* configure.tgt: Add sh* case.
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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) 1992-2011, Free Software Foundation, Inc. --
10 -- --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
20 -- --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
23 -- --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Debug; use Debug;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Expander; use Expander;
33 with Exp_Util; use Exp_Util;
34 with Exp_Ch3; use Exp_Ch3;
35 with Exp_Ch6; use Exp_Ch6;
36 with Exp_Ch7; use Exp_Ch7;
37 with Exp_Ch9; use Exp_Ch9;
38 with Exp_Disp; use Exp_Disp;
39 with Exp_Tss; use Exp_Tss;
40 with Fname; use Fname;
41 with Freeze; use Freeze;
42 with Itypes; use Itypes;
43 with Lib; use Lib;
44 with Namet; use Namet;
45 with Nmake; use Nmake;
46 with Nlists; use Nlists;
47 with Opt; use Opt;
48 with Restrict; use Restrict;
49 with Rident; use Rident;
50 with Rtsfind; use Rtsfind;
51 with Ttypes; use Ttypes;
52 with Sem; use Sem;
53 with Sem_Aggr; use Sem_Aggr;
54 with Sem_Aux; use Sem_Aux;
55 with Sem_Ch3; use Sem_Ch3;
56 with Sem_Eval; use Sem_Eval;
57 with Sem_Res; use Sem_Res;
58 with Sem_Util; use Sem_Util;
59 with Sinfo; use Sinfo;
60 with Snames; use Snames;
61 with Stand; use Stand;
62 with Targparm; use Targparm;
63 with Tbuild; use Tbuild;
64 with Uintp; use Uintp;
66 package body Exp_Aggr is
68 type Case_Bounds is record
69 Choice_Lo : Node_Id;
70 Choice_Hi : Node_Id;
71 Choice_Node : Node_Id;
72 end record;
74 type Case_Table_Type is array (Nat range <>) of Case_Bounds;
75 -- Table type used by Check_Case_Choices procedure
77 function Has_Default_Init_Comps (N : Node_Id) return Boolean;
78 -- N is an aggregate (record or array). Checks the presence of default
79 -- initialization (<>) in any component (Ada 2005: AI-287).
81 function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean;
82 -- Returns true if N is an aggregate used to initialize the components
83 -- of an statically allocated dispatch table.
85 function Must_Slide
86 (Obj_Type : Entity_Id;
87 Typ : Entity_Id) return Boolean;
88 -- A static array aggregate in an object declaration can in most cases be
89 -- expanded in place. The one exception is when the aggregate is given
90 -- with component associations that specify different bounds from those of
91 -- the type definition in the object declaration. In this pathological
92 -- case the aggregate must slide, and we must introduce an intermediate
93 -- temporary to hold it.
95 -- The same holds in an assignment to one-dimensional array of arrays,
96 -- when a component may be given with bounds that differ from those of the
97 -- component type.
99 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
100 -- Sort the Case Table using the Lower Bound of each Choice as the key.
101 -- A simple insertion sort is used since the number of choices in a case
102 -- statement of variant part will usually be small and probably in near
103 -- sorted order.
105 ------------------------------------------------------
106 -- Local subprograms for Record Aggregate Expansion --
107 ------------------------------------------------------
109 function Build_Record_Aggr_Code
110 (N : Node_Id;
111 Typ : Entity_Id;
112 Lhs : Node_Id) return List_Id;
113 -- N is an N_Aggregate or an N_Extension_Aggregate. Typ is the type of the
114 -- aggregate. Target is an expression containing the location on which the
115 -- component by component assignments will take place. Returns the list of
116 -- assignments plus all other adjustments needed for tagged and controlled
117 -- types.
119 procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id);
120 -- N is an N_Aggregate or an N_Extension_Aggregate. Typ is the type of the
121 -- aggregate (which can only be a record type, this procedure is only used
122 -- for record types). Transform the given aggregate into a sequence of
123 -- assignments performed component by component.
125 procedure Expand_Record_Aggregate
126 (N : Node_Id;
127 Orig_Tag : Node_Id := Empty;
128 Parent_Expr : Node_Id := Empty);
129 -- This is the top level procedure for record aggregate expansion.
130 -- Expansion for record aggregates needs expand aggregates for tagged
131 -- record types. Specifically Expand_Record_Aggregate adds the Tag
132 -- field in front of the Component_Association list that was created
133 -- during resolution by Resolve_Record_Aggregate.
135 -- N is the record aggregate node.
136 -- Orig_Tag is the value of the Tag that has to be provided for this
137 -- specific aggregate. It carries the tag corresponding to the type
138 -- of the outermost aggregate during the recursive expansion
139 -- Parent_Expr is the ancestor part of the original extension
140 -- aggregate
142 function Has_Mutable_Components (Typ : Entity_Id) return Boolean;
143 -- Return true if one of the component is of a discriminated type with
144 -- defaults. An aggregate for a type with mutable components must be
145 -- expanded into individual assignments.
147 procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id);
148 -- If the type of the aggregate is a type extension with renamed discrimi-
149 -- nants, we must initialize the hidden discriminants of the parent.
150 -- Otherwise, the target object must not be initialized. The discriminants
151 -- are initialized by calling the initialization procedure for the type.
152 -- This is incorrect if the initialization of other components has any
153 -- side effects. We restrict this call to the case where the parent type
154 -- has a variant part, because this is the only case where the hidden
155 -- discriminants are accessed, namely when calling discriminant checking
156 -- functions of the parent type, and when applying a stream attribute to
157 -- an object of the derived type.
159 -----------------------------------------------------
160 -- Local Subprograms for Array Aggregate Expansion --
161 -----------------------------------------------------
163 function Aggr_Size_OK (N : Node_Id; Typ : Entity_Id) return Boolean;
164 -- Very large static aggregates present problems to the back-end, and are
165 -- transformed into assignments and loops. This function verifies that the
166 -- total number of components of an aggregate is acceptable for rewriting
167 -- into a purely positional static form. Aggr_Size_OK must be called before
168 -- calling Flatten.
170 -- This function also detects and warns about one-component aggregates that
171 -- appear in a non-static context. Even if the component value is static,
172 -- such an aggregate must be expanded into an assignment.
174 function Backend_Processing_Possible (N : Node_Id) return Boolean;
175 -- This function checks if array aggregate N can be processed directly
176 -- by the backend. If this is the case True is returned.
178 function Build_Array_Aggr_Code
179 (N : Node_Id;
180 Ctype : Entity_Id;
181 Index : Node_Id;
182 Into : Node_Id;
183 Scalar_Comp : Boolean;
184 Indexes : List_Id := No_List) return List_Id;
185 -- This recursive routine returns a list of statements containing the
186 -- loops and assignments that are needed for the expansion of the array
187 -- aggregate N.
189 -- N is the (sub-)aggregate node to be expanded into code. This node has
190 -- been fully analyzed, and its Etype is properly set.
192 -- Index is the index node corresponding to the array sub-aggregate N
194 -- Into is the target expression into which we are copying the aggregate.
195 -- Note that this node may not have been analyzed yet, and so the Etype
196 -- field may not be set.
198 -- Scalar_Comp is True if the component type of the aggregate is scalar
200 -- Indexes is the current list of expressions used to index the object we
201 -- are writing into.
203 procedure Convert_Array_Aggr_In_Allocator
204 (Decl : Node_Id;
205 Aggr : Node_Id;
206 Target : Node_Id);
207 -- If the aggregate appears within an allocator and can be expanded in
208 -- place, this routine generates the individual assignments to components
209 -- of the designated object. This is an optimization over the general
210 -- case, where a temporary is first created on the stack and then used to
211 -- construct the allocated object on the heap.
213 procedure Convert_To_Positional
214 (N : Node_Id;
215 Max_Others_Replicate : Nat := 5;
216 Handle_Bit_Packed : Boolean := False);
217 -- If possible, convert named notation to positional notation. This
218 -- conversion is possible only in some static cases. If the conversion is
219 -- possible, then N is rewritten with the analyzed converted aggregate.
220 -- The parameter Max_Others_Replicate controls the maximum number of
221 -- values corresponding to an others choice that will be converted to
222 -- positional notation (the default of 5 is the normal limit, and reflects
223 -- the fact that normally the loop is better than a lot of separate
224 -- assignments). Note that this limit gets overridden in any case if
225 -- either of the restrictions No_Elaboration_Code or No_Implicit_Loops is
226 -- set. The parameter Handle_Bit_Packed is usually set False (since we do
227 -- not expect the back end to handle bit packed arrays, so the normal case
228 -- of conversion is pointless), but in the special case of a call from
229 -- Packed_Array_Aggregate_Handled, we set this parameter to True, since
230 -- these are cases we handle in there.
232 -- It would seem worthwhile to have a higher default value for Max_Others_
233 -- replicate, but aggregates in the compiler make this impossible: the
234 -- compiler bootstrap fails if Max_Others_Replicate is greater than 25.
235 -- This is unexpected ???
237 procedure Expand_Array_Aggregate (N : Node_Id);
238 -- This is the top-level routine to perform array aggregate expansion.
239 -- N is the N_Aggregate node to be expanded.
241 function Late_Expansion
242 (N : Node_Id;
243 Typ : Entity_Id;
244 Target : Node_Id) return List_Id;
245 -- This routine implements top-down expansion of nested aggregates. In
246 -- doing so, it avoids the generation of temporaries at each level. N is a
247 -- nested (record or array) aggregate that has been marked with 'Delay_
248 -- Expansion'. Typ is the expected type of the aggregate. Target is a
249 -- (duplicable) expression that will hold the result of the aggregate
250 -- expansion.
252 function Make_OK_Assignment_Statement
253 (Sloc : Source_Ptr;
254 Name : Node_Id;
255 Expression : Node_Id) return Node_Id;
256 -- This is like Make_Assignment_Statement, except that Assignment_OK
257 -- is set in the left operand. All assignments built by this unit
258 -- use this routine. This is needed to deal with assignments to
259 -- initialized constants that are done in place.
261 function Number_Of_Choices (N : Node_Id) return Nat;
262 -- Returns the number of discrete choices (not including the others choice
263 -- if present) contained in (sub-)aggregate N.
265 function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean;
266 -- Given an array aggregate, this function handles the case of a packed
267 -- array aggregate with all constant values, where the aggregate can be
268 -- evaluated at compile time. If this is possible, then N is rewritten
269 -- to be its proper compile time value with all the components properly
270 -- assembled. The expression is analyzed and resolved and True is
271 -- returned. If this transformation is not possible, N is unchanged
272 -- and False is returned
274 function Safe_Slice_Assignment (N : Node_Id) return Boolean;
275 -- If a slice assignment has an aggregate with a single others_choice,
276 -- the assignment can be done in place even if bounds are not static,
277 -- by converting it into a loop over the discrete range of the slice.
279 ------------------
280 -- Aggr_Size_OK --
281 ------------------
283 function Aggr_Size_OK (N : Node_Id; Typ : Entity_Id) return Boolean is
284 Lo : Node_Id;
285 Hi : Node_Id;
286 Indx : Node_Id;
287 Siz : Int;
288 Lov : Uint;
289 Hiv : Uint;
291 -- The following constant determines the maximum size of an array
292 -- aggregate produced by converting named to positional notation (e.g.
293 -- from others clauses). This avoids running away with attempts to
294 -- convert huge aggregates, which hit memory limits in the backend.
296 -- The normal limit is 5000, but we increase this limit to 2**24 (about
297 -- 16 million) if Restrictions (No_Elaboration_Code) or Restrictions
298 -- (No_Implicit_Loops) is specified, since in either case, we are at
299 -- risk of declaring the program illegal because of this limit.
301 Max_Aggr_Size : constant Nat :=
302 5000 + (2 ** 24 - 5000) *
303 Boolean'Pos
304 (Restriction_Active (No_Elaboration_Code)
305 or else
306 Restriction_Active (No_Implicit_Loops));
308 function Component_Count (T : Entity_Id) return Int;
309 -- The limit is applied to the total number of components that the
310 -- aggregate will have, which is the number of static expressions
311 -- that will appear in the flattened array. This requires a recursive
312 -- computation of the number of scalar components of the structure.
314 ---------------------
315 -- Component_Count --
316 ---------------------
318 function Component_Count (T : Entity_Id) return Int is
319 Res : Int := 0;
320 Comp : Entity_Id;
322 begin
323 if Is_Scalar_Type (T) then
324 return 1;
326 elsif Is_Record_Type (T) then
327 Comp := First_Component (T);
328 while Present (Comp) loop
329 Res := Res + Component_Count (Etype (Comp));
330 Next_Component (Comp);
331 end loop;
333 return Res;
335 elsif Is_Array_Type (T) then
336 declare
337 Lo : constant Node_Id :=
338 Type_Low_Bound (Etype (First_Index (T)));
339 Hi : constant Node_Id :=
340 Type_High_Bound (Etype (First_Index (T)));
342 Siz : constant Int := Component_Count (Component_Type (T));
344 begin
345 if not Compile_Time_Known_Value (Lo)
346 or else not Compile_Time_Known_Value (Hi)
347 then
348 return 0;
349 else
350 return
351 Siz * UI_To_Int (Expr_Value (Hi) - Expr_Value (Lo) + 1);
352 end if;
353 end;
355 else
356 -- Can only be a null for an access type
358 return 1;
359 end if;
360 end Component_Count;
362 -- Start of processing for Aggr_Size_OK
364 begin
365 Siz := Component_Count (Component_Type (Typ));
367 Indx := First_Index (Typ);
368 while Present (Indx) loop
369 Lo := Type_Low_Bound (Etype (Indx));
370 Hi := Type_High_Bound (Etype (Indx));
372 -- Bounds need to be known at compile time
374 if not Compile_Time_Known_Value (Lo)
375 or else not Compile_Time_Known_Value (Hi)
376 then
377 return False;
378 end if;
380 Lov := Expr_Value (Lo);
381 Hiv := Expr_Value (Hi);
383 -- A flat array is always safe
385 if Hiv < Lov then
386 return True;
387 end if;
389 -- One-component aggregates are suspicious, and if the context type
390 -- is an object declaration with non-static bounds it will trip gcc;
391 -- such an aggregate must be expanded into a single assignment.
393 if Hiv = Lov
394 and then Nkind (Parent (N)) = N_Object_Declaration
395 then
396 declare
397 Index_Type : constant Entity_Id :=
398 Etype
399 (First_Index
400 (Etype (Defining_Identifier (Parent (N)))));
401 Indx : Node_Id;
403 begin
404 if not Compile_Time_Known_Value (Type_Low_Bound (Index_Type))
405 or else not Compile_Time_Known_Value
406 (Type_High_Bound (Index_Type))
407 then
408 if Present (Component_Associations (N)) then
409 Indx :=
410 First (Choices (First (Component_Associations (N))));
411 if Is_Entity_Name (Indx)
412 and then not Is_Type (Entity (Indx))
413 then
414 Error_Msg_N
415 ("single component aggregate in non-static context?",
416 Indx);
417 Error_Msg_N ("\maybe subtype name was meant?", Indx);
418 end if;
419 end if;
421 return False;
422 end if;
423 end;
424 end if;
426 declare
427 Rng : constant Uint := Hiv - Lov + 1;
429 begin
430 -- Check if size is too large
432 if not UI_Is_In_Int_Range (Rng) then
433 return False;
434 end if;
436 Siz := Siz * UI_To_Int (Rng);
437 end;
439 if Siz <= 0
440 or else Siz > Max_Aggr_Size
441 then
442 return False;
443 end if;
445 -- Bounds must be in integer range, for later array construction
447 if not UI_Is_In_Int_Range (Lov)
448 or else
449 not UI_Is_In_Int_Range (Hiv)
450 then
451 return False;
452 end if;
454 Next_Index (Indx);
455 end loop;
457 return True;
458 end Aggr_Size_OK;
460 ---------------------------------
461 -- Backend_Processing_Possible --
462 ---------------------------------
464 -- Backend processing by Gigi/gcc is possible only if all the following
465 -- conditions are met:
467 -- 1. N is fully positional
469 -- 2. N is not a bit-packed array aggregate;
471 -- 3. The size of N's array type must be known at compile time. Note
472 -- that this implies that the component size is also known
474 -- 4. The array type of N does not follow the Fortran layout convention
475 -- or if it does it must be 1 dimensional.
477 -- 5. The array component type may not be tagged (which could necessitate
478 -- reassignment of proper tags).
480 -- 6. The array component type must not have unaligned bit components
482 -- 7. None of the components of the aggregate may be bit unaligned
483 -- components.
485 -- 8. There cannot be delayed components, since we do not know enough
486 -- at this stage to know if back end processing is possible.
488 -- 9. There cannot be any discriminated record components, since the
489 -- back end cannot handle this complex case.
491 -- 10. No controlled actions need to be generated for components
493 -- 11. For a VM back end, the array should have no aliased components
495 function Backend_Processing_Possible (N : Node_Id) return Boolean is
496 Typ : constant Entity_Id := Etype (N);
497 -- Typ is the correct constrained array subtype of the aggregate
499 function Component_Check (N : Node_Id; Index : Node_Id) return Boolean;
500 -- This routine checks components of aggregate N, enforcing checks
501 -- 1, 7, 8, and 9. In the multi-dimensional case, these checks are
502 -- performed on subaggregates. The Index value is the current index
503 -- being checked in the multi-dimensional case.
505 ---------------------
506 -- Component_Check --
507 ---------------------
509 function Component_Check (N : Node_Id; Index : Node_Id) return Boolean is
510 Expr : Node_Id;
512 begin
513 -- Checks 1: (no component associations)
515 if Present (Component_Associations (N)) then
516 return False;
517 end if;
519 -- Checks on components
521 -- Recurse to check subaggregates, which may appear in qualified
522 -- expressions. If delayed, the front-end will have to expand.
523 -- If the component is a discriminated record, treat as non-static,
524 -- as the back-end cannot handle this properly.
526 Expr := First (Expressions (N));
527 while Present (Expr) loop
529 -- Checks 8: (no delayed components)
531 if Is_Delayed_Aggregate (Expr) then
532 return False;
533 end if;
535 -- Checks 9: (no discriminated records)
537 if Present (Etype (Expr))
538 and then Is_Record_Type (Etype (Expr))
539 and then Has_Discriminants (Etype (Expr))
540 then
541 return False;
542 end if;
544 -- Checks 7. Component must not be bit aligned component
546 if Possible_Bit_Aligned_Component (Expr) then
547 return False;
548 end if;
550 -- Recursion to following indexes for multiple dimension case
552 if Present (Next_Index (Index))
553 and then not Component_Check (Expr, Next_Index (Index))
554 then
555 return False;
556 end if;
558 -- All checks for that component finished, on to next
560 Next (Expr);
561 end loop;
563 return True;
564 end Component_Check;
566 -- Start of processing for Backend_Processing_Possible
568 begin
569 -- Checks 2 (array not bit packed) and 10 (no controlled actions)
571 if Is_Bit_Packed_Array (Typ) or else Needs_Finalization (Typ) then
572 return False;
573 end if;
575 -- If component is limited, aggregate must be expanded because each
576 -- component assignment must be built in place.
578 if Is_Immutably_Limited_Type (Component_Type (Typ)) then
579 return False;
580 end if;
582 -- Checks 4 (array must not be multi-dimensional Fortran case)
584 if Convention (Typ) = Convention_Fortran
585 and then Number_Dimensions (Typ) > 1
586 then
587 return False;
588 end if;
590 -- Checks 3 (size of array must be known at compile time)
592 if not Size_Known_At_Compile_Time (Typ) then
593 return False;
594 end if;
596 -- Checks on components
598 if not Component_Check (N, First_Index (Typ)) then
599 return False;
600 end if;
602 -- Checks 5 (if the component type is tagged, then we may need to do
603 -- tag adjustments. Perhaps this should be refined to check for any
604 -- component associations that actually need tag adjustment, similar
605 -- to the test in Component_Not_OK_For_Backend for record aggregates
606 -- with tagged components, but not clear whether it's worthwhile ???;
607 -- in the case of the JVM, object tags are handled implicitly)
609 if Is_Tagged_Type (Component_Type (Typ))
610 and then Tagged_Type_Expansion
611 then
612 return False;
613 end if;
615 -- Checks 6 (component type must not have bit aligned components)
617 if Type_May_Have_Bit_Aligned_Components (Component_Type (Typ)) then
618 return False;
619 end if;
621 -- Checks 11: Array aggregates with aliased components are currently
622 -- not well supported by the VM backend; disable temporarily this
623 -- backend processing until it is definitely supported.
625 if VM_Target /= No_VM
626 and then Has_Aliased_Components (Base_Type (Typ))
627 then
628 return False;
629 end if;
631 -- Backend processing is possible
633 Set_Size_Known_At_Compile_Time (Etype (N), True);
634 return True;
635 end Backend_Processing_Possible;
637 ---------------------------
638 -- Build_Array_Aggr_Code --
639 ---------------------------
641 -- The code that we generate from a one dimensional aggregate is
643 -- 1. If the sub-aggregate contains discrete choices we
645 -- (a) Sort the discrete choices
647 -- (b) Otherwise for each discrete choice that specifies a range we
648 -- emit a loop. If a range specifies a maximum of three values, or
649 -- we are dealing with an expression we emit a sequence of
650 -- assignments instead of a loop.
652 -- (c) Generate the remaining loops to cover the others choice if any
654 -- 2. If the aggregate contains positional elements we
656 -- (a) translate the positional elements in a series of assignments
658 -- (b) Generate a final loop to cover the others choice if any.
659 -- Note that this final loop has to be a while loop since the case
661 -- L : Integer := Integer'Last;
662 -- H : Integer := Integer'Last;
663 -- A : array (L .. H) := (1, others =>0);
665 -- cannot be handled by a for loop. Thus for the following
667 -- array (L .. H) := (.. positional elements.., others =>E);
669 -- we always generate something like:
671 -- J : Index_Type := Index_Of_Last_Positional_Element;
672 -- while J < H loop
673 -- J := Index_Base'Succ (J)
674 -- Tmp (J) := E;
675 -- end loop;
677 function Build_Array_Aggr_Code
678 (N : Node_Id;
679 Ctype : Entity_Id;
680 Index : Node_Id;
681 Into : Node_Id;
682 Scalar_Comp : Boolean;
683 Indexes : List_Id := No_List) return List_Id
685 Loc : constant Source_Ptr := Sloc (N);
686 Index_Base : constant Entity_Id := Base_Type (Etype (Index));
687 Index_Base_L : constant Node_Id := Type_Low_Bound (Index_Base);
688 Index_Base_H : constant Node_Id := Type_High_Bound (Index_Base);
690 function Add (Val : Int; To : Node_Id) return Node_Id;
691 -- Returns an expression where Val is added to expression To, unless
692 -- To+Val is provably out of To's base type range. To must be an
693 -- already analyzed expression.
695 function Empty_Range (L, H : Node_Id) return Boolean;
696 -- Returns True if the range defined by L .. H is certainly empty
698 function Equal (L, H : Node_Id) return Boolean;
699 -- Returns True if L = H for sure
701 function Index_Base_Name return Node_Id;
702 -- Returns a new reference to the index type name
704 function Gen_Assign (Ind : Node_Id; Expr : Node_Id) return List_Id;
705 -- Ind must be a side-effect free expression. If the input aggregate
706 -- N to Build_Loop contains no sub-aggregates, then this function
707 -- returns the assignment statement:
709 -- Into (Indexes, Ind) := Expr;
711 -- Otherwise we call Build_Code recursively
713 -- Ada 2005 (AI-287): In case of default initialized component, Expr
714 -- is empty and we generate a call to the corresponding IP subprogram.
716 function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id;
717 -- Nodes L and H must be side-effect free expressions.
718 -- If the input aggregate N to Build_Loop contains no sub-aggregates,
719 -- This routine returns the for loop statement
721 -- for J in Index_Base'(L) .. Index_Base'(H) loop
722 -- Into (Indexes, J) := Expr;
723 -- end loop;
725 -- Otherwise we call Build_Code recursively.
726 -- As an optimization if the loop covers 3 or less scalar elements we
727 -- generate a sequence of assignments.
729 function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id;
730 -- Nodes L and H must be side-effect free expressions.
731 -- If the input aggregate N to Build_Loop contains no sub-aggregates,
732 -- This routine returns the while loop statement
734 -- J : Index_Base := L;
735 -- while J < H loop
736 -- J := Index_Base'Succ (J);
737 -- Into (Indexes, J) := Expr;
738 -- end loop;
740 -- Otherwise we call Build_Code recursively
742 function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean;
743 function Local_Expr_Value (E : Node_Id) return Uint;
744 -- These two Local routines are used to replace the corresponding ones
745 -- in sem_eval because while processing the bounds of an aggregate with
746 -- discrete choices whose index type is an enumeration, we build static
747 -- expressions not recognized by Compile_Time_Known_Value as such since
748 -- they have not yet been analyzed and resolved. All the expressions in
749 -- question are things like Index_Base_Name'Val (Const) which we can
750 -- easily recognize as being constant.
752 ---------
753 -- Add --
754 ---------
756 function Add (Val : Int; To : Node_Id) return Node_Id is
757 Expr_Pos : Node_Id;
758 Expr : Node_Id;
759 To_Pos : Node_Id;
760 U_To : Uint;
761 U_Val : constant Uint := UI_From_Int (Val);
763 begin
764 -- Note: do not try to optimize the case of Val = 0, because
765 -- we need to build a new node with the proper Sloc value anyway.
767 -- First test if we can do constant folding
769 if Local_Compile_Time_Known_Value (To) then
770 U_To := Local_Expr_Value (To) + Val;
772 -- Determine if our constant is outside the range of the index.
773 -- If so return an Empty node. This empty node will be caught
774 -- by Empty_Range below.
