1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2009, 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 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Expander; use Expander;
32 with Exp_Tss; use Exp_Tss;
33 with Exp_Util; use Exp_Util;
34 with Freeze; use Freeze;
35 with Itypes; use Itypes;
37 with Lib.Xref; use Lib.Xref;
38 with Namet; use Namet;
39 with Namet.Sp; use Namet.Sp;
40 with Nmake; use Nmake;
41 with Nlists; use Nlists;
44 with Sem_Aux; use Sem_Aux;
45 with Sem_Cat; use Sem_Cat;
46 with Sem_Ch3; use Sem_Ch3;
47 with Sem_Ch13; use Sem_Ch13;
48 with Sem_Eval; use Sem_Eval;
49 with Sem_Res; use Sem_Res;
50 with Sem_Util; use Sem_Util;
51 with Sem_Type; use Sem_Type;
52 with Sem_Warn; use Sem_Warn;
53 with Sinfo; use Sinfo;
54 with Snames; use Snames;
55 with Stringt; use Stringt;
56 with Stand; use Stand;
57 with Targparm; use Targparm;
58 with Tbuild; use Tbuild;
59 with Uintp; use Uintp;
61 package body Sem_Aggr is
63 type Case_Bounds is record
66 Choice_Node : Node_Id;
69 type Case_Table_Type is array (Nat range <>) of Case_Bounds;
70 -- Table type used by Check_Case_Choices procedure
72 -----------------------
73 -- Local Subprograms --
74 -----------------------
76 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
77 -- Sort the Case Table using the Lower Bound of each Choice as the key.
78 -- A simple insertion sort is used since the number of choices in a case
79 -- statement of variant part will usually be small and probably in near
82 procedure Check_Can_Never_Be_Null (Typ : Entity_Id; Expr : Node_Id);
83 -- Ada 2005 (AI-231): Check bad usage of null for a component for which
84 -- null exclusion (NOT NULL) is specified. Typ can be an E_Array_Type for
85 -- the array case (the component type of the array will be used) or an
86 -- E_Component/E_Discriminant entity in the record case, in which case the
87 -- type of the component will be used for the test. If Typ is any other
88 -- kind of entity, the call is ignored. Expr is the component node in the
89 -- aggregate which is known to have a null value. A warning message will be
90 -- issued if the component is null excluding.
92 -- It would be better to pass the proper type for Typ ???
94 procedure Check_Expr_OK_In_Limited_Aggregate (Expr : Node_Id);
95 -- Check that Expr is either not limited or else is one of the cases of
96 -- expressions allowed for a limited component association (namely, an
97 -- aggregate, function call, or <> notation). Report error for violations.
99 ------------------------------------------------------
100 -- Subprograms used for RECORD AGGREGATE Processing --
101 ------------------------------------------------------
103 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id);
104 -- This procedure performs all the semantic checks required for record
105 -- aggregates. Note that for aggregates analysis and resolution go
106 -- hand in hand. Aggregate analysis has been delayed up to here and
107 -- it is done while resolving the aggregate.
109 -- N is the N_Aggregate node.
110 -- Typ is the record type for the aggregate resolution
112 -- While performing the semantic checks, this procedure builds a new
113 -- Component_Association_List where each record field appears alone in a
114 -- Component_Choice_List along with its corresponding expression. The
115 -- record fields in the Component_Association_List appear in the same order
116 -- in which they appear in the record type Typ.
118 -- Once this new Component_Association_List is built and all the semantic
119 -- checks performed, the original aggregate subtree is replaced with the
120 -- new named record aggregate just built. Note that subtree substitution is
121 -- performed with Rewrite so as to be able to retrieve the original
124 -- The aggregate subtree manipulation performed by Resolve_Record_Aggregate
125 -- yields the aggregate format expected by Gigi. Typically, this kind of
126 -- tree manipulations are done in the expander. However, because the
127 -- semantic checks that need to be performed on record aggregates really go
128 -- hand in hand with the record aggregate normalization, the aggregate
129 -- subtree transformation is performed during resolution rather than
130 -- expansion. Had we decided otherwise we would have had to duplicate most
131 -- of the code in the expansion procedure Expand_Record_Aggregate. Note,
132 -- however, that all the expansion concerning aggregates for tagged records
133 -- is done in Expand_Record_Aggregate.
135 -- The algorithm of Resolve_Record_Aggregate proceeds as follows:
137 -- 1. Make sure that the record type against which the record aggregate
138 -- has to be resolved is not abstract. Furthermore if the type is a
139 -- null aggregate make sure the input aggregate N is also null.
141 -- 2. Verify that the structure of the aggregate is that of a record
142 -- aggregate. Specifically, look for component associations and ensure
143 -- that each choice list only has identifiers or the N_Others_Choice
144 -- node. Also make sure that if present, the N_Others_Choice occurs
145 -- last and by itself.
147 -- 3. If Typ contains discriminants, the values for each discriminant is
148 -- looked for. If the record type Typ has variants, we check that the
149 -- expressions corresponding to each discriminant ruling the (possibly
150 -- nested) variant parts of Typ, are static. This allows us to determine
151 -- the variant parts to which the rest of the aggregate must conform.
152 -- The names of discriminants with their values are saved in a new
153 -- association list, New_Assoc_List which is later augmented with the
154 -- names and values of the remaining components in the record type.
156 -- During this phase we also make sure that every discriminant is
157 -- assigned exactly one value. Note that when several values for a given
158 -- discriminant are found, semantic processing continues looking for
159 -- further errors. In this case it's the first discriminant value found
160 -- which we will be recorded.
162 -- IMPORTANT NOTE: For derived tagged types this procedure expects
163 -- First_Discriminant and Next_Discriminant to give the correct list
164 -- of discriminants, in the correct order.
166 -- 4. After all the discriminant values have been gathered, we can set the
167 -- Etype of the record aggregate. If Typ contains no discriminants this
168 -- is straightforward: the Etype of N is just Typ, otherwise a new
169 -- implicit constrained subtype of Typ is built to be the Etype of N.
171 -- 5. Gather the remaining record components according to the discriminant
172 -- values. This involves recursively traversing the record type
173 -- structure to see what variants are selected by the given discriminant
174 -- values. This processing is a little more convoluted if Typ is a
175 -- derived tagged types since we need to retrieve the record structure
176 -- of all the ancestors of Typ.
178 -- 6. After gathering the record components we look for their values in the
179 -- record aggregate and emit appropriate error messages should we not
180 -- find such values or should they be duplicated.
182 -- 7. We then make sure no illegal component names appear in the record
183 -- aggregate and make sure that the type of the record components
184 -- appearing in a same choice list is the same. Finally we ensure that
185 -- the others choice, if present, is used to provide the value of at
186 -- least a record component.
188 -- 8. The original aggregate node is replaced with the new named aggregate
189 -- built in steps 3 through 6, as explained earlier.
