1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2003 Free Software Foundation, Inc. --
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 2, 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 COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Exp_Util; use Exp_Util;
33 with Freeze; use Freeze;
34 with Itypes; use Itypes;
35 with Lib.Xref; use Lib.Xref;
36 with Namet; use Namet;
37 with Nmake; use Nmake;
38 with Nlists; use Nlists;
41 with Sem_Cat; use Sem_Cat;
42 with Sem_Ch8; use Sem_Ch8;
43 with Sem_Ch13; use Sem_Ch13;
44 with Sem_Eval; use Sem_Eval;
45 with Sem_Res; use Sem_Res;
46 with Sem_Util; use Sem_Util;
47 with Sem_Type; use Sem_Type;
48 with Sem_Warn; use Sem_Warn;
49 with Sinfo; use Sinfo;
50 with Snames; use Snames;
51 with Stringt; use Stringt;
52 with Stand; use Stand;
53 with Targparm; use Targparm;
54 with Tbuild; use Tbuild;
55 with Uintp; use Uintp;
57 with GNAT.Spelling_Checker; use GNAT.Spelling_Checker;
59 package body Sem_Aggr is
61 type Case_Bounds is record
64 Choice_Node : Node_Id;
67 type Case_Table_Type is array (Nat range <>) of Case_Bounds;
68 -- Table type used by Check_Case_Choices procedure
70 -----------------------
71 -- Local Subprograms --
72 -----------------------
74 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
75 -- Sort the Case Table using the Lower Bound of each Choice as the key.
76 -- A simple insertion sort is used since the number of choices in a case
77 -- statement of variant part will usually be small and probably in near
80 ------------------------------------------------------
81 -- Subprograms used for RECORD AGGREGATE Processing --
82 ------------------------------------------------------
84 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id);
85 -- This procedure performs all the semantic checks required for record
86 -- aggregates. Note that for aggregates analysis and resolution go
87 -- hand in hand. Aggregate analysis has been delayed up to here and
88 -- it is done while resolving the aggregate.
90 -- N is the N_Aggregate node.
91 -- Typ is the record type for the aggregate resolution
93 -- While performing the semantic checks, this procedure
94 -- builds a new Component_Association_List where each record field
95 -- appears alone in a Component_Choice_List along with its corresponding
96 -- expression. The record fields in the Component_Association_List
97 -- appear in the same order in which they appear in the record type Typ.
99 -- Once this new Component_Association_List is built and all the
100 -- semantic checks performed, the original aggregate subtree is replaced
101 -- with the new named record aggregate just built. Note that the subtree
102 -- substitution is performed with Rewrite so as to be
103 -- able to retrieve the original aggregate.
105 -- The aggregate subtree manipulation performed by Resolve_Record_Aggregate
106 -- yields the aggregate format expected by Gigi. Typically, this kind of
107 -- tree manipulations are done in the expander. However, because the
108 -- semantic checks that need to be performed on record aggregates really
109 -- go hand in hand with the record aggregate normalization, the aggregate
110 -- subtree transformation is performed during resolution rather than
111 -- expansion. Had we decided otherwise we would have had to duplicate
112 -- most of the code in the expansion procedure Expand_Record_Aggregate.
113 -- Note, however, that all the expansion concerning aggegates for tagged
114 -- records is done in Expand_Record_Aggregate.
116 -- The algorithm of Resolve_Record_Aggregate proceeds as follows:
118 -- 1. Make sure that the record type against which the record aggregate
119 -- has to be resolved is not abstract. Furthermore if the type is
120 -- a null aggregate make sure the input aggregate N is also null.
122 -- 2. Verify that the structure of the aggregate is that of a record
123 -- aggregate. Specifically, look for component associations and ensure
124 -- that each choice list only has identifiers or the N_Others_Choice
125 -- node. Also make sure that if present, the N_Others_Choice occurs
126 -- last and by itself.
128 -- 3. If Typ contains discriminants, the values for each discriminant
129 -- is looked for. If the record type Typ has variants, we check
130 -- that the expressions corresponding to each discriminant ruling
131 -- the (possibly nested) variant parts of Typ, are static. This
132 -- allows us to determine the variant parts to which the rest of
133 -- the aggregate must conform. The names of discriminants with their
134 -- values are saved in a new association list, New_Assoc_List which
135 -- is later augmented with the names and values of the remaining
136 -- components in the record type.
138 -- During this phase we also make sure that every discriminant is
139 -- assigned exactly one value. Note that when several values
140 -- for a given discriminant are found, semantic processing continues
141 -- looking for further errors. In this case it's the first
142 -- discriminant value found which we will be recorded.
144 -- IMPORTANT NOTE: For derived tagged types this procedure expects
145 -- First_Discriminant and Next_Discriminant to give the correct list
146 -- of discriminants, in the correct order.
148 -- 4. After all the discriminant values have been gathered, we can
149 -- set the Etype of the record aggregate. If Typ contains no
150 -- discriminants this is straightforward: the Etype of N is just
151 -- Typ, otherwise a new implicit constrained subtype of Typ is
152 -- built to be the Etype of N.
154 -- 5. Gather the remaining record components according to the discriminant
155 -- values. This involves recursively traversing the record type
156 -- structure to see what variants are selected by the given discriminant
157 -- values. This processing is a little more convoluted if Typ is a
158 -- derived tagged types since we need to retrieve the record structure
159 -- of all the ancestors of Typ.
161 -- 6. After gathering the record components we look for their values
162 -- in the record aggregate and emit appropriate error messages
163 -- should we not find such values or should they be duplicated.
165 -- 7. We then make sure no illegal component names appear in the
166 -- record aggegate and make sure that the type of the record
167 -- components appearing in a same choice list is the same.
168 -- Finally we ensure that the others choice, if present, is
169 -- used to provide the value of at least a record component.
171 -- 8. The original aggregate node is replaced with the new named
172 -- aggregate built in steps 3 through 6, as explained earlier.
174 -- Given the complexity of record aggregate resolution, the primary
175 -- goal of this routine is clarity and simplicity rather than execution
176 -- and storage efficiency. If there are only positional components in the
177 -- aggregate the running time is linear. If there are associations
178 -- the running time is still linear as long as the order of the
179 -- associations is not too far off the order of the components in the
180 -- record type. If this is not the case the running time is at worst
181 -- quadratic in the size of the association list.
183 procedure Check_Misspelled_Component
184 (Elements : Elist_Id;
185 Component : Node_Id);
186 -- Give possible misspelling diagnostic if Component is likely to be
187 -- a misspelling of one of the components of the Assoc_List.
188 -- This is called by Resolv_Aggr_Expr after producing
189 -- an invalid component error message.
191 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id);
192 -- An optimization: determine whether a discriminated subtype has a
193 -- static constraint, and contains array components whose length is also
194 -- static, either because they are constrained by the discriminant, or
195 -- because the original component bounds are static.
197 -----------------------------------------------------
198 -- Subprograms used for ARRAY AGGREGATE Processing --
199 -----------------------------------------------------
201 function Resolve_Array_Aggregate
204 Index_Constr : Node_Id;
205 Component_Typ : Entity_Id;
206 Others_Allowed : Boolean)
208 -- This procedure performs the semantic checks for an array aggregate.
209 -- True is returned if the aggregate resolution succeeds.
210 -- The procedure works by recursively checking each nested aggregate.
211 -- Specifically, after checking a sub-aggreate nested at the i-th level
212 -- we recursively check all the subaggregates at the i+1-st level (if any).
213 -- Note that for aggregates analysis and resolution go hand in hand.
214 -- Aggregate analysis has been delayed up to here and it is done while
215 -- resolving the aggregate.
217 -- N is the current N_Aggregate node to be checked.
219 -- Index is the index node corresponding to the array sub-aggregate that
220 -- we are currently checking (RM 4.3.3 (8)). Its Etype is the
221 -- corresponding index type (or subtype).
223 -- Index_Constr is the node giving the applicable index constraint if
224 -- any (RM 4.3.3 (10)). It "is a constraint provided by certain
225 -- contexts [...] that can be used to determine the bounds of the array
226 -- value specified by the aggregate". If Others_Allowed below is False
227 -- there is no applicable index constraint and this node is set to Index.
229 -- Component_Typ is the array component type.
231 -- Others_Allowed indicates whether an others choice is allowed
232 -- in the context where the top-level aggregate appeared.
234 -- The algorithm of Resolve_Array_Aggregate proceeds as follows:
236 -- 1. Make sure that the others choice, if present, is by itself and
237 -- appears last in the sub-aggregate. Check that we do not have
238 -- positional and named components in the array sub-aggregate (unless
239 -- the named association is an others choice). Finally if an others
240 -- choice is present, make sure it is allowed in the aggregate contex.
242 -- 2. If the array sub-aggregate contains discrete_choices:
244 -- (A) Verify their validity. Specifically verify that:
246 -- (a) If a null range is present it must be the only possible
247 -- choice in the array aggregate.
249 -- (b) Ditto for a non static range.
251 -- (c) Ditto for a non static expression.
253 -- In addition this step analyzes and resolves each discrete_choice,
254 -- making sure that its type is the type of the corresponding Index.
255 -- If we are not at the lowest array aggregate level (in the case of
256 -- multi-dimensional aggregates) then invoke Resolve_Array_Aggregate
257 -- recursively on each component expression. Otherwise, resolve the
258 -- bottom level component expressions against the expected component
259 -- type ONLY IF the component corresponds to a single discrete choice
260 -- which is not an others choice (to see why read the DELAYED
261 -- COMPONENT RESOLUTION below).
263 -- (B) Determine the bounds of the sub-aggregate and lowest and
264 -- highest choice values.
266 -- 3. For positional aggregates:
268 -- (A) Loop over the component expressions either recursively invoking
269 -- Resolve_Array_Aggregate on each of these for multi-dimensional
270 -- array aggregates or resolving the bottom level component
271 -- expressions against the expected component type.
273 -- (B) Determine the bounds of the positional sub-aggregates.
275 -- 4. Try to determine statically whether the evaluation of the array
276 -- sub-aggregate raises Constraint_Error. If yes emit proper
277 -- warnings. The precise checks are the following:
279 -- (A) Check that the index range defined by aggregate bounds is
280 -- compatible with corresponding index subtype.
281 -- We also check against the base type. In fact it could be that
282 -- Low/High bounds of the base type are static whereas those of
283 -- the index subtype are not. Thus if we can statically catch
284 -- a problem with respect to the base type we are guaranteed
285 -- that the same problem will arise with the index subtype
287 -- (B) If we are dealing with a named aggregate containing an others
288 -- choice and at least one discrete choice then make sure the range
289 -- specified by the discrete choices does not overflow the
290 -- aggregate bounds. We also check against the index type and base
291 -- type bounds for the same reasons given in (A).
293 -- (C) If we are dealing with a positional aggregate with an others
294 -- choice make sure the number of positional elements specified
295 -- does not overflow the aggregate bounds. We also check against
296 -- the index type and base type bounds as mentioned in (A).
298 -- Finally construct an N_Range node giving the sub-aggregate bounds.
