[multiple changes]
[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) 1992-2009, Free Software Foundation, Inc. --
10 -- --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
20 -- --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
23 -- --
24 ------------------------------------------------------------------------------
25
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Debug; use Debug;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Expander; use Expander;
33 with Exp_Util; use Exp_Util;
34 with Exp_Ch3; use Exp_Ch3;
35 with Exp_Ch7; use Exp_Ch7;
36 with Exp_Ch9; use Exp_Ch9;
37 with Exp_Tss; use Exp_Tss;
38 with Fname; use Fname;
39 with Freeze; use Freeze;
40 with Itypes; use Itypes;
41 with Lib; use Lib;
42 with Namet; use Namet;
43 with Nmake; use Nmake;
44 with Nlists; use Nlists;
45 with Opt; use Opt;
46 with Restrict; use Restrict;
47 with Rident; use Rident;
48 with Rtsfind; use Rtsfind;
49 with Ttypes; use Ttypes;
50 with Sem; use Sem;
51 with Sem_Aux; use Sem_Aux;
52 with Sem_Ch3; use Sem_Ch3;
53 with Sem_Eval; use Sem_Eval;
54 with Sem_Res; use Sem_Res;
55 with Sem_Util; use Sem_Util;
56 with Sinfo; use Sinfo;
57 with Snames; use Snames;
58 with Stand; use Stand;
59 with Targparm; use Targparm;
60 with Tbuild; use Tbuild;
61 with Uintp; use Uintp;
62
63 package body Exp_Aggr is
64
65 type Case_Bounds is record
66 Choice_Lo : Node_Id;
67 Choice_Hi : Node_Id;
68 Choice_Node : Node_Id;
69 end record;
70
71 type Case_Table_Type is array (Nat range <>) of Case_Bounds;
72 -- Table type used by Check_Case_Choices procedure
73
74 function Must_Slide
75 (Obj_Type : Entity_Id;
76 Typ : Entity_Id) return Boolean;
77 -- A static array aggregate in an object declaration can in most cases be
78 -- expanded in place. The one exception is when the aggregate is given
79 -- with component associations that specify different bounds from those of
80 -- the type definition in the object declaration. In this pathological
81 -- case the aggregate must slide, and we must introduce an intermediate
82 -- temporary to hold it.
83 --
84 -- The same holds in an assignment to one-dimensional array of arrays,
85 -- when a component may be given with bounds that differ from those of the
86 -- component type.
87
88 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
89 -- Sort the Case Table using the Lower Bound of each Choice as the key.
90 -- A simple insertion sort is used since the number of choices in a case
91 -- statement of variant part will usually be small and probably in near
92 -- sorted order.
93
94 function Has_Default_Init_Comps (N : Node_Id) return Boolean;
95 -- N is an aggregate (record or array). Checks the presence of default
96 -- initialization (<>) in any component (Ada 2005: AI-287)
97
98 function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean;
99 -- Returns true if N is an aggregate used to initialize the components
100 -- of an statically allocated dispatch table.
101
102 ------------------------------------------------------
103 -- Local subprograms for Record Aggregate Expansion --
104 ------------------------------------------------------
105
106 procedure Expand_Record_Aggregate
107 (N : Node_Id;
108 Orig_Tag : Node_Id := Empty;
109 Parent_Expr : Node_Id := Empty);
110 -- This is the top level procedure for record aggregate expansion.
111 -- Expansion for record aggregates needs expand aggregates for tagged
112 -- record types. Specifically Expand_Record_Aggregate adds the Tag
113 -- field in front of the Component_Association list that was created
114 -- during resolution by Resolve_Record_Aggregate.
115 --
116 -- N is the record aggregate node.
117 -- Orig_Tag is the value of the Tag that has to be provided for this
118 -- specific aggregate. It carries the tag corresponding to the type
119 -- of the outermost aggregate during the recursive expansion
120 -- Parent_Expr is the ancestor part of the original extension
121 -- aggregate
122
123 procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id);
124 -- N is an N_Aggregate or an N_Extension_Aggregate. Typ is the type of the
125 -- aggregate (which can only be a record type, this procedure is only used
126 -- for record types). Transform the given aggregate into a sequence of
127 -- assignments performed component by component.
128
129 function Build_Record_Aggr_Code
130 (N : Node_Id;
131 Typ : Entity_Id;
132 Lhs : Node_Id;
133 Flist : Node_Id := Empty;
134 Obj : Entity_Id := Empty;
135 Is_Limited_Ancestor_Expansion : Boolean := False) return List_Id;
136 -- N is an N_Aggregate or an N_Extension_Aggregate. Typ is the type of the
137 -- aggregate. Target is an expression containing the location on which the
138 -- component by component assignments will take place. Returns the list of
139 -- assignments plus all other adjustments needed for tagged and controlled
140 -- types. Flist is an expression representing the finalization list on
141 -- which to attach the controlled components if any. Obj is present in the
142 -- object declaration and dynamic allocation cases, it contains an entity
143 -- that allows to know if the value being created needs to be attached to
144 -- the final list in case of pragma Finalize_Storage_Only.
145 --
146 -- ???
147 -- The meaning of the Obj formal is extremely unclear. *What* entity
148 -- should be passed? For the object declaration case we may guess that
149 -- this is the object being declared, but what about the allocator case?
150 --
151 -- Is_Limited_Ancestor_Expansion indicates that the function has been
152 -- called recursively to expand the limited ancestor to avoid copying it.
153
154 function Has_Mutable_Components (Typ : Entity_Id) return Boolean;
155 -- Return true if one of the component is of a discriminated type with
156 -- defaults. An aggregate for a type with mutable components must be
157 -- expanded into individual assignments.
158
159 procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id);
160 -- If the type of the aggregate is a type extension with renamed discrimi-
161 -- nants, we must initialize the hidden discriminants of the parent.
162 -- Otherwise, the target object must not be initialized. The discriminants
163 -- are initialized by calling the initialization procedure for the type.
164 -- This is incorrect if the initialization of other components has any
165 -- side effects. We restrict this call to the case where the parent type
166 -- has a variant part, because this is the only case where the hidden
167 -- discriminants are accessed, namely when calling discriminant checking
168 -- functions of the parent type, and when applying a stream attribute to
169 -- an object of the derived type.
170
171 -----------------------------------------------------
172 -- Local Subprograms for Array Aggregate Expansion --
173 -----------------------------------------------------
174
175 function Aggr_Size_OK (N : Node_Id; Typ : Entity_Id) return Boolean;
176 -- Very large static aggregates present problems to the back-end, and
177 -- are transformed into assignments and loops. This function verifies
178 -- that the total number of components of an aggregate is acceptable
179 -- for transformation into a purely positional static form. It is called
180 -- prior to calling Flatten.
181 -- This function also detects and warns about one-component aggregates
182 -- that appear in a non-static context. Even if the component value is
183 -- static, such an aggregate must be expanded into an assignment.
184
185 procedure Convert_Array_Aggr_In_Allocator
186 (Decl : Node_Id;
187 Aggr : Node_Id;
188 Target : Node_Id);
189 -- If the aggregate appears within an allocator and can be expanded in
190 -- place, this routine generates the individual assignments to components
191 -- of the designated object. This is an optimization over the general
192 -- case, where a temporary is first created on the stack and then used to
193 -- construct the allocated object on the heap.
194
195 procedure Convert_To_Positional
196 (N : Node_Id;
197 Max_Others_Replicate : Nat := 5;
198 Handle_Bit_Packed : Boolean := False);
199 -- If possible, convert named notation to positional notation. This
200 -- conversion is possible only in some static cases. If the conversion is
201 -- possible, then N is rewritten with the analyzed converted aggregate.
202 -- The parameter Max_Others_Replicate controls the maximum number of
203 -- values corresponding to an others choice that will be converted to
204 -- positional notation (the default of 5 is the normal limit, and reflects
205 -- the fact that normally the loop is better than a lot of separate
206 -- assignments). Note that this limit gets overridden in any case if
207 -- either of the restrictions No_Elaboration_Code or No_Implicit_Loops is
208 -- set. The parameter Handle_Bit_Packed is usually set False (since we do
209 -- not expect the back end to handle bit packed arrays, so the normal case
210 -- of conversion is pointless), but in the special case of a call from
211 -- Packed_Array_Aggregate_Handled, we set this parameter to True, since
212 -- these are cases we handle in there.
213
214 procedure Expand_Array_Aggregate (N : Node_Id);
215 -- This is the top-level routine to perform array aggregate expansion.
216 -- N is the N_Aggregate node to be expanded.
217
218 function Backend_Processing_Possible (N : Node_Id) return Boolean;
219 -- This function checks if array aggregate N can be processed directly
220 -- by the backend. If this is the case True is returned.
221
222 function Build_Array_Aggr_Code
223 (N : Node_Id;
224 Ctype : Entity_Id;
225 Index : Node_Id;
226 Into : Node_Id;
227 Scalar_Comp : Boolean;
228 Indices : List_Id := No_List;
229 Flist : Node_Id := Empty) return List_Id;
230 -- This recursive routine returns a list of statements containing the
231 -- loops and assignments that are needed for the expansion of the array
232 -- aggregate N.
233 --
234 -- N is the (sub-)aggregate node to be expanded into code. This node
235 -- has been fully analyzed, and its Etype is properly set.
236 --
237 -- Index is the index node corresponding to the array sub-aggregate N.
238 --
239 -- Into is the target expression into which we are copying the aggregate.
240 -- Note that this node may not have been analyzed yet, and so the Etype
241 -- field may not be set.
242 --
243 -- Scalar_Comp is True if the component type of the aggregate is scalar.
244 --
245 -- Indices is the current list of expressions used to index the
246 -- object we are writing into.
247 --
248 -- Flist is an expression representing the finalization list on which
249 -- to attach the controlled components if any.
250
251 function Number_Of_Choices (N : Node_Id) return Nat;
252 -- Returns the number of discrete choices (not including the others choice
253 -- if present) contained in (sub-)aggregate N.
254
255 function Late_Expansion
256 (N : Node_Id;
257 Typ : Entity_Id;
258 Target : Node_Id;
259 Flist : Node_Id := Empty;
260 Obj : Entity_Id := Empty) return List_Id;
261 -- N is a nested (record or array) aggregate that has been marked with
262 -- 'Delay_Expansion'. Typ is the expected type of the aggregate and Target
263 -- is a (duplicable) expression that will hold the result of the aggregate
264 -- expansion. Flist is the finalization list to be used to attach
265 -- controlled components. 'Obj' when non empty, carries the original
266 -- object being initialized in order to know if it needs to be attached to
267 -- the previous parameter which may not be the case in the case where
268 -- Finalize_Storage_Only is set. Basically this procedure is used to
269 -- implement top-down expansions of nested aggregates. This is necessary
270 -- for avoiding temporaries at each level as well as for propagating the
271 -- right internal finalization list.
272
273 function Make_OK_Assignment_Statement
274 (Sloc : Source_Ptr;
275 Name : Node_Id;
276 Expression : Node_Id) return Node_Id;
277 -- This is like Make_Assignment_Statement, except that Assignment_OK
278 -- is set in the left operand. All assignments built by this unit
279 -- use this routine. This is needed to deal with assignments to
280 -- initialized constants that are done in place.
281
282 function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean;
283 -- Given an array aggregate, this function handles the case of a packed
284 -- array aggregate with all constant values, where the aggregate can be
285 -- evaluated at compile time. If this is possible, then N is rewritten
286 -- to be its proper compile time value with all the components properly
287 -- assembled. The expression is analyzed and resolved and True is
288 -- returned. If this transformation is not possible, N is unchanged
289 -- and False is returned
290
291 function Safe_Slice_Assignment (N : Node_Id) return Boolean;
292 -- If a slice assignment has an aggregate with a single others_choice,
293 -- the assignment can be done in place even if bounds are not static,
294 -- by converting it into a loop over the discrete range of the slice.
295
296 ------------------
297 -- Aggr_Size_OK --
298 ------------------
299
300 function Aggr_Size_OK (N : Node_Id; Typ : Entity_Id) return Boolean is
301 Lo : Node_Id;
302 Hi : Node_Id;
303 Indx : Node_Id;
304 Siz : Int;
305 Lov : Uint;
306 Hiv : Uint;
307
308 -- The following constant determines the maximum size of an
309 -- array aggregate produced by converting named to positional
310 -- notation (e.g. from others clauses). This avoids running
311 -- away with attempts to convert huge aggregates, which hit
312 -- memory limits in the backend.
313
314 -- The normal limit is 5000, but we increase this limit to
315 -- 2**24 (about 16 million) if Restrictions (No_Elaboration_Code)
316 -- or Restrictions (No_Implicit_Loops) is specified, since in
317 -- either case, we are at risk of declaring the program illegal
318 -- because of this limit.
319
320 Max_Aggr_Size : constant Nat :=
321 5000 + (2 ** 24 - 5000) *
322 Boolean'Pos
323 (Restriction_Active (No_Elaboration_Code)
324 or else
325 Restriction_Active (No_Implicit_Loops));
326
327 function Component_Count (T : Entity_Id) return Int;
328 -- The limit is applied to the total number of components that the
329 -- aggregate will have, which is the number of static expressions
330 -- that will appear in the flattened array. This requires a recursive
331 -- computation of the number of scalar components of the structure.
332
333 ---------------------
334 -- Component_Count --
335 ---------------------
336
337 function Component_Count (T : Entity_Id) return Int is
338 Res : Int := 0;
339 Comp : Entity_Id;
340
341 begin
342 if Is_Scalar_Type (T) then
343 return 1;
344
345 elsif Is_Record_Type (T) then
346 Comp := First_Component (T);
347 while Present (Comp) loop
348 Res := Res + Component_Count (Etype (Comp));
349 Next_Component (Comp);
350 end loop;
351
352 return Res;
353
354 elsif Is_Array_Type (T) then
355 declare
356 Lo : constant Node_Id :=
357 Type_Low_Bound (Etype (First_Index (T)));
358 Hi : constant Node_Id :=
359 Type_High_Bound (Etype (First_Index (T)));
360
361 Siz : constant Int := Component_Count (Component_Type (T));
362
363 begin
364 if not Compile_Time_Known_Value (Lo)
365 or else not Compile_Time_Known_Value (Hi)
366 then
367 return 0;
368 else
369 return
370 Siz * UI_To_Int (Expr_Value (Hi) - Expr_Value (Lo) + 1);
371 end if;
372 end;
373
374 else
375 -- Can only be a null for an access type
376
377 return 1;
378 end if;
379 end Component_Count;
380
381 -- Start of processing for Aggr_Size_OK
382
383 begin
384 Siz := Component_Count (Component_Type (Typ));
385
386 Indx := First_Index (Typ);
387 while Present (Indx) loop
388 Lo := Type_Low_Bound (Etype (Indx));
389 Hi := Type_High_Bound (Etype (Indx));
390
391 -- Bounds need to be known at compile time
392
393 if not Compile_Time_Known_Value (Lo)
394 or else not Compile_Time_Known_Value (Hi)
395 then
396 return False;
397 end if;
398
399 Lov := Expr_Value (Lo);
400 Hiv := Expr_Value (Hi);
401
402 -- A flat array is always safe
403
404 if Hiv < Lov then
405 return True;
406 end if;
407
408 -- One-component aggregates are suspicious, and if the context type
409 -- is an object declaration with non-static bounds it will trip gcc;
410 -- such an aggregate must be expanded into a single assignment.
411
412 if Hiv = Lov
413 and then Nkind (Parent (N)) = N_Object_Declaration
414 then
415 declare
416 Index_Type : constant Entity_Id :=
417 Etype
418 (First_Index
419 (Etype (Defining_Identifier (Parent (N)))));
420 Indx : Node_Id;
421
422 begin
423 if not Compile_Time_Known_Value (Type_Low_Bound (Index_Type))
424 or else not Compile_Time_Known_Value
425 (Type_High_Bound (Index_Type))
426 then
427 if Present (Component_Associations (N)) then
428 Indx :=
429 First (Choices (First (Component_Associations (N))));
430 if Is_Entity_Name (Indx)
431 and then not Is_Type (Entity (Indx))
432 then
433 Error_Msg_N
434 ("single component aggregate in non-static context?",
435 Indx);
436 Error_Msg_N ("\maybe subtype name was meant?", Indx);
437 end if;
438 end if;
439
440 return False;
441 end if;
442 end;
443 end if;
444
445 declare
446 Rng : constant Uint := Hiv - Lov + 1;
447
448 begin
449 -- Check if size is too large
450
451 if not UI_Is_In_Int_Range (Rng) then
452 return False;
453 end if;
454
455 Siz := Siz * UI_To_Int (Rng);
456 end;
457
458 if Siz <= 0
459 or else Siz > Max_Aggr_Size
460 then
461 return False;
462 end if;
463
464 -- Bounds must be in integer range, for later array construction
465
466 if not UI_Is_In_Int_Range (Lov)
467 or else
468 not UI_Is_In_Int_Range (Hiv)
469 then
470 return False;
471 end if;
472
473 Next_Index (Indx);
474 end loop;
475
476 return True;
477 end Aggr_Size_OK;
478
479 ---------------------------------
480 -- Backend_Processing_Possible --
481 ---------------------------------
482
483 -- Backend processing by Gigi/gcc is possible only if all the following
484 -- conditions are met:
485
486 -- 1. N is fully positional
487
488 -- 2. N is not a bit-packed array aggregate;
489
490 -- 3. The size of N's array type must be known at compile time. Note
491 -- that this implies that the component size is also known
492
493 -- 4. The array type of N does not follow the Fortran layout convention
494 -- or if it does it must be 1 dimensional.
495
496 -- 5. The array component type may not be tagged (which could necessitate
497 -- reassignment of proper tags).
498
499 -- 6. The array component type must not have unaligned bit components
500
501 -- 7. None of the components of the aggregate may be bit unaligned
502 -- components.
503
504 -- 8. There cannot be delayed components, since we do not know enough
505 -- at this stage to know if back end processing is possible.
506
507 -- 9. There cannot be any discriminated record components, since the
508 -- back end cannot handle this complex case.
509
510 -- 10. No controlled actions need to be generated for components
511
512 -- 11. The backend is a No_VM backend and the array has aliased components
513
514 function Backend_Processing_Possible (N : Node_Id) return Boolean is
515 Typ : constant Entity_Id := Etype (N);
516 -- Typ is the correct constrained array subtype of the aggregate
517
518 function Component_Check (N : Node_Id; Index : Node_Id) return Boolean;
519 -- This routine checks components of aggregate N, enforcing checks
520 -- 1, 7, 8, and 9. In the multi-dimensional case, these checks are
521 -- performed on subaggregates. The Index value is the current index
522 -- being checked in the multi-dimensional case.
523
524 ---------------------
525 -- Component_Check --
526 ---------------------
527
528 function Component_Check (N : Node_Id; Index : Node_Id) return Boolean is
529 Expr : Node_Id;
530
531 begin
532 -- Checks 1: (no component associations)
533
534 if Present (Component_Associations (N)) then
535 return False;
536 end if;
537
538 -- Checks on components
539
540 -- Recurse to check subaggregates, which may appear in qualified
541 -- expressions. If delayed, the front-end will have to expand.
542 -- If the component is a discriminated record, treat as non-static,
543 -- as the back-end cannot handle this properly.
544
545 Expr := First (Expressions (N));
546 while Present (Expr) loop
547
548 -- Checks 8: (no delayed components)
549
550 if Is_Delayed_Aggregate (Expr) then
551 return False;
552 end if;
553
554 -- Checks 9: (no discriminated records)
555
556 if Present (Etype (Expr))
557 and then Is_Record_Type (Etype (Expr))
558 and then Has_Discriminants (Etype (Expr))
559 then
560 return False;
561 end if;
562
563 -- Checks 7. Component must not be bit aligned component
564
565 if Possible_Bit_Aligned_Component (Expr) then
566 return False;
567 end if;
568
569 -- Recursion to following indexes for multiple dimension case
570
571 if Present (Next_Index (Index))
572 and then not Component_Check (Expr, Next_Index (Index))
573 then
574 return False;
575 end if;
576
577 -- All checks for that component finished, on to next
578
579 Next (Expr);
580 end loop;
581
582 return True;
583 end Component_Check;
584
585 -- Start of processing for Backend_Processing_Possible
586
587 begin
588 -- Checks 2 (array not bit packed) and 10 (no controlled actions)
589
590 if Is_Bit_Packed_Array (Typ) or else Needs_Finalization (Typ) then
591 return False;
592 end if;
593
594 -- If component is limited, aggregate must be expanded because each
595 -- component assignment must be built in place.
596
597 if Is_Inherently_Limited_Type (Component_Type (Typ)) then
598 return False;
599 end if;
600
601 -- Checks 4 (array must not be multi-dimensional Fortran case)
602
603 if Convention (Typ) = Convention_Fortran
604 and then Number_Dimensions (Typ) > 1
605 then
606 return False;
607 end if;
608
609 -- Checks 3 (size of array must be known at compile time)
610
611 if not Size_Known_At_Compile_Time (Typ) then
612 return False;
613 end if;
614
615 -- Checks on components
616
617 if not Component_Check (N, First_Index (Typ)) then
618 return False;
619 end if;
620
621 -- Checks 5 (if the component type is tagged, then we may need to do
622 -- tag adjustments. Perhaps this should be refined to check for any
623 -- component associations that actually need tag adjustment, similar
624 -- to the test in Component_Not_OK_For_Backend for record aggregates
625 -- with tagged components, but not clear whether it's worthwhile ???;
626 -- in the case of the JVM, object tags are handled implicitly)
627
628 if Is_Tagged_Type (Component_Type (Typ))
629 and then Tagged_Type_Expansion
630 then
631 return False;
632 end if;
633
634 -- Checks 6 (component type must not have bit aligned components)
635
636 if Type_May_Have_Bit_Aligned_Components (Component_Type (Typ)) then
637 return False;
638 end if;
639
640 -- Checks 11: Array aggregates with aliased components are currently
641 -- not well supported by the VM backend; disable temporarily this
642 -- backend processing until it is definitely supported.
643
644 if VM_Target /= No_VM
645 and then Has_Aliased_Components (Base_Type (Typ))
646 then
647 return False;
648 end if;
649
650 -- Backend processing is possible
651
652 Set_Size_Known_At_Compile_Time (Etype (N), True);
653 return True;
654 end Backend_Processing_Possible;
655
656 ---------------------------
657 -- Build_Array_Aggr_Code --
658 ---------------------------
659
660 -- The code that we generate from a one dimensional aggregate is
661
662 -- 1. If the sub-aggregate contains discrete choices we
663
664 -- (a) Sort the discrete choices
665
666 -- (b) Otherwise for each discrete choice that specifies a range we
667 -- emit a loop. If a range specifies a maximum of three values, or
668 -- we are dealing with an expression we emit a sequence of
669 -- assignments instead of a loop.
670
671 -- (c) Generate the remaining loops to cover the others choice if any
672
673 -- 2. If the aggregate contains positional elements we
674
675 -- (a) translate the positional elements in a series of assignments
676
677 -- (b) Generate a final loop to cover the others choice if any.
678 -- Note that this final loop has to be a while loop since the case
679
680 -- L : Integer := Integer'Last;
681 -- H : Integer := Integer'Last;
682 -- A : array (L .. H) := (1, others =>0);
683
684 -- cannot be handled by a for loop. Thus for the following
685
686 -- array (L .. H) := (.. positional elements.., others =>E);
687
688 -- we always generate something like:
689
690 -- J : Index_Type := Index_Of_Last_Positional_Element;
691 -- while J < H loop
692 -- J := Index_Base'Succ (J)
693 -- Tmp (J) := E;
694 -- end loop;
695
696 function Build_Array_Aggr_Code
697 (N : Node_Id;
698 Ctype : Entity_Id;
699 Index : Node_Id;
700 Into : Node_Id;
701 Scalar_Comp : Boolean;
702 Indices : List_Id := No_List;
703 Flist : Node_Id := Empty) return List_Id
704 is
705 Loc : constant Source_Ptr := Sloc (N);
706 Index_Base : constant Entity_Id := Base_Type (Etype (Index));
707 Index_Base_L : constant Node_Id := Type_Low_Bound (Index_Base);
708 Index_Base_H : constant Node_Id := Type_High_Bound (Index_Base);
709
710 function Add (Val : Int; To : Node_Id) return Node_Id;
711 -- Returns an expression where Val is added to expression To, unless
712 -- To+Val is provably out of To's base type range. To must be an
713 -- already analyzed expression.
714
715 function Empty_Range (L, H : Node_Id) return Boolean;
716 -- Returns True if the range defined by L .. H is certainly empty
717
718 function Equal (L, H : Node_Id) return Boolean;
719 -- Returns True if L = H for sure
720
721 function Index_Base_Name return Node_Id;
722 -- Returns a new reference to the index type name
723
724 function Gen_Assign (Ind : Node_Id; Expr : Node_Id) return List_Id;
725 -- Ind must be a side-effect free expression. If the input aggregate
726 -- N to Build_Loop contains no sub-aggregates, then this function
727 -- returns the assignment statement:
728 --
729 -- Into (Indices, Ind) := Expr;
730 --
731 -- Otherwise we call Build_Code recursively
732 --
733 -- Ada 2005 (AI-287): In case of default initialized component, Expr
734 -- is empty and we generate a call to the corresponding IP subprogram.
735
736 function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id;
737 -- Nodes L and H must be side-effect free expressions.
738 -- If the input aggregate N to Build_Loop contains no sub-aggregates,
739 -- This routine returns the for loop statement
740 --
741 -- for J in Index_Base'(L) .. Index_Base'(H) loop
742 -- Into (Indices, J) := Expr;
743 -- end loop;
744 --
745 -- Otherwise we call Build_Code recursively.
746 -- As an optimization if the loop covers 3 or less scalar elements we
747 -- generate a sequence of assignments.
748
749 function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id;
750 -- Nodes L and H must be side-effect free expressions.
751 -- If the input aggregate N to Build_Loop contains no sub-aggregates,
752 -- This routine returns the while loop statement
753 --
754 -- J : Index_Base := L;
755 -- while J < H loop
756 -- J := Index_Base'Succ (J);
757 -- Into (Indices, J) := Expr;
758 -- end loop;
759 --
760 -- Otherwise we call Build_Code recursively
761
762 function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean;
763 function Local_Expr_Value (E : Node_Id) return Uint;
764 -- These two Local routines are used to replace the corresponding ones
765 -- in sem_eval because while processing the bounds of an aggregate with
766 -- discrete choices whose index type is an enumeration, we build static
767 -- expressions not recognized by Compile_Time_Known_Value as such since
768 -- they have not yet been analyzed and resolved. All the expressions in
769 -- question are things like Index_Base_Name'Val (Const) which we can
770 -- easily recognize as being constant.
771
772 ---------
773 -- Add --
774 ---------
775
776 function Add (Val : Int; To : Node_Id) return Node_Id is
777 Expr_Pos : Node_Id;
778 Expr : Node_Id;
779 To_Pos : Node_Id;
780 U_To : Uint;
781 U_Val : constant Uint := UI_From_Int (Val);
782
783 begin
784 -- Note: do not try to optimize the case of Val = 0, because
785 -- we need to build a new node with the proper Sloc value anyway.
786
787 -- First test if we can do constant folding
788
789 if Local_Compile_Time_Known_Value (To) then
790 U_To := Local_Expr_Value (To) + Val;
791
792 -- Determine if our constant is outside the range of the index.
793 -- If so return an Empty node. This empty node will be caught
794 -- by Empty_Range below.
795
796 if Compile_Time_Known_Value (Index_Base_L)
797 and then U_To < Expr_Value (Index_Base_L)
798 then
799 return Empty;
800
801 elsif Compile_Time_Known_Value (Index_Base_H)
802 and then U_To > Expr_Value (Index_Base_H)
803 then
804 return Empty;
805 end if;
806
807 Expr_Pos := Make_Integer_Literal (Loc, U_To);
808 Set_Is_Static_Expression (Expr_Pos);
809
810 if not Is_Enumeration_Type (Index_Base) then
811 Expr := Expr_Pos;
812
813 -- If we are dealing with enumeration return
814 -- Index_Base'Val (Expr_Pos)
815
816 else
817 Expr :=
818 Make_Attribute_Reference
819 (Loc,
820 Prefix => Index_Base_Name,
821 Attribute_Name => Name_Val,
822 Expressions => New_List (Expr_Pos));
823 end if;
824
825 return Expr;
826 end if;
827
828 -- If we are here no constant folding possible
829
830 if not Is_Enumeration_Type (Index_Base) then
831 Expr :=
832 Make_Op_Add (Loc,
833 Left_Opnd => Duplicate_Subexpr (To),
834 Right_Opnd => Make_Integer_Literal (Loc, U_Val));
835
836 -- If we are dealing with enumeration return
837 -- Index_Base'Val (Index_Base'Pos (To) + Val)
838
839 else
840 To_Pos :=
841 Make_Attribute_Reference
842 (Loc,
843 Prefix => Index_Base_Name,
844 Attribute_Name => Name_Pos,
845 Expressions => New_List (Duplicate_Subexpr (To)));
846
847 Expr_Pos :=
848 Make_Op_Add (Loc,
849 Left_Opnd => To_Pos,
850 Right_Opnd => Make_Integer_Literal (Loc, U_Val));
851
852 Expr :=
853 Make_Attribute_Reference
854 (Loc,
855 Prefix => Index_Base_Name,
856 Attribute_Name => Name_Val,
857 Expressions => New_List (Expr_Pos));
858 end if;
859
860 return Expr;
861 end Add;
862
863 -----------------
864 -- Empty_Range --
865 -----------------
866
867 function Empty_Range (L, H : Node_Id) return Boolean is
868 Is_Empty : Boolean := False;
869 Low : Node_Id;
870 High : Node_Id;
871
872 begin
873 -- First check if L or H were already detected as overflowing the
874 -- index base range type by function Add above. If this is so Add
875 -- returns the empty node.
