ada: Simplify "not Present" with "No"
[official-gcc.git] / gcc / ada / exp_aggr.adb
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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) 1992-2023, Free Software Foundation, Inc. --
10 -- --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
20 -- --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
23 -- --
24 ------------------------------------------------------------------------------
26 with Aspects; use Aspects;
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Debug; use Debug;
30 with Einfo; use Einfo;
31 with Einfo.Entities; use Einfo.Entities;
32 with Einfo.Utils; use Einfo.Utils;
33 with Elists; use Elists;
34 with Errout; use Errout;
35 with Expander; use Expander;
36 with Exp_Util; use Exp_Util;
37 with Exp_Ch3; use Exp_Ch3;
38 with Exp_Ch6; use Exp_Ch6;
39 with Exp_Ch7; use Exp_Ch7;
40 with Exp_Ch9; use Exp_Ch9;
41 with Exp_Disp; use Exp_Disp;
42 with Exp_Tss; use Exp_Tss;
43 with Freeze; use Freeze;
44 with Itypes; use Itypes;
45 with Lib; use Lib;
46 with Namet; use Namet;
47 with Nmake; use Nmake;
48 with Nlists; use Nlists;
49 with Opt; use Opt;
50 with Restrict; use Restrict;
51 with Rident; use Rident;
52 with Rtsfind; use Rtsfind;
53 with Ttypes; use Ttypes;
54 with Sem; use Sem;
55 with Sem_Aggr; use Sem_Aggr;
56 with Sem_Aux; use Sem_Aux;
57 with Sem_Case; use Sem_Case;
58 with Sem_Ch3; use Sem_Ch3;
59 with Sem_Ch8; use Sem_Ch8;
60 with Sem_Ch13; use Sem_Ch13;
61 with Sem_Eval; use Sem_Eval;
62 with Sem_Mech; use Sem_Mech;
63 with Sem_Res; use Sem_Res;
64 with Sem_Type; use Sem_Type;
65 with Sem_Util; use Sem_Util;
66 use Sem_Util.Storage_Model_Support;
67 with Sinfo; use Sinfo;
68 with Sinfo.Nodes; use Sinfo.Nodes;
69 with Sinfo.Utils; use Sinfo.Utils;
70 with Snames; use Snames;
71 with Stand; use Stand;
72 with Stringt; use Stringt;
73 with Tbuild; use Tbuild;
74 with Uintp; use Uintp;
75 with Urealp; use Urealp;
76 with Warnsw; use Warnsw;
78 package body Exp_Aggr is
80 function Build_Assignment_With_Temporary
81 (Target : Node_Id;
82 Typ : Entity_Id;
83 Source : Node_Id) return List_Id;
84 -- Returns a list of actions to assign Source to Target of type Typ using
85 -- an extra temporary, which can potentially be large.
87 type Case_Bounds is record
88 Choice_Lo : Node_Id;
89 Choice_Hi : Node_Id;
90 Choice_Node : Node_Id;
91 end record;
93 type Case_Table_Type is array (Nat range <>) of Case_Bounds;
94 -- Table type used by Check_Case_Choices procedure
96 procedure Expand_Delta_Array_Aggregate (N : Node_Id; Deltas : List_Id);
97 procedure Expand_Delta_Record_Aggregate (N : Node_Id; Deltas : List_Id);
98 procedure Expand_Container_Aggregate (N : Node_Id);
100 function Get_Base_Object (N : Node_Id) return Entity_Id;
101 -- Return the base object, i.e. the outermost prefix object, that N refers
102 -- to statically, or Empty if it cannot be determined. The assumption is
103 -- that all dereferences are explicit in the tree rooted at N.
105 function Has_Default_Init_Comps (N : Node_Id) return Boolean;
106 -- N is an aggregate (record or array). Checks the presence of default
107 -- initialization (<>) in any component (Ada 2005: AI-287).
109 procedure Initialize_Component
110 (N : Node_Id;
111 Comp : Node_Id;
112 Comp_Typ : Node_Id;
113 Init_Expr : Node_Id;
114 Stmts : List_Id);
115 -- Perform the initialization of component Comp with expected type
116 -- Comp_Typ of aggregate N. Init_Expr denotes the initialization
117 -- expression of the component. All generated code is added to Stmts.
119 function Is_CCG_Supported_Aggregate (N : Node_Id) return Boolean;
120 -- Return True if aggregate N is located in a context supported by the
121 -- CCG backend; False otherwise.
123 function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean;
124 -- Returns true if N is an aggregate used to initialize the components
125 -- of a statically allocated dispatch table.
127 function Late_Expansion
128 (N : Node_Id;
129 Typ : Entity_Id;
130 Target : Node_Id) return List_Id;
131 -- This routine implements top-down expansion of nested aggregates. In
132 -- doing so, it avoids the generation of temporaries at each level. N is
133 -- a nested record or array aggregate with the Expansion_Delayed flag.
134 -- Typ is the expected type of the aggregate. Target is a (duplicatable)
135 -- expression that will hold the result of the aggregate expansion.
137 function Make_OK_Assignment_Statement
138 (Sloc : Source_Ptr;
139 Name : Node_Id;
140 Expression : Node_Id) return Node_Id;
141 -- This is like Make_Assignment_Statement, except that Assignment_OK
142 -- is set in the left operand. All assignments built by this unit use
143 -- this routine. This is needed to deal with assignments to initialized
144 -- constants that are done in place.
146 function Must_Slide
147 (Aggr : Node_Id;
148 Obj_Type : Entity_Id;
149 Typ : Entity_Id) return Boolean;
150 -- A static array aggregate in an object declaration can in most cases be
151 -- expanded in place. The one exception is when the aggregate is given
152 -- with component associations that specify different bounds from those of
153 -- the type definition in the object declaration. In this pathological
154 -- case the aggregate must slide, and we must introduce an intermediate
155 -- temporary to hold it.
157 -- The same holds in an assignment to one-dimensional array of arrays,
158 -- when a component may be given with bounds that differ from those of the
159 -- component type.
161 function Number_Of_Choices (N : Node_Id) return Nat;
162 -- Returns the number of discrete choices (not including the others choice
163 -- if present) contained in (sub-)aggregate N.
165 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
166 -- Sort the Case Table using the Lower Bound of each Choice as the key.
167 -- A simple insertion sort is used since the number of choices in a case
168 -- statement of variant part will usually be small and probably in near
169 -- sorted order.
171 ------------------------------------------------------
172 -- Local subprograms for Record Aggregate Expansion --
173 ------------------------------------------------------
175 function Is_Build_In_Place_Aggregate_Return (N : Node_Id) return Boolean;
176 -- True if N is an aggregate (possibly qualified or a dependent expression
177 -- of a conditional expression, and possibly recursively so) that is being
178 -- returned from a build-in-place function. Such qualified and conditional
179 -- expressions are transparent for this purpose because an enclosing return
180 -- is propagated resp. distributed into these expressions by the expander.
182 function Build_Record_Aggr_Code
183 (N : Node_Id;
184 Typ : Entity_Id;
185 Lhs : Node_Id) return List_Id;
186 -- N is an N_Aggregate or an N_Extension_Aggregate. Typ is the type of the
187 -- aggregate. Target is an expression containing the location on which the
188 -- component by component assignments will take place. Returns the list of
189 -- assignments plus all other adjustments needed for tagged and controlled
190 -- types.
192 procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id);
193 -- Transform a record aggregate into a sequence of assignments performed
194 -- component by component. N is an N_Aggregate or N_Extension_Aggregate.
195 -- Typ is the type of the record aggregate.
197 procedure Expand_Record_Aggregate
198 (N : Node_Id;
199 Orig_Tag : Node_Id := Empty;
200 Parent_Expr : Node_Id := Empty);
201 -- This is the top level procedure for record aggregate expansion.
202 -- Expansion for record aggregates needs expand aggregates for tagged
203 -- record types. Specifically Expand_Record_Aggregate adds the Tag
204 -- field in front of the Component_Association list that was created
205 -- during resolution by Resolve_Record_Aggregate.
207 -- N is the record aggregate node.
208 -- Orig_Tag is the value of the Tag that has to be provided for this
209 -- specific aggregate. It carries the tag corresponding to the type
210 -- of the outermost aggregate during the recursive expansion
211 -- Parent_Expr is the ancestor part of the original extension
212 -- aggregate
214 function Has_Mutable_Components (Typ : Entity_Id) return Boolean;
215 -- Return true if one of the components is of a discriminated type with
216 -- defaults. An aggregate for a type with mutable components must be
217 -- expanded into individual assignments.
219 function In_Place_Assign_OK
220 (N : Node_Id;
221 Target_Object : Entity_Id := Empty) return Boolean;
222 -- Predicate to determine whether an aggregate assignment can be done in
223 -- place, because none of the new values can depend on the components of
224 -- the target of the assignment.
226 procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id);
227 -- If the type of the aggregate is a type extension with renamed discrimi-
228 -- nants, we must initialize the hidden discriminants of the parent.
229 -- Otherwise, the target object must not be initialized. The discriminants
230 -- are initialized by calling the initialization procedure for the type.
231 -- This is incorrect if the initialization of other components has any
232 -- side effects. We restrict this call to the case where the parent type
233 -- has a variant part, because this is the only case where the hidden
234 -- discriminants are accessed, namely when calling discriminant checking
235 -- functions of the parent type, and when applying a stream attribute to
236 -- an object of the derived type.
238 -----------------------------------------------------
239 -- Local Subprograms for Array Aggregate Expansion --
240 -----------------------------------------------------
242 function Aggr_Assignment_OK_For_Backend (N : Node_Id) return Boolean;
243 -- Returns true if an aggregate assignment can be done by the back end
245 function Aggr_Size_OK (N : Node_Id) return Boolean;
246 -- Very large static aggregates present problems to the back-end, and are
247 -- transformed into assignments and loops. This function verifies that the
248 -- total number of components of an aggregate is acceptable for rewriting
249 -- into a purely positional static form. Aggr_Size_OK must be called before
250 -- calling Flatten.
252 -- This function also detects and warns about one-component aggregates that
253 -- appear in a nonstatic context. Even if the component value is static,
254 -- such an aggregate must be expanded into an assignment.
256 function Backend_Processing_Possible (N : Node_Id) return Boolean;
257 -- This function checks if array aggregate N can be processed directly
258 -- by the backend. If this is the case, True is returned.
260 function Build_Array_Aggr_Code
261 (N : Node_Id;
262 Ctype : Entity_Id;
263 Index : Node_Id;
264 Into : Node_Id;
265 Scalar_Comp : Boolean;
266 Indexes : List_Id := No_List) return List_Id;
267 -- This recursive routine returns a list of statements containing the
268 -- loops and assignments that are needed for the expansion of the array
269 -- aggregate N.
271 -- N is the (sub-)aggregate node to be expanded into code. This node has
272 -- been fully analyzed, and its Etype is properly set.
274 -- Index is the index node corresponding to the array subaggregate N
276 -- Into is the target expression into which we are copying the aggregate.
277 -- Note that this node may not have been analyzed yet, and so the Etype
278 -- field may not be set.
280 -- Scalar_Comp is True if the component type of the aggregate is scalar
282 -- Indexes is the current list of expressions used to index the object we
283 -- are writing into.
285 procedure Convert_Array_Aggr_In_Allocator
286 (Decl : Node_Id;
287 Aggr : Node_Id;
288 Target : Node_Id);
289 -- If the aggregate appears within an allocator and can be expanded in
290 -- place, this routine generates the individual assignments to components
291 -- of the designated object. This is an optimization over the general
292 -- case, where a temporary is first created on the stack and then used to
293 -- construct the allocated object on the heap.
295 procedure Convert_To_Positional
296 (N : Node_Id;
297 Handle_Bit_Packed : Boolean := False);
298 -- If possible, convert named notation to positional notation. This
299 -- conversion is possible only in some static cases. If the conversion is
300 -- possible, then N is rewritten with the analyzed converted aggregate.
301 -- The parameter Handle_Bit_Packed is usually set False (since we do
302 -- not expect the back end to handle bit packed arrays, so the normal case
303 -- of conversion is pointless), but in the special case of a call from
304 -- Packed_Array_Aggregate_Handled, we set this parameter to True, since
305 -- these are cases we handle in there.
307 procedure Expand_Array_Aggregate (N : Node_Id);
308 -- This is the top-level routine to perform array aggregate expansion.
309 -- N is the N_Aggregate node to be expanded.
311 function Is_Two_Dim_Packed_Array (Typ : Entity_Id) return Boolean;
312 -- For 2D packed array aggregates with constant bounds and constant scalar
313 -- components, it is preferable to pack the inner aggregates because the
314 -- whole matrix can then be presented to the back-end as a one-dimensional
315 -- list of literals. This is much more efficient than expanding into single
316 -- component assignments. This function determines if the type Typ is for
317 -- an array that is suitable for this optimization: it returns True if Typ
318 -- is a two dimensional bit packed array with component size 1, 2, or 4.
320 function Max_Aggregate_Size
321 (N : Node_Id;
322 Default_Size : Nat := 5000) return Nat;
323 -- Return the max size for a static aggregate N. Return Default_Size if no
324 -- other special criteria trigger.
326 function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean;
327 -- Given an array aggregate, this function handles the case of a packed
328 -- array aggregate with all constant values, where the aggregate can be
329 -- evaluated at compile time. If this is possible, then N is rewritten
330 -- to be its proper compile time value with all the components properly
331 -- assembled. The expression is analyzed and resolved and True is returned.
332 -- If this transformation is not possible, N is unchanged and False is
333 -- returned.
335 function Two_Dim_Packed_Array_Handled (N : Node_Id) return Boolean;
336 -- If the type of the aggregate is a two-dimensional bit_packed array
337 -- it may be transformed into an array of bytes with constant values,
338 -- and presented to the back-end as a static value. The function returns
339 -- false if this transformation cannot be performed. THis is similar to,
340 -- and reuses part of the machinery in Packed_Array_Aggregate_Handled.
342 ------------------------------------
343 -- Aggr_Assignment_OK_For_Backend --
344 ------------------------------------
346 -- Back-end processing by Gigi/gcc is possible only if all the following
347 -- conditions are met:
349 -- 1. N consists of a single OTHERS choice, possibly recursively, or
350 -- of a single choice, possibly recursively, if it is surrounded by
351 -- a qualified expression whose subtype mark is unconstrained.
353 -- 2. The array type has no null ranges (the purpose of this is to
354 -- avoid a bogus warning for an out-of-range value).
356 -- 3. The array type has no atomic components
358 -- 4. The component type is elementary
360 -- 5. The component size is a multiple of Storage_Unit
362 -- 6. The component size is Storage_Unit or the value is of the form
363 -- M * (1 + A**1 + A**2 + .. A**(K-1)) where A = 2**(Storage_Unit)
364 -- and M in 0 .. A-1. This can also be viewed as K occurrences of
365 -- the Storage_Unit value M, concatenated together.
367 -- The ultimate goal is to generate a call to a fast memset routine
368 -- specifically optimized for the target.
370 function Aggr_Assignment_OK_For_Backend (N : Node_Id) return Boolean is
372 function Is_OK_Aggregate (Aggr : Node_Id) return Boolean;
373 -- Return true if Aggr is suitable for back-end assignment
375 ---------------------
376 -- Is_OK_Aggregate --
377 ---------------------
379 function Is_OK_Aggregate (Aggr : Node_Id) return Boolean is
380 Assoc : constant List_Id := Component_Associations (Aggr);
382 begin
383 -- An "others" aggregate is most likely OK, but see below
385 if Is_Others_Aggregate (Aggr) then
386 null;
388 -- An aggregate with a single choice requires a qualified expression
389 -- whose subtype mark is an unconstrained type because we need it to
390 -- have the semantics of an "others" aggregate.
392 elsif Nkind (Parent (N)) = N_Qualified_Expression
393 and then not Is_Constrained (Entity (Subtype_Mark (Parent (N))))
394 and then Is_Single_Aggregate (Aggr)
395 then
396 null;
398 -- The other cases are not OK
400 else
401 return False;
402 end if;
404 -- In any case we do not support an iterated association
406 return Nkind (First (Assoc)) /= N_Iterated_Component_Association;
407 end Is_OK_Aggregate;
409 Bounds : Range_Nodes;
410 Csiz : Uint := No_Uint;
411 Ctyp : Entity_Id;
412 Expr : Node_Id;
413 Index : Entity_Id;
414 Nunits : Int;
415 Remainder : Uint;
416 Value : Uint;
418 -- Start of processing for Aggr_Assignment_OK_For_Backend
420 begin
421 -- Back end doesn't know about <>
423 if Has_Default_Init_Comps (N) then
424 return False;
425 end if;
427 -- Recurse as far as possible to find the innermost component type
429 Ctyp := Etype (N);
430 Expr := N;
431 while Is_Array_Type (Ctyp) loop
432 if Nkind (Expr) /= N_Aggregate
433 or else not Is_OK_Aggregate (Expr)
434 then
435 return False;
436 end if;
438 Index := First_Index (Ctyp);
439 while Present (Index) loop
440 Bounds := Get_Index_Bounds (Index);
442 if Is_Null_Range (Bounds.First, Bounds.Last) then
443 return False;
444 end if;
446 Next_Index (Index);
447 end loop;
449 Expr := Expression (First (Component_Associations (Expr)));
451 for J in 1 .. Number_Dimensions (Ctyp) - 1 loop
452 if Nkind (Expr) /= N_Aggregate
453 or else not Is_OK_Aggregate (Expr)
454 then
455 return False;
456 end if;
458 Expr := Expression (First (Component_Associations (Expr)));
459 end loop;
461 if Has_Atomic_Components (Ctyp) then
462 return False;
463 end if;
465 Csiz := Component_Size (Ctyp);
466 Ctyp := Component_Type (Ctyp);
468 if Is_Full_Access (Ctyp) then
469 return False;
470 end if;
471 end loop;
473 -- Access types need to be dealt with specially
475 if Is_Access_Type (Ctyp) then
477 -- Component_Size is not set by Layout_Type if the component
478 -- type is an access type ???
480 Csiz := Esize (Ctyp);
482 -- Fat pointers are rejected as they are not really elementary
483 -- for the backend.
485 if No (Csiz) or else Csiz /= System_Address_Size then
486 return False;
487 end if;
489 -- The supported expressions are NULL and constants, others are
490 -- rejected upfront to avoid being analyzed below, which can be
491 -- problematic for some of them, for example allocators.
493 if Nkind (Expr) /= N_Null and then not Is_Entity_Name (Expr) then
494 return False;
495 end if;
497 -- Scalar types are OK if their size is a multiple of Storage_Unit
499 elsif Is_Scalar_Type (Ctyp) and then Present (Csiz) then
501 if Csiz mod System_Storage_Unit /= 0 then
502 return False;
503 end if;
505 -- Composite types are rejected
507 else
508 return False;
509 end if;
511 -- If the expression has side effects (e.g. contains calls with
512 -- potential side effects) reject as well. We only preanalyze the
513 -- expression to prevent the removal of intended side effects.
515 Preanalyze_And_Resolve (Expr, Ctyp);
517 if not Side_Effect_Free (Expr) then
518 return False;
519 end if;
521 -- The expression needs to be analyzed if True is returned
523 Analyze_And_Resolve (Expr, Ctyp);
525 -- Strip away any conversions from the expression as they simply
526 -- qualify the real expression.
528 while Nkind (Expr) in N_Unchecked_Type_Conversion | N_Type_Conversion
529 loop
530 Expr := Expression (Expr);
531 end loop;
533 Nunits := UI_To_Int (Csiz) / System_Storage_Unit;
535 if Nunits = 1 then
536 return True;
537 end if;
539 if not Compile_Time_Known_Value (Expr) then
540 return False;
541 end if;
543 -- The only supported value for floating point is 0.0
545 if Is_Floating_Point_Type (Ctyp) then
546 return Expr_Value_R (Expr) = Ureal_0;
547 end if;
549 -- For other types, we can look into the value as an integer, which
550 -- means the representation value for enumeration literals.
552 Value := Expr_Rep_Value (Expr);
554 if Has_Biased_Representation (Ctyp) then
555 Value := Value - Expr_Value (Type_Low_Bound (Ctyp));
556 end if;
558 -- Values 0 and -1 immediately satisfy the last check
560 if Value = Uint_0 or else Value = Uint_Minus_1 then
561 return True;
562 end if;
564 -- We need to work with an unsigned value
566 if Value < 0 then
567 Value := Value + 2**(System_Storage_Unit * Nunits);
568 end if;
570 Remainder := Value rem 2**System_Storage_Unit;
572 for J in 1 .. Nunits - 1 loop
573 Value := Value / 2**System_Storage_Unit;
575 if Value rem 2**System_Storage_Unit /= Remainder then
576 return False;
577 end if;
578 end loop;
580 return True;
581 end Aggr_Assignment_OK_For_Backend;
583 ------------------
584 -- Aggr_Size_OK --
585 ------------------
587 function Aggr_Size_OK (N : Node_Id) return Boolean is
588 Typ : constant Entity_Id := Etype (N);
589 Lo : Node_Id;
590 Hi : Node_Id;
591 Indx : Node_Id;
592 Size : Uint;
593 Lov : Uint;
594 Hiv : Uint;
596 Max_Aggr_Size : Nat;
597 -- Determines the maximum size of an array aggregate produced by
598 -- converting named to positional notation (e.g. from others clauses).
599 -- This avoids running away with attempts to convert huge aggregates,
600 -- which hit memory limits in the backend.
602 function Component_Count (T : Entity_Id) return Nat;
603 -- The limit is applied to the total number of subcomponents that the
604 -- aggregate will have, which is the number of static expressions
605 -- that will appear in the flattened array. This requires a recursive
606 -- computation of the number of scalar components of the structure.
608 ---------------------
609 -- Component_Count --
610 ---------------------
612 function Component_Count (T : Entity_Id) return Nat is
613 Res : Nat := 0;
614 Comp : Entity_Id;
616 begin
617 if Is_Scalar_Type (T) then
618 return 1;
620 elsif Is_Record_Type (T) then
621 Comp := First_Component (T);
622 while Present (Comp) loop
623 Res := Res + Component_Count (Etype (Comp));
624 Next_Component (Comp);
625 end loop;
627 return Res;
629 elsif Is_Array_Type (T) then
630 declare
631 Lo : constant Node_Id :=
632 Type_Low_Bound (Etype (First_Index (T)));
633 Hi : constant Node_Id :=
634 Type_High_Bound (Etype (First_Index (T)));
636 Siz : constant Nat := Component_Count (Component_Type (T));
638 begin
639 -- Check for superflat arrays, i.e. arrays with such bounds
640 -- as 4 .. 2, to insure that this function never returns a
641 -- meaningless negative value.
643 if not Compile_Time_Known_Value (Lo)
644 or else not Compile_Time_Known_Value (Hi)
645 or else Expr_Value (Hi) < Expr_Value (Lo)
646 then
647 return 0;
649 else
650 -- If the number of components is greater than Int'Last,
651 -- then return Int'Last, so caller will return False (Aggr
652 -- size is not OK). Otherwise, UI_To_Int will crash.
654 declare
655 UI : constant Uint :=
656 (Expr_Value (Hi) - Expr_Value (Lo) + 1) * Siz;
657 begin
658 if UI_Is_In_Int_Range (UI) then
659 return UI_To_Int (UI);
660 else
661 return Int'Last;
662 end if;
663 end;
664 end if;
665 end;
667 else
668 -- Can only be a null for an access type
670 return 1;
671 end if;
672 end Component_Count;
674 -- Start of processing for Aggr_Size_OK
676 begin
677 -- We bump the maximum size unless the aggregate has a single component
678 -- association, which will be more efficient if implemented with a loop.
679 -- The -gnatd_g switch disables this bumping.
681 if (No (Expressions (N))
682 and then No (Next (First (Component_Associations (N)))))
683 or else Debug_Flag_Underscore_G
684 then
685 Max_Aggr_Size := Max_Aggregate_Size (N);
686 else
687 Max_Aggr_Size := Max_Aggregate_Size (N, 500_000);
688 end if;
690 Size := UI_From_Int (Component_Count (Component_Type (Typ)));
692 Indx := First_Index (Typ);
693 while Present (Indx) loop
694 Lo := Type_Low_Bound (Etype (Indx));
695 Hi := Type_High_Bound (Etype (Indx));
697 -- Bounds need to be known at compile time
699 if not Compile_Time_Known_Value (Lo)
700 or else not Compile_Time_Known_Value (Hi)
701 then
702 return False;
703 end if;
705 Lov := Expr_Value (Lo);
706 Hiv := Expr_Value (Hi);
708 -- A flat array is always safe
710 if Hiv < Lov then
711 return True;
712 end if;
714 -- One-component aggregates are suspicious, and if the context type
715 -- is an object declaration with nonstatic bounds it will trip gcc;
716 -- such an aggregate must be expanded into a single assignment.
718 if Hiv = Lov and then Nkind (Parent (N)) = N_Object_Declaration then
719 declare
720 Index_Type : constant Entity_Id :=
721 Etype
722 (First_Index (Etype (Defining_Identifier (Parent (N)))));
723 Indx : Node_Id;
725 begin
726 if not Compile_Time_Known_Value (Type_Low_Bound (Index_Type))
727 or else not Compile_Time_Known_Value
728 (Type_High_Bound (Index_Type))
729 then
730 if Present (Component_Associations (N)) then
731 Indx :=
732 First
733 (Choice_List (First (Component_Associations (N))));
735 if Is_Entity_Name (Indx)
736 and then not Is_Type (Entity (Indx))
737 then
738 Error_Msg_N
739 ("single component aggregate in "
740 & "non-static context??", Indx);
741 Error_Msg_N ("\maybe subtype name was meant??", Indx);
742 end if;
743 end if;
745 return False;
746 end if;
747 end;
748 end if;
750 declare
751 Rng : constant Uint := Hiv - Lov + 1;
753 begin
754 -- Check if size is too large
756 if not UI_Is_In_Int_Range (Rng) then
757 return False;
758 end if;
760 -- Compute the size using universal arithmetic to avoid the
761 -- possibility of overflow on very large aggregates.
763 Size := Size * Rng;
765 if Size <= 0
766 or else Size > Max_Aggr_Size
767 then
768 return False;
769 end if;
770 end;
772 -- Bounds must be in integer range, for later array construction
774 if not UI_Is_In_Int_Range (Lov)
775 or else
776 not UI_Is_In_Int_Range (Hiv)
777 then
778 return False;
779 end if;
781 Next_Index (Indx);
782 end loop;
784 return True;
785 end Aggr_Size_OK;
787 ---------------------------------
788 -- Backend_Processing_Possible --
789 ---------------------------------
791 -- Backend processing by Gigi/gcc is possible only if all the following
792 -- conditions are met:
794 -- 1. N is fully positional
796 -- 2. N is not a bit-packed array aggregate;
798 -- 3. The size of N's array type must be known at compile time. Note
799 -- that this implies that the component size is also known
801 -- 4. The array type of N does not follow the Fortran layout convention
802 -- or if it does it must be 1 dimensional.
804 -- 5. The array component type may not be tagged (which could necessitate
805 -- reassignment of proper tags).
807 -- 6. The array component type must not have unaligned bit components
809 -- 7. None of the components of the aggregate may be bit unaligned
810 -- components.
812 -- 8. There cannot be delayed components, since we do not know enough
813 -- at this stage to know if back end processing is possible.
815 -- 9. There cannot be any discriminated record components, since the
816 -- back end cannot handle this complex case.
818 -- 10. No controlled actions need to be generated for components
820 -- 11. When generating C code, N must be part of a N_Object_Declaration
822 -- 12. When generating C code, N must not include function calls
824 function Backend_Processing_Possible (N : Node_Id) return Boolean is
825 Typ : constant Entity_Id := Etype (N);
826 -- Typ is the correct constrained array subtype of the aggregate
828 function Component_Check (N : Node_Id; Index : Node_Id) return Boolean;
829 -- This routine checks components of aggregate N, enforcing checks
830 -- 1, 7, 8, 9, 11, and 12. In the multidimensional case, these checks
831 -- are performed on subaggregates. The Index value is the current index
832 -- being checked in the multidimensional case.
834 ---------------------
835 -- Component_Check --
836 ---------------------
838 function Component_Check (N : Node_Id; Index : Node_Id) return Boolean is
839 function Ultimate_Original_Expression (N : Node_Id) return Node_Id;
840 -- Given a type conversion or an unchecked type conversion N, return
841 -- its innermost original expression.
843 ----------------------------------
844 -- Ultimate_Original_Expression --
845 ----------------------------------
847 function Ultimate_Original_Expression (N : Node_Id) return Node_Id is
848 Expr : Node_Id := Original_Node (N);
850 begin
851 while Nkind (Expr) in
852 N_Type_Conversion | N_Unchecked_Type_Conversion
853 loop
854 Expr := Original_Node (Expression (Expr));
855 end loop;
857 return Expr;
858 end Ultimate_Original_Expression;
860 -- Local variables
862 Expr : Node_Id;
864 -- Start of processing for Component_Check
866 begin
867 -- Checks 1: (no component associations)
869 if Present (Component_Associations (N)) then
870 return False;
871 end if;
873 -- Checks 11: The C code generator cannot handle aggregates that are
874 -- not part of an object declaration.
876 if Modify_Tree_For_C and then not Is_CCG_Supported_Aggregate (N) then
877 return False;
878 end if;
880 -- Checks on components
882 -- Recurse to check subaggregates, which may appear in qualified
883 -- expressions. If delayed, the front-end will have to expand.
884 -- If the component is a discriminated record, treat as nonstatic,
885 -- as the back-end cannot handle this properly.
887 Expr := First (Expressions (N));
888 while Present (Expr) loop
890 -- Checks 8: (no delayed components)
892 if Is_Delayed_Aggregate (Expr) then
893 return False;
894 end if;
896 -- Checks 9: (no discriminated records)
898 if Present (Etype (Expr))
899 and then Is_Record_Type (Etype (Expr))
900 and then Has_Discriminants (Etype (Expr))
901 then
902 return False;
903 end if;
905 -- Checks 7. Component must not be bit aligned component
907 if Possible_Bit_Aligned_Component (Expr) then
908 return False;
909 end if;
911 -- Checks 12: (no function call)
913 if Modify_Tree_For_C
914 and then
915 Nkind (Ultimate_Original_Expression (Expr)) = N_Function_Call
916 then
917 return False;
918 end if;
920 -- Recursion to following indexes for multiple dimension case
922 if Present (Next_Index (Index))
923 and then not Component_Check (Expr, Next_Index (Index))
924 then
925 return False;
926 end if;
928 -- All checks for that component finished, on to next
930 Next (Expr);
931 end loop;
933 return True;
934 end Component_Check;
936 -- Start of processing for Backend_Processing_Possible
938 begin
939 -- Checks 2 (array not bit packed) and 10 (no controlled actions)
941 if Is_Bit_Packed_Array (Typ) or else Needs_Finalization (Typ) then
942 return False;
943 end if;
945 -- If component is limited, aggregate must be expanded because each
946 -- component assignment must be built in place.
948 if Is_Limited_View (Component_Type (Typ)) then
949 return False;
950 end if;
952 -- Checks 4 (array must not be multidimensional Fortran case)
954 if Convention (Typ) = Convention_Fortran
955 and then Number_Dimensions (Typ) > 1
956 then
957 return False;
958 end if;
960 -- Checks 3 (size of array must be known at compile time)
962 if not Size_Known_At_Compile_Time (Typ) then
963 return False;
964 end if;
966 -- Checks on components
968 if not Component_Check (N, First_Index (Typ)) then
969 return False;
970 end if;
972 -- Checks 5 (if the component type is tagged, then we may need to do
973 -- tag adjustments. Perhaps this should be refined to check for any
974 -- component associations that actually need tag adjustment, similar
975 -- to the test in Component_OK_For_Backend for record aggregates with
976 -- tagged components, but not clear whether it's worthwhile ???; in the
977 -- case of virtual machines (no Tagged_Type_Expansion), object tags are
978 -- handled implicitly).
980 if Is_Tagged_Type (Component_Type (Typ))
981 and then Tagged_Type_Expansion
982 then
983 return False;
984 end if;
986 -- Checks 6 (component type must not have bit aligned components)
988 if Type_May_Have_Bit_Aligned_Components (Component_Type (Typ)) then
989 return False;
990 end if;
992 -- Backend processing is possible
994 return True;
995 end Backend_Processing_Possible;
997 ---------------------------
998 -- Build_Array_Aggr_Code --
999 ---------------------------
1001 -- The code that we generate from a one dimensional aggregate is
1003 -- 1. If the subaggregate contains discrete choices we
1005 -- (a) Sort the discrete choices
1007 -- (b) Otherwise for each discrete choice that specifies a range we
1008 -- emit a loop. If a range specifies a maximum of three values, or
1009 -- we are dealing with an expression we emit a sequence of
1010 -- assignments instead of a loop.
1012 -- (c) Generate the remaining loops to cover the others choice if any
1014 -- 2. If the aggregate contains positional elements we
1016 -- (a) Translate the positional elements in a series of assignments
1018 -- (b) Generate a final loop to cover the others choice if any.
1019 -- Note that this final loop has to be a while loop since the case
1021 -- L : Integer := Integer'Last;
1022 -- H : Integer := Integer'Last;
1023 -- A : array (L .. H) := (1, others =>0);
1025 -- cannot be handled by a for loop. Thus for the following
1027 -- array (L .. H) := (.. positional elements.., others => E);
1029 -- we always generate something like:
1031 -- J : Index_Type := Index_Of_Last_Positional_Element;
1032 -- while J < H loop
1033 -- J := Index_Base'Succ (J)
1034 -- Tmp (J) := E;
1035 -- end loop;
1037 function Build_Array_Aggr_Code
1038 (N : Node_Id;
1039 Ctype : Entity_Id;
1040 Index : Node_Id;
1041 Into : Node_Id;
1042 Scalar_Comp : Boolean;
1043 Indexes : List_Id := No_List) return List_Id
1045 Loc : constant Source_Ptr := Sloc (N);
1046 Typ : constant Entity_Id := Etype (N);
1047 Index_Base : constant Entity_Id := Base_Type (Etype (Index));
1048 Index_Base_L : constant Node_Id := Type_Low_Bound (Index_Base);
1049 Index_Base_H : constant Node_Id := Type_High_Bound (Index_Base);
1051 function Add (Val : Int; To : Node_Id) return Node_Id;
1052 -- Returns an expression where Val is added to expression To, unless
1053 -- To+Val is provably out of To's base type range. To must be an
1054 -- already analyzed expression.
1056 function Empty_Range (L, H : Node_Id) return Boolean;
1057 -- Returns True if the range defined by L .. H is certainly empty
1059 function Equal (L, H : Node_Id) return Boolean;
1060 -- Returns True if L = H for sure
1062 function Index_Base_Name return Node_Id;
1063 -- Returns a new reference to the index type name
1065 function Gen_Assign
1066 (Ind : Node_Id;
1067 Expr : Node_Id) return List_Id;
1068 -- Ind must be a side-effect-free expression. If the input aggregate N
1069 -- to Build_Loop contains no subaggregates, then this function returns
1070 -- the assignment statement:
1072 -- Into (Indexes, Ind) := Expr;
1074 -- Otherwise we call Build_Code recursively.
1076 -- Ada 2005 (AI-287): In case of default initialized component, Expr
1077 -- is empty and we generate a call to the corresponding IP subprogram.
1079 function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id;
1080 -- Nodes L and H must be side-effect-free expressions. If the input
1081 -- aggregate N to Build_Loop contains no subaggregates, this routine
1082 -- returns the for loop statement:
1084 -- for J in Index_Base'(L) .. Index_Base'(H) loop
1085 -- Into (Indexes, J) := Expr;
1086 -- end loop;
1088 -- Otherwise we call Build_Code recursively. As an optimization if the
1089 -- loop covers 3 or fewer scalar elements we generate a sequence of
1090 -- assignments.
1091 -- If the component association that generates the loop comes from an
1092 -- Iterated_Component_Association, the loop parameter has the name of
1093 -- the corresponding parameter in the original construct.
1095 function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id;
1096 -- Nodes L and H must be side-effect-free expressions. If the input
1097 -- aggregate N to Build_Loop contains no subaggregates, this routine
1098 -- returns the while loop statement:
1100 -- J : Index_Base := L;
1101 -- while J < H loop
1102 -- J := Index_Base'Succ (J);
1103 -- Into (Indexes, J) := Expr;
1104 -- end loop;
1106 -- Otherwise we call Build_Code recursively
1108 function Get_Assoc_Expr (Assoc : Node_Id) return Node_Id;
1109 -- For an association with a box, use value given by aspect
1110 -- Default_Component_Value of array type if specified, else use
1111 -- value given by aspect Default_Value for component type itself
1112 -- if specified, else return Empty.
1114 function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean;
1115 function Local_Expr_Value (E : Node_Id) return Uint;
1116 -- These two Local routines are used to replace the corresponding ones
1117 -- in sem_eval because while processing the bounds of an aggregate with
1118 -- discrete choices whose index type is an enumeration, we build static
1119 -- expressions not recognized by Compile_Time_Known_Value as such since
1120 -- they have not yet been analyzed and resolved. All the expressions in
1121 -- question are things like Index_Base_Name'Val (Const) which we can
1122 -- easily recognize as being constant.
1124 ---------
1125 -- Add --
1126 ---------
1128 function Add (Val : Int; To : Node_Id) return Node_Id is
1129 Expr_Pos : Node_Id;
1130 Expr : Node_Id;
1131 To_Pos : Node_Id;
1132 U_To : Uint;
1133 U_Val : constant Uint := UI_From_Int (Val);
1135 begin
1136 -- Note: do not try to optimize the case of Val = 0, because
1137 -- we need to build a new node with the proper Sloc value anyway.
1139 -- First test if we can do constant folding
1141 if Local_Compile_Time_Known_Value (To) then
1142 U_To := Local_Expr_Value (To) + Val;
1144 -- Determine if our constant is outside the range of the index.
1145 -- If so return an Empty node. This empty node will be caught
1146 -- by Empty_Range below.
1148 if Compile_Time_Known_Value (Index_Base_L)
1149 and then U_To < Expr_Value (Index_Base_L)
1150 then
1151 return Empty;
1153 elsif Compile_Time_Known_Value (Index_Base_H)
1154 and then U_To > Expr_Value (Index_Base_H)
1155 then
1156 return Empty;
1157 end if;
1159 Expr_Pos := Make_Integer_Literal (Loc, U_To);
1160 Set_Is_Static_Expression (Expr_Pos);
1162 if not Is_Enumeration_Type (Index_Base) then
1163 Expr := Expr_Pos;
1165 -- If we are dealing with enumeration return
1166 -- Index_Base'Val (Expr_Pos)
1168 else
1169 Expr :=
1170 Make_Attribute_Reference
1171 (Loc,
1172 Prefix => Index_Base_Name,
1173 Attribute_Name => Name_Val,
1174 Expressions => New_List (Expr_Pos));
1175 end if;
1177 return Expr;
1178 end if;
1180 -- If we are here no constant folding possible
1182 if not Is_Enumeration_Type (Index_Base) then
1183 Expr :=
1184 Make_Op_Add (Loc,
1185 Left_Opnd => Duplicate_Subexpr (To),
1186 Right_Opnd => Make_Integer_Literal (Loc, U_Val));
1188 -- If we are dealing with enumeration return
1189 -- Index_Base'Val (Index_Base'Pos (To) + Val)
1191 else
1192 To_Pos :=
1193 Make_Attribute_Reference
1194 (Loc,
1195 Prefix => Index_Base_Name,
1196 Attribute_Name => Name_Pos,
1197 Expressions => New_List (Duplicate_Subexpr (To)));
1199 Expr_Pos :=
1200 Make_Op_Add (Loc,
1201 Left_Opnd => To_Pos,
1202 Right_Opnd => Make_Integer_Literal (Loc, U_Val));
1204 Expr :=
1205 Make_Attribute_Reference
1206 (Loc,
1207 Prefix => Index_Base_Name,
1208 Attribute_Name => Name_Val,
1209 Expressions => New_List (Expr_Pos));
1210 end if;
1212 return Expr;
1213 end Add;
1215 -----------------
1216 -- Empty_Range --
1217 -----------------
1219 function Empty_Range (L, H : Node_Id) return Boolean is
1220 Is_Empty : Boolean := False;
1221 Low : Node_Id;
1222 High : Node_Id;
1224 begin
1225 -- First check if L or H were already detected as overflowing the
1226 -- index base range type by function Add above. If this is so Add
1227 -- returns the empty node.