776 if Compile_Time_Known_Value (Index_Base_L)
777 and then U_To < Expr_Value (Index_Base_L)
778 then
779 return Empty;
781 elsif Compile_Time_Known_Value (Index_Base_H)
782 and then U_To > Expr_Value (Index_Base_H)
783 then
784 return Empty;
785 end if;
787 Expr_Pos := Make_Integer_Literal (Loc, U_To);
788 Set_Is_Static_Expression (Expr_Pos);
790 if not Is_Enumeration_Type (Index_Base) then
791 Expr := Expr_Pos;
793 -- If we are dealing with enumeration return
794 -- Index_Base'Val (Expr_Pos)
796 else
797 Expr :=
798 Make_Attribute_Reference
799 (Loc,
800 Prefix => Index_Base_Name,
801 Attribute_Name => Name_Val,
802 Expressions => New_List (Expr_Pos));
803 end if;
805 return Expr;
806 end if;
808 -- If we are here no constant folding possible
810 if not Is_Enumeration_Type (Index_Base) then
811 Expr :=
812 Make_Op_Add (Loc,
813 Left_Opnd => Duplicate_Subexpr (To),
814 Right_Opnd => Make_Integer_Literal (Loc, U_Val));
816 -- If we are dealing with enumeration return
817 -- Index_Base'Val (Index_Base'Pos (To) + Val)
819 else
820 To_Pos :=
821 Make_Attribute_Reference
822 (Loc,
823 Prefix => Index_Base_Name,
824 Attribute_Name => Name_Pos,
825 Expressions => New_List (Duplicate_Subexpr (To)));
827 Expr_Pos :=
828 Make_Op_Add (Loc,
829 Left_Opnd => To_Pos,
830 Right_Opnd => Make_Integer_Literal (Loc, U_Val));
832 Expr :=
833 Make_Attribute_Reference
834 (Loc,
835 Prefix => Index_Base_Name,
836 Attribute_Name => Name_Val,
837 Expressions => New_List (Expr_Pos));
838 end if;
840 return Expr;
841 end Add;
843 -----------------
844 -- Empty_Range --
845 -----------------
847 function Empty_Range (L, H : Node_Id) return Boolean is
848 Is_Empty : Boolean := False;
849 Low : Node_Id;
850 High : Node_Id;
852 begin
853 -- First check if L or H were already detected as overflowing the
854 -- index base range type by function Add above. If this is so Add
855 -- returns the empty node.
857 if No (L) or else No (H) then
858 return True;
859 end if;
861 for J in 1 .. 3 loop
862 case J is
864 -- L > H range is empty
866 when 1 =>
867 Low := L;
868 High := H;
870 -- B_L > H range must be empty
872 when 2 =>
873 Low := Index_Base_L;
874 High := H;
876 -- L > B_H range must be empty
878 when 3 =>
879 Low := L;
880 High := Index_Base_H;
881 end case;
883 if Local_Compile_Time_Known_Value (Low)
884 and then Local_Compile_Time_Known_Value (High)
885 then
886 Is_Empty :=
887 UI_Gt (Local_Expr_Value (Low), Local_Expr_Value (High));
888 end if;
890 exit when Is_Empty;
891 end loop;
893 return Is_Empty;
894 end Empty_Range;
896 -----------
897 -- Equal --
898 -----------
900 function Equal (L, H : Node_Id) return Boolean is
901 begin
902 if L = H then
903 return True;
905 elsif Local_Compile_Time_Known_Value (L)
906 and then Local_Compile_Time_Known_Value (H)
907 then
908 return UI_Eq (Local_Expr_Value (L), Local_Expr_Value (H));
909 end if;
911 return False;
912 end Equal;
914 ----------------
915 -- Gen_Assign --
916 ----------------
918 function Gen_Assign (Ind : Node_Id; Expr : Node_Id) return List_Id is
919 L : constant List_Id := New_List;
920 A : Node_Id;
922 New_Indexes : List_Id;
923 Indexed_Comp : Node_Id;
924 Expr_Q : Node_Id;
925 Comp_Type : Entity_Id := Empty;
927 function Add_Loop_Actions (Lis : List_Id) return List_Id;
928 -- Collect insert_actions generated in the construction of a
929 -- loop, and prepend them to the sequence of assignments to
930 -- complete the eventual body of the loop.
932 ----------------------
933 -- Add_Loop_Actions --
934 ----------------------
936 function Add_Loop_Actions (Lis : List_Id) return List_Id is
937 Res : List_Id;
939 begin
940 -- Ada 2005 (AI-287): Do nothing else in case of default
941 -- initialized component.
943 if No (Expr) then
944 return Lis;
946 elsif Nkind (Parent (Expr)) = N_Component_Association
947 and then Present (Loop_Actions (Parent (Expr)))
948 then
949 Append_List (Lis, Loop_Actions (Parent (Expr)));
950 Res := Loop_Actions (Parent (Expr));
951 Set_Loop_Actions (Parent (Expr), No_List);
952 return Res;
954 else
955 return Lis;
956 end if;
957 end Add_Loop_Actions;
959 -- Start of processing for Gen_Assign
961 begin
962 if No (Indexes) then
963 New_Indexes := New_List;
964 else
965 New_Indexes := New_Copy_List_Tree (Indexes);
966 end if;
968 Append_To (New_Indexes, Ind);
970 if Present (Next_Index (Index)) then
971 return
972 Add_Loop_Actions (
973 Build_Array_Aggr_Code
974 (N => Expr,
975 Ctype => Ctype,
976 Index => Next_Index (Index),
977 Into => Into,
978 Scalar_Comp => Scalar_Comp,
979 Indexes => New_Indexes));
980 end if;
982 -- If we get here then we are at a bottom-level (sub-)aggregate
984 Indexed_Comp :=
985 Checks_Off
986 (Make_Indexed_Component (Loc,
987 Prefix => New_Copy_Tree (Into),
988 Expressions => New_Indexes));
990 Set_Assignment_OK (Indexed_Comp);
992 -- Ada 2005 (AI-287): In case of default initialized component, Expr
993 -- is not present (and therefore we also initialize Expr_Q to empty).
995 if No (Expr) then
996 Expr_Q := Empty;
997 elsif Nkind (Expr) = N_Qualified_Expression then
998 Expr_Q := Expression (Expr);
999 else
1000 Expr_Q := Expr;
1001 end if;
1003 if Present (Etype (N))
1004 and then Etype (N) /= Any_Composite
1005 then
1006 Comp_Type := Component_Type (Etype (N));
1007 pragma Assert (Comp_Type = Ctype); -- AI-287
1009 elsif Present (Next (First (New_Indexes))) then
1011 -- Ada 2005 (AI-287): Do nothing in case of default initialized
1012 -- component because we have received the component type in
1013 -- the formal parameter Ctype.
1015 -- ??? Some assert pragmas have been added to check if this new
1016 -- formal can be used to replace this code in all cases.
1018 if Present (Expr) then
1020 -- This is a multidimensional array. Recover the component
1021 -- type from the outermost aggregate, because subaggregates
1022 -- do not have an assigned type.
1024 declare
1025 P : Node_Id;
1027 begin
1028 P := Parent (Expr);
1029 while Present (P) loop
1030 if Nkind (P) = N_Aggregate
1031 and then Present (Etype (P))
1032 then
1033 Comp_Type := Component_Type (Etype (P));
1034 exit;
1036 else
1037 P := Parent (P);
1038 end if;
1039 end loop;
1041 pragma Assert (Comp_Type = Ctype); -- AI-287
1042 end;
1043 end if;
1044 end if;
1046 -- Ada 2005 (AI-287): We only analyze the expression in case of non-
1047 -- default initialized components (otherwise Expr_Q is not present).
1049 if Present (Expr_Q)
1050 and then Nkind_In (Expr_Q, N_Aggregate, N_Extension_Aggregate)
1051 then
1052 -- At this stage the Expression may not have been analyzed yet
1053 -- because the array aggregate code has not been updated to use
1054 -- the Expansion_Delayed flag and avoid analysis altogether to
1055 -- solve the same problem (see Resolve_Aggr_Expr). So let us do
1056 -- the analysis of non-array aggregates now in order to get the
1057 -- value of Expansion_Delayed flag for the inner aggregate ???
1059 if Present (Comp_Type) and then not Is_Array_Type (Comp_Type) then
1060 Analyze_And_Resolve (Expr_Q, Comp_Type);
1061 end if;
1063 if Is_Delayed_Aggregate (Expr_Q) then
1065 -- This is either a subaggregate of a multidimensional array,
1066 -- or a component of an array type whose component type is
1067 -- also an array. In the latter case, the expression may have
1068 -- component associations that provide different bounds from
1069 -- those of the component type, and sliding must occur. Instead
1070 -- of decomposing the current aggregate assignment, force the
1071 -- re-analysis of the assignment, so that a temporary will be
1072 -- generated in the usual fashion, and sliding will take place.
1074 if Nkind (Parent (N)) = N_Assignment_Statement
1075 and then Is_Array_Type (Comp_Type)
1076 and then Present (Component_Associations (Expr_Q))
1077 and then Must_Slide (Comp_Type, Etype (Expr_Q))
1078 then
1079 Set_Expansion_Delayed (Expr_Q, False);
1080 Set_Analyzed (Expr_Q, False);
1082 else
1083 return
1084 Add_Loop_Actions (
1085 Late_Expansion (Expr_Q, Etype (Expr_Q), Indexed_Comp));
1086 end if;
1087 end if;
1088 end if;
1090 -- Ada 2005 (AI-287): In case of default initialized component, call
1091 -- the initialization subprogram associated with the component type.
1092 -- If the component type is an access type, add an explicit null
1093 -- assignment, because for the back-end there is an initialization
1094 -- present for the whole aggregate, and no default initialization
1095 -- will take place.
1097 -- In addition, if the component type is controlled, we must call
1098 -- its Initialize procedure explicitly, because there is no explicit
1099 -- object creation that will invoke it otherwise.
1101 if No (Expr) then
1102 if Present (Base_Init_Proc (Base_Type (Ctype)))
1103 or else Has_Task (Base_Type (Ctype))
1104 then
1105 Append_List_To (L,
1106 Build_Initialization_Call (Loc,
1107 Id_Ref => Indexed_Comp,
1108 Typ => Ctype,
1109 With_Default_Init => True));
1111 elsif Is_Access_Type (Ctype) then
1112 Append_To (L,
1113 Make_Assignment_Statement (Loc,
1114 Name => Indexed_Comp,
1115 Expression => Make_Null (Loc)));
1116 end if;
1118 if Needs_Finalization (Ctype) then
1119 Append_To (L,
1120 Make_Init_Call (
1121 Obj_Ref => New_Copy_Tree (Indexed_Comp),
1122 Typ => Ctype));
1123 end if;
1125 else
1126 -- Now generate the assignment with no associated controlled
1127 -- actions since the target of the assignment may not have been
1128 -- initialized, it is not possible to Finalize it as expected by
1129 -- normal controlled assignment. The rest of the controlled
1130 -- actions are done manually with the proper finalization list
1131 -- coming from the context.
1133 A :=
1134 Make_OK_Assignment_Statement (Loc,
1135 Name => Indexed_Comp,
1136 Expression => New_Copy_Tree (Expr));
1138 if Present (Comp_Type) and then Needs_Finalization (Comp_Type) then
1139 Set_No_Ctrl_Actions (A);
1141 -- If this is an aggregate for an array of arrays, each
1142 -- sub-aggregate will be expanded as well, and even with
1143 -- No_Ctrl_Actions the assignments of inner components will
1144 -- require attachment in their assignments to temporaries.
1145 -- These temporaries must be finalized for each subaggregate,
1146 -- to prevent multiple attachments of the same temporary
1147 -- location to same finalization chain (and consequently
1148 -- circular lists). To ensure that finalization takes place
1149 -- for each subaggregate we wrap the assignment in a block.
1151 if Is_Array_Type (Comp_Type)
1152 and then Nkind (Expr) = N_Aggregate
1153 then
1154 A :=
1155 Make_Block_Statement (Loc,
1156 Handled_Statement_Sequence =>
1157 Make_Handled_Sequence_Of_Statements (Loc,
1158 Statements => New_List (A)));
1159 end if;
1160 end if;
1162 Append_To (L, A);
1164 -- Adjust the tag if tagged (because of possible view
1165 -- conversions), unless compiling for a VM where
1166 -- tags are implicit.
1168 if Present (Comp_Type)
1169 and then Is_Tagged_Type (Comp_Type)
1170 and then Tagged_Type_Expansion
1171 then
1172 declare
1173 Full_Typ : constant Entity_Id := Underlying_Type (Comp_Type);
1175 begin
1176 A :=
1177 Make_OK_Assignment_Statement (Loc,
1178 Name =>
1179 Make_Selected_Component (Loc,
1180 Prefix => New_Copy_Tree (Indexed_Comp),
1181 Selector_Name =>
1182 New_Reference_To
1183 (First_Tag_Component (Full_Typ), Loc)),
1185 Expression =>
1186 Unchecked_Convert_To (RTE (RE_Tag),
1187 New_Reference_To
1188 (Node (First_Elmt (Access_Disp_Table (Full_Typ))),
1189 Loc)));
1191 Append_To (L, A);
1192 end;
1193 end if;
1195 -- Adjust and attach the component to the proper final list, which
1196 -- can be the controller of the outer record object or the final
1197 -- list associated with the scope.
1199 -- If the component is itself an array of controlled types, whose
1200 -- value is given by a sub-aggregate, then the attach calls have
1201 -- been generated when individual subcomponent are assigned, and
1202 -- must not be done again to prevent malformed finalization chains
1203 -- (see comments above, concerning the creation of a block to hold
1204 -- inner finalization actions).
1206 if Present (Comp_Type)
1207 and then Needs_Finalization (Comp_Type)
1208 and then not Is_Limited_Type (Comp_Type)
1209 and then not
1210 (Is_Array_Type (Comp_Type)
1211 and then Is_Controlled (Component_Type (Comp_Type))
1212 and then Nkind (Expr) = N_Aggregate)
1213 then
1214 Append_To (L,
1215 Make_Adjust_Call (
1216 Obj_Ref => New_Copy_Tree (Indexed_Comp),
1217 Typ => Comp_Type));
1218 end if;
1219 end if;
1221 return Add_Loop_Actions (L);
1222 end Gen_Assign;
1224 --------------
1225 -- Gen_Loop --
1226 --------------
1228 function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id is
1229 L_J : Node_Id;
1231 L_L : Node_Id;
1232 -- Index_Base'(L)
1234 L_H : Node_Id;
1235 -- Index_Base'(H)
1237 L_Range : Node_Id;
1238 -- Index_Base'(L) .. Index_Base'(H)
1240 L_Iteration_Scheme : Node_Id;
1241 -- L_J in Index_Base'(L) .. Index_Base'(H)
1243 L_Body : List_Id;
1244 -- The statements to execute in the loop
1246 S : constant List_Id := New_List;
1247 -- List of statements
1249 Tcopy : Node_Id;
1250 -- Copy of expression tree, used for checking purposes
1252 begin
1253 -- If loop bounds define an empty range return the null statement
1255 if Empty_Range (L, H) then
1256 Append_To (S, Make_Null_Statement (Loc));
1258 -- Ada 2005 (AI-287): Nothing else need to be done in case of
1259 -- default initialized component.
1261 if No (Expr) then
1262 null;
1264 else
1265 -- The expression must be type-checked even though no component
1266 -- of the aggregate will have this value. This is done only for
1267 -- actual components of the array, not for subaggregates. Do
1268 -- the check on a copy, because the expression may be shared
1269 -- among several choices, some of which might be non-null.
1271 if Present (Etype (N))
1272 and then Is_Array_Type (Etype (N))
1273 and then No (Next_Index (Index))
1274 then
1275 Expander_Mode_Save_And_Set (False);
1276 Tcopy := New_Copy_Tree (Expr);
1277 Set_Parent (Tcopy, N);
1278 Analyze_And_Resolve (Tcopy, Component_Type (Etype (N)));
1279 Expander_Mode_Restore;
1280 end if;
1281 end if;
1283 return S;
1285 -- If loop bounds are the same then generate an assignment
1287 elsif Equal (L, H) then
1288 return Gen_Assign (New_Copy_Tree (L), Expr);
1290 -- If H - L <= 2 then generate a sequence of assignments when we are
1291 -- processing the bottom most aggregate and it contains scalar
1292 -- components.
1294 elsif No (Next_Index (Index))
1295 and then Scalar_Comp
1296 and then Local_Compile_Time_Known_Value (L)
1297 and then Local_Compile_Time_Known_Value (H)
1298 and then Local_Expr_Value (H) - Local_Expr_Value (L) <= 2
1299 then
1301 Append_List_To (S, Gen_Assign (New_Copy_Tree (L), Expr));
1302 Append_List_To (S, Gen_Assign (Add (1, To => L), Expr));
1304 if Local_Expr_Value (H) - Local_Expr_Value (L) = 2 then
1305 Append_List_To (S, Gen_Assign (Add (2, To => L), Expr));
1306 end if;
1308 return S;
1309 end if;
1311 -- Otherwise construct the loop, starting with the loop index L_J
1313 L_J := Make_Temporary (Loc, 'J', L);
1315 -- Construct "L .. H" in Index_Base. We use a qualified expression
1316 -- for the bound to convert to the index base, but we don't need
1317 -- to do that if we already have the base type at hand.
1319 if Etype (L) = Index_Base then
1320 L_L := L;
1321 else
1322 L_L :=
1323 Make_Qualified_Expression (Loc,
1324 Subtype_Mark => Index_Base_Name,
1325 Expression => L);
1326 end if;
1328 if Etype (H) = Index_Base then
1329 L_H := H;
1330 else
1331 L_H :=
1332 Make_Qualified_Expression (Loc,
1333 Subtype_Mark => Index_Base_Name,
1334 Expression => H);
1335 end if;
1337 L_Range :=
1338 Make_Range (Loc,
1339 Low_Bound => L_L,
1340 High_Bound => L_H);
1342 -- Construct "for L_J in Index_Base range L .. H"
1344 L_Iteration_Scheme :=
1345 Make_Iteration_Scheme
1346 (Loc,
1347 Loop_Parameter_Specification =>
1348 Make_Loop_Parameter_Specification
1349 (Loc,
1350 Defining_Identifier => L_J,
1351 Discrete_Subtype_Definition => L_Range));
1353 -- Construct the statements to execute in the loop body
1355 L_Body := Gen_Assign (New_Reference_To (L_J, Loc), Expr);
1357 -- Construct the final loop
1359 Append_To (S, Make_Implicit_Loop_Statement
1360 (Node => N,
1361 Identifier => Empty,
1362 Iteration_Scheme => L_Iteration_Scheme,
1363 Statements => L_Body));
1365 -- A small optimization: if the aggregate is initialized with a box
1366 -- and the component type has no initialization procedure, remove the
1367 -- useless empty loop.
1369 if Nkind (First (S)) = N_Loop_Statement
1370 and then Is_Empty_List (Statements (First (S)))
1371 then
1372 return New_List (Make_Null_Statement (Loc));
1373 else
1374 return S;
1375 end if;
1376 end Gen_Loop;
1378 ---------------
1379 -- Gen_While --
1380 ---------------
1382 -- The code built is
1384 -- W_J : Index_Base := L;
1385 -- while W_J < H loop
1386 -- W_J := Index_Base'Succ (W);
1387 -- L_Body;
1388 -- end loop;
1390 function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id is
1391 W_J : Node_Id;
1393 W_Decl : Node_Id;
1394 -- W_J : Base_Type := L;
1396 W_Iteration_Scheme : Node_Id;
1397 -- while W_J < H
1399 W_Index_Succ : Node_Id;
1400 -- Index_Base'Succ (J)
1402 W_Increment : Node_Id;
1403 -- W_J := Index_Base'Succ (W)
1405 W_Body : constant List_Id := New_List;
1406 -- The statements to execute in the loop
1408 S : constant List_Id := New_List;
1409 -- list of statement
1411 begin
1412 -- If loop bounds define an empty range or are equal return null
1414 if Empty_Range (L, H) or else Equal (L, H) then
1415 Append_To (S, Make_Null_Statement (Loc));
1416 return S;
1417 end if;
1419 -- Build the decl of W_J
1421 W_J := Make_Temporary (Loc, 'J', L);
1422 W_Decl :=
1423 Make_Object_Declaration
1424 (Loc,
1425 Defining_Identifier => W_J,
1426 Object_Definition => Index_Base_Name,
1427 Expression => L);
1429 -- Theoretically we should do a New_Copy_Tree (L) here, but we know
1430 -- that in this particular case L is a fresh Expr generated by
1431 -- Add which we are the only ones to use.
1433 Append_To (S, W_Decl);
1435 -- Construct " while W_J < H"
1437 W_Iteration_Scheme :=
1438 Make_Iteration_Scheme
1439 (Loc,
1440 Condition => Make_Op_Lt
1441 (Loc,
1442 Left_Opnd => New_Reference_To (W_J, Loc),
1443 Right_Opnd => New_Copy_Tree (H)));
1445 -- Construct the statements to execute in the loop body
1447 W_Index_Succ :=
1448 Make_Attribute_Reference
1449 (Loc,
1450 Prefix => Index_Base_Name,
1451 Attribute_Name => Name_Succ,
1452 Expressions => New_List (New_Reference_To (W_J, Loc)));
1454 W_Increment :=
1455 Make_OK_Assignment_Statement
1456 (Loc,
1457 Name => New_Reference_To (W_J, Loc),
1458 Expression => W_Index_Succ);
1460 Append_To (W_Body, W_Increment);
1461 Append_List_To (W_Body,
1462 Gen_Assign (New_Reference_To (W_J, Loc), Expr));
1464 -- Construct the final loop
1466 Append_To (S, Make_Implicit_Loop_Statement
1467 (Node => N,
1468 Identifier => Empty,
1469 Iteration_Scheme => W_Iteration_Scheme,
1470 Statements => W_Body));
1472 return S;
1473 end Gen_While;
1475 ---------------------
1476 -- Index_Base_Name --
1477 ---------------------
1479 function Index_Base_Name return Node_Id is
1480 begin
1481 return New_Reference_To (Index_Base, Sloc (N));
1482 end Index_Base_Name;
1484 ------------------------------------
1485 -- Local_Compile_Time_Known_Value --
1486 ------------------------------------
1488 function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean is
1489 begin
1490 return Compile_Time_Known_Value (E)
1491 or else
1492 (Nkind (E) = N_Attribute_Reference
1493 and then Attribute_Name (E) = Name_Val
1494 and then Compile_Time_Known_Value (First (Expressions (E))));
1495 end Local_Compile_Time_Known_Value;
1497 ----------------------
1498 -- Local_Expr_Value --
1499 ----------------------
1501 function Local_Expr_Value (E : Node_Id) return Uint is
1502 begin
1503 if Compile_Time_Known_Value (E) then
1504 return Expr_Value (E);
1505 else
1506 return Expr_Value (First (Expressions (E)));
1507 end if;
1508 end Local_Expr_Value;
1510 -- Build_Array_Aggr_Code Variables
1512 Assoc : Node_Id;
1513 Choice : Node_Id;
1514 Expr : Node_Id;
1515 Typ : Entity_Id;
1517 Others_Expr : Node_Id := Empty;
1518 Others_Box_Present : Boolean := False;
1520 Aggr_L : constant Node_Id := Low_Bound (Aggregate_Bounds (N));
1521 Aggr_H : constant Node_Id := High_Bound (Aggregate_Bounds (N));
1522 -- The aggregate bounds of this specific sub-aggregate. Note that if
1523 -- the code generated by Build_Array_Aggr_Code is executed then these
1524 -- bounds are OK. Otherwise a Constraint_Error would have been raised.
1526 Aggr_Low : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_L);
1527 Aggr_High : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_H);
1528 -- After Duplicate_Subexpr these are side-effect free
1530 Low : Node_Id;
1531 High : Node_Id;
1533 Nb_Choices : Nat := 0;
1534 Table : Case_Table_Type (1 .. Number_Of_Choices (N));
1535 -- Used to sort all the different choice values
1537 Nb_Elements : Int;
1538 -- Number of elements in the positional aggregate
1540 New_Code : constant List_Id := New_List;
1542 -- Start of processing for Build_Array_Aggr_Code
1544 begin
1545 -- First before we start, a special case. if we have a bit packed
1546 -- array represented as a modular type, then clear the value to
1547 -- zero first, to ensure that unused bits are properly cleared.
1549 Typ := Etype (N);
1551 if Present (Typ)
1552 and then Is_Bit_Packed_Array (Typ)
1553 and then Is_Modular_Integer_Type (Packed_Array_Type (Typ))
1554 then
1555 Append_To (New_Code,
1556 Make_Assignment_Statement (Loc,
1557 Name => New_Copy_Tree (Into),
1558 Expression =>
1559 Unchecked_Convert_To (Typ,
1560 Make_Integer_Literal (Loc, Uint_0))));
1561 end if;
1563 -- If the component type contains tasks, we need to build a Master
1564 -- entity in the current scope, because it will be needed if build-
1565 -- in-place functions are called in the expanded code.
1567 if Nkind (Parent (N)) = N_Object_Declaration
1568 and then Has_Task (Typ)
1569 then
1570 Build_Master_Entity (Defining_Identifier (Parent (N)));
1571 end if;
1573 -- STEP 1: Process component associations
1575 -- For those associations that may generate a loop, initialize
1576 -- Loop_Actions to collect inserted actions that may be crated.
1578 -- Skip this if no component associations
1580 if No (Expressions (N)) then
1582 -- STEP 1 (a): Sort the discrete choices
1584 Assoc := First (Component_Associations (N));
1585 while Present (Assoc) loop
1586 Choice := First (Choices (Assoc));
1587 while Present (Choice) loop
1588 if Nkind (Choice) = N_Others_Choice then
1589 Set_Loop_Actions (Assoc, New_List);
1591 if Box_Present (Assoc) then
1592 Others_Box_Present := True;
1593 else
1594 Others_Expr := Expression (Assoc);
1595 end if;
1596 exit;
1597 end if;
1599 Get_Index_Bounds (Choice, Low, High);
1601 if Low /= High then
1602 Set_Loop_Actions (Assoc, New_List);
1603 end if;
1605 Nb_Choices := Nb_Choices + 1;
1606 if Box_Present (Assoc) then
1607 Table (Nb_Choices) := (Choice_Lo => Low,
1608 Choice_Hi => High,
1609 Choice_Node => Empty);
1610 else
1611 Table (Nb_Choices) := (Choice_Lo => Low,
1612 Choice_Hi => High,
1613 Choice_Node => Expression (Assoc));
1614 end if;
1615 Next (Choice);
1616 end loop;
1618 Next (Assoc);
1619 end loop;
1621 -- If there is more than one set of choices these must be static
1622 -- and we can therefore sort them. Remember that Nb_Choices does not
1623 -- account for an others choice.