876
877 if No (L) or else No (H) then
878 return True;
879 end if;
880
881 for J in 1 .. 3 loop
882 case J is
883
884 -- L > H range is empty
885
886 when 1 =>
887 Low := L;
888 High := H;
889
890 -- B_L > H range must be empty
891
892 when 2 =>
893 Low := Index_Base_L;
894 High := H;
895
896 -- L > B_H range must be empty
897
898 when 3 =>
899 Low := L;
900 High := Index_Base_H;
901 end case;
902
903 if Local_Compile_Time_Known_Value (Low)
904 and then Local_Compile_Time_Known_Value (High)
905 then
906 Is_Empty :=
907 UI_Gt (Local_Expr_Value (Low), Local_Expr_Value (High));
908 end if;
909
910 exit when Is_Empty;
911 end loop;
912
913 return Is_Empty;
914 end Empty_Range;
915
916 -----------
917 -- Equal --
918 -----------
919
920 function Equal (L, H : Node_Id) return Boolean is
921 begin
922 if L = H then
923 return True;
924
925 elsif Local_Compile_Time_Known_Value (L)
926 and then Local_Compile_Time_Known_Value (H)
927 then
928 return UI_Eq (Local_Expr_Value (L), Local_Expr_Value (H));
929 end if;
930
931 return False;
932 end Equal;
933
934 ----------------
935 -- Gen_Assign --
936 ----------------
937
938 function Gen_Assign (Ind : Node_Id; Expr : Node_Id) return List_Id is
939 L : constant List_Id := New_List;
940 F : Entity_Id;
941 A : Node_Id;
942
943 New_Indices : List_Id;
944 Indexed_Comp : Node_Id;
945 Expr_Q : Node_Id;
946 Comp_Type : Entity_Id := Empty;
947
948 function Add_Loop_Actions (Lis : List_Id) return List_Id;
949 -- Collect insert_actions generated in the construction of a
950 -- loop, and prepend them to the sequence of assignments to
951 -- complete the eventual body of the loop.
952
953 ----------------------
954 -- Add_Loop_Actions --
955 ----------------------
956
957 function Add_Loop_Actions (Lis : List_Id) return List_Id is
958 Res : List_Id;
959
960 begin
961 -- Ada 2005 (AI-287): Do nothing else in case of default
962 -- initialized component.
963
964 if No (Expr) then
965 return Lis;
966
967 elsif Nkind (Parent (Expr)) = N_Component_Association
968 and then Present (Loop_Actions (Parent (Expr)))
969 then
970 Append_List (Lis, Loop_Actions (Parent (Expr)));
971 Res := Loop_Actions (Parent (Expr));
972 Set_Loop_Actions (Parent (Expr), No_List);
973 return Res;
974
975 else
976 return Lis;
977 end if;
978 end Add_Loop_Actions;
979
980 -- Start of processing for Gen_Assign
981
982 begin
983 if No (Indices) then
984 New_Indices := New_List;
985 else
986 New_Indices := New_Copy_List_Tree (Indices);
987 end if;
988
989 Append_To (New_Indices, Ind);
990
991 if Present (Flist) then
992 F := New_Copy_Tree (Flist);
993
994 elsif Present (Etype (N)) and then Needs_Finalization (Etype (N)) then
995 if Is_Entity_Name (Into)
996 and then Present (Scope (Entity (Into)))
997 then
998 F := Find_Final_List (Scope (Entity (Into)));
999 else
1000 F := Find_Final_List (Current_Scope);
1001 end if;
1002 else
1003 F := Empty;
1004 end if;
1005
1006 if Present (Next_Index (Index)) then
1007 return
1008 Add_Loop_Actions (
1009 Build_Array_Aggr_Code
1010 (N => Expr,
1011 Ctype => Ctype,
1012 Index => Next_Index (Index),
1013 Into => Into,
1014 Scalar_Comp => Scalar_Comp,
1015 Indices => New_Indices,
1016 Flist => F));
1017 end if;
1018
1019 -- If we get here then we are at a bottom-level (sub-)aggregate
1020
1021 Indexed_Comp :=
1022 Checks_Off
1023 (Make_Indexed_Component (Loc,
1024 Prefix => New_Copy_Tree (Into),
1025 Expressions => New_Indices));
1026
1027 Set_Assignment_OK (Indexed_Comp);
1028
1029 -- Ada 2005 (AI-287): In case of default initialized component, Expr
1030 -- is not present (and therefore we also initialize Expr_Q to empty).
1031
1032 if No (Expr) then
1033 Expr_Q := Empty;
1034 elsif Nkind (Expr) = N_Qualified_Expression then
1035 Expr_Q := Expression (Expr);
1036 else
1037 Expr_Q := Expr;
1038 end if;
1039
1040 if Present (Etype (N))
1041 and then Etype (N) /= Any_Composite
1042 then
1043 Comp_Type := Component_Type (Etype (N));
1044 pragma Assert (Comp_Type = Ctype); -- AI-287
1045
1046 elsif Present (Next (First (New_Indices))) then
1047
1048 -- Ada 2005 (AI-287): Do nothing in case of default initialized
1049 -- component because we have received the component type in
1050 -- the formal parameter Ctype.
1051
1052 -- ??? Some assert pragmas have been added to check if this new
1053 -- formal can be used to replace this code in all cases.
1054
1055 if Present (Expr) then
1056
1057 -- This is a multidimensional array. Recover the component
1058 -- type from the outermost aggregate, because subaggregates
1059 -- do not have an assigned type.
1060
1061 declare
1062 P : Node_Id;
1063
1064 begin
1065 P := Parent (Expr);
1066 while Present (P) loop
1067 if Nkind (P) = N_Aggregate
1068 and then Present (Etype (P))
1069 then
1070 Comp_Type := Component_Type (Etype (P));
1071 exit;
1072
1073 else
1074 P := Parent (P);
1075 end if;
1076 end loop;
1077
1078 pragma Assert (Comp_Type = Ctype); -- AI-287
1079 end;
1080 end if;
1081 end if;
1082
1083 -- Ada 2005 (AI-287): We only analyze the expression in case of non-
1084 -- default initialized components (otherwise Expr_Q is not present).
1085
1086 if Present (Expr_Q)
1087 and then Nkind_In (Expr_Q, N_Aggregate, N_Extension_Aggregate)
1088 then
1089 -- At this stage the Expression may not have been analyzed yet
1090 -- because the array aggregate code has not been updated to use
1091 -- the Expansion_Delayed flag and avoid analysis altogether to
1092 -- solve the same problem (see Resolve_Aggr_Expr). So let us do
1093 -- the analysis of non-array aggregates now in order to get the
1094 -- value of Expansion_Delayed flag for the inner aggregate ???
1095
1096 if Present (Comp_Type) and then not Is_Array_Type (Comp_Type) then
1097 Analyze_And_Resolve (Expr_Q, Comp_Type);
1098 end if;
1099
1100 if Is_Delayed_Aggregate (Expr_Q) then
1101
1102 -- This is either a subaggregate of a multidimentional array,
1103 -- or a component of an array type whose component type is
1104 -- also an array. In the latter case, the expression may have
1105 -- component associations that provide different bounds from
1106 -- those of the component type, and sliding must occur. Instead
1107 -- of decomposing the current aggregate assignment, force the
1108 -- re-analysis of the assignment, so that a temporary will be
1109 -- generated in the usual fashion, and sliding will take place.
1110
1111 if Nkind (Parent (N)) = N_Assignment_Statement
1112 and then Is_Array_Type (Comp_Type)
1113 and then Present (Component_Associations (Expr_Q))
1114 and then Must_Slide (Comp_Type, Etype (Expr_Q))
1115 then
1116 Set_Expansion_Delayed (Expr_Q, False);
1117 Set_Analyzed (Expr_Q, False);
1118
1119 else
1120 return
1121 Add_Loop_Actions (
1122 Late_Expansion (
1123 Expr_Q, Etype (Expr_Q), Indexed_Comp, F));
1124 end if;
1125 end if;
1126 end if;
1127
1128 -- Ada 2005 (AI-287): In case of default initialized component, call
1129 -- the initialization subprogram associated with the component type.
1130 -- If the component type is an access type, add an explicit null
1131 -- assignment, because for the back-end there is an initialization
1132 -- present for the whole aggregate, and no default initialization
1133 -- will take place.
1134
1135 -- In addition, if the component type is controlled, we must call
1136 -- its Initialize procedure explicitly, because there is no explicit
1137 -- object creation that will invoke it otherwise.
1138
1139 if No (Expr) then
1140 if Present (Base_Init_Proc (Base_Type (Ctype)))
1141 or else Has_Task (Base_Type (Ctype))
1142 then
1143 Append_List_To (L,
1144 Build_Initialization_Call (Loc,
1145 Id_Ref => Indexed_Comp,
1146 Typ => Ctype,
1147 With_Default_Init => True));
1148
1149 elsif Is_Access_Type (Ctype) then
1150 Append_To (L,
1151 Make_Assignment_Statement (Loc,
1152 Name => Indexed_Comp,
1153 Expression => Make_Null (Loc)));
1154 end if;
1155
1156 if Needs_Finalization (Ctype) then
1157 Append_List_To (L,
1158 Make_Init_Call (
1159 Ref => New_Copy_Tree (Indexed_Comp),
1160 Typ => Ctype,
1161 Flist_Ref => Find_Final_List (Current_Scope),
1162 With_Attach => Make_Integer_Literal (Loc, 1)));
1163 end if;
1164
1165 else
1166 -- Now generate the assignment with no associated controlled
1167 -- actions since the target of the assignment may not have been
1168 -- initialized, it is not possible to Finalize it as expected by
1169 -- normal controlled assignment. The rest of the controlled
1170 -- actions are done manually with the proper finalization list
1171 -- coming from the context.
1172
1173 A :=
1174 Make_OK_Assignment_Statement (Loc,
1175 Name => Indexed_Comp,
1176 Expression => New_Copy_Tree (Expr));
1177
1178 if Present (Comp_Type) and then Needs_Finalization (Comp_Type) then
1179 Set_No_Ctrl_Actions (A);
1180
1181 -- If this is an aggregate for an array of arrays, each
1182 -- sub-aggregate will be expanded as well, and even with
1183 -- No_Ctrl_Actions the assignments of inner components will
1184 -- require attachment in their assignments to temporaries.
1185 -- These temporaries must be finalized for each subaggregate,
1186 -- to prevent multiple attachments of the same temporary
1187 -- location to same finalization chain (and consequently
1188 -- circular lists). To ensure that finalization takes place
1189 -- for each subaggregate we wrap the assignment in a block.
1190
1191 if Is_Array_Type (Comp_Type)
1192 and then Nkind (Expr) = N_Aggregate
1193 then
1194 A :=
1195 Make_Block_Statement (Loc,
1196 Handled_Statement_Sequence =>
1197 Make_Handled_Sequence_Of_Statements (Loc,
1198 Statements => New_List (A)));
1199 end if;
1200 end if;
1201
1202 Append_To (L, A);
1203
1204 -- Adjust the tag if tagged (because of possible view
1205 -- conversions), unless compiling for a VM where
1206 -- tags are implicit.
1207
1208 if Present (Comp_Type)
1209 and then Is_Tagged_Type (Comp_Type)
1210 and then Tagged_Type_Expansion
1211 then
1212 A :=
1213 Make_OK_Assignment_Statement (Loc,
1214 Name =>
1215 Make_Selected_Component (Loc,
1216 Prefix => New_Copy_Tree (Indexed_Comp),
1217 Selector_Name =>
1218 New_Reference_To
1219 (First_Tag_Component (Comp_Type), Loc)),
1220
1221 Expression =>
1222 Unchecked_Convert_To (RTE (RE_Tag),
1223 New_Reference_To
1224 (Node (First_Elmt (Access_Disp_Table (Comp_Type))),
1225 Loc)));
1226
1227 Append_To (L, A);
1228 end if;
1229
1230 -- Adjust and attach the component to the proper final list, which
1231 -- can be the controller of the outer record object or the final
1232 -- list associated with the scope.
1233
1234 -- If the component is itself an array of controlled types, whose
1235 -- value is given by a sub-aggregate, then the attach calls have
1236 -- been generated when individual subcomponent are assigned, and
1237 -- must not be done again to prevent malformed finalization chains
1238 -- (see comments above, concerning the creation of a block to hold
1239 -- inner finalization actions).
1240
1241 if Present (Comp_Type)
1242 and then Needs_Finalization (Comp_Type)
1243 and then not Is_Limited_Type (Comp_Type)
1244 and then not
1245 (Is_Array_Type (Comp_Type)
1246 and then Is_Controlled (Component_Type (Comp_Type))
1247 and then Nkind (Expr) = N_Aggregate)
1248 then
1249 Append_List_To (L,
1250 Make_Adjust_Call (
1251 Ref => New_Copy_Tree (Indexed_Comp),
1252 Typ => Comp_Type,
1253 Flist_Ref => F,
1254 With_Attach => Make_Integer_Literal (Loc, 1)));
1255 end if;
1256 end if;
1257
1258 return Add_Loop_Actions (L);
1259 end Gen_Assign;
1260
1261 --------------
1262 -- Gen_Loop --
1263 --------------
1264
1265 function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id is
1266 L_J : Node_Id;
1267
1268 L_L : Node_Id;
1269 -- Index_Base'(L)
1270
1271 L_H : Node_Id;
1272 -- Index_Base'(H)
1273
1274 L_Range : Node_Id;
1275 -- Index_Base'(L) .. Index_Base'(H)
1276
1277 L_Iteration_Scheme : Node_Id;
1278 -- L_J in Index_Base'(L) .. Index_Base'(H)
1279
1280 L_Body : List_Id;
1281 -- The statements to execute in the loop
1282
1283 S : constant List_Id := New_List;
1284 -- List of statements
1285
1286 Tcopy : Node_Id;
1287 -- Copy of expression tree, used for checking purposes
1288
1289 begin
1290 -- If loop bounds define an empty range return the null statement
1291
1292 if Empty_Range (L, H) then
1293 Append_To (S, Make_Null_Statement (Loc));
1294
1295 -- Ada 2005 (AI-287): Nothing else need to be done in case of
1296 -- default initialized component.
1297
1298 if No (Expr) then
1299 null;
1300
1301 else
1302 -- The expression must be type-checked even though no component
1303 -- of the aggregate will have this value. This is done only for
1304 -- actual components of the array, not for subaggregates. Do
1305 -- the check on a copy, because the expression may be shared
1306 -- among several choices, some of which might be non-null.
1307
1308 if Present (Etype (N))
1309 and then Is_Array_Type (Etype (N))
1310 and then No (Next_Index (Index))
1311 then
1312 Expander_Mode_Save_And_Set (False);
1313 Tcopy := New_Copy_Tree (Expr);
1314 Set_Parent (Tcopy, N);
1315 Analyze_And_Resolve (Tcopy, Component_Type (Etype (N)));
1316 Expander_Mode_Restore;
1317 end if;
1318 end if;
1319
1320 return S;
1321
1322 -- If loop bounds are the same then generate an assignment
1323
1324 elsif Equal (L, H) then
1325 return Gen_Assign (New_Copy_Tree (L), Expr);
1326
1327 -- If H - L <= 2 then generate a sequence of assignments when we are
1328 -- processing the bottom most aggregate and it contains scalar
1329 -- components.
1330
1331 elsif No (Next_Index (Index))
1332 and then Scalar_Comp
1333 and then Local_Compile_Time_Known_Value (L)
1334 and then Local_Compile_Time_Known_Value (H)
1335 and then Local_Expr_Value (H) - Local_Expr_Value (L) <= 2
1336 then
1337
1338 Append_List_To (S, Gen_Assign (New_Copy_Tree (L), Expr));
1339 Append_List_To (S, Gen_Assign (Add (1, To => L), Expr));
1340
1341 if Local_Expr_Value (H) - Local_Expr_Value (L) = 2 then
1342 Append_List_To (S, Gen_Assign (Add (2, To => L), Expr));
1343 end if;
1344
1345 return S;
1346 end if;
1347
1348 -- Otherwise construct the loop, starting with the loop index L_J
1349
1350 L_J := Make_Defining_Identifier (Loc, New_Internal_Name ('J'));
1351
1352 -- Construct "L .. H" in Index_Base. We use a qualified expression
1353 -- for the bound to convert to the index base, but we don't need
1354 -- to do that if we already have the base type at hand.
1355
1356 if Etype (L) = Index_Base then
1357 L_L := L;
1358 else
1359 L_L :=
1360 Make_Qualified_Expression (Loc,
1361 Subtype_Mark => Index_Base_Name,
1362 Expression => L);
1363 end if;
1364
1365 if Etype (H) = Index_Base then
1366 L_H := H;
1367 else
1368 L_H :=
1369 Make_Qualified_Expression (Loc,
1370 Subtype_Mark => Index_Base_Name,
1371 Expression => H);
1372 end if;
1373
1374 L_Range :=
1375 Make_Range (Loc,
1376 Low_Bound => L_L,
1377 High_Bound => L_H);
1378
1379 -- Construct "for L_J in Index_Base range L .. H"
1380
1381 L_Iteration_Scheme :=
1382 Make_Iteration_Scheme
1383 (Loc,
1384 Loop_Parameter_Specification =>
1385 Make_Loop_Parameter_Specification
1386 (Loc,
1387 Defining_Identifier => L_J,
1388 Discrete_Subtype_Definition => L_Range));
1389
1390 -- Construct the statements to execute in the loop body
1391
1392 L_Body := Gen_Assign (New_Reference_To (L_J, Loc), Expr);
1393
1394 -- Construct the final loop
1395
1396 Append_To (S, Make_Implicit_Loop_Statement
1397 (Node => N,
1398 Identifier => Empty,
1399 Iteration_Scheme => L_Iteration_Scheme,
1400 Statements => L_Body));
1401
1402 -- A small optimization: if the aggregate is initialized with a box
1403 -- and the component type has no initialization procedure, remove the
1404 -- useless empty loop.
1405
1406 if Nkind (First (S)) = N_Loop_Statement
1407 and then Is_Empty_List (Statements (First (S)))
1408 then
1409 return New_List (Make_Null_Statement (Loc));
1410 else
1411 return S;
1412 end if;
1413 end Gen_Loop;
1414
1415 ---------------
1416 -- Gen_While --
1417 ---------------
1418
1419 -- The code built is
1420
1421 -- W_J : Index_Base := L;
1422 -- while W_J < H loop
1423 -- W_J := Index_Base'Succ (W);
1424 -- L_Body;
1425 -- end loop;
1426
1427 function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id is
1428 W_J : Node_Id;
1429
1430 W_Decl : Node_Id;
1431 -- W_J : Base_Type := L;
1432
1433 W_Iteration_Scheme : Node_Id;
1434 -- while W_J < H
1435
1436 W_Index_Succ : Node_Id;
1437 -- Index_Base'Succ (J)
1438
1439 W_Increment : Node_Id;
1440 -- W_J := Index_Base'Succ (W)
1441
1442 W_Body : constant List_Id := New_List;
1443 -- The statements to execute in the loop
1444
1445 S : constant List_Id := New_List;
1446 -- list of statement
1447
1448 begin
1449 -- If loop bounds define an empty range or are equal return null
1450
1451 if Empty_Range (L, H) or else Equal (L, H) then
1452 Append_To (S, Make_Null_Statement (Loc));
1453 return S;
1454 end if;
1455
1456 -- Build the decl of W_J
1457
1458 W_J := Make_Defining_Identifier (Loc, New_Internal_Name ('J'));
1459 W_Decl :=
1460 Make_Object_Declaration
1461 (Loc,
1462 Defining_Identifier => W_J,
1463 Object_Definition => Index_Base_Name,
1464 Expression => L);
1465
1466 -- Theoretically we should do a New_Copy_Tree (L) here, but we know
1467 -- that in this particular case L is a fresh Expr generated by
1468 -- Add which we are the only ones to use.
1469
1470 Append_To (S, W_Decl);
1471
1472 -- Construct " while W_J < H"
1473
1474 W_Iteration_Scheme :=
1475 Make_Iteration_Scheme
1476 (Loc,
1477 Condition => Make_Op_Lt
1478 (Loc,
1479 Left_Opnd => New_Reference_To (W_J, Loc),
1480 Right_Opnd => New_Copy_Tree (H)));
1481
1482 -- Construct the statements to execute in the loop body
1483
1484 W_Index_Succ :=
1485 Make_Attribute_Reference
1486 (Loc,
1487 Prefix => Index_Base_Name,
1488 Attribute_Name => Name_Succ,
1489 Expressions => New_List (New_Reference_To (W_J, Loc)));
1490
1491 W_Increment :=
1492 Make_OK_Assignment_Statement
1493 (Loc,
1494 Name => New_Reference_To (W_J, Loc),
1495 Expression => W_Index_Succ);
1496
1497 Append_To (W_Body, W_Increment);
1498 Append_List_To (W_Body,
1499 Gen_Assign (New_Reference_To (W_J, Loc), Expr));
1500
1501 -- Construct the final loop
1502
1503 Append_To (S, Make_Implicit_Loop_Statement
1504 (Node => N,
1505 Identifier => Empty,
1506 Iteration_Scheme => W_Iteration_Scheme,
1507 Statements => W_Body));
1508
1509 return S;
1510 end Gen_While;
1511
1512 ---------------------
1513 -- Index_Base_Name --
1514 ---------------------
1515
1516 function Index_Base_Name return Node_Id is
1517 begin
1518 return New_Reference_To (Index_Base, Sloc (N));
1519 end Index_Base_Name;
1520
1521 ------------------------------------
1522 -- Local_Compile_Time_Known_Value --
1523 ------------------------------------
1524
1525 function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean is
1526 begin
1527 return Compile_Time_Known_Value (E)
1528 or else
1529 (Nkind (E) = N_Attribute_Reference
1530 and then Attribute_Name (E) = Name_Val
1531 and then Compile_Time_Known_Value (First (Expressions (E))));
1532 end Local_Compile_Time_Known_Value;
1533
1534 ----------------------
1535 -- Local_Expr_Value --
1536 ----------------------
1537
1538 function Local_Expr_Value (E : Node_Id) return Uint is
1539 begin
1540 if Compile_Time_Known_Value (E) then
1541 return Expr_Value (E);
1542 else
1543 return Expr_Value (First (Expressions (E)));
1544 end if;
1545 end Local_Expr_Value;
1546
1547 -- Build_Array_Aggr_Code Variables
1548
1549 Assoc : Node_Id;
1550 Choice : Node_Id;
1551 Expr : Node_Id;
1552 Typ : Entity_Id;
1553
1554 Others_Expr : Node_Id := Empty;
1555 Others_Box_Present : Boolean := False;
1556
1557 Aggr_L : constant Node_Id := Low_Bound (Aggregate_Bounds (N));
1558 Aggr_H : constant Node_Id := High_Bound (Aggregate_Bounds (N));
1559 -- The aggregate bounds of this specific sub-aggregate. Note that if
1560 -- the code generated by Build_Array_Aggr_Code is executed then these
1561 -- bounds are OK. Otherwise a Constraint_Error would have been raised.
1562
1563 Aggr_Low : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_L);
1564 Aggr_High : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_H);
1565 -- After Duplicate_Subexpr these are side-effect free
1566
1567 Low : Node_Id;
1568 High : Node_Id;
1569
1570 Nb_Choices : Nat := 0;
1571 Table : Case_Table_Type (1 .. Number_Of_Choices (N));
1572 -- Used to sort all the different choice values
1573
1574 Nb_Elements : Int;
1575 -- Number of elements in the positional aggregate
1576
1577 New_Code : constant List_Id := New_List;
1578
1579 -- Start of processing for Build_Array_Aggr_Code
1580
1581 begin
1582 -- First before we start, a special case. if we have a bit packed
1583 -- array represented as a modular type, then clear the value to
1584 -- zero first, to ensure that unused bits are properly cleared.
1585
1586 Typ := Etype (N);
1587
1588 if Present (Typ)
1589 and then Is_Bit_Packed_Array (Typ)
1590 and then Is_Modular_Integer_Type (Packed_Array_Type (Typ))
1591 then
1592 Append_To (New_Code,
1593 Make_Assignment_Statement (Loc,
1594 Name => New_Copy_Tree (Into),
1595 Expression =>
1596 Unchecked_Convert_To (Typ,
1597 Make_Integer_Literal (Loc, Uint_0))));
1598 end if;
1599
1600 -- If the component type contains tasks, we need to build a Master
1601 -- entity in the current scope, because it will be needed if build-
1602 -- in-place functions are called in the expanded code.
1603
1604 if Nkind (Parent (N)) = N_Object_Declaration
1605 and then Has_Task (Typ)
1606 then
1607 Build_Master_Entity (Defining_Identifier (Parent (N)));
1608 end if;
1609
1610 -- STEP 1: Process component associations
1611
1612 -- For those associations that may generate a loop, initialize
1613 -- Loop_Actions to collect inserted actions that may be crated.
1614
1615 -- Skip this if no component associations
1616
1617 if No (Expressions (N)) then
1618
1619 -- STEP 1 (a): Sort the discrete choices
1620
1621 Assoc := First (Component_Associations (N));
1622 while Present (Assoc) loop
1623 Choice := First (Choices (Assoc));
1624 while Present (Choice) loop
1625 if Nkind (Choice) = N_Others_Choice then
1626 Set_Loop_Actions (Assoc, New_List);
1627
1628 if Box_Present (Assoc) then
1629 Others_Box_Present := True;
1630 else
1631 Others_Expr := Expression (Assoc);
1632 end if;
1633 exit;
1634 end if;
1635
1636 Get_Index_Bounds (Choice, Low, High);
1637
1638 if Low /= High then
1639 Set_Loop_Actions (Assoc, New_List);
1640 end if;
1641
1642 Nb_Choices := Nb_Choices + 1;
1643 if Box_Present (Assoc) then
1644 Table (Nb_Choices) := (Choice_Lo => Low,
1645 Choice_Hi => High,
1646 Choice_Node => Empty);
1647 else
1648 Table (Nb_Choices) := (Choice_Lo => Low,
1649 Choice_Hi => High,
1650 Choice_Node => Expression (Assoc));
1651 end if;
1652 Next (Choice);
1653 end loop;
1654
1655 Next (Assoc);
1656 end loop;
1657
1658 -- If there is more than one set of choices these must be static
1659 -- and we can therefore sort them. Remember that Nb_Choices does not
1660 -- account for an others choice.
1661
1662 if Nb_Choices > 1 then
1663 Sort_Case_Table (Table);
1664 end if;
1665
1666 -- STEP 1 (b): take care of the whole set of discrete choices
1667
1668 for J in 1 .. Nb_Choices loop
1669 Low := Table (J).Choice_Lo;
1670 High := Table (J).Choice_Hi;
1671 Expr := Table (J).Choice_Node;
1672 Append_List (Gen_Loop (Low, High, Expr), To => New_Code);
1673 end loop;
1674
1675 -- STEP 1 (c): generate the remaining loops to cover others choice
1676 -- We don't need to generate loops over empty gaps, but if there is
1677 -- a single empty range we must analyze the expression for semantics
1678
1679 if Present (Others_Expr) or else Others_Box_Present then
1680 declare
1681 First : Boolean := True;
1682
1683 begin
1684 for J in 0 .. Nb_Choices loop
1685 if J = 0 then
1686 Low := Aggr_Low;
1687 else
1688 Low := Add (1, To => Table (J).Choice_Hi);
1689 end if;
1690
1691 if J = Nb_Choices then
1692 High := Aggr_High;
1693 else
1694 High := Add (-1, To => Table (J + 1).Choice_Lo);
1695 end if;
1696
1697 -- If this is an expansion within an init proc, make
1698 -- sure that discriminant references are replaced by
1699 -- the corresponding discriminal.
