1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
10 -- Copyright (C) 1992-2002 Free Software Foundation, Inc. --
12 -- GNAT is free software; you can redistribute it and/or modify it under --
13 -- terms of the GNU General Public License as published by the Free Soft- --
14 -- ware Foundation; either version 2, or (at your option) any later ver- --
15 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
16 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
17 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
18 -- for more details. You should have received a copy of the GNU General --
19 -- Public License distributed with GNAT; see file COPYING. If not, write --
20 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
21 -- MA 02111-1307, USA. --
23 -- GNAT was originally developed by the GNAT team at New York University. --
24 -- Extensive contributions were provided by Ada Core Technologies Inc. --
26 ------------------------------------------------------------------------------
28 with Atree; use Atree;
29 with Checks; use Checks;
30 with Einfo; use Einfo;
31 with Elists; use Elists;
32 with Errout; use Errout;
33 with Exp_Util; use Exp_Util;
34 with Freeze; use Freeze;
35 with Itypes; use Itypes;
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 Sinfo; use Sinfo;
49 with Snames; use Snames;
50 with Stringt; use Stringt;
51 with Stand; use Stand;
52 with Tbuild; use Tbuild;
53 with Uintp; use Uintp;
55 with GNAT.Spelling_Checker; use GNAT.Spelling_Checker;
57 package body Sem_Aggr is
59 type Case_Bounds is record
62 Choice_Node : Node_Id;
65 type Case_Table_Type is array (Nat range <>) of Case_Bounds;
66 -- Table type used by Check_Case_Choices procedure
68 -----------------------
69 -- Local Subprograms --
70 -----------------------
72 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
73 -- Sort the Case Table using the Lower Bound of each Choice as the key.
74 -- A simple insertion sort is used since the number of choices in a case
75 -- statement of variant part will usually be small and probably in near
78 ------------------------------------------------------
79 -- Subprograms used for RECORD AGGREGATE Processing --
80 ------------------------------------------------------
82 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id);
83 -- This procedure performs all the semantic checks required for record
84 -- aggregates. Note that for aggregates analysis and resolution go
85 -- hand in hand. Aggregate analysis has been delayed up to here and
86 -- it is done while resolving the aggregate.
88 -- N is the N_Aggregate node.
89 -- Typ is the record type for the aggregate resolution
91 -- While performing the semantic checks, this procedure
92 -- builds a new Component_Association_List where each record field
93 -- appears alone in a Component_Choice_List along with its corresponding
94 -- expression. The record fields in the Component_Association_List
95 -- appear in the same order in which they appear in the record type Typ.
97 -- Once this new Component_Association_List is built and all the
98 -- semantic checks performed, the original aggregate subtree is replaced
99 -- with the new named record aggregate just built. Note that the subtree
100 -- substitution is performed with Rewrite so as to be
101 -- able to retrieve the original aggregate.
103 -- The aggregate subtree manipulation performed by Resolve_Record_Aggregate
104 -- yields the aggregate format expected by Gigi. Typically, this kind of
105 -- tree manipulations are done in the expander. However, because the
106 -- semantic checks that need to be performed on record aggregates really
107 -- go hand in hand with the record aggreagate normalization, the aggregate
108 -- subtree transformation is performed during resolution rather than
109 -- expansion. Had we decided otherwise we would have had to duplicate
110 -- most of the code in the expansion procedure Expand_Record_Aggregate.
111 -- Note, however, that all the expansion concerning aggegates for tagged
112 -- records is done in Expand_Record_Aggregate.
114 -- The algorithm of Resolve_Record_Aggregate proceeds as follows:
116 -- 1. Make sure that the record type against which the record aggregate
117 -- has to be resolved is not abstract. Furthermore if the type is
118 -- a null aggregate make sure the input aggregate N is also null.
120 -- 2. Verify that the structure of the aggregate is that of a record
121 -- aggregate. Specifically, look for component associations and ensure
122 -- that each choice list only has identifiers or the N_Others_Choice
123 -- node. Also make sure that if present, the N_Others_Choice occurs
124 -- last and by itself.
126 -- 3. If Typ contains discriminants, the values for each discriminant
127 -- is looked for. If the record type Typ has variants, we check
128 -- that the expressions corresponding to each discriminant ruling
129 -- the (possibly nested) variant parts of Typ, are static. This
130 -- allows us to determine the variant parts to which the rest of
131 -- the aggregate must conform. The names of discriminants with their
132 -- values are saved in a new association list, New_Assoc_List which
133 -- is later augmented with the names and values of the remaining
134 -- components in the record type.
136 -- During this phase we also make sure that every discriminant is
137 -- assigned exactly one value. Note that when several values
138 -- for a given discriminant are found, semantic processing continues
139 -- looking for further errors. In this case it's the first
140 -- discriminant value found which we will be recorded.
142 -- IMPORTANT NOTE: For derived tagged types this procedure expects
143 -- First_Discriminant and Next_Discriminant to give the correct list
144 -- of discriminants, in the correct order.
146 -- 4. After all the discriminant values have been gathered, we can
147 -- set the Etype of the record aggregate. If Typ contains no
148 -- discriminants this is straightforward: the Etype of N is just
149 -- Typ, otherwise a new implicit constrained subtype of Typ is
150 -- built to be the Etype of N.
152 -- 5. Gather the remaining record components according to the discriminant
153 -- values. This involves recursively traversing the record type
154 -- structure to see what variants are selected by the given discriminant
155 -- values. This processing is a little more convoluted if Typ is a
156 -- derived tagged types since we need to retrieve the record structure
157 -- of all the ancestors of Typ.
159 -- 6. After gathering the record components we look for their values
160 -- in the record aggregate and emit appropriate error messages
161 -- should we not find such values or should they be duplicated.
163 -- 7. We then make sure no illegal component names appear in the
164 -- record aggegate and make sure that the type of the record
165 -- components appearing in a same choice list is the same.
166 -- Finally we ensure that the others choice, if present, is
167 -- used to provide the value of at least a record component.
169 -- 8. The original aggregate node is replaced with the new named
170 -- aggregate built in steps 3 through 6, as explained earlier.
172 -- Given the complexity of record aggregate resolution, the primary
173 -- goal of this routine is clarity and simplicity rather than execution
174 -- and storage efficiency. If there are only positional components in the
175 -- aggregate the running time is linear. If there are associations
176 -- the running time is still linear as long as the order of the
177 -- associations is not too far off the order of the components in the
178 -- record type. If this is not the case the running time is at worst
179 -- quadratic in the size of the association list.
181 procedure Check_Misspelled_Component
182 (Elements : Elist_Id;
183 Component : Node_Id);
184 -- Give possible misspelling diagnostic if Component is likely to be
185 -- a misspelling of one of the components of the Assoc_List.
186 -- This is called by Resolv_Aggr_Expr after producing
187 -- an invalid component error message.
189 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id);
190 -- An optimization: determine whether a discriminated subtype has a
191 -- static constraint, and contains array components whose length is also
192 -- static, either because they are constrained by the discriminant, or
193 -- because the original component bounds are static.
195 -----------------------------------------------------
196 -- Subprograms used for ARRAY AGGREGATE Processing --
197 -----------------------------------------------------
199 function Resolve_Array_Aggregate
202 Index_Constr : Node_Id;
203 Component_Typ : Entity_Id;
204 Others_Allowed : Boolean)
206 -- This procedure performs the semantic checks for an array aggregate.
207 -- True is returned if the aggregate resolution succeeds.
208 -- The procedure works by recursively checking each nested aggregate.
209 -- Specifically, after checking a sub-aggreate nested at the i-th level
210 -- we recursively check all the subaggregates at the i+1-st level (if any).
211 -- Note that for aggregates analysis and resolution go hand in hand.
212 -- Aggregate analysis has been delayed up to here and it is done while
213 -- resolving the aggregate.
215 -- N is the current N_Aggregate node to be checked.
217 -- Index is the index node corresponding to the array sub-aggregate that
218 -- we are currently checking (RM 4.3.3 (8)). Its Etype is the
219 -- corresponding index type (or subtype).
221 -- Index_Constr is the node giving the applicable index constraint if
222 -- any (RM 4.3.3 (10)). It "is a constraint provided by certain
223 -- contexts [...] that can be used to determine the bounds of the array
224 -- value specified by the aggregate". If Others_Allowed below is False
225 -- there is no applicable index constraint and this node is set to Index.
227 -- Component_Typ is the array component type.
229 -- Others_Allowed indicates whether an others choice is allowed
230 -- in the context where the top-level aggregate appeared.
232 -- The algorithm of Resolve_Array_Aggregate proceeds as follows:
234 -- 1. Make sure that the others choice, if present, is by itself and
235 -- appears last in the sub-aggregate. Check that we do not have
236 -- positional and named components in the array sub-aggregate (unless
237 -- the named association is an others choice). Finally if an others
238 -- choice is present, make sure it is allowed in the aggregate contex.
240 -- 2. If the array sub-aggregate contains discrete_choices:
242 -- (A) Verify their validity. Specifically verify that:
244 -- (a) If a null range is present it must be the only possible
245 -- choice in the array aggregate.
247 -- (b) Ditto for a non static range.
249 -- (c) Ditto for a non static expression.
251 -- In addition this step analyzes and resolves each discrete_choice,
252 -- making sure that its type is the type of the corresponding Index.
253 -- If we are not at the lowest array aggregate level (in the case of
254 -- multi-dimensional aggregates) then invoke Resolve_Array_Aggregate
255 -- recursively on each component expression. Otherwise, resolve the
256 -- bottom level component expressions against the expected component
257 -- type ONLY IF the component corresponds to a single discrete choice
258 -- which is not an others choice (to see why read the DELAYED
259 -- COMPONENT RESOLUTION below).
261 -- (B) Determine the bounds of the sub-aggregate and lowest and
262 -- highest choice values.
264 -- 3. For positional aggregates:
266 -- (A) Loop over the component expressions either recursively invoking
267 -- Resolve_Array_Aggregate on each of these for multi-dimensional
268 -- array aggregates or resolving the bottom level component
269 -- expressions against the expected component type.
271 -- (B) Determine the bounds of the positional sub-aggregates.
273 -- 4. Try to determine statically whether the evaluation of the array
274 -- sub-aggregate raises Constraint_Error. If yes emit proper
275 -- warnings. The precise checks are the following:
277 -- (A) Check that the index range defined by aggregate bounds is
278 -- compatible with corresponding index subtype.
