraint_Error
8076 then
8077 return False;
8078 end if;
8079
8080 Next_Index (Indx);
8081 end loop;
8082 end if;
8083 end;
8084
8085 -- Return False if the aggregate has any associations for tagged
8086 -- components that may require tag adjustment.
8087
8088 -- These are cases where the source expression may have a tag that
8089 -- could differ from the component tag (e.g., can occur for type
8090 -- conversions and formal parameters). (Tag adjustment not needed
8091 -- if Tagged_Type_Expansion because object tags are implicit in
8092 -- the machine.)
8093
8094 if Is_Tagged_Type (Etype (Expr_Q))
8095 and then
8096 (Nkind (Expr_Q) = N_Type_Conversion
8097 or else
8098 (Is_Entity_Name (Expr_Q)
8099 and then Is_Formal (Entity (Expr_Q))))
8100 and then Tagged_Type_Expansion
8101 then
8102 Static_Components := False;
8103 return False;
8104
8105 elsif Is_Delayed_Aggregate (Expr_Q) then
8106 Static_Components := False;
8107 return False;
8108
8109 elsif Nkind (Expr_Q) = N_Quantified_Expression then
8110 Static_Components := False;
8111 return False;
8112
8113 elsif Possible_Bit_Aligned_Component (Expr_Q) then
8114 Static_Components := False;
8115 return False;
8116
8117 elsif Modify_Tree_For_C
8118 and then Nkind (C) = N_Component_Association
8119 and then Has_Per_Object_Constraint (Choices (C))
8120 then
8121 Static_Components := False;
8122 return False;
8123
8124 elsif Modify_Tree_For_C
8125 and then Nkind (Expr_Q) = N_Identifier
8126 and then Is_Array_Type (Etype (Expr_Q))
8127 then
8128 Static_Components := False;
8129 return False;
8130
8131 elsif Modify_Tree_For_C
8132 and then Nkind (Expr_Q) = N_Type_Conversion
8133 and then Is_Array_Type (Etype (Expr_Q))
8134 then
8135 Static_Components := False;
8136 return False;
8137 end if;
8138
8139 if Is_Elementary_Type (Etype (Expr_Q)) then
8140 if not Compile_Time_Known_Value (Expr_Q) then
8141 Static_Components := False;
8142 end if;
8143
8144 elsif not Compile_Time_Known_Composite_Value (Expr_Q) then
8145 Static_Components := False;
8146
8147 if Is_Private_Type (Etype (Expr_Q))
8148 and then Has_Discriminants (Etype (Expr_Q))
8149 then
8150 return False;
8151 end if;
8152 end if;
8153
8154 Next (C);
8155 end loop;
8156
8157 return True;
8158 end Component_OK_For_Backend;
8159
8160 -------------------------------
8161 -- Has_Per_Object_Constraint --
8162 -------------------------------
8163
8164 function Has_Per_Object_Constraint (L : List_Id) return Boolean is
8165 N : Node_Id := First (L);
8166 begin
8167 while Present (N) loop
8168 if Is_Entity_Name (N)
8169 and then Present (Entity (N))
8170 and then Has_Per_Object_Constraint (Entity (N))
8171 then
8172 return True;
8173 end if;
8174
8175 Next (N);
8176 end loop;
8177
8178 return False;
8179 end Has_Per_Object_Constraint;
8180
8181 -----------------------------------
8182 -- Has_Visible_Private_Ancestor --
8183 -----------------------------------
8184
8185 function Has_Visible_Private_Ancestor (Id : E) return Boolean is
8186 R : constant Entity_Id := Root_Type (Id);
8187 T1 : Entity_Id := Id;
8188
8189 begin
8190 loop
8191 if Is_Private_Type (T1) then
8192 return True;
8193
8194 elsif T1 = R then
8195 return False;
8196
8197 else
8198 T1 := Etype (T1);
8199 end if;
8200 end loop;
8201 end Has_Visible_Private_Ancestor;
8202
8203 -------------------------
8204 -- Top_Level_Aggregate --
8205 -------------------------
8206
8207 function Top_Level_Aggregate (N : Node_Id) return Node_Id is
8208 Aggr : Node_Id;
8209
8210 begin
8211 Aggr := N;
8212 while Present (Parent (Aggr))
8213 and then Nkind (Parent (Aggr)) in
8214 N_Aggregate | N_Component_Association
8215 loop
8216 Aggr := Parent (Aggr);
8217 end loop;
8218
8219 return Aggr;
8220 end Top_Level_Aggregate;
8221
8222 -- Local variables
8223
8224 Top_Level_Aggr : constant Node_Id := Top_Level_Aggregate (N);
8225
8226 -- Start of processing for Expand_Record_Aggregate
8227
8228 begin
8229 -- No special management required for aggregates used to initialize
8230 -- statically allocated dispatch tables
8231
8232 if Is_Static_Dispatch_Table_Aggregate (N) then
8233 return;
8234
8235 -- Case pattern aggregates need to remain as aggregates
8236
8237 elsif Is_Case_Choice_Pattern (N) then
8238 return;
8239 end if;
8240
8241 -- If the pragma Aggregate_Individually_Assign is set, always convert to
8242 -- assignments.
8243
8244 if Aggregate_Individually_Assign then
8245 Convert_To_Assignments (N, Typ);
8246
8247 -- Ada 2005 (AI-318-2): We need to convert to assignments if components
8248 -- are build-in-place function calls. The assignments will each turn
8249 -- into a build-in-place function call. If components are all static,
8250 -- we can pass the aggregate to the back end regardless of limitedness.
8251
8252 -- Extension aggregates, aggregates in extended return statements, and
8253 -- aggregates for C++ imported types must be expanded.
8254
8255 elsif Ada_Version >= Ada_2005
8256 and then Is_Inherently_Limited_Type (Typ)
8257 then
8258 if Nkind (Parent (N)) not in
8259 N_Component_Association | N_Object_Declaration
8260 then
8261 Convert_To_Assignments (N, Typ);
8262
8263 elsif Nkind (N) = N_Extension_Aggregate
8264 or else Convention (Typ) = Convention_CPP
8265 then
8266 Convert_To_Assignments (N, Typ);
8267
8268 elsif not Size_Known_At_Compile_Time (Typ)
8269 or else not Component_OK_For_Backend
8270 or else not Static_Components
8271 then
8272 Convert_To_Assignments (N, Typ);
8273
8274 -- In all other cases, build a proper aggregate to be handled by
8275 -- the back-end.
