* include/parallel/numeric.h: Do not use default arguments in function
[official-gcc.git] / gcc / ada / exp_aggr.adb
blobac67a5724e2c9054eb13f5a0a240e9615d15cc0a
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) 1992-2014, 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 Stringt; use Stringt;
63 with Targparm; use Targparm;
64 with Tbuild; use Tbuild;
65 with Uintp; use Uintp;
67 package body Exp_Aggr is
69 type Case_Bounds is record
70 Choice_Lo : Node_Id;
71 Choice_Hi : Node_Id;
72 Choice_Node : Node_Id;
73 end record;
75 type Case_Table_Type is array (Nat range <>) of Case_Bounds;
76 -- Table type used by Check_Case_Choices procedure
78 procedure Collect_Initialization_Statements
79 (Obj : Entity_Id;
80 N : Node_Id;
81 Node_After : Node_Id);
82 -- If Obj is not frozen, collect actions inserted after N until, but not
83 -- including, Node_After, for initialization of Obj, and move them to an
84 -- expression with actions, which becomes the Initialization_Statements for
85 -- Obj.
87 function Has_Default_Init_Comps (N : Node_Id) return Boolean;
88 -- N is an aggregate (record or array). Checks the presence of default
89 -- initialization (<>) in any component (Ada 2005: AI-287).
91 function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean;
92 -- Returns true if N is an aggregate used to initialize the components
93 -- of a statically allocated dispatch table.
95 function Must_Slide
96 (Obj_Type : Entity_Id;
97 Typ : Entity_Id) return Boolean;
98 -- A static array aggregate in an object declaration can in most cases be
99 -- expanded in place. The one exception is when the aggregate is given
100 -- with component associations that specify different bounds from those of
101 -- the type definition in the object declaration. In this pathological
102 -- case the aggregate must slide, and we must introduce an intermediate
103 -- temporary to hold it.
105 -- The same holds in an assignment to one-dimensional array of arrays,
106 -- when a component may be given with bounds that differ from those of the
107 -- component type.
109 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
110 -- Sort the Case Table using the Lower Bound of each Choice as the key.
111 -- A simple insertion sort is used since the number of choices in a case
112 -- statement of variant part will usually be small and probably in near
113 -- sorted order.
115 ------------------------------------------------------
116 -- Local subprograms for Record Aggregate Expansion --
117 ------------------------------------------------------
119 function Build_Record_Aggr_Code
120 (N : Node_Id;
121 Typ : Entity_Id;
122 Lhs : Node_Id) return List_Id;
123 -- N is an N_Aggregate or an N_Extension_Aggregate. Typ is the type of the
124 -- aggregate. Target is an expression containing the location on which the
125 -- component by component assignments will take place. Returns the list of
126 -- assignments plus all other adjustments needed for tagged and controlled
127 -- types.
129 procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id);
130 -- N is an N_Aggregate or an N_Extension_Aggregate. Typ is the type of the
131 -- aggregate (which can only be a record type, this procedure is only used
132 -- for record types). Transform the given aggregate into a sequence of
133 -- assignments performed component by component.
135 procedure Expand_Record_Aggregate
136 (N : Node_Id;
137 Orig_Tag : Node_Id := Empty;
138 Parent_Expr : Node_Id := Empty);
139 -- This is the top level procedure for record aggregate expansion.
140 -- Expansion for record aggregates needs expand aggregates for tagged
141 -- record types. Specifically Expand_Record_Aggregate adds the Tag
142 -- field in front of the Component_Association list that was created
143 -- during resolution by Resolve_Record_Aggregate.
145 -- N is the record aggregate node.
146 -- Orig_Tag is the value of the Tag that has to be provided for this
147 -- specific aggregate. It carries the tag corresponding to the type
148 -- of the outermost aggregate during the recursive expansion
149 -- Parent_Expr is the ancestor part of the original extension
150 -- aggregate
152 function Has_Mutable_Components (Typ : Entity_Id) return Boolean;
153 -- Return true if one of the components is of a discriminated type with
154 -- defaults. An aggregate for a type with mutable components must be
155 -- expanded into individual assignments.
157 procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id);
158 -- If the type of the aggregate is a type extension with renamed discrimi-
159 -- nants, we must initialize the hidden discriminants of the parent.
160 -- Otherwise, the target object must not be initialized. The discriminants
161 -- are initialized by calling the initialization procedure for the type.
162 -- This is incorrect if the initialization of other components has any
163 -- side effects. We restrict this call to the case where the parent type
164 -- has a variant part, because this is the only case where the hidden
165 -- discriminants are accessed, namely when calling discriminant checking
166 -- functions of the parent type, and when applying a stream attribute to
167 -- an object of the derived type.
169 -----------------------------------------------------
170 -- Local Subprograms for Array Aggregate Expansion --
171 -----------------------------------------------------
173 function Aggr_Size_OK (N : Node_Id; Typ : Entity_Id) return Boolean;
174 -- Very large static aggregates present problems to the back-end, and are
175 -- transformed into assignments and loops. This function verifies that the
176 -- total number of components of an aggregate is acceptable for rewriting
177 -- into a purely positional static form. Aggr_Size_OK must be called before
178 -- calling Flatten.
180 -- This function also detects and warns about one-component aggregates that
181 -- appear in a non-static context. Even if the component value is static,
182 -- such an aggregate must be expanded into an assignment.
184 function Backend_Processing_Possible (N : Node_Id) return Boolean;
185 -- This function checks if array aggregate N can be processed directly
186 -- by the backend. If this is the case, True is returned.
188 function Build_Array_Aggr_Code
189 (N : Node_Id;
190 Ctype : Entity_Id;
191 Index : Node_Id;
192 Into : Node_Id;
193 Scalar_Comp : Boolean;
194 Indexes : List_Id := No_List) return List_Id;
195 -- This recursive routine returns a list of statements containing the
196 -- loops and assignments that are needed for the expansion of the array
197 -- aggregate N.
199 -- N is the (sub-)aggregate node to be expanded into code. This node has
200 -- been fully analyzed, and its Etype is properly set.
202 -- Index is the index node corresponding to the array sub-aggregate N
204 -- Into is the target expression into which we are copying the aggregate.
205 -- Note that this node may not have been analyzed yet, and so the Etype
206 -- field may not be set.
208 -- Scalar_Comp is True if the component type of the aggregate is scalar
210 -- Indexes is the current list of expressions used to index the object we
211 -- are writing into.
213 procedure Convert_Array_Aggr_In_Allocator
214 (Decl : Node_Id;
215 Aggr : Node_Id;
216 Target : Node_Id);
217 -- If the aggregate appears within an allocator and can be expanded in
218 -- place, this routine generates the individual assignments to components
219 -- of the designated object. This is an optimization over the general
220 -- case, where a temporary is first created on the stack and then used to
221 -- construct the allocated object on the heap.
223 procedure Convert_To_Positional
224 (N : Node_Id;
225 Max_Others_Replicate : Nat := 5;
226 Handle_Bit_Packed : Boolean := False);
227 -- If possible, convert named notation to positional notation. This
228 -- conversion is possible only in some static cases. If the conversion is
229 -- possible, then N is rewritten with the analyzed converted aggregate.
230 -- The parameter Max_Others_Replicate controls the maximum number of
231 -- values corresponding to an others choice that will be converted to
232 -- positional notation (the default of 5 is the normal limit, and reflects
233 -- the fact that normally the loop is better than a lot of separate
234 -- assignments). Note that this limit gets overridden in any case if
235 -- either of the restrictions No_Elaboration_Code or No_Implicit_Loops is
236 -- set. The parameter Handle_Bit_Packed is usually set False (since we do
237 -- not expect the back end to handle bit packed arrays, so the normal case
238 -- of conversion is pointless), but in the special case of a call from
239 -- Packed_Array_Aggregate_Handled, we set this parameter to True, since
240 -- these are cases we handle in there.
242 -- It would seem worthwhile to have a higher default value for Max_Others_
243 -- replicate, but aggregates in the compiler make this impossible: the
244 -- compiler bootstrap fails if Max_Others_Replicate is greater than 25.
245 -- This is unexpected ???
247 procedure Expand_Array_Aggregate (N : Node_Id);
248 -- This is the top-level routine to perform array aggregate expansion.
249 -- N is the N_Aggregate node to be expanded.
251 function Is_Two_Dim_Packed_Array (Typ : Entity_Id) return Boolean;
252 -- For two-dimensional packed aggregates with constant bounds and constant
253 -- components, it is preferable to pack the inner aggregates because the
254 -- whole matrix can then be presented to the back-end as a one-dimensional
255 -- list of literals. This is much more efficient than expanding into single
256 -- component assignments. This function determines if the type Typ is for
257 -- an array that is suitable for this optimization: it returns True if Typ
258 -- is a two dimensional bit packed array with component size 1, 2, or 4.
260 function Late_Expansion
261 (N : Node_Id;
262 Typ : Entity_Id;
263 Target : Node_Id) return List_Id;
264 -- This routine implements top-down expansion of nested aggregates. In
265 -- doing so, it avoids the generation of temporaries at each level. N is
266 -- a nested record or array aggregate with the Expansion_Delayed flag.
267 -- Typ is the expected type of the aggregate. Target is a (duplicatable)
268 -- expression that will hold the result of the aggregate expansion.
270 function Make_OK_Assignment_Statement
271 (Sloc : Source_Ptr;
272 Name : Node_Id;
273 Expression : Node_Id) return Node_Id;
274 -- This is like Make_Assignment_Statement, except that Assignment_OK
275 -- is set in the left operand. All assignments built by this unit use
276 -- this routine. This is needed to deal with assignments to initialized
277 -- constants that are done in place.
279 function Number_Of_Choices (N : Node_Id) return Nat;
280 -- Returns the number of discrete choices (not including the others choice
281 -- if present) contained in (sub-)aggregate N.
283 function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean;
284 -- Given an array aggregate, this function handles the case of a packed
285 -- array aggregate with all constant values, where the aggregate can be
286 -- evaluated at compile time. If this is possible, then N is rewritten
287 -- to be its proper compile time value with all the components properly
288 -- assembled. The expression is analyzed and resolved and True is returned.
289 -- If this transformation is not possible, N is unchanged and False is
290 -- returned.
292 function Two_Dim_Packed_Array_Handled (N : Node_Id) return Boolean;
293 -- If the type of the aggregate is a two-dimensional bit_packed array
294 -- it may be transformed into an array of bytes with constant values,
295 -- and presented to the back-end as a static value. The function returns
296 -- false if this transformation cannot be performed. THis is similar to,
297 -- and reuses part of the machinery in Packed_Array_Aggregate_Handled.
299 ------------------
300 -- Aggr_Size_OK --
301 ------------------
303 function Aggr_Size_OK (N : Node_Id; Typ : Entity_Id) return Boolean is
304 Lo : Node_Id;
305 Hi : Node_Id;
306 Indx : Node_Id;
307 Siz : Int;
308 Lov : Uint;
309 Hiv : Uint;
311 Max_Aggr_Size : Nat;
312 -- Determines the maximum size of an array aggregate produced by
313 -- converting named to positional notation (e.g. from others clauses).
314 -- This avoids running away with attempts to convert huge aggregates,
315 -- which hit memory limits in the backend.
317 function Component_Count (T : Entity_Id) return Int;
318 -- The limit is applied to the total number of components that the
319 -- aggregate will have, which is the number of static expressions
320 -- that will appear in the flattened array. This requires a recursive
321 -- computation of the number of scalar components of the structure.
323 ---------------------
324 -- Component_Count --
325 ---------------------
327 function Component_Count (T : Entity_Id) return Int is
328 Res : Int := 0;
329 Comp : Entity_Id;
331 begin
332 if Is_Scalar_Type (T) then
333 return 1;
335 elsif Is_Record_Type (T) then
336 Comp := First_Component (T);
337 while Present (Comp) loop
338 Res := Res + Component_Count (Etype (Comp));
339 Next_Component (Comp);
340 end loop;
342 return Res;
344 elsif Is_Array_Type (T) then
345 declare
346 Lo : constant Node_Id :=
347 Type_Low_Bound (Etype (First_Index (T)));
348 Hi : constant Node_Id :=
349 Type_High_Bound (Etype (First_Index (T)));
351 Siz : constant Int := Component_Count (Component_Type (T));
353 begin
354 if not Compile_Time_Known_Value (Lo)
355 or else not Compile_Time_Known_Value (Hi)
356 then
357 return 0;
358 else
359 return
360 Siz * UI_To_Int (Expr_Value (Hi) - Expr_Value (Lo) + 1);
361 end if;
362 end;
364 else
365 -- Can only be a null for an access type
367 return 1;
368 end if;
369 end Component_Count;
371 -- Start of processing for Aggr_Size_OK
373 begin
374 -- The normal aggregate limit is 50000, but we increase this limit to
375 -- 2**24 (about 16 million) if Restrictions (No_Elaboration_Code) or
376 -- Restrictions (No_Implicit_Loops) is specified, since in either case
377 -- we are at risk of declaring the program illegal because of this
378 -- limit. We also increase the limit when Static_Elaboration_Desired,
379 -- given that this means that objects are intended to be placed in data
380 -- memory.
382 -- We also increase the limit if the aggregate is for a packed two-
383 -- dimensional array, because if components are static it is much more
384 -- efficient to construct a one-dimensional equivalent array with static
385 -- components.
387 -- Conversely, we decrease the maximum size if none of the above
388 -- requirements apply, and if the aggregate has a single component
389 -- association, which will be more efficient if implemented with a loop.
391 -- Finally, we use a small limit in CodePeer mode where we favor loops
392 -- instead of thousands of single assignments (from large aggregates).
394 Max_Aggr_Size := 50000;
396 if CodePeer_Mode then
397 Max_Aggr_Size := 100;
399 elsif Restriction_Active (No_Elaboration_Code)
400 or else Restriction_Active (No_Implicit_Loops)
401 or else Is_Two_Dim_Packed_Array (Typ)
402 or else (Ekind (Current_Scope) = E_Package
403 and then Static_Elaboration_Desired (Current_Scope))
404 then
405 Max_Aggr_Size := 2 ** 24;
407 elsif No (Expressions (N))
408 and then No (Next (First (Component_Associations (N))))
409 then
410 Max_Aggr_Size := 5000;
411 end if;
413 Siz := Component_Count (Component_Type (Typ));
415 Indx := First_Index (Typ);
416 while Present (Indx) loop
417 Lo := Type_Low_Bound (Etype (Indx));
418 Hi := Type_High_Bound (Etype (Indx));
420 -- Bounds need to be known at compile time
422 if not Compile_Time_Known_Value (Lo)
423 or else not Compile_Time_Known_Value (Hi)
424 then
425 return False;
426 end if;
428 Lov := Expr_Value (Lo);
429 Hiv := Expr_Value (Hi);
431 -- A flat array is always safe
433 if Hiv < Lov then
434 return True;
435 end if;
437 -- One-component aggregates are suspicious, and if the context type
438 -- is an object declaration with non-static bounds it will trip gcc;
439 -- such an aggregate must be expanded into a single assignment.
441 if Hiv = Lov and then Nkind (Parent (N)) = N_Object_Declaration then
442 declare
443 Index_Type : constant Entity_Id :=
444 Etype
445 (First_Index (Etype (Defining_Identifier (Parent (N)))));
446 Indx : Node_Id;
448 begin
449 if not Compile_Time_Known_Value (Type_Low_Bound (Index_Type))
450 or else not Compile_Time_Known_Value
451 (Type_High_Bound (Index_Type))
452 then
453 if Present (Component_Associations (N)) then
454 Indx :=
455 First (Choices (First (Component_Associations (N))));
457 if Is_Entity_Name (Indx)
458 and then not Is_Type (Entity (Indx))
459 then
460 Error_Msg_N
461 ("single component aggregate in "
462 & "non-static context??", Indx);
463 Error_Msg_N ("\maybe subtype name was meant??", Indx);
464 end if;
465 end if;
467 return False;
468 end if;
469 end;
470 end if;
472 declare
473 Rng : constant Uint := Hiv - Lov + 1;
475 begin
476 -- Check if size is too large
478 if not UI_Is_In_Int_Range (Rng) then
479 return False;
480 end if;
482 Siz := Siz * UI_To_Int (Rng);
483 end;
485 if Siz <= 0
486 or else Siz > Max_Aggr_Size
487 then
488 return False;
489 end if;
491 -- Bounds must be in integer range, for later array construction
493 if not UI_Is_In_Int_Range (Lov)
494 or else
495 not UI_Is_In_Int_Range (Hiv)
496 then
497 return False;
498 end if;
500 Next_Index (Indx);
501 end loop;
503 return True;
504 end Aggr_Size_OK;
506 ---------------------------------
507 -- Backend_Processing_Possible --
508 ---------------------------------
510 -- Backend processing by Gigi/gcc is possible only if all the following
511 -- conditions are met:
513 -- 1. N is fully positional
515 -- 2. N is not a bit-packed array aggregate;
517 -- 3. The size of N's array type must be known at compile time. Note
518 -- that this implies that the component size is also known
520 -- 4. The array type of N does not follow the Fortran layout convention
521 -- or if it does it must be 1 dimensional.
523 -- 5. The array component type may not be tagged (which could necessitate
524 -- reassignment of proper tags).
526 -- 6. The array component type must not have unaligned bit components
528 -- 7. None of the components of the aggregate may be bit unaligned
529 -- components.
531 -- 8. There cannot be delayed components, since we do not know enough
532 -- at this stage to know if back end processing is possible.
534 -- 9. There cannot be any discriminated record components, since the
535 -- back end cannot handle this complex case.
537 -- 10. No controlled actions need to be generated for components
539 -- 11. For a VM back end, the array should have no aliased components
541 function Backend_Processing_Possible (N : Node_Id) return Boolean is
542 Typ : constant Entity_Id := Etype (N);
543 -- Typ is the correct constrained array subtype of the aggregate
545 function Component_Check (N : Node_Id; Index : Node_Id) return Boolean;
546 -- This routine checks components of aggregate N, enforcing checks
547 -- 1, 7, 8, and 9. In the multi-dimensional case, these checks are
548 -- performed on subaggregates. The Index value is the current index
549 -- being checked in the multi-dimensional case.
551 ---------------------
552 -- Component_Check --
553 ---------------------
555 function Component_Check (N : Node_Id; Index : Node_Id) return Boolean is
556 Expr : Node_Id;
558 begin
559 -- Checks 1: (no component associations)
561 if Present (Component_Associations (N)) then
562 return False;
563 end if;
565 -- Checks on components
567 -- Recurse to check subaggregates, which may appear in qualified
568 -- expressions. If delayed, the front-end will have to expand.
569 -- If the component is a discriminated record, treat as non-static,
570 -- as the back-end cannot handle this properly.
572 Expr := First (Expressions (N));
573 while Present (Expr) loop
575 -- Checks 8: (no delayed components)
577 if Is_Delayed_Aggregate (Expr) then
578 return False;
579 end if;
581 -- Checks 9: (no discriminated records)
583 if Present (Etype (Expr))
584 and then Is_Record_Type (Etype (Expr))
585 and then Has_Discriminants (Etype (Expr))
586 then
587 return False;
588 end if;
590 -- Checks 7. Component must not be bit aligned component
592 if Possible_Bit_Aligned_Component (Expr) then
593 return False;
594 end if;
596 -- Recursion to following indexes for multiple dimension case
598 if Present (Next_Index (Index))
599 and then not Component_Check (Expr, Next_Index (Index))
600 then
601 return False;
602 end if;
604 -- All checks for that component finished, on to next
606 Next (Expr);
607 end loop;
609 return True;
610 end Component_Check;
612 -- Start of processing for Backend_Processing_Possible
614 begin
615 -- Checks 2 (array not bit packed) and 10 (no controlled actions)
617 if Is_Bit_Packed_Array (Typ) or else Needs_Finalization (Typ) then
618 return False;
619 end if;
621 -- If component is limited, aggregate must be expanded because each
622 -- component assignment must be built in place.
624 if Is_Limited_View (Component_Type (Typ)) then
625 return False;
626 end if;
628 -- Checks 4 (array must not be multi-dimensional Fortran case)
630 if Convention (Typ) = Convention_Fortran
631 and then Number_Dimensions (Typ) > 1
632 then
633 return False;
634 end if;
636 -- Checks 3 (size of array must be known at compile time)
638 if not Size_Known_At_Compile_Time (Typ) then
639 return False;
640 end if;
642 -- Checks on components
644 if not Component_Check (N, First_Index (Typ)) then
645 return False;
646 end if;
648 -- Checks 5 (if the component type is tagged, then we may need to do
649 -- tag adjustments. Perhaps this should be refined to check for any
650 -- component associations that actually need tag adjustment, similar
651 -- to the test in Component_Not_OK_For_Backend for record aggregates
652 -- with tagged components, but not clear whether it's worthwhile ???;
653 -- in the case of the JVM, object tags are handled implicitly)
655 if Is_Tagged_Type (Component_Type (Typ))
656 and then Tagged_Type_Expansion
657 then
658 return False;
659 end if;
661 -- Checks 6 (component type must not have bit aligned components)
663 if Type_May_Have_Bit_Aligned_Components (Component_Type (Typ)) then
664 return False;
665 end if;
667 -- Checks 11: Array aggregates with aliased components are currently
668 -- not well supported by the VM backend; disable temporarily this
669 -- backend processing until it is definitely supported.
671 if VM_Target /= No_VM
672 and then Has_Aliased_Components (Base_Type (Typ))
673 then
674 return False;
675 end if;
677 -- Backend processing is possible
679 Set_Size_Known_At_Compile_Time (Etype (N), True);
680 return True;
681 end Backend_Processing_Possible;
683 ---------------------------
684 -- Build_Array_Aggr_Code --
685 ---------------------------
687 -- The code that we generate from a one dimensional aggregate is
689 -- 1. If the sub-aggregate contains discrete choices we
691 -- (a) Sort the discrete choices
693 -- (b) Otherwise for each discrete choice that specifies a range we
694 -- emit a loop. If a range specifies a maximum of three values, or
695 -- we are dealing with an expression we emit a sequence of
696 -- assignments instead of a loop.
698 -- (c) Generate the remaining loops to cover the others choice if any
700 -- 2. If the aggregate contains positional elements we
702 -- (a) translate the positional elements in a series of assignments
704 -- (b) Generate a final loop to cover the others choice if any.
705 -- Note that this final loop has to be a while loop since the case
707 -- L : Integer := Integer'Last;
708 -- H : Integer := Integer'Last;
709 -- A : array (L .. H) := (1, others =>0);
711 -- cannot be handled by a for loop. Thus for the following
713 -- array (L .. H) := (.. positional elements.., others =>E);
715 -- we always generate something like:
717 -- J : Index_Type := Index_Of_Last_Positional_Element;
718 -- while J < H loop
719 -- J := Index_Base'Succ (J)
720 -- Tmp (J) := E;
721 -- end loop;
723 function Build_Array_Aggr_Code
724 (N : Node_Id;
725 Ctype : Entity_Id;
726 Index : Node_Id;
727 Into : Node_Id;
728 Scalar_Comp : Boolean;
729 Indexes : List_Id := No_List) return List_Id
731 Loc : constant Source_Ptr := Sloc (N);
732 Index_Base : constant Entity_Id := Base_Type (Etype (Index));
733 Index_Base_L : constant Node_Id := Type_Low_Bound (Index_Base);
734 Index_Base_H : constant Node_Id := Type_High_Bound (Index_Base);
736 function Add (Val : Int; To : Node_Id) return Node_Id;
737 -- Returns an expression where Val is added to expression To, unless
738 -- To+Val is provably out of To's base type range. To must be an
739 -- already analyzed expression.
741 function Empty_Range (L, H : Node_Id) return Boolean;
742 -- Returns True if the range defined by L .. H is certainly empty
744 function Equal (L, H : Node_Id) return Boolean;
745 -- Returns True if L = H for sure
747 function Index_Base_Name return Node_Id;
748 -- Returns a new reference to the index type name
750 function Gen_Assign (Ind : Node_Id; Expr : Node_Id) return List_Id;
751 -- Ind must be a side-effect free expression. If the input aggregate
752 -- N to Build_Loop contains no sub-aggregates, then this function
753 -- returns the assignment statement:
755 -- Into (Indexes, Ind) := Expr;
757 -- Otherwise we call Build_Code recursively
759 -- Ada 2005 (AI-287): In case of default initialized component, Expr
760 -- is empty and we generate a call to the corresponding IP subprogram.
762 function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id;
763 -- Nodes L and H must be side-effect free expressions.
764 -- If the input aggregate N to Build_Loop contains no sub-aggregates,
765 -- This routine returns the for loop statement
767 -- for J in Index_Base'(L) .. Index_Base'(H) loop
768 -- Into (Indexes, J) := Expr;
769 -- end loop;
771 -- Otherwise we call Build_Code recursively.
772 -- As an optimization if the loop covers 3 or less scalar elements we
773 -- generate a sequence of assignments.
775 function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id;
776 -- Nodes L and H must be side-effect free expressions.
777 -- If the input aggregate N to Build_Loop contains no sub-aggregates,
778 -- This routine returns the while loop statement
780 -- J : Index_Base := L;
781 -- while J < H loop
782 -- J := Index_Base'Succ (J);
783 -- Into (Indexes, J) := Expr;
784 -- end loop;
786 -- Otherwise we call Build_Code recursively
788 function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean;
789 function Local_Expr_Value (E : Node_Id) return Uint;
790 -- These two Local routines are used to replace the corresponding ones
791 -- in sem_eval because while processing the bounds of an aggregate with
792 -- discrete choices whose index type is an enumeration, we build static
793 -- expressions not recognized by Compile_Time_Known_Value as such since
794 -- they have not yet been analyzed and resolved. All the expressions in
795 -- question are things like Index_Base_Name'Val (Const) which we can
796 -- easily recognize as being constant.
798 ---------
799 -- Add --
800 ---------
802 function Add (Val : Int; To : Node_Id) return Node_Id is
803 Expr_Pos : Node_Id;
804 Expr : Node_Id;
805 To_Pos : Node_Id;
806 U_To : Uint;
807 U_Val : constant Uint := UI_From_Int (Val);
809 begin
810 -- Note: do not try to optimize the case of Val = 0, because
811 -- we need to build a new node with the proper Sloc value anyway.
813 -- First test if we can do constant folding
815 if Local_Compile_Time_Known_Value (To) then
816 U_To := Local_Expr_Value (To) + Val;
818 -- Determine if our constant is outside the range of the index.
819 -- If so return an Empty node. This empty node will be caught
820 -- by Empty_Range below.
822 if Compile_Time_Known_Value (Index_Base_L)
823 and then U_To < Expr_Value (Index_Base_L)
824 then
825 return Empty;
827 elsif Compile_Time_Known_Value (Index_Base_H)
828 and then U_To > Expr_Value (Index_Base_H)
829 then
830 return Empty;
831 end if;
833 Expr_Pos := Make_Integer_Literal (Loc, U_To);
834 Set_Is_Static_Expression (Expr_Pos);
836 if not Is_Enumeration_Type (Index_Base) then
837 Expr := Expr_Pos;
839 -- If we are dealing with enumeration return
840 -- Index_Base'Val (Expr_Pos)
842 else
843 Expr :=
844 Make_Attribute_Reference
845 (Loc,
846 Prefix => Index_Base_Name,
847 Attribute_Name => Name_Val,
848 Expressions => New_List (Expr_Pos));
849 end if;
851 return Expr;
852 end if;
854 -- If we are here no constant folding possible
856 if not Is_Enumeration_Type (Index_Base) then
857 Expr :=
858 Make_Op_Add (Loc,
859 Left_Opnd => Duplicate_Subexpr (To),
860 Right_Opnd => Make_Integer_Literal (Loc, U_Val));
862 -- If we are dealing with enumeration return
863 -- Index_Base'Val (Index_Base'Pos (To) + Val)
865 else
866 To_Pos :=
867 Make_Attribute_Reference
868 (Loc,
869 Prefix => Index_Base_Name,
870 Attribute_Name => Name_Pos,
871 Expressions => New_List (Duplicate_Subexpr (To)));
873 Expr_Pos :=
874 Make_Op_Add (Loc,
875 Left_Opnd => To_Pos,
876 Right_Opnd => Make_Integer_Literal (Loc, U_Val));
878 Expr :=
879 Make_Attribute_Reference
880 (Loc,
881 Prefix => Index_Base_Name,
882 Attribute_Name => Name_Val,
883 Expressions => New_List (Expr_Pos));
884 end if;
886 return Expr;
887 end Add;
889 -----------------
890 -- Empty_Range --
891 -----------------
893 function Empty_Range (L, H : Node_Id) return Boolean is
894 Is_Empty : Boolean := False;
895 Low : Node_Id;
896 High : Node_Id;
898 begin
899 -- First check if L or H were already detected as overflowing the
900 -- index base range type by function Add above. If this is so Add
901 -- returns the empty node.
903 if No (L) or else No (H) then
904 return True;
905 end if;
907 for J in 1 .. 3 loop
908 case J is
910 -- L > H range is empty
912 when 1 =>
913 Low := L;
914 High := H;
916 -- B_L > H range must be empty
918 when 2 =>
919 Low := Index_Base_L;
920 High := H;
922 -- L > B_H range must be empty
924 when 3 =>
925 Low := L;
926 High := Index_Base_H;
927 end case;
929 if Local_Compile_Time_Known_Value (Low)
930 and then
931 Local_Compile_Time_Known_Value (High)
932 then
933 Is_Empty :=
934 UI_Gt (Local_Expr_Value (Low), Local_Expr_Value (High));
935 end if;
937 exit when Is_Empty;
938 end loop;
940 return Is_Empty;
941 end Empty_Range;
943 -----------
944 -- Equal --
945 -----------
947 function Equal (L, H : Node_Id) return Boolean is
948 begin
949 if L = H then
950 return True;
952 elsif Local_Compile_Time_Known_Value (L)
953 and then
954 Local_Compile_Time_Known_Value (H)
955 then
956 return UI_Eq (Local_Expr_Value (L), Local_Expr_Value (H));
957 end if;
959 return False;
960 end Equal;
962 ----------------
963 -- Gen_Assign --
964 ----------------
966 function Gen_Assign (Ind : Node_Id; Expr : Node_Id) return List_Id is
967 L : constant List_Id := New_List;
968 A : Node_Id;
970 New_Indexes : List_Id;
971 Indexed_Comp : Node_Id;
972 Expr_Q : Node_Id;
973 Comp_Type : Entity_Id := Empty;
975 function Add_Loop_Actions (Lis : List_Id) return List_Id;
976 -- Collect insert_actions generated in the construction of a
977 -- loop, and prepend them to the sequence of assignments to
978 -- complete the eventual body of the loop.