1700
1701 if Inside_Init_Proc then
1702 if Is_Entity_Name (Low)
1703 and then Ekind (Entity (Low)) = E_Discriminant
1704 then
1705 Set_Entity (Low, Discriminal (Entity (Low)));
1706 end if;
1707
1708 if Is_Entity_Name (High)
1709 and then Ekind (Entity (High)) = E_Discriminant
1710 then
1711 Set_Entity (High, Discriminal (Entity (High)));
1712 end if;
1713 end if;
1714
1715 if First
1716 or else not Empty_Range (Low, High)
1717 then
1718 First := False;
1719 Append_List
1720 (Gen_Loop (Low, High, Others_Expr), To => New_Code);
1721 end if;
1722 end loop;
1723 end;
1724 end if;
1725
1726 -- STEP 2: Process positional components
1727
1728 else
1729 -- STEP 2 (a): Generate the assignments for each positional element
1730 -- Note that here we have to use Aggr_L rather than Aggr_Low because
1731 -- Aggr_L is analyzed and Add wants an analyzed expression.
1732
1733 Expr := First (Expressions (N));
1734 Nb_Elements := -1;
1735 while Present (Expr) loop
1736 Nb_Elements := Nb_Elements + 1;
1737 Append_List (Gen_Assign (Add (Nb_Elements, To => Aggr_L), Expr),
1738 To => New_Code);
1739 Next (Expr);
1740 end loop;
1741
1742 -- STEP 2 (b): Generate final loop if an others choice is present
1743 -- Here Nb_Elements gives the offset of the last positional element.
1744
1745 if Present (Component_Associations (N)) then
1746 Assoc := Last (Component_Associations (N));
1747
1748 -- Ada 2005 (AI-287)
1749
1750 if Box_Present (Assoc) then
1751 Append_List (Gen_While (Add (Nb_Elements, To => Aggr_L),
1752 Aggr_High,
1753 Empty),
1754 To => New_Code);
1755 else
1756 Expr := Expression (Assoc);
1757
1758 Append_List (Gen_While (Add (Nb_Elements, To => Aggr_L),
1759 Aggr_High,
1760 Expr), -- AI-287
1761 To => New_Code);
1762 end if;
1763 end if;
1764 end if;
1765
1766 return New_Code;
1767 end Build_Array_Aggr_Code;
1768
1769 ----------------------------
1770 -- Build_Record_Aggr_Code --
1771 ----------------------------
1772
1773 function Build_Record_Aggr_Code
1774 (N : Node_Id;
1775 Typ : Entity_Id;
1776 Lhs : Node_Id;
1777 Flist : Node_Id := Empty;
1778 Obj : Entity_Id := Empty;
1779 Is_Limited_Ancestor_Expansion : Boolean := False) return List_Id
1780 is
1781 Loc : constant Source_Ptr := Sloc (N);
1782 L : constant List_Id := New_List;
1783 N_Typ : constant Entity_Id := Etype (N);
1784
1785 Comp : Node_Id;
1786 Instr : Node_Id;
1787 Ref : Node_Id;
1788 Target : Entity_Id;
1789 F : Node_Id;
1790 Comp_Type : Entity_Id;
1791 Selector : Entity_Id;
1792 Comp_Expr : Node_Id;
1793 Expr_Q : Node_Id;
1794
1795 Internal_Final_List : Node_Id := Empty;
1796
1797 -- If this is an internal aggregate, the External_Final_List is an
1798 -- expression for the controller record of the enclosing type.
1799
1800 -- If the current aggregate has several controlled components, this
1801 -- expression will appear in several calls to attach to the finali-
1802 -- zation list, and it must not be shared.
1803
1804 External_Final_List : Node_Id;
1805 Ancestor_Is_Expression : Boolean := False;
1806 Ancestor_Is_Subtype_Mark : Boolean := False;
1807
1808 Init_Typ : Entity_Id := Empty;
1809 Attach : Node_Id;
1810
1811 Ctrl_Stuff_Done : Boolean := False;
1812 -- True if Gen_Ctrl_Actions_For_Aggr has already been called; calls
1813 -- after the first do nothing.
1814
1815 function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id;
1816 -- Returns the value that the given discriminant of an ancestor type
1817 -- should receive (in the absence of a conflict with the value provided
1818 -- by an ancestor part of an extension aggregate).
1819
1820 procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id);
1821 -- Check that each of the discriminant values defined by the ancestor
1822 -- part of an extension aggregate match the corresponding values
1823 -- provided by either an association of the aggregate or by the
1824 -- constraint imposed by a parent type (RM95-4.3.2(8)).
1825
1826 function Compatible_Int_Bounds
1827 (Agg_Bounds : Node_Id;
1828 Typ_Bounds : Node_Id) return Boolean;
1829 -- Return true if Agg_Bounds are equal or within Typ_Bounds. It is
1830 -- assumed that both bounds are integer ranges.
1831
1832 procedure Gen_Ctrl_Actions_For_Aggr;
1833 -- Deal with the various controlled type data structure initializations
1834 -- (but only if it hasn't been done already).
1835
1836 function Get_Constraint_Association (T : Entity_Id) return Node_Id;
1837 -- Returns the first discriminant association in the constraint
1838 -- associated with T, if any, otherwise returns Empty.
1839
1840 function Init_Controller
1841 (Target : Node_Id;
1842 Typ : Entity_Id;
1843 F : Node_Id;
1844 Attach : Node_Id;
1845 Init_Pr : Boolean) return List_Id;
1846 -- Returns the list of statements necessary to initialize the internal
1847 -- controller of the (possible) ancestor typ into target and attach it
1848 -- to finalization list F. Init_Pr conditions the call to the init proc
1849 -- since it may already be done due to ancestor initialization.
1850
1851 function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean;
1852 -- Check whether Bounds is a range node and its lower and higher bounds
1853 -- are integers literals.
1854
1855 ---------------------------------
1856 -- Ancestor_Discriminant_Value --
1857 ---------------------------------
1858
1859 function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id is
1860 Assoc : Node_Id;
1861 Assoc_Elmt : Elmt_Id;
1862 Aggr_Comp : Entity_Id;
1863 Corresp_Disc : Entity_Id;
1864 Current_Typ : Entity_Id := Base_Type (Typ);
1865 Parent_Typ : Entity_Id;
1866 Parent_Disc : Entity_Id;
1867 Save_Assoc : Node_Id := Empty;
1868
1869 begin
1870 -- First check any discriminant associations to see if any of them
1871 -- provide a value for the discriminant.
1872
1873 if Present (Discriminant_Specifications (Parent (Current_Typ))) then
1874 Assoc := First (Component_Associations (N));
1875 while Present (Assoc) loop
1876 Aggr_Comp := Entity (First (Choices (Assoc)));
1877
1878 if Ekind (Aggr_Comp) = E_Discriminant then
1879 Save_Assoc := Expression (Assoc);
1880
1881 Corresp_Disc := Corresponding_Discriminant (Aggr_Comp);
1882 while Present (Corresp_Disc) loop
1883
1884 -- If found a corresponding discriminant then return the
1885 -- value given in the aggregate. (Note: this is not
1886 -- correct in the presence of side effects. ???)
1887
1888 if Disc = Corresp_Disc then
1889 return Duplicate_Subexpr (Expression (Assoc));
1890 end if;
1891
1892 Corresp_Disc :=
1893 Corresponding_Discriminant (Corresp_Disc);
1894 end loop;
1895 end if;
1896
1897 Next (Assoc);
1898 end loop;
1899 end if;
1900
1901 -- No match found in aggregate, so chain up parent types to find
1902 -- a constraint that defines the value of the discriminant.
1903
1904 Parent_Typ := Etype (Current_Typ);
1905 while Current_Typ /= Parent_Typ loop
1906 if Has_Discriminants (Parent_Typ)
1907 and then not Has_Unknown_Discriminants (Parent_Typ)
1908 then
1909 Parent_Disc := First_Discriminant (Parent_Typ);
1910
1911 -- We either get the association from the subtype indication
1912 -- of the type definition itself, or from the discriminant
1913 -- constraint associated with the type entity (which is
1914 -- preferable, but it's not always present ???)
1915
1916 if Is_Empty_Elmt_List (
1917 Discriminant_Constraint (Current_Typ))
1918 then
1919 Assoc := Get_Constraint_Association (Current_Typ);
1920 Assoc_Elmt := No_Elmt;
1921 else
1922 Assoc_Elmt :=
1923 First_Elmt (Discriminant_Constraint (Current_Typ));
1924 Assoc := Node (Assoc_Elmt);
1925 end if;
1926
1927 -- Traverse the discriminants of the parent type looking
1928 -- for one that corresponds.
1929
1930 while Present (Parent_Disc) and then Present (Assoc) loop
1931 Corresp_Disc := Parent_Disc;
1932 while Present (Corresp_Disc)
1933 and then Disc /= Corresp_Disc
1934 loop
1935 Corresp_Disc :=
1936 Corresponding_Discriminant (Corresp_Disc);
1937 end loop;
1938
1939 if Disc = Corresp_Disc then
1940 if Nkind (Assoc) = N_Discriminant_Association then
1941 Assoc := Expression (Assoc);
1942 end if;
1943
1944 -- If the located association directly denotes a
1945 -- discriminant, then use the value of a saved
1946 -- association of the aggregate. This is a kludge to
1947 -- handle certain cases involving multiple discriminants
1948 -- mapped to a single discriminant of a descendant. It's
1949 -- not clear how to locate the appropriate discriminant
1950 -- value for such cases. ???
1951
1952 if Is_Entity_Name (Assoc)
1953 and then Ekind (Entity (Assoc)) = E_Discriminant
1954 then
1955 Assoc := Save_Assoc;
1956 end if;
1957
1958 return Duplicate_Subexpr (Assoc);
1959 end if;
1960
1961 Next_Discriminant (Parent_Disc);
1962
1963 if No (Assoc_Elmt) then
1964 Next (Assoc);
1965 else
1966 Next_Elmt (Assoc_Elmt);
1967 if Present (Assoc_Elmt) then
1968 Assoc := Node (Assoc_Elmt);
1969 else
1970 Assoc := Empty;
1971 end if;
1972 end if;
1973 end loop;
1974 end if;
1975
1976 Current_Typ := Parent_Typ;
1977 Parent_Typ := Etype (Current_Typ);
1978 end loop;
1979
1980 -- In some cases there's no ancestor value to locate (such as
1981 -- when an ancestor part given by an expression defines the
1982 -- discriminant value).
1983
1984 return Empty;
1985 end Ancestor_Discriminant_Value;
1986
1987 ----------------------------------
1988 -- Check_Ancestor_Discriminants --
1989 ----------------------------------
1990
1991 procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id) is
1992 Discr : Entity_Id;
1993 Disc_Value : Node_Id;
1994 Cond : Node_Id;
1995
1996 begin
1997 Discr := First_Discriminant (Base_Type (Anc_Typ));
1998 while Present (Discr) loop
1999 Disc_Value := Ancestor_Discriminant_Value (Discr);
2000
2001 if Present (Disc_Value) then
2002 Cond := Make_Op_Ne (Loc,
2003 Left_Opnd =>
2004 Make_Selected_Component (Loc,
2005 Prefix => New_Copy_Tree (Target),
2006 Selector_Name => New_Occurrence_Of (Discr, Loc)),
2007 Right_Opnd => Disc_Value);
2008
2009 Append_To (L,
2010 Make_Raise_Constraint_Error (Loc,
2011 Condition => Cond,
2012 Reason => CE_Discriminant_Check_Failed));
2013 end if;
2014
2015 Next_Discriminant (Discr);
2016 end loop;
2017 end Check_Ancestor_Discriminants;
2018
2019 ---------------------------
2020 -- Compatible_Int_Bounds --
2021 ---------------------------
2022
2023 function Compatible_Int_Bounds
2024 (Agg_Bounds : Node_Id;
2025 Typ_Bounds : Node_Id) return Boolean
2026 is
2027 Agg_Lo : constant Uint := Intval (Low_Bound (Agg_Bounds));
2028 Agg_Hi : constant Uint := Intval (High_Bound (Agg_Bounds));
2029 Typ_Lo : constant Uint := Intval (Low_Bound (Typ_Bounds));
2030 Typ_Hi : constant Uint := Intval (High_Bound (Typ_Bounds));
2031 begin
2032 return Typ_Lo <= Agg_Lo and then Agg_Hi <= Typ_Hi;
2033 end Compatible_Int_Bounds;
2034
2035 --------------------------------
2036 -- Get_Constraint_Association --
2037 --------------------------------
2038
2039 function Get_Constraint_Association (T : Entity_Id) return Node_Id is
2040 Typ_Def : constant Node_Id := Type_Definition (Parent (T));
2041 Indic : constant Node_Id := Subtype_Indication (Typ_Def);
2042
2043 begin
2044 -- ??? Also need to cover case of a type mark denoting a subtype
2045 -- with constraint.
2046
2047 if Nkind (Indic) = N_Subtype_Indication
2048 and then Present (Constraint (Indic))
2049 then
2050 return First (Constraints (Constraint (Indic)));
2051 end if;
2052
2053 return Empty;
2054 end Get_Constraint_Association;
2055
2056 ---------------------
2057 -- Init_Controller --
2058 ---------------------
2059
2060 function Init_Controller
2061 (Target : Node_Id;
2062 Typ : Entity_Id;
2063 F : Node_Id;
2064 Attach : Node_Id;
2065 Init_Pr : Boolean) return List_Id
2066 is
2067 L : constant List_Id := New_List;
2068 Ref : Node_Id;
2069 RC : RE_Id;
2070 Target_Type : Entity_Id;
2071
2072 begin
2073 -- Generate:
2074 -- init-proc (target._controller);
2075 -- initialize (target._controller);
2076 -- Attach_to_Final_List (target._controller, F);
2077
2078 Ref :=
2079 Make_Selected_Component (Loc,
2080 Prefix => Convert_To (Typ, New_Copy_Tree (Target)),
2081 Selector_Name => Make_Identifier (Loc, Name_uController));
2082 Set_Assignment_OK (Ref);
2083
2084 -- Ada 2005 (AI-287): Give support to aggregates of limited types.
2085 -- If the type is intrinsically limited the controller is limited as
2086 -- well. If it is tagged and limited then so is the controller.
2087 -- Otherwise an untagged type may have limited components without its
2088 -- full view being limited, so the controller is not limited.
2089
2090 if Nkind (Target) = N_Identifier then
2091 Target_Type := Etype (Target);
2092
2093 elsif Nkind (Target) = N_Selected_Component then
2094 Target_Type := Etype (Selector_Name (Target));
2095
2096 elsif Nkind (Target) = N_Unchecked_Type_Conversion then
2097 Target_Type := Etype (Target);
2098
2099 elsif Nkind (Target) = N_Unchecked_Expression
2100 and then Nkind (Expression (Target)) = N_Indexed_Component
2101 then
2102 Target_Type := Etype (Prefix (Expression (Target)));
2103
2104 else
2105 Target_Type := Etype (Target);
2106 end if;
2107
2108 -- If the target has not been analyzed yet, as will happen with
2109 -- delayed expansion, use the given type (either the aggregate type
2110 -- or an ancestor) to determine limitedness.
2111
2112 if No (Target_Type) then
2113 Target_Type := Typ;
2114 end if;
2115
2116 if (Is_Tagged_Type (Target_Type))
2117 and then Is_Limited_Type (Target_Type)
2118 then
2119 RC := RE_Limited_Record_Controller;
2120
2121 elsif Is_Inherently_Limited_Type (Target_Type) then
2122 RC := RE_Limited_Record_Controller;
2123
2124 else
2125 RC := RE_Record_Controller;
2126 end if;
2127
2128 if Init_Pr then
2129 Append_List_To (L,
2130 Build_Initialization_Call (Loc,
2131 Id_Ref => Ref,
2132 Typ => RTE (RC),
2133 In_Init_Proc => Within_Init_Proc));
2134 end if;
2135
2136 Append_To (L,
2137 Make_Procedure_Call_Statement (Loc,
2138 Name =>
2139 New_Reference_To (
2140 Find_Prim_Op (RTE (RC), Name_Initialize), Loc),
2141 Parameter_Associations =>
2142 New_List (New_Copy_Tree (Ref))));
2143
2144 Append_To (L,
2145 Make_Attach_Call (
2146 Obj_Ref => New_Copy_Tree (Ref),
2147 Flist_Ref => F,
2148 With_Attach => Attach));
2149
2150 return L;
2151 end Init_Controller;
2152
2153 -------------------------
2154 -- Is_Int_Range_Bounds --
2155 -------------------------
2156
2157 function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean is
2158 begin
2159 return Nkind (Bounds) = N_Range
2160 and then Nkind (Low_Bound (Bounds)) = N_Integer_Literal
2161 and then Nkind (High_Bound (Bounds)) = N_Integer_Literal;
2162 end Is_Int_Range_Bounds;
2163
2164 -------------------------------
2165 -- Gen_Ctrl_Actions_For_Aggr --
2166 -------------------------------
2167
2168 procedure Gen_Ctrl_Actions_For_Aggr is
2169 Alloc : Node_Id := Empty;
2170
2171 begin
2172 -- Do the work only the first time this is called
2173
2174 if Ctrl_Stuff_Done then
2175 return;
2176 end if;
2177
2178 Ctrl_Stuff_Done := True;
2179
2180 if Present (Obj)
2181 and then Finalize_Storage_Only (Typ)
2182 and then
2183 (Is_Library_Level_Entity (Obj)
2184 or else Entity (Constant_Value (RTE (RE_Garbage_Collected))) =
2185 Standard_True)
2186
2187 -- why not Is_True (Expr_Value (RTE (RE_Garbaage_Collected) ???
2188 then
2189 Attach := Make_Integer_Literal (Loc, 0);
2190
2191 elsif Nkind (Parent (N)) = N_Qualified_Expression
2192 and then Nkind (Parent (Parent (N))) = N_Allocator
2193 then
2194 Alloc := Parent (Parent (N));
2195 Attach := Make_Integer_Literal (Loc, 2);
2196
2197 else
2198 Attach := Make_Integer_Literal (Loc, 1);
2199 end if;
2200
2201 -- Determine the external finalization list. It is either the
2202 -- finalization list of the outer-scope or the one coming from
2203 -- an outer aggregate. When the target is not a temporary, the
2204 -- proper scope is the scope of the target rather than the
2205 -- potentially transient current scope.
2206
2207 if Needs_Finalization (Typ) then
2208
2209 -- The current aggregate belongs to an allocator which creates
2210 -- an object through an anonymous access type or acts as the root
2211 -- of a coextension chain.
2212
2213 if Present (Alloc)
2214 and then
2215 (Is_Coextension_Root (Alloc)
2216 or else Ekind (Etype (Alloc)) = E_Anonymous_Access_Type)
2217 then
2218 if No (Associated_Final_Chain (Etype (Alloc))) then
2219 Build_Final_List (Alloc, Etype (Alloc));
2220 end if;
2221
2222 External_Final_List :=
2223 Make_Selected_Component (Loc,
2224 Prefix =>
2225 New_Reference_To (
2226 Associated_Final_Chain (Etype (Alloc)), Loc),
2227 Selector_Name =>
2228 Make_Identifier (Loc, Name_F));
2229
2230 elsif Present (Flist) then
2231 External_Final_List := New_Copy_Tree (Flist);
2232
2233 elsif Is_Entity_Name (Target)
2234 and then Present (Scope (Entity (Target)))
2235 then
2236 External_Final_List :=
2237 Find_Final_List (Scope (Entity (Target)));
2238
2239 else
2240 External_Final_List := Find_Final_List (Current_Scope);
2241 end if;
2242 else
2243 External_Final_List := Empty;
2244 end if;
2245
2246 -- Initialize and attach the outer object in the is_controlled case
2247
2248 if Is_Controlled (Typ) then
2249 if Ancestor_Is_Subtype_Mark then
2250 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2251 Set_Assignment_OK (Ref);
2252 Append_To (L,
2253 Make_Procedure_Call_Statement (Loc,
2254 Name =>
2255 New_Reference_To
2256 (Find_Prim_Op (Init_Typ, Name_Initialize), Loc),
2257 Parameter_Associations => New_List (New_Copy_Tree (Ref))));
2258 end if;
2259
2260 if not Has_Controlled_Component (Typ) then
2261 Ref := New_Copy_Tree (Target);
2262 Set_Assignment_OK (Ref);
2263
2264 -- This is an aggregate of a coextension. Do not produce a
2265 -- finalization call, but rather attach the reference of the
2266 -- aggregate to its coextension chain.
2267
2268 if Present (Alloc)
2269 and then Is_Dynamic_Coextension (Alloc)
2270 then
2271 if No (Coextensions (Alloc)) then
2272 Set_Coextensions (Alloc, New_Elmt_List);
2273 end if;
2274
2275 Append_Elmt (Ref, Coextensions (Alloc));
2276 else
2277 Append_To (L,
2278 Make_Attach_Call (
2279 Obj_Ref => Ref,
2280 Flist_Ref => New_Copy_Tree (External_Final_List),
2281 With_Attach => Attach));
2282 end if;
2283 end if;
2284 end if;
2285
2286 -- In the Has_Controlled component case, all the intermediate
2287 -- controllers must be initialized.
2288
2289 if Has_Controlled_Component (Typ)
2290 and not Is_Limited_Ancestor_Expansion
2291 then
2292 declare
2293 Inner_Typ : Entity_Id;
2294 Outer_Typ : Entity_Id;
2295 At_Root : Boolean;
2296
2297 begin
2298 -- Find outer type with a controller
2299
2300 Outer_Typ := Base_Type (Typ);
2301 while Outer_Typ /= Init_Typ
2302 and then not Has_New_Controlled_Component (Outer_Typ)
2303 loop
2304 Outer_Typ := Etype (Outer_Typ);
2305 end loop;
2306
2307 -- Attach it to the outer record controller to the external
2308 -- final list.
2309
2310 if Outer_Typ = Init_Typ then
2311 Append_List_To (L,
2312 Init_Controller (
2313 Target => Target,
2314 Typ => Outer_Typ,
2315 F => External_Final_List,
2316 Attach => Attach,
2317 Init_Pr => False));
2318
2319 At_Root := True;
2320 Inner_Typ := Init_Typ;
2321
2322 else
2323 Append_List_To (L,
2324 Init_Controller (
2325 Target => Target,
2326 Typ => Outer_Typ,
2327 F => External_Final_List,
2328 Attach => Attach,
2329 Init_Pr => True));
2330
2331 Inner_Typ := Etype (Outer_Typ);
2332 At_Root :=
2333 not Is_Tagged_Type (Typ) or else Inner_Typ = Outer_Typ;
2334 end if;
2335
2336 -- The outer object has to be attached as well
2337
2338 if Is_Controlled (Typ) then
2339 Ref := New_Copy_Tree (Target);
2340 Set_Assignment_OK (Ref);
2341 Append_To (L,
2342 Make_Attach_Call (
2343 Obj_Ref => Ref,
2344 Flist_Ref => New_Copy_Tree (External_Final_List),
2345 With_Attach => New_Copy_Tree (Attach)));
2346 end if;
2347
2348 -- Initialize the internal controllers for tagged types with
2349 -- more than one controller.
2350
2351 while not At_Root and then Inner_Typ /= Init_Typ loop
2352 if Has_New_Controlled_Component (Inner_Typ) then
2353 F :=
2354 Make_Selected_Component (Loc,
2355 Prefix =>
2356 Convert_To (Outer_Typ, New_Copy_Tree (Target)),
2357 Selector_Name =>
2358 Make_Identifier (Loc, Name_uController));
2359 F :=
2360 Make_Selected_Component (Loc,
2361 Prefix => F,
2362 Selector_Name => Make_Identifier (Loc, Name_F));
2363
2364 Append_List_To (L,
2365 Init_Controller (
2366 Target => Target,
2367 Typ => Inner_Typ,
2368 F => F,
2369 Attach => Make_Integer_Literal (Loc, 1),
2370 Init_Pr => True));
2371 Outer_Typ := Inner_Typ;
2372 end if;
2373
2374 -- Stop at the root
2375
2376 At_Root := Inner_Typ = Etype (Inner_Typ);
2377 Inner_Typ := Etype (Inner_Typ);
2378 end loop;
2379
2380 -- If not done yet attach the controller of the ancestor part
2381
2382 if Outer_Typ /= Init_Typ
2383 and then Inner_Typ = Init_Typ
2384 and then Has_Controlled_Component (Init_Typ)
2385 then
2386 F :=
2387 Make_Selected_Component (Loc,
2388 Prefix => Convert_To (Outer_Typ, New_Copy_Tree (Target)),
2389 Selector_Name =>
2390 Make_Identifier (Loc, Name_uController));
2391 F :=
2392 Make_Selected_Component (Loc,
2393 Prefix => F,
2394 Selector_Name => Make_Identifier (Loc, Name_F));
2395
2396 Attach := Make_Integer_Literal (Loc, 1);
2397 Append_List_To (L,
2398 Init_Controller (
2399 Target => Target,
2400 Typ => Init_Typ,
2401 F => F,
2402 Attach => Attach,
2403 Init_Pr => False));
2404
2405 -- Note: Init_Pr is False because the ancestor part has
2406 -- already been initialized either way (by default, if
2407 -- given by a type name, otherwise from the expression).
2408
2409 end if;
2410 end;
2411 end if;
2412 end Gen_Ctrl_Actions_For_Aggr;
2413
2414 function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result;
2415 -- If default expression of a component mentions a discriminant of the
2416 -- type, it must be rewritten as the discriminant of the target object.
2417
2418 function Replace_Type (Expr : Node_Id) return Traverse_Result;
2419 -- If the aggregate contains a self-reference, traverse each expression
2420 -- to replace a possible self-reference with a reference to the proper
2421 -- component of the target of the assignment.
2422
2423 --------------------------
2424 -- Rewrite_Discriminant --
2425 --------------------------
2426
2427 function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result is
2428 begin
2429 if Nkind (Expr) = N_Identifier
2430 and then Present (Entity (Expr))
2431 and then Ekind (Entity (Expr)) = E_In_Parameter
2432 and then Present (Discriminal_Link (Entity (Expr)))
2433 then
2434 Rewrite (Expr,
2435 Make_Selected_Component (Loc,
2436 Prefix => New_Occurrence_Of (Obj, Loc),
2437 Selector_Name => Make_Identifier (Loc, Chars (Expr))));
2438 end if;
2439 return OK;
2440 end Rewrite_Discriminant;
2441
2442 ------------------
2443 -- Replace_Type --
2444 ------------------
2445
2446 function Replace_Type (Expr : Node_Id) return Traverse_Result is
2447 begin
2448 -- Note regarding the Root_Type test below: Aggregate components for
2449 -- self-referential types include attribute references to the current
2450 -- instance, of the form: Typ'access, etc.. These references are
2451 -- rewritten as references to the target of the aggregate: the
2452 -- left-hand side of an assignment, the entity in a declaration,
2453 -- or a temporary. Without this test, we would improperly extended
2454 -- this rewriting to attribute references whose prefix was not the
2455 -- type of the aggregate.
2456
2457 if Nkind (Expr) = N_Attribute_Reference
2458 and then Is_Entity_Name (Prefix (Expr))
2459 and then Is_Type (Entity (Prefix (Expr)))
2460 and then Root_Type (Etype (N)) = Root_Type (Entity (Prefix (Expr)))
2461 then
2462 if Is_Entity_Name (Lhs) then
2463 Rewrite (Prefix (Expr),
2464 New_Occurrence_Of (Entity (Lhs), Loc));
2465
2466 elsif Nkind (Lhs) = N_Selected_Component then
2467 Rewrite (Expr,
2468 Make_Attribute_Reference (Loc,
2469 Attribute_Name => Name_Unrestricted_Access,
2470 Prefix => New_Copy_Tree (Prefix (Lhs))));
2471 Set_Analyzed (Parent (Expr), False);
2472
2473 else
2474 Rewrite (Expr,
2475 Make_Attribute_Reference (Loc,
2476 Attribute_Name => Name_Unrestricted_Access,
2477 Prefix => New_Copy_Tree (Lhs)));
2478 Set_Analyzed (Parent (Expr), False);
2479 end if;
2480 end if;
2481
2482 return OK;
2483 end Replace_Type;
2484
2485 procedure Replace_Self_Reference is
2486 new Traverse_Proc (Replace_Type);
2487
2488 procedure Replace_Discriminants is
2489 new Traverse_Proc (Rewrite_Discriminant);
2490
2491 -- Start of processing for Build_Record_Aggr_Code
2492
2493 begin
2494 if Has_Self_Reference (N) then
2495 Replace_Self_Reference (N);
2496 end if;
2497
2498 -- If the target of the aggregate is class-wide, we must convert it
2499 -- to the actual type of the aggregate, so that the proper components
2500 -- are visible. We know already that the types are compatible.