279 -- We also check against the base type. In fact it could be that
280 -- Low/High bounds of the base type are static whereas those of
281 -- the index subtype are not. Thus if we can statically catch
282 -- a problem with respect to the base type we are guaranteed
283 -- that the same problem will arise with the index subtype
285 -- (B) If we are dealing with a named aggregate containing an others
286 -- choice and at least one discrete choice then make sure the range
287 -- specified by the discrete choices does not overflow the
288 -- aggregate bounds. We also check against the index type and base
289 -- type bounds for the same reasons given in (A).
291 -- (C) If we are dealing with a positional aggregate with an others
292 -- choice make sure the number of positional elements specified
293 -- does not overflow the aggregate bounds. We also check against
294 -- the index type and base type bounds as mentioned in (A).
296 -- Finally construct an N_Range node giving the sub-aggregate bounds.
297 -- Set the Aggregate_Bounds field of the sub-aggregate to be this
298 -- N_Range. The routine Array_Aggr_Subtype below uses such N_Ranges
299 -- to build the appropriate aggregate subtype. Aggregate_Bounds
300 -- information is needed during expansion.
302 -- DELAYED COMPONENT RESOLUTION: The resolution of bottom level component
303 -- expressions in an array aggregate may call Duplicate_Subexpr or some
304 -- other routine that inserts code just outside the outermost aggregate.
305 -- If the array aggregate contains discrete choices or an others choice,
306 -- this may be wrong. Consider for instance the following example.
308 -- type Rec is record
312 -- type Acc_Rec is access Rec;
313 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => new Rec);
315 -- Then the transformation of "new Rec" that occurs during resolution
316 -- entails the following code modifications
318 -- P7b : constant Acc_Rec := new Rec;
319 -- Rec_init_proc (P7b.all);
320 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => P7b);
322 -- This code transformation is clearly wrong, since we need to call
323 -- "new Rec" for each of the 3 array elements. To avoid this problem we
324 -- delay resolution of the components of non positional array aggregates
325 -- to the expansion phase. As an optimization, if the discrete choice
326 -- specifies a single value we do not delay resolution.
328 function Array_Aggr_Subtype (N : Node_Id; Typ : Node_Id) return Entity_Id;
329 -- This routine returns the type or subtype of an array aggregate.
331 -- N is the array aggregate node whose type we return.
333 -- Typ is the context type in which N occurs.
335 -- This routine creates an implicit array subtype whose bouds are
336 -- those defined by the aggregate. When this routine is invoked
337 -- Resolve_Array_Aggregate has already processed aggregate N. Thus the
338 -- Aggregate_Bounds of each sub-aggregate, is an N_Range node giving the
339 -- sub-aggregate bounds. When building the aggegate itype, this function
340 -- traverses the array aggregate N collecting such Aggregate_Bounds and
341 -- constructs the proper array aggregate itype.
343 -- Note that in the case of multidimensional aggregates each inner
344 -- sub-aggregate corresponding to a given array dimension, may provide a
345 -- different bounds. If it is possible to determine statically that
346 -- some sub-aggregates corresponding to the same index do not have the
347 -- same bounds, then a warning is emitted. If such check is not possible
348 -- statically (because some sub-aggregate bounds are dynamic expressions)
349 -- then this job is left to the expander. In all cases the particular
350 -- bounds that this function will chose for a given dimension is the first
351 -- N_Range node for a sub-aggregate corresponding to that dimension.
353 -- Note that the Raises_Constraint_Error flag of an array aggregate
354 -- whose evaluation is determined to raise CE by Resolve_Array_Aggregate,
355 -- is set in Resolve_Array_Aggregate but the aggregate is not
356 -- immediately replaced with a raise CE. In fact, Array_Aggr_Subtype must
357 -- first construct the proper itype for the aggregate (Gigi needs
358 -- this). After constructing the proper itype we will eventually replace
359 -- the top-level aggregate with a raise CE (done in Resolve_Aggregate).
360 -- Of course in cases such as:
362 -- type Arr is array (integer range <>) of Integer;
363 -- A : Arr := (positive range -1 .. 2 => 0);
365 -- The bounds of the aggregate itype are cooked up to look reasonable
366 -- (in this particular case the bounds will be 1 .. 2).
368 procedure Aggregate_Constraint_Checks
370 Check_Typ : Entity_Id);
371 -- Checks expression Exp against subtype Check_Typ. If Exp is an
372 -- aggregate and Check_Typ a constrained record type with discriminants,
373 -- we generate the appropriate discriminant checks. If Exp is an array
374 -- aggregate then emit the appropriate length checks. If Exp is a scalar
375 -- type, or a string literal, Exp is changed into Check_Typ'(Exp) to
376 -- ensure that range checks are performed at run time.
378 procedure Make_String_Into_Aggregate (N : Node_Id);
379 -- A string literal can appear in a context in which a one dimensional
380 -- array of characters is expected. This procedure simply rewrites the
381 -- string as an aggregate, prior to resolution.
383 ---------------------------------
384 -- Aggregate_Constraint_Checks --
385 ---------------------------------
387 procedure Aggregate_Constraint_Checks
389 Check_Typ : Entity_Id)
391 Exp_Typ : constant Entity_Id := Etype (Exp);
394 if Raises_Constraint_Error (Exp) then
398 -- This is really expansion activity, so make sure that expansion
399 -- is on and is allowed.
401 if not Expander_Active or else In_Default_Expression then
405 -- First check if we have to insert discriminant checks
407 if Has_Discriminants (Exp_Typ) then
408 Apply_Discriminant_Check (Exp, Check_Typ);
410 -- Next emit length checks for array aggregates
412 elsif Is_Array_Type (Exp_Typ) then
413 Apply_Length_Check (Exp, Check_Typ);
415 -- Finally emit scalar and string checks. If we are dealing with a
416 -- scalar literal we need to check by hand because the Etype of
417 -- literals is not necessarily correct.
419 elsif Is_Scalar_Type (Exp_Typ)
420 and then Compile_Time_Known_Value (Exp)
422 if Is_Out_Of_Range (Exp, Base_Type (Check_Typ)) then
423 Apply_Compile_Time_Constraint_Error
424 (Exp, "value not in range of}?", CE_Range_Check_Failed,
425 Ent => Base_Type (Check_Typ),
426 Typ => Base_Type (Check_Typ));
428 elsif Is_Out_Of_Range (Exp, Check_Typ) then
429 Apply_Compile_Time_Constraint_Error
430 (Exp, "value not in range of}?", CE_Range_Check_Failed,
434 elsif not Range_Checks_Suppressed (Check_Typ) then
435 Apply_Scalar_Range_Check (Exp, Check_Typ);
438 elsif (Is_Scalar_Type (Exp_Typ)
439 or else Nkind (Exp) = N_String_Literal)
440 and then Exp_Typ /= Check_Typ
442 if Is_Entity_Name (Exp)
443 and then Ekind (Entity (Exp)) = E_Constant
445 -- If expression is a constant, it is worthwhile checking whether
446 -- it is a bound of the type.
448 if (Is_Entity_Name (Type_Low_Bound (Check_Typ))
449 and then Entity (Exp) = Entity (Type_Low_Bound (Check_Typ)))
450 or else (Is_Entity_Name (Type_High_Bound (Check_Typ))
451 and then Entity (Exp) = Entity (Type_High_Bound (Check_Typ)))
456 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
457 Analyze_And_Resolve (Exp, Check_Typ);
460 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
461 Analyze_And_Resolve (Exp, Check_Typ);
465 end Aggregate_Constraint_Checks;
467 ------------------------
468 -- Array_Aggr_Subtype --
469 ------------------------
471 function Array_Aggr_Subtype
476 Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
477 -- Number of aggregate index dimensions.
479 Aggr_Range : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
480 -- Constrained N_Range of each index dimension in our aggregate itype.
482 Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
483 Aggr_High : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
484 -- Low and High bounds for each index dimension in our aggregate itype.
486 Is_Fully_Positional : Boolean := True;
488 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos);
489 -- N is an array (sub-)aggregate. Dim is the dimension corresponding to
490 -- (sub-)aggregate N. This procedure collects the constrained N_Range
491 -- nodes corresponding to each index dimension of our aggregate itype.
492 -- These N_Range nodes are collected in Aggr_Range above.
493 -- Likewise collect in Aggr_Low & Aggr_High above the low and high
494 -- bounds of each index dimension. If, when collecting, two bounds
495 -- corresponding to the same dimension are static and found to differ,
496 -- then emit a warning, and mark N as raising Constraint_Error.
498 -------------------------
499 -- Collect_Aggr_Bounds --
500 -------------------------
502 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos) is
503 This_Range : constant Node_Id := Aggregate_Bounds (N);
504 -- The aggregate range node of this specific sub-aggregate.
506 This_Low : constant Node_Id := Low_Bound (Aggregate_Bounds (N));
507 This_High : constant Node_Id := High_Bound (Aggregate_Bounds (N));
508 -- The aggregate bounds of this specific sub-aggregate.
514 -- Collect the first N_Range for a given dimension that you find.
515 -- For a given dimension they must be all equal anyway.
517 if No (Aggr_Range (Dim)) then
518 Aggr_Low (Dim) := This_Low;
519 Aggr_High (Dim) := This_High;
520 Aggr_Range (Dim) := This_Range;
523 if Compile_Time_Known_Value (This_Low) then
524 if not Compile_Time_Known_Value (Aggr_Low (Dim)) then
525 Aggr_Low (Dim) := This_Low;
527 elsif Expr_Value (This_Low) /= Expr_Value (Aggr_Low (Dim)) then
528 Set_Raises_Constraint_Error (N);
529 Error_Msg_N ("Sub-aggregate low bound mismatch?", N);
530 Error_Msg_N ("Constraint_Error will be raised at run-time?",
535 if Compile_Time_Known_Value (This_High) then
536 if not Compile_Time_Known_Value (Aggr_High (Dim)) then
537 Aggr_High (Dim) := This_High;
540 Expr_Value (This_High) /= Expr_Value (Aggr_High (Dim))
542 Set_Raises_Constraint_Error (N);
543 Error_Msg_N ("Sub-aggregate high bound mismatch?", N);
544 Error_Msg_N ("Constraint_Error will be raised at run-time?",
550 if Dim < Aggr_Dimension then
552 -- Process positional components
554 if Present (Expressions (N)) then
555 Expr := First (Expressions (N));
556 while Present (Expr) loop
557 Collect_Aggr_Bounds (Expr, Dim + 1);
562 -- Process component associations
564 if Present (Component_Associations (N)) then
565 Is_Fully_Positional := False;
567 Assoc := First (Component_Associations (N));
568 while Present (Assoc) loop
569 Expr := Expression (Assoc);
570 Collect_Aggr_Bounds (Expr, Dim + 1);
575 end Collect_Aggr_Bounds;
577 -- Array_Aggr_Subtype variables
580 -- the final itype of the overall aggregate
582 Index_Constraints : List_Id := New_List;
583 -- The list of index constraints of the aggregate itype.