1229 if No (L) or else No (H) then
1230 return True;
1231 end if;
1233 for J in 1 .. 3 loop
1234 case J is
1236 -- L > H range is empty
1238 when 1 =>
1239 Low := L;
1240 High := H;
1242 -- B_L > H range must be empty
1244 when 2 =>
1245 Low := Index_Base_L;
1246 High := H;
1248 -- L > B_H range must be empty
1250 when 3 =>
1251 Low := L;
1252 High := Index_Base_H;
1253 end case;
1255 if Local_Compile_Time_Known_Value (Low)
1256 and then
1257 Local_Compile_Time_Known_Value (High)
1258 then
1259 Is_Empty :=
1260 UI_Gt (Local_Expr_Value (Low), Local_Expr_Value (High));
1261 end if;
1263 exit when Is_Empty;
1264 end loop;
1266 return Is_Empty;
1267 end Empty_Range;
1269 -----------
1270 -- Equal --
1271 -----------
1273 function Equal (L, H : Node_Id) return Boolean is
1274 begin
1275 if L = H then
1276 return True;
1278 elsif Local_Compile_Time_Known_Value (L)
1279 and then
1280 Local_Compile_Time_Known_Value (H)
1281 then
1282 return UI_Eq (Local_Expr_Value (L), Local_Expr_Value (H));
1283 end if;
1285 return False;
1286 end Equal;
1288 ----------------
1289 -- Gen_Assign --
1290 ----------------
1292 function Gen_Assign
1293 (Ind : Node_Id;
1294 Expr : Node_Id) return List_Id
1296 function Add_Loop_Actions (Lis : List_Id) return List_Id;
1297 -- Collect insert_actions generated in the construction of a loop,
1298 -- and prepend them to the sequence of assignments to complete the
1299 -- eventual body of the loop.
1301 ----------------------
1302 -- Add_Loop_Actions --
1303 ----------------------
1305 function Add_Loop_Actions (Lis : List_Id) return List_Id is
1306 Res : List_Id;
1308 begin
1309 -- Ada 2005 (AI-287): Do nothing else in case of default
1310 -- initialized component.
1312 if No (Expr) then
1313 return Lis;
1315 elsif Nkind (Parent (Expr)) = N_Component_Association
1316 and then Present (Loop_Actions (Parent (Expr)))
1317 then
1318 Append_List (Lis, Loop_Actions (Parent (Expr)));
1319 Res := Loop_Actions (Parent (Expr));
1320 Set_Loop_Actions (Parent (Expr), No_List);
1321 return Res;
1323 else
1324 return Lis;
1325 end if;
1326 end Add_Loop_Actions;
1328 -- Local variables
1330 Stmts : constant List_Id := New_List;
1332 Comp_Typ : Entity_Id := Empty;
1333 Expr_Q : Node_Id;
1334 Indexed_Comp : Node_Id;
1335 Init_Call : Node_Id;
1336 New_Indexes : List_Id;
1338 -- Start of processing for Gen_Assign
1340 begin
1341 if No (Indexes) then
1342 New_Indexes := New_List;
1343 else
1344 New_Indexes := New_Copy_List_Tree (Indexes);
1345 end if;
1347 Append_To (New_Indexes, Ind);
1349 if Present (Next_Index (Index)) then
1350 return
1351 Add_Loop_Actions (
1352 Build_Array_Aggr_Code
1353 (N => Expr,
1354 Ctype => Ctype,
1355 Index => Next_Index (Index),
1356 Into => Into,
1357 Scalar_Comp => Scalar_Comp,
1358 Indexes => New_Indexes));
1359 end if;
1361 -- If we get here then we are at a bottom-level (sub-)aggregate
1363 Indexed_Comp :=
1364 Checks_Off
1365 (Make_Indexed_Component (Loc,
1366 Prefix => New_Copy_Tree (Into),
1367 Expressions => New_Indexes));
1369 Set_Assignment_OK (Indexed_Comp);
1371 -- Ada 2005 (AI-287): In case of default initialized component, Expr
1372 -- is not present (and therefore we also initialize Expr_Q to empty).
1374 Expr_Q := Unqualify (Expr);
1376 if Present (Etype (N)) and then Etype (N) /= Any_Composite then
1377 Comp_Typ := Component_Type (Etype (N));
1378 pragma Assert (Comp_Typ = Ctype); -- AI-287
1380 elsif Present (Next (First (New_Indexes))) then
1382 -- Ada 2005 (AI-287): Do nothing in case of default initialized
1383 -- component because we have received the component type in
1384 -- the formal parameter Ctype.
1386 -- ??? Some assert pragmas have been added to check if this new
1387 -- formal can be used to replace this code in all cases.
1389 if Present (Expr) then
1391 -- This is a multidimensional array. Recover the component type
1392 -- from the outermost aggregate, because subaggregates do not
1393 -- have an assigned type.
1395 declare
1396 P : Node_Id;
1398 begin
1399 P := Parent (Expr);
1400 while Present (P) loop
1401 if Nkind (P) = N_Aggregate
1402 and then Present (Etype (P))
1403 then
1404 Comp_Typ := Component_Type (Etype (P));
1405 exit;
1407 else
1408 P := Parent (P);
1409 end if;
1410 end loop;
1412 pragma Assert (Comp_Typ = Ctype); -- AI-287
1413 end;
1414 end if;
1415 end if;
1417 -- Ada 2005 (AI-287): We only analyze the expression in case of non-
1418 -- default initialized components (otherwise Expr_Q is not present).
1420 if Present (Expr_Q)
1421 and then Nkind (Expr_Q) in N_Aggregate | N_Extension_Aggregate
1422 then
1423 -- At this stage the Expression may not have been analyzed yet
1424 -- because the array aggregate code has not been updated to use
1425 -- the Expansion_Delayed flag and avoid analysis altogether to
1426 -- solve the same problem (see Resolve_Aggr_Expr). So let us do
1427 -- the analysis of non-array aggregates now in order to get the
1428 -- value of Expansion_Delayed flag for the inner aggregate ???
1430 -- In the case of an iterated component association, the analysis
1431 -- of the generated loop will analyze the expression in the
1432 -- proper context, in which the loop parameter is visible.
1434 if Present (Comp_Typ) and then not Is_Array_Type (Comp_Typ) then
1435 if Nkind (Parent (Expr_Q)) = N_Iterated_Component_Association
1436 or else Nkind (Parent (Parent ((Expr_Q)))) =
1437 N_Iterated_Component_Association
1438 then
1439 null;
1440 else
1441 Analyze_And_Resolve (Expr_Q, Comp_Typ);
1442 end if;
1443 end if;
1445 if Is_Delayed_Aggregate (Expr_Q) then
1447 -- This is either a subaggregate of a multidimensional array,
1448 -- or a component of an array type whose component type is
1449 -- also an array. In the latter case, the expression may have
1450 -- component associations that provide different bounds from
1451 -- those of the component type, and sliding must occur. Instead
1452 -- of decomposing the current aggregate assignment, force the
1453 -- reanalysis of the assignment, so that a temporary will be
1454 -- generated in the usual fashion, and sliding will take place.
1456 if Nkind (Parent (N)) = N_Assignment_Statement
1457 and then Is_Array_Type (Comp_Typ)
1458 and then Present (Component_Associations (Expr_Q))
1459 and then Must_Slide (N, Comp_Typ, Etype (Expr_Q))
1460 then
1461 Set_Expansion_Delayed (Expr_Q, False);
1462 Set_Analyzed (Expr_Q, False);
1464 else
1465 return
1466 Add_Loop_Actions (
1467 Late_Expansion (Expr_Q, Etype (Expr_Q), Indexed_Comp));
1468 end if;
1469 end if;
1470 end if;
1472 if Present (Expr) then
1473 Initialize_Component
1474 (N => N,
1475 Comp => Indexed_Comp,
1476 Comp_Typ => Comp_Typ,
1477 Init_Expr => Expr,
1478 Stmts => Stmts);
1480 -- Ada 2005 (AI-287): In case of default initialized component, call
1481 -- the initialization subprogram associated with the component type.
1482 -- If the component type is an access type, add an explicit null
1483 -- assignment, because for the back-end there is an initialization
1484 -- present for the whole aggregate, and no default initialization
1485 -- will take place.
1487 -- In addition, if the component type is controlled, we must call
1488 -- its Initialize procedure explicitly, because there is no explicit
1489 -- object creation that will invoke it otherwise.
1491 else
1492 if Present (Base_Init_Proc (Base_Type (Ctype)))
1493 or else Has_Task (Base_Type (Ctype))
1494 then
1495 Append_List_To (Stmts,
1496 Build_Initialization_Call (Loc,
1497 Id_Ref => Indexed_Comp,
1498 Typ => Ctype,
1499 With_Default_Init => True));
1501 -- If the component type has invariants, add an invariant
1502 -- check after the component is default-initialized. It will
1503 -- be analyzed and resolved before the code for initialization
1504 -- of other components.
1506 if Has_Invariants (Ctype) then
1507 Set_Etype (Indexed_Comp, Ctype);
1508 Append_To (Stmts, Make_Invariant_Call (Indexed_Comp));
1509 end if;
1510 end if;
1512 if Needs_Finalization (Ctype) then
1513 Init_Call :=
1514 Make_Init_Call
1515 (Obj_Ref => New_Copy_Tree (Indexed_Comp),
1516 Typ => Ctype);
1518 -- Guard against a missing [Deep_]Initialize when the component
1519 -- type was not properly frozen.
1521 if Present (Init_Call) then
1522 Append_To (Stmts, Init_Call);
1523 end if;
1524 end if;
1526 -- If Default_Initial_Condition applies to the component type,
1527 -- add a DIC check after the component is default-initialized,
1528 -- as well as after an Initialize procedure is called, in the
1529 -- case of components of a controlled type. It will be analyzed
1530 -- and resolved before the code for initialization of other
1531 -- components.
1533 -- Theoretically this might also be needed for cases where Expr
1534 -- is not empty, but a default init still applies, such as for
1535 -- Default_Value cases, in which case we won't get here. ???
1537 if Has_DIC (Ctype) and then Present (DIC_Procedure (Ctype)) then
1538 Append_To (Stmts,
1539 Build_DIC_Call (Loc, New_Copy_Tree (Indexed_Comp), Ctype));
1540 end if;
1541 end if;
1543 return Add_Loop_Actions (Stmts);
1544 end Gen_Assign;
1546 --------------
1547 -- Gen_Loop --
1548 --------------
1550 function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id is
1551 Is_Iterated_Component : constant Boolean :=
1552 Parent_Kind (Expr) = N_Iterated_Component_Association;
1554 Ent : Entity_Id;
1556 L_J : Node_Id;
1558 L_L : Node_Id;
1559 -- Index_Base'(L)
1561 L_H : Node_Id;
1562 -- Index_Base'(H)
1564 L_Range : Node_Id;
1565 -- Index_Base'(L) .. Index_Base'(H)
1567 L_Iteration_Scheme : Node_Id;
1568 -- L_J in Index_Base'(L) .. Index_Base'(H)
1570 L_Body : List_Id;
1571 -- The statements to execute in the loop
1573 S : constant List_Id := New_List;
1574 -- List of statements
1576 Tcopy : Node_Id;
1577 -- Copy of expression tree, used for checking purposes
1579 begin
1580 -- If loop bounds define an empty range return the null statement
1582 if Empty_Range (L, H) then
1583 Append_To (S, Make_Null_Statement (Loc));
1585 -- Ada 2005 (AI-287): Nothing else need to be done in case of
1586 -- default initialized component.
1588 if No (Expr) then
1589 null;
1591 else
1592 -- The expression must be type-checked even though no component
1593 -- of the aggregate will have this value. This is done only for
1594 -- actual components of the array, not for subaggregates. Do
1595 -- the check on a copy, because the expression may be shared
1596 -- among several choices, some of which might be non-null.
1598 if Present (Etype (N))
1599 and then Is_Array_Type (Etype (N))
1600 and then No (Next_Index (Index))
1601 then
1602 Expander_Mode_Save_And_Set (False);
1603 Tcopy := New_Copy_Tree (Expr);
1604 Set_Parent (Tcopy, N);
1606 -- For iterated_component_association analyze and resolve
1607 -- the expression with name of the index parameter visible.
1608 -- To manipulate scopes, we use entity of the implicit loop.
1610 if Is_Iterated_Component then
1611 declare
1612 Index_Parameter : constant Entity_Id :=
1613 Defining_Identifier (Parent (Expr));
1614 begin
1615 Push_Scope (Scope (Index_Parameter));
1616 Enter_Name (Index_Parameter);
1617 Analyze_And_Resolve
1618 (Tcopy, Component_Type (Etype (N)));
1619 End_Scope;
1620 end;
1622 -- For ordinary component association, just analyze and
1623 -- resolve the expression.
1625 else
1626 Analyze_And_Resolve (Tcopy, Component_Type (Etype (N)));
1627 end if;
1629 Expander_Mode_Restore;
1630 end if;
1631 end if;
1633 return S;
1635 -- If loop bounds are the same then generate an assignment, unless
1636 -- the parent construct is an Iterated_Component_Association.
1638 elsif Equal (L, H) and then not Is_Iterated_Component then
1639 return Gen_Assign (New_Copy_Tree (L), Expr);
1641 -- If H - L <= 2 then generate a sequence of assignments when we are
1642 -- processing the bottom most aggregate and it contains scalar
1643 -- components.
1645 elsif No (Next_Index (Index))
1646 and then Scalar_Comp
1647 and then Local_Compile_Time_Known_Value (L)
1648 and then Local_Compile_Time_Known_Value (H)
1649 and then Local_Expr_Value (H) - Local_Expr_Value (L) <= 2
1650 and then not Is_Iterated_Component
1651 then
1652 Append_List_To (S, Gen_Assign (New_Copy_Tree (L), Expr));
1653 Append_List_To (S, Gen_Assign (Add (1, To => L), Expr));
1655 if Local_Expr_Value (H) - Local_Expr_Value (L) = 2 then
1656 Append_List_To (S, Gen_Assign (Add (2, To => L), Expr));
1657 end if;
1659 return S;
1660 end if;
1662 -- Otherwise construct the loop, starting with the loop index L_J
1664 if Is_Iterated_Component then
1666 -- Create a new scope for the loop variable so that the
1667 -- following Gen_Assign (that ends up calling
1668 -- Preanalyze_And_Resolve) can correctly find it.
1670 Ent := New_Internal_Entity (E_Loop,
1671 Current_Scope, Loc, 'L');
1672 Set_Etype (Ent, Standard_Void_Type);
1673 Set_Parent (Ent, Parent (Parent (Expr)));
1674 Push_Scope (Ent);
1676 L_J :=
1677 Make_Defining_Identifier (Loc,
1678 Chars => (Chars (Defining_Identifier (Parent (Expr)))));
1680 Enter_Name (L_J);
1682 -- The Etype will be set by a later Analyze call.
1683 Set_Etype (L_J, Any_Type);
1685 Mutate_Ekind (L_J, E_Variable);
1686 Set_Is_Not_Self_Hidden (L_J);
1687 Set_Scope (L_J, Ent);
1688 else
1689 L_J := Make_Temporary (Loc, 'J', L);
1690 end if;
1692 -- Construct "L .. H" in Index_Base. We use a qualified expression
1693 -- for the bound to convert to the index base, but we don't need
1694 -- to do that if we already have the base type at hand.
1696 if Etype (L) = Index_Base then
1697 L_L := New_Copy_Tree (L);
1698 else
1699 L_L :=
1700 Make_Qualified_Expression (Loc,
1701 Subtype_Mark => Index_Base_Name,
1702 Expression => New_Copy_Tree (L));
1703 end if;
1705 if Etype (H) = Index_Base then
1706 L_H := New_Copy_Tree (H);
1707 else
1708 L_H :=
1709 Make_Qualified_Expression (Loc,
1710 Subtype_Mark => Index_Base_Name,
1711 Expression => New_Copy_Tree (H));
1712 end if;
1714 L_Range :=
1715 Make_Range (Loc,
1716 Low_Bound => L_L,
1717 High_Bound => L_H);
1719 -- Construct "for L_J in Index_Base range L .. H"
1721 L_Iteration_Scheme :=
1722 Make_Iteration_Scheme (Loc,
1723 Loop_Parameter_Specification =>
1724 Make_Loop_Parameter_Specification (Loc,
1725 Defining_Identifier => L_J,
1726 Discrete_Subtype_Definition => L_Range));
1728 -- Construct the statements to execute in the loop body
1730 L_Body := Gen_Assign (New_Occurrence_Of (L_J, Loc), Expr);
1732 -- Construct the final loop
1734 Append_To (S,
1735 Make_Implicit_Loop_Statement
1736 (Node => N,
1737 Identifier => Empty,
1738 Iteration_Scheme => L_Iteration_Scheme,
1739 Statements => L_Body));
1741 if Is_Iterated_Component then
1742 End_Scope;
1743 end if;
1745 -- A small optimization: if the aggregate is initialized with a box
1746 -- and the component type has no initialization procedure, remove the
1747 -- useless empty loop.
1749 if Nkind (First (S)) = N_Loop_Statement
1750 and then Is_Empty_List (Statements (First (S)))
1751 then
1752 return New_List (Make_Null_Statement (Loc));
1753 else
1754 return S;
1755 end if;
1756 end Gen_Loop;
1758 ---------------
1759 -- Gen_While --
1760 ---------------
1762 -- The code built is
1764 -- W_J : Index_Base := L;
1765 -- while W_J < H loop
1766 -- W_J := Index_Base'Succ (W);
1767 -- L_Body;
1768 -- end loop;
1770 function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id is
1771 W_J : Node_Id;
1773 W_Decl : Node_Id;
1774 -- W_J : Base_Type := L;
1776 W_Iteration_Scheme : Node_Id;
1777 -- while W_J < H
1779 W_Index_Succ : Node_Id;
1780 -- Index_Base'Succ (J)
1782 W_Increment : Node_Id;
1783 -- W_J := Index_Base'Succ (W)
1785 W_Body : constant List_Id := New_List;
1786 -- The statements to execute in the loop
1788 S : constant List_Id := New_List;
1789 -- list of statement
1791 begin
1792 -- If loop bounds define an empty range or are equal return null
1794 if Empty_Range (L, H) or else Equal (L, H) then
1795 Append_To (S, Make_Null_Statement (Loc));
1796 return S;
1797 end if;
1799 -- Build the decl of W_J
1801 W_J := Make_Temporary (Loc, 'J', L);
1802 W_Decl :=
1803 Make_Object_Declaration
1804 (Loc,
1805 Defining_Identifier => W_J,
1806 Object_Definition => Index_Base_Name,
1807 Expression => L);
1809 -- Theoretically we should do a New_Copy_Tree (L) here, but we know
1810 -- that in this particular case L is a fresh Expr generated by
1811 -- Add which we are the only ones to use.
1813 Append_To (S, W_Decl);
1815 -- Construct " while W_J < H"
1817 W_Iteration_Scheme :=
1818 Make_Iteration_Scheme
1819 (Loc,
1820 Condition => Make_Op_Lt
1821 (Loc,
1822 Left_Opnd => New_Occurrence_Of (W_J, Loc),
1823 Right_Opnd => New_Copy_Tree (H)));
1825 -- Construct the statements to execute in the loop body
1827 W_Index_Succ :=
1828 Make_Attribute_Reference
1829 (Loc,
1830 Prefix => Index_Base_Name,
1831 Attribute_Name => Name_Succ,
1832 Expressions => New_List (New_Occurrence_Of (W_J, Loc)));
1834 W_Increment :=
1835 Make_OK_Assignment_Statement
1836 (Loc,
1837 Name => New_Occurrence_Of (W_J, Loc),
1838 Expression => W_Index_Succ);
1840 Append_To (W_Body, W_Increment);
1842 Append_List_To (W_Body,
1843 Gen_Assign (New_Occurrence_Of (W_J, Loc), Expr));
1845 -- Construct the final loop
1847 Append_To (S,
1848 Make_Implicit_Loop_Statement
1849 (Node => N,
1850 Identifier => Empty,
1851 Iteration_Scheme => W_Iteration_Scheme,
1852 Statements => W_Body));
1854 return S;
1855 end Gen_While;
1857 --------------------
1858 -- Get_Assoc_Expr --
1859 --------------------
1861 -- Duplicate the expression in case we will be generating several loops.
1862 -- As a result the expression is no longer shared between the loops and
1863 -- is reevaluated for each such loop.
1865 function Get_Assoc_Expr (Assoc : Node_Id) return Node_Id is
1866 Typ : constant Entity_Id := Base_Type (Etype (N));
1868 begin
1869 if Box_Present (Assoc) then
1870 if Present (Default_Aspect_Component_Value (Typ)) then
1871 return New_Copy_Tree (Default_Aspect_Component_Value (Typ));
1872 elsif Needs_Simple_Initialization (Ctype) then
1873 return New_Copy_Tree (Get_Simple_Init_Val (Ctype, N));
1874 else
1875 return Empty;
1876 end if;
1878 else
1879 -- The expression will be passed to Gen_Loop, which immediately
1880 -- calls Parent_Kind on it, so we set Parent when it matters.
1882 return
1883 Expr : constant Node_Id := New_Copy_Tree (Expression (Assoc))
1885 Copy_Parent (To => Expr, From => Expression (Assoc));
1886 end return;
1887 end if;
1888 end Get_Assoc_Expr;
1890 ---------------------
1891 -- Index_Base_Name --
1892 ---------------------
1894 function Index_Base_Name return Node_Id is
1895 begin
1896 return New_Occurrence_Of (Index_Base, Sloc (N));
1897 end Index_Base_Name;
1899 ------------------------------------
1900 -- Local_Compile_Time_Known_Value --
1901 ------------------------------------
1903 function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean is
1904 begin
1905 return Compile_Time_Known_Value (E)
1906 or else
1907 (Nkind (E) = N_Attribute_Reference
1908 and then Attribute_Name (E) = Name_Val
1909 and then Compile_Time_Known_Value (First (Expressions (E))));
1910 end Local_Compile_Time_Known_Value;
1912 ----------------------
1913 -- Local_Expr_Value --
1914 ----------------------
1916 function Local_Expr_Value (E : Node_Id) return Uint is
1917 begin
1918 if Compile_Time_Known_Value (E) then
1919 return Expr_Value (E);
1920 else
1921 return Expr_Value (First (Expressions (E)));
1922 end if;
1923 end Local_Expr_Value;
1925 -- Local variables
1927 New_Code : constant List_Id := New_List;
1929 Aggr_Bounds : constant Range_Nodes :=
1930 Get_Index_Bounds (Aggregate_Bounds (N));
1931 Aggr_L : Node_Id renames Aggr_Bounds.First;
1932 Aggr_H : Node_Id renames Aggr_Bounds.Last;
1933 -- The aggregate bounds of this specific subaggregate. Note that if the
1934 -- code generated by Build_Array_Aggr_Code is executed then these bounds
1935 -- are OK. Otherwise a Constraint_Error would have been raised.
1937 Aggr_Low : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_L);
1938 Aggr_High : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_H);
1939 -- After Duplicate_Subexpr these are side-effect free
1941 Assoc : Node_Id;
1942 Choice : Node_Id;
1943 Expr : Node_Id;
1945 Bounds : Range_Nodes;
1946 Low : Node_Id renames Bounds.First;
1947 High : Node_Id renames Bounds.Last;
1949 Nb_Choices : Nat := 0;
1950 Table : Case_Table_Type (1 .. Number_Of_Choices (N));
1951 -- Used to sort all the different choice values
1953 Nb_Elements : Int;
1954 -- Number of elements in the positional aggregate
1956 Others_Assoc : Node_Id := Empty;
1958 -- Start of processing for Build_Array_Aggr_Code
1960 begin
1961 -- First before we start, a special case. If we have a bit packed
1962 -- array represented as a modular type, then clear the value to
1963 -- zero first, to ensure that unused bits are properly cleared.
1965 if Present (Typ)
1966 and then Is_Bit_Packed_Array (Typ)
1967 and then Is_Modular_Integer_Type (Packed_Array_Impl_Type (Typ))
1968 then
1969 declare
1970 Zero : constant Node_Id := Make_Integer_Literal (Loc, Uint_0);
1971 begin
1972 Analyze_And_Resolve (Zero, Packed_Array_Impl_Type (Typ));
1973 Append_To (New_Code,
1974 Make_Assignment_Statement (Loc,
1975 Name => New_Copy_Tree (Into),
1976 Expression => Unchecked_Convert_To (Typ, Zero)));
1977 end;
1978 end if;
1980 -- If the component type contains tasks, we need to build a Master
1981 -- entity in the current scope, because it will be needed if build-
1982 -- in-place functions are called in the expanded code.
1984 if Nkind (Parent (N)) = N_Object_Declaration and then Has_Task (Typ) then
1985 Build_Master_Entity (Defining_Identifier (Parent (N)));
1986 end if;
1988 -- STEP 1: Process component associations
1990 -- For those associations that may generate a loop, initialize
1991 -- Loop_Actions to collect inserted actions that may be crated.
1993 -- Skip this if no component associations
1995 if Is_Null_Aggregate (N) then
1996 null;
1998 elsif No (Expressions (N)) then
2000 -- STEP 1 (a): Sort the discrete choices
2002 Assoc := First (Component_Associations (N));
2003 while Present (Assoc) loop
2004 Choice := First (Choice_List (Assoc));
2005 while Present (Choice) loop
2006 if Nkind (Choice) = N_Others_Choice then
2007 Others_Assoc := Assoc;
2008 exit;
2009 end if;
2011 Bounds := Get_Index_Bounds (Choice);
2013 if Low /= High then
2014 Set_Loop_Actions (Assoc, New_List);
2015 end if;
2017 Nb_Choices := Nb_Choices + 1;
2019 Table (Nb_Choices) :=
2020 (Choice_Lo => Low,
2021 Choice_Hi => High,
2022 Choice_Node => Get_Assoc_Expr (Assoc));
2024 Next (Choice);
2025 end loop;
2027 Next (Assoc);
2028 end loop;
2030 -- If there is more than one set of choices these must be static
2031 -- and we can therefore sort them. Remember that Nb_Choices does not
2032 -- account for an others choice.
2034 if Nb_Choices > 1 then
2035 Sort_Case_Table (Table);
2036 end if;
2038 -- STEP 1 (b): take care of the whole set of discrete choices
2040 for J in 1 .. Nb_Choices loop
2041 Low := Table (J).Choice_Lo;
2042 High := Table (J).Choice_Hi;
2043 Expr := Table (J).Choice_Node;
2044 Append_List (Gen_Loop (Low, High, Expr), To => New_Code);
2045 end loop;
2047 -- STEP 1 (c): generate the remaining loops to cover others choice
2048 -- We don't need to generate loops over empty gaps, but if there is
2049 -- a single empty range we must analyze the expression for semantics
2051 if Present (Others_Assoc) then
2052 declare
2053 First : Boolean := True;
2055 begin
2056 for J in 0 .. Nb_Choices loop
2057 if J = 0 then
2058 Low := Aggr_Low;
2059 else
2060 Low := Add (1, To => Table (J).Choice_Hi);
2061 end if;
2063 if J = Nb_Choices then
2064 High := Aggr_High;
2065 else
2066 High := Add (-1, To => Table (J + 1).Choice_Lo);
2067 end if;
2069 -- If this is an expansion within an init proc, make
2070 -- sure that discriminant references are replaced by
2071 -- the corresponding discriminal.
2073 if Inside_Init_Proc then
2074 if Is_Entity_Name (Low)
2075 and then Ekind (Entity (Low)) = E_Discriminant
2076 then
2077 Set_Entity (Low, Discriminal (Entity (Low)));
2078 end if;
2080 if Is_Entity_Name (High)
2081 and then Ekind (Entity (High)) = E_Discriminant
2082 then
2083 Set_Entity (High, Discriminal (Entity (High)));
2084 end if;
2085 end if;
2087 if First or else not Empty_Range (Low, High) then
2088 First := False;
2089 Set_Loop_Actions (Others_Assoc, New_List);
2090 Expr := Get_Assoc_Expr (Others_Assoc);
2091 Append_List (Gen_Loop (Low, High, Expr), To => New_Code);
2092 end if;
2093 end loop;
2094 end;
2095 end if;
2097 -- STEP 2: Process positional components
2099 else
2100 -- STEP 2 (a): Generate the assignments for each positional element
2101 -- Note that here we have to use Aggr_L rather than Aggr_Low because
2102 -- Aggr_L is analyzed and Add wants an analyzed expression.
2104 Expr := First (Expressions (N));
2105 Nb_Elements := -1;
2106 while Present (Expr) loop
2107 Nb_Elements := Nb_Elements + 1;
2108 Append_List (Gen_Assign (Add (Nb_Elements, To => Aggr_L), Expr),
2109 To => New_Code);
2110 Next (Expr);
2111 end loop;
2113 -- STEP 2 (b): Generate final loop if an others choice is present.
2114 -- Here Nb_Elements gives the offset of the last positional element.
2116 if Present (Component_Associations (N)) then
2117 Assoc := Last (Component_Associations (N));
2119 if Nkind (Assoc) = N_Iterated_Component_Association then
2120 -- Ada 2022: generate a loop to have a proper scope for
2121 -- the identifier that typically appears in the expression.
2122 -- The lower bound of the loop is the position after all
2123 -- previous positional components.
2125 Append_List (Gen_Loop (Add (Nb_Elements + 1, To => Aggr_L),
2126 Aggr_High,
2127 Expression (Assoc)),
2128 To => New_Code);
2129 else
2130 -- Ada 2005 (AI-287)
2132 Append_List (Gen_While (Add (Nb_Elements, To => Aggr_L),
2133 Aggr_High,
2134 Get_Assoc_Expr (Assoc)),
2135 To => New_Code);
2136 end if;
2137 end if;
2138 end if;
2140 return New_Code;
2141 end Build_Array_Aggr_Code;
2143 -------------------------------------
2144 -- Build_Assignment_With_Temporary --
2145 -------------------------------------
2147 function Build_Assignment_With_Temporary
2148 (Target : Node_Id;
2149 Typ : Entity_Id;
2150 Source : Node_Id) return List_Id
2152 Loc : constant Source_Ptr := Sloc (Source);
2154 Aggr_Code : List_Id;
2155 Tmp : Entity_Id;
2157 begin
2158 Aggr_Code := New_List;
2160 Tmp := Build_Temporary_On_Secondary_Stack (Loc, Typ, Aggr_Code);
2162 Append_To (Aggr_Code,
2163 Make_OK_Assignment_Statement (Loc,
2164 Name =>
2165 Make_Explicit_Dereference (Loc,
2166 Prefix => New_Occurrence_Of (Tmp, Loc)),
2167 Expression => Source));
2169 Append_To (Aggr_Code,
2170 Make_OK_Assignment_Statement (Loc,
2171 Name => Target,
2172 Expression =>
2173 Make_Explicit_Dereference (Loc,
2174 Prefix => New_Occurrence_Of (Tmp, Loc))));
2176 return Aggr_Code;
2177 end Build_Assignment_With_Temporary;
2179 ----------------------------
2180 -- Build_Record_Aggr_Code --
2181 ----------------------------
2183 function Build_Record_Aggr_Code
2184 (N : Node_Id;
2185 Typ : Entity_Id;
2186 Lhs : Node_Id) return List_Id
2188 Loc : constant Source_Ptr := Sloc (N);
2189 L : constant List_Id := New_List;
2190 N_Typ : constant Entity_Id := Etype (N);
2192 Comp : Node_Id;
2193 Instr : Node_Id;
2194 Ref : Node_Id;
2195 Target : Entity_Id;
2196 Comp_Type : Entity_Id;
2197 Selector : Entity_Id;
2198 Comp_Expr : Node_Id;
2199 Expr_Q : Node_Id;
2201 Ancestor_Is_Subtype_Mark : Boolean := False;
2203 Init_Typ : Entity_Id := Empty;
2205 Finalization_Done : Boolean := False;
2206 -- True if Generate_Finalization_Actions has already been called; calls
2207 -- after the first do nothing.
2209 function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id;
2210 -- Returns the value that the given discriminant of an ancestor type
2211 -- should receive (in the absence of a conflict with the value provided
2212 -- by an ancestor part of an extension aggregate).
2214 procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id);
2215 -- Check that each of the discriminant values defined by the ancestor
2216 -- part of an extension aggregate match the corresponding values
2217 -- provided by either an association of the aggregate or by the
2218 -- constraint imposed by a parent type (RM95-4.3.2(8)).
2220 function Compatible_Int_Bounds
2221 (Agg_Bounds : Node_Id;
2222 Typ_Bounds : Node_Id) return Boolean;
2223 -- Return true if Agg_Bounds are equal or within Typ_Bounds. It is
2224 -- assumed that both bounds are integer ranges.
2226 procedure Generate_Finalization_Actions;
2227 -- Deal with the various controlled type data structure initializations
2228 -- (but only if it hasn't been done already).
2230 function Get_Constraint_Association (T : Entity_Id) return Node_Id;
2231 -- Returns the first discriminant association in the constraint
2232 -- associated with T, if any, otherwise returns Empty.
2234 function Get_Explicit_Discriminant_Value (D : Entity_Id) return Node_Id;
2235 -- If the ancestor part is an unconstrained type and further ancestors
2236 -- do not provide discriminants for it, check aggregate components for
2237 -- values of the discriminants.
2239 procedure Init_Hidden_Discriminants (Typ : Entity_Id; List : List_Id);
2240 -- If Typ is derived, and constrains discriminants of the parent type,
2241 -- these discriminants are not components of the aggregate, and must be
2242 -- initialized. The assignments are appended to List. The same is done
2243 -- if Typ derives from an already constrained subtype of a discriminated
2244 -- parent type.
2246 procedure Init_Stored_Discriminants;
2247 -- If the type is derived and has inherited discriminants, generate
2248 -- explicit assignments for each, using the store constraint of the
2249 -- type. Note that both visible and stored discriminants must be
2250 -- initialized in case the derived type has some renamed and some
2251 -- constrained discriminants.
2253 procedure Init_Visible_Discriminants;
2254 -- If type has discriminants, retrieve their values from aggregate,
2255 -- and generate explicit assignments for each. This does not include
2256 -- discriminants inherited from ancestor, which are handled above.
2257 -- The type of the aggregate is a subtype created ealier using the
2258 -- given values of the discriminant components of the aggregate.
2260 function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean;
2261 -- Check whether Bounds is a range node and its lower and higher bounds
2262 -- are integers literals.
2264 function Replace_Type (Expr : Node_Id) return Traverse_Result;
2265 -- If the aggregate contains a self-reference, traverse each expression
2266 -- to replace a possible self-reference with a reference to the proper
2267 -- component of the target of the assignment.
2269 function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result;
2270 -- If default expression of a component mentions a discriminant of the
2271 -- type, it must be rewritten as the discriminant of the target object.
2273 ---------------------------------
2274 -- Ancestor_Discriminant_Value --
2275 ---------------------------------
2277 function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id is
2278 Assoc : Node_Id;
2279 Assoc_Elmt : Elmt_Id;
2280 Aggr_Comp : Entity_Id;
2281 Corresp_Disc : Entity_Id;
2282 Current_Typ : Entity_Id := Base_Type (Typ);
2283 Parent_Typ : Entity_Id;
2284 Parent_Disc : Entity_Id;
2285 Save_Assoc : Node_Id := Empty;
2287 begin
2288 -- First check any discriminant associations to see if any of them
2289 -- provide a value for the discriminant.
2291 if Present (Discriminant_Specifications (Parent (Current_Typ))) then
2292 Assoc := First (Component_Associations (N));
2293 while Present (Assoc) loop
2294 Aggr_Comp := Entity (First (Choices (Assoc)));
2296 if Ekind (Aggr_Comp) = E_Discriminant then
2297 Save_Assoc := Expression (Assoc);
2299 Corresp_Disc := Corresponding_Discriminant (Aggr_Comp);
2300 while Present (Corresp_Disc) loop
2302 -- If found a corresponding discriminant then return the
2303 -- value given in the aggregate. (Note: this is not
2304 -- correct in the presence of side effects. ???)
2306 if Disc = Corresp_Disc then
2307 return Duplicate_Subexpr (Expression (Assoc));
2308 end if;
2310 Corresp_Disc := Corresponding_Discriminant (Corresp_Disc);
2311 end loop;
2312 end if;
2314 Next (Assoc);
2315 end loop;
2316 end if;
2318 -- No match found in aggregate, so chain up parent types to find
2319 -- a constraint that defines the value of the discriminant.
2321 Parent_Typ := Etype (Current_Typ);
2322 while Current_Typ /= Parent_Typ loop
2323 if Has_Discriminants (Parent_Typ)
2324 and then not Has_Unknown_Discriminants (Parent_Typ)
2325 then
2326 Parent_Disc := First_Discriminant (Parent_Typ);
2328 -- We either get the association from the subtype indication
2329 -- of the type definition itself, or from the discriminant
2330 -- constraint associated with the type entity (which is
2331 -- preferable, but it's not always present ???)
2333 if Is_Empty_Elmt_List (Discriminant_Constraint (Current_Typ))
2334 then
2335 Assoc := Get_Constraint_Association (Current_Typ);
2336 Assoc_Elmt := No_Elmt;
2337 else
2338 Assoc_Elmt :=
2339 First_Elmt (Discriminant_Constraint (Current_Typ));
2340 Assoc := Node (Assoc_Elmt);
2341 end if;
2343 -- Traverse the discriminants of the parent type looking
2344 -- for one that corresponds.
2346 while Present (Parent_Disc) and then Present (Assoc) loop
2347 Corresp_Disc := Parent_Disc;
2348 while Present (Corresp_Disc)
2349 and then Disc /= Corresp_Disc
2350 loop
2351 Corresp_Disc := Corresponding_Discriminant (Corresp_Disc);
2352 end loop;
2354 if Disc = Corresp_Disc then
2355 if Nkind (Assoc) = N_Discriminant_Association then
2356 Assoc := Expression (Assoc);
2357 end if;
2359 -- If the located association directly denotes
2360 -- a discriminant, then use the value of a saved
2361 -- association of the aggregate. This is an approach
2362 -- used to handle certain cases involving multiple
2363 -- discriminants mapped to a single discriminant of
2364 -- a descendant. It's not clear how to locate the
2365 -- appropriate discriminant value for such cases. ???
2367 if Is_Entity_Name (Assoc)
2368 and then Ekind (Entity (Assoc)) = E_Discriminant
2369 then
2370 Assoc := Save_Assoc;
2371 end if;
2373 return Duplicate_Subexpr (Assoc);
2374 end if;
2376 Next_Discriminant (Parent_Disc);
2378 if No (Assoc_Elmt) then
2379 Next (Assoc);
2381 else
2382 Next_Elmt (Assoc_Elmt);
2384 if Present (Assoc_Elmt) then
2385 Assoc := Node (Assoc_Elmt);
2386 else
2387 Assoc := Empty;
2388 end if;
2389 end if;
2390 end loop;
2391 end if;
2393 Current_Typ := Parent_Typ;
2394 Parent_Typ := Etype (Current_Typ);
2395 end loop;
2397 -- In some cases there's no ancestor value to locate (such as
2398 -- when an ancestor part given by an expression defines the
2399 -- discriminant value).