8276
8277 else
8278 Build_Back_End_Aggregate;
8279 end if;
8280
8281 -- Gigi doesn't properly handle temporaries of variable size so we
8282 -- generate it in the front-end
8283
8284 elsif not Size_Known_At_Compile_Time (Typ)
8285 and then Tagged_Type_Expansion
8286 then
8287 Convert_To_Assignments (N, Typ);
8288
8289 -- An aggregate used to initialize a controlled object must be turned
8290 -- into component assignments as the components themselves may require
8291 -- finalization actions such as adjustment.
8292
8293 elsif Needs_Finalization (Typ) then
8294 Convert_To_Assignments (N, Typ);
8295
8296 -- Ada 2005 (AI-287): In case of default initialized components we
8297 -- convert the aggregate into assignments.
8298
8299 elsif Has_Default_Init_Comps (N) then
8300 Convert_To_Assignments (N, Typ);
8301
8302 -- Check components
8303
8304 elsif not Component_OK_For_Backend then
8305 Convert_To_Assignments (N, Typ);
8306
8307 -- If an ancestor is private, some components are not inherited and we
8308 -- cannot expand into a record aggregate.
8309
8310 elsif Has_Visible_Private_Ancestor (Typ) then
8311 Convert_To_Assignments (N, Typ);
8312
8313 -- ??? The following was done to compile fxacc00.ads in the ACVCs. Gigi
8314 -- is not able to handle the aggregate for Late_Request.
8315
8316 elsif Is_Tagged_Type (Typ) and then Has_Discriminants (Typ) then
8317 Convert_To_Assignments (N, Typ);
8318
8319 -- If the tagged types covers interface types we need to initialize all
8320 -- hidden components containing pointers to secondary dispatch tables.
8321
8322 elsif Is_Tagged_Type (Typ) and then Has_Interfaces (Typ) then
8323 Convert_To_Assignments (N, Typ);
8324
8325 -- If some components are mutable, the size of the aggregate component
8326 -- may be distinct from the default size of the type component, so
8327 -- we need to expand to insure that the back-end copies the proper
8328 -- size of the data. However, if the aggregate is the initial value of
8329 -- a constant, the target is immutable and might be built statically
8330 -- if components are appropriate.
8331
8332 elsif Has_Mutable_Components (Typ)
8333 and then
8334 (Nkind (Parent (Top_Level_Aggr)) /= N_Object_Declaration
8335 or else not Constant_Present (Parent (Top_Level_Aggr))
8336 or else not Static_Components)
8337 then
8338 Convert_To_Assignments (N, Typ);
8339
8340 -- If the type involved has bit aligned components, then we are not sure
8341 -- that the back end can handle this case correctly.
8342
8343 elsif Type_May_Have_Bit_Aligned_Components (Typ) then
8344 Convert_To_Assignments (N, Typ);
8345
8346 -- When generating C, only generate an aggregate when declaring objects
8347 -- since C does not support aggregates in e.g. assignment statements.
8348
8349 elsif Modify_Tree_For_C and then not Is_CCG_Supported_Aggregate (N) then
8350 Convert_To_Assignments (N, Typ);
8351
8352 -- In all other cases, build a proper aggregate to be handled by gigi
8353
8354 else
8355 Build_Back_End_Aggregate;
8356 end if;
8357 end Expand_Record_Aggregate;
8358
8359 ---------------------
8360 -- Get_Base_Object --
8361 ---------------------
8362
8363 function Get_Base_Object (N : Node_Id) return Entity_Id is
8364 R : Node_Id;
8365
8366 begin
8367 R := Get_Referenced_Object (N);
8368
8369 while Nkind (R) in N_Indexed_Component | N_Selected_Component | N_Slice
8370 loop
8371 R := Get_Referenced_Object (Prefix (R));
8372 end loop;
8373
8374 if Is_Entity_Name (R) and then Is_Object (Entity (R)) then
8375 return Entity (R);
8376 else
8377 return Empty;
8378 end if;
8379 end Get_Base_Object;
8380
8381 ----------------------------
8382 -- Has_Default_Init_Comps --
8383 ----------------------------
8384
8385 function Has_Default_Init_Comps (N : Node_Id) return Boolean is
8386 Assoc : Node_Id;
8387 Expr : Node_Id;
8388 -- Component association and expression, respectively
8389
8390 begin
8391 pragma Assert (Nkind (N) in N_Aggregate | N_Extension_Aggregate);
8392
8393 if Has_Self_Reference (N) then
8394 return True;
8395 end if;
8396
8397 Assoc := First (Component_Associations (N));
8398 while Present (Assoc) loop
8399 -- Each component association has either a box or an expression
8400
8401 pragma Assert (Box_Present (Assoc) xor Present (Expression (Assoc)));
8402
8403 -- Check if any direct component has default initialized components
8404
8405 if Box_Present (Assoc) then
8406 return True;
8407
8408 -- Recursive call in case of aggregate expression
8409
8410 else
8411 Expr := Expression (Assoc);
8412
8413 if Nkind (Expr) in N_Aggregate | N_Extension_Aggregate
8414 and then Has_Default_Init_Comps (Expr)
8415 then
8416 return True;
8417 end if;
8418 end if;
8419
8420 Next (Assoc);
8421 end loop;
8422
8423 return False;
8424 end Has_Default_Init_Comps;
8425
8426 --------------------------
8427 -- Initialize_Component --
8428 --------------------------
8429
8430 procedure Initialize_Component
8431 (N : Node_Id;
8432 Comp : Node_Id;
8433 Comp_Typ : Node_Id;
8434 Init_Expr : Node_Id;
8435 Stmts : List_Id)
8436 is
8437 Exceptions_OK : constant Boolean :=
8438 not Restriction_Active (No_Exception_Propagation);
8439 Finalization_OK : constant Boolean :=
8440 Present (Comp_Typ)
8441 and then Needs_Finalization (Comp_Typ);
8442 Loc : constant Source_Ptr := Sloc (N);
8443
8444 Blk_Stmts : List_Id;
8445 Init_Stmt : Node_Id;
8446
8447 begin
8448 pragma Assert (Nkind (Init_Expr) in N_Subexpr);
8449
8450 -- Protect the initialization statements from aborts. Generate:
8451
8452 -- Abort_Defer;
8453
8454 if Finalization_OK and Abort_Allowed then
8455 if Exceptions_OK then
8456 Blk_Stmts := New_List;
8457 else
8458 Blk_Stmts := Stmts;
8459 end if;
8460
8461 Append_To (Blk_Stmts, Build_Runtime_Call (Loc, RE_Abort_Defer));
8462
8463 -- Otherwise aborts are not allowed. All generated code is added
8464 -- directly to the input list.