299 -- Set the Aggregate_Bounds field of the sub-aggregate to be this
300 -- N_Range. The routine Array_Aggr_Subtype below uses such N_Ranges
301 -- to build the appropriate aggregate subtype. Aggregate_Bounds
302 -- information is needed during expansion.
304 -- DELAYED COMPONENT RESOLUTION: The resolution of bottom level component
305 -- expressions in an array aggregate may call Duplicate_Subexpr or some
306 -- other routine that inserts code just outside the outermost aggregate.
307 -- If the array aggregate contains discrete choices or an others choice,
308 -- this may be wrong. Consider for instance the following example.
310 -- type Rec is record
314 -- type Acc_Rec is access Rec;
315 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => new Rec);
317 -- Then the transformation of "new Rec" that occurs during resolution
318 -- entails the following code modifications
320 -- P7b : constant Acc_Rec := new Rec;
322 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => P7b);
324 -- This code transformation is clearly wrong, since we need to call
325 -- "new Rec" for each of the 3 array elements. To avoid this problem we
326 -- delay resolution of the components of non positional array aggregates
327 -- to the expansion phase. As an optimization, if the discrete choice
328 -- specifies a single value we do not delay resolution.
330 function Array_Aggr_Subtype (N : Node_Id; Typ : Node_Id) return Entity_Id;
331 -- This routine returns the type or subtype of an array aggregate.
333 -- N is the array aggregate node whose type we return.
335 -- Typ is the context type in which N occurs.
337 -- This routine creates an implicit array subtype whose bouds are
338 -- those defined by the aggregate. When this routine is invoked
339 -- Resolve_Array_Aggregate has already processed aggregate N. Thus the
340 -- Aggregate_Bounds of each sub-aggregate, is an N_Range node giving the
341 -- sub-aggregate bounds. When building the aggegate itype, this function
342 -- traverses the array aggregate N collecting such Aggregate_Bounds and
343 -- constructs the proper array aggregate itype.
345 -- Note that in the case of multidimensional aggregates each inner
346 -- sub-aggregate corresponding to a given array dimension, may provide a
347 -- different bounds. If it is possible to determine statically that
348 -- some sub-aggregates corresponding to the same index do not have the
349 -- same bounds, then a warning is emitted. If such check is not possible
350 -- statically (because some sub-aggregate bounds are dynamic expressions)
351 -- then this job is left to the expander. In all cases the particular
352 -- bounds that this function will chose for a given dimension is the first
353 -- N_Range node for a sub-aggregate corresponding to that dimension.
355 -- Note that the Raises_Constraint_Error flag of an array aggregate
356 -- whose evaluation is determined to raise CE by Resolve_Array_Aggregate,
357 -- is set in Resolve_Array_Aggregate but the aggregate is not
358 -- immediately replaced with a raise CE. In fact, Array_Aggr_Subtype must
359 -- first construct the proper itype for the aggregate (Gigi needs
360 -- this). After constructing the proper itype we will eventually replace
361 -- the top-level aggregate with a raise CE (done in Resolve_Aggregate).
362 -- Of course in cases such as:
364 -- type Arr is array (integer range <>) of Integer;
365 -- A : Arr := (positive range -1 .. 2 => 0);
367 -- The bounds of the aggregate itype are cooked up to look reasonable
368 -- (in this particular case the bounds will be 1 .. 2).
370 procedure Aggregate_Constraint_Checks
372 Check_Typ : Entity_Id);
373 -- Checks expression Exp against subtype Check_Typ. If Exp is an
374 -- aggregate and Check_Typ a constrained record type with discriminants,
375 -- we generate the appropriate discriminant checks. If Exp is an array
376 -- aggregate then emit the appropriate length checks. If Exp is a scalar
377 -- type, or a string literal, Exp is changed into Check_Typ'(Exp) to
378 -- ensure that range checks are performed at run time.
380 procedure Make_String_Into_Aggregate (N : Node_Id);
381 -- A string literal can appear in a context in which a one dimensional
382 -- array of characters is expected. This procedure simply rewrites the
383 -- string as an aggregate, prior to resolution.
385 ---------------------------------
386 -- Aggregate_Constraint_Checks --
387 ---------------------------------
389 procedure Aggregate_Constraint_Checks
391 Check_Typ : Entity_Id)
393 Exp_Typ : constant Entity_Id := Etype (Exp);
396 if Raises_Constraint_Error (Exp) then
400 -- This is really expansion activity, so make sure that expansion
401 -- is on and is allowed.
403 if not Expander_Active or else In_Default_Expression then
407 -- First check if we have to insert discriminant checks
409 if Has_Discriminants (Exp_Typ) then
410 Apply_Discriminant_Check (Exp, Check_Typ);
412 -- Next emit length checks for array aggregates
414 elsif Is_Array_Type (Exp_Typ) then
415 Apply_Length_Check (Exp, Check_Typ);
417 -- Finally emit scalar and string checks. If we are dealing with a
418 -- scalar literal we need to check by hand because the Etype of
419 -- literals is not necessarily correct.
421 elsif Is_Scalar_Type (Exp_Typ)
422 and then Compile_Time_Known_Value (Exp)
424 if Is_Out_Of_Range (Exp, Base_Type (Check_Typ)) then
425 Apply_Compile_Time_Constraint_Error
426 (Exp, "value not in range of}?", CE_Range_Check_Failed,
427 Ent => Base_Type (Check_Typ),
428 Typ => Base_Type (Check_Typ));
430 elsif Is_Out_Of_Range (Exp, Check_Typ) then
431 Apply_Compile_Time_Constraint_Error
432 (Exp, "value not in range of}?", CE_Range_Check_Failed,
436 elsif not Range_Checks_Suppressed (Check_Typ) then
437 Apply_Scalar_Range_Check (Exp, Check_Typ);
440 elsif (Is_Scalar_Type (Exp_Typ)
441 or else Nkind (Exp) = N_String_Literal)
442 and then Exp_Typ /= Check_Typ
444 if Is_Entity_Name (Exp)
445 and then Ekind (Entity (Exp)) = E_Constant
447 -- If expression is a constant, it is worthwhile checking whether
448 -- it is a bound of the type.
450 if (Is_Entity_Name (Type_Low_Bound (Check_Typ))
451 and then Entity (Exp) = Entity (Type_Low_Bound (Check_Typ)))
452 or else (Is_Entity_Name (Type_High_Bound (Check_Typ))
453 and then Entity (Exp) = Entity (Type_High_Bound (Check_Typ)))
458 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
459 Analyze_And_Resolve (Exp, Check_Typ);
460 Check_Unset_Reference (Exp);
463 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
464 Analyze_And_Resolve (Exp, Check_Typ);
465 Check_Unset_Reference (Exp);
468 end Aggregate_Constraint_Checks;
470 ------------------------
471 -- Array_Aggr_Subtype --
472 ------------------------
474 function Array_Aggr_Subtype
479 Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
480 -- Number of aggregate index dimensions.
482 Aggr_Range : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
483 -- Constrained N_Range of each index dimension in our aggregate itype.
485 Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
486 Aggr_High : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
487 -- Low and High bounds for each index dimension in our aggregate itype.
489 Is_Fully_Positional : Boolean := True;
491 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos);
492 -- N is an array (sub-)aggregate. Dim is the dimension corresponding to
493 -- (sub-)aggregate N. This procedure collects the constrained N_Range
494 -- nodes corresponding to each index dimension of our aggregate itype.
495 -- These N_Range nodes are collected in Aggr_Range above.
496 -- Likewise collect in Aggr_Low & Aggr_High above the low and high
497 -- bounds of each index dimension. If, when collecting, two bounds
498 -- corresponding to the same dimension are static and found to differ,
499 -- then emit a warning, and mark N as raising Constraint_Error.
501 -------------------------
502 -- Collect_Aggr_Bounds --
503 -------------------------
505 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos) is
506 This_Range : constant Node_Id := Aggregate_Bounds (N);
507 -- The aggregate range node of this specific sub-aggregate.
509 This_Low : constant Node_Id := Low_Bound (Aggregate_Bounds (N));
510 This_High : constant Node_Id := High_Bound (Aggregate_Bounds (N));
511 -- The aggregate bounds of this specific sub-aggregate.
517 -- Collect the first N_Range for a given dimension that you find.
518 -- For a given dimension they must be all equal anyway.
520 if No (Aggr_Range (Dim)) then
521 Aggr_Low (Dim) := This_Low;
522 Aggr_High (Dim) := This_High;
523 Aggr_Range (Dim) := This_Range;
526 if Compile_Time_Known_Value (This_Low) then
527 if not Compile_Time_Known_Value (Aggr_Low (Dim)) then
528 Aggr_Low (Dim) := This_Low;
530 elsif Expr_Value (This_Low) /= Expr_Value (Aggr_Low (Dim)) then
531 Set_Raises_Constraint_Error (N);
532 Error_Msg_N ("Sub-aggregate low bound mismatch?", N);
533 Error_Msg_N ("Constraint_Error will be raised at run-time?",
538 if Compile_Time_Known_Value (This_High) then
539 if not Compile_Time_Known_Value (Aggr_High (Dim)) then
540 Aggr_High (Dim) := This_High;
543 Expr_Value (This_High) /= Expr_Value (Aggr_High (Dim))
545 Set_Raises_Constraint_Error (N);
546 Error_Msg_N ("Sub-aggregate high bound mismatch?", N);
547 Error_Msg_N ("Constraint_Error will be raised at run-time?",
553 if Dim < Aggr_Dimension then
555 -- Process positional components
557 if Present (Expressions (N)) then
558 Expr := First (Expressions (N));
559 while Present (Expr) loop
560 Collect_Aggr_Bounds (Expr, Dim + 1);
565 -- Process component associations
567 if Present (Component_Associations (N)) then
568 Is_Fully_Positional := False;
570 Assoc := First (Component_Associations (N));
571 while Present (Assoc) loop
572 Expr := Expression (Assoc);
573 Collect_Aggr_Bounds (Expr, Dim + 1);
578 end Collect_Aggr_Bounds;
580 -- Array_Aggr_Subtype variables
583 -- the final itype of the overall aggregate
585 Index_Constraints : constant List_Id := New_List;
586 -- The list of index constraints of the aggregate itype.
588 -- Start of processing for Array_Aggr_Subtype
591 -- Make sure that the list of index constraints is properly attached
592 -- to the tree, and then collect the aggregate bounds.
594 Set_Parent (Index_Constraints, N);
595 Collect_Aggr_Bounds (N, 1);
597 -- Build the list of constrained indices of our aggregate itype.