2401 return Empty;
2402 end Ancestor_Discriminant_Value;
2404 ----------------------------------
2405 -- Check_Ancestor_Discriminants --
2406 ----------------------------------
2408 procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id) is
2409 Discr : Entity_Id;
2410 Disc_Value : Node_Id;
2411 Cond : Node_Id;
2413 begin
2414 Discr := First_Discriminant (Base_Type (Anc_Typ));
2415 while Present (Discr) loop
2416 Disc_Value := Ancestor_Discriminant_Value (Discr);
2418 if Present (Disc_Value) then
2419 Cond := Make_Op_Ne (Loc,
2420 Left_Opnd =>
2421 Make_Selected_Component (Loc,
2422 Prefix => New_Copy_Tree (Target),
2423 Selector_Name => New_Occurrence_Of (Discr, Loc)),
2424 Right_Opnd => Disc_Value);
2426 Append_To (L,
2427 Make_Raise_Constraint_Error (Loc,
2428 Condition => Cond,
2429 Reason => CE_Discriminant_Check_Failed));
2430 end if;
2432 Next_Discriminant (Discr);
2433 end loop;
2434 end Check_Ancestor_Discriminants;
2436 ---------------------------
2437 -- Compatible_Int_Bounds --
2438 ---------------------------
2440 function Compatible_Int_Bounds
2441 (Agg_Bounds : Node_Id;
2442 Typ_Bounds : Node_Id) return Boolean
2444 Agg_Lo : constant Uint := Intval (Low_Bound (Agg_Bounds));
2445 Agg_Hi : constant Uint := Intval (High_Bound (Agg_Bounds));
2446 Typ_Lo : constant Uint := Intval (Low_Bound (Typ_Bounds));
2447 Typ_Hi : constant Uint := Intval (High_Bound (Typ_Bounds));
2448 begin
2449 return Typ_Lo <= Agg_Lo and then Agg_Hi <= Typ_Hi;
2450 end Compatible_Int_Bounds;
2452 -----------------------------------
2453 -- Generate_Finalization_Actions --
2454 -----------------------------------
2456 procedure Generate_Finalization_Actions is
2457 begin
2458 -- Do the work only the first time this is called
2460 if Finalization_Done then
2461 return;
2462 end if;
2464 Finalization_Done := True;
2466 -- Determine the external finalization list. It is either the
2467 -- finalization list of the outer scope or the one coming from an
2468 -- outer aggregate. When the target is not a temporary, the proper
2469 -- scope is the scope of the target rather than the potentially
2470 -- transient current scope.
2472 if Is_Controlled (Typ) and then Ancestor_Is_Subtype_Mark then
2473 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2474 Set_Assignment_OK (Ref);
2476 Append_To (L,
2477 Make_Procedure_Call_Statement (Loc,
2478 Name =>
2479 New_Occurrence_Of
2480 (Find_Prim_Op (Init_Typ, Name_Initialize), Loc),
2481 Parameter_Associations => New_List (New_Copy_Tree (Ref))));
2482 end if;
2483 end Generate_Finalization_Actions;
2485 --------------------------------
2486 -- Get_Constraint_Association --
2487 --------------------------------
2489 function Get_Constraint_Association (T : Entity_Id) return Node_Id is
2490 Indic : Node_Id;
2491 Typ : Entity_Id;
2493 begin
2494 Typ := T;
2496 -- If type is private, get constraint from full view. This was
2497 -- previously done in an instance context, but is needed whenever
2498 -- the ancestor part has a discriminant, possibly inherited through
2499 -- multiple derivations.
2501 if Is_Private_Type (Typ) and then Present (Full_View (Typ)) then
2502 Typ := Full_View (Typ);
2503 end if;
2505 Indic := Subtype_Indication (Type_Definition (Parent (Typ)));
2507 -- Verify that the subtype indication carries a constraint
2509 if Nkind (Indic) = N_Subtype_Indication
2510 and then Present (Constraint (Indic))
2511 then
2512 return First (Constraints (Constraint (Indic)));
2513 end if;
2515 return Empty;
2516 end Get_Constraint_Association;
2518 -------------------------------------
2519 -- Get_Explicit_Discriminant_Value --
2520 -------------------------------------
2522 function Get_Explicit_Discriminant_Value
2523 (D : Entity_Id) return Node_Id
2525 Assoc : Node_Id;
2526 Choice : Node_Id;
2527 Val : Node_Id;
2529 begin
2530 -- The aggregate has been normalized and all associations have a
2531 -- single choice.
2533 Assoc := First (Component_Associations (N));
2534 while Present (Assoc) loop
2535 Choice := First (Choices (Assoc));
2537 if Chars (Choice) = Chars (D) then
2538 Val := Expression (Assoc);
2539 Remove (Assoc);
2540 return Val;
2541 end if;
2543 Next (Assoc);
2544 end loop;
2546 return Empty;
2547 end Get_Explicit_Discriminant_Value;
2549 -------------------------------
2550 -- Init_Hidden_Discriminants --
2551 -------------------------------
2553 procedure Init_Hidden_Discriminants (Typ : Entity_Id; List : List_Id) is
2554 function Is_Completely_Hidden_Discriminant
2555 (Discr : Entity_Id) return Boolean;
2556 -- Determine whether Discr is a completely hidden discriminant of
2557 -- type Typ.
2559 ---------------------------------------
2560 -- Is_Completely_Hidden_Discriminant --
2561 ---------------------------------------
2563 function Is_Completely_Hidden_Discriminant
2564 (Discr : Entity_Id) return Boolean
2566 Item : Entity_Id;
2568 begin
2569 -- Use First/Next_Entity as First/Next_Discriminant do not yield
2570 -- completely hidden discriminants.
2572 Item := First_Entity (Typ);
2573 while Present (Item) loop
2574 if Ekind (Item) = E_Discriminant
2575 and then Is_Completely_Hidden (Item)
2576 and then Chars (Original_Record_Component (Item)) =
2577 Chars (Discr)
2578 then
2579 return True;
2580 end if;
2582 Next_Entity (Item);
2583 end loop;
2585 return False;
2586 end Is_Completely_Hidden_Discriminant;
2588 -- Local variables
2590 Base_Typ : Entity_Id;
2591 Discr : Entity_Id;
2592 Discr_Constr : Elmt_Id;
2593 Discr_Init : Node_Id;
2594 Discr_Val : Node_Id;
2595 In_Aggr_Type : Boolean;
2596 Par_Typ : Entity_Id;
2598 -- Start of processing for Init_Hidden_Discriminants
2600 begin
2601 -- The constraints on the hidden discriminants, if present, are kept
2602 -- in the Stored_Constraint list of the type itself, or in that of
2603 -- the base type. If not in the constraints of the aggregate itself,
2604 -- we examine ancestors to find discriminants that are not renamed
2605 -- by other discriminants but constrained explicitly.
2607 In_Aggr_Type := True;
2609 Base_Typ := Base_Type (Typ);
2610 while Is_Derived_Type (Base_Typ)
2611 and then
2612 (Present (Stored_Constraint (Base_Typ))
2613 or else
2614 (In_Aggr_Type and then Present (Stored_Constraint (Typ))))
2615 loop
2616 Par_Typ := Etype (Base_Typ);
2618 if not Has_Discriminants (Par_Typ) then
2619 return;
2620 end if;
2622 Discr := First_Discriminant (Par_Typ);
2624 -- We know that one of the stored-constraint lists is present
2626 if Present (Stored_Constraint (Base_Typ)) then
2627 Discr_Constr := First_Elmt (Stored_Constraint (Base_Typ));
2629 -- For private extension, stored constraint may be on full view
2631 elsif Is_Private_Type (Base_Typ)
2632 and then Present (Full_View (Base_Typ))
2633 and then Present (Stored_Constraint (Full_View (Base_Typ)))
2634 then
2635 Discr_Constr :=
2636 First_Elmt (Stored_Constraint (Full_View (Base_Typ)));
2638 -- Otherwise, no discriminant to process
2640 else
2641 Discr_Constr := No_Elmt;
2642 end if;
2644 while Present (Discr) and then Present (Discr_Constr) loop
2645 Discr_Val := Node (Discr_Constr);
2647 -- The parent discriminant is renamed in the derived type,
2648 -- nothing to initialize.
2650 -- type Deriv_Typ (Discr : ...)
2651 -- is new Parent_Typ (Discr => Discr);
2653 if Is_Entity_Name (Discr_Val)
2654 and then Ekind (Entity (Discr_Val)) = E_Discriminant
2655 then
2656 null;
2658 -- When the parent discriminant is constrained at the type
2659 -- extension level, it does not appear in the derived type.
2661 -- type Deriv_Typ (Discr : ...)
2662 -- is new Parent_Typ (Discr => Discr,
2663 -- Hidden_Discr => Expression);
2665 elsif Is_Completely_Hidden_Discriminant (Discr) then
2666 null;
2668 -- Otherwise initialize the discriminant
2670 else
2671 Discr_Init :=
2672 Make_OK_Assignment_Statement (Loc,
2673 Name =>
2674 Make_Selected_Component (Loc,
2675 Prefix => New_Copy_Tree (Target),
2676 Selector_Name => New_Occurrence_Of (Discr, Loc)),
2677 Expression => New_Copy_Tree (Discr_Val));
2679 Append_To (List, Discr_Init);
2680 end if;
2682 Next_Elmt (Discr_Constr);
2683 Next_Discriminant (Discr);
2684 end loop;
2686 In_Aggr_Type := False;
2687 Base_Typ := Base_Type (Par_Typ);
2688 end loop;
2689 end Init_Hidden_Discriminants;
2691 --------------------------------
2692 -- Init_Visible_Discriminants --
2693 --------------------------------
2695 procedure Init_Visible_Discriminants is
2696 Discriminant : Entity_Id;
2697 Discriminant_Value : Node_Id;
2699 begin
2700 Discriminant := First_Discriminant (Typ);
2701 while Present (Discriminant) loop
2702 Comp_Expr :=
2703 Make_Selected_Component (Loc,
2704 Prefix => New_Copy_Tree (Target),
2705 Selector_Name => New_Occurrence_Of (Discriminant, Loc));
2707 Discriminant_Value :=
2708 Get_Discriminant_Value
2709 (Discriminant, Typ, Discriminant_Constraint (N_Typ));
2711 Instr :=
2712 Make_OK_Assignment_Statement (Loc,
2713 Name => Comp_Expr,
2714 Expression => New_Copy_Tree (Discriminant_Value));
2716 Append_To (L, Instr);
2718 Next_Discriminant (Discriminant);
2719 end loop;
2720 end Init_Visible_Discriminants;
2722 -------------------------------
2723 -- Init_Stored_Discriminants --
2724 -------------------------------
2726 procedure Init_Stored_Discriminants is
2727 Discriminant : Entity_Id;
2728 Discriminant_Value : Node_Id;
2730 begin
2731 Discriminant := First_Stored_Discriminant (Typ);
2732 while Present (Discriminant) loop
2733 Comp_Expr :=
2734 Make_Selected_Component (Loc,
2735 Prefix => New_Copy_Tree (Target),
2736 Selector_Name => New_Occurrence_Of (Discriminant, Loc));
2738 Discriminant_Value :=
2739 Get_Discriminant_Value
2740 (Discriminant, N_Typ, Discriminant_Constraint (N_Typ));
2742 Instr :=
2743 Make_OK_Assignment_Statement (Loc,
2744 Name => Comp_Expr,
2745 Expression => New_Copy_Tree (Discriminant_Value));
2747 Append_To (L, Instr);
2749 Next_Stored_Discriminant (Discriminant);
2750 end loop;
2751 end Init_Stored_Discriminants;
2753 -------------------------
2754 -- Is_Int_Range_Bounds --
2755 -------------------------
2757 function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean is
2758 begin
2759 return Nkind (Bounds) = N_Range
2760 and then Nkind (Low_Bound (Bounds)) = N_Integer_Literal
2761 and then Nkind (High_Bound (Bounds)) = N_Integer_Literal;
2762 end Is_Int_Range_Bounds;
2764 ------------------
2765 -- Replace_Type --
2766 ------------------
2768 function Replace_Type (Expr : Node_Id) return Traverse_Result is
2769 begin
2770 -- Note about the Is_Ancestor test below: aggregate components for
2771 -- self-referential types include attribute references to the current
2772 -- instance, of the form: Typ'access, etc. These references are
2773 -- rewritten as references to the target of the aggregate: the
2774 -- left-hand side of an assignment, the entity in a declaration,
2775 -- or a temporary. Without this test, we would improperly extend
2776 -- this rewriting to attribute references whose prefix is not the
2777 -- type of the aggregate.
2779 if Nkind (Expr) = N_Attribute_Reference
2780 and then Is_Entity_Name (Prefix (Expr))
2781 and then Is_Type (Entity (Prefix (Expr)))
2782 and then
2783 Is_Ancestor
2784 (Entity (Prefix (Expr)), Etype (N), Use_Full_View => True)
2785 then
2786 if Is_Entity_Name (Lhs) then
2787 Rewrite (Prefix (Expr), New_Occurrence_Of (Entity (Lhs), Loc));
2789 else
2790 Rewrite (Expr,
2791 Make_Attribute_Reference (Loc,
2792 Attribute_Name => Name_Unrestricted_Access,
2793 Prefix => New_Copy_Tree (Lhs)));
2794 Set_Analyzed (Parent (Expr), False);
2795 end if;
2796 end if;
2798 return OK;
2799 end Replace_Type;
2801 --------------------------
2802 -- Rewrite_Discriminant --
2803 --------------------------
2805 function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result is
2806 begin
2807 if Is_Entity_Name (Expr)
2808 and then Present (Entity (Expr))
2809 and then Ekind (Entity (Expr)) = E_In_Parameter
2810 and then Present (Discriminal_Link (Entity (Expr)))
2811 and then Scope (Discriminal_Link (Entity (Expr))) =
2812 Base_Type (Etype (N))
2813 then
2814 Rewrite (Expr,
2815 Make_Selected_Component (Loc,
2816 Prefix => New_Copy_Tree (Lhs),
2817 Selector_Name => Make_Identifier (Loc, Chars (Expr))));
2819 -- The generated code will be reanalyzed, but if the reference
2820 -- to the discriminant appears within an already analyzed
2821 -- expression (e.g. a conditional) we must set its proper entity
2822 -- now. Context is an initialization procedure.
2824 Analyze (Expr);
2825 end if;
2827 return OK;
2828 end Rewrite_Discriminant;
2830 procedure Replace_Discriminants is
2831 new Traverse_Proc (Rewrite_Discriminant);
2833 procedure Replace_Self_Reference is
2834 new Traverse_Proc (Replace_Type);
2836 -- Start of processing for Build_Record_Aggr_Code
2838 begin
2839 if Has_Self_Reference (N) then
2840 Replace_Self_Reference (N);
2841 end if;
2843 -- If the target of the aggregate is class-wide, we must convert it
2844 -- to the actual type of the aggregate, so that the proper components
2845 -- are visible. We know already that the types are compatible.
2847 if Present (Etype (Lhs)) and then Is_Class_Wide_Type (Etype (Lhs)) then
2848 Target := Unchecked_Convert_To (Typ, Lhs);
2849 else
2850 Target := Lhs;
2851 end if;
2853 -- Deal with the ancestor part of extension aggregates or with the
2854 -- discriminants of the root type.
2856 if Nkind (N) = N_Extension_Aggregate then
2857 declare
2858 Ancestor : constant Node_Id := Ancestor_Part (N);
2859 Ancestor_Q : constant Node_Id := Unqualify (Ancestor);
2861 Assign : List_Id;
2863 begin
2864 -- If the ancestor part is a subtype mark T, we generate
2866 -- init-proc (T (tmp)); if T is constrained and
2867 -- init-proc (S (tmp)); where S applies an appropriate
2868 -- constraint if T is unconstrained
2870 if Is_Entity_Name (Ancestor)
2871 and then Is_Type (Entity (Ancestor))
2872 then
2873 Ancestor_Is_Subtype_Mark := True;
2875 if Is_Constrained (Entity (Ancestor)) then
2876 Init_Typ := Entity (Ancestor);
2878 -- For an ancestor part given by an unconstrained type mark,
2879 -- create a subtype constrained by appropriate corresponding
2880 -- discriminant values coming from either associations of the
2881 -- aggregate or a constraint on a parent type. The subtype will
2882 -- be used to generate the correct default value for the
2883 -- ancestor part.
2885 elsif Has_Discriminants (Entity (Ancestor)) then
2886 declare
2887 Anc_Typ : constant Entity_Id := Entity (Ancestor);
2888 Anc_Constr : constant List_Id := New_List;
2889 Discrim : Entity_Id;
2890 Disc_Value : Node_Id;
2891 New_Indic : Node_Id;
2892 Subt_Decl : Node_Id;
2894 begin
2895 Discrim := First_Discriminant (Anc_Typ);
2896 while Present (Discrim) loop
2897 Disc_Value := Ancestor_Discriminant_Value (Discrim);
2899 -- If no usable discriminant in ancestors, check
2900 -- whether aggregate has an explicit value for it.
2902 if No (Disc_Value) then
2903 Disc_Value :=
2904 Get_Explicit_Discriminant_Value (Discrim);
2905 end if;
2907 Append_To (Anc_Constr, Disc_Value);
2908 Next_Discriminant (Discrim);
2909 end loop;
2911 New_Indic :=
2912 Make_Subtype_Indication (Loc,
2913 Subtype_Mark => New_Occurrence_Of (Anc_Typ, Loc),
2914 Constraint =>
2915 Make_Index_Or_Discriminant_Constraint (Loc,
2916 Constraints => Anc_Constr));
2918 Init_Typ := Create_Itype (Ekind (Anc_Typ), N);
2920 Subt_Decl :=
2921 Make_Subtype_Declaration (Loc,
2922 Defining_Identifier => Init_Typ,
2923 Subtype_Indication => New_Indic);
2925 -- Itypes must be analyzed with checks off Declaration
2926 -- must have a parent for proper handling of subsidiary
2927 -- actions.
2929 Set_Parent (Subt_Decl, N);
2930 Analyze (Subt_Decl, Suppress => All_Checks);
2931 end;
2932 end if;
2934 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2935 Set_Assignment_OK (Ref);
2937 if not Is_Interface (Init_Typ) then
2938 Append_List_To (L,
2939 Build_Initialization_Call (Loc,
2940 Id_Ref => Ref,
2941 Typ => Init_Typ,
2942 In_Init_Proc => Within_Init_Proc,
2943 With_Default_Init => Has_Default_Init_Comps (N)
2944 or else
2945 Has_Task (Base_Type (Init_Typ))));
2947 if Is_Constrained (Entity (Ancestor))
2948 and then Has_Discriminants (Entity (Ancestor))
2949 then
2950 Check_Ancestor_Discriminants (Entity (Ancestor));
2951 end if;
2953 -- If ancestor type has Default_Initialization_Condition,
2954 -- add a DIC check after the ancestor object is initialized
2955 -- by default.
2957 if Has_DIC (Entity (Ancestor))
2958 and then Present (DIC_Procedure (Entity (Ancestor)))
2959 then
2960 Append_To (L,
2961 Build_DIC_Call
2962 (Loc, New_Copy_Tree (Ref), Entity (Ancestor)));
2963 end if;
2964 end if;
2966 -- Handle calls to C++ constructors
2968 elsif Is_CPP_Constructor_Call (Ancestor) then
2969 Init_Typ := Etype (Ancestor);
2970 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2971 Set_Assignment_OK (Ref);
2973 Append_List_To (L,
2974 Build_Initialization_Call (Loc,
2975 Id_Ref => Ref,
2976 Typ => Init_Typ,
2977 In_Init_Proc => Within_Init_Proc,
2978 With_Default_Init => Has_Default_Init_Comps (N),
2979 Constructor_Ref => Ancestor));
2981 -- Ada 2005 (AI-287): If the ancestor part is an aggregate of
2982 -- limited type, a recursive call expands the ancestor. Note that
2983 -- in the limited case, the ancestor part must be either a
2984 -- function call (possibly qualified) or aggregate (definitely
2985 -- qualified).
2987 elsif Is_Limited_Type (Etype (Ancestor))
2988 and then Nkind (Ancestor_Q) in N_Aggregate
2989 | N_Extension_Aggregate
2990 then
2991 Append_List_To (L,
2992 Build_Record_Aggr_Code
2993 (N => Ancestor_Q,
2994 Typ => Etype (Ancestor_Q),
2995 Lhs => Target));
2997 -- If the ancestor part is an expression E of type T, we generate
2999 -- T (tmp) := E;
3001 -- In Ada 2005, this includes the case of a (possibly qualified)
3002 -- limited function call. The assignment will later be turned into
3003 -- a build-in-place function call (for further details, see
3004 -- Make_Build_In_Place_Call_In_Assignment).
3006 else
3007 Init_Typ := Etype (Ancestor);
3009 -- If the ancestor part is an aggregate, force its full
3010 -- expansion, which was delayed.
3012 if Nkind (Ancestor_Q) in N_Aggregate | N_Extension_Aggregate
3013 then
3014 Set_Analyzed (Ancestor, False);
3015 Set_Analyzed (Expression (Ancestor), False);
3016 end if;
3018 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
3020 Assign := New_List (
3021 Make_OK_Assignment_Statement (Loc,
3022 Name => Ref,
3023 Expression => Ancestor));
3025 -- Arrange for the component to be adjusted if need be (the
3026 -- call will be generated by Make_Tag_Ctrl_Assignment).
3028 if Needs_Finalization (Init_Typ)
3029 and then not Is_Limited_View (Init_Typ)
3030 then
3031 Set_No_Finalize_Actions (First (Assign));
3032 else
3033 Set_No_Ctrl_Actions (First (Assign));
3034 end if;
3036 Append_To (L,
3037 Make_Suppress_Block (Loc, Name_Discriminant_Check, Assign));
3039 if Has_Discriminants (Init_Typ) then
3040 Check_Ancestor_Discriminants (Init_Typ);
3041 end if;
3042 end if;
3043 end;
3045 -- Generate assignments of hidden discriminants. If the base type is
3046 -- an unchecked union, the discriminants are unknown to the back-end
3047 -- and absent from a value of the type, so assignments for them are
3048 -- not emitted.
3050 if Has_Discriminants (Typ)
3051 and then not Is_Unchecked_Union (Base_Type (Typ))
3052 then
3053 Init_Hidden_Discriminants (Typ, L);
3054 end if;
3056 -- Normal case (not an extension aggregate)
3058 else
3059 -- Generate the discriminant expressions, component by component.
3060 -- If the base type is an unchecked union, the discriminants are
3061 -- unknown to the back-end and absent from a value of the type, so
3062 -- assignments for them are not emitted.
3064 if Has_Discriminants (Typ)
3065 and then not Is_Unchecked_Union (Base_Type (Typ))
3066 then
3067 Init_Hidden_Discriminants (Typ, L);
3069 -- Generate discriminant init values for the visible discriminants
3071 Init_Visible_Discriminants;
3073 if Is_Derived_Type (N_Typ) then
3074 Init_Stored_Discriminants;
3075 end if;
3076 end if;
3077 end if;
3079 -- For CPP types we generate an implicit call to the C++ default
3080 -- constructor to ensure the proper initialization of the _Tag
3081 -- component.
3083 if Is_CPP_Class (Root_Type (Typ)) and then CPP_Num_Prims (Typ) > 0 then
3084 Invoke_Constructor : declare
3085 CPP_Parent : constant Entity_Id := Enclosing_CPP_Parent (Typ);
3087 procedure Invoke_IC_Proc (T : Entity_Id);
3088 -- Recursive routine used to climb to parents. Required because
3089 -- parents must be initialized before descendants to ensure
3090 -- propagation of inherited C++ slots.
3092 --------------------
3093 -- Invoke_IC_Proc --
3094 --------------------
3096 procedure Invoke_IC_Proc (T : Entity_Id) is
3097 begin
3098 -- Avoid generating extra calls. Initialization required
3099 -- only for types defined from the level of derivation of
3100 -- type of the constructor and the type of the aggregate.
3102 if T = CPP_Parent then
3103 return;
3104 end if;
3106 Invoke_IC_Proc (Etype (T));
3108 -- Generate call to the IC routine
3110 if Present (CPP_Init_Proc (T)) then
3111 Append_To (L,
3112 Make_Procedure_Call_Statement (Loc,
3113 Name => New_Occurrence_Of (CPP_Init_Proc (T), Loc)));
3114 end if;
3115 end Invoke_IC_Proc;
3117 -- Start of processing for Invoke_Constructor
3119 begin
3120 -- Implicit invocation of the C++ constructor
3122 if Nkind (N) = N_Aggregate then
3123 Append_To (L,
3124 Make_Procedure_Call_Statement (Loc,
3125 Name =>
3126 New_Occurrence_Of (Base_Init_Proc (CPP_Parent), Loc),
3127 Parameter_Associations => New_List (
3128 Unchecked_Convert_To (CPP_Parent,
3129 New_Copy_Tree (Lhs)))));
3130 end if;
3132 Invoke_IC_Proc (Typ);
3133 end Invoke_Constructor;
3134 end if;
3136 -- Generate the assignments, component by component
3138 -- tmp.comp1 := Expr1_From_Aggr;
3139 -- tmp.comp2 := Expr2_From_Aggr;
3140 -- ....
3142 Comp := First (Component_Associations (N));
3143 while Present (Comp) loop
3144 Selector := Entity (First (Choices (Comp)));
3145 pragma Assert (Present (Selector));
3147 -- C++ constructors
3149 if Is_CPP_Constructor_Call (Expression (Comp)) then
3150 Append_List_To (L,
3151 Build_Initialization_Call (Loc,
3152 Id_Ref =>
3153 Make_Selected_Component (Loc,
3154 Prefix => New_Copy_Tree (Target),
3155 Selector_Name => New_Occurrence_Of (Selector, Loc)),
3156 Typ => Etype (Selector),
3157 Enclos_Type => Typ,
3158 With_Default_Init => True,
3159 Constructor_Ref => Expression (Comp)));
3161 elsif Box_Present (Comp)
3162 and then Needs_Simple_Initialization (Etype (Selector))
3163 then
3164 Comp_Expr :=
3165 Make_Selected_Component (Loc,
3166 Prefix => New_Copy_Tree (Target),
3167 Selector_Name => New_Occurrence_Of (Selector, Loc));
3169 Initialize_Component
3170 (N => N,
3171 Comp => Comp_Expr,
3172 Comp_Typ => Etype (Selector),
3173 Init_Expr => Get_Simple_Init_Val
3174 (Typ => Etype (Selector),
3175 N => Comp,
3176 Size =>
3177 (if Known_Esize (Selector)
3178 then Esize (Selector)
3179 else Uint_0)),
3180 Stmts => L);
3182 -- Ada 2005 (AI-287): For each default-initialized component generate
3183 -- a call to the corresponding IP subprogram if available.
3185 elsif Box_Present (Comp)
3186 and then Has_Non_Null_Base_Init_Proc (Etype (Selector))
3187 then
3188 if Ekind (Selector) /= E_Discriminant then
3189 Generate_Finalization_Actions;
3190 end if;
3192 -- Ada 2005 (AI-287): If the component type has tasks then
3193 -- generate the activation chain and master entities (except
3194 -- in case of an allocator because in that case these entities
3195 -- are generated by Build_Task_Allocate_Block_With_Init_Stmts).
3197 declare
3198 Ctype : constant Entity_Id := Etype (Selector);
3199 Inside_Allocator : Boolean := False;
3200 P : Node_Id := Parent (N);
3202 begin
3203 if Is_Task_Type (Ctype) or else Has_Task (Ctype) then
3204 while Present (P) loop
3205 if Nkind (P) = N_Allocator then
3206 Inside_Allocator := True;
3207 exit;
3208 end if;
3210 P := Parent (P);
3211 end loop;
3213 if not Inside_Init_Proc and not Inside_Allocator then
3214 Build_Activation_Chain_Entity (N);
3215 end if;
3216 end if;
3217 end;
3219 Append_List_To (L,
3220 Build_Initialization_Call (Loc,
3221 Id_Ref => Make_Selected_Component (Loc,
3222 Prefix => New_Copy_Tree (Target),
3223 Selector_Name =>
3224 New_Occurrence_Of (Selector, Loc)),
3225 Typ => Etype (Selector),
3226 Enclos_Type => Typ,
3227 With_Default_Init => True));
3229 -- Prepare for component assignment
3231 elsif Ekind (Selector) /= E_Discriminant
3232 or else Nkind (N) = N_Extension_Aggregate
3233 then
3234 -- All the discriminants have now been assigned
3236 -- This is now a good moment to initialize and attach all the
3237 -- controllers. Their position may depend on the discriminants.
3239 if Ekind (Selector) /= E_Discriminant then
3240 Generate_Finalization_Actions;
3241 end if;
3243 Comp_Type := Underlying_Type (Etype (Selector));
3244 Comp_Expr :=
3245 Make_Selected_Component (Loc,
3246 Prefix => New_Copy_Tree (Target),
3247 Selector_Name => New_Occurrence_Of (Selector, Loc));
3249 Expr_Q := Unqualify (Expression (Comp));
3251 -- Now either create the assignment or generate the code for the
3252 -- inner aggregate top-down.
3254 if Is_Delayed_Aggregate (Expr_Q) then
3256 -- We have the following case of aggregate nesting inside
3257 -- an object declaration:
3259 -- type Arr_Typ is array (Integer range <>) of ...;
3261 -- type Rec_Typ (...) is record
3262 -- Obj_Arr_Typ : Arr_Typ (A .. B);
3263 -- end record;
3265 -- Obj_Rec_Typ : Rec_Typ := (...,
3266 -- Obj_Arr_Typ => (X => (...), Y => (...)));
3268 -- The length of the ranges of the aggregate and Obj_Add_Typ
3269 -- are equal (B - A = Y - X), but they do not coincide (X /=
3270 -- A and B /= Y). This case requires array sliding which is
3271 -- performed in the following manner:
3273 -- subtype Arr_Sub is Arr_Typ (X .. Y);
3274 -- Temp : Arr_Sub;
3275 -- Temp (X) := (...);
3276 -- ...
3277 -- Temp (Y) := (...);
3278 -- Obj_Rec_Typ.Obj_Arr_Typ := Temp;
3280 if Ekind (Comp_Type) = E_Array_Subtype
3281 and then Is_Int_Range_Bounds (Aggregate_Bounds (Expr_Q))
3282 and then Is_Int_Range_Bounds (First_Index (Comp_Type))
3283 and then not
3284 Compatible_Int_Bounds
3285 (Agg_Bounds => Aggregate_Bounds (Expr_Q),
3286 Typ_Bounds => First_Index (Comp_Type))
3287 then
3288 -- Create the array subtype with bounds equal to those of
3289 -- the corresponding aggregate.
3291 declare
3292 SubE : constant Entity_Id := Make_Temporary (Loc, 'T');
3294 SubD : constant Node_Id :=
3295 Make_Subtype_Declaration (Loc,
3296 Defining_Identifier => SubE,
3297 Subtype_Indication =>
3298 Make_Subtype_Indication (Loc,
3299 Subtype_Mark =>
3300 New_Occurrence_Of (Etype (Comp_Type), Loc),
3301 Constraint =>
3302 Make_Index_Or_Discriminant_Constraint
3303 (Loc,
3304 Constraints => New_List (
3305 New_Copy_Tree
3306 (Aggregate_Bounds (Expr_Q))))));
3308 -- Create a temporary array of the above subtype which
3309 -- will be used to capture the aggregate assignments.
3311 TmpE : constant Entity_Id := Make_Temporary (Loc, 'A', N);
3313 TmpD : constant Node_Id :=
3314 Make_Object_Declaration (Loc,
3315 Defining_Identifier => TmpE,
3316 Object_Definition => New_Occurrence_Of (SubE, Loc));
3318 begin
3319 Set_No_Initialization (TmpD);
3320 Append_To (L, SubD);
3321 Append_To (L, TmpD);
3323 -- Expand aggregate into assignments to the temp array
3325 Append_List_To (L,
3326 Late_Expansion (Expr_Q, Comp_Type,
3327 New_Occurrence_Of (TmpE, Loc)));
3329 -- Slide
3331 Append_To (L,
3332 Make_Assignment_Statement (Loc,
3333 Name => New_Copy_Tree (Comp_Expr),
3334 Expression => New_Occurrence_Of (TmpE, Loc)));
3335 end;
3337 -- Normal case (sliding not required)
3339 else
3340 Append_List_To (L,
3341 Late_Expansion (Expr_Q, Comp_Type, Comp_Expr));
3342 end if;
3344 -- Expr_Q is not delayed aggregate
3346 else
3347 if Has_Discriminants (Typ) then
3348 Replace_Discriminants (Expr_Q);
3350 -- If the component is an array type that depends on
3351 -- discriminants, and the expression is a single Others
3352 -- clause, create an explicit subtype for it because the
3353 -- backend has troubles recovering the actual bounds.
3355 if Nkind (Expr_Q) = N_Aggregate
3356 and then Is_Array_Type (Comp_Type)
3357 and then Present (Component_Associations (Expr_Q))
3358 then
3359 declare
3360 Assoc : constant Node_Id :=
3361 First (Component_Associations (Expr_Q));
3362 Decl : Node_Id;
3364 begin
3365 if Present (Assoc)
3366 and then
3367 Nkind (First (Choices (Assoc))) = N_Others_Choice
3368 then
3369 Decl :=
3370 Build_Actual_Subtype_Of_Component
3371 (Comp_Type, Comp_Expr);
3373 -- If the component type does not in fact depend on
3374 -- discriminants, the subtype declaration is empty.
3376 if Present (Decl) then
3377 Append_To (L, Decl);
3378 Set_Etype (Comp_Expr, Defining_Entity (Decl));
3379 end if;
3380 end if;
3381 end;
3382 end if;
3383 end if;
3385 if Modify_Tree_For_C
3386 and then Nkind (Expr_Q) = N_Aggregate
3387 and then Is_Array_Type (Etype (Expr_Q))
3388 and then Present (First_Index (Etype (Expr_Q)))
3389 then
3390 declare
3391 Expr_Q_Type : constant Entity_Id := Etype (Expr_Q);
3392 begin
3393 Append_List_To (L,
3394 Build_Array_Aggr_Code
3395 (N => Expr_Q,
3396 Ctype => Component_Type (Expr_Q_Type),
3397 Index => First_Index (Expr_Q_Type),
3398 Into => Comp_Expr,
3399 Scalar_Comp =>
3400 Is_Scalar_Type (Component_Type (Expr_Q_Type))));
3401 end;
3403 else
3404 Initialize_Component
3405 (N => N,
3406 Comp => Comp_Expr,
3407 Comp_Typ => Etype (Selector),
3408 Init_Expr => Expr_Q,
3409 Stmts => L);
3410 end if;
3411 end if;
3413 -- comment would be good here ???
3415 elsif Ekind (Selector) = E_Discriminant
3416 and then Nkind (N) /= N_Extension_Aggregate
3417 and then Nkind (Parent (N)) = N_Component_Association
3418 and then Is_Constrained (Typ)
3419 then
3420 -- We must check that the discriminant value imposed by the
3421 -- context is the same as the value given in the subaggregate,
3422 -- because after the expansion into assignments there is no
3423 -- record on which to perform a regular discriminant check.
3425 declare
3426 D_Val : Elmt_Id;
3427 Disc : Entity_Id;
3429 begin
3430 D_Val := First_Elmt (Discriminant_Constraint (Typ));
3431 Disc := First_Discriminant (Typ);
3432 while Chars (Disc) /= Chars (Selector) loop
3433 Next_Discriminant (Disc);
3434 Next_Elmt (D_Val);
3435 end loop;
3437 pragma Assert (Present (D_Val));
3439 -- This check cannot performed for components that are
3440 -- constrained by a current instance, because this is not a
3441 -- value that can be compared with the actual constraint.
3443 if Nkind (Node (D_Val)) /= N_Attribute_Reference
3444 or else not Is_Entity_Name (Prefix (Node (D_Val)))
3445 or else not Is_Type (Entity (Prefix (Node (D_Val))))
3446 then
3447 Append_To (L,
3448 Make_Raise_Constraint_Error (Loc,
3449 Condition =>
3450 Make_Op_Ne (Loc,
3451 Left_Opnd => New_Copy_Tree (Node (D_Val)),
3452 Right_Opnd => Expression (Comp)),
3453 Reason => CE_Discriminant_Check_Failed));
3455 else
3456 -- Find self-reference in previous discriminant assignment,
3457 -- and replace with proper expression.
3459 declare
3460 Ass : Node_Id;
3462 begin
3463 Ass := First (L);
3464 while Present (Ass) loop
3465 if Nkind (Ass) = N_Assignment_Statement
3466 and then Nkind (Name (Ass)) = N_Selected_Component
3467 and then Chars (Selector_Name (Name (Ass))) =
3468 Chars (Disc)
3469 then
3470 Set_Expression
3471 (Ass, New_Copy_Tree (Expression (Comp)));
3472 exit;
3473 end if;
3474 Next (Ass);
3475 end loop;
3476 end;
3477 end if;
3478 end;
3479 end if;
3481 -- If the component association was specified with a box and the
3482 -- component type has a Default_Initial_Condition, then generate
3483 -- a call to the DIC procedure.
3485 if Has_DIC (Etype (Selector))
3486 and then Was_Default_Init_Box_Association (Comp)
3487 and then Present (DIC_Procedure (Etype (Selector)))
3488 then
3489 Append_To (L,
3490 Build_DIC_Call (Loc,
3491 Make_Selected_Component (Loc,
3492 Prefix => New_Copy_Tree (Target),
3493 Selector_Name => New_Occurrence_Of (Selector, Loc)),
3494 Etype (Selector)));
3495 end if;
3497 Next (Comp);
3498 end loop;
3500 -- For CPP types we generated a call to the C++ default constructor
3501 -- before the components have been initialized to ensure the proper
3502 -- initialization of the _Tag component (see above).
3504 if Is_CPP_Class (Typ) then
3505 null;
3507 -- If the type is tagged, the tag needs to be initialized (unless we
3508 -- are in VM-mode where tags are implicit). It is done late in the
3509 -- initialization process because in some cases, we call the init
3510 -- proc of an ancestor which will not leave out the right tag.
3512 elsif Is_Tagged_Type (Typ) and then Tagged_Type_Expansion then
3513 Instr :=
3514 Make_Tag_Assignment_From_Type
3515 (Loc, New_Copy_Tree (Target), Base_Type (Typ));
3517 Append_To (L, Instr);
3519 -- Ada 2005 (AI-251): If the tagged type has been derived from an
3520 -- abstract interfaces we must also initialize the tags of the
3521 -- secondary dispatch tables.
3523 if Has_Interfaces (Base_Type (Typ)) then
3524 Init_Secondary_Tags
3525 (Typ => Base_Type (Typ),
3526 Target => Target,
3527 Stmts_List => L,
3528 Init_Tags_List => L);
3529 end if;
3530 end if;
3532 -- If the controllers have not been initialized yet (by lack of non-
3533 -- discriminant components), let's do it now.
3535 Generate_Finalization_Actions;
3537 return L;
3538 end Build_Record_Aggr_Code;
3540 -------------------------------
3541 -- Convert_Aggr_In_Allocator --
3542 -------------------------------
3544 procedure Convert_Aggr_In_Allocator
3545 (Alloc : Node_Id;
3546 Decl : Node_Id;
3547 Aggr : Node_Id)
3549 Loc : constant Source_Ptr := Sloc (Aggr);
3550 Typ : constant Entity_Id := Etype (Aggr);
3551 Temp : constant Entity_Id := Defining_Identifier (Decl);
3553 Occ : constant Node_Id :=
3554 Unchecked_Convert_To (Typ,
3555 Make_Explicit_Dereference (Loc, New_Occurrence_Of (Temp, Loc)));
3557 begin
3558 if Is_Array_Type (Typ) then
3559 Convert_Array_Aggr_In_Allocator (Decl, Aggr, Occ);
3561 elsif Has_Default_Init_Comps (Aggr) then
3562 declare
3563 L : constant List_Id := New_List;
3564 Init_Stmts : List_Id;
3566 begin
3567 Init_Stmts := Late_Expansion (Aggr, Typ, Occ);
3569 if Has_Task (Typ) then
3570 Build_Task_Allocate_Block_With_Init_Stmts (L, Aggr, Init_Stmts);
3571 Insert_Actions (Alloc, L);
3572 else
3573 Insert_Actions (Alloc, Init_Stmts);
3574 end if;
3575 end;
3577 else
3578 Insert_Actions (Alloc, Late_Expansion (Aggr, Typ, Occ));
3579 end if;
3580 end Convert_Aggr_In_Allocator;
3582 --------------------------------
3583 -- Convert_Aggr_In_Assignment --
3584 --------------------------------
3586 procedure Convert_Aggr_In_Assignment (N : Node_Id) is
3587 Aggr : constant Node_Id := Unqualify (Expression (N));
3588 Typ : constant Entity_Id := Etype (Aggr);
3589 Occ : constant Node_Id := New_Copy_Tree (Name (N));
3591 begin
3592 Insert_Actions_After (N, Late_Expansion (Aggr, Typ, Occ));
3593 end Convert_Aggr_In_Assignment;
3595 ---------------------------------
3596 -- Convert_Aggr_In_Object_Decl --
3597 ---------------------------------
3599 procedure Convert_Aggr_In_Object_Decl (N : Node_Id) is
3600 Obj : constant Entity_Id := Defining_Identifier (N);
3601 Aggr : constant Node_Id := Unqualify (Expression (N));
3602 Loc : constant Source_Ptr := Sloc (Aggr);
3603 Typ : constant Entity_Id := Etype (Aggr);
3604 Occ : constant Node_Id := New_Occurrence_Of (Obj, Loc);
3606 Has_Transient_Scope : Boolean := False;
3608 function Discriminants_Ok return Boolean;
3609 -- If the object type is constrained, the discriminants in the
3610 -- aggregate must be checked against the discriminants of the subtype.