8465
8466 else
8467 Blk_Stmts := Stmts;
8468 end if;
8469
8470 -- Initialize the component. Generate:
8471
8472 -- Comp := Init_Expr;
8473
8474 -- Note that the initialization expression is not duplicated because
8475 -- either only a single component may be initialized by it (record)
8476 -- or it has already been duplicated if need be (array).
8477
8478 Init_Stmt :=
8479 Make_OK_Assignment_Statement (Loc,
8480 Name => New_Copy_Tree (Comp),
8481 Expression => Relocate_Node (Init_Expr));
8482
8483 Append_To (Blk_Stmts, Init_Stmt);
8484
8485 -- Arrange for the component to be adjusted if need be (the call will be
8486 -- generated by Make_Tag_Ctrl_Assignment). But, in the case of an array
8487 -- aggregate, controlled subaggregates are not considered because each
8488 -- of their individual elements will receive an adjustment of its own.
8489
8490 if Finalization_OK
8491 and then not Is_Inherently_Limited_Type (Comp_Typ)
8492 and then not
8493 (Is_Array_Type (Etype (N))
8494 and then Is_Array_Type (Comp_Typ)
8495 and then Needs_Finalization (Component_Type (Comp_Typ))
8496 and then Nkind (Unqualify (Init_Expr)) = N_Aggregate)
8497 then
8498 Set_No_Finalize_Actions (Init_Stmt);
8499
8500 -- Or else, only adjust the tag due to a possible view conversion
8501
8502 else
8503 Set_No_Ctrl_Actions (Init_Stmt);
8504
8505 if Tagged_Type_Expansion and then Is_Tagged_Type (Comp_Typ) then
8506 Append_To (Blk_Stmts,
8507 Make_Tag_Assignment_From_Type
8508 (Loc, New_Copy_Tree (Comp), Underlying_Type (Comp_Typ)));
8509 end if;
8510 end if;
8511
8512 -- Complete the protection of the initialization statements
8513
8514 if Finalization_OK and Abort_Allowed then
8515
8516 -- Wrap the initialization statements in a block to catch a
8517 -- potential exception. Generate:
8518
8519 -- begin
8520 -- Abort_Defer;
8521 -- Comp := Init_Expr;
8522 -- Comp._tag := Full_TypP;
8523 -- [Deep_]Adjust (Comp);
8524 -- at end
8525 -- Abort_Undefer_Direct;
8526 -- end;
8527
8528 if Exceptions_OK then
8529 Append_To (Stmts,
8530 Build_Abort_Undefer_Block (Loc,
8531 Stmts => Blk_Stmts,
8532 Context => N));
8533
8534 -- Otherwise exceptions are not propagated. Generate:
8535
8536 -- Abort_Defer;
8537 -- Comp := Init_Expr;
8538 -- Comp._tag := Full_TypP;
8539 -- [Deep_]Adjust (Comp);
8540 -- Abort_Undefer;
8541
8542 else
8543 Append_To (Blk_Stmts,
8544 Build_Runtime_Call (Loc, RE_Abort_Undefer));
8545 end if;
8546 end if;
8547 end Initialize_Component;
8548
8549 ----------------------------------------
8550 -- Is_Build_In_Place_Aggregate_Return --
8551 ----------------------------------------
8552
8553 function Is_Build_In_Place_Aggregate_Return (N : Node_Id) return Boolean is
8554 P : Node_Id := Parent (N);
8555
8556 begin
8557 while Nkind (P) in N_Case_Expression
8558 | N_Case_Expression_Alternative
8559 | N_If_Expression
8560 | N_Qualified_Expression
8561 loop
8562 P := Parent (P);
8563 end loop;
8564
8565 if Nkind (P) = N_Simple_Return_Statement then
8566 null;
8567
8568 elsif Nkind (Parent (P)) = N_Extended_Return_Statement then
8569 P := Parent (P);
8570
8571 else
8572 return False;
8573 end if;
8574
8575 return
8576 Is_Build_In_Place_Function
8577 (Return_Applies_To (Return_Statement_Entity (P)));
8578 end Is_Build_In_Place_Aggregate_Return;
8579
8580 --------------------------
8581 -- Is_Delayed_Aggregate --
8582 --------------------------
8583
8584 function Is_Delayed_Aggregate (N : Node_Id) return Boolean is
8585 Unqual_N : constant Node_Id := Unqualify (N);
8586
8587 begin
8588 return Nkind (Unqual_N) in N_Aggregate | N_Extension_Aggregate
8589 and then Expansion_Delayed (Unqual_N);
8590 end Is_Delayed_Aggregate;
8591
8592 --------------------------------
8593 -- Is_CCG_Supported_Aggregate --
8594 --------------------------------
8595
8596 function Is_CCG_Supported_Aggregate
8597 (N : Node_Id) return Boolean
8598 is
8599 P : Node_Id := Parent (N);
8600
8601 begin
8602 -- Aggregates are not supported for nonstandard rep clauses, since they
8603 -- may lead to extra padding fields in CCG.