1625 if Nb_Choices > 1 then
1626 Sort_Case_Table (Table);
1627 end if;
1629 -- STEP 1 (b): take care of the whole set of discrete choices
1631 for J in 1 .. Nb_Choices loop
1632 Low := Table (J).Choice_Lo;
1633 High := Table (J).Choice_Hi;
1634 Expr := Table (J).Choice_Node;
1635 Append_List (Gen_Loop (Low, High, Expr), To => New_Code);
1636 end loop;
1638 -- STEP 1 (c): generate the remaining loops to cover others choice
1639 -- We don't need to generate loops over empty gaps, but if there is
1640 -- a single empty range we must analyze the expression for semantics
1642 if Present (Others_Expr) or else Others_Box_Present then
1643 declare
1644 First : Boolean := True;
1646 begin
1647 for J in 0 .. Nb_Choices loop
1648 if J = 0 then
1649 Low := Aggr_Low;
1650 else
1651 Low := Add (1, To => Table (J).Choice_Hi);
1652 end if;
1654 if J = Nb_Choices then
1655 High := Aggr_High;
1656 else
1657 High := Add (-1, To => Table (J + 1).Choice_Lo);
1658 end if;
1660 -- If this is an expansion within an init proc, make
1661 -- sure that discriminant references are replaced by
1662 -- the corresponding discriminal.
1664 if Inside_Init_Proc then
1665 if Is_Entity_Name (Low)
1666 and then Ekind (Entity (Low)) = E_Discriminant
1667 then
1668 Set_Entity (Low, Discriminal (Entity (Low)));
1669 end if;
1671 if Is_Entity_Name (High)
1672 and then Ekind (Entity (High)) = E_Discriminant
1673 then
1674 Set_Entity (High, Discriminal (Entity (High)));
1675 end if;
1676 end if;
1678 if First
1679 or else not Empty_Range (Low, High)
1680 then
1681 First := False;
1682 Append_List
1683 (Gen_Loop (Low, High, Others_Expr), To => New_Code);
1684 end if;
1685 end loop;
1686 end;
1687 end if;
1689 -- STEP 2: Process positional components
1691 else
1692 -- STEP 2 (a): Generate the assignments for each positional element
1693 -- Note that here we have to use Aggr_L rather than Aggr_Low because
1694 -- Aggr_L is analyzed and Add wants an analyzed expression.
1696 Expr := First (Expressions (N));
1697 Nb_Elements := -1;
1698 while Present (Expr) loop
1699 Nb_Elements := Nb_Elements + 1;
1700 Append_List (Gen_Assign (Add (Nb_Elements, To => Aggr_L), Expr),
1701 To => New_Code);
1702 Next (Expr);
1703 end loop;
1705 -- STEP 2 (b): Generate final loop if an others choice is present
1706 -- Here Nb_Elements gives the offset of the last positional element.
1708 if Present (Component_Associations (N)) then
1709 Assoc := Last (Component_Associations (N));
1711 -- Ada 2005 (AI-287)
1713 if Box_Present (Assoc) then
1714 Append_List (Gen_While (Add (Nb_Elements, To => Aggr_L),
1715 Aggr_High,
1716 Empty),
1717 To => New_Code);
1718 else
1719 Expr := Expression (Assoc);
1721 Append_List (Gen_While (Add (Nb_Elements, To => Aggr_L),
1722 Aggr_High,
1723 Expr), -- AI-287
1724 To => New_Code);
1725 end if;
1726 end if;
1727 end if;
1729 return New_Code;
1730 end Build_Array_Aggr_Code;
1732 ----------------------------
1733 -- Build_Record_Aggr_Code --
1734 ----------------------------
1736 function Build_Record_Aggr_Code
1737 (N : Node_Id;
1738 Typ : Entity_Id;
1739 Lhs : Node_Id) return List_Id
1741 Loc : constant Source_Ptr := Sloc (N);
1742 L : constant List_Id := New_List;
1743 N_Typ : constant Entity_Id := Etype (N);
1745 Comp : Node_Id;
1746 Instr : Node_Id;
1747 Ref : Node_Id;
1748 Target : Entity_Id;
1749 Comp_Type : Entity_Id;
1750 Selector : Entity_Id;
1751 Comp_Expr : Node_Id;
1752 Expr_Q : Node_Id;
1754 -- If this is an internal aggregate, the External_Final_List is an
1755 -- expression for the controller record of the enclosing type.
1757 -- If the current aggregate has several controlled components, this
1758 -- expression will appear in several calls to attach to the finali-
1759 -- zation list, and it must not be shared.
1761 Ancestor_Is_Expression : Boolean := False;
1762 Ancestor_Is_Subtype_Mark : Boolean := False;
1764 Init_Typ : Entity_Id := Empty;
1766 Finalization_Done : Boolean := False;
1767 -- True if Generate_Finalization_Actions has already been called; calls
1768 -- after the first do nothing.
1770 function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id;
1771 -- Returns the value that the given discriminant of an ancestor type
1772 -- should receive (in the absence of a conflict with the value provided
1773 -- by an ancestor part of an extension aggregate).
1775 procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id);
1776 -- Check that each of the discriminant values defined by the ancestor
1777 -- part of an extension aggregate match the corresponding values
1778 -- provided by either an association of the aggregate or by the
1779 -- constraint imposed by a parent type (RM95-4.3.2(8)).
1781 function Compatible_Int_Bounds
1782 (Agg_Bounds : Node_Id;
1783 Typ_Bounds : Node_Id) return Boolean;
1784 -- Return true if Agg_Bounds are equal or within Typ_Bounds. It is
1785 -- assumed that both bounds are integer ranges.
1787 procedure Generate_Finalization_Actions;
1788 -- Deal with the various controlled type data structure initializations
1789 -- (but only if it hasn't been done already).
1791 function Get_Constraint_Association (T : Entity_Id) return Node_Id;
1792 -- Returns the first discriminant association in the constraint
1793 -- associated with T, if any, otherwise returns Empty.
1795 procedure Init_Hidden_Discriminants (Typ : Entity_Id; List : List_Id);
1796 -- If Typ is derived, and constrains discriminants of the parent type,
1797 -- these discriminants are not components of the aggregate, and must be
1798 -- initialized. The assignments are appended to List.
1800 function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean;
1801 -- Check whether Bounds is a range node and its lower and higher bounds
1802 -- are integers literals.
1804 ---------------------------------
1805 -- Ancestor_Discriminant_Value --
1806 ---------------------------------
1808 function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id is
1809 Assoc : Node_Id;
1810 Assoc_Elmt : Elmt_Id;
1811 Aggr_Comp : Entity_Id;
1812 Corresp_Disc : Entity_Id;
1813 Current_Typ : Entity_Id := Base_Type (Typ);
1814 Parent_Typ : Entity_Id;
1815 Parent_Disc : Entity_Id;
1816 Save_Assoc : Node_Id := Empty;
1818 begin
1819 -- First check any discriminant associations to see if any of them
1820 -- provide a value for the discriminant.
1822 if Present (Discriminant_Specifications (Parent (Current_Typ))) then
1823 Assoc := First (Component_Associations (N));
1824 while Present (Assoc) loop
1825 Aggr_Comp := Entity (First (Choices (Assoc)));
1827 if Ekind (Aggr_Comp) = E_Discriminant then
1828 Save_Assoc := Expression (Assoc);
1830 Corresp_Disc := Corresponding_Discriminant (Aggr_Comp);
1831 while Present (Corresp_Disc) loop
1833 -- If found a corresponding discriminant then return the
1834 -- value given in the aggregate. (Note: this is not
1835 -- correct in the presence of side effects. ???)
1837 if Disc = Corresp_Disc then
1838 return Duplicate_Subexpr (Expression (Assoc));
1839 end if;
1841 Corresp_Disc :=
1842 Corresponding_Discriminant (Corresp_Disc);
1843 end loop;
1844 end if;
1846 Next (Assoc);
1847 end loop;
1848 end if;
1850 -- No match found in aggregate, so chain up parent types to find
1851 -- a constraint that defines the value of the discriminant.
1853 Parent_Typ := Etype (Current_Typ);
1854 while Current_Typ /= Parent_Typ loop
1855 if Has_Discriminants (Parent_Typ)
1856 and then not Has_Unknown_Discriminants (Parent_Typ)
1857 then
1858 Parent_Disc := First_Discriminant (Parent_Typ);
1860 -- We either get the association from the subtype indication
1861 -- of the type definition itself, or from the discriminant
1862 -- constraint associated with the type entity (which is
1863 -- preferable, but it's not always present ???)
1865 if Is_Empty_Elmt_List (
1866 Discriminant_Constraint (Current_Typ))
1867 then
1868 Assoc := Get_Constraint_Association (Current_Typ);
1869 Assoc_Elmt := No_Elmt;
1870 else
1871 Assoc_Elmt :=
1872 First_Elmt (Discriminant_Constraint (Current_Typ));
1873 Assoc := Node (Assoc_Elmt);
1874 end if;
1876 -- Traverse the discriminants of the parent type looking
1877 -- for one that corresponds.
1879 while Present (Parent_Disc) and then Present (Assoc) loop
1880 Corresp_Disc := Parent_Disc;
1881 while Present (Corresp_Disc)
1882 and then Disc /= Corresp_Disc
1883 loop
1884 Corresp_Disc :=
1885 Corresponding_Discriminant (Corresp_Disc);
1886 end loop;
1888 if Disc = Corresp_Disc then
1889 if Nkind (Assoc) = N_Discriminant_Association then
1890 Assoc := Expression (Assoc);
1891 end if;
1893 -- If the located association directly denotes a
1894 -- discriminant, then use the value of a saved
1895 -- association of the aggregate. This is a kludge to
1896 -- handle certain cases involving multiple discriminants
1897 -- mapped to a single discriminant of a descendant. It's
1898 -- not clear how to locate the appropriate discriminant
1899 -- value for such cases. ???
1901 if Is_Entity_Name (Assoc)
1902 and then Ekind (Entity (Assoc)) = E_Discriminant
1903 then
1904 Assoc := Save_Assoc;
1905 end if;
1907 return Duplicate_Subexpr (Assoc);
1908 end if;
1910 Next_Discriminant (Parent_Disc);
1912 if No (Assoc_Elmt) then
1913 Next (Assoc);
1914 else
1915 Next_Elmt (Assoc_Elmt);
1916 if Present (Assoc_Elmt) then
1917 Assoc := Node (Assoc_Elmt);
1918 else
1919 Assoc := Empty;
1920 end if;
1921 end if;
1922 end loop;
1923 end if;
1925 Current_Typ := Parent_Typ;
1926 Parent_Typ := Etype (Current_Typ);
1927 end loop;
1929 -- In some cases there's no ancestor value to locate (such as
1930 -- when an ancestor part given by an expression defines the
1931 -- discriminant value).
1933 return Empty;
1934 end Ancestor_Discriminant_Value;
1936 ----------------------------------
1937 -- Check_Ancestor_Discriminants --
1938 ----------------------------------
1940 procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id) is
1941 Discr : Entity_Id;
1942 Disc_Value : Node_Id;
1943 Cond : Node_Id;
1945 begin
1946 Discr := First_Discriminant (Base_Type (Anc_Typ));
1947 while Present (Discr) loop
1948 Disc_Value := Ancestor_Discriminant_Value (Discr);
1950 if Present (Disc_Value) then
1951 Cond := Make_Op_Ne (Loc,
1952 Left_Opnd =>
1953 Make_Selected_Component (Loc,
1954 Prefix => New_Copy_Tree (Target),
1955 Selector_Name => New_Occurrence_Of (Discr, Loc)),
1956 Right_Opnd => Disc_Value);
1958 Append_To (L,
1959 Make_Raise_Constraint_Error (Loc,
1960 Condition => Cond,
1961 Reason => CE_Discriminant_Check_Failed));
1962 end if;
1964 Next_Discriminant (Discr);
1965 end loop;
1966 end Check_Ancestor_Discriminants;
1968 ---------------------------
1969 -- Compatible_Int_Bounds --
1970 ---------------------------
1972 function Compatible_Int_Bounds
1973 (Agg_Bounds : Node_Id;
1974 Typ_Bounds : Node_Id) return Boolean
1976 Agg_Lo : constant Uint := Intval (Low_Bound (Agg_Bounds));
1977 Agg_Hi : constant Uint := Intval (High_Bound (Agg_Bounds));
1978 Typ_Lo : constant Uint := Intval (Low_Bound (Typ_Bounds));
1979 Typ_Hi : constant Uint := Intval (High_Bound (Typ_Bounds));
1980 begin
1981 return Typ_Lo <= Agg_Lo and then Agg_Hi <= Typ_Hi;
1982 end Compatible_Int_Bounds;
1984 --------------------------------
1985 -- Get_Constraint_Association --
1986 --------------------------------
1988 function Get_Constraint_Association (T : Entity_Id) return Node_Id is
1989 Indic : Node_Id;
1990 Typ : Entity_Id;
1992 begin
1993 Typ := T;
1995 -- Handle private types in instances
1997 if In_Instance
1998 and then Is_Private_Type (Typ)
1999 and then Present (Full_View (Typ))
2000 then
2001 Typ := Full_View (Typ);
2002 end if;
2004 Indic := Subtype_Indication (Type_Definition (Parent (Typ)));
2006 -- ??? Also need to cover case of a type mark denoting a subtype
2007 -- with constraint.
2009 if Nkind (Indic) = N_Subtype_Indication
2010 and then Present (Constraint (Indic))
2011 then
2012 return First (Constraints (Constraint (Indic)));
2013 end if;
2015 return Empty;
2016 end Get_Constraint_Association;
2018 -------------------------------
2019 -- Init_Hidden_Discriminants --
2020 -------------------------------
2022 procedure Init_Hidden_Discriminants (Typ : Entity_Id; List : List_Id) is
2023 Btype : Entity_Id;
2024 Parent_Type : Entity_Id;
2025 Disc : Entity_Id;
2026 Discr_Val : Elmt_Id;
2028 begin
2029 Btype := Base_Type (Typ);
2030 while Is_Derived_Type (Btype)
2031 and then Present (Stored_Constraint (Btype))
2032 loop
2033 Parent_Type := Etype (Btype);
2035 Disc := First_Discriminant (Parent_Type);
2036 Discr_Val := First_Elmt (Stored_Constraint (Base_Type (Typ)));
2037 while Present (Discr_Val) loop
2039 -- Only those discriminants of the parent that are not
2040 -- renamed by discriminants of the derived type need to
2041 -- be added explicitly.
2043 if not Is_Entity_Name (Node (Discr_Val))
2044 or else Ekind (Entity (Node (Discr_Val))) /= E_Discriminant
2045 then
2046 Comp_Expr :=
2047 Make_Selected_Component (Loc,
2048 Prefix => New_Copy_Tree (Target),
2049 Selector_Name => New_Occurrence_Of (Disc, Loc));
2051 Instr :=
2052 Make_OK_Assignment_Statement (Loc,
2053 Name => Comp_Expr,
2054 Expression => New_Copy_Tree (Node (Discr_Val)));
2056 Set_No_Ctrl_Actions (Instr);
2057 Append_To (List, Instr);
2058 end if;
2060 Next_Discriminant (Disc);
2061 Next_Elmt (Discr_Val);
2062 end loop;
2064 Btype := Base_Type (Parent_Type);
2065 end loop;
2066 end Init_Hidden_Discriminants;
2068 -------------------------
2069 -- Is_Int_Range_Bounds --
2070 -------------------------
2072 function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean is
2073 begin
2074 return Nkind (Bounds) = N_Range
2075 and then Nkind (Low_Bound (Bounds)) = N_Integer_Literal
2076 and then Nkind (High_Bound (Bounds)) = N_Integer_Literal;
2077 end Is_Int_Range_Bounds;
2079 -----------------------------------
2080 -- Generate_Finalization_Actions --
2081 -----------------------------------
2083 procedure Generate_Finalization_Actions is
2084 begin
2085 -- Do the work only the first time this is called
2087 if Finalization_Done then
2088 return;
2089 end if;
2091 Finalization_Done := True;
2093 -- Determine the external finalization list. It is either the
2094 -- finalization list of the outer-scope or the one coming from
2095 -- an outer aggregate. When the target is not a temporary, the
2096 -- proper scope is the scope of the target rather than the
2097 -- potentially transient current scope.
2099 if Is_Controlled (Typ)
2100 and then Ancestor_Is_Subtype_Mark
2101 then
2102 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2103 Set_Assignment_OK (Ref);
2105 Append_To (L,
2106 Make_Procedure_Call_Statement (Loc,
2107 Name =>
2108 New_Reference_To
2109 (Find_Prim_Op (Init_Typ, Name_Initialize), Loc),
2110 Parameter_Associations => New_List (New_Copy_Tree (Ref))));
2111 end if;
2112 end Generate_Finalization_Actions;
2114 function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result;
2115 -- If default expression of a component mentions a discriminant of the
2116 -- type, it must be rewritten as the discriminant of the target object.
2118 function Replace_Type (Expr : Node_Id) return Traverse_Result;
2119 -- If the aggregate contains a self-reference, traverse each expression
2120 -- to replace a possible self-reference with a reference to the proper
2121 -- component of the target of the assignment.
2123 --------------------------
2124 -- Rewrite_Discriminant --
2125 --------------------------
2127 function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result is
2128 begin
2129 if Is_Entity_Name (Expr)
2130 and then Present (Entity (Expr))
2131 and then Ekind (Entity (Expr)) = E_In_Parameter
2132 and then Present (Discriminal_Link (Entity (Expr)))
2133 and then Scope (Discriminal_Link (Entity (Expr)))
2134 = Base_Type (Etype (N))
2135 then
2136 Rewrite (Expr,
2137 Make_Selected_Component (Loc,
2138 Prefix => New_Copy_Tree (Lhs),
2139 Selector_Name => Make_Identifier (Loc, Chars (Expr))));
2140 end if;
2141 return OK;
2142 end Rewrite_Discriminant;
2144 ------------------
2145 -- Replace_Type --
2146 ------------------
2148 function Replace_Type (Expr : Node_Id) return Traverse_Result is
2149 begin
2150 -- Note regarding the Root_Type test below: Aggregate components for
2151 -- self-referential types include attribute references to the current
2152 -- instance, of the form: Typ'access, etc.. These references are
2153 -- rewritten as references to the target of the aggregate: the
2154 -- left-hand side of an assignment, the entity in a declaration,
2155 -- or a temporary. Without this test, we would improperly extended
2156 -- this rewriting to attribute references whose prefix was not the
2157 -- type of the aggregate.
2159 if Nkind (Expr) = N_Attribute_Reference
2160 and then Is_Entity_Name (Prefix (Expr))
2161 and then Is_Type (Entity (Prefix (Expr)))
2162 and then Root_Type (Etype (N)) = Root_Type (Entity (Prefix (Expr)))
2163 then
2164 if Is_Entity_Name (Lhs) then
2165 Rewrite (Prefix (Expr),
2166 New_Occurrence_Of (Entity (Lhs), Loc));
2168 elsif Nkind (Lhs) = N_Selected_Component then
2169 Rewrite (Expr,
2170 Make_Attribute_Reference (Loc,
2171 Attribute_Name => Name_Unrestricted_Access,
2172 Prefix => New_Copy_Tree (Lhs)));
2173 Set_Analyzed (Parent (Expr), False);
2175 else
2176 Rewrite (Expr,
2177 Make_Attribute_Reference (Loc,
2178 Attribute_Name => Name_Unrestricted_Access,
2179 Prefix => New_Copy_Tree (Lhs)));
2180 Set_Analyzed (Parent (Expr), False);
2181 end if;
2182 end if;
2184 return OK;
2185 end Replace_Type;
2187 procedure Replace_Self_Reference is
2188 new Traverse_Proc (Replace_Type);
2190 procedure Replace_Discriminants is
2191 new Traverse_Proc (Rewrite_Discriminant);
2193 -- Start of processing for Build_Record_Aggr_Code
2195 begin
2196 if Has_Self_Reference (N) then
2197 Replace_Self_Reference (N);
2198 end if;
2200 -- If the target of the aggregate is class-wide, we must convert it
2201 -- to the actual type of the aggregate, so that the proper components
2202 -- are visible. We know already that the types are compatible.
2204 if Present (Etype (Lhs))
2205 and then Is_Class_Wide_Type (Etype (Lhs))
2206 then
2207 Target := Unchecked_Convert_To (Typ, Lhs);
2208 else
2209 Target := Lhs;
2210 end if;
2212 -- Deal with the ancestor part of extension aggregates or with the
2213 -- discriminants of the root type.
2215 if Nkind (N) = N_Extension_Aggregate then
2216 declare
2217 Ancestor : constant Node_Id := Ancestor_Part (N);
2218 Assign : List_Id;
2220 begin
2221 -- If the ancestor part is a subtype mark "T", we generate
2223 -- init-proc (T (tmp)); if T is constrained and
2224 -- init-proc (S (tmp)); where S applies an appropriate
2225 -- constraint if T is unconstrained
2227 if Is_Entity_Name (Ancestor)
2228 and then Is_Type (Entity (Ancestor))
2229 then
2230 Ancestor_Is_Subtype_Mark := True;
2232 if Is_Constrained (Entity (Ancestor)) then
2233 Init_Typ := Entity (Ancestor);
2235 -- For an ancestor part given by an unconstrained type mark,
2236 -- create a subtype constrained by appropriate corresponding
2237 -- discriminant values coming from either associations of the
2238 -- aggregate or a constraint on a parent type. The subtype will
2239 -- be used to generate the correct default value for the
2240 -- ancestor part.
2242 elsif Has_Discriminants (Entity (Ancestor)) then
2243 declare
2244 Anc_Typ : constant Entity_Id := Entity (Ancestor);
2245 Anc_Constr : constant List_Id := New_List;
2246 Discrim : Entity_Id;
2247 Disc_Value : Node_Id;
2248 New_Indic : Node_Id;
2249 Subt_Decl : Node_Id;
2251 begin
2252 Discrim := First_Discriminant (Anc_Typ);
2253 while Present (Discrim) loop
2254 Disc_Value := Ancestor_Discriminant_Value (Discrim);
2255 Append_To (Anc_Constr, Disc_Value);
2256 Next_Discriminant (Discrim);
2257 end loop;
2259 New_Indic :=
2260 Make_Subtype_Indication (Loc,
2261 Subtype_Mark => New_Occurrence_Of (Anc_Typ, Loc),
2262 Constraint =>
2263 Make_Index_Or_Discriminant_Constraint (Loc,
2264 Constraints => Anc_Constr));
2266 Init_Typ := Create_Itype (Ekind (Anc_Typ), N);
2268 Subt_Decl :=
2269 Make_Subtype_Declaration (Loc,
2270 Defining_Identifier => Init_Typ,
2271 Subtype_Indication => New_Indic);
2273 -- Itypes must be analyzed with checks off Declaration
2274 -- must have a parent for proper handling of subsidiary
2275 -- actions.
2277 Set_Parent (Subt_Decl, N);
2278 Analyze (Subt_Decl, Suppress => All_Checks);
2279 end;
2280 end if;
2282 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2283 Set_Assignment_OK (Ref);
2285 if not Is_Interface (Init_Typ) then
2286 Append_List_To (L,
2287 Build_Initialization_Call (Loc,
2288 Id_Ref => Ref,
2289 Typ => Init_Typ,
2290 In_Init_Proc => Within_Init_Proc,
2291 With_Default_Init => Has_Default_Init_Comps (N)
2292 or else
2293 Has_Task (Base_Type (Init_Typ))));
2295 if Is_Constrained (Entity (Ancestor))
2296 and then Has_Discriminants (Entity (Ancestor))
2297 then
2298 Check_Ancestor_Discriminants (Entity (Ancestor));
2299 end if;
2300 end if;
2302 -- Handle calls to C++ constructors
2304 elsif Is_CPP_Constructor_Call (Ancestor) then
2305 Init_Typ := Etype (Ancestor);
2306 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2307 Set_Assignment_OK (Ref);
2309 Append_List_To (L,
2310 Build_Initialization_Call (Loc,
2311 Id_Ref => Ref,
2312 Typ => Init_Typ,
2313 In_Init_Proc => Within_Init_Proc,
2314 With_Default_Init => Has_Default_Init_Comps (N),
2315 Constructor_Ref => Ancestor));
2317 -- Ada 2005 (AI-287): If the ancestor part is an aggregate of
2318 -- limited type, a recursive call expands the ancestor. Note that
2319 -- in the limited case, the ancestor part must be either a
2320 -- function call (possibly qualified, or wrapped in an unchecked
2321 -- conversion) or aggregate (definitely qualified).
2322 -- The ancestor part can also be a function call (that may be
2323 -- transformed into an explicit dereference) or a qualification
2324 -- of one such.
2326 elsif Is_Limited_Type (Etype (Ancestor))
2327 and then Nkind_In (Unqualify (Ancestor), N_Aggregate,
2328 N_Extension_Aggregate)
2329 then
2330 Ancestor_Is_Expression := True;
2332 -- Set up finalization data for enclosing record, because
2333 -- controlled subcomponents of the ancestor part will be
2334 -- attached to it.
2336 Generate_Finalization_Actions;
2338 Append_List_To (L,
2339 Build_Record_Aggr_Code
2340 (N => Unqualify (Ancestor),
2341 Typ => Etype (Unqualify (Ancestor)),
2342 Lhs => Target));
2344 -- If the ancestor part is an expression "E", we generate
2346 -- T (tmp) := E;
2348 -- In Ada 2005, this includes the case of a (possibly qualified)
2349 -- limited function call. The assignment will turn into a
2350 -- build-in-place function call (for further details, see
2351 -- Make_Build_In_Place_Call_In_Assignment).
2353 else
2354 Ancestor_Is_Expression := True;
2355 Init_Typ := Etype (Ancestor);
2357 -- If the ancestor part is an aggregate, force its full
2358 -- expansion, which was delayed.
2360 if Nkind_In (Unqualify (Ancestor), N_Aggregate,
2361 N_Extension_Aggregate)
2362 then
2363 Set_Analyzed (Ancestor, False);
2364 Set_Analyzed (Expression (Ancestor), False);
2365 end if;
2367 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2368 Set_Assignment_OK (Ref);
2370 -- Make the assignment without usual controlled actions since
2371 -- we only want the post adjust but not the pre finalize here
2372 -- Add manual adjust when necessary.
2374 Assign := New_List (
2375 Make_OK_Assignment_Statement (Loc,
2376 Name => Ref,
2377 Expression => Ancestor));
2378 Set_No_Ctrl_Actions (First (Assign));
2380 -- Assign the tag now to make sure that the dispatching call in
2381 -- the subsequent deep_adjust works properly (unless VM_Target,
2382 -- where tags are implicit).