2501
2502 if Present (Etype (Lhs))
2503 and then Is_Class_Wide_Type (Etype (Lhs))
2504 then
2505 Target := Unchecked_Convert_To (Typ, Lhs);
2506 else
2507 Target := Lhs;
2508 end if;
2509
2510 -- Deal with the ancestor part of extension aggregates or with the
2511 -- discriminants of the root type.
2512
2513 if Nkind (N) = N_Extension_Aggregate then
2514 declare
2515 A : constant Node_Id := Ancestor_Part (N);
2516 Assign : List_Id;
2517
2518 begin
2519 -- If the ancestor part is a subtype mark "T", we generate
2520
2521 -- init-proc (T(tmp)); if T is constrained and
2522 -- init-proc (S(tmp)); where S applies an appropriate
2523 -- constraint if T is unconstrained
2524
2525 if Is_Entity_Name (A) and then Is_Type (Entity (A)) then
2526 Ancestor_Is_Subtype_Mark := True;
2527
2528 if Is_Constrained (Entity (A)) then
2529 Init_Typ := Entity (A);
2530
2531 -- For an ancestor part given by an unconstrained type mark,
2532 -- create a subtype constrained by appropriate corresponding
2533 -- discriminant values coming from either associations of the
2534 -- aggregate or a constraint on a parent type. The subtype will
2535 -- be used to generate the correct default value for the
2536 -- ancestor part.
2537
2538 elsif Has_Discriminants (Entity (A)) then
2539 declare
2540 Anc_Typ : constant Entity_Id := Entity (A);
2541 Anc_Constr : constant List_Id := New_List;
2542 Discrim : Entity_Id;
2543 Disc_Value : Node_Id;
2544 New_Indic : Node_Id;
2545 Subt_Decl : Node_Id;
2546
2547 begin
2548 Discrim := First_Discriminant (Anc_Typ);
2549 while Present (Discrim) loop
2550 Disc_Value := Ancestor_Discriminant_Value (Discrim);
2551 Append_To (Anc_Constr, Disc_Value);
2552 Next_Discriminant (Discrim);
2553 end loop;
2554
2555 New_Indic :=
2556 Make_Subtype_Indication (Loc,
2557 Subtype_Mark => New_Occurrence_Of (Anc_Typ, Loc),
2558 Constraint =>
2559 Make_Index_Or_Discriminant_Constraint (Loc,
2560 Constraints => Anc_Constr));
2561
2562 Init_Typ := Create_Itype (Ekind (Anc_Typ), N);
2563
2564 Subt_Decl :=
2565 Make_Subtype_Declaration (Loc,
2566 Defining_Identifier => Init_Typ,
2567 Subtype_Indication => New_Indic);
2568
2569 -- Itypes must be analyzed with checks off Declaration
2570 -- must have a parent for proper handling of subsidiary
2571 -- actions.
2572
2573 Set_Parent (Subt_Decl, N);
2574 Analyze (Subt_Decl, Suppress => All_Checks);
2575 end;
2576 end if;
2577
2578 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2579 Set_Assignment_OK (Ref);
2580
2581 Append_List_To (L,
2582 Build_Initialization_Call (Loc,
2583 Id_Ref => Ref,
2584 Typ => Init_Typ,
2585 In_Init_Proc => Within_Init_Proc,
2586 With_Default_Init => Has_Default_Init_Comps (N)
2587 or else
2588 Has_Task (Base_Type (Init_Typ))));
2589
2590 if Is_Constrained (Entity (A))
2591 and then Has_Discriminants (Entity (A))
2592 then
2593 Check_Ancestor_Discriminants (Entity (A));
2594 end if;
2595
2596 -- Handle calls to C++ constructors
2597
2598 elsif Is_CPP_Constructor_Call (A) then
2599 Init_Typ := Etype (A);
2600 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2601 Set_Assignment_OK (Ref);
2602
2603 Append_List_To (L,
2604 Build_Initialization_Call (Loc,
2605 Id_Ref => Ref,
2606 Typ => Init_Typ,
2607 In_Init_Proc => Within_Init_Proc,
2608 With_Default_Init => Has_Default_Init_Comps (N),
2609 Constructor_Ref => A));
2610
2611 -- Ada 2005 (AI-287): If the ancestor part is an aggregate of
2612 -- limited type, a recursive call expands the ancestor. Note that
2613 -- in the limited case, the ancestor part must be either a
2614 -- function call (possibly qualified, or wrapped in an unchecked
2615 -- conversion) or aggregate (definitely qualified).
2616 -- The ancestor part can also be a function call (that may be
2617 -- transformed into an explicit dereference) or a qualification
2618 -- of one such.
2619
2620 elsif Is_Limited_Type (Etype (A))
2621 and then Nkind_In (Unqualify (A), N_Aggregate,
2622 N_Extension_Aggregate)
2623 then
2624 Ancestor_Is_Expression := True;
2625
2626 -- Set up finalization data for enclosing record, because
2627 -- controlled subcomponents of the ancestor part will be
2628 -- attached to it.
2629
2630 Gen_Ctrl_Actions_For_Aggr;
2631
2632 Append_List_To (L,
2633 Build_Record_Aggr_Code (
2634 N => Unqualify (A),
2635 Typ => Etype (Unqualify (A)),
2636 Lhs => Target,
2637 Flist => Flist,
2638 Obj => Obj,
2639 Is_Limited_Ancestor_Expansion => True));
2640
2641 -- If the ancestor part is an expression "E", we generate
2642
2643 -- T(tmp) := E;
2644
2645 -- In Ada 2005, this includes the case of a (possibly qualified)
2646 -- limited function call. The assignment will turn into a
2647 -- build-in-place function call (for further details, see
2648 -- Make_Build_In_Place_Call_In_Assignment).
2649
2650 else
2651 Ancestor_Is_Expression := True;
2652 Init_Typ := Etype (A);
2653
2654 -- If the ancestor part is an aggregate, force its full
2655 -- expansion, which was delayed.
2656
2657 if Nkind_In (Unqualify (A), N_Aggregate,
2658 N_Extension_Aggregate)
2659 then
2660 Set_Analyzed (A, False);
2661 Set_Analyzed (Expression (A), False);
2662 end if;
2663
2664 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2665 Set_Assignment_OK (Ref);
2666
2667 -- Make the assignment without usual controlled actions since
2668 -- we only want the post adjust but not the pre finalize here
2669 -- Add manual adjust when necessary.
2670
2671 Assign := New_List (
2672 Make_OK_Assignment_Statement (Loc,
2673 Name => Ref,
2674 Expression => A));
2675 Set_No_Ctrl_Actions (First (Assign));
2676
2677 -- Assign the tag now to make sure that the dispatching call in
2678 -- the subsequent deep_adjust works properly (unless VM_Target,
2679 -- where tags are implicit).
2680
2681 if Tagged_Type_Expansion then
2682 Instr :=
2683 Make_OK_Assignment_Statement (Loc,
2684 Name =>
2685 Make_Selected_Component (Loc,
2686 Prefix => New_Copy_Tree (Target),
2687 Selector_Name =>
2688 New_Reference_To
2689 (First_Tag_Component (Base_Type (Typ)), Loc)),
2690
2691 Expression =>
2692 Unchecked_Convert_To (RTE (RE_Tag),
2693 New_Reference_To
2694 (Node (First_Elmt
2695 (Access_Disp_Table (Base_Type (Typ)))),
2696 Loc)));
2697
2698 Set_Assignment_OK (Name (Instr));
2699 Append_To (Assign, Instr);
2700
2701 -- Ada 2005 (AI-251): If tagged type has progenitors we must
2702 -- also initialize tags of the secondary dispatch tables.
2703
2704 if Has_Interfaces (Base_Type (Typ)) then
2705 Init_Secondary_Tags
2706 (Typ => Base_Type (Typ),
2707 Target => Target,
2708 Stmts_List => Assign);
2709 end if;
2710 end if;
2711
2712 -- Call Adjust manually
2713
2714 if Needs_Finalization (Etype (A))
2715 and then not Is_Limited_Type (Etype (A))
2716 then
2717 Append_List_To (Assign,
2718 Make_Adjust_Call (
2719 Ref => New_Copy_Tree (Ref),
2720 Typ => Etype (A),
2721 Flist_Ref => New_Reference_To (
2722 RTE (RE_Global_Final_List), Loc),
2723 With_Attach => Make_Integer_Literal (Loc, 0)));
2724 end if;
2725
2726 Append_To (L,
2727 Make_Unsuppress_Block (Loc, Name_Discriminant_Check, Assign));
2728
2729 if Has_Discriminants (Init_Typ) then
2730 Check_Ancestor_Discriminants (Init_Typ);
2731 end if;
2732 end if;
2733 end;
2734
2735 -- Normal case (not an extension aggregate)
2736
2737 else
2738 -- Generate the discriminant expressions, component by component.
2739 -- If the base type is an unchecked union, the discriminants are
2740 -- unknown to the back-end and absent from a value of the type, so
2741 -- assignments for them are not emitted.
2742
2743 if Has_Discriminants (Typ)
2744 and then not Is_Unchecked_Union (Base_Type (Typ))
2745 then
2746 -- If the type is derived, and constrains discriminants of the
2747 -- parent type, these discriminants are not components of the
2748 -- aggregate, and must be initialized explicitly. They are not
2749 -- visible components of the object, but can become visible with
2750 -- a view conversion to the ancestor.
2751
2752 declare
2753 Btype : Entity_Id;
2754 Parent_Type : Entity_Id;
2755 Disc : Entity_Id;
2756 Discr_Val : Elmt_Id;
2757
2758 begin
2759 Btype := Base_Type (Typ);
2760 while Is_Derived_Type (Btype)
2761 and then Present (Stored_Constraint (Btype))
2762 loop
2763 Parent_Type := Etype (Btype);
2764
2765 Disc := First_Discriminant (Parent_Type);
2766 Discr_Val :=
2767 First_Elmt (Stored_Constraint (Base_Type (Typ)));
2768 while Present (Discr_Val) loop
2769
2770 -- Only those discriminants of the parent that are not
2771 -- renamed by discriminants of the derived type need to
2772 -- be added explicitly.
2773
2774 if not Is_Entity_Name (Node (Discr_Val))
2775 or else
2776 Ekind (Entity (Node (Discr_Val))) /= E_Discriminant
2777 then
2778 Comp_Expr :=
2779 Make_Selected_Component (Loc,
2780 Prefix => New_Copy_Tree (Target),
2781 Selector_Name => New_Occurrence_Of (Disc, Loc));
2782
2783 Instr :=
2784 Make_OK_Assignment_Statement (Loc,
2785 Name => Comp_Expr,
2786 Expression => New_Copy_Tree (Node (Discr_Val)));
2787
2788 Set_No_Ctrl_Actions (Instr);
2789 Append_To (L, Instr);
2790 end if;
2791
2792 Next_Discriminant (Disc);
2793 Next_Elmt (Discr_Val);
2794 end loop;
2795
2796 Btype := Base_Type (Parent_Type);
2797 end loop;
2798 end;
2799
2800 -- Generate discriminant init values for the visible discriminants
2801
2802 declare
2803 Discriminant : Entity_Id;
2804 Discriminant_Value : Node_Id;
2805
2806 begin
2807 Discriminant := First_Stored_Discriminant (Typ);
2808 while Present (Discriminant) loop
2809 Comp_Expr :=
2810 Make_Selected_Component (Loc,
2811 Prefix => New_Copy_Tree (Target),
2812 Selector_Name => New_Occurrence_Of (Discriminant, Loc));
2813
2814 Discriminant_Value :=
2815 Get_Discriminant_Value (
2816 Discriminant,
2817 N_Typ,
2818 Discriminant_Constraint (N_Typ));
2819
2820 Instr :=
2821 Make_OK_Assignment_Statement (Loc,
2822 Name => Comp_Expr,
2823 Expression => New_Copy_Tree (Discriminant_Value));
2824
2825 Set_No_Ctrl_Actions (Instr);
2826 Append_To (L, Instr);
2827
2828 Next_Stored_Discriminant (Discriminant);
2829 end loop;
2830 end;
2831 end if;
2832 end if;
2833
2834 -- For CPP types we generate an implicit call to the C++ default
2835 -- constructor to ensure the proper initialization of the _Tag
2836 -- component.
2837
2838 if Is_CPP_Class (Typ) then
2839 pragma Assert (Present (Base_Init_Proc (Typ)));
2840 Append_List_To (L,
2841 Build_Initialization_Call (Loc,
2842 Id_Ref => Lhs,
2843 Typ => Typ));
2844 end if;
2845
2846 -- Generate the assignments, component by component
2847
2848 -- tmp.comp1 := Expr1_From_Aggr;
2849 -- tmp.comp2 := Expr2_From_Aggr;
2850 -- ....
2851
2852 Comp := First (Component_Associations (N));
2853 while Present (Comp) loop
2854 Selector := Entity (First (Choices (Comp)));
2855
2856 -- C++ constructors
2857
2858 if Is_CPP_Constructor_Call (Expression (Comp)) then
2859 Append_List_To (L,
2860 Build_Initialization_Call (Loc,
2861 Id_Ref => Make_Selected_Component (Loc,
2862 Prefix => New_Copy_Tree (Target),
2863 Selector_Name => New_Occurrence_Of (Selector,
2864 Loc)),
2865 Typ => Etype (Selector),
2866 Enclos_Type => Typ,
2867 With_Default_Init => True,
2868 Constructor_Ref => Expression (Comp)));
2869
2870 -- Ada 2005 (AI-287): For each default-initialized component generate
2871 -- a call to the corresponding IP subprogram if available.
2872
2873 elsif Box_Present (Comp)
2874 and then Has_Non_Null_Base_Init_Proc (Etype (Selector))
2875 then
2876 if Ekind (Selector) /= E_Discriminant then
2877 Gen_Ctrl_Actions_For_Aggr;
2878 end if;
2879
2880 -- Ada 2005 (AI-287): If the component type has tasks then
2881 -- generate the activation chain and master entities (except
2882 -- in case of an allocator because in that case these entities
2883 -- are generated by Build_Task_Allocate_Block_With_Init_Stmts).
2884
2885 declare
2886 Ctype : constant Entity_Id := Etype (Selector);
2887 Inside_Allocator : Boolean := False;
2888 P : Node_Id := Parent (N);
2889
2890 begin
2891 if Is_Task_Type (Ctype) or else Has_Task (Ctype) then
2892 while Present (P) loop
2893 if Nkind (P) = N_Allocator then
2894 Inside_Allocator := True;
2895 exit;
2896 end if;
2897
2898 P := Parent (P);
2899 end loop;
2900
2901 if not Inside_Init_Proc and not Inside_Allocator then
2902 Build_Activation_Chain_Entity (N);
2903 end if;
2904 end if;
2905 end;
2906
2907 Append_List_To (L,
2908 Build_Initialization_Call (Loc,
2909 Id_Ref => Make_Selected_Component (Loc,
2910 Prefix => New_Copy_Tree (Target),
2911 Selector_Name => New_Occurrence_Of (Selector,
2912 Loc)),
2913 Typ => Etype (Selector),
2914 Enclos_Type => Typ,
2915 With_Default_Init => True));
2916
2917 -- Prepare for component assignment
2918
2919 elsif Ekind (Selector) /= E_Discriminant
2920 or else Nkind (N) = N_Extension_Aggregate
2921 then
2922 -- All the discriminants have now been assigned
2923
2924 -- This is now a good moment to initialize and attach all the
2925 -- controllers. Their position may depend on the discriminants.
2926
2927 if Ekind (Selector) /= E_Discriminant then
2928 Gen_Ctrl_Actions_For_Aggr;
2929 end if;
2930
2931 Comp_Type := Etype (Selector);
2932 Comp_Expr :=
2933 Make_Selected_Component (Loc,
2934 Prefix => New_Copy_Tree (Target),
2935 Selector_Name => New_Occurrence_Of (Selector, Loc));
2936
2937 if Nkind (Expression (Comp)) = N_Qualified_Expression then
2938 Expr_Q := Expression (Expression (Comp));
2939 else
2940 Expr_Q := Expression (Comp);
2941 end if;
2942
2943 -- The controller is the one of the parent type defining the
2944 -- component (in case of inherited components).
2945
2946 if Needs_Finalization (Comp_Type) then
2947 Internal_Final_List :=
2948 Make_Selected_Component (Loc,
2949 Prefix => Convert_To (
2950 Scope (Original_Record_Component (Selector)),
2951 New_Copy_Tree (Target)),
2952 Selector_Name =>
2953 Make_Identifier (Loc, Name_uController));
2954
2955 Internal_Final_List :=
2956 Make_Selected_Component (Loc,
2957 Prefix => Internal_Final_List,
2958 Selector_Name => Make_Identifier (Loc, Name_F));
2959
2960 -- The internal final list can be part of a constant object
2961
2962 Set_Assignment_OK (Internal_Final_List);
2963
2964 else
2965 Internal_Final_List := Empty;
2966 end if;
2967
2968 -- Now either create the assignment or generate the code for the
2969 -- inner aggregate top-down.
2970
2971 if Is_Delayed_Aggregate (Expr_Q) then
2972
2973 -- We have the following case of aggregate nesting inside
2974 -- an object declaration:
2975
2976 -- type Arr_Typ is array (Integer range <>) of ...;
2977
2978 -- type Rec_Typ (...) is record
2979 -- Obj_Arr_Typ : Arr_Typ (A .. B);
2980 -- end record;
2981
2982 -- Obj_Rec_Typ : Rec_Typ := (...,
2983 -- Obj_Arr_Typ => (X => (...), Y => (...)));
2984
2985 -- The length of the ranges of the aggregate and Obj_Add_Typ
2986 -- are equal (B - A = Y - X), but they do not coincide (X /=
2987 -- A and B /= Y). This case requires array sliding which is
2988 -- performed in the following manner:
2989
2990 -- subtype Arr_Sub is Arr_Typ (X .. Y);
2991 -- Temp : Arr_Sub;
2992 -- Temp (X) := (...);
2993 -- ...
2994 -- Temp (Y) := (...);
2995 -- Obj_Rec_Typ.Obj_Arr_Typ := Temp;
2996
2997 if Ekind (Comp_Type) = E_Array_Subtype
2998 and then Is_Int_Range_Bounds (Aggregate_Bounds (Expr_Q))
2999 and then Is_Int_Range_Bounds (First_Index (Comp_Type))
3000 and then not
3001 Compatible_Int_Bounds
3002 (Agg_Bounds => Aggregate_Bounds (Expr_Q),
3003 Typ_Bounds => First_Index (Comp_Type))
3004 then
3005 -- Create the array subtype with bounds equal to those of
3006 -- the corresponding aggregate.
3007
3008 declare
3009 SubE : constant Entity_Id :=
3010 Make_Defining_Identifier (Loc,
3011 Chars => New_Internal_Name ('T'));
3012
3013 SubD : constant Node_Id :=
3014 Make_Subtype_Declaration (Loc,
3015 Defining_Identifier => SubE,
3016 Subtype_Indication =>
3017 Make_Subtype_Indication (Loc,
3018 Subtype_Mark =>
3019 New_Reference_To
3020 (Etype (Comp_Type), Loc),
3021 Constraint =>
3022 Make_Index_Or_Discriminant_Constraint
3023 (Loc,
3024 Constraints => New_List (
3025 New_Copy_Tree
3026 (Aggregate_Bounds (Expr_Q))))));
3027
3028 -- Create a temporary array of the above subtype which
3029 -- will be used to capture the aggregate assignments.
3030
3031 TmpE : constant Entity_Id := Make_Temporary (Loc, 'A', N);
3032
3033 TmpD : constant Node_Id :=
3034 Make_Object_Declaration (Loc,
3035 Defining_Identifier => TmpE,
3036 Object_Definition =>
3037 New_Reference_To (SubE, Loc));
3038
3039 begin
3040 Set_No_Initialization (TmpD);
3041 Append_To (L, SubD);
3042 Append_To (L, TmpD);
3043
3044 -- Expand aggregate into assignments to the temp array
3045
3046 Append_List_To (L,
3047 Late_Expansion (Expr_Q, Comp_Type,
3048 New_Reference_To (TmpE, Loc), Internal_Final_List));
3049
3050 -- Slide
3051
3052 Append_To (L,
3053 Make_Assignment_Statement (Loc,
3054 Name => New_Copy_Tree (Comp_Expr),
3055 Expression => New_Reference_To (TmpE, Loc)));
3056
3057 -- Do not pass the original aggregate to Gigi as is,
3058 -- since it will potentially clobber the front or the end
3059 -- of the array. Setting the expression to empty is safe
3060 -- since all aggregates are expanded into assignments.
3061
3062 if Present (Obj) then
3063 Set_Expression (Parent (Obj), Empty);
3064 end if;
3065 end;
3066
3067 -- Normal case (sliding not required)
3068
3069 else
3070 Append_List_To (L,
3071 Late_Expansion (Expr_Q, Comp_Type, Comp_Expr,
3072 Internal_Final_List));
3073 end if;
3074
3075 -- Expr_Q is not delayed aggregate
3076
3077 else
3078 if Has_Discriminants (Typ) then
3079 Replace_Discriminants (Expr_Q);
3080 end if;
3081
3082 Instr :=
3083 Make_OK_Assignment_Statement (Loc,
3084 Name => Comp_Expr,
3085 Expression => Expr_Q);
3086
3087 Set_No_Ctrl_Actions (Instr);
3088 Append_To (L, Instr);
3089
3090 -- Adjust the tag if tagged (because of possible view
3091 -- conversions), unless compiling for a VM where tags are
3092 -- implicit.
3093
3094 -- tmp.comp._tag := comp_typ'tag;
3095
3096 if Is_Tagged_Type (Comp_Type)
3097 and then Tagged_Type_Expansion
3098 then
3099 Instr :=
3100 Make_OK_Assignment_Statement (Loc,
3101 Name =>
3102 Make_Selected_Component (Loc,
3103 Prefix => New_Copy_Tree (Comp_Expr),
3104 Selector_Name =>
3105 New_Reference_To
3106 (First_Tag_Component (Comp_Type), Loc)),
3107
3108 Expression =>
3109 Unchecked_Convert_To (RTE (RE_Tag),
3110 New_Reference_To
3111 (Node (First_Elmt (Access_Disp_Table (Comp_Type))),
3112 Loc)));
3113
3114 Append_To (L, Instr);
3115 end if;
3116
3117 -- Adjust and Attach the component to the proper controller
3118
3119 -- Adjust (tmp.comp);
3120 -- Attach_To_Final_List (tmp.comp,
3121 -- comp_typ (tmp)._record_controller.f)
3122
3123 if Needs_Finalization (Comp_Type)
3124 and then not Is_Limited_Type (Comp_Type)
3125 then
3126 Append_List_To (L,
3127 Make_Adjust_Call (
3128 Ref => New_Copy_Tree (Comp_Expr),
3129 Typ => Comp_Type,
3130 Flist_Ref => Internal_Final_List,
3131 With_Attach => Make_Integer_Literal (Loc, 1)));
3132 end if;
3133 end if;
3134
3135 -- ???
3136
3137 elsif Ekind (Selector) = E_Discriminant
3138 and then Nkind (N) /= N_Extension_Aggregate
3139 and then Nkind (Parent (N)) = N_Component_Association
3140 and then Is_Constrained (Typ)
3141 then
3142 -- We must check that the discriminant value imposed by the
3143 -- context is the same as the value given in the subaggregate,
3144 -- because after the expansion into assignments there is no
3145 -- record on which to perform a regular discriminant check.
3146
3147 declare
3148 D_Val : Elmt_Id;
3149 Disc : Entity_Id;
3150
3151 begin
3152 D_Val := First_Elmt (Discriminant_Constraint (Typ));
3153 Disc := First_Discriminant (Typ);
3154 while Chars (Disc) /= Chars (Selector) loop
3155 Next_Discriminant (Disc);
3156 Next_Elmt (D_Val);
3157 end loop;
3158
3159 pragma Assert (Present (D_Val));
3160
3161 -- This check cannot performed for components that are
3162 -- constrained by a current instance, because this is not a
3163 -- value that can be compared with the actual constraint.
3164
3165 if Nkind (Node (D_Val)) /= N_Attribute_Reference
3166 or else not Is_Entity_Name (Prefix (Node (D_Val)))
3167 or else not Is_Type (Entity (Prefix (Node (D_Val))))
3168 then
3169 Append_To (L,
3170 Make_Raise_Constraint_Error (Loc,
3171 Condition =>
3172 Make_Op_Ne (Loc,
3173 Left_Opnd => New_Copy_Tree (Node (D_Val)),
3174 Right_Opnd => Expression (Comp)),
3175 Reason => CE_Discriminant_Check_Failed));
3176
3177 else
3178 -- Find self-reference in previous discriminant assignment,
3179 -- and replace with proper expression.
3180
3181 declare
3182 Ass : Node_Id;
3183
3184 begin
3185 Ass := First (L);
3186 while Present (Ass) loop
3187 if Nkind (Ass) = N_Assignment_Statement
3188 and then Nkind (Name (Ass)) = N_Selected_Component
3189 and then Chars (Selector_Name (Name (Ass))) =
3190 Chars (Disc)
3191 then
3192 Set_Expression
3193 (Ass, New_Copy_Tree (Expression (Comp)));
3194 exit;
3195 end if;
3196 Next (Ass);
3197 end loop;
3198 end;
3199 end if;
3200 end;
3201 end if;
3202
3203 Next (Comp);
3204 end loop;
3205
3206 -- If the type is tagged, the tag needs to be initialized (unless
3207 -- compiling for the Java VM where tags are implicit). It is done
3208 -- late in the initialization process because in some cases, we call
3209 -- the init proc of an ancestor which will not leave out the right tag
3210
3211 if Ancestor_Is_Expression then
3212 null;
3213
3214 -- For CPP types we generated a call to the C++ default constructor
3215 -- before the components have been initialized to ensure the proper
3216 -- initialization of the _Tag component (see above).
3217
3218 elsif Is_CPP_Class (Typ) then
3219 null;
3220
3221 elsif Is_Tagged_Type (Typ) and then Tagged_Type_Expansion then
3222 Instr :=
3223 Make_OK_Assignment_Statement (Loc,
3224 Name =>
3225 Make_Selected_Component (Loc,
3226 Prefix => New_Copy_Tree (Target),
3227 Selector_Name =>
3228 New_Reference_To
3229 (First_Tag_Component (Base_Type (Typ)), Loc)),
3230
3231 Expression =>
3232 Unchecked_Convert_To (RTE (RE_Tag),
3233 New_Reference_To
3234 (Node (First_Elmt (Access_Disp_Table (Base_Type (Typ)))),
3235 Loc)));
3236
3237 Append_To (L, Instr);
3238
3239 -- Ada 2005 (AI-251): If the tagged type has been derived from
3240 -- abstract interfaces we must also initialize the tags of the
3241 -- secondary dispatch tables.
3242
3243 if Has_Interfaces (Base_Type (Typ)) then
3244 Init_Secondary_Tags
3245 (Typ => Base_Type (Typ),
3246 Target => Target,
3247 Stmts_List => L);
3248 end if;
3249 end if;
3250
3251 -- If the controllers have not been initialized yet (by lack of non-
3252 -- discriminant components), let's do it now.
3253
3254 Gen_Ctrl_Actions_For_Aggr;
3255
3256 return L;
3257 end Build_Record_Aggr_Code;
3258
3259 -------------------------------
3260 -- Convert_Aggr_In_Allocator --
3261 -------------------------------
3262
3263 procedure Convert_Aggr_In_Allocator
3264 (Alloc : Node_Id;
3265 Decl : Node_Id;
3266 Aggr : Node_Id)
3267 is
3268 Loc : constant Source_Ptr := Sloc (Aggr);
3269 Typ : constant Entity_Id := Etype (Aggr);
3270 Temp : constant Entity_Id := Defining_Identifier (Decl);
3271
3272 Occ : constant Node_Id :=
3273 Unchecked_Convert_To (Typ,
3274 Make_Explicit_Dereference (Loc,
3275 New_Reference_To (Temp, Loc)));
3276
3277 Access_Type : constant Entity_Id := Etype (Temp);
3278 Flist : Entity_Id;
3279
3280 begin
3281 -- If the allocator is for an access discriminant, there is no
3282 -- finalization list for the anonymous access type, and the eventual
3283 -- finalization of the object is handled through the coextension
3284 -- mechanism. If the enclosing object is not dynamically allocated,
3285 -- the access discriminant is itself placed on the stack. Otherwise,
3286 -- some other finalization list is used (see exp_ch4.adb).