8604
8605 if Is_Record_Type (Etype (N))
8606 and then Has_Non_Standard_Rep (Etype (N))
8607 then
8608 return False;
8609 end if;
8610
8611 while Present (P) and then Nkind (P) = N_Aggregate loop
8612 P := Parent (P);
8613 end loop;
8614
8615 -- Check cases where aggregates are supported by the CCG backend
8616
8617 if Nkind (P) = N_Object_Declaration then
8618 declare
8619 P_Typ : constant Entity_Id := Etype (Defining_Identifier (P));
8620
8621 begin
8622 if Is_Record_Type (P_Typ) then
8623 return True;
8624 else
8625 return Compile_Time_Known_Bounds (P_Typ);
8626 end if;
8627 end;
8628
8629 elsif Nkind (P) = N_Qualified_Expression then
8630 if Nkind (Parent (P)) = N_Object_Declaration then
8631 declare
8632 P_Typ : constant Entity_Id :=
8633 Etype (Defining_Identifier (Parent (P)));
8634 begin
8635 if Is_Record_Type (P_Typ) then
8636 return True;
8637 else
8638 return Compile_Time_Known_Bounds (P_Typ);
8639 end if;
8640 end;
8641
8642 elsif Nkind (Parent (P)) = N_Allocator then
8643 return True;
8644 end if;
8645 end if;
8646
8647 return False;
8648 end Is_CCG_Supported_Aggregate;
8649
8650 ----------------------------------------
8651 -- Is_Static_Dispatch_Table_Aggregate --
8652 ----------------------------------------
8653
8654 function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean is
8655 Typ : constant Entity_Id := Base_Type (Etype (N));
8656
8657 begin
8658 return Building_Static_Dispatch_Tables
8659 and then Tagged_Type_Expansion
8660
8661 -- Avoid circularity when rebuilding the compiler
8662
8663 and then not Is_RTU (Cunit_Entity (Get_Source_Unit (N)), Ada_Tags)
8664 and then (Is_RTE (Typ, RE_Dispatch_Table_Wrapper)
8665 or else
8666 Is_RTE (Typ, RE_Address_Array)
8667 or else
8668 Is_RTE (Typ, RE_Type_Specific_Data)
8669 or else
8670 Is_RTE (Typ, RE_Tag_Table)
8671 or else
8672 Is_RTE (Typ, RE_Object_Specific_Data)
8673 or else
8674 Is_RTE (Typ, RE_Interface_Data)
8675 or else
8676 Is_RTE (Typ, RE_Interfaces_Array)
8677 or else
8678 Is_RTE (Typ, RE_Interface_Data_Element));
8679 end Is_Static_Dispatch_Table_Aggregate;
8680
8681 -----------------------------
8682 -- Is_Two_Dim_Packed_Array --
8683 -----------------------------
8684
8685 function Is_Two_Dim_Packed_Array (Typ : Entity_Id) return Boolean is
8686 C : constant Uint := Component_Size (Typ);
8687
8688 begin
8689 return Number_Dimensions (Typ) = 2
8690 and then Is_Bit_Packed_Array (Typ)
8691 and then Is_Scalar_Type (Component_Type (Typ))
8692 and then C in Uint_1 | Uint_2 | Uint_4; -- False if No_Uint
8693 end Is_Two_Dim_Packed_Array;
8694
8695 --------------------
8696 -- Late_Expansion --
8697 --------------------
8698
8699 function Late_Expansion
8700 (N : Node_Id;
8701 Typ : Entity_Id;
8702 Target : Node_Id) return List_Id
8703 is
8704 Aggr_Code : List_Id;
8705 New_Aggr : Node_Id;
8706
8707 begin
8708 if Is_Array_Type (Typ) then
8709 -- If the assignment can be done directly by the back end, then
8710 -- reset Set_Expansion_Delayed and do not expand further.
8711
8712 if not CodePeer_Mode
8713 and then not Modify_Tree_For_C
8714 and then not Possible_Bit_Aligned_Component (Target)
8715 and then not Is_Possibly_Unaligned_Slice (Target)
8716 and then Aggr_Assignment_OK_For_Backend (N)
8717 then
8718 New_Aggr := New_Copy_Tree (N);
8719 Set_Expansion_Delayed (New_Aggr, False);
8720
8721 Aggr_Code :=
8722 New_List (
8723 Make_OK_Assignment_Statement (Sloc (New_Aggr),
8724 Name => Target,
8725 Expression => New_Aggr));
8726
8727 -- Or else, generate component assignments to it
8728
8729 else
8730 Aggr_Code :=
8731 Build_Array_Aggr_Code
8732 (N => N,
8733 Ctype => Component_Type (Typ),
8734 Index => First_Index (Typ),
8735 Into => Target,
8736 Scalar_Comp => Is_Scalar_Type (Component_Type (Typ)),
8737 Indexes => No_List);
8738 end if;
8739
8740 -- Directly or indirectly (e.g. access protected procedure) a record
8741
8742 else
8743 Aggr_Code := Build_Record_Aggr_Code (N, Typ, Target);
8744 end if;
8745
8746 -- Save the last assignment statement associated with the aggregate
8747 -- when building a controlled object. This reference is utilized by
8748 -- the finalization machinery when marking an object as successfully
8749 -- initialized.
8750
8751 if Needs_Finalization (Typ)
8752 and then Is_Entity_Name (Target)
8753 and then Present (Entity (Target))
8754 and then Ekind (Entity (Target)) in E_Constant | E_Variable
8755 then
8756 Set_Last_Aggregate_Assignment (Entity (Target), Last (Aggr_Code));
8757 end if;
8758
8759 return Aggr_Code;
8760 end Late_Expansion;
8761
8762 ----------------------------------
8763 -- Make_OK_Assignment_Statement --
8764 ----------------------------------
8765
8766 function Make_OK_Assignment_Statement
8767 (Sloc : Source_Ptr;
8768 Name : Node_Id;
8769 Expression : Node_Id) return Node_Id
8770 is
8771 begin
8772 Set_Assignment_OK (Name);
8773 return Make_Assignment_Statement (Sloc, Name, Expression);
8774 end Make_OK_Assignment_Statement;
8775
8776 ------------------------
8777 -- Max_Aggregate_Size --
8778 ------------------------
8779
8780 function Max_Aggregate_Size
8781 (N : Node_Id;
8782 Default_Size : Nat := 5000) return Nat
8783 is
8784 function Use_Small_Size (N : Node_Id) return Boolean;
8785 -- True if we should return a very small size, which means large
8786 -- aggregates will be implemented as a loop when possible (potentially
8787 -- transformed to memset calls).
8788
8789 function Aggr_Context (N : Node_Id) return Node_Id;
8790 -- Return the context in which the aggregate appears, not counting
8791 -- qualified expressions and similar.
8792
8793 ------------------
8794 -- Aggr_Context --
8795 ------------------
8796
8797 function Aggr_Context (N : Node_Id) return Node_Id is
8798 Result : Node_Id := Parent (N);
8799 begin
8800 if Nkind (Result) in N_Qualified_Expression
8801 | N_Type_Conversion
8802 | N_Unchecked_Type_Conversion
8803 | N_If_Expression
8804 | N_Case_Expression
8805 | N_Component_Association
8806 | N_Aggregate
8807 then
8808 Result := Aggr_Context (Result);
8809 end if;
8810
8811 return Result;
8812 end Aggr_Context;
8813
8814 --------------------
8815 -- Use_Small_Size --
8816 --------------------
8817
8818 function Use_Small_Size (N : Node_Id) return Boolean is
8819 C : constant Node_Id := Aggr_Context (N);
8820 -- The decision depends on the context in which the aggregate occurs,
8821 -- and for variable declarations, whether we are nested inside a
8822 -- subprogram.
8823 begin
8824 case Nkind (C) is
8825 -- True for assignment statements and similar
8826
8827 when N_Assignment_Statement
8828 | N_Simple_Return_Statement
8829 | N_Allocator
8830 | N_Attribute_Reference
8831 =>
8832 return True;
8833
8834 -- True for nested variable declarations. False for library level
8835 -- variables, and for constants (whether or not nested).