585 -- Start of processing for Array_Aggr_Subtype
588 -- Make sure that the list of index constraints is properly attached
589 -- to the tree, and then collect the aggregate bounds.
591 Set_Parent (Index_Constraints, N);
592 Collect_Aggr_Bounds (N, 1);
594 -- Build the list of constrained indices of our aggregate itype.
596 for J in 1 .. Aggr_Dimension loop
597 Create_Index : declare
598 Index_Base : Entity_Id := Base_Type (Etype (Aggr_Range (J)));
599 Index_Typ : Entity_Id;
602 -- Construct the Index subtype
604 Index_Typ := Create_Itype (Subtype_Kind (Ekind (Index_Base)), N);
606 Set_Etype (Index_Typ, Index_Base);
608 if Is_Character_Type (Index_Base) then
609 Set_Is_Character_Type (Index_Typ);
612 Set_Size_Info (Index_Typ, (Index_Base));
613 Set_RM_Size (Index_Typ, RM_Size (Index_Base));
614 Set_First_Rep_Item (Index_Typ, First_Rep_Item (Index_Base));
615 Set_Scalar_Range (Index_Typ, Aggr_Range (J));
617 if Is_Discrete_Or_Fixed_Point_Type (Index_Typ) then
618 Set_RM_Size (Index_Typ, UI_From_Int (Minimum_Size (Index_Typ)));
621 Set_Etype (Aggr_Range (J), Index_Typ);
623 Append (Aggr_Range (J), To => Index_Constraints);
627 -- Now build the Itype
629 Itype := Create_Itype (E_Array_Subtype, N);
631 Set_First_Rep_Item (Itype, First_Rep_Item (Typ));
632 Set_Convention (Itype, Convention (Typ));
633 Set_Depends_On_Private (Itype, Has_Private_Component (Typ));
634 Set_Etype (Itype, Base_Type (Typ));
635 Set_Has_Alignment_Clause (Itype, Has_Alignment_Clause (Typ));
636 Set_Is_Aliased (Itype, Is_Aliased (Typ));
637 Set_Suppress_Index_Checks (Itype, Suppress_Index_Checks (Typ));
638 Set_Suppress_Length_Checks (Itype, Suppress_Length_Checks (Typ));
639 Set_Depends_On_Private (Itype, Depends_On_Private (Typ));
641 Set_First_Index (Itype, First (Index_Constraints));
642 Set_Is_Constrained (Itype, True);
643 Set_Is_Internal (Itype, True);
644 Init_Size_Align (Itype);
646 -- A simple optimization: purely positional aggregates of static
647 -- components should be passed to gigi unexpanded whenever possible,
648 -- and regardless of the staticness of the bounds themselves. Subse-
649 -- quent checks in exp_aggr verify that type is not packed, etc.
651 Set_Size_Known_At_Compile_Time (Itype,
653 and then Comes_From_Source (N)
654 and then Size_Known_At_Compile_Time (Component_Type (Typ)));
656 -- We always need a freeze node for a packed array subtype, so that
657 -- we can build the Packed_Array_Type corresponding to the subtype.
658 -- If expansion is disabled, the packed array subtype is not built,
659 -- and we must not generate a freeze node for the type, or else it
660 -- will appear incomplete to gigi.
662 if Is_Packed (Itype) and then not In_Default_Expression
663 and then Expander_Active
665 Freeze_Itype (Itype, N);
669 end Array_Aggr_Subtype;
671 --------------------------------
672 -- Check_Misspelled_Component --
673 --------------------------------
675 procedure Check_Misspelled_Component
676 (Elements : Elist_Id;
679 Max_Suggestions : constant := 2;
681 Nr_Of_Suggestions : Natural := 0;
682 Suggestion_1 : Entity_Id := Empty;
683 Suggestion_2 : Entity_Id := Empty;
684 Component_Elmt : Elmt_Id;
687 -- All the components of List are matched against Component and
688 -- a count is maintained of possible misspellings. When at the
689 -- end of the analysis there are one or two (not more!) possible
690 -- misspellings, these misspellings will be suggested as
691 -- possible correction.
693 Get_Name_String (Chars (Component));
696 S : constant String (1 .. Name_Len) :=
697 Name_Buffer (1 .. Name_Len);
701 Component_Elmt := First_Elmt (Elements);
703 while Nr_Of_Suggestions <= Max_Suggestions
704 and then Present (Component_Elmt)
707 Get_Name_String (Chars (Node (Component_Elmt)));
709 if Is_Bad_Spelling_Of (Name_Buffer (1 .. Name_Len), S) then
710 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
712 case Nr_Of_Suggestions is
713 when 1 => Suggestion_1 := Node (Component_Elmt);
714 when 2 => Suggestion_2 := Node (Component_Elmt);
719 Next_Elmt (Component_Elmt);
722 -- Report at most two suggestions
724 if Nr_Of_Suggestions = 1 then
725 Error_Msg_NE ("\possible misspelling of&",
726 Component, Suggestion_1);
728 elsif Nr_Of_Suggestions = 2 then
729 Error_Msg_Node_2 := Suggestion_2;
730 Error_Msg_NE ("\possible misspelling of& or&",
731 Component, Suggestion_1);
734 end Check_Misspelled_Component;
736 ----------------------------------------
737 -- Check_Static_Discriminated_Subtype --
738 ----------------------------------------
740 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id) is
741 Disc : constant Entity_Id := First_Discriminant (T);
746 if Has_Record_Rep_Clause (T) then
749 elsif Present (Next_Discriminant (Disc)) then
752 elsif Nkind (V) /= N_Integer_Literal then
756 Comp := First_Component (T);
758 while Present (Comp) loop
760 if Is_Scalar_Type (Etype (Comp)) then
763 elsif Is_Private_Type (Etype (Comp))
764 and then Present (Full_View (Etype (Comp)))
765 and then Is_Scalar_Type (Full_View (Etype (Comp)))
769 elsif Is_Array_Type (Etype (Comp)) then
771 if Is_Bit_Packed_Array (Etype (Comp)) then
775 Ind := First_Index (Etype (Comp));
777 while Present (Ind) loop
779 if Nkind (Ind) /= N_Range
780 or else Nkind (Low_Bound (Ind)) /= N_Integer_Literal
781 or else Nkind (High_Bound (Ind)) /= N_Integer_Literal
793 Next_Component (Comp);
796 -- On exit, all components have statically known sizes.
798 Set_Size_Known_At_Compile_Time (T);
799 end Check_Static_Discriminated_Subtype;
801 --------------------------------
802 -- Make_String_Into_Aggregate --
803 --------------------------------
805 procedure Make_String_Into_Aggregate (N : Node_Id) is
808 Exprs : List_Id := New_List;
809 Loc : constant Source_Ptr := Sloc (N);
811 P : Source_Ptr := Loc + 1;
812 Str : constant String_Id := Strval (N);
813 Strlen : constant Nat := String_Length (Str);
816 for J in 1 .. Strlen loop
817 C := Get_String_Char (Str, J);
818 Set_Character_Literal_Name (C);
820 C_Node := Make_Character_Literal (P, Name_Find, C);
821 Set_Etype (C_Node, Any_Character);
822 Append_To (Exprs, C_Node);
825 -- something special for wide strings ?
828 New_N := Make_Aggregate (Loc, Expressions => Exprs);
829 Set_Analyzed (New_N);
830 Set_Etype (New_N, Any_Composite);
833 end Make_String_Into_Aggregate;
835 -----------------------
836 -- Resolve_Aggregate --
837 -----------------------
839 procedure Resolve_Aggregate (N : Node_Id; Typ : Entity_Id) is
840 Pkind : constant Node_Kind := Nkind (Parent (N));
842 Aggr_Subtyp : Entity_Id;
843 -- The actual aggregate subtype. This is not necessarily the same as Typ
844 -- which is the subtype of the context in which the aggregate was found.
847 if Is_Limited_Type (Typ) then
848 Error_Msg_N ("aggregate type cannot be limited", N);
850 elsif Is_Limited_Composite (Typ) then
851 Error_Msg_N ("aggregate type cannot have limited component", N);
853 elsif Is_Class_Wide_Type (Typ) then
854 Error_Msg_N ("type of aggregate cannot be class-wide", N);
856 elsif Typ = Any_String
857 or else Typ = Any_Composite
859 Error_Msg_N ("no unique type for aggregate", N);
860 Set_Etype (N, Any_Composite);
862 elsif Is_Array_Type (Typ) and then Null_Record_Present (N) then
863 Error_Msg_N ("null record forbidden in array aggregate", N);
865 elsif Is_Record_Type (Typ) then
866 Resolve_Record_Aggregate (N, Typ);
868 elsif Is_Array_Type (Typ) then
870 -- First a special test, for the case of a positional aggregate
871 -- of characters which can be replaced by a string literal.
872 -- Do not perform this transformation if this was a string literal
873 -- to start with, whose components needed constraint checks, or if
874 -- the component type is non-static, because it will require those
875 -- checks and be transformed back into an aggregate.
877 if Number_Dimensions (Typ) = 1
879 (Root_Type (Component_Type (Typ)) = Standard_Character
881 Root_Type (Component_Type (Typ)) = Standard_Wide_Character)
882 and then No (Component_Associations (N))
883 and then not Is_Limited_Composite (Typ)
884 and then not Is_Private_Composite (Typ)
885 and then not Is_Bit_Packed_Array (Typ)
886 and then Nkind (Original_Node (Parent (N))) /= N_String_Literal
887 and then Is_Static_Subtype (Component_Type (Typ))
893 Expr := First (Expressions (N));
894 while Present (Expr) loop
895 exit when Nkind (Expr) /= N_Character_Literal;
902 Expr := First (Expressions (N));
903 while Present (Expr) loop
904 Store_String_Char (Char_Literal_Value (Expr));
909 Make_String_Literal (Sloc (N), End_String));
911 Analyze_And_Resolve (N, Typ);
917 -- Here if we have a real aggregate to deal with
919 Array_Aggregate : declare
920 Aggr_Resolved : Boolean;
921 Aggr_Typ : Entity_Id := Etype (Typ);
922 -- This is the unconstrained array type, which is the type
923 -- against which the aggregate is to be resoved. Typ itself
924 -- is the array type of the context which may not be the same
925 -- subtype as the subtype for the final aggregate.
928 -- In the following we determine whether an others choice is
929 -- allowed inside the array aggregate. The test checks the context
930 -- in which the array aggregate occurs. If the context does not
931 -- permit it, or the aggregate type is unconstrained, an others
932 -- choice is not allowed.