980 ----------------------
981 -- Add_Loop_Actions --
982 ----------------------
984 function Add_Loop_Actions (Lis : List_Id) return List_Id is
985 Res : List_Id;
987 begin
988 -- Ada 2005 (AI-287): Do nothing else in case of default
989 -- initialized component.
991 if No (Expr) then
992 return Lis;
994 elsif Nkind (Parent (Expr)) = N_Component_Association
995 and then Present (Loop_Actions (Parent (Expr)))
996 then
997 Append_List (Lis, Loop_Actions (Parent (Expr)));
998 Res := Loop_Actions (Parent (Expr));
999 Set_Loop_Actions (Parent (Expr), No_List);
1000 return Res;
1002 else
1003 return Lis;
1004 end if;
1005 end Add_Loop_Actions;
1007 -- Start of processing for Gen_Assign
1009 begin
1010 if No (Indexes) then
1011 New_Indexes := New_List;
1012 else
1013 New_Indexes := New_Copy_List_Tree (Indexes);
1014 end if;
1016 Append_To (New_Indexes, Ind);
1018 if Present (Next_Index (Index)) then
1019 return
1020 Add_Loop_Actions (
1021 Build_Array_Aggr_Code
1022 (N => Expr,
1023 Ctype => Ctype,
1024 Index => Next_Index (Index),
1025 Into => Into,
1026 Scalar_Comp => Scalar_Comp,
1027 Indexes => New_Indexes));
1028 end if;
1030 -- If we get here then we are at a bottom-level (sub-)aggregate
1032 Indexed_Comp :=
1033 Checks_Off
1034 (Make_Indexed_Component (Loc,
1035 Prefix => New_Copy_Tree (Into),
1036 Expressions => New_Indexes));
1038 Set_Assignment_OK (Indexed_Comp);
1040 -- Ada 2005 (AI-287): In case of default initialized component, Expr
1041 -- is not present (and therefore we also initialize Expr_Q to empty).
1043 if No (Expr) then
1044 Expr_Q := Empty;
1045 elsif Nkind (Expr) = N_Qualified_Expression then
1046 Expr_Q := Expression (Expr);
1047 else
1048 Expr_Q := Expr;
1049 end if;
1051 if Present (Etype (N)) and then Etype (N) /= Any_Composite then
1052 Comp_Type := Component_Type (Etype (N));
1053 pragma Assert (Comp_Type = Ctype); -- AI-287
1055 elsif Present (Next (First (New_Indexes))) then
1057 -- Ada 2005 (AI-287): Do nothing in case of default initialized
1058 -- component because we have received the component type in
1059 -- the formal parameter Ctype.
1061 -- ??? Some assert pragmas have been added to check if this new
1062 -- formal can be used to replace this code in all cases.
1064 if Present (Expr) then
1066 -- This is a multidimensional array. Recover the component type
1067 -- from the outermost aggregate, because subaggregates do not
1068 -- have an assigned type.
1070 declare
1071 P : Node_Id;
1073 begin
1074 P := Parent (Expr);
1075 while Present (P) loop
1076 if Nkind (P) = N_Aggregate
1077 and then Present (Etype (P))
1078 then
1079 Comp_Type := Component_Type (Etype (P));
1080 exit;
1082 else
1083 P := Parent (P);
1084 end if;
1085 end loop;
1087 pragma Assert (Comp_Type = Ctype); -- AI-287
1088 end;
1089 end if;
1090 end if;
1092 -- Ada 2005 (AI-287): We only analyze the expression in case of non-
1093 -- default initialized components (otherwise Expr_Q is not present).
1095 if Present (Expr_Q)
1096 and then Nkind_In (Expr_Q, N_Aggregate, N_Extension_Aggregate)
1097 then
1098 -- At this stage the Expression may not have been analyzed yet
1099 -- because the array aggregate code has not been updated to use
1100 -- the Expansion_Delayed flag and avoid analysis altogether to
1101 -- solve the same problem (see Resolve_Aggr_Expr). So let us do
1102 -- the analysis of non-array aggregates now in order to get the
1103 -- value of Expansion_Delayed flag for the inner aggregate ???
1105 if Present (Comp_Type) and then not Is_Array_Type (Comp_Type) then
1106 Analyze_And_Resolve (Expr_Q, Comp_Type);
1107 end if;
1109 if Is_Delayed_Aggregate (Expr_Q) then
1111 -- This is either a subaggregate of a multidimensional array,
1112 -- or a component of an array type whose component type is
1113 -- also an array. In the latter case, the expression may have
1114 -- component associations that provide different bounds from
1115 -- those of the component type, and sliding must occur. Instead
1116 -- of decomposing the current aggregate assignment, force the
1117 -- re-analysis of the assignment, so that a temporary will be
1118 -- generated in the usual fashion, and sliding will take place.
1120 if Nkind (Parent (N)) = N_Assignment_Statement
1121 and then Is_Array_Type (Comp_Type)
1122 and then Present (Component_Associations (Expr_Q))
1123 and then Must_Slide (Comp_Type, Etype (Expr_Q))
1124 then
1125 Set_Expansion_Delayed (Expr_Q, False);
1126 Set_Analyzed (Expr_Q, False);
1128 else
1129 return
1130 Add_Loop_Actions (
1131 Late_Expansion (Expr_Q, Etype (Expr_Q), Indexed_Comp));
1132 end if;
1133 end if;
1134 end if;
1136 -- Ada 2005 (AI-287): In case of default initialized component, call
1137 -- the initialization subprogram associated with the component type.
1138 -- If the component type is an access type, add an explicit null
1139 -- assignment, because for the back-end there is an initialization
1140 -- present for the whole aggregate, and no default initialization
1141 -- will take place.
1143 -- In addition, if the component type is controlled, we must call
1144 -- its Initialize procedure explicitly, because there is no explicit
1145 -- object creation that will invoke it otherwise.
1147 if No (Expr) then
1148 if Present (Base_Init_Proc (Base_Type (Ctype)))
1149 or else Has_Task (Base_Type (Ctype))
1150 then
1151 Append_List_To (L,
1152 Build_Initialization_Call (Loc,
1153 Id_Ref => Indexed_Comp,
1154 Typ => Ctype,
1155 With_Default_Init => True));
1157 elsif Is_Access_Type (Ctype) then
1158 Append_To (L,
1159 Make_Assignment_Statement (Loc,
1160 Name => Indexed_Comp,
1161 Expression => Make_Null (Loc)));
1162 end if;
1164 if Needs_Finalization (Ctype) then
1165 Append_To (L,
1166 Make_Init_Call
1167 (Obj_Ref => New_Copy_Tree (Indexed_Comp),
1168 Typ => Ctype));
1169 end if;
1171 else
1172 A :=
1173 Make_OK_Assignment_Statement (Loc,
1174 Name => Indexed_Comp,
1175 Expression => New_Copy_Tree (Expr));
1177 -- The target of the assignment may not have been initialized,
1178 -- so it is not possible to call Finalize as expected in normal
1179 -- controlled assignments. We must also avoid using the primitive
1180 -- _assign (which depends on a valid target, and may for example
1181 -- perform discriminant checks on it).
1183 -- Both Finalize and usage of _assign are disabled by setting
1184 -- No_Ctrl_Actions on the assignment. The rest of the controlled
1185 -- actions are done manually with the proper finalization list
1186 -- coming from the context.
1188 Set_No_Ctrl_Actions (A);
1190 -- If this is an aggregate for an array of arrays, each
1191 -- sub-aggregate will be expanded as well, and even with
1192 -- No_Ctrl_Actions the assignments of inner components will
1193 -- require attachment in their assignments to temporaries. These
1194 -- temporaries must be finalized for each subaggregate, to prevent
1195 -- multiple attachments of the same temporary location to same
1196 -- finalization chain (and consequently circular lists). To ensure
1197 -- that finalization takes place for each subaggregate we wrap the
1198 -- assignment in a block.
1200 if Present (Comp_Type)
1201 and then Needs_Finalization (Comp_Type)
1202 and then Is_Array_Type (Comp_Type)
1203 and then Present (Expr)
1204 then
1205 A :=
1206 Make_Block_Statement (Loc,
1207 Handled_Statement_Sequence =>
1208 Make_Handled_Sequence_Of_Statements (Loc,
1209 Statements => New_List (A)));
1210 end if;
1212 Append_To (L, A);
1214 -- Adjust the tag if tagged (because of possible view
1215 -- conversions), unless compiling for a VM where tags
1216 -- are implicit.
1218 if Present (Comp_Type)
1219 and then Is_Tagged_Type (Comp_Type)
1220 and then Tagged_Type_Expansion
1221 then
1222 declare
1223 Full_Typ : constant Entity_Id := Underlying_Type (Comp_Type);
1225 begin
1226 A :=
1227 Make_OK_Assignment_Statement (Loc,
1228 Name =>
1229 Make_Selected_Component (Loc,
1230 Prefix => New_Copy_Tree (Indexed_Comp),
1231 Selector_Name =>
1232 New_Occurrence_Of
1233 (First_Tag_Component (Full_Typ), Loc)),
1235 Expression =>
1236 Unchecked_Convert_To (RTE (RE_Tag),
1237 New_Occurrence_Of
1238 (Node (First_Elmt (Access_Disp_Table (Full_Typ))),
1239 Loc)));
1241 Append_To (L, A);
1242 end;
1243 end if;
1245 -- Adjust and attach the component to the proper final list, which
1246 -- can be the controller of the outer record object or the final
1247 -- list associated with the scope.
1249 -- If the component is itself an array of controlled types, whose
1250 -- value is given by a sub-aggregate, then the attach calls have
1251 -- been generated when individual subcomponent are assigned, and
1252 -- must not be done again to prevent malformed finalization chains
1253 -- (see comments above, concerning the creation of a block to hold
1254 -- inner finalization actions).
1256 if Present (Comp_Type)
1257 and then Needs_Finalization (Comp_Type)
1258 and then not Is_Limited_Type (Comp_Type)
1259 and then not
1260 (Is_Array_Type (Comp_Type)
1261 and then Is_Controlled (Component_Type (Comp_Type))
1262 and then Nkind (Expr) = N_Aggregate)
1263 then
1264 Append_To (L,
1265 Make_Adjust_Call
1266 (Obj_Ref => New_Copy_Tree (Indexed_Comp),
1267 Typ => Comp_Type));
1268 end if;
1269 end if;
1271 return Add_Loop_Actions (L);
1272 end Gen_Assign;
1274 --------------
1275 -- Gen_Loop --
1276 --------------
1278 function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id is
1279 L_J : Node_Id;
1281 L_L : Node_Id;
1282 -- Index_Base'(L)
1284 L_H : Node_Id;
1285 -- Index_Base'(H)
1287 L_Range : Node_Id;
1288 -- Index_Base'(L) .. Index_Base'(H)
1290 L_Iteration_Scheme : Node_Id;
1291 -- L_J in Index_Base'(L) .. Index_Base'(H)
1293 L_Body : List_Id;
1294 -- The statements to execute in the loop
1296 S : constant List_Id := New_List;
1297 -- List of statements
1299 Tcopy : Node_Id;
1300 -- Copy of expression tree, used for checking purposes
1302 begin
1303 -- If loop bounds define an empty range return the null statement
1305 if Empty_Range (L, H) then
1306 Append_To (S, Make_Null_Statement (Loc));
1308 -- Ada 2005 (AI-287): Nothing else need to be done in case of
1309 -- default initialized component.
1311 if No (Expr) then
1312 null;
1314 else
1315 -- The expression must be type-checked even though no component
1316 -- of the aggregate will have this value. This is done only for
1317 -- actual components of the array, not for subaggregates. Do
1318 -- the check on a copy, because the expression may be shared
1319 -- among several choices, some of which might be non-null.
1321 if Present (Etype (N))
1322 and then Is_Array_Type (Etype (N))
1323 and then No (Next_Index (Index))
1324 then
1325 Expander_Mode_Save_And_Set (False);
1326 Tcopy := New_Copy_Tree (Expr);
1327 Set_Parent (Tcopy, N);
1328 Analyze_And_Resolve (Tcopy, Component_Type (Etype (N)));
1329 Expander_Mode_Restore;
1330 end if;
1331 end if;
1333 return S;
1335 -- If loop bounds are the same then generate an assignment
1337 elsif Equal (L, H) then
1338 return Gen_Assign (New_Copy_Tree (L), Expr);
1340 -- If H - L <= 2 then generate a sequence of assignments when we are
1341 -- processing the bottom most aggregate and it contains scalar
1342 -- components.
1344 elsif No (Next_Index (Index))
1345 and then Scalar_Comp
1346 and then Local_Compile_Time_Known_Value (L)
1347 and then Local_Compile_Time_Known_Value (H)
1348 and then Local_Expr_Value (H) - Local_Expr_Value (L) <= 2
1349 then
1351 Append_List_To (S, Gen_Assign (New_Copy_Tree (L), Expr));
1352 Append_List_To (S, Gen_Assign (Add (1, To => L), Expr));
1354 if Local_Expr_Value (H) - Local_Expr_Value (L) = 2 then
1355 Append_List_To (S, Gen_Assign (Add (2, To => L), Expr));
1356 end if;
1358 return S;
1359 end if;
1361 -- Otherwise construct the loop, starting with the loop index L_J
1363 L_J := Make_Temporary (Loc, 'J', L);
1365 -- Construct "L .. H" in Index_Base. We use a qualified expression
1366 -- for the bound to convert to the index base, but we don't need
1367 -- to do that if we already have the base type at hand.
1369 if Etype (L) = Index_Base then
1370 L_L := L;
1371 else
1372 L_L :=
1373 Make_Qualified_Expression (Loc,
1374 Subtype_Mark => Index_Base_Name,
1375 Expression => L);
1376 end if;
1378 if Etype (H) = Index_Base then
1379 L_H := H;
1380 else
1381 L_H :=
1382 Make_Qualified_Expression (Loc,
1383 Subtype_Mark => Index_Base_Name,
1384 Expression => H);
1385 end if;
1387 L_Range :=
1388 Make_Range (Loc,
1389 Low_Bound => L_L,
1390 High_Bound => L_H);
1392 -- Construct "for L_J in Index_Base range L .. H"
1394 L_Iteration_Scheme :=
1395 Make_Iteration_Scheme
1396 (Loc,
1397 Loop_Parameter_Specification =>
1398 Make_Loop_Parameter_Specification
1399 (Loc,
1400 Defining_Identifier => L_J,
1401 Discrete_Subtype_Definition => L_Range));
1403 -- Construct the statements to execute in the loop body
1405 L_Body := Gen_Assign (New_Occurrence_Of (L_J, Loc), Expr);
1407 -- Construct the final loop
1409 Append_To (S,
1410 Make_Implicit_Loop_Statement
1411 (Node => N,
1412 Identifier => Empty,
1413 Iteration_Scheme => L_Iteration_Scheme,
1414 Statements => L_Body));
1416 -- A small optimization: if the aggregate is initialized with a box
1417 -- and the component type has no initialization procedure, remove the
1418 -- useless empty loop.
1420 if Nkind (First (S)) = N_Loop_Statement
1421 and then Is_Empty_List (Statements (First (S)))
1422 then
1423 return New_List (Make_Null_Statement (Loc));
1424 else
1425 return S;
1426 end if;
1427 end Gen_Loop;
1429 ---------------
1430 -- Gen_While --
1431 ---------------
1433 -- The code built is
1435 -- W_J : Index_Base := L;
1436 -- while W_J < H loop
1437 -- W_J := Index_Base'Succ (W);
1438 -- L_Body;
1439 -- end loop;
1441 function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id is
1442 W_J : Node_Id;
1444 W_Decl : Node_Id;
1445 -- W_J : Base_Type := L;
1447 W_Iteration_Scheme : Node_Id;
1448 -- while W_J < H
1450 W_Index_Succ : Node_Id;
1451 -- Index_Base'Succ (J)
1453 W_Increment : Node_Id;
1454 -- W_J := Index_Base'Succ (W)
1456 W_Body : constant List_Id := New_List;
1457 -- The statements to execute in the loop
1459 S : constant List_Id := New_List;
1460 -- list of statement
1462 begin
1463 -- If loop bounds define an empty range or are equal return null
1465 if Empty_Range (L, H) or else Equal (L, H) then
1466 Append_To (S, Make_Null_Statement (Loc));
1467 return S;
1468 end if;
1470 -- Build the decl of W_J
1472 W_J := Make_Temporary (Loc, 'J', L);
1473 W_Decl :=
1474 Make_Object_Declaration
1475 (Loc,
1476 Defining_Identifier => W_J,
1477 Object_Definition => Index_Base_Name,
1478 Expression => L);
1480 -- Theoretically we should do a New_Copy_Tree (L) here, but we know
1481 -- that in this particular case L is a fresh Expr generated by
1482 -- Add which we are the only ones to use.
1484 Append_To (S, W_Decl);
1486 -- Construct " while W_J < H"
1488 W_Iteration_Scheme :=
1489 Make_Iteration_Scheme
1490 (Loc,
1491 Condition => Make_Op_Lt
1492 (Loc,
1493 Left_Opnd => New_Occurrence_Of (W_J, Loc),
1494 Right_Opnd => New_Copy_Tree (H)));
1496 -- Construct the statements to execute in the loop body
1498 W_Index_Succ :=
1499 Make_Attribute_Reference
1500 (Loc,
1501 Prefix => Index_Base_Name,
1502 Attribute_Name => Name_Succ,
1503 Expressions => New_List (New_Occurrence_Of (W_J, Loc)));
1505 W_Increment :=
1506 Make_OK_Assignment_Statement
1507 (Loc,
1508 Name => New_Occurrence_Of (W_J, Loc),
1509 Expression => W_Index_Succ);
1511 Append_To (W_Body, W_Increment);
1512 Append_List_To (W_Body,
1513 Gen_Assign (New_Occurrence_Of (W_J, Loc), Expr));
1515 -- Construct the final loop
1517 Append_To (S,
1518 Make_Implicit_Loop_Statement
1519 (Node => N,
1520 Identifier => Empty,
1521 Iteration_Scheme => W_Iteration_Scheme,
1522 Statements => W_Body));
1524 return S;
1525 end Gen_While;
1527 ---------------------
1528 -- Index_Base_Name --
1529 ---------------------
1531 function Index_Base_Name return Node_Id is
1532 begin
1533 return New_Occurrence_Of (Index_Base, Sloc (N));
1534 end Index_Base_Name;
1536 ------------------------------------
1537 -- Local_Compile_Time_Known_Value --
1538 ------------------------------------
1540 function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean is
1541 begin
1542 return Compile_Time_Known_Value (E)
1543 or else
1544 (Nkind (E) = N_Attribute_Reference
1545 and then Attribute_Name (E) = Name_Val
1546 and then Compile_Time_Known_Value (First (Expressions (E))));
1547 end Local_Compile_Time_Known_Value;
1549 ----------------------
1550 -- Local_Expr_Value --
1551 ----------------------
1553 function Local_Expr_Value (E : Node_Id) return Uint is
1554 begin
1555 if Compile_Time_Known_Value (E) then
1556 return Expr_Value (E);
1557 else
1558 return Expr_Value (First (Expressions (E)));
1559 end if;
1560 end Local_Expr_Value;
1562 -- Build_Array_Aggr_Code Variables
1564 Assoc : Node_Id;
1565 Choice : Node_Id;
1566 Expr : Node_Id;
1567 Typ : Entity_Id;
1569 Others_Expr : Node_Id := Empty;
1570 Others_Box_Present : Boolean := False;
1572 Aggr_L : constant Node_Id := Low_Bound (Aggregate_Bounds (N));
1573 Aggr_H : constant Node_Id := High_Bound (Aggregate_Bounds (N));
1574 -- The aggregate bounds of this specific sub-aggregate. Note that if
1575 -- the code generated by Build_Array_Aggr_Code is executed then these
1576 -- bounds are OK. Otherwise a Constraint_Error would have been raised.
1578 Aggr_Low : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_L);
1579 Aggr_High : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_H);
1580 -- After Duplicate_Subexpr these are side-effect free
1582 Low : Node_Id;
1583 High : Node_Id;
1585 Nb_Choices : Nat := 0;
1586 Table : Case_Table_Type (1 .. Number_Of_Choices (N));
1587 -- Used to sort all the different choice values
1589 Nb_Elements : Int;
1590 -- Number of elements in the positional aggregate
1592 New_Code : constant List_Id := New_List;
1594 -- Start of processing for Build_Array_Aggr_Code
1596 begin
1597 -- First before we start, a special case. if we have a bit packed
1598 -- array represented as a modular type, then clear the value to
1599 -- zero first, to ensure that unused bits are properly cleared.
1601 Typ := Etype (N);
1603 if Present (Typ)
1604 and then Is_Bit_Packed_Array (Typ)
1605 and then Is_Modular_Integer_Type (Packed_Array_Impl_Type (Typ))
1606 then
1607 Append_To (New_Code,
1608 Make_Assignment_Statement (Loc,
1609 Name => New_Copy_Tree (Into),
1610 Expression =>
1611 Unchecked_Convert_To (Typ,
1612 Make_Integer_Literal (Loc, Uint_0))));
1613 end if;
1615 -- If the component type contains tasks, we need to build a Master
1616 -- entity in the current scope, because it will be needed if build-
1617 -- in-place functions are called in the expanded code.
1619 if Nkind (Parent (N)) = N_Object_Declaration and then Has_Task (Typ) then
1620 Build_Master_Entity (Defining_Identifier (Parent (N)));
1621 end if;
1623 -- STEP 1: Process component associations
1625 -- For those associations that may generate a loop, initialize
1626 -- Loop_Actions to collect inserted actions that may be crated.
1628 -- Skip this if no component associations
1630 if No (Expressions (N)) then
1632 -- STEP 1 (a): Sort the discrete choices
1634 Assoc := First (Component_Associations (N));
1635 while Present (Assoc) loop
1636 Choice := First (Choices (Assoc));
1637 while Present (Choice) loop
1638 if Nkind (Choice) = N_Others_Choice then
1639 Set_Loop_Actions (Assoc, New_List);
1641 if Box_Present (Assoc) then
1642 Others_Box_Present := True;
1643 else
1644 Others_Expr := Expression (Assoc);
1645 end if;
1646 exit;
1647 end if;
1649 Get_Index_Bounds (Choice, Low, High);
1651 if Low /= High then
1652 Set_Loop_Actions (Assoc, New_List);
1653 end if;
1655 Nb_Choices := Nb_Choices + 1;
1656 if Box_Present (Assoc) then
1657 Table (Nb_Choices) := (Choice_Lo => Low,
1658 Choice_Hi => High,
1659 Choice_Node => Empty);
1660 else
1661 Table (Nb_Choices) := (Choice_Lo => Low,
1662 Choice_Hi => High,
1663 Choice_Node => Expression (Assoc));
1664 end if;
1665 Next (Choice);
1666 end loop;
1668 Next (Assoc);
1669 end loop;
1671 -- If there is more than one set of choices these must be static
1672 -- and we can therefore sort them. Remember that Nb_Choices does not
1673 -- account for an others choice.
1675 if Nb_Choices > 1 then
1676 Sort_Case_Table (Table);
1677 end if;
1679 -- STEP 1 (b): take care of the whole set of discrete choices
1681 for J in 1 .. Nb_Choices loop
1682 Low := Table (J).Choice_Lo;
1683 High := Table (J).Choice_Hi;
1684 Expr := Table (J).Choice_Node;
1685 Append_List (Gen_Loop (Low, High, Expr), To => New_Code);
1686 end loop;
1688 -- STEP 1 (c): generate the remaining loops to cover others choice
1689 -- We don't need to generate loops over empty gaps, but if there is
1690 -- a single empty range we must analyze the expression for semantics
1692 if Present (Others_Expr) or else Others_Box_Present then
1693 declare
1694 First : Boolean := True;
1696 begin
1697 for J in 0 .. Nb_Choices loop
1698 if J = 0 then
1699 Low := Aggr_Low;
1700 else
1701 Low := Add (1, To => Table (J).Choice_Hi);
1702 end if;
1704 if J = Nb_Choices then
1705 High := Aggr_High;
1706 else
1707 High := Add (-1, To => Table (J + 1).Choice_Lo);
1708 end if;
1710 -- If this is an expansion within an init proc, make
1711 -- sure that discriminant references are replaced by
1712 -- the corresponding discriminal.
1714 if Inside_Init_Proc then
1715 if Is_Entity_Name (Low)
1716 and then Ekind (Entity (Low)) = E_Discriminant
1717 then
1718 Set_Entity (Low, Discriminal (Entity (Low)));
1719 end if;
1721 if Is_Entity_Name (High)
1722 and then Ekind (Entity (High)) = E_Discriminant
1723 then
1724 Set_Entity (High, Discriminal (Entity (High)));
1725 end if;
1726 end if;
1728 if First
1729 or else not Empty_Range (Low, High)
1730 then
1731 First := False;
1732 Append_List
1733 (Gen_Loop (Low, High, Others_Expr), To => New_Code);
1734 end if;
1735 end loop;
1736 end;
1737 end if;
1739 -- STEP 2: Process positional components
1741 else
1742 -- STEP 2 (a): Generate the assignments for each positional element
1743 -- Note that here we have to use Aggr_L rather than Aggr_Low because
1744 -- Aggr_L is analyzed and Add wants an analyzed expression.
1746 Expr := First (Expressions (N));
1747 Nb_Elements := -1;
1748 while Present (Expr) loop
1749 Nb_Elements := Nb_Elements + 1;
1750 Append_List (Gen_Assign (Add (Nb_Elements, To => Aggr_L), Expr),
1751 To => New_Code);
1752 Next (Expr);
1753 end loop;
1755 -- STEP 2 (b): Generate final loop if an others choice is present
1756 -- Here Nb_Elements gives the offset of the last positional element.
1758 if Present (Component_Associations (N)) then
1759 Assoc := Last (Component_Associations (N));
1761 -- Ada 2005 (AI-287)
1763 if Box_Present (Assoc) then
1764 Append_List (Gen_While (Add (Nb_Elements, To => Aggr_L),
1765 Aggr_High,
1766 Empty),
1767 To => New_Code);
1768 else
1769 Expr := Expression (Assoc);
1771 Append_List (Gen_While (Add (Nb_Elements, To => Aggr_L),
1772 Aggr_High,
1773 Expr), -- AI-287
1774 To => New_Code);
1775 end if;
1776 end if;
1777 end if;
1779 return New_Code;
1780 end Build_Array_Aggr_Code;
1782 ----------------------------
1783 -- Build_Record_Aggr_Code --
1784 ----------------------------
1786 function Build_Record_Aggr_Code
1787 (N : Node_Id;
1788 Typ : Entity_Id;
1789 Lhs : Node_Id) return List_Id
1791 Loc : constant Source_Ptr := Sloc (N);
1792 L : constant List_Id := New_List;
1793 N_Typ : constant Entity_Id := Etype (N);
1795 Comp : Node_Id;
1796 Instr : Node_Id;
1797 Ref : Node_Id;
1798 Target : Entity_Id;
1799 Comp_Type : Entity_Id;
1800 Selector : Entity_Id;
1801 Comp_Expr : Node_Id;
1802 Expr_Q : Node_Id;
1804 -- If this is an internal aggregate, the External_Final_List is an
1805 -- expression for the controller record of the enclosing type.
1807 -- If the current aggregate has several controlled components, this
1808 -- expression will appear in several calls to attach to the finali-
1809 -- zation list, and it must not be shared.
1811 Ancestor_Is_Expression : Boolean := False;
1812 Ancestor_Is_Subtype_Mark : Boolean := False;
1814 Init_Typ : Entity_Id := Empty;
1816 Finalization_Done : Boolean := False;
1817 -- True if Generate_Finalization_Actions has already been called; calls
1818 -- after the first do nothing.
1820 function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id;
1821 -- Returns the value that the given discriminant of an ancestor type
1822 -- should receive (in the absence of a conflict with the value provided
1823 -- by an ancestor part of an extension aggregate).
1825 procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id);
1826 -- Check that each of the discriminant values defined by the ancestor
1827 -- part of an extension aggregate match the corresponding values
1828 -- provided by either an association of the aggregate or by the
1829 -- constraint imposed by a parent type (RM95-4.3.2(8)).
1831 function Compatible_Int_Bounds
1832 (Agg_Bounds : Node_Id;
1833 Typ_Bounds : Node_Id) return Boolean;
1834 -- Return true if Agg_Bounds are equal or within Typ_Bounds. It is
1835 -- assumed that both bounds are integer ranges.
1837 procedure Generate_Finalization_Actions;
1838 -- Deal with the various controlled type data structure initializations
1839 -- (but only if it hasn't been done already).
1841 function Get_Constraint_Association (T : Entity_Id) return Node_Id;
1842 -- Returns the first discriminant association in the constraint
1843 -- associated with T, if any, otherwise returns Empty.