8836
8837 when N_Object_Declaration =>
8838 return not Constant_Present (C)
8839 and then Is_Subprogram (Current_Scope);
8840
8841 -- False for all other contexts
8842
8843 when others =>
8844 return False;
8845 end case;
8846 end Use_Small_Size;
8847
8848 -- Local variables
8849
8850 Typ : constant Entity_Id := Etype (N);
8851
8852 -- Start of processing for Max_Aggregate_Size
8853
8854 begin
8855 -- We use a small limit in CodePeer mode where we favor loops instead of
8856 -- thousands of single assignments (from large aggregates).
8857
8858 -- We also increase the limit to 2**24 (about 16 million) if
8859 -- Restrictions (No_Elaboration_Code) or Restrictions
8860 -- (No_Implicit_Loops) is specified, since in either case we are at risk
8861 -- of declaring the program illegal because of this limit. We also
8862 -- increase the limit when Static_Elaboration_Desired, given that this
8863 -- means that objects are intended to be placed in data memory.
8864
8865 -- Same if the aggregate is for a packed two-dimensional array, because
8866 -- if components are static it is much more efficient to construct a
8867 -- one-dimensional equivalent array with static components.
8868
8869 if CodePeer_Mode then
8870 return 100;
8871 elsif Restriction_Active (No_Elaboration_Code)
8872 or else Restriction_Active (No_Implicit_Loops)
8873 or else Is_Two_Dim_Packed_Array (Typ)
8874 or else (Ekind (Current_Scope) = E_Package
8875 and then Static_Elaboration_Desired (Current_Scope))
8876 then
8877 return 2 ** 24;
8878 elsif Use_Small_Size (N) then
8879 return 64;
8880 end if;
8881
8882 return Default_Size;
8883 end Max_Aggregate_Size;
8884
8885 -----------------------
8886 -- Number_Of_Choices --
8887 -----------------------
8888
8889 function Number_Of_Choices (N : Node_Id) return Nat is
8890 Assoc : Node_Id;
8891 Choice : Node_Id;
8892
8893 Nb_Choices : Nat := 0;
8894
8895 begin
8896 if Present (Expressions (N)) then
8897 return 0;
8898 end if;
8899
8900 Assoc := First (Component_Associations (N));
8901 while Present (Assoc) loop
8902 Choice := First (Choice_List (Assoc));
8903 while Present (Choice) loop
8904 if Nkind (Choice) /= N_Others_Choice then
8905 Nb_Choices := Nb_Choices + 1;
8906 end if;
8907
8908 Next (Choice);
8909 end loop;
8910
8911 Next (Assoc);
8912 end loop;
8913
8914 return Nb_Choices;
8915 end Number_Of_Choices;
8916
8917 ------------------------------------
8918 -- Packed_Array_Aggregate_Handled --
8919 ------------------------------------
8920
8921 -- The current version of this procedure will handle at compile time
8922 -- any array aggregate that meets these conditions:
8923
8924 -- One and two dimensional, bit packed
8925 -- Underlying packed type is modular type
8926 -- Bounds are within 32-bit Int range
8927 -- All bounds and values are static
8928
8929 -- Note: for now, in the 2-D case, we only handle component sizes of
8930 -- 1, 2, 4 (cases where an integral number of elements occupies a byte).
8931
8932 function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean is
8933 Loc : constant Source_Ptr := Sloc (N);
8934 Typ : constant Entity_Id := Etype (N);
8935 Ctyp : constant Entity_Id := Component_Type (Typ);
8936
8937 Not_Handled : exception;
8938 -- Exception raised if this aggregate cannot be handled
8939
8940 begin
8941 -- Handle one- or two dimensional bit packed array
8942
8943 if not Is_Bit_Packed_Array (Typ)
8944 or else Number_Dimensions (Typ) > 2
8945 then
8946 return False;
8947 end if;
8948
8949 -- If two-dimensional, check whether it can be folded, and transformed
8950 -- into a one-dimensional aggregate for the Packed_Array_Impl_Type of
8951 -- the original type.
8952
8953 if Number_Dimensions (Typ) = 2 then
8954 return Two_Dim_Packed_Array_Handled (N);
8955 end if;
8956
8957 if not Is_Modular_Integer_Type (Packed_Array_Impl_Type (Typ)) then
8958 return False;
8959 end if;
8960
8961 if not Is_Scalar_Type (Ctyp) then
8962 return False;
8963 end if;
8964
8965 declare
8966 Csiz : constant Nat := UI_To_Int (Component_Size (Typ));
8967
8968 function Get_Component_Val (N : Node_Id) return Uint;
8969 -- Given a expression value N of the component type Ctyp, returns a
8970 -- value of Csiz (component size) bits representing this value. If
8971 -- the value is nonstatic or any other reason exists why the value
8972 -- cannot be returned, then Not_Handled is raised.
8973
8974 -----------------------
8975 -- Get_Component_Val --
8976 -----------------------
8977
8978 function Get_Component_Val (N : Node_Id) return Uint is
8979 Val : Uint;
8980
8981 begin
8982 -- We have to analyze the expression here before doing any further
8983 -- processing here. The analysis of such expressions is deferred
8984 -- till expansion to prevent some problems of premature analysis.
8985
8986 Analyze_And_Resolve (N, Ctyp);
8987
8988 -- Must have a compile time value. String literals have to be
8989 -- converted into temporaries as well, because they cannot easily
8990 -- be converted into their bit representation.
8991
8992 if not Compile_Time_Known_Value (N)
8993 or else Nkind (N) = N_String_Literal
8994 then
8995 raise Not_Handled;
8996 end if;
8997
8998 Val := Expr_Rep_Value (N);
8999
9000 -- Adjust for bias, and strip proper number of bits
9001
9002 if Has_Biased_Representation (Ctyp) then
9003 Val := Val - Expr_Value (Type_Low_Bound (Ctyp));
9004 end if;
9005
9006 return Val mod Uint_2 ** Csiz;
9007 end Get_Component_Val;
9008
9009 Bounds : constant Range_Nodes := Get_Index_Bounds (First_Index (Typ));
9010
9011 -- Here we know we have a one dimensional bit packed array
9012
9013 begin
9014 -- Cannot do anything if bounds are dynamic
9015
9016 if not (Compile_Time_Known_Value (Bounds.First)
9017 and then
9018 Compile_Time_Known_Value (Bounds.Last))
9019 then
9020 return False;
9021 end if;
9022
9023 declare
9024 Bounds_Vals : Range_Values;
9025 -- Compile-time known values of bounds
9026 begin
9027 -- Or are silly out of range of int bounds
9028
9029 Bounds_Vals.First := Expr_Value (Bounds.First);
9030 Bounds_Vals.Last := Expr_Value (Bounds.Last);
9031
9032 if not UI_Is_In_Int_Range (Bounds_Vals.First)
9033 or else
9034 not UI_Is_In_Int_Range (Bounds_Vals.Last)
9035 then
9036 return False;
9037 end if;
9038
9039 -- At this stage we have a suitable aggregate for handling at
9040 -- compile time. The only remaining checks are that the values of
9041 -- expressions in the aggregate are compile-time known (checks are
9042 -- performed by Get_Component_Val), and that any subtypes or
9043 -- ranges are statically known.