934 -- Note that there is no node for Explicit_Actual_Parameter.
935 -- To test for this context we therefore have to test for node
936 -- N_Parameter_Association which itself appears only if there is a
937 -- formal parameter. Consequently we also need to test for
938 -- N_Procedure_Call_Statement or N_Function_Call.
940 if Is_Constrained (Typ) and then
941 (Pkind = N_Assignment_Statement or else
942 Pkind = N_Parameter_Association or else
943 Pkind = N_Function_Call or else
944 Pkind = N_Procedure_Call_Statement or else
945 Pkind = N_Generic_Association or else
946 Pkind = N_Formal_Object_Declaration or else
947 Pkind = N_Return_Statement or else
948 Pkind = N_Object_Declaration or else
949 Pkind = N_Component_Declaration or else
950 Pkind = N_Parameter_Specification or else
951 Pkind = N_Qualified_Expression or else
952 Pkind = N_Aggregate or else
953 Pkind = N_Extension_Aggregate or else
954 Pkind = N_Component_Association)
957 Resolve_Array_Aggregate
959 Index => First_Index (Aggr_Typ),
960 Index_Constr => First_Index (Typ),
961 Component_Typ => Component_Type (Typ),
962 Others_Allowed => True);
966 Resolve_Array_Aggregate
968 Index => First_Index (Aggr_Typ),
969 Index_Constr => First_Index (Aggr_Typ),
970 Component_Typ => Component_Type (Typ),
971 Others_Allowed => False);
974 if not Aggr_Resolved then
975 Aggr_Subtyp := Any_Composite;
977 Aggr_Subtyp := Array_Aggr_Subtype (N, Typ);
980 Set_Etype (N, Aggr_Subtyp);
984 Error_Msg_N ("illegal context for aggregate", N);
988 -- If we can determine statically that the evaluation of the
989 -- aggregate raises Constraint_Error, then replace the
990 -- aggregate with an N_Raise_Constraint_Error node, but set the
991 -- Etype to the right aggregate subtype. Gigi needs this.
993 if Raises_Constraint_Error (N) then
994 Aggr_Subtyp := Etype (N);
996 Make_Raise_Constraint_Error (Sloc (N),
997 Reason => CE_Range_Check_Failed));
998 Set_Raises_Constraint_Error (N);
999 Set_Etype (N, Aggr_Subtyp);
1003 end Resolve_Aggregate;
1005 -----------------------------
1006 -- Resolve_Array_Aggregate --
1007 -----------------------------
1009 function Resolve_Array_Aggregate
1012 Index_Constr : Node_Id;
1013 Component_Typ : Entity_Id;
1014 Others_Allowed : Boolean)
1017 Loc : constant Source_Ptr := Sloc (N);
1019 Failure : constant Boolean := False;
1020 Success : constant Boolean := True;
1022 Index_Typ : constant Entity_Id := Etype (Index);
1023 Index_Typ_Low : constant Node_Id := Type_Low_Bound (Index_Typ);
1024 Index_Typ_High : constant Node_Id := Type_High_Bound (Index_Typ);
1025 -- The type of the index corresponding to the array sub-aggregate
1026 -- along with its low and upper bounds
1028 Index_Base : constant Entity_Id := Base_Type (Index_Typ);
1029 Index_Base_Low : constant Node_Id := Type_Low_Bound (Index_Base);
1030 Index_Base_High : constant Node_Id := Type_High_Bound (Index_Base);
1031 -- ditto for the base type
1033 function Add (Val : Uint; To : Node_Id) return Node_Id;
1034 -- Creates a new expression node where Val is added to expression To.
1035 -- Tries to constant fold whenever possible. To must be an already
1036 -- analyzed expression.
1038 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id);
1039 -- Checks that AH (the upper bound of an array aggregate) is <= BH
1040 -- (the upper bound of the index base type). If the check fails a
1041 -- warning is emitted, the Raises_Constraint_Error Flag of N is set,
1042 -- and AH is replaced with a duplicate of BH.
1044 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id);
1045 -- Checks that range AL .. AH is compatible with range L .. H. Emits a
1046 -- warning if not and sets the Raises_Constraint_Error Flag in N.
1048 procedure Check_Length (L, H : Node_Id; Len : Uint);
1049 -- Checks that range L .. H contains at least Len elements. Emits a
1050 -- warning if not and sets the Raises_Constraint_Error Flag in N.
1052 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean;
1053 -- Returns True if range L .. H is dynamic or null.
1055 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean);
1056 -- Given expression node From, this routine sets OK to False if it
1057 -- cannot statically evaluate From. Otherwise it stores this static
1058 -- value into Value.
1060 function Resolve_Aggr_Expr
1062 Single_Elmt : Boolean)
1064 -- Resolves aggregate expression Expr. Returs False if resolution
1065 -- fails. If Single_Elmt is set to False, the expression Expr may be
1066 -- used to initialize several array aggregate elements (this can
1067 -- happen for discrete choices such as "L .. H => Expr" or the others
1068 -- choice). In this event we do not resolve Expr unless expansion is
1069 -- disabled. To know why, see the DELAYED COMPONENT RESOLUTION
1076 function Add (Val : Uint; To : Node_Id) return Node_Id is
1082 if Raises_Constraint_Error (To) then
1086 -- First test if we can do constant folding
1088 if Compile_Time_Known_Value (To)
1089 or else Nkind (To) = N_Integer_Literal
1091 Expr_Pos := Make_Integer_Literal (Loc, Expr_Value (To) + Val);
1092 Set_Is_Static_Expression (Expr_Pos);
1093 Set_Etype (Expr_Pos, Etype (To));
1094 Set_Analyzed (Expr_Pos, Analyzed (To));
1096 if not Is_Enumeration_Type (Index_Typ) then
1099 -- If we are dealing with enumeration return
1100 -- Index_Typ'Val (Expr_Pos)
1104 Make_Attribute_Reference
1106 Prefix => New_Reference_To (Index_Typ, Loc),
1107 Attribute_Name => Name_Val,
1108 Expressions => New_List (Expr_Pos));
1114 -- If we are here no constant folding possible
1116 if not Is_Enumeration_Type (Index_Base) then
1119 Left_Opnd => Duplicate_Subexpr (To),
1120 Right_Opnd => Make_Integer_Literal (Loc, Val));
1122 -- If we are dealing with enumeration return
1123 -- Index_Typ'Val (Index_Typ'Pos (To) + Val)
1127 Make_Attribute_Reference
1129 Prefix => New_Reference_To (Index_Typ, Loc),
1130 Attribute_Name => Name_Pos,
1131 Expressions => New_List (Duplicate_Subexpr (To)));
1135 Left_Opnd => To_Pos,
1136 Right_Opnd => Make_Integer_Literal (Loc, Val));
1139 Make_Attribute_Reference
1141 Prefix => New_Reference_To (Index_Typ, Loc),
1142 Attribute_Name => Name_Val,
1143 Expressions => New_List (Expr_Pos));
1153 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id) is
1161 Get (Value => Val_BH, From => BH, OK => OK_BH);
1162 Get (Value => Val_AH, From => AH, OK => OK_AH);
1164 if OK_BH and then OK_AH and then Val_BH < Val_AH then
1165 Set_Raises_Constraint_Error (N);
1166 Error_Msg_N ("upper bound out of range?", AH);
1167 Error_Msg_N ("Constraint_Error will be raised at run-time?", AH);
1169 -- You need to set AH to BH or else in the case of enumerations
1170 -- indices we will not be able to resolve the aggregate bounds.
1172 AH := Duplicate_Subexpr (BH);
1180 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id) is
1192 if Raises_Constraint_Error (N)
1193 or else Dynamic_Or_Null_Range (AL, AH)
1198 Get (Value => Val_L, From => L, OK => OK_L);
1199 Get (Value => Val_H, From => H, OK => OK_H);
1201 Get (Value => Val_AL, From => AL, OK => OK_AL);
1202 Get (Value => Val_AH, From => AH, OK => OK_AH);
1204 if OK_L and then Val_L > Val_AL then
1205 Set_Raises_Constraint_Error (N);
1206 Error_Msg_N ("lower bound of aggregate out of range?", N);
1207 Error_Msg_N ("Constraint_Error will be raised at run-time?", N);
1210 if OK_H and then Val_H < Val_AH then
1211 Set_Raises_Constraint_Error (N);
1212 Error_Msg_N ("upper bound of aggregate out of range?", N);
1213 Error_Msg_N ("Constraint_Error will be raised at run-time?", N);
1221 procedure Check_Length (L, H : Node_Id; Len : Uint) is
1231 if Raises_Constraint_Error (N) then
1235 Get (Value => Val_L, From => L, OK => OK_L);
1236 Get (Value => Val_H, From => H, OK => OK_H);
1238 if not OK_L or else not OK_H then
1242 -- If null range length is zero
1244 if Val_L > Val_H then
1245 Range_Len := Uint_0;
1247 Range_Len := Val_H - Val_L + 1;
1250 if Range_Len < Len then
1251 Set_Raises_Constraint_Error (N);
1252 Error_Msg_N ("Too many elements?", N);
1253 Error_Msg_N ("Constraint_Error will be raised at run-time?", N);
1257 ---------------------------
1258 -- Dynamic_Or_Null_Range --
1259 ---------------------------
1261 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean is
1269 Get (Value => Val_L, From => L, OK => OK_L);
1270 Get (Value => Val_H, From => H, OK => OK_H);
1272 return not OK_L or else not OK_H
1273 or else not Is_OK_Static_Expression (L)
1274 or else not Is_OK_Static_Expression (H)
1275 or else Val_L > Val_H;
1276 end Dynamic_Or_Null_Range;
1282 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean) is
1286 if Compile_Time_Known_Value (From) then
1287 Value := Expr_Value (From);
1289 -- If expression From is something like Some_Type'Val (10) then
1292 elsif Nkind (From) = N_Attribute_Reference
1293 and then Attribute_Name (From) = Name_Val
1294 and then Compile_Time_Known_Value (First (Expressions (From)))
1296 Value := Expr_Value (First (Expressions (From)));
1304 -----------------------
1305 -- Resolve_Aggr_Expr --
1306 -----------------------
1308 function Resolve_Aggr_Expr
1310 Single_Elmt : Boolean)
1313 Nxt_Ind : Node_Id := Next_Index (Index);
1314 Nxt_Ind_Constr : Node_Id := Next_Index (Index_Constr);
1315 -- Index is the current index corresponding to the expression.
1317 Resolution_OK : Boolean := True;
1318 -- Set to False if resolution of the expression failed.