1845 procedure Init_Hidden_Discriminants (Typ : Entity_Id; List : List_Id);
1846 -- If Typ is derived, and constrains discriminants of the parent type,
1847 -- these discriminants are not components of the aggregate, and must be
1848 -- initialized. The assignments are appended to List. The same is done
1849 -- if Typ derives fron an already constrained subtype of a discriminated
1850 -- parent type.
1852 function Get_Explicit_Discriminant_Value (D : Entity_Id) return Node_Id;
1853 -- If the ancestor part is an unconstrained type and further ancestors
1854 -- do not provide discriminants for it, check aggregate components for
1855 -- values of the discriminants.
1857 function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean;
1858 -- Check whether Bounds is a range node and its lower and higher bounds
1859 -- are integers literals.
1861 ---------------------------------
1862 -- Ancestor_Discriminant_Value --
1863 ---------------------------------
1865 function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id is
1866 Assoc : Node_Id;
1867 Assoc_Elmt : Elmt_Id;
1868 Aggr_Comp : Entity_Id;
1869 Corresp_Disc : Entity_Id;
1870 Current_Typ : Entity_Id := Base_Type (Typ);
1871 Parent_Typ : Entity_Id;
1872 Parent_Disc : Entity_Id;
1873 Save_Assoc : Node_Id := Empty;
1875 begin
1876 -- First check any discriminant associations to see if any of them
1877 -- provide a value for the discriminant.
1879 if Present (Discriminant_Specifications (Parent (Current_Typ))) then
1880 Assoc := First (Component_Associations (N));
1881 while Present (Assoc) loop
1882 Aggr_Comp := Entity (First (Choices (Assoc)));
1884 if Ekind (Aggr_Comp) = E_Discriminant then
1885 Save_Assoc := Expression (Assoc);
1887 Corresp_Disc := Corresponding_Discriminant (Aggr_Comp);
1888 while Present (Corresp_Disc) loop
1890 -- If found a corresponding discriminant then return the
1891 -- value given in the aggregate. (Note: this is not
1892 -- correct in the presence of side effects. ???)
1894 if Disc = Corresp_Disc then
1895 return Duplicate_Subexpr (Expression (Assoc));
1896 end if;
1898 Corresp_Disc :=
1899 Corresponding_Discriminant (Corresp_Disc);
1900 end loop;
1901 end if;
1903 Next (Assoc);
1904 end loop;
1905 end if;
1907 -- No match found in aggregate, so chain up parent types to find
1908 -- a constraint that defines the value of the discriminant.
1910 Parent_Typ := Etype (Current_Typ);
1911 while Current_Typ /= Parent_Typ loop
1912 if Has_Discriminants (Parent_Typ)
1913 and then not Has_Unknown_Discriminants (Parent_Typ)
1914 then
1915 Parent_Disc := First_Discriminant (Parent_Typ);
1917 -- We either get the association from the subtype indication
1918 -- of the type definition itself, or from the discriminant
1919 -- constraint associated with the type entity (which is
1920 -- preferable, but it's not always present ???)
1922 if Is_Empty_Elmt_List (
1923 Discriminant_Constraint (Current_Typ))
1924 then
1925 Assoc := Get_Constraint_Association (Current_Typ);
1926 Assoc_Elmt := No_Elmt;
1927 else
1928 Assoc_Elmt :=
1929 First_Elmt (Discriminant_Constraint (Current_Typ));
1930 Assoc := Node (Assoc_Elmt);
1931 end if;
1933 -- Traverse the discriminants of the parent type looking
1934 -- for one that corresponds.
1936 while Present (Parent_Disc) and then Present (Assoc) loop
1937 Corresp_Disc := Parent_Disc;
1938 while Present (Corresp_Disc)
1939 and then Disc /= Corresp_Disc
1940 loop
1941 Corresp_Disc :=
1942 Corresponding_Discriminant (Corresp_Disc);
1943 end loop;
1945 if Disc = Corresp_Disc then
1946 if Nkind (Assoc) = N_Discriminant_Association then
1947 Assoc := Expression (Assoc);
1948 end if;
1950 -- If the located association directly denotes
1951 -- a discriminant, then use the value of a saved
1952 -- association of the aggregate. This is an approach
1953 -- used to handle certain cases involving multiple
1954 -- discriminants mapped to a single discriminant of
1955 -- a descendant. It's not clear how to locate the
1956 -- appropriate discriminant value for such cases. ???
1958 if Is_Entity_Name (Assoc)
1959 and then Ekind (Entity (Assoc)) = E_Discriminant
1960 then
1961 Assoc := Save_Assoc;
1962 end if;
1964 return Duplicate_Subexpr (Assoc);
1965 end if;
1967 Next_Discriminant (Parent_Disc);
1969 if No (Assoc_Elmt) then
1970 Next (Assoc);
1971 else
1972 Next_Elmt (Assoc_Elmt);
1973 if Present (Assoc_Elmt) then
1974 Assoc := Node (Assoc_Elmt);
1975 else
1976 Assoc := Empty;
1977 end if;
1978 end if;
1979 end loop;
1980 end if;
1982 Current_Typ := Parent_Typ;
1983 Parent_Typ := Etype (Current_Typ);
1984 end loop;
1986 -- In some cases there's no ancestor value to locate (such as
1987 -- when an ancestor part given by an expression defines the
1988 -- discriminant value).
1990 return Empty;
1991 end Ancestor_Discriminant_Value;
1993 ----------------------------------
1994 -- Check_Ancestor_Discriminants --
1995 ----------------------------------
1997 procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id) is
1998 Discr : Entity_Id;
1999 Disc_Value : Node_Id;
2000 Cond : Node_Id;
2002 begin
2003 Discr := First_Discriminant (Base_Type (Anc_Typ));
2004 while Present (Discr) loop
2005 Disc_Value := Ancestor_Discriminant_Value (Discr);
2007 if Present (Disc_Value) then
2008 Cond := Make_Op_Ne (Loc,
2009 Left_Opnd =>
2010 Make_Selected_Component (Loc,
2011 Prefix => New_Copy_Tree (Target),
2012 Selector_Name => New_Occurrence_Of (Discr, Loc)),
2013 Right_Opnd => Disc_Value);
2015 Append_To (L,
2016 Make_Raise_Constraint_Error (Loc,
2017 Condition => Cond,
2018 Reason => CE_Discriminant_Check_Failed));
2019 end if;
2021 Next_Discriminant (Discr);
2022 end loop;
2023 end Check_Ancestor_Discriminants;
2025 ---------------------------
2026 -- Compatible_Int_Bounds --
2027 ---------------------------
2029 function Compatible_Int_Bounds
2030 (Agg_Bounds : Node_Id;
2031 Typ_Bounds : Node_Id) return Boolean
2033 Agg_Lo : constant Uint := Intval (Low_Bound (Agg_Bounds));
2034 Agg_Hi : constant Uint := Intval (High_Bound (Agg_Bounds));
2035 Typ_Lo : constant Uint := Intval (Low_Bound (Typ_Bounds));
2036 Typ_Hi : constant Uint := Intval (High_Bound (Typ_Bounds));
2037 begin
2038 return Typ_Lo <= Agg_Lo and then Agg_Hi <= Typ_Hi;
2039 end Compatible_Int_Bounds;
2041 --------------------------------
2042 -- Get_Constraint_Association --
2043 --------------------------------
2045 function Get_Constraint_Association (T : Entity_Id) return Node_Id is
2046 Indic : Node_Id;
2047 Typ : Entity_Id;
2049 begin
2050 Typ := T;
2052 -- Handle private types in instances
2054 if In_Instance
2055 and then Is_Private_Type (Typ)
2056 and then Present (Full_View (Typ))
2057 then
2058 Typ := Full_View (Typ);
2059 end if;
2061 Indic := Subtype_Indication (Type_Definition (Parent (Typ)));
2063 -- ??? Also need to cover case of a type mark denoting a subtype
2064 -- with constraint.
2066 if Nkind (Indic) = N_Subtype_Indication
2067 and then Present (Constraint (Indic))
2068 then
2069 return First (Constraints (Constraint (Indic)));
2070 end if;
2072 return Empty;
2073 end Get_Constraint_Association;
2075 -------------------------------------
2076 -- Get_Explicit_Discriminant_Value --
2077 -------------------------------------
2079 function Get_Explicit_Discriminant_Value
2080 (D : Entity_Id) return Node_Id
2082 Assoc : Node_Id;
2083 Choice : Node_Id;
2084 Val : Node_Id;
2086 begin
2087 -- The aggregate has been normalized and all associations have a
2088 -- single choice.
2090 Assoc := First (Component_Associations (N));
2091 while Present (Assoc) loop
2092 Choice := First (Choices (Assoc));
2094 if Chars (Choice) = Chars (D) then
2095 Val := Expression (Assoc);
2096 Remove (Assoc);
2097 return Val;
2098 end if;
2100 Next (Assoc);
2101 end loop;
2103 return Empty;
2104 end Get_Explicit_Discriminant_Value;
2106 -------------------------------
2107 -- Init_Hidden_Discriminants --
2108 -------------------------------
2110 procedure Init_Hidden_Discriminants (Typ : Entity_Id; List : List_Id) is
2111 Btype : Entity_Id;
2112 Parent_Type : Entity_Id;
2113 Disc : Entity_Id;
2114 Discr_Val : Elmt_Id;
2116 begin
2117 -- The constraints on the hidden discriminants, if present, are kept
2118 -- in the Stored_Constraint list of the type itself, or in that of
2119 -- the base type.
2121 Btype := Base_Type (Typ);
2122 while Is_Derived_Type (Btype)
2123 and then (Present (Stored_Constraint (Btype))
2124 or else
2125 Present (Stored_Constraint (Typ)))
2126 loop
2127 Parent_Type := Etype (Btype);
2129 if not Has_Discriminants (Parent_Type) then
2130 return;
2131 end if;
2133 Disc := First_Discriminant (Parent_Type);
2135 -- We know that one of the stored-constraint lists is present
2137 if Present (Stored_Constraint (Btype)) then
2138 Discr_Val := First_Elmt (Stored_Constraint (Btype));
2140 -- For private extension, stored constraint may be on full view
2142 elsif Is_Private_Type (Btype)
2143 and then Present (Full_View (Btype))
2144 and then Present (Stored_Constraint (Full_View (Btype)))
2145 then
2146 Discr_Val := First_Elmt (Stored_Constraint (Full_View (Btype)));
2148 else
2149 Discr_Val := First_Elmt (Stored_Constraint (Typ));
2150 end if;
2152 while Present (Discr_Val) loop
2154 -- Only those discriminants of the parent that are not
2155 -- renamed by discriminants of the derived type need to
2156 -- be added explicitly.
2158 if not Is_Entity_Name (Node (Discr_Val))
2159 or else Ekind (Entity (Node (Discr_Val))) /= E_Discriminant
2160 then
2161 Comp_Expr :=
2162 Make_Selected_Component (Loc,
2163 Prefix => New_Copy_Tree (Target),
2164 Selector_Name => New_Occurrence_Of (Disc, Loc));
2166 Instr :=
2167 Make_OK_Assignment_Statement (Loc,
2168 Name => Comp_Expr,
2169 Expression => New_Copy_Tree (Node (Discr_Val)));
2171 Set_No_Ctrl_Actions (Instr);
2172 Append_To (List, Instr);
2173 end if;
2175 Next_Discriminant (Disc);
2176 Next_Elmt (Discr_Val);
2177 end loop;
2179 Btype := Base_Type (Parent_Type);
2180 end loop;
2181 end Init_Hidden_Discriminants;
2183 -------------------------
2184 -- Is_Int_Range_Bounds --
2185 -------------------------
2187 function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean is
2188 begin
2189 return Nkind (Bounds) = N_Range
2190 and then Nkind (Low_Bound (Bounds)) = N_Integer_Literal
2191 and then Nkind (High_Bound (Bounds)) = N_Integer_Literal;
2192 end Is_Int_Range_Bounds;
2194 -----------------------------------
2195 -- Generate_Finalization_Actions --
2196 -----------------------------------
2198 procedure Generate_Finalization_Actions is
2199 begin
2200 -- Do the work only the first time this is called
2202 if Finalization_Done then
2203 return;
2204 end if;
2206 Finalization_Done := True;
2208 -- Determine the external finalization list. It is either the
2209 -- finalization list of the outer-scope or the one coming from an
2210 -- outer aggregate. When the target is not a temporary, the proper
2211 -- scope is the scope of the target rather than the potentially
2212 -- transient current scope.
2214 if Is_Controlled (Typ) and then Ancestor_Is_Subtype_Mark then
2215 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2216 Set_Assignment_OK (Ref);
2218 Append_To (L,
2219 Make_Procedure_Call_Statement (Loc,
2220 Name =>
2221 New_Occurrence_Of
2222 (Find_Prim_Op (Init_Typ, Name_Initialize), Loc),
2223 Parameter_Associations => New_List (New_Copy_Tree (Ref))));
2224 end if;
2225 end Generate_Finalization_Actions;
2227 function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result;
2228 -- If default expression of a component mentions a discriminant of the
2229 -- type, it must be rewritten as the discriminant of the target object.
2231 function Replace_Type (Expr : Node_Id) return Traverse_Result;
2232 -- If the aggregate contains a self-reference, traverse each expression
2233 -- to replace a possible self-reference with a reference to the proper
2234 -- component of the target of the assignment.
2236 --------------------------
2237 -- Rewrite_Discriminant --
2238 --------------------------
2240 function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result is
2241 begin
2242 if Is_Entity_Name (Expr)
2243 and then Present (Entity (Expr))
2244 and then Ekind (Entity (Expr)) = E_In_Parameter
2245 and then Present (Discriminal_Link (Entity (Expr)))
2246 and then Scope (Discriminal_Link (Entity (Expr))) =
2247 Base_Type (Etype (N))
2248 then
2249 Rewrite (Expr,
2250 Make_Selected_Component (Loc,
2251 Prefix => New_Copy_Tree (Lhs),
2252 Selector_Name => Make_Identifier (Loc, Chars (Expr))));
2253 end if;
2255 return OK;
2256 end Rewrite_Discriminant;
2258 ------------------
2259 -- Replace_Type --
2260 ------------------
2262 function Replace_Type (Expr : Node_Id) return Traverse_Result is
2263 begin
2264 -- Note regarding the Root_Type test below: Aggregate components for
2265 -- self-referential types include attribute references to the current
2266 -- instance, of the form: Typ'access, etc.. These references are
2267 -- rewritten as references to the target of the aggregate: the
2268 -- left-hand side of an assignment, the entity in a declaration,
2269 -- or a temporary. Without this test, we would improperly extended
2270 -- this rewriting to attribute references whose prefix was not the
2271 -- type of the aggregate.
2273 if Nkind (Expr) = N_Attribute_Reference
2274 and then Is_Entity_Name (Prefix (Expr))
2275 and then Is_Type (Entity (Prefix (Expr)))
2276 and then Root_Type (Etype (N)) = Root_Type (Entity (Prefix (Expr)))
2277 then
2278 if Is_Entity_Name (Lhs) then
2279 Rewrite (Prefix (Expr),
2280 New_Occurrence_Of (Entity (Lhs), Loc));
2282 elsif Nkind (Lhs) = N_Selected_Component then
2283 Rewrite (Expr,
2284 Make_Attribute_Reference (Loc,
2285 Attribute_Name => Name_Unrestricted_Access,
2286 Prefix => New_Copy_Tree (Lhs)));
2287 Set_Analyzed (Parent (Expr), False);
2289 else
2290 Rewrite (Expr,
2291 Make_Attribute_Reference (Loc,
2292 Attribute_Name => Name_Unrestricted_Access,
2293 Prefix => New_Copy_Tree (Lhs)));
2294 Set_Analyzed (Parent (Expr), False);
2295 end if;
2296 end if;
2298 return OK;
2299 end Replace_Type;
2301 procedure Replace_Self_Reference is
2302 new Traverse_Proc (Replace_Type);
2304 procedure Replace_Discriminants is
2305 new Traverse_Proc (Rewrite_Discriminant);
2307 -- Start of processing for Build_Record_Aggr_Code
2309 begin
2310 if Has_Self_Reference (N) then
2311 Replace_Self_Reference (N);
2312 end if;
2314 -- If the target of the aggregate is class-wide, we must convert it
2315 -- to the actual type of the aggregate, so that the proper components
2316 -- are visible. We know already that the types are compatible.
2318 if Present (Etype (Lhs))
2319 and then Is_Class_Wide_Type (Etype (Lhs))
2320 then
2321 Target := Unchecked_Convert_To (Typ, Lhs);
2322 else
2323 Target := Lhs;
2324 end if;
2326 -- Deal with the ancestor part of extension aggregates or with the
2327 -- discriminants of the root type.
2329 if Nkind (N) = N_Extension_Aggregate then
2330 declare
2331 Ancestor : constant Node_Id := Ancestor_Part (N);
2332 Assign : List_Id;
2334 begin
2335 -- If the ancestor part is a subtype mark "T", we generate
2337 -- init-proc (T (tmp)); if T is constrained and
2338 -- init-proc (S (tmp)); where S applies an appropriate
2339 -- constraint if T is unconstrained
2341 if Is_Entity_Name (Ancestor)
2342 and then Is_Type (Entity (Ancestor))
2343 then
2344 Ancestor_Is_Subtype_Mark := True;
2346 if Is_Constrained (Entity (Ancestor)) then
2347 Init_Typ := Entity (Ancestor);
2349 -- For an ancestor part given by an unconstrained type mark,
2350 -- create a subtype constrained by appropriate corresponding
2351 -- discriminant values coming from either associations of the
2352 -- aggregate or a constraint on a parent type. The subtype will
2353 -- be used to generate the correct default value for the
2354 -- ancestor part.
2356 elsif Has_Discriminants (Entity (Ancestor)) then
2357 declare
2358 Anc_Typ : constant Entity_Id := Entity (Ancestor);
2359 Anc_Constr : constant List_Id := New_List;
2360 Discrim : Entity_Id;
2361 Disc_Value : Node_Id;
2362 New_Indic : Node_Id;
2363 Subt_Decl : Node_Id;
2365 begin
2366 Discrim := First_Discriminant (Anc_Typ);
2367 while Present (Discrim) loop
2368 Disc_Value := Ancestor_Discriminant_Value (Discrim);
2370 -- If no usable discriminant in ancestors, check
2371 -- whether aggregate has an explicit value for it.
2373 if No (Disc_Value) then
2374 Disc_Value :=
2375 Get_Explicit_Discriminant_Value (Discrim);
2376 end if;
2378 Append_To (Anc_Constr, Disc_Value);
2379 Next_Discriminant (Discrim);
2380 end loop;
2382 New_Indic :=
2383 Make_Subtype_Indication (Loc,
2384 Subtype_Mark => New_Occurrence_Of (Anc_Typ, Loc),
2385 Constraint =>
2386 Make_Index_Or_Discriminant_Constraint (Loc,
2387 Constraints => Anc_Constr));
2389 Init_Typ := Create_Itype (Ekind (Anc_Typ), N);
2391 Subt_Decl :=
2392 Make_Subtype_Declaration (Loc,
2393 Defining_Identifier => Init_Typ,
2394 Subtype_Indication => New_Indic);
2396 -- Itypes must be analyzed with checks off Declaration
2397 -- must have a parent for proper handling of subsidiary
2398 -- actions.
2400 Set_Parent (Subt_Decl, N);
2401 Analyze (Subt_Decl, Suppress => All_Checks);
2402 end;
2403 end if;
2405 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2406 Set_Assignment_OK (Ref);
2408 if not Is_Interface (Init_Typ) then
2409 Append_List_To (L,
2410 Build_Initialization_Call (Loc,
2411 Id_Ref => Ref,
2412 Typ => Init_Typ,
2413 In_Init_Proc => Within_Init_Proc,
2414 With_Default_Init => Has_Default_Init_Comps (N)
2415 or else
2416 Has_Task (Base_Type (Init_Typ))));
2418 if Is_Constrained (Entity (Ancestor))
2419 and then Has_Discriminants (Entity (Ancestor))
2420 then
2421 Check_Ancestor_Discriminants (Entity (Ancestor));
2422 end if;
2423 end if;
2425 -- Handle calls to C++ constructors
2427 elsif Is_CPP_Constructor_Call (Ancestor) then
2428 Init_Typ := Etype (Ancestor);
2429 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2430 Set_Assignment_OK (Ref);
2432 Append_List_To (L,
2433 Build_Initialization_Call (Loc,
2434 Id_Ref => Ref,
2435 Typ => Init_Typ,
2436 In_Init_Proc => Within_Init_Proc,
2437 With_Default_Init => Has_Default_Init_Comps (N),
2438 Constructor_Ref => Ancestor));
2440 -- Ada 2005 (AI-287): If the ancestor part is an aggregate of
2441 -- limited type, a recursive call expands the ancestor. Note that
2442 -- in the limited case, the ancestor part must be either a
2443 -- function call (possibly qualified, or wrapped in an unchecked
2444 -- conversion) or aggregate (definitely qualified).
2446 -- The ancestor part can also be a function call (that may be
2447 -- transformed into an explicit dereference) or a qualification
2448 -- of one such.
2450 elsif Is_Limited_Type (Etype (Ancestor))
2451 and then Nkind_In (Unqualify (Ancestor), N_Aggregate,
2452 N_Extension_Aggregate)
2453 then
2454 Ancestor_Is_Expression := True;
2456 -- Set up finalization data for enclosing record, because
2457 -- controlled subcomponents of the ancestor part will be
2458 -- attached to it.
2460 Generate_Finalization_Actions;
2462 Append_List_To (L,
2463 Build_Record_Aggr_Code
2464 (N => Unqualify (Ancestor),
2465 Typ => Etype (Unqualify (Ancestor)),
2466 Lhs => Target));
2468 -- If the ancestor part is an expression "E", we generate
2470 -- T (tmp) := E;
2472 -- In Ada 2005, this includes the case of a (possibly qualified)
2473 -- limited function call. The assignment will turn into a
2474 -- build-in-place function call (for further details, see
2475 -- Make_Build_In_Place_Call_In_Assignment).
2477 else
2478 Ancestor_Is_Expression := True;
2479 Init_Typ := Etype (Ancestor);
2481 -- If the ancestor part is an aggregate, force its full
2482 -- expansion, which was delayed.
2484 if Nkind_In (Unqualify (Ancestor), N_Aggregate,
2485 N_Extension_Aggregate)
2486 then
2487 Set_Analyzed (Ancestor, False);
2488 Set_Analyzed (Expression (Ancestor), False);
2489 end if;
2491 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2492 Set_Assignment_OK (Ref);
2494 -- Make the assignment without usual controlled actions, since
2495 -- we only want to Adjust afterwards, but not to Finalize
2496 -- beforehand. Add manual Adjust when necessary.
2498 Assign := New_List (
2499 Make_OK_Assignment_Statement (Loc,
2500 Name => Ref,
2501 Expression => Ancestor));
2502 Set_No_Ctrl_Actions (First (Assign));
2504 -- Assign the tag now to make sure that the dispatching call in
2505 -- the subsequent deep_adjust works properly (unless VM_Target,
2506 -- where tags are implicit).
2508 if Tagged_Type_Expansion then
2509 Instr :=
2510 Make_OK_Assignment_Statement (Loc,
2511 Name =>
2512 Make_Selected_Component (Loc,
2513 Prefix => New_Copy_Tree (Target),
2514 Selector_Name =>
2515 New_Occurrence_Of
2516 (First_Tag_Component (Base_Type (Typ)), Loc)),
2518 Expression =>
2519 Unchecked_Convert_To (RTE (RE_Tag),
2520 New_Occurrence_Of
2521 (Node (First_Elmt
2522 (Access_Disp_Table (Base_Type (Typ)))),
2523 Loc)));
2525 Set_Assignment_OK (Name (Instr));
2526 Append_To (Assign, Instr);
2528 -- Ada 2005 (AI-251): If tagged type has progenitors we must
2529 -- also initialize tags of the secondary dispatch tables.
2531 if Has_Interfaces (Base_Type (Typ)) then
2532 Init_Secondary_Tags
2533 (Typ => Base_Type (Typ),
2534 Target => Target,
2535 Stmts_List => Assign);
2536 end if;
2537 end if;
2539 -- Call Adjust manually
2541 if Needs_Finalization (Etype (Ancestor))
2542 and then not Is_Limited_Type (Etype (Ancestor))
2543 then
2544 Append_To (Assign,
2545 Make_Adjust_Call
2546 (Obj_Ref => New_Copy_Tree (Ref),
2547 Typ => Etype (Ancestor)));
2548 end if;
2550 Append_To (L,
2551 Make_Unsuppress_Block (Loc, Name_Discriminant_Check, Assign));
2553 if Has_Discriminants (Init_Typ) then
2554 Check_Ancestor_Discriminants (Init_Typ);
2555 end if;
2556 end if;
2557 end;
2559 -- Generate assignments of hidden discriminants. If the base type is
2560 -- an unchecked union, the discriminants are unknown to the back-end
2561 -- and absent from a value of the type, so assignments for them are
2562 -- not emitted.
2564 if Has_Discriminants (Typ)
2565 and then not Is_Unchecked_Union (Base_Type (Typ))
2566 then
2567 Init_Hidden_Discriminants (Typ, L);
2568 end if;
2570 -- Normal case (not an extension aggregate)
2572 else
2573 -- Generate the discriminant expressions, component by component.
2574 -- If the base type is an unchecked union, the discriminants are
2575 -- unknown to the back-end and absent from a value of the type, so
2576 -- assignments for them are not emitted.
2578 if Has_Discriminants (Typ)
2579 and then not Is_Unchecked_Union (Base_Type (Typ))
2580 then
2581 Init_Hidden_Discriminants (Typ, L);
2583 -- Generate discriminant init values for the visible discriminants
2585 declare
2586 Discriminant : Entity_Id;
2587 Discriminant_Value : Node_Id;
2589 begin
2590 Discriminant := First_Stored_Discriminant (Typ);
2591 while Present (Discriminant) loop
2592 Comp_Expr :=
2593 Make_Selected_Component (Loc,
2594 Prefix => New_Copy_Tree (Target),
2595 Selector_Name => New_Occurrence_Of (Discriminant, Loc));
2597 Discriminant_Value :=
2598 Get_Discriminant_Value (
2599 Discriminant,
2600 N_Typ,
2601 Discriminant_Constraint (N_Typ));
2603 Instr :=
2604 Make_OK_Assignment_Statement (Loc,
2605 Name => Comp_Expr,
2606 Expression => New_Copy_Tree (Discriminant_Value));
2608 Set_No_Ctrl_Actions (Instr);
2609 Append_To (L, Instr);
2611 Next_Stored_Discriminant (Discriminant);
2612 end loop;
2613 end;
2614 end if;
2615 end if;
2617 -- For CPP types we generate an implicit call to the C++ default
2618 -- constructor to ensure the proper initialization of the _Tag
2619 -- component.
2621 if Is_CPP_Class (Root_Type (Typ)) and then CPP_Num_Prims (Typ) > 0 then
2622 Invoke_Constructor : declare
2623 CPP_Parent : constant Entity_Id := Enclosing_CPP_Parent (Typ);
2625 procedure Invoke_IC_Proc (T : Entity_Id);
2626 -- Recursive routine used to climb to parents. Required because
2627 -- parents must be initialized before descendants to ensure
2628 -- propagation of inherited C++ slots.
2630 --------------------
2631 -- Invoke_IC_Proc --
2632 --------------------
2634 procedure Invoke_IC_Proc (T : Entity_Id) is
2635 begin
2636 -- Avoid generating extra calls. Initialization required
2637 -- only for types defined from the level of derivation of
2638 -- type of the constructor and the type of the aggregate.
2640 if T = CPP_Parent then
2641 return;
2642 end if;
2644 Invoke_IC_Proc (Etype (T));
2646 -- Generate call to the IC routine
2648 if Present (CPP_Init_Proc (T)) then
2649 Append_To (L,
2650 Make_Procedure_Call_Statement (Loc,
2651 New_Occurrence_Of (CPP_Init_Proc (T), Loc)));
2652 end if;
2653 end Invoke_IC_Proc;
2655 -- Start of processing for Invoke_Constructor
2657 begin
2658 -- Implicit invocation of the C++ constructor
2660 if Nkind (N) = N_Aggregate then
2661 Append_To (L,
2662 Make_Procedure_Call_Statement (Loc,
2663 Name =>
2664 New_Occurrence_Of (Base_Init_Proc (CPP_Parent), Loc),
2665 Parameter_Associations => New_List (
2666 Unchecked_Convert_To (CPP_Parent,
2667 New_Copy_Tree (Lhs)))));
2668 end if;
2670 Invoke_IC_Proc (Typ);
2671 end Invoke_Constructor;
2672 end if;
2674 -- Generate the assignments, component by component
2676 -- tmp.comp1 := Expr1_From_Aggr;
2677 -- tmp.comp2 := Expr2_From_Aggr;
2678 -- ....
2680 Comp := First (Component_Associations (N));
2681 while Present (Comp) loop
2682 Selector := Entity (First (Choices (Comp)));
2684 -- C++ constructors
2686 if Is_CPP_Constructor_Call (Expression (Comp)) then
2687 Append_List_To (L,
2688 Build_Initialization_Call (Loc,
2689 Id_Ref =>
2690 Make_Selected_Component (Loc,
2691 Prefix => New_Copy_Tree (Target),
2692 Selector_Name => New_Occurrence_Of (Selector, Loc)),
2693 Typ => Etype (Selector),
2694 Enclos_Type => Typ,
2695 With_Default_Init => True,
2696 Constructor_Ref => Expression (Comp)));
2698 -- Ada 2005 (AI-287): For each default-initialized component generate
2699 -- a call to the corresponding IP subprogram if available.