9044
9045 -- If the aggregate is not fully positional at this stage, then
9046 -- convert it to positional form. Either this will fail, in which
9047 -- case we can do nothing, or it will succeed, in which case we
9048 -- have succeeded in handling the aggregate and transforming it
9049 -- into a modular value, or it will stay an aggregate, in which
9050 -- case we have failed to create a packed value for it.
9051
9052 if Present (Component_Associations (N)) then
9053 Convert_To_Positional (N, Handle_Bit_Packed => True);
9054 return Nkind (N) /= N_Aggregate;
9055 end if;
9056
9057 -- Otherwise we are all positional, so convert to proper value
9058
9059 declare
9060 Len : constant Nat :=
9061 Int'Max (0, UI_To_Int (Bounds_Vals.Last) -
9062 UI_To_Int (Bounds_Vals.First) + 1);
9063 -- The length of the array (number of elements)
9064
9065 Aggregate_Val : Uint;
9066 -- Value of aggregate. The value is set in the low order bits
9067 -- of this value. For the little-endian case, the values are
9068 -- stored from low-order to high-order and for the big-endian
9069 -- case the values are stored from high order to low order.
9070 -- Note that gigi will take care of the conversions to left
9071 -- justify the value in the big endian case (because of left
9072 -- justified modular type processing), so we do not have to
9073 -- worry about that here.
9074
9075 Lit : Node_Id;
9076 -- Integer literal for resulting constructed value
9077
9078 Shift : Nat;
9079 -- Shift count from low order for next value
9080
9081 Incr : Int;
9082 -- Shift increment for loop
9083
9084 Expr : Node_Id;
9085 -- Next expression from positional parameters of aggregate
9086
9087 Left_Justified : Boolean;
9088 -- Set True if we are filling the high order bits of the target
9089 -- value (i.e. the value is left justified).
9090
9091 begin
9092 -- For little endian, we fill up the low order bits of the
9093 -- target value. For big endian we fill up the high order bits
9094 -- of the target value (which is a left justified modular
9095 -- value).
9096
9097 Left_Justified := Bytes_Big_Endian;
9098
9099 -- Switch justification if using -gnatd8
9100
9101 if Debug_Flag_8 then
9102 Left_Justified := not Left_Justified;
9103 end if;
9104
9105 -- Switch justfification if reverse storage order
9106
9107 if Reverse_Storage_Order (Base_Type (Typ)) then
9108 Left_Justified := not Left_Justified;
9109 end if;
9110
9111 if Left_Justified then
9112 Shift := Csiz * (Len - 1);
9113 Incr := -Csiz;
9114 else
9115 Shift := 0;
9116 Incr := +Csiz;
9117 end if;
9118
9119 -- Loop to set the values
9120
9121 if Len = 0 then
9122 Aggregate_Val := Uint_0;
9123 else
9124 Expr := First (Expressions (N));
9125 Aggregate_Val := Get_Component_Val (Expr) * Uint_2 ** Shift;
9126
9127 for J in 2 .. Len loop
9128 Shift := Shift + Incr;
9129 Next (Expr);
9130 Aggregate_Val :=
9131 Aggregate_Val +
9132 Get_Component_Val (Expr) * Uint_2 ** Shift;
9133 end loop;
9134 end if;
9135
9136 -- Now we can rewrite with the proper value
9137
9138 Lit := Make_Integer_Literal (Loc, Intval => Aggregate_Val);
9139 Set_Print_In_Hex (Lit);
9140
9141 -- Construct the expression using this literal. Note that it
9142 -- is important to qualify the literal with its proper modular
9143 -- type since universal integer does not have the required
9144 -- range and also this is a left justified modular type,
9145 -- which is important in the big-endian case.
9146
9147 Rewrite (N,
9148 Unchecked_Convert_To (Typ,
9149 Make_Qualified_Expression (Loc,
9150 Subtype_Mark =>
9151 New_Occurrence_Of (Packed_Array_Impl_Type (Typ), Loc),
9152 Expression => Lit)));
9153
9154 Analyze_And_Resolve (N, Typ);
9155 return True;
9156 end;
9157 end;
9158 end;
9159
9160 exception
9161 when Not_Handled =>
9162 return False;
9163 end Packed_Array_Aggregate_Handled;
9164
9165 ----------------------------
9166 -- Has_Mutable_Components --
9167 ----------------------------
9168
9169 function Has_Mutable_Components (Typ : Entity_Id) return Boolean is
9170 Comp : Entity_Id;
9171 Ctyp : Entity_Id;
9172
9173 begin
9174 Comp := First_Component (Typ);
9175 while Present (Comp) loop
9176 Ctyp := Underlying_Type (Etype (Comp));
9177 if Is_Record_Type (Ctyp)
9178 and then Has_Discriminants (Ctyp)
9179 and then not Is_Constrained (Ctyp)
9180 then
9181 return True;
9182 end if;
9183
9184 Next_Component (Comp);
9185 end loop;
9186
9187 return False;
9188 end Has_Mutable_Components;
9189
9190 ------------------------------
9191 -- Initialize_Discriminants --
9192 ------------------------------
9193
9194 procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id) is
9195 Loc : constant Source_Ptr := Sloc (N);
9196 Bas : constant Entity_Id := Base_Type (Typ);
9197 Par : constant Entity_Id := Etype (Bas);
9198 Decl : constant Node_Id := Parent (Par);
9199 Ref : Node_Id;
9200
9201 begin
9202 if Is_Tagged_Type (Bas)
9203 and then Is_Derived_Type (Bas)
9204 and then Has_Discriminants (Par)
9205 and then Has_Discriminants (Bas)
9206 and then Number_Discriminants (Bas) /= Number_Discriminants (Par)
9207 and then Nkind (Decl) = N_Full_Type_Declaration
9208 and then Nkind (Type_Definition (Decl)) = N_Record_Definition
9209 and then
9210 Present (Variant_Part (Component_List (Type_Definition (Decl))))
9211 and then Nkind (N) /= N_Extension_Aggregate
9212 then
9213
9214 -- Call init proc to set discriminants.