2384 if Tagged_Type_Expansion then
2385 Instr :=
2386 Make_OK_Assignment_Statement (Loc,
2387 Name =>
2388 Make_Selected_Component (Loc,
2389 Prefix => New_Copy_Tree (Target),
2390 Selector_Name =>
2391 New_Reference_To
2392 (First_Tag_Component (Base_Type (Typ)), Loc)),
2394 Expression =>
2395 Unchecked_Convert_To (RTE (RE_Tag),
2396 New_Reference_To
2397 (Node (First_Elmt
2398 (Access_Disp_Table (Base_Type (Typ)))),
2399 Loc)));
2401 Set_Assignment_OK (Name (Instr));
2402 Append_To (Assign, Instr);
2404 -- Ada 2005 (AI-251): If tagged type has progenitors we must
2405 -- also initialize tags of the secondary dispatch tables.
2407 if Has_Interfaces (Base_Type (Typ)) then
2408 Init_Secondary_Tags
2409 (Typ => Base_Type (Typ),
2410 Target => Target,
2411 Stmts_List => Assign);
2412 end if;
2413 end if;
2415 -- Call Adjust manually
2417 if Needs_Finalization (Etype (Ancestor))
2418 and then not Is_Limited_Type (Etype (Ancestor))
2419 then
2420 Append_To (Assign,
2421 Make_Adjust_Call (
2422 Obj_Ref => New_Copy_Tree (Ref),
2423 Typ => Etype (Ancestor)));
2424 end if;
2426 Append_To (L,
2427 Make_Unsuppress_Block (Loc, Name_Discriminant_Check, Assign));
2429 if Has_Discriminants (Init_Typ) then
2430 Check_Ancestor_Discriminants (Init_Typ);
2431 end if;
2432 end if;
2433 end;
2435 -- Generate assignments of hidden assignments. If the base type is an
2436 -- unchecked union, the discriminants are unknown to the back-end and
2437 -- absent from a value of the type, so assignments for them are not
2438 -- emitted.
2440 if Has_Discriminants (Typ)
2441 and then not Is_Unchecked_Union (Base_Type (Typ))
2442 then
2443 Init_Hidden_Discriminants (Typ, L);
2444 end if;
2446 -- Normal case (not an extension aggregate)
2448 else
2449 -- Generate the discriminant expressions, component by component.
2450 -- If the base type is an unchecked union, the discriminants are
2451 -- unknown to the back-end and absent from a value of the type, so
2452 -- assignments for them are not emitted.
2454 if Has_Discriminants (Typ)
2455 and then not Is_Unchecked_Union (Base_Type (Typ))
2456 then
2457 Init_Hidden_Discriminants (Typ, L);
2459 -- Generate discriminant init values for the visible discriminants
2461 declare
2462 Discriminant : Entity_Id;
2463 Discriminant_Value : Node_Id;
2465 begin
2466 Discriminant := First_Stored_Discriminant (Typ);
2467 while Present (Discriminant) loop
2468 Comp_Expr :=
2469 Make_Selected_Component (Loc,
2470 Prefix => New_Copy_Tree (Target),
2471 Selector_Name => New_Occurrence_Of (Discriminant, Loc));
2473 Discriminant_Value :=
2474 Get_Discriminant_Value (
2475 Discriminant,
2476 N_Typ,
2477 Discriminant_Constraint (N_Typ));
2479 Instr :=
2480 Make_OK_Assignment_Statement (Loc,
2481 Name => Comp_Expr,
2482 Expression => New_Copy_Tree (Discriminant_Value));
2484 Set_No_Ctrl_Actions (Instr);
2485 Append_To (L, Instr);
2487 Next_Stored_Discriminant (Discriminant);
2488 end loop;
2489 end;
2490 end if;
2491 end if;
2493 -- For CPP types we generate an implicit call to the C++ default
2494 -- constructor to ensure the proper initialization of the _Tag
2495 -- component.
2497 if Is_CPP_Class (Root_Type (Typ))
2498 and then CPP_Num_Prims (Typ) > 0
2499 then
2500 Invoke_Constructor : declare
2501 CPP_Parent : constant Entity_Id :=
2502 Enclosing_CPP_Parent (Typ);
2504 procedure Invoke_IC_Proc (T : Entity_Id);
2505 -- Recursive routine used to climb to parents. Required because
2506 -- parents must be initialized before descendants to ensure
2507 -- propagation of inherited C++ slots.
2509 --------------------
2510 -- Invoke_IC_Proc --
2511 --------------------
2513 procedure Invoke_IC_Proc (T : Entity_Id) is
2514 begin
2515 -- Avoid generating extra calls. Initialization required
2516 -- only for types defined from the level of derivation of
2517 -- type of the constructor and the type of the aggregate.
2519 if T = CPP_Parent then
2520 return;
2521 end if;
2523 Invoke_IC_Proc (Etype (T));
2525 -- Generate call to the IC routine
2527 if Present (CPP_Init_Proc (T)) then
2528 Append_To (L,
2529 Make_Procedure_Call_Statement (Loc,
2530 New_Reference_To (CPP_Init_Proc (T), Loc)));
2531 end if;
2532 end Invoke_IC_Proc;
2534 -- Start of processing for Invoke_Constructor
2536 begin
2537 -- Implicit invocation of the C++ constructor
2539 if Nkind (N) = N_Aggregate then
2540 Append_To (L,
2541 Make_Procedure_Call_Statement (Loc,
2542 Name =>
2543 New_Reference_To
2544 (Base_Init_Proc (CPP_Parent), Loc),
2545 Parameter_Associations => New_List (
2546 Unchecked_Convert_To (CPP_Parent,
2547 New_Copy_Tree (Lhs)))));
2548 end if;
2550 Invoke_IC_Proc (Typ);
2551 end Invoke_Constructor;
2552 end if;
2554 -- Generate the assignments, component by component
2556 -- tmp.comp1 := Expr1_From_Aggr;
2557 -- tmp.comp2 := Expr2_From_Aggr;
2558 -- ....
2560 Comp := First (Component_Associations (N));
2561 while Present (Comp) loop
2562 Selector := Entity (First (Choices (Comp)));
2564 -- C++ constructors
2566 if Is_CPP_Constructor_Call (Expression (Comp)) then
2567 Append_List_To (L,
2568 Build_Initialization_Call (Loc,
2569 Id_Ref => Make_Selected_Component (Loc,
2570 Prefix => New_Copy_Tree (Target),
2571 Selector_Name =>
2572 New_Occurrence_Of (Selector, Loc)),
2573 Typ => Etype (Selector),
2574 Enclos_Type => Typ,
2575 With_Default_Init => True,
2576 Constructor_Ref => Expression (Comp)));
2578 -- Ada 2005 (AI-287): For each default-initialized component generate
2579 -- a call to the corresponding IP subprogram if available.
2581 elsif Box_Present (Comp)
2582 and then Has_Non_Null_Base_Init_Proc (Etype (Selector))
2583 then
2584 if Ekind (Selector) /= E_Discriminant then
2585 Generate_Finalization_Actions;
2586 end if;
2588 -- Ada 2005 (AI-287): If the component type has tasks then
2589 -- generate the activation chain and master entities (except
2590 -- in case of an allocator because in that case these entities
2591 -- are generated by Build_Task_Allocate_Block_With_Init_Stmts).
2593 declare
2594 Ctype : constant Entity_Id := Etype (Selector);
2595 Inside_Allocator : Boolean := False;
2596 P : Node_Id := Parent (N);
2598 begin
2599 if Is_Task_Type (Ctype) or else Has_Task (Ctype) then
2600 while Present (P) loop
2601 if Nkind (P) = N_Allocator then
2602 Inside_Allocator := True;
2603 exit;
2604 end if;
2606 P := Parent (P);
2607 end loop;
2609 if not Inside_Init_Proc and not Inside_Allocator then
2610 Build_Activation_Chain_Entity (N);
2611 end if;
2612 end if;
2613 end;
2615 Append_List_To (L,
2616 Build_Initialization_Call (Loc,
2617 Id_Ref => Make_Selected_Component (Loc,
2618 Prefix => New_Copy_Tree (Target),
2619 Selector_Name =>
2620 New_Occurrence_Of (Selector, Loc)),
2621 Typ => Etype (Selector),
2622 Enclos_Type => Typ,
2623 With_Default_Init => True));
2625 -- Prepare for component assignment
2627 elsif Ekind (Selector) /= E_Discriminant
2628 or else Nkind (N) = N_Extension_Aggregate
2629 then
2630 -- All the discriminants have now been assigned
2632 -- This is now a good moment to initialize and attach all the
2633 -- controllers. Their position may depend on the discriminants.
2635 if Ekind (Selector) /= E_Discriminant then
2636 Generate_Finalization_Actions;
2637 end if;
2639 Comp_Type := Underlying_Type (Etype (Selector));
2640 Comp_Expr :=
2641 Make_Selected_Component (Loc,
2642 Prefix => New_Copy_Tree (Target),
2643 Selector_Name => New_Occurrence_Of (Selector, Loc));
2645 if Nkind (Expression (Comp)) = N_Qualified_Expression then
2646 Expr_Q := Expression (Expression (Comp));
2647 else
2648 Expr_Q := Expression (Comp);
2649 end if;
2651 -- Now either create the assignment or generate the code for the
2652 -- inner aggregate top-down.
2654 if Is_Delayed_Aggregate (Expr_Q) then
2656 -- We have the following case of aggregate nesting inside
2657 -- an object declaration:
2659 -- type Arr_Typ is array (Integer range <>) of ...;
2661 -- type Rec_Typ (...) is record
2662 -- Obj_Arr_Typ : Arr_Typ (A .. B);
2663 -- end record;
2665 -- Obj_Rec_Typ : Rec_Typ := (...,
2666 -- Obj_Arr_Typ => (X => (...), Y => (...)));
2668 -- The length of the ranges of the aggregate and Obj_Add_Typ
2669 -- are equal (B - A = Y - X), but they do not coincide (X /=
2670 -- A and B /= Y). This case requires array sliding which is
2671 -- performed in the following manner:
2673 -- subtype Arr_Sub is Arr_Typ (X .. Y);
2674 -- Temp : Arr_Sub;
2675 -- Temp (X) := (...);
2676 -- ...
2677 -- Temp (Y) := (...);
2678 -- Obj_Rec_Typ.Obj_Arr_Typ := Temp;
2680 if Ekind (Comp_Type) = E_Array_Subtype
2681 and then Is_Int_Range_Bounds (Aggregate_Bounds (Expr_Q))
2682 and then Is_Int_Range_Bounds (First_Index (Comp_Type))
2683 and then not
2684 Compatible_Int_Bounds
2685 (Agg_Bounds => Aggregate_Bounds (Expr_Q),
2686 Typ_Bounds => First_Index (Comp_Type))
2687 then
2688 -- Create the array subtype with bounds equal to those of
2689 -- the corresponding aggregate.
2691 declare
2692 SubE : constant Entity_Id := Make_Temporary (Loc, 'T');
2694 SubD : constant Node_Id :=
2695 Make_Subtype_Declaration (Loc,
2696 Defining_Identifier => SubE,
2697 Subtype_Indication =>
2698 Make_Subtype_Indication (Loc,
2699 Subtype_Mark =>
2700 New_Reference_To
2701 (Etype (Comp_Type), Loc),
2702 Constraint =>
2703 Make_Index_Or_Discriminant_Constraint
2704 (Loc,
2705 Constraints => New_List (
2706 New_Copy_Tree
2707 (Aggregate_Bounds (Expr_Q))))));
2709 -- Create a temporary array of the above subtype which
2710 -- will be used to capture the aggregate assignments.
2712 TmpE : constant Entity_Id := Make_Temporary (Loc, 'A', N);
2714 TmpD : constant Node_Id :=
2715 Make_Object_Declaration (Loc,
2716 Defining_Identifier => TmpE,
2717 Object_Definition =>
2718 New_Reference_To (SubE, Loc));
2720 begin
2721 Set_No_Initialization (TmpD);
2722 Append_To (L, SubD);
2723 Append_To (L, TmpD);
2725 -- Expand aggregate into assignments to the temp array
2727 Append_List_To (L,
2728 Late_Expansion (Expr_Q, Comp_Type,
2729 New_Reference_To (TmpE, Loc)));
2731 -- Slide
2733 Append_To (L,
2734 Make_Assignment_Statement (Loc,
2735 Name => New_Copy_Tree (Comp_Expr),
2736 Expression => New_Reference_To (TmpE, Loc)));
2737 end;
2739 -- Normal case (sliding not required)
2741 else
2742 Append_List_To (L,
2743 Late_Expansion (Expr_Q, Comp_Type, Comp_Expr));
2744 end if;
2746 -- Expr_Q is not delayed aggregate
2748 else
2749 if Has_Discriminants (Typ) then
2750 Replace_Discriminants (Expr_Q);
2751 end if;
2753 Instr :=
2754 Make_OK_Assignment_Statement (Loc,
2755 Name => Comp_Expr,
2756 Expression => Expr_Q);
2758 Set_No_Ctrl_Actions (Instr);
2759 Append_To (L, Instr);
2761 -- Adjust the tag if tagged (because of possible view
2762 -- conversions), unless compiling for a VM where tags are
2763 -- implicit.
2765 -- tmp.comp._tag := comp_typ'tag;
2767 if Is_Tagged_Type (Comp_Type)
2768 and then Tagged_Type_Expansion
2769 then
2770 Instr :=
2771 Make_OK_Assignment_Statement (Loc,
2772 Name =>
2773 Make_Selected_Component (Loc,
2774 Prefix => New_Copy_Tree (Comp_Expr),
2775 Selector_Name =>
2776 New_Reference_To
2777 (First_Tag_Component (Comp_Type), Loc)),
2779 Expression =>
2780 Unchecked_Convert_To (RTE (RE_Tag),
2781 New_Reference_To
2782 (Node (First_Elmt (Access_Disp_Table (Comp_Type))),
2783 Loc)));
2785 Append_To (L, Instr);
2786 end if;
2788 -- Generate:
2789 -- Adjust (tmp.comp);
2791 if Needs_Finalization (Comp_Type)
2792 and then not Is_Limited_Type (Comp_Type)
2793 then
2794 Append_To (L,
2795 Make_Adjust_Call (
2796 Obj_Ref => New_Copy_Tree (Comp_Expr),
2797 Typ => Comp_Type));
2798 end if;
2799 end if;
2801 -- ???
2803 elsif Ekind (Selector) = E_Discriminant
2804 and then Nkind (N) /= N_Extension_Aggregate
2805 and then Nkind (Parent (N)) = N_Component_Association
2806 and then Is_Constrained (Typ)
2807 then
2808 -- We must check that the discriminant value imposed by the
2809 -- context is the same as the value given in the subaggregate,
2810 -- because after the expansion into assignments there is no
2811 -- record on which to perform a regular discriminant check.
2813 declare
2814 D_Val : Elmt_Id;
2815 Disc : Entity_Id;
2817 begin
2818 D_Val := First_Elmt (Discriminant_Constraint (Typ));
2819 Disc := First_Discriminant (Typ);
2820 while Chars (Disc) /= Chars (Selector) loop
2821 Next_Discriminant (Disc);
2822 Next_Elmt (D_Val);
2823 end loop;
2825 pragma Assert (Present (D_Val));
2827 -- This check cannot performed for components that are
2828 -- constrained by a current instance, because this is not a
2829 -- value that can be compared with the actual constraint.
2831 if Nkind (Node (D_Val)) /= N_Attribute_Reference
2832 or else not Is_Entity_Name (Prefix (Node (D_Val)))
2833 or else not Is_Type (Entity (Prefix (Node (D_Val))))
2834 then
2835 Append_To (L,
2836 Make_Raise_Constraint_Error (Loc,
2837 Condition =>
2838 Make_Op_Ne (Loc,
2839 Left_Opnd => New_Copy_Tree (Node (D_Val)),
2840 Right_Opnd => Expression (Comp)),
2841 Reason => CE_Discriminant_Check_Failed));
2843 else
2844 -- Find self-reference in previous discriminant assignment,
2845 -- and replace with proper expression.
2847 declare
2848 Ass : Node_Id;
2850 begin
2851 Ass := First (L);
2852 while Present (Ass) loop
2853 if Nkind (Ass) = N_Assignment_Statement
2854 and then Nkind (Name (Ass)) = N_Selected_Component
2855 and then Chars (Selector_Name (Name (Ass))) =
2856 Chars (Disc)
2857 then
2858 Set_Expression
2859 (Ass, New_Copy_Tree (Expression (Comp)));
2860 exit;
2861 end if;
2862 Next (Ass);
2863 end loop;
2864 end;
2865 end if;
2866 end;
2867 end if;
2869 Next (Comp);
2870 end loop;
2872 -- If the type is tagged, the tag needs to be initialized (unless
2873 -- compiling for the Java VM where tags are implicit). It is done
2874 -- late in the initialization process because in some cases, we call
2875 -- the init proc of an ancestor which will not leave out the right tag
2877 if Ancestor_Is_Expression then
2878 null;
2880 -- For CPP types we generated a call to the C++ default constructor
2881 -- before the components have been initialized to ensure the proper
2882 -- initialization of the _Tag component (see above).
2884 elsif Is_CPP_Class (Typ) then
2885 null;
2887 elsif Is_Tagged_Type (Typ) and then Tagged_Type_Expansion then
2888 Instr :=
2889 Make_OK_Assignment_Statement (Loc,
2890 Name =>
2891 Make_Selected_Component (Loc,
2892 Prefix => New_Copy_Tree (Target),
2893 Selector_Name =>
2894 New_Reference_To
2895 (First_Tag_Component (Base_Type (Typ)), Loc)),
2897 Expression =>
2898 Unchecked_Convert_To (RTE (RE_Tag),
2899 New_Reference_To
2900 (Node (First_Elmt (Access_Disp_Table (Base_Type (Typ)))),
2901 Loc)));
2903 Append_To (L, Instr);
2905 -- Ada 2005 (AI-251): If the tagged type has been derived from
2906 -- abstract interfaces we must also initialize the tags of the
2907 -- secondary dispatch tables.
2909 if Has_Interfaces (Base_Type (Typ)) then
2910 Init_Secondary_Tags
2911 (Typ => Base_Type (Typ),
2912 Target => Target,
2913 Stmts_List => L);
2914 end if;
2915 end if;
2917 -- If the controllers have not been initialized yet (by lack of non-
2918 -- discriminant components), let's do it now.
2920 Generate_Finalization_Actions;
2922 return L;
2923 end Build_Record_Aggr_Code;
2925 -------------------------------
2926 -- Convert_Aggr_In_Allocator --
2927 -------------------------------
2929 procedure Convert_Aggr_In_Allocator
2930 (Alloc : Node_Id;
2931 Decl : Node_Id;
2932 Aggr : Node_Id)
2934 Loc : constant Source_Ptr := Sloc (Aggr);
2935 Typ : constant Entity_Id := Etype (Aggr);
2936 Temp : constant Entity_Id := Defining_Identifier (Decl);
2938 Occ : constant Node_Id :=
2939 Unchecked_Convert_To (Typ,
2940 Make_Explicit_Dereference (Loc,
2941 New_Reference_To (Temp, Loc)));
2943 begin
2944 if Is_Array_Type (Typ) then
2945 Convert_Array_Aggr_In_Allocator (Decl, Aggr, Occ);
2947 elsif Has_Default_Init_Comps (Aggr) then
2948 declare
2949 L : constant List_Id := New_List;
2950 Init_Stmts : List_Id;
2952 begin
2953 Init_Stmts := Late_Expansion (Aggr, Typ, Occ);
2955 if Has_Task (Typ) then
2956 Build_Task_Allocate_Block_With_Init_Stmts (L, Aggr, Init_Stmts);
2957 Insert_Actions (Alloc, L);
2958 else
2959 Insert_Actions (Alloc, Init_Stmts);
2960 end if;
2961 end;
2963 else
2964 Insert_Actions (Alloc, Late_Expansion (Aggr, Typ, Occ));
2965 end if;
2966 end Convert_Aggr_In_Allocator;
2968 --------------------------------
2969 -- Convert_Aggr_In_Assignment --
2970 --------------------------------
2972 procedure Convert_Aggr_In_Assignment (N : Node_Id) is
2973 Aggr : Node_Id := Expression (N);
2974 Typ : constant Entity_Id := Etype (Aggr);
2975 Occ : constant Node_Id := New_Copy_Tree (Name (N));
2977 begin
2978 if Nkind (Aggr) = N_Qualified_Expression then
2979 Aggr := Expression (Aggr);
2980 end if;
2982 Insert_Actions_After (N, Late_Expansion (Aggr, Typ, Occ));
2983 end Convert_Aggr_In_Assignment;
2985 ---------------------------------
2986 -- Convert_Aggr_In_Object_Decl --
2987 ---------------------------------
2989 procedure Convert_Aggr_In_Object_Decl (N : Node_Id) is
2990 Obj : constant Entity_Id := Defining_Identifier (N);
2991 Aggr : Node_Id := Expression (N);
2992 Loc : constant Source_Ptr := Sloc (Aggr);
2993 Typ : constant Entity_Id := Etype (Aggr);
2994 Occ : constant Node_Id := New_Occurrence_Of (Obj, Loc);
2996 function Discriminants_Ok return Boolean;
2997 -- If the object type is constrained, the discriminants in the
2998 -- aggregate must be checked against the discriminants of the subtype.
2999 -- This cannot be done using Apply_Discriminant_Checks because after
3000 -- expansion there is no aggregate left to check.
3002 ----------------------
3003 -- Discriminants_Ok --
3004 ----------------------
3006 function Discriminants_Ok return Boolean is
3007 Cond : Node_Id := Empty;
3008 Check : Node_Id;
3009 D : Entity_Id;
3010 Disc1 : Elmt_Id;
3011 Disc2 : Elmt_Id;
3012 Val1 : Node_Id;
3013 Val2 : Node_Id;
3015 begin
3016 D := First_Discriminant (Typ);
3017 Disc1 := First_Elmt (Discriminant_Constraint (Typ));
3018 Disc2 := First_Elmt (Discriminant_Constraint (Etype (Obj)));
3019 while Present (Disc1) and then Present (Disc2) loop
3020 Val1 := Node (Disc1);
3021 Val2 := Node (Disc2);
3023 if not Is_OK_Static_Expression (Val1)
3024 or else not Is_OK_Static_Expression (Val2)
3025 then
3026 Check := Make_Op_Ne (Loc,
3027 Left_Opnd => Duplicate_Subexpr (Val1),
3028 Right_Opnd => Duplicate_Subexpr (Val2));
3030 if No (Cond) then
3031 Cond := Check;
3033 else
3034 Cond := Make_Or_Else (Loc,
3035 Left_Opnd => Cond,
3036 Right_Opnd => Check);
3037 end if;
3039 elsif Expr_Value (Val1) /= Expr_Value (Val2) then
3040 Apply_Compile_Time_Constraint_Error (Aggr,
3041 Msg => "incorrect value for discriminant&?",
3042 Reason => CE_Discriminant_Check_Failed,
3043 Ent => D);
3044 return False;
3045 end if;
3047 Next_Discriminant (D);
3048 Next_Elmt (Disc1);
3049 Next_Elmt (Disc2);
3050 end loop;
3052 -- If any discriminant constraint is non-static, emit a check
3054 if Present (Cond) then
3055 Insert_Action (N,
3056 Make_Raise_Constraint_Error (Loc,
3057 Condition => Cond,
3058 Reason => CE_Discriminant_Check_Failed));
3059 end if;
3061 return True;
3062 end Discriminants_Ok;
3064 -- Start of processing for Convert_Aggr_In_Object_Decl
3066 begin
3067 Set_Assignment_OK (Occ);
3069 if Nkind (Aggr) = N_Qualified_Expression then
3070 Aggr := Expression (Aggr);
3071 end if;
3073 if Has_Discriminants (Typ)
3074 and then Typ /= Etype (Obj)
3075 and then Is_Constrained (Etype (Obj))
3076 and then not Discriminants_Ok
3077 then
3078 return;
3079 end if;
3081 -- If the context is an extended return statement, it has its own
3082 -- finalization machinery (i.e. works like a transient scope) and
3083 -- we do not want to create an additional one, because objects on
3084 -- the finalization list of the return must be moved to the caller's
3085 -- finalization list to complete the return.
3087 -- However, if the aggregate is limited, it is built in place, and the
3088 -- controlled components are not assigned to intermediate temporaries
3089 -- so there is no need for a transient scope in this case either.
3091 if Requires_Transient_Scope (Typ)
3092 and then Ekind (Current_Scope) /= E_Return_Statement
3093 and then not Is_Limited_Type (Typ)
3094 then
3095 Establish_Transient_Scope
3096 (Aggr,
3097 Sec_Stack =>
3098 Is_Controlled (Typ) or else Has_Controlled_Component (Typ));
3099 end if;
3101 Insert_Actions_After (N, Late_Expansion (Aggr, Typ, Occ));
3102 Set_No_Initialization (N);
3103 Initialize_Discriminants (N, Typ);
3104 end Convert_Aggr_In_Object_Decl;
3106 -------------------------------------
3107 -- Convert_Array_Aggr_In_Allocator --
3108 -------------------------------------
3110 procedure Convert_Array_Aggr_In_Allocator
3111 (Decl : Node_Id;
3112 Aggr : Node_Id;
3113 Target : Node_Id)
3115 Aggr_Code : List_Id;
3116 Typ : constant Entity_Id := Etype (Aggr);
3117 Ctyp : constant Entity_Id := Component_Type (Typ);
3119 begin
3120 -- The target is an explicit dereference of the allocated object.
3121 -- Generate component assignments to it, as for an aggregate that
3122 -- appears on the right-hand side of an assignment statement.
3124 Aggr_Code :=
3125 Build_Array_Aggr_Code (Aggr,
3126 Ctype => Ctyp,
3127 Index => First_Index (Typ),
3128 Into => Target,
3129 Scalar_Comp => Is_Scalar_Type (Ctyp));
3131 Insert_Actions_After (Decl, Aggr_Code);
3132 end Convert_Array_Aggr_In_Allocator;
3134 ----------------------------
3135 -- Convert_To_Assignments --
3136 ----------------------------
3138 procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id) is
3139 Loc : constant Source_Ptr := Sloc (N);
3140 T : Entity_Id;
3141 Temp : Entity_Id;
3143 Instr : Node_Id;
3144 Target_Expr : Node_Id;
3145 Parent_Kind : Node_Kind;
3146 Unc_Decl : Boolean := False;
3147 Parent_Node : Node_Id;
3149 begin
3150 pragma Assert (not Is_Static_Dispatch_Table_Aggregate (N));
3151 pragma Assert (Is_Record_Type (Typ));
3153 Parent_Node := Parent (N);
3154 Parent_Kind := Nkind (Parent_Node);
3156 if Parent_Kind = N_Qualified_Expression then
3158 -- Check if we are in a unconstrained declaration because in this
3159 -- case the current delayed expansion mechanism doesn't work when
3160 -- the declared object size depend on the initializing expr.