3611 -- This cannot be done using Apply_Discriminant_Checks because after
3612 -- expansion there is no aggregate left to check.
3614 ----------------------
3615 -- Discriminants_Ok --
3616 ----------------------
3618 function Discriminants_Ok return Boolean is
3619 Cond : Node_Id := Empty;
3620 Check : Node_Id;
3621 D : Entity_Id;
3622 Disc1 : Elmt_Id;
3623 Disc2 : Elmt_Id;
3624 Val1 : Node_Id;
3625 Val2 : Node_Id;
3627 begin
3628 D := First_Discriminant (Typ);
3629 Disc1 := First_Elmt (Discriminant_Constraint (Typ));
3630 Disc2 := First_Elmt (Discriminant_Constraint (Etype (Obj)));
3631 while Present (Disc1) and then Present (Disc2) loop
3632 Val1 := Node (Disc1);
3633 Val2 := Node (Disc2);
3635 if not Is_OK_Static_Expression (Val1)
3636 or else not Is_OK_Static_Expression (Val2)
3637 then
3638 Check := Make_Op_Ne (Loc,
3639 Left_Opnd => Duplicate_Subexpr (Val1),
3640 Right_Opnd => Duplicate_Subexpr (Val2));
3642 if No (Cond) then
3643 Cond := Check;
3645 else
3646 Cond := Make_Or_Else (Loc,
3647 Left_Opnd => Cond,
3648 Right_Opnd => Check);
3649 end if;
3651 elsif Expr_Value (Val1) /= Expr_Value (Val2) then
3652 Apply_Compile_Time_Constraint_Error (Aggr,
3653 Msg => "incorrect value for discriminant&??",
3654 Reason => CE_Discriminant_Check_Failed,
3655 Ent => D);
3656 return False;
3657 end if;
3659 Next_Discriminant (D);
3660 Next_Elmt (Disc1);
3661 Next_Elmt (Disc2);
3662 end loop;
3664 -- If any discriminant constraint is nonstatic, emit a check
3666 if Present (Cond) then
3667 Insert_Action (N,
3668 Make_Raise_Constraint_Error (Loc,
3669 Condition => Cond,
3670 Reason => CE_Discriminant_Check_Failed));
3671 end if;
3673 return True;
3674 end Discriminants_Ok;
3676 -- Start of processing for Convert_Aggr_In_Object_Decl
3678 begin
3679 Set_Assignment_OK (Occ);
3681 if Has_Discriminants (Typ)
3682 and then Typ /= Etype (Obj)
3683 and then Is_Constrained (Etype (Obj))
3684 and then not Discriminants_Ok
3685 then
3686 return;
3687 end if;
3689 -- If the context is an extended return statement, it has its own
3690 -- finalization machinery (i.e. works like a transient scope) and
3691 -- we do not want to create an additional one, because objects on
3692 -- the finalization list of the return must be moved to the caller's
3693 -- finalization list to complete the return.
3695 -- Similarly if the aggregate is limited, it is built in place, and the
3696 -- controlled components are not assigned to intermediate temporaries
3697 -- so there is no need for a transient scope in this case either.
3699 if Requires_Transient_Scope (Typ)
3700 and then Ekind (Current_Scope) /= E_Return_Statement
3701 and then not Is_Limited_Type (Typ)
3702 then
3703 Establish_Transient_Scope (Aggr, Manage_Sec_Stack => False);
3704 Has_Transient_Scope := True;
3705 end if;
3707 declare
3708 Stmts : constant List_Id := Late_Expansion (Aggr, Typ, Occ);
3709 Stmt : Node_Id;
3710 Param : Node_Id;
3712 begin
3713 -- If Obj is already frozen or if N is wrapped in a transient scope,
3714 -- Stmts do not need to be saved in Initialization_Statements since
3715 -- there is no freezing issue.
3717 if Is_Frozen (Obj) or else Has_Transient_Scope then
3718 Insert_Actions_After (N, Stmts);
3719 else
3720 Stmt := Make_Compound_Statement (Sloc (N), Actions => Stmts);
3721 Insert_Action_After (N, Stmt);
3723 -- Insert_Action_After may freeze Obj in which case we should
3724 -- remove the compound statement just created and simply insert
3725 -- Stmts after N.
3727 if Is_Frozen (Obj) then
3728 Remove (Stmt);
3729 Insert_Actions_After (N, Stmts);
3730 else
3731 Set_Initialization_Statements (Obj, Stmt);
3732 end if;
3733 end if;
3735 -- If Typ has controlled components and a call to a Slice_Assign
3736 -- procedure is part of the initialization statements, then we
3737 -- need to initialize the array component since Slice_Assign will
3738 -- need to adjust it.
3740 if Has_Controlled_Component (Typ) then
3741 Stmt := First (Stmts);
3743 while Present (Stmt) loop
3744 if Nkind (Stmt) = N_Procedure_Call_Statement
3745 and then Is_TSS (Entity (Name (Stmt)), TSS_Slice_Assign)
3746 then
3747 Param := First (Parameter_Associations (Stmt));
3748 Insert_Actions
3749 (Stmt,
3750 Build_Initialization_Call
3751 (Sloc (N), New_Copy_Tree (Param), Etype (Param)));
3752 end if;
3754 Next (Stmt);
3755 end loop;
3756 end if;
3757 end;
3759 Set_No_Initialization (N);
3761 -- After expansion the expression can be removed from the declaration
3762 -- except if the object is class-wide, in which case the aggregate
3763 -- provides the actual type.
3765 if not Is_Class_Wide_Type (Etype (Obj)) then
3766 Set_Expression (N, Empty);
3767 end if;
3769 Initialize_Discriminants (N, Typ);
3770 end Convert_Aggr_In_Object_Decl;
3772 -------------------------------------
3773 -- Convert_Array_Aggr_In_Allocator --
3774 -------------------------------------
3776 procedure Convert_Array_Aggr_In_Allocator
3777 (Decl : Node_Id;
3778 Aggr : Node_Id;
3779 Target : Node_Id)
3781 Typ : constant Entity_Id := Etype (Aggr);
3782 Ctyp : constant Entity_Id := Component_Type (Typ);
3783 Aggr_Code : List_Id;
3784 New_Aggr : Node_Id;
3786 begin
3787 -- The target is an explicit dereference of the allocated object
3789 -- If the assignment can be done directly by the back end, then
3790 -- reset Set_Expansion_Delayed and do not expand further.
3792 if not CodePeer_Mode
3793 and then not Modify_Tree_For_C
3794 and then Aggr_Assignment_OK_For_Backend (Aggr)
3795 then
3796 New_Aggr := New_Copy_Tree (Aggr);
3797 Set_Expansion_Delayed (New_Aggr, False);
3799 -- In the case of Target's type using the Designated_Storage_Model
3800 -- aspect with a Copy_To procedure, insert a temporary and have the
3801 -- back end handle the assignment to it. Copy the result to the
3802 -- original target.
3804 if Has_Designated_Storage_Model_Aspect
3805 (Etype (Prefix (Expression (Target))))
3806 and then Present (Storage_Model_Copy_To
3807 (Storage_Model_Object
3808 (Etype (Prefix (Expression (Target))))))
3809 then
3810 Aggr_Code :=
3811 Build_Assignment_With_Temporary (Target, Typ, New_Aggr);
3813 else
3814 Aggr_Code :=
3815 New_List (
3816 Make_OK_Assignment_Statement (Sloc (New_Aggr),
3817 Name => Target,
3818 Expression => New_Aggr));
3819 end if;
3821 -- Or else, generate component assignments to it, as for an aggregate
3822 -- that appears on the right-hand side of an assignment statement.
3823 else
3824 Aggr_Code :=
3825 Build_Array_Aggr_Code (Aggr,
3826 Ctype => Ctyp,
3827 Index => First_Index (Typ),
3828 Into => Target,
3829 Scalar_Comp => Is_Scalar_Type (Ctyp));
3830 end if;
3832 Insert_Actions_After (Decl, Aggr_Code);
3833 end Convert_Array_Aggr_In_Allocator;
3835 ------------------------
3836 -- In_Place_Assign_OK --
3837 ------------------------
3839 function In_Place_Assign_OK
3840 (N : Node_Id;
3841 Target_Object : Entity_Id := Empty) return Boolean
3843 Is_Array : constant Boolean := Is_Array_Type (Etype (N));
3845 Aggr_In : Node_Id;
3846 Aggr_Bounds : Range_Nodes;
3847 Obj_In : Node_Id;
3848 Obj_Bounds : Range_Nodes;
3849 Parent_Kind : Node_Kind;
3850 Parent_Node : Node_Id;
3852 function Safe_Aggregate (Aggr : Node_Id) return Boolean;
3853 -- Check recursively that each component of a (sub)aggregate does not
3854 -- depend on the variable being assigned to.
3856 function Safe_Component (Expr : Node_Id) return Boolean;
3857 -- Verify that an expression cannot depend on the target being assigned
3858 -- to. Return true for compile-time known values, stand-alone objects,
3859 -- parameters passed by copy, calls to functions that return by copy,
3860 -- selected components thereof only if the aggregate's type is an array,
3861 -- indexed components and slices thereof only if the aggregate's type is
3862 -- a record, and simple expressions involving only these as operands.
3863 -- This is OK whatever the target because, for a component to overlap
3864 -- with the target, it must be either a direct reference to a component
3865 -- of the target, in which case there must be a matching selection or
3866 -- indexation or slicing, or an indirect reference to such a component,
3867 -- which is excluded by the above condition. Additionally, if the target
3868 -- is statically known, return true for arbitrarily nested selections,
3869 -- indexations or slicings, provided that their ultimate prefix is not
3870 -- the target itself.
3872 --------------------
3873 -- Safe_Aggregate --
3874 --------------------
3876 function Safe_Aggregate (Aggr : Node_Id) return Boolean is
3877 Expr : Node_Id;
3879 begin
3880 if Nkind (Parent (Aggr)) = N_Iterated_Component_Association then
3881 return False;
3882 end if;
3884 if Present (Expressions (Aggr)) then
3885 Expr := First (Expressions (Aggr));
3886 while Present (Expr) loop
3887 if Nkind (Expr) = N_Aggregate then
3888 if not Safe_Aggregate (Expr) then
3889 return False;
3890 end if;
3892 elsif not Safe_Component (Expr) then
3893 return False;
3894 end if;
3896 Next (Expr);
3897 end loop;
3898 end if;
3900 if Present (Component_Associations (Aggr)) then
3901 Expr := First (Component_Associations (Aggr));
3902 while Present (Expr) loop
3903 if Nkind (Expression (Expr)) = N_Aggregate then
3904 if not Safe_Aggregate (Expression (Expr)) then
3905 return False;
3906 end if;
3908 -- If association has a box, no way to determine yet whether
3909 -- default can be assigned in place.
3911 elsif Box_Present (Expr) then
3912 return False;
3914 elsif not Safe_Component (Expression (Expr)) then
3915 return False;
3916 end if;
3918 Next (Expr);
3919 end loop;
3920 end if;
3922 return True;
3923 end Safe_Aggregate;
3925 --------------------
3926 -- Safe_Component --
3927 --------------------
3929 function Safe_Component (Expr : Node_Id) return Boolean is
3930 Comp : Node_Id := Expr;
3932 function Check_Component (C : Node_Id; T_OK : Boolean) return Boolean;
3933 -- Do the recursive traversal, after copy. If T_OK is True, return
3934 -- True for a stand-alone object only if the target is statically
3935 -- known and distinct from the object. At the top level, we start
3936 -- with T_OK set to False and set it to True at a deeper level only
3937 -- if we cannot disambiguate the component here without statically
3938 -- knowing the target. Note that this is not optimal, we should do
3939 -- something along the lines of Denotes_Same_Prefix for that.
3941 ---------------------
3942 -- Check_Component --
3943 ---------------------
3945 function Check_Component (C : Node_Id; T_OK : Boolean) return Boolean
3948 function SDO (E : Entity_Id) return Uint;
3949 -- Return the Scope Depth Of the enclosing dynamic scope of E
3951 ---------
3952 -- SDO --
3953 ---------
3955 function SDO (E : Entity_Id) return Uint is
3956 begin
3957 return Scope_Depth (Enclosing_Dynamic_Scope (E));
3958 end SDO;
3960 -- Start of processing for Check_Component
3962 begin
3963 if Is_Overloaded (C) then
3964 return False;
3966 elsif Compile_Time_Known_Value (C) then
3967 return True;
3968 end if;
3970 case Nkind (C) is
3971 when N_Attribute_Reference =>
3972 return Check_Component (Prefix (C), T_OK);
3974 when N_Function_Call =>
3975 if Nkind (Name (C)) = N_Explicit_Dereference then
3976 return not Returns_By_Ref (Etype (Name (C)));
3977 else
3978 return not Returns_By_Ref (Entity (Name (C)));
3979 end if;
3981 when N_Indexed_Component | N_Slice =>
3982 -- In a target record, these operations cannot determine
3983 -- alone a component so we can recurse whatever the target.
3984 return Check_Component (Prefix (C), T_OK or else Is_Array);
3986 when N_Selected_Component =>
3987 -- In a target array, this operation cannot determine alone
3988 -- a component so we can recurse whatever the target.
3989 return
3990 Check_Component (Prefix (C), T_OK or else not Is_Array);
3992 when N_Type_Conversion | N_Unchecked_Type_Conversion =>
3993 return Check_Component (Expression (C), T_OK);
3995 when N_Binary_Op =>
3996 return Check_Component (Left_Opnd (C), T_OK)
3997 and then Check_Component (Right_Opnd (C), T_OK);
3999 when N_Unary_Op =>
4000 return Check_Component (Right_Opnd (C), T_OK);
4002 when others =>
4003 if Is_Entity_Name (C) and then Is_Object (Entity (C)) then
4004 -- Case of a formal parameter component. It's either
4005 -- trivial if passed by copy or very annoying if not,
4006 -- because in the latter case it's almost equivalent
4007 -- to a dereference, so the path-based disambiguation
4008 -- logic is totally off and we always need the target.
4010 if Is_Formal (Entity (C)) then
4012 -- If it is passed by copy, then this is safe
4014 if Mechanism (Entity (C)) = By_Copy then
4015 return True;
4017 -- Otherwise, this is safe if the target is present
4018 -- and is at least as deeply nested as the component.
4020 else
4021 return Present (Target_Object)
4022 and then not Is_Formal (Target_Object)
4023 and then SDO (Target_Object) >= SDO (Entity (C));
4024 end if;
4026 -- For a renamed object, recurse
4028 elsif Present (Renamed_Object (Entity (C))) then
4029 return
4030 Check_Component (Renamed_Object (Entity (C)), T_OK);
4032 -- If this is safe whatever the target, we are done
4034 elsif not T_OK then
4035 return True;
4037 -- If there is no target or the component is the target,
4038 -- this is not safe.
4040 elsif No (Target_Object)
4041 or else Entity (C) = Target_Object
4042 then
4043 return False;
4045 -- Case of a formal parameter target. This is safe if it
4046 -- is at most as deeply nested as the component.
4048 elsif Is_Formal (Target_Object) then
4049 return SDO (Target_Object) <= SDO (Entity (C));
4051 -- For distinct stand-alone objects, this is safe
4053 else
4054 return True;
4055 end if;
4057 -- For anything else than an object, this is not safe
4059 else
4060 return False;
4061 end if;
4062 end case;
4063 end Check_Component;
4065 -- Start of processing for Safe_Component
4067 begin
4068 -- If the component appears in an association that may correspond
4069 -- to more than one element, it is not analyzed before expansion
4070 -- into assignments, to avoid side effects. We analyze, but do not
4071 -- resolve the copy, to obtain sufficient entity information for
4072 -- the checks that follow. If component is overloaded we assume
4073 -- an unsafe function call.
4075 if not Analyzed (Comp) then
4076 if Is_Overloaded (Expr) then
4077 return False;
4079 elsif Nkind (Expr) = N_Allocator then
4081 -- For now, too complex to analyze
4083 return False;
4085 elsif Nkind (Parent (Expr)) = N_Iterated_Component_Association then
4087 -- Ditto for iterated component associations, which in general
4088 -- require an enclosing loop and involve nonstatic expressions.
4090 return False;
4091 end if;
4093 Comp := New_Copy_Tree (Expr);
4094 Set_Parent (Comp, Parent (Expr));
4095 Analyze (Comp);
4096 end if;
4098 if Nkind (Comp) = N_Aggregate then
4099 return Safe_Aggregate (Comp);
4100 else
4101 return Check_Component (Comp, False);
4102 end if;
4103 end Safe_Component;
4105 -- Start of processing for In_Place_Assign_OK
4107 begin
4108 -- By-copy semantic cannot be guaranteed for controlled objects
4110 if Needs_Finalization (Etype (N)) then
4111 return False;
4112 end if;
4114 Parent_Node := Parent (N);
4115 Parent_Kind := Nkind (Parent_Node);
4117 if Parent_Kind = N_Qualified_Expression then
4118 Parent_Node := Parent (Parent_Node);
4119 Parent_Kind := Nkind (Parent_Node);
4120 end if;
4122 -- On assignment, sliding can take place, so we cannot do the
4123 -- assignment in place unless the bounds of the aggregate are
4124 -- statically equal to those of the target.
4126 -- If the aggregate is given by an others choice, the bounds are
4127 -- derived from the left-hand side, and the assignment is safe if
4128 -- the expression is.
4130 if Is_Array
4131 and then Present (Component_Associations (N))
4132 and then not Is_Others_Aggregate (N)
4133 then
4134 Aggr_In := First_Index (Etype (N));
4136 -- Context is an assignment
4138 if Parent_Kind = N_Assignment_Statement then
4139 Obj_In := First_Index (Etype (Name (Parent_Node)));
4141 -- Context is an allocator. Check the bounds of the aggregate against
4142 -- those of the designated type, except in the case where the type is
4143 -- unconstrained (and then we can directly return true, see below).
4145 else pragma Assert (Parent_Kind = N_Allocator);
4146 declare
4147 Desig_Typ : constant Entity_Id :=
4148 Designated_Type (Etype (Parent_Node));
4149 begin
4150 if not Is_Constrained (Desig_Typ) then
4151 return True;
4152 end if;
4154 Obj_In := First_Index (Desig_Typ);
4155 end;
4156 end if;
4158 while Present (Aggr_In) loop
4159 Aggr_Bounds := Get_Index_Bounds (Aggr_In);
4160 Obj_Bounds := Get_Index_Bounds (Obj_In);
4162 -- We require static bounds for the target and a static matching
4163 -- of low bound for the aggregate.
4165 if not Compile_Time_Known_Value (Obj_Bounds.First)
4166 or else not Compile_Time_Known_Value (Obj_Bounds.Last)
4167 or else not Compile_Time_Known_Value (Aggr_Bounds.First)
4168 or else Expr_Value (Aggr_Bounds.First) /=
4169 Expr_Value (Obj_Bounds.First)
4170 then
4171 return False;
4173 -- For an assignment statement we require static matching of
4174 -- bounds. Ditto for an allocator whose qualified expression
4175 -- is a constrained type. If the expression in the allocator
4176 -- is an unconstrained array, we accept an upper bound that
4177 -- is not static, to allow for nonstatic expressions of the
4178 -- base type. Clearly there are further possibilities (with
4179 -- diminishing returns) for safely building arrays in place
4180 -- here.
4182 elsif Parent_Kind = N_Assignment_Statement
4183 or else Is_Constrained (Etype (Parent_Node))
4184 then
4185 if not Compile_Time_Known_Value (Aggr_Bounds.Last)
4186 or else Expr_Value (Aggr_Bounds.Last) /=
4187 Expr_Value (Obj_Bounds.Last)
4188 then
4189 return False;
4190 end if;
4191 end if;
4193 Next_Index (Aggr_In);
4194 Next_Index (Obj_In);
4195 end loop;
4196 end if;
4198 -- Now check the component values themselves, except for an allocator
4199 -- for which the target is newly allocated memory.
4201 if Parent_Kind = N_Allocator then
4202 return True;
4203 else
4204 return Safe_Aggregate (N);
4205 end if;
4206 end In_Place_Assign_OK;
4208 ----------------------------
4209 -- Convert_To_Assignments --
4210 ----------------------------
4212 procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id) is
4213 Loc : constant Source_Ptr := Sloc (N);
4214 T : Entity_Id;
4215 Temp : Entity_Id;
4217 Aggr_Code : List_Id;
4218 Instr : Node_Id;
4219 Target_Expr : Node_Id;
4220 Parent_Kind : Node_Kind;
4221 Unc_Decl : Boolean := False;
4222 Parent_Node : Node_Id;
4224 begin
4225 pragma Assert (Nkind (N) in N_Aggregate | N_Extension_Aggregate);
4226 pragma Assert (not Is_Static_Dispatch_Table_Aggregate (N));
4227 pragma Assert (Is_Record_Type (Typ));
4229 Parent_Node := Parent (N);
4230 Parent_Kind := Nkind (Parent_Node);
4232 if Parent_Kind = N_Qualified_Expression then
4233 -- Check if we are in an unconstrained declaration because in this
4234 -- case the current delayed expansion mechanism doesn't work when
4235 -- the declared object size depends on the initializing expr.
4237 Parent_Node := Parent (Parent_Node);
4238 Parent_Kind := Nkind (Parent_Node);
4240 if Parent_Kind = N_Object_Declaration then
4241 Unc_Decl :=
4242 not Is_Entity_Name (Object_Definition (Parent_Node))
4243 or else (Nkind (N) = N_Aggregate
4244 and then
4245 Has_Discriminants
4246 (Entity (Object_Definition (Parent_Node))))
4247 or else Is_Class_Wide_Type
4248 (Entity (Object_Definition (Parent_Node)));
4249 end if;
4250 end if;
4252 -- Just set the Delay flag in the cases where the transformation will be
4253 -- done top down from above.
4256 -- Internal aggregates (transformed when expanding the parent),
4257 -- excluding container aggregates as these are transformed into
4258 -- subprogram calls later.
4260 (Parent_Kind = N_Component_Association
4261 and then not Is_Container_Aggregate (Parent (Parent_Node)))
4263 or else (Parent_Kind in N_Aggregate | N_Extension_Aggregate
4264 and then not Is_Container_Aggregate (Parent_Node))
4266 -- Allocator (see Convert_Aggr_In_Allocator)
4268 or else Parent_Kind = N_Allocator
4270 -- Object declaration (see Convert_Aggr_In_Object_Decl)
4272 or else (Parent_Kind = N_Object_Declaration and then not Unc_Decl)
4274 -- Safe assignment (see Convert_Aggr_Assignments). So far only the
4275 -- assignments in init procs are taken into account.
4277 or else (Parent_Kind = N_Assignment_Statement
4278 and then Inside_Init_Proc)
4280 -- (Ada 2005) An inherently limited type in a return statement, which
4281 -- will be handled in a build-in-place fashion, and may be rewritten
4282 -- as an extended return and have its own finalization machinery.
4283 -- In the case of a simple return, the aggregate needs to be delayed
4284 -- until the scope for the return statement has been created, so
4285 -- that any finalization chain will be associated with that scope.
4286 -- For extended returns, we delay expansion to avoid the creation
4287 -- of an unwanted transient scope that could result in premature
4288 -- finalization of the return object (which is built in place
4289 -- within the caller's scope).
4291 or else Is_Build_In_Place_Aggregate_Return (N)
4292 then
4293 Set_Expansion_Delayed (N);
4294 return;
4295 end if;
4297 -- Otherwise, if a transient scope is required, create it now. If we
4298 -- are within an initialization procedure do not create such, because
4299 -- the target of the assignment must not be declared within a local
4300 -- block, and because cleanup will take place on return from the
4301 -- initialization procedure.
4303 -- Should the condition be more restrictive ???
4305 if Requires_Transient_Scope (Typ) and then not Inside_Init_Proc then
4306 Establish_Transient_Scope (N, Manage_Sec_Stack => False);
4307 end if;
4309 -- If the aggregate is nonlimited, create a temporary, since aggregates
4310 -- have "by copy" semantics. If it is limited and context is an
4311 -- assignment, this is a subaggregate for an enclosing aggregate being
4312 -- expanded. It must be built in place, so use target of the current
4313 -- assignment.
4315 if Is_Limited_Type (Typ)
4316 and then Parent_Kind = N_Assignment_Statement
4317 then
4318 Target_Expr := New_Copy_Tree (Name (Parent_Node));
4319 Insert_Actions (Parent_Node,
4320 Build_Record_Aggr_Code (N, Typ, Target_Expr));
4321 Rewrite (Parent_Node, Make_Null_Statement (Loc));
4323 -- Do not declare a temporary to initialize an aggregate assigned to
4324 -- a target when in-place assignment is possible, i.e. preserving the
4325 -- by-copy semantic of aggregates. This avoids large stack usage and
4326 -- generates more efficient code.
4328 elsif Parent_Kind = N_Assignment_Statement
4329 and then In_Place_Assign_OK (N, Get_Base_Object (Name (Parent_Node)))
4330 then
4331 declare
4332 Lhs : constant Node_Id := Name (Parent_Node);
4333 begin
4334 -- Apply discriminant check if required
4336 if Has_Discriminants (Etype (N)) then
4337 Apply_Discriminant_Check (N, Etype (Lhs), Lhs);
4338 end if;
4340 -- The check just above may have replaced the aggregate with a CE
4342 if Nkind (N) in N_Aggregate | N_Extension_Aggregate then
4343 Target_Expr := New_Copy_Tree (Lhs);
4344 Insert_Actions (Parent_Node,
4345 Build_Record_Aggr_Code (N, Typ, Target_Expr));
4346 Rewrite (Parent_Node, Make_Null_Statement (Loc));
4347 end if;
4348 end;
4350 else
4351 Temp := Make_Temporary (Loc, 'A', N);
4353 -- If the type inherits unknown discriminants, use the view with
4354 -- known discriminants if available.
4356 if Has_Unknown_Discriminants (Typ)
4357 and then Present (Underlying_Record_View (Typ))
4358 then
4359 T := Underlying_Record_View (Typ);
4360 else
4361 T := Typ;
4362 end if;
4364 Instr :=
4365 Make_Object_Declaration (Loc,
4366 Defining_Identifier => Temp,
4367 Object_Definition => New_Occurrence_Of (T, Loc));
4369 Set_No_Initialization (Instr);
4370 Insert_Action (N, Instr);
4371 Initialize_Discriminants (Instr, T);
4373 Target_Expr := New_Occurrence_Of (Temp, Loc);
4374 Aggr_Code := Build_Record_Aggr_Code (N, T, Target_Expr);
4376 -- Save the last assignment statement associated with the aggregate
4377 -- when building a controlled object. This reference is utilized by
4378 -- the finalization machinery when marking an object as successfully
4379 -- initialized.
4381 if Needs_Finalization (T) then
4382 Set_Last_Aggregate_Assignment (Temp, Last (Aggr_Code));
4383 end if;
4385 Insert_Actions (N, Aggr_Code);
4386 Rewrite (N, New_Occurrence_Of (Temp, Loc));
4387 Analyze_And_Resolve (N, T);
4388 end if;
4389 end Convert_To_Assignments;
4391 ---------------------------
4392 -- Convert_To_Positional --
4393 ---------------------------
4395 procedure Convert_To_Positional
4396 (N : Node_Id;
4397 Handle_Bit_Packed : Boolean := False)
4399 Typ : constant Entity_Id := Etype (N);
4400 Dims : constant Nat := Number_Dimensions (Typ);
4401 Max_Others_Replicate : constant Nat := Max_Aggregate_Size (N);
4403 Static_Components : Boolean := True;
4405 procedure Check_Static_Components;
4406 -- Check whether all components of the aggregate are compile-time known
4407 -- values, and can be passed as is to the back-end without further
4408 -- expansion.
4410 function Flatten
4411 (N : Node_Id;
4412 Dims : Nat;
4413 Ix : Node_Id;
4414 Ixb : Node_Id) return Boolean;
4415 -- Convert the aggregate into a purely positional form if possible after
4416 -- checking that the bounds of all dimensions are known to be static.
4418 function Is_Flat (N : Node_Id; Dims : Nat) return Boolean;
4419 -- Return True if the aggregate N is flat (which is not trivial in the
4420 -- case of multidimensional aggregates).
4422 function Is_Static_Element (N : Node_Id; Dims : Nat) return Boolean;
4423 -- Return True if N, an element of a component association list, i.e.
4424 -- N_Component_Association or N_Iterated_Component_Association, has a
4425 -- compile-time known value and can be passed as is to the back-end
4426 -- without further expansion.
4427 -- An Iterated_Component_Association is treated as nonstatic in most
4428 -- cases for now, so there are possibilities for optimization.
4430 -----------------------------
4431 -- Check_Static_Components --
4432 -----------------------------
4434 -- Could use some comments in this body ???
4436 procedure Check_Static_Components is
4437 Assoc : Node_Id;
4438 Expr : Node_Id;
4440 begin
4441 Static_Components := True;
4443 if Nkind (N) = N_String_Literal then
4444 null;
4446 elsif Present (Expressions (N)) then
4447 Expr := First (Expressions (N));
4448 while Present (Expr) loop
4449 if Nkind (Expr) /= N_Aggregate
4450 or else not Compile_Time_Known_Aggregate (Expr)
4451 or else Expansion_Delayed (Expr)
4452 then
4453 Static_Components := False;
4454 exit;
4455 end if;
4457 Next (Expr);
4458 end loop;
4459 end if;
4461 if Nkind (N) = N_Aggregate
4462 and then Present (Component_Associations (N))
4463 then
4464 Assoc := First (Component_Associations (N));
4465 while Present (Assoc) loop
4466 if not Is_Static_Element (Assoc, Dims) then
4467 Static_Components := False;
4468 exit;
4469 end if;
4471 Next (Assoc);
4472 end loop;
4473 end if;
4474 end Check_Static_Components;
4476 -------------
4477 -- Flatten --
4478 -------------
4480 function Flatten
4481 (N : Node_Id;
4482 Dims : Nat;
4483 Ix : Node_Id;
4484 Ixb : Node_Id) return Boolean
4486 Loc : constant Source_Ptr := Sloc (N);
4487 Blo : constant Node_Id := Type_Low_Bound (Etype (Ixb));
4488 Lo : constant Node_Id := Type_Low_Bound (Etype (Ix));
4489 Hi : constant Node_Id := Type_High_Bound (Etype (Ix));
4491 function Cannot_Flatten_Next_Aggr (Expr : Node_Id) return Boolean;
4492 -- Return true if Expr is an aggregate for the next dimension that
4493 -- cannot be recursively flattened.
4495 ------------------------------
4496 -- Cannot_Flatten_Next_Aggr --
4497 ------------------------------
4499 function Cannot_Flatten_Next_Aggr (Expr : Node_Id) return Boolean is
4500 begin
4501 return Nkind (Expr) = N_Aggregate
4502 and then Present (Next_Index (Ix))
4503 and then not
4504 Flatten (Expr, Dims - 1, Next_Index (Ix), Next_Index (Ixb));
4505 end Cannot_Flatten_Next_Aggr;
4507 -- Local variables
4509 Lov : Uint;
4510 Hiv : Uint;
4511 Others_Present : Boolean;
4513 -- Start of processing for Flatten
4515 begin
4516 if Nkind (Original_Node (N)) = N_String_Literal then
4517 return True;
4518 end if;
4520 if not Compile_Time_Known_Value (Lo)
4521 or else not Compile_Time_Known_Value (Hi)
4522 then
4523 return False;
4524 end if;
4526 Lov := Expr_Value (Lo);
4527 Hiv := Expr_Value (Hi);
4529 -- Check if there is an others choice
4531 Others_Present := False;
4533 if Present (Component_Associations (N)) then
4534 if Is_Empty_List (Component_Associations (N)) then
4535 -- an expanded null array aggregate
4536 return False;
4537 end if;
4539 declare
4540 Assoc : Node_Id;
4541 Choice : Node_Id;
4543 begin
4544 Assoc := First (Component_Associations (N));
4545 while Present (Assoc) loop
4547 -- If this is a box association, flattening is in general
4548 -- not possible because at this point we cannot tell if the
4549 -- default is static or even exists.
4551 if Box_Present (Assoc) then
4552 return False;
4554 elsif Nkind (Assoc) = N_Iterated_Component_Association then
4555 return False;
4556 end if;
4558 Choice := First (Choice_List (Assoc));
4560 while Present (Choice) loop
4561 if Nkind (Choice) = N_Others_Choice then
4562 Others_Present := True;
4563 end if;
4565 Next (Choice);
4566 end loop;
4568 Next (Assoc);
4569 end loop;
4570 end;
4571 end if;
4573 -- If the low bound is not known at compile time and others is not
4574 -- present we can proceed since the bounds can be obtained from the
4575 -- aggregate.
4577 if Hiv < Lov
4578 or else (not Compile_Time_Known_Value (Blo) and then Others_Present)
4579 then
4580 return False;
4581 end if;
4583 -- Determine if set of alternatives is suitable for conversion and
4584 -- build an array containing the values in sequence.
4586 declare
4587 Vals : array (UI_To_Int (Lov) .. UI_To_Int (Hiv))
4588 of Node_Id := (others => Empty);
4589 -- The values in the aggregate sorted appropriately
4591 Vlist : List_Id;
4592 -- Same data as Vals in list form
4594 Rep_Count : Nat;
4595 -- Used to validate Max_Others_Replicate limit
4597 Elmt : Node_Id;
4598 Expr : Node_Id;
4599 Num : Int := UI_To_Int (Lov);
4600 Choice_Index : Int;
4601 Choice : Node_Id;
4602 Lo, Hi : Node_Id;
4604 begin
4605 if Present (Expressions (N)) then
4606 Elmt := First (Expressions (N));
4607 while Present (Elmt) loop
4608 -- In the case of a multidimensional array, check that the
4609 -- aggregate can be recursively flattened.
4611 if Cannot_Flatten_Next_Aggr (Elmt) then
4612 return False;
4613 end if;
4615 -- Duplicate expression for each index it covers
4617 Vals (Num) := New_Copy_Tree (Elmt);
4618 Num := Num + 1;
4620 Next (Elmt);
4621 end loop;
4622 end if;
4624 if No (Component_Associations (N)) then
4625 return True;
4626 end if;
4628 Elmt := First (Component_Associations (N));
4630 Component_Loop : while Present (Elmt) loop
4631 Expr := Expression (Elmt);
4633 -- In the case of a multidimensional array, check that the
4634 -- aggregate can be recursively flattened.
4636 if Cannot_Flatten_Next_Aggr (Expr) then
4637 return False;
4638 end if;
4640 Choice := First (Choice_List (Elmt));
4641 Choice_Loop : while Present (Choice) loop
4643 -- If we have an others choice, fill in the missing elements
4644 -- subject to the limit established by Max_Others_Replicate.
4646 if Nkind (Choice) = N_Others_Choice then
4647 Rep_Count := 0;
4649 -- If the expression involves a construct that generates
4650 -- a loop, we must generate individual assignments and
4651 -- no flattening is possible.
4653 if Nkind (Expr) = N_Quantified_Expression then
4654 return False;
4655 end if;
4657 for J in Vals'Range loop
4658 if No (Vals (J)) then
4659 Vals (J) := New_Copy_Tree (Expr);
4660 Rep_Count := Rep_Count + 1;
4662 -- Check for maximum others replication. Note that
4663 -- we skip this test if either of the restrictions
4664 -- No_Implicit_Loops or No_Elaboration_Code is
4665 -- active, if this is a preelaborable unit or
4666 -- a predefined unit, or if the unit must be
4667 -- placed in data memory. This also ensures that
4668 -- predefined units get the same level of constant
4669 -- folding in Ada 95 and Ada 2005, where their
4670 -- categorization has changed.
4672 declare
4673 P : constant Entity_Id :=
4674 Cunit_Entity (Current_Sem_Unit);
4676 begin
4677 -- Check if duplication is always OK and, if so,
4678 -- continue processing.
4680 if Restriction_Active (No_Implicit_Loops) then
4681 null;
4683 -- If duplication is not always OK, continue
4684 -- only if either the element is static or is
4685 -- an aggregate (we already know it is OK).
4687 elsif not Is_Static_Element (Elmt, Dims)
4688 and then Nkind (Expr) /= N_Aggregate
4689 then
4690 return False;
4692 -- Check if duplication is OK for elaboration
4693 -- purposes and, if so, continue processing.
4695 elsif Restriction_Active (No_Elaboration_Code)
4696 or else
4697 (Ekind (Current_Scope) = E_Package
4698 and then
4699 Static_Elaboration_Desired (Current_Scope))
4700 or else Is_Preelaborated (P)
4701 or else (Ekind (P) = E_Package_Body
4702 and then
4703 Is_Preelaborated (Spec_Entity (P)))
4704 or else
4705 Is_Predefined_Unit (Get_Source_Unit (P))
4706 then
4707 null;
4709 -- Otherwise, check that the replication count
4710 -- is not too high.
4712 elsif Rep_Count > Max_Others_Replicate then
4713 return False;
4714 end if;
4715 end;
4716 end if;
4717 end loop;
4719 if Rep_Count = 0
4720 and then Warn_On_Redundant_Constructs
4721 then
4722 Error_Msg_N ("there are no others?r?", Elmt);
4723 end if;
4725 exit Component_Loop;
4727 -- Case of a subtype mark, identifier or expanded name
4729 elsif Is_Entity_Name (Choice)
4730 and then Is_Type (Entity (Choice))
4731 then
4732 Lo := Type_Low_Bound (Etype (Choice));
4733 Hi := Type_High_Bound (Etype (Choice));
4735 -- Case of subtype indication
4737 elsif Nkind (Choice) = N_Subtype_Indication then
4738 Lo := Low_Bound (Range_Expression (Constraint (Choice)));
4739 Hi := High_Bound (Range_Expression (Constraint (Choice)));
4741 -- Case of a range
4743 elsif Nkind (Choice) = N_Range then
4744 Lo := Low_Bound (Choice);
4745 Hi := High_Bound (Choice);
4747 -- Normal subexpression case
4749 else pragma Assert (Nkind (Choice) in N_Subexpr);
4750 if not Compile_Time_Known_Value (Choice) then
4751 return False;
4753 else
4754 Choice_Index := UI_To_Int (Expr_Value (Choice));
4756 if Choice_Index in Vals'Range then
4757 Vals (Choice_Index) := New_Copy_Tree (Expr);
4758 goto Continue;
4760 -- Choice is statically out-of-range, will be
4761 -- rewritten to raise Constraint_Error.
4763 else
4764 return False;
4765 end if;
4766 end if;
4767 end if;
4769 -- Range cases merge with Lo,Hi set
4771 if not Compile_Time_Known_Value (Lo)
4772 or else
4773 not Compile_Time_Known_Value (Hi)
4774 then
4775 return False;
4777 else
4778 for J in UI_To_Int (Expr_Value (Lo)) ..