9215 -- There should eventually be a special procedure for this ???
9216
9217 Ref := New_Occurrence_Of (Defining_Identifier (N), Loc);
9218 Insert_Actions_After (N,
9219 Build_Initialization_Call (Sloc (N), Ref, Typ));
9220 end if;
9221 end Initialize_Discriminants;
9222
9223 ----------------
9224 -- Must_Slide --
9225 ----------------
9226
9227 function Must_Slide
9228 (Aggr : Node_Id;
9229 Obj_Type : Entity_Id;
9230 Typ : Entity_Id) return Boolean
9231 is
9232 begin
9233 -- No sliding if the type of the object is not established yet, if it is
9234 -- an unconstrained type whose actual subtype comes from the aggregate,
9235 -- or if the two types are identical. If the aggregate contains only
9236 -- an Others_Clause it gets its type from the context and no sliding
9237 -- is involved either.
9238
9239 if not Is_Array_Type (Obj_Type) then
9240 return False;
9241
9242 elsif not Is_Constrained (Obj_Type) then
9243 return False;
9244
9245 elsif Typ = Obj_Type then
9246 return False;
9247
9248 elsif Is_Others_Aggregate (Aggr) then
9249 return False;
9250
9251 else
9252 -- Sliding can only occur along the first dimension
9253 -- If any the bounds of non-static sliding is required
9254 -- to force potential range checks.
9255
9256 declare
9257 Bounds1 : constant Range_Nodes :=
9258 Get_Index_Bounds (First_Index (Typ));
9259 Bounds2 : constant Range_Nodes :=
9260 Get_Index_Bounds (First_Index (Obj_Type));
9261
9262 begin
9263 if not Is_OK_Static_Expression (Bounds1.First) or else
9264 not Is_OK_Static_Expression (Bounds2.First) or else
9265 not Is_OK_Static_Expression (Bounds1.Last) or else
9266 not Is_OK_Static_Expression (Bounds2.Last)
9267 then
9268 return True;
9269
9270 else
9271 return Expr_Value (Bounds1.First) /= Expr_Value (Bounds2.First)
9272 or else
9273 Expr_Value (Bounds1.Last) /= Expr_Value (Bounds2.Last);
9274 end if;
9275 end;
9276 end if;
9277 end Must_Slide;
9278
9279 ---------------------
9280 -- Sort_Case_Table --
9281 ---------------------
9282
9283 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
9284 L : constant Int := Case_Table'First;
9285 U : constant Int := Case_Table'Last;
9286 K : Int;
9287 J : Int;
9288 T : Case_Bounds;
9289
9290 begin
9291 K := L;
9292 while K /= U loop
9293 T := Case_Table (K + 1);
9294
9295 J := K + 1;
9296 while J /= L
9297 and then Expr_Value (Case_Table (J - 1).Choice_Lo) >
9298 Expr_Value (T.Choice_Lo)
9299 loop
9300 Case_Table (J) := Case_Table (J - 1);
9301 J := J - 1;
9302 end loop;
9303
9304 Case_Table (J) := T;
9305 K := K + 1;
9306 end loop;
9307 end Sort_Case_Table;
9308
9309 ----------------------------
9310 -- Static_Array_Aggregate --
9311 ----------------------------
9312
9313 function Static_Array_Aggregate (N : Node_Id) return Boolean is
9314 function Is_Static_Component (Nod : Node_Id) return Boolean;
9315 -- Return True if Nod has a compile-time known value and can be passed
9316 -- as is to the back-end without further expansion.
9317
9318 ---------------------------
9319 -- Is_Static_Component --
9320 ---------------------------
9321
9322 function Is_Static_Component (Nod : Node_Id) return Boolean is
9323 begin
9324 if Nkind (Nod) in N_Integer_Literal | N_Real_Literal then
9325 return True;
9326
9327 elsif Is_Entity_Name (Nod)
9328 and then Present (Entity (Nod))
9329 and then Ekind (Entity (Nod)) = E_Enumeration_Literal
9330 then
9331 return True;
9332
9333 elsif Nkind (Nod) = N_Aggregate
9334 and then Compile_Time_Known_Aggregate (Nod)
9335 then
9336 return True;
9337
9338 else
9339 return False;
9340 end if;
9341 end Is_Static_Component;
9342
9343 -- Local variables
9344
9345 Bounds : constant Node_Id := Aggregate_Bounds (N);
9346 Typ : constant Entity_Id := Etype (N);
9347
9348 Agg : Node_Id;
9349 Expr : Node_Id;
9350 Lo : Node_Id;
9351 Hi : Node_Id;
9352
9353 -- Start of processing for Static_Array_Aggregate
9354
9355 begin
9356 if Is_Packed (Typ) or else Has_Discriminants (Component_Type (Typ)) then
9357 return False;
9358 end if;
9359
9360 if Present (Bounds)
9361 and then Nkind (Bounds) = N_Range
9362 and then Nkind (Low_Bound (Bounds)) = N_Integer_Literal
9363 and then Nkind (High_Bound (Bounds)) = N_Integer_Literal
9364 then
9365 Lo := Low_Bound (Bounds);
9366 Hi := High_Bound (Bounds);
9367
9368 if No (Component_Associations (N)) then
9369
9370 -- Verify that all components are static
9371
9372 Expr := First (Expressions (N));
9373 while Present (Expr) loop
9374 if not Is_Static_Component (Expr) then
9375 return False;
9376 end if;
9377
9378 Next (Expr);
9379 end loop;
9380
9381 return True;
9382
9383 else
9384 -- We allow only a single named association, either a static
9385 -- range or an others_clause, with a static expression.
9386
9387 Expr := First (Component_Associations (N));
9388
9389 if Present (Expressions (N)) then
9390 return False;
9391
9392 elsif Present (Next (Expr)) then
9393 return False;
9394
9395 elsif Present (Next (First (Choice_List (Expr)))) then
9396 return False;
9397
9398 else
9399 -- The aggregate is static if all components are literals,
9400 -- or else all its components are static aggregates for the
9401 -- component type. We also limit the size of a static aggregate
9402 -- to prevent runaway static expressions.
9403
9404 if not Is_Static_Component (Expression (Expr)) then
9405 return False;
9406 end if;
9407
9408 if not Aggr_Size_OK (N) then
9409 return False;
9410 end if;
9411
9412 -- Create a positional aggregate with the right number of
9413 -- copies of the expression.