191 -- Given the complexity of record aggregate resolution, the primary goal of
192 -- this routine is clarity and simplicity rather than execution and storage
193 -- efficiency. If there are only positional components in the aggregate the
194 -- running time is linear. If there are associations the running time is
195 -- still linear as long as the order of the associations is not too far off
196 -- the order of the components in the record type. If this is not the case
197 -- the running time is at worst quadratic in the size of the association
200 procedure Check_Misspelled_Component
201 (Elements : Elist_Id;
202 Component : Node_Id);
203 -- Give possible misspelling diagnostic if Component is likely to be a
204 -- misspelling of one of the components of the Assoc_List. This is called
205 -- by Resolve_Aggr_Expr after producing an invalid component error message.
207 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id);
208 -- An optimization: determine whether a discriminated subtype has a static
209 -- constraint, and contains array components whose length is also static,
210 -- either because they are constrained by the discriminant, or because the
211 -- original component bounds are static.
213 -----------------------------------------------------
214 -- Subprograms used for ARRAY AGGREGATE Processing --
215 -----------------------------------------------------
217 function Resolve_Array_Aggregate
220 Index_Constr : Node_Id;
221 Component_Typ : Entity_Id;
222 Others_Allowed : Boolean) return Boolean;
223 -- This procedure performs the semantic checks for an array aggregate.
224 -- True is returned if the aggregate resolution succeeds.
226 -- The procedure works by recursively checking each nested aggregate.
227 -- Specifically, after checking a sub-aggregate nested at the i-th level
228 -- we recursively check all the subaggregates at the i+1-st level (if any).
229 -- Note that for aggregates analysis and resolution go hand in hand.
230 -- Aggregate analysis has been delayed up to here and it is done while
231 -- resolving the aggregate.
233 -- N is the current N_Aggregate node to be checked.
235 -- Index is the index node corresponding to the array sub-aggregate that
236 -- we are currently checking (RM 4.3.3 (8)). Its Etype is the
237 -- corresponding index type (or subtype).
239 -- Index_Constr is the node giving the applicable index constraint if
240 -- any (RM 4.3.3 (10)). It "is a constraint provided by certain
241 -- contexts [...] that can be used to determine the bounds of the array
242 -- value specified by the aggregate". If Others_Allowed below is False
243 -- there is no applicable index constraint and this node is set to Index.
245 -- Component_Typ is the array component type.
247 -- Others_Allowed indicates whether an others choice is allowed
248 -- in the context where the top-level aggregate appeared.
250 -- The algorithm of Resolve_Array_Aggregate proceeds as follows:
252 -- 1. Make sure that the others choice, if present, is by itself and
253 -- appears last in the sub-aggregate. Check that we do not have
254 -- positional and named components in the array sub-aggregate (unless
255 -- the named association is an others choice). Finally if an others
256 -- choice is present, make sure it is allowed in the aggregate context.
258 -- 2. If the array sub-aggregate contains discrete_choices:
260 -- (A) Verify their validity. Specifically verify that:
262 -- (a) If a null range is present it must be the only possible
263 -- choice in the array aggregate.
265 -- (b) Ditto for a non static range.
267 -- (c) Ditto for a non static expression.
269 -- In addition this step analyzes and resolves each discrete_choice,
270 -- making sure that its type is the type of the corresponding Index.
271 -- If we are not at the lowest array aggregate level (in the case of
272 -- multi-dimensional aggregates) then invoke Resolve_Array_Aggregate
273 -- recursively on each component expression. Otherwise, resolve the
274 -- bottom level component expressions against the expected component
275 -- type ONLY IF the component corresponds to a single discrete choice
276 -- which is not an others choice (to see why read the DELAYED
277 -- COMPONENT RESOLUTION below).
279 -- (B) Determine the bounds of the sub-aggregate and lowest and
280 -- highest choice values.
282 -- 3. For positional aggregates:
284 -- (A) Loop over the component expressions either recursively invoking
285 -- Resolve_Array_Aggregate on each of these for multi-dimensional
286 -- array aggregates or resolving the bottom level component
287 -- expressions against the expected component type.
289 -- (B) Determine the bounds of the positional sub-aggregates.
291 -- 4. Try to determine statically whether the evaluation of the array
292 -- sub-aggregate raises Constraint_Error. If yes emit proper
293 -- warnings. The precise checks are the following:
295 -- (A) Check that the index range defined by aggregate bounds is
296 -- compatible with corresponding index subtype.
297 -- We also check against the base type. In fact it could be that
298 -- Low/High bounds of the base type are static whereas those of
299 -- the index subtype are not. Thus if we can statically catch
300 -- a problem with respect to the base type we are guaranteed
301 -- that the same problem will arise with the index subtype
303 -- (B) If we are dealing with a named aggregate containing an others
304 -- choice and at least one discrete choice then make sure the range
305 -- specified by the discrete choices does not overflow the
306 -- aggregate bounds. We also check against the index type and base
307 -- type bounds for the same reasons given in (A).
309 -- (C) If we are dealing with a positional aggregate with an others
310 -- choice make sure the number of positional elements specified
311 -- does not overflow the aggregate bounds. We also check against
312 -- the index type and base type bounds as mentioned in (A).
314 -- Finally construct an N_Range node giving the sub-aggregate bounds.
315 -- Set the Aggregate_Bounds field of the sub-aggregate to be this
316 -- N_Range. The routine Array_Aggr_Subtype below uses such N_Ranges
317 -- to build the appropriate aggregate subtype. Aggregate_Bounds
318 -- information is needed during expansion.
320 -- DELAYED COMPONENT RESOLUTION: The resolution of bottom level component
321 -- expressions in an array aggregate may call Duplicate_Subexpr or some
322 -- other routine that inserts code just outside the outermost aggregate.
323 -- If the array aggregate contains discrete choices or an others choice,
324 -- this may be wrong. Consider for instance the following example.
326 -- type Rec is record
330 -- type Acc_Rec is access Rec;
331 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => new Rec);
333 -- Then the transformation of "new Rec" that occurs during resolution
334 -- entails the following code modifications
336 -- P7b : constant Acc_Rec := new Rec;
338 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => P7b);
340 -- This code transformation is clearly wrong, since we need to call
341 -- "new Rec" for each of the 3 array elements. To avoid this problem we
342 -- delay resolution of the components of non positional array aggregates
343 -- to the expansion phase. As an optimization, if the discrete choice
344 -- specifies a single value we do not delay resolution.
346 function Array_Aggr_Subtype (N : Node_Id; Typ : Node_Id) return Entity_Id;
347 -- This routine returns the type or subtype of an array aggregate.
349 -- N is the array aggregate node whose type we return.
351 -- Typ is the context type in which N occurs.
353 -- This routine creates an implicit array subtype whose bounds are
354 -- those defined by the aggregate. When this routine is invoked
355 -- Resolve_Array_Aggregate has already processed aggregate N. Thus the
356 -- Aggregate_Bounds of each sub-aggregate, is an N_Range node giving the
357 -- sub-aggregate bounds. When building the aggregate itype, this function
358 -- traverses the array aggregate N collecting such Aggregate_Bounds and
359 -- constructs the proper array aggregate itype.