1321 -- If the array type against which we are resolving the aggregate
1322 -- has several dimensions, the expressions nested inside the
1323 -- aggregate must be further aggregates (or strings).
1325 if Present (Nxt_Ind) then
1326 if Nkind (Expr) /= N_Aggregate then
1328 -- A string literal can appear where a one-dimensional array
1329 -- of characters is expected. If the literal looks like an
1330 -- operator, it is still an operator symbol, which will be
1331 -- transformed into a string when analyzed.
1333 if Is_Character_Type (Component_Typ)
1334 and then No (Next_Index (Nxt_Ind))
1335 and then (Nkind (Expr) = N_String_Literal
1336 or else Nkind (Expr) = N_Operator_Symbol)
1338 -- A string literal used in a multidimensional array
1339 -- aggregate in place of the final one-dimensional
1340 -- aggregate must not be enclosed in parentheses.
1342 if Paren_Count (Expr) /= 0 then
1343 Error_Msg_N ("No parenthesis allowed here", Expr);
1346 Make_String_Into_Aggregate (Expr);
1349 Error_Msg_N ("nested array aggregate expected", Expr);
1354 Resolution_OK := Resolve_Array_Aggregate
1355 (Expr, Nxt_Ind, Nxt_Ind_Constr, Component_Typ, Others_Allowed);
1357 -- Do not resolve the expressions of discrete or others choices
1358 -- unless the expression covers a single component, or the expander
1362 or else not Expander_Active
1363 or else In_Default_Expression
1365 Analyze_And_Resolve (Expr, Component_Typ);
1366 Check_Non_Static_Context (Expr);
1367 Aggregate_Constraint_Checks (Expr, Component_Typ);
1370 if Raises_Constraint_Error (Expr)
1371 and then Nkind (Parent (Expr)) /= N_Component_Association
1373 Set_Raises_Constraint_Error (N);
1376 return Resolution_OK;
1377 end Resolve_Aggr_Expr;
1379 -- Variables local to Resolve_Array_Aggregate
1385 Who_Cares : Node_Id;
1387 Aggr_Low : Node_Id := Empty;
1388 Aggr_High : Node_Id := Empty;
1389 -- The actual low and high bounds of this sub-aggegate
1391 Choices_Low : Node_Id := Empty;
1392 Choices_High : Node_Id := Empty;
1393 -- The lowest and highest discrete choices values for a named aggregate
1395 Nb_Elements : Uint := Uint_0;
1396 -- The number of elements in a positional aggegate
1398 Others_Present : Boolean := False;
1400 Nb_Choices : Nat := 0;
1401 -- Contains the overall number of named choices in this sub-aggregate
1403 Nb_Discrete_Choices : Nat := 0;
1404 -- The overall number of discrete choices (not counting others choice)
1406 Case_Table_Size : Nat;
1407 -- Contains the size of the case table needed to sort aggregate choices
1409 -- Start of processing for Resolve_Array_Aggregate
1412 -- STEP 1: make sure the aggregate is correctly formatted
1414 if Present (Component_Associations (N)) then
1415 Assoc := First (Component_Associations (N));
1416 while Present (Assoc) loop
1417 Choice := First (Choices (Assoc));
1418 while Present (Choice) loop
1419 if Nkind (Choice) = N_Others_Choice then
1420 Others_Present := True;
1422 if Choice /= First (Choices (Assoc))
1423 or else Present (Next (Choice))
1426 ("OTHERS must appear alone in a choice list", Choice);
1430 if Present (Next (Assoc)) then
1432 ("OTHERS must appear last in an aggregate", Choice);
1437 and then Assoc /= First (Component_Associations (N))
1438 and then (Nkind (Parent (N)) = N_Assignment_Statement
1440 Nkind (Parent (N)) = N_Object_Declaration)
1443 ("(Ada 83) illegal context for OTHERS choice", N);
1447 Nb_Choices := Nb_Choices + 1;
1455 -- At this point we know that the others choice, if present, is by
1456 -- itself and appears last in the aggregate. Check if we have mixed
1457 -- positional and discrete associations (other than the others choice).
1459 if Present (Expressions (N))
1460 and then (Nb_Choices > 1
1461 or else (Nb_Choices = 1 and then not Others_Present))
1464 ("named association cannot follow positional association",
1465 First (Choices (First (Component_Associations (N)))));
1469 -- Test for the validity of an others choice if present
1471 if Others_Present and then not Others_Allowed then
1473 ("OTHERS choice not allowed here",
1474 First (Choices (First (Component_Associations (N)))));
1478 -- Protect against cascaded errors
1480 if Etype (Index_Typ) = Any_Type then
1484 -- STEP 2: Process named components
1486 if No (Expressions (N)) then
1488 if Others_Present then
1489 Case_Table_Size := Nb_Choices - 1;
1491 Case_Table_Size := Nb_Choices;
1497 -- Denote the lowest and highest values in an aggregate choice
1501 -- High end of one range and Low end of the next. Should be
1502 -- contiguous if there is no hole in the list of values.
1504 Missing_Values : Boolean;
1505 -- Set True if missing index values
1507 S_Low : Node_Id := Empty;
1508 S_High : Node_Id := Empty;
1509 -- if a choice in an aggregate is a subtype indication these
1510 -- denote the lowest and highest values of the subtype
1512 Table : Case_Table_Type (1 .. Case_Table_Size);
1513 -- Used to sort all the different choice values
1515 Single_Choice : Boolean;
1516 -- Set to true every time there is a single discrete choice in a
1517 -- discrete association
1519 Prev_Nb_Discrete_Choices : Nat;
1520 -- Used to keep track of the number of discrete choices
1521 -- in the current association.
1524 -- STEP 2 (A): Check discrete choices validity.
1526 Assoc := First (Component_Associations (N));
1527 while Present (Assoc) loop
1529 Prev_Nb_Discrete_Choices := Nb_Discrete_Choices;
1530 Choice := First (Choices (Assoc));
1534 if Nkind (Choice) = N_Others_Choice then
1535 Single_Choice := False;
1538 -- Test for subtype mark without constraint
1540 elsif Is_Entity_Name (Choice) and then
1541 Is_Type (Entity (Choice))
1543 if Base_Type (Entity (Choice)) /= Index_Base then
1545 ("invalid subtype mark in aggregate choice",
1550 elsif Nkind (Choice) = N_Subtype_Indication then
1551 Resolve_Discrete_Subtype_Indication (Choice, Index_Base);
1553 -- Does the subtype indication evaluation raise CE ?
1555 Get_Index_Bounds (Subtype_Mark (Choice), S_Low, S_High);
1556 Get_Index_Bounds (Choice, Low, High);
1557 Check_Bounds (S_Low, S_High, Low, High);
1559 else -- Choice is a range or an expression
1560 Resolve (Choice, Index_Base);
1561 Check_Non_Static_Context (Choice);
1563 -- Do not range check a choice. This check is redundant
1564 -- since this test is already performed when we check
1565 -- that the bounds of the array aggregate are within
1568 Set_Do_Range_Check (Choice, False);
1571 -- If we could not resolve the discrete choice stop here
1573 if Etype (Choice) = Any_Type then
1576 -- If the discrete choice raises CE get its original bounds.
1578 elsif Nkind (Choice) = N_Raise_Constraint_Error then
1579 Set_Raises_Constraint_Error (N);
1580 Get_Index_Bounds (Original_Node (Choice), Low, High);
1582 -- Otherwise get its bounds as usual
1585 Get_Index_Bounds (Choice, Low, High);
1588 if (Dynamic_Or_Null_Range (Low, High)
1589 or else (Nkind (Choice) = N_Subtype_Indication
1591 Dynamic_Or_Null_Range (S_Low, S_High)))
1592 and then Nb_Choices /= 1
1595 ("dynamic or empty choice in aggregate " &
1596 "must be the only choice", Choice);
1600 Nb_Discrete_Choices := Nb_Discrete_Choices + 1;
1601 Table (Nb_Discrete_Choices).Choice_Lo := Low;
1602 Table (Nb_Discrete_Choices).Choice_Hi := High;
1607 -- Check if we have a single discrete choice and whether
1608 -- this discrete choice specifies a single value.