3287
3288 -- Decl has been inserted in the code ahead of the allocator, using
3289 -- Insert_Actions. We use Insert_Actions below as well, to ensure that
3290 -- subsequent insertions are done in the proper order. Using (for
3291 -- example) Insert_Actions_After to place the expanded aggregate
3292 -- immediately after Decl may lead to out-of-order references if the
3293 -- allocator has generated a finalization list, as when the designated
3294 -- object is controlled and there is an open transient scope.
3295
3296 if Ekind (Access_Type) = E_Anonymous_Access_Type
3297 and then Nkind (Associated_Node_For_Itype (Access_Type)) =
3298 N_Discriminant_Specification
3299 then
3300 Flist := Empty;
3301 else
3302 Flist := Find_Final_List (Access_Type);
3303 end if;
3304
3305 if Is_Array_Type (Typ) then
3306 Convert_Array_Aggr_In_Allocator (Decl, Aggr, Occ);
3307
3308 elsif Has_Default_Init_Comps (Aggr) then
3309 declare
3310 L : constant List_Id := New_List;
3311 Init_Stmts : List_Id;
3312
3313 begin
3314 Init_Stmts :=
3315 Late_Expansion
3316 (Aggr, Typ, Occ,
3317 Flist,
3318 Associated_Final_Chain (Base_Type (Access_Type)));
3319
3320 -- ??? Dubious actual for Obj: expect 'the original object being
3321 -- initialized'
3322
3323 if Has_Task (Typ) then
3324 Build_Task_Allocate_Block_With_Init_Stmts (L, Aggr, Init_Stmts);
3325 Insert_Actions (Alloc, L);
3326 else
3327 Insert_Actions (Alloc, Init_Stmts);
3328 end if;
3329 end;
3330
3331 else
3332 Insert_Actions (Alloc,
3333 Late_Expansion
3334 (Aggr, Typ, Occ, Flist,
3335 Associated_Final_Chain (Base_Type (Access_Type))));
3336
3337 -- ??? Dubious actual for Obj: expect 'the original object being
3338 -- initialized'
3339
3340 end if;
3341 end Convert_Aggr_In_Allocator;
3342
3343 --------------------------------
3344 -- Convert_Aggr_In_Assignment --
3345 --------------------------------
3346
3347 procedure Convert_Aggr_In_Assignment (N : Node_Id) is
3348 Aggr : Node_Id := Expression (N);
3349 Typ : constant Entity_Id := Etype (Aggr);
3350 Occ : constant Node_Id := New_Copy_Tree (Name (N));
3351
3352 begin
3353 if Nkind (Aggr) = N_Qualified_Expression then
3354 Aggr := Expression (Aggr);
3355 end if;
3356
3357 Insert_Actions_After (N,
3358 Late_Expansion
3359 (Aggr, Typ, Occ,
3360 Find_Final_List (Typ, New_Copy_Tree (Occ))));
3361 end Convert_Aggr_In_Assignment;
3362
3363 ---------------------------------
3364 -- Convert_Aggr_In_Object_Decl --
3365 ---------------------------------
3366
3367 procedure Convert_Aggr_In_Object_Decl (N : Node_Id) is
3368 Obj : constant Entity_Id := Defining_Identifier (N);
3369 Aggr : Node_Id := Expression (N);
3370 Loc : constant Source_Ptr := Sloc (Aggr);
3371 Typ : constant Entity_Id := Etype (Aggr);
3372 Occ : constant Node_Id := New_Occurrence_Of (Obj, Loc);
3373
3374 function Discriminants_Ok return Boolean;
3375 -- If the object type is constrained, the discriminants in the
3376 -- aggregate must be checked against the discriminants of the subtype.
3377 -- This cannot be done using Apply_Discriminant_Checks because after
3378 -- expansion there is no aggregate left to check.
3379
3380 ----------------------
3381 -- Discriminants_Ok --
3382 ----------------------
3383
3384 function Discriminants_Ok return Boolean is
3385 Cond : Node_Id := Empty;
3386 Check : Node_Id;
3387 D : Entity_Id;
3388 Disc1 : Elmt_Id;
3389 Disc2 : Elmt_Id;
3390 Val1 : Node_Id;
3391 Val2 : Node_Id;
3392
3393 begin
3394 D := First_Discriminant (Typ);
3395 Disc1 := First_Elmt (Discriminant_Constraint (Typ));
3396 Disc2 := First_Elmt (Discriminant_Constraint (Etype (Obj)));
3397 while Present (Disc1) and then Present (Disc2) loop
3398 Val1 := Node (Disc1);
3399 Val2 := Node (Disc2);
3400
3401 if not Is_OK_Static_Expression (Val1)
3402 or else not Is_OK_Static_Expression (Val2)
3403 then
3404 Check := Make_Op_Ne (Loc,
3405 Left_Opnd => Duplicate_Subexpr (Val1),
3406 Right_Opnd => Duplicate_Subexpr (Val2));
3407
3408 if No (Cond) then
3409 Cond := Check;
3410
3411 else
3412 Cond := Make_Or_Else (Loc,
3413 Left_Opnd => Cond,
3414 Right_Opnd => Check);
3415 end if;
3416
3417 elsif Expr_Value (Val1) /= Expr_Value (Val2) then
3418 Apply_Compile_Time_Constraint_Error (Aggr,
3419 Msg => "incorrect value for discriminant&?",
3420 Reason => CE_Discriminant_Check_Failed,
3421 Ent => D);
3422 return False;
3423 end if;
3424
3425 Next_Discriminant (D);
3426 Next_Elmt (Disc1);
3427 Next_Elmt (Disc2);
3428 end loop;
3429
3430 -- If any discriminant constraint is non-static, emit a check
3431
3432 if Present (Cond) then
3433 Insert_Action (N,
3434 Make_Raise_Constraint_Error (Loc,
3435 Condition => Cond,
3436 Reason => CE_Discriminant_Check_Failed));
3437 end if;
3438
3439 return True;
3440 end Discriminants_Ok;
3441
3442 -- Start of processing for Convert_Aggr_In_Object_Decl
3443
3444 begin
3445 Set_Assignment_OK (Occ);
3446
3447 if Nkind (Aggr) = N_Qualified_Expression then
3448 Aggr := Expression (Aggr);
3449 end if;
3450
3451 if Has_Discriminants (Typ)
3452 and then Typ /= Etype (Obj)
3453 and then Is_Constrained (Etype (Obj))
3454 and then not Discriminants_Ok
3455 then
3456 return;
3457 end if;
3458
3459 -- If the context is an extended return statement, it has its own
3460 -- finalization machinery (i.e. works like a transient scope) and
3461 -- we do not want to create an additional one, because objects on
3462 -- the finalization list of the return must be moved to the caller's
3463 -- finalization list to complete the return.
3464
3465 -- However, if the aggregate is limited, it is built in place, and the
3466 -- controlled components are not assigned to intermediate temporaries
3467 -- so there is no need for a transient scope in this case either.
3468
3469 if Requires_Transient_Scope (Typ)
3470 and then Ekind (Current_Scope) /= E_Return_Statement
3471 and then not Is_Limited_Type (Typ)
3472 then
3473 Establish_Transient_Scope
3474 (Aggr,
3475 Sec_Stack =>
3476 Is_Controlled (Typ) or else Has_Controlled_Component (Typ));
3477 end if;
3478
3479 Insert_Actions_After (N, Late_Expansion (Aggr, Typ, Occ, Obj => Obj));
3480 Set_No_Initialization (N);
3481 Initialize_Discriminants (N, Typ);
3482 end Convert_Aggr_In_Object_Decl;
3483
3484 -------------------------------------
3485 -- Convert_Array_Aggr_In_Allocator --
3486 -------------------------------------
3487
3488 procedure Convert_Array_Aggr_In_Allocator
3489 (Decl : Node_Id;
3490 Aggr : Node_Id;
3491 Target : Node_Id)
3492 is
3493 Aggr_Code : List_Id;
3494 Typ : constant Entity_Id := Etype (Aggr);
3495 Ctyp : constant Entity_Id := Component_Type (Typ);
3496
3497 begin
3498 -- The target is an explicit dereference of the allocated object.
3499 -- Generate component assignments to it, as for an aggregate that
3500 -- appears on the right-hand side of an assignment statement.
3501
3502 Aggr_Code :=
3503 Build_Array_Aggr_Code (Aggr,
3504 Ctype => Ctyp,
3505 Index => First_Index (Typ),
3506 Into => Target,
3507 Scalar_Comp => Is_Scalar_Type (Ctyp));
3508
3509 Insert_Actions_After (Decl, Aggr_Code);
3510 end Convert_Array_Aggr_In_Allocator;
3511
3512 ----------------------------
3513 -- Convert_To_Assignments --
3514 ----------------------------
3515
3516 procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id) is
3517 Loc : constant Source_Ptr := Sloc (N);
3518 T : Entity_Id;
3519 Temp : Entity_Id;
3520
3521 Instr : Node_Id;
3522 Target_Expr : Node_Id;
3523 Parent_Kind : Node_Kind;
3524 Unc_Decl : Boolean := False;
3525 Parent_Node : Node_Id;
3526
3527 begin
3528 pragma Assert (not Is_Static_Dispatch_Table_Aggregate (N));
3529 pragma Assert (Is_Record_Type (Typ));
3530
3531 Parent_Node := Parent (N);
3532 Parent_Kind := Nkind (Parent_Node);
3533
3534 if Parent_Kind = N_Qualified_Expression then
3535
3536 -- Check if we are in a unconstrained declaration because in this
3537 -- case the current delayed expansion mechanism doesn't work when
3538 -- the declared object size depend on the initializing expr.
3539
3540 begin
3541 Parent_Node := Parent (Parent_Node);
3542 Parent_Kind := Nkind (Parent_Node);
3543
3544 if Parent_Kind = N_Object_Declaration then
3545 Unc_Decl :=
3546 not Is_Entity_Name (Object_Definition (Parent_Node))
3547 or else Has_Discriminants
3548 (Entity (Object_Definition (Parent_Node)))
3549 or else Is_Class_Wide_Type
3550 (Entity (Object_Definition (Parent_Node)));
3551 end if;
3552 end;
3553 end if;
3554
3555 -- Just set the Delay flag in the cases where the transformation will be
3556 -- done top down from above.
3557
3558 if False
3559
3560 -- Internal aggregate (transformed when expanding the parent)
3561
3562 or else Parent_Kind = N_Aggregate
3563 or else Parent_Kind = N_Extension_Aggregate
3564 or else Parent_Kind = N_Component_Association
3565
3566 -- Allocator (see Convert_Aggr_In_Allocator)
3567
3568 or else Parent_Kind = N_Allocator
3569
3570 -- Object declaration (see Convert_Aggr_In_Object_Decl)
3571
3572 or else (Parent_Kind = N_Object_Declaration and then not Unc_Decl)
3573
3574 -- Safe assignment (see Convert_Aggr_Assignments). So far only the
3575 -- assignments in init procs are taken into account.
3576
3577 or else (Parent_Kind = N_Assignment_Statement
3578 and then Inside_Init_Proc)
3579
3580 -- (Ada 2005) An inherently limited type in a return statement,
3581 -- which will be handled in a build-in-place fashion, and may be
3582 -- rewritten as an extended return and have its own finalization
3583 -- machinery. In the case of a simple return, the aggregate needs
3584 -- to be delayed until the scope for the return statement has been
3585 -- created, so that any finalization chain will be associated with
3586 -- that scope. For extended returns, we delay expansion to avoid the
3587 -- creation of an unwanted transient scope that could result in
3588 -- premature finalization of the return object (which is built in
3589 -- in place within the caller's scope).
3590
3591 or else
3592 (Is_Inherently_Limited_Type (Typ)
3593 and then
3594 (Nkind (Parent (Parent_Node)) = N_Extended_Return_Statement
3595 or else Nkind (Parent_Node) = N_Simple_Return_Statement))
3596 then
3597 Set_Expansion_Delayed (N);
3598 return;
3599 end if;
3600
3601 if Requires_Transient_Scope (Typ) then
3602 Establish_Transient_Scope
3603 (N, Sec_Stack =>
3604 Is_Controlled (Typ) or else Has_Controlled_Component (Typ));
3605 end if;
3606
3607 -- If the aggregate is non-limited, create a temporary. If it is limited
3608 -- and the context is an assignment, this is a subaggregate for an
3609 -- enclosing aggregate being expanded. It must be built in place, so use
3610 -- the target of the current assignment.
3611
3612 if Is_Limited_Type (Typ)
3613 and then Nkind (Parent (N)) = N_Assignment_Statement
3614 then
3615 Target_Expr := New_Copy_Tree (Name (Parent (N)));
3616 Insert_Actions
3617 (Parent (N), Build_Record_Aggr_Code (N, Typ, Target_Expr));
3618 Rewrite (Parent (N), Make_Null_Statement (Loc));
3619
3620 else
3621 Temp := Make_Temporary (Loc, 'A', N);
3622
3623 -- If the type inherits unknown discriminants, use the view with
3624 -- known discriminants if available.
3625
3626 if Has_Unknown_Discriminants (Typ)
3627 and then Present (Underlying_Record_View (Typ))
3628 then
3629 T := Underlying_Record_View (Typ);
3630 else
3631 T := Typ;
3632 end if;
3633
3634 Instr :=
3635 Make_Object_Declaration (Loc,
3636 Defining_Identifier => Temp,
3637 Object_Definition => New_Occurrence_Of (T, Loc));
3638
3639 Set_No_Initialization (Instr);
3640 Insert_Action (N, Instr);
3641 Initialize_Discriminants (Instr, T);
3642 Target_Expr := New_Occurrence_Of (Temp, Loc);
3643 Insert_Actions (N, Build_Record_Aggr_Code (N, T, Target_Expr));
3644 Rewrite (N, New_Occurrence_Of (Temp, Loc));
3645 Analyze_And_Resolve (N, T);
3646 end if;
3647 end Convert_To_Assignments;
3648
3649 ---------------------------
3650 -- Convert_To_Positional --
3651 ---------------------------
3652
3653 procedure Convert_To_Positional
3654 (N : Node_Id;
3655 Max_Others_Replicate : Nat := 5;
3656 Handle_Bit_Packed : Boolean := False)
3657 is
3658 Typ : constant Entity_Id := Etype (N);
3659
3660 Static_Components : Boolean := True;
3661
3662 procedure Check_Static_Components;
3663 -- Check whether all components of the aggregate are compile-time known
3664 -- values, and can be passed as is to the back-end without further
3665 -- expansion.
3666
3667 function Flatten
3668 (N : Node_Id;
3669 Ix : Node_Id;
3670 Ixb : Node_Id) return Boolean;
3671 -- Convert the aggregate into a purely positional form if possible. On
3672 -- entry the bounds of all dimensions are known to be static, and the
3673 -- total number of components is safe enough to expand.
3674
3675 function Is_Flat (N : Node_Id; Dims : Int) return Boolean;
3676 -- Return True iff the array N is flat (which is not rivial in the case
3677 -- of multidimensionsl aggregates).
3678
3679 -----------------------------
3680 -- Check_Static_Components --
3681 -----------------------------
3682
3683 procedure Check_Static_Components is
3684 Expr : Node_Id;
3685
3686 begin
3687 Static_Components := True;
3688
3689 if Nkind (N) = N_String_Literal then
3690 null;
3691
3692 elsif Present (Expressions (N)) then
3693 Expr := First (Expressions (N));
3694 while Present (Expr) loop
3695 if Nkind (Expr) /= N_Aggregate
3696 or else not Compile_Time_Known_Aggregate (Expr)
3697 or else Expansion_Delayed (Expr)
3698 then
3699 Static_Components := False;
3700 exit;
3701 end if;
3702
3703 Next (Expr);
3704 end loop;
3705 end if;
3706
3707 if Nkind (N) = N_Aggregate
3708 and then Present (Component_Associations (N))
3709 then
3710 Expr := First (Component_Associations (N));
3711 while Present (Expr) loop
3712 if Nkind (Expression (Expr)) = N_Integer_Literal then
3713 null;
3714
3715 elsif Nkind (Expression (Expr)) /= N_Aggregate
3716 or else
3717 not Compile_Time_Known_Aggregate (Expression (Expr))
3718 or else Expansion_Delayed (Expression (Expr))
3719 then
3720 Static_Components := False;
3721 exit;
3722 end if;
3723
3724 Next (Expr);
3725 end loop;
3726 end if;
3727 end Check_Static_Components;
3728
3729 -------------
3730 -- Flatten --
3731 -------------
3732
3733 function Flatten
3734 (N : Node_Id;
3735 Ix : Node_Id;
3736 Ixb : Node_Id) return Boolean
3737 is
3738 Loc : constant Source_Ptr := Sloc (N);
3739 Blo : constant Node_Id := Type_Low_Bound (Etype (Ixb));
3740 Lo : constant Node_Id := Type_Low_Bound (Etype (Ix));
3741 Hi : constant Node_Id := Type_High_Bound (Etype (Ix));
3742 Lov : Uint;
3743 Hiv : Uint;
3744
3745 begin
3746 if Nkind (Original_Node (N)) = N_String_Literal then
3747 return True;
3748 end if;
3749
3750 if not Compile_Time_Known_Value (Lo)
3751 or else not Compile_Time_Known_Value (Hi)
3752 then
3753 return False;
3754 end if;
3755
3756 Lov := Expr_Value (Lo);
3757 Hiv := Expr_Value (Hi);
3758
3759 if Hiv < Lov
3760 or else not Compile_Time_Known_Value (Blo)
3761 then
3762 return False;
3763 end if;
3764
3765 -- Determine if set of alternatives is suitable for conversion and
3766 -- build an array containing the values in sequence.
3767
3768 declare
3769 Vals : array (UI_To_Int (Lov) .. UI_To_Int (Hiv))
3770 of Node_Id := (others => Empty);
3771 -- The values in the aggregate sorted appropriately
3772
3773 Vlist : List_Id;
3774 -- Same data as Vals in list form
3775
3776 Rep_Count : Nat;
3777 -- Used to validate Max_Others_Replicate limit
3778
3779 Elmt : Node_Id;
3780 Num : Int := UI_To_Int (Lov);
3781 Choice : Node_Id;
3782 Lo, Hi : Node_Id;
3783
3784 begin
3785 if Present (Expressions (N)) then
3786 Elmt := First (Expressions (N));
3787 while Present (Elmt) loop
3788 if Nkind (Elmt) = N_Aggregate
3789 and then Present (Next_Index (Ix))
3790 and then
3791 not Flatten (Elmt, Next_Index (Ix), Next_Index (Ixb))
3792 then
3793 return False;
3794 end if;
3795
3796 Vals (Num) := Relocate_Node (Elmt);
3797 Num := Num + 1;
3798
3799 Next (Elmt);
3800 end loop;
3801 end if;
3802
3803 if No (Component_Associations (N)) then
3804 return True;
3805 end if;
3806
3807 Elmt := First (Component_Associations (N));
3808
3809 if Nkind (Expression (Elmt)) = N_Aggregate then
3810 if Present (Next_Index (Ix))
3811 and then
3812 not Flatten
3813 (Expression (Elmt), Next_Index (Ix), Next_Index (Ixb))
3814 then
3815 return False;
3816 end if;
3817 end if;
3818
3819 Component_Loop : while Present (Elmt) loop
3820 Choice := First (Choices (Elmt));
3821 Choice_Loop : while Present (Choice) loop
3822
3823 -- If we have an others choice, fill in the missing elements
3824 -- subject to the limit established by Max_Others_Replicate.
3825
3826 if Nkind (Choice) = N_Others_Choice then
3827 Rep_Count := 0;
3828
3829 for J in Vals'Range loop
3830 if No (Vals (J)) then
3831 Vals (J) := New_Copy_Tree (Expression (Elmt));
3832 Rep_Count := Rep_Count + 1;
3833
3834 -- Check for maximum others replication. Note that
3835 -- we skip this test if either of the restrictions
3836 -- No_Elaboration_Code or No_Implicit_Loops is
3837 -- active, if this is a preelaborable unit or a
3838 -- predefined unit. This ensures that predefined
3839 -- units get the same level of constant folding in
3840 -- Ada 95 and Ada 05, where their categorization
3841 -- has changed.
3842
3843 declare
3844 P : constant Entity_Id :=
3845 Cunit_Entity (Current_Sem_Unit);
3846
3847 begin
3848 -- Check if duplication OK and if so continue
3849 -- processing.
3850
3851 if Restriction_Active (No_Elaboration_Code)
3852 or else Restriction_Active (No_Implicit_Loops)
3853 or else Is_Preelaborated (P)
3854 or else (Ekind (P) = E_Package_Body
3855 and then
3856 Is_Preelaborated (Spec_Entity (P)))
3857 or else
3858 Is_Predefined_File_Name
3859 (Unit_File_Name (Get_Source_Unit (P)))
3860 then
3861 null;
3862
3863 -- If duplication not OK, then we return False
3864 -- if the replication count is too high
3865
3866 elsif Rep_Count > Max_Others_Replicate then
3867 return False;
3868
3869 -- Continue on if duplication not OK, but the
3870 -- replication count is not excessive.
3871
3872 else
3873 null;
3874 end if;
3875 end;
3876 end if;
3877 end loop;
3878
3879 exit Component_Loop;
3880
3881 -- Case of a subtype mark
3882
3883 elsif Nkind (Choice) = N_Identifier
3884 and then Is_Type (Entity (Choice))
3885 then
3886 Lo := Type_Low_Bound (Etype (Choice));
3887 Hi := Type_High_Bound (Etype (Choice));
3888
3889 -- Case of subtype indication
3890
3891 elsif Nkind (Choice) = N_Subtype_Indication then
3892 Lo := Low_Bound (Range_Expression (Constraint (Choice)));
3893 Hi := High_Bound (Range_Expression (Constraint (Choice)));
3894
3895 -- Case of a range
3896
3897 elsif Nkind (Choice) = N_Range then
3898 Lo := Low_Bound (Choice);
3899 Hi := High_Bound (Choice);
3900
3901 -- Normal subexpression case
3902
3903 else pragma Assert (Nkind (Choice) in N_Subexpr);
3904 if not Compile_Time_Known_Value (Choice) then
3905 return False;
3906
3907 else
3908 Vals (UI_To_Int (Expr_Value (Choice))) :=
3909 New_Copy_Tree (Expression (Elmt));
3910 goto Continue;
3911 end if;
3912 end if;
3913
3914 -- Range cases merge with Lo,Hi said
3915
3916 if not Compile_Time_Known_Value (Lo)
3917 or else
3918 not Compile_Time_Known_Value (Hi)
3919 then
3920 return False;
3921 else
3922 for J in UI_To_Int (Expr_Value (Lo)) ..
3923 UI_To_Int (Expr_Value (Hi))
3924 loop
3925 Vals (J) := New_Copy_Tree (Expression (Elmt));
3926 end loop;
3927 end if;
3928
3929 <<Continue>>
3930 Next (Choice);
3931 end loop Choice_Loop;
3932
3933 Next (Elmt);
3934 end loop Component_Loop;
3935
3936 -- If we get here the conversion is possible
3937
3938 Vlist := New_List;
3939 for J in Vals'Range loop
3940 Append (Vals (J), Vlist);
3941 end loop;
3942
3943 Rewrite (N, Make_Aggregate (Loc, Expressions => Vlist));
3944 Set_Aggregate_Bounds (N, Aggregate_Bounds (Original_Node (N)));
3945 return True;
3946 end;
3947 end Flatten;
3948
3949 -------------
3950 -- Is_Flat --
3951 -------------
3952
3953 function Is_Flat (N : Node_Id; Dims : Int) return Boolean is
3954 Elmt : Node_Id;
3955
3956 begin
3957 if Dims = 0 then
3958 return True;
3959
3960 elsif Nkind (N) = N_Aggregate then
3961 if Present (Component_Associations (N)) then
3962 return False;
3963
3964 else
3965 Elmt := First (Expressions (N));
3966 while Present (Elmt) loop
3967 if not Is_Flat (Elmt, Dims - 1) then
3968 return False;
3969 end if;
3970
3971 Next (Elmt);
3972 end loop;
3973
3974 return True;
3975 end if;
3976 else
3977 return True;
3978 end if;
3979 end Is_Flat;
3980
3981 -- Start of processing for Convert_To_Positional
3982
3983 begin
3984 -- Ada 2005 (AI-287): Do not convert in case of default initialized
3985 -- components because in this case will need to call the corresponding
3986 -- IP procedure.
3987
3988 if Has_Default_Init_Comps (N) then
3989 return;
3990 end if;
3991
3992 if Is_Flat (N, Number_Dimensions (Typ)) then
3993 return;
3994 end if;
3995
3996 if Is_Bit_Packed_Array (Typ)
3997 and then not Handle_Bit_Packed
3998 then
3999 return;
4000 end if;
4001
4002 -- Do not convert to positional if controlled components are involved
4003 -- since these require special processing
4004
4005 if Has_Controlled_Component (Typ) then
4006 return;
4007 end if;
4008
4009 Check_Static_Components;
4010
4011 -- If the size is known, or all the components are static, try to
4012 -- build a fully positional aggregate.
4013
4014 -- The size of the type may not be known for an aggregate with
4015 -- discriminated array components, but if the components are static
4016 -- it is still possible to verify statically that the length is
4017 -- compatible with the upper bound of the type, and therefore it is
4018 -- worth flattening such aggregates as well.
4019
4020 -- For now the back-end expands these aggregates into individual
4021 -- assignments to the target anyway, but it is conceivable that
4022 -- it will eventually be able to treat such aggregates statically???
4023
4024 if Aggr_Size_OK (N, Typ)
4025 and then Flatten (N, First_Index (Typ), First_Index (Base_Type (Typ)))
4026 then
4027 if Static_Components then
4028 Set_Compile_Time_Known_Aggregate (N);
4029 Set_Expansion_Delayed (N, False);
4030 end if;
4031
4032 Analyze_And_Resolve (N, Typ);
4033 end if;
4034 end Convert_To_Positional;
4035
4036 ----------------------------
4037 -- Expand_Array_Aggregate --
4038 ----------------------------
4039
4040 -- Array aggregate expansion proceeds as follows:
4041
4042 -- 1. If requested we generate code to perform all the array aggregate
4043 -- bound checks, specifically
4044
4045 -- (a) Check that the index range defined by aggregate bounds is
4046 -- compatible with corresponding index subtype.
4047
4048 -- (b) If an others choice is present check that no aggregate
4049 -- index is outside the bounds of the index constraint.
4050
4051 -- (c) For multidimensional arrays make sure that all subaggregates
4052 -- corresponding to the same dimension have the same bounds.
4053
4054 -- 2. Check for packed array aggregate which can be converted to a
4055 -- constant so that the aggregate disappeares completely.
4056
4057 -- 3. Check case of nested aggregate. Generally nested aggregates are
4058 -- handled during the processing of the parent aggregate.
4059
4060 -- 4. Check if the aggregate can be statically processed. If this is the
4061 -- case pass it as is to Gigi. Note that a necessary condition for
4062 -- static processing is that the aggregate be fully positional.
4063
4064 -- 5. If in place aggregate expansion is possible (i.e. no need to create
4065 -- a temporary) then mark the aggregate as such and return. Otherwise
4066 -- create a new temporary and generate the appropriate initialization
4067 -- code.
4068
4069 procedure Expand_Array_Aggregate (N : Node_Id) is
4070 Loc : constant Source_Ptr := Sloc (N);
4071
4072 Typ : constant Entity_Id := Etype (N);
4073 Ctyp : constant Entity_Id := Component_Type (Typ);
4074 -- Typ is the correct constrained array subtype of the aggregate
4075 -- Ctyp is the corresponding component type.
4076
4077 Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
4078 -- Number of aggregate index dimensions
4079
4080 Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id;
4081 Aggr_High : array (1 .. Aggr_Dimension) of Node_Id;
4082 -- Low and High bounds of the constraint for each aggregate index
4083
4084 Aggr_Index_Typ : array (1 .. Aggr_Dimension) of Entity_Id;
4085 -- The type of each index
4086
4087 Maybe_In_Place_OK : Boolean;
4088 -- If the type is neither controlled nor packed and the aggregate
4089 -- is the expression in an assignment, assignment in place may be
4090 -- possible, provided other conditions are met on the LHS.
4091
4092 Others_Present : array (1 .. Aggr_Dimension) of Boolean :=
4093 (others => False);
4094 -- If Others_Present (J) is True, then there is an others choice
4095 -- in one of the sub-aggregates of N at dimension J.
4096
4097 procedure Build_Constrained_Type (Positional : Boolean);
4098 -- If the subtype is not static or unconstrained, build a constrained
4099 -- type using the computable sizes of the aggregate and its sub-
4100 -- aggregates.