3162 begin
3163 Parent_Node := Parent (Parent_Node);
3164 Parent_Kind := Nkind (Parent_Node);
3166 if Parent_Kind = N_Object_Declaration then
3167 Unc_Decl :=
3168 not Is_Entity_Name (Object_Definition (Parent_Node))
3169 or else Has_Discriminants
3170 (Entity (Object_Definition (Parent_Node)))
3171 or else Is_Class_Wide_Type
3172 (Entity (Object_Definition (Parent_Node)));
3173 end if;
3174 end;
3175 end if;
3177 -- Just set the Delay flag in the cases where the transformation will be
3178 -- done top down from above.
3180 if False
3182 -- Internal aggregate (transformed when expanding the parent)
3184 or else Parent_Kind = N_Aggregate
3185 or else Parent_Kind = N_Extension_Aggregate
3186 or else Parent_Kind = N_Component_Association
3188 -- Allocator (see Convert_Aggr_In_Allocator)
3190 or else Parent_Kind = N_Allocator
3192 -- Object declaration (see Convert_Aggr_In_Object_Decl)
3194 or else (Parent_Kind = N_Object_Declaration and then not Unc_Decl)
3196 -- Safe assignment (see Convert_Aggr_Assignments). So far only the
3197 -- assignments in init procs are taken into account.
3199 or else (Parent_Kind = N_Assignment_Statement
3200 and then Inside_Init_Proc)
3202 -- (Ada 2005) An inherently limited type in a return statement,
3203 -- which will be handled in a build-in-place fashion, and may be
3204 -- rewritten as an extended return and have its own finalization
3205 -- machinery. In the case of a simple return, the aggregate needs
3206 -- to be delayed until the scope for the return statement has been
3207 -- created, so that any finalization chain will be associated with
3208 -- that scope. For extended returns, we delay expansion to avoid the
3209 -- creation of an unwanted transient scope that could result in
3210 -- premature finalization of the return object (which is built in
3211 -- in place within the caller's scope).
3213 or else
3214 (Is_Immutably_Limited_Type (Typ)
3215 and then
3216 (Nkind (Parent (Parent_Node)) = N_Extended_Return_Statement
3217 or else Nkind (Parent_Node) = N_Simple_Return_Statement))
3218 then
3219 Set_Expansion_Delayed (N);
3220 return;
3221 end if;
3223 if Requires_Transient_Scope (Typ) then
3224 Establish_Transient_Scope
3225 (N, Sec_Stack =>
3226 Is_Controlled (Typ) or else Has_Controlled_Component (Typ));
3227 end if;
3229 -- If the aggregate is non-limited, create a temporary. If it is limited
3230 -- and the context is an assignment, this is a subaggregate for an
3231 -- enclosing aggregate being expanded. It must be built in place, so use
3232 -- the target of the current assignment.
3234 if Is_Limited_Type (Typ)
3235 and then Nkind (Parent (N)) = N_Assignment_Statement
3236 then
3237 Target_Expr := New_Copy_Tree (Name (Parent (N)));
3238 Insert_Actions (Parent (N),
3239 Build_Record_Aggr_Code (N, Typ, Target_Expr));
3240 Rewrite (Parent (N), Make_Null_Statement (Loc));
3242 else
3243 Temp := Make_Temporary (Loc, 'A', N);
3245 -- If the type inherits unknown discriminants, use the view with
3246 -- known discriminants if available.
3248 if Has_Unknown_Discriminants (Typ)
3249 and then Present (Underlying_Record_View (Typ))
3250 then
3251 T := Underlying_Record_View (Typ);
3252 else
3253 T := Typ;
3254 end if;
3256 Instr :=
3257 Make_Object_Declaration (Loc,
3258 Defining_Identifier => Temp,
3259 Object_Definition => New_Occurrence_Of (T, Loc));
3261 Set_No_Initialization (Instr);
3262 Insert_Action (N, Instr);
3263 Initialize_Discriminants (Instr, T);
3264 Target_Expr := New_Occurrence_Of (Temp, Loc);
3265 Insert_Actions (N, Build_Record_Aggr_Code (N, T, Target_Expr));
3266 Rewrite (N, New_Occurrence_Of (Temp, Loc));
3267 Analyze_And_Resolve (N, T);
3268 end if;
3269 end Convert_To_Assignments;
3271 ---------------------------
3272 -- Convert_To_Positional --
3273 ---------------------------
3275 procedure Convert_To_Positional
3276 (N : Node_Id;
3277 Max_Others_Replicate : Nat := 5;
3278 Handle_Bit_Packed : Boolean := False)
3280 Typ : constant Entity_Id := Etype (N);
3282 Static_Components : Boolean := True;
3284 procedure Check_Static_Components;
3285 -- Check whether all components of the aggregate are compile-time known
3286 -- values, and can be passed as is to the back-end without further
3287 -- expansion.
3289 function Flatten
3290 (N : Node_Id;
3291 Ix : Node_Id;
3292 Ixb : Node_Id) return Boolean;
3293 -- Convert the aggregate into a purely positional form if possible. On
3294 -- entry the bounds of all dimensions are known to be static, and the
3295 -- total number of components is safe enough to expand.
3297 function Is_Flat (N : Node_Id; Dims : Int) return Boolean;
3298 -- Return True iff the array N is flat (which is not trivial in the case
3299 -- of multidimensional aggregates).
3301 -----------------------------
3302 -- Check_Static_Components --
3303 -----------------------------
3305 procedure Check_Static_Components is
3306 Expr : Node_Id;
3308 begin
3309 Static_Components := True;
3311 if Nkind (N) = N_String_Literal then
3312 null;
3314 elsif Present (Expressions (N)) then
3315 Expr := First (Expressions (N));
3316 while Present (Expr) loop
3317 if Nkind (Expr) /= N_Aggregate
3318 or else not Compile_Time_Known_Aggregate (Expr)
3319 or else Expansion_Delayed (Expr)
3320 then
3321 Static_Components := False;
3322 exit;
3323 end if;
3325 Next (Expr);
3326 end loop;
3327 end if;
3329 if Nkind (N) = N_Aggregate
3330 and then Present (Component_Associations (N))
3331 then
3332 Expr := First (Component_Associations (N));
3333 while Present (Expr) loop
3334 if Nkind_In (Expression (Expr), N_Integer_Literal,
3335 N_Real_Literal)
3336 then
3337 null;
3339 elsif Is_Entity_Name (Expression (Expr))
3340 and then Present (Entity (Expression (Expr)))
3341 and then Ekind (Entity (Expression (Expr))) =
3342 E_Enumeration_Literal
3343 then
3344 null;
3346 elsif Nkind (Expression (Expr)) /= N_Aggregate
3347 or else not Compile_Time_Known_Aggregate (Expression (Expr))
3348 or else Expansion_Delayed (Expression (Expr))
3349 then
3350 Static_Components := False;
3351 exit;
3352 end if;
3354 Next (Expr);
3355 end loop;
3356 end if;
3357 end Check_Static_Components;
3359 -------------
3360 -- Flatten --
3361 -------------
3363 function Flatten
3364 (N : Node_Id;
3365 Ix : Node_Id;
3366 Ixb : Node_Id) return Boolean
3368 Loc : constant Source_Ptr := Sloc (N);
3369 Blo : constant Node_Id := Type_Low_Bound (Etype (Ixb));
3370 Lo : constant Node_Id := Type_Low_Bound (Etype (Ix));
3371 Hi : constant Node_Id := Type_High_Bound (Etype (Ix));
3372 Lov : Uint;
3373 Hiv : Uint;
3375 Others_Present : Boolean := False;
3377 begin
3378 if Nkind (Original_Node (N)) = N_String_Literal then
3379 return True;
3380 end if;
3382 if not Compile_Time_Known_Value (Lo)
3383 or else not Compile_Time_Known_Value (Hi)
3384 then
3385 return False;
3386 end if;
3388 Lov := Expr_Value (Lo);
3389 Hiv := Expr_Value (Hi);
3391 -- Check if there is an others choice
3393 if Present (Component_Associations (N)) then
3394 declare
3395 Assoc : Node_Id;
3396 Choice : Node_Id;
3398 begin
3399 Assoc := First (Component_Associations (N));
3400 while Present (Assoc) loop
3402 -- If this is a box association, flattening is in general
3403 -- not possible because at this point we cannot tell if the
3404 -- default is static or even exists.
3406 if Box_Present (Assoc) then
3407 return False;
3408 end if;
3410 Choice := First (Choices (Assoc));
3412 while Present (Choice) loop
3413 if Nkind (Choice) = N_Others_Choice then
3414 Others_Present := True;
3415 end if;
3417 Next (Choice);
3418 end loop;
3420 Next (Assoc);
3421 end loop;
3422 end;
3423 end if;
3425 -- If the low bound is not known at compile time and others is not
3426 -- present we can proceed since the bounds can be obtained from the
3427 -- aggregate.
3429 -- Note: This case is required in VM platforms since their backends
3430 -- normalize array indexes in the range 0 .. N-1. Hence, if we do
3431 -- not flat an array whose bounds cannot be obtained from the type
3432 -- of the index the backend has no way to properly generate the code.
3433 -- See ACATS c460010 for an example.
3435 if Hiv < Lov
3436 or else (not Compile_Time_Known_Value (Blo)
3437 and then Others_Present)
3438 then
3439 return False;
3440 end if;
3442 -- Determine if set of alternatives is suitable for conversion and
3443 -- build an array containing the values in sequence.
3445 declare
3446 Vals : array (UI_To_Int (Lov) .. UI_To_Int (Hiv))
3447 of Node_Id := (others => Empty);
3448 -- The values in the aggregate sorted appropriately
3450 Vlist : List_Id;
3451 -- Same data as Vals in list form
3453 Rep_Count : Nat;
3454 -- Used to validate Max_Others_Replicate limit
3456 Elmt : Node_Id;
3457 Num : Int := UI_To_Int (Lov);
3458 Choice_Index : Int;
3459 Choice : Node_Id;
3460 Lo, Hi : Node_Id;
3462 begin
3463 if Present (Expressions (N)) then
3464 Elmt := First (Expressions (N));
3465 while Present (Elmt) loop
3466 if Nkind (Elmt) = N_Aggregate
3467 and then Present (Next_Index (Ix))
3468 and then
3469 not Flatten (Elmt, Next_Index (Ix), Next_Index (Ixb))
3470 then
3471 return False;
3472 end if;
3474 Vals (Num) := Relocate_Node (Elmt);
3475 Num := Num + 1;
3477 Next (Elmt);
3478 end loop;
3479 end if;
3481 if No (Component_Associations (N)) then
3482 return True;
3483 end if;
3485 Elmt := First (Component_Associations (N));
3487 if Nkind (Expression (Elmt)) = N_Aggregate then
3488 if Present (Next_Index (Ix))
3489 and then
3490 not Flatten
3491 (Expression (Elmt), Next_Index (Ix), Next_Index (Ixb))
3492 then
3493 return False;
3494 end if;
3495 end if;
3497 Component_Loop : while Present (Elmt) loop
3498 Choice := First (Choices (Elmt));
3499 Choice_Loop : while Present (Choice) loop
3501 -- If we have an others choice, fill in the missing elements
3502 -- subject to the limit established by Max_Others_Replicate.
3504 if Nkind (Choice) = N_Others_Choice then
3505 Rep_Count := 0;
3507 for J in Vals'Range loop
3508 if No (Vals (J)) then
3509 Vals (J) := New_Copy_Tree (Expression (Elmt));
3510 Rep_Count := Rep_Count + 1;
3512 -- Check for maximum others replication. Note that
3513 -- we skip this test if either of the restrictions
3514 -- No_Elaboration_Code or No_Implicit_Loops is
3515 -- active, if this is a preelaborable unit or a
3516 -- predefined unit. This ensures that predefined
3517 -- units get the same level of constant folding in
3518 -- Ada 95 and Ada 2005, where their categorization
3519 -- has changed.
3521 declare
3522 P : constant Entity_Id :=
3523 Cunit_Entity (Current_Sem_Unit);
3525 begin
3526 -- Check if duplication OK and if so continue
3527 -- processing.
3529 if Restriction_Active (No_Elaboration_Code)
3530 or else Restriction_Active (No_Implicit_Loops)
3531 or else Is_Preelaborated (P)
3532 or else (Ekind (P) = E_Package_Body
3533 and then
3534 Is_Preelaborated (Spec_Entity (P)))
3535 or else
3536 Is_Predefined_File_Name
3537 (Unit_File_Name (Get_Source_Unit (P)))
3538 then
3539 null;
3541 -- If duplication not OK, then we return False
3542 -- if the replication count is too high
3544 elsif Rep_Count > Max_Others_Replicate then
3545 return False;
3547 -- Continue on if duplication not OK, but the
3548 -- replication count is not excessive.
3550 else
3551 null;
3552 end if;
3553 end;
3554 end if;
3555 end loop;
3557 exit Component_Loop;
3559 -- Case of a subtype mark, identifier or expanded name
3561 elsif Is_Entity_Name (Choice)
3562 and then Is_Type (Entity (Choice))
3563 then
3564 Lo := Type_Low_Bound (Etype (Choice));
3565 Hi := Type_High_Bound (Etype (Choice));
3567 -- Case of subtype indication
3569 elsif Nkind (Choice) = N_Subtype_Indication then
3570 Lo := Low_Bound (Range_Expression (Constraint (Choice)));
3571 Hi := High_Bound (Range_Expression (Constraint (Choice)));
3573 -- Case of a range
3575 elsif Nkind (Choice) = N_Range then
3576 Lo := Low_Bound (Choice);
3577 Hi := High_Bound (Choice);
3579 -- Normal subexpression case
3581 else pragma Assert (Nkind (Choice) in N_Subexpr);
3582 if not Compile_Time_Known_Value (Choice) then
3583 return False;
3585 else
3586 Choice_Index := UI_To_Int (Expr_Value (Choice));
3587 if Choice_Index in Vals'Range then
3588 Vals (Choice_Index) :=
3589 New_Copy_Tree (Expression (Elmt));
3590 goto Continue;
3592 else
3593 -- Choice is statically out-of-range, will be
3594 -- rewritten to raise Constraint_Error.
3596 return False;
3597 end if;
3598 end if;
3599 end if;
3601 -- Range cases merge with Lo,Hi set
3603 if not Compile_Time_Known_Value (Lo)
3604 or else
3605 not Compile_Time_Known_Value (Hi)
3606 then
3607 return False;
3608 else
3609 for J in UI_To_Int (Expr_Value (Lo)) ..
3610 UI_To_Int (Expr_Value (Hi))
3611 loop
3612 Vals (J) := New_Copy_Tree (Expression (Elmt));
3613 end loop;
3614 end if;
3616 <<Continue>>
3617 Next (Choice);
3618 end loop Choice_Loop;
3620 Next (Elmt);
3621 end loop Component_Loop;
3623 -- If we get here the conversion is possible
3625 Vlist := New_List;
3626 for J in Vals'Range loop
3627 Append (Vals (J), Vlist);
3628 end loop;
3630 Rewrite (N, Make_Aggregate (Loc, Expressions => Vlist));
3631 Set_Aggregate_Bounds (N, Aggregate_Bounds (Original_Node (N)));
3632 return True;
3633 end;
3634 end Flatten;
3636 -------------
3637 -- Is_Flat --
3638 -------------
3640 function Is_Flat (N : Node_Id; Dims : Int) return Boolean is
3641 Elmt : Node_Id;
3643 begin
3644 if Dims = 0 then
3645 return True;
3647 elsif Nkind (N) = N_Aggregate then
3648 if Present (Component_Associations (N)) then
3649 return False;
3651 else
3652 Elmt := First (Expressions (N));
3653 while Present (Elmt) loop
3654 if not Is_Flat (Elmt, Dims - 1) then
3655 return False;
3656 end if;
3658 Next (Elmt);
3659 end loop;
3661 return True;
3662 end if;
3663 else
3664 return True;
3665 end if;
3666 end Is_Flat;
3668 -- Start of processing for Convert_To_Positional
3670 begin
3671 -- Ada 2005 (AI-287): Do not convert in case of default initialized
3672 -- components because in this case will need to call the corresponding
3673 -- IP procedure.
3675 if Has_Default_Init_Comps (N) then
3676 return;
3677 end if;
3679 if Is_Flat (N, Number_Dimensions (Typ)) then
3680 return;
3681 end if;
3683 if Is_Bit_Packed_Array (Typ)
3684 and then not Handle_Bit_Packed
3685 then
3686 return;
3687 end if;
3689 -- Do not convert to positional if controlled components are involved
3690 -- since these require special processing
3692 if Has_Controlled_Component (Typ) then
3693 return;
3694 end if;
3696 Check_Static_Components;
3698 -- If the size is known, or all the components are static, try to
3699 -- build a fully positional aggregate.
3701 -- The size of the type may not be known for an aggregate with
3702 -- discriminated array components, but if the components are static
3703 -- it is still possible to verify statically that the length is
3704 -- compatible with the upper bound of the type, and therefore it is
3705 -- worth flattening such aggregates as well.
3707 -- For now the back-end expands these aggregates into individual
3708 -- assignments to the target anyway, but it is conceivable that
3709 -- it will eventually be able to treat such aggregates statically???
3711 if Aggr_Size_OK (N, Typ)
3712 and then Flatten (N, First_Index (Typ), First_Index (Base_Type (Typ)))
3713 then
3714 if Static_Components then
3715 Set_Compile_Time_Known_Aggregate (N);
3716 Set_Expansion_Delayed (N, False);
3717 end if;
3719 Analyze_And_Resolve (N, Typ);
3720 end if;
3721 end Convert_To_Positional;
3723 ----------------------------
3724 -- Expand_Array_Aggregate --
3725 ----------------------------
3727 -- Array aggregate expansion proceeds as follows:
3729 -- 1. If requested we generate code to perform all the array aggregate
3730 -- bound checks, specifically
3732 -- (a) Check that the index range defined by aggregate bounds is
3733 -- compatible with corresponding index subtype.
3735 -- (b) If an others choice is present check that no aggregate
3736 -- index is outside the bounds of the index constraint.
3738 -- (c) For multidimensional arrays make sure that all subaggregates
3739 -- corresponding to the same dimension have the same bounds.
3741 -- 2. Check for packed array aggregate which can be converted to a
3742 -- constant so that the aggregate disappeares completely.
3744 -- 3. Check case of nested aggregate. Generally nested aggregates are
3745 -- handled during the processing of the parent aggregate.
3747 -- 4. Check if the aggregate can be statically processed. If this is the
3748 -- case pass it as is to Gigi. Note that a necessary condition for
3749 -- static processing is that the aggregate be fully positional.
3751 -- 5. If in place aggregate expansion is possible (i.e. no need to create
3752 -- a temporary) then mark the aggregate as such and return. Otherwise
3753 -- create a new temporary and generate the appropriate initialization
3754 -- code.
3756 procedure Expand_Array_Aggregate (N : Node_Id) is
3757 Loc : constant Source_Ptr := Sloc (N);
3759 Typ : constant Entity_Id := Etype (N);
3760 Ctyp : constant Entity_Id := Component_Type (Typ);
3761 -- Typ is the correct constrained array subtype of the aggregate
3762 -- Ctyp is the corresponding component type.
3764 Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
3765 -- Number of aggregate index dimensions
3767 Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id;
3768 Aggr_High : array (1 .. Aggr_Dimension) of Node_Id;
3769 -- Low and High bounds of the constraint for each aggregate index
3771 Aggr_Index_Typ : array (1 .. Aggr_Dimension) of Entity_Id;
3772 -- The type of each index
3774 Maybe_In_Place_OK : Boolean;
3775 -- If the type is neither controlled nor packed and the aggregate
3776 -- is the expression in an assignment, assignment in place may be
3777 -- possible, provided other conditions are met on the LHS.
3779 Others_Present : array (1 .. Aggr_Dimension) of Boolean :=
3780 (others => False);
3781 -- If Others_Present (J) is True, then there is an others choice
3782 -- in one of the sub-aggregates of N at dimension J.
3784 procedure Build_Constrained_Type (Positional : Boolean);
3785 -- If the subtype is not static or unconstrained, build a constrained
3786 -- type using the computable sizes of the aggregate and its sub-
3787 -- aggregates.
3789 procedure Check_Bounds (Aggr_Bounds : Node_Id; Index_Bounds : Node_Id);
3790 -- Checks that the bounds of Aggr_Bounds are within the bounds defined
3791 -- by Index_Bounds.
3793 procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos);
3794 -- Checks that in a multi-dimensional array aggregate all subaggregates
3795 -- corresponding to the same dimension have the same bounds.
3796 -- Sub_Aggr is an array sub-aggregate. Dim is the dimension
3797 -- corresponding to the sub-aggregate.
3799 procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos);
3800 -- Computes the values of array Others_Present. Sub_Aggr is the
3801 -- array sub-aggregate we start the computation from. Dim is the
3802 -- dimension corresponding to the sub-aggregate.
3804 function In_Place_Assign_OK return Boolean;
3805 -- Simple predicate to determine whether an aggregate assignment can
3806 -- be done in place, because none of the new values can depend on the
3807 -- components of the target of the assignment.
3809 procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos);
3810 -- Checks that if an others choice is present in any sub-aggregate no
3811 -- aggregate index is outside the bounds of the index constraint.
3812 -- Sub_Aggr is an array sub-aggregate. Dim is the dimension
3813 -- corresponding to the sub-aggregate.
3815 function Safe_Left_Hand_Side (N : Node_Id) return Boolean;
3816 -- In addition to Maybe_In_Place_OK, in order for an aggregate to be
3817 -- built directly into the target of the assignment it must be free
3818 -- of side-effects.
3820 ----------------------------
3821 -- Build_Constrained_Type --
3822 ----------------------------
3824 procedure Build_Constrained_Type (Positional : Boolean) is
3825 Loc : constant Source_Ptr := Sloc (N);
3826 Agg_Type : constant Entity_Id := Make_Temporary (Loc, 'A');
3827 Comp : Node_Id;
3828 Decl : Node_Id;
3829 Typ : constant Entity_Id := Etype (N);
3830 Indexes : constant List_Id := New_List;
3831 Num : Int;
3832 Sub_Agg : Node_Id;
3834 begin
3835 -- If the aggregate is purely positional, all its subaggregates
3836 -- have the same size. We collect the dimensions from the first
3837 -- subaggregate at each level.
3839 if Positional then
3840 Sub_Agg := N;
3842 for D in 1 .. Number_Dimensions (Typ) loop
3843 Sub_Agg := First (Expressions (Sub_Agg));
3845 Comp := Sub_Agg;
3846 Num := 0;
3847 while Present (Comp) loop
3848 Num := Num + 1;
3849 Next (Comp);
3850 end loop;
3852 Append_To (Indexes,
3853 Make_Range (Loc,
3854 Low_Bound => Make_Integer_Literal (Loc, 1),
3855 High_Bound => Make_Integer_Literal (Loc, Num)));
3856 end loop;
3858 else
3859 -- We know the aggregate type is unconstrained and the aggregate
3860 -- is not processable by the back end, therefore not necessarily
3861 -- positional. Retrieve each dimension bounds (computed earlier).
3863 for D in 1 .. Number_Dimensions (Typ) loop
3864 Append (
3865 Make_Range (Loc,
3866 Low_Bound => Aggr_Low (D),
3867 High_Bound => Aggr_High (D)),
3868 Indexes);
3869 end loop;
3870 end if;
3872 Decl :=
3873 Make_Full_Type_Declaration (Loc,
3874 Defining_Identifier => Agg_Type,
3875 Type_Definition =>
3876 Make_Constrained_Array_Definition (Loc,
3877 Discrete_Subtype_Definitions => Indexes,
3878 Component_Definition =>
3879 Make_Component_Definition (Loc,
3880 Aliased_Present => False,
3881 Subtype_Indication =>
3882 New_Occurrence_Of (Component_Type (Typ), Loc))));
3884 Insert_Action (N, Decl);
3885 Analyze (Decl);
3886 Set_Etype (N, Agg_Type);
3887 Set_Is_Itype (Agg_Type);
3888 Freeze_Itype (Agg_Type, N);
3889 end Build_Constrained_Type;
3891 ------------------
3892 -- Check_Bounds --
3893 ------------------
3895 procedure Check_Bounds (Aggr_Bounds : Node_Id; Index_Bounds : Node_Id) is
3896 Aggr_Lo : Node_Id;
3897 Aggr_Hi : Node_Id;
3899 Ind_Lo : Node_Id;
3900 Ind_Hi : Node_Id;
3902 Cond : Node_Id := Empty;
3904 begin
3905 Get_Index_Bounds (Aggr_Bounds, Aggr_Lo, Aggr_Hi);
3906 Get_Index_Bounds (Index_Bounds, Ind_Lo, Ind_Hi);
3908 -- Generate the following test:
3910 -- [constraint_error when
3911 -- Aggr_Lo <= Aggr_Hi and then
3912 -- (Aggr_Lo < Ind_Lo or else Aggr_Hi > Ind_Hi)]
3914 -- As an optimization try to see if some tests are trivially vacuous
3915 -- because we are comparing an expression against itself.
3917 if Aggr_Lo = Ind_Lo and then Aggr_Hi = Ind_Hi then
3918 Cond := Empty;
3920 elsif Aggr_Hi = Ind_Hi then
3921 Cond :=
3922 Make_Op_Lt (Loc,
3923 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
3924 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Lo));
3926 elsif Aggr_Lo = Ind_Lo then
3927 Cond :=
3928 Make_Op_Gt (Loc,
3929 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi),
3930 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Hi));
3932 else
3933 Cond :=
3934 Make_Or_Else (Loc,
3935 Left_Opnd =>
3936 Make_Op_Lt (Loc,
3937 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
3938 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Lo)),
3940 Right_Opnd =>
3941 Make_Op_Gt (Loc,
3942 Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
3943 Right_Opnd => Duplicate_Subexpr (Ind_Hi)));
3944 end if;
3946 if Present (Cond) then
3947 Cond :=
3948 Make_And_Then (Loc,
3949 Left_Opnd =>
3950 Make_Op_Le (Loc,
3951 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
3952 Right_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi)),
3954 Right_Opnd => Cond);
3956 Set_Analyzed (Left_Opnd (Left_Opnd (Cond)), False);
3957 Set_Analyzed (Right_Opnd (Left_Opnd (Cond)), False);
3958 Insert_Action (N,
3959 Make_Raise_Constraint_Error (Loc,
3960 Condition => Cond,
3961 Reason => CE_Length_Check_Failed));
3962 end if;
3963 end Check_Bounds;
3965 ----------------------------
3966 -- Check_Same_Aggr_Bounds --
3967 ----------------------------
3969 procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos) is
3970 Sub_Lo : constant Node_Id := Low_Bound (Aggregate_Bounds (Sub_Aggr));
3971 Sub_Hi : constant Node_Id := High_Bound (Aggregate_Bounds (Sub_Aggr));
3972 -- The bounds of this specific sub-aggregate
3974 Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
3975 Aggr_Hi : constant Node_Id := Aggr_High (Dim);
3976 -- The bounds of the aggregate for this dimension
3978 Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
3979 -- The index type for this dimension.xxx
3981 Cond : Node_Id := Empty;
3982 Assoc : Node_Id;
3983 Expr : Node_Id;
3985 begin
3986 -- If index checks are on generate the test
3988 -- [constraint_error when
3989 -- Aggr_Lo /= Sub_Lo or else Aggr_Hi /= Sub_Hi]
3991 -- As an optimization try to see if some tests are trivially vacuos
3992 -- because we are comparing an expression against itself. Also for
3993 -- the first dimension the test is trivially vacuous because there
3994 -- is just one aggregate for dimension 1.