4779 UI_To_Int (Expr_Value (Hi))
4780 loop
4781 Vals (J) := New_Copy_Tree (Expr);
4782 end loop;
4783 end if;
4785 <<Continue>>
4786 Next (Choice);
4787 end loop Choice_Loop;
4789 Next (Elmt);
4790 end loop Component_Loop;
4792 -- If we get here the conversion is possible
4794 Vlist := New_List;
4795 for J in Vals'Range loop
4796 Append (Vals (J), Vlist);
4797 end loop;
4799 Rewrite (N, Make_Aggregate (Loc, Expressions => Vlist));
4800 Set_Aggregate_Bounds (N, Aggregate_Bounds (Original_Node (N)));
4801 return True;
4802 end;
4803 end Flatten;
4805 -------------
4806 -- Is_Flat --
4807 -------------
4809 function Is_Flat (N : Node_Id; Dims : Nat) return Boolean is
4810 Elmt : Node_Id;
4812 begin
4813 if Dims = 0 then
4814 return True;
4816 elsif Nkind (N) = N_Aggregate then
4817 if Present (Component_Associations (N)) then
4818 return False;
4820 else
4821 Elmt := First (Expressions (N));
4822 while Present (Elmt) loop
4823 if not Is_Flat (Elmt, Dims - 1) then
4824 return False;
4825 end if;
4827 Next (Elmt);
4828 end loop;
4830 return True;
4831 end if;
4832 else
4833 return True;
4834 end if;
4835 end Is_Flat;
4837 -------------------------
4838 -- Is_Static_Element --
4839 -------------------------
4841 function Is_Static_Element (N : Node_Id; Dims : Nat) return Boolean is
4842 Expr : constant Node_Id := Expression (N);
4844 begin
4845 -- In most cases the interesting expressions are unambiguously static
4847 if Compile_Time_Known_Value (Expr) then
4848 return True;
4850 elsif Nkind (N) = N_Iterated_Component_Association then
4851 return False;
4853 elsif Nkind (Expr) = N_Aggregate
4854 and then Compile_Time_Known_Aggregate (Expr)
4855 and then not Expansion_Delayed (Expr)
4856 then
4857 return True;
4859 -- However, one may write static expressions that are syntactically
4860 -- ambiguous, so preanalyze the expression before checking it again,
4861 -- but only at the innermost level for a multidimensional array.
4863 elsif Dims = 1 then
4864 Preanalyze_And_Resolve (Expr, Component_Type (Typ));
4865 return Compile_Time_Known_Value (Expr);
4867 else
4868 return False;
4869 end if;
4870 end Is_Static_Element;
4872 -- Start of processing for Convert_To_Positional
4874 begin
4875 -- Only convert to positional when generating C in case of an
4876 -- object declaration, this is the only case where aggregates are
4877 -- supported in C.
4879 if Modify_Tree_For_C and then not Is_CCG_Supported_Aggregate (N) then
4880 return;
4881 end if;
4883 -- Ada 2005 (AI-287): Do not convert in case of default initialized
4884 -- components because in this case will need to call the corresponding
4885 -- IP procedure.
4887 if Has_Default_Init_Comps (N) then
4888 return;
4889 end if;
4891 -- A subaggregate may have been flattened but is not known to be
4892 -- Compile_Time_Known. Set that flag in cases that cannot require
4893 -- elaboration code, so that the aggregate can be used as the
4894 -- initial value of a thread-local variable.
4896 if Is_Flat (N, Dims) then
4897 if Static_Array_Aggregate (N) then
4898 Set_Compile_Time_Known_Aggregate (N);
4899 end if;
4901 return;
4902 end if;
4904 if Is_Bit_Packed_Array (Typ) and then not Handle_Bit_Packed then
4905 return;
4906 end if;
4908 -- Do not convert to positional if controlled components are involved
4909 -- since these require special processing
4911 if Has_Controlled_Component (Typ) then
4912 return;
4913 end if;
4915 Check_Static_Components;
4917 -- If the size is known, or all the components are static, try to
4918 -- build a fully positional aggregate.
4920 -- The size of the type may not be known for an aggregate with
4921 -- discriminated array components, but if the components are static
4922 -- it is still possible to verify statically that the length is
4923 -- compatible with the upper bound of the type, and therefore it is
4924 -- worth flattening such aggregates as well.
4926 if Aggr_Size_OK (N)
4927 and then
4928 Flatten (N, Dims, First_Index (Typ), First_Index (Base_Type (Typ)))
4929 then
4930 if Static_Components then
4931 Set_Compile_Time_Known_Aggregate (N);
4932 Set_Expansion_Delayed (N, False);
4933 end if;
4935 Analyze_And_Resolve (N, Typ);
4936 end if;
4938 -- If Static_Elaboration_Desired has been specified, diagnose aggregates
4939 -- that will still require initialization code.
4941 if (Ekind (Current_Scope) = E_Package
4942 and then Static_Elaboration_Desired (Current_Scope))
4943 and then Nkind (Parent (N)) = N_Object_Declaration
4944 then
4945 declare
4946 Expr : Node_Id;
4948 begin
4949 if Nkind (N) = N_Aggregate and then Present (Expressions (N)) then
4950 Expr := First (Expressions (N));
4951 while Present (Expr) loop
4952 if not Compile_Time_Known_Value (Expr) then
4953 Error_Msg_N
4954 ("non-static object requires elaboration code??", N);
4955 exit;
4956 end if;
4958 Next (Expr);
4959 end loop;
4961 if Present (Component_Associations (N)) then
4962 Error_Msg_N ("object requires elaboration code??", N);
4963 end if;
4964 end if;
4965 end;
4966 end if;
4967 end Convert_To_Positional;
4969 ----------------------------
4970 -- Expand_Array_Aggregate --
4971 ----------------------------
4973 -- Array aggregate expansion proceeds as follows:
4975 -- 1. If requested we generate code to perform all the array aggregate
4976 -- bound checks, specifically
4978 -- (a) Check that the index range defined by aggregate bounds is
4979 -- compatible with corresponding index subtype.
4981 -- (b) If an others choice is present check that no aggregate
4982 -- index is outside the bounds of the index constraint.
4984 -- (c) For multidimensional arrays make sure that all subaggregates
4985 -- corresponding to the same dimension have the same bounds.
4987 -- 2. Check for packed array aggregate which can be converted to a
4988 -- constant so that the aggregate disappears completely.
4990 -- 3. Check case of nested aggregate. Generally nested aggregates are
4991 -- handled during the processing of the parent aggregate.
4993 -- 4. Check if the aggregate can be statically processed. If this is the
4994 -- case pass it as is to Gigi. Note that a necessary condition for
4995 -- static processing is that the aggregate be fully positional.
4997 -- 5. If in-place aggregate expansion is possible (i.e. no need to create
4998 -- a temporary) then mark the aggregate as such and return. Otherwise
4999 -- create a new temporary and generate the appropriate initialization
5000 -- code.
5002 procedure Expand_Array_Aggregate (N : Node_Id) is
5003 Loc : constant Source_Ptr := Sloc (N);
5005 Typ : constant Entity_Id := Etype (N);
5006 Ctyp : constant Entity_Id := Component_Type (Typ);
5007 -- Typ is the correct constrained array subtype of the aggregate
5008 -- Ctyp is the corresponding component type.
5010 Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
5011 -- Number of aggregate index dimensions
5013 Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id;
5014 Aggr_High : array (1 .. Aggr_Dimension) of Node_Id;
5015 -- Low and High bounds of the constraint for each aggregate index
5017 Aggr_Index_Typ : array (1 .. Aggr_Dimension) of Entity_Id;
5018 -- The type of each index
5020 In_Place_Assign_OK_For_Declaration : Boolean := False;
5021 -- True if we are to generate an in-place assignment for a declaration
5023 Maybe_In_Place_OK : Boolean;
5024 -- If the type is neither controlled nor packed and the aggregate
5025 -- is the expression in an assignment, assignment in place may be
5026 -- possible, provided other conditions are met on the LHS.
5028 Others_Present : array (1 .. Aggr_Dimension) of Boolean :=
5029 (others => False);
5030 -- If Others_Present (J) is True, then there is an others choice in one
5031 -- of the subaggregates of N at dimension J.
5033 procedure Build_Constrained_Type (Positional : Boolean);
5034 -- If the subtype is not static or unconstrained, build a constrained
5035 -- type using the computable sizes of the aggregate and its sub-
5036 -- aggregates.
5038 procedure Check_Bounds (Aggr_Bounds_Node, Index_Bounds_Node : Node_Id);
5039 -- Checks that the bounds of Aggr_Bounds are within the bounds defined
5040 -- by Index_Bounds. For null array aggregate (Ada 2022) check that the
5041 -- aggregate bounds define a null range.
5043 procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos);
5044 -- Checks that in a multidimensional array aggregate all subaggregates
5045 -- corresponding to the same dimension have the same bounds. Sub_Aggr is
5046 -- an array subaggregate. Dim is the dimension corresponding to the
5047 -- subaggregate.
5049 procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos);
5050 -- Computes the values of array Others_Present. Sub_Aggr is the array
5051 -- subaggregate we start the computation from. Dim is the dimension
5052 -- corresponding to the subaggregate.
5054 procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos);
5055 -- Checks that if an others choice is present in any subaggregate, no
5056 -- aggregate index is outside the bounds of the index constraint.
5057 -- Sub_Aggr is an array subaggregate. Dim is the dimension corresponding
5058 -- to the subaggregate.
5060 function Safe_Left_Hand_Side (N : Node_Id) return Boolean;
5061 -- In addition to Maybe_In_Place_OK, in order for an aggregate to be
5062 -- built directly into the target of the assignment it must be free
5063 -- of side effects. N is the LHS of an assignment.
5065 procedure Two_Pass_Aggregate_Expansion (N : Node_Id);
5066 -- If the aggregate consists only of iterated associations then the
5067 -- aggregate is constructed in two steps:
5068 -- a) Build an expression to compute the number of elements
5069 -- generated by each iterator, and use the expression to allocate
5070 -- the destination aggregate.
5071 -- b) Generate the loops corresponding to each iterator to insert
5072 -- the elements in their proper positions.
5074 ----------------------------
5075 -- Build_Constrained_Type --
5076 ----------------------------
5078 procedure Build_Constrained_Type (Positional : Boolean) is
5079 Agg_Type : constant Entity_Id := Make_Temporary (Loc, 'A');
5080 Decl : Node_Id;
5081 Indexes : constant List_Id := New_List;
5082 Num : Nat;
5083 Sub_Agg : Node_Id;
5085 begin
5086 -- If the aggregate is purely positional, all its subaggregates
5087 -- have the same size. We collect the dimensions from the first
5088 -- subaggregate at each level.
5090 if Positional then
5091 Sub_Agg := N;
5093 for D in 1 .. Aggr_Dimension loop
5094 Num := List_Length (Expressions (Sub_Agg));
5096 Append_To (Indexes,
5097 Make_Range (Loc,
5098 Low_Bound => Make_Integer_Literal (Loc, Uint_1),
5099 High_Bound => Make_Integer_Literal (Loc, Num)));
5101 Sub_Agg := First (Expressions (Sub_Agg));
5102 end loop;
5104 else
5105 -- We know the aggregate type is unconstrained and the aggregate
5106 -- is not processable by the back end, therefore not necessarily
5107 -- positional. Retrieve each dimension bounds (computed earlier).
5109 for D in 1 .. Aggr_Dimension loop
5110 Append_To (Indexes,
5111 Make_Range (Loc,
5112 Low_Bound => Aggr_Low (D),
5113 High_Bound => Aggr_High (D)));
5114 end loop;
5115 end if;
5117 Decl :=
5118 Make_Full_Type_Declaration (Loc,
5119 Defining_Identifier => Agg_Type,
5120 Type_Definition =>
5121 Make_Constrained_Array_Definition (Loc,
5122 Discrete_Subtype_Definitions => Indexes,
5123 Component_Definition =>
5124 Make_Component_Definition (Loc,
5125 Subtype_Indication =>
5126 New_Occurrence_Of (Component_Type (Typ), Loc))));
5128 Insert_Action (N, Decl);
5129 Analyze (Decl);
5130 Set_Etype (N, Agg_Type);
5131 Set_Is_Itype (Agg_Type);
5132 Freeze_Itype (Agg_Type, N);
5133 end Build_Constrained_Type;
5135 ------------------
5136 -- Check_Bounds --
5137 ------------------
5139 procedure Check_Bounds (Aggr_Bounds_Node, Index_Bounds_Node : Node_Id) is
5140 Aggr_Bounds : constant Range_Nodes :=
5141 Get_Index_Bounds (Aggr_Bounds_Node);
5142 Ind_Bounds : constant Range_Nodes :=
5143 Get_Index_Bounds (Index_Bounds_Node);
5145 Cond : Node_Id;
5147 begin
5148 -- For a null array aggregate check that high bound (i.e., low
5149 -- bound predecessor) exists. Fail if low bound is low bound of
5150 -- base subtype (in all cases, including modular).
5152 if Is_Null_Aggregate (N) then
5153 Insert_Action (N,
5154 Make_Raise_Constraint_Error (Loc,
5155 Condition =>
5156 Make_Op_Eq (Loc,
5157 New_Copy_Tree (Aggr_Bounds.First),
5158 New_Copy_Tree
5159 (Type_Low_Bound (Base_Type (Etype (Ind_Bounds.First))))),
5160 Reason => CE_Range_Check_Failed));
5161 return;
5162 end if;
5164 -- Generate the following test:
5166 -- [constraint_error when
5167 -- Aggr_Bounds.First <= Aggr_Bounds.Last and then
5168 -- (Aggr_Bounds.First < Ind_Bounds.First
5169 -- or else Aggr_Bounds.Last > Ind_Bounds.Last)]
5171 -- As an optimization try to see if some tests are trivially vacuous
5172 -- because we are comparing an expression against itself.
5174 if Aggr_Bounds.First = Ind_Bounds.First
5175 and then Aggr_Bounds.Last = Ind_Bounds.Last
5176 then
5177 Cond := Empty;
5179 elsif Aggr_Bounds.Last = Ind_Bounds.Last then
5180 Cond :=
5181 Make_Op_Lt (Loc,
5182 Left_Opnd =>
5183 Duplicate_Subexpr_Move_Checks (Aggr_Bounds.First),
5184 Right_Opnd =>
5185 Duplicate_Subexpr_Move_Checks (Ind_Bounds.First));
5187 elsif Aggr_Bounds.First = Ind_Bounds.First then
5188 Cond :=
5189 Make_Op_Gt (Loc,
5190 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Bounds.Last),
5191 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Bounds.Last));
5193 else
5194 Cond :=
5195 Make_Or_Else (Loc,
5196 Left_Opnd =>
5197 Make_Op_Lt (Loc,
5198 Left_Opnd =>
5199 Duplicate_Subexpr_Move_Checks (Aggr_Bounds.First),
5200 Right_Opnd =>
5201 Duplicate_Subexpr_Move_Checks (Ind_Bounds.First)),
5203 Right_Opnd =>
5204 Make_Op_Gt (Loc,
5205 Left_Opnd => Duplicate_Subexpr (Aggr_Bounds.Last),
5206 Right_Opnd => Duplicate_Subexpr (Ind_Bounds.Last)));
5207 end if;
5209 if Present (Cond) then
5210 Cond :=
5211 Make_And_Then (Loc,
5212 Left_Opnd =>
5213 Make_Op_Le (Loc,
5214 Left_Opnd =>
5215 Duplicate_Subexpr_Move_Checks (Aggr_Bounds.First),
5216 Right_Opnd =>
5217 Duplicate_Subexpr_Move_Checks (Aggr_Bounds.Last)),
5219 Right_Opnd => Cond);
5221 Set_Analyzed (Left_Opnd (Left_Opnd (Cond)), False);
5222 Set_Analyzed (Right_Opnd (Left_Opnd (Cond)), False);
5223 Insert_Action (N,
5224 Make_Raise_Constraint_Error (Loc,
5225 Condition => Cond,
5226 Reason => CE_Range_Check_Failed));
5227 end if;
5228 end Check_Bounds;
5230 ----------------------------
5231 -- Check_Same_Aggr_Bounds --
5232 ----------------------------
5234 procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos) is
5235 Sub_Bounds : constant Range_Nodes :=
5236 Get_Index_Bounds (Aggregate_Bounds (Sub_Aggr));
5237 Sub_Lo : Node_Id renames Sub_Bounds.First;
5238 Sub_Hi : Node_Id renames Sub_Bounds.Last;
5239 -- The bounds of this specific subaggregate
5241 Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
5242 Aggr_Hi : constant Node_Id := Aggr_High (Dim);
5243 -- The bounds of the aggregate for this dimension
5245 Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
5246 -- The index type for this dimension.xxx
5248 Cond : Node_Id;
5249 Assoc : Node_Id;
5250 Expr : Node_Id;
5252 begin
5253 -- If index checks are on generate the test
5255 -- [constraint_error when
5256 -- Aggr_Lo /= Sub_Lo or else Aggr_Hi /= Sub_Hi]
5258 -- As an optimization try to see if some tests are trivially vacuos
5259 -- because we are comparing an expression against itself. Also for
5260 -- the first dimension the test is trivially vacuous because there
5261 -- is just one aggregate for dimension 1.
5263 if Index_Checks_Suppressed (Ind_Typ) then
5264 Cond := Empty;
5266 elsif Dim = 1 or else (Aggr_Lo = Sub_Lo and then Aggr_Hi = Sub_Hi)
5267 then
5268 Cond := Empty;
5270 elsif Aggr_Hi = Sub_Hi then
5271 Cond :=
5272 Make_Op_Ne (Loc,
5273 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
5274 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo));
5276 elsif Aggr_Lo = Sub_Lo then
5277 Cond :=
5278 Make_Op_Ne (Loc,
5279 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi),
5280 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Hi));
5282 else
5283 Cond :=
5284 Make_Or_Else (Loc,
5285 Left_Opnd =>
5286 Make_Op_Ne (Loc,
5287 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
5288 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo)),
5290 Right_Opnd =>
5291 Make_Op_Ne (Loc,
5292 Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
5293 Right_Opnd => Duplicate_Subexpr (Sub_Hi)));
5294 end if;
5296 if Present (Cond) then
5297 Insert_Action (N,
5298 Make_Raise_Constraint_Error (Loc,
5299 Condition => Cond,
5300 Reason => CE_Length_Check_Failed));
5301 end if;
5303 -- Now look inside the subaggregate to see if there is more work
5305 if Dim < Aggr_Dimension then
5307 -- Process positional components
5309 if Present (Expressions (Sub_Aggr)) then
5310 Expr := First (Expressions (Sub_Aggr));
5311 while Present (Expr) loop
5312 Check_Same_Aggr_Bounds (Expr, Dim + 1);
5313 Next (Expr);
5314 end loop;
5315 end if;
5317 -- Process component associations
5319 if Present (Component_Associations (Sub_Aggr)) then
5320 Assoc := First (Component_Associations (Sub_Aggr));
5321 while Present (Assoc) loop
5322 Expr := Expression (Assoc);
5323 Check_Same_Aggr_Bounds (Expr, Dim + 1);
5324 Next (Assoc);
5325 end loop;
5326 end if;
5327 end if;
5328 end Check_Same_Aggr_Bounds;
5330 ----------------------------
5331 -- Compute_Others_Present --
5332 ----------------------------
5334 procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos) is
5335 Assoc : Node_Id;
5336 Expr : Node_Id;
5338 begin
5339 if Present (Component_Associations (Sub_Aggr)) then
5340 Assoc := Last (Component_Associations (Sub_Aggr));
5342 if Present (Assoc)
5343 and then Nkind (First (Choice_List (Assoc))) = N_Others_Choice
5344 then
5345 Others_Present (Dim) := True;
5347 -- An others_clause may be superfluous if previous components
5348 -- cover the full given range of a constrained array. In such
5349 -- a case an others_clause does not contribute any additional
5350 -- components and has not been analyzed. We analyze it now to
5351 -- detect type errors in the expression, even though no code
5352 -- will be generated for it.
5354 if Dim = Aggr_Dimension
5355 and then Nkind (Assoc) /= N_Iterated_Component_Association
5356 and then not Analyzed (Expression (Assoc))
5357 and then not Box_Present (Assoc)
5358 then
5359 Preanalyze_And_Resolve (Expression (Assoc), Ctyp);
5360 end if;
5361 end if;
5362 end if;
5364 -- Now look inside the subaggregate to see if there is more work
5366 if Dim < Aggr_Dimension then
5368 -- Process positional components
5370 if Present (Expressions (Sub_Aggr)) then
5371 Expr := First (Expressions (Sub_Aggr));
5372 while Present (Expr) loop
5373 Compute_Others_Present (Expr, Dim + 1);
5374 Next (Expr);
5375 end loop;
5376 end if;
5378 -- Process component associations
5380 if Present (Component_Associations (Sub_Aggr)) then
5381 Assoc := First (Component_Associations (Sub_Aggr));
5382 while Present (Assoc) loop
5383 Expr := Expression (Assoc);
5384 Compute_Others_Present (Expr, Dim + 1);
5385 Next (Assoc);
5386 end loop;
5387 end if;
5388 end if;
5389 end Compute_Others_Present;
5391 ------------------
5392 -- Others_Check --
5393 ------------------
5395 procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos) is
5396 Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
5397 Aggr_Hi : constant Node_Id := Aggr_High (Dim);
5398 -- The bounds of the aggregate for this dimension
5400 Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
5401 -- The index type for this dimension
5403 Need_To_Check : Boolean := False;
5405 Choices_Lo : Node_Id := Empty;
5406 Choices_Hi : Node_Id := Empty;
5407 -- The lowest and highest discrete choices for a named subaggregate
5409 Nb_Choices : Int := -1;
5410 -- The number of discrete non-others choices in this subaggregate
5412 Nb_Elements : Uint := Uint_0;
5413 -- The number of elements in a positional aggregate
5415 Cond : Node_Id := Empty;
5417 Assoc : Node_Id;
5418 Choice : Node_Id;
5419 Expr : Node_Id;
5421 begin
5422 -- Check if we have an others choice. If we do make sure that this
5423 -- subaggregate contains at least one element in addition to the
5424 -- others choice.
5426 if Range_Checks_Suppressed (Ind_Typ) then
5427 Need_To_Check := False;
5429 elsif Present (Expressions (Sub_Aggr))
5430 and then Present (Component_Associations (Sub_Aggr))
5431 then
5432 Need_To_Check :=
5433 not (Is_Empty_List (Expressions (Sub_Aggr))
5434 and then Is_Empty_List
5435 (Component_Associations (Sub_Aggr)));
5437 elsif Present (Component_Associations (Sub_Aggr)) then
5438 Assoc := Last (Component_Associations (Sub_Aggr));
5440 if Nkind (First (Choice_List (Assoc))) /= N_Others_Choice then
5441 Need_To_Check := False;
5443 else
5444 -- Count the number of discrete choices. Start with -1 because
5445 -- the others choice does not count.
5447 -- Is there some reason we do not use List_Length here ???
5449 Nb_Choices := -1;
5450 Assoc := First (Component_Associations (Sub_Aggr));
5451 while Present (Assoc) loop
5452 Choice := First (Choice_List (Assoc));
5453 while Present (Choice) loop
5454 Nb_Choices := Nb_Choices + 1;
5455 Next (Choice);
5456 end loop;
5458 Next (Assoc);
5459 end loop;
5461 -- If there is only an others choice nothing to do
5463 Need_To_Check := (Nb_Choices > 0);
5464 end if;
5466 else
5467 Need_To_Check := False;
5468 end if;
5470 -- If we are dealing with a positional subaggregate with an others
5471 -- choice then compute the number or positional elements.
5473 if Need_To_Check and then Present (Expressions (Sub_Aggr)) then
5474 Expr := First (Expressions (Sub_Aggr));
5475 Nb_Elements := Uint_0;
5476 while Present (Expr) loop
5477 Nb_Elements := Nb_Elements + 1;
5478 Next (Expr);
5479 end loop;
5481 -- If the aggregate contains discrete choices and an others choice
5482 -- compute the smallest and largest discrete choice values.
5484 elsif Need_To_Check then
5485 Compute_Choices_Lo_And_Choices_Hi : declare
5487 Table : Case_Table_Type (1 .. Nb_Choices);
5488 -- Used to sort all the different choice values
5490 J : Pos := 1;
5492 begin
5493 Assoc := First (Component_Associations (Sub_Aggr));
5494 while Present (Assoc) loop
5495 Choice := First (Choice_List (Assoc));
5496 while Present (Choice) loop
5497 if Nkind (Choice) = N_Others_Choice then
5498 exit;
5499 end if;
5501 declare
5502 Bounds : constant Range_Nodes :=
5503 Get_Index_Bounds (Choice);
5504 begin
5505 Table (J).Choice_Lo := Bounds.First;
5506 Table (J).Choice_Hi := Bounds.Last;
5507 end;
5509 J := J + 1;
5510 Next (Choice);
5511 end loop;
5513 Next (Assoc);
5514 end loop;
5516 -- Sort the discrete choices
5518 Sort_Case_Table (Table);
5520 Choices_Lo := Table (1).Choice_Lo;
5521 Choices_Hi := Table (Nb_Choices).Choice_Hi;
5522 end Compute_Choices_Lo_And_Choices_Hi;
5523 end if;
5525 -- If no others choice in this subaggregate, or the aggregate
5526 -- comprises only an others choice, nothing to do.
5528 if not Need_To_Check then
5529 Cond := Empty;
5531 -- If we are dealing with an aggregate containing an others choice
5532 -- and positional components, we generate the following test:
5534 -- if Ind_Typ'Pos (Aggr_Lo) + (Nb_Elements - 1) >
5535 -- Ind_Typ'Pos (Aggr_Hi)
5536 -- then
5537 -- raise Constraint_Error;
5538 -- end if;
5540 -- in the general case, but the following simpler test:
5542 -- [constraint_error when
5543 -- Aggr_Lo + (Nb_Elements - 1) > Aggr_Hi];
5545 -- instead if the index type is a signed integer.
5547 elsif Nb_Elements > Uint_0 then
5548 if Nb_Elements = Uint_1 then
5549 Cond :=
5550 Make_Op_Gt (Loc,
5551 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
5552 Right_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi));
5554 elsif Is_Signed_Integer_Type (Ind_Typ) then
5555 Cond :=
5556 Make_Op_Gt (Loc,
5557 Left_Opnd =>
5558 Make_Op_Add (Loc,
5559 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
5560 Right_Opnd =>
5561 Make_Integer_Literal (Loc, Nb_Elements - 1)),
5562 Right_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi));
5564 else
5565 Cond :=
5566 Make_Op_Gt (Loc,
5567 Left_Opnd =>
5568 Make_Op_Add (Loc,
5569 Left_Opnd =>
5570 Make_Attribute_Reference (Loc,
5571 Prefix => New_Occurrence_Of (Ind_Typ, Loc),
5572 Attribute_Name => Name_Pos,
5573 Expressions =>
5574 New_List
5575 (Duplicate_Subexpr_Move_Checks (Aggr_Lo))),
5576 Right_Opnd => Make_Integer_Literal (Loc, Nb_Elements - 1)),
5578 Right_Opnd =>
5579 Make_Attribute_Reference (Loc,
5580 Prefix => New_Occurrence_Of (Ind_Typ, Loc),
5581 Attribute_Name => Name_Pos,
5582 Expressions => New_List (
5583 Duplicate_Subexpr_Move_Checks (Aggr_Hi))));
5584 end if;
5586 -- If we are dealing with an aggregate containing an others choice
5587 -- and discrete choices we generate the following test:
5589 -- [constraint_error when
5590 -- Choices_Lo < Aggr_Lo or else Choices_Hi > Aggr_Hi];
5592 else
5593 Cond :=
5594 Make_Or_Else (Loc,
5595 Left_Opnd =>
5596 Make_Op_Lt (Loc,
5597 Left_Opnd => Duplicate_Subexpr_Move_Checks (Choices_Lo),
5598 Right_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo)),
5600 Right_Opnd =>
5601 Make_Op_Gt (Loc,
5602 Left_Opnd => Duplicate_Subexpr (Choices_Hi),
5603 Right_Opnd => Duplicate_Subexpr (Aggr_Hi)));
5604 end if;
5606 if Present (Cond) then
5607 Insert_Action (N,
5608 Make_Raise_Constraint_Error (Loc,
5609 Condition => Cond,
5610 Reason => CE_Length_Check_Failed));
5611 -- Questionable reason code, shouldn't that be a
5612 -- CE_Range_Check_Failed ???
5613 end if;
5615 -- Now look inside the subaggregate to see if there is more work
5617 if Dim < Aggr_Dimension then
5619 -- Process positional components
5621 if Present (Expressions (Sub_Aggr)) then
5622 Expr := First (Expressions (Sub_Aggr));
5623 while Present (Expr) loop
5624 Others_Check (Expr, Dim + 1);
5625 Next (Expr);
5626 end loop;
5627 end if;
5629 -- Process component associations
5631 if Present (Component_Associations (Sub_Aggr)) then
5632 Assoc := First (Component_Associations (Sub_Aggr));
5633 while Present (Assoc) loop
5634 Expr := Expression (Assoc);
5635 Others_Check (Expr, Dim + 1);
5636 Next (Assoc);
5637 end loop;
5638 end if;
5639 end if;
5640 end Others_Check;
5642 -------------------------
5643 -- Safe_Left_Hand_Side --
5644 -------------------------
5646 function Safe_Left_Hand_Side (N : Node_Id) return Boolean is
5647 function Is_Safe_Index (Indx : Node_Id) return Boolean;
5648 -- If the left-hand side includes an indexed component, check that
5649 -- the indexes are free of side effects.
5651 -------------------
5652 -- Is_Safe_Index --
5653 -------------------
5655 function Is_Safe_Index (Indx : Node_Id) return Boolean is
5656 begin
5657 if Is_Entity_Name (Indx) then
5658 return True;
5660 elsif Nkind (Indx) = N_Integer_Literal then
5661 return True;
5663 elsif Nkind (Indx) = N_Function_Call
5664 and then Is_Entity_Name (Name (Indx))
5665 and then Has_Pragma_Pure_Function (Entity (Name (Indx)))
5666 then
5667 return True;
5669 elsif Nkind (Indx) = N_Type_Conversion
5670 and then Is_Safe_Index (Expression (Indx))
5671 then
5672 return True;
5674 else
5675 return False;
5676 end if;
5677 end Is_Safe_Index;
5679 -- Start of processing for Safe_Left_Hand_Side
5681 begin
5682 if Is_Entity_Name (N) then
5683 return True;
5685 elsif Nkind (N) in N_Explicit_Dereference | N_Selected_Component
5686 and then Safe_Left_Hand_Side (Prefix (N))
5687 then
5688 return True;
5690 elsif Nkind (N) = N_Indexed_Component
5691 and then Safe_Left_Hand_Side (Prefix (N))
5692 and then Is_Safe_Index (First (Expressions (N)))
5693 then
5694 return True;
5696 elsif Nkind (N) = N_Unchecked_Type_Conversion then
5697 return Safe_Left_Hand_Side (Expression (N));
5699 else
5700 return False;
5701 end if;
5702 end Safe_Left_Hand_Side;
5704 ----------------------------------
5705 -- Two_Pass_Aggregate_Expansion --
5706 ----------------------------------
5708 procedure Two_Pass_Aggregate_Expansion (N : Node_Id) is
5709 Loc : constant Source_Ptr := Sloc (N);
5710 Comp_Type : constant Entity_Id := Etype (N);
5711 Index_Id : constant Entity_Id := Make_Temporary (Loc, 'I', N);
5712 Index_Type : constant Entity_Id := Etype (First_Index (Etype (N)));
5713 Size_Id : constant Entity_Id := Make_Temporary (Loc, 'I', N);
5714 TmpE : constant Entity_Id := Make_Temporary (Loc, 'A', N);
5716 Assoc : Node_Id := First (Component_Associations (N));
5717 Incr : Node_Id;
5718 Iter : Node_Id;
5719 New_Comp : Node_Id;
5720 One_Loop : Node_Id;
5722 Size_Expr_Code : List_Id;
5723 Insertion_Code : List_Id := New_List;
5725 begin
5726 Size_Expr_Code := New_List (
5727 Make_Object_Declaration (Loc,
5728 Defining_Identifier => Size_Id,
5729 Object_Definition => New_Occurrence_Of (Standard_Integer, Loc),
5730 Expression => Make_Integer_Literal (Loc, 0)));
5732 -- First pass: execute the iterators to count the number of elements
5733 -- that will be generated.
5735 while Present (Assoc) loop
5736 Iter := Iterator_Specification (Assoc);
5737 Incr := Make_Assignment_Statement (Loc,
5738 Name => New_Occurrence_Of (Size_Id, Loc),
5739 Expression =>
5740 Make_Op_Add (Loc,
5741 Left_Opnd => New_Occurrence_Of (Size_Id, Loc),
5742 Right_Opnd => Make_Integer_Literal (Loc, 1)));
5744 One_Loop := Make_Implicit_Loop_Statement (N,
5745 Iteration_Scheme =>
5746 Make_Iteration_Scheme (Loc,
5747 Iterator_Specification => New_Copy_Tree (Iter)),
5748 Statements => New_List (Incr));
5750 Append (One_Loop, Size_Expr_Code);
5751 Next (Assoc);
5752 end loop;
5754 Insert_Actions (N, Size_Expr_Code);
5756 -- Build a constrained subtype with the calculated length
5757 -- and declare the proper bounded aggregate object.
5758 -- The index type is some discrete type, so the bounds of the
5759 -- constructed array are computed as T'Val (T'Pos (ineger bound));
5761 declare
5762 Pos_Lo : constant Node_Id :=
5763 Make_Attribute_Reference (Loc,
5764 Prefix => New_Occurrence_Of (Index_Type, Loc),
5765 Attribute_Name => Name_Pos,
5766 Expressions => New_List (
5767 Make_Attribute_Reference (Loc,
5768 Prefix => New_Occurrence_Of (Index_Type, Loc),
5769 Attribute_Name => Name_First)));
5771 Aggr_Lo : constant Node_Id :=
5772 Make_Attribute_Reference (Loc,
5773 Prefix => New_Occurrence_Of (Index_Type, Loc),
5774 Attribute_Name => Name_Val,
5775 Expressions => New_List (New_Copy_Tree (Pos_Lo)));
5777 -- Hi = Index_type'Pos (Lo + Size -1).
5779 Pos_Hi : constant Node_Id :=
5780 Make_Op_Add (Loc,
5781 Left_Opnd => New_Copy_Tree (Pos_Lo),
5782 Right_Opnd =>
5783 Make_Op_Subtract (Loc,
5784 Left_Opnd => New_Occurrence_Of (Size_Id, Loc),
5785 Right_Opnd => Make_Integer_Literal (Loc, 1)));
5787 -- Corresponding index value
5789 Aggr_Hi : constant Node_Id :=
5790 Make_Attribute_Reference (Loc,
5791 Prefix => New_Occurrence_Of (Index_Type, Loc),
5792 Attribute_Name => Name_Val,
5793 Expressions => New_List (New_Copy_Tree (Pos_Hi)));
5795 SubE : constant Entity_Id := Make_Temporary (Loc, 'T');
5796 SubD : constant Node_Id :=
5797 Make_Subtype_Declaration (Loc,
5798 Defining_Identifier => SubE,
5799 Subtype_Indication =>
5800 Make_Subtype_Indication (Loc,
5801 Subtype_Mark =>
5802 New_Occurrence_Of (Etype (Comp_Type), Loc),
5803 Constraint =>
5804 Make_Index_Or_Discriminant_Constraint
5805 (Loc,
5806 Constraints =>
5807 New_List (Make_Range (Loc, Aggr_Lo, Aggr_Hi)))));
5809 -- Create a temporary array of the above subtype which
5810 -- will be used to capture the aggregate assignments.
5812 TmpD : constant Node_Id :=
5813 Make_Object_Declaration (Loc,
5814 Defining_Identifier => TmpE,
5815 Object_Definition => New_Occurrence_Of (SubE, Loc));
5816 begin
5817 Insert_Actions (N, New_List (SubD, TmpD));
5818 end;
5820 -- Second pass: use the iterators to generate the elements of the
5821 -- aggregate. Insertion index starts at Index_Type'First. We
5822 -- assume that the second evaluation of each iterator generates
5823 -- the same number of elements as the first pass, and consider
5824 -- that the execution is erroneous (even if the RM does not state
5825 -- this explicitly) if the number of elements generated differs
5826 -- between first and second pass.
5828 Assoc := First (Component_Associations (N));
5830 -- Initialize insertion position to first array component.
5832 Insertion_Code := New_List (
5833 Make_Object_Declaration (Loc,
5834 Defining_Identifier => Index_Id,
5835 Object_Definition =>
5836 New_Occurrence_Of (Index_Type, Loc),
5837 Expression =>
5838 Make_Attribute_Reference (Loc,
5839 Prefix => New_Occurrence_Of (Index_Type, Loc),
5840 Attribute_Name => Name_First)));
5842 while Present (Assoc) loop
5843 Iter := Iterator_Specification (Assoc);
5844 New_Comp := Make_Assignment_Statement (Loc,
5845 Name =>
5846 Make_Indexed_Component (Loc,
5847 Prefix => New_Occurrence_Of (TmpE, Loc),
5848 Expressions =>
5849 New_List (New_Occurrence_Of (Index_Id, Loc))),
5850 Expression => Copy_Separate_Tree (Expression (Assoc)));
5852 -- Advance index position for insertion.
5854 Incr := Make_Assignment_Statement (Loc,
5855 Name => New_Occurrence_Of (Index_Id, Loc),
5856 Expression =>
5857 Make_Attribute_Reference (Loc,
5858 Prefix =>
5859 New_Occurrence_Of (Index_Type, Loc),
5860 Attribute_Name => Name_Succ,
5861 Expressions =>
5862 New_List (New_Occurrence_Of (Index_Id, Loc))));
5864 -- Add guard to skip last increment when upper bound is reached.
5866 Incr := Make_If_Statement (Loc,
5867 Condition =>
5868 Make_Op_Ne (Loc,
5869 Left_Opnd => New_Occurrence_Of (Index_Id, Loc),
5870 Right_Opnd =>
5871 Make_Attribute_Reference (Loc,
5872 Prefix => New_Occurrence_Of (Index_Type, Loc),
5873 Attribute_Name => Name_Last)),
5874 Then_Statements => New_List (Incr));
5876 One_Loop := Make_Implicit_Loop_Statement (N,
5877 Iteration_Scheme =>
5878 Make_Iteration_Scheme (Loc,
5879 Iterator_Specification => Copy_Separate_Tree (Iter)),
5880 Statements => New_List (New_Comp, Incr));
5882 Append (One_Loop, Insertion_Code);
5883 Next (Assoc);
5884 end loop;
5886 Insert_Actions (N, Insertion_Code);
5888 -- Depending on context this may not work for build-in-place
5889 -- arrays ???
5891 Rewrite (N, New_Occurrence_Of (TmpE, Loc));
5893 end Two_Pass_Aggregate_Expansion;
5895 -- Local variables
5897 Tmp : Entity_Id;
5898 -- Holds the temporary aggregate value
5900 Tmp_Decl : Node_Id;
5901 -- Holds the declaration of Tmp
5903 Aggr_Code : List_Id;
5904 Parent_Node : Node_Id;
5905 Parent_Kind : Node_Kind;
5907 -- Start of processing for Expand_Array_Aggregate
5909 begin
5910 -- Do not touch the special aggregates of attributes used for Asm calls
5912 if Is_RTE (Ctyp, RE_Asm_Input_Operand)
5913 or else Is_RTE (Ctyp, RE_Asm_Output_Operand)
5914 then
5915 return;
5917 elsif Present (Component_Associations (N))
5918 and then Nkind (First (Component_Associations (N))) =
5919 N_Iterated_Component_Association
5920 and then
5921 Present (Iterator_Specification (First (Component_Associations (N))))
5922 then
5923 Two_Pass_Aggregate_Expansion (N);
5924 return;
5926 -- Do not attempt expansion if error already detected. We may reach this
5927 -- point in spite of previous errors when compiling with -gnatq, to
5928 -- force all possible errors (this is the usual ACATS mode).