1611 (Nb_Discrete_Choices = Prev_Nb_Discrete_Choices + 1)
1612 and then (Low = High);
1620 (Expression (Assoc), Single_Elmt => Single_Choice)
1628 -- If aggregate contains more than one choice then these must be
1629 -- static. Sort them and check that they are contiguous
1631 if Nb_Discrete_Choices > 1 then
1632 Sort_Case_Table (Table);
1633 Missing_Values := False;
1635 Outer : for J in 1 .. Nb_Discrete_Choices - 1 loop
1636 if Expr_Value (Table (J).Choice_Hi) >=
1637 Expr_Value (Table (J + 1).Choice_Lo)
1640 ("duplicate choice values in array aggregate",
1641 Table (J).Choice_Hi);
1644 elsif not Others_Present then
1646 Hi_Val := Expr_Value (Table (J).Choice_Hi);
1647 Lo_Val := Expr_Value (Table (J + 1).Choice_Lo);
1649 -- If missing values, output error messages
1651 if Lo_Val - Hi_Val > 1 then
1653 -- Header message if not first missing value
1655 if not Missing_Values then
1657 ("missing index value(s) in array aggregate", N);
1658 Missing_Values := True;
1661 -- Output values of missing indexes
1663 Lo_Val := Lo_Val - 1;
1664 Hi_Val := Hi_Val + 1;
1666 -- Enumeration type case
1668 if Is_Enumeration_Type (Index_Typ) then
1671 (Get_Enum_Lit_From_Pos
1672 (Index_Typ, Hi_Val, Loc));
1674 if Lo_Val = Hi_Val then
1675 Error_Msg_N ("\ %", N);
1679 (Get_Enum_Lit_From_Pos
1680 (Index_Typ, Lo_Val, Loc));
1681 Error_Msg_N ("\ % .. %", N);
1684 -- Integer types case
1687 Error_Msg_Uint_1 := Hi_Val;
1689 if Lo_Val = Hi_Val then
1690 Error_Msg_N ("\ ^", N);
1692 Error_Msg_Uint_2 := Lo_Val;
1693 Error_Msg_N ("\ ^ .. ^", N);
1700 if Missing_Values then
1701 Set_Etype (N, Any_Composite);
1706 -- STEP 2 (B): Compute aggregate bounds and min/max choices values
1708 if Nb_Discrete_Choices > 0 then
1709 Choices_Low := Table (1).Choice_Lo;
1710 Choices_High := Table (Nb_Discrete_Choices).Choice_Hi;
1713 if Others_Present then
1714 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
1717 Aggr_Low := Choices_Low;
1718 Aggr_High := Choices_High;
1722 -- STEP 3: Process positional components
1725 -- STEP 3 (A): Process positional elements
1727 Expr := First (Expressions (N));
1728 Nb_Elements := Uint_0;
1729 while Present (Expr) loop
1730 Nb_Elements := Nb_Elements + 1;
1732 if not Resolve_Aggr_Expr (Expr, Single_Elmt => True) then
1739 if Others_Present then
1740 Assoc := Last (Component_Associations (N));
1741 if not Resolve_Aggr_Expr (Expression (Assoc),
1742 Single_Elmt => False)
1748 -- STEP 3 (B): Compute the aggregate bounds
1750 if Others_Present then
1751 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
1754 if Others_Allowed then
1755 Get_Index_Bounds (Index_Constr, Aggr_Low, Who_Cares);
1757 Aggr_Low := Index_Typ_Low;
1760 Aggr_High := Add (Nb_Elements - 1, To => Aggr_Low);
1761 Check_Bound (Index_Base_High, Aggr_High);
1765 -- STEP 4: Perform static aggregate checks and save the bounds
1769 Check_Bounds (Index_Typ_Low, Index_Typ_High, Aggr_Low, Aggr_High);
1770 Check_Bounds (Index_Base_Low, Index_Base_High, Aggr_Low, Aggr_High);
1774 if Others_Present and then Nb_Discrete_Choices > 0 then
1775 Check_Bounds (Aggr_Low, Aggr_High, Choices_Low, Choices_High);
1776 Check_Bounds (Index_Typ_Low, Index_Typ_High,
1777 Choices_Low, Choices_High);
1778 Check_Bounds (Index_Base_Low, Index_Base_High,
1779 Choices_Low, Choices_High);
1783 elsif Others_Present and then Nb_Elements > 0 then
1784 Check_Length (Aggr_Low, Aggr_High, Nb_Elements);
1785 Check_Length (Index_Typ_Low, Index_Typ_High, Nb_Elements);
1786 Check_Length (Index_Base_Low, Index_Base_High, Nb_Elements);
1790 if Raises_Constraint_Error (Aggr_Low)
1791 or else Raises_Constraint_Error (Aggr_High)
1793 Set_Raises_Constraint_Error (N);
1796 Aggr_Low := Duplicate_Subexpr (Aggr_Low);
1798 -- Do not duplicate Aggr_High if Aggr_High = Aggr_Low + Nb_Elements
1799 -- since the addition node returned by Add is not yet analyzed. Attach
1800 -- to tree and analyze first. Reset analyzed flag to insure it will get
1801 -- analyzed when it is a literal bound whose type must be properly
1804 if Others_Present or else Nb_Discrete_Choices > 0 then
1805 Aggr_High := Duplicate_Subexpr (Aggr_High);
1807 if Etype (Aggr_High) = Universal_Integer then
1808 Set_Analyzed (Aggr_High, False);
1812 Set_Aggregate_Bounds
1813 (N, Make_Range (Loc, Low_Bound => Aggr_Low, High_Bound => Aggr_High));
1815 -- The bounds may contain expressions that must be inserted upwards.
1816 -- Attach them fully to the tree. After analysis, remove side effects
1817 -- from upper bound, if still needed.
1819 Set_Parent (Aggregate_Bounds (N), N);
1820 Analyze_And_Resolve (Aggregate_Bounds (N), Index_Typ);
1822 if not Others_Present and then Nb_Discrete_Choices = 0 then
1823 Set_High_Bound (Aggregate_Bounds (N),
1824 Duplicate_Subexpr (High_Bound (Aggregate_Bounds (N))));
1828 end Resolve_Array_Aggregate;
1830 ---------------------------------
1831 -- Resolve_Extension_Aggregate --
1832 ---------------------------------
1834 -- There are two cases to consider:
1836 -- a) If the ancestor part is a type mark, the components needed are
1837 -- the difference between the components of the expected type and the
1838 -- components of the given type mark.
1840 -- b) If the ancestor part is an expression, it must be unambiguous,
1841 -- and once we have its type we can also compute the needed components
1842 -- as in the previous case. In both cases, if the ancestor type is not
1843 -- the immediate ancestor, we have to build this ancestor recursively.
1845 -- In both cases discriminants of the ancestor type do not play a
1846 -- role in the resolution of the needed components, because inherited
1847 -- discriminants cannot be used in a type extension. As a result we can
1848 -- compute independently the list of components of the ancestor type and
1849 -- of the expected type.
1851 procedure Resolve_Extension_Aggregate (N : Node_Id; Typ : Entity_Id) is
1852 A : constant Node_Id := Ancestor_Part (N);
1856 Imm_Type : Entity_Id;
1858 function Valid_Ancestor_Type return Boolean;
1859 -- Verify that the type of the ancestor part is a non-private ancestor
1860 -- of the expected type.
1862 function Valid_Ancestor_Type return Boolean is
1863 Imm_Type : Entity_Id;
1866 Imm_Type := Base_Type (Typ);
1867 while Is_Derived_Type (Imm_Type)
1868 and then Etype (Imm_Type) /= Base_Type (A_Type)
1870 Imm_Type := Etype (Base_Type (Imm_Type));
1873 if Etype (Imm_Type) /= Base_Type (A_Type) then
1874 Error_Msg_NE ("expect ancestor type of &", A, Typ);
1879 end Valid_Ancestor_Type;
1881 -- Start of processing for Resolve_Extension_Aggregate
1886 if not Is_Tagged_Type (Typ) then
1887 Error_Msg_N ("type of extension aggregate must be tagged", N);
1890 elsif Is_Limited_Type (Typ) then
1891 Error_Msg_N ("aggregate type cannot be limited", N);
1894 elsif Is_Class_Wide_Type (Typ) then
1895 Error_Msg_N ("aggregate cannot be of a class-wide type", N);
1899 if Is_Entity_Name (A)
1900 and then Is_Type (Entity (A))
1902 A_Type := Get_Full_View (Entity (A));
1903 Imm_Type := Base_Type (Typ);
1905 if Valid_Ancestor_Type then
1906 Set_Entity (A, A_Type);
1907 Set_Etype (A, A_Type);
1909 Validate_Ancestor_Part (N);
1910 Resolve_Record_Aggregate (N, Typ);
1913 elsif Nkind (A) /= N_Aggregate then
1914 if Is_Overloaded (A) then
1916 Get_First_Interp (A, I, It);
1918 while Present (It.Typ) loop
1920 if Is_Tagged_Type (It.Typ)
1921 and then not Is_Limited_Type (It.Typ)
1923 if A_Type /= Any_Type then
1924 Error_Msg_N ("cannot resolve expression", A);
1931 Get_Next_Interp (I, It);
1934 if A_Type = Any_Type then
1936 ("ancestor part must be non-limited tagged type", A);
1941 A_Type := Etype (A);
1944 if Valid_Ancestor_Type then
1945 Resolve (A, A_Type);
1946 Check_Non_Static_Context (A);
1947 Resolve_Record_Aggregate (N, Typ);
1951 Error_Msg_N (" No unique type for this aggregate", A);
1954 end Resolve_Extension_Aggregate;
1956 ------------------------------
1957 -- Resolve_Record_Aggregate --
1958 ------------------------------
1960 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id) is
1961 Regular_Aggr : constant Boolean := Nkind (N) /= N_Extension_Aggregate;
1963 New_Assoc_List : List_Id := New_List;
1964 New_Assoc : Node_Id;
1965 -- New_Assoc_List is the newly built list of N_Component_Association
1966 -- nodes. New_Assoc is one such N_Component_Association node in it.
1967 -- Please note that while Assoc and New_Assoc contain the same
1968 -- kind of nodes, they are used to iterate over two different
1969 -- N_Component_Association lists.
1971 Others_Etype : Entity_Id := Empty;
1972 -- This variable is used to save the Etype of the last record component
1973 -- that takes its value from the others choice. Its purpose is:
1975 -- (a) make sure the others choice is useful
1977 -- (b) make sure the type of all the components whose value is
1978 -- subsumed by the others choice are the same.
1980 -- This variable is updated as a side effect of function Get_Value
1982 procedure Add_Association (Component : Entity_Id; Expr : Node_Id);
1983 -- Builds a new N_Component_Association node which associates
1984 -- Component to expression Expr and adds it to the new association
1985 -- list New_Assoc_List being built.
1987 function Discr_Present (Discr : Entity_Id) return Boolean;
1988 -- If aggregate N is a regular aggregate this routine will return True.
1989 -- Otherwise, if N is an extension aggreagte, Discr is a discriminant
1990 -- whose value may already have been specified by N's ancestor part,
1991 -- this routine checks whether this is indeed the case and if so
1992 -- returns False, signaling that no value for Discr should appear in the
1993 -- N's aggregate part. Also, in this case, the routine appends to
1994 -- New_Assoc_List Discr the discriminant value specified in the ancestor
2000 Consider_Others_Choice : Boolean := False)
2002 -- Given a record component stored in parameter Compon, the
2003 -- following function returns its value as it appears in the list
2004 -- From, which is a list of N_Component_Association nodes. If no
2005 -- component association has a choice for the searched component,
2006 -- the value provided by the others choice is returned, if there
2007 -- is one and Consider_Others_Choice is set to true. Otherwise
2008 -- Empty is returned. If there is more than one component association
2009 -- giving a value for the searched record component, an error message
2010 -- is emitted and the first found value is returned.
2012 -- If Consider_Others_Choice is set and the returned expression comes
2013 -- from the others choice, then Others_Etype is set as a side effect.
2014 -- An error message is emitted if the components taking their value
2015 -- from the others choice do not have same type.
2017 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id);
2018 -- Analyzes and resolves expression Expr against the Etype of the
2019 -- Component. This routine also applies all appropriate checks to Expr.
2020 -- It finally saves a Expr in the newly created association list that
2021 -- will be attached to the final record aggregate. Note that if the
2022 -- Parent pointer of Expr is not set then Expr was produced with a
2023 -- New_copy_Tree or some such.