4101
4102 procedure Check_Bounds (Aggr_Bounds : Node_Id; Index_Bounds : Node_Id);
4103 -- Checks that the bounds of Aggr_Bounds are within the bounds defined
4104 -- by Index_Bounds.
4105
4106 procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos);
4107 -- Checks that in a multi-dimensional array aggregate all subaggregates
4108 -- corresponding to the same dimension have the same bounds.
4109 -- Sub_Aggr is an array sub-aggregate. Dim is the dimension
4110 -- corresponding to the sub-aggregate.
4111
4112 procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos);
4113 -- Computes the values of array Others_Present. Sub_Aggr is the
4114 -- array sub-aggregate we start the computation from. Dim is the
4115 -- dimension corresponding to the sub-aggregate.
4116
4117 function Has_Address_Clause (D : Node_Id) return Boolean;
4118 -- If the aggregate is the expression in an object declaration, it
4119 -- cannot be expanded in place. This function does a lookahead in the
4120 -- current declarative part to find an address clause for the object
4121 -- being declared.
4122
4123 function In_Place_Assign_OK return Boolean;
4124 -- Simple predicate to determine whether an aggregate assignment can
4125 -- be done in place, because none of the new values can depend on the
4126 -- components of the target of the assignment.
4127
4128 procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos);
4129 -- Checks that if an others choice is present in any sub-aggregate no
4130 -- aggregate index is outside the bounds of the index constraint.
4131 -- Sub_Aggr is an array sub-aggregate. Dim is the dimension
4132 -- corresponding to the sub-aggregate.
4133
4134 ----------------------------
4135 -- Build_Constrained_Type --
4136 ----------------------------
4137
4138 procedure Build_Constrained_Type (Positional : Boolean) is
4139 Loc : constant Source_Ptr := Sloc (N);
4140 Agg_Type : Entity_Id;
4141 Comp : Node_Id;
4142 Decl : Node_Id;
4143 Typ : constant Entity_Id := Etype (N);
4144 Indices : constant List_Id := New_List;
4145 Num : Int;
4146 Sub_Agg : Node_Id;
4147
4148 begin
4149 Agg_Type :=
4150 Make_Defining_Identifier (
4151 Loc, New_Internal_Name ('A'));
4152
4153 -- If the aggregate is purely positional, all its subaggregates
4154 -- have the same size. We collect the dimensions from the first
4155 -- subaggregate at each level.
4156
4157 if Positional then
4158 Sub_Agg := N;
4159
4160 for D in 1 .. Number_Dimensions (Typ) loop
4161 Sub_Agg := First (Expressions (Sub_Agg));
4162
4163 Comp := Sub_Agg;
4164 Num := 0;
4165 while Present (Comp) loop
4166 Num := Num + 1;
4167 Next (Comp);
4168 end loop;
4169
4170 Append (
4171 Make_Range (Loc,
4172 Low_Bound => Make_Integer_Literal (Loc, 1),
4173 High_Bound =>
4174 Make_Integer_Literal (Loc, Num)),
4175 Indices);
4176 end loop;
4177
4178 else
4179 -- We know the aggregate type is unconstrained and the aggregate
4180 -- is not processable by the back end, therefore not necessarily
4181 -- positional. Retrieve each dimension bounds (computed earlier).
4182 -- earlier.
4183
4184 for D in 1 .. Number_Dimensions (Typ) loop
4185 Append (
4186 Make_Range (Loc,
4187 Low_Bound => Aggr_Low (D),
4188 High_Bound => Aggr_High (D)),
4189 Indices);
4190 end loop;
4191 end if;
4192
4193 Decl :=
4194 Make_Full_Type_Declaration (Loc,
4195 Defining_Identifier => Agg_Type,
4196 Type_Definition =>
4197 Make_Constrained_Array_Definition (Loc,
4198 Discrete_Subtype_Definitions => Indices,
4199 Component_Definition =>
4200 Make_Component_Definition (Loc,
4201 Aliased_Present => False,
4202 Subtype_Indication =>
4203 New_Occurrence_Of (Component_Type (Typ), Loc))));
4204
4205 Insert_Action (N, Decl);
4206 Analyze (Decl);
4207 Set_Etype (N, Agg_Type);
4208 Set_Is_Itype (Agg_Type);
4209 Freeze_Itype (Agg_Type, N);
4210 end Build_Constrained_Type;
4211
4212 ------------------
4213 -- Check_Bounds --
4214 ------------------
4215
4216 procedure Check_Bounds (Aggr_Bounds : Node_Id; Index_Bounds : Node_Id) is
4217 Aggr_Lo : Node_Id;
4218 Aggr_Hi : Node_Id;
4219
4220 Ind_Lo : Node_Id;
4221 Ind_Hi : Node_Id;
4222
4223 Cond : Node_Id := Empty;
4224
4225 begin
4226 Get_Index_Bounds (Aggr_Bounds, Aggr_Lo, Aggr_Hi);
4227 Get_Index_Bounds (Index_Bounds, Ind_Lo, Ind_Hi);
4228
4229 -- Generate the following test:
4230 --
4231 -- [constraint_error when
4232 -- Aggr_Lo <= Aggr_Hi and then
4233 -- (Aggr_Lo < Ind_Lo or else Aggr_Hi > Ind_Hi)]
4234
4235 -- As an optimization try to see if some tests are trivially vacuous
4236 -- because we are comparing an expression against itself.
4237
4238 if Aggr_Lo = Ind_Lo and then Aggr_Hi = Ind_Hi then
4239 Cond := Empty;
4240
4241 elsif Aggr_Hi = Ind_Hi then
4242 Cond :=
4243 Make_Op_Lt (Loc,
4244 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4245 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Lo));
4246
4247 elsif Aggr_Lo = Ind_Lo then
4248 Cond :=
4249 Make_Op_Gt (Loc,
4250 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi),
4251 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Hi));
4252
4253 else
4254 Cond :=
4255 Make_Or_Else (Loc,
4256 Left_Opnd =>
4257 Make_Op_Lt (Loc,
4258 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4259 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Lo)),
4260
4261 Right_Opnd =>
4262 Make_Op_Gt (Loc,
4263 Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
4264 Right_Opnd => Duplicate_Subexpr (Ind_Hi)));
4265 end if;
4266
4267 if Present (Cond) then
4268 Cond :=
4269 Make_And_Then (Loc,
4270 Left_Opnd =>
4271 Make_Op_Le (Loc,
4272 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4273 Right_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi)),
4274
4275 Right_Opnd => Cond);
4276
4277 Set_Analyzed (Left_Opnd (Left_Opnd (Cond)), False);
4278 Set_Analyzed (Right_Opnd (Left_Opnd (Cond)), False);
4279 Insert_Action (N,
4280 Make_Raise_Constraint_Error (Loc,
4281 Condition => Cond,
4282 Reason => CE_Length_Check_Failed));
4283 end if;
4284 end Check_Bounds;
4285
4286 ----------------------------
4287 -- Check_Same_Aggr_Bounds --
4288 ----------------------------
4289
4290 procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos) is
4291 Sub_Lo : constant Node_Id := Low_Bound (Aggregate_Bounds (Sub_Aggr));
4292 Sub_Hi : constant Node_Id := High_Bound (Aggregate_Bounds (Sub_Aggr));
4293 -- The bounds of this specific sub-aggregate
4294
4295 Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
4296 Aggr_Hi : constant Node_Id := Aggr_High (Dim);
4297 -- The bounds of the aggregate for this dimension
4298
4299 Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
4300 -- The index type for this dimension.xxx
4301
4302 Cond : Node_Id := Empty;
4303 Assoc : Node_Id;
4304 Expr : Node_Id;
4305
4306 begin
4307 -- If index checks are on generate the test
4308
4309 -- [constraint_error when
4310 -- Aggr_Lo /= Sub_Lo or else Aggr_Hi /= Sub_Hi]
4311
4312 -- As an optimization try to see if some tests are trivially vacuos
4313 -- because we are comparing an expression against itself. Also for
4314 -- the first dimension the test is trivially vacuous because there
4315 -- is just one aggregate for dimension 1.
4316
4317 if Index_Checks_Suppressed (Ind_Typ) then
4318 Cond := Empty;
4319
4320 elsif Dim = 1
4321 or else (Aggr_Lo = Sub_Lo and then Aggr_Hi = Sub_Hi)
4322 then
4323 Cond := Empty;
4324
4325 elsif Aggr_Hi = Sub_Hi then
4326 Cond :=
4327 Make_Op_Ne (Loc,
4328 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4329 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo));
4330
4331 elsif Aggr_Lo = Sub_Lo then
4332 Cond :=
4333 Make_Op_Ne (Loc,
4334 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi),
4335 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Hi));
4336
4337 else
4338 Cond :=
4339 Make_Or_Else (Loc,
4340 Left_Opnd =>
4341 Make_Op_Ne (Loc,
4342 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4343 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo)),
4344
4345 Right_Opnd =>
4346 Make_Op_Ne (Loc,
4347 Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
4348 Right_Opnd => Duplicate_Subexpr (Sub_Hi)));
4349 end if;
4350
4351 if Present (Cond) then
4352 Insert_Action (N,
4353 Make_Raise_Constraint_Error (Loc,
4354 Condition => Cond,
4355 Reason => CE_Length_Check_Failed));
4356 end if;
4357
4358 -- Now look inside the sub-aggregate to see if there is more work
4359
4360 if Dim < Aggr_Dimension then
4361
4362 -- Process positional components
4363
4364 if Present (Expressions (Sub_Aggr)) then
4365 Expr := First (Expressions (Sub_Aggr));
4366 while Present (Expr) loop
4367 Check_Same_Aggr_Bounds (Expr, Dim + 1);
4368 Next (Expr);
4369 end loop;
4370 end if;
4371
4372 -- Process component associations
4373
4374 if Present (Component_Associations (Sub_Aggr)) then
4375 Assoc := First (Component_Associations (Sub_Aggr));
4376 while Present (Assoc) loop
4377 Expr := Expression (Assoc);
4378 Check_Same_Aggr_Bounds (Expr, Dim + 1);
4379 Next (Assoc);
4380 end loop;
4381 end if;
4382 end if;
4383 end Check_Same_Aggr_Bounds;
4384
4385 ----------------------------
4386 -- Compute_Others_Present --
4387 ----------------------------
4388
4389 procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos) is
4390 Assoc : Node_Id;
4391 Expr : Node_Id;
4392
4393 begin
4394 if Present (Component_Associations (Sub_Aggr)) then
4395 Assoc := Last (Component_Associations (Sub_Aggr));
4396
4397 if Nkind (First (Choices (Assoc))) = N_Others_Choice then
4398 Others_Present (Dim) := True;
4399 end if;
4400 end if;
4401
4402 -- Now look inside the sub-aggregate to see if there is more work
4403
4404 if Dim < Aggr_Dimension then
4405
4406 -- Process positional components
4407
4408 if Present (Expressions (Sub_Aggr)) then
4409 Expr := First (Expressions (Sub_Aggr));
4410 while Present (Expr) loop
4411 Compute_Others_Present (Expr, Dim + 1);
4412 Next (Expr);
4413 end loop;
4414 end if;
4415
4416 -- Process component associations
4417
4418 if Present (Component_Associations (Sub_Aggr)) then
4419 Assoc := First (Component_Associations (Sub_Aggr));
4420 while Present (Assoc) loop
4421 Expr := Expression (Assoc);
4422 Compute_Others_Present (Expr, Dim + 1);
4423 Next (Assoc);
4424 end loop;
4425 end if;
4426 end if;
4427 end Compute_Others_Present;
4428
4429 ------------------------
4430 -- Has_Address_Clause --
4431 ------------------------
4432
4433 function Has_Address_Clause (D : Node_Id) return Boolean is
4434 Id : constant Entity_Id := Defining_Identifier (D);
4435 Decl : Node_Id;
4436
4437 begin
4438 Decl := Next (D);
4439 while Present (Decl) loop
4440 if Nkind (Decl) = N_At_Clause
4441 and then Chars (Identifier (Decl)) = Chars (Id)
4442 then
4443 return True;
4444
4445 elsif Nkind (Decl) = N_Attribute_Definition_Clause
4446 and then Chars (Decl) = Name_Address
4447 and then Chars (Name (Decl)) = Chars (Id)
4448 then
4449 return True;
4450 end if;
4451
4452 Next (Decl);
4453 end loop;
4454
4455 return False;
4456 end Has_Address_Clause;
4457
4458 ------------------------
4459 -- In_Place_Assign_OK --
4460 ------------------------
4461
4462 function In_Place_Assign_OK return Boolean is
4463 Aggr_In : Node_Id;
4464 Aggr_Lo : Node_Id;
4465 Aggr_Hi : Node_Id;
4466 Obj_In : Node_Id;
4467 Obj_Lo : Node_Id;
4468 Obj_Hi : Node_Id;
4469
4470 function Is_Others_Aggregate (Aggr : Node_Id) return Boolean;
4471 -- Aggregates that consist of a single Others choice are safe
4472 -- if the single expression is.
4473
4474 function Safe_Aggregate (Aggr : Node_Id) return Boolean;
4475 -- Check recursively that each component of a (sub)aggregate does
4476 -- not depend on the variable being assigned to.
4477
4478 function Safe_Component (Expr : Node_Id) return Boolean;
4479 -- Verify that an expression cannot depend on the variable being
4480 -- assigned to. Room for improvement here (but less than before).
4481
4482 -------------------------
4483 -- Is_Others_Aggregate --
4484 -------------------------
4485
4486 function Is_Others_Aggregate (Aggr : Node_Id) return Boolean is
4487 begin
4488 return No (Expressions (Aggr))
4489 and then Nkind
4490 (First (Choices (First (Component_Associations (Aggr)))))
4491 = N_Others_Choice;
4492 end Is_Others_Aggregate;
4493
4494 --------------------
4495 -- Safe_Aggregate --
4496 --------------------
4497
4498 function Safe_Aggregate (Aggr : Node_Id) return Boolean is
4499 Expr : Node_Id;
4500
4501 begin
4502 if Present (Expressions (Aggr)) then
4503 Expr := First (Expressions (Aggr));
4504 while Present (Expr) loop
4505 if Nkind (Expr) = N_Aggregate then
4506 if not Safe_Aggregate (Expr) then
4507 return False;
4508 end if;
4509
4510 elsif not Safe_Component (Expr) then
4511 return False;
4512 end if;
4513
4514 Next (Expr);
4515 end loop;
4516 end if;
4517
4518 if Present (Component_Associations (Aggr)) then
4519 Expr := First (Component_Associations (Aggr));
4520 while Present (Expr) loop
4521 if Nkind (Expression (Expr)) = N_Aggregate then
4522 if not Safe_Aggregate (Expression (Expr)) then
4523 return False;
4524 end if;
4525
4526 elsif not Safe_Component (Expression (Expr)) then
4527 return False;
4528 end if;
4529
4530 Next (Expr);
4531 end loop;
4532 end if;
4533
4534 return True;
4535 end Safe_Aggregate;
4536
4537 --------------------
4538 -- Safe_Component --
4539 --------------------
4540
4541 function Safe_Component (Expr : Node_Id) return Boolean is
4542 Comp : Node_Id := Expr;
4543
4544 function Check_Component (Comp : Node_Id) return Boolean;
4545 -- Do the recursive traversal, after copy
4546
4547 ---------------------
4548 -- Check_Component --
4549 ---------------------
4550
4551 function Check_Component (Comp : Node_Id) return Boolean is
4552 begin
4553 if Is_Overloaded (Comp) then
4554 return False;
4555 end if;
4556
4557 return Compile_Time_Known_Value (Comp)
4558
4559 or else (Is_Entity_Name (Comp)
4560 and then Present (Entity (Comp))
4561 and then No (Renamed_Object (Entity (Comp))))
4562
4563 or else (Nkind (Comp) = N_Attribute_Reference
4564 and then Check_Component (Prefix (Comp)))
4565
4566 or else (Nkind (Comp) in N_Binary_Op
4567 and then Check_Component (Left_Opnd (Comp))
4568 and then Check_Component (Right_Opnd (Comp)))
4569
4570 or else (Nkind (Comp) in N_Unary_Op
4571 and then Check_Component (Right_Opnd (Comp)))
4572
4573 or else (Nkind (Comp) = N_Selected_Component
4574 and then Check_Component (Prefix (Comp)))
4575
4576 or else (Nkind (Comp) = N_Unchecked_Type_Conversion
4577 and then Check_Component (Expression (Comp)));
4578 end Check_Component;
4579
4580 -- Start of processing for Safe_Component
4581
4582 begin
4583 -- If the component appears in an association that may
4584 -- correspond to more than one element, it is not analyzed
4585 -- before the expansion into assignments, to avoid side effects.
4586 -- We analyze, but do not resolve the copy, to obtain sufficient
4587 -- entity information for the checks that follow. If component is
4588 -- overloaded we assume an unsafe function call.
4589
4590 if not Analyzed (Comp) then
4591 if Is_Overloaded (Expr) then
4592 return False;
4593
4594 elsif Nkind (Expr) = N_Aggregate
4595 and then not Is_Others_Aggregate (Expr)
4596 then
4597 return False;
4598
4599 elsif Nkind (Expr) = N_Allocator then
4600
4601 -- For now, too complex to analyze
4602
4603 return False;
4604 end if;
4605
4606 Comp := New_Copy_Tree (Expr);
4607 Set_Parent (Comp, Parent (Expr));
4608 Analyze (Comp);
4609 end if;
4610
4611 if Nkind (Comp) = N_Aggregate then
4612 return Safe_Aggregate (Comp);
4613 else
4614 return Check_Component (Comp);
4615 end if;
4616 end Safe_Component;
4617
4618 -- Start of processing for In_Place_Assign_OK
4619
4620 begin
4621 if Present (Component_Associations (N)) then
4622
4623 -- On assignment, sliding can take place, so we cannot do the
4624 -- assignment in place unless the bounds of the aggregate are
4625 -- statically equal to those of the target.
4626
4627 -- If the aggregate is given by an others choice, the bounds
4628 -- are derived from the left-hand side, and the assignment is
4629 -- safe if the expression is.
4630
4631 if Is_Others_Aggregate (N) then
4632 return
4633 Safe_Component
4634 (Expression (First (Component_Associations (N))));
4635 end if;
4636
4637 Aggr_In := First_Index (Etype (N));
4638
4639 if Nkind (Parent (N)) = N_Assignment_Statement then
4640 Obj_In := First_Index (Etype (Name (Parent (N))));
4641
4642 else
4643 -- Context is an allocator. Check bounds of aggregate
4644 -- against given type in qualified expression.
4645
4646 pragma Assert (Nkind (Parent (Parent (N))) = N_Allocator);
4647 Obj_In :=
4648 First_Index (Etype (Entity (Subtype_Mark (Parent (N)))));
4649 end if;
4650
4651 while Present (Aggr_In) loop
4652 Get_Index_Bounds (Aggr_In, Aggr_Lo, Aggr_Hi);
4653 Get_Index_Bounds (Obj_In, Obj_Lo, Obj_Hi);
4654
4655 if not Compile_Time_Known_Value (Aggr_Lo)
4656 or else not Compile_Time_Known_Value (Aggr_Hi)
4657 or else not Compile_Time_Known_Value (Obj_Lo)
4658 or else not Compile_Time_Known_Value (Obj_Hi)
4659 or else Expr_Value (Aggr_Lo) /= Expr_Value (Obj_Lo)
4660 or else Expr_Value (Aggr_Hi) /= Expr_Value (Obj_Hi)
4661 then
4662 return False;
4663 end if;
4664
4665 Next_Index (Aggr_In);
4666 Next_Index (Obj_In);
4667 end loop;
4668 end if;
4669
4670 -- Now check the component values themselves
4671
4672 return Safe_Aggregate (N);
4673 end In_Place_Assign_OK;
4674
4675 ------------------
4676 -- Others_Check --
4677 ------------------
4678
4679 procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos) is
4680 Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
4681 Aggr_Hi : constant Node_Id := Aggr_High (Dim);
4682 -- The bounds of the aggregate for this dimension
4683
4684 Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
4685 -- The index type for this dimension
4686
4687 Need_To_Check : Boolean := False;
4688
4689 Choices_Lo : Node_Id := Empty;
4690 Choices_Hi : Node_Id := Empty;
4691 -- The lowest and highest discrete choices for a named sub-aggregate
4692
4693 Nb_Choices : Int := -1;
4694 -- The number of discrete non-others choices in this sub-aggregate
4695
4696 Nb_Elements : Uint := Uint_0;
4697 -- The number of elements in a positional aggregate
4698
4699 Cond : Node_Id := Empty;
4700
4701 Assoc : Node_Id;
4702 Choice : Node_Id;
4703 Expr : Node_Id;
4704
4705 begin
4706 -- Check if we have an others choice. If we do make sure that this
4707 -- sub-aggregate contains at least one element in addition to the
4708 -- others choice.
4709
4710 if Range_Checks_Suppressed (Ind_Typ) then
4711 Need_To_Check := False;
4712
4713 elsif Present (Expressions (Sub_Aggr))
4714 and then Present (Component_Associations (Sub_Aggr))
4715 then
4716 Need_To_Check := True;
4717
4718 elsif Present (Component_Associations (Sub_Aggr)) then
4719 Assoc := Last (Component_Associations (Sub_Aggr));
4720
4721 if Nkind (First (Choices (Assoc))) /= N_Others_Choice then
4722 Need_To_Check := False;
4723
4724 else
4725 -- Count the number of discrete choices. Start with -1 because
4726 -- the others choice does not count.
4727
4728 Nb_Choices := -1;
4729 Assoc := First (Component_Associations (Sub_Aggr));
4730 while Present (Assoc) loop
4731 Choice := First (Choices (Assoc));
4732 while Present (Choice) loop
4733 Nb_Choices := Nb_Choices + 1;
4734 Next (Choice);
4735 end loop;
4736
4737 Next (Assoc);
4738 end loop;
4739
4740 -- If there is only an others choice nothing to do
4741
4742 Need_To_Check := (Nb_Choices > 0);
4743 end if;
4744
4745 else
4746 Need_To_Check := False;
4747 end if;
4748
4749 -- If we are dealing with a positional sub-aggregate with an others
4750 -- choice then compute the number or positional elements.
4751
4752 if Need_To_Check and then Present (Expressions (Sub_Aggr)) then
4753 Expr := First (Expressions (Sub_Aggr));
4754 Nb_Elements := Uint_0;
4755 while Present (Expr) loop
4756 Nb_Elements := Nb_Elements + 1;
4757 Next (Expr);
4758 end loop;
4759
4760 -- If the aggregate contains discrete choices and an others choice
4761 -- compute the smallest and largest discrete choice values.
4762
4763 elsif Need_To_Check then
4764 Compute_Choices_Lo_And_Choices_Hi : declare
4765
4766 Table : Case_Table_Type (1 .. Nb_Choices);
4767 -- Used to sort all the different choice values
4768
4769 J : Pos := 1;
4770 Low : Node_Id;
4771 High : Node_Id;
4772
4773 begin
4774 Assoc := First (Component_Associations (Sub_Aggr));
4775 while Present (Assoc) loop
4776 Choice := First (Choices (Assoc));
4777 while Present (Choice) loop
4778 if Nkind (Choice) = N_Others_Choice then
4779 exit;
4780 end if;
4781
4782 Get_Index_Bounds (Choice, Low, High);
4783 Table (J).Choice_Lo := Low;
4784 Table (J).Choice_Hi := High;
4785
4786 J := J + 1;
4787 Next (Choice);
4788 end loop;
4789
4790 Next (Assoc);
4791 end loop;
4792
4793 -- Sort the discrete choices
4794
4795 Sort_Case_Table (Table);
4796
4797 Choices_Lo := Table (1).Choice_Lo;
4798 Choices_Hi := Table (Nb_Choices).Choice_Hi;
4799 end Compute_Choices_Lo_And_Choices_Hi;
4800 end if;
4801
4802 -- If no others choice in this sub-aggregate, or the aggregate
4803 -- comprises only an others choice, nothing to do.
4804
4805 if not Need_To_Check then
4806 Cond := Empty;
4807
4808 -- If we are dealing with an aggregate containing an others choice
4809 -- and positional components, we generate the following test:
4810
4811 -- if Ind_Typ'Pos (Aggr_Lo) + (Nb_Elements - 1) >
4812 -- Ind_Typ'Pos (Aggr_Hi)
4813 -- then
4814 -- raise Constraint_Error;
4815 -- end if;
4816
4817 elsif Nb_Elements > Uint_0 then
4818 Cond :=
4819 Make_Op_Gt (Loc,
4820 Left_Opnd =>
4821 Make_Op_Add (Loc,
4822 Left_Opnd =>
4823 Make_Attribute_Reference (Loc,
4824 Prefix => New_Reference_To (Ind_Typ, Loc),
4825 Attribute_Name => Name_Pos,
4826 Expressions =>
4827 New_List
4828 (Duplicate_Subexpr_Move_Checks (Aggr_Lo))),
4829 Right_Opnd => Make_Integer_Literal (Loc, Nb_Elements - 1)),
4830
4831 Right_Opnd =>
4832 Make_Attribute_Reference (Loc,
4833 Prefix => New_Reference_To (Ind_Typ, Loc),
4834 Attribute_Name => Name_Pos,
4835 Expressions => New_List (
4836 Duplicate_Subexpr_Move_Checks (Aggr_Hi))));
4837
4838 -- If we are dealing with an aggregate containing an others choice
4839 -- and discrete choices we generate the following test:
4840
4841 -- [constraint_error when
4842 -- Choices_Lo < Aggr_Lo or else Choices_Hi > Aggr_Hi];
4843
4844 else
4845 Cond :=
4846 Make_Or_Else (Loc,
4847 Left_Opnd =>
4848 Make_Op_Lt (Loc,
4849 Left_Opnd =>
4850 Duplicate_Subexpr_Move_Checks (Choices_Lo),
4851 Right_Opnd =>
4852 Duplicate_Subexpr_Move_Checks (Aggr_Lo)),
4853
4854 Right_Opnd =>
4855 Make_Op_Gt (Loc,
4856 Left_Opnd =>
4857 Duplicate_Subexpr (Choices_Hi),
4858 Right_Opnd =>
4859 Duplicate_Subexpr (Aggr_Hi)));
4860 end if;
4861
4862 if Present (Cond) then
4863 Insert_Action (N,
4864 Make_Raise_Constraint_Error (Loc,
4865 Condition => Cond,
4866 Reason => CE_Length_Check_Failed));
4867 -- Questionable reason code, shouldn't that be a
4868 -- CE_Range_Check_Failed ???
4869 end if;
4870
4871 -- Now look inside the sub-aggregate to see if there is more work
4872
4873 if Dim < Aggr_Dimension then
4874
4875 -- Process positional components
4876
4877 if Present (Expressions (Sub_Aggr)) then
4878 Expr := First (Expressions (Sub_Aggr));
4879 while Present (Expr) loop
4880 Others_Check (Expr, Dim + 1);
4881 Next (Expr);
4882 end loop;
4883 end if;
4884
4885 -- Process component associations
4886
4887 if Present (Component_Associations (Sub_Aggr)) then
4888 Assoc := First (Component_Associations (Sub_Aggr));
4889 while Present (Assoc) loop
4890 Expr := Expression (Assoc);
4891 Others_Check (Expr, Dim + 1);
4892 Next (Assoc);
4893 end loop;
4894 end if;
4895 end if;
4896 end Others_Check;
4897
4898 -- Remaining Expand_Array_Aggregate variables
4899
4900 Tmp : Entity_Id;
4901 -- Holds the temporary aggregate value
4902
4903 Tmp_Decl : Node_Id;
4904 -- Holds the declaration of Tmp
4905
4906 Aggr_Code : List_Id;
4907 Parent_Node : Node_Id;
4908 Parent_Kind : Node_Kind;
4909
4910 -- Start of processing for Expand_Array_Aggregate
4911
4912 begin
4913 -- Do not touch the special aggregates of attributes used for Asm calls
4914
4915 if Is_RTE (Ctyp, RE_Asm_Input_Operand)
4916 or else Is_RTE (Ctyp, RE_Asm_Output_Operand)
4917 then
4918 return;
4919 end if;
4920
4921 -- If the semantic analyzer has determined that aggregate N will raise
4922 -- Constraint_Error at run-time, then the aggregate node has been
4923 -- replaced with an N_Raise_Constraint_Error node and we should
4924 -- never get here.
4925
4926 pragma Assert (not Raises_Constraint_Error (N));
4927
4928 -- STEP 1a
4929
4930 -- Check that the index range defined by aggregate bounds is
4931 -- compatible with corresponding index subtype.