5930 elsif Error_Posted (N) then
5931 return;
5932 end if;
5934 -- If the semantic analyzer has determined that aggregate N will raise
5935 -- Constraint_Error at run time, then the aggregate node has been
5936 -- replaced with an N_Raise_Constraint_Error node and we should
5937 -- never get here.
5939 pragma Assert (not Raises_Constraint_Error (N));
5941 -- STEP 1a
5943 -- Check that the index range defined by aggregate bounds is
5944 -- compatible with corresponding index subtype.
5946 Index_Compatibility_Check : declare
5947 Aggr_Index_Range : Node_Id := First_Index (Typ);
5948 -- The current aggregate index range
5950 Index_Constraint : Node_Id := First_Index (Etype (Typ));
5951 -- The corresponding index constraint against which we have to
5952 -- check the above aggregate index range.
5954 begin
5955 Compute_Others_Present (N, 1);
5957 for J in 1 .. Aggr_Dimension loop
5958 -- There is no need to emit a check if an others choice is present
5959 -- for this array aggregate dimension since in this case one of
5960 -- N's subaggregates has taken its bounds from the context and
5961 -- these bounds must have been checked already. In addition all
5962 -- subaggregates corresponding to the same dimension must all have
5963 -- the same bounds (checked in (c) below).
5965 if not Range_Checks_Suppressed (Etype (Index_Constraint))
5966 and then not Others_Present (J)
5967 then
5968 -- We don't use Checks.Apply_Range_Check here because it emits
5969 -- a spurious check. Namely it checks that the range defined by
5970 -- the aggregate bounds is nonempty. But we know this already
5971 -- if we get here.
5973 Check_Bounds (Aggr_Index_Range, Index_Constraint);
5974 end if;
5976 -- Save the low and high bounds of the aggregate index as well as
5977 -- the index type for later use in checks (b) and (c) below.
5979 Get_Index_Bounds
5980 (Aggr_Index_Range, L => Aggr_Low (J), H => Aggr_High (J));
5982 Aggr_Index_Typ (J) := Etype (Index_Constraint);
5984 Next_Index (Aggr_Index_Range);
5985 Next_Index (Index_Constraint);
5986 end loop;
5987 end Index_Compatibility_Check;
5989 -- STEP 1b
5991 -- If an others choice is present check that no aggregate index is
5992 -- outside the bounds of the index constraint.
5994 Others_Check (N, 1);
5996 -- STEP 1c
5998 -- For multidimensional arrays make sure that all subaggregates
5999 -- corresponding to the same dimension have the same bounds.
6001 if Aggr_Dimension > 1 then
6002 Check_Same_Aggr_Bounds (N, 1);
6003 end if;
6005 -- STEP 1d
6007 -- If we have a default component value, or simple initialization is
6008 -- required for the component type, then we replace <> in component
6009 -- associations by the required default value.
6011 declare
6012 Default_Val : Node_Id;
6013 Assoc : Node_Id;
6015 begin
6016 if (Present (Default_Aspect_Component_Value (Typ))
6017 or else Needs_Simple_Initialization (Ctyp))
6018 and then Present (Component_Associations (N))
6019 then
6020 Assoc := First (Component_Associations (N));
6021 while Present (Assoc) loop
6022 if Nkind (Assoc) = N_Component_Association
6023 and then Box_Present (Assoc)
6024 then
6025 Set_Box_Present (Assoc, False);
6027 if Present (Default_Aspect_Component_Value (Typ)) then
6028 Default_Val := Default_Aspect_Component_Value (Typ);
6029 else
6030 Default_Val := Get_Simple_Init_Val (Ctyp, N);
6031 end if;
6033 Set_Expression (Assoc, New_Copy_Tree (Default_Val));
6034 Analyze_And_Resolve (Expression (Assoc), Ctyp);
6035 end if;
6037 Next (Assoc);
6038 end loop;
6039 end if;
6040 end;
6042 -- STEP 2
6044 -- Here we test for is packed array aggregate that we can handle at
6045 -- compile time. If so, return with transformation done. Note that we do
6046 -- this even if the aggregate is nested, because once we have done this
6047 -- processing, there is no more nested aggregate.
6049 if Packed_Array_Aggregate_Handled (N) then
6050 return;
6051 end if;
6053 -- At this point we try to convert to positional form
6055 Convert_To_Positional (N);
6057 -- If the result is no longer an aggregate (e.g. it may be a string
6058 -- literal, or a temporary which has the needed value), then we are
6059 -- done, since there is no longer a nested aggregate.
6061 if Nkind (N) /= N_Aggregate then
6062 return;
6064 -- We are also done if the result is an analyzed aggregate, indicating
6065 -- that Convert_To_Positional succeeded and reanalyzed the rewritten
6066 -- aggregate.
6068 elsif Analyzed (N) and then Is_Rewrite_Substitution (N) then
6069 return;
6070 end if;
6072 -- If all aggregate components are compile-time known and the aggregate
6073 -- has been flattened, nothing left to do. The same occurs if the
6074 -- aggregate is used to initialize the components of a statically
6075 -- allocated dispatch table.
6077 if Compile_Time_Known_Aggregate (N)
6078 or else Is_Static_Dispatch_Table_Aggregate (N)
6079 then
6080 Set_Expansion_Delayed (N, False);
6081 return;
6082 end if;
6084 -- Now see if back end processing is possible
6086 if Backend_Processing_Possible (N) then
6088 -- If the aggregate is static but the constraints are not, build
6089 -- a static subtype for the aggregate, so that Gigi can place it
6090 -- in static memory. Perform an unchecked_conversion to the non-
6091 -- static type imposed by the context.
6093 declare
6094 Itype : constant Entity_Id := Etype (N);
6095 Index : Node_Id;
6096 Needs_Type : Boolean := False;
6098 begin
6099 Index := First_Index (Itype);
6100 while Present (Index) loop
6101 if not Is_OK_Static_Subtype (Etype (Index)) then
6102 Needs_Type := True;
6103 exit;
6104 else
6105 Next_Index (Index);
6106 end if;
6107 end loop;
6109 if Needs_Type then
6110 Build_Constrained_Type (Positional => True);
6111 Rewrite (N, Unchecked_Convert_To (Itype, N));
6112 Analyze (N);
6113 end if;
6114 end;
6116 return;
6117 end if;
6119 -- STEP 3
6121 -- Delay expansion for nested aggregates: it will be taken care of when
6122 -- the parent aggregate is expanded, excluding container aggregates as
6123 -- these are transformed into subprogram calls later.
6125 Parent_Node := Parent (N);
6126 Parent_Kind := Nkind (Parent_Node);
6128 if Parent_Kind = N_Qualified_Expression then
6129 Parent_Node := Parent (Parent_Node);
6130 Parent_Kind := Nkind (Parent_Node);
6131 end if;
6133 if (Parent_Kind = N_Component_Association
6134 and then not Is_Container_Aggregate (Parent (Parent_Node)))
6135 or else (Parent_Kind in N_Aggregate | N_Extension_Aggregate
6136 and then not Is_Container_Aggregate (Parent_Node))
6137 or else (Parent_Kind = N_Object_Declaration
6138 and then (Needs_Finalization (Typ)
6139 or else Is_Special_Return_Object
6140 (Defining_Identifier (Parent_Node))))
6141 or else (Parent_Kind = N_Assignment_Statement
6142 and then Inside_Init_Proc)
6143 then
6144 Set_Expansion_Delayed (N, not Static_Array_Aggregate (N));
6145 return;
6146 end if;
6148 -- STEP 4
6150 -- Check whether in-place aggregate expansion is possible
6152 -- For object declarations we build the aggregate in place, unless
6153 -- the array is bit-packed.
6155 -- For assignments we do the assignment in place if all the component
6156 -- associations have compile-time known values, or are default-
6157 -- initialized limited components, e.g. tasks. For other cases we
6158 -- create a temporary. A full analysis for safety of in-place assignment
6159 -- is delicate.
6161 -- For allocators we assign to the designated object in place if the
6162 -- aggregate meets the same conditions as other in-place assignments.
6163 -- In this case the aggregate may not come from source but was created
6164 -- for default initialization, e.g. with Initialize_Scalars.
6166 if Requires_Transient_Scope (Typ) then
6167 Establish_Transient_Scope (N, Manage_Sec_Stack => False);
6168 end if;
6170 -- An array of limited components is built in place
6172 if Is_Limited_Type (Typ) then
6173 Maybe_In_Place_OK := True;
6175 elsif Has_Default_Init_Comps (N) then
6176 Maybe_In_Place_OK := False;
6178 elsif Is_Bit_Packed_Array (Typ)
6179 or else Has_Controlled_Component (Typ)
6180 then
6181 Maybe_In_Place_OK := False;
6183 elsif Parent_Kind = N_Assignment_Statement then
6184 Maybe_In_Place_OK :=
6185 In_Place_Assign_OK (N, Get_Base_Object (Name (Parent_Node)));
6187 elsif Parent_Kind = N_Allocator then
6188 Maybe_In_Place_OK := In_Place_Assign_OK (N);
6190 else
6191 Maybe_In_Place_OK := False;
6192 end if;
6194 -- If this is an array of tasks, it will be expanded into build-in-place
6195 -- assignments. Build an activation chain for the tasks now.
6197 if Has_Task (Typ) then
6198 Build_Activation_Chain_Entity (N);
6199 end if;
6201 -- Perform in-place expansion of aggregate in an object declaration.
6202 -- Note: actions generated for the aggregate will be captured in an
6203 -- expression-with-actions statement so that they can be transferred
6204 -- to freeze actions later if there is an address clause for the
6205 -- object. (Note: we don't use a block statement because this would
6206 -- cause generated freeze nodes to be elaborated in the wrong scope).
6208 -- Arrays of limited components must be built in place. The code
6209 -- previously excluded controlled components but this is an old
6210 -- oversight: the rules in 7.6 (17) are clear.
6212 if Comes_From_Source (Parent_Node)
6213 and then Parent_Kind = N_Object_Declaration
6214 and then Present (Expression (Parent_Node))
6215 and then not
6216 Must_Slide (N, Etype (Defining_Identifier (Parent_Node)), Typ)
6217 and then not Is_Bit_Packed_Array (Typ)
6218 then
6219 In_Place_Assign_OK_For_Declaration := True;
6220 Tmp := Defining_Identifier (Parent_Node);
6221 Set_No_Initialization (Parent_Node);
6222 Set_Expression (Parent_Node, Empty);
6224 -- Set kind and type of the entity, for use in the analysis
6225 -- of the subsequent assignments. If the nominal type is not
6226 -- constrained, build a subtype from the known bounds of the
6227 -- aggregate. If the declaration has a subtype mark, use it,
6228 -- otherwise use the itype of the aggregate.
6230 Mutate_Ekind (Tmp, E_Variable);
6232 if not Is_Constrained (Typ) then
6233 Build_Constrained_Type (Positional => False);
6235 elsif Is_Entity_Name (Object_Definition (Parent_Node))
6236 and then Is_Constrained (Entity (Object_Definition (Parent_Node)))
6237 then
6238 Set_Etype (Tmp, Entity (Object_Definition (Parent_Node)));
6240 else
6241 Set_Size_Known_At_Compile_Time (Typ, False);
6242 Set_Etype (Tmp, Typ);
6243 end if;
6245 elsif Maybe_In_Place_OK and then Parent_Kind = N_Allocator then
6246 Set_Expansion_Delayed (N);
6247 return;
6249 -- Limited arrays in return statements are expanded when
6250 -- enclosing construct is expanded.
6252 elsif Maybe_In_Place_OK
6253 and then Parent_Kind = N_Simple_Return_Statement
6254 then
6255 Set_Expansion_Delayed (N);
6256 return;
6258 -- In the remaining cases the aggregate appears in the RHS of an
6259 -- assignment, which may be part of the expansion of an object
6260 -- declaration. If the aggregate is an actual in a call, itself
6261 -- possibly in a RHS, building it in the target is not possible.
6263 elsif Maybe_In_Place_OK
6264 and then Nkind (Parent_Node) not in N_Subprogram_Call
6265 and then Safe_Left_Hand_Side (Name (Parent_Node))
6266 then
6267 Tmp := Name (Parent_Node);
6269 if Etype (Tmp) /= Etype (N) then
6270 Apply_Length_Check (N, Etype (Tmp));
6272 if Nkind (N) = N_Raise_Constraint_Error then
6274 -- Static error, nothing further to expand
6276 return;
6277 end if;
6278 end if;
6280 -- If a slice assignment has an aggregate with a single others_choice,
6281 -- the assignment can be done in place even if bounds are not static,
6282 -- by converting it into a loop over the discrete range of the slice.
6284 elsif Maybe_In_Place_OK
6285 and then Nkind (Name (Parent_Node)) = N_Slice
6286 and then Is_Others_Aggregate (N)
6287 then
6288 Tmp := Name (Parent_Node);
6290 -- Set type of aggregate to be type of lhs in assignment, in order
6291 -- to suppress redundant length checks.
6293 Set_Etype (N, Etype (Tmp));
6295 -- Step 5
6297 -- In-place aggregate expansion is not possible
6299 else
6300 Maybe_In_Place_OK := False;
6301 Tmp := Make_Temporary (Loc, 'A', N);
6302 Tmp_Decl :=
6303 Make_Object_Declaration (Loc,
6304 Defining_Identifier => Tmp,
6305 Object_Definition => New_Occurrence_Of (Typ, Loc));
6306 Set_No_Initialization (Tmp_Decl, True);
6308 -- If we are within a loop, the temporary will be pushed on the
6309 -- stack at each iteration. If the aggregate is the expression
6310 -- for an allocator, it will be immediately copied to the heap
6311 -- and can be reclaimed at once. We create a transient scope
6312 -- around the aggregate for this purpose.
6314 if Ekind (Current_Scope) = E_Loop
6315 and then Parent_Kind = N_Allocator
6316 then
6317 Establish_Transient_Scope (N, Manage_Sec_Stack => False);
6319 -- If the parent is an assignment for which no controlled actions
6320 -- should take place, prevent the temporary from being finalized.
6322 elsif Parent_Kind = N_Assignment_Statement
6323 and then No_Ctrl_Actions (Parent_Node)
6324 then
6325 Mutate_Ekind (Tmp, E_Variable);
6326 Set_Is_Ignored_Transient (Tmp);
6327 end if;
6329 Insert_Action (N, Tmp_Decl);
6330 end if;
6332 -- Construct and insert the aggregate code. We can safely suppress index
6333 -- checks because this code is guaranteed not to raise CE on index
6334 -- checks. However we should *not* suppress all checks.
6336 declare
6337 Target : Node_Id;
6339 begin
6340 if Nkind (Tmp) = N_Defining_Identifier then
6341 Target := New_Occurrence_Of (Tmp, Loc);
6343 else
6344 if Has_Default_Init_Comps (N)
6345 and then not Maybe_In_Place_OK
6346 then
6347 -- Ada 2005 (AI-287): This case has not been analyzed???
6349 raise Program_Error;
6350 end if;
6352 -- Name in assignment is explicit dereference
6354 Target := New_Copy (Tmp);
6355 end if;
6357 -- If we are to generate an in-place assignment for a declaration or
6358 -- an assignment statement, and the assignment can be done directly
6359 -- by the back end, then do not expand further.
6361 -- ??? We can also do that if in-place expansion is not possible but
6362 -- then we could go into an infinite recursion.
6364 if (In_Place_Assign_OK_For_Declaration or else Maybe_In_Place_OK)
6365 and then not CodePeer_Mode
6366 and then not Modify_Tree_For_C
6367 and then not Possible_Bit_Aligned_Component (Target)
6368 and then not Is_Possibly_Unaligned_Slice (Target)
6369 and then Aggr_Assignment_OK_For_Backend (N)
6370 then
6372 -- In the case of an assignment using an access with the
6373 -- Designated_Storage_Model aspect with a Copy_To procedure,
6374 -- insert a temporary and have the back end handle the assignment
6375 -- to it. Copy the result to the original target.
6377 if Parent_Kind = N_Assignment_Statement
6378 and then Nkind (Name (Parent_Node)) = N_Explicit_Dereference
6379 and then Has_Designated_Storage_Model_Aspect
6380 (Etype (Prefix (Name (Parent_Node))))
6381 and then Present (Storage_Model_Copy_To
6382 (Storage_Model_Object
6383 (Etype (Prefix (Name (Parent_Node))))))
6384 then
6385 Aggr_Code := Build_Assignment_With_Temporary
6386 (Target, Typ, New_Copy_Tree (N));
6388 else
6389 if Maybe_In_Place_OK then
6390 return;
6391 end if;
6393 Aggr_Code := New_List (
6394 Make_Assignment_Statement (Loc,
6395 Name => Target,
6396 Expression => New_Copy_Tree (N)));
6397 end if;
6399 else
6400 Aggr_Code :=
6401 Build_Array_Aggr_Code (N,
6402 Ctype => Ctyp,
6403 Index => First_Index (Typ),
6404 Into => Target,
6405 Scalar_Comp => Is_Scalar_Type (Ctyp));
6406 end if;
6408 -- Save the last assignment statement associated with the aggregate
6409 -- when building a controlled object. This reference is utilized by
6410 -- the finalization machinery when marking an object as successfully
6411 -- initialized.
6413 if Needs_Finalization (Typ)
6414 and then Is_Entity_Name (Target)
6415 and then Present (Entity (Target))
6416 and then Ekind (Entity (Target)) in E_Constant | E_Variable
6417 then
6418 Set_Last_Aggregate_Assignment (Entity (Target), Last (Aggr_Code));
6419 end if;
6420 end;
6422 -- If the aggregate is the expression in a declaration, the expanded
6423 -- code must be inserted after it. The defining entity might not come
6424 -- from source if this is part of an inlined body, but the declaration
6425 -- itself will.
6426 -- The test below looks very specialized and kludgy???
6428 if Comes_From_Source (Tmp)
6429 or else
6430 (Nkind (Parent (N)) = N_Object_Declaration
6431 and then Comes_From_Source (Parent (N))
6432 and then Tmp = Defining_Entity (Parent (N)))
6433 then
6434 if Parent_Kind /= N_Object_Declaration or else Is_Frozen (Tmp) then
6435 Insert_Actions_After (Parent_Node, Aggr_Code);
6436 else
6437 declare
6438 Comp_Stmt : constant Node_Id :=
6439 Make_Compound_Statement
6440 (Sloc (Parent_Node), Actions => Aggr_Code);
6441 begin
6442 Insert_Action_After (Parent_Node, Comp_Stmt);
6443 Set_Initialization_Statements (Tmp, Comp_Stmt);
6444 end;
6445 end if;
6446 else
6447 Insert_Actions (N, Aggr_Code);
6448 end if;
6450 -- If the aggregate has been assigned in place, remove the original
6451 -- assignment.
6453 if Parent_Kind = N_Assignment_Statement and then Maybe_In_Place_OK then
6454 Rewrite (Parent_Node, Make_Null_Statement (Loc));
6456 -- Or else, if a temporary was created, replace the aggregate with it
6458 elsif Parent_Kind /= N_Object_Declaration
6459 or else Tmp /= Defining_Identifier (Parent_Node)
6460 then
6461 Rewrite (N, New_Occurrence_Of (Tmp, Loc));
6462 Analyze_And_Resolve (N, Typ);
6463 end if;
6464 end Expand_Array_Aggregate;
6466 ------------------------
6467 -- Expand_N_Aggregate --
6468 ------------------------
6470 procedure Expand_N_Aggregate (N : Node_Id) is
6471 T : constant Entity_Id := Etype (N);
6472 begin
6473 -- Record aggregate case
6475 if Is_Record_Type (T)
6476 and then not Is_Private_Type (T)
6477 and then not Is_Homogeneous_Aggregate (N)
6478 then
6479 Expand_Record_Aggregate (N);
6481 elsif Has_Aspect (T, Aspect_Aggregate) then
6482 Expand_Container_Aggregate (N);
6484 -- Array aggregate case
6486 else
6487 -- A special case, if we have a string subtype with bounds 1 .. N,
6488 -- where N is known at compile time, and the aggregate is of the
6489 -- form (others => 'x'), with a single choice and no expressions,
6490 -- and N is less than 80 (an arbitrary limit for now), then replace
6491 -- the aggregate by the equivalent string literal (but do not mark
6492 -- it as static since it is not).
6494 -- Note: this entire circuit is redundant with respect to code in
6495 -- Expand_Array_Aggregate that collapses others choices to positional
6496 -- form, but there are two problems with that circuit:
6498 -- a) It is limited to very small cases due to ill-understood
6499 -- interactions with bootstrapping. That limit is removed by
6500 -- use of the No_Implicit_Loops restriction.
6502 -- b) It incorrectly ends up with the resulting expressions being
6503 -- considered static when they are not. For example, the
6504 -- following test should fail:
6506 -- pragma Restrictions (No_Implicit_Loops);
6507 -- package NonSOthers4 is
6508 -- B : constant String (1 .. 6) := (others => 'A');
6509 -- DH : constant String (1 .. 8) := B & "BB";
6510 -- X : Integer;
6511 -- pragma Export (C, X, Link_Name => DH);
6512 -- end;
6514 -- But it succeeds (DH looks static to pragma Export)
6516 -- To be sorted out ???
6518 if Present (Component_Associations (N)) then
6519 declare
6520 CA : constant Node_Id := First (Component_Associations (N));
6521 MX : constant := 80;
6523 begin
6524 if Present (CA)
6525 and then Nkind (First (Choice_List (CA))) = N_Others_Choice
6526 and then Nkind (Expression (CA)) = N_Character_Literal
6527 and then No (Expressions (N))
6528 then
6529 declare
6530 X : constant Node_Id := First_Index (T);
6531 EC : constant Node_Id := Expression (CA);
6532 CV : constant Uint := Char_Literal_Value (EC);
6533 CC : constant Char_Code := UI_To_CC (CV);
6535 begin
6536 if Nkind (X) = N_Range
6537 and then Compile_Time_Known_Value (Low_Bound (X))
6538 and then Expr_Value (Low_Bound (X)) = 1
6539 and then Compile_Time_Known_Value (High_Bound (X))
6540 then
6541 declare
6542 Hi : constant Uint := Expr_Value (High_Bound (X));
6544 begin
6545 if Hi <= MX then
6546 Start_String;
6548 for J in 1 .. UI_To_Int (Hi) loop
6549 Store_String_Char (CC);
6550 end loop;
6552 Rewrite (N,
6553 Make_String_Literal (Sloc (N),
6554 Strval => End_String));
6556 if In_Character_Range (CC) then
6557 null;
6558 elsif In_Wide_Character_Range (CC) then
6559 Set_Has_Wide_Character (N);
6560 else
6561 Set_Has_Wide_Wide_Character (N);
6562 end if;
6564 Analyze_And_Resolve (N, T);
6565 Set_Is_Static_Expression (N, False);
6566 return;
6567 end if;
6568 end;
6569 end if;
6570 end;
6571 end if;
6572 end;
6573 end if;
6575 -- Not that special case, so normal expansion of array aggregate
6577 Expand_Array_Aggregate (N);
6578 end if;
6580 exception
6581 when RE_Not_Available =>
6582 return;
6583 end Expand_N_Aggregate;
6585 --------------------------------
6586 -- Expand_Container_Aggregate --
6587 --------------------------------
6589 procedure Expand_Container_Aggregate (N : Node_Id) is
6590 Loc : constant Source_Ptr := Sloc (N);
6591 Typ : constant Entity_Id := Etype (N);
6592 Asp : constant Node_Id := Find_Value_Of_Aspect (Typ, Aspect_Aggregate);
6594 Empty_Subp : Node_Id := Empty;
6595 Add_Named_Subp : Node_Id := Empty;
6596 Add_Unnamed_Subp : Node_Id := Empty;
6597 New_Indexed_Subp : Node_Id := Empty;
6598 Assign_Indexed_Subp : Node_Id := Empty;
6600 Aggr_Code : constant List_Id := New_List;
6601 Temp : constant Entity_Id := Make_Temporary (Loc, 'C', N);
6603 Comp : Node_Id;
6604 Decl : Node_Id;
6605 Default : Node_Id;
6606 Init_Stat : Node_Id;
6607 Siz : Int;
6609 -- The following are used when the size of the aggregate is not
6610 -- static and requires a dynamic evaluation.
6611 Siz_Decl : Node_Id;
6612 Siz_Exp : Node_Id := Empty;
6613 Count_Type : Entity_Id;
6615 function Aggregate_Size return Int;
6616 -- Compute number of entries in aggregate, including choices
6617 -- that cover a range or subtype, as well as iterated constructs.
6618 -- Return -1 if the size is not known statically, in which case
6619 -- allocate a default size for the aggregate, or build an expression
6620 -- to estimate the size dynamically.
6622 function Build_Siz_Exp (Comp : Node_Id) return Int;
6623 -- When the aggregate contains a single Iterated_Component_Association
6624 -- or Element_Association with non-static bounds, build an expression
6625 -- to be used as the allocated size of the container. This may be an
6626 -- overestimate if a filter is present, but is a safe approximation.
6627 -- If bounds are dynamic the aggregate is created in two passes, and
6628 -- the first generates a loop for the sole purpose of computing the
6629 -- number of elements that will be generated on the second pass.
6631 procedure Expand_Iterated_Component (Comp : Node_Id);
6632 -- Handle iterated_component_association and iterated_Element
6633 -- association by generating a loop over the specified range,
6634 -- given either by a loop parameter specification or an iterator
6635 -- specification.
6637 --------------------
6638 -- Aggregate_Size --
6639 --------------------
6641 function Aggregate_Size return Int is
6642 Comp : Node_Id;
6643 Choice : Node_Id;
6644 Lo, Hi : Node_Id;
6645 Siz : Int;
6647 procedure Add_Range_Size;
6648 -- Compute number of components specified by a component association
6649 -- given by a range or subtype name.
6651 --------------------
6652 -- Add_Range_Size --
6653 --------------------
6655 procedure Add_Range_Size is
6656 begin
6657 -- The bounds of the discrete range are integers or enumeration
6658 -- literals
6660 if Nkind (Lo) = N_Integer_Literal then
6661 Siz := Siz + UI_To_Int (Intval (Hi))
6662 - UI_To_Int (Intval (Lo)) + 1;
6663 else
6664 Siz := Siz + UI_To_Int (Enumeration_Pos (Hi))
6665 - UI_To_Int (Enumeration_Pos (Lo)) + 1;
6666 end if;
6667 end Add_Range_Size;
6669 begin
6670 -- Aggregate is either all positional or all named
6672 Siz := List_Length (Expressions (N));
6674 if Present (Component_Associations (N)) then
6675 Comp := First (Component_Associations (N));
6676 -- If there is a single component association it can be
6677 -- an iterated component with dynamic bounds or an element
6678 -- iterator over an iterable object. If it is an array
6679 -- we can use the attribute Length to get its size;
6680 -- for a predefined container the function Length plays
6681 -- the same role. There is no available mechanism for
6682 -- user-defined containers. For now we treat all of these
6683 -- as dynamic.
6685 if List_Length (Component_Associations (N)) = 1
6686 and then Nkind (Comp) in N_Iterated_Component_Association |
6687 N_Iterated_Element_Association
6688 then
6689 return Build_Siz_Exp (Comp);
6690 end if;
6692 -- Otherwise all associations must specify static sizes.
6694 while Present (Comp) loop
6695 Choice := First (Choice_List (Comp));
6697 while Present (Choice) loop
6698 Analyze (Choice);
6700 if Nkind (Choice) = N_Range then
6701 Lo := Low_Bound (Choice);
6702 Hi := High_Bound (Choice);
6703 Add_Range_Size;
6705 elsif Is_Entity_Name (Choice)
6706 and then Is_Type (Entity (Choice))
6707 then
6708 Lo := Type_Low_Bound (Entity (Choice));
6709 Hi := Type_High_Bound (Entity (Choice));
6710 Add_Range_Size;
6712 Rewrite (Choice,
6713 Make_Range (Loc,
6714 New_Copy_Tree (Lo),
6715 New_Copy_Tree (Hi)));
6717 else
6718 -- Single choice (syntax excludes a subtype
6719 -- indication).
6721 Siz := Siz + 1;
6722 end if;
6724 Next (Choice);
6725 end loop;
6726 Next (Comp);
6727 end loop;
6728 end if;
6730 return Siz;
6731 end Aggregate_Size;
6733 -------------------
6734 -- Build_Siz_Exp --
6735 -------------------
6737 function Build_Siz_Exp (Comp : Node_Id) return Int is
6738 Lo, Hi : Node_Id;
6739 begin
6740 if Nkind (Comp) = N_Range then
6741 Lo := Low_Bound (Comp);
6742 Hi := High_Bound (Comp);
6743 Analyze (Lo);
6744 Analyze (Hi);
6746 -- Compute static size when possible.
6748 if Is_Static_Expression (Lo)
6749 and then Is_Static_Expression (Hi)
6750 then
6751 if Nkind (Lo) = N_Integer_Literal then
6752 Siz := UI_To_Int (Intval (Hi)) - UI_To_Int (Intval (Lo)) + 1;
6753 else
6754 Siz := UI_To_Int (Enumeration_Pos (Hi))
6755 - UI_To_Int (Enumeration_Pos (Lo)) + 1;
6756 end if;
6757 return Siz;
6759 else
6760 Siz_Exp :=
6761 Make_Op_Add (Sloc (Comp),
6762 Left_Opnd =>
6763 Make_Op_Subtract (Sloc (Comp),
6764 Left_Opnd => New_Copy_Tree (Hi),
6765 Right_Opnd => New_Copy_Tree (Lo)),
6766 Right_Opnd =>
6767 Make_Integer_Literal (Loc, 1));
6768 return -1;
6769 end if;
6771 elsif Nkind (Comp) = N_Iterated_Component_Association then
6772 return Build_Siz_Exp (First (Discrete_Choices (Comp)));
6774 elsif Nkind (Comp) = N_Iterated_Element_Association then
6775 return -1;
6777 -- ??? Need to create code for a loop and add to generated code,
6778 -- as is done for array aggregates with iterated element
6779 -- associations, instead of using Append operations.
6781 else
6782 return -1;
6783 end if;
6784 end Build_Siz_Exp;
6786 -------------------------------
6787 -- Expand_Iterated_Component --
6788 -------------------------------
6790 procedure Expand_Iterated_Component (Comp : Node_Id) is
6791 Expr : constant Node_Id := Expression (Comp);
6793 Key_Expr : Node_Id := Empty;
6794 Loop_Id : Entity_Id;
6795 L_Range : Node_Id;
6796 L_Iteration_Scheme : Node_Id;
6797 Loop_Stat : Node_Id;
6798 Params : List_Id;
6799 Stats : List_Id;
6801 begin
6802 if Nkind (Comp) = N_Iterated_Element_Association then
6803 Key_Expr := Key_Expression (Comp);
6805 -- We create a new entity as loop identifier in all cases,
6806 -- as is done for generated loops elsewhere, as the loop
6807 -- structure has been previously analyzed.
6809 if Present (Iterator_Specification (Comp)) then
6811 -- Either an Iterator_Specification or a Loop_Parameter_
6812 -- Specification is present.
6814 L_Iteration_Scheme :=
6815 Make_Iteration_Scheme (Loc,
6816 Iterator_Specification => Iterator_Specification (Comp));
6817 Loop_Id :=
6818 Make_Defining_Identifier (Loc,
6819 Chars => Chars (Defining_Identifier
6820 (Iterator_Specification (Comp))));
6821 Set_Defining_Identifier
6822 (Iterator_Specification (L_Iteration_Scheme), Loop_Id);
6824 else
6825 L_Iteration_Scheme :=
6826 Make_Iteration_Scheme (Loc,
6827 Loop_Parameter_Specification =>
6828 Loop_Parameter_Specification (Comp));
6829 Loop_Id :=
6830 Make_Defining_Identifier (Loc,
6831 Chars => Chars (Defining_Identifier
6832 (Loop_Parameter_Specification (Comp))));
6833 Set_Defining_Identifier
6834 (Loop_Parameter_Specification
6835 (L_Iteration_Scheme), Loop_Id);
6836 end if;
6837 else
6839 -- Iterated_Component_Association.
6841 if Present (Iterator_Specification (Comp)) then
6842 Loop_Id :=
6843 Make_Defining_Identifier (Loc,
6844 Chars => Chars (Defining_Identifier
6845 (Iterator_Specification (Comp))));
6846 L_Iteration_Scheme :=
6847 Make_Iteration_Scheme (Loc,
6848 Iterator_Specification => Iterator_Specification (Comp));
6850 else
6851 -- Loop_Parameter_Specification is parsed with a choice list.
6852 -- where the range is the first (and only) choice.
6854 Loop_Id :=
6855 Make_Defining_Identifier (Loc,
6856 Chars => Chars (Defining_Identifier (Comp)));
6857 L_Range := Relocate_Node (First (Discrete_Choices (Comp)));
6859 L_Iteration_Scheme :=
6860 Make_Iteration_Scheme (Loc,
6861 Loop_Parameter_Specification =>
6862 Make_Loop_Parameter_Specification (Loc,
6863 Defining_Identifier => Loop_Id,
6864 Discrete_Subtype_Definition => L_Range));
6865 end if;
6866 end if;
6868 -- Build insertion statement. For a positional aggregate, only the
6869 -- expression is needed. For a named aggregate, the loop variable,
6870 -- whose type is that of the key, is an additional parameter for
6871 -- the insertion operation.
6872 -- If a Key_Expression is present, it serves as the additional
6873 -- parameter. Otherwise the key is given by the loop parameter
6874 -- itself.
6876 if Present (Add_Unnamed_Subp)
6877 and then No (Add_Named_Subp)
6878 then
6879 Stats := New_List
6880 (Make_Procedure_Call_Statement (Loc,
6881 Name => New_Occurrence_Of (Entity (Add_Unnamed_Subp), Loc),
6882 Parameter_Associations =>
6883 New_List (New_Occurrence_Of (Temp, Loc),
6884 New_Copy_Tree (Expr))));
6885 else
6886 -- Named or indexed aggregate, for which a key is present,
6887 -- possibly with a specified key_expression.
6889 if Present (Key_Expr) then
6890 Params := New_List (New_Occurrence_Of (Temp, Loc),
6891 New_Copy_Tree (Key_Expr),
6892 New_Copy_Tree (Expr));
6893 else
6894 Params := New_List (New_Occurrence_Of (Temp, Loc),
6895 New_Occurrence_Of (Loop_Id, Loc),
6896 New_Copy_Tree (Expr));
6897 end if;
6899 Stats := New_List
6900 (Make_Procedure_Call_Statement (Loc,
6901 Name => New_Occurrence_Of (Entity (Add_Named_Subp), Loc),
6902 Parameter_Associations => Params));
6903 end if;
6905 Loop_Stat := Make_Implicit_Loop_Statement
6906 (Node => N,
6907 Identifier => Empty,
6908 Iteration_Scheme => L_Iteration_Scheme,
6909 Statements => Stats);
6910 Append (Loop_Stat, Aggr_Code);
6912 end Expand_Iterated_Component;
6914 -- Start of processing for Expand_Container_Aggregate
6916 begin
6917 Parse_Aspect_Aggregate (Asp,
6918 Empty_Subp, Add_Named_Subp, Add_Unnamed_Subp,
6919 New_Indexed_Subp, Assign_Indexed_Subp);
6921 -- The constructor for bounded containers is a function with
6922 -- a parameter that sets the size of the container. If the
6923 -- size cannot be determined statically we use a default value
6924 -- or a dynamic expression.
6926 Siz := Aggregate_Size;
6928 ---------------------
6929 -- Empty function --
6930 ---------------------
6932 if Ekind (Entity (Empty_Subp)) = E_Function
6933 and then Present (First_Formal (Entity (Empty_Subp)))
6934 then
6935 Default := Default_Value (First_Formal (Entity (Empty_Subp)));
6937 -- If aggregate size is not static, we can use default value
6938 -- of formal parameter for allocation. We assume that this
6939 -- (implementation-dependent) value is static, even though
6940 -- the AI does not require it.
6942 -- Create declaration for size: a constant literal in the simple
6943 -- case, an expression if iterated component associations may be
6944 -- involved, the default otherwise.
6946 Count_Type := Etype (First_Formal (Entity (Empty_Subp)));
6947 if Siz = -1 then
6948 if No (Siz_Exp) then
6949 Siz := UI_To_Int (Intval (Default));
6950 Siz_Exp := Make_Integer_Literal (Loc, Siz);
6952 else
6953 Siz_Exp := Make_Type_Conversion (Loc,
6954 Subtype_Mark =>
6955 New_Occurrence_Of (Count_Type, Loc),
6956 Expression => Siz_Exp);
6957 end if;
6959 else
6960 Siz_Exp := Make_Integer_Literal (Loc, Siz);
6961 end if;
6963 Siz_Decl := Make_Object_Declaration (Loc,
6964 Defining_Identifier => Make_Temporary (Loc, 'S', N),
6965 Object_Definition =>
6966 New_Occurrence_Of (Count_Type, Loc),
6967 Expression => Siz_Exp);
6968 Append (Siz_Decl, Aggr_Code);
6970 if Nkind (Siz_Exp) = N_Integer_Literal then
6971 Init_Stat :=
6972 Make_Object_Declaration (Loc,
6973 Defining_Identifier => Temp,
6974 Object_Definition => New_Occurrence_Of (Typ, Loc),
6975 Expression => Make_Function_Call (Loc,
6976 Name => New_Occurrence_Of (Entity (Empty_Subp), Loc),
6977 Parameter_Associations =>
6978 New_List
6979 (New_Occurrence_Of
6980 (Defining_Identifier (Siz_Decl), Loc))));
6982 else
6983 Init_Stat :=
6984 Make_Object_Declaration (Loc,
6985 Defining_Identifier => Temp,
6986 Object_Definition => New_Occurrence_Of (Typ, Loc),
6987 Expression => Make_Function_Call (Loc,
6988 Name =>
6989 New_Occurrence_Of (Entity (New_Indexed_Subp), Loc),
6990 Parameter_Associations =>
6991 New_List (
6992 Make_Integer_Literal (Loc, 1),
6993 New_Occurrence_Of
6994 (Defining_Identifier (Siz_Decl), Loc))));
6995 end if;
6997 Append (Init_Stat, Aggr_Code);
6999 -- Size is dynamic: Create declaration for object, and initialize
7000 -- with a call to the null container, or an assignment to it.
7002 else
7003 Decl :=
7004 Make_Object_Declaration (Loc,
7005 Defining_Identifier => Temp,
7006 Object_Definition => New_Occurrence_Of (Typ, Loc));
7008 Insert_Action (N, Decl);
7010 -- The Empty entity is either a parameterless function, or
7011 -- a constant.
7013 if Ekind (Entity (Empty_Subp)) = E_Function then
7014 Init_Stat := Make_Assignment_Statement (Loc,
7015 Name => New_Occurrence_Of (Temp, Loc),
7016 Expression => Make_Function_Call (Loc,
7017 Name => New_Occurrence_Of (Entity (Empty_Subp), Loc)));
7019 else
7020 Init_Stat := Make_Assignment_Statement (Loc,
7021 Name => New_Occurrence_Of (Temp, Loc),
7022 Expression => New_Occurrence_Of (Entity (Empty_Subp), Loc));
7023 end if;
7025 Append (Init_Stat, Aggr_Code);
7026 end if;
7028 -- Report warning on infinite recursion if an empty container aggregate
7029 -- appears in the return statement of its Empty function.
7031 if Ekind (Entity (Empty_Subp)) = E_Function
7032 and then Nkind (Parent (N)) = N_Simple_Return_Statement
7033 and then Is_Empty_List (Expressions (N))
7034 and then Is_Empty_List (Component_Associations (N))
7035 and then Entity (Empty_Subp) = Current_Scope
7036 then
7037 Error_Msg_Warn := SPARK_Mode /= On;
7038 Error_Msg_N
7039 ("!empty aggregate returned by the empty function of a container"
7040 & " aggregate<<<", Parent (N));
7041 Error_Msg_N
7042 ("\this will result in infinite recursion??", Parent (N));
7043 end if;
7045 ---------------------------
7046 -- Positional aggregate --
7047 ---------------------------
7049 -- If the aggregate is positional the aspect must include
7050 -- an Add_Unnamed subprogram.
7052 if Present (Add_Unnamed_Subp) then
7053 if Present (Expressions (N)) then
7054 declare
7055 Insert : constant Entity_Id := Entity (Add_Unnamed_Subp);
7056 Comp : Node_Id;
7057 Stat : Node_Id;
7059 begin
7060 Comp := First (Expressions (N));
7061 while Present (Comp) loop
7062 Stat := Make_Procedure_Call_Statement (Loc,
7063 Name => New_Occurrence_Of (Insert, Loc),
7064 Parameter_Associations =>
7065 New_List (New_Occurrence_Of (Temp, Loc),
7066 New_Copy_Tree (Comp)));
7067 Append (Stat, Aggr_Code);
7068 Next (Comp);
7069 end loop;
7070 end;
7071 end if;
7073 -- Indexed aggregates are handled below. Unnamed aggregates
7074 -- such as sets may include iterated component associations.
7076 if No (New_Indexed_Subp) then
7077 Comp := First (Component_Associations (N));
7078 while Present (Comp) loop
7079 if Nkind (Comp) = N_Iterated_Component_Association then
7080 Expand_Iterated_Component (Comp);
7081 end if;
7082 Next (Comp);
7083 end loop;
7084 end if;
7086 ---------------------
7087 -- Named_Aggregate --
7088 ---------------------
7090 elsif Present (Add_Named_Subp) then
7091 declare
7092 Insert : constant Entity_Id := Entity (Add_Named_Subp);
7093 Stat : Node_Id;
7094 Key : Node_Id;
7095 begin
7096 Comp := First (Component_Associations (N));
7098 -- Each component association may contain several choices;
7099 -- generate an insertion statement for each.
7101 while Present (Comp) loop
7102 if Nkind (Comp) in N_Iterated_Component_Association
7103 | N_Iterated_Element_Association
7104 then
7105 Expand_Iterated_Component (Comp);
7106 else
7107 Key := First (Choices (Comp));
7109 while Present (Key) loop
7110 Stat := Make_Procedure_Call_Statement (Loc,
7111 Name => New_Occurrence_Of (Insert, Loc),
7112 Parameter_Associations =>
7113 New_List (New_Occurrence_Of (Temp, Loc),
7114 New_Copy_Tree (Key),
7115 New_Copy_Tree (Expression (Comp))));
7116 Append (Stat, Aggr_Code);
7118 Next (Key);
7119 end loop;
7120 end if;
7122 Next (Comp);
7123 end loop;
7124 end;
7125 end if;
7127 -----------------------
7128 -- Indexed_Aggregate --
7129 -----------------------
7131 -- For an indexed aggregate there must be an Assigned_Indexeed
7132 -- subprogram. Note that unlike array aggregates, a container
7133 -- aggregate must be fully positional or fully indexed. In the
7134 -- first case the expansion has already taken place.
7135 -- TBA: the keys for an indexed aggregate must provide a dense
7136 -- range with no repetitions.
7138 if Present (Assign_Indexed_Subp)
7139 and then Present (Component_Associations (N))
7140 then
7141 declare
7142 Insert : constant Entity_Id := Entity (Assign_Indexed_Subp);
7143 Index_Type : constant Entity_Id :=
7144 Etype (Next_Formal (First_Formal (Insert)));
7146 function Expand_Range_Component
7147 (Rng : Node_Id;
7148 Expr : Node_Id) return Node_Id;
7149 -- Transform a component assoication with a range into an
7150 -- explicit loop. If the choice is a subtype name, it is
7151 -- rewritten as a range with the corresponding bounds, which
7152 -- are known to be static.
7154 Comp : Node_Id;
7155 Index : Node_Id;
7156 Pos : Int := 0;
7157 Stat : Node_Id;
7158 Key : Node_Id;
7160 -----------------------------
7161 -- Expand_Raange_Component --
7162 -----------------------------
7164 function Expand_Range_Component
7165 (Rng : Node_Id;
7166 Expr : Node_Id) return Node_Id
7168 Loop_Id : constant Entity_Id :=
7169 Make_Temporary (Loc, 'T');
7171 L_Iteration_Scheme : Node_Id;
7172 Stats : List_Id;
7174 begin
7175 L_Iteration_Scheme :=
7176 Make_Iteration_Scheme (Loc,
7177 Loop_Parameter_Specification =>
7178 Make_Loop_Parameter_Specification (Loc,
7179 Defining_Identifier => Loop_Id,
7180 Discrete_Subtype_Definition => New_Copy_Tree (Rng)));
7182 Stats := New_List
7183 (Make_Procedure_Call_Statement (Loc,
7184 Name =>
7185 New_Occurrence_Of (Entity (Assign_Indexed_Subp), Loc),
7186 Parameter_Associations =>
7187 New_List (New_Occurrence_Of (Temp, Loc),
7188 New_Occurrence_Of (Loop_Id, Loc),
7189 New_Copy_Tree (Expr))));
7191 return Make_Implicit_Loop_Statement
7192 (Node => N,
7193 Identifier => Empty,
7194 Iteration_Scheme => L_Iteration_Scheme,
7195 Statements => Stats);
7196 end Expand_Range_Component;
7198 begin
7199 if Siz > 0 then
7201 -- Modify the call to the constructor to allocate the
7202 -- required size for the aggregwte : call the provided
7203 -- constructor rather than the Empty aggregate.
7205 Index := Make_Op_Add (Loc,
7206 Left_Opnd => New_Copy_Tree (Type_Low_Bound (Index_Type)),
7207 Right_Opnd => Make_Integer_Literal (Loc, Siz - 1));
7209 Set_Expression (Init_Stat,
7210 Make_Function_Call (Loc,
7211 Name =>
7212 New_Occurrence_Of (Entity (New_Indexed_Subp), Loc),
7213 Parameter_Associations =>
7214 New_List (
7215 New_Copy_Tree (Type_Low_Bound (Index_Type)),
7216 Index)));
7217 end if;
7219 if Present (Expressions (N)) then
7220 Comp := First (Expressions (N));
7222 while Present (Comp) loop
7224 -- Compute index position for successive components
7225 -- in the list of expressions, and use the indexed
7226 -- assignment procedure for each.
7228 Index := Make_Op_Add (Loc,
7229 Left_Opnd => Type_Low_Bound (Index_Type),
7230 Right_Opnd => Make_Integer_Literal (Loc, Pos));
7232 Stat := Make_Procedure_Call_Statement (Loc,
7233 Name => New_Occurrence_Of (Insert, Loc),
7234 Parameter_Associations =>
7235 New_List (New_Occurrence_Of (Temp, Loc),
7236 Index,
7237 New_Copy_Tree (Comp)));
7239 Pos := Pos + 1;
7241 Append (Stat, Aggr_Code);
7242 Next (Comp);
7243 end loop;
7244 end if;
7246 if Present (Component_Associations (N)) then
7247 Comp := First (Component_Associations (N));
7249 -- The choice may be a static value, or a range with
7250 -- static bounds.
7252 while Present (Comp) loop
7253 if Nkind (Comp) = N_Component_Association then
7254 Key := First (Choices (Comp));
7255 while Present (Key) loop
7257 -- If the expression is a box, the corresponding
7258 -- component (s) is left uninitialized.
7260 if Box_Present (Comp) then
7261 goto Next_Key;
7263 elsif Nkind (Key) = N_Range then
7265 -- Create loop for tne specified range,
7266 -- with copies of the expression.
7268 Stat :=
7269 Expand_Range_Component (Key, Expression (Comp));
7271 else
7272 Stat := Make_Procedure_Call_Statement (Loc,
7273 Name => New_Occurrence_Of
7274 (Entity (Assign_Indexed_Subp), Loc),
7275 Parameter_Associations =>
7276 New_List (New_Occurrence_Of (Temp, Loc),
7277 New_Copy_Tree (Key),
7278 New_Copy_Tree (Expression (Comp))));
7279 end if;
7281 Append (Stat, Aggr_Code);
7283 <<Next_Key>>
7284 Next (Key);
7285 end loop;
7287 else
7288 -- Iterated component association. Discard
7289 -- positional insertion procedure.
7291 if No (Iterator_Specification (Comp)) then
7292 Add_Named_Subp := Assign_Indexed_Subp;
7293 Add_Unnamed_Subp := Empty;
7294 end if;
7296 Expand_Iterated_Component (Comp);
7297 end if;
7299 Next (Comp);
7300 end loop;
7301 end if;
7302 end;
7303 end if;
7305 Insert_Actions (N, Aggr_Code);
7306 Rewrite (N, New_Occurrence_Of (Temp, Loc));
7307 Analyze_And_Resolve (N, Typ);
7308 end Expand_Container_Aggregate;
7310 ------------------------------
7311 -- Expand_N_Delta_Aggregate --
7312 ------------------------------
7314 procedure Expand_N_Delta_Aggregate (N : Node_Id) is
7315 Loc : constant Source_Ptr := Sloc (N);
7316 Typ : constant Entity_Id := Etype (Expression (N));
7317 Decl : Node_Id;
7319 begin
7320 Decl :=
7321 Make_Object_Declaration (Loc,
7322 Defining_Identifier => Make_Temporary (Loc, 'T'),
7323 Object_Definition => New_Occurrence_Of (Typ, Loc),
7324 Expression => New_Copy_Tree (Expression (N)));
7326 if Is_Array_Type (Etype (N)) then
7327 Expand_Delta_Array_Aggregate (N, New_List (Decl));
7328 else
7329 Expand_Delta_Record_Aggregate (N, New_List (Decl));
7330 end if;
7331 end Expand_N_Delta_Aggregate;
7333 ----------------------------------
7334 -- Expand_Delta_Array_Aggregate --
7335 ----------------------------------
7337 procedure Expand_Delta_Array_Aggregate (N : Node_Id; Deltas : List_Id) is
7338 Loc : constant Source_Ptr := Sloc (N);
7339 Temp : constant Entity_Id := Defining_Identifier (First (Deltas));
7340 Assoc : Node_Id;
7342 function Generate_Loop (C : Node_Id) return Node_Id;
7343 -- Generate a loop containing individual component assignments for
7344 -- choices that are ranges, subtype indications, subtype names, and
7345 -- iterated component associations.
7347 -------------------
7348 -- Generate_Loop --
7349 -------------------
7351 function Generate_Loop (C : Node_Id) return Node_Id is
7352 Sl : constant Source_Ptr := Sloc (C);
7353 Ix : Entity_Id;
7355 begin
7356 if Nkind (Parent (C)) = N_Iterated_Component_Association then
7357 Ix :=
7358 Make_Defining_Identifier (Loc,
7359 Chars => (Chars (Defining_Identifier (Parent (C)))));
7360 else
7361 Ix := Make_Temporary (Sl, 'I');
7362 end if;
7364 return
7365 Make_Implicit_Loop_Statement (C,
7366 Iteration_Scheme =>
7367 Make_Iteration_Scheme (Sl,
7368 Loop_Parameter_Specification =>
7369 Make_Loop_Parameter_Specification (Sl,
7370 Defining_Identifier => Ix,
7371 Discrete_Subtype_Definition => New_Copy_Tree (C))),
7373 Statements => New_List (
7374 Make_Assignment_Statement (Sl,
7375 Name =>
7376 Make_Indexed_Component (Sl,
7377 Prefix => New_Occurrence_Of (Temp, Sl),
7378 Expressions => New_List (New_Occurrence_Of (Ix, Sl))),
7379 Expression => New_Copy_Tree (Expression (Assoc)))),
7380 End_Label => Empty);
7381 end Generate_Loop;
7383 -- Local variables
7385 Choice : Node_Id;
7387 -- Start of processing for Expand_Delta_Array_Aggregate
7389 begin
7390 Assoc := First (Component_Associations (N));
7391 while Present (Assoc) loop
7392 Choice := First (Choice_List (Assoc));
7393 if Nkind (Assoc) = N_Iterated_Component_Association then
7394 while Present (Choice) loop
7395 Append_To (Deltas, Generate_Loop (Choice));
7396 Next (Choice);
7397 end loop;
7399 else
7400 while Present (Choice) loop
7402 -- Choice can be given by a range, a subtype indication, a
7403 -- subtype name, a scalar value, or an entity.
7405 if Nkind (Choice) = N_Range
7406 or else (Is_Entity_Name (Choice)
7407 and then Is_Type (Entity (Choice)))
7408 then
7409 Append_To (Deltas, Generate_Loop (Choice));
7411 elsif Nkind (Choice) = N_Subtype_Indication then
7412 Append_To (Deltas,
7413 Generate_Loop (Range_Expression (Constraint (Choice))));
7415 else
7416 Append_To (Deltas,
7417 Make_Assignment_Statement (Sloc (Choice),
7418 Name =>
7419 Make_Indexed_Component (Sloc (Choice),
7420 Prefix => New_Occurrence_Of (Temp, Loc),
7421 Expressions => New_List (New_Copy_Tree (Choice))),
7422 Expression => New_Copy_Tree (Expression (Assoc))));
7423 end if;
7425 Next (Choice);
7426 end loop;
7427 end if;
7429 Next (Assoc);
7430 end loop;
7432 Insert_Actions (N, Deltas);
7433 Rewrite (N, New_Occurrence_Of (Temp, Loc));
7434 end Expand_Delta_Array_Aggregate;
7436 -----------------------------------
7437 -- Expand_Delta_Record_Aggregate --
7438 -----------------------------------
7440 procedure Expand_Delta_Record_Aggregate (N : Node_Id; Deltas : List_Id) is
7441 Loc : constant Source_Ptr := Sloc (N);
7442 Temp : constant Entity_Id := Defining_Identifier (First (Deltas));
7443 Assoc : Node_Id;
7444 Choice : Node_Id;
7446 begin
7447 Assoc := First (Component_Associations (N));
7449 while Present (Assoc) loop
7450 Choice := First (Choice_List (Assoc));
7451 while Present (Choice) loop
7452 Append_To (Deltas,
7453 Make_Assignment_Statement (Sloc (Choice),
7454 Name =>
7455 Make_Selected_Component (Sloc (Choice),
7456 Prefix => New_Occurrence_Of (Temp, Loc),
7457 Selector_Name => Make_Identifier (Loc, Chars (Choice))),
7458 Expression => New_Copy_Tree (Expression (Assoc))));
7459 Next (Choice);
7460 end loop;
7462 Next (Assoc);
7463 end loop;
7465 Insert_Actions (N, Deltas);
7466 Rewrite (N, New_Occurrence_Of (Temp, Loc));
7467 end Expand_Delta_Record_Aggregate;
7469 ----------------------------------
7470 -- Expand_N_Extension_Aggregate --
7471 ----------------------------------
7473 -- If the ancestor part is an expression, add a component association for
7474 -- the parent field. If the type of the ancestor part is not the direct
7475 -- parent of the expected type, build recursively the needed ancestors.
7476 -- If the ancestor part is a subtype_mark, replace aggregate with a
7477 -- declaration for a temporary of the expected type, followed by
7478 -- individual assignments to the given components.
7480 procedure Expand_N_Extension_Aggregate (N : Node_Id) is
7481 A : constant Node_Id := Ancestor_Part (N);
7482 Loc : constant Source_Ptr := Sloc (N);
7483 Typ : constant Entity_Id := Etype (N);
7485 begin
7486 -- If the ancestor is a subtype mark, an init proc must be called
7487 -- on the resulting object which thus has to be materialized in
7488 -- the front-end
7490 if Is_Entity_Name (A) and then Is_Type (Entity (A)) then
7491 Convert_To_Assignments (N, Typ);
7493 -- The extension aggregate is transformed into a record aggregate
7494 -- of the following form (c1 and c2 are inherited components)
7496 -- (Exp with c3 => a, c4 => b)
7497 -- ==> (c1 => Exp.c1, c2 => Exp.c2, c3 => a, c4 => b)
7499 else
7500 Set_Etype (N, Typ);
7502 if Tagged_Type_Expansion then
7503 Expand_Record_Aggregate (N,
7504 Orig_Tag =>
7505 New_Occurrence_Of
7506 (Node (First_Elmt (Access_Disp_Table (Typ))), Loc),
7507 Parent_Expr => A);
7509 -- No tag is needed in the case of a VM
7511 else
7512 Expand_Record_Aggregate (N, Parent_Expr => A);
7513 end if;
7514 end if;
7516 exception
7517 when RE_Not_Available =>
7518 return;
7519 end Expand_N_Extension_Aggregate;
7521 -----------------------------
7522 -- Expand_Record_Aggregate --
7523 -----------------------------
7525 procedure Expand_Record_Aggregate
7526 (N : Node_Id;
7527 Orig_Tag : Node_Id := Empty;
7528 Parent_Expr : Node_Id := Empty)
7530 Loc : constant Source_Ptr := Sloc (N);
7531 Comps : constant List_Id := Component_Associations (N);
7532 Typ : constant Entity_Id := Etype (N);
7533 Base_Typ : constant Entity_Id := Base_Type (Typ);
7535 Static_Components : Boolean := True;
7536 -- Flag to indicate whether all components are compile-time known,
7537 -- and the aggregate can be constructed statically and handled by
7538 -- the back-end. Set to False by Component_OK_For_Backend.
7540 procedure Build_Back_End_Aggregate;
7541 -- Build a proper aggregate to be handled by the back-end
7543 function Compile_Time_Known_Composite_Value (N : Node_Id) return Boolean;
7544 -- Returns true if N is an expression of composite type which can be
7545 -- fully evaluated at compile time without raising constraint error.
7546 -- Such expressions can be passed as is to Gigi without any expansion.
7548 -- This returns true for N_Aggregate with Compile_Time_Known_Aggregate
7549 -- set and constants whose expression is such an aggregate, recursively.
7551 function Component_OK_For_Backend return Boolean;
7552 -- Check for presence of a component which makes it impossible for the
7553 -- backend to process the aggregate, thus requiring the use of a series
7554 -- of assignment statements. Cases checked for are a nested aggregate
7555 -- needing Late_Expansion, the presence of a tagged component which may
7556 -- need tag adjustment, and a bit unaligned component reference.
7558 -- We also force expansion into assignments if a component is of a
7559 -- mutable type (including a private type with discriminants) because
7560 -- in that case the size of the component to be copied may be smaller
7561 -- than the side of the target, and there is no simple way for gigi
7562 -- to compute the size of the object to be copied.
7564 -- NOTE: This is part of the ongoing work to define precisely the
7565 -- interface between front-end and back-end handling of aggregates.
7566 -- In general it is desirable to pass aggregates as they are to gigi,
7567 -- in order to minimize elaboration code. This is one case where the
7568 -- semantics of Ada complicate the analysis and lead to anomalies in
7569 -- the gcc back-end if the aggregate is not expanded into assignments.
7571 -- NOTE: This sets the global Static_Components to False in most, but
7572 -- not all, cases when it returns False.
7574 function Has_Per_Object_Constraint (L : List_Id) return Boolean;
7575 -- Return True if any element of L has Has_Per_Object_Constraint set.
7576 -- L should be the Choices component of an N_Component_Association.
7578 function Has_Visible_Private_Ancestor (Id : E) return Boolean;
7579 -- If any ancestor of the current type is private, the aggregate
7580 -- cannot be built in place. We cannot rely on Has_Private_Ancestor,
7581 -- because it will not be set when type and its parent are in the
7582 -- same scope, and the parent component needs expansion.
7584 function Top_Level_Aggregate (N : Node_Id) return Node_Id;
7585 -- For nested aggregates return the ultimate enclosing aggregate; for
7586 -- non-nested aggregates return N.
7588 ------------------------------
7589 -- Build_Back_End_Aggregate --
7590 ------------------------------
7592 procedure Build_Back_End_Aggregate is
7593 Comp : Entity_Id;
7594 New_Comp : Node_Id;
7595 Tag_Value : Node_Id;
7597 begin
7598 if Nkind (N) = N_Aggregate then
7600 -- If the aggregate is static and can be handled by the back-end,
7601 -- nothing left to do.
7603 if Static_Components then
7604 Set_Compile_Time_Known_Aggregate (N);
7605 Set_Expansion_Delayed (N, False);
7606 end if;
7607 end if;
7609 -- If no discriminants, nothing special to do
7611 if not Has_Discriminants (Typ) then
7612 null;
7614 -- Case of discriminants present
7616 elsif Is_Derived_Type (Typ) then
7618 -- For untagged types, non-stored discriminants are replaced with
7619 -- stored discriminants, which are the ones that gigi uses to
7620 -- describe the type and its components.
7622 Generate_Aggregate_For_Derived_Type : declare
7623 procedure Prepend_Stored_Values (T : Entity_Id);
7624 -- Scan the list of stored discriminants of the type, and add
7625 -- their values to the aggregate being built.
7627 ---------------------------
7628 -- Prepend_Stored_Values --
7629 ---------------------------
7631 procedure Prepend_Stored_Values (T : Entity_Id) is
7632 Discr : Entity_Id;
7633 First_Comp : Node_Id := Empty;
7635 begin
7636 Discr := First_Stored_Discriminant (T);
7637 while Present (Discr) loop
7638 New_Comp :=
7639 Make_Component_Association (Loc,
7640 Choices => New_List (
7641 New_Occurrence_Of (Discr, Loc)),
7642 Expression =>
7643 New_Copy_Tree
7644 (Get_Discriminant_Value
7645 (Discr,
7646 Typ,
7647 Discriminant_Constraint (Typ))));
7649 if No (First_Comp) then
7650 Prepend_To (Component_Associations (N), New_Comp);
7651 else
7652 Insert_After (First_Comp, New_Comp);
7653 end if;
7655 First_Comp := New_Comp;
7656 Next_Stored_Discriminant (Discr);
7657 end loop;
7658 end Prepend_Stored_Values;
7660 -- Local variables
7662 Constraints : constant List_Id := New_List;
7664 Discr : Entity_Id;
7665 Decl : Node_Id;
7666 Num_Disc : Nat := 0;
7667 Num_Stor : Nat := 0;
7669 -- Start of processing for Generate_Aggregate_For_Derived_Type
7671 begin
7672 -- Remove the associations for the discriminant of derived type
7674 declare
7675 First_Comp : Node_Id;
7677 begin
7678 First_Comp := First (Component_Associations (N));
7679 while Present (First_Comp) loop
7680 Comp := First_Comp;
7681 Next (First_Comp);
7683 if Ekind (Entity (First (Choices (Comp)))) =
7684 E_Discriminant
7685 then
7686 Remove (Comp);
7687 Num_Disc := Num_Disc + 1;
7688 end if;
7689 end loop;
7690 end;
7692 -- Insert stored discriminant associations in the correct
7693 -- order. If there are more stored discriminants than new
7694 -- discriminants, there is at least one new discriminant that
7695 -- constrains more than one of the stored discriminants. In
7696 -- this case we need to construct a proper subtype of the
7697 -- parent type, in order to supply values to all the
7698 -- components. Otherwise there is one-one correspondence
7699 -- between the constraints and the stored discriminants.
7701 Discr := First_Stored_Discriminant (Base_Type (Typ));
7702 while Present (Discr) loop
7703 Num_Stor := Num_Stor + 1;
7704 Next_Stored_Discriminant (Discr);
7705 end loop;
7707 -- Case of more stored discriminants than new discriminants
7709 if Num_Stor > Num_Disc then
7711 -- Create a proper subtype of the parent type, which is the
7712 -- proper implementation type for the aggregate, and convert
7713 -- it to the intended target type.
7715 Discr := First_Stored_Discriminant (Base_Type (Typ));
7716 while Present (Discr) loop
7717 New_Comp :=
7718 New_Copy_Tree
7719 (Get_Discriminant_Value
7720 (Discr,
7721 Typ,
7722 Discriminant_Constraint (Typ)));
7724 Append (New_Comp, Constraints);
7725 Next_Stored_Discriminant (Discr);
7726 end loop;
7728 Decl :=
7729 Make_Subtype_Declaration (Loc,
7730 Defining_Identifier => Make_Temporary (Loc, 'T'),
7731 Subtype_Indication =>
7732 Make_Subtype_Indication (Loc,
7733 Subtype_Mark =>
7734 New_Occurrence_Of (Etype (Base_Type (Typ)), Loc),
7735 Constraint =>
7736 Make_Index_Or_Discriminant_Constraint
7737 (Loc, Constraints)));
7739 Insert_Action (N, Decl);
7740 Prepend_Stored_Values (Base_Type (Typ));
7742 Set_Etype (N, Defining_Identifier (Decl));
7743 Set_Analyzed (N);
7745 Rewrite (N, Unchecked_Convert_To (Typ, N));
7746 Analyze (N);
7748 -- Case where we do not have fewer new discriminants than
7749 -- stored discriminants, so in this case we can simply use the
7750 -- stored discriminants of the subtype.
7752 else
7753 Prepend_Stored_Values (Typ);
7754 end if;
7755 end Generate_Aggregate_For_Derived_Type;
7756 end if;
7758 if Is_Tagged_Type (Typ) then
7760 -- In the tagged case, _parent and _tag component must be created
7762 -- Reset Null_Present unconditionally. Tagged records always have
7763 -- at least one field (the tag or the parent).
7765 Set_Null_Record_Present (N, False);
7767 -- When the current aggregate comes from the expansion of an
7768 -- extension aggregate, the parent expr is replaced by an
7769 -- aggregate formed by selected components of this expr.
7771 if Present (Parent_Expr) and then Is_Empty_List (Comps) then
7772 Comp := First_Component_Or_Discriminant (Typ);
7773 while Present (Comp) loop
7775 -- Skip all expander-generated components
7777 if not Comes_From_Source (Original_Record_Component (Comp))
7778 then
7779 null;
7781 else
7782 New_Comp :=
7783 Make_Selected_Component (Loc,
7784 Prefix =>
7785 Unchecked_Convert_To (Typ,
7786 Duplicate_Subexpr (Parent_Expr, True)),
7787 Selector_Name => New_Occurrence_Of (Comp, Loc));
7789 Append_To (Comps,
7790 Make_Component_Association (Loc,
7791 Choices => New_List (
7792 New_Occurrence_Of (Comp, Loc)),
7793 Expression => New_Comp));
7795 Analyze_And_Resolve (New_Comp, Etype (Comp));
7796 end if;
7798 Next_Component_Or_Discriminant (Comp);
7799 end loop;
7800 end if;
7802 -- Compute the value for the Tag now, if the type is a root it
7803 -- will be included in the aggregate right away, otherwise it will
7804 -- be propagated to the parent aggregate.
7806 if Present (Orig_Tag) then
7807 Tag_Value := Orig_Tag;
7809 elsif not Tagged_Type_Expansion then
7810 Tag_Value := Empty;
7812 else
7813 Tag_Value :=
7814 New_Occurrence_Of
7815 (Node (First_Elmt (Access_Disp_Table (Typ))), Loc);
7816 end if;
7818 -- For a derived type, an aggregate for the parent is formed with
7819 -- all the inherited components.
7821 if Is_Derived_Type (Typ) then
7822 declare
7823 First_Comp : Node_Id;
7824 Parent_Comps : List_Id;
7825 Parent_Aggr : Node_Id;
7826 Parent_Name : Node_Id;
7828 begin
7829 First_Comp := First (Component_Associations (N));
7830 Parent_Comps := New_List;
7832 -- First skip the discriminants
7834 while Present (First_Comp)
7835 and then Ekind (Entity (First (Choices (First_Comp))))
7836 = E_Discriminant
7837 loop
7838 Next (First_Comp);
7839 end loop;
7841 -- Then remove the inherited component association from the
7842 -- aggregate and store them in the parent aggregate
7844 while Present (First_Comp)
7845 and then
7846 Scope (Original_Record_Component
7847 (Entity (First (Choices (First_Comp))))) /=
7848 Base_Typ
7849 loop
7850 Comp := First_Comp;
7851 Next (First_Comp);
7852 Remove (Comp);
7853 Append (Comp, Parent_Comps);
7854 end loop;
7856 Parent_Aggr :=
7857 Make_Aggregate (Loc,
7858 Component_Associations => Parent_Comps);
7859 Set_Etype (Parent_Aggr, Etype (Base_Type (Typ)));
7861 -- Find the _parent component
7863 Comp := First_Component (Typ);
7864 while Chars (Comp) /= Name_uParent loop
7865 Next_Component (Comp);
7866 end loop;
7868 Parent_Name := New_Occurrence_Of (Comp, Loc);
7870 -- Insert the parent aggregate
7872 Prepend_To (Component_Associations (N),
7873 Make_Component_Association (Loc,
7874 Choices => New_List (Parent_Name),
7875 Expression => Parent_Aggr));
7877 -- Expand recursively the parent propagating the right Tag
7879 Expand_Record_Aggregate
7880 (Parent_Aggr, Tag_Value, Parent_Expr);
7882 -- The ancestor part may be a nested aggregate that has
7883 -- delayed expansion: recheck now.
7885 if not Component_OK_For_Backend then
7886 Convert_To_Assignments (N, Typ);
7887 end if;
7888 end;
7890 -- For a root type, the tag component is added (unless compiling
7891 -- for the VMs, where tags are implicit).
7893 elsif Tagged_Type_Expansion then
7894 declare
7895 Tag_Name : constant Node_Id :=
7896 New_Occurrence_Of
7897 (First_Tag_Component (Typ), Loc);
7898 Typ_Tag : constant Entity_Id := RTE (RE_Tag);
7899 Conv_Node : constant Node_Id :=
7900 Unchecked_Convert_To (Typ_Tag, Tag_Value);
7902 begin
7903 Set_Etype (Conv_Node, Typ_Tag);
7904 Prepend_To (Component_Associations (N),
7905 Make_Component_Association (Loc,
7906 Choices => New_List (Tag_Name),
7907 Expression => Conv_Node));
7908 end;
7909 end if;
7910 end if;
7911 end Build_Back_End_Aggregate;
7913 ----------------------------------------
7914 -- Compile_Time_Known_Composite_Value --
7915 ----------------------------------------
7917 function Compile_Time_Known_Composite_Value
7918 (N : Node_Id) return Boolean
7920 begin
7921 -- If we have an entity name, then see if it is the name of a
7922 -- constant and if so, test the corresponding constant value.
7924 if Is_Entity_Name (N) then
7925 declare
7926 E : constant Entity_Id := Entity (N);
7927 V : Node_Id;
7928 begin
7929 if Ekind (E) /= E_Constant then
7930 return False;
7931 else
7932 V := Constant_Value (E);
7933 return Present (V)
7934 and then Compile_Time_Known_Composite_Value (V);
7935 end if;
7936 end;
7938 -- We have a value, see if it is compile time known
7940 else
7941 if Nkind (N) = N_Aggregate then
7942 return Compile_Time_Known_Aggregate (N);
7943 end if;
7945 -- All other types of values are not known at compile time
7947 return False;
7948 end if;
7950 end Compile_Time_Known_Composite_Value;
7952 ------------------------------
7953 -- Component_OK_For_Backend --
7954 ------------------------------
7956 function Component_OK_For_Backend return Boolean is
7957 C : Node_Id;
7958 Expr_Q : Node_Id;
7960 begin
7961 C := First (Comps);
7962 while Present (C) loop
7964 -- If the component has box initialization, expansion is needed
7965 -- and component is not ready for backend.
7967 if Box_Present (C) then
7968 return False;
7969 end if;
7971 Expr_Q := Unqualify (Expression (C));
7973 -- Return False for array components whose bounds raise
7974 -- constraint error.
7976 declare
7977 Comp : constant Entity_Id := First (Choices (C));
7978 Indx : Node_Id;
7980 begin
7981 if Present (Etype (Comp))
7982 and then Is_Array_Type (Etype (Comp))
7983 then
7984 Indx := First_Index (Etype (Comp));
7985 while Present (Indx) loop
7986 if Nkind (Type_Low_Bound (Etype (Indx))) =
7987 N_Raise_Constraint_Error
7988 or else Nkind (Type_High_Bound (Etype (Indx))) =
7989 N_Raise_Constraint_Error
7990 then
7991 return False;
7992 end if;
7994 Next_Index (Indx);
7995 end loop;
7996 end if;
7997 end;
7999 -- Return False if the aggregate has any associations for tagged
8000 -- components that may require tag adjustment.
8002 -- These are cases where the source expression may have a tag that
8003 -- could differ from the component tag (e.g., can occur for type
8004 -- conversions and formal parameters). (Tag adjustment not needed
8005 -- if Tagged_Type_Expansion because object tags are implicit in
8006 -- the machine.)
8008 if Is_Tagged_Type (Etype (Expr_Q))
8009 and then
8010 (Nkind (Expr_Q) = N_Type_Conversion
8011 or else
8012 (Is_Entity_Name (Expr_Q)
8013 and then Is_Formal (Entity (Expr_Q))))
8014 and then Tagged_Type_Expansion
8015 then
8016 Static_Components := False;
8017 return False;
8019 elsif Is_Delayed_Aggregate (Expr_Q) then
8020 Static_Components := False;
8021 return False;
8023 elsif Nkind (Expr_Q) = N_Quantified_Expression then
8024 Static_Components := False;
8025 return False;
8027 elsif Possible_Bit_Aligned_Component (Expr_Q) then
8028 Static_Components := False;
8029 return False;
8031 elsif Modify_Tree_For_C
8032 and then Nkind (C) = N_Component_Association
8033 and then Has_Per_Object_Constraint (Choices (C))
8034 then
8035 Static_Components := False;
8036 return False;
8038 elsif Modify_Tree_For_C
8039 and then Nkind (Expr_Q) = N_Identifier
8040 and then Is_Array_Type (Etype (Expr_Q))
8041 then
8042 Static_Components := False;
8043 return False;
8045 elsif Modify_Tree_For_C
8046 and then Nkind (Expr_Q) = N_Type_Conversion
8047 and then Is_Array_Type (Etype (Expr_Q))
8048 then
8049 Static_Components := False;
8050 return False;
8051 end if;
8053 if Is_Elementary_Type (Etype (Expr_Q)) then
8054 if not Compile_Time_Known_Value (Expr_Q) then
8055 Static_Components := False;
8056 end if;
8058 elsif not Compile_Time_Known_Composite_Value (Expr_Q) then
8059 Static_Components := False;
8061 if Is_Private_Type (Etype (Expr_Q))
8062 and then Has_Discriminants (Etype (Expr_Q))
8063 then
8064 return False;
8065 end if;
8066 end if;
8068 Next (C);
8069 end loop;
8071 return True;
8072 end Component_OK_For_Backend;
8074 -------------------------------
8075 -- Has_Per_Object_Constraint --
8076 -------------------------------
8078 function Has_Per_Object_Constraint (L : List_Id) return Boolean is
8079 N : Node_Id := First (L);
8080 begin
8081 while Present (N) loop
8082 if Is_Entity_Name (N)
8083 and then Present (Entity (N))
8084 and then Has_Per_Object_Constraint (Entity (N))
8085 then
8086 return True;
8087 end if;
8089 Next (N);
8090 end loop;
8092 return False;
8093 end Has_Per_Object_Constraint;
8095 -----------------------------------
8096 -- Has_Visible_Private_Ancestor --
8097 -----------------------------------
8099 function Has_Visible_Private_Ancestor (Id : E) return Boolean is
8100 R : constant Entity_Id := Root_Type (Id);
8101 T1 : Entity_Id := Id;
8103 begin
8104 loop
8105 if Is_Private_Type (T1) then
8106 return True;
8108 elsif T1 = R then
8109 return False;
8111 else
8112 T1 := Etype (T1);
8113 end if;
8114 end loop;
8115 end Has_Visible_Private_Ancestor;
8117 -------------------------
8118 -- Top_Level_Aggregate --
8119 -------------------------
8121 function Top_Level_Aggregate (N : Node_Id) return Node_Id is
8122 Aggr : Node_Id;
8124 begin
8125 Aggr := N;
8126 while Present (Parent (Aggr))
8127 and then Nkind (Parent (Aggr)) in
8128 N_Aggregate | N_Component_Association
8129 loop
8130 Aggr := Parent (Aggr);
8131 end loop;
8133 return Aggr;
8134 end Top_Level_Aggregate;
8136 -- Local variables
8138 Top_Level_Aggr : constant Node_Id := Top_Level_Aggregate (N);
8140 -- Start of processing for Expand_Record_Aggregate
8142 begin
8143 -- No special management required for aggregates used to initialize
8144 -- statically allocated dispatch tables
8146 if Is_Static_Dispatch_Table_Aggregate (N) then
8147 return;
8149 -- Case pattern aggregates need to remain as aggregates
8151 elsif Is_Case_Choice_Pattern (N) then
8152 return;
8153 end if;
8155 -- If the pragma Aggregate_Individually_Assign is set, always convert to
8156 -- assignments.
8158 if Aggregate_Individually_Assign then
8159 Convert_To_Assignments (N, Typ);
8161 -- Ada 2005 (AI-318-2): We need to convert to assignments if components
8162 -- are build-in-place function calls. The assignments will each turn
8163 -- into a build-in-place function call. If components are all static,
8164 -- we can pass the aggregate to the back end regardless of limitedness.
8166 -- Extension aggregates, aggregates in extended return statements, and
8167 -- aggregates for C++ imported types must be expanded.
8169 elsif Ada_Version >= Ada_2005 and then Is_Limited_View (Typ) then
8170 if Nkind (Parent (N)) not in
8171 N_Component_Association | N_Object_Declaration
8172 then
8173 Convert_To_Assignments (N, Typ);
8175 elsif Nkind (N) = N_Extension_Aggregate
8176 or else Convention (Typ) = Convention_CPP
8177 then
8178 Convert_To_Assignments (N, Typ);
8180 elsif not Size_Known_At_Compile_Time (Typ)
8181 or else not Component_OK_For_Backend
8182 or else not Static_Components
8183 then
8184 Convert_To_Assignments (N, Typ);
8186 -- In all other cases, build a proper aggregate to be handled by
8187 -- the back-end.
8189 else
8190 Build_Back_End_Aggregate;
8191 end if;
8193 -- Gigi doesn't properly handle temporaries of variable size so we
8194 -- generate it in the front-end
8196 elsif not Size_Known_At_Compile_Time (Typ)
8197 and then Tagged_Type_Expansion
8198 then
8199 Convert_To_Assignments (N, Typ);
8201 -- An aggregate used to initialize a controlled object must be turned
8202 -- into component assignments as the components themselves may require
8203 -- finalization actions such as adjustment.
8205 elsif Needs_Finalization (Typ) then
8206 Convert_To_Assignments (N, Typ);
8208 -- Ada 2005 (AI-287): In case of default initialized components we
8209 -- convert the aggregate into assignments.
8211 elsif Has_Default_Init_Comps (N) then
8212 Convert_To_Assignments (N, Typ);
8214 -- Check components
8216 elsif not Component_OK_For_Backend then
8217 Convert_To_Assignments (N, Typ);
8219 -- If an ancestor is private, some components are not inherited and we
8220 -- cannot expand into a record aggregate.
8222 elsif Has_Visible_Private_Ancestor (Typ) then
8223 Convert_To_Assignments (N, Typ);
8225 -- ??? The following was done to compile fxacc00.ads in the ACVCs. Gigi
8226 -- is not able to handle the aggregate for Late_Request.
8228 elsif Is_Tagged_Type (Typ) and then Has_Discriminants (Typ) then
8229 Convert_To_Assignments (N, Typ);
8231 -- If the tagged types covers interface types we need to initialize all
8232 -- hidden components containing pointers to secondary dispatch tables.
8234 elsif Is_Tagged_Type (Typ) and then Has_Interfaces (Typ) then
8235 Convert_To_Assignments (N, Typ);
8237 -- If some components are mutable, the size of the aggregate component
8238 -- may be distinct from the default size of the type component, so
8239 -- we need to expand to insure that the back-end copies the proper
8240 -- size of the data. However, if the aggregate is the initial value of
8241 -- a constant, the target is immutable and might be built statically
8242 -- if components are appropriate.
8244 elsif Has_Mutable_Components (Typ)
8245 and then
8246 (Nkind (Parent (Top_Level_Aggr)) /= N_Object_Declaration
8247 or else not Constant_Present (Parent (Top_Level_Aggr))
8248 or else not Static_Components)
8249 then
8250 Convert_To_Assignments (N, Typ);
8252 -- If the type involved has bit aligned components, then we are not sure
8253 -- that the back end can handle this case correctly.