2025 ---------------------
2026 -- Add_Association --
2027 ---------------------
2029 procedure Add_Association (Component : Entity_Id; Expr : Node_Id) is
2030 New_Assoc : Node_Id;
2031 Choice_List : List_Id := New_List;
2034 Append (New_Occurrence_Of (Component, Sloc (Expr)), Choice_List);
2036 Make_Component_Association (Sloc (Expr),
2037 Choices => Choice_List,
2038 Expression => Expr);
2039 Append (New_Assoc, New_Assoc_List);
2040 end Add_Association;
2046 function Discr_Present (Discr : Entity_Id) return Boolean is
2050 Discr_Expr : Node_Id;
2052 Ancestor_Typ : Entity_Id;
2053 Orig_Discr : Entity_Id;
2055 D_Val : Elmt_Id := No_Elmt; -- stop junk warning
2057 Ancestor_Is_Subtyp : Boolean;
2060 if Regular_Aggr then
2064 Ancestor := Ancestor_Part (N);
2065 Ancestor_Typ := Etype (Ancestor);
2066 Loc := Sloc (Ancestor);
2068 Ancestor_Is_Subtyp :=
2069 Is_Entity_Name (Ancestor) and then Is_Type (Entity (Ancestor));
2071 -- If the ancestor part has no discriminants clearly N's aggregate
2072 -- part must provide a value for Discr.
2074 if not Has_Discriminants (Ancestor_Typ) then
2077 -- If the ancestor part is an unconstrained subtype mark then the
2078 -- Discr must be present in N's aggregate part.
2080 elsif Ancestor_Is_Subtyp
2081 and then not Is_Constrained (Entity (Ancestor))
2086 -- Now look to see if Discr was specified in the ancestor part.
2088 Orig_Discr := Original_Record_Component (Discr);
2089 D := First_Discriminant (Ancestor_Typ);
2091 if Ancestor_Is_Subtyp then
2092 D_Val := First_Elmt (Discriminant_Constraint (Entity (Ancestor)));
2095 while Present (D) loop
2096 -- If Ancestor has already specified Disc value than
2097 -- insert its value in the final aggregate.
2099 if Original_Record_Component (D) = Orig_Discr then
2100 if Ancestor_Is_Subtyp then
2101 Discr_Expr := New_Copy_Tree (Node (D_Val));
2104 Make_Selected_Component (Loc,
2105 Prefix => Duplicate_Subexpr (Ancestor),
2106 Selector_Name => New_Occurrence_Of (Discr, Loc));
2109 Resolve_Aggr_Expr (Discr_Expr, Discr);
2113 Next_Discriminant (D);
2115 if Ancestor_Is_Subtyp then
2130 Consider_Others_Choice : Boolean := False)
2134 Expr : Node_Id := Empty;
2135 Selector_Name : Node_Id;
2138 if Present (From) then
2139 Assoc := First (From);
2144 while Present (Assoc) loop
2145 Selector_Name := First (Choices (Assoc));
2146 while Present (Selector_Name) loop
2147 if Nkind (Selector_Name) = N_Others_Choice then
2148 if Consider_Others_Choice and then No (Expr) then
2149 if Present (Others_Etype) and then
2150 Base_Type (Others_Etype) /= Base_Type (Etype (Compon))
2152 Error_Msg_N ("components in OTHERS choice must " &
2153 "have same type", Selector_Name);
2156 Others_Etype := Etype (Compon);
2158 -- We need to duplicate the expression for each
2159 -- successive component covered by the others choice.
2160 -- If the expression is itself an array aggregate with
2161 -- "others", its subtype must be obtained from the
2162 -- current component, and therefore it must be (at least
2163 -- partly) reanalyzed.
2165 if Analyzed (Expression (Assoc)) then
2166 Expr := New_Copy_Tree (Expression (Assoc));
2168 if Nkind (Expr) = N_Aggregate
2169 and then Is_Array_Type (Etype (Expr))
2170 and then No (Expressions (Expr))
2172 Nkind (First (Choices
2173 (First (Component_Associations (Expr)))))
2176 Set_Analyzed (Expr, False);
2182 return Expression (Assoc);
2186 elsif Chars (Compon) = Chars (Selector_Name) then
2188 -- We need to duplicate the expression when several
2189 -- components are grouped together with a "|" choice.
2190 -- For instance "filed1 | filed2 => Expr"
2192 if Present (Next (Selector_Name)) then
2193 Expr := New_Copy_Tree (Expression (Assoc));
2195 Expr := Expression (Assoc);
2200 ("more than one value supplied for &",
2201 Selector_Name, Compon);
2206 Next (Selector_Name);
2215 -----------------------
2216 -- Resolve_Aggr_Expr --
2217 -----------------------
2219 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id) is
2220 New_C : Entity_Id := Component;
2221 Expr_Type : Entity_Id := Empty;
2223 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean;
2224 -- If the expression is an aggregate (possibly qualified) then its
2225 -- expansion is delayed until the enclosing aggregate is expanded
2226 -- into assignments. In that case, do not generate checks on the
2227 -- expression, because they will be generated later, and will other-
2228 -- wise force a copy (to remove side-effects) that would leave a
2229 -- dynamic-sized aggregate in the code, something that gigi cannot
2233 -- Set to True if the resolved Expr node needs to be relocated
2234 -- when attached to the newly created association list. This node
2235 -- need not be relocated if its parent pointer is not set.
2236 -- In fact in this case Expr is the output of a New_Copy_Tree call.
2237 -- if Relocate is True then we have analyzed the expression node
2238 -- in the original aggregate and hence it needs to be relocated
2239 -- when moved over the new association list.
2241 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean is
2242 Kind : constant Node_Kind := Nkind (Expr);
2245 return ((Kind = N_Aggregate
2246 or else Kind = N_Extension_Aggregate)
2247 and then Present (Etype (Expr))
2248 and then Is_Record_Type (Etype (Expr))
2249 and then Expansion_Delayed (Expr))
2251 or else (Kind = N_Qualified_Expression
2252 and then Has_Expansion_Delayed (Expression (Expr)));
2253 end Has_Expansion_Delayed;
2255 -- Start of processing for Resolve_Aggr_Expr
2258 -- If the type of the component is elementary or the type of the
2259 -- aggregate does not contain discriminants, use the type of the
2260 -- component to resolve Expr.
2262 if Is_Elementary_Type (Etype (Component))
2263 or else not Has_Discriminants (Etype (N))
2265 Expr_Type := Etype (Component);
2267 -- Otherwise we have to pick up the new type of the component from
2268 -- the new costrained subtype of the aggregate. In fact components
2269 -- which are of a composite type might be constrained by a
2270 -- discriminant, and we want to resolve Expr against the subtype were
2271 -- all discriminant occurrences are replaced with their actual value.
2274 New_C := First_Component (Etype (N));
2275 while Present (New_C) loop
2276 if Chars (New_C) = Chars (Component) then
2277 Expr_Type := Etype (New_C);
2281 Next_Component (New_C);
2284 pragma Assert (Present (Expr_Type));
2286 -- For each range in an array type where a discriminant has been
2287 -- replaced with the constraint, check that this range is within
2288 -- the range of the base type. This checks is done in the
2289 -- _init_proc for regular objects, but has to be done here for
2290 -- aggregates since no _init_proc is called for them.
2292 if Is_Array_Type (Expr_Type) then
2294 Index : Node_Id := First_Index (Expr_Type);
2295 -- Range of the current constrained index in the array.
2297 Orig_Index : Node_Id := First_Index (Etype (Component));
2298 -- Range corresponding to the range Index above in the
2299 -- original unconstrained record type. The bounds of this
2300 -- range may be governed by discriminants.
2302 Unconstr_Index : Node_Id := First_Index (Etype (Expr_Type));
2303 -- Range corresponding to the range Index above for the
2304 -- unconstrained array type. This range is needed to apply
2308 while Present (Index) loop
2309 if Depends_On_Discriminant (Orig_Index) then
2310 Apply_Range_Check (Index, Etype (Unconstr_Index));
2314 Next_Index (Orig_Index);
2315 Next_Index (Unconstr_Index);
2321 -- If the Parent pointer of Expr is not set, Expr is an expression
2322 -- duplicated by New_Tree_Copy (this happens for record aggregates
2323 -- that look like (Field1 | Filed2 => Expr) or (others => Expr)).
2324 -- Such a duplicated expression must be attached to the tree
2325 -- before analysis and resolution to enforce the rule that a tree
2326 -- fragment should never be analyzed or resolved unless it is
2327 -- attached to the current compilation unit.
2329 if No (Parent (Expr)) then
2330 Set_Parent (Expr, N);
2336 Analyze_And_Resolve (Expr, Expr_Type);
2337 Check_Non_Static_Context (Expr);
2339 if not Has_Expansion_Delayed (Expr) then
2340 Aggregate_Constraint_Checks (Expr, Expr_Type);
2343 if Raises_Constraint_Error (Expr) then
2344 Set_Raises_Constraint_Error (N);
2348 Add_Association (New_C, Relocate_Node (Expr));
2350 Add_Association (New_C, Expr);
2353 end Resolve_Aggr_Expr;
2355 -- Resolve_Record_Aggregate local variables
2358 -- N_Component_Association node belonging to the input aggregate N
2361 Positional_Expr : Node_Id;
2363 Component : Entity_Id;
2364 Component_Elmt : Elmt_Id;
2365 Components : Elist_Id := New_Elmt_List;
2366 -- Components is the list of the record components whose value must
2367 -- be provided in the aggregate. This list does include discriminants.
2369 -- Start of processing for Resolve_Record_Aggregate
2372 -- We may end up calling Duplicate_Subexpr on expressions that are
2373 -- attached to New_Assoc_List. For this reason we need to attach it
2374 -- to the tree by setting its parent pointer to N. This parent point
2375 -- will change in STEP 8 below.