3996 if Index_Checks_Suppressed (Ind_Typ) then
3997 Cond := Empty;
3999 elsif Dim = 1
4000 or else (Aggr_Lo = Sub_Lo and then Aggr_Hi = Sub_Hi)
4001 then
4002 Cond := Empty;
4004 elsif Aggr_Hi = Sub_Hi then
4005 Cond :=
4006 Make_Op_Ne (Loc,
4007 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4008 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo));
4010 elsif Aggr_Lo = Sub_Lo then
4011 Cond :=
4012 Make_Op_Ne (Loc,
4013 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi),
4014 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Hi));
4016 else
4017 Cond :=
4018 Make_Or_Else (Loc,
4019 Left_Opnd =>
4020 Make_Op_Ne (Loc,
4021 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4022 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo)),
4024 Right_Opnd =>
4025 Make_Op_Ne (Loc,
4026 Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
4027 Right_Opnd => Duplicate_Subexpr (Sub_Hi)));
4028 end if;
4030 if Present (Cond) then
4031 Insert_Action (N,
4032 Make_Raise_Constraint_Error (Loc,
4033 Condition => Cond,
4034 Reason => CE_Length_Check_Failed));
4035 end if;
4037 -- Now look inside the sub-aggregate to see if there is more work
4039 if Dim < Aggr_Dimension then
4041 -- Process positional components
4043 if Present (Expressions (Sub_Aggr)) then
4044 Expr := First (Expressions (Sub_Aggr));
4045 while Present (Expr) loop
4046 Check_Same_Aggr_Bounds (Expr, Dim + 1);
4047 Next (Expr);
4048 end loop;
4049 end if;
4051 -- Process component associations
4053 if Present (Component_Associations (Sub_Aggr)) then
4054 Assoc := First (Component_Associations (Sub_Aggr));
4055 while Present (Assoc) loop
4056 Expr := Expression (Assoc);
4057 Check_Same_Aggr_Bounds (Expr, Dim + 1);
4058 Next (Assoc);
4059 end loop;
4060 end if;
4061 end if;
4062 end Check_Same_Aggr_Bounds;
4064 ----------------------------
4065 -- Compute_Others_Present --
4066 ----------------------------
4068 procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos) is
4069 Assoc : Node_Id;
4070 Expr : Node_Id;
4072 begin
4073 if Present (Component_Associations (Sub_Aggr)) then
4074 Assoc := Last (Component_Associations (Sub_Aggr));
4076 if Nkind (First (Choices (Assoc))) = N_Others_Choice then
4077 Others_Present (Dim) := True;
4078 end if;
4079 end if;
4081 -- Now look inside the sub-aggregate to see if there is more work
4083 if Dim < Aggr_Dimension then
4085 -- Process positional components
4087 if Present (Expressions (Sub_Aggr)) then
4088 Expr := First (Expressions (Sub_Aggr));
4089 while Present (Expr) loop
4090 Compute_Others_Present (Expr, Dim + 1);
4091 Next (Expr);
4092 end loop;
4093 end if;
4095 -- Process component associations
4097 if Present (Component_Associations (Sub_Aggr)) then
4098 Assoc := First (Component_Associations (Sub_Aggr));
4099 while Present (Assoc) loop
4100 Expr := Expression (Assoc);
4101 Compute_Others_Present (Expr, Dim + 1);
4102 Next (Assoc);
4103 end loop;
4104 end if;
4105 end if;
4106 end Compute_Others_Present;
4108 ------------------------
4109 -- In_Place_Assign_OK --
4110 ------------------------
4112 function In_Place_Assign_OK return Boolean is
4113 Aggr_In : Node_Id;
4114 Aggr_Lo : Node_Id;
4115 Aggr_Hi : Node_Id;
4116 Obj_In : Node_Id;
4117 Obj_Lo : Node_Id;
4118 Obj_Hi : Node_Id;
4120 function Safe_Aggregate (Aggr : Node_Id) return Boolean;
4121 -- Check recursively that each component of a (sub)aggregate does
4122 -- not depend on the variable being assigned to.
4124 function Safe_Component (Expr : Node_Id) return Boolean;
4125 -- Verify that an expression cannot depend on the variable being
4126 -- assigned to. Room for improvement here (but less than before).
4128 --------------------
4129 -- Safe_Aggregate --
4130 --------------------
4132 function Safe_Aggregate (Aggr : Node_Id) return Boolean is
4133 Expr : Node_Id;
4135 begin
4136 if Present (Expressions (Aggr)) then
4137 Expr := First (Expressions (Aggr));
4138 while Present (Expr) loop
4139 if Nkind (Expr) = N_Aggregate then
4140 if not Safe_Aggregate (Expr) then
4141 return False;
4142 end if;
4144 elsif not Safe_Component (Expr) then
4145 return False;
4146 end if;
4148 Next (Expr);
4149 end loop;
4150 end if;
4152 if Present (Component_Associations (Aggr)) then
4153 Expr := First (Component_Associations (Aggr));
4154 while Present (Expr) loop
4155 if Nkind (Expression (Expr)) = N_Aggregate then
4156 if not Safe_Aggregate (Expression (Expr)) then
4157 return False;
4158 end if;
4160 -- If association has a box, no way to determine yet
4161 -- whether default can be assigned in place.
4163 elsif Box_Present (Expr) then
4164 return False;
4166 elsif not Safe_Component (Expression (Expr)) then
4167 return False;
4168 end if;
4170 Next (Expr);
4171 end loop;
4172 end if;
4174 return True;
4175 end Safe_Aggregate;
4177 --------------------
4178 -- Safe_Component --
4179 --------------------
4181 function Safe_Component (Expr : Node_Id) return Boolean is
4182 Comp : Node_Id := Expr;
4184 function Check_Component (Comp : Node_Id) return Boolean;
4185 -- Do the recursive traversal, after copy
4187 ---------------------
4188 -- Check_Component --
4189 ---------------------
4191 function Check_Component (Comp : Node_Id) return Boolean is
4192 begin
4193 if Is_Overloaded (Comp) then
4194 return False;
4195 end if;
4197 return Compile_Time_Known_Value (Comp)
4199 or else (Is_Entity_Name (Comp)
4200 and then Present (Entity (Comp))
4201 and then No (Renamed_Object (Entity (Comp))))
4203 or else (Nkind (Comp) = N_Attribute_Reference
4204 and then Check_Component (Prefix (Comp)))
4206 or else (Nkind (Comp) in N_Binary_Op
4207 and then Check_Component (Left_Opnd (Comp))
4208 and then Check_Component (Right_Opnd (Comp)))
4210 or else (Nkind (Comp) in N_Unary_Op
4211 and then Check_Component (Right_Opnd (Comp)))
4213 or else (Nkind (Comp) = N_Selected_Component
4214 and then Check_Component (Prefix (Comp)))
4216 or else (Nkind (Comp) = N_Unchecked_Type_Conversion
4217 and then Check_Component (Expression (Comp)));
4218 end Check_Component;
4220 -- Start of processing for Safe_Component
4222 begin
4223 -- If the component appears in an association that may
4224 -- correspond to more than one element, it is not analyzed
4225 -- before the expansion into assignments, to avoid side effects.
4226 -- We analyze, but do not resolve the copy, to obtain sufficient
4227 -- entity information for the checks that follow. If component is
4228 -- overloaded we assume an unsafe function call.
4230 if not Analyzed (Comp) then
4231 if Is_Overloaded (Expr) then
4232 return False;
4234 elsif Nkind (Expr) = N_Aggregate
4235 and then not Is_Others_Aggregate (Expr)
4236 then
4237 return False;
4239 elsif Nkind (Expr) = N_Allocator then
4241 -- For now, too complex to analyze
4243 return False;
4244 end if;
4246 Comp := New_Copy_Tree (Expr);
4247 Set_Parent (Comp, Parent (Expr));
4248 Analyze (Comp);
4249 end if;
4251 if Nkind (Comp) = N_Aggregate then
4252 return Safe_Aggregate (Comp);
4253 else
4254 return Check_Component (Comp);
4255 end if;
4256 end Safe_Component;
4258 -- Start of processing for In_Place_Assign_OK
4260 begin
4261 if Present (Component_Associations (N)) then
4263 -- On assignment, sliding can take place, so we cannot do the
4264 -- assignment in place unless the bounds of the aggregate are
4265 -- statically equal to those of the target.
4267 -- If the aggregate is given by an others choice, the bounds
4268 -- are derived from the left-hand side, and the assignment is
4269 -- safe if the expression is.
4271 if Is_Others_Aggregate (N) then
4272 return
4273 Safe_Component
4274 (Expression (First (Component_Associations (N))));
4275 end if;
4277 Aggr_In := First_Index (Etype (N));
4279 if Nkind (Parent (N)) = N_Assignment_Statement then
4280 Obj_In := First_Index (Etype (Name (Parent (N))));
4282 else
4283 -- Context is an allocator. Check bounds of aggregate
4284 -- against given type in qualified expression.
4286 pragma Assert (Nkind (Parent (Parent (N))) = N_Allocator);
4287 Obj_In :=
4288 First_Index (Etype (Entity (Subtype_Mark (Parent (N)))));
4289 end if;
4291 while Present (Aggr_In) loop
4292 Get_Index_Bounds (Aggr_In, Aggr_Lo, Aggr_Hi);
4293 Get_Index_Bounds (Obj_In, Obj_Lo, Obj_Hi);
4295 if not Compile_Time_Known_Value (Aggr_Lo)
4296 or else not Compile_Time_Known_Value (Aggr_Hi)
4297 or else not Compile_Time_Known_Value (Obj_Lo)
4298 or else not Compile_Time_Known_Value (Obj_Hi)
4299 or else Expr_Value (Aggr_Lo) /= Expr_Value (Obj_Lo)
4300 or else Expr_Value (Aggr_Hi) /= Expr_Value (Obj_Hi)
4301 then
4302 return False;
4303 end if;
4305 Next_Index (Aggr_In);
4306 Next_Index (Obj_In);
4307 end loop;
4308 end if;
4310 -- Now check the component values themselves
4312 return Safe_Aggregate (N);
4313 end In_Place_Assign_OK;
4315 ------------------
4316 -- Others_Check --
4317 ------------------
4319 procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos) is
4320 Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
4321 Aggr_Hi : constant Node_Id := Aggr_High (Dim);
4322 -- The bounds of the aggregate for this dimension
4324 Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
4325 -- The index type for this dimension
4327 Need_To_Check : Boolean := False;
4329 Choices_Lo : Node_Id := Empty;
4330 Choices_Hi : Node_Id := Empty;
4331 -- The lowest and highest discrete choices for a named sub-aggregate
4333 Nb_Choices : Int := -1;
4334 -- The number of discrete non-others choices in this sub-aggregate
4336 Nb_Elements : Uint := Uint_0;
4337 -- The number of elements in a positional aggregate
4339 Cond : Node_Id := Empty;
4341 Assoc : Node_Id;
4342 Choice : Node_Id;
4343 Expr : Node_Id;
4345 begin
4346 -- Check if we have an others choice. If we do make sure that this
4347 -- sub-aggregate contains at least one element in addition to the
4348 -- others choice.
4350 if Range_Checks_Suppressed (Ind_Typ) then
4351 Need_To_Check := False;
4353 elsif Present (Expressions (Sub_Aggr))
4354 and then Present (Component_Associations (Sub_Aggr))
4355 then
4356 Need_To_Check := True;
4358 elsif Present (Component_Associations (Sub_Aggr)) then
4359 Assoc := Last (Component_Associations (Sub_Aggr));
4361 if Nkind (First (Choices (Assoc))) /= N_Others_Choice then
4362 Need_To_Check := False;
4364 else
4365 -- Count the number of discrete choices. Start with -1 because
4366 -- the others choice does not count.
4368 Nb_Choices := -1;
4369 Assoc := First (Component_Associations (Sub_Aggr));
4370 while Present (Assoc) loop
4371 Choice := First (Choices (Assoc));
4372 while Present (Choice) loop
4373 Nb_Choices := Nb_Choices + 1;
4374 Next (Choice);
4375 end loop;
4377 Next (Assoc);
4378 end loop;
4380 -- If there is only an others choice nothing to do
4382 Need_To_Check := (Nb_Choices > 0);
4383 end if;
4385 else
4386 Need_To_Check := False;
4387 end if;
4389 -- If we are dealing with a positional sub-aggregate with an others
4390 -- choice then compute the number or positional elements.
4392 if Need_To_Check and then Present (Expressions (Sub_Aggr)) then
4393 Expr := First (Expressions (Sub_Aggr));
4394 Nb_Elements := Uint_0;
4395 while Present (Expr) loop
4396 Nb_Elements := Nb_Elements + 1;
4397 Next (Expr);
4398 end loop;
4400 -- If the aggregate contains discrete choices and an others choice
4401 -- compute the smallest and largest discrete choice values.
4403 elsif Need_To_Check then
4404 Compute_Choices_Lo_And_Choices_Hi : declare
4406 Table : Case_Table_Type (1 .. Nb_Choices);
4407 -- Used to sort all the different choice values
4409 J : Pos := 1;
4410 Low : Node_Id;
4411 High : Node_Id;
4413 begin
4414 Assoc := First (Component_Associations (Sub_Aggr));
4415 while Present (Assoc) loop
4416 Choice := First (Choices (Assoc));
4417 while Present (Choice) loop
4418 if Nkind (Choice) = N_Others_Choice then
4419 exit;
4420 end if;
4422 Get_Index_Bounds (Choice, Low, High);
4423 Table (J).Choice_Lo := Low;
4424 Table (J).Choice_Hi := High;
4426 J := J + 1;
4427 Next (Choice);
4428 end loop;
4430 Next (Assoc);
4431 end loop;
4433 -- Sort the discrete choices
4435 Sort_Case_Table (Table);
4437 Choices_Lo := Table (1).Choice_Lo;
4438 Choices_Hi := Table (Nb_Choices).Choice_Hi;
4439 end Compute_Choices_Lo_And_Choices_Hi;
4440 end if;
4442 -- If no others choice in this sub-aggregate, or the aggregate
4443 -- comprises only an others choice, nothing to do.
4445 if not Need_To_Check then
4446 Cond := Empty;
4448 -- If we are dealing with an aggregate containing an others choice
4449 -- and positional components, we generate the following test:
4451 -- if Ind_Typ'Pos (Aggr_Lo) + (Nb_Elements - 1) >
4452 -- Ind_Typ'Pos (Aggr_Hi)
4453 -- then
4454 -- raise Constraint_Error;
4455 -- end if;
4457 elsif Nb_Elements > Uint_0 then
4458 Cond :=
4459 Make_Op_Gt (Loc,
4460 Left_Opnd =>
4461 Make_Op_Add (Loc,
4462 Left_Opnd =>
4463 Make_Attribute_Reference (Loc,
4464 Prefix => New_Reference_To (Ind_Typ, Loc),
4465 Attribute_Name => Name_Pos,
4466 Expressions =>
4467 New_List
4468 (Duplicate_Subexpr_Move_Checks (Aggr_Lo))),
4469 Right_Opnd => Make_Integer_Literal (Loc, Nb_Elements - 1)),
4471 Right_Opnd =>
4472 Make_Attribute_Reference (Loc,
4473 Prefix => New_Reference_To (Ind_Typ, Loc),
4474 Attribute_Name => Name_Pos,
4475 Expressions => New_List (
4476 Duplicate_Subexpr_Move_Checks (Aggr_Hi))));
4478 -- If we are dealing with an aggregate containing an others choice
4479 -- and discrete choices we generate the following test:
4481 -- [constraint_error when
4482 -- Choices_Lo < Aggr_Lo or else Choices_Hi > Aggr_Hi];
4484 else
4485 Cond :=
4486 Make_Or_Else (Loc,
4487 Left_Opnd =>
4488 Make_Op_Lt (Loc,
4489 Left_Opnd =>
4490 Duplicate_Subexpr_Move_Checks (Choices_Lo),
4491 Right_Opnd =>
4492 Duplicate_Subexpr_Move_Checks (Aggr_Lo)),
4494 Right_Opnd =>
4495 Make_Op_Gt (Loc,
4496 Left_Opnd =>
4497 Duplicate_Subexpr (Choices_Hi),
4498 Right_Opnd =>
4499 Duplicate_Subexpr (Aggr_Hi)));
4500 end if;
4502 if Present (Cond) then
4503 Insert_Action (N,
4504 Make_Raise_Constraint_Error (Loc,
4505 Condition => Cond,
4506 Reason => CE_Length_Check_Failed));
4507 -- Questionable reason code, shouldn't that be a
4508 -- CE_Range_Check_Failed ???
4509 end if;
4511 -- Now look inside the sub-aggregate to see if there is more work
4513 if Dim < Aggr_Dimension then
4515 -- Process positional components
4517 if Present (Expressions (Sub_Aggr)) then
4518 Expr := First (Expressions (Sub_Aggr));
4519 while Present (Expr) loop
4520 Others_Check (Expr, Dim + 1);
4521 Next (Expr);
4522 end loop;
4523 end if;
4525 -- Process component associations
4527 if Present (Component_Associations (Sub_Aggr)) then
4528 Assoc := First (Component_Associations (Sub_Aggr));
4529 while Present (Assoc) loop
4530 Expr := Expression (Assoc);
4531 Others_Check (Expr, Dim + 1);
4532 Next (Assoc);
4533 end loop;
4534 end if;
4535 end if;
4536 end Others_Check;
4538 -------------------------
4539 -- Safe_Left_Hand_Side --
4540 -------------------------
4542 function Safe_Left_Hand_Side (N : Node_Id) return Boolean is
4543 function Is_Safe_Index (Indx : Node_Id) return Boolean;
4544 -- If the left-hand side includes an indexed component, check that
4545 -- the indexes are free of side-effect.
4547 -------------------
4548 -- Is_Safe_Index --
4549 -------------------
4551 function Is_Safe_Index (Indx : Node_Id) return Boolean is
4552 begin
4553 if Is_Entity_Name (Indx) then
4554 return True;
4556 elsif Nkind (Indx) = N_Integer_Literal then
4557 return True;
4559 elsif Nkind (Indx) = N_Function_Call
4560 and then Is_Entity_Name (Name (Indx))
4561 and then
4562 Has_Pragma_Pure_Function (Entity (Name (Indx)))
4563 then
4564 return True;
4566 elsif Nkind (Indx) = N_Type_Conversion
4567 and then Is_Safe_Index (Expression (Indx))
4568 then
4569 return True;
4571 else
4572 return False;
4573 end if;
4574 end Is_Safe_Index;
4576 -- Start of processing for Safe_Left_Hand_Side
4578 begin
4579 if Is_Entity_Name (N) then
4580 return True;
4582 elsif Nkind_In (N, N_Explicit_Dereference, N_Selected_Component)
4583 and then Safe_Left_Hand_Side (Prefix (N))
4584 then
4585 return True;
4587 elsif Nkind (N) = N_Indexed_Component
4588 and then Safe_Left_Hand_Side (Prefix (N))
4589 and then
4590 Is_Safe_Index (First (Expressions (N)))
4591 then
4592 return True;
4594 elsif Nkind (N) = N_Unchecked_Type_Conversion then
4595 return Safe_Left_Hand_Side (Expression (N));
4597 else
4598 return False;
4599 end if;
4600 end Safe_Left_Hand_Side;
4602 -- Local variables
4604 Tmp : Entity_Id;
4605 -- Holds the temporary aggregate value
4607 Tmp_Decl : Node_Id;
4608 -- Holds the declaration of Tmp
4610 Aggr_Code : List_Id;
4611 Parent_Node : Node_Id;
4612 Parent_Kind : Node_Kind;
4614 -- Start of processing for Expand_Array_Aggregate
4616 begin
4617 -- Do not touch the special aggregates of attributes used for Asm calls
4619 if Is_RTE (Ctyp, RE_Asm_Input_Operand)
4620 or else Is_RTE (Ctyp, RE_Asm_Output_Operand)
4621 then
4622 return;
4624 -- Do not expand an aggregate for an array type which contains tasks if
4625 -- the aggregate is associated with an unexpanded return statement of a
4626 -- build-in-place function. The aggregate is expanded when the related
4627 -- return statement (rewritten into an extended return) is processed.
4628 -- This delay ensures that any temporaries and initialization code
4629 -- generated for the aggregate appear in the proper return block and
4630 -- use the correct _chain and _master.
4632 elsif Has_Task (Base_Type (Etype (N)))
4633 and then Nkind (Parent (N)) = N_Simple_Return_Statement
4634 and then Is_Build_In_Place_Function
4635 (Return_Applies_To (Return_Statement_Entity (Parent (N))))
4636 then
4637 return;
4638 end if;
4640 -- If the semantic analyzer has determined that aggregate N will raise
4641 -- Constraint_Error at run time, then the aggregate node has been
4642 -- replaced with an N_Raise_Constraint_Error node and we should
4643 -- never get here.
4645 pragma Assert (not Raises_Constraint_Error (N));
4647 -- STEP 1a
4649 -- Check that the index range defined by aggregate bounds is
4650 -- compatible with corresponding index subtype.
4652 Index_Compatibility_Check : declare
4653 Aggr_Index_Range : Node_Id := First_Index (Typ);
4654 -- The current aggregate index range
4656 Index_Constraint : Node_Id := First_Index (Etype (Typ));
4657 -- The corresponding index constraint against which we have to
4658 -- check the above aggregate index range.
4660 begin
4661 Compute_Others_Present (N, 1);
4663 for J in 1 .. Aggr_Dimension loop
4664 -- There is no need to emit a check if an others choice is
4665 -- present for this array aggregate dimension since in this
4666 -- case one of N's sub-aggregates has taken its bounds from the
4667 -- context and these bounds must have been checked already. In
4668 -- addition all sub-aggregates corresponding to the same
4669 -- dimension must all have the same bounds (checked in (c) below).
4671 if not Range_Checks_Suppressed (Etype (Index_Constraint))
4672 and then not Others_Present (J)
4673 then
4674 -- We don't use Checks.Apply_Range_Check here because it emits
4675 -- a spurious check. Namely it checks that the range defined by
4676 -- the aggregate bounds is non empty. But we know this already
4677 -- if we get here.
4679 Check_Bounds (Aggr_Index_Range, Index_Constraint);
4680 end if;
4682 -- Save the low and high bounds of the aggregate index as well as
4683 -- the index type for later use in checks (b) and (c) below.
4685 Aggr_Low (J) := Low_Bound (Aggr_Index_Range);
4686 Aggr_High (J) := High_Bound (Aggr_Index_Range);
4688 Aggr_Index_Typ (J) := Etype (Index_Constraint);
4690 Next_Index (Aggr_Index_Range);
4691 Next_Index (Index_Constraint);
4692 end loop;
4693 end Index_Compatibility_Check;
4695 -- STEP 1b
4697 -- If an others choice is present check that no aggregate index is
4698 -- outside the bounds of the index constraint.
4700 Others_Check (N, 1);
4702 -- STEP 1c
4704 -- For multidimensional arrays make sure that all subaggregates
4705 -- corresponding to the same dimension have the same bounds.
4707 if Aggr_Dimension > 1 then
4708 Check_Same_Aggr_Bounds (N, 1);
4709 end if;
4711 -- STEP 2
4713 -- Here we test for is packed array aggregate that we can handle at
4714 -- compile time. If so, return with transformation done. Note that we do
4715 -- this even if the aggregate is nested, because once we have done this
4716 -- processing, there is no more nested aggregate!
4718 if Packed_Array_Aggregate_Handled (N) then
4719 return;
4720 end if;
4722 -- At this point we try to convert to positional form
4724 if Ekind (Current_Scope) = E_Package
4725 and then Static_Elaboration_Desired (Current_Scope)
4726 then
4727 Convert_To_Positional (N, Max_Others_Replicate => 100);
4728 else
4729 Convert_To_Positional (N);
4730 end if;
4732 -- if the result is no longer an aggregate (e.g. it may be a string
4733 -- literal, or a temporary which has the needed value), then we are
4734 -- done, since there is no longer a nested aggregate.
4736 if Nkind (N) /= N_Aggregate then
4737 return;
4739 -- We are also done if the result is an analyzed aggregate
4740 -- This case could use more comments ???
4742 elsif Analyzed (N)
4743 and then N /= Original_Node (N)
4744 then
4745 return;
4746 end if;
4748 -- If all aggregate components are compile-time known and the aggregate
4749 -- has been flattened, nothing left to do. The same occurs if the
4750 -- aggregate is used to initialize the components of an statically
4751 -- allocated dispatch table.
4753 if Compile_Time_Known_Aggregate (N)
4754 or else Is_Static_Dispatch_Table_Aggregate (N)
4755 then
4756 Set_Expansion_Delayed (N, False);
4757 return;
4758 end if;
4760 -- Now see if back end processing is possible
4762 if Backend_Processing_Possible (N) then
4764 -- If the aggregate is static but the constraints are not, build
4765 -- a static subtype for the aggregate, so that Gigi can place it
4766 -- in static memory. Perform an unchecked_conversion to the non-
4767 -- static type imposed by the context.
4769 declare
4770 Itype : constant Entity_Id := Etype (N);
4771 Index : Node_Id;
4772 Needs_Type : Boolean := False;
4774 begin
4775 Index := First_Index (Itype);
4776 while Present (Index) loop
4777 if not Is_Static_Subtype (Etype (Index)) then
4778 Needs_Type := True;
4779 exit;
4780 else
4781 Next_Index (Index);
4782 end if;
4783 end loop;
4785 if Needs_Type then
4786 Build_Constrained_Type (Positional => True);
4787 Rewrite (N, Unchecked_Convert_To (Itype, N));
4788 Analyze (N);
4789 end if;
4790 end;
4792 return;
4793 end if;
4795 -- STEP 3
4797 -- Delay expansion for nested aggregates: it will be taken care of
4798 -- when the parent aggregate is expanded.
4800 Parent_Node := Parent (N);
4801 Parent_Kind := Nkind (Parent_Node);
4803 if Parent_Kind = N_Qualified_Expression then
4804 Parent_Node := Parent (Parent_Node);
4805 Parent_Kind := Nkind (Parent_Node);
4806 end if;
4808 if Parent_Kind = N_Aggregate
4809 or else Parent_Kind = N_Extension_Aggregate
4810 or else Parent_Kind = N_Component_Association
4811 or else (Parent_Kind = N_Object_Declaration
4812 and then Needs_Finalization (Typ))
4813 or else (Parent_Kind = N_Assignment_Statement
4814 and then Inside_Init_Proc)
4815 then
4816 if Static_Array_Aggregate (N)
4817 or else Compile_Time_Known_Aggregate (N)
4818 then
4819 Set_Expansion_Delayed (N, False);
4820 return;
4821 else
4822 Set_Expansion_Delayed (N);
4823 return;
4824 end if;
4825 end if;
4827 -- STEP 4
4829 -- Look if in place aggregate expansion is possible
4831 -- For object declarations we build the aggregate in place, unless
4832 -- the array is bit-packed or the component is controlled.
4834 -- For assignments we do the assignment in place if all the component
4835 -- associations have compile-time known values. For other cases we
4836 -- create a temporary. The analysis for safety of on-line assignment
4837 -- is delicate, i.e. we don't know how to do it fully yet ???
4839 -- For allocators we assign to the designated object in place if the
4840 -- aggregate meets the same conditions as other in-place assignments.
4841 -- In this case the aggregate may not come from source but was created
4842 -- for default initialization, e.g. with Initialize_Scalars.
4844 if Requires_Transient_Scope (Typ) then
4845 Establish_Transient_Scope
4846 (N, Sec_Stack => Has_Controlled_Component (Typ));
4847 end if;
4849 if Has_Default_Init_Comps (N) then
4850 Maybe_In_Place_OK := False;
4852 elsif Is_Bit_Packed_Array (Typ)
4853 or else Has_Controlled_Component (Typ)
4854 then
4855 Maybe_In_Place_OK := False;
4857 else
4858 Maybe_In_Place_OK :=
4859 (Nkind (Parent (N)) = N_Assignment_Statement
4860 and then Comes_From_Source (N)
4861 and then In_Place_Assign_OK)
4863 or else
4864 (Nkind (Parent (Parent (N))) = N_Allocator
4865 and then In_Place_Assign_OK);
4866 end if;
4868 -- If this is an array of tasks, it will be expanded into build-in-place
4869 -- assignments. Build an activation chain for the tasks now.
4871 if Has_Task (Etype (N)) then
4872 Build_Activation_Chain_Entity (N);
4873 end if;
4875 -- Should document these individual tests ???
4877 if not Has_Default_Init_Comps (N)
4878 and then Comes_From_Source (Parent (N))
4879 and then Nkind (Parent (N)) = N_Object_Declaration
4880 and then not
4881 Must_Slide (Etype (Defining_Identifier (Parent (N))), Typ)
4882 and then N = Expression (Parent (N))
4883 and then not Is_Bit_Packed_Array (Typ)
4884 and then not Has_Controlled_Component (Typ)
4886 -- If the aggregate is the expression in an object declaration, it
4887 -- cannot be expanded in place. Lookahead in the current declarative
4888 -- part to find an address clause for the object being declared. If
4889 -- one is present, we cannot build in place. Unclear comment???
4891 and then not Has_Following_Address_Clause (Parent (N))
4892 then
4893 Tmp := Defining_Identifier (Parent (N));
4894 Set_No_Initialization (Parent (N));
4895 Set_Expression (Parent (N), Empty);
4897 -- Set the type of the entity, for use in the analysis of the
4898 -- subsequent indexed assignments. If the nominal type is not
4899 -- constrained, build a subtype from the known bounds of the
4900 -- aggregate. If the declaration has a subtype mark, use it,
4901 -- otherwise use the itype of the aggregate.
4903 if not Is_Constrained (Typ) then
4904 Build_Constrained_Type (Positional => False);
4905 elsif Is_Entity_Name (Object_Definition (Parent (N)))
4906 and then Is_Constrained (Entity (Object_Definition (Parent (N))))
4907 then
4908 Set_Etype (Tmp, Entity (Object_Definition (Parent (N))));
4909 else
4910 Set_Size_Known_At_Compile_Time (Typ, False);
4911 Set_Etype (Tmp, Typ);
4912 end if;
4914 elsif Maybe_In_Place_OK
4915 and then Nkind (Parent (N)) = N_Qualified_Expression
4916 and then Nkind (Parent (Parent (N))) = N_Allocator
4917 then
4918 Set_Expansion_Delayed (N);
4919 return;
4921 -- In the remaining cases the aggregate is the RHS of an assignment
4923 elsif Maybe_In_Place_OK
4924 and then Safe_Left_Hand_Side (Name (Parent (N)))
4925 then
4926 Tmp := Name (Parent (N));
4928 if Etype (Tmp) /= Etype (N) then
4929 Apply_Length_Check (N, Etype (Tmp));
4931 if Nkind (N) = N_Raise_Constraint_Error then
4933 -- Static error, nothing further to expand
4935 return;
4936 end if;
4937 end if;
4939 elsif Maybe_In_Place_OK
4940 and then Nkind (Name (Parent (N))) = N_Slice
4941 and then Safe_Slice_Assignment (N)
4942 then
4943 -- Safe_Slice_Assignment rewrites assignment as a loop
4945 return;
4947 -- Step 5
4949 -- In place aggregate expansion is not possible
4951 else
4952 Maybe_In_Place_OK := False;
4953 Tmp := Make_Temporary (Loc, 'A', N);
4954 Tmp_Decl :=
4955 Make_Object_Declaration
4956 (Loc,
4957 Defining_Identifier => Tmp,
4958 Object_Definition => New_Occurrence_Of (Typ, Loc));
4959 Set_No_Initialization (Tmp_Decl, True);
4961 -- If we are within a loop, the temporary will be pushed on the
4962 -- stack at each iteration. If the aggregate is the expression for an
4963 -- allocator, it will be immediately copied to the heap and can
4964 -- be reclaimed at once. We create a transient scope around the
4965 -- aggregate for this purpose.
4967 if Ekind (Current_Scope) = E_Loop
4968 and then Nkind (Parent (Parent (N))) = N_Allocator
4969 then
4970 Establish_Transient_Scope (N, False);
4971 end if;
4973 Insert_Action (N, Tmp_Decl);
4974 end if;
4976 -- Construct and insert the aggregate code. We can safely suppress index
4977 -- checks because this code is guaranteed not to raise CE on index
4978 -- checks. However we should *not* suppress all checks.
4980 declare
4981 Target : Node_Id;
4983 begin
4984 if Nkind (Tmp) = N_Defining_Identifier then
4985 Target := New_Reference_To (Tmp, Loc);
4987 else
4989 if Has_Default_Init_Comps (N) then
4991 -- Ada 2005 (AI-287): This case has not been analyzed???
4993 raise Program_Error;
4994 end if;
4996 -- Name in assignment is explicit dereference
4998 Target := New_Copy (Tmp);
4999 end if;
5001 Aggr_Code :=
5002 Build_Array_Aggr_Code (N,
5003 Ctype => Ctyp,
5004 Index => First_Index (Typ),
5005 Into => Target,
5006 Scalar_Comp => Is_Scalar_Type (Ctyp));
5007 end;
5009 if Comes_From_Source (Tmp) then
5010 Insert_Actions_After (Parent (N), Aggr_Code);
5012 else
5013 Insert_Actions (N, Aggr_Code);
5014 end if;
5016 -- If the aggregate has been assigned in place, remove the original
5017 -- assignment.
5019 if Nkind (Parent (N)) = N_Assignment_Statement
5020 and then Maybe_In_Place_OK
5021 then
5022 Rewrite (Parent (N), Make_Null_Statement (Loc));
5024 elsif Nkind (Parent (N)) /= N_Object_Declaration
5025 or else Tmp /= Defining_Identifier (Parent (N))
5026 then
5027 Rewrite (N, New_Occurrence_Of (Tmp, Loc));
5028 Analyze_And_Resolve (N, Typ);
5029 end if;
5030 end Expand_Array_Aggregate;
5032 ------------------------
5033 -- Expand_N_Aggregate --
5034 ------------------------
5036 procedure Expand_N_Aggregate (N : Node_Id) is
5037 begin
5038 if Is_Record_Type (Etype (N)) then
5039 Expand_Record_Aggregate (N);
5040 else
5041 Expand_Array_Aggregate (N);
5042 end if;
5043 exception
5044 when RE_Not_Available =>
5045 return;
5046 end Expand_N_Aggregate;
5048 ----------------------------------
5049 -- Expand_N_Extension_Aggregate --
5050 ----------------------------------
5052 -- If the ancestor part is an expression, add a component association for
5053 -- the parent field. If the type of the ancestor part is not the direct
5054 -- parent of the expected type, build recursively the needed ancestors.
5055 -- If the ancestor part is a subtype_mark, replace aggregate with a decla-
5056 -- ration for a temporary of the expected type, followed by individual
5057 -- assignments to the given components.
5059 procedure Expand_N_Extension_Aggregate (N : Node_Id) is
5060 Loc : constant Source_Ptr := Sloc (N);
5061 A : constant Node_Id := Ancestor_Part (N);
5062 Typ : constant Entity_Id := Etype (N);
5064 begin
5065 -- If the ancestor is a subtype mark, an init proc must be called
5066 -- on the resulting object which thus has to be materialized in
5067 -- the front-end
5069 if Is_Entity_Name (A) and then Is_Type (Entity (A)) then
5070 Convert_To_Assignments (N, Typ);
5072 -- The extension aggregate is transformed into a record aggregate
5073 -- of the following form (c1 and c2 are inherited components)
5075 -- (Exp with c3 => a, c4 => b)
5076 -- ==> (c1 => Exp.c1, c2 => Exp.c2, c3 => a, c4 => b)
5078 else
5079 Set_Etype (N, Typ);
5081 if Tagged_Type_Expansion then
5082 Expand_Record_Aggregate (N,
5083 Orig_Tag =>
5084 New_Occurrence_Of
5085 (Node (First_Elmt (Access_Disp_Table (Typ))), Loc),
5086 Parent_Expr => A);
5088 -- No tag is needed in the case of a VM
5090 else
5091 Expand_Record_Aggregate (N, Parent_Expr => A);
5092 end if;
5093 end if;
5095 exception
5096 when RE_Not_Available =>
5097 return;
5098 end Expand_N_Extension_Aggregate;
5100 -----------------------------
5101 -- Expand_Record_Aggregate --
5102 -----------------------------
5104 procedure Expand_Record_Aggregate
5105 (N : Node_Id;
5106 Orig_Tag : Node_Id := Empty;
5107 Parent_Expr : Node_Id := Empty)
5109 Loc : constant Source_Ptr := Sloc (N);
5110 Comps : constant List_Id := Component_Associations (N);
5111 Typ : constant Entity_Id := Etype (N);
5112 Base_Typ : constant Entity_Id := Base_Type (Typ);
5114 Static_Components : Boolean := True;
5115 -- Flag to indicate whether all components are compile-time known,
5116 -- and the aggregate can be constructed statically and handled by
5117 -- the back-end.
5119 function Component_Not_OK_For_Backend return Boolean;
5120 -- Check for presence of component which makes it impossible for the
5121 -- backend to process the aggregate, thus requiring the use of a series
5122 -- of assignment statements. Cases checked for are a nested aggregate
5123 -- needing Late_Expansion, the presence of a tagged component which may
5124 -- need tag adjustment, and a bit unaligned component reference.
5126 -- We also force expansion into assignments if a component is of a
5127 -- mutable type (including a private type with discriminants) because
5128 -- in that case the size of the component to be copied may be smaller
5129 -- than the side of the target, and there is no simple way for gigi
5130 -- to compute the size of the object to be copied.
5132 -- NOTE: This is part of the ongoing work to define precisely the
5133 -- interface between front-end and back-end handling of aggregates.
5134 -- In general it is desirable to pass aggregates as they are to gigi,
5135 -- in order to minimize elaboration code. This is one case where the
5136 -- semantics of Ada complicate the analysis and lead to anomalies in
5137 -- the gcc back-end if the aggregate is not expanded into assignments.
5139 function Has_Visible_Private_Ancestor (Id : E) return Boolean;
5140 -- If any ancestor of the current type is private, the aggregate
5141 -- cannot be built in place. We canot rely on Has_Private_Ancestor,
5142 -- because it will not be set when type and its parent are in the
5143 -- same scope, and the parent component needs expansion.
5145 function Top_Level_Aggregate (N : Node_Id) return Node_Id;
5146 -- For nested aggregates return the ultimate enclosing aggregate; for
5147 -- non-nested aggregates return N.
5149 ----------------------------------
5150 -- Component_Not_OK_For_Backend --
5151 ----------------------------------
5153 function Component_Not_OK_For_Backend return Boolean is
5154 C : Node_Id;
5155 Expr_Q : Node_Id;
5157 begin
5158 if No (Comps) then
5159 return False;
5160 end if;
5162 C := First (Comps);
5163 while Present (C) loop
5165 -- If the component has box initialization, expansion is needed
5166 -- and component is not ready for backend.
5168 if Box_Present (C) then
5169 return True;
5170 end if;
5172 if Nkind (Expression (C)) = N_Qualified_Expression then
5173 Expr_Q := Expression (Expression (C));
5174 else
5175 Expr_Q := Expression (C);
5176 end if;
5178 -- Return true if the aggregate has any associations for tagged
5179 -- components that may require tag adjustment.
5181 -- These are cases where the source expression may have a tag that
5182 -- could differ from the component tag (e.g., can occur for type
5183 -- conversions and formal parameters). (Tag adjustment not needed
5184 -- if VM_Target because object tags are implicit in the machine.)
5186 if Is_Tagged_Type (Etype (Expr_Q))
5187 and then (Nkind (Expr_Q) = N_Type_Conversion
5188 or else (Is_Entity_Name (Expr_Q)
5189 and then
5190 Ekind (Entity (Expr_Q)) in Formal_Kind))
5191 and then Tagged_Type_Expansion
5192 then
5193 Static_Components := False;
5194 return True;
5196 elsif Is_Delayed_Aggregate (Expr_Q) then
5197 Static_Components := False;
5198 return True;
5200 elsif Possible_Bit_Aligned_Component (Expr_Q) then
5201 Static_Components := False;
5202 return True;
5203 end if;
5205 if Is_Scalar_Type (Etype (Expr_Q)) then
5206 if not Compile_Time_Known_Value (Expr_Q) then
5207 Static_Components := False;
5208 end if;
5210 elsif Nkind (Expr_Q) /= N_Aggregate
5211 or else not Compile_Time_Known_Aggregate (Expr_Q)
5212 then
5213 Static_Components := False;
5215 if Is_Private_Type (Etype (Expr_Q))
5216 and then Has_Discriminants (Etype (Expr_Q))
5217 then
5218 return True;
5219 end if;
5220 end if;
5222 Next (C);
5223 end loop;
5225 return False;
5226 end Component_Not_OK_For_Backend;
5228 -----------------------------------
5229 -- Has_Visible_Private_Ancestor --
5230 -----------------------------------
5232 function Has_Visible_Private_Ancestor (Id : E) return Boolean is
5233 R : constant Entity_Id := Root_Type (Id);
5234 T1 : Entity_Id := Id;
5236 begin
5237 loop
5238 if Is_Private_Type (T1) then
5239 return True;
5241 elsif T1 = R then
5242 return False;
5244 else
5245 T1 := Etype (T1);
5246 end if;
5247 end loop;
5248 end Has_Visible_Private_Ancestor;
5250 -------------------------
5251 -- Top_Level_Aggregate --
5252 -------------------------
5254 function Top_Level_Aggregate (N : Node_Id) return Node_Id is
5255 Aggr : Node_Id;
5257 begin
5258 Aggr := N;
5259 while Present (Parent (Aggr))
5260 and then Nkind_In (Parent (Aggr), N_Component_Association,
5261 N_Aggregate)
5262 loop
5263 Aggr := Parent (Aggr);
5264 end loop;
5266 return Aggr;
5267 end Top_Level_Aggregate;
5269 -- Local variables
5271 Top_Level_Aggr : constant Node_Id := Top_Level_Aggregate (N);
5272 Tag_Value : Node_Id;
5273 Comp : Entity_Id;
5274 New_Comp : Node_Id;
5276 -- Start of processing for Expand_Record_Aggregate
5278 begin
5279 -- If the aggregate is to be assigned to an atomic variable, we
5280 -- have to prevent a piecemeal assignment even if the aggregate
5281 -- is to be expanded. We create a temporary for the aggregate, and
5282 -- assign the temporary instead, so that the back end can generate
5283 -- an atomic move for it.
5285 if Is_Atomic (Typ)
5286 and then Comes_From_Source (Parent (N))
5287 and then Is_Atomic_Aggregate (N, Typ)
5288 then
5289 return;
5291 -- No special management required for aggregates used to initialize
5292 -- statically allocated dispatch tables
5294 elsif Is_Static_Dispatch_Table_Aggregate (N) then
5295 return;
5296 end if;
5298 -- Ada 2005 (AI-318-2): We need to convert to assignments if components
5299 -- are build-in-place function calls. The assignments will each turn
5300 -- into a build-in-place function call. If components are all static,
5301 -- we can pass the aggregate to the backend regardless of limitedness.
5303 -- Extension aggregates, aggregates in extended return statements, and
5304 -- aggregates for C++ imported types must be expanded.
5306 if Ada_Version >= Ada_2005 and then Is_Immutably_Limited_Type (Typ) then
5307 if not Nkind_In (Parent (N), N_Object_Declaration,
5308 N_Component_Association)
5309 then
5310 Convert_To_Assignments (N, Typ);
5312 elsif Nkind (N) = N_Extension_Aggregate
5313 or else Convention (Typ) = Convention_CPP
5314 then
5315 Convert_To_Assignments (N, Typ);
5317 elsif not Size_Known_At_Compile_Time (Typ)
5318 or else Component_Not_OK_For_Backend
5319 or else not Static_Components
5320 then
5321 Convert_To_Assignments (N, Typ);
5323 else
5324 Set_Compile_Time_Known_Aggregate (N);
5325 Set_Expansion_Delayed (N, False);
5326 end if;
5328 -- Gigi doesn't properly handle temporaries of variable size so we
5329 -- generate it in the front-end
5331 elsif not Size_Known_At_Compile_Time (Typ)
5332 and then Tagged_Type_Expansion
5333 then
5334 Convert_To_Assignments (N, Typ);
5336 -- Temporaries for controlled aggregates need to be attached to a final
5337 -- chain in order to be properly finalized, so it has to be created in
5338 -- the front-end
5340 elsif Is_Controlled (Typ)
5341 or else Has_Controlled_Component (Base_Type (Typ))
5342 then
5343 Convert_To_Assignments (N, Typ);
5345 -- Ada 2005 (AI-287): In case of default initialized components we
5346 -- convert the aggregate into assignments.
5348 elsif Has_Default_Init_Comps (N) then
5349 Convert_To_Assignments (N, Typ);
5351 -- Check components
5353 elsif Component_Not_OK_For_Backend then
5354 Convert_To_Assignments (N, Typ);
5356 -- If an ancestor is private, some components are not inherited and
5357 -- we cannot expand into a record aggregate
5359 elsif Has_Visible_Private_Ancestor (Typ) then
5360 Convert_To_Assignments (N, Typ);
5362 -- ??? The following was done to compile fxacc00.ads in the ACVCs. Gigi
5363 -- is not able to handle the aggregate for Late_Request.
5365 elsif Is_Tagged_Type (Typ) and then Has_Discriminants (Typ) then
5366 Convert_To_Assignments (N, Typ);
5368 -- If the tagged types covers interface types we need to initialize all
5369 -- hidden components containing pointers to secondary dispatch tables.
5371 elsif Is_Tagged_Type (Typ) and then Has_Interfaces (Typ) then
5372 Convert_To_Assignments (N, Typ);
5374 -- If some components are mutable, the size of the aggregate component
5375 -- may be distinct from the default size of the type component, so
5376 -- we need to expand to insure that the back-end copies the proper
5377 -- size of the data. However, if the aggregate is the initial value of
5378 -- a constant, the target is immutable and may be built statically.
5380 elsif Has_Mutable_Components (Typ)
5381 and then
5382 (Nkind (Parent (Top_Level_Aggr)) /= N_Object_Declaration
5383 or else not Constant_Present (Parent (Top_Level_Aggr)))
5384 then
5385 Convert_To_Assignments (N, Typ);
5387 -- If the type involved has any non-bit aligned components, then we are
5388 -- not sure that the back end can handle this case correctly.
5390 elsif Type_May_Have_Bit_Aligned_Components (Typ) then
5391 Convert_To_Assignments (N, Typ);
5393 -- In all other cases, build a proper aggregate handlable by gigi
5395 else
5396 if Nkind (N) = N_Aggregate then
5398 -- If the aggregate is static and can be handled by the back-end,
5399 -- nothing left to do.
5401 if Static_Components then
5402 Set_Compile_Time_Known_Aggregate (N);
5403 Set_Expansion_Delayed (N, False);
5404 end if;
5405 end if;
5407 -- If no discriminants, nothing special to do
5409 if not Has_Discriminants (Typ) then
5410 null;
5412 -- Case of discriminants present
5414 elsif Is_Derived_Type (Typ) then
5416 -- For untagged types, non-stored discriminants are replaced
5417 -- with stored discriminants, which are the ones that gigi uses
5418 -- to describe the type and its components.
5420 Generate_Aggregate_For_Derived_Type : declare
5421 Constraints : constant List_Id := New_List;
5422 First_Comp : Node_Id;
5423 Discriminant : Entity_Id;
5424 Decl : Node_Id;
5425 Num_Disc : Int := 0;
5426 Num_Gird : Int := 0;
5428 procedure Prepend_Stored_Values (T : Entity_Id);
5429 -- Scan the list of stored discriminants of the type, and add
5430 -- their values to the aggregate being built.
5432 ---------------------------
5433 -- Prepend_Stored_Values --
5434 ---------------------------
5436 procedure Prepend_Stored_Values (T : Entity_Id) is
5437 begin
5438 Discriminant := First_Stored_Discriminant (T);
5439 while Present (Discriminant) loop
5440 New_Comp :=
5441 Make_Component_Association (Loc,
5442 Choices =>
5443 New_List (New_Occurrence_Of (Discriminant, Loc)),
5445 Expression =>
5446 New_Copy_Tree (
5447 Get_Discriminant_Value (
5448 Discriminant,
5449 Typ,
5450 Discriminant_Constraint (Typ))));
5452 if No (First_Comp) then
5453 Prepend_To (Component_Associations (N), New_Comp);
5454 else
5455 Insert_After (First_Comp, New_Comp);
5456 end if;
5458 First_Comp := New_Comp;
5459 Next_Stored_Discriminant (Discriminant);
5460 end loop;
5461 end Prepend_Stored_Values;
5463 -- Start of processing for Generate_Aggregate_For_Derived_Type
5465 begin
5466 -- Remove the associations for the discriminant of derived type
5468 First_Comp := First (Component_Associations (N));
5469 while Present (First_Comp) loop
5470 Comp := First_Comp;
5471 Next (First_Comp);
5473 if Ekind (Entity
5474 (First (Choices (Comp)))) = E_Discriminant
5475 then
5476 Remove (Comp);
5477 Num_Disc := Num_Disc + 1;
5478 end if;
5479 end loop;
5481 -- Insert stored discriminant associations in the correct
5482 -- order. If there are more stored discriminants than new
5483 -- discriminants, there is at least one new discriminant that
5484 -- constrains more than one of the stored discriminants. In
5485 -- this case we need to construct a proper subtype of the
5486 -- parent type, in order to supply values to all the
5487 -- components. Otherwise there is one-one correspondence
5488 -- between the constraints and the stored discriminants.
5490 First_Comp := Empty;
5492 Discriminant := First_Stored_Discriminant (Base_Type (Typ));
5493 while Present (Discriminant) loop
5494 Num_Gird := Num_Gird + 1;
5495 Next_Stored_Discriminant (Discriminant);
5496 end loop;
5498 -- Case of more stored discriminants than new discriminants
5500 if Num_Gird > Num_Disc then
5502 -- Create a proper subtype of the parent type, which is the
5503 -- proper implementation type for the aggregate, and convert
5504 -- it to the intended target type.
5506 Discriminant := First_Stored_Discriminant (Base_Type (Typ));
5507 while Present (Discriminant) loop
5508 New_Comp :=
5509 New_Copy_Tree (
5510 Get_Discriminant_Value (
5511 Discriminant,
5512 Typ,
5513 Discriminant_Constraint (Typ)));
5514 Append (New_Comp, Constraints);
5515 Next_Stored_Discriminant (Discriminant);
5516 end loop;
5518 Decl :=
5519 Make_Subtype_Declaration (Loc,
5520 Defining_Identifier => Make_Temporary (Loc, 'T'),
5521 Subtype_Indication =>
5522 Make_Subtype_Indication (Loc,
5523 Subtype_Mark =>
5524 New_Occurrence_Of (Etype (Base_Type (Typ)), Loc),
5525 Constraint =>
5526 Make_Index_Or_Discriminant_Constraint
5527 (Loc, Constraints)));
5529 Insert_Action (N, Decl);
5530 Prepend_Stored_Values (Base_Type (Typ));
5532 Set_Etype (N, Defining_Identifier (Decl));
5533 Set_Analyzed (N);
5535 Rewrite (N, Unchecked_Convert_To (Typ, N));
5536 Analyze (N);
5538 -- Case where we do not have fewer new discriminants than
5539 -- stored discriminants, so in this case we can simply use the
5540 -- stored discriminants of the subtype.