9414
9415 Agg := Make_Aggregate (Sloc (N), New_List, No_List);
9416
9417 for I in UI_To_Int (Intval (Lo)) .. UI_To_Int (Intval (Hi))
9418 loop
9419 Append_To (Expressions (Agg), New_Copy (Expression (Expr)));
9420
9421 -- The copied expression must be analyzed and resolved.
9422 -- Besides setting the type, this ensures that static
9423 -- expressions are appropriately marked as such.
9424
9425 Analyze_And_Resolve
9426 (Last (Expressions (Agg)), Component_Type (Typ));
9427 end loop;
9428
9429 Set_Aggregate_Bounds (Agg, Bounds);
9430 Set_Etype (Agg, Typ);
9431 Set_Analyzed (Agg);
9432 Rewrite (N, Agg);
9433 Set_Compile_Time_Known_Aggregate (N);
9434
9435 return True;
9436 end if;
9437 end if;
9438
9439 else
9440 return False;
9441 end if;
9442 end Static_Array_Aggregate;
9443
9444 ----------------------------------
9445 -- Two_Dim_Packed_Array_Handled --
9446 ----------------------------------
9447
9448 function Two_Dim_Packed_Array_Handled (N : Node_Id) return Boolean is
9449 Loc : constant Source_Ptr := Sloc (N);
9450 Typ : constant Entity_Id := Etype (N);
9451 Ctyp : constant Entity_Id := Component_Type (Typ);
9452 Comp_Size : constant Int := UI_To_Int (Component_Size (Typ));
9453 Packed_Array : constant Entity_Id :=
9454 Packed_Array_Impl_Type (Base_Type (Typ));
9455
9456 One_Comp : Node_Id;
9457 -- Expression in original aggregate
9458
9459 One_Dim : Node_Id;
9460 -- One-dimensional subaggregate
9461
9462 begin
9463
9464 -- For now, only deal with cases where an integral number of elements
9465 -- fit in a single byte. This includes the most common boolean case.
9466
9467 if not (Comp_Size = 1 or else
9468 Comp_Size = 2 or else
9469 Comp_Size = 4)
9470 then
9471 return False;
9472 end if;
9473
9474 Convert_To_Positional (N, Handle_Bit_Packed => True);
9475
9476 -- Verify that all components are static
9477
9478 if Nkind (N) = N_Aggregate
9479 and then Compile_Time_Known_Aggregate (N)
9480 then
9481 null;
9482
9483 -- The aggregate may have been reanalyzed and converted already
9484
9485 elsif Nkind (N) /= N_Aggregate then
9486 return True;
9487
9488 -- If component associations remain, the aggregate is not static
9489
9490 elsif Present (Component_Associations (N)) then
9491 return False;
9492
9493 else
9494 One_Dim := First (Expressions (N));
9495 while Present (One_Dim) loop
9496 if Present (Component_Associations (One_Dim)) then
9497 return False;
9498 end if;
9499
9500 One_Comp := First (Expressions (One_Dim));
9501 while Present (One_Comp) loop
9502 if not Is_OK_Static_Expression (One_Comp) then
9503 return False;
9504 end if;
9505
9506 Next (One_Comp);
9507 end loop;
9508
9509 Next (One_Dim);
9510 end loop;
9511 end if;
9512
9513 -- Two-dimensional aggregate is now fully positional so pack one
9514 -- dimension to create a static one-dimensional array, and rewrite
9515 -- as an unchecked conversion to the original type.
9516
9517 declare
9518 Byte_Size : constant Int := UI_To_Int (Component_Size (Packed_Array));
9519 -- The packed array type is a byte array
9520
9521 Packed_Num : Nat;
9522 -- Number of components accumulated in current byte
9523
9524 Comps : List_Id;
9525 -- Assembled list of packed values for equivalent aggregate
9526
9527 Comp_Val : Uint;
9528 -- Integer value of component
9529
9530 Incr : Int;
9531 -- Step size for packing
9532
9533 Init_Shift : Int;
9534 -- Endian-dependent start position for packing
9535
9536 Shift : Int;
9537 -- Current insertion position
9538
9539 Val : Int;
9540 -- Component of packed array being assembled
9541
9542 begin
9543 Comps := New_List;
9544 Val := 0;
9545 Packed_Num := 0;
9546
9547 -- Account for endianness. See corresponding comment in
9548 -- Packed_Array_Aggregate_Handled concerning the following.
9549
9550 if Bytes_Big_Endian
9551 xor Debug_Flag_8
9552 xor Reverse_Storage_Order (Base_Type (Typ))
9553 then
9554 Init_Shift := Byte_Size - Comp_Size;
9555 Incr := -Comp_Size;
9556 else
9557 Init_Shift := 0;
9558 Incr := +Comp_Size;
9559 end if;
9560
9561 -- Iterate over each subaggregate
9562
9563 Shift := Init_Shift;
9564 One_Dim := First (Expressions (N));
9565 while Present (One_Dim) loop
9566 One_Comp := First (Expressions (One_Dim));
9567 while Present (One_Comp) loop
9568 if Packed_Num = Byte_Size / Comp_Size then
9569
9570 -- Byte is complete, add to list of expressions
9571
9572 Append (Make_Integer_Literal (Sloc (One_Dim), Val), Comps);
9573 Val := 0;
9574 Shift := Init_Shift;
9575 Packed_Num := 0;
9576
9577 else
9578 Comp_Val := Expr_Rep_Value (One_Comp);
9579
9580 -- Adjust for bias, and strip proper number of bits
9581
9582 if Has_Biased_Representation (Ctyp) then
9583 Comp_Val := Comp_Val - Expr_Value (Type_Low_Bound (Ctyp));
9584 end if;
9585
9586 Comp_Val := Comp_Val mod Uint_2 ** Comp_Size;
9587 Val := UI_To_Int (Val + Comp_Val * Uint_2 ** Shift);
9588 Shift := Shift + Incr;
9589 Next (One_Comp);
9590 Packed_Num := Packed_Num + 1;
9591 end if;
9592 end loop;
9593
9594 Next (One_Dim);
9595 end loop;
9596
9597 if Packed_Num > 0 then
9598
9599 -- Add final incomplete byte if present
9600
9601 Append (Make_Integer_Literal (Sloc (One_Dim), Val), Comps);
9602 end if;
9603
9604 Rewrite (N,
9605 Unchecked_Convert_To (Typ,
9606 Make_Qualified_Expression (Loc,
9607 Subtype_Mark => New_Occurrence_Of (Packed_Array, Loc),
9608 Expression => Make_Aggregate (Loc, Expressions => Comps))));
9609 Analyze_And_Resolve (N);
9610 return True;
9611 end;
9612 end Two_Dim_Packed_Array_Handled;
9613
9614 end Exp_Aggr;