2701 elsif Box_Present (Comp)
2702 and then Has_Non_Null_Base_Init_Proc (Etype (Selector))
2703 then
2704 if Ekind (Selector) /= E_Discriminant then
2705 Generate_Finalization_Actions;
2706 end if;
2708 -- Ada 2005 (AI-287): If the component type has tasks then
2709 -- generate the activation chain and master entities (except
2710 -- in case of an allocator because in that case these entities
2711 -- are generated by Build_Task_Allocate_Block_With_Init_Stmts).
2713 declare
2714 Ctype : constant Entity_Id := Etype (Selector);
2715 Inside_Allocator : Boolean := False;
2716 P : Node_Id := Parent (N);
2718 begin
2719 if Is_Task_Type (Ctype) or else Has_Task (Ctype) then
2720 while Present (P) loop
2721 if Nkind (P) = N_Allocator then
2722 Inside_Allocator := True;
2723 exit;
2724 end if;
2726 P := Parent (P);
2727 end loop;
2729 if not Inside_Init_Proc and not Inside_Allocator then
2730 Build_Activation_Chain_Entity (N);
2731 end if;
2732 end if;
2733 end;
2735 Append_List_To (L,
2736 Build_Initialization_Call (Loc,
2737 Id_Ref => Make_Selected_Component (Loc,
2738 Prefix => New_Copy_Tree (Target),
2739 Selector_Name =>
2740 New_Occurrence_Of (Selector, Loc)),
2741 Typ => Etype (Selector),
2742 Enclos_Type => Typ,
2743 With_Default_Init => True));
2745 -- Prepare for component assignment
2747 elsif Ekind (Selector) /= E_Discriminant
2748 or else Nkind (N) = N_Extension_Aggregate
2749 then
2750 -- All the discriminants have now been assigned
2752 -- This is now a good moment to initialize and attach all the
2753 -- controllers. Their position may depend on the discriminants.
2755 if Ekind (Selector) /= E_Discriminant then
2756 Generate_Finalization_Actions;
2757 end if;
2759 Comp_Type := Underlying_Type (Etype (Selector));
2760 Comp_Expr :=
2761 Make_Selected_Component (Loc,
2762 Prefix => New_Copy_Tree (Target),
2763 Selector_Name => New_Occurrence_Of (Selector, Loc));
2765 if Nkind (Expression (Comp)) = N_Qualified_Expression then
2766 Expr_Q := Expression (Expression (Comp));
2767 else
2768 Expr_Q := Expression (Comp);
2769 end if;
2771 -- Now either create the assignment or generate the code for the
2772 -- inner aggregate top-down.
2774 if Is_Delayed_Aggregate (Expr_Q) then
2776 -- We have the following case of aggregate nesting inside
2777 -- an object declaration:
2779 -- type Arr_Typ is array (Integer range <>) of ...;
2781 -- type Rec_Typ (...) is record
2782 -- Obj_Arr_Typ : Arr_Typ (A .. B);
2783 -- end record;
2785 -- Obj_Rec_Typ : Rec_Typ := (...,
2786 -- Obj_Arr_Typ => (X => (...), Y => (...)));
2788 -- The length of the ranges of the aggregate and Obj_Add_Typ
2789 -- are equal (B - A = Y - X), but they do not coincide (X /=
2790 -- A and B /= Y). This case requires array sliding which is
2791 -- performed in the following manner:
2793 -- subtype Arr_Sub is Arr_Typ (X .. Y);
2794 -- Temp : Arr_Sub;
2795 -- Temp (X) := (...);
2796 -- ...
2797 -- Temp (Y) := (...);
2798 -- Obj_Rec_Typ.Obj_Arr_Typ := Temp;
2800 if Ekind (Comp_Type) = E_Array_Subtype
2801 and then Is_Int_Range_Bounds (Aggregate_Bounds (Expr_Q))
2802 and then Is_Int_Range_Bounds (First_Index (Comp_Type))
2803 and then not
2804 Compatible_Int_Bounds
2805 (Agg_Bounds => Aggregate_Bounds (Expr_Q),
2806 Typ_Bounds => First_Index (Comp_Type))
2807 then
2808 -- Create the array subtype with bounds equal to those of
2809 -- the corresponding aggregate.
2811 declare
2812 SubE : constant Entity_Id := Make_Temporary (Loc, 'T');
2814 SubD : constant Node_Id :=
2815 Make_Subtype_Declaration (Loc,
2816 Defining_Identifier => SubE,
2817 Subtype_Indication =>
2818 Make_Subtype_Indication (Loc,
2819 Subtype_Mark =>
2820 New_Occurrence_Of (Etype (Comp_Type), Loc),
2821 Constraint =>
2822 Make_Index_Or_Discriminant_Constraint
2823 (Loc,
2824 Constraints => New_List (
2825 New_Copy_Tree
2826 (Aggregate_Bounds (Expr_Q))))));
2828 -- Create a temporary array of the above subtype which
2829 -- will be used to capture the aggregate assignments.
2831 TmpE : constant Entity_Id := Make_Temporary (Loc, 'A', N);
2833 TmpD : constant Node_Id :=
2834 Make_Object_Declaration (Loc,
2835 Defining_Identifier => TmpE,
2836 Object_Definition => New_Occurrence_Of (SubE, Loc));
2838 begin
2839 Set_No_Initialization (TmpD);
2840 Append_To (L, SubD);
2841 Append_To (L, TmpD);
2843 -- Expand aggregate into assignments to the temp array
2845 Append_List_To (L,
2846 Late_Expansion (Expr_Q, Comp_Type,
2847 New_Occurrence_Of (TmpE, Loc)));
2849 -- Slide
2851 Append_To (L,
2852 Make_Assignment_Statement (Loc,
2853 Name => New_Copy_Tree (Comp_Expr),
2854 Expression => New_Occurrence_Of (TmpE, Loc)));
2855 end;
2857 -- Normal case (sliding not required)
2859 else
2860 Append_List_To (L,
2861 Late_Expansion (Expr_Q, Comp_Type, Comp_Expr));
2862 end if;
2864 -- Expr_Q is not delayed aggregate
2866 else
2867 if Has_Discriminants (Typ) then
2868 Replace_Discriminants (Expr_Q);
2870 -- If the component is an array type that depends on
2871 -- discriminants, and the expression is a single Others
2872 -- clause, create an explicit subtype for it because the
2873 -- backend has troubles recovering the actual bounds.
2875 if Nkind (Expr_Q) = N_Aggregate
2876 and then Is_Array_Type (Comp_Type)
2877 and then Present (Component_Associations (Expr_Q))
2878 then
2879 declare
2880 Assoc : constant Node_Id :=
2881 First (Component_Associations (Expr_Q));
2882 Decl : Node_Id;
2884 begin
2885 if Nkind (First (Choices (Assoc))) = N_Others_Choice
2886 then
2887 Decl :=
2888 Build_Actual_Subtype_Of_Component
2889 (Comp_Type, Comp_Expr);
2891 -- If the component type does not in fact depend on
2892 -- discriminants, the subtype declaration is empty.
2894 if Present (Decl) then
2895 Append_To (L, Decl);
2896 Set_Etype (Comp_Expr, Defining_Entity (Decl));
2897 end if;
2898 end if;
2899 end;
2900 end if;
2901 end if;
2903 Instr :=
2904 Make_OK_Assignment_Statement (Loc,
2905 Name => Comp_Expr,
2906 Expression => Expr_Q);
2908 Set_No_Ctrl_Actions (Instr);
2909 Append_To (L, Instr);
2911 -- Adjust the tag if tagged (because of possible view
2912 -- conversions), unless compiling for a VM where tags are
2913 -- implicit.
2915 -- tmp.comp._tag := comp_typ'tag;
2917 if Is_Tagged_Type (Comp_Type)
2918 and then Tagged_Type_Expansion
2919 then
2920 Instr :=
2921 Make_OK_Assignment_Statement (Loc,
2922 Name =>
2923 Make_Selected_Component (Loc,
2924 Prefix => New_Copy_Tree (Comp_Expr),
2925 Selector_Name =>
2926 New_Occurrence_Of
2927 (First_Tag_Component (Comp_Type), Loc)),
2929 Expression =>
2930 Unchecked_Convert_To (RTE (RE_Tag),
2931 New_Occurrence_Of
2932 (Node (First_Elmt (Access_Disp_Table (Comp_Type))),
2933 Loc)));
2935 Append_To (L, Instr);
2936 end if;
2938 -- Generate:
2939 -- Adjust (tmp.comp);
2941 if Needs_Finalization (Comp_Type)
2942 and then not Is_Limited_Type (Comp_Type)
2943 then
2944 Append_To (L,
2945 Make_Adjust_Call
2946 (Obj_Ref => New_Copy_Tree (Comp_Expr),
2947 Typ => Comp_Type));
2948 end if;
2949 end if;
2951 -- comment would be good here ???
2953 elsif Ekind (Selector) = E_Discriminant
2954 and then Nkind (N) /= N_Extension_Aggregate
2955 and then Nkind (Parent (N)) = N_Component_Association
2956 and then Is_Constrained (Typ)
2957 then
2958 -- We must check that the discriminant value imposed by the
2959 -- context is the same as the value given in the subaggregate,
2960 -- because after the expansion into assignments there is no
2961 -- record on which to perform a regular discriminant check.
2963 declare
2964 D_Val : Elmt_Id;
2965 Disc : Entity_Id;
2967 begin
2968 D_Val := First_Elmt (Discriminant_Constraint (Typ));
2969 Disc := First_Discriminant (Typ);
2970 while Chars (Disc) /= Chars (Selector) loop
2971 Next_Discriminant (Disc);
2972 Next_Elmt (D_Val);
2973 end loop;
2975 pragma Assert (Present (D_Val));
2977 -- This check cannot performed for components that are
2978 -- constrained by a current instance, because this is not a
2979 -- value that can be compared with the actual constraint.
2981 if Nkind (Node (D_Val)) /= N_Attribute_Reference
2982 or else not Is_Entity_Name (Prefix (Node (D_Val)))
2983 or else not Is_Type (Entity (Prefix (Node (D_Val))))
2984 then
2985 Append_To (L,
2986 Make_Raise_Constraint_Error (Loc,
2987 Condition =>
2988 Make_Op_Ne (Loc,
2989 Left_Opnd => New_Copy_Tree (Node (D_Val)),
2990 Right_Opnd => Expression (Comp)),
2991 Reason => CE_Discriminant_Check_Failed));
2993 else
2994 -- Find self-reference in previous discriminant assignment,
2995 -- and replace with proper expression.
2997 declare
2998 Ass : Node_Id;
3000 begin
3001 Ass := First (L);
3002 while Present (Ass) loop
3003 if Nkind (Ass) = N_Assignment_Statement
3004 and then Nkind (Name (Ass)) = N_Selected_Component
3005 and then Chars (Selector_Name (Name (Ass))) =
3006 Chars (Disc)
3007 then
3008 Set_Expression
3009 (Ass, New_Copy_Tree (Expression (Comp)));
3010 exit;
3011 end if;
3012 Next (Ass);
3013 end loop;
3014 end;
3015 end if;
3016 end;
3017 end if;
3019 Next (Comp);
3020 end loop;
3022 -- If the type is tagged, the tag needs to be initialized (unless we
3023 -- are in VM-mode where tags are implicit). It is done late in the
3024 -- initialization process because in some cases, we call the init
3025 -- proc of an ancestor which will not leave out the right tag.
3027 if Ancestor_Is_Expression then
3028 null;
3030 -- For CPP types we generated a call to the C++ default constructor
3031 -- before the components have been initialized to ensure the proper
3032 -- initialization of the _Tag component (see above).
3034 elsif Is_CPP_Class (Typ) then
3035 null;
3037 elsif Is_Tagged_Type (Typ) and then Tagged_Type_Expansion then
3038 Instr :=
3039 Make_OK_Assignment_Statement (Loc,
3040 Name =>
3041 Make_Selected_Component (Loc,
3042 Prefix => New_Copy_Tree (Target),
3043 Selector_Name =>
3044 New_Occurrence_Of
3045 (First_Tag_Component (Base_Type (Typ)), Loc)),
3047 Expression =>
3048 Unchecked_Convert_To (RTE (RE_Tag),
3049 New_Occurrence_Of
3050 (Node (First_Elmt (Access_Disp_Table (Base_Type (Typ)))),
3051 Loc)));
3053 Append_To (L, Instr);
3055 -- Ada 2005 (AI-251): If the tagged type has been derived from an
3056 -- abstract interfaces we must also initialize the tags of the
3057 -- secondary dispatch tables.
3059 if Has_Interfaces (Base_Type (Typ)) then
3060 Init_Secondary_Tags
3061 (Typ => Base_Type (Typ),
3062 Target => Target,
3063 Stmts_List => L);
3064 end if;
3065 end if;
3067 -- If the controllers have not been initialized yet (by lack of non-
3068 -- discriminant components), let's do it now.
3070 Generate_Finalization_Actions;
3072 return L;
3073 end Build_Record_Aggr_Code;
3075 ---------------------------------------
3076 -- Collect_Initialization_Statements --
3077 ---------------------------------------
3079 procedure Collect_Initialization_Statements
3080 (Obj : Entity_Id;
3081 N : Node_Id;
3082 Node_After : Node_Id)
3084 Loc : constant Source_Ptr := Sloc (N);
3085 Init_Actions : constant List_Id := New_List;
3086 Init_Node : Node_Id;
3087 Comp_Stmt : Node_Id;
3089 begin
3090 -- Nothing to do if Obj is already frozen, as in this case we known we
3091 -- won't need to move the initialization statements about later on.
3093 if Is_Frozen (Obj) then
3094 return;
3095 end if;
3097 Init_Node := N;
3098 while Next (Init_Node) /= Node_After loop
3099 Append_To (Init_Actions, Remove_Next (Init_Node));
3100 end loop;
3102 if not Is_Empty_List (Init_Actions) then
3103 Comp_Stmt := Make_Compound_Statement (Loc, Actions => Init_Actions);
3104 Insert_Action_After (Init_Node, Comp_Stmt);
3105 Set_Initialization_Statements (Obj, Comp_Stmt);
3106 end if;
3107 end Collect_Initialization_Statements;
3109 -------------------------------
3110 -- Convert_Aggr_In_Allocator --
3111 -------------------------------
3113 procedure Convert_Aggr_In_Allocator
3114 (Alloc : Node_Id;
3115 Decl : Node_Id;
3116 Aggr : Node_Id)
3118 Loc : constant Source_Ptr := Sloc (Aggr);
3119 Typ : constant Entity_Id := Etype (Aggr);
3120 Temp : constant Entity_Id := Defining_Identifier (Decl);
3122 Occ : constant Node_Id :=
3123 Unchecked_Convert_To (Typ,
3124 Make_Explicit_Dereference (Loc, New_Occurrence_Of (Temp, Loc)));
3126 begin
3127 if Is_Array_Type (Typ) then
3128 Convert_Array_Aggr_In_Allocator (Decl, Aggr, Occ);
3130 elsif Has_Default_Init_Comps (Aggr) then
3131 declare
3132 L : constant List_Id := New_List;
3133 Init_Stmts : List_Id;
3135 begin
3136 Init_Stmts := Late_Expansion (Aggr, Typ, Occ);
3138 if Has_Task (Typ) then
3139 Build_Task_Allocate_Block_With_Init_Stmts (L, Aggr, Init_Stmts);
3140 Insert_Actions (Alloc, L);
3141 else
3142 Insert_Actions (Alloc, Init_Stmts);
3143 end if;
3144 end;
3146 else
3147 Insert_Actions (Alloc, Late_Expansion (Aggr, Typ, Occ));
3148 end if;
3149 end Convert_Aggr_In_Allocator;
3151 --------------------------------
3152 -- Convert_Aggr_In_Assignment --
3153 --------------------------------
3155 procedure Convert_Aggr_In_Assignment (N : Node_Id) is
3156 Aggr : Node_Id := Expression (N);
3157 Typ : constant Entity_Id := Etype (Aggr);
3158 Occ : constant Node_Id := New_Copy_Tree (Name (N));
3160 begin
3161 if Nkind (Aggr) = N_Qualified_Expression then
3162 Aggr := Expression (Aggr);
3163 end if;
3165 Insert_Actions_After (N, Late_Expansion (Aggr, Typ, Occ));
3166 end Convert_Aggr_In_Assignment;
3168 ---------------------------------
3169 -- Convert_Aggr_In_Object_Decl --
3170 ---------------------------------
3172 procedure Convert_Aggr_In_Object_Decl (N : Node_Id) is
3173 Obj : constant Entity_Id := Defining_Identifier (N);
3174 Aggr : Node_Id := Expression (N);
3175 Loc : constant Source_Ptr := Sloc (Aggr);
3176 Typ : constant Entity_Id := Etype (Aggr);
3177 Occ : constant Node_Id := New_Occurrence_Of (Obj, Loc);
3179 function Discriminants_Ok return Boolean;
3180 -- If the object type is constrained, the discriminants in the
3181 -- aggregate must be checked against the discriminants of the subtype.
3182 -- This cannot be done using Apply_Discriminant_Checks because after
3183 -- expansion there is no aggregate left to check.
3185 ----------------------
3186 -- Discriminants_Ok --
3187 ----------------------
3189 function Discriminants_Ok return Boolean is
3190 Cond : Node_Id := Empty;
3191 Check : Node_Id;
3192 D : Entity_Id;
3193 Disc1 : Elmt_Id;
3194 Disc2 : Elmt_Id;
3195 Val1 : Node_Id;
3196 Val2 : Node_Id;
3198 begin
3199 D := First_Discriminant (Typ);
3200 Disc1 := First_Elmt (Discriminant_Constraint (Typ));
3201 Disc2 := First_Elmt (Discriminant_Constraint (Etype (Obj)));
3202 while Present (Disc1) and then Present (Disc2) loop
3203 Val1 := Node (Disc1);
3204 Val2 := Node (Disc2);
3206 if not Is_OK_Static_Expression (Val1)
3207 or else not Is_OK_Static_Expression (Val2)
3208 then
3209 Check := Make_Op_Ne (Loc,
3210 Left_Opnd => Duplicate_Subexpr (Val1),
3211 Right_Opnd => Duplicate_Subexpr (Val2));
3213 if No (Cond) then
3214 Cond := Check;
3216 else
3217 Cond := Make_Or_Else (Loc,
3218 Left_Opnd => Cond,
3219 Right_Opnd => Check);
3220 end if;
3222 elsif Expr_Value (Val1) /= Expr_Value (Val2) then
3223 Apply_Compile_Time_Constraint_Error (Aggr,
3224 Msg => "incorrect value for discriminant&??",
3225 Reason => CE_Discriminant_Check_Failed,
3226 Ent => D);
3227 return False;
3228 end if;
3230 Next_Discriminant (D);
3231 Next_Elmt (Disc1);
3232 Next_Elmt (Disc2);
3233 end loop;
3235 -- If any discriminant constraint is non-static, emit a check
3237 if Present (Cond) then
3238 Insert_Action (N,
3239 Make_Raise_Constraint_Error (Loc,
3240 Condition => Cond,
3241 Reason => CE_Discriminant_Check_Failed));
3242 end if;
3244 return True;
3245 end Discriminants_Ok;
3247 -- Start of processing for Convert_Aggr_In_Object_Decl
3249 begin
3250 Set_Assignment_OK (Occ);
3252 if Nkind (Aggr) = N_Qualified_Expression then
3253 Aggr := Expression (Aggr);
3254 end if;
3256 if Has_Discriminants (Typ)
3257 and then Typ /= Etype (Obj)
3258 and then Is_Constrained (Etype (Obj))
3259 and then not Discriminants_Ok
3260 then
3261 return;
3262 end if;
3264 -- If the context is an extended return statement, it has its own
3265 -- finalization machinery (i.e. works like a transient scope) and
3266 -- we do not want to create an additional one, because objects on
3267 -- the finalization list of the return must be moved to the caller's
3268 -- finalization list to complete the return.
3270 -- However, if the aggregate is limited, it is built in place, and the
3271 -- controlled components are not assigned to intermediate temporaries
3272 -- so there is no need for a transient scope in this case either.
3274 if Requires_Transient_Scope (Typ)
3275 and then Ekind (Current_Scope) /= E_Return_Statement
3276 and then not Is_Limited_Type (Typ)
3277 then
3278 Establish_Transient_Scope
3279 (Aggr,
3280 Sec_Stack =>
3281 Is_Controlled (Typ) or else Has_Controlled_Component (Typ));
3282 end if;
3284 declare
3285 Node_After : constant Node_Id := Next (N);
3286 begin
3287 Insert_Actions_After (N, Late_Expansion (Aggr, Typ, Occ));
3288 Collect_Initialization_Statements (Obj, N, Node_After);
3289 end;
3290 Set_No_Initialization (N);
3291 Initialize_Discriminants (N, Typ);
3292 end Convert_Aggr_In_Object_Decl;
3294 -------------------------------------
3295 -- Convert_Array_Aggr_In_Allocator --
3296 -------------------------------------
3298 procedure Convert_Array_Aggr_In_Allocator
3299 (Decl : Node_Id;
3300 Aggr : Node_Id;
3301 Target : Node_Id)
3303 Aggr_Code : List_Id;
3304 Typ : constant Entity_Id := Etype (Aggr);
3305 Ctyp : constant Entity_Id := Component_Type (Typ);
3307 begin
3308 -- The target is an explicit dereference of the allocated object.
3309 -- Generate component assignments to it, as for an aggregate that
3310 -- appears on the right-hand side of an assignment statement.
3312 Aggr_Code :=
3313 Build_Array_Aggr_Code (Aggr,
3314 Ctype => Ctyp,
3315 Index => First_Index (Typ),
3316 Into => Target,
3317 Scalar_Comp => Is_Scalar_Type (Ctyp));
3319 Insert_Actions_After (Decl, Aggr_Code);
3320 end Convert_Array_Aggr_In_Allocator;
3322 ----------------------------
3323 -- Convert_To_Assignments --
3324 ----------------------------
3326 procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id) is
3327 Loc : constant Source_Ptr := Sloc (N);
3328 T : Entity_Id;
3329 Temp : Entity_Id;
3331 Aggr_Code : List_Id;
3332 Instr : Node_Id;
3333 Target_Expr : Node_Id;
3334 Parent_Kind : Node_Kind;
3335 Unc_Decl : Boolean := False;
3336 Parent_Node : Node_Id;
3338 begin
3339 pragma Assert (not Is_Static_Dispatch_Table_Aggregate (N));
3340 pragma Assert (Is_Record_Type (Typ));
3342 Parent_Node := Parent (N);
3343 Parent_Kind := Nkind (Parent_Node);
3345 if Parent_Kind = N_Qualified_Expression then
3347 -- Check if we are in a unconstrained declaration because in this
3348 -- case the current delayed expansion mechanism doesn't work when
3349 -- the declared object size depend on the initializing expr.
3351 begin
3352 Parent_Node := Parent (Parent_Node);
3353 Parent_Kind := Nkind (Parent_Node);
3355 if Parent_Kind = N_Object_Declaration then
3356 Unc_Decl :=
3357 not Is_Entity_Name (Object_Definition (Parent_Node))
3358 or else Has_Discriminants
3359 (Entity (Object_Definition (Parent_Node)))
3360 or else Is_Class_Wide_Type
3361 (Entity (Object_Definition (Parent_Node)));
3362 end if;
3363 end;
3364 end if;
3366 -- Just set the Delay flag in the cases where the transformation will be
3367 -- done top down from above.
3369 if False
3371 -- Internal aggregate (transformed when expanding the parent)
3373 or else Parent_Kind = N_Aggregate
3374 or else Parent_Kind = N_Extension_Aggregate
3375 or else Parent_Kind = N_Component_Association
3377 -- Allocator (see Convert_Aggr_In_Allocator)
3379 or else Parent_Kind = N_Allocator
3381 -- Object declaration (see Convert_Aggr_In_Object_Decl)
3383 or else (Parent_Kind = N_Object_Declaration and then not Unc_Decl)
3385 -- Safe assignment (see Convert_Aggr_Assignments). So far only the
3386 -- assignments in init procs are taken into account.
3388 or else (Parent_Kind = N_Assignment_Statement
3389 and then Inside_Init_Proc)
3391 -- (Ada 2005) An inherently limited type in a return statement, which
3392 -- will be handled in a build-in-place fashion, and may be rewritten
3393 -- as an extended return and have its own finalization machinery.
3394 -- In the case of a simple return, the aggregate needs to be delayed
3395 -- until the scope for the return statement has been created, so
3396 -- that any finalization chain will be associated with that scope.
3397 -- For extended returns, we delay expansion to avoid the creation
3398 -- of an unwanted transient scope that could result in premature
3399 -- finalization of the return object (which is built in place
3400 -- within the caller's scope).
3402 or else
3403 (Is_Limited_View (Typ)
3404 and then
3405 (Nkind (Parent (Parent_Node)) = N_Extended_Return_Statement
3406 or else Nkind (Parent_Node) = N_Simple_Return_Statement))
3407 then
3408 Set_Expansion_Delayed (N);
3409 return;
3410 end if;
3412 -- Otherwise, if a transient scope is required, create it now. If we
3413 -- are within an initialization procedure do not create such, because
3414 -- the target of the assignment must not be declared within a local
3415 -- block, and because cleanup will take place on return from the
3416 -- initialization procedure.
3417 -- Should the condition be more restrictive ???
3419 if Requires_Transient_Scope (Typ) and then not Inside_Init_Proc then
3420 Establish_Transient_Scope (N, Sec_Stack => Needs_Finalization (Typ));
3421 end if;
3423 -- If the aggregate is non-limited, create a temporary. If it is limited
3424 -- and context is an assignment, this is a subaggregate for an enclosing
3425 -- aggregate being expanded. It must be built in place, so use target of
3426 -- the current assignment.
3428 if Is_Limited_Type (Typ)
3429 and then Nkind (Parent (N)) = N_Assignment_Statement
3430 then
3431 Target_Expr := New_Copy_Tree (Name (Parent (N)));
3432 Insert_Actions (Parent (N),
3433 Build_Record_Aggr_Code (N, Typ, Target_Expr));
3434 Rewrite (Parent (N), Make_Null_Statement (Loc));
3436 else
3437 Temp := Make_Temporary (Loc, 'A', N);
3439 -- If the type inherits unknown discriminants, use the view with
3440 -- known discriminants if available.
3442 if Has_Unknown_Discriminants (Typ)
3443 and then Present (Underlying_Record_View (Typ))
3444 then
3445 T := Underlying_Record_View (Typ);
3446 else
3447 T := Typ;
3448 end if;
3450 Instr :=
3451 Make_Object_Declaration (Loc,
3452 Defining_Identifier => Temp,
3453 Object_Definition => New_Occurrence_Of (T, Loc));
3455 Set_No_Initialization (Instr);
3456 Insert_Action (N, Instr);
3457 Initialize_Discriminants (Instr, T);
3459 Target_Expr := New_Occurrence_Of (Temp, Loc);
3460 Aggr_Code := Build_Record_Aggr_Code (N, T, Target_Expr);
3462 -- Save the last assignment statement associated with the aggregate
3463 -- when building a controlled object. This reference is utilized by
3464 -- the finalization machinery when marking an object as successfully
3465 -- initialized.
3467 if Needs_Finalization (T) then
3468 Set_Last_Aggregate_Assignment (Temp, Last (Aggr_Code));
3469 end if;
3471 Insert_Actions (N, Aggr_Code);
3472 Rewrite (N, New_Occurrence_Of (Temp, Loc));
3473 Analyze_And_Resolve (N, T);
3474 end if;
3475 end Convert_To_Assignments;
3477 ---------------------------
3478 -- Convert_To_Positional --
3479 ---------------------------
3481 procedure Convert_To_Positional
3482 (N : Node_Id;
3483 Max_Others_Replicate : Nat := 5;
3484 Handle_Bit_Packed : Boolean := False)
3486 Typ : constant Entity_Id := Etype (N);
3488 Static_Components : Boolean := True;
3490 procedure Check_Static_Components;
3491 -- Check whether all components of the aggregate are compile-time known
3492 -- values, and can be passed as is to the back-end without further
3493 -- expansion.
3495 function Flatten
3496 (N : Node_Id;
3497 Ix : Node_Id;
3498 Ixb : Node_Id) return Boolean;
3499 -- Convert the aggregate into a purely positional form if possible. On
3500 -- entry the bounds of all dimensions are known to be static, and the
3501 -- total number of components is safe enough to expand.
3503 function Is_Flat (N : Node_Id; Dims : Int) return Boolean;
3504 -- Return True iff the array N is flat (which is not trivial in the case
3505 -- of multidimensional aggregates).
3507 -----------------------------
3508 -- Check_Static_Components --
3509 -----------------------------
3511 -- Could use some comments in this body ???