5542 else
5543 Prepend_Stored_Values (Typ);
5544 end if;
5545 end Generate_Aggregate_For_Derived_Type;
5546 end if;
5548 if Is_Tagged_Type (Typ) then
5550 -- The tagged case, _parent and _tag component must be created
5552 -- Reset null_present unconditionally. tagged records always have
5553 -- at least one field (the tag or the parent)
5555 Set_Null_Record_Present (N, False);
5557 -- When the current aggregate comes from the expansion of an
5558 -- extension aggregate, the parent expr is replaced by an
5559 -- aggregate formed by selected components of this expr
5561 if Present (Parent_Expr)
5562 and then Is_Empty_List (Comps)
5563 then
5564 Comp := First_Component_Or_Discriminant (Typ);
5565 while Present (Comp) loop
5567 -- Skip all expander-generated components
5570 not Comes_From_Source (Original_Record_Component (Comp))
5571 then
5572 null;
5574 else
5575 New_Comp :=
5576 Make_Selected_Component (Loc,
5577 Prefix =>
5578 Unchecked_Convert_To (Typ,
5579 Duplicate_Subexpr (Parent_Expr, True)),
5581 Selector_Name => New_Occurrence_Of (Comp, Loc));
5583 Append_To (Comps,
5584 Make_Component_Association (Loc,
5585 Choices =>
5586 New_List (New_Occurrence_Of (Comp, Loc)),
5587 Expression =>
5588 New_Comp));
5590 Analyze_And_Resolve (New_Comp, Etype (Comp));
5591 end if;
5593 Next_Component_Or_Discriminant (Comp);
5594 end loop;
5595 end if;
5597 -- Compute the value for the Tag now, if the type is a root it
5598 -- will be included in the aggregate right away, otherwise it will
5599 -- be propagated to the parent aggregate
5601 if Present (Orig_Tag) then
5602 Tag_Value := Orig_Tag;
5603 elsif not Tagged_Type_Expansion then
5604 Tag_Value := Empty;
5605 else
5606 Tag_Value :=
5607 New_Occurrence_Of
5608 (Node (First_Elmt (Access_Disp_Table (Typ))), Loc);
5609 end if;
5611 -- For a derived type, an aggregate for the parent is formed with
5612 -- all the inherited components.
5614 if Is_Derived_Type (Typ) then
5616 declare
5617 First_Comp : Node_Id;
5618 Parent_Comps : List_Id;
5619 Parent_Aggr : Node_Id;
5620 Parent_Name : Node_Id;
5622 begin
5623 -- Remove the inherited component association from the
5624 -- aggregate and store them in the parent aggregate
5626 First_Comp := First (Component_Associations (N));
5627 Parent_Comps := New_List;
5628 while Present (First_Comp)
5629 and then Scope (Original_Record_Component (
5630 Entity (First (Choices (First_Comp))))) /= Base_Typ
5631 loop
5632 Comp := First_Comp;
5633 Next (First_Comp);
5634 Remove (Comp);
5635 Append (Comp, Parent_Comps);
5636 end loop;
5638 Parent_Aggr := Make_Aggregate (Loc,
5639 Component_Associations => Parent_Comps);
5640 Set_Etype (Parent_Aggr, Etype (Base_Type (Typ)));
5642 -- Find the _parent component
5644 Comp := First_Component (Typ);
5645 while Chars (Comp) /= Name_uParent loop
5646 Comp := Next_Component (Comp);
5647 end loop;
5649 Parent_Name := New_Occurrence_Of (Comp, Loc);
5651 -- Insert the parent aggregate
5653 Prepend_To (Component_Associations (N),
5654 Make_Component_Association (Loc,
5655 Choices => New_List (Parent_Name),
5656 Expression => Parent_Aggr));
5658 -- Expand recursively the parent propagating the right Tag
5660 Expand_Record_Aggregate (
5661 Parent_Aggr, Tag_Value, Parent_Expr);
5662 end;
5664 -- For a root type, the tag component is added (unless compiling
5665 -- for the VMs, where tags are implicit).
5667 elsif Tagged_Type_Expansion then
5668 declare
5669 Tag_Name : constant Node_Id :=
5670 New_Occurrence_Of
5671 (First_Tag_Component (Typ), Loc);
5672 Typ_Tag : constant Entity_Id := RTE (RE_Tag);
5673 Conv_Node : constant Node_Id :=
5674 Unchecked_Convert_To (Typ_Tag, Tag_Value);
5676 begin
5677 Set_Etype (Conv_Node, Typ_Tag);
5678 Prepend_To (Component_Associations (N),
5679 Make_Component_Association (Loc,
5680 Choices => New_List (Tag_Name),
5681 Expression => Conv_Node));
5682 end;
5683 end if;
5684 end if;
5685 end if;
5687 end Expand_Record_Aggregate;
5689 ----------------------------
5690 -- Has_Default_Init_Comps --
5691 ----------------------------
5693 function Has_Default_Init_Comps (N : Node_Id) return Boolean is
5694 Comps : constant List_Id := Component_Associations (N);
5695 C : Node_Id;
5696 Expr : Node_Id;
5697 begin
5698 pragma Assert (Nkind_In (N, N_Aggregate, N_Extension_Aggregate));
5700 if No (Comps) then
5701 return False;
5702 end if;
5704 if Has_Self_Reference (N) then
5705 return True;
5706 end if;
5708 -- Check if any direct component has default initialized components
5710 C := First (Comps);
5711 while Present (C) loop
5712 if Box_Present (C) then
5713 return True;
5714 end if;
5716 Next (C);
5717 end loop;
5719 -- Recursive call in case of aggregate expression
5721 C := First (Comps);
5722 while Present (C) loop
5723 Expr := Expression (C);
5725 if Present (Expr)
5726 and then
5727 Nkind_In (Expr, N_Aggregate, N_Extension_Aggregate)
5728 and then Has_Default_Init_Comps (Expr)
5729 then
5730 return True;
5731 end if;
5733 Next (C);
5734 end loop;
5736 return False;
5737 end Has_Default_Init_Comps;
5739 --------------------------
5740 -- Is_Delayed_Aggregate --
5741 --------------------------
5743 function Is_Delayed_Aggregate (N : Node_Id) return Boolean is
5744 Node : Node_Id := N;
5745 Kind : Node_Kind := Nkind (Node);
5747 begin
5748 if Kind = N_Qualified_Expression then
5749 Node := Expression (Node);
5750 Kind := Nkind (Node);
5751 end if;
5753 if Kind /= N_Aggregate and then Kind /= N_Extension_Aggregate then
5754 return False;
5755 else
5756 return Expansion_Delayed (Node);
5757 end if;
5758 end Is_Delayed_Aggregate;
5760 ----------------------------------------
5761 -- Is_Static_Dispatch_Table_Aggregate --
5762 ----------------------------------------
5764 function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean is
5765 Typ : constant Entity_Id := Base_Type (Etype (N));
5767 begin
5768 return Static_Dispatch_Tables
5769 and then Tagged_Type_Expansion
5770 and then RTU_Loaded (Ada_Tags)
5772 -- Avoid circularity when rebuilding the compiler
5774 and then Cunit_Entity (Get_Source_Unit (N)) /= RTU_Entity (Ada_Tags)
5775 and then (Typ = RTE (RE_Dispatch_Table_Wrapper)
5776 or else
5777 Typ = RTE (RE_Address_Array)
5778 or else
5779 Typ = RTE (RE_Type_Specific_Data)
5780 or else
5781 Typ = RTE (RE_Tag_Table)
5782 or else
5783 (RTE_Available (RE_Interface_Data)
5784 and then Typ = RTE (RE_Interface_Data))
5785 or else
5786 (RTE_Available (RE_Interfaces_Array)
5787 and then Typ = RTE (RE_Interfaces_Array))
5788 or else
5789 (RTE_Available (RE_Interface_Data_Element)
5790 and then Typ = RTE (RE_Interface_Data_Element)));
5791 end Is_Static_Dispatch_Table_Aggregate;
5793 --------------------
5794 -- Late_Expansion --
5795 --------------------
5797 function Late_Expansion
5798 (N : Node_Id;
5799 Typ : Entity_Id;
5800 Target : Node_Id) return List_Id
5802 begin
5803 if Is_Record_Type (Etype (N)) then
5804 return Build_Record_Aggr_Code (N, Typ, Target);
5806 else pragma Assert (Is_Array_Type (Etype (N)));
5807 return
5808 Build_Array_Aggr_Code
5809 (N => N,
5810 Ctype => Component_Type (Etype (N)),
5811 Index => First_Index (Typ),
5812 Into => Target,
5813 Scalar_Comp => Is_Scalar_Type (Component_Type (Typ)),
5814 Indexes => No_List);
5815 end if;
5816 end Late_Expansion;
5818 ----------------------------------
5819 -- Make_OK_Assignment_Statement --
5820 ----------------------------------
5822 function Make_OK_Assignment_Statement
5823 (Sloc : Source_Ptr;
5824 Name : Node_Id;
5825 Expression : Node_Id) return Node_Id
5827 begin
5828 Set_Assignment_OK (Name);
5830 return Make_Assignment_Statement (Sloc, Name, Expression);
5831 end Make_OK_Assignment_Statement;
5833 -----------------------
5834 -- Number_Of_Choices --
5835 -----------------------
5837 function Number_Of_Choices (N : Node_Id) return Nat is
5838 Assoc : Node_Id;
5839 Choice : Node_Id;
5841 Nb_Choices : Nat := 0;
5843 begin
5844 if Present (Expressions (N)) then
5845 return 0;
5846 end if;
5848 Assoc := First (Component_Associations (N));
5849 while Present (Assoc) loop
5850 Choice := First (Choices (Assoc));
5851 while Present (Choice) loop
5852 if Nkind (Choice) /= N_Others_Choice then
5853 Nb_Choices := Nb_Choices + 1;
5854 end if;
5856 Next (Choice);
5857 end loop;
5859 Next (Assoc);
5860 end loop;
5862 return Nb_Choices;
5863 end Number_Of_Choices;
5865 ------------------------------------
5866 -- Packed_Array_Aggregate_Handled --
5867 ------------------------------------
5869 -- The current version of this procedure will handle at compile time
5870 -- any array aggregate that meets these conditions:
5872 -- One dimensional, bit packed
5873 -- Underlying packed type is modular type
5874 -- Bounds are within 32-bit Int range
5875 -- All bounds and values are static
5877 function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean is
5878 Loc : constant Source_Ptr := Sloc (N);
5879 Typ : constant Entity_Id := Etype (N);
5880 Ctyp : constant Entity_Id := Component_Type (Typ);
5882 Not_Handled : exception;
5883 -- Exception raised if this aggregate cannot be handled
5885 begin
5886 -- For now, handle only one dimensional bit packed arrays
5888 if not Is_Bit_Packed_Array (Typ)
5889 or else Number_Dimensions (Typ) > 1
5890 or else not Is_Modular_Integer_Type (Packed_Array_Type (Typ))
5891 then
5892 return False;
5893 end if;
5895 if not Is_Scalar_Type (Component_Type (Typ))
5896 and then Has_Non_Standard_Rep (Component_Type (Typ))
5897 then
5898 return False;
5899 end if;
5901 declare
5902 Csiz : constant Nat := UI_To_Int (Component_Size (Typ));
5904 Lo : Node_Id;
5905 Hi : Node_Id;
5906 -- Bounds of index type
5908 Lob : Uint;
5909 Hib : Uint;
5910 -- Values of bounds if compile time known
5912 function Get_Component_Val (N : Node_Id) return Uint;
5913 -- Given a expression value N of the component type Ctyp, returns a
5914 -- value of Csiz (component size) bits representing this value. If
5915 -- the value is non-static or any other reason exists why the value
5916 -- cannot be returned, then Not_Handled is raised.
5918 -----------------------
5919 -- Get_Component_Val --
5920 -----------------------
5922 function Get_Component_Val (N : Node_Id) return Uint is
5923 Val : Uint;
5925 begin
5926 -- We have to analyze the expression here before doing any further
5927 -- processing here. The analysis of such expressions is deferred
5928 -- till expansion to prevent some problems of premature analysis.
5930 Analyze_And_Resolve (N, Ctyp);
5932 -- Must have a compile time value. String literals have to be
5933 -- converted into temporaries as well, because they cannot easily
5934 -- be converted into their bit representation.
5936 if not Compile_Time_Known_Value (N)
5937 or else Nkind (N) = N_String_Literal
5938 then
5939 raise Not_Handled;
5940 end if;
5942 Val := Expr_Rep_Value (N);
5944 -- Adjust for bias, and strip proper number of bits
5946 if Has_Biased_Representation (Ctyp) then
5947 Val := Val - Expr_Value (Type_Low_Bound (Ctyp));
5948 end if;
5950 return Val mod Uint_2 ** Csiz;
5951 end Get_Component_Val;
5953 -- Here we know we have a one dimensional bit packed array
5955 begin
5956 Get_Index_Bounds (First_Index (Typ), Lo, Hi);
5958 -- Cannot do anything if bounds are dynamic
5960 if not Compile_Time_Known_Value (Lo)
5961 or else
5962 not Compile_Time_Known_Value (Hi)
5963 then
5964 return False;
5965 end if;
5967 -- Or are silly out of range of int bounds
5969 Lob := Expr_Value (Lo);
5970 Hib := Expr_Value (Hi);
5972 if not UI_Is_In_Int_Range (Lob)
5973 or else
5974 not UI_Is_In_Int_Range (Hib)
5975 then
5976 return False;
5977 end if;
5979 -- At this stage we have a suitable aggregate for handling at compile
5980 -- time (the only remaining checks are that the values of expressions
5981 -- in the aggregate are compile time known (check is performed by
5982 -- Get_Component_Val), and that any subtypes or ranges are statically
5983 -- known.
5985 -- If the aggregate is not fully positional at this stage, then
5986 -- convert it to positional form. Either this will fail, in which
5987 -- case we can do nothing, or it will succeed, in which case we have
5988 -- succeeded in handling the aggregate, or it will stay an aggregate,
5989 -- in which case we have failed to handle this case.
5991 if Present (Component_Associations (N)) then
5992 Convert_To_Positional
5993 (N, Max_Others_Replicate => 64, Handle_Bit_Packed => True);
5994 return Nkind (N) /= N_Aggregate;
5995 end if;
5997 -- Otherwise we are all positional, so convert to proper value
5999 declare
6000 Lov : constant Int := UI_To_Int (Lob);
6001 Hiv : constant Int := UI_To_Int (Hib);
6003 Len : constant Nat := Int'Max (0, Hiv - Lov + 1);
6004 -- The length of the array (number of elements)
6006 Aggregate_Val : Uint;
6007 -- Value of aggregate. The value is set in the low order bits of
6008 -- this value. For the little-endian case, the values are stored
6009 -- from low-order to high-order and for the big-endian case the
6010 -- values are stored from high-order to low-order. Note that gigi
6011 -- will take care of the conversions to left justify the value in
6012 -- the big endian case (because of left justified modular type
6013 -- processing), so we do not have to worry about that here.
6015 Lit : Node_Id;
6016 -- Integer literal for resulting constructed value
6018 Shift : Nat;
6019 -- Shift count from low order for next value
6021 Incr : Int;
6022 -- Shift increment for loop
6024 Expr : Node_Id;
6025 -- Next expression from positional parameters of aggregate
6027 begin
6028 -- For little endian, we fill up the low order bits of the target
6029 -- value. For big endian we fill up the high order bits of the
6030 -- target value (which is a left justified modular value).
6032 if Bytes_Big_Endian xor Debug_Flag_8 then
6033 Shift := Csiz * (Len - 1);
6034 Incr := -Csiz;
6035 else
6036 Shift := 0;
6037 Incr := +Csiz;
6038 end if;
6040 -- Loop to set the values
6042 if Len = 0 then
6043 Aggregate_Val := Uint_0;
6044 else
6045 Expr := First (Expressions (N));
6046 Aggregate_Val := Get_Component_Val (Expr) * Uint_2 ** Shift;
6048 for J in 2 .. Len loop
6049 Shift := Shift + Incr;
6050 Next (Expr);
6051 Aggregate_Val :=
6052 Aggregate_Val + Get_Component_Val (Expr) * Uint_2 ** Shift;
6053 end loop;
6054 end if;
6056 -- Now we can rewrite with the proper value
6058 Lit :=
6059 Make_Integer_Literal (Loc,
6060 Intval => Aggregate_Val);
6061 Set_Print_In_Hex (Lit);
6063 -- Construct the expression using this literal. Note that it is
6064 -- important to qualify the literal with its proper modular type
6065 -- since universal integer does not have the required range and
6066 -- also this is a left justified modular type, which is important
6067 -- in the big-endian case.
6069 Rewrite (N,
6070 Unchecked_Convert_To (Typ,
6071 Make_Qualified_Expression (Loc,
6072 Subtype_Mark =>
6073 New_Occurrence_Of (Packed_Array_Type (Typ), Loc),
6074 Expression => Lit)));
6076 Analyze_And_Resolve (N, Typ);
6077 return True;
6078 end;
6079 end;
6081 exception
6082 when Not_Handled =>
6083 return False;
6084 end Packed_Array_Aggregate_Handled;
6086 ----------------------------
6087 -- Has_Mutable_Components --
6088 ----------------------------
6090 function Has_Mutable_Components (Typ : Entity_Id) return Boolean is
6091 Comp : Entity_Id;
6093 begin
6094 Comp := First_Component (Typ);
6095 while Present (Comp) loop
6096 if Is_Record_Type (Etype (Comp))
6097 and then Has_Discriminants (Etype (Comp))
6098 and then not Is_Constrained (Etype (Comp))
6099 then
6100 return True;
6101 end if;
6103 Next_Component (Comp);
6104 end loop;
6106 return False;
6107 end Has_Mutable_Components;
6109 ------------------------------
6110 -- Initialize_Discriminants --
6111 ------------------------------
6113 procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id) is
6114 Loc : constant Source_Ptr := Sloc (N);
6115 Bas : constant Entity_Id := Base_Type (Typ);
6116 Par : constant Entity_Id := Etype (Bas);
6117 Decl : constant Node_Id := Parent (Par);
6118 Ref : Node_Id;
6120 begin
6121 if Is_Tagged_Type (Bas)
6122 and then Is_Derived_Type (Bas)
6123 and then Has_Discriminants (Par)
6124 and then Has_Discriminants (Bas)
6125 and then Number_Discriminants (Bas) /= Number_Discriminants (Par)
6126 and then Nkind (Decl) = N_Full_Type_Declaration
6127 and then Nkind (Type_Definition (Decl)) = N_Record_Definition
6128 and then Present
6129 (Variant_Part (Component_List (Type_Definition (Decl))))
6130 and then Nkind (N) /= N_Extension_Aggregate
6131 then
6133 -- Call init proc to set discriminants.
6134 -- There should eventually be a special procedure for this ???
6136 Ref := New_Reference_To (Defining_Identifier (N), Loc);
6137 Insert_Actions_After (N,
6138 Build_Initialization_Call (Sloc (N), Ref, Typ));
6139 end if;
6140 end Initialize_Discriminants;
6142 ----------------
6143 -- Must_Slide --
6144 ----------------
6146 function Must_Slide
6147 (Obj_Type : Entity_Id;
6148 Typ : Entity_Id) return Boolean
6150 L1, L2, H1, H2 : Node_Id;
6151 begin
6152 -- No sliding if the type of the object is not established yet, if it is
6153 -- an unconstrained type whose actual subtype comes from the aggregate,
6154 -- or if the two types are identical.
6156 if not Is_Array_Type (Obj_Type) then
6157 return False;
6159 elsif not Is_Constrained (Obj_Type) then
6160 return False;
6162 elsif Typ = Obj_Type then
6163 return False;
6165 else
6166 -- Sliding can only occur along the first dimension
6168 Get_Index_Bounds (First_Index (Typ), L1, H1);
6169 Get_Index_Bounds (First_Index (Obj_Type), L2, H2);
6171 if not Is_Static_Expression (L1)
6172 or else not Is_Static_Expression (L2)
6173 or else not Is_Static_Expression (H1)
6174 or else not Is_Static_Expression (H2)
6175 then
6176 return False;
6177 else
6178 return Expr_Value (L1) /= Expr_Value (L2)
6179 or else Expr_Value (H1) /= Expr_Value (H2);
6180 end if;
6181 end if;
6182 end Must_Slide;
6184 ---------------------------
6185 -- Safe_Slice_Assignment --
6186 ---------------------------
6188 function Safe_Slice_Assignment (N : Node_Id) return Boolean is
6189 Loc : constant Source_Ptr := Sloc (Parent (N));
6190 Pref : constant Node_Id := Prefix (Name (Parent (N)));
6191 Range_Node : constant Node_Id := Discrete_Range (Name (Parent (N)));
6192 Expr : Node_Id;
6193 L_J : Entity_Id;
6194 L_Iter : Node_Id;
6195 L_Body : Node_Id;
6196 Stat : Node_Id;
6198 begin
6199 -- Generate: for J in Range loop Pref (J) := Expr; end loop;
6201 if Comes_From_Source (N)
6202 and then No (Expressions (N))
6203 and then Nkind (First (Choices (First (Component_Associations (N)))))
6204 = N_Others_Choice
6205 then
6206 Expr := Expression (First (Component_Associations (N)));
6207 L_J := Make_Temporary (Loc, 'J');
6209 L_Iter :=
6210 Make_Iteration_Scheme (Loc,
6211 Loop_Parameter_Specification =>
6212 Make_Loop_Parameter_Specification
6213 (Loc,
6214 Defining_Identifier => L_J,
6215 Discrete_Subtype_Definition => Relocate_Node (Range_Node)));
6217 L_Body :=
6218 Make_Assignment_Statement (Loc,
6219 Name =>
6220 Make_Indexed_Component (Loc,
6221 Prefix => Relocate_Node (Pref),
6222 Expressions => New_List (New_Occurrence_Of (L_J, Loc))),
6223 Expression => Relocate_Node (Expr));
6225 -- Construct the final loop
6227 Stat :=
6228 Make_Implicit_Loop_Statement
6229 (Node => Parent (N),
6230 Identifier => Empty,
6231 Iteration_Scheme => L_Iter,
6232 Statements => New_List (L_Body));
6234 -- Set type of aggregate to be type of lhs in assignment,
6235 -- to suppress redundant length checks.
6237 Set_Etype (N, Etype (Name (Parent (N))));
6239 Rewrite (Parent (N), Stat);
6240 Analyze (Parent (N));
6241 return True;
6243 else
6244 return False;
6245 end if;
6246 end Safe_Slice_Assignment;
6248 ---------------------
6249 -- Sort_Case_Table --
6250 ---------------------
6252 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
6253 L : constant Int := Case_Table'First;
6254 U : constant Int := Case_Table'Last;
6255 K : Int;
6256 J : Int;
6257 T : Case_Bounds;
6259 begin
6260 K := L;
6261 while K /= U loop
6262 T := Case_Table (K + 1);
6264 J := K + 1;
6265 while J /= L
6266 and then Expr_Value (Case_Table (J - 1).Choice_Lo) >
6267 Expr_Value (T.Choice_Lo)
6268 loop
6269 Case_Table (J) := Case_Table (J - 1);
6270 J := J - 1;
6271 end loop;
6273 Case_Table (J) := T;
6274 K := K + 1;
6275 end loop;
6276 end Sort_Case_Table;
6278 ----------------------------
6279 -- Static_Array_Aggregate --
6280 ----------------------------
6282 function Static_Array_Aggregate (N : Node_Id) return Boolean is
6283 Bounds : constant Node_Id := Aggregate_Bounds (N);
6285 Typ : constant Entity_Id := Etype (N);
6286 Comp_Type : constant Entity_Id := Component_Type (Typ);
6287 Agg : Node_Id;
6288 Expr : Node_Id;
6289 Lo : Node_Id;
6290 Hi : Node_Id;
6292 begin
6293 if Is_Tagged_Type (Typ)
6294 or else Is_Controlled (Typ)
6295 or else Is_Packed (Typ)
6296 then
6297 return False;
6298 end if;
6300 if Present (Bounds)
6301 and then Nkind (Bounds) = N_Range
6302 and then Nkind (Low_Bound (Bounds)) = N_Integer_Literal
6303 and then Nkind (High_Bound (Bounds)) = N_Integer_Literal
6304 then
6305 Lo := Low_Bound (Bounds);
6306 Hi := High_Bound (Bounds);
6308 if No (Component_Associations (N)) then
6310 -- Verify that all components are static integers
6312 Expr := First (Expressions (N));
6313 while Present (Expr) loop
6314 if Nkind (Expr) /= N_Integer_Literal then
6315 return False;
6316 end if;
6318 Next (Expr);
6319 end loop;
6321 return True;
6323 else
6324 -- We allow only a single named association, either a static
6325 -- range or an others_clause, with a static expression.
6327 Expr := First (Component_Associations (N));
6329 if Present (Expressions (N)) then
6330 return False;
6332 elsif Present (Next (Expr)) then
6333 return False;
6335 elsif Present (Next (First (Choices (Expr)))) then
6336 return False;
6338 else
6339 -- The aggregate is static if all components are literals,
6340 -- or else all its components are static aggregates for the
6341 -- component type. We also limit the size of a static aggregate
6342 -- to prevent runaway static expressions.
6344 if Is_Array_Type (Comp_Type)
6345 or else Is_Record_Type (Comp_Type)
6346 then
6347 if Nkind (Expression (Expr)) /= N_Aggregate
6348 or else
6349 not Compile_Time_Known_Aggregate (Expression (Expr))
6350 then
6351 return False;
6352 end if;
6354 elsif Nkind (Expression (Expr)) /= N_Integer_Literal then
6355 return False;
6356 end if;
6358 if not Aggr_Size_OK (N, Typ) then
6359 return False;
6360 end if;
6362 -- Create a positional aggregate with the right number of
6363 -- copies of the expression.
6365 Agg := Make_Aggregate (Sloc (N), New_List, No_List);
6367 for I in UI_To_Int (Intval (Lo)) .. UI_To_Int (Intval (Hi))
6368 loop
6369 Append_To
6370 (Expressions (Agg), New_Copy (Expression (Expr)));
6372 -- The copied expression must be analyzed and resolved.
6373 -- Besides setting the type, this ensures that static
6374 -- expressions are appropriately marked as such.
6376 Analyze_And_Resolve
6377 (Last (Expressions (Agg)), Component_Type (Typ));
6378 end loop;
6380 Set_Aggregate_Bounds (Agg, Bounds);
6381 Set_Etype (Agg, Typ);
6382 Set_Analyzed (Agg);
6383 Rewrite (N, Agg);
6384 Set_Compile_Time_Known_Aggregate (N);
6386 return True;
6387 end if;
6388 end if;
6390 else
6391 return False;
6392 end if;
6393 end Static_Array_Aggregate;
6395 end Exp_Aggr;