599 for J in 1 .. Aggr_Dimension loop
600 Create_Index : declare
601 Index_Base : constant Entity_Id :=
602 Base_Type (Etype (Aggr_Range (J)));
603 Index_Typ : Entity_Id;
606 -- Construct the Index subtype
608 Index_Typ := Create_Itype (Subtype_Kind (Ekind (Index_Base)), N);
610 Set_Etype (Index_Typ, Index_Base);
612 if Is_Character_Type (Index_Base) then
613 Set_Is_Character_Type (Index_Typ);
616 Set_Size_Info (Index_Typ, (Index_Base));
617 Set_RM_Size (Index_Typ, RM_Size (Index_Base));
618 Set_First_Rep_Item (Index_Typ, First_Rep_Item (Index_Base));
619 Set_Scalar_Range (Index_Typ, Aggr_Range (J));
621 if Is_Discrete_Or_Fixed_Point_Type (Index_Typ) then
622 Set_RM_Size (Index_Typ, UI_From_Int (Minimum_Size (Index_Typ)));
625 Set_Etype (Aggr_Range (J), Index_Typ);
627 Append (Aggr_Range (J), To => Index_Constraints);
631 -- Now build the Itype
633 Itype := Create_Itype (E_Array_Subtype, N);
635 Set_First_Rep_Item (Itype, First_Rep_Item (Typ));
636 Set_Convention (Itype, Convention (Typ));
637 Set_Depends_On_Private (Itype, Has_Private_Component (Typ));
638 Set_Etype (Itype, Base_Type (Typ));
639 Set_Has_Alignment_Clause (Itype, Has_Alignment_Clause (Typ));
640 Set_Is_Aliased (Itype, Is_Aliased (Typ));
641 Set_Depends_On_Private (Itype, Depends_On_Private (Typ));
643 Copy_Suppress_Status (Index_Check, Typ, Itype);
644 Copy_Suppress_Status (Length_Check, Typ, Itype);
646 Set_First_Index (Itype, First (Index_Constraints));
647 Set_Is_Constrained (Itype, True);
648 Set_Is_Internal (Itype, True);
649 Init_Size_Align (Itype);
651 -- A simple optimization: purely positional aggregates of static
652 -- components should be passed to gigi unexpanded whenever possible,
653 -- and regardless of the staticness of the bounds themselves. Subse-
654 -- quent checks in exp_aggr verify that type is not packed, etc.
656 Set_Size_Known_At_Compile_Time (Itype,
658 and then Comes_From_Source (N)
659 and then Size_Known_At_Compile_Time (Component_Type (Typ)));
661 -- We always need a freeze node for a packed array subtype, so that
662 -- we can build the Packed_Array_Type corresponding to the subtype.
663 -- If expansion is disabled, the packed array subtype is not built,
664 -- and we must not generate a freeze node for the type, or else it
665 -- will appear incomplete to gigi.
667 if Is_Packed (Itype) and then not In_Default_Expression
668 and then Expander_Active
670 Freeze_Itype (Itype, N);
674 end Array_Aggr_Subtype;
676 --------------------------------
677 -- Check_Misspelled_Component --
678 --------------------------------
680 procedure Check_Misspelled_Component
681 (Elements : Elist_Id;
684 Max_Suggestions : constant := 2;
686 Nr_Of_Suggestions : Natural := 0;
687 Suggestion_1 : Entity_Id := Empty;
688 Suggestion_2 : Entity_Id := Empty;
689 Component_Elmt : Elmt_Id;
692 -- All the components of List are matched against Component and
693 -- a count is maintained of possible misspellings. When at the
694 -- end of the analysis there are one or two (not more!) possible
695 -- misspellings, these misspellings will be suggested as
696 -- possible correction.
698 Get_Name_String (Chars (Component));
701 S : constant String (1 .. Name_Len) :=
702 Name_Buffer (1 .. Name_Len);
706 Component_Elmt := First_Elmt (Elements);
708 while Nr_Of_Suggestions <= Max_Suggestions
709 and then Present (Component_Elmt)
712 Get_Name_String (Chars (Node (Component_Elmt)));
714 if Is_Bad_Spelling_Of (Name_Buffer (1 .. Name_Len), S) then
715 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
717 case Nr_Of_Suggestions is
718 when 1 => Suggestion_1 := Node (Component_Elmt);
719 when 2 => Suggestion_2 := Node (Component_Elmt);
724 Next_Elmt (Component_Elmt);
727 -- Report at most two suggestions
729 if Nr_Of_Suggestions = 1 then
730 Error_Msg_NE ("\possible misspelling of&",
731 Component, Suggestion_1);
733 elsif Nr_Of_Suggestions = 2 then
734 Error_Msg_Node_2 := Suggestion_2;
735 Error_Msg_NE ("\possible misspelling of& or&",
736 Component, Suggestion_1);
739 end Check_Misspelled_Component;
741 ----------------------------------------
742 -- Check_Static_Discriminated_Subtype --
743 ----------------------------------------
745 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id) is
746 Disc : constant Entity_Id := First_Discriminant (T);
751 if Has_Record_Rep_Clause (T) then
754 elsif Present (Next_Discriminant (Disc)) then
757 elsif Nkind (V) /= N_Integer_Literal then
761 Comp := First_Component (T);
763 while Present (Comp) loop
765 if Is_Scalar_Type (Etype (Comp)) then
768 elsif Is_Private_Type (Etype (Comp))
769 and then Present (Full_View (Etype (Comp)))
770 and then Is_Scalar_Type (Full_View (Etype (Comp)))
774 elsif Is_Array_Type (Etype (Comp)) then
776 if Is_Bit_Packed_Array (Etype (Comp)) then
780 Ind := First_Index (Etype (Comp));
782 while Present (Ind) loop
784 if Nkind (Ind) /= N_Range
785 or else Nkind (Low_Bound (Ind)) /= N_Integer_Literal
786 or else Nkind (High_Bound (Ind)) /= N_Integer_Literal
798 Next_Component (Comp);
801 -- On exit, all components have statically known sizes.
803 Set_Size_Known_At_Compile_Time (T);
804 end Check_Static_Discriminated_Subtype;
806 --------------------------------
807 -- Make_String_Into_Aggregate --
808 --------------------------------
810 procedure Make_String_Into_Aggregate (N : Node_Id) is
811 Exprs : constant List_Id := New_List;
812 Loc : constant Source_Ptr := Sloc (N);
813 Str : constant String_Id := Strval (N);
814 Strlen : constant Nat := String_Length (Str);
822 for J in 1 .. Strlen loop
823 C := Get_String_Char (Str, J);
824 Set_Character_Literal_Name (C);
826 C_Node := Make_Character_Literal (P, Name_Find, C);
827 Set_Etype (C_Node, Any_Character);
828 Append_To (Exprs, C_Node);
831 -- something special for wide strings ???
834 New_N := Make_Aggregate (Loc, Expressions => Exprs);
835 Set_Analyzed (New_N);
836 Set_Etype (New_N, Any_Composite);
839 end Make_String_Into_Aggregate;
841 -----------------------
842 -- Resolve_Aggregate --
843 -----------------------
845 procedure Resolve_Aggregate (N : Node_Id; Typ : Entity_Id) is
846 Pkind : constant Node_Kind := Nkind (Parent (N));
848 Aggr_Subtyp : Entity_Id;
849 -- The actual aggregate subtype. This is not necessarily the same as Typ
850 -- which is the subtype of the context in which the aggregate was found.
853 -- Check for aggregates not allowed in configurable run-time mode.
854 -- We allow all cases of aggregates that do not come from source,
855 -- since these are all assumed to be small (e.g. bounds of a string
856 -- literal). We also allow aggregates of types we know to be small.
858 if not Support_Aggregates_On_Target
859 and then Comes_From_Source (N)
860 and then (not Known_Static_Esize (Typ) or else Esize (Typ) > 64)
862 Error_Msg_CRT ("aggregate", N);
865 if Is_Limited_Composite (Typ) then
866 Error_Msg_N ("aggregate type cannot have limited component", N);
867 Explain_Limited_Type (Typ, N);
869 elsif Is_Limited_Type (Typ)
870 and not Extensions_Allowed
872 Error_Msg_N ("aggregate type cannot be limited", N);
873 Explain_Limited_Type (Typ, N);
875 elsif Is_Class_Wide_Type (Typ) then
876 Error_Msg_N ("type of aggregate cannot be class-wide", N);
878 elsif Typ = Any_String
879 or else Typ = Any_Composite
881 Error_Msg_N ("no unique type for aggregate", N);
882 Set_Etype (N, Any_Composite);
884 elsif Is_Array_Type (Typ) and then Null_Record_Present (N) then
885 Error_Msg_N ("null record forbidden in array aggregate", N);
887 elsif Is_Record_Type (Typ) then
888 Resolve_Record_Aggregate (N, Typ);
890 elsif Is_Array_Type (Typ) then
892 -- First a special test, for the case of a positional aggregate
893 -- of characters which can be replaced by a string literal.
894 -- Do not perform this transformation if this was a string literal
895 -- to start with, whose components needed constraint checks, or if
896 -- the component type is non-static, because it will require those
897 -- checks and be transformed back into an aggregate.
899 if Number_Dimensions (Typ) = 1
901 (Root_Type (Component_Type (Typ)) = Standard_Character
903 Root_Type (Component_Type (Typ)) = Standard_Wide_Character)
904 and then No (Component_Associations (N))
905 and then not Is_Limited_Composite (Typ)
906 and then not Is_Private_Composite (Typ)
907 and then not Is_Bit_Packed_Array (Typ)
908 and then Nkind (Original_Node (Parent (N))) /= N_String_Literal
909 and then Is_Static_Subtype (Component_Type (Typ))
915 Expr := First (Expressions (N));
916 while Present (Expr) loop
917 exit when Nkind (Expr) /= N_Character_Literal;
924 Expr := First (Expressions (N));
925 while Present (Expr) loop
926 Store_String_Char (Char_Literal_Value (Expr));
931 Make_String_Literal (Sloc (N), End_String));
933 Analyze_And_Resolve (N, Typ);
939 -- Here if we have a real aggregate to deal with
941 Array_Aggregate : declare
942 Aggr_Resolved : Boolean;
944 Aggr_Typ : constant Entity_Id := Etype (Typ);
945 -- This is the unconstrained array type, which is the type
946 -- against which the aggregate is to be resoved. Typ itself
947 -- is the array type of the context which may not be the same
948 -- subtype as the subtype for the final aggregate.
951 -- In the following we determine whether an others choice is
952 -- allowed inside the array aggregate. The test checks the context
953 -- in which the array aggregate occurs. If the context does not
954 -- permit it, or the aggregate type is unconstrained, an others
955 -- choice is not allowed.
957 -- Note that there is no node for Explicit_Actual_Parameter.
958 -- To test for this context we therefore have to test for node
959 -- N_Parameter_Association which itself appears only if there is a
960 -- formal parameter. Consequently we also need to test for
961 -- N_Procedure_Call_Statement or N_Function_Call.
963 if Is_Constrained (Typ) and then
964 (Pkind = N_Assignment_Statement or else
965 Pkind = N_Parameter_Association or else
966 Pkind = N_Function_Call or else
967 Pkind = N_Procedure_Call_Statement or else
968 Pkind = N_Generic_Association or else
969 Pkind = N_Formal_Object_Declaration or else
970 Pkind = N_Return_Statement or else
971 Pkind = N_Object_Declaration or else
972 Pkind = N_Component_Declaration or else
973 Pkind = N_Parameter_Specification or else
974 Pkind = N_Qualified_Expression or else
975 Pkind = N_Aggregate or else
976 Pkind = N_Extension_Aggregate or else
977 Pkind = N_Component_Association)
980 Resolve_Array_Aggregate
982 Index => First_Index (Aggr_Typ),
983 Index_Constr => First_Index (Typ),
984 Component_Typ => Component_Type (Typ),
985 Others_Allowed => True);
989 Resolve_Array_Aggregate
991 Index => First_Index (Aggr_Typ),
992 Index_Constr => First_Index (Aggr_Typ),
993 Component_Typ => Component_Type (Typ),
994 Others_Allowed => False);
997 if not Aggr_Resolved then
998 Aggr_Subtyp := Any_Composite;
1000 Aggr_Subtyp := Array_Aggr_Subtype (N, Typ);
1003 Set_Etype (N, Aggr_Subtyp);
1004 end Array_Aggregate;
1007 Error_Msg_N ("illegal context for aggregate", N);
1011 -- If we can determine statically that the evaluation of the
1012 -- aggregate raises Constraint_Error, then replace the
1013 -- aggregate with an N_Raise_Constraint_Error node, but set the
1014 -- Etype to the right aggregate subtype. Gigi needs this.
1016 if Raises_Constraint_Error (N) then
1017 Aggr_Subtyp := Etype (N);
1019 Make_Raise_Constraint_Error (Sloc (N),
1020 Reason => CE_Range_Check_Failed));
1021 Set_Raises_Constraint_Error (N);
1022 Set_Etype (N, Aggr_Subtyp);
1025 end Resolve_Aggregate;
1027 -----------------------------
1028 -- Resolve_Array_Aggregate --
1029 -----------------------------
1031 function Resolve_Array_Aggregate
1034 Index_Constr : Node_Id;
1035 Component_Typ : Entity_Id;
1036 Others_Allowed : Boolean)
1039 Loc : constant Source_Ptr := Sloc (N);
1041 Failure : constant Boolean := False;
1042 Success : constant Boolean := True;
1044 Index_Typ : constant Entity_Id := Etype (Index);
1045 Index_Typ_Low : constant Node_Id := Type_Low_Bound (Index_Typ);
1046 Index_Typ_High : constant Node_Id := Type_High_Bound (Index_Typ);
1047 -- The type of the index corresponding to the array sub-aggregate
1048 -- along with its low and upper bounds
1050 Index_Base : constant Entity_Id := Base_Type (Index_Typ);
1051 Index_Base_Low : constant Node_Id := Type_Low_Bound (Index_Base);
1052 Index_Base_High : constant Node_Id := Type_High_Bound (Index_Base);
1053 -- ditto for the base type
1055 function Add (Val : Uint; To : Node_Id) return Node_Id;
1056 -- Creates a new expression node where Val is added to expression To.
1057 -- Tries to constant fold whenever possible. To must be an already
1058 -- analyzed expression.
1060 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id);
1061 -- Checks that AH (the upper bound of an array aggregate) is <= BH
1062 -- (the upper bound of the index base type). If the check fails a
1063 -- warning is emitted, the Raises_Constraint_Error Flag of N is set,
1064 -- and AH is replaced with a duplicate of BH.
1066 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id);
1067 -- Checks that range AL .. AH is compatible with range L .. H. Emits a
1068 -- warning if not and sets the Raises_Constraint_Error Flag in N.
1070 procedure Check_Length (L, H : Node_Id; Len : Uint);
1071 -- Checks that range L .. H contains at least Len elements. Emits a
1072 -- warning if not and sets the Raises_Constraint_Error Flag in N.
1074 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean;
1075 -- Returns True if range L .. H is dynamic or null.
1077 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean);
1078 -- Given expression node From, this routine sets OK to False if it
1079 -- cannot statically evaluate From. Otherwise it stores this static
1080 -- value into Value.
1082 function Resolve_Aggr_Expr
1084 Single_Elmt : Boolean)
1086 -- Resolves aggregate expression Expr. Returs False if resolution
1087 -- fails. If Single_Elmt is set to False, the expression Expr may be
1088 -- used to initialize several array aggregate elements (this can
1089 -- happen for discrete choices such as "L .. H => Expr" or the others
1090 -- choice). In this event we do not resolve Expr unless expansion is
1091 -- disabled. To know why, see the DELAYED COMPONENT RESOLUTION
1098 function Add (Val : Uint; To : Node_Id) return Node_Id is
1104 if Raises_Constraint_Error (To) then
1108 -- First test if we can do constant folding
1110 if Compile_Time_Known_Value (To)
1111 or else Nkind (To) = N_Integer_Literal
1113 Expr_Pos := Make_Integer_Literal (Loc, Expr_Value (To) + Val);
1114 Set_Is_Static_Expression (Expr_Pos);
1115 Set_Etype (Expr_Pos, Etype (To));
1116 Set_Analyzed (Expr_Pos, Analyzed (To));
1118 if not Is_Enumeration_Type (Index_Typ) then
1121 -- If we are dealing with enumeration return
1122 -- Index_Typ'Val (Expr_Pos)
1126 Make_Attribute_Reference
1128 Prefix => New_Reference_To (Index_Typ, Loc),
1129 Attribute_Name => Name_Val,
1130 Expressions => New_List (Expr_Pos));
1136 -- If we are here no constant folding possible
1138 if not Is_Enumeration_Type (Index_Base) then
1141 Left_Opnd => Duplicate_Subexpr (To),
1142 Right_Opnd => Make_Integer_Literal (Loc, Val));
1144 -- If we are dealing with enumeration return
1145 -- Index_Typ'Val (Index_Typ'Pos (To) + Val)
1149 Make_Attribute_Reference
1151 Prefix => New_Reference_To (Index_Typ, Loc),
1152 Attribute_Name => Name_Pos,
1153 Expressions => New_List (Duplicate_Subexpr (To)));
1157 Left_Opnd => To_Pos,
1158 Right_Opnd => Make_Integer_Literal (Loc, Val));
1161 Make_Attribute_Reference
1163 Prefix => New_Reference_To (Index_Typ, Loc),
1164 Attribute_Name => Name_Val,
1165 Expressions => New_List (Expr_Pos));
1175 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id) is
1183 Get (Value => Val_BH, From => BH, OK => OK_BH);
1184 Get (Value => Val_AH, From => AH, OK => OK_AH);
1186 if OK_BH and then OK_AH and then Val_BH < Val_AH then
1187 Set_Raises_Constraint_Error (N);
1188 Error_Msg_N ("upper bound out of range?", AH);
1189 Error_Msg_N ("Constraint_Error will be raised at run-time?", AH);
1191 -- You need to set AH to BH or else in the case of enumerations
1192 -- indices we will not be able to resolve the aggregate bounds.
1194 AH := Duplicate_Subexpr (BH);
1202 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id) is
1214 if Raises_Constraint_Error (N)
1215 or else Dynamic_Or_Null_Range (AL, AH)
1220 Get (Value => Val_L, From => L, OK => OK_L);
1221 Get (Value => Val_H, From => H, OK => OK_H);
1223 Get (Value => Val_AL, From => AL, OK => OK_AL);
1224 Get (Value => Val_AH, From => AH, OK => OK_AH);
1226 if OK_L and then Val_L > Val_AL then
1227 Set_Raises_Constraint_Error (N);
1228 Error_Msg_N ("lower bound of aggregate out of range?", N);
1229 Error_Msg_N ("\Constraint_Error will be raised at run-time?", N);
1232 if OK_H and then Val_H < Val_AH then
1233 Set_Raises_Constraint_Error (N);
1234 Error_Msg_N ("upper bound of aggregate out of range?", N);
1235 Error_Msg_N ("\Constraint_Error will be raised at run-time?", N);
1243 procedure Check_Length (L, H : Node_Id; Len : Uint) is
1253 if Raises_Constraint_Error (N) then
1257 Get (Value => Val_L, From => L, OK => OK_L);
1258 Get (Value => Val_H, From => H, OK => OK_H);
1260 if not OK_L or else not OK_H then
1264 -- If null range length is zero
1266 if Val_L > Val_H then
1267 Range_Len := Uint_0;
1269 Range_Len := Val_H - Val_L + 1;
1272 if Range_Len < Len then
1273 Set_Raises_Constraint_Error (N);
1274 Error_Msg_N ("Too many elements?", N);
1275 Error_Msg_N ("Constraint_Error will be raised at run-time?", N);
1279 ---------------------------
1280 -- Dynamic_Or_Null_Range --
1281 ---------------------------
1283 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean is
1291 Get (Value => Val_L, From => L, OK => OK_L);
1292 Get (Value => Val_H, From => H, OK => OK_H);
1294 return not OK_L or else not OK_H
1295 or else not Is_OK_Static_Expression (L)
1296 or else not Is_OK_Static_Expression (H)
1297 or else Val_L > Val_H;
1298 end Dynamic_Or_Null_Range;
1304 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean) is
1308 if Compile_Time_Known_Value (From) then
1309 Value := Expr_Value (From);
1311 -- If expression From is something like Some_Type'Val (10) then
1314 elsif Nkind (From) = N_Attribute_Reference
1315 and then Attribute_Name (From) = Name_Val
1316 and then Compile_Time_Known_Value (First (Expressions (From)))
1318 Value := Expr_Value (First (Expressions (From)));
1326 -----------------------
1327 -- Resolve_Aggr_Expr --
1328 -----------------------
1330 function Resolve_Aggr_Expr
1332 Single_Elmt : Boolean)
1335 Nxt_Ind : constant Node_Id := Next_Index (Index);
1336 Nxt_Ind_Constr : constant Node_Id := Next_Index (Index_Constr);
1337 -- Index is the current index corresponding to the expresion.
1339 Resolution_OK : Boolean := True;
1340 -- Set to False if resolution of the expression failed.
1343 -- If the array type against which we are resolving the aggregate
1344 -- has several dimensions, the expressions nested inside the
1345 -- aggregate must be further aggregates (or strings).
1347 if Present (Nxt_Ind) then
1348 if Nkind (Expr) /= N_Aggregate then
1350 -- A string literal can appear where a one-dimensional array
1351 -- of characters is expected. If the literal looks like an
1352 -- operator, it is still an operator symbol, which will be
1353 -- transformed into a string when analyzed.
1355 if Is_Character_Type (Component_Typ)
1356 and then No (Next_Index (Nxt_Ind))
1357 and then (Nkind (Expr) = N_String_Literal
1358 or else Nkind (Expr) = N_Operator_Symbol)
1360 -- A string literal used in a multidimensional array
1361 -- aggregate in place of the final one-dimensional
1362 -- aggregate must not be enclosed in parentheses.
1364 if Paren_Count (Expr) /= 0 then
1365 Error_Msg_N ("No parenthesis allowed here", Expr);
1368 Make_String_Into_Aggregate (Expr);
1371 Error_Msg_N ("nested array aggregate expected", Expr);
1376 Resolution_OK := Resolve_Array_Aggregate
1377 (Expr, Nxt_Ind, Nxt_Ind_Constr, Component_Typ, Others_Allowed);
1379 -- Do not resolve the expressions of discrete or others choices
1380 -- unless the expression covers a single component, or the expander
1384 or else not Expander_Active
1385 or else In_Default_Expression
1387 Analyze_And_Resolve (Expr, Component_Typ);
1388 Check_Non_Static_Context (Expr);
1389 Aggregate_Constraint_Checks (Expr, Component_Typ);
1390 Check_Unset_Reference (Expr);
1393 if Raises_Constraint_Error (Expr)
1394 and then Nkind (Parent (Expr)) /= N_Component_Association
1396 Set_Raises_Constraint_Error (N);
1399 return Resolution_OK;
1400 end Resolve_Aggr_Expr;
1402 -- Variables local to Resolve_Array_Aggregate
1408 Who_Cares : Node_Id;
1410 Aggr_Low : Node_Id := Empty;
1411 Aggr_High : Node_Id := Empty;
1412 -- The actual low and high bounds of this sub-aggegate
1414 Choices_Low : Node_Id := Empty;
1415 Choices_High : Node_Id := Empty;
1416 -- The lowest and highest discrete choices values for a named aggregate
1418 Nb_Elements : Uint := Uint_0;
1419 -- The number of elements in a positional aggegate
1421 Others_Present : Boolean := False;
1423 Nb_Choices : Nat := 0;
1424 -- Contains the overall number of named choices in this sub-aggregate
1426 Nb_Discrete_Choices : Nat := 0;
1427 -- The overall number of discrete choices (not counting others choice)
1429 Case_Table_Size : Nat;
1430 -- Contains the size of the case table needed to sort aggregate choices
1432 -- Start of processing for Resolve_Array_Aggregate
1435 -- STEP 1: make sure the aggregate is correctly formatted
1437 if Present (Component_Associations (N)) then
1438 Assoc := First (Component_Associations (N));
1439 while Present (Assoc) loop
1440 Choice := First (Choices (Assoc));
1441 while Present (Choice) loop
1442 if Nkind (Choice) = N_Others_Choice then
1443 Others_Present := True;
1445 if Choice /= First (Choices (Assoc))
1446 or else Present (Next (Choice))
1449 ("OTHERS must appear alone in a choice list", Choice);
1453 if Present (Next (Assoc)) then
1455 ("OTHERS must appear last in an aggregate", Choice);
1460 and then Assoc /= First (Component_Associations (N))
1461 and then (Nkind (Parent (N)) = N_Assignment_Statement
1463 Nkind (Parent (N)) = N_Object_Declaration)
1466 ("(Ada 83) illegal context for OTHERS choice", N);
1470 Nb_Choices := Nb_Choices + 1;
1478 -- At this point we know that the others choice, if present, is by
1479 -- itself and appears last in the aggregate. Check if we have mixed
1480 -- positional and discrete associations (other than the others choice).
1482 if Present (Expressions (N))
1483 and then (Nb_Choices > 1
1484 or else (Nb_Choices = 1 and then not Others_Present))
1487 ("named association cannot follow positional association",
1488 First (Choices (First (Component_Associations (N)))));
1492 -- Test for the validity of an others choice if present
1494 if Others_Present and then not Others_Allowed then
1496 ("OTHERS choice not allowed here",
1497 First (Choices (First (Component_Associations (N)))));
1501 -- Protect against cascaded errors
1503 if Etype (Index_Typ) = Any_Type then
1507 -- STEP 2: Process named components
1509 if No (Expressions (N)) then
1511 if Others_Present then
1512 Case_Table_Size := Nb_Choices - 1;
1514 Case_Table_Size := Nb_Choices;
1520 -- Denote the lowest and highest values in an aggregate choice
1524 -- High end of one range and Low end of the next. Should be
1525 -- contiguous if there is no hole in the list of values.
1527 Missing_Values : Boolean;
1528 -- Set True if missing index values
1530 S_Low : Node_Id := Empty;
1531 S_High : Node_Id := Empty;
1532 -- if a choice in an aggregate is a subtype indication these
1533 -- denote the lowest and highest values of the subtype
1535 Table : Case_Table_Type (1 .. Case_Table_Size);
1536 -- Used to sort all the different choice values
1538 Single_Choice : Boolean;
1539 -- Set to true every time there is a single discrete choice in a
1540 -- discrete association
1542 Prev_Nb_Discrete_Choices : Nat;
1543 -- Used to keep track of the number of discrete choices
1544 -- in the current association.
1547 -- STEP 2 (A): Check discrete choices validity.
1549 Assoc := First (Component_Associations (N));
1550 while Present (Assoc) loop
1552 Prev_Nb_Discrete_Choices := Nb_Discrete_Choices;
1553 Choice := First (Choices (Assoc));
1557 if Nkind (Choice) = N_Others_Choice then
1558 Single_Choice := False;
1561 -- Test for subtype mark without constraint
1563 elsif Is_Entity_Name (Choice) and then
1564 Is_Type (Entity (Choice))
1566 if Base_Type (Entity (Choice)) /= Index_Base then
1568 ("invalid subtype mark in aggregate choice",
1573 elsif Nkind (Choice) = N_Subtype_Indication then
1574 Resolve_Discrete_Subtype_Indication (Choice, Index_Base);
1576 -- Does the subtype indication evaluation raise CE ?
1578 Get_Index_Bounds (Subtype_Mark (Choice), S_Low, S_High);
1579 Get_Index_Bounds (Choice, Low, High);
1580 Check_Bounds (S_Low, S_High, Low, High);
1582 else -- Choice is a range or an expression
1583 Resolve (Choice, Index_Base);
1584 Check_Unset_Reference (Choice);
1585 Check_Non_Static_Context (Choice);
1587 -- Do not range check a choice. This check is redundant
1588 -- since this test is already performed when we check
1589 -- that the bounds of the array aggregate are within
1592 Set_Do_Range_Check (Choice, False);
1595 -- If we could not resolve the discrete choice stop here
1597 if Etype (Choice) = Any_Type then
1600 -- If the discrete choice raises CE get its original bounds.
1602 elsif Nkind (Choice) = N_Raise_Constraint_Error then
1603 Set_Raises_Constraint_Error (N);
1604 Get_Index_Bounds (Original_Node (Choice), Low, High);
1606 -- Otherwise get its bounds as usual
1609 Get_Index_Bounds (Choice, Low, High);
1612 if (Dynamic_Or_Null_Range (Low, High)
1613 or else (Nkind (Choice) = N_Subtype_Indication
1615 Dynamic_Or_Null_Range (S_Low, S_High)))
1616 and then Nb_Choices /= 1
1619 ("dynamic or empty choice in aggregate " &
1620 "must be the only choice", Choice);
1624 Nb_Discrete_Choices := Nb_Discrete_Choices + 1;
1625 Table (Nb_Discrete_Choices).Choice_Lo := Low;
1626 Table (Nb_Discrete_Choices).Choice_Hi := High;
1631 -- Check if we have a single discrete choice and whether
1632 -- this discrete choice specifies a single value.
1635 (Nb_Discrete_Choices = Prev_Nb_Discrete_Choices + 1)
1636 and then (Low = High);
1644 (Expression (Assoc), Single_Elmt => Single_Choice)
1652 -- If aggregate contains more than one choice then these must be
1653 -- static. Sort them and check that they are contiguous
1655 if Nb_Discrete_Choices > 1 then
1656 Sort_Case_Table (Table);
1657 Missing_Values := False;
1659 Outer : for J in 1 .. Nb_Discrete_Choices - 1 loop
1660 if Expr_Value (Table (J).Choice_Hi) >=
1661 Expr_Value (Table (J + 1).Choice_Lo)
1664 ("duplicate choice values in array aggregate",
1665 Table (J).Choice_Hi);
1668 elsif not Others_Present then
1670 Hi_Val := Expr_Value (Table (J).Choice_Hi);
1671 Lo_Val := Expr_Value (Table (J + 1).Choice_Lo);
1673 -- If missing values, output error messages
1675 if Lo_Val - Hi_Val > 1 then
1677 -- Header message if not first missing value
1679 if not Missing_Values then
1681 ("missing index value(s) in array aggregate", N);
1682 Missing_Values := True;
1685 -- Output values of missing indexes
1687 Lo_Val := Lo_Val - 1;
1688 Hi_Val := Hi_Val + 1;
1690 -- Enumeration type case
1692 if Is_Enumeration_Type (Index_Typ) then
1695 (Get_Enum_Lit_From_Pos
1696 (Index_Typ, Hi_Val, Loc));
1698 if Lo_Val = Hi_Val then
1699 Error_Msg_N ("\ %", N);
1703 (Get_Enum_Lit_From_Pos
1704 (Index_Typ, Lo_Val, Loc));
1705 Error_Msg_N ("\ % .. %", N);
1708 -- Integer types case
1711 Error_Msg_Uint_1 := Hi_Val;
1713 if Lo_Val = Hi_Val then
1714 Error_Msg_N ("\ ^", N);
1716 Error_Msg_Uint_2 := Lo_Val;
1717 Error_Msg_N ("\ ^ .. ^", N);
1724 if Missing_Values then
1725 Set_Etype (N, Any_Composite);
1730 -- STEP 2 (B): Compute aggregate bounds and min/max choices values
1732 if Nb_Discrete_Choices > 0 then
1733 Choices_Low := Table (1).Choice_Lo;
1734 Choices_High := Table (Nb_Discrete_Choices).Choice_Hi;
1737 if Others_Present then
1738 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
1741 Aggr_Low := Choices_Low;
1742 Aggr_High := Choices_High;
1746 -- STEP 3: Process positional components
1749 -- STEP 3 (A): Process positional elements
1751 Expr := First (Expressions (N));
1752 Nb_Elements := Uint_0;
1753 while Present (Expr) loop
1754 Nb_Elements := Nb_Elements + 1;
1756 if not Resolve_Aggr_Expr (Expr, Single_Elmt => True) then
1763 if Others_Present then
1764 Assoc := Last (Component_Associations (N));
1765 if not Resolve_Aggr_Expr (Expression (Assoc),
1766 Single_Elmt => False)
1772 -- STEP 3 (B): Compute the aggregate bounds
1774 if Others_Present then
1775 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
1778 if Others_Allowed then
1779 Get_Index_Bounds (Index_Constr, Aggr_Low, Who_Cares);
1781 Aggr_Low := Index_Typ_Low;
1784 Aggr_High := Add (Nb_Elements - 1, To => Aggr_Low);
1785 Check_Bound (Index_Base_High, Aggr_High);
1789 -- STEP 4: Perform static aggregate checks and save the bounds
1793 Check_Bounds (Index_Typ_Low, Index_Typ_High, Aggr_Low, Aggr_High);
1794 Check_Bounds (Index_Base_Low, Index_Base_High, Aggr_Low, Aggr_High);
1798 if Others_Present and then Nb_Discrete_Choices > 0 then
1799 Check_Bounds (Aggr_Low, Aggr_High, Choices_Low, Choices_High);
1800 Check_Bounds (Index_Typ_Low, Index_Typ_High,
1801 Choices_Low, Choices_High);
1802 Check_Bounds (Index_Base_Low, Index_Base_High,
1803 Choices_Low, Choices_High);
1807 elsif Others_Present and then Nb_Elements > 0 then
1808 Check_Length (Aggr_Low, Aggr_High, Nb_Elements);
1809 Check_Length (Index_Typ_Low, Index_Typ_High, Nb_Elements);
1810 Check_Length (Index_Base_Low, Index_Base_High, Nb_Elements);
1814 if Raises_Constraint_Error (Aggr_Low)
1815 or else Raises_Constraint_Error (Aggr_High)
1817 Set_Raises_Constraint_Error (N);
1820 Aggr_Low := Duplicate_Subexpr (Aggr_Low);
1822 -- Do not duplicate Aggr_High if Aggr_High = Aggr_Low + Nb_Elements
1823 -- since the addition node returned by Add is not yet analyzed. Attach
1824 -- to tree and analyze first. Reset analyzed flag to insure it will get
1825 -- analyzed when it is a literal bound whose type must be properly
1828 if Others_Present or else Nb_Discrete_Choices > 0 then
1829 Aggr_High := Duplicate_Subexpr (Aggr_High);
1831 if Etype (Aggr_High) = Universal_Integer then
1832 Set_Analyzed (Aggr_High, False);
1836 Set_Aggregate_Bounds
1837 (N, Make_Range (Loc, Low_Bound => Aggr_Low, High_Bound => Aggr_High));
1839 -- The bounds may contain expressions that must be inserted upwards.
1840 -- Attach them fully to the tree. After analysis, remove side effects
1841 -- from upper bound, if still needed.
1843 Set_Parent (Aggregate_Bounds (N), N);
1844 Analyze_And_Resolve (Aggregate_Bounds (N), Index_Typ);
1845 Check_Unset_Reference (Aggregate_Bounds (N));
1847 if not Others_Present and then Nb_Discrete_Choices = 0 then
1848 Set_High_Bound (Aggregate_Bounds (N),
1849 Duplicate_Subexpr (High_Bound (Aggregate_Bounds (N))));
1853 end Resolve_Array_Aggregate;
1855 ---------------------------------
1856 -- Resolve_Extension_Aggregate --
1857 ---------------------------------
1859 -- There are two cases to consider:
1861 -- a) If the ancestor part is a type mark, the components needed are
1862 -- the difference between the components of the expected type and the
1863 -- components of the given type mark.
1865 -- b) If the ancestor part is an expression, it must be unambiguous,
1866 -- and once we have its type we can also compute the needed components
1867 -- as in the previous case. In both cases, if the ancestor type is not
1868 -- the immediate ancestor, we have to build this ancestor recursively.
1870 -- In both cases discriminants of the ancestor type do not play a
1871 -- role in the resolution of the needed components, because inherited
1872 -- discriminants cannot be used in a type extension. As a result we can
1873 -- compute independently the list of components of the ancestor type and
1874 -- of the expected type.
1876 procedure Resolve_Extension_Aggregate (N : Node_Id; Typ : Entity_Id) is
1877 A : constant Node_Id := Ancestor_Part (N);
1882 function Valid_Ancestor_Type return Boolean;
1883 -- Verify that the type of the ancestor part is a non-private ancestor
1884 -- of the expected type.
1886 -------------------------
1887 -- Valid_Ancestor_Type --
1888 -------------------------
1890 function Valid_Ancestor_Type return Boolean is
1891 Imm_Type : Entity_Id;
1894 Imm_Type := Base_Type (Typ);
1895 while Is_Derived_Type (Imm_Type)
1896 and then Etype (Imm_Type) /= Base_Type (A_Type)
1898 Imm_Type := Etype (Base_Type (Imm_Type));
1901 if Etype (Imm_Type) /= Base_Type (A_Type) then
1902 Error_Msg_NE ("expect ancestor type of &", A, Typ);
1907 end Valid_Ancestor_Type;
1909 -- Start of processing for Resolve_Extension_Aggregate
1914 if not Is_Tagged_Type (Typ) then
1915 Error_Msg_N ("type of extension aggregate must be tagged", N);
1918 elsif Is_Limited_Type (Typ)
1919 and not Extensions_Allowed
1921 Error_Msg_N ("aggregate type cannot be limited", N);
1922 Explain_Limited_Type (Typ, N);
1925 elsif Is_Class_Wide_Type (Typ) then
1926 Error_Msg_N ("aggregate cannot be of a class-wide type", N);
1930 if Is_Entity_Name (A)
1931 and then Is_Type (Entity (A))
1933 A_Type := Get_Full_View (Entity (A));
1935 if Valid_Ancestor_Type then
1936 Set_Entity (A, A_Type);
1937 Set_Etype (A, A_Type);
1939 Validate_Ancestor_Part (N);
1940 Resolve_Record_Aggregate (N, Typ);
1943 elsif Nkind (A) /= N_Aggregate then
1944 if Is_Overloaded (A) then
1946 Get_First_Interp (A, I, It);
1948 while Present (It.Typ) loop
1950 if Is_Tagged_Type (It.Typ)
1951 and then not Is_Limited_Type (It.Typ)
1953 if A_Type /= Any_Type then
1954 Error_Msg_N ("cannot resolve expression", A);
1961 Get_Next_Interp (I, It);
1964 if A_Type = Any_Type then
1966 ("ancestor part must be non-limited tagged type", A);
1971 A_Type := Etype (A);
1974 if Valid_Ancestor_Type then
1975 Resolve (A, A_Type);
1976 Check_Unset_Reference (A);
1977 Check_Non_Static_Context (A);
1979 if Is_Class_Wide_Type (Etype (A))
1980 and then Nkind (Original_Node (A)) = N_Function_Call
1982 -- If the ancestor part is a dispatching call, it appears
1983 -- statically to be a legal ancestor, but it yields any
1984 -- member of the class, and it is not possible to determine
1985 -- whether it is an ancestor of the extension aggregate (much
1986 -- less which ancestor). It is not possible to determine the
1987 -- required components of the extension part.
1989 Error_Msg_N ("ancestor part must be statically tagged", A);
1991 Resolve_Record_Aggregate (N, Typ);
1996 Error_Msg_N (" No unique type for this aggregate", A);
1998 end Resolve_Extension_Aggregate;
2000 ------------------------------
2001 -- Resolve_Record_Aggregate --
2002 ------------------------------
2004 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id) is
2005 New_Assoc_List : constant List_Id := New_List;
2006 New_Assoc : Node_Id;
2007 -- New_Assoc_List is the newly built list of N_Component_Association
2008 -- nodes. New_Assoc is one such N_Component_Association node in it.
2009 -- Please note that while Assoc and New_Assoc contain the same
2010 -- kind of nodes, they are used to iterate over two different
2011 -- N_Component_Association lists.
2013 Others_Etype : Entity_Id := Empty;
2014 -- This variable is used to save the Etype of the last record component
2015 -- that takes its value from the others choice. Its purpose is:
2017 -- (a) make sure the others choice is useful
2019 -- (b) make sure the type of all the components whose value is
2020 -- subsumed by the others choice are the same.
2022 -- This variable is updated as a side effect of function Get_Value
2024 Mbox_Present : Boolean := False;
2025 Others_Mbox : Boolean := False;
2026 -- Variables used in case of default initialization to provide a
2027 -- functionality similar to Others_Etype. Mbox_Present indicates
2028 -- that the component takes its default initialization; Others_Mbox
2029 -- indicates that at least one component takes its default initiali-
2030 -- zation. Similar to Others_Etype, they are also updated as a side
2031 -- effect of function Get_Value.
2033 procedure Add_Association
2034 (Component : Entity_Id;
2036 Box_Present : Boolean := False);
2037 -- Builds a new N_Component_Association node which associates
2038 -- Component to expression Expr and adds it to the new association
2039 -- list New_Assoc_List being built.
2041 function Discr_Present (Discr : Entity_Id) return Boolean;
2042 -- If aggregate N is a regular aggregate this routine will return True.
2043 -- Otherwise, if N is an extension aggregate, Discr is a discriminant
2044 -- whose value may already have been specified by N's ancestor part,
2045 -- this routine checks whether this is indeed the case and if so
2046 -- returns False, signaling that no value for Discr should appear in the
2047 -- N's aggregate part. Also, in this case, the routine appends to
2048 -- New_Assoc_List Discr the discriminant value specified in the ancestor
2054 Consider_Others_Choice : Boolean := False)
2056 -- Given a record component stored in parameter Compon, the
2057 -- following function returns its value as it appears in the list
2058 -- From, which is a list of N_Component_Association nodes. If no
2059 -- component association has a choice for the searched component,
2060 -- the value provided by the others choice is returned, if there
2061 -- is one and Consider_Others_Choice is set to true. Otherwise
2062 -- Empty is returned. If there is more than one component association
2063 -- giving a value for the searched record component, an error message
2064 -- is emitted and the first found value is returned.
2066 -- If Consider_Others_Choice is set and the returned expression comes
2067 -- from the others choice, then Others_Etype is set as a side effect.
2068 -- An error message is emitted if the components taking their value
2069 -- from the others choice do not have same type.
2071 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id);
2072 -- Analyzes and resolves expression Expr against the Etype of the
2073 -- Component. This routine also applies all appropriate checks to Expr.
2074 -- It finally saves a Expr in the newly created association list that
2075 -- will be attached to the final record aggregate. Note that if the
2076 -- Parent pointer of Expr is not set then Expr was produced with a
2077 -- New_Copy_Tree or some such.
2079 ---------------------
2080 -- Add_Association --
2081 ---------------------
2083 procedure Add_Association
2084 (Component : Entity_Id;
2086 Box_Present : Boolean := False)
2088 Choice_List : constant List_Id := New_List;
2089 New_Assoc : Node_Id;
2092 Append (New_Occurrence_Of (Component, Sloc (Expr)), Choice_List);
2094 Make_Component_Association (Sloc (Expr),
2095 Choices => Choice_List,
2097 Box_Present => Box_Present);
2098 Append (New_Assoc, New_Assoc_List);
2099 end Add_Association;
2105 function Discr_Present (Discr : Entity_Id) return Boolean is
2106 Regular_Aggr : constant Boolean := Nkind (N) /= N_Extension_Aggregate;
2111 Discr_Expr : Node_Id;
2113 Ancestor_Typ : Entity_Id;
2114 Orig_Discr : Entity_Id;
2116 D_Val : Elmt_Id := No_Elmt; -- stop junk warning
2118 Ancestor_Is_Subtyp : Boolean;
2121 if Regular_Aggr then
2125 Ancestor := Ancestor_Part (N);
2126 Ancestor_Typ := Etype (Ancestor);
2127 Loc := Sloc (Ancestor);
2129 Ancestor_Is_Subtyp :=
2130 Is_Entity_Name (Ancestor) and then Is_Type (Entity (Ancestor));
2132 -- If the ancestor part has no discriminants clearly N's aggregate
2133 -- part must provide a value for Discr.
2135 if not Has_Discriminants (Ancestor_Typ) then
2138 -- If the ancestor part is an unconstrained subtype mark then the
2139 -- Discr must be present in N's aggregate part.
2141 elsif Ancestor_Is_Subtyp
2142 and then not Is_Constrained (Entity (Ancestor))
2147 -- Now look to see if Discr was specified in the ancestor part.
2149 Orig_Discr := Original_Record_Component (Discr);
2150 D := First_Discriminant (Ancestor_Typ);
2152 if Ancestor_Is_Subtyp then
2153 D_Val := First_Elmt (Discriminant_Constraint (Entity (Ancestor)));
2156 while Present (D) loop
2157 -- If Ancestor has already specified Disc value than
2158 -- insert its value in the final aggregate.
2160 if Original_Record_Component (D) = Orig_Discr then
2161 if Ancestor_Is_Subtyp then
2162 Discr_Expr := New_Copy_Tree (Node (D_Val));
2165 Make_Selected_Component (Loc,
2166 Prefix => Duplicate_Subexpr (Ancestor),
2167 Selector_Name => New_Occurrence_Of (Discr, Loc));
2170 Resolve_Aggr_Expr (Discr_Expr, Discr);
2174 Next_Discriminant (D);
2176 if Ancestor_Is_Subtyp then
2191 Consider_Others_Choice : Boolean := False)
2195 Expr : Node_Id := Empty;
2196 Selector_Name : Node_Id;
2198 procedure Check_Non_Limited_Type;
2199 -- Relax check to allow the default initialization of limited types.
2202 -- C : Lim := (..., others => <>);
2205 procedure Check_Non_Limited_Type is
2207 if Is_Limited_Type (Etype (Compon))
2208 and then Comes_From_Source (Compon)
2209 and then not In_Instance_Body
2212 if Extensions_Allowed
2213 and then Present (Expression (Assoc))
2214 and then Nkind (Expression (Assoc)) = N_Aggregate
2219 ("initialization not allowed for limited types", N);
2220 Explain_Limited_Type (Etype (Compon), Compon);
2224 end Check_Non_Limited_Type;
2227 Mbox_Present := False;
2229 if Present (From) then
2230 Assoc := First (From);
2235 while Present (Assoc) loop
2236 Selector_Name := First (Choices (Assoc));
2237 while Present (Selector_Name) loop
2238 if Nkind (Selector_Name) = N_Others_Choice then
2239 if Consider_Others_Choice and then No (Expr) then
2241 -- We need to duplicate the expression for each
2242 -- successive component covered by the others choice.
2243 -- This is redundant if the others_choice covers only
2244 -- one component (small optimization possible???), but
2245 -- indispensable otherwise, because each one must be
2246 -- expanded individually to preserve side-effects.
2248 if Box_Present (Assoc) then
2249 Others_Mbox := True;
2250 Mbox_Present := True;
2252 if Expander_Active then
2253 return New_Copy_Tree (Expression (Parent (Compon)));
2255 return Expression (Parent (Compon));
2259 Check_Non_Limited_Type;
2261 if Present (Others_Etype) and then
2262 Base_Type (Others_Etype) /= Base_Type (Etype
2265 Error_Msg_N ("components in OTHERS choice must " &
2266 "have same type", Selector_Name);
2269 Others_Etype := Etype (Compon);
2271 if Expander_Active then
2272 return New_Copy_Tree (Expression (Assoc));
2274 return Expression (Assoc);
2279 elsif Chars (Compon) = Chars (Selector_Name) then
2282 -- We need to duplicate the expression when several
2283 -- components are grouped together with a "|" choice.
2284 -- For instance "filed1 | filed2 => Expr"
2286 if Box_Present (Assoc) then
2287 Mbox_Present := True;
2289 -- Duplicate the default expression of the component
2290 -- from the record type declaration
2292 if Present (Next (Selector_Name)) then
2293 Expr := New_Copy_Tree
2294 (Expression (Parent (Compon)));
2296 Expr := Expression (Parent (Compon));
2300 Check_Non_Limited_Type;
2302 if Present (Next (Selector_Name)) then
2303 Expr := New_Copy_Tree (Expression (Assoc));
2305 Expr := Expression (Assoc);
2309 Generate_Reference (Compon, Selector_Name);
2313 ("more than one value supplied for &",
2314 Selector_Name, Compon);
2319 Next (Selector_Name);
2328 -----------------------
2329 -- Resolve_Aggr_Expr --
2330 -----------------------
2332 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id) is
2333 New_C : Entity_Id := Component;
2334 Expr_Type : Entity_Id := Empty;
2336 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean;
2337 -- If the expression is an aggregate (possibly qualified) then its
2338 -- expansion is delayed until the enclosing aggregate is expanded
2339 -- into assignments. In that case, do not generate checks on the
2340 -- expression, because they will be generated later, and will other-
2341 -- wise force a copy (to remove side-effects) that would leave a
2342 -- dynamic-sized aggregate in the code, something that gigi cannot
2346 -- Set to True if the resolved Expr node needs to be relocated
2347 -- when attached to the newly created association list. This node
2348 -- need not be relocated if its parent pointer is not set.
2349 -- In fact in this case Expr is the output of a New_Copy_Tree call.
2350 -- if Relocate is True then we have analyzed the expression node
2351 -- in the original aggregate and hence it needs to be relocated
2352 -- when moved over the new association list.
2354 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean is
2355 Kind : constant Node_Kind := Nkind (Expr);
2358 return ((Kind = N_Aggregate
2359 or else Kind = N_Extension_Aggregate)
2360 and then Present (Etype (Expr))
2361 and then Is_Record_Type (Etype (Expr))
2362 and then Expansion_Delayed (Expr))
2364 or else (Kind = N_Qualified_Expression
2365 and then Has_Expansion_Delayed (Expression (Expr)));
2366 end Has_Expansion_Delayed;
2368 -- Start of processing for Resolve_Aggr_Expr
2371 -- If the type of the component is elementary or the type of the
2372 -- aggregate does not contain discriminants, use the type of the
2373 -- component to resolve Expr.
2375 if Is_Elementary_Type (Etype (Component))
2376 or else not Has_Discriminants (Etype (N))
2378 Expr_Type := Etype (Component);
2380 -- Otherwise we have to pick up the new type of the component from
2381 -- the new costrained subtype of the aggregate. In fact components
2382 -- which are of a composite type might be constrained by a
2383 -- discriminant, and we want to resolve Expr against the subtype were
2384 -- all discriminant occurrences are replaced with their actual value.
2387 New_C := First_Component (Etype (N));
2388 while Present (New_C) loop
2389 if Chars (New_C) = Chars (Component) then
2390 Expr_Type := Etype (New_C);
2394 Next_Component (New_C);
2397 pragma Assert (Present (Expr_Type));
2399 -- For each range in an array type where a discriminant has been
2400 -- replaced with the constraint, check that this range is within
2401 -- the range of the base type. This checks is done in the
2402 -- init proc for regular objects, but has to be done here for
2403 -- aggregates since no init proc is called for them.
2405 if Is_Array_Type (Expr_Type) then
2407 Index : Node_Id := First_Index (Expr_Type);
2408 -- Range of the current constrained index in the array.
2410 Orig_Index : Node_Id := First_Index (Etype (Component));
2411 -- Range corresponding to the range Index above in the
2412 -- original unconstrained record type. The bounds of this
2413 -- range may be governed by discriminants.
2415 Unconstr_Index : Node_Id := First_Index (Etype (Expr_Type));
2416 -- Range corresponding to the range Index above for the
2417 -- unconstrained array type. This range is needed to apply
2421 while Present (Index) loop
2422 if Depends_On_Discriminant (Orig_Index) then
2423 Apply_Range_Check (Index, Etype (Unconstr_Index));
2427 Next_Index (Orig_Index);
2428 Next_Index (Unconstr_Index);
2434 -- If the Parent pointer of Expr is not set, Expr is an expression
2435 -- duplicated by New_Tree_Copy (this happens for record aggregates
2436 -- that look like (Field1 | Filed2 => Expr) or (others => Expr)).
2437 -- Such a duplicated expression must be attached to the tree
2438 -- before analysis and resolution to enforce the rule that a tree
2439 -- fragment should never be analyzed or resolved unless it is
2440 -- attached to the current compilation unit.
2442 if No (Parent (Expr)) then
2443 Set_Parent (Expr, N);
2449 Analyze_And_Resolve (Expr, Expr_Type);
2450 Check_Non_Static_Context (Expr);
2451 Check_Unset_Reference (Expr);
2453 if not Has_Expansion_Delayed (Expr) then
2454 Aggregate_Constraint_Checks (Expr, Expr_Type);
2457 if Raises_Constraint_Error (Expr) then
2458 Set_Raises_Constraint_Error (N);
2462 Add_Association (New_C, Relocate_Node (Expr));
2464 Add_Association (New_C, Expr);
2466 end Resolve_Aggr_Expr;
2468 -- Resolve_Record_Aggregate local variables
2471 -- N_Component_Association node belonging to the input aggregate N
2474 Positional_Expr : Node_Id;
2475 Component : Entity_Id;
2476 Component_Elmt : Elmt_Id;
2478 Components : constant Elist_Id := New_Elmt_List;
2479 -- Components is the list of the record components whose value must
2480 -- be provided in the aggregate. This list does include discriminants.
2482 -- Start of processing for Resolve_Record_Aggregate
2485 -- We may end up calling Duplicate_Subexpr on expressions that are
2486 -- attached to New_Assoc_List. For this reason we need to attach it
2487 -- to the tree by setting its parent pointer to N. This parent point
2488 -- will change in STEP 8 below.
2490 Set_Parent (New_Assoc_List, N);
2492 -- STEP 1: abstract type and null record verification
2494 if Is_Abstract (Typ) then
2495 Error_Msg_N ("type of aggregate cannot be abstract", N);
2498 if No (First_Entity (Typ)) and then Null_Record_Present (N) then
2502 elsif Present (First_Entity (Typ))
2503 and then Null_Record_Present (N)
2504 and then not Is_Tagged_Type (Typ)
2506 Error_Msg_N ("record aggregate cannot be null", N);
2509 elsif No (First_Entity (Typ)) then
2510 Error_Msg_N ("record aggregate must be null", N);
2514 -- STEP 2: Verify aggregate structure
2517 Selector_Name : Node_Id;
2518 Bad_Aggregate : Boolean := False;
2521 if Present (Component_Associations (N)) then
2522 Assoc := First (Component_Associations (N));
2527 while Present (Assoc) loop
2528 Selector_Name := First (Choices (Assoc));
2529 while Present (Selector_Name) loop
2530 if Nkind (Selector_Name) = N_Identifier then
2533 elsif Nkind (Selector_Name) = N_Others_Choice then
2534 if Selector_Name /= First (Choices (Assoc))
2535 or else Present (Next (Selector_Name))
2537 Error_Msg_N ("OTHERS must appear alone in a choice list",
2541 elsif Present (Next (Assoc)) then
2542 Error_Msg_N ("OTHERS must appear last in an aggregate",
2549 ("selector name should be identifier or OTHERS",
2551 Bad_Aggregate := True;
2554 Next (Selector_Name);
2560 if Bad_Aggregate then
2565 -- STEP 3: Find discriminant Values
2568 Discrim : Entity_Id;
2569 Missing_Discriminants : Boolean := False;
2572 if Present (Expressions (N)) then
2573 Positional_Expr := First (Expressions (N));
2575 Positional_Expr := Empty;
2578 if Has_Discriminants (Typ) then
2579 Discrim := First_Discriminant (Typ);
2584 -- First find the discriminant values in the positional components
2586 while Present (Discrim) and then Present (Positional_Expr) loop
2587 if Discr_Present (Discrim) then
2588 Resolve_Aggr_Expr (Positional_Expr, Discrim);
2589 Next (Positional_Expr);
2592 if Present (Get_Value (Discrim, Component_Associations (N))) then
2594 ("more than one value supplied for discriminant&",
2598 Next_Discriminant (Discrim);
2601 -- Find remaining discriminant values, if any, among named components
2603 while Present (Discrim) loop
2604 Expr := Get_Value (Discrim, Component_Associations (N), True);
2606 if not Discr_Present (Discrim) then
2607 if Present (Expr) then
2609 ("more than one value supplied for discriminant&",
2613 elsif No (Expr) then
2615 ("no value supplied for discriminant &", N, Discrim);
2616 Missing_Discriminants := True;
2619 Resolve_Aggr_Expr (Expr, Discrim);
2622 Next_Discriminant (Discrim);
2625 if Missing_Discriminants then
2629 -- At this point and until the beginning of STEP 6, New_Assoc_List
2630 -- contains only the discriminants and their values.
2634 -- STEP 4: Set the Etype of the record aggregate
2636 -- ??? This code is pretty much a copy of Sem_Ch3.Build_Subtype. That
2637 -- routine should really be exported in sem_util or some such and used
2638 -- in sem_ch3 and here rather than have a copy of the code which is a
2639 -- maintenance nightmare.
2641 -- ??? Performace WARNING. The current implementation creates a new
2642 -- itype for all aggregates whose base type is discriminated.
2643 -- This means that for record aggregates nested inside an array
2644 -- aggregate we will create a new itype for each record aggregate
2645 -- if the array cmponent type has discriminants. For large aggregates
2646 -- this may be a problem. What should be done in this case is
2647 -- to reuse itypes as much as possible.
2649 if Has_Discriminants (Typ) then
2650 Build_Constrained_Itype : declare
2651 Loc : constant Source_Ptr := Sloc (N);
2653 Subtyp_Decl : Node_Id;
2656 C : constant List_Id := New_List;
2659 New_Assoc := First (New_Assoc_List);
2660 while Present (New_Assoc) loop
2661 Append (Duplicate_Subexpr (Expression (New_Assoc)), To => C);
2666 Make_Subtype_Indication (Loc,
2667 Subtype_Mark => New_Occurrence_Of (Base_Type (Typ), Loc),
2668 Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
2670 Def_Id := Create_Itype (Ekind (Typ), N);
2673 Make_Subtype_Declaration (Loc,
2674 Defining_Identifier => Def_Id,
2675 Subtype_Indication => Indic);
2676 Set_Parent (Subtyp_Decl, Parent (N));
2678 -- Itypes must be analyzed with checks off (see itypes.ads).
2680 Analyze (Subtyp_Decl, Suppress => All_Checks);
2682 Set_Etype (N, Def_Id);
2683 Check_Static_Discriminated_Subtype
2684 (Def_Id, Expression (First (New_Assoc_List)));
2685 end Build_Constrained_Itype;
2691 -- STEP 5: Get remaining components according to discriminant values
2694 Record_Def : Node_Id;
2695 Parent_Typ : Entity_Id;
2696 Root_Typ : Entity_Id;
2697 Parent_Typ_List : Elist_Id;
2698 Parent_Elmt : Elmt_Id;
2699 Errors_Found : Boolean := False;
2703 if Is_Derived_Type (Typ) and then Is_Tagged_Type (Typ) then
2704 Parent_Typ_List := New_Elmt_List;
2706 -- If this is an extension aggregate, the component list must
2707 -- include all components that are not in the given ancestor
2708 -- type. Otherwise, the component list must include components
2709 -- of all ancestors, starting with the root.
2711 if Nkind (N) = N_Extension_Aggregate then
2712 Root_Typ := Base_Type (Etype (Ancestor_Part (N)));
2714 Root_Typ := Root_Type (Typ);
2716 if Nkind (Parent (Base_Type (Root_Typ)))
2717 = N_Private_Type_Declaration
2720 ("type of aggregate has private ancestor&!",
2722 Error_Msg_N ("must use extension aggregate!", N);
2726 Dnode := Declaration_Node (Base_Type (Root_Typ));
2728 -- If we don't get a full declaration, then we have some
2729 -- error which will get signalled later so skip this part.
2730 -- Otherwise, gather components of root that apply to the
2731 -- aggregate type. We use the base type in case there is an
2732 -- applicable stored constraint that renames the discriminants
2735 if Nkind (Dnode) = N_Full_Type_Declaration then
2736 Record_Def := Type_Definition (Dnode);
2737 Gather_Components (Base_Type (Typ),
2738 Component_List (Record_Def),
2739 Governed_By => New_Assoc_List,
2741 Report_Errors => Errors_Found);
2745 Parent_Typ := Base_Type (Typ);
2746 while Parent_Typ /= Root_Typ loop
2748 Prepend_Elmt (Parent_Typ, To => Parent_Typ_List);
2749 Parent_Typ := Etype (Parent_Typ);
2751 if Nkind (Parent (Base_Type (Parent_Typ))) =
2752 N_Private_Type_Declaration
2753 or else Nkind (Parent (Base_Type (Parent_Typ))) =
2754 N_Private_Extension_Declaration
2756 if Nkind (N) /= N_Extension_Aggregate then
2758 ("type of aggregate has private ancestor&!",
2760 Error_Msg_N ("must use extension aggregate!", N);
2763 elsif Parent_Typ /= Root_Typ then
2765 ("ancestor part of aggregate must be private type&",
2766 Ancestor_Part (N), Parent_Typ);
2772 -- Now collect components from all other ancestors.
2774 Parent_Elmt := First_Elmt (Parent_Typ_List);
2775 while Present (Parent_Elmt) loop
2776 Parent_Typ := Node (Parent_Elmt);
2777 Record_Def := Type_Definition (Parent (Base_Type (Parent_Typ)));
2778 Gather_Components (Empty,
2779 Component_List (Record_Extension_Part (Record_Def)),
2780 Governed_By => New_Assoc_List,
2782 Report_Errors => Errors_Found);
2784 Next_Elmt (Parent_Elmt);
2788 Record_Def := Type_Definition (Parent (Base_Type (Typ)));
2790 if Null_Present (Record_Def) then
2793 Gather_Components (Base_Type (Typ),
2794 Component_List (Record_Def),
2795 Governed_By => New_Assoc_List,
2797 Report_Errors => Errors_Found);
2801 if Errors_Found then
2806 -- STEP 6: Find component Values
2809 Component_Elmt := First_Elmt (Components);
2811 -- First scan the remaining positional associations in the aggregate.
2812 -- Remember that at this point Positional_Expr contains the current
2813 -- positional association if any is left after looking for discriminant
2814 -- values in step 3.
2816 while Present (Positional_Expr) and then Present (Component_Elmt) loop
2817 Component := Node (Component_Elmt);
2818 Resolve_Aggr_Expr (Positional_Expr, Component);
2820 if Present (Get_Value (Component, Component_Associations (N))) then
2822 ("more than one value supplied for Component &", N, Component);
2825 Next (Positional_Expr);
2826 Next_Elmt (Component_Elmt);
2829 if Present (Positional_Expr) then
2831 ("too many components for record aggregate", Positional_Expr);
2834 -- Now scan for the named arguments of the aggregate
2836 while Present (Component_Elmt) loop
2837 Component := Node (Component_Elmt);
2838 Expr := Get_Value (Component, Component_Associations (N), True);
2840 if Mbox_Present and then Is_Limited_Type (Etype (Component)) then
2842 -- In case of default initialization of a limited component we
2843 -- pass the limited component to the expander. The expander will
2844 -- generate calls to the corresponding initialization subprograms.
2847 (Component => Component,
2849 Box_Present => True);
2851 elsif No (Expr) then
2852 Error_Msg_NE ("no value supplied for component &!", N, Component);
2854 Resolve_Aggr_Expr (Expr, Component);
2857 Next_Elmt (Component_Elmt);
2860 -- STEP 7: check for invalid components + check type in choice list
2867 -- Type of first component in choice list
2870 if Present (Component_Associations (N)) then
2871 Assoc := First (Component_Associations (N));
2876 Verification : while Present (Assoc) loop
2877 Selectr := First (Choices (Assoc));
2880 if Nkind (Selectr) = N_Others_Choice then
2881 if No (Others_Etype)
2882 and then not Others_Mbox
2885 ("OTHERS must represent at least one component", Selectr);
2891 while Present (Selectr) loop
2892 New_Assoc := First (New_Assoc_List);
2893 while Present (New_Assoc) loop
2894 Component := First (Choices (New_Assoc));
2895 exit when Chars (Selectr) = Chars (Component);
2899 -- If no association, this is not a legal component of
2900 -- of the type in question, except if this is an internal
2901 -- component supplied by a previous expansion.
2903 if No (New_Assoc) then
2904 if Box_Present (Parent (Selectr)) then
2907 elsif Chars (Selectr) /= Name_uTag
2908 and then Chars (Selectr) /= Name_uParent
2909 and then Chars (Selectr) /= Name_uController
2911 if not Has_Discriminants (Typ) then
2912 Error_Msg_Node_2 := Typ;
2914 ("& is not a component of}",
2918 ("& is not a component of the aggregate subtype",
2922 Check_Misspelled_Component (Components, Selectr);
2925 elsif No (Typech) then
2926 Typech := Base_Type (Etype (Component));
2928 elsif Typech /= Base_Type (Etype (Component)) then
2930 if not Box_Present (Parent (Selectr)) then
2932 ("components in choice list must have same type",
2942 end loop Verification;
2945 -- STEP 8: replace the original aggregate
2948 New_Aggregate : constant Node_Id := New_Copy (N);
2951 Set_Expressions (New_Aggregate, No_List);
2952 Set_Etype (New_Aggregate, Etype (N));
2953 Set_Component_Associations (New_Aggregate, New_Assoc_List);
2955 Rewrite (N, New_Aggregate);
2957 end Resolve_Record_Aggregate;
2959 ---------------------
2960 -- Sort_Case_Table --
2961 ---------------------
2963 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
2964 L : constant Int := Case_Table'First;
2965 U : constant Int := Case_Table'Last;
2974 T := Case_Table (K + 1);
2978 and then Expr_Value (Case_Table (J - 1).Choice_Lo) >
2979 Expr_Value (T.Choice_Lo)
2981 Case_Table (J) := Case_Table (J - 1);
2985 Case_Table (J) := T;
2988 end Sort_Case_Table;
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