2377 Set_Parent (New_Assoc_List, N);
2379 -- STEP 1: abstract type and null record verification
2381 if Is_Abstract (Typ) then
2382 Error_Msg_N ("type of aggregate cannot be abstract", N);
2385 if No (First_Entity (Typ)) and then Null_Record_Present (N) then
2389 elsif Present (First_Entity (Typ))
2390 and then Null_Record_Present (N)
2391 and then not Is_Tagged_Type (Typ)
2393 Error_Msg_N ("record aggregate cannot be null", N);
2396 elsif No (First_Entity (Typ)) then
2397 Error_Msg_N ("record aggregate must be null", N);
2401 -- STEP 2: Verify aggregate structure
2404 Selector_Name : Node_Id;
2405 Bad_Aggregate : Boolean := False;
2408 if Present (Component_Associations (N)) then
2409 Assoc := First (Component_Associations (N));
2414 while Present (Assoc) loop
2415 Selector_Name := First (Choices (Assoc));
2416 while Present (Selector_Name) loop
2417 if Nkind (Selector_Name) = N_Identifier then
2420 elsif Nkind (Selector_Name) = N_Others_Choice then
2421 if Selector_Name /= First (Choices (Assoc))
2422 or else Present (Next (Selector_Name))
2424 Error_Msg_N ("OTHERS must appear alone in a choice list",
2428 elsif Present (Next (Assoc)) then
2429 Error_Msg_N ("OTHERS must appear last in an aggregate",
2436 ("selector name should be identifier or OTHERS",
2438 Bad_Aggregate := True;
2441 Next (Selector_Name);
2447 if Bad_Aggregate then
2452 -- STEP 3: Find discriminant Values
2455 Discrim : Entity_Id;
2456 Missing_Discriminants : Boolean := False;
2459 if Present (Expressions (N)) then
2460 Positional_Expr := First (Expressions (N));
2462 Positional_Expr := Empty;
2465 if Has_Discriminants (Typ) then
2466 Discrim := First_Discriminant (Typ);
2471 -- First find the discriminant values in the positional components
2473 while Present (Discrim) and then Present (Positional_Expr) loop
2474 if Discr_Present (Discrim) then
2475 Resolve_Aggr_Expr (Positional_Expr, Discrim);
2476 Next (Positional_Expr);
2479 if Present (Get_Value (Discrim, Component_Associations (N))) then
2481 ("more than one value supplied for discriminant&",
2485 Next_Discriminant (Discrim);
2488 -- Find remaining discriminant values, if any, among named components
2490 while Present (Discrim) loop
2491 Expr := Get_Value (Discrim, Component_Associations (N), True);
2493 if not Discr_Present (Discrim) then
2494 if Present (Expr) then
2496 ("more than one value supplied for discriminant&",
2500 elsif No (Expr) then
2502 ("no value supplied for discriminant &", N, Discrim);
2503 Missing_Discriminants := True;
2506 Resolve_Aggr_Expr (Expr, Discrim);
2509 Next_Discriminant (Discrim);
2512 if Missing_Discriminants then
2516 -- At this point and until the beginning of STEP 6, New_Assoc_List
2517 -- contains only the discriminants and their values.
2521 -- STEP 4: Set the Etype of the record aggregate
2523 -- ??? This code is pretty much a copy of Sem_Ch3.Build_Subtype. That
2524 -- routine should really be exported in sem_util or some such and used
2525 -- in sem_ch3 and here rather than have a copy of the code which is a
2526 -- maintenance nightmare.
2528 -- ??? Performace WARNING. The current implementation creates a new
2529 -- itype for all aggregates whose base type is discriminated.
2530 -- This means that for record aggregates nested inside an array
2531 -- aggregate we will create a new itype for each record aggregate
2532 -- if the array cmponent type has discriminants. For large aggregates
2533 -- this may be a problem. What should be done in this case is
2534 -- to reuse itypes as much as possible.
2536 if Has_Discriminants (Typ) then
2537 Build_Constrained_Itype : declare
2538 Loc : constant Source_Ptr := Sloc (N);
2540 Subtyp_Decl : Node_Id;
2543 C : List_Id := New_List;
2546 New_Assoc := First (New_Assoc_List);
2547 while Present (New_Assoc) loop
2548 Append (Duplicate_Subexpr (Expression (New_Assoc)), To => C);
2553 Make_Subtype_Indication (Loc,
2554 Subtype_Mark => New_Occurrence_Of (Base_Type (Typ), Loc),
2555 Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
2557 Def_Id := Create_Itype (Ekind (Typ), N);
2560 Make_Subtype_Declaration (Loc,
2561 Defining_Identifier => Def_Id,
2562 Subtype_Indication => Indic);
2563 Set_Parent (Subtyp_Decl, Parent (N));
2565 -- Itypes must be analyzed with checks off (see itypes.ads).
2567 Analyze (Subtyp_Decl, Suppress => All_Checks);
2569 Set_Etype (N, Def_Id);
2570 Check_Static_Discriminated_Subtype
2571 (Def_Id, Expression (First (New_Assoc_List)));
2572 end Build_Constrained_Itype;
2578 -- STEP 5: Get remaining components according to discriminant values
2581 Record_Def : Node_Id;
2582 Parent_Typ : Entity_Id;
2583 Root_Typ : Entity_Id;
2584 Parent_Typ_List : Elist_Id;
2585 Parent_Elmt : Elmt_Id;
2586 Errors_Found : Boolean := False;
2590 if Is_Derived_Type (Typ) and then Is_Tagged_Type (Typ) then
2591 Parent_Typ_List := New_Elmt_List;
2593 -- If this is an extension aggregate, the component list must
2594 -- include all components that are not in the given ancestor
2595 -- type. Otherwise, the component list must include components
2596 -- of all ancestors, starting with the root.
2598 if Nkind (N) = N_Extension_Aggregate then
2599 Root_Typ := Base_Type (Etype (Ancestor_Part (N)));
2601 Root_Typ := Root_Type (Typ);
2603 if Nkind (Parent (Base_Type (Root_Typ)))
2604 = N_Private_Type_Declaration
2607 ("type of aggregate has private ancestor&!",
2609 Error_Msg_N ("must use extension aggregate!", N);
2613 Dnode := Declaration_Node (Base_Type (Root_Typ));
2615 -- If we don't get a full declaration, then we have some
2616 -- error which will get signalled later so skip this part.
2617 -- Otherwise, gather components of root that apply to the
2618 -- aggregate type. We use the base type in case there is an
2619 -- applicable girder constraint that renames the discriminants
2622 if Nkind (Dnode) = N_Full_Type_Declaration then
2623 Record_Def := Type_Definition (Dnode);
2624 Gather_Components (Base_Type (Typ),
2625 Component_List (Record_Def),
2626 Governed_By => New_Assoc_List,
2628 Report_Errors => Errors_Found);
2632 Parent_Typ := Base_Type (Typ);
2633 while Parent_Typ /= Root_Typ loop
2635 Prepend_Elmt (Parent_Typ, To => Parent_Typ_List);
2636 Parent_Typ := Etype (Parent_Typ);
2638 if (Nkind (Parent (Base_Type (Parent_Typ))) =
2639 N_Private_Type_Declaration
2640 or else Nkind (Parent (Base_Type (Parent_Typ))) =
2641 N_Private_Extension_Declaration)
2643 if Nkind (N) /= N_Extension_Aggregate then
2645 ("type of aggregate has private ancestor&!",
2647 Error_Msg_N ("must use extension aggregate!", N);
2650 elsif Parent_Typ /= Root_Typ then
2652 ("ancestor part of aggregate must be private type&",
2653 Ancestor_Part (N), Parent_Typ);
2659 -- Now collect components from all other ancestors.
2661 Parent_Elmt := First_Elmt (Parent_Typ_List);
2662 while Present (Parent_Elmt) loop
2663 Parent_Typ := Node (Parent_Elmt);
2664 Record_Def := Type_Definition (Parent (Base_Type (Parent_Typ)));
2665 Gather_Components (Empty,
2666 Component_List (Record_Extension_Part (Record_Def)),
2667 Governed_By => New_Assoc_List,
2669 Report_Errors => Errors_Found);
2671 Next_Elmt (Parent_Elmt);
2675 Record_Def := Type_Definition (Parent (Base_Type (Typ)));
2677 if Null_Present (Record_Def) then
2680 Gather_Components (Base_Type (Typ),
2681 Component_List (Record_Def),
2682 Governed_By => New_Assoc_List,
2684 Report_Errors => Errors_Found);
2688 if Errors_Found then
2693 -- STEP 6: Find component Values
2696 Component_Elmt := First_Elmt (Components);
2698 -- First scan the remaining positional associations in the aggregate.
2699 -- Remember that at this point Positional_Expr contains the current
2700 -- positional association if any is left after looking for discriminant
2701 -- values in step 3.
2703 while Present (Positional_Expr) and then Present (Component_Elmt) loop
2704 Component := Node (Component_Elmt);
2705 Resolve_Aggr_Expr (Positional_Expr, Component);
2707 if Present (Get_Value (Component, Component_Associations (N))) then
2709 ("more than one value supplied for Component &", N, Component);
2712 Next (Positional_Expr);
2713 Next_Elmt (Component_Elmt);
2716 if Present (Positional_Expr) then
2718 ("too many components for record aggregate", Positional_Expr);
2721 -- Now scan for the named arguments of the aggregate
2723 while Present (Component_Elmt) loop
2724 Component := Node (Component_Elmt);
2725 Expr := Get_Value (Component, Component_Associations (N), True);
2728 Error_Msg_NE ("no value supplied for component &!", N, Component);
2730 Resolve_Aggr_Expr (Expr, Component);
2733 Next_Elmt (Component_Elmt);
2736 -- STEP 7: check for invalid components + check type in choice list
2743 -- Type of first component in choice list
2746 if Present (Component_Associations (N)) then
2747 Assoc := First (Component_Associations (N));
2752 Verification : while Present (Assoc) loop
2753 Selectr := First (Choices (Assoc));
2756 if Nkind (Selectr) = N_Others_Choice then
2757 if No (Others_Etype) then
2759 ("OTHERS must represent at least one component", Selectr);
2765 while Present (Selectr) loop
2766 New_Assoc := First (New_Assoc_List);
2767 while Present (New_Assoc) loop
2768 Component := First (Choices (New_Assoc));
2769 exit when Chars (Selectr) = Chars (Component);
2773 -- If no association, this is not a legal component of
2774 -- of the type in question, except if this is an internal
2775 -- component supplied by a previous expansion.
2777 if No (New_Assoc) then
2779 if Chars (Selectr) /= Name_uTag
2780 and then Chars (Selectr) /= Name_uParent
2781 and then Chars (Selectr) /= Name_uController
2783 if not Has_Discriminants (Typ) then
2784 Error_Msg_Node_2 := Typ;
2786 ("& is not a component of}",
2790 ("& is not a component of the aggregate subtype",
2794 Check_Misspelled_Component (Components, Selectr);
2797 elsif No (Typech) then
2798 Typech := Base_Type (Etype (Component));
2800 elsif Typech /= Base_Type (Etype (Component)) then
2802 ("components in choice list must have same type", Selectr);
2809 end loop Verification;
2812 -- STEP 8: replace the original aggregate
2815 New_Aggregate : Node_Id := New_Copy (N);
2818 Set_Expressions (New_Aggregate, No_List);
2819 Set_Etype (New_Aggregate, Etype (N));
2820 Set_Component_Associations (New_Aggregate, New_Assoc_List);
2822 Rewrite (N, New_Aggregate);
2824 end Resolve_Record_Aggregate;
2826 ---------------------
2827 -- Sort_Case_Table --
2828 ---------------------
2830 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
2831 L : Int := Case_Table'First;
2832 U : Int := Case_Table'Last;
2841 T := Case_Table (K + 1);
2845 and then Expr_Value (Case_Table (J - 1).Choice_Lo) >
2846 Expr_Value (T.Choice_Lo)
2848 Case_Table (J) := Case_Table (J - 1);
2852 Case_Table (J) := T;
2855 end Sort_Case_Table;
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