4932
4933 Index_Compatibility_Check : declare
4934 Aggr_Index_Range : Node_Id := First_Index (Typ);
4935 -- The current aggregate index range
4936
4937 Index_Constraint : Node_Id := First_Index (Etype (Typ));
4938 -- The corresponding index constraint against which we have to
4939 -- check the above aggregate index range.
4940
4941 begin
4942 Compute_Others_Present (N, 1);
4943
4944 for J in 1 .. Aggr_Dimension loop
4945 -- There is no need to emit a check if an others choice is
4946 -- present for this array aggregate dimension since in this
4947 -- case one of N's sub-aggregates has taken its bounds from the
4948 -- context and these bounds must have been checked already. In
4949 -- addition all sub-aggregates corresponding to the same
4950 -- dimension must all have the same bounds (checked in (c) below).
4951
4952 if not Range_Checks_Suppressed (Etype (Index_Constraint))
4953 and then not Others_Present (J)
4954 then
4955 -- We don't use Checks.Apply_Range_Check here because it emits
4956 -- a spurious check. Namely it checks that the range defined by
4957 -- the aggregate bounds is non empty. But we know this already
4958 -- if we get here.
4959
4960 Check_Bounds (Aggr_Index_Range, Index_Constraint);
4961 end if;
4962
4963 -- Save the low and high bounds of the aggregate index as well as
4964 -- the index type for later use in checks (b) and (c) below.
4965
4966 Aggr_Low (J) := Low_Bound (Aggr_Index_Range);
4967 Aggr_High (J) := High_Bound (Aggr_Index_Range);
4968
4969 Aggr_Index_Typ (J) := Etype (Index_Constraint);
4970
4971 Next_Index (Aggr_Index_Range);
4972 Next_Index (Index_Constraint);
4973 end loop;
4974 end Index_Compatibility_Check;
4975
4976 -- STEP 1b
4977
4978 -- If an others choice is present check that no aggregate index is
4979 -- outside the bounds of the index constraint.
4980
4981 Others_Check (N, 1);
4982
4983 -- STEP 1c
4984
4985 -- For multidimensional arrays make sure that all subaggregates
4986 -- corresponding to the same dimension have the same bounds.
4987
4988 if Aggr_Dimension > 1 then
4989 Check_Same_Aggr_Bounds (N, 1);
4990 end if;
4991
4992 -- STEP 2
4993
4994 -- Here we test for is packed array aggregate that we can handle at
4995 -- compile time. If so, return with transformation done. Note that we do
4996 -- this even if the aggregate is nested, because once we have done this
4997 -- processing, there is no more nested aggregate!
4998
4999 if Packed_Array_Aggregate_Handled (N) then
5000 return;
5001 end if;
5002
5003 -- At this point we try to convert to positional form
5004
5005 if Ekind (Current_Scope) = E_Package
5006 and then Static_Elaboration_Desired (Current_Scope)
5007 then
5008 Convert_To_Positional (N, Max_Others_Replicate => 100);
5009
5010 else
5011 Convert_To_Positional (N);
5012 end if;
5013
5014 -- if the result is no longer an aggregate (e.g. it may be a string
5015 -- literal, or a temporary which has the needed value), then we are
5016 -- done, since there is no longer a nested aggregate.
5017
5018 if Nkind (N) /= N_Aggregate then
5019 return;
5020
5021 -- We are also done if the result is an analyzed aggregate
5022 -- This case could use more comments ???
5023
5024 elsif Analyzed (N)
5025 and then N /= Original_Node (N)
5026 then
5027 return;
5028 end if;
5029
5030 -- If all aggregate components are compile-time known and the aggregate
5031 -- has been flattened, nothing left to do. The same occurs if the
5032 -- aggregate is used to initialize the components of an statically
5033 -- allocated dispatch table.
5034
5035 if Compile_Time_Known_Aggregate (N)
5036 or else Is_Static_Dispatch_Table_Aggregate (N)
5037 then
5038 Set_Expansion_Delayed (N, False);
5039 return;
5040 end if;
5041
5042 -- Now see if back end processing is possible
5043
5044 if Backend_Processing_Possible (N) then
5045
5046 -- If the aggregate is static but the constraints are not, build
5047 -- a static subtype for the aggregate, so that Gigi can place it
5048 -- in static memory. Perform an unchecked_conversion to the non-
5049 -- static type imposed by the context.
5050
5051 declare
5052 Itype : constant Entity_Id := Etype (N);
5053 Index : Node_Id;
5054 Needs_Type : Boolean := False;
5055
5056 begin
5057 Index := First_Index (Itype);
5058 while Present (Index) loop
5059 if not Is_Static_Subtype (Etype (Index)) then
5060 Needs_Type := True;
5061 exit;
5062 else
5063 Next_Index (Index);
5064 end if;
5065 end loop;
5066
5067 if Needs_Type then
5068 Build_Constrained_Type (Positional => True);
5069 Rewrite (N, Unchecked_Convert_To (Itype, N));
5070 Analyze (N);
5071 end if;
5072 end;
5073
5074 return;
5075 end if;
5076
5077 -- STEP 3
5078
5079 -- Delay expansion for nested aggregates: it will be taken care of
5080 -- when the parent aggregate is expanded.
5081
5082 Parent_Node := Parent (N);
5083 Parent_Kind := Nkind (Parent_Node);
5084
5085 if Parent_Kind = N_Qualified_Expression then
5086 Parent_Node := Parent (Parent_Node);
5087 Parent_Kind := Nkind (Parent_Node);
5088 end if;
5089
5090 if Parent_Kind = N_Aggregate
5091 or else Parent_Kind = N_Extension_Aggregate
5092 or else Parent_Kind = N_Component_Association
5093 or else (Parent_Kind = N_Object_Declaration
5094 and then Needs_Finalization (Typ))
5095 or else (Parent_Kind = N_Assignment_Statement
5096 and then Inside_Init_Proc)
5097 then
5098 if Static_Array_Aggregate (N)
5099 or else Compile_Time_Known_Aggregate (N)
5100 then
5101 Set_Expansion_Delayed (N, False);
5102 return;
5103 else
5104 Set_Expansion_Delayed (N);
5105 return;
5106 end if;
5107 end if;
5108
5109 -- STEP 4
5110
5111 -- Look if in place aggregate expansion is possible
5112
5113 -- For object declarations we build the aggregate in place, unless
5114 -- the array is bit-packed or the component is controlled.
5115
5116 -- For assignments we do the assignment in place if all the component
5117 -- associations have compile-time known values. For other cases we
5118 -- create a temporary. The analysis for safety of on-line assignment
5119 -- is delicate, i.e. we don't know how to do it fully yet ???
5120
5121 -- For allocators we assign to the designated object in place if the
5122 -- aggregate meets the same conditions as other in-place assignments.
5123 -- In this case the aggregate may not come from source but was created
5124 -- for default initialization, e.g. with Initialize_Scalars.
5125
5126 if Requires_Transient_Scope (Typ) then
5127 Establish_Transient_Scope
5128 (N, Sec_Stack => Has_Controlled_Component (Typ));
5129 end if;
5130
5131 if Has_Default_Init_Comps (N) then
5132 Maybe_In_Place_OK := False;
5133
5134 elsif Is_Bit_Packed_Array (Typ)
5135 or else Has_Controlled_Component (Typ)
5136 then
5137 Maybe_In_Place_OK := False;
5138
5139 else
5140 Maybe_In_Place_OK :=
5141 (Nkind (Parent (N)) = N_Assignment_Statement
5142 and then Comes_From_Source (N)
5143 and then In_Place_Assign_OK)
5144
5145 or else
5146 (Nkind (Parent (Parent (N))) = N_Allocator
5147 and then In_Place_Assign_OK);
5148 end if;
5149
5150 -- If this is an array of tasks, it will be expanded into build-in-place
5151 -- assignments. Build an activation chain for the tasks now.
5152
5153 if Has_Task (Etype (N)) then
5154 Build_Activation_Chain_Entity (N);
5155 end if;
5156
5157 if not Has_Default_Init_Comps (N)
5158 and then Comes_From_Source (Parent (N))
5159 and then Nkind (Parent (N)) = N_Object_Declaration
5160 and then not
5161 Must_Slide (Etype (Defining_Identifier (Parent (N))), Typ)
5162 and then N = Expression (Parent (N))
5163 and then not Is_Bit_Packed_Array (Typ)
5164 and then not Has_Controlled_Component (Typ)
5165 and then not Has_Address_Clause (Parent (N))
5166 then
5167 Tmp := Defining_Identifier (Parent (N));
5168 Set_No_Initialization (Parent (N));
5169 Set_Expression (Parent (N), Empty);
5170
5171 -- Set the type of the entity, for use in the analysis of the
5172 -- subsequent indexed assignments. If the nominal type is not
5173 -- constrained, build a subtype from the known bounds of the
5174 -- aggregate. If the declaration has a subtype mark, use it,
5175 -- otherwise use the itype of the aggregate.
5176
5177 if not Is_Constrained (Typ) then
5178 Build_Constrained_Type (Positional => False);
5179 elsif Is_Entity_Name (Object_Definition (Parent (N)))
5180 and then Is_Constrained (Entity (Object_Definition (Parent (N))))
5181 then
5182 Set_Etype (Tmp, Entity (Object_Definition (Parent (N))));
5183 else
5184 Set_Size_Known_At_Compile_Time (Typ, False);
5185 Set_Etype (Tmp, Typ);
5186 end if;
5187
5188 elsif Maybe_In_Place_OK
5189 and then Nkind (Parent (N)) = N_Qualified_Expression
5190 and then Nkind (Parent (Parent (N))) = N_Allocator
5191 then
5192 Set_Expansion_Delayed (N);
5193 return;
5194
5195 -- In the remaining cases the aggregate is the RHS of an assignment
5196
5197 elsif Maybe_In_Place_OK
5198 and then Is_Entity_Name (Name (Parent (N)))
5199 then
5200 Tmp := Entity (Name (Parent (N)));
5201
5202 if Etype (Tmp) /= Etype (N) then
5203 Apply_Length_Check (N, Etype (Tmp));
5204
5205 if Nkind (N) = N_Raise_Constraint_Error then
5206
5207 -- Static error, nothing further to expand
5208
5209 return;
5210 end if;
5211 end if;
5212
5213 elsif Maybe_In_Place_OK
5214 and then Nkind (Name (Parent (N))) = N_Explicit_Dereference
5215 and then Is_Entity_Name (Prefix (Name (Parent (N))))
5216 then
5217 Tmp := Name (Parent (N));
5218
5219 if Etype (Tmp) /= Etype (N) then
5220 Apply_Length_Check (N, Etype (Tmp));
5221 end if;
5222
5223 elsif Maybe_In_Place_OK
5224 and then Nkind (Name (Parent (N))) = N_Slice
5225 and then Safe_Slice_Assignment (N)
5226 then
5227 -- Safe_Slice_Assignment rewrites assignment as a loop
5228
5229 return;
5230
5231 -- Step 5
5232
5233 -- In place aggregate expansion is not possible
5234
5235 else
5236 Maybe_In_Place_OK := False;
5237 Tmp := Make_Temporary (Loc, 'A', N);
5238 Tmp_Decl :=
5239 Make_Object_Declaration
5240 (Loc,
5241 Defining_Identifier => Tmp,
5242 Object_Definition => New_Occurrence_Of (Typ, Loc));
5243 Set_No_Initialization (Tmp_Decl, True);
5244
5245 -- If we are within a loop, the temporary will be pushed on the
5246 -- stack at each iteration. If the aggregate is the expression for an
5247 -- allocator, it will be immediately copied to the heap and can
5248 -- be reclaimed at once. We create a transient scope around the
5249 -- aggregate for this purpose.
5250
5251 if Ekind (Current_Scope) = E_Loop
5252 and then Nkind (Parent (Parent (N))) = N_Allocator
5253 then
5254 Establish_Transient_Scope (N, False);
5255 end if;
5256
5257 Insert_Action (N, Tmp_Decl);
5258 end if;
5259
5260 -- Construct and insert the aggregate code. We can safely suppress index
5261 -- checks because this code is guaranteed not to raise CE on index
5262 -- checks. However we should *not* suppress all checks.
5263
5264 declare
5265 Target : Node_Id;
5266
5267 begin
5268 if Nkind (Tmp) = N_Defining_Identifier then
5269 Target := New_Reference_To (Tmp, Loc);
5270
5271 else
5272
5273 if Has_Default_Init_Comps (N) then
5274
5275 -- Ada 2005 (AI-287): This case has not been analyzed???
5276
5277 raise Program_Error;
5278 end if;
5279
5280 -- Name in assignment is explicit dereference
5281
5282 Target := New_Copy (Tmp);
5283 end if;
5284
5285 Aggr_Code :=
5286 Build_Array_Aggr_Code (N,
5287 Ctype => Ctyp,
5288 Index => First_Index (Typ),
5289 Into => Target,
5290 Scalar_Comp => Is_Scalar_Type (Ctyp));
5291 end;
5292
5293 if Comes_From_Source (Tmp) then
5294 Insert_Actions_After (Parent (N), Aggr_Code);
5295
5296 else
5297 Insert_Actions (N, Aggr_Code);
5298 end if;
5299
5300 -- If the aggregate has been assigned in place, remove the original
5301 -- assignment.
5302
5303 if Nkind (Parent (N)) = N_Assignment_Statement
5304 and then Maybe_In_Place_OK
5305 then
5306 Rewrite (Parent (N), Make_Null_Statement (Loc));
5307
5308 elsif Nkind (Parent (N)) /= N_Object_Declaration
5309 or else Tmp /= Defining_Identifier (Parent (N))
5310 then
5311 Rewrite (N, New_Occurrence_Of (Tmp, Loc));
5312 Analyze_And_Resolve (N, Typ);
5313 end if;
5314 end Expand_Array_Aggregate;
5315
5316 ------------------------
5317 -- Expand_N_Aggregate --
5318 ------------------------
5319
5320 procedure Expand_N_Aggregate (N : Node_Id) is
5321 begin
5322 if Is_Record_Type (Etype (N)) then
5323 Expand_Record_Aggregate (N);
5324 else
5325 Expand_Array_Aggregate (N);
5326 end if;
5327 exception
5328 when RE_Not_Available =>
5329 return;
5330 end Expand_N_Aggregate;
5331
5332 ----------------------------------
5333 -- Expand_N_Extension_Aggregate --
5334 ----------------------------------
5335
5336 -- If the ancestor part is an expression, add a component association for
5337 -- the parent field. If the type of the ancestor part is not the direct
5338 -- parent of the expected type, build recursively the needed ancestors.
5339 -- If the ancestor part is a subtype_mark, replace aggregate with a decla-
5340 -- ration for a temporary of the expected type, followed by individual
5341 -- assignments to the given components.
5342
5343 procedure Expand_N_Extension_Aggregate (N : Node_Id) is
5344 Loc : constant Source_Ptr := Sloc (N);
5345 A : constant Node_Id := Ancestor_Part (N);
5346 Typ : constant Entity_Id := Etype (N);
5347
5348 begin
5349 -- If the ancestor is a subtype mark, an init proc must be called
5350 -- on the resulting object which thus has to be materialized in
5351 -- the front-end
5352
5353 if Is_Entity_Name (A) and then Is_Type (Entity (A)) then
5354 Convert_To_Assignments (N, Typ);
5355
5356 -- The extension aggregate is transformed into a record aggregate
5357 -- of the following form (c1 and c2 are inherited components)
5358
5359 -- (Exp with c3 => a, c4 => b)
5360 -- ==> (c1 => Exp.c1, c2 => Exp.c2, c1 => a, c2 => b)
5361
5362 else
5363 Set_Etype (N, Typ);
5364
5365 if Tagged_Type_Expansion then
5366 Expand_Record_Aggregate (N,
5367 Orig_Tag =>
5368 New_Occurrence_Of
5369 (Node (First_Elmt (Access_Disp_Table (Typ))), Loc),
5370 Parent_Expr => A);
5371 else
5372 -- No tag is needed in the case of a VM
5373 Expand_Record_Aggregate (N,
5374 Parent_Expr => A);
5375 end if;
5376 end if;
5377
5378 exception
5379 when RE_Not_Available =>
5380 return;
5381 end Expand_N_Extension_Aggregate;
5382
5383 -----------------------------
5384 -- Expand_Record_Aggregate --
5385 -----------------------------
5386
5387 procedure Expand_Record_Aggregate
5388 (N : Node_Id;
5389 Orig_Tag : Node_Id := Empty;
5390 Parent_Expr : Node_Id := Empty)
5391 is
5392 Loc : constant Source_Ptr := Sloc (N);
5393 Comps : constant List_Id := Component_Associations (N);
5394 Typ : constant Entity_Id := Etype (N);
5395 Base_Typ : constant Entity_Id := Base_Type (Typ);
5396
5397 Static_Components : Boolean := True;
5398 -- Flag to indicate whether all components are compile-time known,
5399 -- and the aggregate can be constructed statically and handled by
5400 -- the back-end.
5401
5402 function Component_Not_OK_For_Backend return Boolean;
5403 -- Check for presence of component which makes it impossible for the
5404 -- backend to process the aggregate, thus requiring the use of a series
5405 -- of assignment statements. Cases checked for are a nested aggregate
5406 -- needing Late_Expansion, the presence of a tagged component which may
5407 -- need tag adjustment, and a bit unaligned component reference.
5408 --
5409 -- We also force expansion into assignments if a component is of a
5410 -- mutable type (including a private type with discriminants) because
5411 -- in that case the size of the component to be copied may be smaller
5412 -- than the side of the target, and there is no simple way for gigi
5413 -- to compute the size of the object to be copied.
5414 --
5415 -- NOTE: This is part of the ongoing work to define precisely the
5416 -- interface between front-end and back-end handling of aggregates.
5417 -- In general it is desirable to pass aggregates as they are to gigi,
5418 -- in order to minimize elaboration code. This is one case where the
5419 -- semantics of Ada complicate the analysis and lead to anomalies in
5420 -- the gcc back-end if the aggregate is not expanded into assignments.
5421
5422 ----------------------------------
5423 -- Component_Not_OK_For_Backend --
5424 ----------------------------------
5425
5426 function Component_Not_OK_For_Backend return Boolean is
5427 C : Node_Id;
5428 Expr_Q : Node_Id;
5429
5430 begin
5431 if No (Comps) then
5432 return False;
5433 end if;
5434
5435 C := First (Comps);
5436 while Present (C) loop
5437 if Nkind (Expression (C)) = N_Qualified_Expression then
5438 Expr_Q := Expression (Expression (C));
5439 else
5440 Expr_Q := Expression (C);
5441 end if;
5442
5443 -- Return true if the aggregate has any associations for tagged
5444 -- components that may require tag adjustment.
5445
5446 -- These are cases where the source expression may have a tag that
5447 -- could differ from the component tag (e.g., can occur for type
5448 -- conversions and formal parameters). (Tag adjustment not needed
5449 -- if VM_Target because object tags are implicit in the machine.)
5450
5451 if Is_Tagged_Type (Etype (Expr_Q))
5452 and then (Nkind (Expr_Q) = N_Type_Conversion
5453 or else (Is_Entity_Name (Expr_Q)
5454 and then
5455 Ekind (Entity (Expr_Q)) in Formal_Kind))
5456 and then Tagged_Type_Expansion
5457 then
5458 Static_Components := False;
5459 return True;
5460
5461 elsif Is_Delayed_Aggregate (Expr_Q) then
5462 Static_Components := False;
5463 return True;
5464
5465 elsif Possible_Bit_Aligned_Component (Expr_Q) then
5466 Static_Components := False;
5467 return True;
5468 end if;
5469
5470 if Is_Scalar_Type (Etype (Expr_Q)) then
5471 if not Compile_Time_Known_Value (Expr_Q) then
5472 Static_Components := False;
5473 end if;
5474
5475 elsif Nkind (Expr_Q) /= N_Aggregate
5476 or else not Compile_Time_Known_Aggregate (Expr_Q)
5477 then
5478 Static_Components := False;
5479
5480 if Is_Private_Type (Etype (Expr_Q))
5481 and then Has_Discriminants (Etype (Expr_Q))
5482 then
5483 return True;
5484 end if;
5485 end if;
5486
5487 Next (C);
5488 end loop;
5489
5490 return False;
5491 end Component_Not_OK_For_Backend;
5492
5493 -- Remaining Expand_Record_Aggregate variables
5494
5495 Tag_Value : Node_Id;
5496 Comp : Entity_Id;
5497 New_Comp : Node_Id;
5498
5499 -- Start of processing for Expand_Record_Aggregate
5500
5501 begin
5502 -- If the aggregate is to be assigned to an atomic variable, we
5503 -- have to prevent a piecemeal assignment even if the aggregate
5504 -- is to be expanded. We create a temporary for the aggregate, and
5505 -- assign the temporary instead, so that the back end can generate
5506 -- an atomic move for it.
5507
5508 if Is_Atomic (Typ)
5509 and then Comes_From_Source (Parent (N))
5510 and then Is_Atomic_Aggregate (N, Typ)
5511 then
5512 return;
5513
5514 -- No special management required for aggregates used to initialize
5515 -- statically allocated dispatch tables
5516
5517 elsif Is_Static_Dispatch_Table_Aggregate (N) then
5518 return;
5519 end if;
5520
5521 -- Ada 2005 (AI-318-2): We need to convert to assignments if components
5522 -- are build-in-place function calls. This test could be more specific,
5523 -- but doing it for all inherently limited aggregates seems harmless.
5524 -- The assignments will turn into build-in-place function calls (see
5525 -- Make_Build_In_Place_Call_In_Assignment).
5526
5527 if Ada_Version >= Ada_05 and then Is_Inherently_Limited_Type (Typ) then
5528 Convert_To_Assignments (N, Typ);
5529
5530 -- Gigi doesn't handle properly temporaries of variable size
5531 -- so we generate it in the front-end
5532
5533 elsif not Size_Known_At_Compile_Time (Typ) then
5534 Convert_To_Assignments (N, Typ);
5535
5536 -- Temporaries for controlled aggregates need to be attached to a
5537 -- final chain in order to be properly finalized, so it has to
5538 -- be created in the front-end
5539
5540 elsif Is_Controlled (Typ)
5541 or else Has_Controlled_Component (Base_Type (Typ))
5542 then
5543 Convert_To_Assignments (N, Typ);
5544
5545 -- Ada 2005 (AI-287): In case of default initialized components we
5546 -- convert the aggregate into assignments.
5547
5548 elsif Has_Default_Init_Comps (N) then
5549 Convert_To_Assignments (N, Typ);
5550
5551 -- Check components
5552
5553 elsif Component_Not_OK_For_Backend then
5554 Convert_To_Assignments (N, Typ);
5555
5556 -- If an ancestor is private, some components are not inherited and
5557 -- we cannot expand into a record aggregate
5558
5559 elsif Has_Private_Ancestor (Typ) then
5560 Convert_To_Assignments (N, Typ);
5561
5562 -- ??? The following was done to compile fxacc00.ads in the ACVCs. Gigi
5563 -- is not able to handle the aggregate for Late_Request.
5564
5565 elsif Is_Tagged_Type (Typ) and then Has_Discriminants (Typ) then
5566 Convert_To_Assignments (N, Typ);
5567
5568 -- If the tagged types covers interface types we need to initialize all
5569 -- hidden components containing pointers to secondary dispatch tables.
5570
5571 elsif Is_Tagged_Type (Typ) and then Has_Interfaces (Typ) then
5572 Convert_To_Assignments (N, Typ);
5573
5574 -- If some components are mutable, the size of the aggregate component
5575 -- may be distinct from the default size of the type component, so
5576 -- we need to expand to insure that the back-end copies the proper
5577 -- size of the data.
5578
5579 elsif Has_Mutable_Components (Typ) then
5580 Convert_To_Assignments (N, Typ);
5581
5582 -- If the type involved has any non-bit aligned components, then we are
5583 -- not sure that the back end can handle this case correctly.
5584
5585 elsif Type_May_Have_Bit_Aligned_Components (Typ) then
5586 Convert_To_Assignments (N, Typ);
5587
5588 -- In all other cases, build a proper aggregate handlable by gigi
5589
5590 else
5591 if Nkind (N) = N_Aggregate then
5592
5593 -- If the aggregate is static and can be handled by the back-end,
5594 -- nothing left to do.
5595
5596 if Static_Components then
5597 Set_Compile_Time_Known_Aggregate (N);
5598 Set_Expansion_Delayed (N, False);
5599 end if;
5600 end if;
5601
5602 -- If no discriminants, nothing special to do
5603
5604 if not Has_Discriminants (Typ) then
5605 null;
5606
5607 -- Case of discriminants present
5608
5609 elsif Is_Derived_Type (Typ) then
5610
5611 -- For untagged types, non-stored discriminants are replaced
5612 -- with stored discriminants, which are the ones that gigi uses
5613 -- to describe the type and its components.
5614
5615 Generate_Aggregate_For_Derived_Type : declare
5616 Constraints : constant List_Id := New_List;
5617 First_Comp : Node_Id;
5618 Discriminant : Entity_Id;
5619 Decl : Node_Id;
5620 Num_Disc : Int := 0;
5621 Num_Gird : Int := 0;
5622
5623 procedure Prepend_Stored_Values (T : Entity_Id);
5624 -- Scan the list of stored discriminants of the type, and add
5625 -- their values to the aggregate being built.
5626
5627 ---------------------------
5628 -- Prepend_Stored_Values --
5629 ---------------------------
5630
5631 procedure Prepend_Stored_Values (T : Entity_Id) is
5632 begin
5633 Discriminant := First_Stored_Discriminant (T);
5634 while Present (Discriminant) loop
5635 New_Comp :=
5636 Make_Component_Association (Loc,
5637 Choices =>
5638 New_List (New_Occurrence_Of (Discriminant, Loc)),
5639
5640 Expression =>
5641 New_Copy_Tree (
5642 Get_Discriminant_Value (
5643 Discriminant,
5644 Typ,
5645 Discriminant_Constraint (Typ))));
5646
5647 if No (First_Comp) then
5648 Prepend_To (Component_Associations (N), New_Comp);
5649 else
5650 Insert_After (First_Comp, New_Comp);
5651 end if;
5652
5653 First_Comp := New_Comp;
5654 Next_Stored_Discriminant (Discriminant);
5655 end loop;
5656 end Prepend_Stored_Values;
5657
5658 -- Start of processing for Generate_Aggregate_For_Derived_Type
5659
5660 begin
5661 -- Remove the associations for the discriminant of derived type
5662
5663 First_Comp := First (Component_Associations (N));
5664 while Present (First_Comp) loop
5665 Comp := First_Comp;
5666 Next (First_Comp);
5667
5668 if Ekind (Entity
5669 (First (Choices (Comp)))) = E_Discriminant
5670 then
5671 Remove (Comp);
5672 Num_Disc := Num_Disc + 1;
5673 end if;
5674 end loop;
5675
5676 -- Insert stored discriminant associations in the correct
5677 -- order. If there are more stored discriminants than new
5678 -- discriminants, there is at least one new discriminant that
5679 -- constrains more than one of the stored discriminants. In
5680 -- this case we need to construct a proper subtype of the
5681 -- parent type, in order to supply values to all the
5682 -- components. Otherwise there is one-one correspondence
5683 -- between the constraints and the stored discriminants.
5684
5685 First_Comp := Empty;
5686
5687 Discriminant := First_Stored_Discriminant (Base_Type (Typ));
5688 while Present (Discriminant) loop
5689 Num_Gird := Num_Gird + 1;
5690 Next_Stored_Discriminant (Discriminant);
5691 end loop;
5692
5693 -- Case of more stored discriminants than new discriminants
5694
5695 if Num_Gird > Num_Disc then
5696
5697 -- Create a proper subtype of the parent type, which is the
5698 -- proper implementation type for the aggregate, and convert
5699 -- it to the intended target type.
5700
5701 Discriminant := First_Stored_Discriminant (Base_Type (Typ));
5702 while Present (Discriminant) loop
5703 New_Comp :=
5704 New_Copy_Tree (
5705 Get_Discriminant_Value (
5706 Discriminant,
5707 Typ,
5708 Discriminant_Constraint (Typ)));
5709 Append (New_Comp, Constraints);
5710 Next_Stored_Discriminant (Discriminant);
5711 end loop;
5712
5713 Decl :=
5714 Make_Subtype_Declaration (Loc,
5715 Defining_Identifier =>
5716 Make_Defining_Identifier (Loc,
5717 New_Internal_Name ('T')),
5718 Subtype_Indication =>
5719 Make_Subtype_Indication (Loc,
5720 Subtype_Mark =>
5721 New_Occurrence_Of (Etype (Base_Type (Typ)), Loc),
5722 Constraint =>
5723 Make_Index_Or_Discriminant_Constraint
5724 (Loc, Constraints)));
5725
5726 Insert_Action (N, Decl);
5727 Prepend_Stored_Values (Base_Type (Typ));
5728
5729 Set_Etype (N, Defining_Identifier (Decl));
5730 Set_Analyzed (N);
5731
5732 Rewrite (N, Unchecked_Convert_To (Typ, N));
5733 Analyze (N);
5734
5735 -- Case where we do not have fewer new discriminants than
5736 -- stored discriminants, so in this case we can simply use the
5737 -- stored discriminants of the subtype.
5738
5739 else
5740 Prepend_Stored_Values (Typ);
5741 end if;
5742 end Generate_Aggregate_For_Derived_Type;
5743 end if;
5744
5745 if Is_Tagged_Type (Typ) then
5746
5747 -- The tagged case, _parent and _tag component must be created
5748
5749 -- Reset null_present unconditionally. tagged records always have
5750 -- at least one field (the tag or the parent)
5751
5752 Set_Null_Record_Present (N, False);
5753
5754 -- When the current aggregate comes from the expansion of an
5755 -- extension aggregate, the parent expr is replaced by an
5756 -- aggregate formed by selected components of this expr
5757
5758 if Present (Parent_Expr)
5759 and then Is_Empty_List (Comps)
5760 then
5761 Comp := First_Component_Or_Discriminant (Typ);
5762 while Present (Comp) loop
5763
5764 -- Skip all expander-generated components
5765
5766 if
5767 not Comes_From_Source (Original_Record_Component (Comp))
5768 then
5769 null;
5770
5771 else
5772 New_Comp :=
5773 Make_Selected_Component (Loc,
5774 Prefix =>
5775 Unchecked_Convert_To (Typ,
5776 Duplicate_Subexpr (Parent_Expr, True)),
5777
5778 Selector_Name => New_Occurrence_Of (Comp, Loc));
5779
5780 Append_To (Comps,
5781 Make_Component_Association (Loc,
5782 Choices =>
5783 New_List (New_Occurrence_Of (Comp, Loc)),
5784 Expression =>
5785 New_Comp));
5786
5787 Analyze_And_Resolve (New_Comp, Etype (Comp));
5788 end if;
5789
5790 Next_Component_Or_Discriminant (Comp);
5791 end loop;
5792 end if;
5793
5794 -- Compute the value for the Tag now, if the type is a root it
5795 -- will be included in the aggregate right away, otherwise it will
5796 -- be propagated to the parent aggregate
5797
5798 if Present (Orig_Tag) then
5799 Tag_Value := Orig_Tag;
5800 elsif not Tagged_Type_Expansion then
5801 Tag_Value := Empty;
5802 else
5803 Tag_Value :=
5804 New_Occurrence_Of
5805 (Node (First_Elmt (Access_Disp_Table (Typ))), Loc);
5806 end if;
5807
5808 -- For a derived type, an aggregate for the parent is formed with
5809 -- all the inherited components.
5810
5811 if Is_Derived_Type (Typ) then
5812
5813 declare
5814 First_Comp : Node_Id;
5815 Parent_Comps : List_Id;
5816 Parent_Aggr : Node_Id;
5817 Parent_Name : Node_Id;
5818
5819 begin
5820 -- Remove the inherited component association from the
5821 -- aggregate and store them in the parent aggregate
5822
5823 First_Comp := First (Component_Associations (N));
5824 Parent_Comps := New_List;
5825 while Present (First_Comp)
5826 and then Scope (Original_Record_Component (
5827 Entity (First (Choices (First_Comp))))) /= Base_Typ
5828 loop
5829 Comp := First_Comp;
5830 Next (First_Comp);
5831 Remove (Comp);
5832 Append (Comp, Parent_Comps);
5833 end loop;
5834
5835 Parent_Aggr := Make_Aggregate (Loc,
5836 Component_Associations => Parent_Comps);
5837 Set_Etype (Parent_Aggr, Etype (Base_Type (Typ)));
5838
5839 -- Find the _parent component
5840
5841 Comp := First_Component (Typ);
5842 while Chars (Comp) /= Name_uParent loop
5843 Comp := Next_Component (Comp);
5844 end loop;
5845
5846 Parent_Name := New_Occurrence_Of (Comp, Loc);
5847
5848 -- Insert the parent aggregate
5849
5850 Prepend_To (Component_Associations (N),
5851 Make_Component_Association (Loc,
5852 Choices => New_List (Parent_Name),
5853 Expression => Parent_Aggr));
5854
5855 -- Expand recursively the parent propagating the right Tag
5856
5857 Expand_Record_Aggregate (
5858 Parent_Aggr, Tag_Value, Parent_Expr);
5859 end;
5860
5861 -- For a root type, the tag component is added (unless compiling
5862 -- for the VMs, where tags are implicit).
5863
5864 elsif Tagged_Type_Expansion then
5865 declare
5866 Tag_Name : constant Node_Id :=
5867 New_Occurrence_Of
5868 (First_Tag_Component (Typ), Loc);
5869 Typ_Tag : constant Entity_Id := RTE (RE_Tag);
5870 Conv_Node : constant Node_Id :=
5871 Unchecked_Convert_To (Typ_Tag, Tag_Value);
5872
5873 begin
5874 Set_Etype (Conv_Node, Typ_Tag);
5875 Prepend_To (Component_Associations (N),
5876 Make_Component_Association (Loc,
5877 Choices => New_List (Tag_Name),
5878 Expression => Conv_Node));
5879 end;
5880 end if;
5881 end if;
5882 end if;
5883
5884 end Expand_Record_Aggregate;
5885
5886 ----------------------------
5887 -- Has_Default_Init_Comps --
5888 ----------------------------
5889
5890 function Has_Default_Init_Comps (N : Node_Id) return Boolean is
5891 Comps : constant List_Id := Component_Associations (N);
5892 C : Node_Id;
5893 Expr : Node_Id;
5894 begin
5895 pragma Assert (Nkind_In (N, N_Aggregate, N_Extension_Aggregate));
5896
5897 if No (Comps) then
5898 return False;
5899 end if;
5900
5901 if Has_Self_Reference (N) then
5902 return True;
5903 end if;
5904
5905 -- Check if any direct component has default initialized components
5906
5907 C := First (Comps);
5908 while Present (C) loop
5909 if Box_Present (C) then
5910 return True;
5911 end if;
5912
5913 Next (C);
5914 end loop;
5915
5916 -- Recursive call in case of aggregate expression
5917
5918 C := First (Comps);
5919 while Present (C) loop
5920 Expr := Expression (C);
5921
5922 if Present (Expr)
5923 and then
5924 Nkind_In (Expr, N_Aggregate, N_Extension_Aggregate)
5925 and then Has_Default_Init_Comps (Expr)
5926 then
5927 return True;
5928 end if;
5929
5930 Next (C);
5931 end loop;
5932
5933 return False;
5934 end Has_Default_Init_Comps;
5935
5936 --------------------------
5937 -- Is_Delayed_Aggregate --
5938 --------------------------
5939
5940 function Is_Delayed_Aggregate (N : Node_Id) return Boolean is
5941 Node : Node_Id := N;
5942 Kind : Node_Kind := Nkind (Node);
5943
5944 begin
5945 if Kind = N_Qualified_Expression then
5946 Node := Expression (Node);
5947 Kind := Nkind (Node);
5948 end if;
5949
5950 if Kind /= N_Aggregate and then Kind /= N_Extension_Aggregate then
5951 return False;
5952 else
5953 return Expansion_Delayed (Node);
5954 end if;
5955 end Is_Delayed_Aggregate;
5956
5957 ----------------------------------------
5958 -- Is_Static_Dispatch_Table_Aggregate --
5959 ----------------------------------------
5960
5961 function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean is
5962 Typ : constant Entity_Id := Base_Type (Etype (N));
5963
5964 begin
5965 return Static_Dispatch_Tables
5966 and then Tagged_Type_Expansion
5967 and then RTU_Loaded (Ada_Tags)
5968
5969 -- Avoid circularity when rebuilding the compiler
5970
5971 and then Cunit_Entity (Get_Source_Unit (N)) /= RTU_Entity (Ada_Tags)
5972 and then (Typ = RTE (RE_Dispatch_Table_Wrapper)
5973 or else
5974 Typ = RTE (RE_Address_Array)
5975 or else
5976 Typ = RTE (RE_Type_Specific_Data)
5977 or else
5978 Typ = RTE (RE_Tag_Table)
5979 or else
5980 (RTE_Available (RE_Interface_Data)
5981 and then Typ = RTE (RE_Interface_Data))
5982 or else
5983 (RTE_Available (RE_Interfaces_Array)
5984 and then Typ = RTE (RE_Interfaces_Array))
5985 or else
5986 (RTE_Available (RE_Interface_Data_Element)
5987 and then Typ = RTE (RE_Interface_Data_Element)));
5988 end Is_Static_Dispatch_Table_Aggregate;
5989
5990 --------------------
5991 -- Late_Expansion --
5992 --------------------
5993
5994 function Late_Expansion
5995 (N : Node_Id;
5996 Typ : Entity_Id;
5997 Target : Node_Id;
5998 Flist : Node_Id := Empty;
5999 Obj : Entity_Id := Empty) return List_Id
6000 is
6001 begin
6002 if Is_Record_Type (Etype (N)) then
6003 return Build_Record_Aggr_Code (N, Typ, Target, Flist, Obj);
6004
6005 else pragma Assert (Is_Array_Type (Etype (N)));
6006 return
6007 Build_Array_Aggr_Code
6008 (N => N,
6009 Ctype => Component_Type (Etype (N)),
6010 Index => First_Index (Typ),
6011 Into => Target,
6012 Scalar_Comp => Is_Scalar_Type (Component_Type (Typ)),
6013 Indices => No_List,
6014 Flist => Flist);
6015 end if;
6016 end Late_Expansion;
6017
6018 ----------------------------------
6019 -- Make_OK_Assignment_Statement --
6020 ----------------------------------
6021
6022 function Make_OK_Assignment_Statement
6023 (Sloc : Source_Ptr;
6024 Name : Node_Id;
6025 Expression : Node_Id) return Node_Id
6026 is
6027 begin
6028 Set_Assignment_OK (Name);
6029
6030 return Make_Assignment_Statement (Sloc, Name, Expression);
6031 end Make_OK_Assignment_Statement;
6032
6033 -----------------------
6034 -- Number_Of_Choices --
6035 -----------------------
6036
6037 function Number_Of_Choices (N : Node_Id) return Nat is
6038 Assoc : Node_Id;
6039 Choice : Node_Id;
6040
6041 Nb_Choices : Nat := 0;
6042
6043 begin
6044 if Present (Expressions (N)) then
6045 return 0;
6046 end if;
6047
6048 Assoc := First (Component_Associations (N));
6049 while Present (Assoc) loop
6050 Choice := First (Choices (Assoc));
6051 while Present (Choice) loop
6052 if Nkind (Choice) /= N_Others_Choice then
6053 Nb_Choices := Nb_Choices + 1;
6054 end if;
6055
6056 Next (Choice);
6057 end loop;
6058
6059 Next (Assoc);
6060 end loop;
6061
6062 return Nb_Choices;
6063 end Number_Of_Choices;
6064
6065 ------------------------------------
6066 -- Packed_Array_Aggregate_Handled --
6067 ------------------------------------
6068
6069 -- The current version of this procedure will handle at compile time
6070 -- any array aggregate that meets these conditions:
6071
6072 -- One dimensional, bit packed
6073 -- Underlying packed type is modular type
6074 -- Bounds are within 32-bit Int range
6075 -- All bounds and values are static
6076
6077 function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean is
6078 Loc : constant Source_Ptr := Sloc (N);
6079 Typ : constant Entity_Id := Etype (N);
6080 Ctyp : constant Entity_Id := Component_Type (Typ);
6081
6082 Not_Handled : exception;
6083 -- Exception raised if this aggregate cannot be handled
6084
6085 begin
6086 -- For now, handle only one dimensional bit packed arrays
6087
6088 if not Is_Bit_Packed_Array (Typ)
6089 or else Number_Dimensions (Typ) > 1
6090 or else not Is_Modular_Integer_Type (Packed_Array_Type (Typ))
6091 then
6092 return False;
6093 end if;
6094
6095 if not Is_Scalar_Type (Component_Type (Typ))
6096 and then Has_Non_Standard_Rep (Component_Type (Typ))
6097 then
6098 return False;
6099 end if;
6100
6101 declare
6102 Csiz : constant Nat := UI_To_Int (Component_Size (Typ));
6103
6104 Lo : Node_Id;
6105 Hi : Node_Id;
6106 -- Bounds of index type
6107
6108 Lob : Uint;
6109 Hib : Uint;
6110 -- Values of bounds if compile time known
6111
6112 function Get_Component_Val (N : Node_Id) return Uint;
6113 -- Given a expression value N of the component type Ctyp, returns a
6114 -- value of Csiz (component size) bits representing this value. If
6115 -- the value is non-static or any other reason exists why the value
6116 -- cannot be returned, then Not_Handled is raised.
6117
6118 -----------------------
6119 -- Get_Component_Val --
6120 -----------------------
6121
6122 function Get_Component_Val (N : Node_Id) return Uint is
6123 Val : Uint;
6124
6125 begin
6126 -- We have to analyze the expression here before doing any further
6127 -- processing here. The analysis of such expressions is deferred
6128 -- till expansion to prevent some problems of premature analysis.
6129
6130 Analyze_And_Resolve (N, Ctyp);
6131
6132 -- Must have a compile time value. String literals have to be
6133 -- converted into temporaries as well, because they cannot easily
6134 -- be converted into their bit representation.
6135
6136 if not Compile_Time_Known_Value (N)
6137 or else Nkind (N) = N_String_Literal
6138 then
6139 raise Not_Handled;
6140 end if;
6141
6142 Val := Expr_Rep_Value (N);
6143
6144 -- Adjust for bias, and strip proper number of bits
6145
6146 if Has_Biased_Representation (Ctyp) then
6147 Val := Val - Expr_Value (Type_Low_Bound (Ctyp));
6148 end if;
6149
6150 return Val mod Uint_2 ** Csiz;
6151 end Get_Component_Val;
6152
6153 -- Here we know we have a one dimensional bit packed array
6154
6155 begin
6156 Get_Index_Bounds (First_Index (Typ), Lo, Hi);
6157
6158 -- Cannot do anything if bounds are dynamic
6159
6160 if not Compile_Time_Known_Value (Lo)
6161 or else
6162 not Compile_Time_Known_Value (Hi)
6163 then
6164 return False;
6165 end if;
6166
6167 -- Or are silly out of range of int bounds
6168
6169 Lob := Expr_Value (Lo);
6170 Hib := Expr_Value (Hi);
6171
6172 if not UI_Is_In_Int_Range (Lob)
6173 or else
6174 not UI_Is_In_Int_Range (Hib)
6175 then
6176 return False;
6177 end if;
6178
6179 -- At this stage we have a suitable aggregate for handling at compile
6180 -- time (the only remaining checks are that the values of expressions
6181 -- in the aggregate are compile time known (check is performed by
6182 -- Get_Component_Val), and that any subtypes or ranges are statically
6183 -- known.
6184
6185 -- If the aggregate is not fully positional at this stage, then
6186 -- convert it to positional form. Either this will fail, in which
6187 -- case we can do nothing, or it will succeed, in which case we have
6188 -- succeeded in handling the aggregate, or it will stay an aggregate,
6189 -- in which case we have failed to handle this case.
6190
6191 if Present (Component_Associations (N)) then
6192 Convert_To_Positional
6193 (N, Max_Others_Replicate => 64, Handle_Bit_Packed => True);
6194 return Nkind (N) /= N_Aggregate;
6195 end if;
6196
6197 -- Otherwise we are all positional, so convert to proper value
6198
6199 declare
6200 Lov : constant Int := UI_To_Int (Lob);
6201 Hiv : constant Int := UI_To_Int (Hib);
6202
6203 Len : constant Nat := Int'Max (0, Hiv - Lov + 1);
6204 -- The length of the array (number of elements)
6205
6206 Aggregate_Val : Uint;
6207 -- Value of aggregate. The value is set in the low order bits of
6208 -- this value. For the little-endian case, the values are stored
6209 -- from low-order to high-order and for the big-endian case the
6210 -- values are stored from high-order to low-order. Note that gigi
6211 -- will take care of the conversions to left justify the value in
6212 -- the big endian case (because of left justified modular type
6213 -- processing), so we do not have to worry about that here.
6214
6215 Lit : Node_Id;
6216 -- Integer literal for resulting constructed value
6217
6218 Shift : Nat;
6219 -- Shift count from low order for next value
6220
6221 Incr : Int;
6222 -- Shift increment for loop
6223
6224 Expr : Node_Id;
6225 -- Next expression from positional parameters of aggregate
6226
6227 begin
6228 -- For little endian, we fill up the low order bits of the target
6229 -- value. For big endian we fill up the high order bits of the
6230 -- target value (which is a left justified modular value).
6231
6232 if Bytes_Big_Endian xor Debug_Flag_8 then
6233 Shift := Csiz * (Len - 1);
6234 Incr := -Csiz;
6235 else
6236 Shift := 0;
6237 Incr := +Csiz;
6238 end if;
6239
6240 -- Loop to set the values
6241
6242 if Len = 0 then
6243 Aggregate_Val := Uint_0;
6244 else
6245 Expr := First (Expressions (N));
6246 Aggregate_Val := Get_Component_Val (Expr) * Uint_2 ** Shift;
6247
6248 for J in 2 .. Len loop
6249 Shift := Shift + Incr;
6250 Next (Expr);
6251 Aggregate_Val :=
6252 Aggregate_Val + Get_Component_Val (Expr) * Uint_2 ** Shift;
6253 end loop;
6254 end if;
6255
6256 -- Now we can rewrite with the proper value
6257
6258 Lit :=
6259 Make_Integer_Literal (Loc,
6260 Intval => Aggregate_Val);
6261 Set_Print_In_Hex (Lit);
6262
6263 -- Construct the expression using this literal. Note that it is
6264 -- important to qualify the literal with its proper modular type
6265 -- since universal integer does not have the required range and
6266 -- also this is a left justified modular type, which is important
6267 -- in the big-endian case.
6268
6269 Rewrite (N,
6270 Unchecked_Convert_To (Typ,
6271 Make_Qualified_Expression (Loc,
6272 Subtype_Mark =>
6273 New_Occurrence_Of (Packed_Array_Type (Typ), Loc),
6274 Expression => Lit)));
6275
6276 Analyze_And_Resolve (N, Typ);
6277 return True;
6278 end;
6279 end;
6280
6281 exception
6282 when Not_Handled =>
6283 return False;
6284 end Packed_Array_Aggregate_Handled;
6285
6286 ----------------------------
6287 -- Has_Mutable_Components --
6288 ----------------------------
6289
6290 function Has_Mutable_Components (Typ : Entity_Id) return Boolean is
6291 Comp : Entity_Id;
6292
6293 begin
6294 Comp := First_Component (Typ);
6295 while Present (Comp) loop
6296 if Is_Record_Type (Etype (Comp))
6297 and then Has_Discriminants (Etype (Comp))
6298 and then not Is_Constrained (Etype (Comp))
6299 then
6300 return True;
6301 end if;
6302
6303 Next_Component (Comp);
6304 end loop;
6305
6306 return False;
6307 end Has_Mutable_Components;
6308
6309 ------------------------------
6310 -- Initialize_Discriminants --
6311 ------------------------------
6312
6313 procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id) is
6314 Loc : constant Source_Ptr := Sloc (N);
6315 Bas : constant Entity_Id := Base_Type (Typ);
6316 Par : constant Entity_Id := Etype (Bas);
6317 Decl : constant Node_Id := Parent (Par);
6318 Ref : Node_Id;
6319
6320 begin
6321 if Is_Tagged_Type (Bas)
6322 and then Is_Derived_Type (Bas)
6323 and then Has_Discriminants (Par)
6324 and then Has_Discriminants (Bas)
6325 and then Number_Discriminants (Bas) /= Number_Discriminants (Par)
6326 and then Nkind (Decl) = N_Full_Type_Declaration
6327 and then Nkind (Type_Definition (Decl)) = N_Record_Definition
6328 and then Present
6329 (Variant_Part (Component_List (Type_Definition (Decl))))
6330 and then Nkind (N) /= N_Extension_Aggregate
6331 then
6332
6333 -- Call init proc to set discriminants.
6334 -- There should eventually be a special procedure for this ???
6335
6336 Ref := New_Reference_To (Defining_Identifier (N), Loc);
6337 Insert_Actions_After (N,
6338 Build_Initialization_Call (Sloc (N), Ref, Typ));
6339 end if;
6340 end Initialize_Discriminants;
6341
6342 ----------------
6343 -- Must_Slide --
6344 ----------------
6345
6346 function Must_Slide
6347 (Obj_Type : Entity_Id;
6348 Typ : Entity_Id) return Boolean
6349 is
6350 L1, L2, H1, H2 : Node_Id;
6351 begin
6352 -- No sliding if the type of the object is not established yet, if it is
6353 -- an unconstrained type whose actual subtype comes from the aggregate,
6354 -- or if the two types are identical.
6355
6356 if not Is_Array_Type (Obj_Type) then
6357 return False;
6358
6359 elsif not Is_Constrained (Obj_Type) then
6360 return False;
6361
6362 elsif Typ = Obj_Type then
6363 return False;
6364
6365 else
6366 -- Sliding can only occur along the first dimension
6367
6368 Get_Index_Bounds (First_Index (Typ), L1, H1);
6369 Get_Index_Bounds (First_Index (Obj_Type), L2, H2);
6370
6371 if not Is_Static_Expression (L1)
6372 or else not Is_Static_Expression (L2)
6373 or else not Is_Static_Expression (H1)
6374 or else not Is_Static_Expression (H2)
6375 then
6376 return False;
6377 else
6378 return Expr_Value (L1) /= Expr_Value (L2)
6379 or else Expr_Value (H1) /= Expr_Value (H2);
6380 end if;
6381 end if;
6382 end Must_Slide;
6383
6384 ---------------------------
6385 -- Safe_Slice_Assignment --
6386 ---------------------------
6387
6388 function Safe_Slice_Assignment (N : Node_Id) return Boolean is
6389 Loc : constant Source_Ptr := Sloc (Parent (N));
6390 Pref : constant Node_Id := Prefix (Name (Parent (N)));
6391 Range_Node : constant Node_Id := Discrete_Range (Name (Parent (N)));
6392 Expr : Node_Id;
6393 L_J : Entity_Id;
6394 L_Iter : Node_Id;
6395 L_Body : Node_Id;
6396 Stat : Node_Id;
6397
6398 begin
6399 -- Generate: for J in Range loop Pref (J) := Expr; end loop;
6400
6401 if Comes_From_Source (N)
6402 and then No (Expressions (N))
6403 and then Nkind (First (Choices (First (Component_Associations (N)))))
6404 = N_Others_Choice
6405 then
6406 Expr :=
6407 Expression (First (Component_Associations (N)));
6408 L_J := Make_Defining_Identifier (Loc, New_Internal_Name ('J'));
6409
6410 L_Iter :=
6411 Make_Iteration_Scheme (Loc,
6412 Loop_Parameter_Specification =>
6413 Make_Loop_Parameter_Specification
6414 (Loc,
6415 Defining_Identifier => L_J,
6416 Discrete_Subtype_Definition => Relocate_Node (Range_Node)));
6417
6418 L_Body :=
6419 Make_Assignment_Statement (Loc,
6420 Name =>
6421 Make_Indexed_Component (Loc,
6422 Prefix => Relocate_Node (Pref),
6423 Expressions => New_List (New_Occurrence_Of (L_J, Loc))),
6424 Expression => Relocate_Node (Expr));
6425
6426 -- Construct the final loop
6427
6428 Stat :=
6429 Make_Implicit_Loop_Statement
6430 (Node => Parent (N),
6431 Identifier => Empty,
6432 Iteration_Scheme => L_Iter,
6433 Statements => New_List (L_Body));
6434
6435 -- Set type of aggregate to be type of lhs in assignment,
6436 -- to suppress redundant length checks.
6437
6438 Set_Etype (N, Etype (Name (Parent (N))));
6439
6440 Rewrite (Parent (N), Stat);
6441 Analyze (Parent (N));
6442 return True;
6443
6444 else
6445 return False;
6446 end if;
6447 end Safe_Slice_Assignment;
6448
6449 ---------------------
6450 -- Sort_Case_Table --
6451 ---------------------
6452
6453 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
6454 L : constant Int := Case_Table'First;
6455 U : constant Int := Case_Table'Last;
6456 K : Int;
6457 J : Int;
6458 T : Case_Bounds;
6459
6460 begin
6461 K := L;
6462 while K /= U loop
6463 T := Case_Table (K + 1);
6464
6465 J := K + 1;
6466 while J /= L
6467 and then Expr_Value (Case_Table (J - 1).Choice_Lo) >
6468 Expr_Value (T.Choice_Lo)
6469 loop
6470 Case_Table (J) := Case_Table (J - 1);
6471 J := J - 1;
6472 end loop;
6473
6474 Case_Table (J) := T;
6475 K := K + 1;
6476 end loop;
6477 end Sort_Case_Table;
6478
6479 ----------------------------
6480 -- Static_Array_Aggregate --
6481 ----------------------------
6482
6483 function Static_Array_Aggregate (N : Node_Id) return Boolean is
6484 Bounds : constant Node_Id := Aggregate_Bounds (N);
6485
6486 Typ : constant Entity_Id := Etype (N);
6487 Comp_Type : constant Entity_Id := Component_Type (Typ);
6488 Agg : Node_Id;
6489 Expr : Node_Id;
6490 Lo : Node_Id;
6491 Hi : Node_Id;
6492
6493 begin
6494 if Is_Tagged_Type (Typ)
6495 or else Is_Controlled (Typ)
6496 or else Is_Packed (Typ)
6497 then
6498 return False;
6499 end if;
6500
6501 if Present (Bounds)
6502 and then Nkind (Bounds) = N_Range
6503 and then Nkind (Low_Bound (Bounds)) = N_Integer_Literal
6504 and then Nkind (High_Bound (Bounds)) = N_Integer_Literal
6505 then
6506 Lo := Low_Bound (Bounds);
6507 Hi := High_Bound (Bounds);
6508
6509 if No (Component_Associations (N)) then
6510
6511 -- Verify that all components are static integers
6512
6513 Expr := First (Expressions (N));
6514 while Present (Expr) loop
6515 if Nkind (Expr) /= N_Integer_Literal then
6516 return False;
6517 end if;
6518
6519 Next (Expr);
6520 end loop;
6521
6522 return True;
6523
6524 else
6525 -- We allow only a single named association, either a static
6526 -- range or an others_clause, with a static expression.
6527
6528 Expr := First (Component_Associations (N));
6529
6530 if Present (Expressions (N)) then
6531 return False;
6532
6533 elsif Present (Next (Expr)) then
6534 return False;
6535
6536 elsif Present (Next (First (Choices (Expr)))) then
6537 return False;
6538
6539 else
6540 -- The aggregate is static if all components are literals,
6541 -- or else all its components are static aggregates for the
6542 -- component type. We also limit the size of a static aggregate
6543 -- to prevent runaway static expressions.
6544
6545 if Is_Array_Type (Comp_Type)
6546 or else Is_Record_Type (Comp_Type)
6547 then
6548 if Nkind (Expression (Expr)) /= N_Aggregate
6549 or else
6550 not Compile_Time_Known_Aggregate (Expression (Expr))
6551 then
6552 return False;
6553 end if;
6554
6555 elsif Nkind (Expression (Expr)) /= N_Integer_Literal then
6556 return False;
6557
6558 elsif not Aggr_Size_OK (N, Typ) then
6559 return False;
6560 end if;
6561
6562 -- Create a positional aggregate with the right number of
6563 -- copies of the expression.
6564
6565 Agg := Make_Aggregate (Sloc (N), New_List, No_List);
6566
6567 for I in UI_To_Int (Intval (Lo)) .. UI_To_Int (Intval (Hi))
6568 loop
6569 Append_To
6570 (Expressions (Agg), New_Copy (Expression (Expr)));
6571
6572 -- The copied expression must be analyzed and resolved.
6573 -- Besides setting the type, this ensures that static
6574 -- expressions are appropriately marked as such.
6575
6576 Analyze_And_Resolve
6577 (Last (Expressions (Agg)), Component_Type (Typ));
6578 end loop;
6579
6580 Set_Aggregate_Bounds (Agg, Bounds);
6581 Set_Etype (Agg, Typ);
6582 Set_Analyzed (Agg);
6583 Rewrite (N, Agg);
6584 Set_Compile_Time_Known_Aggregate (N);
6585
6586 return True;
6587 end if;
6588 end if;
6589
6590 else
6591 return False;
6592 end if;
6593 end Static_Array_Aggregate;
6594
6595 end Exp_Aggr;