3513 procedure Check_Static_Components is
3514 Expr : Node_Id;
3516 begin
3517 Static_Components := True;
3519 if Nkind (N) = N_String_Literal then
3520 null;
3522 elsif Present (Expressions (N)) then
3523 Expr := First (Expressions (N));
3524 while Present (Expr) loop
3525 if Nkind (Expr) /= N_Aggregate
3526 or else not Compile_Time_Known_Aggregate (Expr)
3527 or else Expansion_Delayed (Expr)
3528 then
3529 Static_Components := False;
3530 exit;
3531 end if;
3533 Next (Expr);
3534 end loop;
3535 end if;
3537 if Nkind (N) = N_Aggregate
3538 and then Present (Component_Associations (N))
3539 then
3540 Expr := First (Component_Associations (N));
3541 while Present (Expr) loop
3542 if Nkind_In (Expression (Expr), N_Integer_Literal,
3543 N_Real_Literal)
3544 then
3545 null;
3547 elsif Is_Entity_Name (Expression (Expr))
3548 and then Present (Entity (Expression (Expr)))
3549 and then Ekind (Entity (Expression (Expr))) =
3550 E_Enumeration_Literal
3551 then
3552 null;
3554 elsif Nkind (Expression (Expr)) /= N_Aggregate
3555 or else not Compile_Time_Known_Aggregate (Expression (Expr))
3556 or else Expansion_Delayed (Expression (Expr))
3557 then
3558 Static_Components := False;
3559 exit;
3560 end if;
3562 Next (Expr);
3563 end loop;
3564 end if;
3565 end Check_Static_Components;
3567 -------------
3568 -- Flatten --
3569 -------------
3571 function Flatten
3572 (N : Node_Id;
3573 Ix : Node_Id;
3574 Ixb : Node_Id) return Boolean
3576 Loc : constant Source_Ptr := Sloc (N);
3577 Blo : constant Node_Id := Type_Low_Bound (Etype (Ixb));
3578 Lo : constant Node_Id := Type_Low_Bound (Etype (Ix));
3579 Hi : constant Node_Id := Type_High_Bound (Etype (Ix));
3580 Lov : Uint;
3581 Hiv : Uint;
3583 Others_Present : Boolean := False;
3585 begin
3586 if Nkind (Original_Node (N)) = N_String_Literal then
3587 return True;
3588 end if;
3590 if not Compile_Time_Known_Value (Lo)
3591 or else not Compile_Time_Known_Value (Hi)
3592 then
3593 return False;
3594 end if;
3596 Lov := Expr_Value (Lo);
3597 Hiv := Expr_Value (Hi);
3599 -- Check if there is an others choice
3601 if Present (Component_Associations (N)) then
3602 declare
3603 Assoc : Node_Id;
3604 Choice : Node_Id;
3606 begin
3607 Assoc := First (Component_Associations (N));
3608 while Present (Assoc) loop
3610 -- If this is a box association, flattening is in general
3611 -- not possible because at this point we cannot tell if the
3612 -- default is static or even exists.
3614 if Box_Present (Assoc) then
3615 return False;
3616 end if;
3618 Choice := First (Choices (Assoc));
3620 while Present (Choice) loop
3621 if Nkind (Choice) = N_Others_Choice then
3622 Others_Present := True;
3623 end if;
3625 Next (Choice);
3626 end loop;
3628 Next (Assoc);
3629 end loop;
3630 end;
3631 end if;
3633 -- If the low bound is not known at compile time and others is not
3634 -- present we can proceed since the bounds can be obtained from the
3635 -- aggregate.
3637 -- Note: This case is required in VM platforms since their backends
3638 -- normalize array indexes in the range 0 .. N-1. Hence, if we do
3639 -- not flat an array whose bounds cannot be obtained from the type
3640 -- of the index the backend has no way to properly generate the code.
3641 -- See ACATS c460010 for an example.
3643 if Hiv < Lov
3644 or else (not Compile_Time_Known_Value (Blo) and then Others_Present)
3645 then
3646 return False;
3647 end if;
3649 -- Determine if set of alternatives is suitable for conversion and
3650 -- build an array containing the values in sequence.
3652 declare
3653 Vals : array (UI_To_Int (Lov) .. UI_To_Int (Hiv))
3654 of Node_Id := (others => Empty);
3655 -- The values in the aggregate sorted appropriately
3657 Vlist : List_Id;
3658 -- Same data as Vals in list form
3660 Rep_Count : Nat;
3661 -- Used to validate Max_Others_Replicate limit
3663 Elmt : Node_Id;
3664 Num : Int := UI_To_Int (Lov);
3665 Choice_Index : Int;
3666 Choice : Node_Id;
3667 Lo, Hi : Node_Id;
3669 begin
3670 if Present (Expressions (N)) then
3671 Elmt := First (Expressions (N));
3672 while Present (Elmt) loop
3673 if Nkind (Elmt) = N_Aggregate
3674 and then Present (Next_Index (Ix))
3675 and then
3676 not Flatten (Elmt, Next_Index (Ix), Next_Index (Ixb))
3677 then
3678 return False;
3679 end if;
3681 Vals (Num) := Relocate_Node (Elmt);
3682 Num := Num + 1;
3684 Next (Elmt);
3685 end loop;
3686 end if;
3688 if No (Component_Associations (N)) then
3689 return True;
3690 end if;
3692 Elmt := First (Component_Associations (N));
3694 if Nkind (Expression (Elmt)) = N_Aggregate then
3695 if Present (Next_Index (Ix))
3696 and then
3697 not Flatten
3698 (Expression (Elmt), Next_Index (Ix), Next_Index (Ixb))
3699 then
3700 return False;
3701 end if;
3702 end if;
3704 Component_Loop : while Present (Elmt) loop
3705 Choice := First (Choices (Elmt));
3706 Choice_Loop : while Present (Choice) loop
3708 -- If we have an others choice, fill in the missing elements
3709 -- subject to the limit established by Max_Others_Replicate.
3711 if Nkind (Choice) = N_Others_Choice then
3712 Rep_Count := 0;
3714 for J in Vals'Range loop
3715 if No (Vals (J)) then
3716 Vals (J) := New_Copy_Tree (Expression (Elmt));
3717 Rep_Count := Rep_Count + 1;
3719 -- Check for maximum others replication. Note that
3720 -- we skip this test if either of the restrictions
3721 -- No_Elaboration_Code or No_Implicit_Loops is
3722 -- active, if this is a preelaborable unit or
3723 -- a predefined unit, or if the unit must be
3724 -- placed in data memory. This also ensures that
3725 -- predefined units get the same level of constant
3726 -- folding in Ada 95 and Ada 2005, where their
3727 -- categorization has changed.
3729 declare
3730 P : constant Entity_Id :=
3731 Cunit_Entity (Current_Sem_Unit);
3733 begin
3734 -- Check if duplication OK and if so continue
3735 -- processing.
3737 if Restriction_Active (No_Elaboration_Code)
3738 or else Restriction_Active (No_Implicit_Loops)
3739 or else
3740 (Ekind (Current_Scope) = E_Package
3741 and then Static_Elaboration_Desired
3742 (Current_Scope))
3743 or else Is_Preelaborated (P)
3744 or else (Ekind (P) = E_Package_Body
3745 and then
3746 Is_Preelaborated (Spec_Entity (P)))
3747 or else
3748 Is_Predefined_File_Name
3749 (Unit_File_Name (Get_Source_Unit (P)))
3750 then
3751 null;
3753 -- If duplication not OK, then we return False
3754 -- if the replication count is too high
3756 elsif Rep_Count > Max_Others_Replicate then
3757 return False;
3759 -- Continue on if duplication not OK, but the
3760 -- replication count is not excessive.
3762 else
3763 null;
3764 end if;
3765 end;
3766 end if;
3767 end loop;
3769 exit Component_Loop;
3771 -- Case of a subtype mark, identifier or expanded name
3773 elsif Is_Entity_Name (Choice)
3774 and then Is_Type (Entity (Choice))
3775 then
3776 Lo := Type_Low_Bound (Etype (Choice));
3777 Hi := Type_High_Bound (Etype (Choice));
3779 -- Case of subtype indication
3781 elsif Nkind (Choice) = N_Subtype_Indication then
3782 Lo := Low_Bound (Range_Expression (Constraint (Choice)));
3783 Hi := High_Bound (Range_Expression (Constraint (Choice)));
3785 -- Case of a range
3787 elsif Nkind (Choice) = N_Range then
3788 Lo := Low_Bound (Choice);
3789 Hi := High_Bound (Choice);
3791 -- Normal subexpression case
3793 else pragma Assert (Nkind (Choice) in N_Subexpr);
3794 if not Compile_Time_Known_Value (Choice) then
3795 return False;
3797 else
3798 Choice_Index := UI_To_Int (Expr_Value (Choice));
3800 if Choice_Index in Vals'Range then
3801 Vals (Choice_Index) :=
3802 New_Copy_Tree (Expression (Elmt));
3803 goto Continue;
3805 -- Choice is statically out-of-range, will be
3806 -- rewritten to raise Constraint_Error.
3808 else
3809 return False;
3810 end if;
3811 end if;
3812 end if;
3814 -- Range cases merge with Lo,Hi set
3816 if not Compile_Time_Known_Value (Lo)
3817 or else
3818 not Compile_Time_Known_Value (Hi)
3819 then
3820 return False;
3822 else
3823 for J in UI_To_Int (Expr_Value (Lo)) ..
3824 UI_To_Int (Expr_Value (Hi))
3825 loop
3826 Vals (J) := New_Copy_Tree (Expression (Elmt));
3827 end loop;
3828 end if;
3830 <<Continue>>
3831 Next (Choice);
3832 end loop Choice_Loop;
3834 Next (Elmt);
3835 end loop Component_Loop;
3837 -- If we get here the conversion is possible
3839 Vlist := New_List;
3840 for J in Vals'Range loop
3841 Append (Vals (J), Vlist);
3842 end loop;
3844 Rewrite (N, Make_Aggregate (Loc, Expressions => Vlist));
3845 Set_Aggregate_Bounds (N, Aggregate_Bounds (Original_Node (N)));
3846 return True;
3847 end;
3848 end Flatten;
3850 -------------
3851 -- Is_Flat --
3852 -------------
3854 function Is_Flat (N : Node_Id; Dims : Int) return Boolean is
3855 Elmt : Node_Id;
3857 begin
3858 if Dims = 0 then
3859 return True;
3861 elsif Nkind (N) = N_Aggregate then
3862 if Present (Component_Associations (N)) then
3863 return False;
3865 else
3866 Elmt := First (Expressions (N));
3867 while Present (Elmt) loop
3868 if not Is_Flat (Elmt, Dims - 1) then
3869 return False;
3870 end if;
3872 Next (Elmt);
3873 end loop;
3875 return True;
3876 end if;
3877 else
3878 return True;
3879 end if;
3880 end Is_Flat;
3882 -- Start of processing for Convert_To_Positional
3884 begin
3885 -- Ada 2005 (AI-287): Do not convert in case of default initialized
3886 -- components because in this case will need to call the corresponding
3887 -- IP procedure.
3889 if Has_Default_Init_Comps (N) then
3890 return;
3891 end if;
3893 if Is_Flat (N, Number_Dimensions (Typ)) then
3894 return;
3895 end if;
3897 if Is_Bit_Packed_Array (Typ) and then not Handle_Bit_Packed then
3898 return;
3899 end if;
3901 -- Do not convert to positional if controlled components are involved
3902 -- since these require special processing
3904 if Has_Controlled_Component (Typ) then
3905 return;
3906 end if;
3908 Check_Static_Components;
3910 -- If the size is known, or all the components are static, try to
3911 -- build a fully positional aggregate.
3913 -- The size of the type may not be known for an aggregate with
3914 -- discriminated array components, but if the components are static
3915 -- it is still possible to verify statically that the length is
3916 -- compatible with the upper bound of the type, and therefore it is
3917 -- worth flattening such aggregates as well.
3919 -- For now the back-end expands these aggregates into individual
3920 -- assignments to the target anyway, but it is conceivable that
3921 -- it will eventually be able to treat such aggregates statically???
3923 if Aggr_Size_OK (N, Typ)
3924 and then Flatten (N, First_Index (Typ), First_Index (Base_Type (Typ)))
3925 then
3926 if Static_Components then
3927 Set_Compile_Time_Known_Aggregate (N);
3928 Set_Expansion_Delayed (N, False);
3929 end if;
3931 Analyze_And_Resolve (N, Typ);
3932 end if;
3934 -- Is Static_Eaboration_Desired has been specified, diagnose aggregates
3935 -- that will still require initialization code.
3937 if (Ekind (Current_Scope) = E_Package
3938 and then Static_Elaboration_Desired (Current_Scope))
3939 and then Nkind (Parent (N)) = N_Object_Declaration
3940 then
3941 declare
3942 Expr : Node_Id;
3944 begin
3945 if Nkind (N) = N_Aggregate and then Present (Expressions (N)) then
3946 Expr := First (Expressions (N));
3947 while Present (Expr) loop
3948 if Nkind_In (Expr, N_Integer_Literal, N_Real_Literal)
3949 or else
3950 (Is_Entity_Name (Expr)
3951 and then Ekind (Entity (Expr)) = E_Enumeration_Literal)
3952 then
3953 null;
3955 else
3956 Error_Msg_N
3957 ("non-static object requires elaboration code??", N);
3958 exit;
3959 end if;
3961 Next (Expr);
3962 end loop;
3964 if Present (Component_Associations (N)) then
3965 Error_Msg_N ("object requires elaboration code??", N);
3966 end if;
3967 end if;
3968 end;
3969 end if;
3970 end Convert_To_Positional;
3972 ----------------------------
3973 -- Expand_Array_Aggregate --
3974 ----------------------------
3976 -- Array aggregate expansion proceeds as follows:
3978 -- 1. If requested we generate code to perform all the array aggregate
3979 -- bound checks, specifically
3981 -- (a) Check that the index range defined by aggregate bounds is
3982 -- compatible with corresponding index subtype.
3984 -- (b) If an others choice is present check that no aggregate
3985 -- index is outside the bounds of the index constraint.
3987 -- (c) For multidimensional arrays make sure that all subaggregates
3988 -- corresponding to the same dimension have the same bounds.
3990 -- 2. Check for packed array aggregate which can be converted to a
3991 -- constant so that the aggregate disappears completely.
3993 -- 3. Check case of nested aggregate. Generally nested aggregates are
3994 -- handled during the processing of the parent aggregate.
3996 -- 4. Check if the aggregate can be statically processed. If this is the
3997 -- case pass it as is to Gigi. Note that a necessary condition for
3998 -- static processing is that the aggregate be fully positional.
4000 -- 5. If in place aggregate expansion is possible (i.e. no need to create
4001 -- a temporary) then mark the aggregate as such and return. Otherwise
4002 -- create a new temporary and generate the appropriate initialization
4003 -- code.
4005 procedure Expand_Array_Aggregate (N : Node_Id) is
4006 Loc : constant Source_Ptr := Sloc (N);
4008 Typ : constant Entity_Id := Etype (N);
4009 Ctyp : constant Entity_Id := Component_Type (Typ);
4010 -- Typ is the correct constrained array subtype of the aggregate
4011 -- Ctyp is the corresponding component type.
4013 Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
4014 -- Number of aggregate index dimensions
4016 Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id;
4017 Aggr_High : array (1 .. Aggr_Dimension) of Node_Id;
4018 -- Low and High bounds of the constraint for each aggregate index
4020 Aggr_Index_Typ : array (1 .. Aggr_Dimension) of Entity_Id;
4021 -- The type of each index
4023 In_Place_Assign_OK_For_Declaration : Boolean := False;
4024 -- True if we are to generate an in place assignment for a declaration
4026 Maybe_In_Place_OK : Boolean;
4027 -- If the type is neither controlled nor packed and the aggregate
4028 -- is the expression in an assignment, assignment in place may be
4029 -- possible, provided other conditions are met on the LHS.
4031 Others_Present : array (1 .. Aggr_Dimension) of Boolean :=
4032 (others => False);
4033 -- If Others_Present (J) is True, then there is an others choice
4034 -- in one of the sub-aggregates of N at dimension J.
4036 function Aggr_Assignment_OK_For_Backend (N : Node_Id) return Boolean;
4037 -- Returns true if an aggregate assignment can be done by the back end
4039 procedure Build_Constrained_Type (Positional : Boolean);
4040 -- If the subtype is not static or unconstrained, build a constrained
4041 -- type using the computable sizes of the aggregate and its sub-
4042 -- aggregates.
4044 procedure Check_Bounds (Aggr_Bounds : Node_Id; Index_Bounds : Node_Id);
4045 -- Checks that the bounds of Aggr_Bounds are within the bounds defined
4046 -- by Index_Bounds.
4048 procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos);
4049 -- Checks that in a multi-dimensional array aggregate all subaggregates
4050 -- corresponding to the same dimension have the same bounds.
4051 -- Sub_Aggr is an array sub-aggregate. Dim is the dimension
4052 -- corresponding to the sub-aggregate.
4054 procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos);
4055 -- Computes the values of array Others_Present. Sub_Aggr is the
4056 -- array sub-aggregate we start the computation from. Dim is the
4057 -- dimension corresponding to the sub-aggregate.
4059 function In_Place_Assign_OK return Boolean;
4060 -- Simple predicate to determine whether an aggregate assignment can
4061 -- be done in place, because none of the new values can depend on the
4062 -- components of the target of the assignment.
4064 procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos);
4065 -- Checks that if an others choice is present in any sub-aggregate no
4066 -- aggregate index is outside the bounds of the index constraint.
4067 -- Sub_Aggr is an array sub-aggregate. Dim is the dimension
4068 -- corresponding to the sub-aggregate.
4070 function Safe_Left_Hand_Side (N : Node_Id) return Boolean;
4071 -- In addition to Maybe_In_Place_OK, in order for an aggregate to be
4072 -- built directly into the target of the assignment it must be free
4073 -- of side-effects.
4075 ------------------------------------
4076 -- Aggr_Assignment_OK_For_Backend --
4077 ------------------------------------
4079 -- Backend processing by Gigi/gcc is possible only if all the following
4080 -- conditions are met:
4082 -- 1. N consists of a single OTHERS choice, possibly recursively
4084 -- 2. The array type is not packed
4086 -- 3. The array type has no atomic components
4088 -- 4. The array type has no null ranges (the purpose of this is to
4089 -- avoid a bogus warning for an out-of-range value).
4091 -- 5. The component type is discrete
4093 -- 6. The component size is Storage_Unit or the value is of the form
4094 -- M * (1 + A**1 + A**2 + .. A**(K-1)) where A = 2**(Storage_Unit)
4095 -- and M in 1 .. A-1. This can also be viewed as K occurrences of
4096 -- the 8-bit value M, concatenated together.
4098 -- The ultimate goal is to generate a call to a fast memset routine
4099 -- specifically optimized for the target.
4101 function Aggr_Assignment_OK_For_Backend (N : Node_Id) return Boolean is
4102 Ctyp : Entity_Id;
4103 Index : Entity_Id;
4104 Expr : Node_Id := N;
4105 Low : Node_Id;
4106 High : Node_Id;
4107 Remainder : Uint;
4108 Value : Uint;
4109 Nunits : Nat;
4111 begin
4112 -- Recurse as far as possible to find the innermost component type
4114 Ctyp := Etype (N);
4115 while Is_Array_Type (Ctyp) loop
4116 if Nkind (Expr) /= N_Aggregate
4117 or else not Is_Others_Aggregate (Expr)
4118 then
4119 return False;
4120 end if;
4122 if Present (Packed_Array_Impl_Type (Ctyp)) then
4123 return False;
4124 end if;
4126 if Has_Atomic_Components (Ctyp) then
4127 return False;
4128 end if;
4130 Index := First_Index (Ctyp);
4131 while Present (Index) loop
4132 Get_Index_Bounds (Index, Low, High);
4134 if Is_Null_Range (Low, High) then
4135 return False;
4136 end if;
4138 Next_Index (Index);
4139 end loop;
4141 Expr := Expression (First (Component_Associations (Expr)));
4143 for J in 1 .. Number_Dimensions (Ctyp) - 1 loop
4144 if Nkind (Expr) /= N_Aggregate
4145 or else not Is_Others_Aggregate (Expr)
4146 then
4147 return False;
4148 end if;
4150 Expr := Expression (First (Component_Associations (Expr)));
4151 end loop;
4153 Ctyp := Component_Type (Ctyp);
4155 if Is_Atomic (Ctyp) then
4156 return False;
4157 end if;
4158 end loop;
4160 if not Is_Discrete_Type (Ctyp) then
4161 return False;
4162 end if;
4164 -- The expression needs to be analyzed if True is returned
4166 Analyze_And_Resolve (Expr, Ctyp);
4168 -- The back end uses the Esize as the precision of the type
4170 Nunits := UI_To_Int (Esize (Ctyp)) / System_Storage_Unit;
4172 if Nunits = 1 then
4173 return True;
4174 end if;
4176 if not Compile_Time_Known_Value (Expr) then
4177 return False;
4178 end if;
4180 Value := Expr_Value (Expr);
4182 if Has_Biased_Representation (Ctyp) then
4183 Value := Value - Expr_Value (Type_Low_Bound (Ctyp));
4184 end if;
4186 -- Values 0 and -1 immediately satisfy the last check
4188 if Value = Uint_0 or else Value = Uint_Minus_1 then
4189 return True;
4190 end if;
4192 -- We need to work with an unsigned value
4194 if Value < 0 then
4195 Value := Value + 2**(System_Storage_Unit * Nunits);
4196 end if;
4198 Remainder := Value rem 2**System_Storage_Unit;
4200 for J in 1 .. Nunits - 1 loop
4201 Value := Value / 2**System_Storage_Unit;
4203 if Value rem 2**System_Storage_Unit /= Remainder then
4204 return False;
4205 end if;
4206 end loop;
4208 return True;
4209 end Aggr_Assignment_OK_For_Backend;
4211 ----------------------------
4212 -- Build_Constrained_Type --
4213 ----------------------------
4215 procedure Build_Constrained_Type (Positional : Boolean) is
4216 Loc : constant Source_Ptr := Sloc (N);
4217 Agg_Type : constant Entity_Id := Make_Temporary (Loc, 'A');
4218 Comp : Node_Id;
4219 Decl : Node_Id;
4220 Typ : constant Entity_Id := Etype (N);
4221 Indexes : constant List_Id := New_List;
4222 Num : Int;
4223 Sub_Agg : Node_Id;
4225 begin
4226 -- If the aggregate is purely positional, all its subaggregates
4227 -- have the same size. We collect the dimensions from the first
4228 -- subaggregate at each level.
4230 if Positional then
4231 Sub_Agg := N;
4233 for D in 1 .. Number_Dimensions (Typ) loop
4234 Sub_Agg := First (Expressions (Sub_Agg));
4236 Comp := Sub_Agg;
4237 Num := 0;
4238 while Present (Comp) loop
4239 Num := Num + 1;
4240 Next (Comp);
4241 end loop;
4243 Append_To (Indexes,
4244 Make_Range (Loc,
4245 Low_Bound => Make_Integer_Literal (Loc, 1),
4246 High_Bound => Make_Integer_Literal (Loc, Num)));
4247 end loop;
4249 else
4250 -- We know the aggregate type is unconstrained and the aggregate
4251 -- is not processable by the back end, therefore not necessarily
4252 -- positional. Retrieve each dimension bounds (computed earlier).
4254 for D in 1 .. Number_Dimensions (Typ) loop
4255 Append_To (Indexes,
4256 Make_Range (Loc,
4257 Low_Bound => Aggr_Low (D),
4258 High_Bound => Aggr_High (D)));
4259 end loop;
4260 end if;
4262 Decl :=
4263 Make_Full_Type_Declaration (Loc,
4264 Defining_Identifier => Agg_Type,
4265 Type_Definition =>
4266 Make_Constrained_Array_Definition (Loc,
4267 Discrete_Subtype_Definitions => Indexes,
4268 Component_Definition =>
4269 Make_Component_Definition (Loc,
4270 Aliased_Present => False,
4271 Subtype_Indication =>
4272 New_Occurrence_Of (Component_Type (Typ), Loc))));
4274 Insert_Action (N, Decl);
4275 Analyze (Decl);
4276 Set_Etype (N, Agg_Type);
4277 Set_Is_Itype (Agg_Type);
4278 Freeze_Itype (Agg_Type, N);
4279 end Build_Constrained_Type;
4281 ------------------
4282 -- Check_Bounds --
4283 ------------------
4285 procedure Check_Bounds (Aggr_Bounds : Node_Id; Index_Bounds : Node_Id) is
4286 Aggr_Lo : Node_Id;
4287 Aggr_Hi : Node_Id;
4289 Ind_Lo : Node_Id;
4290 Ind_Hi : Node_Id;
4292 Cond : Node_Id := Empty;
4294 begin
4295 Get_Index_Bounds (Aggr_Bounds, Aggr_Lo, Aggr_Hi);
4296 Get_Index_Bounds (Index_Bounds, Ind_Lo, Ind_Hi);
4298 -- Generate the following test:
4300 -- [constraint_error when
4301 -- Aggr_Lo <= Aggr_Hi and then
4302 -- (Aggr_Lo < Ind_Lo or else Aggr_Hi > Ind_Hi)]
4304 -- As an optimization try to see if some tests are trivially vacuous
4305 -- because we are comparing an expression against itself.
4307 if Aggr_Lo = Ind_Lo and then Aggr_Hi = Ind_Hi then
4308 Cond := Empty;
4310 elsif Aggr_Hi = Ind_Hi then
4311 Cond :=
4312 Make_Op_Lt (Loc,
4313 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4314 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Lo));
4316 elsif Aggr_Lo = Ind_Lo then
4317 Cond :=
4318 Make_Op_Gt (Loc,
4319 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi),
4320 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Hi));
4322 else
4323 Cond :=
4324 Make_Or_Else (Loc,
4325 Left_Opnd =>
4326 Make_Op_Lt (Loc,
4327 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4328 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Lo)),
4330 Right_Opnd =>
4331 Make_Op_Gt (Loc,
4332 Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
4333 Right_Opnd => Duplicate_Subexpr (Ind_Hi)));
4334 end if;
4336 if Present (Cond) then
4337 Cond :=
4338 Make_And_Then (Loc,
4339 Left_Opnd =>
4340 Make_Op_Le (Loc,
4341 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4342 Right_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi)),
4344 Right_Opnd => Cond);
4346 Set_Analyzed (Left_Opnd (Left_Opnd (Cond)), False);
4347 Set_Analyzed (Right_Opnd (Left_Opnd (Cond)), False);
4348 Insert_Action (N,
4349 Make_Raise_Constraint_Error (Loc,
4350 Condition => Cond,
4351 Reason => CE_Range_Check_Failed));
4352 end if;
4353 end Check_Bounds;
4355 ----------------------------
4356 -- Check_Same_Aggr_Bounds --
4357 ----------------------------
4359 procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos) is
4360 Sub_Lo : constant Node_Id := Low_Bound (Aggregate_Bounds (Sub_Aggr));
4361 Sub_Hi : constant Node_Id := High_Bound (Aggregate_Bounds (Sub_Aggr));
4362 -- The bounds of this specific sub-aggregate
4364 Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
4365 Aggr_Hi : constant Node_Id := Aggr_High (Dim);
4366 -- The bounds of the aggregate for this dimension
4368 Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
4369 -- The index type for this dimension.xxx
4371 Cond : Node_Id := Empty;
4372 Assoc : Node_Id;
4373 Expr : Node_Id;
4375 begin
4376 -- If index checks are on generate the test
4378 -- [constraint_error when
4379 -- Aggr_Lo /= Sub_Lo or else Aggr_Hi /= Sub_Hi]
4381 -- As an optimization try to see if some tests are trivially vacuos
4382 -- because we are comparing an expression against itself. Also for
4383 -- the first dimension the test is trivially vacuous because there
4384 -- is just one aggregate for dimension 1.
4386 if Index_Checks_Suppressed (Ind_Typ) then
4387 Cond := Empty;
4389 elsif Dim = 1 or else (Aggr_Lo = Sub_Lo and then Aggr_Hi = Sub_Hi)
4390 then
4391 Cond := Empty;
4393 elsif Aggr_Hi = Sub_Hi then
4394 Cond :=
4395 Make_Op_Ne (Loc,
4396 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4397 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo));
4399 elsif Aggr_Lo = Sub_Lo then
4400 Cond :=
4401 Make_Op_Ne (Loc,
4402 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi),
4403 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Hi));
4405 else
4406 Cond :=
4407 Make_Or_Else (Loc,
4408 Left_Opnd =>
4409 Make_Op_Ne (Loc,
4410 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4411 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo)),
4413 Right_Opnd =>
4414 Make_Op_Ne (Loc,
4415 Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
4416 Right_Opnd => Duplicate_Subexpr (Sub_Hi)));
4417 end if;
4419 if Present (Cond) then
4420 Insert_Action (N,
4421 Make_Raise_Constraint_Error (Loc,
4422 Condition => Cond,
4423 Reason => CE_Length_Check_Failed));
4424 end if;
4426 -- Now look inside the sub-aggregate to see if there is more work
4428 if Dim < Aggr_Dimension then
4430 -- Process positional components
4432 if Present (Expressions (Sub_Aggr)) then
4433 Expr := First (Expressions (Sub_Aggr));
4434 while Present (Expr) loop
4435 Check_Same_Aggr_Bounds (Expr, Dim + 1);
4436 Next (Expr);
4437 end loop;
4438 end if;
4440 -- Process component associations
4442 if Present (Component_Associations (Sub_Aggr)) then
4443 Assoc := First (Component_Associations (Sub_Aggr));
4444 while Present (Assoc) loop
4445 Expr := Expression (Assoc);
4446 Check_Same_Aggr_Bounds (Expr, Dim + 1);
4447 Next (Assoc);
4448 end loop;
4449 end if;
4450 end if;
4451 end Check_Same_Aggr_Bounds;
4453 ----------------------------
4454 -- Compute_Others_Present --
4455 ----------------------------
4457 procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos) is
4458 Assoc : Node_Id;
4459 Expr : Node_Id;
4461 begin
4462 if Present (Component_Associations (Sub_Aggr)) then
4463 Assoc := Last (Component_Associations (Sub_Aggr));
4465 if Nkind (First (Choices (Assoc))) = N_Others_Choice then
4466 Others_Present (Dim) := True;
4467 end if;
4468 end if;
4470 -- Now look inside the sub-aggregate to see if there is more work
4472 if Dim < Aggr_Dimension then
4474 -- Process positional components
4476 if Present (Expressions (Sub_Aggr)) then
4477 Expr := First (Expressions (Sub_Aggr));
4478 while Present (Expr) loop
4479 Compute_Others_Present (Expr, Dim + 1);
4480 Next (Expr);
4481 end loop;
4482 end if;
4484 -- Process component associations
4486 if Present (Component_Associations (Sub_Aggr)) then
4487 Assoc := First (Component_Associations (Sub_Aggr));
4488 while Present (Assoc) loop
4489 Expr := Expression (Assoc);
4490 Compute_Others_Present (Expr, Dim + 1);
4491 Next (Assoc);
4492 end loop;
4493 end if;
4494 end if;
4495 end Compute_Others_Present;
4497 ------------------------
4498 -- In_Place_Assign_OK --
4499 ------------------------
4501 function In_Place_Assign_OK return Boolean is
4502 Aggr_In : Node_Id;
4503 Aggr_Lo : Node_Id;
4504 Aggr_Hi : Node_Id;
4505 Obj_In : Node_Id;
4506 Obj_Lo : Node_Id;
4507 Obj_Hi : Node_Id;
4509 function Safe_Aggregate (Aggr : Node_Id) return Boolean;
4510 -- Check recursively that each component of a (sub)aggregate does
4511 -- not depend on the variable being assigned to.