361 -- Note that in the case of multidimensional aggregates each inner
362 -- sub-aggregate corresponding to a given array dimension, may provide a
363 -- different bounds. If it is possible to determine statically that
364 -- some sub-aggregates corresponding to the same index do not have the
365 -- same bounds, then a warning is emitted. If such check is not possible
366 -- statically (because some sub-aggregate bounds are dynamic expressions)
367 -- then this job is left to the expander. In all cases the particular
368 -- bounds that this function will chose for a given dimension is the first
369 -- N_Range node for a sub-aggregate corresponding to that dimension.
371 -- Note that the Raises_Constraint_Error flag of an array aggregate
372 -- whose evaluation is determined to raise CE by Resolve_Array_Aggregate,
373 -- is set in Resolve_Array_Aggregate but the aggregate is not
374 -- immediately replaced with a raise CE. In fact, Array_Aggr_Subtype must
375 -- first construct the proper itype for the aggregate (Gigi needs
376 -- this). After constructing the proper itype we will eventually replace
377 -- the top-level aggregate with a raise CE (done in Resolve_Aggregate).
378 -- Of course in cases such as:
380 -- type Arr is array (integer range <>) of Integer;
381 -- A : Arr := (positive range -1 .. 2 => 0);
383 -- The bounds of the aggregate itype are cooked up to look reasonable
384 -- (in this particular case the bounds will be 1 .. 2).
386 procedure Aggregate_Constraint_Checks
388 Check_Typ : Entity_Id);
389 -- Checks expression Exp against subtype Check_Typ. If Exp is an
390 -- aggregate and Check_Typ a constrained record type with discriminants,
391 -- we generate the appropriate discriminant checks. If Exp is an array
392 -- aggregate then emit the appropriate length checks. If Exp is a scalar
393 -- type, or a string literal, Exp is changed into Check_Typ'(Exp) to
394 -- ensure that range checks are performed at run time.
396 procedure Make_String_Into_Aggregate (N : Node_Id);
397 -- A string literal can appear in a context in which a one dimensional
398 -- array of characters is expected. This procedure simply rewrites the
399 -- string as an aggregate, prior to resolution.
401 ---------------------------------
402 -- Aggregate_Constraint_Checks --
403 ---------------------------------
405 procedure Aggregate_Constraint_Checks
407 Check_Typ : Entity_Id)
409 Exp_Typ : constant Entity_Id := Etype (Exp);
412 if Raises_Constraint_Error (Exp) then
416 -- Ada 2005 (AI-230): Generate a conversion to an anonymous access
417 -- component's type to force the appropriate accessibility checks.
419 -- Ada 2005 (AI-231): Generate conversion to the null-excluding
420 -- type to force the corresponding run-time check
422 if Is_Access_Type (Check_Typ)
423 and then ((Is_Local_Anonymous_Access (Check_Typ))
424 or else (Can_Never_Be_Null (Check_Typ)
425 and then not Can_Never_Be_Null (Exp_Typ)))
427 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
428 Analyze_And_Resolve (Exp, Check_Typ);
429 Check_Unset_Reference (Exp);
432 -- This is really expansion activity, so make sure that expansion
433 -- is on and is allowed.
435 if not Expander_Active or else In_Spec_Expression then
439 -- First check if we have to insert discriminant checks
441 if Has_Discriminants (Exp_Typ) then
442 Apply_Discriminant_Check (Exp, Check_Typ);
444 -- Next emit length checks for array aggregates
446 elsif Is_Array_Type (Exp_Typ) then
447 Apply_Length_Check (Exp, Check_Typ);
449 -- Finally emit scalar and string checks. If we are dealing with a
450 -- scalar literal we need to check by hand because the Etype of
451 -- literals is not necessarily correct.
453 elsif Is_Scalar_Type (Exp_Typ)
454 and then Compile_Time_Known_Value (Exp)
456 if Is_Out_Of_Range (Exp, Base_Type (Check_Typ)) then
457 Apply_Compile_Time_Constraint_Error
458 (Exp, "value not in range of}?", CE_Range_Check_Failed,
459 Ent => Base_Type (Check_Typ),
460 Typ => Base_Type (Check_Typ));
462 elsif Is_Out_Of_Range (Exp, Check_Typ) then
463 Apply_Compile_Time_Constraint_Error
464 (Exp, "value not in range of}?", CE_Range_Check_Failed,
468 elsif not Range_Checks_Suppressed (Check_Typ) then
469 Apply_Scalar_Range_Check (Exp, Check_Typ);
472 -- Verify that target type is also scalar, to prevent view anomalies
473 -- in instantiations.
475 elsif (Is_Scalar_Type (Exp_Typ)
476 or else Nkind (Exp) = N_String_Literal)
477 and then Is_Scalar_Type (Check_Typ)
478 and then Exp_Typ /= Check_Typ
480 if Is_Entity_Name (Exp)
481 and then Ekind (Entity (Exp)) = E_Constant
483 -- If expression is a constant, it is worthwhile checking whether
484 -- it is a bound of the type.
486 if (Is_Entity_Name (Type_Low_Bound (Check_Typ))
487 and then Entity (Exp) = Entity (Type_Low_Bound (Check_Typ)))
488 or else (Is_Entity_Name (Type_High_Bound (Check_Typ))
489 and then Entity (Exp) = Entity (Type_High_Bound (Check_Typ)))
494 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
495 Analyze_And_Resolve (Exp, Check_Typ);
496 Check_Unset_Reference (Exp);
499 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
500 Analyze_And_Resolve (Exp, Check_Typ);
501 Check_Unset_Reference (Exp);
505 end Aggregate_Constraint_Checks;
507 ------------------------
508 -- Array_Aggr_Subtype --
509 ------------------------
511 function Array_Aggr_Subtype
516 Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
517 -- Number of aggregate index dimensions
519 Aggr_Range : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
520 -- Constrained N_Range of each index dimension in our aggregate itype
522 Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
523 Aggr_High : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
524 -- Low and High bounds for each index dimension in our aggregate itype
526 Is_Fully_Positional : Boolean := True;
528 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos);
529 -- N is an array (sub-)aggregate. Dim is the dimension corresponding to
530 -- (sub-)aggregate N. This procedure collects the constrained N_Range
531 -- nodes corresponding to each index dimension of our aggregate itype.
532 -- These N_Range nodes are collected in Aggr_Range above.
534 -- Likewise collect in Aggr_Low & Aggr_High above the low and high
535 -- bounds of each index dimension. If, when collecting, two bounds
536 -- corresponding to the same dimension are static and found to differ,
537 -- then emit a warning, and mark N as raising Constraint_Error.
539 -------------------------
540 -- Collect_Aggr_Bounds --
541 -------------------------
543 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos) is
544 This_Range : constant Node_Id := Aggregate_Bounds (N);
545 -- The aggregate range node of this specific sub-aggregate
547 This_Low : constant Node_Id := Low_Bound (Aggregate_Bounds (N));
548 This_High : constant Node_Id := High_Bound (Aggregate_Bounds (N));
549 -- The aggregate bounds of this specific sub-aggregate
555 -- Collect the first N_Range for a given dimension that you find.
556 -- For a given dimension they must be all equal anyway.
558 if No (Aggr_Range (Dim)) then
559 Aggr_Low (Dim) := This_Low;
560 Aggr_High (Dim) := This_High;
561 Aggr_Range (Dim) := This_Range;
564 if Compile_Time_Known_Value (This_Low) then
565 if not Compile_Time_Known_Value (Aggr_Low (Dim)) then
566 Aggr_Low (Dim) := This_Low;
568 elsif Expr_Value (This_Low) /= Expr_Value (Aggr_Low (Dim)) then
569 Set_Raises_Constraint_Error (N);
570 Error_Msg_N ("sub-aggregate low bound mismatch?", N);
572 ("\Constraint_Error will be raised at run-time?", N);
576 if Compile_Time_Known_Value (This_High) then
577 if not Compile_Time_Known_Value (Aggr_High (Dim)) then
578 Aggr_High (Dim) := This_High;
581 Expr_Value (This_High) /= Expr_Value (Aggr_High (Dim))
583 Set_Raises_Constraint_Error (N);
584 Error_Msg_N ("sub-aggregate high bound mismatch?", N);
586 ("\Constraint_Error will be raised at run-time?", N);
591 if Dim < Aggr_Dimension then
593 -- Process positional components
595 if Present (Expressions (N)) then
596 Expr := First (Expressions (N));
597 while Present (Expr) loop
598 Collect_Aggr_Bounds (Expr, Dim + 1);
603 -- Process component associations
605 if Present (Component_Associations (N)) then
606 Is_Fully_Positional := False;
608 Assoc := First (Component_Associations (N));
609 while Present (Assoc) loop
610 Expr := Expression (Assoc);
611 Collect_Aggr_Bounds (Expr, Dim + 1);
616 end Collect_Aggr_Bounds;
618 -- Array_Aggr_Subtype variables
621 -- the final itype of the overall aggregate
623 Index_Constraints : constant List_Id := New_List;
624 -- The list of index constraints of the aggregate itype
626 -- Start of processing for Array_Aggr_Subtype
629 -- Make sure that the list of index constraints is properly attached
630 -- to the tree, and then collect the aggregate bounds.
632 Set_Parent (Index_Constraints, N);
633 Collect_Aggr_Bounds (N, 1);
635 -- Build the list of constrained indices of our aggregate itype
637 for J in 1 .. Aggr_Dimension loop
638 Create_Index : declare
639 Index_Base : constant Entity_Id :=
640 Base_Type (Etype (Aggr_Range (J)));
641 Index_Typ : Entity_Id;
644 -- Construct the Index subtype, and associate it with the range
645 -- construct that generates it.
648 Create_Itype (Subtype_Kind (Ekind (Index_Base)), Aggr_Range (J));
650 Set_Etype (Index_Typ, Index_Base);
652 if Is_Character_Type (Index_Base) then
653 Set_Is_Character_Type (Index_Typ);
656 Set_Size_Info (Index_Typ, (Index_Base));
657 Set_RM_Size (Index_Typ, RM_Size (Index_Base));
658 Set_First_Rep_Item (Index_Typ, First_Rep_Item (Index_Base));
659 Set_Scalar_Range (Index_Typ, Aggr_Range (J));
661 if Is_Discrete_Or_Fixed_Point_Type (Index_Typ) then
662 Set_RM_Size (Index_Typ, UI_From_Int (Minimum_Size (Index_Typ)));
665 Set_Etype (Aggr_Range (J), Index_Typ);
667 Append (Aggr_Range (J), To => Index_Constraints);
671 -- Now build the Itype
673 Itype := Create_Itype (E_Array_Subtype, N);
675 Set_First_Rep_Item (Itype, First_Rep_Item (Typ));
676 Set_Convention (Itype, Convention (Typ));
677 Set_Depends_On_Private (Itype, Has_Private_Component (Typ));
678 Set_Etype (Itype, Base_Type (Typ));
679 Set_Has_Alignment_Clause (Itype, Has_Alignment_Clause (Typ));
680 Set_Is_Aliased (Itype, Is_Aliased (Typ));
681 Set_Depends_On_Private (Itype, Depends_On_Private (Typ));
683 Copy_Suppress_Status (Index_Check, Typ, Itype);
684 Copy_Suppress_Status (Length_Check, Typ, Itype);
686 Set_First_Index (Itype, First (Index_Constraints));
687 Set_Is_Constrained (Itype, True);
688 Set_Is_Internal (Itype, True);
690 -- A simple optimization: purely positional aggregates of static
691 -- components should be passed to gigi unexpanded whenever possible,
692 -- and regardless of the staticness of the bounds themselves. Subse-
693 -- quent checks in exp_aggr verify that type is not packed, etc.
695 Set_Size_Known_At_Compile_Time (Itype,
697 and then Comes_From_Source (N)
698 and then Size_Known_At_Compile_Time (Component_Type (Typ)));
700 -- We always need a freeze node for a packed array subtype, so that
701 -- we can build the Packed_Array_Type corresponding to the subtype.
702 -- If expansion is disabled, the packed array subtype is not built,
703 -- and we must not generate a freeze node for the type, or else it
704 -- will appear incomplete to gigi.
706 if Is_Packed (Itype) and then not In_Spec_Expression
707 and then Expander_Active
709 Freeze_Itype (Itype, N);
713 end Array_Aggr_Subtype;
715 --------------------------------
716 -- Check_Misspelled_Component --
717 --------------------------------
719 procedure Check_Misspelled_Component
720 (Elements : Elist_Id;
723 Max_Suggestions : constant := 2;
725 Nr_Of_Suggestions : Natural := 0;
726 Suggestion_1 : Entity_Id := Empty;
727 Suggestion_2 : Entity_Id := Empty;
728 Component_Elmt : Elmt_Id;
731 -- All the components of List are matched against Component and
732 -- a count is maintained of possible misspellings. When at the
733 -- end of the analysis there are one or two (not more!) possible
734 -- misspellings, these misspellings will be suggested as
735 -- possible correction.
737 Component_Elmt := First_Elmt (Elements);
738 while Nr_Of_Suggestions <= Max_Suggestions
739 and then Present (Component_Elmt)
741 if Is_Bad_Spelling_Of
742 (Chars (Node (Component_Elmt)),
745 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
747 case Nr_Of_Suggestions is
748 when 1 => Suggestion_1 := Node (Component_Elmt);
749 when 2 => Suggestion_2 := Node (Component_Elmt);
754 Next_Elmt (Component_Elmt);
757 -- Report at most two suggestions
759 if Nr_Of_Suggestions = 1 then
760 Error_Msg_NE -- CODEFIX
761 ("\possible misspelling of&", Component, Suggestion_1);
763 elsif Nr_Of_Suggestions = 2 then
764 Error_Msg_Node_2 := Suggestion_2;
765 Error_Msg_NE -- CODEFIX
766 ("\possible misspelling of& or&", Component, Suggestion_1);
768 end Check_Misspelled_Component;
770 ----------------------------------------
771 -- Check_Expr_OK_In_Limited_Aggregate --
772 ----------------------------------------
774 procedure Check_Expr_OK_In_Limited_Aggregate (Expr : Node_Id) is
776 if Is_Limited_Type (Etype (Expr))
777 and then Comes_From_Source (Expr)
778 and then not In_Instance_Body
780 if not OK_For_Limited_Init (Etype (Expr), Expr) then
781 Error_Msg_N ("initialization not allowed for limited types", Expr);
782 Explain_Limited_Type (Etype (Expr), Expr);
785 end Check_Expr_OK_In_Limited_Aggregate;
787 ----------------------------------------
788 -- Check_Static_Discriminated_Subtype --
789 ----------------------------------------
791 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id) is
792 Disc : constant Entity_Id := First_Discriminant (T);
797 if Has_Record_Rep_Clause (T) then
800 elsif Present (Next_Discriminant (Disc)) then
803 elsif Nkind (V) /= N_Integer_Literal then
807 Comp := First_Component (T);
808 while Present (Comp) loop
809 if Is_Scalar_Type (Etype (Comp)) then
812 elsif Is_Private_Type (Etype (Comp))
813 and then Present (Full_View (Etype (Comp)))
814 and then Is_Scalar_Type (Full_View (Etype (Comp)))
818 elsif Is_Array_Type (Etype (Comp)) then
819 if Is_Bit_Packed_Array (Etype (Comp)) then
823 Ind := First_Index (Etype (Comp));
824 while Present (Ind) loop
825 if Nkind (Ind) /= N_Range
826 or else Nkind (Low_Bound (Ind)) /= N_Integer_Literal
827 or else Nkind (High_Bound (Ind)) /= N_Integer_Literal
839 Next_Component (Comp);
842 -- On exit, all components have statically known sizes
844 Set_Size_Known_At_Compile_Time (T);
845 end Check_Static_Discriminated_Subtype;
847 --------------------------------
848 -- Make_String_Into_Aggregate --
849 --------------------------------
851 procedure Make_String_Into_Aggregate (N : Node_Id) is
852 Exprs : constant List_Id := New_List;
853 Loc : constant Source_Ptr := Sloc (N);
854 Str : constant String_Id := Strval (N);
855 Strlen : constant Nat := String_Length (Str);
863 for J in 1 .. Strlen loop
864 C := Get_String_Char (Str, J);
865 Set_Character_Literal_Name (C);
868 Make_Character_Literal (P,
870 Char_Literal_Value => UI_From_CC (C));
871 Set_Etype (C_Node, Any_Character);
872 Append_To (Exprs, C_Node);
875 -- something special for wide strings ???
878 New_N := Make_Aggregate (Loc, Expressions => Exprs);
879 Set_Analyzed (New_N);
880 Set_Etype (New_N, Any_Composite);
883 end Make_String_Into_Aggregate;
885 -----------------------
886 -- Resolve_Aggregate --
887 -----------------------
889 procedure Resolve_Aggregate (N : Node_Id; Typ : Entity_Id) is
890 Pkind : constant Node_Kind := Nkind (Parent (N));
892 Aggr_Subtyp : Entity_Id;
893 -- The actual aggregate subtype. This is not necessarily the same as Typ
894 -- which is the subtype of the context in which the aggregate was found.
897 -- Ignore junk empty aggregate resulting from parser error
899 if No (Expressions (N))
900 and then No (Component_Associations (N))
901 and then not Null_Record_Present (N)
906 -- Check for aggregates not allowed in configurable run-time mode.
907 -- We allow all cases of aggregates that do not come from source,
908 -- since these are all assumed to be small (e.g. bounds of a string
909 -- literal). We also allow aggregates of types we know to be small.
911 if not Support_Aggregates_On_Target
912 and then Comes_From_Source (N)
913 and then (not Known_Static_Esize (Typ) or else Esize (Typ) > 64)
915 Error_Msg_CRT ("aggregate", N);
918 -- Ada 2005 (AI-287): Limited aggregates allowed
920 if Is_Limited_Type (Typ) and then Ada_Version < Ada_05 then
921 Error_Msg_N ("aggregate type cannot be limited", N);
922 Explain_Limited_Type (Typ, N);
924 elsif Is_Class_Wide_Type (Typ) then
925 Error_Msg_N ("type of aggregate cannot be class-wide", N);
927 elsif Typ = Any_String
928 or else Typ = Any_Composite
930 Error_Msg_N ("no unique type for aggregate", N);
931 Set_Etype (N, Any_Composite);
933 elsif Is_Array_Type (Typ) and then Null_Record_Present (N) then
934 Error_Msg_N ("null record forbidden in array aggregate", N);
936 elsif Is_Record_Type (Typ) then
937 Resolve_Record_Aggregate (N, Typ);
939 elsif Is_Array_Type (Typ) then
941 -- First a special test, for the case of a positional aggregate
942 -- of characters which can be replaced by a string literal.
944 -- Do not perform this transformation if this was a string literal
945 -- to start with, whose components needed constraint checks, or if
946 -- the component type is non-static, because it will require those
947 -- checks and be transformed back into an aggregate.
949 if Number_Dimensions (Typ) = 1
950 and then Is_Standard_Character_Type (Component_Type (Typ))
951 and then No (Component_Associations (N))
952 and then not Is_Limited_Composite (Typ)
953 and then not Is_Private_Composite (Typ)
954 and then not Is_Bit_Packed_Array (Typ)
955 and then Nkind (Original_Node (Parent (N))) /= N_String_Literal
956 and then Is_Static_Subtype (Component_Type (Typ))
962 Expr := First (Expressions (N));
963 while Present (Expr) loop
964 exit when Nkind (Expr) /= N_Character_Literal;
971 Expr := First (Expressions (N));
972 while Present (Expr) loop
973 Store_String_Char (UI_To_CC (Char_Literal_Value (Expr)));
978 Make_String_Literal (Sloc (N), End_String));
980 Analyze_And_Resolve (N, Typ);
986 -- Here if we have a real aggregate to deal with
988 Array_Aggregate : declare
989 Aggr_Resolved : Boolean;
991 Aggr_Typ : constant Entity_Id := Etype (Typ);
992 -- This is the unconstrained array type, which is the type
993 -- against which the aggregate is to be resolved. Typ itself
994 -- is the array type of the context which may not be the same
995 -- subtype as the subtype for the final aggregate.
998 -- In the following we determine whether an others choice is
999 -- allowed inside the array aggregate. The test checks the context
1000 -- in which the array aggregate occurs. If the context does not
1001 -- permit it, or the aggregate type is unconstrained, an others
1002 -- choice is not allowed.
1004 -- If expansion is disabled (generic context, or semantics-only
1005 -- mode) actual subtypes cannot be constructed, and the type of
1006 -- an object may be its unconstrained nominal type. However, if
1007 -- the context is an assignment, we assume that "others" is
1008 -- allowed, because the target of the assignment will have a
1009 -- constrained subtype when fully compiled.
1011 -- Note that there is no node for Explicit_Actual_Parameter.
1012 -- To test for this context we therefore have to test for node
1013 -- N_Parameter_Association which itself appears only if there is a
1014 -- formal parameter. Consequently we also need to test for
1015 -- N_Procedure_Call_Statement or N_Function_Call.
1017 Set_Etype (N, Aggr_Typ); -- may be overridden later on
1019 if Is_Constrained (Typ) and then
1020 (Pkind = N_Assignment_Statement or else
1021 Pkind = N_Parameter_Association or else
1022 Pkind = N_Function_Call or else
1023 Pkind = N_Procedure_Call_Statement or else
1024 Pkind = N_Generic_Association or else
1025 Pkind = N_Formal_Object_Declaration or else
1026 Pkind = N_Simple_Return_Statement or else
1027 Pkind = N_Object_Declaration or else
1028 Pkind = N_Component_Declaration or else
1029 Pkind = N_Parameter_Specification or else
1030 Pkind = N_Qualified_Expression or else
1031 Pkind = N_Aggregate or else
1032 Pkind = N_Extension_Aggregate or else
1033 Pkind = N_Component_Association)
1036 Resolve_Array_Aggregate
1038 Index => First_Index (Aggr_Typ),
1039 Index_Constr => First_Index (Typ),
1040 Component_Typ => Component_Type (Typ),
1041 Others_Allowed => True);
1043 elsif not Expander_Active
1044 and then Pkind = N_Assignment_Statement
1047 Resolve_Array_Aggregate
1049 Index => First_Index (Aggr_Typ),
1050 Index_Constr => First_Index (Typ),
1051 Component_Typ => Component_Type (Typ),
1052 Others_Allowed => True);
1055 Resolve_Array_Aggregate
1057 Index => First_Index (Aggr_Typ),
1058 Index_Constr => First_Index (Aggr_Typ),
1059 Component_Typ => Component_Type (Typ),
1060 Others_Allowed => False);
1063 if not Aggr_Resolved then
1064 Aggr_Subtyp := Any_Composite;
1066 Aggr_Subtyp := Array_Aggr_Subtype (N, Typ);
1069 Set_Etype (N, Aggr_Subtyp);
1070 end Array_Aggregate;
1072 elsif Is_Private_Type (Typ)
1073 and then Present (Full_View (Typ))
1074 and then In_Inlined_Body
1075 and then Is_Composite_Type (Full_View (Typ))
1077 Resolve (N, Full_View (Typ));
1080 Error_Msg_N ("illegal context for aggregate", N);
1083 -- If we can determine statically that the evaluation of the
1084 -- aggregate raises Constraint_Error, then replace the
1085 -- aggregate with an N_Raise_Constraint_Error node, but set the
1086 -- Etype to the right aggregate subtype. Gigi needs this.
1088 if Raises_Constraint_Error (N) then
1089 Aggr_Subtyp := Etype (N);
1091 Make_Raise_Constraint_Error (Sloc (N),
1092 Reason => CE_Range_Check_Failed));
1093 Set_Raises_Constraint_Error (N);
1094 Set_Etype (N, Aggr_Subtyp);
1097 end Resolve_Aggregate;
1099 -----------------------------
1100 -- Resolve_Array_Aggregate --
1101 -----------------------------
1103 function Resolve_Array_Aggregate
1106 Index_Constr : Node_Id;
1107 Component_Typ : Entity_Id;
1108 Others_Allowed : Boolean) return Boolean
1110 Loc : constant Source_Ptr := Sloc (N);
1112 Failure : constant Boolean := False;
1113 Success : constant Boolean := True;
1115 Index_Typ : constant Entity_Id := Etype (Index);
1116 Index_Typ_Low : constant Node_Id := Type_Low_Bound (Index_Typ);
1117 Index_Typ_High : constant Node_Id := Type_High_Bound (Index_Typ);
1118 -- The type of the index corresponding to the array sub-aggregate
1119 -- along with its low and upper bounds
1121 Index_Base : constant Entity_Id := Base_Type (Index_Typ);
1122 Index_Base_Low : constant Node_Id := Type_Low_Bound (Index_Base);
1123 Index_Base_High : constant Node_Id := Type_High_Bound (Index_Base);
1124 -- ditto for the base type
1126 function Add (Val : Uint; To : Node_Id) return Node_Id;
1127 -- Creates a new expression node where Val is added to expression To.
1128 -- Tries to constant fold whenever possible. To must be an already
1129 -- analyzed expression.
1131 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id);
1132 -- Checks that AH (the upper bound of an array aggregate) is <= BH
1133 -- (the upper bound of the index base type). If the check fails a
1134 -- warning is emitted, the Raises_Constraint_Error Flag of N is set,
1135 -- and AH is replaced with a duplicate of BH.
1137 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id);
1138 -- Checks that range AL .. AH is compatible with range L .. H. Emits a
1139 -- warning if not and sets the Raises_Constraint_Error Flag in N.
1141 procedure Check_Length (L, H : Node_Id; Len : Uint);
1142 -- Checks that range L .. H contains at least Len elements. Emits a
1143 -- warning if not and sets the Raises_Constraint_Error Flag in N.
1145 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean;
1146 -- Returns True if range L .. H is dynamic or null
1148 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean);
1149 -- Given expression node From, this routine sets OK to False if it
1150 -- cannot statically evaluate From. Otherwise it stores this static
1151 -- value into Value.
1153 function Resolve_Aggr_Expr
1155 Single_Elmt : Boolean) return Boolean;
1156 -- Resolves aggregate expression Expr. Returns False if resolution
1157 -- fails. If Single_Elmt is set to False, the expression Expr may be
1158 -- used to initialize several array aggregate elements (this can
1159 -- happen for discrete choices such as "L .. H => Expr" or the others
1160 -- choice). In this event we do not resolve Expr unless expansion is
1161 -- disabled. To know why, see the DELAYED COMPONENT RESOLUTION
1168 function Add (Val : Uint; To : Node_Id) return Node_Id is
1174 if Raises_Constraint_Error (To) then
1178 -- First test if we can do constant folding
1180 if Compile_Time_Known_Value (To)
1181 or else Nkind (To) = N_Integer_Literal
1183 Expr_Pos := Make_Integer_Literal (Loc, Expr_Value (To) + Val);
1184 Set_Is_Static_Expression (Expr_Pos);
1185 Set_Etype (Expr_Pos, Etype (To));
1186 Set_Analyzed (Expr_Pos, Analyzed (To));
1188 if not Is_Enumeration_Type (Index_Typ) then
1191 -- If we are dealing with enumeration return
1192 -- Index_Typ'Val (Expr_Pos)
1196 Make_Attribute_Reference
1198 Prefix => New_Reference_To (Index_Typ, Loc),
1199 Attribute_Name => Name_Val,
1200 Expressions => New_List (Expr_Pos));
1206 -- If we are here no constant folding possible
1208 if not Is_Enumeration_Type (Index_Base) then
1211 Left_Opnd => Duplicate_Subexpr (To),
1212 Right_Opnd => Make_Integer_Literal (Loc, Val));
1214 -- If we are dealing with enumeration return
1215 -- Index_Typ'Val (Index_Typ'Pos (To) + Val)
1219 Make_Attribute_Reference
1221 Prefix => New_Reference_To (Index_Typ, Loc),
1222 Attribute_Name => Name_Pos,
1223 Expressions => New_List (Duplicate_Subexpr (To)));
1227 Left_Opnd => To_Pos,
1228 Right_Opnd => Make_Integer_Literal (Loc, Val));
1231 Make_Attribute_Reference
1233 Prefix => New_Reference_To (Index_Typ, Loc),
1234 Attribute_Name => Name_Val,
1235 Expressions => New_List (Expr_Pos));
1245 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id) is
1253 Get (Value => Val_BH, From => BH, OK => OK_BH);
1254 Get (Value => Val_AH, From => AH, OK => OK_AH);
1256 if OK_BH and then OK_AH and then Val_BH < Val_AH then
1257 Set_Raises_Constraint_Error (N);
1258 Error_Msg_N ("upper bound out of range?", AH);
1259 Error_Msg_N ("\Constraint_Error will be raised at run-time?", AH);
1261 -- You need to set AH to BH or else in the case of enumerations
1262 -- indices we will not be able to resolve the aggregate bounds.
1264 AH := Duplicate_Subexpr (BH);
1272 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id) is
1283 pragma Warnings (Off, OK_AL);
1284 pragma Warnings (Off, OK_AH);
1287 if Raises_Constraint_Error (N)
1288 or else Dynamic_Or_Null_Range (AL, AH)
1293 Get (Value => Val_L, From => L, OK => OK_L);
1294 Get (Value => Val_H, From => H, OK => OK_H);
1296 Get (Value => Val_AL, From => AL, OK => OK_AL);
1297 Get (Value => Val_AH, From => AH, OK => OK_AH);
1299 if OK_L and then Val_L > Val_AL then
1300 Set_Raises_Constraint_Error (N);
1301 Error_Msg_N ("lower bound of aggregate out of range?", N);
1302 Error_Msg_N ("\Constraint_Error will be raised at run-time?", N);
1305 if OK_H and then Val_H < Val_AH then
1306 Set_Raises_Constraint_Error (N);
1307 Error_Msg_N ("upper bound of aggregate out of range?", N);
1308 Error_Msg_N ("\Constraint_Error will be raised at run-time?", N);
1316 procedure Check_Length (L, H : Node_Id; Len : Uint) is
1326 if Raises_Constraint_Error (N) then
1330 Get (Value => Val_L, From => L, OK => OK_L);
1331 Get (Value => Val_H, From => H, OK => OK_H);
1333 if not OK_L or else not OK_H then
1337 -- If null range length is zero
1339 if Val_L > Val_H then
1340 Range_Len := Uint_0;
1342 Range_Len := Val_H - Val_L + 1;
1345 if Range_Len < Len then
1346 Set_Raises_Constraint_Error (N);
1347 Error_Msg_N ("too many elements?", N);
1348 Error_Msg_N ("\Constraint_Error will be raised at run-time?", N);
1352 ---------------------------
1353 -- Dynamic_Or_Null_Range --
1354 ---------------------------
1356 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean is
1364 Get (Value => Val_L, From => L, OK => OK_L);
1365 Get (Value => Val_H, From => H, OK => OK_H);
1367 return not OK_L or else not OK_H
1368 or else not Is_OK_Static_Expression (L)
1369 or else not Is_OK_Static_Expression (H)
1370 or else Val_L > Val_H;
1371 end Dynamic_Or_Null_Range;
1377 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean) is
1381 if Compile_Time_Known_Value (From) then
1382 Value := Expr_Value (From);
1384 -- If expression From is something like Some_Type'Val (10) then
1387 elsif Nkind (From) = N_Attribute_Reference
1388 and then Attribute_Name (From) = Name_Val
1389 and then Compile_Time_Known_Value (First (Expressions (From)))
1391 Value := Expr_Value (First (Expressions (From)));
1399 -----------------------
1400 -- Resolve_Aggr_Expr --
1401 -----------------------
1403 function Resolve_Aggr_Expr
1405 Single_Elmt : Boolean) return Boolean
1407 Nxt_Ind : constant Node_Id := Next_Index (Index);
1408 Nxt_Ind_Constr : constant Node_Id := Next_Index (Index_Constr);
1409 -- Index is the current index corresponding to the expression
1411 Resolution_OK : Boolean := True;
1412 -- Set to False if resolution of the expression failed
1415 -- If the array type against which we are resolving the aggregate
1416 -- has several dimensions, the expressions nested inside the
1417 -- aggregate must be further aggregates (or strings).
1419 if Present (Nxt_Ind) then
1420 if Nkind (Expr) /= N_Aggregate then
1422 -- A string literal can appear where a one-dimensional array
1423 -- of characters is expected. If the literal looks like an
1424 -- operator, it is still an operator symbol, which will be
1425 -- transformed into a string when analyzed.
1427 if Is_Character_Type (Component_Typ)
1428 and then No (Next_Index (Nxt_Ind))
1429 and then Nkind_In (Expr, N_String_Literal, N_Operator_Symbol)
1431 -- A string literal used in a multidimensional array
1432 -- aggregate in place of the final one-dimensional
1433 -- aggregate must not be enclosed in parentheses.
1435 if Paren_Count (Expr) /= 0 then
1436 Error_Msg_N ("no parenthesis allowed here", Expr);
1439 Make_String_Into_Aggregate (Expr);
1442 Error_Msg_N ("nested array aggregate expected", Expr);
1444 -- If the expression is parenthesized, this may be
1445 -- a missing component association for a 1-aggregate.
1447 if Paren_Count (Expr) > 0 then
1448 Error_Msg_N ("\if single-component aggregate is intended,"
1449 & " write e.g. (1 ='> ...)", Expr);
1455 -- Ada 2005 (AI-231): Propagate the type to the nested aggregate.
1456 -- Required to check the null-exclusion attribute (if present).
1457 -- This value may be overridden later on.
1459 Set_Etype (Expr, Etype (N));
1461 Resolution_OK := Resolve_Array_Aggregate
1462 (Expr, Nxt_Ind, Nxt_Ind_Constr, Component_Typ, Others_Allowed);
1464 -- Do not resolve the expressions of discrete or others choices
1465 -- unless the expression covers a single component, or the expander
1469 or else not Expander_Active
1470 or else In_Spec_Expression
1472 Analyze_And_Resolve (Expr, Component_Typ);
1473 Check_Expr_OK_In_Limited_Aggregate (Expr);
1474 Check_Non_Static_Context (Expr);
1475 Aggregate_Constraint_Checks (Expr, Component_Typ);
1476 Check_Unset_Reference (Expr);
1479 if Raises_Constraint_Error (Expr)
1480 and then Nkind (Parent (Expr)) /= N_Component_Association
1482 Set_Raises_Constraint_Error (N);
1485 -- If the expression has been marked as requiring a range check,
1486 -- then generate it here.
1488 if Do_Range_Check (Expr) then
1489 Set_Do_Range_Check (Expr, False);
1490 Generate_Range_Check (Expr, Component_Typ, CE_Range_Check_Failed);
1493 return Resolution_OK;
1494 end Resolve_Aggr_Expr;
1496 -- Variables local to Resolve_Array_Aggregate
1503 pragma Warnings (Off, Discard);
1505 Aggr_Low : Node_Id := Empty;
1506 Aggr_High : Node_Id := Empty;
1507 -- The actual low and high bounds of this sub-aggregate
1509 Choices_Low : Node_Id := Empty;
1510 Choices_High : Node_Id := Empty;
1511 -- The lowest and highest discrete choices values for a named aggregate
1513 Nb_Elements : Uint := Uint_0;
1514 -- The number of elements in a positional aggregate
1516 Others_Present : Boolean := False;
1518 Nb_Choices : Nat := 0;
1519 -- Contains the overall number of named choices in this sub-aggregate
1521 Nb_Discrete_Choices : Nat := 0;
1522 -- The overall number of discrete choices (not counting others choice)
1524 Case_Table_Size : Nat;
1525 -- Contains the size of the case table needed to sort aggregate choices
1527 -- Start of processing for Resolve_Array_Aggregate
1530 -- Ignore junk empty aggregate resulting from parser error
1532 if No (Expressions (N))
1533 and then No (Component_Associations (N))
1534 and then not Null_Record_Present (N)
1539 -- STEP 1: make sure the aggregate is correctly formatted
1541 if Present (Component_Associations (N)) then
1542 Assoc := First (Component_Associations (N));
1543 while Present (Assoc) loop
1544 Choice := First (Choices (Assoc));
1545 while Present (Choice) loop
1546 if Nkind (Choice) = N_Others_Choice then
1547 Others_Present := True;
1549 if Choice /= First (Choices (Assoc))
1550 or else Present (Next (Choice))
1553 ("OTHERS must appear alone in a choice list", Choice);
1557 if Present (Next (Assoc)) then
1559 ("OTHERS must appear last in an aggregate", Choice);
1563 if Ada_Version = Ada_83
1564 and then Assoc /= First (Component_Associations (N))
1565 and then Nkind_In (Parent (N), N_Assignment_Statement,
1566 N_Object_Declaration)
1569 ("(Ada 83) illegal context for OTHERS choice", N);
1573 Nb_Choices := Nb_Choices + 1;
1581 -- At this point we know that the others choice, if present, is by
1582 -- itself and appears last in the aggregate. Check if we have mixed
1583 -- positional and discrete associations (other than the others choice).
1585 if Present (Expressions (N))
1586 and then (Nb_Choices > 1
1587 or else (Nb_Choices = 1 and then not Others_Present))
1590 ("named association cannot follow positional association",
1591 First (Choices (First (Component_Associations (N)))));
1595 -- Test for the validity of an others choice if present
1597 if Others_Present and then not Others_Allowed then
1599 ("OTHERS choice not allowed here",
1600 First (Choices (First (Component_Associations (N)))));
1604 -- Protect against cascaded errors
1606 if Etype (Index_Typ) = Any_Type then
1610 -- STEP 2: Process named components
1612 if No (Expressions (N)) then
1613 if Others_Present then
1614 Case_Table_Size := Nb_Choices - 1;
1616 Case_Table_Size := Nb_Choices;
1622 -- Denote the lowest and highest values in an aggregate choice
1626 -- High end of one range and Low end of the next. Should be
1627 -- contiguous if there is no hole in the list of values.
1629 Missing_Values : Boolean;
1630 -- Set True if missing index values
1632 S_Low : Node_Id := Empty;
1633 S_High : Node_Id := Empty;
1634 -- if a choice in an aggregate is a subtype indication these
1635 -- denote the lowest and highest values of the subtype
1637 Table : Case_Table_Type (1 .. Case_Table_Size);
1638 -- Used to sort all the different choice values
1640 Single_Choice : Boolean;
1641 -- Set to true every time there is a single discrete choice in a
1642 -- discrete association
1644 Prev_Nb_Discrete_Choices : Nat;
1645 -- Used to keep track of the number of discrete choices
1646 -- in the current association.
1649 -- STEP 2 (A): Check discrete choices validity
1651 Assoc := First (Component_Associations (N));
1652 while Present (Assoc) loop
1653 Prev_Nb_Discrete_Choices := Nb_Discrete_Choices;
1654 Choice := First (Choices (Assoc));
1658 if Nkind (Choice) = N_Others_Choice then
1659 Single_Choice := False;
1662 -- Test for subtype mark without constraint
1664 elsif Is_Entity_Name (Choice) and then
1665 Is_Type (Entity (Choice))
1667 if Base_Type (Entity (Choice)) /= Index_Base then
1669 ("invalid subtype mark in aggregate choice",
1674 -- Case of subtype indication
1676 elsif Nkind (Choice) = N_Subtype_Indication then
1677 Resolve_Discrete_Subtype_Indication (Choice, Index_Base);
1679 -- Does the subtype indication evaluation raise CE ?
1681 Get_Index_Bounds (Subtype_Mark (Choice), S_Low, S_High);
1682 Get_Index_Bounds (Choice, Low, High);
1683 Check_Bounds (S_Low, S_High, Low, High);
1685 -- Case of range or expression
1688 Resolve (Choice, Index_Base);
1689 Check_Unset_Reference (Choice);
1690 Check_Non_Static_Context (Choice);
1692 -- Do not range check a choice. This check is redundant
1693 -- since this test is already performed when we check
1694 -- that the bounds of the array aggregate are within
1697 Set_Do_Range_Check (Choice, False);
1700 -- If we could not resolve the discrete choice stop here
1702 if Etype (Choice) = Any_Type then
1705 -- If the discrete choice raises CE get its original bounds
1707 elsif Nkind (Choice) = N_Raise_Constraint_Error then
1708 Set_Raises_Constraint_Error (N);
1709 Get_Index_Bounds (Original_Node (Choice), Low, High);
1711 -- Otherwise get its bounds as usual
1714 Get_Index_Bounds (Choice, Low, High);
1717 if (Dynamic_Or_Null_Range (Low, High)
1718 or else (Nkind (Choice) = N_Subtype_Indication
1720 Dynamic_Or_Null_Range (S_Low, S_High)))
1721 and then Nb_Choices /= 1
1724 ("dynamic or empty choice in aggregate " &
1725 "must be the only choice", Choice);
1729 Nb_Discrete_Choices := Nb_Discrete_Choices + 1;
1730 Table (Nb_Discrete_Choices).Choice_Lo := Low;
1731 Table (Nb_Discrete_Choices).Choice_Hi := High;
1737 -- Check if we have a single discrete choice and whether
1738 -- this discrete choice specifies a single value.
1741 (Nb_Discrete_Choices = Prev_Nb_Discrete_Choices + 1)
1742 and then (Low = High);
1748 -- Ada 2005 (AI-231)
1750 if Ada_Version >= