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1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- E X P _ A G G R --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2009, 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 ------------------------------------------------------------------------------
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;
63 package body Exp_Aggr is
65 type Case_Bounds is record
66 Choice_Lo : Node_Id;
67 Choice_Hi : Node_Id;
68 Choice_Node : Node_Id;
69 end record;
71 type Case_Table_Type is array (Nat range <>) of Case_Bounds;
72 -- Table type used by Check_Case_Choices procedure
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.
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.
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.
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)
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.
102 ------------------------------------------------------
103 -- Local subprograms for Record Aggregate Expansion --
104 ------------------------------------------------------
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.
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
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.
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.
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?
151 -- Is_Limited_Ancestor_Expansion indicates that the function has been
152 -- called recursively to expand the limited ancestor to avoid copying it.
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.
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.
171 -----------------------------------------------------
172 -- Local Subprograms for Array Aggregate Expansion --
173 -----------------------------------------------------
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.
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.
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.
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.
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.
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.
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.
237 -- Index is the index node corresponding to the array sub-aggregate N.
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.
243 -- Scalar_Comp is True if the component type of the aggregate is scalar.
245 -- Indices is the current list of expressions used to index the
246 -- object we are writing into.
248 -- Flist is an expression representing the finalization list on which
249 -- to attach the controlled components if any.
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.
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.
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.
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
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.
296 ------------------
297 -- Aggr_Size_OK --
298 ------------------
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;
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.
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.
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));
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.
333 ---------------------
334 -- Component_Count --
335 ---------------------
337 function Component_Count (T : Entity_Id) return Int is
338 Res : Int := 0;
339 Comp : Entity_Id;
341 begin
342 if Is_Scalar_Type (T) then
343 return 1;
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;
352 return Res;
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)));
361 Siz : constant Int := Component_Count (Component_Type (T));
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;
374 else
375 -- Can only be a null for an access type
377 return 1;
378 end if;
379 end Component_Count;
381 -- Start of processing for Aggr_Size_OK
383 begin
384 Siz := Component_Count (Component_Type (Typ));
386 Indx := First_Index (Typ);
387 while Present (Indx) loop
388 Lo := Type_Low_Bound (Etype (Indx));
389 Hi := Type_High_Bound (Etype (Indx));
391 -- Bounds need to be known at compile time
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;
399 Lov := Expr_Value (Lo);
400 Hiv := Expr_Value (Hi);
402 -- A flat array is always safe
404 if Hiv < Lov then
405 return True;
406 end if;
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.
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;
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;
440 return False;
441 end if;
442 end;
443 end if;
445 declare
446 Rng : constant Uint := Hiv - Lov + 1;
448 begin
449 -- Check if size is too large
451 if not UI_Is_In_Int_Range (Rng) then
452 return False;
453 end if;
455 Siz := Siz * UI_To_Int (Rng);
456 end;
458 if Siz <= 0
459 or else Siz > Max_Aggr_Size
460 then
461 return False;
462 end if;
464 -- Bounds must be in integer range, for later array construction
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;
473 Next_Index (Indx);
474 end loop;
476 return True;
477 end Aggr_Size_OK;
479 ---------------------------------
480 -- Backend_Processing_Possible --
481 ---------------------------------
483 -- Backend processing by Gigi/gcc is possible only if all the following
484 -- conditions are met:
486 -- 1. N is fully positional
488 -- 2. N is not a bit-packed array aggregate;
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
493 -- 4. The array type of N does not follow the Fortran layout convention
494 -- or if it does it must be 1 dimensional.
496 -- 5. The array component type may not be tagged (which could necessitate
497 -- reassignment of proper tags).
499 -- 6. The array component type must not have unaligned bit components
501 -- 7. None of the components of the aggregate may be bit unaligned
502 -- components.
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.
507 -- 9. There cannot be any discriminated record components, since the
508 -- back end cannot handle this complex case.
510 -- 10. No controlled actions need to be generated for components
512 -- 11. For a VM back end, the array should have no aliased components
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
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.
524 ---------------------
525 -- Component_Check --
526 ---------------------
528 function Component_Check (N : Node_Id; Index : Node_Id) return Boolean is
529 Expr : Node_Id;
531 begin
532 -- Checks 1: (no component associations)
534 if Present (Component_Associations (N)) then
535 return False;
536 end if;
538 -- Checks on components
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.
545 Expr := First (Expressions (N));
546 while Present (Expr) loop
548 -- Checks 8: (no delayed components)
550 if Is_Delayed_Aggregate (Expr) then
551 return False;
552 end if;
554 -- Checks 9: (no discriminated records)
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;
563 -- Checks 7. Component must not be bit aligned component
565 if Possible_Bit_Aligned_Component (Expr) then
566 return False;
567 end if;
569 -- Recursion to following indexes for multiple dimension case
571 if Present (Next_Index (Index))
572 and then not Component_Check (Expr, Next_Index (Index))
573 then
574 return False;
575 end if;
577 -- All checks for that component finished, on to next
579 Next (Expr);
580 end loop;
582 return True;
583 end Component_Check;
585 -- Start of processing for Backend_Processing_Possible
587 begin
588 -- Checks 2 (array not bit packed) and 10 (no controlled actions)
590 if Is_Bit_Packed_Array (Typ) or else Needs_Finalization (Typ) then
591 return False;
592 end if;
594 -- If component is limited, aggregate must be expanded because each
595 -- component assignment must be built in place.
597 if Is_Inherently_Limited_Type (Component_Type (Typ)) then
598 return False;
599 end if;
601 -- Checks 4 (array must not be multi-dimensional Fortran case)
603 if Convention (Typ) = Convention_Fortran
604 and then Number_Dimensions (Typ) > 1
605 then
606 return False;
607 end if;
609 -- Checks 3 (size of array must be known at compile time)
611 if not Size_Known_At_Compile_Time (Typ) then
612 return False;
613 end if;
615 -- Checks on components
617 if not Component_Check (N, First_Index (Typ)) then
618 return False;
619 end if;
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)
628 if Is_Tagged_Type (Component_Type (Typ))
629 and then Tagged_Type_Expansion
630 then
631 return False;
632 end if;
634 -- Checks 6 (component type must not have bit aligned components)
636 if Type_May_Have_Bit_Aligned_Components (Component_Type (Typ)) then
637 return False;
638 end if;
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.
644 if VM_Target /= No_VM
645 and then Has_Aliased_Components (Base_Type (Typ))
646 then
647 return False;
648 end if;
650 -- Backend processing is possible
652 Set_Size_Known_At_Compile_Time (Etype (N), True);
653 return True;
654 end Backend_Processing_Possible;
656 ---------------------------
657 -- Build_Array_Aggr_Code --
658 ---------------------------
660 -- The code that we generate from a one dimensional aggregate is
662 -- 1. If the sub-aggregate contains discrete choices we
664 -- (a) Sort the discrete choices
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.
671 -- (c) Generate the remaining loops to cover the others choice if any
673 -- 2. If the aggregate contains positional elements we
675 -- (a) translate the positional elements in a series of assignments
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
680 -- L : Integer := Integer'Last;
681 -- H : Integer := Integer'Last;
682 -- A : array (L .. H) := (1, others =>0);
684 -- cannot be handled by a for loop. Thus for the following
686 -- array (L .. H) := (.. positional elements.., others =>E);
688 -- we always generate something like:
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;
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
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);
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.
715 function Empty_Range (L, H : Node_Id) return Boolean;
716 -- Returns True if the range defined by L .. H is certainly empty
718 function Equal (L, H : Node_Id) return Boolean;
719 -- Returns True if L = H for sure
721 function Index_Base_Name return Node_Id;
722 -- Returns a new reference to the index type name
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:
729 -- Into (Indices, Ind) := Expr;
731 -- Otherwise we call Build_Code recursively
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.
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
741 -- for J in Index_Base'(L) .. Index_Base'(H) loop
742 -- Into (Indices, J) := Expr;
743 -- end loop;
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.
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
754 -- J : Index_Base := L;
755 -- while J < H loop
756 -- J := Index_Base'Succ (J);
757 -- Into (Indices, J) := Expr;
758 -- end loop;
760 -- Otherwise we call Build_Code recursively
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.
772 ---------
773 -- Add --
774 ---------
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);
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.
787 -- First test if we can do constant folding
789 if Local_Compile_Time_Known_Value (To) then
790 U_To := Local_Expr_Value (To) + Val;
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.
796 if Compile_Time_Known_Value (Index_Base_L)
797 and then U_To < Expr_Value (Index_Base_L)
798 then
799 return Empty;
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;
807 Expr_Pos := Make_Integer_Literal (Loc, U_To);
808 Set_Is_Static_Expression (Expr_Pos);
810 if not Is_Enumeration_Type (Index_Base) then
811 Expr := Expr_Pos;
813 -- If we are dealing with enumeration return
814 -- Index_Base'Val (Expr_Pos)
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;
825 return Expr;
826 end if;
828 -- If we are here no constant folding possible
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));
836 -- If we are dealing with enumeration return
837 -- Index_Base'Val (Index_Base'Pos (To) + Val)
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)));
847 Expr_Pos :=
848 Make_Op_Add (Loc,
849 Left_Opnd => To_Pos,
850 Right_Opnd => Make_Integer_Literal (Loc, U_Val));
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;
860 return Expr;
861 end Add;
863 -----------------
864 -- Empty_Range --
865 -----------------
867 function Empty_Range (L, H : Node_Id) return Boolean is
868 Is_Empty : Boolean := False;
869 Low : Node_Id;
870 High : Node_Id;
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.
877 if No (L) or else No (H) then
878 return True;
879 end if;
881 for J in 1 .. 3 loop
882 case J is
884 -- L > H range is empty
886 when 1 =>
887 Low := L;
888 High := H;
890 -- B_L > H range must be empty
892 when 2 =>
893 Low := Index_Base_L;
894 High := H;
896 -- L > B_H range must be empty
898 when 3 =>
899 Low := L;
900 High := Index_Base_H;
901 end case;
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;
910 exit when Is_Empty;
911 end loop;
913 return Is_Empty;
914 end Empty_Range;
916 -----------
917 -- Equal --
918 -----------
920 function Equal (L, H : Node_Id) return Boolean is
921 begin
922 if L = H then
923 return True;
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;
931 return False;
932 end Equal;
934 ----------------
935 -- Gen_Assign --
936 ----------------
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;
943 New_Indices : List_Id;
944 Indexed_Comp : Node_Id;
945 Expr_Q : Node_Id;
946 Comp_Type : Entity_Id := Empty;
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.
953 ----------------------
954 -- Add_Loop_Actions --
955 ----------------------
957 function Add_Loop_Actions (Lis : List_Id) return List_Id is
958 Res : List_Id;
960 begin
961 -- Ada 2005 (AI-287): Do nothing else in case of default
962 -- initialized component.
964 if No (Expr) then
965 return Lis;
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;
975 else
976 return Lis;
977 end if;
978 end Add_Loop_Actions;
980 -- Start of processing for Gen_Assign
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;
989 Append_To (New_Indices, Ind);
991 if Present (Flist) then
992 F := New_Copy_Tree (Flist);
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;
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;
1019 -- If we get here then we are at a bottom-level (sub-)aggregate
1021 Indexed_Comp :=
1022 Checks_Off
1023 (Make_Indexed_Component (Loc,
1024 Prefix => New_Copy_Tree (Into),
1025 Expressions => New_Indices));
1027 Set_Assignment_OK (Indexed_Comp);
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).
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;
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
1046 elsif Present (Next (First (New_Indices))) then
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.
1052 -- ??? Some assert pragmas have been added to check if this new
1053 -- formal can be used to replace this code in all cases.
1055 if Present (Expr) then
1057 -- This is a multidimensional array. Recover the component
1058 -- type from the outermost aggregate, because subaggregates
1059 -- do not have an assigned type.
1061 declare
1062 P : Node_Id;
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;
1073 else
1074 P := Parent (P);
1075 end if;
1076 end loop;
1078 pragma Assert (Comp_Type = Ctype); -- AI-287
1079 end;
1080 end if;
1081 end if;
1083 -- Ada 2005 (AI-287): We only analyze the expression in case of non-
1084 -- default initialized components (otherwise Expr_Q is not present).
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 ???
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;
1100 if Is_Delayed_Aggregate (Expr_Q) then
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.
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);
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;
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.
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.
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));
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;
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;
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.
1173 A :=
1174 Make_OK_Assignment_Statement (Loc,
1175 Name => Indexed_Comp,
1176 Expression => New_Copy_Tree (Expr));
1178 if Present (Comp_Type) and then Needs_Finalization (Comp_Type) then
1179 Set_No_Ctrl_Actions (A);
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.
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;
1202 Append_To (L, A);
1204 -- Adjust the tag if tagged (because of possible view
1205 -- conversions), unless compiling for a VM where
1206 -- tags are implicit.
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)),
1221 Expression =>
1222 Unchecked_Convert_To (RTE (RE_Tag),
1223 New_Reference_To
1224 (Node (First_Elmt (Access_Disp_Table (Comp_Type))),
1225 Loc)));
1227 Append_To (L, A);
1228 end if;
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.
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).
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;
1258 return Add_Loop_Actions (L);
1259 end Gen_Assign;
1261 --------------
1262 -- Gen_Loop --
1263 --------------
1265 function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id is
1266 L_J : Node_Id;
1268 L_L : Node_Id;
1269 -- Index_Base'(L)
1271 L_H : Node_Id;
1272 -- Index_Base'(H)
1274 L_Range : Node_Id;
1275 -- Index_Base'(L) .. Index_Base'(H)
1277 L_Iteration_Scheme : Node_Id;
1278 -- L_J in Index_Base'(L) .. Index_Base'(H)
1280 L_Body : List_Id;
1281 -- The statements to execute in the loop
1283 S : constant List_Id := New_List;
1284 -- List of statements
1286 Tcopy : Node_Id;
1287 -- Copy of expression tree, used for checking purposes
1289 begin
1290 -- If loop bounds define an empty range return the null statement
1292 if Empty_Range (L, H) then
1293 Append_To (S, Make_Null_Statement (Loc));
1295 -- Ada 2005 (AI-287): Nothing else need to be done in case of
1296 -- default initialized component.
1298 if No (Expr) then
1299 null;
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.
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;
1320 return S;
1322 -- If loop bounds are the same then generate an assignment
1324 elsif Equal (L, H) then
1325 return Gen_Assign (New_Copy_Tree (L), Expr);
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.
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
1338 Append_List_To (S, Gen_Assign (New_Copy_Tree (L), Expr));
1339 Append_List_To (S, Gen_Assign (Add (1, To => L), Expr));
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;
1345 return S;
1346 end if;
1348 -- Otherwise construct the loop, starting with the loop index L_J
1350 L_J := Make_Defining_Identifier (Loc, New_Internal_Name ('J'));
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.
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;
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;
1374 L_Range :=
1375 Make_Range (Loc,
1376 Low_Bound => L_L,
1377 High_Bound => L_H);
1379 -- Construct "for L_J in Index_Base range L .. H"
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));
1390 -- Construct the statements to execute in the loop body
1392 L_Body := Gen_Assign (New_Reference_To (L_J, Loc), Expr);
1394 -- Construct the final loop
1396 Append_To (S, Make_Implicit_Loop_Statement
1397 (Node => N,
1398 Identifier => Empty,
1399 Iteration_Scheme => L_Iteration_Scheme,
1400 Statements => L_Body));
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.
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;
1415 ---------------
1416 -- Gen_While --
1417 ---------------
1419 -- The code built is
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;
1427 function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id is
1428 W_J : Node_Id;
1430 W_Decl : Node_Id;
1431 -- W_J : Base_Type := L;
1433 W_Iteration_Scheme : Node_Id;
1434 -- while W_J < H
1436 W_Index_Succ : Node_Id;
1437 -- Index_Base'Succ (J)
1439 W_Increment : Node_Id;
1440 -- W_J := Index_Base'Succ (W)
1442 W_Body : constant List_Id := New_List;
1443 -- The statements to execute in the loop
1445 S : constant List_Id := New_List;
1446 -- list of statement
1448 begin
1449 -- If loop bounds define an empty range or are equal return null
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;
1456 -- Build the decl of W_J
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);
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.
1470 Append_To (S, W_Decl);
1472 -- Construct " while W_J < H"
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)));
1482 -- Construct the statements to execute in the loop body
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)));
1491 W_Increment :=
1492 Make_OK_Assignment_Statement
1493 (Loc,
1494 Name => New_Reference_To (W_J, Loc),
1495 Expression => W_Index_Succ);
1497 Append_To (W_Body, W_Increment);
1498 Append_List_To (W_Body,
1499 Gen_Assign (New_Reference_To (W_J, Loc), Expr));
1501 -- Construct the final loop
1503 Append_To (S, Make_Implicit_Loop_Statement
1504 (Node => N,
1505 Identifier => Empty,
1506 Iteration_Scheme => W_Iteration_Scheme,
1507 Statements => W_Body));
1509 return S;
1510 end Gen_While;
1512 ---------------------
1513 -- Index_Base_Name --
1514 ---------------------
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;
1521 ------------------------------------
1522 -- Local_Compile_Time_Known_Value --
1523 ------------------------------------
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;
1534 ----------------------
1535 -- Local_Expr_Value --
1536 ----------------------
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;
1547 -- Build_Array_Aggr_Code Variables
1549 Assoc : Node_Id;
1550 Choice : Node_Id;
1551 Expr : Node_Id;
1552 Typ : Entity_Id;
1554 Others_Expr : Node_Id := Empty;
1555 Others_Box_Present : Boolean := False;
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.
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
1567 Low : Node_Id;
1568 High : Node_Id;
1570 Nb_Choices : Nat := 0;
1571 Table : Case_Table_Type (1 .. Number_Of_Choices (N));
1572 -- Used to sort all the different choice values
1574 Nb_Elements : Int;
1575 -- Number of elements in the positional aggregate
1577 New_Code : constant List_Id := New_List;
1579 -- Start of processing for Build_Array_Aggr_Code
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.
1586 Typ := Etype (N);
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;
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.
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;
1610 -- STEP 1: Process component associations
1612 -- For those associations that may generate a loop, initialize
1613 -- Loop_Actions to collect inserted actions that may be crated.
1615 -- Skip this if no component associations
1617 if No (Expressions (N)) then
1619 -- STEP 1 (a): Sort the discrete choices
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);
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;
1636 Get_Index_Bounds (Choice, Low, High);
1638 if Low /= High then
1639 Set_Loop_Actions (Assoc, New_List);
1640 end if;
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;
1655 Next (Assoc);
1656 end loop;
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.
1662 if Nb_Choices > 1 then
1663 Sort_Case_Table (Table);
1664 end if;
1666 -- STEP 1 (b): take care of the whole set of discrete choices
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;
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
1679 if Present (Others_Expr) or else Others_Box_Present then
1680 declare
1681 First : Boolean := True;
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;
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;
1697 -- If this is an expansion within an init proc, make
1698 -- sure that discriminant references are replaced by
1699 -- the corresponding discriminal.
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;
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;
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;
1726 -- STEP 2: Process positional components
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.
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;
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.
1745 if Present (Component_Associations (N)) then
1746 Assoc := Last (Component_Associations (N));
1748 -- Ada 2005 (AI-287)
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);
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;
1766 return New_Code;
1767 end Build_Array_Aggr_Code;
1769 ----------------------------
1770 -- Build_Record_Aggr_Code --
1771 ----------------------------
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
1781 Loc : constant Source_Ptr := Sloc (N);
1782 L : constant List_Id := New_List;
1783 N_Typ : constant Entity_Id := Etype (N);
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;
1795 Internal_Final_List : Node_Id := Empty;
1797 -- If this is an internal aggregate, the External_Final_List is an
1798 -- expression for the controller record of the enclosing type.
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.
1804 External_Final_List : Node_Id;
1805 Ancestor_Is_Expression : Boolean := False;
1806 Ancestor_Is_Subtype_Mark : Boolean := False;
1808 Init_Typ : Entity_Id := Empty;
1809 Attach : Node_Id;
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.
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).
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)).
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.
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).
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.
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.
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.
1855 ---------------------------------
1856 -- Ancestor_Discriminant_Value --
1857 ---------------------------------
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;
1869 begin
1870 -- First check any discriminant associations to see if any of them
1871 -- provide a value for the discriminant.
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)));
1878 if Ekind (Aggr_Comp) = E_Discriminant then
1879 Save_Assoc := Expression (Assoc);
1881 Corresp_Disc := Corresponding_Discriminant (Aggr_Comp);
1882 while Present (Corresp_Disc) loop
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. ???)
1888 if Disc = Corresp_Disc then
1889 return Duplicate_Subexpr (Expression (Assoc));
1890 end if;
1892 Corresp_Disc :=
1893 Corresponding_Discriminant (Corresp_Disc);
1894 end loop;
1895 end if;
1897 Next (Assoc);
1898 end loop;
1899 end if;
1901 -- No match found in aggregate, so chain up parent types to find
1902 -- a constraint that defines the value of the discriminant.
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);
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 ???)
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;
1927 -- Traverse the discriminants of the parent type looking
1928 -- for one that corresponds.
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;
1939 if Disc = Corresp_Disc then
1940 if Nkind (Assoc) = N_Discriminant_Association then
1941 Assoc := Expression (Assoc);
1942 end if;
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. ???
1952 if Is_Entity_Name (Assoc)
1953 and then Ekind (Entity (Assoc)) = E_Discriminant
1954 then
1955 Assoc := Save_Assoc;
1956 end if;
1958 return Duplicate_Subexpr (Assoc);
1959 end if;
1961 Next_Discriminant (Parent_Disc);
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;
1976 Current_Typ := Parent_Typ;
1977 Parent_Typ := Etype (Current_Typ);
1978 end loop;
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).
1984 return Empty;
1985 end Ancestor_Discriminant_Value;
1987 ----------------------------------
1988 -- Check_Ancestor_Discriminants --
1989 ----------------------------------
1991 procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id) is
1992 Discr : Entity_Id;
1993 Disc_Value : Node_Id;
1994 Cond : Node_Id;
1996 begin
1997 Discr := First_Discriminant (Base_Type (Anc_Typ));
1998 while Present (Discr) loop
1999 Disc_Value := Ancestor_Discriminant_Value (Discr);
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);
2009 Append_To (L,
2010 Make_Raise_Constraint_Error (Loc,
2011 Condition => Cond,
2012 Reason => CE_Discriminant_Check_Failed));
2013 end if;
2015 Next_Discriminant (Discr);
2016 end loop;
2017 end Check_Ancestor_Discriminants;
2019 ---------------------------
2020 -- Compatible_Int_Bounds --
2021 ---------------------------
2023 function Compatible_Int_Bounds
2024 (Agg_Bounds : Node_Id;
2025 Typ_Bounds : Node_Id) return Boolean
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;
2035 --------------------------------
2036 -- Get_Constraint_Association --
2037 --------------------------------
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);
2043 begin
2044 -- ??? Also need to cover case of a type mark denoting a subtype
2045 -- with constraint.
2047 if Nkind (Indic) = N_Subtype_Indication
2048 and then Present (Constraint (Indic))
2049 then
2050 return First (Constraints (Constraint (Indic)));
2051 end if;
2053 return Empty;
2054 end Get_Constraint_Association;
2056 ---------------------
2057 -- Init_Controller --
2058 ---------------------
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
2067 L : constant List_Id := New_List;
2068 Ref : Node_Id;
2069 RC : RE_Id;
2070 Target_Type : Entity_Id;
2072 begin
2073 -- Generate:
2074 -- init-proc (target._controller);
2075 -- initialize (target._controller);
2076 -- Attach_to_Final_List (target._controller, F);
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);
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.
2090 if Nkind (Target) = N_Identifier then
2091 Target_Type := Etype (Target);
2093 elsif Nkind (Target) = N_Selected_Component then
2094 Target_Type := Etype (Selector_Name (Target));
2096 elsif Nkind (Target) = N_Unchecked_Type_Conversion then
2097 Target_Type := Etype (Target);
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)));
2104 else
2105 Target_Type := Etype (Target);
2106 end if;
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.
2112 if No (Target_Type) then
2113 Target_Type := Typ;
2114 end if;
2116 if (Is_Tagged_Type (Target_Type))
2117 and then Is_Limited_Type (Target_Type)
2118 then
2119 RC := RE_Limited_Record_Controller;
2121 elsif Is_Inherently_Limited_Type (Target_Type) then
2122 RC := RE_Limited_Record_Controller;
2124 else
2125 RC := RE_Record_Controller;
2126 end if;
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;
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))));
2144 Append_To (L,
2145 Make_Attach_Call (
2146 Obj_Ref => New_Copy_Tree (Ref),
2147 Flist_Ref => F,
2148 With_Attach => Attach));
2150 return L;
2151 end Init_Controller;
2153 -------------------------
2154 -- Is_Int_Range_Bounds --
2155 -------------------------
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;
2164 -------------------------------
2165 -- Gen_Ctrl_Actions_For_Aggr --
2166 -------------------------------
2168 procedure Gen_Ctrl_Actions_For_Aggr is
2169 Alloc : Node_Id := Empty;
2171 begin
2172 -- Do the work only the first time this is called
2174 if Ctrl_Stuff_Done then
2175 return;
2176 end if;
2178 Ctrl_Stuff_Done := True;
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)
2187 -- why not Is_True (Expr_Value (RTE (RE_Garbaage_Collected) ???
2188 then
2189 Attach := Make_Integer_Literal (Loc, 0);
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);
2197 else
2198 Attach := Make_Integer_Literal (Loc, 1);
2199 end if;
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.
2207 if Needs_Finalization (Typ) then
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.
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;
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));
2230 elsif Present (Flist) then
2231 External_Final_List := New_Copy_Tree (Flist);
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)));
2239 else
2240 External_Final_List := Find_Final_List (Current_Scope);
2241 end if;
2242 else
2243 External_Final_List := Empty;
2244 end if;
2246 -- Initialize and attach the outer object in the is_controlled case
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;
2260 if not Has_Controlled_Component (Typ) then
2261 Ref := New_Copy_Tree (Target);
2262 Set_Assignment_OK (Ref);
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.
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;
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;
2286 -- In the Has_Controlled component case, all the intermediate
2287 -- controllers must be initialized.
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;
2297 begin
2298 -- Find outer type with a controller
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;
2307 -- Attach it to the outer record controller to the external
2308 -- final list.
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));
2319 At_Root := True;
2320 Inner_Typ := Init_Typ;
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));
2331 Inner_Typ := Etype (Outer_Typ);
2332 At_Root :=
2333 not Is_Tagged_Type (Typ) or else Inner_Typ = Outer_Typ;
2334 end if;
2336 -- The outer object has to be attached as well
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;
2348 -- Initialize the internal controllers for tagged types with
2349 -- more than one controller.
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));
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;
2374 -- Stop at the root
2376 At_Root := Inner_Typ = Etype (Inner_Typ);
2377 Inner_Typ := Etype (Inner_Typ);
2378 end loop;
2380 -- If not done yet attach the controller of the ancestor part
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));
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));
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).
2409 end if;
2410 end;
2411 end if;
2412 end Gen_Ctrl_Actions_For_Aggr;
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.
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.
2423 --------------------------
2424 -- Rewrite_Discriminant --
2425 --------------------------
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;
2442 ------------------
2443 -- Replace_Type --
2444 ------------------
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.
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));
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);
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;
2482 return OK;
2483 end Replace_Type;
2485 procedure Replace_Self_Reference is
2486 new Traverse_Proc (Replace_Type);
2488 procedure Replace_Discriminants is
2489 new Traverse_Proc (Rewrite_Discriminant);
2491 -- Start of processing for Build_Record_Aggr_Code
2493 begin
2494 if Has_Self_Reference (N) then
2495 Replace_Self_Reference (N);
2496 end if;
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.
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;
2510 -- Deal with the ancestor part of extension aggregates or with the
2511 -- discriminants of the root type.
2513 if Nkind (N) = N_Extension_Aggregate then
2514 declare
2515 A : constant Node_Id := Ancestor_Part (N);
2516 Assign : List_Id;
2518 begin
2519 -- If the ancestor part is a subtype mark "T", we generate
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
2525 if Is_Entity_Name (A) and then Is_Type (Entity (A)) then
2526 Ancestor_Is_Subtype_Mark := True;
2528 if Is_Constrained (Entity (A)) then
2529 Init_Typ := Entity (A);
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.
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;
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;
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));
2562 Init_Typ := Create_Itype (Ekind (Anc_Typ), N);
2564 Subt_Decl :=
2565 Make_Subtype_Declaration (Loc,
2566 Defining_Identifier => Init_Typ,
2567 Subtype_Indication => New_Indic);
2569 -- Itypes must be analyzed with checks off Declaration
2570 -- must have a parent for proper handling of subsidiary
2571 -- actions.
2573 Set_Parent (Subt_Decl, N);
2574 Analyze (Subt_Decl, Suppress => All_Checks);
2575 end;
2576 end if;
2578 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2579 Set_Assignment_OK (Ref);
2581 if not Is_Interface (Init_Typ) then
2582 Append_List_To (L,
2583 Build_Initialization_Call (Loc,
2584 Id_Ref => Ref,
2585 Typ => Init_Typ,
2586 In_Init_Proc => Within_Init_Proc,
2587 With_Default_Init => Has_Default_Init_Comps (N)
2588 or else
2589 Has_Task (Base_Type (Init_Typ))));
2591 if Is_Constrained (Entity (A))
2592 and then Has_Discriminants (Entity (A))
2593 then
2594 Check_Ancestor_Discriminants (Entity (A));
2595 end if;
2596 end if;
2598 -- Handle calls to C++ constructors
2600 elsif Is_CPP_Constructor_Call (A) then
2601 Init_Typ := Etype (A);
2602 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2603 Set_Assignment_OK (Ref);
2605 Append_List_To (L,
2606 Build_Initialization_Call (Loc,
2607 Id_Ref => Ref,
2608 Typ => Init_Typ,
2609 In_Init_Proc => Within_Init_Proc,
2610 With_Default_Init => Has_Default_Init_Comps (N),
2611 Constructor_Ref => A));
2613 -- Ada 2005 (AI-287): If the ancestor part is an aggregate of
2614 -- limited type, a recursive call expands the ancestor. Note that
2615 -- in the limited case, the ancestor part must be either a
2616 -- function call (possibly qualified, or wrapped in an unchecked
2617 -- conversion) or aggregate (definitely qualified).
2618 -- The ancestor part can also be a function call (that may be
2619 -- transformed into an explicit dereference) or a qualification
2620 -- of one such.
2622 elsif Is_Limited_Type (Etype (A))
2623 and then Nkind_In (Unqualify (A), N_Aggregate,
2624 N_Extension_Aggregate)
2625 then
2626 Ancestor_Is_Expression := True;
2628 -- Set up finalization data for enclosing record, because
2629 -- controlled subcomponents of the ancestor part will be
2630 -- attached to it.
2632 Gen_Ctrl_Actions_For_Aggr;
2634 Append_List_To (L,
2635 Build_Record_Aggr_Code (
2636 N => Unqualify (A),
2637 Typ => Etype (Unqualify (A)),
2638 Lhs => Target,
2639 Flist => Flist,
2640 Obj => Obj,
2641 Is_Limited_Ancestor_Expansion => True));
2643 -- If the ancestor part is an expression "E", we generate
2645 -- T(tmp) := E;
2647 -- In Ada 2005, this includes the case of a (possibly qualified)
2648 -- limited function call. The assignment will turn into a
2649 -- build-in-place function call (for further details, see
2650 -- Make_Build_In_Place_Call_In_Assignment).
2652 else
2653 Ancestor_Is_Expression := True;
2654 Init_Typ := Etype (A);
2656 -- If the ancestor part is an aggregate, force its full
2657 -- expansion, which was delayed.
2659 if Nkind_In (Unqualify (A), N_Aggregate,
2660 N_Extension_Aggregate)
2661 then
2662 Set_Analyzed (A, False);
2663 Set_Analyzed (Expression (A), False);
2664 end if;
2666 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2667 Set_Assignment_OK (Ref);
2669 -- Make the assignment without usual controlled actions since
2670 -- we only want the post adjust but not the pre finalize here
2671 -- Add manual adjust when necessary.
2673 Assign := New_List (
2674 Make_OK_Assignment_Statement (Loc,
2675 Name => Ref,
2676 Expression => A));
2677 Set_No_Ctrl_Actions (First (Assign));
2679 -- Assign the tag now to make sure that the dispatching call in
2680 -- the subsequent deep_adjust works properly (unless VM_Target,
2681 -- where tags are implicit).
2683 if Tagged_Type_Expansion then
2684 Instr :=
2685 Make_OK_Assignment_Statement (Loc,
2686 Name =>
2687 Make_Selected_Component (Loc,
2688 Prefix => New_Copy_Tree (Target),
2689 Selector_Name =>
2690 New_Reference_To
2691 (First_Tag_Component (Base_Type (Typ)), Loc)),
2693 Expression =>
2694 Unchecked_Convert_To (RTE (RE_Tag),
2695 New_Reference_To
2696 (Node (First_Elmt
2697 (Access_Disp_Table (Base_Type (Typ)))),
2698 Loc)));
2700 Set_Assignment_OK (Name (Instr));
2701 Append_To (Assign, Instr);
2703 -- Ada 2005 (AI-251): If tagged type has progenitors we must
2704 -- also initialize tags of the secondary dispatch tables.
2706 if Has_Interfaces (Base_Type (Typ)) then
2707 Init_Secondary_Tags
2708 (Typ => Base_Type (Typ),
2709 Target => Target,
2710 Stmts_List => Assign);
2711 end if;
2712 end if;
2714 -- Call Adjust manually
2716 if Needs_Finalization (Etype (A))
2717 and then not Is_Limited_Type (Etype (A))
2718 then
2719 Append_List_To (Assign,
2720 Make_Adjust_Call (
2721 Ref => New_Copy_Tree (Ref),
2722 Typ => Etype (A),
2723 Flist_Ref => New_Reference_To (
2724 RTE (RE_Global_Final_List), Loc),
2725 With_Attach => Make_Integer_Literal (Loc, 0)));
2726 end if;
2728 Append_To (L,
2729 Make_Unsuppress_Block (Loc, Name_Discriminant_Check, Assign));
2731 if Has_Discriminants (Init_Typ) then
2732 Check_Ancestor_Discriminants (Init_Typ);
2733 end if;
2734 end if;
2735 end;
2737 -- Normal case (not an extension aggregate)
2739 else
2740 -- Generate the discriminant expressions, component by component.
2741 -- If the base type is an unchecked union, the discriminants are
2742 -- unknown to the back-end and absent from a value of the type, so
2743 -- assignments for them are not emitted.
2745 if Has_Discriminants (Typ)
2746 and then not Is_Unchecked_Union (Base_Type (Typ))
2747 then
2748 -- If the type is derived, and constrains discriminants of the
2749 -- parent type, these discriminants are not components of the
2750 -- aggregate, and must be initialized explicitly. They are not
2751 -- visible components of the object, but can become visible with
2752 -- a view conversion to the ancestor.
2754 declare
2755 Btype : Entity_Id;
2756 Parent_Type : Entity_Id;
2757 Disc : Entity_Id;
2758 Discr_Val : Elmt_Id;
2760 begin
2761 Btype := Base_Type (Typ);
2762 while Is_Derived_Type (Btype)
2763 and then Present (Stored_Constraint (Btype))
2764 loop
2765 Parent_Type := Etype (Btype);
2767 Disc := First_Discriminant (Parent_Type);
2768 Discr_Val :=
2769 First_Elmt (Stored_Constraint (Base_Type (Typ)));
2770 while Present (Discr_Val) loop
2772 -- Only those discriminants of the parent that are not
2773 -- renamed by discriminants of the derived type need to
2774 -- be added explicitly.
2776 if not Is_Entity_Name (Node (Discr_Val))
2777 or else
2778 Ekind (Entity (Node (Discr_Val))) /= E_Discriminant
2779 then
2780 Comp_Expr :=
2781 Make_Selected_Component (Loc,
2782 Prefix => New_Copy_Tree (Target),
2783 Selector_Name => New_Occurrence_Of (Disc, Loc));
2785 Instr :=
2786 Make_OK_Assignment_Statement (Loc,
2787 Name => Comp_Expr,
2788 Expression => New_Copy_Tree (Node (Discr_Val)));
2790 Set_No_Ctrl_Actions (Instr);
2791 Append_To (L, Instr);
2792 end if;
2794 Next_Discriminant (Disc);
2795 Next_Elmt (Discr_Val);
2796 end loop;
2798 Btype := Base_Type (Parent_Type);
2799 end loop;
2800 end;
2802 -- Generate discriminant init values for the visible discriminants
2804 declare
2805 Discriminant : Entity_Id;
2806 Discriminant_Value : Node_Id;
2808 begin
2809 Discriminant := First_Stored_Discriminant (Typ);
2810 while Present (Discriminant) loop
2811 Comp_Expr :=
2812 Make_Selected_Component (Loc,
2813 Prefix => New_Copy_Tree (Target),
2814 Selector_Name => New_Occurrence_Of (Discriminant, Loc));
2816 Discriminant_Value :=
2817 Get_Discriminant_Value (
2818 Discriminant,
2819 N_Typ,
2820 Discriminant_Constraint (N_Typ));
2822 Instr :=
2823 Make_OK_Assignment_Statement (Loc,
2824 Name => Comp_Expr,
2825 Expression => New_Copy_Tree (Discriminant_Value));
2827 Set_No_Ctrl_Actions (Instr);
2828 Append_To (L, Instr);
2830 Next_Stored_Discriminant (Discriminant);
2831 end loop;
2832 end;
2833 end if;
2834 end if;
2836 -- For CPP types we generate an implicit call to the C++ default
2837 -- constructor to ensure the proper initialization of the _Tag
2838 -- component.
2840 if Is_CPP_Class (Typ) then
2841 pragma Assert (Present (Base_Init_Proc (Typ)));
2842 Append_List_To (L,
2843 Build_Initialization_Call (Loc,
2844 Id_Ref => Lhs,
2845 Typ => Typ));
2846 end if;
2848 -- Generate the assignments, component by component
2850 -- tmp.comp1 := Expr1_From_Aggr;
2851 -- tmp.comp2 := Expr2_From_Aggr;
2852 -- ....
2854 Comp := First (Component_Associations (N));
2855 while Present (Comp) loop
2856 Selector := Entity (First (Choices (Comp)));
2858 -- C++ constructors
2860 if Is_CPP_Constructor_Call (Expression (Comp)) then
2861 Append_List_To (L,
2862 Build_Initialization_Call (Loc,
2863 Id_Ref => Make_Selected_Component (Loc,
2864 Prefix => New_Copy_Tree (Target),
2865 Selector_Name => New_Occurrence_Of (Selector,
2866 Loc)),
2867 Typ => Etype (Selector),
2868 Enclos_Type => Typ,
2869 With_Default_Init => True,
2870 Constructor_Ref => Expression (Comp)));
2872 -- Ada 2005 (AI-287): For each default-initialized component generate
2873 -- a call to the corresponding IP subprogram if available.
2875 elsif Box_Present (Comp)
2876 and then Has_Non_Null_Base_Init_Proc (Etype (Selector))
2877 then
2878 if Ekind (Selector) /= E_Discriminant then
2879 Gen_Ctrl_Actions_For_Aggr;
2880 end if;
2882 -- Ada 2005 (AI-287): If the component type has tasks then
2883 -- generate the activation chain and master entities (except
2884 -- in case of an allocator because in that case these entities
2885 -- are generated by Build_Task_Allocate_Block_With_Init_Stmts).
2887 declare
2888 Ctype : constant Entity_Id := Etype (Selector);
2889 Inside_Allocator : Boolean := False;
2890 P : Node_Id := Parent (N);
2892 begin
2893 if Is_Task_Type (Ctype) or else Has_Task (Ctype) then
2894 while Present (P) loop
2895 if Nkind (P) = N_Allocator then
2896 Inside_Allocator := True;
2897 exit;
2898 end if;
2900 P := Parent (P);
2901 end loop;
2903 if not Inside_Init_Proc and not Inside_Allocator then
2904 Build_Activation_Chain_Entity (N);
2905 end if;
2906 end if;
2907 end;
2909 Append_List_To (L,
2910 Build_Initialization_Call (Loc,
2911 Id_Ref => Make_Selected_Component (Loc,
2912 Prefix => New_Copy_Tree (Target),
2913 Selector_Name => New_Occurrence_Of (Selector,
2914 Loc)),
2915 Typ => Etype (Selector),
2916 Enclos_Type => Typ,
2917 With_Default_Init => True));
2919 -- Prepare for component assignment
2921 elsif Ekind (Selector) /= E_Discriminant
2922 or else Nkind (N) = N_Extension_Aggregate
2923 then
2924 -- All the discriminants have now been assigned
2926 -- This is now a good moment to initialize and attach all the
2927 -- controllers. Their position may depend on the discriminants.
2929 if Ekind (Selector) /= E_Discriminant then
2930 Gen_Ctrl_Actions_For_Aggr;
2931 end if;
2933 Comp_Type := Etype (Selector);
2934 Comp_Expr :=
2935 Make_Selected_Component (Loc,
2936 Prefix => New_Copy_Tree (Target),
2937 Selector_Name => New_Occurrence_Of (Selector, Loc));
2939 if Nkind (Expression (Comp)) = N_Qualified_Expression then
2940 Expr_Q := Expression (Expression (Comp));
2941 else
2942 Expr_Q := Expression (Comp);
2943 end if;
2945 -- The controller is the one of the parent type defining the
2946 -- component (in case of inherited components).
2948 if Needs_Finalization (Comp_Type) then
2949 Internal_Final_List :=
2950 Make_Selected_Component (Loc,
2951 Prefix => Convert_To (
2952 Scope (Original_Record_Component (Selector)),
2953 New_Copy_Tree (Target)),
2954 Selector_Name =>
2955 Make_Identifier (Loc, Name_uController));
2957 Internal_Final_List :=
2958 Make_Selected_Component (Loc,
2959 Prefix => Internal_Final_List,
2960 Selector_Name => Make_Identifier (Loc, Name_F));
2962 -- The internal final list can be part of a constant object
2964 Set_Assignment_OK (Internal_Final_List);
2966 else
2967 Internal_Final_List := Empty;
2968 end if;
2970 -- Now either create the assignment or generate the code for the
2971 -- inner aggregate top-down.
2973 if Is_Delayed_Aggregate (Expr_Q) then
2975 -- We have the following case of aggregate nesting inside
2976 -- an object declaration:
2978 -- type Arr_Typ is array (Integer range <>) of ...;
2980 -- type Rec_Typ (...) is record
2981 -- Obj_Arr_Typ : Arr_Typ (A .. B);
2982 -- end record;
2984 -- Obj_Rec_Typ : Rec_Typ := (...,
2985 -- Obj_Arr_Typ => (X => (...), Y => (...)));
2987 -- The length of the ranges of the aggregate and Obj_Add_Typ
2988 -- are equal (B - A = Y - X), but they do not coincide (X /=
2989 -- A and B /= Y). This case requires array sliding which is
2990 -- performed in the following manner:
2992 -- subtype Arr_Sub is Arr_Typ (X .. Y);
2993 -- Temp : Arr_Sub;
2994 -- Temp (X) := (...);
2995 -- ...
2996 -- Temp (Y) := (...);
2997 -- Obj_Rec_Typ.Obj_Arr_Typ := Temp;
2999 if Ekind (Comp_Type) = E_Array_Subtype
3000 and then Is_Int_Range_Bounds (Aggregate_Bounds (Expr_Q))
3001 and then Is_Int_Range_Bounds (First_Index (Comp_Type))
3002 and then not
3003 Compatible_Int_Bounds
3004 (Agg_Bounds => Aggregate_Bounds (Expr_Q),
3005 Typ_Bounds => First_Index (Comp_Type))
3006 then
3007 -- Create the array subtype with bounds equal to those of
3008 -- the corresponding aggregate.
3010 declare
3011 SubE : constant Entity_Id :=
3012 Make_Defining_Identifier (Loc,
3013 Chars => New_Internal_Name ('T'));
3015 SubD : constant Node_Id :=
3016 Make_Subtype_Declaration (Loc,
3017 Defining_Identifier => SubE,
3018 Subtype_Indication =>
3019 Make_Subtype_Indication (Loc,
3020 Subtype_Mark =>
3021 New_Reference_To
3022 (Etype (Comp_Type), Loc),
3023 Constraint =>
3024 Make_Index_Or_Discriminant_Constraint
3025 (Loc,
3026 Constraints => New_List (
3027 New_Copy_Tree
3028 (Aggregate_Bounds (Expr_Q))))));
3030 -- Create a temporary array of the above subtype which
3031 -- will be used to capture the aggregate assignments.
3033 TmpE : constant Entity_Id := Make_Temporary (Loc, 'A', N);
3035 TmpD : constant Node_Id :=
3036 Make_Object_Declaration (Loc,
3037 Defining_Identifier => TmpE,
3038 Object_Definition =>
3039 New_Reference_To (SubE, Loc));
3041 begin
3042 Set_No_Initialization (TmpD);
3043 Append_To (L, SubD);
3044 Append_To (L, TmpD);
3046 -- Expand aggregate into assignments to the temp array
3048 Append_List_To (L,
3049 Late_Expansion (Expr_Q, Comp_Type,
3050 New_Reference_To (TmpE, Loc), Internal_Final_List));
3052 -- Slide
3054 Append_To (L,
3055 Make_Assignment_Statement (Loc,
3056 Name => New_Copy_Tree (Comp_Expr),
3057 Expression => New_Reference_To (TmpE, Loc)));
3059 -- Do not pass the original aggregate to Gigi as is,
3060 -- since it will potentially clobber the front or the end
3061 -- of the array. Setting the expression to empty is safe
3062 -- since all aggregates are expanded into assignments.
3064 if Present (Obj) then
3065 Set_Expression (Parent (Obj), Empty);
3066 end if;
3067 end;
3069 -- Normal case (sliding not required)
3071 else
3072 Append_List_To (L,
3073 Late_Expansion (Expr_Q, Comp_Type, Comp_Expr,
3074 Internal_Final_List));
3075 end if;
3077 -- Expr_Q is not delayed aggregate
3079 else
3080 if Has_Discriminants (Typ) then
3081 Replace_Discriminants (Expr_Q);
3082 end if;
3084 Instr :=
3085 Make_OK_Assignment_Statement (Loc,
3086 Name => Comp_Expr,
3087 Expression => Expr_Q);
3089 Set_No_Ctrl_Actions (Instr);
3090 Append_To (L, Instr);
3092 -- Adjust the tag if tagged (because of possible view
3093 -- conversions), unless compiling for a VM where tags are
3094 -- implicit.
3096 -- tmp.comp._tag := comp_typ'tag;
3098 if Is_Tagged_Type (Comp_Type)
3099 and then Tagged_Type_Expansion
3100 then
3101 Instr :=
3102 Make_OK_Assignment_Statement (Loc,
3103 Name =>
3104 Make_Selected_Component (Loc,
3105 Prefix => New_Copy_Tree (Comp_Expr),
3106 Selector_Name =>
3107 New_Reference_To
3108 (First_Tag_Component (Comp_Type), Loc)),
3110 Expression =>
3111 Unchecked_Convert_To (RTE (RE_Tag),
3112 New_Reference_To
3113 (Node (First_Elmt (Access_Disp_Table (Comp_Type))),
3114 Loc)));
3116 Append_To (L, Instr);
3117 end if;
3119 -- Adjust and Attach the component to the proper controller
3121 -- Adjust (tmp.comp);
3122 -- Attach_To_Final_List (tmp.comp,
3123 -- comp_typ (tmp)._record_controller.f)
3125 if Needs_Finalization (Comp_Type)
3126 and then not Is_Limited_Type (Comp_Type)
3127 then
3128 Append_List_To (L,
3129 Make_Adjust_Call (
3130 Ref => New_Copy_Tree (Comp_Expr),
3131 Typ => Comp_Type,
3132 Flist_Ref => Internal_Final_List,
3133 With_Attach => Make_Integer_Literal (Loc, 1)));
3134 end if;
3135 end if;
3137 -- ???
3139 elsif Ekind (Selector) = E_Discriminant
3140 and then Nkind (N) /= N_Extension_Aggregate
3141 and then Nkind (Parent (N)) = N_Component_Association
3142 and then Is_Constrained (Typ)
3143 then
3144 -- We must check that the discriminant value imposed by the
3145 -- context is the same as the value given in the subaggregate,
3146 -- because after the expansion into assignments there is no
3147 -- record on which to perform a regular discriminant check.
3149 declare
3150 D_Val : Elmt_Id;
3151 Disc : Entity_Id;
3153 begin
3154 D_Val := First_Elmt (Discriminant_Constraint (Typ));
3155 Disc := First_Discriminant (Typ);
3156 while Chars (Disc) /= Chars (Selector) loop
3157 Next_Discriminant (Disc);
3158 Next_Elmt (D_Val);
3159 end loop;
3161 pragma Assert (Present (D_Val));
3163 -- This check cannot performed for components that are
3164 -- constrained by a current instance, because this is not a
3165 -- value that can be compared with the actual constraint.
3167 if Nkind (Node (D_Val)) /= N_Attribute_Reference
3168 or else not Is_Entity_Name (Prefix (Node (D_Val)))
3169 or else not Is_Type (Entity (Prefix (Node (D_Val))))
3170 then
3171 Append_To (L,
3172 Make_Raise_Constraint_Error (Loc,
3173 Condition =>
3174 Make_Op_Ne (Loc,
3175 Left_Opnd => New_Copy_Tree (Node (D_Val)),
3176 Right_Opnd => Expression (Comp)),
3177 Reason => CE_Discriminant_Check_Failed));
3179 else
3180 -- Find self-reference in previous discriminant assignment,
3181 -- and replace with proper expression.
3183 declare
3184 Ass : Node_Id;
3186 begin
3187 Ass := First (L);
3188 while Present (Ass) loop
3189 if Nkind (Ass) = N_Assignment_Statement
3190 and then Nkind (Name (Ass)) = N_Selected_Component
3191 and then Chars (Selector_Name (Name (Ass))) =
3192 Chars (Disc)
3193 then
3194 Set_Expression
3195 (Ass, New_Copy_Tree (Expression (Comp)));
3196 exit;
3197 end if;
3198 Next (Ass);
3199 end loop;
3200 end;
3201 end if;
3202 end;
3203 end if;
3205 Next (Comp);
3206 end loop;
3208 -- If the type is tagged, the tag needs to be initialized (unless
3209 -- compiling for the Java VM where tags are implicit). It is done
3210 -- late in the initialization process because in some cases, we call
3211 -- the init proc of an ancestor which will not leave out the right tag
3213 if Ancestor_Is_Expression then
3214 null;
3216 -- For CPP types we generated a call to the C++ default constructor
3217 -- before the components have been initialized to ensure the proper
3218 -- initialization of the _Tag component (see above).
3220 elsif Is_CPP_Class (Typ) then
3221 null;
3223 elsif Is_Tagged_Type (Typ) and then Tagged_Type_Expansion then
3224 Instr :=
3225 Make_OK_Assignment_Statement (Loc,
3226 Name =>
3227 Make_Selected_Component (Loc,
3228 Prefix => New_Copy_Tree (Target),
3229 Selector_Name =>
3230 New_Reference_To
3231 (First_Tag_Component (Base_Type (Typ)), Loc)),
3233 Expression =>
3234 Unchecked_Convert_To (RTE (RE_Tag),
3235 New_Reference_To
3236 (Node (First_Elmt (Access_Disp_Table (Base_Type (Typ)))),
3237 Loc)));
3239 Append_To (L, Instr);
3241 -- Ada 2005 (AI-251): If the tagged type has been derived from
3242 -- abstract interfaces we must also initialize the tags of the
3243 -- secondary dispatch tables.
3245 if Has_Interfaces (Base_Type (Typ)) then
3246 Init_Secondary_Tags
3247 (Typ => Base_Type (Typ),
3248 Target => Target,
3249 Stmts_List => L);
3250 end if;
3251 end if;
3253 -- If the controllers have not been initialized yet (by lack of non-
3254 -- discriminant components), let's do it now.
3256 Gen_Ctrl_Actions_For_Aggr;
3258 return L;
3259 end Build_Record_Aggr_Code;
3261 -------------------------------
3262 -- Convert_Aggr_In_Allocator --
3263 -------------------------------
3265 procedure Convert_Aggr_In_Allocator
3266 (Alloc : Node_Id;
3267 Decl : Node_Id;
3268 Aggr : Node_Id)
3270 Loc : constant Source_Ptr := Sloc (Aggr);
3271 Typ : constant Entity_Id := Etype (Aggr);
3272 Temp : constant Entity_Id := Defining_Identifier (Decl);
3274 Occ : constant Node_Id :=
3275 Unchecked_Convert_To (Typ,
3276 Make_Explicit_Dereference (Loc,
3277 New_Reference_To (Temp, Loc)));
3279 Access_Type : constant Entity_Id := Etype (Temp);
3280 Flist : Entity_Id;
3282 begin
3283 -- If the allocator is for an access discriminant, there is no
3284 -- finalization list for the anonymous access type, and the eventual
3285 -- finalization of the object is handled through the coextension
3286 -- mechanism. If the enclosing object is not dynamically allocated,
3287 -- the access discriminant is itself placed on the stack. Otherwise,
3288 -- some other finalization list is used (see exp_ch4.adb).
3290 -- Decl has been inserted in the code ahead of the allocator, using
3291 -- Insert_Actions. We use Insert_Actions below as well, to ensure that
3292 -- subsequent insertions are done in the proper order. Using (for
3293 -- example) Insert_Actions_After to place the expanded aggregate
3294 -- immediately after Decl may lead to out-of-order references if the
3295 -- allocator has generated a finalization list, as when the designated
3296 -- object is controlled and there is an open transient scope.
3298 if Ekind (Access_Type) = E_Anonymous_Access_Type
3299 and then Nkind (Associated_Node_For_Itype (Access_Type)) =
3300 N_Discriminant_Specification
3301 then
3302 Flist := Empty;
3304 elsif Needs_Finalization (Typ) then
3305 Flist := Find_Final_List (Access_Type);
3307 -- Otherwise there are no controlled actions to be performed.
3309 else
3310 Flist := Empty;
3311 end if;
3313 if Is_Array_Type (Typ) then
3314 Convert_Array_Aggr_In_Allocator (Decl, Aggr, Occ);
3316 elsif Has_Default_Init_Comps (Aggr) then
3317 declare
3318 L : constant List_Id := New_List;
3319 Init_Stmts : List_Id;
3321 begin
3322 Init_Stmts :=
3323 Late_Expansion
3324 (Aggr, Typ, Occ,
3325 Flist,
3326 Associated_Final_Chain (Base_Type (Access_Type)));
3328 -- ??? Dubious actual for Obj: expect 'the original object being
3329 -- initialized'
3331 if Has_Task (Typ) then
3332 Build_Task_Allocate_Block_With_Init_Stmts (L, Aggr, Init_Stmts);
3333 Insert_Actions (Alloc, L);
3334 else
3335 Insert_Actions (Alloc, Init_Stmts);
3336 end if;
3337 end;
3339 else
3340 Insert_Actions (Alloc,
3341 Late_Expansion
3342 (Aggr, Typ, Occ, Flist,
3343 Associated_Final_Chain (Base_Type (Access_Type))));
3345 -- ??? Dubious actual for Obj: expect 'the original object being
3346 -- initialized'
3348 end if;
3349 end Convert_Aggr_In_Allocator;
3351 --------------------------------
3352 -- Convert_Aggr_In_Assignment --
3353 --------------------------------
3355 procedure Convert_Aggr_In_Assignment (N : Node_Id) is
3356 Aggr : Node_Id := Expression (N);
3357 Typ : constant Entity_Id := Etype (Aggr);
3358 Occ : constant Node_Id := New_Copy_Tree (Name (N));
3360 begin
3361 if Nkind (Aggr) = N_Qualified_Expression then
3362 Aggr := Expression (Aggr);
3363 end if;
3365 Insert_Actions_After (N,
3366 Late_Expansion
3367 (Aggr, Typ, Occ,
3368 Find_Final_List (Typ, New_Copy_Tree (Occ))));
3369 end Convert_Aggr_In_Assignment;
3371 ---------------------------------
3372 -- Convert_Aggr_In_Object_Decl --
3373 ---------------------------------
3375 procedure Convert_Aggr_In_Object_Decl (N : Node_Id) is
3376 Obj : constant Entity_Id := Defining_Identifier (N);
3377 Aggr : Node_Id := Expression (N);
3378 Loc : constant Source_Ptr := Sloc (Aggr);
3379 Typ : constant Entity_Id := Etype (Aggr);
3380 Occ : constant Node_Id := New_Occurrence_Of (Obj, Loc);
3382 function Discriminants_Ok return Boolean;
3383 -- If the object type is constrained, the discriminants in the
3384 -- aggregate must be checked against the discriminants of the subtype.
3385 -- This cannot be done using Apply_Discriminant_Checks because after
3386 -- expansion there is no aggregate left to check.
3388 ----------------------
3389 -- Discriminants_Ok --
3390 ----------------------
3392 function Discriminants_Ok return Boolean is
3393 Cond : Node_Id := Empty;
3394 Check : Node_Id;
3395 D : Entity_Id;
3396 Disc1 : Elmt_Id;
3397 Disc2 : Elmt_Id;
3398 Val1 : Node_Id;
3399 Val2 : Node_Id;
3401 begin
3402 D := First_Discriminant (Typ);
3403 Disc1 := First_Elmt (Discriminant_Constraint (Typ));
3404 Disc2 := First_Elmt (Discriminant_Constraint (Etype (Obj)));
3405 while Present (Disc1) and then Present (Disc2) loop
3406 Val1 := Node (Disc1);
3407 Val2 := Node (Disc2);
3409 if not Is_OK_Static_Expression (Val1)
3410 or else not Is_OK_Static_Expression (Val2)
3411 then
3412 Check := Make_Op_Ne (Loc,
3413 Left_Opnd => Duplicate_Subexpr (Val1),
3414 Right_Opnd => Duplicate_Subexpr (Val2));
3416 if No (Cond) then
3417 Cond := Check;
3419 else
3420 Cond := Make_Or_Else (Loc,
3421 Left_Opnd => Cond,
3422 Right_Opnd => Check);
3423 end if;
3425 elsif Expr_Value (Val1) /= Expr_Value (Val2) then
3426 Apply_Compile_Time_Constraint_Error (Aggr,
3427 Msg => "incorrect value for discriminant&?",
3428 Reason => CE_Discriminant_Check_Failed,
3429 Ent => D);
3430 return False;
3431 end if;
3433 Next_Discriminant (D);
3434 Next_Elmt (Disc1);
3435 Next_Elmt (Disc2);
3436 end loop;
3438 -- If any discriminant constraint is non-static, emit a check
3440 if Present (Cond) then
3441 Insert_Action (N,
3442 Make_Raise_Constraint_Error (Loc,
3443 Condition => Cond,
3444 Reason => CE_Discriminant_Check_Failed));
3445 end if;
3447 return True;
3448 end Discriminants_Ok;
3450 -- Start of processing for Convert_Aggr_In_Object_Decl
3452 begin
3453 Set_Assignment_OK (Occ);
3455 if Nkind (Aggr) = N_Qualified_Expression then
3456 Aggr := Expression (Aggr);
3457 end if;
3459 if Has_Discriminants (Typ)
3460 and then Typ /= Etype (Obj)
3461 and then Is_Constrained (Etype (Obj))
3462 and then not Discriminants_Ok
3463 then
3464 return;
3465 end if;
3467 -- If the context is an extended return statement, it has its own
3468 -- finalization machinery (i.e. works like a transient scope) and
3469 -- we do not want to create an additional one, because objects on
3470 -- the finalization list of the return must be moved to the caller's
3471 -- finalization list to complete the return.
3473 -- However, if the aggregate is limited, it is built in place, and the
3474 -- controlled components are not assigned to intermediate temporaries
3475 -- so there is no need for a transient scope in this case either.
3477 if Requires_Transient_Scope (Typ)
3478 and then Ekind (Current_Scope) /= E_Return_Statement
3479 and then not Is_Limited_Type (Typ)
3480 then
3481 Establish_Transient_Scope
3482 (Aggr,
3483 Sec_Stack =>
3484 Is_Controlled (Typ) or else Has_Controlled_Component (Typ));
3485 end if;
3487 Insert_Actions_After (N, Late_Expansion (Aggr, Typ, Occ, Obj => Obj));
3488 Set_No_Initialization (N);
3489 Initialize_Discriminants (N, Typ);
3490 end Convert_Aggr_In_Object_Decl;
3492 -------------------------------------
3493 -- Convert_Array_Aggr_In_Allocator --
3494 -------------------------------------
3496 procedure Convert_Array_Aggr_In_Allocator
3497 (Decl : Node_Id;
3498 Aggr : Node_Id;
3499 Target : Node_Id)
3501 Aggr_Code : List_Id;
3502 Typ : constant Entity_Id := Etype (Aggr);
3503 Ctyp : constant Entity_Id := Component_Type (Typ);
3505 begin
3506 -- The target is an explicit dereference of the allocated object.
3507 -- Generate component assignments to it, as for an aggregate that
3508 -- appears on the right-hand side of an assignment statement.
3510 Aggr_Code :=
3511 Build_Array_Aggr_Code (Aggr,
3512 Ctype => Ctyp,
3513 Index => First_Index (Typ),
3514 Into => Target,
3515 Scalar_Comp => Is_Scalar_Type (Ctyp));
3517 Insert_Actions_After (Decl, Aggr_Code);
3518 end Convert_Array_Aggr_In_Allocator;
3520 ----------------------------
3521 -- Convert_To_Assignments --
3522 ----------------------------
3524 procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id) is
3525 Loc : constant Source_Ptr := Sloc (N);
3526 T : Entity_Id;
3527 Temp : Entity_Id;
3529 Instr : Node_Id;
3530 Target_Expr : Node_Id;
3531 Parent_Kind : Node_Kind;
3532 Unc_Decl : Boolean := False;
3533 Parent_Node : Node_Id;
3535 begin
3536 pragma Assert (not Is_Static_Dispatch_Table_Aggregate (N));
3537 pragma Assert (Is_Record_Type (Typ));
3539 Parent_Node := Parent (N);
3540 Parent_Kind := Nkind (Parent_Node);
3542 if Parent_Kind = N_Qualified_Expression then
3544 -- Check if we are in a unconstrained declaration because in this
3545 -- case the current delayed expansion mechanism doesn't work when
3546 -- the declared object size depend on the initializing expr.
3548 begin
3549 Parent_Node := Parent (Parent_Node);
3550 Parent_Kind := Nkind (Parent_Node);
3552 if Parent_Kind = N_Object_Declaration then
3553 Unc_Decl :=
3554 not Is_Entity_Name (Object_Definition (Parent_Node))
3555 or else Has_Discriminants
3556 (Entity (Object_Definition (Parent_Node)))
3557 or else Is_Class_Wide_Type
3558 (Entity (Object_Definition (Parent_Node)));
3559 end if;
3560 end;
3561 end if;
3563 -- Just set the Delay flag in the cases where the transformation will be
3564 -- done top down from above.
3566 if False
3568 -- Internal aggregate (transformed when expanding the parent)
3570 or else Parent_Kind = N_Aggregate
3571 or else Parent_Kind = N_Extension_Aggregate
3572 or else Parent_Kind = N_Component_Association
3574 -- Allocator (see Convert_Aggr_In_Allocator)
3576 or else Parent_Kind = N_Allocator
3578 -- Object declaration (see Convert_Aggr_In_Object_Decl)
3580 or else (Parent_Kind = N_Object_Declaration and then not Unc_Decl)
3582 -- Safe assignment (see Convert_Aggr_Assignments). So far only the
3583 -- assignments in init procs are taken into account.
3585 or else (Parent_Kind = N_Assignment_Statement
3586 and then Inside_Init_Proc)
3588 -- (Ada 2005) An inherently limited type in a return statement,
3589 -- which will be handled in a build-in-place fashion, and may be
3590 -- rewritten as an extended return and have its own finalization
3591 -- machinery. In the case of a simple return, the aggregate needs
3592 -- to be delayed until the scope for the return statement has been
3593 -- created, so that any finalization chain will be associated with
3594 -- that scope. For extended returns, we delay expansion to avoid the
3595 -- creation of an unwanted transient scope that could result in
3596 -- premature finalization of the return object (which is built in
3597 -- in place within the caller's scope).
3599 or else
3600 (Is_Inherently_Limited_Type (Typ)
3601 and then
3602 (Nkind (Parent (Parent_Node)) = N_Extended_Return_Statement
3603 or else Nkind (Parent_Node) = N_Simple_Return_Statement))
3604 then
3605 Set_Expansion_Delayed (N);
3606 return;
3607 end if;
3609 if Requires_Transient_Scope (Typ) then
3610 Establish_Transient_Scope
3611 (N, Sec_Stack =>
3612 Is_Controlled (Typ) or else Has_Controlled_Component (Typ));
3613 end if;
3615 -- If the aggregate is non-limited, create a temporary. If it is limited
3616 -- and the context is an assignment, this is a subaggregate for an
3617 -- enclosing aggregate being expanded. It must be built in place, so use
3618 -- the target of the current assignment.
3620 if Is_Limited_Type (Typ)
3621 and then Nkind (Parent (N)) = N_Assignment_Statement
3622 then
3623 Target_Expr := New_Copy_Tree (Name (Parent (N)));
3624 Insert_Actions
3625 (Parent (N), Build_Record_Aggr_Code (N, Typ, Target_Expr));
3626 Rewrite (Parent (N), Make_Null_Statement (Loc));
3628 else
3629 Temp := Make_Temporary (Loc, 'A', N);
3631 -- If the type inherits unknown discriminants, use the view with
3632 -- known discriminants if available.
3634 if Has_Unknown_Discriminants (Typ)
3635 and then Present (Underlying_Record_View (Typ))
3636 then
3637 T := Underlying_Record_View (Typ);
3638 else
3639 T := Typ;
3640 end if;
3642 Instr :=
3643 Make_Object_Declaration (Loc,
3644 Defining_Identifier => Temp,
3645 Object_Definition => New_Occurrence_Of (T, Loc));
3647 Set_No_Initialization (Instr);
3648 Insert_Action (N, Instr);
3649 Initialize_Discriminants (Instr, T);
3650 Target_Expr := New_Occurrence_Of (Temp, Loc);
3651 Insert_Actions (N, Build_Record_Aggr_Code (N, T, Target_Expr));
3652 Rewrite (N, New_Occurrence_Of (Temp, Loc));
3653 Analyze_And_Resolve (N, T);
3654 end if;
3655 end Convert_To_Assignments;
3657 ---------------------------
3658 -- Convert_To_Positional --
3659 ---------------------------
3661 procedure Convert_To_Positional
3662 (N : Node_Id;
3663 Max_Others_Replicate : Nat := 5;
3664 Handle_Bit_Packed : Boolean := False)
3666 Typ : constant Entity_Id := Etype (N);
3668 Static_Components : Boolean := True;
3670 procedure Check_Static_Components;
3671 -- Check whether all components of the aggregate are compile-time known
3672 -- values, and can be passed as is to the back-end without further
3673 -- expansion.
3675 function Flatten
3676 (N : Node_Id;
3677 Ix : Node_Id;
3678 Ixb : Node_Id) return Boolean;
3679 -- Convert the aggregate into a purely positional form if possible. On
3680 -- entry the bounds of all dimensions are known to be static, and the
3681 -- total number of components is safe enough to expand.
3683 function Is_Flat (N : Node_Id; Dims : Int) return Boolean;
3684 -- Return True iff the array N is flat (which is not trivial in the case
3685 -- of multidimensionsl aggregates).
3687 -----------------------------
3688 -- Check_Static_Components --
3689 -----------------------------
3691 procedure Check_Static_Components is
3692 Expr : Node_Id;
3694 begin
3695 Static_Components := True;
3697 if Nkind (N) = N_String_Literal then
3698 null;
3700 elsif Present (Expressions (N)) then
3701 Expr := First (Expressions (N));
3702 while Present (Expr) loop
3703 if Nkind (Expr) /= N_Aggregate
3704 or else not Compile_Time_Known_Aggregate (Expr)
3705 or else Expansion_Delayed (Expr)
3706 then
3707 Static_Components := False;
3708 exit;
3709 end if;
3711 Next (Expr);
3712 end loop;
3713 end if;
3715 if Nkind (N) = N_Aggregate
3716 and then Present (Component_Associations (N))
3717 then
3718 Expr := First (Component_Associations (N));
3719 while Present (Expr) loop
3720 if Nkind (Expression (Expr)) = N_Integer_Literal then
3721 null;
3723 elsif Nkind (Expression (Expr)) /= N_Aggregate
3724 or else
3725 not Compile_Time_Known_Aggregate (Expression (Expr))
3726 or else Expansion_Delayed (Expression (Expr))
3727 then
3728 Static_Components := False;
3729 exit;
3730 end if;
3732 Next (Expr);
3733 end loop;
3734 end if;
3735 end Check_Static_Components;
3737 -------------
3738 -- Flatten --
3739 -------------
3741 function Flatten
3742 (N : Node_Id;
3743 Ix : Node_Id;
3744 Ixb : Node_Id) return Boolean
3746 Loc : constant Source_Ptr := Sloc (N);
3747 Blo : constant Node_Id := Type_Low_Bound (Etype (Ixb));
3748 Lo : constant Node_Id := Type_Low_Bound (Etype (Ix));
3749 Hi : constant Node_Id := Type_High_Bound (Etype (Ix));
3750 Lov : Uint;
3751 Hiv : Uint;
3753 begin
3754 if Nkind (Original_Node (N)) = N_String_Literal then
3755 return True;
3756 end if;
3758 if not Compile_Time_Known_Value (Lo)
3759 or else not Compile_Time_Known_Value (Hi)
3760 then
3761 return False;
3762 end if;
3764 Lov := Expr_Value (Lo);
3765 Hiv := Expr_Value (Hi);
3767 if Hiv < Lov
3768 or else not Compile_Time_Known_Value (Blo)
3769 then
3770 return False;
3771 end if;
3773 -- Determine if set of alternatives is suitable for conversion and
3774 -- build an array containing the values in sequence.
3776 declare
3777 Vals : array (UI_To_Int (Lov) .. UI_To_Int (Hiv))
3778 of Node_Id := (others => Empty);
3779 -- The values in the aggregate sorted appropriately
3781 Vlist : List_Id;
3782 -- Same data as Vals in list form
3784 Rep_Count : Nat;
3785 -- Used to validate Max_Others_Replicate limit
3787 Elmt : Node_Id;
3788 Num : Int := UI_To_Int (Lov);
3789 Choice : Node_Id;
3790 Lo, Hi : Node_Id;
3792 begin
3793 if Present (Expressions (N)) then
3794 Elmt := First (Expressions (N));
3795 while Present (Elmt) loop
3796 if Nkind (Elmt) = N_Aggregate
3797 and then Present (Next_Index (Ix))
3798 and then
3799 not Flatten (Elmt, Next_Index (Ix), Next_Index (Ixb))
3800 then
3801 return False;
3802 end if;
3804 Vals (Num) := Relocate_Node (Elmt);
3805 Num := Num + 1;
3807 Next (Elmt);
3808 end loop;
3809 end if;
3811 if No (Component_Associations (N)) then
3812 return True;
3813 end if;
3815 Elmt := First (Component_Associations (N));
3817 if Nkind (Expression (Elmt)) = N_Aggregate then
3818 if Present (Next_Index (Ix))
3819 and then
3820 not Flatten
3821 (Expression (Elmt), Next_Index (Ix), Next_Index (Ixb))
3822 then
3823 return False;
3824 end if;
3825 end if;
3827 Component_Loop : while Present (Elmt) loop
3828 Choice := First (Choices (Elmt));
3829 Choice_Loop : while Present (Choice) loop
3831 -- If we have an others choice, fill in the missing elements
3832 -- subject to the limit established by Max_Others_Replicate.
3834 if Nkind (Choice) = N_Others_Choice then
3835 Rep_Count := 0;
3837 for J in Vals'Range loop
3838 if No (Vals (J)) then
3839 Vals (J) := New_Copy_Tree (Expression (Elmt));
3840 Rep_Count := Rep_Count + 1;
3842 -- Check for maximum others replication. Note that
3843 -- we skip this test if either of the restrictions
3844 -- No_Elaboration_Code or No_Implicit_Loops is
3845 -- active, if this is a preelaborable unit or a
3846 -- predefined unit. This ensures that predefined
3847 -- units get the same level of constant folding in
3848 -- Ada 95 and Ada 05, where their categorization
3849 -- has changed.
3851 declare
3852 P : constant Entity_Id :=
3853 Cunit_Entity (Current_Sem_Unit);
3855 begin
3856 -- Check if duplication OK and if so continue
3857 -- processing.
3859 if Restriction_Active (No_Elaboration_Code)
3860 or else Restriction_Active (No_Implicit_Loops)
3861 or else Is_Preelaborated (P)
3862 or else (Ekind (P) = E_Package_Body
3863 and then
3864 Is_Preelaborated (Spec_Entity (P)))
3865 or else
3866 Is_Predefined_File_Name
3867 (Unit_File_Name (Get_Source_Unit (P)))
3868 then
3869 null;
3871 -- If duplication not OK, then we return False
3872 -- if the replication count is too high
3874 elsif Rep_Count > Max_Others_Replicate then
3875 return False;
3877 -- Continue on if duplication not OK, but the
3878 -- replication count is not excessive.
3880 else
3881 null;
3882 end if;
3883 end;
3884 end if;
3885 end loop;
3887 exit Component_Loop;
3889 -- Case of a subtype mark
3891 elsif Nkind (Choice) = N_Identifier
3892 and then Is_Type (Entity (Choice))
3893 then
3894 Lo := Type_Low_Bound (Etype (Choice));
3895 Hi := Type_High_Bound (Etype (Choice));
3897 -- Case of subtype indication
3899 elsif Nkind (Choice) = N_Subtype_Indication then
3900 Lo := Low_Bound (Range_Expression (Constraint (Choice)));
3901 Hi := High_Bound (Range_Expression (Constraint (Choice)));
3903 -- Case of a range
3905 elsif Nkind (Choice) = N_Range then
3906 Lo := Low_Bound (Choice);
3907 Hi := High_Bound (Choice);
3909 -- Normal subexpression case
3911 else pragma Assert (Nkind (Choice) in N_Subexpr);
3912 if not Compile_Time_Known_Value (Choice) then
3913 return False;
3915 else
3916 Vals (UI_To_Int (Expr_Value (Choice))) :=
3917 New_Copy_Tree (Expression (Elmt));
3918 goto Continue;
3919 end if;
3920 end if;
3922 -- Range cases merge with Lo,Hi set
3924 if not Compile_Time_Known_Value (Lo)
3925 or else
3926 not Compile_Time_Known_Value (Hi)
3927 then
3928 return False;
3929 else
3930 for J in UI_To_Int (Expr_Value (Lo)) ..
3931 UI_To_Int (Expr_Value (Hi))
3932 loop
3933 Vals (J) := New_Copy_Tree (Expression (Elmt));
3934 end loop;
3935 end if;
3937 <<Continue>>
3938 Next (Choice);
3939 end loop Choice_Loop;
3941 Next (Elmt);
3942 end loop Component_Loop;
3944 -- If we get here the conversion is possible
3946 Vlist := New_List;
3947 for J in Vals'Range loop
3948 Append (Vals (J), Vlist);
3949 end loop;
3951 Rewrite (N, Make_Aggregate (Loc, Expressions => Vlist));
3952 Set_Aggregate_Bounds (N, Aggregate_Bounds (Original_Node (N)));
3953 return True;
3954 end;
3955 end Flatten;
3957 -------------
3958 -- Is_Flat --
3959 -------------
3961 function Is_Flat (N : Node_Id; Dims : Int) return Boolean is
3962 Elmt : Node_Id;
3964 begin
3965 if Dims = 0 then
3966 return True;
3968 elsif Nkind (N) = N_Aggregate then
3969 if Present (Component_Associations (N)) then
3970 return False;
3972 else
3973 Elmt := First (Expressions (N));
3974 while Present (Elmt) loop
3975 if not Is_Flat (Elmt, Dims - 1) then
3976 return False;
3977 end if;
3979 Next (Elmt);
3980 end loop;
3982 return True;
3983 end if;
3984 else
3985 return True;
3986 end if;
3987 end Is_Flat;
3989 -- Start of processing for Convert_To_Positional
3991 begin
3992 -- Ada 2005 (AI-287): Do not convert in case of default initialized
3993 -- components because in this case will need to call the corresponding
3994 -- IP procedure.
3996 if Has_Default_Init_Comps (N) then
3997 return;
3998 end if;
4000 if Is_Flat (N, Number_Dimensions (Typ)) then
4001 return;
4002 end if;
4004 if Is_Bit_Packed_Array (Typ)
4005 and then not Handle_Bit_Packed
4006 then
4007 return;
4008 end if;
4010 -- Do not convert to positional if controlled components are involved
4011 -- since these require special processing
4013 if Has_Controlled_Component (Typ) then
4014 return;
4015 end if;
4017 Check_Static_Components;
4019 -- If the size is known, or all the components are static, try to
4020 -- build a fully positional aggregate.
4022 -- The size of the type may not be known for an aggregate with
4023 -- discriminated array components, but if the components are static
4024 -- it is still possible to verify statically that the length is
4025 -- compatible with the upper bound of the type, and therefore it is
4026 -- worth flattening such aggregates as well.
4028 -- For now the back-end expands these aggregates into individual
4029 -- assignments to the target anyway, but it is conceivable that
4030 -- it will eventually be able to treat such aggregates statically???
4032 if Aggr_Size_OK (N, Typ)
4033 and then Flatten (N, First_Index (Typ), First_Index (Base_Type (Typ)))
4034 then
4035 if Static_Components then
4036 Set_Compile_Time_Known_Aggregate (N);
4037 Set_Expansion_Delayed (N, False);
4038 end if;
4040 Analyze_And_Resolve (N, Typ);
4041 end if;
4042 end Convert_To_Positional;
4044 ----------------------------
4045 -- Expand_Array_Aggregate --
4046 ----------------------------
4048 -- Array aggregate expansion proceeds as follows:
4050 -- 1. If requested we generate code to perform all the array aggregate
4051 -- bound checks, specifically
4053 -- (a) Check that the index range defined by aggregate bounds is
4054 -- compatible with corresponding index subtype.
4056 -- (b) If an others choice is present check that no aggregate
4057 -- index is outside the bounds of the index constraint.
4059 -- (c) For multidimensional arrays make sure that all subaggregates
4060 -- corresponding to the same dimension have the same bounds.
4062 -- 2. Check for packed array aggregate which can be converted to a
4063 -- constant so that the aggregate disappeares completely.
4065 -- 3. Check case of nested aggregate. Generally nested aggregates are
4066 -- handled during the processing of the parent aggregate.
4068 -- 4. Check if the aggregate can be statically processed. If this is the
4069 -- case pass it as is to Gigi. Note that a necessary condition for
4070 -- static processing is that the aggregate be fully positional.
4072 -- 5. If in place aggregate expansion is possible (i.e. no need to create
4073 -- a temporary) then mark the aggregate as such and return. Otherwise
4074 -- create a new temporary and generate the appropriate initialization
4075 -- code.
4077 procedure Expand_Array_Aggregate (N : Node_Id) is
4078 Loc : constant Source_Ptr := Sloc (N);
4080 Typ : constant Entity_Id := Etype (N);
4081 Ctyp : constant Entity_Id := Component_Type (Typ);
4082 -- Typ is the correct constrained array subtype of the aggregate
4083 -- Ctyp is the corresponding component type.
4085 Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
4086 -- Number of aggregate index dimensions
4088 Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id;
4089 Aggr_High : array (1 .. Aggr_Dimension) of Node_Id;
4090 -- Low and High bounds of the constraint for each aggregate index
4092 Aggr_Index_Typ : array (1 .. Aggr_Dimension) of Entity_Id;
4093 -- The type of each index
4095 Maybe_In_Place_OK : Boolean;
4096 -- If the type is neither controlled nor packed and the aggregate
4097 -- is the expression in an assignment, assignment in place may be
4098 -- possible, provided other conditions are met on the LHS.
4100 Others_Present : array (1 .. Aggr_Dimension) of Boolean :=
4101 (others => False);
4102 -- If Others_Present (J) is True, then there is an others choice
4103 -- in one of the sub-aggregates of N at dimension J.
4105 procedure Build_Constrained_Type (Positional : Boolean);
4106 -- If the subtype is not static or unconstrained, build a constrained
4107 -- type using the computable sizes of the aggregate and its sub-
4108 -- aggregates.
4110 procedure Check_Bounds (Aggr_Bounds : Node_Id; Index_Bounds : Node_Id);
4111 -- Checks that the bounds of Aggr_Bounds are within the bounds defined
4112 -- by Index_Bounds.
4114 procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos);
4115 -- Checks that in a multi-dimensional array aggregate all subaggregates
4116 -- corresponding to the same dimension have the same bounds.
4117 -- Sub_Aggr is an array sub-aggregate. Dim is the dimension
4118 -- corresponding to the sub-aggregate.
4120 procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos);
4121 -- Computes the values of array Others_Present. Sub_Aggr is the
4122 -- array sub-aggregate we start the computation from. Dim is the
4123 -- dimension corresponding to the sub-aggregate.
4125 function Has_Address_Clause (D : Node_Id) return Boolean;
4126 -- If the aggregate is the expression in an object declaration, it
4127 -- cannot be expanded in place. This function does a lookahead in the
4128 -- current declarative part to find an address clause for the object
4129 -- being declared.
4131 function In_Place_Assign_OK return Boolean;
4132 -- Simple predicate to determine whether an aggregate assignment can
4133 -- be done in place, because none of the new values can depend on the
4134 -- components of the target of the assignment.
4136 procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos);
4137 -- Checks that if an others choice is present in any sub-aggregate no
4138 -- aggregate index is outside the bounds of the index constraint.
4139 -- Sub_Aggr is an array sub-aggregate. Dim is the dimension
4140 -- corresponding to the sub-aggregate.
4142 ----------------------------
4143 -- Build_Constrained_Type --
4144 ----------------------------
4146 procedure Build_Constrained_Type (Positional : Boolean) is
4147 Loc : constant Source_Ptr := Sloc (N);
4148 Agg_Type : Entity_Id;
4149 Comp : Node_Id;
4150 Decl : Node_Id;
4151 Typ : constant Entity_Id := Etype (N);
4152 Indices : constant List_Id := New_List;
4153 Num : Int;
4154 Sub_Agg : Node_Id;
4156 begin
4157 Agg_Type :=
4158 Make_Defining_Identifier (
4159 Loc, New_Internal_Name ('A'));
4161 -- If the aggregate is purely positional, all its subaggregates
4162 -- have the same size. We collect the dimensions from the first
4163 -- subaggregate at each level.
4165 if Positional then
4166 Sub_Agg := N;
4168 for D in 1 .. Number_Dimensions (Typ) loop
4169 Sub_Agg := First (Expressions (Sub_Agg));
4171 Comp := Sub_Agg;
4172 Num := 0;
4173 while Present (Comp) loop
4174 Num := Num + 1;
4175 Next (Comp);
4176 end loop;
4178 Append (
4179 Make_Range (Loc,
4180 Low_Bound => Make_Integer_Literal (Loc, 1),
4181 High_Bound =>
4182 Make_Integer_Literal (Loc, Num)),
4183 Indices);
4184 end loop;
4186 else
4187 -- We know the aggregate type is unconstrained and the aggregate
4188 -- is not processable by the back end, therefore not necessarily
4189 -- positional. Retrieve each dimension bounds (computed earlier).
4190 -- earlier.
4192 for D in 1 .. Number_Dimensions (Typ) loop
4193 Append (
4194 Make_Range (Loc,
4195 Low_Bound => Aggr_Low (D),
4196 High_Bound => Aggr_High (D)),
4197 Indices);
4198 end loop;
4199 end if;
4201 Decl :=
4202 Make_Full_Type_Declaration (Loc,
4203 Defining_Identifier => Agg_Type,
4204 Type_Definition =>
4205 Make_Constrained_Array_Definition (Loc,
4206 Discrete_Subtype_Definitions => Indices,
4207 Component_Definition =>
4208 Make_Component_Definition (Loc,
4209 Aliased_Present => False,
4210 Subtype_Indication =>
4211 New_Occurrence_Of (Component_Type (Typ), Loc))));
4213 Insert_Action (N, Decl);
4214 Analyze (Decl);
4215 Set_Etype (N, Agg_Type);
4216 Set_Is_Itype (Agg_Type);
4217 Freeze_Itype (Agg_Type, N);
4218 end Build_Constrained_Type;
4220 ------------------
4221 -- Check_Bounds --
4222 ------------------
4224 procedure Check_Bounds (Aggr_Bounds : Node_Id; Index_Bounds : Node_Id) is
4225 Aggr_Lo : Node_Id;
4226 Aggr_Hi : Node_Id;
4228 Ind_Lo : Node_Id;
4229 Ind_Hi : Node_Id;
4231 Cond : Node_Id := Empty;
4233 begin
4234 Get_Index_Bounds (Aggr_Bounds, Aggr_Lo, Aggr_Hi);
4235 Get_Index_Bounds (Index_Bounds, Ind_Lo, Ind_Hi);
4237 -- Generate the following test:
4239 -- [constraint_error when
4240 -- Aggr_Lo <= Aggr_Hi and then
4241 -- (Aggr_Lo < Ind_Lo or else Aggr_Hi > Ind_Hi)]
4243 -- As an optimization try to see if some tests are trivially vacuous
4244 -- because we are comparing an expression against itself.
4246 if Aggr_Lo = Ind_Lo and then Aggr_Hi = Ind_Hi then
4247 Cond := Empty;
4249 elsif Aggr_Hi = Ind_Hi then
4250 Cond :=
4251 Make_Op_Lt (Loc,
4252 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4253 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Lo));
4255 elsif Aggr_Lo = Ind_Lo then
4256 Cond :=
4257 Make_Op_Gt (Loc,
4258 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi),
4259 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Hi));
4261 else
4262 Cond :=
4263 Make_Or_Else (Loc,
4264 Left_Opnd =>
4265 Make_Op_Lt (Loc,
4266 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4267 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Lo)),
4269 Right_Opnd =>
4270 Make_Op_Gt (Loc,
4271 Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
4272 Right_Opnd => Duplicate_Subexpr (Ind_Hi)));
4273 end if;
4275 if Present (Cond) then
4276 Cond :=
4277 Make_And_Then (Loc,
4278 Left_Opnd =>
4279 Make_Op_Le (Loc,
4280 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4281 Right_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi)),
4283 Right_Opnd => Cond);
4285 Set_Analyzed (Left_Opnd (Left_Opnd (Cond)), False);
4286 Set_Analyzed (Right_Opnd (Left_Opnd (Cond)), False);
4287 Insert_Action (N,
4288 Make_Raise_Constraint_Error (Loc,
4289 Condition => Cond,
4290 Reason => CE_Length_Check_Failed));
4291 end if;
4292 end Check_Bounds;
4294 ----------------------------
4295 -- Check_Same_Aggr_Bounds --
4296 ----------------------------
4298 procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos) is
4299 Sub_Lo : constant Node_Id := Low_Bound (Aggregate_Bounds (Sub_Aggr));
4300 Sub_Hi : constant Node_Id := High_Bound (Aggregate_Bounds (Sub_Aggr));
4301 -- The bounds of this specific sub-aggregate
4303 Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
4304 Aggr_Hi : constant Node_Id := Aggr_High (Dim);
4305 -- The bounds of the aggregate for this dimension
4307 Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
4308 -- The index type for this dimension.xxx
4310 Cond : Node_Id := Empty;
4311 Assoc : Node_Id;
4312 Expr : Node_Id;
4314 begin
4315 -- If index checks are on generate the test
4317 -- [constraint_error when
4318 -- Aggr_Lo /= Sub_Lo or else Aggr_Hi /= Sub_Hi]
4320 -- As an optimization try to see if some tests are trivially vacuos
4321 -- because we are comparing an expression against itself. Also for
4322 -- the first dimension the test is trivially vacuous because there
4323 -- is just one aggregate for dimension 1.
4325 if Index_Checks_Suppressed (Ind_Typ) then
4326 Cond := Empty;
4328 elsif Dim = 1
4329 or else (Aggr_Lo = Sub_Lo and then Aggr_Hi = Sub_Hi)
4330 then
4331 Cond := Empty;
4333 elsif Aggr_Hi = Sub_Hi then
4334 Cond :=
4335 Make_Op_Ne (Loc,
4336 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4337 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo));
4339 elsif Aggr_Lo = Sub_Lo then
4340 Cond :=
4341 Make_Op_Ne (Loc,
4342 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi),
4343 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Hi));
4345 else
4346 Cond :=
4347 Make_Or_Else (Loc,
4348 Left_Opnd =>
4349 Make_Op_Ne (Loc,
4350 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4351 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo)),
4353 Right_Opnd =>
4354 Make_Op_Ne (Loc,
4355 Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
4356 Right_Opnd => Duplicate_Subexpr (Sub_Hi)));
4357 end if;
4359 if Present (Cond) then
4360 Insert_Action (N,
4361 Make_Raise_Constraint_Error (Loc,
4362 Condition => Cond,
4363 Reason => CE_Length_Check_Failed));
4364 end if;
4366 -- Now look inside the sub-aggregate to see if there is more work
4368 if Dim < Aggr_Dimension then
4370 -- Process positional components
4372 if Present (Expressions (Sub_Aggr)) then
4373 Expr := First (Expressions (Sub_Aggr));
4374 while Present (Expr) loop
4375 Check_Same_Aggr_Bounds (Expr, Dim + 1);
4376 Next (Expr);
4377 end loop;
4378 end if;
4380 -- Process component associations
4382 if Present (Component_Associations (Sub_Aggr)) then
4383 Assoc := First (Component_Associations (Sub_Aggr));
4384 while Present (Assoc) loop
4385 Expr := Expression (Assoc);
4386 Check_Same_Aggr_Bounds (Expr, Dim + 1);
4387 Next (Assoc);
4388 end loop;
4389 end if;
4390 end if;
4391 end Check_Same_Aggr_Bounds;
4393 ----------------------------
4394 -- Compute_Others_Present --
4395 ----------------------------
4397 procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos) is
4398 Assoc : Node_Id;
4399 Expr : Node_Id;
4401 begin
4402 if Present (Component_Associations (Sub_Aggr)) then
4403 Assoc := Last (Component_Associations (Sub_Aggr));
4405 if Nkind (First (Choices (Assoc))) = N_Others_Choice then
4406 Others_Present (Dim) := True;
4407 end if;
4408 end if;
4410 -- Now look inside the sub-aggregate to see if there is more work
4412 if Dim < Aggr_Dimension then
4414 -- Process positional components
4416 if Present (Expressions (Sub_Aggr)) then
4417 Expr := First (Expressions (Sub_Aggr));
4418 while Present (Expr) loop
4419 Compute_Others_Present (Expr, Dim + 1);
4420 Next (Expr);
4421 end loop;
4422 end if;
4424 -- Process component associations
4426 if Present (Component_Associations (Sub_Aggr)) then
4427 Assoc := First (Component_Associations (Sub_Aggr));
4428 while Present (Assoc) loop
4429 Expr := Expression (Assoc);
4430 Compute_Others_Present (Expr, Dim + 1);
4431 Next (Assoc);
4432 end loop;
4433 end if;
4434 end if;
4435 end Compute_Others_Present;
4437 ------------------------
4438 -- Has_Address_Clause --
4439 ------------------------
4441 function Has_Address_Clause (D : Node_Id) return Boolean is
4442 Id : constant Entity_Id := Defining_Identifier (D);
4443 Decl : Node_Id;
4445 begin
4446 Decl := Next (D);
4447 while Present (Decl) loop
4448 if Nkind (Decl) = N_At_Clause
4449 and then Chars (Identifier (Decl)) = Chars (Id)
4450 then
4451 return True;
4453 elsif Nkind (Decl) = N_Attribute_Definition_Clause
4454 and then Chars (Decl) = Name_Address
4455 and then Chars (Name (Decl)) = Chars (Id)
4456 then
4457 return True;
4458 end if;
4460 Next (Decl);
4461 end loop;
4463 return False;
4464 end Has_Address_Clause;
4466 ------------------------
4467 -- In_Place_Assign_OK --
4468 ------------------------
4470 function In_Place_Assign_OK return Boolean is
4471 Aggr_In : Node_Id;
4472 Aggr_Lo : Node_Id;
4473 Aggr_Hi : Node_Id;
4474 Obj_In : Node_Id;
4475 Obj_Lo : Node_Id;
4476 Obj_Hi : Node_Id;
4478 function Is_Others_Aggregate (Aggr : Node_Id) return Boolean;
4479 -- Aggregates that consist of a single Others choice are safe
4480 -- if the single expression is.
4482 function Safe_Aggregate (Aggr : Node_Id) return Boolean;
4483 -- Check recursively that each component of a (sub)aggregate does
4484 -- not depend on the variable being assigned to.
4486 function Safe_Component (Expr : Node_Id) return Boolean;
4487 -- Verify that an expression cannot depend on the variable being
4488 -- assigned to. Room for improvement here (but less than before).
4490 -------------------------
4491 -- Is_Others_Aggregate --
4492 -------------------------
4494 function Is_Others_Aggregate (Aggr : Node_Id) return Boolean is
4495 begin
4496 return No (Expressions (Aggr))
4497 and then Nkind
4498 (First (Choices (First (Component_Associations (Aggr)))))
4499 = N_Others_Choice;
4500 end Is_Others_Aggregate;
4502 --------------------
4503 -- Safe_Aggregate --
4504 --------------------
4506 function Safe_Aggregate (Aggr : Node_Id) return Boolean is
4507 Expr : Node_Id;
4509 begin
4510 if Present (Expressions (Aggr)) then
4511 Expr := First (Expressions (Aggr));
4512 while Present (Expr) loop
4513 if Nkind (Expr) = N_Aggregate then
4514 if not Safe_Aggregate (Expr) then
4515 return False;
4516 end if;
4518 elsif not Safe_Component (Expr) then
4519 return False;
4520 end if;
4522 Next (Expr);
4523 end loop;
4524 end if;
4526 if Present (Component_Associations (Aggr)) then
4527 Expr := First (Component_Associations (Aggr));
4528 while Present (Expr) loop
4529 if Nkind (Expression (Expr)) = N_Aggregate then
4530 if not Safe_Aggregate (Expression (Expr)) then
4531 return False;
4532 end if;
4534 elsif not Safe_Component (Expression (Expr)) then
4535 return False;
4536 end if;
4538 Next (Expr);
4539 end loop;
4540 end if;
4542 return True;
4543 end Safe_Aggregate;
4545 --------------------
4546 -- Safe_Component --
4547 --------------------
4549 function Safe_Component (Expr : Node_Id) return Boolean is
4550 Comp : Node_Id := Expr;
4552 function Check_Component (Comp : Node_Id) return Boolean;
4553 -- Do the recursive traversal, after copy
4555 ---------------------
4556 -- Check_Component --
4557 ---------------------
4559 function Check_Component (Comp : Node_Id) return Boolean is
4560 begin
4561 if Is_Overloaded (Comp) then
4562 return False;
4563 end if;
4565 return Compile_Time_Known_Value (Comp)
4567 or else (Is_Entity_Name (Comp)
4568 and then Present (Entity (Comp))
4569 and then No (Renamed_Object (Entity (Comp))))
4571 or else (Nkind (Comp) = N_Attribute_Reference
4572 and then Check_Component (Prefix (Comp)))
4574 or else (Nkind (Comp) in N_Binary_Op
4575 and then Check_Component (Left_Opnd (Comp))
4576 and then Check_Component (Right_Opnd (Comp)))
4578 or else (Nkind (Comp) in N_Unary_Op
4579 and then Check_Component (Right_Opnd (Comp)))
4581 or else (Nkind (Comp) = N_Selected_Component
4582 and then Check_Component (Prefix (Comp)))
4584 or else (Nkind (Comp) = N_Unchecked_Type_Conversion
4585 and then Check_Component (Expression (Comp)));
4586 end Check_Component;
4588 -- Start of processing for Safe_Component
4590 begin
4591 -- If the component appears in an association that may
4592 -- correspond to more than one element, it is not analyzed
4593 -- before the expansion into assignments, to avoid side effects.
4594 -- We analyze, but do not resolve the copy, to obtain sufficient
4595 -- entity information for the checks that follow. If component is
4596 -- overloaded we assume an unsafe function call.
4598 if not Analyzed (Comp) then
4599 if Is_Overloaded (Expr) then
4600 return False;
4602 elsif Nkind (Expr) = N_Aggregate
4603 and then not Is_Others_Aggregate (Expr)
4604 then
4605 return False;
4607 elsif Nkind (Expr) = N_Allocator then
4609 -- For now, too complex to analyze
4611 return False;
4612 end if;
4614 Comp := New_Copy_Tree (Expr);
4615 Set_Parent (Comp, Parent (Expr));
4616 Analyze (Comp);
4617 end if;
4619 if Nkind (Comp) = N_Aggregate then
4620 return Safe_Aggregate (Comp);
4621 else
4622 return Check_Component (Comp);
4623 end if;
4624 end Safe_Component;
4626 -- Start of processing for In_Place_Assign_OK
4628 begin
4629 if Present (Component_Associations (N)) then
4631 -- On assignment, sliding can take place, so we cannot do the
4632 -- assignment in place unless the bounds of the aggregate are
4633 -- statically equal to those of the target.
4635 -- If the aggregate is given by an others choice, the bounds
4636 -- are derived from the left-hand side, and the assignment is
4637 -- safe if the expression is.
4639 if Is_Others_Aggregate (N) then
4640 return
4641 Safe_Component
4642 (Expression (First (Component_Associations (N))));
4643 end if;
4645 Aggr_In := First_Index (Etype (N));
4647 if Nkind (Parent (N)) = N_Assignment_Statement then
4648 Obj_In := First_Index (Etype (Name (Parent (N))));
4650 else
4651 -- Context is an allocator. Check bounds of aggregate
4652 -- against given type in qualified expression.
4654 pragma Assert (Nkind (Parent (Parent (N))) = N_Allocator);
4655 Obj_In :=
4656 First_Index (Etype (Entity (Subtype_Mark (Parent (N)))));
4657 end if;
4659 while Present (Aggr_In) loop
4660 Get_Index_Bounds (Aggr_In, Aggr_Lo, Aggr_Hi);
4661 Get_Index_Bounds (Obj_In, Obj_Lo, Obj_Hi);
4663 if not Compile_Time_Known_Value (Aggr_Lo)
4664 or else not Compile_Time_Known_Value (Aggr_Hi)
4665 or else not Compile_Time_Known_Value (Obj_Lo)
4666 or else not Compile_Time_Known_Value (Obj_Hi)
4667 or else Expr_Value (Aggr_Lo) /= Expr_Value (Obj_Lo)
4668 or else Expr_Value (Aggr_Hi) /= Expr_Value (Obj_Hi)
4669 then
4670 return False;
4671 end if;
4673 Next_Index (Aggr_In);
4674 Next_Index (Obj_In);
4675 end loop;
4676 end if;
4678 -- Now check the component values themselves
4680 return Safe_Aggregate (N);
4681 end In_Place_Assign_OK;
4683 ------------------
4684 -- Others_Check --
4685 ------------------
4687 procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos) is
4688 Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
4689 Aggr_Hi : constant Node_Id := Aggr_High (Dim);
4690 -- The bounds of the aggregate for this dimension
4692 Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
4693 -- The index type for this dimension
4695 Need_To_Check : Boolean := False;
4697 Choices_Lo : Node_Id := Empty;
4698 Choices_Hi : Node_Id := Empty;
4699 -- The lowest and highest discrete choices for a named sub-aggregate
4701 Nb_Choices : Int := -1;
4702 -- The number of discrete non-others choices in this sub-aggregate
4704 Nb_Elements : Uint := Uint_0;
4705 -- The number of elements in a positional aggregate
4707 Cond : Node_Id := Empty;
4709 Assoc : Node_Id;
4710 Choice : Node_Id;
4711 Expr : Node_Id;
4713 begin
4714 -- Check if we have an others choice. If we do make sure that this
4715 -- sub-aggregate contains at least one element in addition to the
4716 -- others choice.
4718 if Range_Checks_Suppressed (Ind_Typ) then
4719 Need_To_Check := False;
4721 elsif Present (Expressions (Sub_Aggr))
4722 and then Present (Component_Associations (Sub_Aggr))
4723 then
4724 Need_To_Check := True;
4726 elsif Present (Component_Associations (Sub_Aggr)) then
4727 Assoc := Last (Component_Associations (Sub_Aggr));
4729 if Nkind (First (Choices (Assoc))) /= N_Others_Choice then
4730 Need_To_Check := False;
4732 else
4733 -- Count the number of discrete choices. Start with -1 because
4734 -- the others choice does not count.
4736 Nb_Choices := -1;
4737 Assoc := First (Component_Associations (Sub_Aggr));
4738 while Present (Assoc) loop
4739 Choice := First (Choices (Assoc));
4740 while Present (Choice) loop
4741 Nb_Choices := Nb_Choices + 1;
4742 Next (Choice);
4743 end loop;
4745 Next (Assoc);
4746 end loop;
4748 -- If there is only an others choice nothing to do
4750 Need_To_Check := (Nb_Choices > 0);
4751 end if;
4753 else
4754 Need_To_Check := False;
4755 end if;
4757 -- If we are dealing with a positional sub-aggregate with an others
4758 -- choice then compute the number or positional elements.
4760 if Need_To_Check and then Present (Expressions (Sub_Aggr)) then
4761 Expr := First (Expressions (Sub_Aggr));
4762 Nb_Elements := Uint_0;
4763 while Present (Expr) loop
4764 Nb_Elements := Nb_Elements + 1;
4765 Next (Expr);
4766 end loop;
4768 -- If the aggregate contains discrete choices and an others choice
4769 -- compute the smallest and largest discrete choice values.
4771 elsif Need_To_Check then
4772 Compute_Choices_Lo_And_Choices_Hi : declare
4774 Table : Case_Table_Type (1 .. Nb_Choices);
4775 -- Used to sort all the different choice values
4777 J : Pos := 1;
4778 Low : Node_Id;
4779 High : Node_Id;
4781 begin
4782 Assoc := First (Component_Associations (Sub_Aggr));
4783 while Present (Assoc) loop
4784 Choice := First (Choices (Assoc));
4785 while Present (Choice) loop
4786 if Nkind (Choice) = N_Others_Choice then
4787 exit;
4788 end if;
4790 Get_Index_Bounds (Choice, Low, High);
4791 Table (J).Choice_Lo := Low;
4792 Table (J).Choice_Hi := High;
4794 J := J + 1;
4795 Next (Choice);
4796 end loop;
4798 Next (Assoc);
4799 end loop;
4801 -- Sort the discrete choices
4803 Sort_Case_Table (Table);
4805 Choices_Lo := Table (1).Choice_Lo;
4806 Choices_Hi := Table (Nb_Choices).Choice_Hi;
4807 end Compute_Choices_Lo_And_Choices_Hi;
4808 end if;
4810 -- If no others choice in this sub-aggregate, or the aggregate
4811 -- comprises only an others choice, nothing to do.
4813 if not Need_To_Check then
4814 Cond := Empty;
4816 -- If we are dealing with an aggregate containing an others choice
4817 -- and positional components, we generate the following test:
4819 -- if Ind_Typ'Pos (Aggr_Lo) + (Nb_Elements - 1) >
4820 -- Ind_Typ'Pos (Aggr_Hi)
4821 -- then
4822 -- raise Constraint_Error;
4823 -- end if;
4825 elsif Nb_Elements > Uint_0 then
4826 Cond :=
4827 Make_Op_Gt (Loc,
4828 Left_Opnd =>
4829 Make_Op_Add (Loc,
4830 Left_Opnd =>
4831 Make_Attribute_Reference (Loc,
4832 Prefix => New_Reference_To (Ind_Typ, Loc),
4833 Attribute_Name => Name_Pos,
4834 Expressions =>
4835 New_List
4836 (Duplicate_Subexpr_Move_Checks (Aggr_Lo))),
4837 Right_Opnd => Make_Integer_Literal (Loc, Nb_Elements - 1)),
4839 Right_Opnd =>
4840 Make_Attribute_Reference (Loc,
4841 Prefix => New_Reference_To (Ind_Typ, Loc),
4842 Attribute_Name => Name_Pos,
4843 Expressions => New_List (
4844 Duplicate_Subexpr_Move_Checks (Aggr_Hi))));
4846 -- If we are dealing with an aggregate containing an others choice
4847 -- and discrete choices we generate the following test:
4849 -- [constraint_error when
4850 -- Choices_Lo < Aggr_Lo or else Choices_Hi > Aggr_Hi];
4852 else
4853 Cond :=
4854 Make_Or_Else (Loc,
4855 Left_Opnd =>
4856 Make_Op_Lt (Loc,
4857 Left_Opnd =>
4858 Duplicate_Subexpr_Move_Checks (Choices_Lo),
4859 Right_Opnd =>
4860 Duplicate_Subexpr_Move_Checks (Aggr_Lo)),
4862 Right_Opnd =>
4863 Make_Op_Gt (Loc,
4864 Left_Opnd =>
4865 Duplicate_Subexpr (Choices_Hi),
4866 Right_Opnd =>
4867 Duplicate_Subexpr (Aggr_Hi)));
4868 end if;
4870 if Present (Cond) then
4871 Insert_Action (N,
4872 Make_Raise_Constraint_Error (Loc,
4873 Condition => Cond,
4874 Reason => CE_Length_Check_Failed));
4875 -- Questionable reason code, shouldn't that be a
4876 -- CE_Range_Check_Failed ???
4877 end if;
4879 -- Now look inside the sub-aggregate to see if there is more work
4881 if Dim < Aggr_Dimension then
4883 -- Process positional components
4885 if Present (Expressions (Sub_Aggr)) then
4886 Expr := First (Expressions (Sub_Aggr));
4887 while Present (Expr) loop
4888 Others_Check (Expr, Dim + 1);
4889 Next (Expr);
4890 end loop;
4891 end if;
4893 -- Process component associations
4895 if Present (Component_Associations (Sub_Aggr)) then
4896 Assoc := First (Component_Associations (Sub_Aggr));
4897 while Present (Assoc) loop
4898 Expr := Expression (Assoc);
4899 Others_Check (Expr, Dim + 1);
4900 Next (Assoc);
4901 end loop;
4902 end if;
4903 end if;
4904 end Others_Check;
4906 -- Remaining Expand_Array_Aggregate variables
4908 Tmp : Entity_Id;
4909 -- Holds the temporary aggregate value
4911 Tmp_Decl : Node_Id;
4912 -- Holds the declaration of Tmp
4914 Aggr_Code : List_Id;
4915 Parent_Node : Node_Id;
4916 Parent_Kind : Node_Kind;
4918 -- Start of processing for Expand_Array_Aggregate
4920 begin
4921 -- Do not touch the special aggregates of attributes used for Asm calls
4923 if Is_RTE (Ctyp, RE_Asm_Input_Operand)
4924 or else Is_RTE (Ctyp, RE_Asm_Output_Operand)
4925 then
4926 return;
4927 end if;
4929 -- If the semantic analyzer has determined that aggregate N will raise
4930 -- Constraint_Error at run-time, then the aggregate node has been
4931 -- replaced with an N_Raise_Constraint_Error node and we should
4932 -- never get here.
4934 pragma Assert (not Raises_Constraint_Error (N));
4936 -- STEP 1a
4938 -- Check that the index range defined by aggregate bounds is
4939 -- compatible with corresponding index subtype.
4941 Index_Compatibility_Check : declare
4942 Aggr_Index_Range : Node_Id := First_Index (Typ);
4943 -- The current aggregate index range
4945 Index_Constraint : Node_Id := First_Index (Etype (Typ));
4946 -- The corresponding index constraint against which we have to
4947 -- check the above aggregate index range.
4949 begin
4950 Compute_Others_Present (N, 1);
4952 for J in 1 .. Aggr_Dimension loop
4953 -- There is no need to emit a check if an others choice is
4954 -- present for this array aggregate dimension since in this
4955 -- case one of N's sub-aggregates has taken its bounds from the
4956 -- context and these bounds must have been checked already. In
4957 -- addition all sub-aggregates corresponding to the same
4958 -- dimension must all have the same bounds (checked in (c) below).
4960 if not Range_Checks_Suppressed (Etype (Index_Constraint))
4961 and then not Others_Present (J)
4962 then
4963 -- We don't use Checks.Apply_Range_Check here because it emits
4964 -- a spurious check. Namely it checks that the range defined by
4965 -- the aggregate bounds is non empty. But we know this already
4966 -- if we get here.
4968 Check_Bounds (Aggr_Index_Range, Index_Constraint);
4969 end if;
4971 -- Save the low and high bounds of the aggregate index as well as
4972 -- the index type for later use in checks (b) and (c) below.
4974 Aggr_Low (J) := Low_Bound (Aggr_Index_Range);
4975 Aggr_High (J) := High_Bound (Aggr_Index_Range);
4977 Aggr_Index_Typ (J) := Etype (Index_Constraint);
4979 Next_Index (Aggr_Index_Range);
4980 Next_Index (Index_Constraint);
4981 end loop;
4982 end Index_Compatibility_Check;
4984 -- STEP 1b
4986 -- If an others choice is present check that no aggregate index is
4987 -- outside the bounds of the index constraint.
4989 Others_Check (N, 1);
4991 -- STEP 1c
4993 -- For multidimensional arrays make sure that all subaggregates
4994 -- corresponding to the same dimension have the same bounds.
4996 if Aggr_Dimension > 1 then
4997 Check_Same_Aggr_Bounds (N, 1);
4998 end if;
5000 -- STEP 2
5002 -- Here we test for is packed array aggregate that we can handle at
5003 -- compile time. If so, return with transformation done. Note that we do
5004 -- this even if the aggregate is nested, because once we have done this
5005 -- processing, there is no more nested aggregate!
5007 if Packed_Array_Aggregate_Handled (N) then
5008 return;
5009 end if;
5011 -- At this point we try to convert to positional form
5013 if Ekind (Current_Scope) = E_Package
5014 and then Static_Elaboration_Desired (Current_Scope)
5015 then
5016 Convert_To_Positional (N, Max_Others_Replicate => 100);
5018 else
5019 Convert_To_Positional (N);
5020 end if;
5022 -- if the result is no longer an aggregate (e.g. it may be a string
5023 -- literal, or a temporary which has the needed value), then we are
5024 -- done, since there is no longer a nested aggregate.
5026 if Nkind (N) /= N_Aggregate then
5027 return;
5029 -- We are also done if the result is an analyzed aggregate
5030 -- This case could use more comments ???
5032 elsif Analyzed (N)
5033 and then N /= Original_Node (N)
5034 then
5035 return;
5036 end if;
5038 -- If all aggregate components are compile-time known and the aggregate
5039 -- has been flattened, nothing left to do. The same occurs if the
5040 -- aggregate is used to initialize the components of an statically
5041 -- allocated dispatch table.
5043 if Compile_Time_Known_Aggregate (N)
5044 or else Is_Static_Dispatch_Table_Aggregate (N)
5045 then
5046 Set_Expansion_Delayed (N, False);
5047 return;
5048 end if;
5050 -- Now see if back end processing is possible
5052 if Backend_Processing_Possible (N) then
5054 -- If the aggregate is static but the constraints are not, build
5055 -- a static subtype for the aggregate, so that Gigi can place it
5056 -- in static memory. Perform an unchecked_conversion to the non-
5057 -- static type imposed by the context.
5059 declare
5060 Itype : constant Entity_Id := Etype (N);
5061 Index : Node_Id;
5062 Needs_Type : Boolean := False;
5064 begin
5065 Index := First_Index (Itype);
5066 while Present (Index) loop
5067 if not Is_Static_Subtype (Etype (Index)) then
5068 Needs_Type := True;
5069 exit;
5070 else
5071 Next_Index (Index);
5072 end if;
5073 end loop;
5075 if Needs_Type then
5076 Build_Constrained_Type (Positional => True);
5077 Rewrite (N, Unchecked_Convert_To (Itype, N));
5078 Analyze (N);
5079 end if;
5080 end;
5082 return;
5083 end if;
5085 -- STEP 3
5087 -- Delay expansion for nested aggregates: it will be taken care of
5088 -- when the parent aggregate is expanded.
5090 Parent_Node := Parent (N);
5091 Parent_Kind := Nkind (Parent_Node);
5093 if Parent_Kind = N_Qualified_Expression then
5094 Parent_Node := Parent (Parent_Node);
5095 Parent_Kind := Nkind (Parent_Node);
5096 end if;
5098 if Parent_Kind = N_Aggregate
5099 or else Parent_Kind = N_Extension_Aggregate
5100 or else Parent_Kind = N_Component_Association
5101 or else (Parent_Kind = N_Object_Declaration
5102 and then Needs_Finalization (Typ))
5103 or else (Parent_Kind = N_Assignment_Statement
5104 and then Inside_Init_Proc)
5105 then
5106 if Static_Array_Aggregate (N)
5107 or else Compile_Time_Known_Aggregate (N)
5108 then
5109 Set_Expansion_Delayed (N, False);
5110 return;
5111 else
5112 Set_Expansion_Delayed (N);
5113 return;
5114 end if;
5115 end if;
5117 -- STEP 4
5119 -- Look if in place aggregate expansion is possible
5121 -- For object declarations we build the aggregate in place, unless
5122 -- the array is bit-packed or the component is controlled.
5124 -- For assignments we do the assignment in place if all the component
5125 -- associations have compile-time known values. For other cases we
5126 -- create a temporary. The analysis for safety of on-line assignment
5127 -- is delicate, i.e. we don't know how to do it fully yet ???
5129 -- For allocators we assign to the designated object in place if the
5130 -- aggregate meets the same conditions as other in-place assignments.
5131 -- In this case the aggregate may not come from source but was created
5132 -- for default initialization, e.g. with Initialize_Scalars.
5134 if Requires_Transient_Scope (Typ) then
5135 Establish_Transient_Scope
5136 (N, Sec_Stack => Has_Controlled_Component (Typ));
5137 end if;
5139 if Has_Default_Init_Comps (N) then
5140 Maybe_In_Place_OK := False;
5142 elsif Is_Bit_Packed_Array (Typ)
5143 or else Has_Controlled_Component (Typ)
5144 then
5145 Maybe_In_Place_OK := False;
5147 else
5148 Maybe_In_Place_OK :=
5149 (Nkind (Parent (N)) = N_Assignment_Statement
5150 and then Comes_From_Source (N)
5151 and then In_Place_Assign_OK)
5153 or else
5154 (Nkind (Parent (Parent (N))) = N_Allocator
5155 and then In_Place_Assign_OK);
5156 end if;
5158 -- If this is an array of tasks, it will be expanded into build-in-place
5159 -- assignments. Build an activation chain for the tasks now.
5161 if Has_Task (Etype (N)) then
5162 Build_Activation_Chain_Entity (N);
5163 end if;
5165 if not Has_Default_Init_Comps (N)
5166 and then Comes_From_Source (Parent (N))
5167 and then Nkind (Parent (N)) = N_Object_Declaration
5168 and then not
5169 Must_Slide (Etype (Defining_Identifier (Parent (N))), Typ)
5170 and then N = Expression (Parent (N))
5171 and then not Is_Bit_Packed_Array (Typ)
5172 and then not Has_Controlled_Component (Typ)
5173 and then not Has_Address_Clause (Parent (N))
5174 then
5175 Tmp := Defining_Identifier (Parent (N));
5176 Set_No_Initialization (Parent (N));
5177 Set_Expression (Parent (N), Empty);
5179 -- Set the type of the entity, for use in the analysis of the
5180 -- subsequent indexed assignments. If the nominal type is not
5181 -- constrained, build a subtype from the known bounds of the
5182 -- aggregate. If the declaration has a subtype mark, use it,
5183 -- otherwise use the itype of the aggregate.
5185 if not Is_Constrained (Typ) then
5186 Build_Constrained_Type (Positional => False);
5187 elsif Is_Entity_Name (Object_Definition (Parent (N)))
5188 and then Is_Constrained (Entity (Object_Definition (Parent (N))))
5189 then
5190 Set_Etype (Tmp, Entity (Object_Definition (Parent (N))));
5191 else
5192 Set_Size_Known_At_Compile_Time (Typ, False);
5193 Set_Etype (Tmp, Typ);
5194 end if;
5196 elsif Maybe_In_Place_OK
5197 and then Nkind (Parent (N)) = N_Qualified_Expression
5198 and then Nkind (Parent (Parent (N))) = N_Allocator
5199 then
5200 Set_Expansion_Delayed (N);
5201 return;
5203 -- In the remaining cases the aggregate is the RHS of an assignment
5205 elsif Maybe_In_Place_OK
5206 and then Is_Entity_Name (Name (Parent (N)))
5207 then
5208 Tmp := Entity (Name (Parent (N)));
5210 if Etype (Tmp) /= Etype (N) then
5211 Apply_Length_Check (N, Etype (Tmp));
5213 if Nkind (N) = N_Raise_Constraint_Error then
5215 -- Static error, nothing further to expand
5217 return;
5218 end if;
5219 end if;
5221 elsif Maybe_In_Place_OK
5222 and then Nkind (Name (Parent (N))) = N_Explicit_Dereference
5223 and then Is_Entity_Name (Prefix (Name (Parent (N))))
5224 then
5225 Tmp := Name (Parent (N));
5227 if Etype (Tmp) /= Etype (N) then
5228 Apply_Length_Check (N, Etype (Tmp));
5229 end if;
5231 elsif Maybe_In_Place_OK
5232 and then Nkind (Name (Parent (N))) = N_Slice
5233 and then Safe_Slice_Assignment (N)
5234 then
5235 -- Safe_Slice_Assignment rewrites assignment as a loop
5237 return;
5239 -- Step 5
5241 -- In place aggregate expansion is not possible
5243 else
5244 Maybe_In_Place_OK := False;
5245 Tmp := Make_Temporary (Loc, 'A', N);
5246 Tmp_Decl :=
5247 Make_Object_Declaration
5248 (Loc,
5249 Defining_Identifier => Tmp,
5250 Object_Definition => New_Occurrence_Of (Typ, Loc));
5251 Set_No_Initialization (Tmp_Decl, True);
5253 -- If we are within a loop, the temporary will be pushed on the
5254 -- stack at each iteration. If the aggregate is the expression for an
5255 -- allocator, it will be immediately copied to the heap and can
5256 -- be reclaimed at once. We create a transient scope around the
5257 -- aggregate for this purpose.
5259 if Ekind (Current_Scope) = E_Loop
5260 and then Nkind (Parent (Parent (N))) = N_Allocator
5261 then
5262 Establish_Transient_Scope (N, False);
5263 end if;
5265 Insert_Action (N, Tmp_Decl);
5266 end if;
5268 -- Construct and insert the aggregate code. We can safely suppress index
5269 -- checks because this code is guaranteed not to raise CE on index
5270 -- checks. However we should *not* suppress all checks.
5272 declare
5273 Target : Node_Id;
5275 begin
5276 if Nkind (Tmp) = N_Defining_Identifier then
5277 Target := New_Reference_To (Tmp, Loc);
5279 else
5281 if Has_Default_Init_Comps (N) then
5283 -- Ada 2005 (AI-287): This case has not been analyzed???
5285 raise Program_Error;
5286 end if;
5288 -- Name in assignment is explicit dereference
5290 Target := New_Copy (Tmp);
5291 end if;
5293 Aggr_Code :=
5294 Build_Array_Aggr_Code (N,
5295 Ctype => Ctyp,
5296 Index => First_Index (Typ),
5297 Into => Target,
5298 Scalar_Comp => Is_Scalar_Type (Ctyp));
5299 end;
5301 if Comes_From_Source (Tmp) then
5302 Insert_Actions_After (Parent (N), Aggr_Code);
5304 else
5305 Insert_Actions (N, Aggr_Code);
5306 end if;
5308 -- If the aggregate has been assigned in place, remove the original
5309 -- assignment.
5311 if Nkind (Parent (N)) = N_Assignment_Statement
5312 and then Maybe_In_Place_OK
5313 then
5314 Rewrite (Parent (N), Make_Null_Statement (Loc));
5316 elsif Nkind (Parent (N)) /= N_Object_Declaration
5317 or else Tmp /= Defining_Identifier (Parent (N))
5318 then
5319 Rewrite (N, New_Occurrence_Of (Tmp, Loc));
5320 Analyze_And_Resolve (N, Typ);
5321 end if;
5322 end Expand_Array_Aggregate;
5324 ------------------------
5325 -- Expand_N_Aggregate --
5326 ------------------------
5328 procedure Expand_N_Aggregate (N : Node_Id) is
5329 begin
5330 if Is_Record_Type (Etype (N)) then
5331 Expand_Record_Aggregate (N);
5332 else
5333 Expand_Array_Aggregate (N);
5334 end if;
5335 exception
5336 when RE_Not_Available =>
5337 return;
5338 end Expand_N_Aggregate;
5340 ----------------------------------
5341 -- Expand_N_Extension_Aggregate --
5342 ----------------------------------
5344 -- If the ancestor part is an expression, add a component association for
5345 -- the parent field. If the type of the ancestor part is not the direct
5346 -- parent of the expected type, build recursively the needed ancestors.
5347 -- If the ancestor part is a subtype_mark, replace aggregate with a decla-
5348 -- ration for a temporary of the expected type, followed by individual
5349 -- assignments to the given components.
5351 procedure Expand_N_Extension_Aggregate (N : Node_Id) is
5352 Loc : constant Source_Ptr := Sloc (N);
5353 A : constant Node_Id := Ancestor_Part (N);
5354 Typ : constant Entity_Id := Etype (N);
5356 begin
5357 -- If the ancestor is a subtype mark, an init proc must be called
5358 -- on the resulting object which thus has to be materialized in
5359 -- the front-end
5361 if Is_Entity_Name (A) and then Is_Type (Entity (A)) then
5362 Convert_To_Assignments (N, Typ);
5364 -- The extension aggregate is transformed into a record aggregate
5365 -- of the following form (c1 and c2 are inherited components)
5367 -- (Exp with c3 => a, c4 => b)
5368 -- ==> (c1 => Exp.c1, c2 => Exp.c2, c1 => a, c2 => b)
5370 else
5371 Set_Etype (N, Typ);
5373 if Tagged_Type_Expansion then
5374 Expand_Record_Aggregate (N,
5375 Orig_Tag =>
5376 New_Occurrence_Of
5377 (Node (First_Elmt (Access_Disp_Table (Typ))), Loc),
5378 Parent_Expr => A);
5379 else
5380 -- No tag is needed in the case of a VM
5381 Expand_Record_Aggregate (N,
5382 Parent_Expr => A);
5383 end if;
5384 end if;
5386 exception
5387 when RE_Not_Available =>
5388 return;
5389 end Expand_N_Extension_Aggregate;
5391 -----------------------------
5392 -- Expand_Record_Aggregate --
5393 -----------------------------
5395 procedure Expand_Record_Aggregate
5396 (N : Node_Id;
5397 Orig_Tag : Node_Id := Empty;
5398 Parent_Expr : Node_Id := Empty)
5400 Loc : constant Source_Ptr := Sloc (N);
5401 Comps : constant List_Id := Component_Associations (N);
5402 Typ : constant Entity_Id := Etype (N);
5403 Base_Typ : constant Entity_Id := Base_Type (Typ);
5405 Static_Components : Boolean := True;
5406 -- Flag to indicate whether all components are compile-time known,
5407 -- and the aggregate can be constructed statically and handled by
5408 -- the back-end.
5410 function Component_Not_OK_For_Backend return Boolean;
5411 -- Check for presence of component which makes it impossible for the
5412 -- backend to process the aggregate, thus requiring the use of a series
5413 -- of assignment statements. Cases checked for are a nested aggregate
5414 -- needing Late_Expansion, the presence of a tagged component which may
5415 -- need tag adjustment, and a bit unaligned component reference.
5417 -- We also force expansion into assignments if a component is of a
5418 -- mutable type (including a private type with discriminants) because
5419 -- in that case the size of the component to be copied may be smaller
5420 -- than the side of the target, and there is no simple way for gigi
5421 -- to compute the size of the object to be copied.
5423 -- NOTE: This is part of the ongoing work to define precisely the
5424 -- interface between front-end and back-end handling of aggregates.
5425 -- In general it is desirable to pass aggregates as they are to gigi,
5426 -- in order to minimize elaboration code. This is one case where the
5427 -- semantics of Ada complicate the analysis and lead to anomalies in
5428 -- the gcc back-end if the aggregate is not expanded into assignments.
5430 ----------------------------------
5431 -- Component_Not_OK_For_Backend --
5432 ----------------------------------
5434 function Component_Not_OK_For_Backend return Boolean is
5435 C : Node_Id;
5436 Expr_Q : Node_Id;
5438 begin
5439 if No (Comps) then
5440 return False;
5441 end if;
5443 C := First (Comps);
5444 while Present (C) loop
5445 if Nkind (Expression (C)) = N_Qualified_Expression then
5446 Expr_Q := Expression (Expression (C));
5447 else
5448 Expr_Q := Expression (C);
5449 end if;
5451 -- Return true if the aggregate has any associations for tagged
5452 -- components that may require tag adjustment.
5454 -- These are cases where the source expression may have a tag that
5455 -- could differ from the component tag (e.g., can occur for type
5456 -- conversions and formal parameters). (Tag adjustment not needed
5457 -- if VM_Target because object tags are implicit in the machine.)
5459 if Is_Tagged_Type (Etype (Expr_Q))
5460 and then (Nkind (Expr_Q) = N_Type_Conversion
5461 or else (Is_Entity_Name (Expr_Q)
5462 and then
5463 Ekind (Entity (Expr_Q)) in Formal_Kind))
5464 and then Tagged_Type_Expansion
5465 then
5466 Static_Components := False;
5467 return True;
5469 elsif Is_Delayed_Aggregate (Expr_Q) then
5470 Static_Components := False;
5471 return True;
5473 elsif Possible_Bit_Aligned_Component (Expr_Q) then
5474 Static_Components := False;
5475 return True;
5476 end if;
5478 if Is_Scalar_Type (Etype (Expr_Q)) then
5479 if not Compile_Time_Known_Value (Expr_Q) then
5480 Static_Components := False;
5481 end if;
5483 elsif Nkind (Expr_Q) /= N_Aggregate
5484 or else not Compile_Time_Known_Aggregate (Expr_Q)
5485 then
5486 Static_Components := False;
5488 if Is_Private_Type (Etype (Expr_Q))
5489 and then Has_Discriminants (Etype (Expr_Q))
5490 then
5491 return True;
5492 end if;
5493 end if;
5495 Next (C);
5496 end loop;
5498 return False;
5499 end Component_Not_OK_For_Backend;
5501 -- Remaining Expand_Record_Aggregate variables
5503 Tag_Value : Node_Id;
5504 Comp : Entity_Id;
5505 New_Comp : Node_Id;
5507 -- Start of processing for Expand_Record_Aggregate
5509 begin
5510 -- If the aggregate is to be assigned to an atomic variable, we
5511 -- have to prevent a piecemeal assignment even if the aggregate
5512 -- is to be expanded. We create a temporary for the aggregate, and
5513 -- assign the temporary instead, so that the back end can generate
5514 -- an atomic move for it.
5516 if Is_Atomic (Typ)
5517 and then Comes_From_Source (Parent (N))
5518 and then Is_Atomic_Aggregate (N, Typ)
5519 then
5520 return;
5522 -- No special management required for aggregates used to initialize
5523 -- statically allocated dispatch tables
5525 elsif Is_Static_Dispatch_Table_Aggregate (N) then
5526 return;
5527 end if;
5529 -- Ada 2005 (AI-318-2): We need to convert to assignments if components
5530 -- are build-in-place function calls. This test could be more specific,
5531 -- but doing it for all inherently limited aggregates seems harmless.
5532 -- The assignments will turn into build-in-place function calls (see
5533 -- Make_Build_In_Place_Call_In_Assignment).
5535 if Ada_Version >= Ada_05 and then Is_Inherently_Limited_Type (Typ) then
5536 Convert_To_Assignments (N, Typ);
5538 -- Gigi doesn't handle properly temporaries of variable size
5539 -- so we generate it in the front-end
5541 elsif not Size_Known_At_Compile_Time (Typ) then
5542 Convert_To_Assignments (N, Typ);
5544 -- Temporaries for controlled aggregates need to be attached to a
5545 -- final chain in order to be properly finalized, so it has to
5546 -- be created in the front-end
5548 elsif Is_Controlled (Typ)
5549 or else Has_Controlled_Component (Base_Type (Typ))
5550 then
5551 Convert_To_Assignments (N, Typ);
5553 -- Ada 2005 (AI-287): In case of default initialized components we
5554 -- convert the aggregate into assignments.
5556 elsif Has_Default_Init_Comps (N) then
5557 Convert_To_Assignments (N, Typ);
5559 -- Check components
5561 elsif Component_Not_OK_For_Backend then
5562 Convert_To_Assignments (N, Typ);
5564 -- If an ancestor is private, some components are not inherited and
5565 -- we cannot expand into a record aggregate
5567 elsif Has_Private_Ancestor (Typ) then
5568 Convert_To_Assignments (N, Typ);
5570 -- ??? The following was done to compile fxacc00.ads in the ACVCs. Gigi
5571 -- is not able to handle the aggregate for Late_Request.
5573 elsif Is_Tagged_Type (Typ) and then Has_Discriminants (Typ) then
5574 Convert_To_Assignments (N, Typ);
5576 -- If the tagged types covers interface types we need to initialize all
5577 -- hidden components containing pointers to secondary dispatch tables.
5579 elsif Is_Tagged_Type (Typ) and then Has_Interfaces (Typ) then
5580 Convert_To_Assignments (N, Typ);
5582 -- If some components are mutable, the size of the aggregate component
5583 -- may be distinct from the default size of the type component, so
5584 -- we need to expand to insure that the back-end copies the proper
5585 -- size of the data.
5587 elsif Has_Mutable_Components (Typ) then
5588 Convert_To_Assignments (N, Typ);
5590 -- If the type involved has any non-bit aligned components, then we are
5591 -- not sure that the back end can handle this case correctly.
5593 elsif Type_May_Have_Bit_Aligned_Components (Typ) then
5594 Convert_To_Assignments (N, Typ);
5596 -- In all other cases, build a proper aggregate handlable by gigi
5598 else
5599 if Nkind (N) = N_Aggregate then
5601 -- If the aggregate is static and can be handled by the back-end,
5602 -- nothing left to do.
5604 if Static_Components then
5605 Set_Compile_Time_Known_Aggregate (N);
5606 Set_Expansion_Delayed (N, False);
5607 end if;
5608 end if;
5610 -- If no discriminants, nothing special to do
5612 if not Has_Discriminants (Typ) then
5613 null;
5615 -- Case of discriminants present
5617 elsif Is_Derived_Type (Typ) then
5619 -- For untagged types, non-stored discriminants are replaced
5620 -- with stored discriminants, which are the ones that gigi uses
5621 -- to describe the type and its components.
5623 Generate_Aggregate_For_Derived_Type : declare
5624 Constraints : constant List_Id := New_List;
5625 First_Comp : Node_Id;
5626 Discriminant : Entity_Id;
5627 Decl : Node_Id;
5628 Num_Disc : Int := 0;
5629 Num_Gird : Int := 0;
5631 procedure Prepend_Stored_Values (T : Entity_Id);
5632 -- Scan the list of stored discriminants of the type, and add
5633 -- their values to the aggregate being built.
5635 ---------------------------
5636 -- Prepend_Stored_Values --
5637 ---------------------------
5639 procedure Prepend_Stored_Values (T : Entity_Id) is
5640 begin
5641 Discriminant := First_Stored_Discriminant (T);
5642 while Present (Discriminant) loop
5643 New_Comp :=
5644 Make_Component_Association (Loc,
5645 Choices =>
5646 New_List (New_Occurrence_Of (Discriminant, Loc)),
5648 Expression =>
5649 New_Copy_Tree (
5650 Get_Discriminant_Value (
5651 Discriminant,
5652 Typ,
5653 Discriminant_Constraint (Typ))));
5655 if No (First_Comp) then
5656 Prepend_To (Component_Associations (N), New_Comp);
5657 else
5658 Insert_After (First_Comp, New_Comp);
5659 end if;
5661 First_Comp := New_Comp;
5662 Next_Stored_Discriminant (Discriminant);
5663 end loop;
5664 end Prepend_Stored_Values;
5666 -- Start of processing for Generate_Aggregate_For_Derived_Type
5668 begin
5669 -- Remove the associations for the discriminant of derived type
5671 First_Comp := First (Component_Associations (N));
5672 while Present (First_Comp) loop
5673 Comp := First_Comp;
5674 Next (First_Comp);
5676 if Ekind (Entity
5677 (First (Choices (Comp)))) = E_Discriminant
5678 then
5679 Remove (Comp);
5680 Num_Disc := Num_Disc + 1;
5681 end if;
5682 end loop;
5684 -- Insert stored discriminant associations in the correct
5685 -- order. If there are more stored discriminants than new
5686 -- discriminants, there is at least one new discriminant that
5687 -- constrains more than one of the stored discriminants. In
5688 -- this case we need to construct a proper subtype of the
5689 -- parent type, in order to supply values to all the
5690 -- components. Otherwise there is one-one correspondence
5691 -- between the constraints and the stored discriminants.
5693 First_Comp := Empty;
5695 Discriminant := First_Stored_Discriminant (Base_Type (Typ));
5696 while Present (Discriminant) loop
5697 Num_Gird := Num_Gird + 1;
5698 Next_Stored_Discriminant (Discriminant);
5699 end loop;
5701 -- Case of more stored discriminants than new discriminants
5703 if Num_Gird > Num_Disc then
5705 -- Create a proper subtype of the parent type, which is the
5706 -- proper implementation type for the aggregate, and convert
5707 -- it to the intended target type.
5709 Discriminant := First_Stored_Discriminant (Base_Type (Typ));
5710 while Present (Discriminant) loop
5711 New_Comp :=
5712 New_Copy_Tree (
5713 Get_Discriminant_Value (
5714 Discriminant,
5715 Typ,
5716 Discriminant_Constraint (Typ)));
5717 Append (New_Comp, Constraints);
5718 Next_Stored_Discriminant (Discriminant);
5719 end loop;
5721 Decl :=
5722 Make_Subtype_Declaration (Loc,
5723 Defining_Identifier =>
5724 Make_Defining_Identifier (Loc,
5725 New_Internal_Name ('T')),
5726 Subtype_Indication =>
5727 Make_Subtype_Indication (Loc,
5728 Subtype_Mark =>
5729 New_Occurrence_Of (Etype (Base_Type (Typ)), Loc),
5730 Constraint =>
5731 Make_Index_Or_Discriminant_Constraint
5732 (Loc, Constraints)));
5734 Insert_Action (N, Decl);
5735 Prepend_Stored_Values (Base_Type (Typ));
5737 Set_Etype (N, Defining_Identifier (Decl));
5738 Set_Analyzed (N);
5740 Rewrite (N, Unchecked_Convert_To (Typ, N));
5741 Analyze (N);
5743 -- Case where we do not have fewer new discriminants than
5744 -- stored discriminants, so in this case we can simply use the
5745 -- stored discriminants of the subtype.
5747 else
5748 Prepend_Stored_Values (Typ);
5749 end if;
5750 end Generate_Aggregate_For_Derived_Type;
5751 end if;
5753 if Is_Tagged_Type (Typ) then
5755 -- The tagged case, _parent and _tag component must be created
5757 -- Reset null_present unconditionally. tagged records always have
5758 -- at least one field (the tag or the parent)
5760 Set_Null_Record_Present (N, False);
5762 -- When the current aggregate comes from the expansion of an
5763 -- extension aggregate, the parent expr is replaced by an
5764 -- aggregate formed by selected components of this expr
5766 if Present (Parent_Expr)
5767 and then Is_Empty_List (Comps)
5768 then
5769 Comp := First_Component_Or_Discriminant (Typ);
5770 while Present (Comp) loop
5772 -- Skip all expander-generated components
5775 not Comes_From_Source (Original_Record_Component (Comp))
5776 then
5777 null;
5779 else
5780 New_Comp :=
5781 Make_Selected_Component (Loc,
5782 Prefix =>
5783 Unchecked_Convert_To (Typ,
5784 Duplicate_Subexpr (Parent_Expr, True)),
5786 Selector_Name => New_Occurrence_Of (Comp, Loc));
5788 Append_To (Comps,
5789 Make_Component_Association (Loc,
5790 Choices =>
5791 New_List (New_Occurrence_Of (Comp, Loc)),
5792 Expression =>
5793 New_Comp));
5795 Analyze_And_Resolve (New_Comp, Etype (Comp));
5796 end if;
5798 Next_Component_Or_Discriminant (Comp);
5799 end loop;
5800 end if;
5802 -- Compute the value for the Tag now, if the type is a root it
5803 -- will be included in the aggregate right away, otherwise it will
5804 -- be propagated to the parent aggregate
5806 if Present (Orig_Tag) then
5807 Tag_Value := Orig_Tag;
5808 elsif not Tagged_Type_Expansion then
5809 Tag_Value := Empty;
5810 else
5811 Tag_Value :=
5812 New_Occurrence_Of
5813 (Node (First_Elmt (Access_Disp_Table (Typ))), Loc);
5814 end if;
5816 -- For a derived type, an aggregate for the parent is formed with
5817 -- all the inherited components.
5819 if Is_Derived_Type (Typ) then
5821 declare
5822 First_Comp : Node_Id;
5823 Parent_Comps : List_Id;
5824 Parent_Aggr : Node_Id;
5825 Parent_Name : Node_Id;
5827 begin
5828 -- Remove the inherited component association from the
5829 -- aggregate and store them in the parent aggregate
5831 First_Comp := First (Component_Associations (N));
5832 Parent_Comps := New_List;
5833 while Present (First_Comp)
5834 and then Scope (Original_Record_Component (
5835 Entity (First (Choices (First_Comp))))) /= Base_Typ
5836 loop
5837 Comp := First_Comp;
5838 Next (First_Comp);
5839 Remove (Comp);
5840 Append (Comp, Parent_Comps);
5841 end loop;
5843 Parent_Aggr := Make_Aggregate (Loc,
5844 Component_Associations => Parent_Comps);
5845 Set_Etype (Parent_Aggr, Etype (Base_Type (Typ)));
5847 -- Find the _parent component
5849 Comp := First_Component (Typ);
5850 while Chars (Comp) /= Name_uParent loop
5851 Comp := Next_Component (Comp);
5852 end loop;
5854 Parent_Name := New_Occurrence_Of (Comp, Loc);
5856 -- Insert the parent aggregate
5858 Prepend_To (Component_Associations (N),
5859 Make_Component_Association (Loc,
5860 Choices => New_List (Parent_Name),
5861 Expression => Parent_Aggr));
5863 -- Expand recursively the parent propagating the right Tag
5865 Expand_Record_Aggregate (
5866 Parent_Aggr, Tag_Value, Parent_Expr);
5867 end;
5869 -- For a root type, the tag component is added (unless compiling
5870 -- for the VMs, where tags are implicit).
5872 elsif Tagged_Type_Expansion then
5873 declare
5874 Tag_Name : constant Node_Id :=
5875 New_Occurrence_Of
5876 (First_Tag_Component (Typ), Loc);
5877 Typ_Tag : constant Entity_Id := RTE (RE_Tag);
5878 Conv_Node : constant Node_Id :=
5879 Unchecked_Convert_To (Typ_Tag, Tag_Value);
5881 begin
5882 Set_Etype (Conv_Node, Typ_Tag);
5883 Prepend_To (Component_Associations (N),
5884 Make_Component_Association (Loc,
5885 Choices => New_List (Tag_Name),
5886 Expression => Conv_Node));
5887 end;
5888 end if;
5889 end if;
5890 end if;
5892 end Expand_Record_Aggregate;
5894 ----------------------------
5895 -- Has_Default_Init_Comps --
5896 ----------------------------
5898 function Has_Default_Init_Comps (N : Node_Id) return Boolean is
5899 Comps : constant List_Id := Component_Associations (N);
5900 C : Node_Id;
5901 Expr : Node_Id;
5902 begin
5903 pragma Assert (Nkind_In (N, N_Aggregate, N_Extension_Aggregate));
5905 if No (Comps) then
5906 return False;
5907 end if;
5909 if Has_Self_Reference (N) then
5910 return True;
5911 end if;
5913 -- Check if any direct component has default initialized components
5915 C := First (Comps);
5916 while Present (C) loop
5917 if Box_Present (C) then
5918 return True;
5919 end if;
5921 Next (C);
5922 end loop;
5924 -- Recursive call in case of aggregate expression
5926 C := First (Comps);
5927 while Present (C) loop
5928 Expr := Expression (C);
5930 if Present (Expr)
5931 and then
5932 Nkind_In (Expr, N_Aggregate, N_Extension_Aggregate)
5933 and then Has_Default_Init_Comps (Expr)
5934 then
5935 return True;
5936 end if;
5938 Next (C);
5939 end loop;
5941 return False;
5942 end Has_Default_Init_Comps;
5944 --------------------------
5945 -- Is_Delayed_Aggregate --
5946 --------------------------
5948 function Is_Delayed_Aggregate (N : Node_Id) return Boolean is
5949 Node : Node_Id := N;
5950 Kind : Node_Kind := Nkind (Node);
5952 begin
5953 if Kind = N_Qualified_Expression then
5954 Node := Expression (Node);
5955 Kind := Nkind (Node);
5956 end if;
5958 if Kind /= N_Aggregate and then Kind /= N_Extension_Aggregate then
5959 return False;
5960 else
5961 return Expansion_Delayed (Node);
5962 end if;
5963 end Is_Delayed_Aggregate;
5965 ----------------------------------------
5966 -- Is_Static_Dispatch_Table_Aggregate --
5967 ----------------------------------------
5969 function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean is
5970 Typ : constant Entity_Id := Base_Type (Etype (N));
5972 begin
5973 return Static_Dispatch_Tables
5974 and then Tagged_Type_Expansion
5975 and then RTU_Loaded (Ada_Tags)
5977 -- Avoid circularity when rebuilding the compiler
5979 and then Cunit_Entity (Get_Source_Unit (N)) /= RTU_Entity (Ada_Tags)
5980 and then (Typ = RTE (RE_Dispatch_Table_Wrapper)
5981 or else
5982 Typ = RTE (RE_Address_Array)
5983 or else
5984 Typ = RTE (RE_Type_Specific_Data)
5985 or else
5986 Typ = RTE (RE_Tag_Table)
5987 or else
5988 (RTE_Available (RE_Interface_Data)
5989 and then Typ = RTE (RE_Interface_Data))
5990 or else
5991 (RTE_Available (RE_Interfaces_Array)
5992 and then Typ = RTE (RE_Interfaces_Array))
5993 or else
5994 (RTE_Available (RE_Interface_Data_Element)
5995 and then Typ = RTE (RE_Interface_Data_Element)));
5996 end Is_Static_Dispatch_Table_Aggregate;
5998 --------------------
5999 -- Late_Expansion --
6000 --------------------
6002 function Late_Expansion
6003 (N : Node_Id;
6004 Typ : Entity_Id;
6005 Target : Node_Id;
6006 Flist : Node_Id := Empty;
6007 Obj : Entity_Id := Empty) return List_Id
6009 begin
6010 if Is_Record_Type (Etype (N)) then
6011 return Build_Record_Aggr_Code (N, Typ, Target, Flist, Obj);
6013 else pragma Assert (Is_Array_Type (Etype (N)));
6014 return
6015 Build_Array_Aggr_Code
6016 (N => N,
6017 Ctype => Component_Type (Etype (N)),
6018 Index => First_Index (Typ),
6019 Into => Target,
6020 Scalar_Comp => Is_Scalar_Type (Component_Type (Typ)),
6021 Indices => No_List,
6022 Flist => Flist);
6023 end if;
6024 end Late_Expansion;
6026 ----------------------------------
6027 -- Make_OK_Assignment_Statement --
6028 ----------------------------------
6030 function Make_OK_Assignment_Statement
6031 (Sloc : Source_Ptr;
6032 Name : Node_Id;
6033 Expression : Node_Id) return Node_Id
6035 begin
6036 Set_Assignment_OK (Name);
6038 return Make_Assignment_Statement (Sloc, Name, Expression);
6039 end Make_OK_Assignment_Statement;
6041 -----------------------
6042 -- Number_Of_Choices --
6043 -----------------------
6045 function Number_Of_Choices (N : Node_Id) return Nat is
6046 Assoc : Node_Id;
6047 Choice : Node_Id;
6049 Nb_Choices : Nat := 0;
6051 begin
6052 if Present (Expressions (N)) then
6053 return 0;
6054 end if;
6056 Assoc := First (Component_Associations (N));
6057 while Present (Assoc) loop
6058 Choice := First (Choices (Assoc));
6059 while Present (Choice) loop
6060 if Nkind (Choice) /= N_Others_Choice then
6061 Nb_Choices := Nb_Choices + 1;
6062 end if;
6064 Next (Choice);
6065 end loop;
6067 Next (Assoc);
6068 end loop;
6070 return Nb_Choices;
6071 end Number_Of_Choices;
6073 ------------------------------------
6074 -- Packed_Array_Aggregate_Handled --
6075 ------------------------------------
6077 -- The current version of this procedure will handle at compile time
6078 -- any array aggregate that meets these conditions:
6080 -- One dimensional, bit packed
6081 -- Underlying packed type is modular type
6082 -- Bounds are within 32-bit Int range
6083 -- All bounds and values are static
6085 function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean is
6086 Loc : constant Source_Ptr := Sloc (N);
6087 Typ : constant Entity_Id := Etype (N);
6088 Ctyp : constant Entity_Id := Component_Type (Typ);
6090 Not_Handled : exception;
6091 -- Exception raised if this aggregate cannot be handled
6093 begin
6094 -- For now, handle only one dimensional bit packed arrays
6096 if not Is_Bit_Packed_Array (Typ)
6097 or else Number_Dimensions (Typ) > 1
6098 or else not Is_Modular_Integer_Type (Packed_Array_Type (Typ))
6099 then
6100 return False;
6101 end if;
6103 if not Is_Scalar_Type (Component_Type (Typ))
6104 and then Has_Non_Standard_Rep (Component_Type (Typ))
6105 then
6106 return False;
6107 end if;
6109 declare
6110 Csiz : constant Nat := UI_To_Int (Component_Size (Typ));
6112 Lo : Node_Id;
6113 Hi : Node_Id;
6114 -- Bounds of index type
6116 Lob : Uint;
6117 Hib : Uint;
6118 -- Values of bounds if compile time known
6120 function Get_Component_Val (N : Node_Id) return Uint;
6121 -- Given a expression value N of the component type Ctyp, returns a
6122 -- value of Csiz (component size) bits representing this value. If
6123 -- the value is non-static or any other reason exists why the value
6124 -- cannot be returned, then Not_Handled is raised.
6126 -----------------------
6127 -- Get_Component_Val --
6128 -----------------------
6130 function Get_Component_Val (N : Node_Id) return Uint is
6131 Val : Uint;
6133 begin
6134 -- We have to analyze the expression here before doing any further
6135 -- processing here. The analysis of such expressions is deferred
6136 -- till expansion to prevent some problems of premature analysis.
6138 Analyze_And_Resolve (N, Ctyp);
6140 -- Must have a compile time value. String literals have to be
6141 -- converted into temporaries as well, because they cannot easily
6142 -- be converted into their bit representation.
6144 if not Compile_Time_Known_Value (N)
6145 or else Nkind (N) = N_String_Literal
6146 then
6147 raise Not_Handled;
6148 end if;
6150 Val := Expr_Rep_Value (N);
6152 -- Adjust for bias, and strip proper number of bits
6154 if Has_Biased_Representation (Ctyp) then
6155 Val := Val - Expr_Value (Type_Low_Bound (Ctyp));
6156 end if;
6158 return Val mod Uint_2 ** Csiz;
6159 end Get_Component_Val;
6161 -- Here we know we have a one dimensional bit packed array
6163 begin
6164 Get_Index_Bounds (First_Index (Typ), Lo, Hi);
6166 -- Cannot do anything if bounds are dynamic
6168 if not Compile_Time_Known_Value (Lo)
6169 or else
6170 not Compile_Time_Known_Value (Hi)
6171 then
6172 return False;
6173 end if;
6175 -- Or are silly out of range of int bounds
6177 Lob := Expr_Value (Lo);
6178 Hib := Expr_Value (Hi);
6180 if not UI_Is_In_Int_Range (Lob)
6181 or else
6182 not UI_Is_In_Int_Range (Hib)
6183 then
6184 return False;
6185 end if;
6187 -- At this stage we have a suitable aggregate for handling at compile
6188 -- time (the only remaining checks are that the values of expressions
6189 -- in the aggregate are compile time known (check is performed by
6190 -- Get_Component_Val), and that any subtypes or ranges are statically
6191 -- known.
6193 -- If the aggregate is not fully positional at this stage, then
6194 -- convert it to positional form. Either this will fail, in which
6195 -- case we can do nothing, or it will succeed, in which case we have
6196 -- succeeded in handling the aggregate, or it will stay an aggregate,
6197 -- in which case we have failed to handle this case.
6199 if Present (Component_Associations (N)) then
6200 Convert_To_Positional
6201 (N, Max_Others_Replicate => 64, Handle_Bit_Packed => True);
6202 return Nkind (N) /= N_Aggregate;
6203 end if;
6205 -- Otherwise we are all positional, so convert to proper value
6207 declare
6208 Lov : constant Int := UI_To_Int (Lob);
6209 Hiv : constant Int := UI_To_Int (Hib);
6211 Len : constant Nat := Int'Max (0, Hiv - Lov + 1);
6212 -- The length of the array (number of elements)
6214 Aggregate_Val : Uint;
6215 -- Value of aggregate. The value is set in the low order bits of
6216 -- this value. For the little-endian case, the values are stored
6217 -- from low-order to high-order and for the big-endian case the
6218 -- values are stored from high-order to low-order. Note that gigi
6219 -- will take care of the conversions to left justify the value in
6220 -- the big endian case (because of left justified modular type
6221 -- processing), so we do not have to worry about that here.
6223 Lit : Node_Id;
6224 -- Integer literal for resulting constructed value
6226 Shift : Nat;
6227 -- Shift count from low order for next value
6229 Incr : Int;
6230 -- Shift increment for loop
6232 Expr : Node_Id;
6233 -- Next expression from positional parameters of aggregate
6235 begin
6236 -- For little endian, we fill up the low order bits of the target
6237 -- value. For big endian we fill up the high order bits of the
6238 -- target value (which is a left justified modular value).
6240 if Bytes_Big_Endian xor Debug_Flag_8 then
6241 Shift := Csiz * (Len - 1);
6242 Incr := -Csiz;
6243 else
6244 Shift := 0;
6245 Incr := +Csiz;
6246 end if;
6248 -- Loop to set the values
6250 if Len = 0 then
6251 Aggregate_Val := Uint_0;
6252 else
6253 Expr := First (Expressions (N));
6254 Aggregate_Val := Get_Component_Val (Expr) * Uint_2 ** Shift;
6256 for J in 2 .. Len loop
6257 Shift := Shift + Incr;
6258 Next (Expr);
6259 Aggregate_Val :=
6260 Aggregate_Val + Get_Component_Val (Expr) * Uint_2 ** Shift;
6261 end loop;
6262 end if;
6264 -- Now we can rewrite with the proper value
6266 Lit :=
6267 Make_Integer_Literal (Loc,
6268 Intval => Aggregate_Val);
6269 Set_Print_In_Hex (Lit);
6271 -- Construct the expression using this literal. Note that it is
6272 -- important to qualify the literal with its proper modular type
6273 -- since universal integer does not have the required range and
6274 -- also this is a left justified modular type, which is important
6275 -- in the big-endian case.
6277 Rewrite (N,
6278 Unchecked_Convert_To (Typ,
6279 Make_Qualified_Expression (Loc,
6280 Subtype_Mark =>
6281 New_Occurrence_Of (Packed_Array_Type (Typ), Loc),
6282 Expression => Lit)));
6284 Analyze_And_Resolve (N, Typ);
6285 return True;
6286 end;
6287 end;
6289 exception
6290 when Not_Handled =>
6291 return False;
6292 end Packed_Array_Aggregate_Handled;
6294 ----------------------------
6295 -- Has_Mutable_Components --
6296 ----------------------------
6298 function Has_Mutable_Components (Typ : Entity_Id) return Boolean is
6299 Comp : Entity_Id;
6301 begin
6302 Comp := First_Component (Typ);
6303 while Present (Comp) loop
6304 if Is_Record_Type (Etype (Comp))
6305 and then Has_Discriminants (Etype (Comp))
6306 and then not Is_Constrained (Etype (Comp))
6307 then
6308 return True;
6309 end if;
6311 Next_Component (Comp);
6312 end loop;
6314 return False;
6315 end Has_Mutable_Components;
6317 ------------------------------
6318 -- Initialize_Discriminants --
6319 ------------------------------
6321 procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id) is
6322 Loc : constant Source_Ptr := Sloc (N);
6323 Bas : constant Entity_Id := Base_Type (Typ);
6324 Par : constant Entity_Id := Etype (Bas);
6325 Decl : constant Node_Id := Parent (Par);
6326 Ref : Node_Id;
6328 begin
6329 if Is_Tagged_Type (Bas)
6330 and then Is_Derived_Type (Bas)
6331 and then Has_Discriminants (Par)
6332 and then Has_Discriminants (Bas)
6333 and then Number_Discriminants (Bas) /= Number_Discriminants (Par)
6334 and then Nkind (Decl) = N_Full_Type_Declaration
6335 and then Nkind (Type_Definition (Decl)) = N_Record_Definition
6336 and then Present
6337 (Variant_Part (Component_List (Type_Definition (Decl))))
6338 and then Nkind (N) /= N_Extension_Aggregate
6339 then
6341 -- Call init proc to set discriminants.
6342 -- There should eventually be a special procedure for this ???
6344 Ref := New_Reference_To (Defining_Identifier (N), Loc);
6345 Insert_Actions_After (N,
6346 Build_Initialization_Call (Sloc (N), Ref, Typ));
6347 end if;
6348 end Initialize_Discriminants;
6350 ----------------
6351 -- Must_Slide --
6352 ----------------
6354 function Must_Slide
6355 (Obj_Type : Entity_Id;
6356 Typ : Entity_Id) return Boolean
6358 L1, L2, H1, H2 : Node_Id;
6359 begin
6360 -- No sliding if the type of the object is not established yet, if it is
6361 -- an unconstrained type whose actual subtype comes from the aggregate,
6362 -- or if the two types are identical.
6364 if not Is_Array_Type (Obj_Type) then
6365 return False;
6367 elsif not Is_Constrained (Obj_Type) then
6368 return False;
6370 elsif Typ = Obj_Type then
6371 return False;
6373 else
6374 -- Sliding can only occur along the first dimension
6376 Get_Index_Bounds (First_Index (Typ), L1, H1);
6377 Get_Index_Bounds (First_Index (Obj_Type), L2, H2);
6379 if not Is_Static_Expression (L1)
6380 or else not Is_Static_Expression (L2)
6381 or else not Is_Static_Expression (H1)
6382 or else not Is_Static_Expression (H2)
6383 then
6384 return False;
6385 else
6386 return Expr_Value (L1) /= Expr_Value (L2)
6387 or else Expr_Value (H1) /= Expr_Value (H2);
6388 end if;
6389 end if;
6390 end Must_Slide;
6392 ---------------------------
6393 -- Safe_Slice_Assignment --
6394 ---------------------------
6396 function Safe_Slice_Assignment (N : Node_Id) return Boolean is
6397 Loc : constant Source_Ptr := Sloc (Parent (N));
6398 Pref : constant Node_Id := Prefix (Name (Parent (N)));
6399 Range_Node : constant Node_Id := Discrete_Range (Name (Parent (N)));
6400 Expr : Node_Id;
6401 L_J : Entity_Id;
6402 L_Iter : Node_Id;
6403 L_Body : Node_Id;
6404 Stat : Node_Id;
6406 begin
6407 -- Generate: for J in Range loop Pref (J) := Expr; end loop;
6409 if Comes_From_Source (N)
6410 and then No (Expressions (N))
6411 and then Nkind (First (Choices (First (Component_Associations (N)))))
6412 = N_Others_Choice
6413 then
6414 Expr :=
6415 Expression (First (Component_Associations (N)));
6416 L_J := Make_Defining_Identifier (Loc, New_Internal_Name ('J'));
6418 L_Iter :=
6419 Make_Iteration_Scheme (Loc,
6420 Loop_Parameter_Specification =>
6421 Make_Loop_Parameter_Specification
6422 (Loc,
6423 Defining_Identifier => L_J,
6424 Discrete_Subtype_Definition => Relocate_Node (Range_Node)));
6426 L_Body :=
6427 Make_Assignment_Statement (Loc,
6428 Name =>
6429 Make_Indexed_Component (Loc,
6430 Prefix => Relocate_Node (Pref),
6431 Expressions => New_List (New_Occurrence_Of (L_J, Loc))),
6432 Expression => Relocate_Node (Expr));
6434 -- Construct the final loop
6436 Stat :=
6437 Make_Implicit_Loop_Statement
6438 (Node => Parent (N),
6439 Identifier => Empty,
6440 Iteration_Scheme => L_Iter,
6441 Statements => New_List (L_Body));
6443 -- Set type of aggregate to be type of lhs in assignment,
6444 -- to suppress redundant length checks.
6446 Set_Etype (N, Etype (Name (Parent (N))));
6448 Rewrite (Parent (N), Stat);
6449 Analyze (Parent (N));
6450 return True;
6452 else
6453 return False;
6454 end if;
6455 end Safe_Slice_Assignment;
6457 ---------------------
6458 -- Sort_Case_Table --
6459 ---------------------
6461 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
6462 L : constant Int := Case_Table'First;
6463 U : constant Int := Case_Table'Last;
6464 K : Int;
6465 J : Int;
6466 T : Case_Bounds;
6468 begin
6469 K := L;
6470 while K /= U loop
6471 T := Case_Table (K + 1);
6473 J := K + 1;
6474 while J /= L
6475 and then Expr_Value (Case_Table (J - 1).Choice_Lo) >
6476 Expr_Value (T.Choice_Lo)
6477 loop
6478 Case_Table (J) := Case_Table (J - 1);
6479 J := J - 1;
6480 end loop;
6482 Case_Table (J) := T;
6483 K := K + 1;
6484 end loop;
6485 end Sort_Case_Table;
6487 ----------------------------
6488 -- Static_Array_Aggregate --
6489 ----------------------------
6491 function Static_Array_Aggregate (N : Node_Id) return Boolean is
6492 Bounds : constant Node_Id := Aggregate_Bounds (N);
6494 Typ : constant Entity_Id := Etype (N);
6495 Comp_Type : constant Entity_Id := Component_Type (Typ);
6496 Agg : Node_Id;
6497 Expr : Node_Id;
6498 Lo : Node_Id;
6499 Hi : Node_Id;
6501 begin
6502 if Is_Tagged_Type (Typ)
6503 or else Is_Controlled (Typ)
6504 or else Is_Packed (Typ)
6505 then
6506 return False;
6507 end if;
6509 if Present (Bounds)
6510 and then Nkind (Bounds) = N_Range
6511 and then Nkind (Low_Bound (Bounds)) = N_Integer_Literal
6512 and then Nkind (High_Bound (Bounds)) = N_Integer_Literal
6513 then
6514 Lo := Low_Bound (Bounds);
6515 Hi := High_Bound (Bounds);
6517 if No (Component_Associations (N)) then
6519 -- Verify that all components are static integers
6521 Expr := First (Expressions (N));
6522 while Present (Expr) loop
6523 if Nkind (Expr) /= N_Integer_Literal then
6524 return False;
6525 end if;
6527 Next (Expr);
6528 end loop;
6530 return True;
6532 else
6533 -- We allow only a single named association, either a static
6534 -- range or an others_clause, with a static expression.
6536 Expr := First (Component_Associations (N));
6538 if Present (Expressions (N)) then
6539 return False;
6541 elsif Present (Next (Expr)) then
6542 return False;
6544 elsif Present (Next (First (Choices (Expr)))) then
6545 return False;
6547 else
6548 -- The aggregate is static if all components are literals,
6549 -- or else all its components are static aggregates for the
6550 -- component type. We also limit the size of a static aggregate
6551 -- to prevent runaway static expressions.
6553 if Is_Array_Type (Comp_Type)
6554 or else Is_Record_Type (Comp_Type)
6555 then
6556 if Nkind (Expression (Expr)) /= N_Aggregate
6557 or else
6558 not Compile_Time_Known_Aggregate (Expression (Expr))
6559 then
6560 return False;
6561 end if;
6563 elsif Nkind (Expression (Expr)) /= N_Integer_Literal then
6564 return False;
6566 elsif not Aggr_Size_OK (N, Typ) then
6567 return False;
6568 end if;
6570 -- Create a positional aggregate with the right number of
6571 -- copies of the expression.
6573 Agg := Make_Aggregate (Sloc (N), New_List, No_List);
6575 for I in UI_To_Int (Intval (Lo)) .. UI_To_Int (Intval (Hi))
6576 loop
6577 Append_To
6578 (Expressions (Agg), New_Copy (Expression (Expr)));
6580 -- The copied expression must be analyzed and resolved.
6581 -- Besides setting the type, this ensures that static
6582 -- expressions are appropriately marked as such.
6584 Analyze_And_Resolve
6585 (Last (Expressions (Agg)), Component_Type (Typ));
6586 end loop;
6588 Set_Aggregate_Bounds (Agg, Bounds);
6589 Set_Etype (Agg, Typ);
6590 Set_Analyzed (Agg);
6591 Rewrite (N, Agg);
6592 Set_Compile_Time_Known_Aggregate (N);
6594 return True;
6595 end if;
6596 end if;
6598 else
6599 return False;
6600 end if;
6601 end Static_Array_Aggregate;
6603 end Exp_Aggr;