4513 function Safe_Component (Expr : Node_Id) return Boolean;
4514 -- Verify that an expression cannot depend on the variable being
4515 -- assigned to. Room for improvement here (but less than before).
4517 --------------------
4518 -- Safe_Aggregate --
4519 --------------------
4521 function Safe_Aggregate (Aggr : Node_Id) return Boolean is
4522 Expr : Node_Id;
4524 begin
4525 if Present (Expressions (Aggr)) then
4526 Expr := First (Expressions (Aggr));
4527 while Present (Expr) loop
4528 if Nkind (Expr) = N_Aggregate then
4529 if not Safe_Aggregate (Expr) then
4530 return False;
4531 end if;
4533 elsif not Safe_Component (Expr) then
4534 return False;
4535 end if;
4537 Next (Expr);
4538 end loop;
4539 end if;
4541 if Present (Component_Associations (Aggr)) then
4542 Expr := First (Component_Associations (Aggr));
4543 while Present (Expr) loop
4544 if Nkind (Expression (Expr)) = N_Aggregate then
4545 if not Safe_Aggregate (Expression (Expr)) then
4546 return False;
4547 end if;
4549 -- If association has a box, no way to determine yet
4550 -- whether default can be assigned in place.
4552 elsif Box_Present (Expr) then
4553 return False;
4555 elsif not Safe_Component (Expression (Expr)) then
4556 return False;
4557 end if;
4559 Next (Expr);
4560 end loop;
4561 end if;
4563 return True;
4564 end Safe_Aggregate;
4566 --------------------
4567 -- Safe_Component --
4568 --------------------
4570 function Safe_Component (Expr : Node_Id) return Boolean is
4571 Comp : Node_Id := Expr;
4573 function Check_Component (Comp : Node_Id) return Boolean;
4574 -- Do the recursive traversal, after copy
4576 ---------------------
4577 -- Check_Component --
4578 ---------------------
4580 function Check_Component (Comp : Node_Id) return Boolean is
4581 begin
4582 if Is_Overloaded (Comp) then
4583 return False;
4584 end if;
4586 return Compile_Time_Known_Value (Comp)
4588 or else (Is_Entity_Name (Comp)
4589 and then Present (Entity (Comp))
4590 and then No (Renamed_Object (Entity (Comp))))
4592 or else (Nkind (Comp) = N_Attribute_Reference
4593 and then Check_Component (Prefix (Comp)))
4595 or else (Nkind (Comp) in N_Binary_Op
4596 and then Check_Component (Left_Opnd (Comp))
4597 and then Check_Component (Right_Opnd (Comp)))
4599 or else (Nkind (Comp) in N_Unary_Op
4600 and then Check_Component (Right_Opnd (Comp)))
4602 or else (Nkind (Comp) = N_Selected_Component
4603 and then Check_Component (Prefix (Comp)))
4605 or else (Nkind (Comp) = N_Unchecked_Type_Conversion
4606 and then Check_Component (Expression (Comp)));
4607 end Check_Component;
4609 -- Start of processing for Safe_Component
4611 begin
4612 -- If the component appears in an association that may correspond
4613 -- to more than one element, it is not analyzed before expansion
4614 -- into assignments, to avoid side effects. We analyze, but do not
4615 -- resolve the copy, to obtain sufficient entity information for
4616 -- the checks that follow. If component is overloaded we assume
4617 -- an unsafe function call.
4619 if not Analyzed (Comp) then
4620 if Is_Overloaded (Expr) then
4621 return False;
4623 elsif Nkind (Expr) = N_Aggregate
4624 and then not Is_Others_Aggregate (Expr)
4625 then
4626 return False;
4628 elsif Nkind (Expr) = N_Allocator then
4630 -- For now, too complex to analyze
4632 return False;
4633 end if;
4635 Comp := New_Copy_Tree (Expr);
4636 Set_Parent (Comp, Parent (Expr));
4637 Analyze (Comp);
4638 end if;
4640 if Nkind (Comp) = N_Aggregate then
4641 return Safe_Aggregate (Comp);
4642 else
4643 return Check_Component (Comp);
4644 end if;
4645 end Safe_Component;
4647 -- Start of processing for In_Place_Assign_OK
4649 begin
4650 if Present (Component_Associations (N)) then
4652 -- On assignment, sliding can take place, so we cannot do the
4653 -- assignment in place unless the bounds of the aggregate are
4654 -- statically equal to those of the target.
4656 -- If the aggregate is given by an others choice, the bounds are
4657 -- derived from the left-hand side, and the assignment is safe if
4658 -- the expression is.
4660 if Is_Others_Aggregate (N) then
4661 return
4662 Safe_Component
4663 (Expression (First (Component_Associations (N))));
4664 end if;
4666 Aggr_In := First_Index (Etype (N));
4668 if Nkind (Parent (N)) = N_Assignment_Statement then
4669 Obj_In := First_Index (Etype (Name (Parent (N))));
4671 else
4672 -- Context is an allocator. Check bounds of aggregate against
4673 -- given type in qualified expression.
4675 pragma Assert (Nkind (Parent (Parent (N))) = N_Allocator);
4676 Obj_In :=
4677 First_Index (Etype (Entity (Subtype_Mark (Parent (N)))));
4678 end if;
4680 while Present (Aggr_In) loop
4681 Get_Index_Bounds (Aggr_In, Aggr_Lo, Aggr_Hi);
4682 Get_Index_Bounds (Obj_In, Obj_Lo, Obj_Hi);
4684 if not Compile_Time_Known_Value (Aggr_Lo)
4685 or else not Compile_Time_Known_Value (Aggr_Hi)
4686 or else not Compile_Time_Known_Value (Obj_Lo)
4687 or else not Compile_Time_Known_Value (Obj_Hi)
4688 or else Expr_Value (Aggr_Lo) /= Expr_Value (Obj_Lo)
4689 or else Expr_Value (Aggr_Hi) /= Expr_Value (Obj_Hi)
4690 then
4691 return False;
4692 end if;
4694 Next_Index (Aggr_In);
4695 Next_Index (Obj_In);
4696 end loop;
4697 end if;
4699 -- Now check the component values themselves
4701 return Safe_Aggregate (N);
4702 end In_Place_Assign_OK;
4704 ------------------
4705 -- Others_Check --
4706 ------------------
4708 procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos) is
4709 Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
4710 Aggr_Hi : constant Node_Id := Aggr_High (Dim);
4711 -- The bounds of the aggregate for this dimension
4713 Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
4714 -- The index type for this dimension
4716 Need_To_Check : Boolean := False;
4718 Choices_Lo : Node_Id := Empty;
4719 Choices_Hi : Node_Id := Empty;
4720 -- The lowest and highest discrete choices for a named sub-aggregate
4722 Nb_Choices : Int := -1;
4723 -- The number of discrete non-others choices in this sub-aggregate
4725 Nb_Elements : Uint := Uint_0;
4726 -- The number of elements in a positional aggregate
4728 Cond : Node_Id := Empty;
4730 Assoc : Node_Id;
4731 Choice : Node_Id;
4732 Expr : Node_Id;
4734 begin
4735 -- Check if we have an others choice. If we do make sure that this
4736 -- sub-aggregate contains at least one element in addition to the
4737 -- others choice.
4739 if Range_Checks_Suppressed (Ind_Typ) then
4740 Need_To_Check := False;
4742 elsif Present (Expressions (Sub_Aggr))
4743 and then Present (Component_Associations (Sub_Aggr))
4744 then
4745 Need_To_Check := True;
4747 elsif Present (Component_Associations (Sub_Aggr)) then
4748 Assoc := Last (Component_Associations (Sub_Aggr));
4750 if Nkind (First (Choices (Assoc))) /= N_Others_Choice then
4751 Need_To_Check := False;
4753 else
4754 -- Count the number of discrete choices. Start with -1 because
4755 -- the others choice does not count.
4757 -- Is there some reason we do not use List_Length here ???
4759 Nb_Choices := -1;
4760 Assoc := First (Component_Associations (Sub_Aggr));
4761 while Present (Assoc) loop
4762 Choice := First (Choices (Assoc));
4763 while Present (Choice) loop
4764 Nb_Choices := Nb_Choices + 1;
4765 Next (Choice);
4766 end loop;
4768 Next (Assoc);
4769 end loop;
4771 -- If there is only an others choice nothing to do
4773 Need_To_Check := (Nb_Choices > 0);
4774 end if;
4776 else
4777 Need_To_Check := False;
4778 end if;
4780 -- If we are dealing with a positional sub-aggregate with an others
4781 -- choice then compute the number or positional elements.
4783 if Need_To_Check and then Present (Expressions (Sub_Aggr)) then
4784 Expr := First (Expressions (Sub_Aggr));
4785 Nb_Elements := Uint_0;
4786 while Present (Expr) loop
4787 Nb_Elements := Nb_Elements + 1;
4788 Next (Expr);
4789 end loop;
4791 -- If the aggregate contains discrete choices and an others choice
4792 -- compute the smallest and largest discrete choice values.
4794 elsif Need_To_Check then
4795 Compute_Choices_Lo_And_Choices_Hi : declare
4797 Table : Case_Table_Type (1 .. Nb_Choices);
4798 -- Used to sort all the different choice values
4800 J : Pos := 1;
4801 Low : Node_Id;
4802 High : Node_Id;
4804 begin
4805 Assoc := First (Component_Associations (Sub_Aggr));
4806 while Present (Assoc) loop
4807 Choice := First (Choices (Assoc));
4808 while Present (Choice) loop
4809 if Nkind (Choice) = N_Others_Choice then
4810 exit;
4811 end if;
4813 Get_Index_Bounds (Choice, Low, High);
4814 Table (J).Choice_Lo := Low;
4815 Table (J).Choice_Hi := High;
4817 J := J + 1;
4818 Next (Choice);
4819 end loop;
4821 Next (Assoc);
4822 end loop;
4824 -- Sort the discrete choices
4826 Sort_Case_Table (Table);
4828 Choices_Lo := Table (1).Choice_Lo;
4829 Choices_Hi := Table (Nb_Choices).Choice_Hi;
4830 end Compute_Choices_Lo_And_Choices_Hi;
4831 end if;
4833 -- If no others choice in this sub-aggregate, or the aggregate
4834 -- comprises only an others choice, nothing to do.
4836 if not Need_To_Check then
4837 Cond := Empty;
4839 -- If we are dealing with an aggregate containing an others choice
4840 -- and positional components, we generate the following test:
4842 -- if Ind_Typ'Pos (Aggr_Lo) + (Nb_Elements - 1) >
4843 -- Ind_Typ'Pos (Aggr_Hi)
4844 -- then
4845 -- raise Constraint_Error;
4846 -- end if;
4848 elsif Nb_Elements > Uint_0 then
4849 Cond :=
4850 Make_Op_Gt (Loc,
4851 Left_Opnd =>
4852 Make_Op_Add (Loc,
4853 Left_Opnd =>
4854 Make_Attribute_Reference (Loc,
4855 Prefix => New_Occurrence_Of (Ind_Typ, Loc),
4856 Attribute_Name => Name_Pos,
4857 Expressions =>
4858 New_List
4859 (Duplicate_Subexpr_Move_Checks (Aggr_Lo))),
4860 Right_Opnd => Make_Integer_Literal (Loc, Nb_Elements - 1)),
4862 Right_Opnd =>
4863 Make_Attribute_Reference (Loc,
4864 Prefix => New_Occurrence_Of (Ind_Typ, Loc),
4865 Attribute_Name => Name_Pos,
4866 Expressions => New_List (
4867 Duplicate_Subexpr_Move_Checks (Aggr_Hi))));
4869 -- If we are dealing with an aggregate containing an others choice
4870 -- and discrete choices we generate the following test:
4872 -- [constraint_error when
4873 -- Choices_Lo < Aggr_Lo or else Choices_Hi > Aggr_Hi];
4875 else
4876 Cond :=
4877 Make_Or_Else (Loc,
4878 Left_Opnd =>
4879 Make_Op_Lt (Loc,
4880 Left_Opnd => Duplicate_Subexpr_Move_Checks (Choices_Lo),
4881 Right_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo)),
4883 Right_Opnd =>
4884 Make_Op_Gt (Loc,
4885 Left_Opnd => Duplicate_Subexpr (Choices_Hi),
4886 Right_Opnd => Duplicate_Subexpr (Aggr_Hi)));
4887 end if;
4889 if Present (Cond) then
4890 Insert_Action (N,
4891 Make_Raise_Constraint_Error (Loc,
4892 Condition => Cond,
4893 Reason => CE_Length_Check_Failed));
4894 -- Questionable reason code, shouldn't that be a
4895 -- CE_Range_Check_Failed ???
4896 end if;
4898 -- Now look inside the sub-aggregate to see if there is more work
4900 if Dim < Aggr_Dimension then
4902 -- Process positional components
4904 if Present (Expressions (Sub_Aggr)) then
4905 Expr := First (Expressions (Sub_Aggr));
4906 while Present (Expr) loop
4907 Others_Check (Expr, Dim + 1);
4908 Next (Expr);
4909 end loop;
4910 end if;
4912 -- Process component associations
4914 if Present (Component_Associations (Sub_Aggr)) then
4915 Assoc := First (Component_Associations (Sub_Aggr));
4916 while Present (Assoc) loop
4917 Expr := Expression (Assoc);
4918 Others_Check (Expr, Dim + 1);
4919 Next (Assoc);
4920 end loop;
4921 end if;
4922 end if;
4923 end Others_Check;
4925 -------------------------
4926 -- Safe_Left_Hand_Side --
4927 -------------------------
4929 function Safe_Left_Hand_Side (N : Node_Id) return Boolean is
4930 function Is_Safe_Index (Indx : Node_Id) return Boolean;
4931 -- If the left-hand side includes an indexed component, check that
4932 -- the indexes are free of side-effect.
4934 -------------------
4935 -- Is_Safe_Index --
4936 -------------------
4938 function Is_Safe_Index (Indx : Node_Id) return Boolean is
4939 begin
4940 if Is_Entity_Name (Indx) then
4941 return True;
4943 elsif Nkind (Indx) = N_Integer_Literal then
4944 return True;
4946 elsif Nkind (Indx) = N_Function_Call
4947 and then Is_Entity_Name (Name (Indx))
4948 and then Has_Pragma_Pure_Function (Entity (Name (Indx)))
4949 then
4950 return True;
4952 elsif Nkind (Indx) = N_Type_Conversion
4953 and then Is_Safe_Index (Expression (Indx))
4954 then
4955 return True;
4957 else
4958 return False;
4959 end if;
4960 end Is_Safe_Index;
4962 -- Start of processing for Safe_Left_Hand_Side
4964 begin
4965 if Is_Entity_Name (N) then
4966 return True;
4968 elsif Nkind_In (N, N_Explicit_Dereference, N_Selected_Component)
4969 and then Safe_Left_Hand_Side (Prefix (N))
4970 then
4971 return True;
4973 elsif Nkind (N) = N_Indexed_Component
4974 and then Safe_Left_Hand_Side (Prefix (N))
4975 and then Is_Safe_Index (First (Expressions (N)))
4976 then
4977 return True;
4979 elsif Nkind (N) = N_Unchecked_Type_Conversion then
4980 return Safe_Left_Hand_Side (Expression (N));
4982 else
4983 return False;
4984 end if;
4985 end Safe_Left_Hand_Side;
4987 -- Local variables
4989 Tmp : Entity_Id;
4990 -- Holds the temporary aggregate value
4992 Tmp_Decl : Node_Id;
4993 -- Holds the declaration of Tmp
4995 Aggr_Code : List_Id;
4996 Parent_Node : Node_Id;
4997 Parent_Kind : Node_Kind;
4999 -- Start of processing for Expand_Array_Aggregate
5001 begin
5002 -- Do not touch the special aggregates of attributes used for Asm calls
5004 if Is_RTE (Ctyp, RE_Asm_Input_Operand)
5005 or else Is_RTE (Ctyp, RE_Asm_Output_Operand)
5006 then
5007 return;
5009 -- Do not expand an aggregate for an array type which contains tasks if
5010 -- the aggregate is associated with an unexpanded return statement of a
5011 -- build-in-place function. The aggregate is expanded when the related
5012 -- return statement (rewritten into an extended return) is processed.
5013 -- This delay ensures that any temporaries and initialization code
5014 -- generated for the aggregate appear in the proper return block and
5015 -- use the correct _chain and _master.
5017 elsif Has_Task (Base_Type (Etype (N)))
5018 and then Nkind (Parent (N)) = N_Simple_Return_Statement
5019 and then Is_Build_In_Place_Function
5020 (Return_Applies_To (Return_Statement_Entity (Parent (N))))
5021 then
5022 return;
5024 -- Do not attempt expansion if error already detected. We may reach this
5025 -- point in spite of previous errors when compiling with -gnatq, to
5026 -- force all possible errors (this is the usual ACATS mode).
5028 elsif Error_Posted (N) then
5029 return;
5030 end if;
5032 -- If the semantic analyzer has determined that aggregate N will raise
5033 -- Constraint_Error at run time, then the aggregate node has been
5034 -- replaced with an N_Raise_Constraint_Error node and we should
5035 -- never get here.
5037 pragma Assert (not Raises_Constraint_Error (N));
5039 -- STEP 1a
5041 -- Check that the index range defined by aggregate bounds is
5042 -- compatible with corresponding index subtype.
5044 Index_Compatibility_Check : declare
5045 Aggr_Index_Range : Node_Id := First_Index (Typ);
5046 -- The current aggregate index range
5048 Index_Constraint : Node_Id := First_Index (Etype (Typ));
5049 -- The corresponding index constraint against which we have to
5050 -- check the above aggregate index range.
5052 begin
5053 Compute_Others_Present (N, 1);
5055 for J in 1 .. Aggr_Dimension loop
5056 -- There is no need to emit a check if an others choice is present
5057 -- for this array aggregate dimension since in this case one of
5058 -- N's sub-aggregates has taken its bounds from the context and
5059 -- these bounds must have been checked already. In addition all
5060 -- sub-aggregates corresponding to the same dimension must all
5061 -- have the same bounds (checked in (c) below).
5063 if not Range_Checks_Suppressed (Etype (Index_Constraint))
5064 and then not Others_Present (J)
5065 then
5066 -- We don't use Checks.Apply_Range_Check here because it emits
5067 -- a spurious check. Namely it checks that the range defined by
5068 -- the aggregate bounds is non empty. But we know this already
5069 -- if we get here.
5071 Check_Bounds (Aggr_Index_Range, Index_Constraint);
5072 end if;
5074 -- Save the low and high bounds of the aggregate index as well as
5075 -- the index type for later use in checks (b) and (c) below.
5077 Aggr_Low (J) := Low_Bound (Aggr_Index_Range);
5078 Aggr_High (J) := High_Bound (Aggr_Index_Range);
5080 Aggr_Index_Typ (J) := Etype (Index_Constraint);
5082 Next_Index (Aggr_Index_Range);
5083 Next_Index (Index_Constraint);
5084 end loop;
5085 end Index_Compatibility_Check;
5087 -- STEP 1b
5089 -- If an others choice is present check that no aggregate index is
5090 -- outside the bounds of the index constraint.
5092 Others_Check (N, 1);
5094 -- STEP 1c
5096 -- For multidimensional arrays make sure that all subaggregates
5097 -- corresponding to the same dimension have the same bounds.
5099 if Aggr_Dimension > 1 then
5100 Check_Same_Aggr_Bounds (N, 1);
5101 end if;
5103 -- STEP 1d
5105 -- If we have a default component value, or simple initialization is
5106 -- required for the component type, then we replace <> in component
5107 -- associations by the required default value.
5109 declare
5110 Default_Val : Node_Id;
5111 Assoc : Node_Id;
5113 begin
5114 if (Present (Default_Aspect_Component_Value (Typ))
5115 or else Needs_Simple_Initialization (Ctyp))
5116 and then Present (Component_Associations (N))
5117 then
5118 Assoc := First (Component_Associations (N));
5119 while Present (Assoc) loop
5120 if Nkind (Assoc) = N_Component_Association
5121 and then Box_Present (Assoc)
5122 then
5123 Set_Box_Present (Assoc, False);
5125 if Present (Default_Aspect_Component_Value (Typ)) then
5126 Default_Val := Default_Aspect_Component_Value (Typ);
5127 else
5128 Default_Val := Get_Simple_Init_Val (Ctyp, N);
5129 end if;
5131 Set_Expression (Assoc, New_Copy_Tree (Default_Val));
5132 Analyze_And_Resolve (Expression (Assoc), Ctyp);
5133 end if;
5135 Next (Assoc);
5136 end loop;
5137 end if;
5138 end;
5140 -- STEP 2
5142 -- Here we test for is packed array aggregate that we can handle at
5143 -- compile time. If so, return with transformation done. Note that we do
5144 -- this even if the aggregate is nested, because once we have done this
5145 -- processing, there is no more nested aggregate.
5147 if Packed_Array_Aggregate_Handled (N) then
5148 return;
5149 end if;
5151 -- At this point we try to convert to positional form
5153 if Ekind (Current_Scope) = E_Package
5154 and then Static_Elaboration_Desired (Current_Scope)
5155 then
5156 Convert_To_Positional (N, Max_Others_Replicate => 100);
5157 else
5158 Convert_To_Positional (N);
5159 end if;
5161 -- if the result is no longer an aggregate (e.g. it may be a string
5162 -- literal, or a temporary which has the needed value), then we are
5163 -- done, since there is no longer a nested aggregate.
5165 if Nkind (N) /= N_Aggregate then
5166 return;
5168 -- We are also done if the result is an analyzed aggregate, indicating
5169 -- that Convert_To_Positional succeeded and reanalyzed the rewritten
5170 -- aggregate.
5172 elsif Analyzed (N) and then N /= Original_Node (N) then
5173 return;
5174 end if;
5176 -- If all aggregate components are compile-time known and the aggregate
5177 -- has been flattened, nothing left to do. The same occurs if the
5178 -- aggregate is used to initialize the components of a statically
5179 -- allocated dispatch table.
5181 if Compile_Time_Known_Aggregate (N)
5182 or else Is_Static_Dispatch_Table_Aggregate (N)
5183 then
5184 Set_Expansion_Delayed (N, False);
5185 return;
5186 end if;
5188 -- Now see if back end processing is possible
5190 if Backend_Processing_Possible (N) then
5192 -- If the aggregate is static but the constraints are not, build
5193 -- a static subtype for the aggregate, so that Gigi can place it
5194 -- in static memory. Perform an unchecked_conversion to the non-
5195 -- static type imposed by the context.
5197 declare
5198 Itype : constant Entity_Id := Etype (N);
5199 Index : Node_Id;
5200 Needs_Type : Boolean := False;
5202 begin
5203 Index := First_Index (Itype);
5204 while Present (Index) loop
5205 if not Is_OK_Static_Subtype (Etype (Index)) then
5206 Needs_Type := True;
5207 exit;
5208 else
5209 Next_Index (Index);
5210 end if;
5211 end loop;
5213 if Needs_Type then
5214 Build_Constrained_Type (Positional => True);
5215 Rewrite (N, Unchecked_Convert_To (Itype, N));
5216 Analyze (N);
5217 end if;
5218 end;
5220 return;
5221 end if;
5223 -- STEP 3
5225 -- Delay expansion for nested aggregates: it will be taken care of
5226 -- when the parent aggregate is expanded.
5228 Parent_Node := Parent (N);
5229 Parent_Kind := Nkind (Parent_Node);
5231 if Parent_Kind = N_Qualified_Expression then
5232 Parent_Node := Parent (Parent_Node);
5233 Parent_Kind := Nkind (Parent_Node);
5234 end if;
5236 if Parent_Kind = N_Aggregate
5237 or else Parent_Kind = N_Extension_Aggregate
5238 or else Parent_Kind = N_Component_Association
5239 or else (Parent_Kind = N_Object_Declaration
5240 and then Needs_Finalization (Typ))
5241 or else (Parent_Kind = N_Assignment_Statement
5242 and then Inside_Init_Proc)
5243 then
5244 if Static_Array_Aggregate (N)
5245 or else Compile_Time_Known_Aggregate (N)
5246 then
5247 Set_Expansion_Delayed (N, False);
5248 return;
5249 else
5250 Set_Expansion_Delayed (N);
5251 return;
5252 end if;
5253 end if;
5255 -- STEP 4
5257 -- Look if in place aggregate expansion is possible
5259 -- For object declarations we build the aggregate in place, unless
5260 -- the array is bit-packed or the component is controlled.
5262 -- For assignments we do the assignment in place if all the component
5263 -- associations have compile-time known values. For other cases we
5264 -- create a temporary. The analysis for safety of on-line assignment
5265 -- is delicate, i.e. we don't know how to do it fully yet ???
5267 -- For allocators we assign to the designated object in place if the
5268 -- aggregate meets the same conditions as other in-place assignments.
5269 -- In this case the aggregate may not come from source but was created
5270 -- for default initialization, e.g. with Initialize_Scalars.
5272 if Requires_Transient_Scope (Typ) then
5273 Establish_Transient_Scope
5274 (N, Sec_Stack => Has_Controlled_Component (Typ));
5275 end if;
5277 if Has_Default_Init_Comps (N) then
5278 Maybe_In_Place_OK := False;
5280 elsif Is_Bit_Packed_Array (Typ)
5281 or else Has_Controlled_Component (Typ)
5282 then
5283 Maybe_In_Place_OK := False;
5285 else
5286 Maybe_In_Place_OK :=
5287 (Nkind (Parent (N)) = N_Assignment_Statement
5288 and then In_Place_Assign_OK)
5290 or else
5291 (Nkind (Parent (Parent (N))) = N_Allocator
5292 and then In_Place_Assign_OK);
5293 end if;
5295 -- If this is an array of tasks, it will be expanded into build-in-place
5296 -- assignments. Build an activation chain for the tasks now.
5298 if Has_Task (Etype (N)) then
5299 Build_Activation_Chain_Entity (N);
5300 end if;
5302 -- Perform in-place expansion of aggregate in an object declaration.
5303 -- Note: actions generated for the aggregate will be captured in an
5304 -- expression-with-actions statement so that they can be transferred
5305 -- to freeze actions later if there is an address clause for the
5306 -- object. (Note: we don't use a block statement because this would
5307 -- cause generated freeze nodes to be elaborated in the wrong scope).
5309 -- Should document these individual tests ???
5311 if not Has_Default_Init_Comps (N)
5312 and then Comes_From_Source (Parent_Node)
5313 and then Parent_Kind = N_Object_Declaration
5314 and then not
5315 Must_Slide (Etype (Defining_Identifier (Parent_Node)), Typ)
5316 and then N = Expression (Parent_Node)
5317 and then not Is_Bit_Packed_Array (Typ)
5318 and then not Has_Controlled_Component (Typ)
5319 then
5320 In_Place_Assign_OK_For_Declaration := True;
5321 Tmp := Defining_Identifier (Parent (N));
5322 Set_No_Initialization (Parent (N));
5323 Set_Expression (Parent (N), Empty);
5325 -- Set kind and type of the entity, for use in the analysis
5326 -- of the subsequent assignments. If the nominal type is not
5327 -- constrained, build a subtype from the known bounds of the
5328 -- aggregate. If the declaration has a subtype mark, use it,
5329 -- otherwise use the itype of the aggregate.
5331 Set_Ekind (Tmp, E_Variable);
5333 if not Is_Constrained (Typ) then
5334 Build_Constrained_Type (Positional => False);
5336 elsif Is_Entity_Name (Object_Definition (Parent (N)))
5337 and then Is_Constrained (Entity (Object_Definition (Parent (N))))
5338 then
5339 Set_Etype (Tmp, Entity (Object_Definition (Parent (N))));
5341 else
5342 Set_Size_Known_At_Compile_Time (Typ, False);
5343 Set_Etype (Tmp, Typ);
5344 end if;
5346 elsif Maybe_In_Place_OK
5347 and then Nkind (Parent (N)) = N_Qualified_Expression
5348 and then Nkind (Parent (Parent (N))) = N_Allocator
5349 then
5350 Set_Expansion_Delayed (N);
5351 return;
5353 -- In the remaining cases the aggregate is the RHS of an assignment
5355 elsif Maybe_In_Place_OK
5356 and then Safe_Left_Hand_Side (Name (Parent (N)))
5357 then
5358 Tmp := Name (Parent (N));
5360 if Etype (Tmp) /= Etype (N) then
5361 Apply_Length_Check (N, Etype (Tmp));
5363 if Nkind (N) = N_Raise_Constraint_Error then
5365 -- Static error, nothing further to expand
5367 return;
5368 end if;
5369 end if;
5371 -- If a slice assignment has an aggregate with a single others_choice,
5372 -- the assignment can be done in place even if bounds are not static,
5373 -- by converting it into a loop over the discrete range of the slice.
5375 elsif Maybe_In_Place_OK
5376 and then Nkind (Name (Parent (N))) = N_Slice
5377 and then Is_Others_Aggregate (N)
5378 then
5379 Tmp := Name (Parent (N));
5381 -- Set type of aggregate to be type of lhs in assignment, in order
5382 -- to suppress redundant length checks.
5384 Set_Etype (N, Etype (Tmp));
5386 -- Step 5
5388 -- In place aggregate expansion is not possible
5390 else
5391 Maybe_In_Place_OK := False;
5392 Tmp := Make_Temporary (Loc, 'A', N);
5393 Tmp_Decl :=
5394 Make_Object_Declaration (Loc,
5395 Defining_Identifier => Tmp,
5396 Object_Definition => New_Occurrence_Of (Typ, Loc));
5397 Set_No_Initialization (Tmp_Decl, True);
5399 -- If we are within a loop, the temporary will be pushed on the
5400 -- stack at each iteration. If the aggregate is the expression for an
5401 -- allocator, it will be immediately copied to the heap and can
5402 -- be reclaimed at once. We create a transient scope around the
5403 -- aggregate for this purpose.
5405 if Ekind (Current_Scope) = E_Loop
5406 and then Nkind (Parent (Parent (N))) = N_Allocator
5407 then
5408 Establish_Transient_Scope (N, False);
5409 end if;
5411 Insert_Action (N, Tmp_Decl);
5412 end if;
5414 -- Construct and insert the aggregate code. We can safely suppress index
5415 -- checks because this code is guaranteed not to raise CE on index
5416 -- checks. However we should *not* suppress all checks.
5418 declare
5419 Target : Node_Id;
5421 begin
5422 if Nkind (Tmp) = N_Defining_Identifier then
5423 Target := New_Occurrence_Of (Tmp, Loc);
5425 else
5426 if Has_Default_Init_Comps (N) then
5428 -- Ada 2005 (AI-287): This case has not been analyzed???
5430 raise Program_Error;
5431 end if;
5433 -- Name in assignment is explicit dereference
5435 Target := New_Copy (Tmp);
5436 end if;
5438 -- If we are to generate an in place assignment for a declaration or
5439 -- an assignment statement, and the assignment can be done directly
5440 -- by the back end, then do not expand further.
5442 -- ??? We can also do that if in place expansion is not possible but
5443 -- then we could go into an infinite recursion.
5445 if (In_Place_Assign_OK_For_Declaration or else Maybe_In_Place_OK)
5446 and then VM_Target = No_VM
5447 and then not AAMP_On_Target
5448 and then not Generate_SCIL
5449 and then not Possible_Bit_Aligned_Component (Target)
5450 and then not Is_Possibly_Unaligned_Slice (Target)
5451 and then Aggr_Assignment_OK_For_Backend (N)
5452 then
5453 if Maybe_In_Place_OK then
5454 return;
5455 end if;
5457 Aggr_Code :=
5458 New_List (
5459 Make_Assignment_Statement (Loc,
5460 Name => Target,
5461 Expression => New_Copy (N)));
5463 else
5464 Aggr_Code :=
5465 Build_Array_Aggr_Code (N,
5466 Ctype => Ctyp,
5467 Index => First_Index (Typ),
5468 Into => Target,
5469 Scalar_Comp => Is_Scalar_Type (Ctyp));
5470 end if;
5472 -- Save the last assignment statement associated with the aggregate
5473 -- when building a controlled object. This reference is utilized by
5474 -- the finalization machinery when marking an object as successfully
5475 -- initialized.
5477 if Needs_Finalization (Typ)
5478 and then Is_Entity_Name (Target)
5479 and then Present (Entity (Target))
5480 and then Ekind_In (Entity (Target), E_Constant, E_Variable)
5481 then
5482 Set_Last_Aggregate_Assignment (Entity (Target), Last (Aggr_Code));
5483 end if;
5484 end;
5486 -- If the aggregate is the expression in a declaration, the expanded
5487 -- code must be inserted after it. The defining entity might not come
5488 -- from source if this is part of an inlined body, but the declaration
5489 -- itself will.
5491 if Comes_From_Source (Tmp)
5492 or else
5493 (Nkind (Parent (N)) = N_Object_Declaration
5494 and then Comes_From_Source (Parent (N))
5495 and then Tmp = Defining_Entity (Parent (N)))
5496 then
5497 declare
5498 Node_After : constant Node_Id := Next (Parent_Node);
5500 begin
5501 Insert_Actions_After (Parent_Node, Aggr_Code);
5503 if Parent_Kind = N_Object_Declaration then
5504 Collect_Initialization_Statements
5505 (Obj => Tmp, N => Parent_Node, Node_After => Node_After);
5506 end if;
5507 end;
5509 else
5510 Insert_Actions (N, Aggr_Code);
5511 end if;
5513 -- If the aggregate has been assigned in place, remove the original
5514 -- assignment.
5516 if Nkind (Parent (N)) = N_Assignment_Statement
5517 and then Maybe_In_Place_OK
5518 then
5519 Rewrite (Parent (N), Make_Null_Statement (Loc));
5521 elsif Nkind (Parent (N)) /= N_Object_Declaration
5522 or else Tmp /= Defining_Identifier (Parent (N))
5523 then
5524 Rewrite (N, New_Occurrence_Of (Tmp, Loc));
5525 Analyze_And_Resolve (N, Typ);
5526 end if;
5527 end Expand_Array_Aggregate;
5529 ------------------------
5530 -- Expand_N_Aggregate --
5531 ------------------------
5533 procedure Expand_N_Aggregate (N : Node_Id) is
5534 begin
5535 -- Record aggregate case
5537 if Is_Record_Type (Etype (N)) then
5538 Expand_Record_Aggregate (N);
5540 -- Array aggregate case
5542 else
5543 -- A special case, if we have a string subtype with bounds 1 .. N,
5544 -- where N is known at compile time, and the aggregate is of the
5545 -- form (others => 'x'), with a single choice and no expressions,
5546 -- and N is less than 80 (an arbitrary limit for now), then replace
5547 -- the aggregate by the equivalent string literal (but do not mark
5548 -- it as static since it is not).
5550 -- Note: this entire circuit is redundant with respect to code in
5551 -- Expand_Array_Aggregate that collapses others choices to positional
5552 -- form, but there are two problems with that circuit:
5554 -- a) It is limited to very small cases due to ill-understood
5555 -- interactions with bootstrapping. That limit is removed by
5556 -- use of the No_Implicit_Loops restriction.
5558 -- b) It incorrectly ends up with the resulting expressions being
5559 -- considered static when they are not. For example, the
5560 -- following test should fail:
5562 -- pragma Restrictions (No_Implicit_Loops);
5563 -- package NonSOthers4 is
5564 -- B : constant String (1 .. 6) := (others => 'A');
5565 -- DH : constant String (1 .. 8) := B & "BB";
5566 -- X : Integer;
5567 -- pragma Export (C, X, Link_Name => DH);
5568 -- end;
5570 -- But it succeeds (DH looks static to pragma Export)
5572 -- To be sorted out ???
5574 if Present (Component_Associations (N)) then
5575 declare
5576 CA : constant Node_Id := First (Component_Associations (N));
5577 MX : constant := 80;
5579 begin
5580 if Nkind (First (Choices (CA))) = N_Others_Choice
5581 and then Nkind (Expression (CA)) = N_Character_Literal
5582 and then No (Expressions (N))
5583 then
5584 declare
5585 T : constant Entity_Id := Etype (N);
5586 X : constant Node_Id := First_Index (T);
5587 EC : constant Node_Id := Expression (CA);
5588 CV : constant Uint := Char_Literal_Value (EC);
5589 CC : constant Int := UI_To_Int (CV);
5591 begin
5592 if Nkind (X) = N_Range
5593 and then Compile_Time_Known_Value (Low_Bound (X))
5594 and then Expr_Value (Low_Bound (X)) = 1
5595 and then Compile_Time_Known_Value (High_Bound (X))
5596 then
5597 declare
5598 Hi : constant Uint := Expr_Value (High_Bound (X));
5600 begin
5601 if Hi <= MX then
5602 Start_String;
5604 for J in 1 .. UI_To_Int (Hi) loop
5605 Store_String_Char (Char_Code (CC));
5606 end loop;
5608 Rewrite (N,
5609 Make_String_Literal (Sloc (N),
5610 Strval => End_String));
5612 if CC >= Int (2 ** 16) then
5613 Set_Has_Wide_Wide_Character (N);
5614 elsif CC >= Int (2 ** 8) then
5615 Set_Has_Wide_Character (N);
5616 end if;
5618 Analyze_And_Resolve (N, T);
5619 Set_Is_Static_Expression (N, False);
5620 return;
5621 end if;
5622 end;
5623 end if;
5624 end;
5625 end if;
5626 end;
5627 end if;
5629 -- Not that special case, so normal expansion of array aggregate
5631 Expand_Array_Aggregate (N);
5632 end if;
5634 exception
5635 when RE_Not_Available =>
5636 return;
5637 end Expand_N_Aggregate;
5639 ----------------------------------
5640 -- Expand_N_Extension_Aggregate --
5641 ----------------------------------
5643 -- If the ancestor part is an expression, add a component association for
5644 -- the parent field. If the type of the ancestor part is not the direct
5645 -- parent of the expected type, build recursively the needed ancestors.
5646 -- If the ancestor part is a subtype_mark, replace aggregate with a decla-
5647 -- ration for a temporary of the expected type, followed by individual
5648 -- assignments to the given components.
5650 procedure Expand_N_Extension_Aggregate (N : Node_Id) is
5651 Loc : constant Source_Ptr := Sloc (N);
5652 A : constant Node_Id := Ancestor_Part (N);
5653 Typ : constant Entity_Id := Etype (N);
5655 begin
5656 -- If the ancestor is a subtype mark, an init proc must be called
5657 -- on the resulting object which thus has to be materialized in
5658 -- the front-end
5660 if Is_Entity_Name (A) and then Is_Type (Entity (A)) then
5661 Convert_To_Assignments (N, Typ);
5663 -- The extension aggregate is transformed into a record aggregate
5664 -- of the following form (c1 and c2 are inherited components)
5666 -- (Exp with c3 => a, c4 => b)
5667 -- ==> (c1 => Exp.c1, c2 => Exp.c2, c3 => a, c4 => b)
5669 else
5670 Set_Etype (N, Typ);
5672 if Tagged_Type_Expansion then
5673 Expand_Record_Aggregate (N,
5674 Orig_Tag =>
5675 New_Occurrence_Of
5676 (Node (First_Elmt (Access_Disp_Table (Typ))), Loc),
5677 Parent_Expr => A);
5679 -- No tag is needed in the case of a VM
5681 else
5682 Expand_Record_Aggregate (N, Parent_Expr => A);
5683 end if;
5684 end if;
5686 exception
5687 when RE_Not_Available =>
5688 return;
5689 end Expand_N_Extension_Aggregate;
5691 -----------------------------
5692 -- Expand_Record_Aggregate --
5693 -----------------------------
5695 procedure Expand_Record_Aggregate
5696 (N : Node_Id;
5697 Orig_Tag : Node_Id := Empty;
5698 Parent_Expr : Node_Id := Empty)
5700 Loc : constant Source_Ptr := Sloc (N);
5701 Comps : constant List_Id := Component_Associations (N);
5702 Typ : constant Entity_Id := Etype (N);
5703 Base_Typ : constant Entity_Id := Base_Type (Typ);
5705 Static_Components : Boolean := True;
5706 -- Flag to indicate whether all components are compile-time known,
5707 -- and the aggregate can be constructed statically and handled by
5708 -- the back-end.
5710 function Compile_Time_Known_Composite_Value (N : Node_Id) return Boolean;
5711 -- Returns true if N is an expression of composite type which can be
5712 -- fully evaluated at compile time without raising constraint error.
5713 -- Such expressions can be passed as is to Gigi without any expansion.
5715 -- This returns true for N_Aggregate with Compile_Time_Known_Aggregate
5716 -- set and constants whose expression is such an aggregate, recursively.
5718 function Component_Not_OK_For_Backend return Boolean;
5719 -- Check for presence of a component which makes it impossible for the
5720 -- backend to process the aggregate, thus requiring the use of a series
5721 -- of assignment statements. Cases checked for are a nested aggregate
5722 -- needing Late_Expansion, the presence of a tagged component which may
5723 -- need tag adjustment, and a bit unaligned component reference.
5725 -- We also force expansion into assignments if a component is of a
5726 -- mutable type (including a private type with discriminants) because
5727 -- in that case the size of the component to be copied may be smaller
5728 -- than the side of the target, and there is no simple way for gigi
5729 -- to compute the size of the object to be copied.
5731 -- NOTE: This is part of the ongoing work to define precisely the
5732 -- interface between front-end and back-end handling of aggregates.
5733 -- In general it is desirable to pass aggregates as they are to gigi,
5734 -- in order to minimize elaboration code. This is one case where the
5735 -- semantics of Ada complicate the analysis and lead to anomalies in
5736 -- the gcc back-end if the aggregate is not expanded into assignments.
5738 function Has_Visible_Private_Ancestor (Id : E) return Boolean;
5739 -- If any ancestor of the current type is private, the aggregate
5740 -- cannot be built in place. We cannot rely on Has_Private_Ancestor,
5741 -- because it will not be set when type and its parent are in the
5742 -- same scope, and the parent component needs expansion.
5744 function Top_Level_Aggregate (N : Node_Id) return Node_Id;
5745 -- For nested aggregates return the ultimate enclosing aggregate; for
5746 -- non-nested aggregates return N.
5748 ----------------------------------------
5749 -- Compile_Time_Known_Composite_Value --
5750 ----------------------------------------
5752 function Compile_Time_Known_Composite_Value
5753 (N : Node_Id) return Boolean
5755 begin
5756 -- If we have an entity name, then see if it is the name of a
5757 -- constant and if so, test the corresponding constant value.
5759 if Is_Entity_Name (N) then
5760 declare
5761 E : constant Entity_Id := Entity (N);
5762 V : Node_Id;
5763 begin
5764 if Ekind (E) /= E_Constant then
5765 return False;
5766 else
5767 V := Constant_Value (E);
5768 return Present (V)
5769 and then Compile_Time_Known_Composite_Value (V);
5770 end if;
5771 end;
5773 -- We have a value, see if it is compile time known
5775 else
5776 if Nkind (N) = N_Aggregate then
5777 return Compile_Time_Known_Aggregate (N);
5778 end if;
5780 -- All other types of values are not known at compile time
5782 return False;
5783 end if;
5785 end Compile_Time_Known_Composite_Value;
5787 ----------------------------------
5788 -- Component_Not_OK_For_Backend --
5789 ----------------------------------
5791 function Component_Not_OK_For_Backend return Boolean is
5792 C : Node_Id;
5793 Expr_Q : Node_Id;
5795 begin
5796 if No (Comps) then
5797 return False;
5798 end if;
5800 C := First (Comps);
5801 while Present (C) loop
5803 -- If the component has box initialization, expansion is needed
5804 -- and component is not ready for backend.
5806 if Box_Present (C) then
5807 return True;
5808 end if;
5810 if Nkind (Expression (C)) = N_Qualified_Expression then
5811 Expr_Q := Expression (Expression (C));
5812 else
5813 Expr_Q := Expression (C);
5814 end if;
5816 -- Return true if the aggregate has any associations for tagged
5817 -- components that may require tag adjustment.
5819 -- These are cases where the source expression may have a tag that
5820 -- could differ from the component tag (e.g., can occur for type
5821 -- conversions and formal parameters). (Tag adjustment not needed
5822 -- if VM_Target because object tags are implicit in the machine.)
5824 if Is_Tagged_Type (Etype (Expr_Q))
5825 and then (Nkind (Expr_Q) = N_Type_Conversion
5826 or else (Is_Entity_Name (Expr_Q)
5827 and then
5828 Ekind (Entity (Expr_Q)) in Formal_Kind))
5829 and then Tagged_Type_Expansion
5830 then
5831 Static_Components := False;
5832 return True;
5834 elsif Is_Delayed_Aggregate (Expr_Q) then
5835 Static_Components := False;
5836 return True;
5838 elsif Possible_Bit_Aligned_Component (Expr_Q) then
5839 Static_Components := False;
5840 return True;
5841 end if;
5843 if Is_Elementary_Type (Etype (Expr_Q)) then
5844 if not Compile_Time_Known_Value (Expr_Q) then
5845 Static_Components := False;
5846 end if;
5848 elsif not Compile_Time_Known_Composite_Value (Expr_Q) then
5849 Static_Components := False;
5851 if Is_Private_Type (Etype (Expr_Q))
5852 and then Has_Discriminants (Etype (Expr_Q))
5853 then
5854 return True;
5855 end if;
5856 end if;
5858 Next (C);
5859 end loop;
5861 return False;
5862 end Component_Not_OK_For_Backend;
5864 -----------------------------------
5865 -- Has_Visible_Private_Ancestor --
5866 -----------------------------------
5868 function Has_Visible_Private_Ancestor (Id : E) return Boolean is
5869 R : constant Entity_Id := Root_Type (Id);
5870 T1 : Entity_Id := Id;
5872 begin
5873 loop
5874 if Is_Private_Type (T1) then
5875 return True;
5877 elsif T1 = R then
5878 return False;
5880 else
5881 T1 := Etype (T1);
5882 end if;
5883 end loop;
5884 end Has_Visible_Private_Ancestor;
5886 -------------------------
5887 -- Top_Level_Aggregate --
5888 -------------------------
5890 function Top_Level_Aggregate (N : Node_Id) return Node_Id is
5891 Aggr : Node_Id;
5893 begin
5894 Aggr := N;
5895 while Present (Parent (Aggr))
5896 and then Nkind_In (Parent (Aggr), N_Component_Association,
5897 N_Aggregate)
5898 loop
5899 Aggr := Parent (Aggr);
5900 end loop;
5902 return Aggr;
5903 end Top_Level_Aggregate;
5905 -- Local variables
5907 Top_Level_Aggr : constant Node_Id := Top_Level_Aggregate (N);
5908 Tag_Value : Node_Id;
5909 Comp : Entity_Id;
5910 New_Comp : Node_Id;
5912 -- Start of processing for Expand_Record_Aggregate
5914 begin
5915 -- If the aggregate is to be assigned to an atomic variable, we have
5916 -- to prevent a piecemeal assignment even if the aggregate is to be
5917 -- expanded. We create a temporary for the aggregate, and assign the
5918 -- temporary instead, so that the back end can generate an atomic move
5919 -- for it.
5921 if Is_Atomic (Typ)
5922 and then Comes_From_Source (Parent (N))
5923 and then Is_Atomic_Aggregate (N, Typ)
5924 then
5925 return;
5927 -- No special management required for aggregates used to initialize
5928 -- statically allocated dispatch tables
5930 elsif Is_Static_Dispatch_Table_Aggregate (N) then
5931 return;
5932 end if;
5934 -- Ada 2005 (AI-318-2): We need to convert to assignments if components
5935 -- are build-in-place function calls. The assignments will each turn
5936 -- into a build-in-place function call. If components are all static,
5937 -- we can pass the aggregate to the backend regardless of limitedness.
5939 -- Extension aggregates, aggregates in extended return statements, and
5940 -- aggregates for C++ imported types must be expanded.
5942 if Ada_Version >= Ada_2005 and then Is_Limited_View (Typ) then
5943 if not Nkind_In (Parent (N), N_Object_Declaration,
5944 N_Component_Association)
5945 then
5946 Convert_To_Assignments (N, Typ);
5948 elsif Nkind (N) = N_Extension_Aggregate
5949 or else Convention (Typ) = Convention_CPP
5950 then
5951 Convert_To_Assignments (N, Typ);
5953 elsif not Size_Known_At_Compile_Time (Typ)
5954 or else Component_Not_OK_For_Backend
5955 or else not Static_Components
5956 then
5957 Convert_To_Assignments (N, Typ);
5959 else
5960 Set_Compile_Time_Known_Aggregate (N);
5961 Set_Expansion_Delayed (N, False);
5962 end if;
5964 -- Gigi doesn't properly handle temporaries of variable size so we
5965 -- generate it in the front-end
5967 elsif not Size_Known_At_Compile_Time (Typ)
5968 and then Tagged_Type_Expansion
5969 then
5970 Convert_To_Assignments (N, Typ);
5972 -- An aggregate used to initialize a controlled object must be turned
5973 -- into component assignments as the components themselves may require
5974 -- finalization actions such as adjustment.
5976 elsif Needs_Finalization (Typ) then
5977 Convert_To_Assignments (N, Typ);
5979 -- Ada 2005 (AI-287): In case of default initialized components we
5980 -- convert the aggregate into assignments.
5982 elsif Has_Default_Init_Comps (N) then
5983 Convert_To_Assignments (N, Typ);
5985 -- Check components
5987 elsif Component_Not_OK_For_Backend then
5988 Convert_To_Assignments (N, Typ);
5990 -- If an ancestor is private, some components are not inherited and we
5991 -- cannot expand into a record aggregate.
5993 elsif Has_Visible_Private_Ancestor (Typ) then
5994 Convert_To_Assignments (N, Typ);
5996 -- ??? The following was done to compile fxacc00.ads in the ACVCs. Gigi
5997 -- is not able to handle the aggregate for Late_Request.
5999 elsif Is_Tagged_Type (Typ) and then Has_Discriminants (Typ) then
6000 Convert_To_Assignments (N, Typ);
6002 -- If the tagged types covers interface types we need to initialize all
6003 -- hidden components containing pointers to secondary dispatch tables.
6005 elsif Is_Tagged_Type (Typ) and then Has_Interfaces (Typ) then
6006 Convert_To_Assignments (N, Typ);
6008 -- If some components are mutable, the size of the aggregate component
6009 -- may be distinct from the default size of the type component, so
6010 -- we need to expand to insure that the back-end copies the proper
6011 -- size of the data. However, if the aggregate is the initial value of
6012 -- a constant, the target is immutable and might be built statically
6013 -- if components are appropriate.
6015 elsif Has_Mutable_Components (Typ)
6016 and then
6017 (Nkind (Parent (Top_Level_Aggr)) /= N_Object_Declaration
6018 or else not Constant_Present (Parent (Top_Level_Aggr))
6019 or else not Static_Components)
6020 then
6021 Convert_To_Assignments (N, Typ);
6023 -- If the type involved has bit aligned components, then we are not sure
6024 -- that the back end can handle this case correctly.
6026 elsif Type_May_Have_Bit_Aligned_Components (Typ) then
6027 Convert_To_Assignments (N, Typ);
6029 -- In all other cases, build a proper aggregate to be handled by gigi
6031 else
6032 if Nkind (N) = N_Aggregate then
6034 -- If the aggregate is static and can be handled by the back-end,
6035 -- nothing left to do.
6037 if Static_Components then
6038 Set_Compile_Time_Known_Aggregate (N);
6039 Set_Expansion_Delayed (N, False);
6040 end if;
6041 end if;
6043 -- If no discriminants, nothing special to do
6045 if not Has_Discriminants (Typ) then
6046 null;
6048 -- Case of discriminants present
6050 elsif Is_Derived_Type (Typ) then
6052 -- For untagged types, non-stored discriminants are replaced
6053 -- with stored discriminants, which are the ones that gigi uses
6054 -- to describe the type and its components.
6056 Generate_Aggregate_For_Derived_Type : declare
6057 Constraints : constant List_Id := New_List;
6058 First_Comp : Node_Id;
6059 Discriminant : Entity_Id;
6060 Decl : Node_Id;
6061 Num_Disc : Int := 0;
6062 Num_Gird : Int := 0;
6064 procedure Prepend_Stored_Values (T : Entity_Id);
6065 -- Scan the list of stored discriminants of the type, and add
6066 -- their values to the aggregate being built.
6068 ---------------------------
6069 -- Prepend_Stored_Values --
6070 ---------------------------
6072 procedure Prepend_Stored_Values (T : Entity_Id) is
6073 begin
6074 Discriminant := First_Stored_Discriminant (T);
6075 while Present (Discriminant) loop
6076 New_Comp :=
6077 Make_Component_Association (Loc,
6078 Choices =>
6079 New_List (New_Occurrence_Of (Discriminant, Loc)),
6081 Expression =>
6082 New_Copy_Tree
6083 (Get_Discriminant_Value
6084 (Discriminant,
6085 Typ,
6086 Discriminant_Constraint (Typ))));
6088 if No (First_Comp) then
6089 Prepend_To (Component_Associations (N), New_Comp);
6090 else
6091 Insert_After (First_Comp, New_Comp);
6092 end if;
6094 First_Comp := New_Comp;
6095 Next_Stored_Discriminant (Discriminant);
6096 end loop;
6097 end Prepend_Stored_Values;
6099 -- Start of processing for Generate_Aggregate_For_Derived_Type
6101 begin
6102 -- Remove the associations for the discriminant of derived type
6104 First_Comp := First (Component_Associations (N));
6105 while Present (First_Comp) loop
6106 Comp := First_Comp;
6107 Next (First_Comp);
6109 if Ekind (Entity (First (Choices (Comp)))) = E_Discriminant
6110 then
6111 Remove (Comp);
6112 Num_Disc := Num_Disc + 1;
6113 end if;
6114 end loop;
6116 -- Insert stored discriminant associations in the correct
6117 -- order. If there are more stored discriminants than new
6118 -- discriminants, there is at least one new discriminant that
6119 -- constrains more than one of the stored discriminants. In
6120 -- this case we need to construct a proper subtype of the
6121 -- parent type, in order to supply values to all the
6122 -- components. Otherwise there is one-one correspondence
6123 -- between the constraints and the stored discriminants.
6125 First_Comp := Empty;
6127 Discriminant := First_Stored_Discriminant (Base_Type (Typ));
6128 while Present (Discriminant) loop
6129 Num_Gird := Num_Gird + 1;
6130 Next_Stored_Discriminant (Discriminant);
6131 end loop;
6133 -- Case of more stored discriminants than new discriminants
6135 if Num_Gird > Num_Disc then
6137 -- Create a proper subtype of the parent type, which is the
6138 -- proper implementation type for the aggregate, and convert
6139 -- it to the intended target type.
6141 Discriminant := First_Stored_Discriminant (Base_Type (Typ));
6142 while Present (Discriminant) loop
6143 New_Comp :=
6144 New_Copy_Tree
6145 (Get_Discriminant_Value
6146 (Discriminant,
6147 Typ,
6148 Discriminant_Constraint (Typ)));
6149 Append (New_Comp, Constraints);
6150 Next_Stored_Discriminant (Discriminant);
6151 end loop;
6153 Decl :=
6154 Make_Subtype_Declaration (Loc,
6155 Defining_Identifier => Make_Temporary (Loc, 'T'),
6156 Subtype_Indication =>
6157 Make_Subtype_Indication (Loc,
6158 Subtype_Mark =>
6159 New_Occurrence_Of (Etype (Base_Type (Typ)), Loc),
6160 Constraint =>
6161 Make_Index_Or_Discriminant_Constraint
6162 (Loc, Constraints)));
6164 Insert_Action (N, Decl);
6165 Prepend_Stored_Values (Base_Type (Typ));
6167 Set_Etype (N, Defining_Identifier (Decl));
6168 Set_Analyzed (N);
6170 Rewrite (N, Unchecked_Convert_To (Typ, N));
6171 Analyze (N);
6173 -- Case where we do not have fewer new discriminants than
6174 -- stored discriminants, so in this case we can simply use the
6175 -- stored discriminants of the subtype.
6177 else
6178 Prepend_Stored_Values (Typ);
6179 end if;
6180 end Generate_Aggregate_For_Derived_Type;
6181 end if;
6183 if Is_Tagged_Type (Typ) then
6185 -- In the tagged case, _parent and _tag component must be created
6187 -- Reset Null_Present unconditionally. Tagged records always have
6188 -- at least one field (the tag or the parent).
6190 Set_Null_Record_Present (N, False);
6192 -- When the current aggregate comes from the expansion of an
6193 -- extension aggregate, the parent expr is replaced by an
6194 -- aggregate formed by selected components of this expr.
6196 if Present (Parent_Expr) and then Is_Empty_List (Comps) then
6197 Comp := First_Component_Or_Discriminant (Typ);
6198 while Present (Comp) loop
6200 -- Skip all expander-generated components
6202 if not Comes_From_Source (Original_Record_Component (Comp))
6203 then
6204 null;
6206 else
6207 New_Comp :=
6208 Make_Selected_Component (Loc,
6209 Prefix =>
6210 Unchecked_Convert_To (Typ,
6211 Duplicate_Subexpr (Parent_Expr, True)),
6212 Selector_Name => New_Occurrence_Of (Comp, Loc));
6214 Append_To (Comps,
6215 Make_Component_Association (Loc,
6216 Choices =>
6217 New_List (New_Occurrence_Of (Comp, Loc)),
6218 Expression => New_Comp));
6220 Analyze_And_Resolve (New_Comp, Etype (Comp));
6221 end if;
6223 Next_Component_Or_Discriminant (Comp);
6224 end loop;
6225 end if;
6227 -- Compute the value for the Tag now, if the type is a root it
6228 -- will be included in the aggregate right away, otherwise it will
6229 -- be propagated to the parent aggregate.
6231 if Present (Orig_Tag) then
6232 Tag_Value := Orig_Tag;
6233 elsif not Tagged_Type_Expansion then
6234 Tag_Value := Empty;
6235 else
6236 Tag_Value :=
6237 New_Occurrence_Of
6238 (Node (First_Elmt (Access_Disp_Table (Typ))), Loc);
6239 end if;
6241 -- For a derived type, an aggregate for the parent is formed with
6242 -- all the inherited components.
6244 if Is_Derived_Type (Typ) then
6246 declare
6247 First_Comp : Node_Id;
6248 Parent_Comps : List_Id;
6249 Parent_Aggr : Node_Id;
6250 Parent_Name : Node_Id;
6252 begin
6253 -- Remove the inherited component association from the
6254 -- aggregate and store them in the parent aggregate
6256 First_Comp := First (Component_Associations (N));
6257 Parent_Comps := New_List;
6258 while Present (First_Comp)
6259 and then
6260 Scope (Original_Record_Component
6261 (Entity (First (Choices (First_Comp))))) /=
6262 Base_Typ
6263 loop
6264 Comp := First_Comp;
6265 Next (First_Comp);
6266 Remove (Comp);
6267 Append (Comp, Parent_Comps);
6268 end loop;
6270 Parent_Aggr :=
6271 Make_Aggregate (Loc,
6272 Component_Associations => Parent_Comps);
6273 Set_Etype (Parent_Aggr, Etype (Base_Type (Typ)));
6275 -- Find the _parent component
6277 Comp := First_Component (Typ);
6278 while Chars (Comp) /= Name_uParent loop
6279 Comp := Next_Component (Comp);
6280 end loop;
6282 Parent_Name := New_Occurrence_Of (Comp, Loc);
6284 -- Insert the parent aggregate
6286 Prepend_To (Component_Associations (N),
6287 Make_Component_Association (Loc,
6288 Choices => New_List (Parent_Name),
6289 Expression => Parent_Aggr));
6291 -- Expand recursively the parent propagating the right Tag
6293 Expand_Record_Aggregate
6294 (Parent_Aggr, Tag_Value, Parent_Expr);
6296 -- The ancestor part may be a nested aggregate that has
6297 -- delayed expansion: recheck now.
6299 if Component_Not_OK_For_Backend then
6300 Convert_To_Assignments (N, Typ);
6301 end if;
6302 end;
6304 -- For a root type, the tag component is added (unless compiling
6305 -- for the VMs, where tags are implicit).
6307 elsif Tagged_Type_Expansion then
6308 declare
6309 Tag_Name : constant Node_Id :=
6310 New_Occurrence_Of (First_Tag_Component (Typ), Loc);
6311 Typ_Tag : constant Entity_Id := RTE (RE_Tag);
6312 Conv_Node : constant Node_Id :=
6313 Unchecked_Convert_To (Typ_Tag, Tag_Value);
6315 begin
6316 Set_Etype (Conv_Node, Typ_Tag);
6317 Prepend_To (Component_Associations (N),
6318 Make_Component_Association (Loc,
6319 Choices => New_List (Tag_Name),
6320 Expression => Conv_Node));
6321 end;
6322 end if;
6323 end if;
6324 end if;
6326 end Expand_Record_Aggregate;
6328 ----------------------------
6329 -- Has_Default_Init_Comps --
6330 ----------------------------
6332 function Has_Default_Init_Comps (N : Node_Id) return Boolean is
6333 Comps : constant List_Id := Component_Associations (N);
6334 C : Node_Id;
6335 Expr : Node_Id;
6337 begin
6338 pragma Assert (Nkind_In (N, N_Aggregate, N_Extension_Aggregate));
6340 if No (Comps) then
6341 return False;
6342 end if;
6344 if Has_Self_Reference (N) then
6345 return True;
6346 end if;
6348 -- Check if any direct component has default initialized components
6350 C := First (Comps);
6351 while Present (C) loop
6352 if Box_Present (C) then
6353 return True;
6354 end if;
6356 Next (C);
6357 end loop;
6359 -- Recursive call in case of aggregate expression
6361 C := First (Comps);
6362 while Present (C) loop
6363 Expr := Expression (C);
6365 if Present (Expr)
6366 and then Nkind_In (Expr, N_Aggregate, N_Extension_Aggregate)
6367 and then Has_Default_Init_Comps (Expr)
6368 then
6369 return True;
6370 end if;
6372 Next (C);
6373 end loop;
6375 return False;
6376 end Has_Default_Init_Comps;
6378 --------------------------
6379 -- Is_Delayed_Aggregate --
6380 --------------------------
6382 function Is_Delayed_Aggregate (N : Node_Id) return Boolean is
6383 Node : Node_Id := N;
6384 Kind : Node_Kind := Nkind (Node);
6386 begin
6387 if Kind = N_Qualified_Expression then
6388 Node := Expression (Node);
6389 Kind := Nkind (Node);
6390 end if;
6392 if not Nkind_In (Kind, N_Aggregate, N_Extension_Aggregate) then
6393 return False;
6394 else
6395 return Expansion_Delayed (Node);
6396 end if;
6397 end Is_Delayed_Aggregate;
6399 ----------------------------------------
6400 -- Is_Static_Dispatch_Table_Aggregate --
6401 ----------------------------------------
6403 function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean is
6404 Typ : constant Entity_Id := Base_Type (Etype (N));
6406 begin
6407 return Static_Dispatch_Tables
6408 and then Tagged_Type_Expansion
6409 and then RTU_Loaded (Ada_Tags)
6411 -- Avoid circularity when rebuilding the compiler
6413 and then Cunit_Entity (Get_Source_Unit (N)) /= RTU_Entity (Ada_Tags)
6414 and then (Typ = RTE (RE_Dispatch_Table_Wrapper)
6415 or else
6416 Typ = RTE (RE_Address_Array)
6417 or else
6418 Typ = RTE (RE_Type_Specific_Data)
6419 or else
6420 Typ = RTE (RE_Tag_Table)
6421 or else
6422 (RTE_Available (RE_Interface_Data)
6423 and then Typ = RTE (RE_Interface_Data))
6424 or else
6425 (RTE_Available (RE_Interfaces_Array)
6426 and then Typ = RTE (RE_Interfaces_Array))
6427 or else
6428 (RTE_Available (RE_Interface_Data_Element)
6429 and then Typ = RTE (RE_Interface_Data_Element)));
6430 end Is_Static_Dispatch_Table_Aggregate;
6432 -----------------------------
6433 -- Is_Two_Dim_Packed_Array --
6434 -----------------------------
6436 function Is_Two_Dim_Packed_Array (Typ : Entity_Id) return Boolean is
6437 C : constant Int := UI_To_Int (Component_Size (Typ));
6438 begin
6439 return Number_Dimensions (Typ) = 2
6440 and then Is_Bit_Packed_Array (Typ)
6441 and then (C = 1 or else C = 2 or else C = 4);
6442 end Is_Two_Dim_Packed_Array;
6444 --------------------
6445 -- Late_Expansion --
6446 --------------------
6448 function Late_Expansion
6449 (N : Node_Id;
6450 Typ : Entity_Id;
6451 Target : Node_Id) return List_Id
6453 Aggr_Code : List_Id;
6455 begin
6456 if Is_Record_Type (Etype (N)) then
6457 Aggr_Code := Build_Record_Aggr_Code (N, Typ, Target);
6459 else pragma Assert (Is_Array_Type (Etype (N)));
6460 Aggr_Code :=
6461 Build_Array_Aggr_Code
6462 (N => N,
6463 Ctype => Component_Type (Etype (N)),
6464 Index => First_Index (Typ),
6465 Into => Target,
6466 Scalar_Comp => Is_Scalar_Type (Component_Type (Typ)),
6467 Indexes => No_List);
6468 end if;
6470 -- Save the last assignment statement associated with the aggregate
6471 -- when building a controlled object. This reference is utilized by
6472 -- the finalization machinery when marking an object as successfully
6473 -- initialized.
6475 if Needs_Finalization (Typ)
6476 and then Is_Entity_Name (Target)
6477 and then Present (Entity (Target))
6478 and then Ekind_In (Entity (Target), E_Constant, E_Variable)
6479 then
6480 Set_Last_Aggregate_Assignment (Entity (Target), Last (Aggr_Code));
6481 end if;
6483 return Aggr_Code;
6484 end Late_Expansion;
6486 ----------------------------------
6487 -- Make_OK_Assignment_Statement --
6488 ----------------------------------
6490 function Make_OK_Assignment_Statement
6491 (Sloc : Source_Ptr;
6492 Name : Node_Id;
6493 Expression : Node_Id) return Node_Id
6495 begin
6496 Set_Assignment_OK (Name);
6497 return Make_Assignment_Statement (Sloc, Name, Expression);
6498 end Make_OK_Assignment_Statement;
6500 -----------------------
6501 -- Number_Of_Choices --
6502 -----------------------
6504 function Number_Of_Choices (N : Node_Id) return Nat is
6505 Assoc : Node_Id;
6506 Choice : Node_Id;
6508 Nb_Choices : Nat := 0;
6510 begin
6511 if Present (Expressions (N)) then
6512 return 0;
6513 end if;
6515 Assoc := First (Component_Associations (N));
6516 while Present (Assoc) loop
6517 Choice := First (Choices (Assoc));
6518 while Present (Choice) loop
6519 if Nkind (Choice) /= N_Others_Choice then
6520 Nb_Choices := Nb_Choices + 1;
6521 end if;
6523 Next (Choice);
6524 end loop;
6526 Next (Assoc);
6527 end loop;
6529 return Nb_Choices;
6530 end Number_Of_Choices;
6532 ------------------------------------
6533 -- Packed_Array_Aggregate_Handled --
6534 ------------------------------------
6536 -- The current version of this procedure will handle at compile time
6537 -- any array aggregate that meets these conditions:
6539 -- One and two dimensional, bit packed
6540 -- Underlying packed type is modular type
6541 -- Bounds are within 32-bit Int range
6542 -- All bounds and values are static
6544 -- Note: for now, in the 2-D case, we only handle component sizes of
6545 -- 1, 2, 4 (cases where an integral number of elements occupies a byte).
6547 function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean is
6548 Loc : constant Source_Ptr := Sloc (N);
6549 Typ : constant Entity_Id := Etype (N);
6550 Ctyp : constant Entity_Id := Component_Type (Typ);
6552 Not_Handled : exception;
6553 -- Exception raised if this aggregate cannot be handled
6555 begin
6556 -- Handle one- or two dimensional bit packed array
6558 if not Is_Bit_Packed_Array (Typ)
6559 or else Number_Dimensions (Typ) > 2
6560 then
6561 return False;
6562 end if;
6564 -- If two-dimensional, check whether it can be folded, and transformed
6565 -- into a one-dimensional aggregate for the Packed_Array_Impl_Type of
6566 -- the original type.
6568 if Number_Dimensions (Typ) = 2 then
6569 return Two_Dim_Packed_Array_Handled (N);
6570 end if;
6572 if not Is_Modular_Integer_Type (Packed_Array_Impl_Type (Typ)) then
6573 return False;
6574 end if;
6576 if not Is_Scalar_Type (Component_Type (Typ))
6577 and then Has_Non_Standard_Rep (Component_Type (Typ))
6578 then
6579 return False;
6580 end if;
6582 declare
6583 Csiz : constant Nat := UI_To_Int (Component_Size (Typ));
6585 Lo : Node_Id;
6586 Hi : Node_Id;
6587 -- Bounds of index type
6589 Lob : Uint;
6590 Hib : Uint;
6591 -- Values of bounds if compile time known
6593 function Get_Component_Val (N : Node_Id) return Uint;
6594 -- Given a expression value N of the component type Ctyp, returns a
6595 -- value of Csiz (component size) bits representing this value. If
6596 -- the value is non-static or any other reason exists why the value
6597 -- cannot be returned, then Not_Handled is raised.
6599 -----------------------
6600 -- Get_Component_Val --
6601 -----------------------
6603 function Get_Component_Val (N : Node_Id) return Uint is
6604 Val : Uint;
6606 begin
6607 -- We have to analyze the expression here before doing any further
6608 -- processing here. The analysis of such expressions is deferred
6609 -- till expansion to prevent some problems of premature analysis.
6611 Analyze_And_Resolve (N, Ctyp);
6613 -- Must have a compile time value. String literals have to be
6614 -- converted into temporaries as well, because they cannot easily
6615 -- be converted into their bit representation.
6617 if not Compile_Time_Known_Value (N)
6618 or else Nkind (N) = N_String_Literal
6619 then
6620 raise Not_Handled;
6621 end if;
6623 Val := Expr_Rep_Value (N);
6625 -- Adjust for bias, and strip proper number of bits
6627 if Has_Biased_Representation (Ctyp) then
6628 Val := Val - Expr_Value (Type_Low_Bound (Ctyp));
6629 end if;
6631 return Val mod Uint_2 ** Csiz;
6632 end Get_Component_Val;
6634 -- Here we know we have a one dimensional bit packed array
6636 begin
6637 Get_Index_Bounds (First_Index (Typ), Lo, Hi);
6639 -- Cannot do anything if bounds are dynamic
6641 if not Compile_Time_Known_Value (Lo)
6642 or else
6643 not Compile_Time_Known_Value (Hi)
6644 then
6645 return False;
6646 end if;
6648 -- Or are silly out of range of int bounds
6650 Lob := Expr_Value (Lo);
6651 Hib := Expr_Value (Hi);
6653 if not UI_Is_In_Int_Range (Lob)
6654 or else
6655 not UI_Is_In_Int_Range (Hib)
6656 then
6657 return False;
6658 end if;
6660 -- At this stage we have a suitable aggregate for handling at compile
6661 -- time. The only remaining checks are that the values of expressions
6662 -- in the aggregate are compile-time known (checks are performed by
6663 -- Get_Component_Val), and that any subtypes or ranges are statically
6664 -- known.
6666 -- If the aggregate is not fully positional at this stage, then
6667 -- convert it to positional form. Either this will fail, in which
6668 -- case we can do nothing, or it will succeed, in which case we have
6669 -- succeeded in handling the aggregate and transforming it into a
6670 -- modular value, or it will stay an aggregate, in which case we
6671 -- have failed to create a packed value for it.
6673 if Present (Component_Associations (N)) then
6674 Convert_To_Positional
6675 (N, Max_Others_Replicate => 64, Handle_Bit_Packed => True);
6676 return Nkind (N) /= N_Aggregate;
6677 end if;
6679 -- Otherwise we are all positional, so convert to proper value
6681 declare
6682 Lov : constant Int := UI_To_Int (Lob);
6683 Hiv : constant Int := UI_To_Int (Hib);
6685 Len : constant Nat := Int'Max (0, Hiv - Lov + 1);
6686 -- The length of the array (number of elements)
6688 Aggregate_Val : Uint;
6689 -- Value of aggregate. The value is set in the low order bits of
6690 -- this value. For the little-endian case, the values are stored
6691 -- from low-order to high-order and for the big-endian case the
6692 -- values are stored from high-order to low-order. Note that gigi
6693 -- will take care of the conversions to left justify the value in
6694 -- the big endian case (because of left justified modular type
6695 -- processing), so we do not have to worry about that here.
6697 Lit : Node_Id;
6698 -- Integer literal for resulting constructed value
6700 Shift : Nat;
6701 -- Shift count from low order for next value
6703 Incr : Int;
6704 -- Shift increment for loop
6706 Expr : Node_Id;
6707 -- Next expression from positional parameters of aggregate
6709 Left_Justified : Boolean;
6710 -- Set True if we are filling the high order bits of the target
6711 -- value (i.e. the value is left justified).
6713 begin
6714 -- For little endian, we fill up the low order bits of the target
6715 -- value. For big endian we fill up the high order bits of the
6716 -- target value (which is a left justified modular value).
6718 Left_Justified := Bytes_Big_Endian;
6720 -- Switch justification if using -gnatd8
6722 if Debug_Flag_8 then
6723 Left_Justified := not Left_Justified;
6724 end if;
6726 -- Switch justfification if reverse storage order
6728 if Reverse_Storage_Order (Base_Type (Typ)) then
6729 Left_Justified := not Left_Justified;
6730 end if;
6732 if Left_Justified then
6733 Shift := Csiz * (Len - 1);
6734 Incr := -Csiz;
6735 else
6736 Shift := 0;
6737 Incr := +Csiz;
6738 end if;
6740 -- Loop to set the values
6742 if Len = 0 then
6743 Aggregate_Val := Uint_0;
6744 else
6745 Expr := First (Expressions (N));
6746 Aggregate_Val := Get_Component_Val (Expr) * Uint_2 ** Shift;
6748 for J in 2 .. Len loop
6749 Shift := Shift + Incr;
6750 Next (Expr);
6751 Aggregate_Val :=
6752 Aggregate_Val + Get_Component_Val (Expr) * Uint_2 ** Shift;
6753 end loop;
6754 end if;
6756 -- Now we can rewrite with the proper value
6758 Lit := Make_Integer_Literal (Loc, Intval => Aggregate_Val);
6759 Set_Print_In_Hex (Lit);
6761 -- Construct the expression using this literal. Note that it is
6762 -- important to qualify the literal with its proper modular type
6763 -- since universal integer does not have the required range and
6764 -- also this is a left justified modular type, which is important
6765 -- in the big-endian case.
6767 Rewrite (N,
6768 Unchecked_Convert_To (Typ,
6769 Make_Qualified_Expression (Loc,
6770 Subtype_Mark =>
6771 New_Occurrence_Of (Packed_Array_Impl_Type (Typ), Loc),
6772 Expression => Lit)));
6774 Analyze_And_Resolve (N, Typ);
6775 return True;
6776 end;
6777 end;
6779 exception
6780 when Not_Handled =>
6781 return False;
6782 end Packed_Array_Aggregate_Handled;
6784 ----------------------------
6785 -- Has_Mutable_Components --
6786 ----------------------------
6788 function Has_Mutable_Components (Typ : Entity_Id) return Boolean is
6789 Comp : Entity_Id;
6791 begin
6792 Comp := First_Component (Typ);
6793 while Present (Comp) loop
6794 if Is_Record_Type (Etype (Comp))
6795 and then Has_Discriminants (Etype (Comp))
6796 and then not Is_Constrained (Etype (Comp))
6797 then
6798 return True;
6799 end if;
6801 Next_Component (Comp);
6802 end loop;
6804 return False;
6805 end Has_Mutable_Components;
6807 ------------------------------
6808 -- Initialize_Discriminants --
6809 ------------------------------
6811 procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id) is
6812 Loc : constant Source_Ptr := Sloc (N);
6813 Bas : constant Entity_Id := Base_Type (Typ);
6814 Par : constant Entity_Id := Etype (Bas);
6815 Decl : constant Node_Id := Parent (Par);
6816 Ref : Node_Id;
6818 begin
6819 if Is_Tagged_Type (Bas)
6820 and then Is_Derived_Type (Bas)
6821 and then Has_Discriminants (Par)
6822 and then Has_Discriminants (Bas)
6823 and then Number_Discriminants (Bas) /= Number_Discriminants (Par)
6824 and then Nkind (Decl) = N_Full_Type_Declaration
6825 and then Nkind (Type_Definition (Decl)) = N_Record_Definition
6826 and then
6827 Present (Variant_Part (Component_List (Type_Definition (Decl))))
6828 and then Nkind (N) /= N_Extension_Aggregate
6829 then
6831 -- Call init proc to set discriminants.
6832 -- There should eventually be a special procedure for this ???
6834 Ref := New_Occurrence_Of (Defining_Identifier (N), Loc);
6835 Insert_Actions_After (N,
6836 Build_Initialization_Call (Sloc (N), Ref, Typ));
6837 end if;
6838 end Initialize_Discriminants;
6840 ----------------
6841 -- Must_Slide --
6842 ----------------
6844 function Must_Slide
6845 (Obj_Type : Entity_Id;
6846 Typ : Entity_Id) return Boolean
6848 L1, L2, H1, H2 : Node_Id;
6850 begin
6851 -- No sliding if the type of the object is not established yet, if it is
6852 -- an unconstrained type whose actual subtype comes from the aggregate,
6853 -- or if the two types are identical.
6855 if not Is_Array_Type (Obj_Type) then
6856 return False;
6858 elsif not Is_Constrained (Obj_Type) then
6859 return False;
6861 elsif Typ = Obj_Type then
6862 return False;
6864 else
6865 -- Sliding can only occur along the first dimension
6867 Get_Index_Bounds (First_Index (Typ), L1, H1);
6868 Get_Index_Bounds (First_Index (Obj_Type), L2, H2);
6870 if not Is_OK_Static_Expression (L1) or else
6871 not Is_OK_Static_Expression (L2) or else
6872 not Is_OK_Static_Expression (H1) or else
6873 not Is_OK_Static_Expression (H2)
6874 then
6875 return False;
6876 else
6877 return Expr_Value (L1) /= Expr_Value (L2)
6878 or else
6879 Expr_Value (H1) /= Expr_Value (H2);
6880 end if;
6881 end if;
6882 end Must_Slide;
6884 ----------------------------------
6885 -- Two_Dim_Packed_Array_Handled --
6886 ----------------------------------
6888 function Two_Dim_Packed_Array_Handled (N : Node_Id) return Boolean is
6889 Loc : constant Source_Ptr := Sloc (N);
6890 Typ : constant Entity_Id := Etype (N);
6891 Ctyp : constant Entity_Id := Component_Type (Typ);
6892 Comp_Size : constant Int := UI_To_Int (Component_Size (Typ));
6893 Packed_Array : constant Entity_Id :=
6894 Packed_Array_Impl_Type (Base_Type (Typ));
6896 One_Comp : Node_Id;
6897 -- Expression in original aggregate
6899 One_Dim : Node_Id;
6900 -- One-dimensional subaggregate
6902 begin
6904 -- For now, only deal with cases where an integral number of elements
6905 -- fit in a single byte. This includes the most common boolean case.
6907 if not (Comp_Size = 1 or else
6908 Comp_Size = 2 or else
6909 Comp_Size = 4)
6910 then
6911 return False;
6912 end if;
6914 Convert_To_Positional
6915 (N, Max_Others_Replicate => 64, Handle_Bit_Packed => True);
6917 -- Verify that all components are static
6919 if Nkind (N) = N_Aggregate
6920 and then Compile_Time_Known_Aggregate (N)
6921 then
6922 null;
6924 -- The aggregate may have been re-analyzed and converted already
6926 elsif Nkind (N) /= N_Aggregate then
6927 return True;
6929 -- If component associations remain, the aggregate is not static
6931 elsif Present (Component_Associations (N)) then
6932 return False;
6934 else
6935 One_Dim := First (Expressions (N));
6936 while Present (One_Dim) loop
6937 if Present (Component_Associations (One_Dim)) then
6938 return False;
6939 end if;
6941 One_Comp := First (Expressions (One_Dim));
6942 while Present (One_Comp) loop
6943 if not Is_OK_Static_Expression (One_Comp) then
6944 return False;
6945 end if;
6947 Next (One_Comp);
6948 end loop;
6950 Next (One_Dim);
6951 end loop;
6952 end if;
6954 -- Two-dimensional aggregate is now fully positional so pack one
6955 -- dimension to create a static one-dimensional array, and rewrite
6956 -- as an unchecked conversion to the original type.
6958 declare
6959 Byte_Size : constant Int := UI_To_Int (Component_Size (Packed_Array));
6960 -- The packed array type is a byte array
6962 Packed_Num : Int;
6963 -- Number of components accumulated in current byte
6965 Comps : List_Id;
6966 -- Assembled list of packed values for equivalent aggregate
6968 Comp_Val : Uint;
6969 -- integer value of component
6971 Incr : Int;
6972 -- Step size for packing
6974 Init_Shift : Int;
6975 -- Endian-dependent start position for packing
6977 Shift : Int;
6978 -- Current insertion position
6980 Val : Int;
6981 -- Component of packed array being assembled.
6983 begin
6984 Comps := New_List;
6985 Val := 0;
6986 Packed_Num := 0;
6988 -- Account for endianness. See corresponding comment in
6989 -- Packed_Array_Aggregate_Handled concerning the following.
6991 if Bytes_Big_Endian
6992 xor Debug_Flag_8
6993 xor Reverse_Storage_Order (Base_Type (Typ))
6994 then
6995 Init_Shift := Byte_Size - Comp_Size;
6996 Incr := -Comp_Size;
6997 else
6998 Init_Shift := 0;
6999 Incr := +Comp_Size;
7000 end if;
7002 -- Iterate over each subaggregate
7004 Shift := Init_Shift;
7005 One_Dim := First (Expressions (N));
7006 while Present (One_Dim) loop
7007 One_Comp := First (Expressions (One_Dim));
7008 while Present (One_Comp) loop
7009 if Packed_Num = Byte_Size / Comp_Size then
7011 -- Byte is complete, add to list of expressions
7013 Append (Make_Integer_Literal (Sloc (One_Dim), Val), Comps);
7014 Val := 0;
7015 Shift := Init_Shift;
7016 Packed_Num := 0;
7018 else
7019 Comp_Val := Expr_Rep_Value (One_Comp);
7021 -- Adjust for bias, and strip proper number of bits
7023 if Has_Biased_Representation (Ctyp) then
7024 Comp_Val := Comp_Val - Expr_Value (Type_Low_Bound (Ctyp));
7025 end if;
7027 Comp_Val := Comp_Val mod Uint_2 ** Comp_Size;
7028 Val := UI_To_Int (Val + Comp_Val * Uint_2 ** Shift);
7029 Shift := Shift + Incr;
7030 One_Comp := Next (One_Comp);
7031 Packed_Num := Packed_Num + 1;
7032 end if;
7033 end loop;
7035 One_Dim := Next (One_Dim);
7036 end loop;
7038 if Packed_Num > 0 then
7040 -- Add final incomplete byte if present
7042 Append (Make_Integer_Literal (Sloc (One_Dim), Val), Comps);
7043 end if;
7045 Rewrite (N,
7046 Unchecked_Convert_To (Typ,
7047 Make_Qualified_Expression (Loc,
7048 Subtype_Mark => New_Occurrence_Of (Packed_Array, Loc),
7049 Expression => Make_Aggregate (Loc, Expressions => Comps))));
7050 Analyze_And_Resolve (N);
7051 return True;
7052 end;
7053 end Two_Dim_Packed_Array_Handled;
7055 ---------------------
7056 -- Sort_Case_Table --
7057 ---------------------
7059 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
7060 L : constant Int := Case_Table'First;
7061 U : constant Int := Case_Table'Last;
7062 K : Int;
7063 J : Int;
7064 T : Case_Bounds;
7066 begin
7067 K := L;
7068 while K /= U loop
7069 T := Case_Table (K + 1);
7071 J := K + 1;
7072 while J /= L
7073 and then Expr_Value (Case_Table (J - 1).Choice_Lo) >
7074 Expr_Value (T.Choice_Lo)
7075 loop
7076 Case_Table (J) := Case_Table (J - 1);
7077 J := J - 1;
7078 end loop;
7080 Case_Table (J) := T;
7081 K := K + 1;
7082 end loop;
7083 end Sort_Case_Table;
7085 ----------------------------
7086 -- Static_Array_Aggregate --
7087 ----------------------------
7089 function Static_Array_Aggregate (N : Node_Id) return Boolean is
7090 Bounds : constant Node_Id := Aggregate_Bounds (N);
7092 Typ : constant Entity_Id := Etype (N);
7093 Comp_Type : constant Entity_Id := Component_Type (Typ);
7094 Agg : Node_Id;
7095 Expr : Node_Id;
7096 Lo : Node_Id;
7097 Hi : Node_Id;
7099 begin
7100 if Is_Tagged_Type (Typ)
7101 or else Is_Controlled (Typ)
7102 or else Is_Packed (Typ)
7103 then
7104 return False;
7105 end if;
7107 if Present (Bounds)
7108 and then Nkind (Bounds) = N_Range
7109 and then Nkind (Low_Bound (Bounds)) = N_Integer_Literal
7110 and then Nkind (High_Bound (Bounds)) = N_Integer_Literal
7111 then
7112 Lo := Low_Bound (Bounds);
7113 Hi := High_Bound (Bounds);
7115 if No (Component_Associations (N)) then
7117 -- Verify that all components are static integers
7119 Expr := First (Expressions (N));
7120 while Present (Expr) loop
7121 if Nkind (Expr) /= N_Integer_Literal then
7122 return False;
7123 end if;
7125 Next (Expr);
7126 end loop;
7128 return True;
7130 else
7131 -- We allow only a single named association, either a static
7132 -- range or an others_clause, with a static expression.
7134 Expr := First (Component_Associations (N));
7136 if Present (Expressions (N)) then
7137 return False;
7139 elsif Present (Next (Expr)) then
7140 return False;
7142 elsif Present (Next (First (Choices (Expr)))) then
7143 return False;
7145 else
7146 -- The aggregate is static if all components are literals,
7147 -- or else all its components are static aggregates for the
7148 -- component type. We also limit the size of a static aggregate
7149 -- to prevent runaway static expressions.
7151 if Is_Array_Type (Comp_Type)
7152 or else Is_Record_Type (Comp_Type)
7153 then
7154 if Nkind (Expression (Expr)) /= N_Aggregate
7155 or else
7156 not Compile_Time_Known_Aggregate (Expression (Expr))
7157 then
7158 return False;
7159 end if;
7161 elsif Nkind (Expression (Expr)) /= N_Integer_Literal then
7162 return False;
7163 end if;
7165 if not Aggr_Size_OK (N, Typ) then
7166 return False;
7167 end if;
7169 -- Create a positional aggregate with the right number of
7170 -- copies of the expression.
7172 Agg := Make_Aggregate (Sloc (N), New_List, No_List);
7174 for I in UI_To_Int (Intval (Lo)) .. UI_To_Int (Intval (Hi))
7175 loop
7176 Append_To (Expressions (Agg), New_Copy (Expression (Expr)));
7178 -- The copied expression must be analyzed and resolved.
7179 -- Besides setting the type, this ensures that static
7180 -- expressions are appropriately marked as such.
7182 Analyze_And_Resolve
7183 (Last (Expressions (Agg)), Component_Type (Typ));
7184 end loop;
7186 Set_Aggregate_Bounds (Agg, Bounds);
7187 Set_Etype (Agg, Typ);
7188 Set_Analyzed (Agg);
7189 Rewrite (N, Agg);
7190 Set_Compile_Time_Known_Aggregate (N);
7192 return True;
7193 end if;
7194 end if;
7196 else
7197 return False;
7198 end if;
7199 end Static_Array_Aggregate;
7201 end Exp_Aggr;