8255 elsif Type_May_Have_Bit_Aligned_Components (Typ) then
8256 Convert_To_Assignments (N, Typ);
8258 -- When generating C, only generate an aggregate when declaring objects
8259 -- since C does not support aggregates in e.g. assignment statements.
8261 elsif Modify_Tree_For_C and then not Is_CCG_Supported_Aggregate (N) then
8262 Convert_To_Assignments (N, Typ);
8264 -- In all other cases, build a proper aggregate to be handled by gigi
8266 else
8267 Build_Back_End_Aggregate;
8268 end if;
8269 end Expand_Record_Aggregate;
8271 ---------------------
8272 -- Get_Base_Object --
8273 ---------------------
8275 function Get_Base_Object (N : Node_Id) return Entity_Id is
8276 R : Node_Id;
8278 begin
8279 R := Get_Referenced_Object (N);
8281 while Nkind (R) in N_Indexed_Component | N_Selected_Component | N_Slice
8282 loop
8283 R := Get_Referenced_Object (Prefix (R));
8284 end loop;
8286 if Is_Entity_Name (R) and then Is_Object (Entity (R)) then
8287 return Entity (R);
8288 else
8289 return Empty;
8290 end if;
8291 end Get_Base_Object;
8293 ----------------------------
8294 -- Has_Default_Init_Comps --
8295 ----------------------------
8297 function Has_Default_Init_Comps (N : Node_Id) return Boolean is
8298 Assoc : Node_Id;
8299 Expr : Node_Id;
8300 -- Component association and expression, respectively
8302 begin
8303 pragma Assert (Nkind (N) in N_Aggregate | N_Extension_Aggregate);
8305 if Has_Self_Reference (N) then
8306 return True;
8307 end if;
8309 Assoc := First (Component_Associations (N));
8310 while Present (Assoc) loop
8311 -- Each component association has either a box or an expression
8313 pragma Assert (Box_Present (Assoc) xor Present (Expression (Assoc)));
8315 -- Check if any direct component has default initialized components
8317 if Box_Present (Assoc) then
8318 return True;
8320 -- Recursive call in case of aggregate expression
8322 else
8323 Expr := Expression (Assoc);
8325 if Nkind (Expr) in N_Aggregate | N_Extension_Aggregate
8326 and then Has_Default_Init_Comps (Expr)
8327 then
8328 return True;
8329 end if;
8330 end if;
8332 Next (Assoc);
8333 end loop;
8335 return False;
8336 end Has_Default_Init_Comps;
8338 --------------------------
8339 -- Initialize_Component --
8340 --------------------------
8342 procedure Initialize_Component
8343 (N : Node_Id;
8344 Comp : Node_Id;
8345 Comp_Typ : Node_Id;
8346 Init_Expr : Node_Id;
8347 Stmts : List_Id)
8349 Exceptions_OK : constant Boolean :=
8350 not Restriction_Active (No_Exception_Propagation);
8351 Finalization_OK : constant Boolean :=
8352 Present (Comp_Typ)
8353 and then Needs_Finalization (Comp_Typ);
8354 Loc : constant Source_Ptr := Sloc (N);
8356 Blk_Stmts : List_Id;
8357 Init_Stmt : Node_Id;
8359 begin
8360 pragma Assert (Nkind (Init_Expr) in N_Subexpr);
8362 -- Protect the initialization statements from aborts. Generate:
8364 -- Abort_Defer;
8366 if Finalization_OK and Abort_Allowed then
8367 if Exceptions_OK then
8368 Blk_Stmts := New_List;
8369 else
8370 Blk_Stmts := Stmts;
8371 end if;
8373 Append_To (Blk_Stmts, Build_Runtime_Call (Loc, RE_Abort_Defer));
8375 -- Otherwise aborts are not allowed. All generated code is added
8376 -- directly to the input list.
8378 else
8379 Blk_Stmts := Stmts;
8380 end if;
8382 -- Initialize the component. Generate:
8384 -- Comp := Init_Expr;
8386 -- Note that the initialization expression is not duplicated because
8387 -- either only a single component may be initialized by it (record)
8388 -- or it has already been duplicated if need be (array).
8390 Init_Stmt :=
8391 Make_OK_Assignment_Statement (Loc,
8392 Name => New_Copy_Tree (Comp),
8393 Expression => Relocate_Node (Init_Expr));
8395 Append_To (Blk_Stmts, Init_Stmt);
8397 -- Arrange for the component to be adjusted if need be (the call will be
8398 -- generated by Make_Tag_Ctrl_Assignment). But, in the case of an array
8399 -- aggregate, controlled subaggregates are not considered because each
8400 -- of their individual elements will receive an adjustment of its own.
8402 if Finalization_OK
8403 and then not Is_Limited_View (Comp_Typ)
8404 and then not
8405 (Is_Array_Type (Etype (N))
8406 and then Is_Array_Type (Comp_Typ)
8407 and then Needs_Finalization (Component_Type (Comp_Typ))
8408 and then Nkind (Unqualify (Init_Expr)) = N_Aggregate)
8409 then
8410 Set_No_Finalize_Actions (Init_Stmt);
8412 -- Or else, only adjust the tag due to a possible view conversion
8414 else
8415 Set_No_Ctrl_Actions (Init_Stmt);
8417 if Tagged_Type_Expansion and then Is_Tagged_Type (Comp_Typ) then
8418 Append_To (Blk_Stmts,
8419 Make_Tag_Assignment_From_Type
8420 (Loc, New_Copy_Tree (Comp), Underlying_Type (Comp_Typ)));
8421 end if;
8422 end if;
8424 -- Complete the protection of the initialization statements
8426 if Finalization_OK and Abort_Allowed then
8428 -- Wrap the initialization statements in a block to catch a
8429 -- potential exception. Generate:
8431 -- begin
8432 -- Abort_Defer;
8433 -- Comp := Init_Expr;
8434 -- Comp._tag := Full_TypP;
8435 -- [Deep_]Adjust (Comp);
8436 -- at end
8437 -- Abort_Undefer_Direct;
8438 -- end;
8440 if Exceptions_OK then
8441 Append_To (Stmts,
8442 Build_Abort_Undefer_Block (Loc,
8443 Stmts => Blk_Stmts,
8444 Context => N));
8446 -- Otherwise exceptions are not propagated. Generate:
8448 -- Abort_Defer;
8449 -- Comp := Init_Expr;
8450 -- Comp._tag := Full_TypP;
8451 -- [Deep_]Adjust (Comp);
8452 -- Abort_Undefer;
8454 else
8455 Append_To (Blk_Stmts,
8456 Build_Runtime_Call (Loc, RE_Abort_Undefer));
8457 end if;
8458 end if;
8459 end Initialize_Component;
8461 ----------------------------------------
8462 -- Is_Build_In_Place_Aggregate_Return --
8463 ----------------------------------------
8465 function Is_Build_In_Place_Aggregate_Return (N : Node_Id) return Boolean is
8466 P : Node_Id := Parent (N);
8468 begin
8469 while Nkind (P) in N_Case_Expression
8470 | N_Case_Expression_Alternative
8471 | N_If_Expression
8472 | N_Qualified_Expression
8473 loop
8474 P := Parent (P);
8475 end loop;
8477 if Nkind (P) = N_Simple_Return_Statement then
8478 null;
8480 elsif Nkind (Parent (P)) = N_Extended_Return_Statement then
8481 P := Parent (P);
8483 else
8484 return False;
8485 end if;
8487 return
8488 Is_Build_In_Place_Function
8489 (Return_Applies_To (Return_Statement_Entity (P)));
8490 end Is_Build_In_Place_Aggregate_Return;
8492 --------------------------
8493 -- Is_Delayed_Aggregate --
8494 --------------------------
8496 function Is_Delayed_Aggregate (N : Node_Id) return Boolean is
8497 Unqual_N : constant Node_Id := Unqualify (N);
8499 begin
8500 return Nkind (Unqual_N) in N_Aggregate | N_Extension_Aggregate
8501 and then Expansion_Delayed (Unqual_N);
8502 end Is_Delayed_Aggregate;
8504 --------------------------------
8505 -- Is_CCG_Supported_Aggregate --
8506 --------------------------------
8508 function Is_CCG_Supported_Aggregate
8509 (N : Node_Id) return Boolean
8511 P : Node_Id := Parent (N);
8513 begin
8514 -- Aggregates are not supported for nonstandard rep clauses, since they
8515 -- may lead to extra padding fields in CCG.
8517 if Is_Record_Type (Etype (N))
8518 and then Has_Non_Standard_Rep (Etype (N))
8519 then
8520 return False;
8521 end if;
8523 while Present (P) and then Nkind (P) = N_Aggregate loop
8524 P := Parent (P);
8525 end loop;
8527 -- Check cases where aggregates are supported by the CCG backend
8529 if Nkind (P) = N_Object_Declaration then
8530 declare
8531 P_Typ : constant Entity_Id := Etype (Defining_Identifier (P));
8533 begin
8534 if Is_Record_Type (P_Typ) then
8535 return True;
8536 else
8537 return Compile_Time_Known_Bounds (P_Typ);
8538 end if;
8539 end;
8541 elsif Nkind (P) = N_Qualified_Expression then
8542 if Nkind (Parent (P)) = N_Object_Declaration then
8543 declare
8544 P_Typ : constant Entity_Id :=
8545 Etype (Defining_Identifier (Parent (P)));
8546 begin
8547 if Is_Record_Type (P_Typ) then
8548 return True;
8549 else
8550 return Compile_Time_Known_Bounds (P_Typ);
8551 end if;
8552 end;
8554 elsif Nkind (Parent (P)) = N_Allocator then
8555 return True;
8556 end if;
8557 end if;
8559 return False;
8560 end Is_CCG_Supported_Aggregate;
8562 ----------------------------------------
8563 -- Is_Static_Dispatch_Table_Aggregate --
8564 ----------------------------------------
8566 function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean is
8567 Typ : constant Entity_Id := Base_Type (Etype (N));
8569 begin
8570 return Building_Static_Dispatch_Tables
8571 and then Tagged_Type_Expansion
8573 -- Avoid circularity when rebuilding the compiler
8575 and then not Is_RTU (Cunit_Entity (Get_Source_Unit (N)), Ada_Tags)
8576 and then (Is_RTE (Typ, RE_Dispatch_Table_Wrapper)
8577 or else
8578 Is_RTE (Typ, RE_Address_Array)
8579 or else
8580 Is_RTE (Typ, RE_Type_Specific_Data)
8581 or else
8582 Is_RTE (Typ, RE_Tag_Table)
8583 or else
8584 Is_RTE (Typ, RE_Object_Specific_Data)
8585 or else
8586 Is_RTE (Typ, RE_Interface_Data)
8587 or else
8588 Is_RTE (Typ, RE_Interfaces_Array)
8589 or else
8590 Is_RTE (Typ, RE_Interface_Data_Element));
8591 end Is_Static_Dispatch_Table_Aggregate;
8593 -----------------------------
8594 -- Is_Two_Dim_Packed_Array --
8595 -----------------------------
8597 function Is_Two_Dim_Packed_Array (Typ : Entity_Id) return Boolean is
8598 C : constant Uint := Component_Size (Typ);
8600 begin
8601 return Number_Dimensions (Typ) = 2
8602 and then Is_Bit_Packed_Array (Typ)
8603 and then Is_Scalar_Type (Component_Type (Typ))
8604 and then C in Uint_1 | Uint_2 | Uint_4; -- False if No_Uint
8605 end Is_Two_Dim_Packed_Array;
8607 --------------------
8608 -- Late_Expansion --
8609 --------------------
8611 function Late_Expansion
8612 (N : Node_Id;
8613 Typ : Entity_Id;
8614 Target : Node_Id) return List_Id
8616 Aggr_Code : List_Id;
8617 New_Aggr : Node_Id;
8619 begin
8620 if Is_Array_Type (Typ) then
8621 -- If the assignment can be done directly by the back end, then
8622 -- reset Set_Expansion_Delayed and do not expand further.
8624 if not CodePeer_Mode
8625 and then not Modify_Tree_For_C
8626 and then not Possible_Bit_Aligned_Component (Target)
8627 and then not Is_Possibly_Unaligned_Slice (Target)
8628 and then Aggr_Assignment_OK_For_Backend (N)
8629 then
8630 New_Aggr := New_Copy_Tree (N);
8631 Set_Expansion_Delayed (New_Aggr, False);
8633 Aggr_Code :=
8634 New_List (
8635 Make_OK_Assignment_Statement (Sloc (New_Aggr),
8636 Name => Target,
8637 Expression => New_Aggr));
8639 -- Or else, generate component assignments to it
8641 else
8642 Aggr_Code :=
8643 Build_Array_Aggr_Code
8644 (N => N,
8645 Ctype => Component_Type (Typ),
8646 Index => First_Index (Typ),
8647 Into => Target,
8648 Scalar_Comp => Is_Scalar_Type (Component_Type (Typ)),
8649 Indexes => No_List);
8650 end if;
8652 -- Directly or indirectly (e.g. access protected procedure) a record
8654 else
8655 Aggr_Code := Build_Record_Aggr_Code (N, Typ, Target);
8656 end if;
8658 -- Save the last assignment statement associated with the aggregate
8659 -- when building a controlled object. This reference is utilized by
8660 -- the finalization machinery when marking an object as successfully
8661 -- initialized.
8663 if Needs_Finalization (Typ)
8664 and then Is_Entity_Name (Target)
8665 and then Present (Entity (Target))
8666 and then Ekind (Entity (Target)) in E_Constant | E_Variable
8667 then
8668 Set_Last_Aggregate_Assignment (Entity (Target), Last (Aggr_Code));
8669 end if;
8671 return Aggr_Code;
8672 end Late_Expansion;
8674 ----------------------------------
8675 -- Make_OK_Assignment_Statement --
8676 ----------------------------------
8678 function Make_OK_Assignment_Statement
8679 (Sloc : Source_Ptr;
8680 Name : Node_Id;
8681 Expression : Node_Id) return Node_Id
8683 begin
8684 Set_Assignment_OK (Name);
8685 return Make_Assignment_Statement (Sloc, Name, Expression);
8686 end Make_OK_Assignment_Statement;
8688 ------------------------
8689 -- Max_Aggregate_Size --
8690 ------------------------
8692 function Max_Aggregate_Size
8693 (N : Node_Id;
8694 Default_Size : Nat := 5000) return Nat
8696 function Use_Small_Size (N : Node_Id) return Boolean;
8697 -- True if we should return a very small size, which means large
8698 -- aggregates will be implemented as a loop when possible (potentially
8699 -- transformed to memset calls).
8701 function Aggr_Context (N : Node_Id) return Node_Id;
8702 -- Return the context in which the aggregate appears, not counting
8703 -- qualified expressions and similar.
8705 ------------------
8706 -- Aggr_Context --
8707 ------------------
8709 function Aggr_Context (N : Node_Id) return Node_Id is
8710 Result : Node_Id := Parent (N);
8711 begin
8712 if Nkind (Result) in N_Qualified_Expression
8713 | N_Type_Conversion
8714 | N_Unchecked_Type_Conversion
8715 | N_If_Expression
8716 | N_Case_Expression
8717 | N_Component_Association
8718 | N_Aggregate
8719 then
8720 Result := Aggr_Context (Result);
8721 end if;
8723 return Result;
8724 end Aggr_Context;
8726 --------------------
8727 -- Use_Small_Size --
8728 --------------------
8730 function Use_Small_Size (N : Node_Id) return Boolean is
8731 C : constant Node_Id := Aggr_Context (N);
8732 -- The decision depends on the context in which the aggregate occurs,
8733 -- and for variable declarations, whether we are nested inside a
8734 -- subprogram.
8735 begin
8736 case Nkind (C) is
8737 -- True for assignment statements and similar
8739 when N_Assignment_Statement
8740 | N_Simple_Return_Statement
8741 | N_Allocator
8742 | N_Attribute_Reference
8744 return True;
8746 -- True for nested variable declarations. False for library level
8747 -- variables, and for constants (whether or not nested).
8749 when N_Object_Declaration =>
8750 return not Constant_Present (C)
8751 and then Is_Subprogram (Current_Scope);
8753 -- False for all other contexts
8755 when others =>
8756 return False;
8757 end case;
8758 end Use_Small_Size;
8760 -- Local variables
8762 Typ : constant Entity_Id := Etype (N);
8764 -- Start of processing for Max_Aggregate_Size
8766 begin
8767 -- We use a small limit in CodePeer mode where we favor loops instead of
8768 -- thousands of single assignments (from large aggregates).
8770 -- We also increase the limit to 2**24 (about 16 million) if
8771 -- Restrictions (No_Elaboration_Code) or Restrictions
8772 -- (No_Implicit_Loops) is specified, since in either case we are at risk
8773 -- of declaring the program illegal because of this limit. We also
8774 -- increase the limit when Static_Elaboration_Desired, given that this
8775 -- means that objects are intended to be placed in data memory.
8777 -- Same if the aggregate is for a packed two-dimensional array, because
8778 -- if components are static it is much more efficient to construct a
8779 -- one-dimensional equivalent array with static components.
8781 if CodePeer_Mode then
8782 return 100;
8783 elsif Restriction_Active (No_Elaboration_Code)
8784 or else Restriction_Active (No_Implicit_Loops)
8785 or else Is_Two_Dim_Packed_Array (Typ)
8786 or else (Ekind (Current_Scope) = E_Package
8787 and then Static_Elaboration_Desired (Current_Scope))
8788 then
8789 return 2 ** 24;
8790 elsif Use_Small_Size (N) then
8791 return 64;
8792 end if;
8794 return Default_Size;
8795 end Max_Aggregate_Size;
8797 -----------------------
8798 -- Number_Of_Choices --
8799 -----------------------
8801 function Number_Of_Choices (N : Node_Id) return Nat is
8802 Assoc : Node_Id;
8803 Choice : Node_Id;
8805 Nb_Choices : Nat := 0;
8807 begin
8808 if Present (Expressions (N)) then
8809 return 0;
8810 end if;
8812 Assoc := First (Component_Associations (N));
8813 while Present (Assoc) loop
8814 Choice := First (Choice_List (Assoc));
8815 while Present (Choice) loop
8816 if Nkind (Choice) /= N_Others_Choice then
8817 Nb_Choices := Nb_Choices + 1;
8818 end if;
8820 Next (Choice);
8821 end loop;
8823 Next (Assoc);
8824 end loop;
8826 return Nb_Choices;
8827 end Number_Of_Choices;
8829 ------------------------------------
8830 -- Packed_Array_Aggregate_Handled --
8831 ------------------------------------
8833 -- The current version of this procedure will handle at compile time
8834 -- any array aggregate that meets these conditions:
8836 -- One and two dimensional, bit packed
8837 -- Underlying packed type is modular type
8838 -- Bounds are within 32-bit Int range
8839 -- All bounds and values are static
8841 -- Note: for now, in the 2-D case, we only handle component sizes of
8842 -- 1, 2, 4 (cases where an integral number of elements occupies a byte).
8844 function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean is
8845 Loc : constant Source_Ptr := Sloc (N);
8846 Typ : constant Entity_Id := Etype (N);
8847 Ctyp : constant Entity_Id := Component_Type (Typ);
8849 Not_Handled : exception;
8850 -- Exception raised if this aggregate cannot be handled
8852 begin
8853 -- Handle one- or two dimensional bit packed array
8855 if not Is_Bit_Packed_Array (Typ)
8856 or else Number_Dimensions (Typ) > 2
8857 then
8858 return False;
8859 end if;
8861 -- If two-dimensional, check whether it can be folded, and transformed
8862 -- into a one-dimensional aggregate for the Packed_Array_Impl_Type of
8863 -- the original type.
8865 if Number_Dimensions (Typ) = 2 then
8866 return Two_Dim_Packed_Array_Handled (N);
8867 end if;
8869 if not Is_Modular_Integer_Type (Packed_Array_Impl_Type (Typ)) then
8870 return False;
8871 end if;
8873 if not Is_Scalar_Type (Ctyp) then
8874 return False;
8875 end if;
8877 declare
8878 Csiz : constant Nat := UI_To_Int (Component_Size (Typ));
8880 function Get_Component_Val (N : Node_Id) return Uint;
8881 -- Given a expression value N of the component type Ctyp, returns a
8882 -- value of Csiz (component size) bits representing this value. If
8883 -- the value is nonstatic or any other reason exists why the value
8884 -- cannot be returned, then Not_Handled is raised.
8886 -----------------------
8887 -- Get_Component_Val --
8888 -----------------------
8890 function Get_Component_Val (N : Node_Id) return Uint is
8891 Val : Uint;
8893 begin
8894 -- We have to analyze the expression here before doing any further
8895 -- processing here. The analysis of such expressions is deferred
8896 -- till expansion to prevent some problems of premature analysis.
8898 Analyze_And_Resolve (N, Ctyp);
8900 -- Must have a compile time value. String literals have to be
8901 -- converted into temporaries as well, because they cannot easily
8902 -- be converted into their bit representation.
8904 if not Compile_Time_Known_Value (N)
8905 or else Nkind (N) = N_String_Literal
8906 then
8907 raise Not_Handled;
8908 end if;
8910 Val := Expr_Rep_Value (N);
8912 -- Adjust for bias, and strip proper number of bits
8914 if Has_Biased_Representation (Ctyp) then
8915 Val := Val - Expr_Value (Type_Low_Bound (Ctyp));
8916 end if;
8918 return Val mod Uint_2 ** Csiz;
8919 end Get_Component_Val;
8921 Bounds : constant Range_Nodes := Get_Index_Bounds (First_Index (Typ));
8923 -- Here we know we have a one dimensional bit packed array
8925 begin
8926 -- Cannot do anything if bounds are dynamic
8928 if not (Compile_Time_Known_Value (Bounds.First)
8929 and then
8930 Compile_Time_Known_Value (Bounds.Last))
8931 then
8932 return False;
8933 end if;
8935 declare
8936 Bounds_Vals : Range_Values;
8937 -- Compile-time known values of bounds
8938 begin
8939 -- Or are silly out of range of int bounds
8941 Bounds_Vals.First := Expr_Value (Bounds.First);
8942 Bounds_Vals.Last := Expr_Value (Bounds.Last);
8944 if not UI_Is_In_Int_Range (Bounds_Vals.First)
8945 or else
8946 not UI_Is_In_Int_Range (Bounds_Vals.Last)
8947 then
8948 return False;
8949 end if;
8951 -- At this stage we have a suitable aggregate for handling at
8952 -- compile time. The only remaining checks are that the values of
8953 -- expressions in the aggregate are compile-time known (checks are
8954 -- performed by Get_Component_Val), and that any subtypes or
8955 -- ranges are statically known.
8957 -- If the aggregate is not fully positional at this stage, then
8958 -- convert it to positional form. Either this will fail, in which
8959 -- case we can do nothing, or it will succeed, in which case we
8960 -- have succeeded in handling the aggregate and transforming it
8961 -- into a modular value, or it will stay an aggregate, in which
8962 -- case we have failed to create a packed value for it.
8964 if Present (Component_Associations (N)) then
8965 Convert_To_Positional (N, Handle_Bit_Packed => True);
8966 return Nkind (N) /= N_Aggregate;
8967 end if;
8969 -- Otherwise we are all positional, so convert to proper value
8971 declare
8972 Len : constant Nat :=
8973 Int'Max (0, UI_To_Int (Bounds_Vals.Last) -
8974 UI_To_Int (Bounds_Vals.First) + 1);
8975 -- The length of the array (number of elements)
8977 Aggregate_Val : Uint;
8978 -- Value of aggregate. The value is set in the low order bits
8979 -- of this value. For the little-endian case, the values are
8980 -- stored from low-order to high-order and for the big-endian
8981 -- case the values are stored from high order to low order.
8982 -- Note that gigi will take care of the conversions to left
8983 -- justify the value in the big endian case (because of left
8984 -- justified modular type processing), so we do not have to
8985 -- worry about that here.
8987 Lit : Node_Id;
8988 -- Integer literal for resulting constructed value
8990 Shift : Nat;
8991 -- Shift count from low order for next value
8993 Incr : Int;
8994 -- Shift increment for loop
8996 Expr : Node_Id;
8997 -- Next expression from positional parameters of aggregate
8999 Left_Justified : Boolean;
9000 -- Set True if we are filling the high order bits of the target
9001 -- value (i.e. the value is left justified).
9003 begin
9004 -- For little endian, we fill up the low order bits of the
9005 -- target value. For big endian we fill up the high order bits
9006 -- of the target value (which is a left justified modular
9007 -- value).
9009 Left_Justified := Bytes_Big_Endian;
9011 -- Switch justification if using -gnatd8
9013 if Debug_Flag_8 then
9014 Left_Justified := not Left_Justified;
9015 end if;
9017 -- Switch justfification if reverse storage order
9019 if Reverse_Storage_Order (Base_Type (Typ)) then
9020 Left_Justified := not Left_Justified;
9021 end if;
9023 if Left_Justified then
9024 Shift := Csiz * (Len - 1);
9025 Incr := -Csiz;
9026 else
9027 Shift := 0;
9028 Incr := +Csiz;
9029 end if;
9031 -- Loop to set the values
9033 if Len = 0 then
9034 Aggregate_Val := Uint_0;
9035 else
9036 Expr := First (Expressions (N));
9037 Aggregate_Val := Get_Component_Val (Expr) * Uint_2 ** Shift;
9039 for J in 2 .. Len loop
9040 Shift := Shift + Incr;
9041 Next (Expr);
9042 Aggregate_Val :=
9043 Aggregate_Val +
9044 Get_Component_Val (Expr) * Uint_2 ** Shift;
9045 end loop;
9046 end if;
9048 -- Now we can rewrite with the proper value
9050 Lit := Make_Integer_Literal (Loc, Intval => Aggregate_Val);
9051 Set_Print_In_Hex (Lit);
9053 -- Construct the expression using this literal. Note that it
9054 -- is important to qualify the literal with its proper modular
9055 -- type since universal integer does not have the required
9056 -- range and also this is a left justified modular type,
9057 -- which is important in the big-endian case.
9059 Rewrite (N,
9060 Unchecked_Convert_To (Typ,
9061 Make_Qualified_Expression (Loc,
9062 Subtype_Mark =>
9063 New_Occurrence_Of (Packed_Array_Impl_Type (Typ), Loc),
9064 Expression => Lit)));
9066 Analyze_And_Resolve (N, Typ);
9067 return True;
9068 end;
9069 end;
9070 end;
9072 exception
9073 when Not_Handled =>
9074 return False;
9075 end Packed_Array_Aggregate_Handled;
9077 ----------------------------
9078 -- Has_Mutable_Components --
9079 ----------------------------
9081 function Has_Mutable_Components (Typ : Entity_Id) return Boolean is
9082 Comp : Entity_Id;
9083 Ctyp : Entity_Id;
9085 begin
9086 Comp := First_Component (Typ);
9087 while Present (Comp) loop
9088 Ctyp := Underlying_Type (Etype (Comp));
9089 if Is_Record_Type (Ctyp)
9090 and then Has_Discriminants (Ctyp)
9091 and then not Is_Constrained (Ctyp)
9092 then
9093 return True;
9094 end if;
9096 Next_Component (Comp);
9097 end loop;
9099 return False;
9100 end Has_Mutable_Components;
9102 ------------------------------
9103 -- Initialize_Discriminants --
9104 ------------------------------
9106 procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id) is
9107 Loc : constant Source_Ptr := Sloc (N);
9108 Bas : constant Entity_Id := Base_Type (Typ);
9109 Par : constant Entity_Id := Etype (Bas);
9110 Decl : constant Node_Id := Parent (Par);
9111 Ref : Node_Id;
9113 begin
9114 if Is_Tagged_Type (Bas)
9115 and then Is_Derived_Type (Bas)
9116 and then Has_Discriminants (Par)
9117 and then Has_Discriminants (Bas)
9118 and then Number_Discriminants (Bas) /= Number_Discriminants (Par)
9119 and then Nkind (Decl) = N_Full_Type_Declaration
9120 and then Nkind (Type_Definition (Decl)) = N_Record_Definition
9121 and then
9122 Present (Variant_Part (Component_List (Type_Definition (Decl))))
9123 and then Nkind (N) /= N_Extension_Aggregate
9124 then
9126 -- Call init proc to set discriminants.
9127 -- There should eventually be a special procedure for this ???
9129 Ref := New_Occurrence_Of (Defining_Identifier (N), Loc);
9130 Insert_Actions_After (N,
9131 Build_Initialization_Call (Sloc (N), Ref, Typ));
9132 end if;
9133 end Initialize_Discriminants;
9135 ----------------
9136 -- Must_Slide --
9137 ----------------
9139 function Must_Slide
9140 (Aggr : Node_Id;
9141 Obj_Type : Entity_Id;
9142 Typ : Entity_Id) return Boolean
9144 begin
9145 -- No sliding if the type of the object is not established yet, if it is
9146 -- an unconstrained type whose actual subtype comes from the aggregate,
9147 -- or if the two types are identical. If the aggregate contains only
9148 -- an Others_Clause it gets its type from the context and no sliding
9149 -- is involved either.
9151 if not Is_Array_Type (Obj_Type) then
9152 return False;
9154 elsif not Is_Constrained (Obj_Type) then
9155 return False;
9157 elsif Typ = Obj_Type then
9158 return False;
9160 elsif Is_Others_Aggregate (Aggr) then
9161 return False;
9163 else
9164 -- Sliding can only occur along the first dimension
9165 -- If any the bounds of non-static sliding is required
9166 -- to force potential range checks.
9168 declare
9169 Bounds1 : constant Range_Nodes :=
9170 Get_Index_Bounds (First_Index (Typ));
9171 Bounds2 : constant Range_Nodes :=
9172 Get_Index_Bounds (First_Index (Obj_Type));
9174 begin
9175 if not Is_OK_Static_Expression (Bounds1.First) or else
9176 not Is_OK_Static_Expression (Bounds2.First) or else
9177 not Is_OK_Static_Expression (Bounds1.Last) or else
9178 not Is_OK_Static_Expression (Bounds2.Last)
9179 then
9180 return True;
9182 else
9183 return Expr_Value (Bounds1.First) /= Expr_Value (Bounds2.First)
9184 or else
9185 Expr_Value (Bounds1.Last) /= Expr_Value (Bounds2.Last);
9186 end if;
9187 end;
9188 end if;
9189 end Must_Slide;
9191 ---------------------
9192 -- Sort_Case_Table --
9193 ---------------------
9195 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
9196 L : constant Int := Case_Table'First;
9197 U : constant Int := Case_Table'Last;
9198 K : Int;
9199 J : Int;
9200 T : Case_Bounds;
9202 begin
9203 K := L;
9204 while K /= U loop
9205 T := Case_Table (K + 1);
9207 J := K + 1;
9208 while J /= L
9209 and then Expr_Value (Case_Table (J - 1).Choice_Lo) >
9210 Expr_Value (T.Choice_Lo)
9211 loop
9212 Case_Table (J) := Case_Table (J - 1);
9213 J := J - 1;
9214 end loop;
9216 Case_Table (J) := T;
9217 K := K + 1;
9218 end loop;
9219 end Sort_Case_Table;
9221 ----------------------------
9222 -- Static_Array_Aggregate --
9223 ----------------------------
9225 function Static_Array_Aggregate (N : Node_Id) return Boolean is
9226 function Is_Static_Component (Nod : Node_Id) return Boolean;
9227 -- Return True if Nod has a compile-time known value and can be passed
9228 -- as is to the back-end without further expansion.
9230 ---------------------------
9231 -- Is_Static_Component --
9232 ---------------------------
9234 function Is_Static_Component (Nod : Node_Id) return Boolean is
9235 begin
9236 if Nkind (Nod) in N_Integer_Literal | N_Real_Literal then
9237 return True;
9239 elsif Is_Entity_Name (Nod)
9240 and then Present (Entity (Nod))
9241 and then Ekind (Entity (Nod)) = E_Enumeration_Literal
9242 then
9243 return True;
9245 elsif Nkind (Nod) = N_Aggregate
9246 and then Compile_Time_Known_Aggregate (Nod)
9247 then
9248 return True;
9250 else
9251 return False;
9252 end if;
9253 end Is_Static_Component;
9255 -- Local variables
9257 Bounds : constant Node_Id := Aggregate_Bounds (N);
9258 Typ : constant Entity_Id := Etype (N);
9260 Agg : Node_Id;
9261 Expr : Node_Id;
9262 Lo : Node_Id;
9263 Hi : Node_Id;
9265 -- Start of processing for Static_Array_Aggregate
9267 begin
9268 if Is_Packed (Typ) or else Has_Discriminants (Component_Type (Typ)) then
9269 return False;
9270 end if;
9272 if Present (Bounds)
9273 and then Nkind (Bounds) = N_Range
9274 and then Nkind (Low_Bound (Bounds)) = N_Integer_Literal
9275 and then Nkind (High_Bound (Bounds)) = N_Integer_Literal
9276 then
9277 Lo := Low_Bound (Bounds);
9278 Hi := High_Bound (Bounds);
9280 if No (Component_Associations (N)) then
9282 -- Verify that all components are static
9284 Expr := First (Expressions (N));
9285 while Present (Expr) loop
9286 if not Is_Static_Component (Expr) then
9287 return False;
9288 end if;
9290 Next (Expr);
9291 end loop;
9293 return True;
9295 else
9296 -- We allow only a single named association, either a static
9297 -- range or an others_clause, with a static expression.
9299 Expr := First (Component_Associations (N));
9301 if Present (Expressions (N)) then
9302 return False;
9304 elsif Present (Next (Expr)) then
9305 return False;
9307 elsif Present (Next (First (Choice_List (Expr)))) then
9308 return False;
9310 else
9311 -- The aggregate is static if all components are literals,
9312 -- or else all its components are static aggregates for the
9313 -- component type. We also limit the size of a static aggregate
9314 -- to prevent runaway static expressions.
9316 if not Is_Static_Component (Expression (Expr)) then
9317 return False;
9318 end if;
9320 if not Aggr_Size_OK (N) then
9321 return False;
9322 end if;
9324 -- Create a positional aggregate with the right number of
9325 -- copies of the expression.
9327 Agg := Make_Aggregate (Sloc (N), New_List, No_List);
9329 for I in UI_To_Int (Intval (Lo)) .. UI_To_Int (Intval (Hi))
9330 loop
9331 Append_To (Expressions (Agg), New_Copy (Expression (Expr)));
9333 -- The copied expression must be analyzed and resolved.
9334 -- Besides setting the type, this ensures that static
9335 -- expressions are appropriately marked as such.
9337 Analyze_And_Resolve
9338 (Last (Expressions (Agg)), Component_Type (Typ));
9339 end loop;
9341 Set_Aggregate_Bounds (Agg, Bounds);
9342 Set_Etype (Agg, Typ);
9343 Set_Analyzed (Agg);
9344 Rewrite (N, Agg);
9345 Set_Compile_Time_Known_Aggregate (N);
9347 return True;
9348 end if;
9349 end if;
9351 else
9352 return False;
9353 end if;
9354 end Static_Array_Aggregate;
9356 ----------------------------------
9357 -- Two_Dim_Packed_Array_Handled --
9358 ----------------------------------
9360 function Two_Dim_Packed_Array_Handled (N : Node_Id) return Boolean is
9361 Loc : constant Source_Ptr := Sloc (N);
9362 Typ : constant Entity_Id := Etype (N);
9363 Ctyp : constant Entity_Id := Component_Type (Typ);
9364 Comp_Size : constant Int := UI_To_Int (Component_Size (Typ));
9365 Packed_Array : constant Entity_Id :=
9366 Packed_Array_Impl_Type (Base_Type (Typ));
9368 One_Comp : Node_Id;
9369 -- Expression in original aggregate
9371 One_Dim : Node_Id;
9372 -- One-dimensional subaggregate
9374 begin
9376 -- For now, only deal with cases where an integral number of elements
9377 -- fit in a single byte. This includes the most common boolean case.
9379 if not (Comp_Size = 1 or else
9380 Comp_Size = 2 or else
9381 Comp_Size = 4)
9382 then
9383 return False;
9384 end if;
9386 Convert_To_Positional (N, Handle_Bit_Packed => True);
9388 -- Verify that all components are static
9390 if Nkind (N) = N_Aggregate
9391 and then Compile_Time_Known_Aggregate (N)
9392 then
9393 null;
9395 -- The aggregate may have been reanalyzed and converted already
9397 elsif Nkind (N) /= N_Aggregate then
9398 return True;
9400 -- If component associations remain, the aggregate is not static
9402 elsif Present (Component_Associations (N)) then
9403 return False;
9405 else
9406 One_Dim := First (Expressions (N));
9407 while Present (One_Dim) loop
9408 if Present (Component_Associations (One_Dim)) then
9409 return False;
9410 end if;
9412 One_Comp := First (Expressions (One_Dim));
9413 while Present (One_Comp) loop
9414 if not Is_OK_Static_Expression (One_Comp) then
9415 return False;
9416 end if;
9418 Next (One_Comp);
9419 end loop;
9421 Next (One_Dim);
9422 end loop;
9423 end if;
9425 -- Two-dimensional aggregate is now fully positional so pack one
9426 -- dimension to create a static one-dimensional array, and rewrite
9427 -- as an unchecked conversion to the original type.
9429 declare
9430 Byte_Size : constant Int := UI_To_Int (Component_Size (Packed_Array));
9431 -- The packed array type is a byte array
9433 Packed_Num : Nat;
9434 -- Number of components accumulated in current byte
9436 Comps : List_Id;
9437 -- Assembled list of packed values for equivalent aggregate
9439 Comp_Val : Uint;
9440 -- Integer value of component
9442 Incr : Int;
9443 -- Step size for packing
9445 Init_Shift : Int;
9446 -- Endian-dependent start position for packing
9448 Shift : Int;
9449 -- Current insertion position
9451 Val : Int;
9452 -- Component of packed array being assembled
9454 begin
9455 Comps := New_List;
9456 Val := 0;
9457 Packed_Num := 0;
9459 -- Account for endianness. See corresponding comment in
9460 -- Packed_Array_Aggregate_Handled concerning the following.
9462 if Bytes_Big_Endian
9463 xor Debug_Flag_8
9464 xor Reverse_Storage_Order (Base_Type (Typ))
9465 then
9466 Init_Shift := Byte_Size - Comp_Size;
9467 Incr := -Comp_Size;
9468 else
9469 Init_Shift := 0;
9470 Incr := +Comp_Size;
9471 end if;
9473 -- Iterate over each subaggregate
9475 Shift := Init_Shift;
9476 One_Dim := First (Expressions (N));
9477 while Present (One_Dim) loop
9478 One_Comp := First (Expressions (One_Dim));
9479 while Present (One_Comp) loop
9480 if Packed_Num = Byte_Size / Comp_Size then
9482 -- Byte is complete, add to list of expressions
9484 Append (Make_Integer_Literal (Sloc (One_Dim), Val), Comps);
9485 Val := 0;
9486 Shift := Init_Shift;
9487 Packed_Num := 0;
9489 else
9490 Comp_Val := Expr_Rep_Value (One_Comp);
9492 -- Adjust for bias, and strip proper number of bits
9494 if Has_Biased_Representation (Ctyp) then
9495 Comp_Val := Comp_Val - Expr_Value (Type_Low_Bound (Ctyp));
9496 end if;
9498 Comp_Val := Comp_Val mod Uint_2 ** Comp_Size;
9499 Val := UI_To_Int (Val + Comp_Val * Uint_2 ** Shift);
9500 Shift := Shift + Incr;
9501 Next (One_Comp);
9502 Packed_Num := Packed_Num + 1;
9503 end if;
9504 end loop;
9506 Next (One_Dim);
9507 end loop;
9509 if Packed_Num > 0 then
9511 -- Add final incomplete byte if present
9513 Append (Make_Integer_Literal (Sloc (One_Dim), Val), Comps);
9514 end if;
9516 Rewrite (N,
9517 Unchecked_Convert_To (Typ,
9518 Make_Qualified_Expression (Loc,
9519 Subtype_Mark => New_Occurrence_Of (Packed_Array, Loc),
9520 Expression => Make_Aggregate (Loc, Expressions => Comps))));
9521 Analyze_And_Resolve (N);
9522 return True;
9523 end;
9524 end Two_Dim_Packed_Array_Handled;
9526 end Exp_Aggr;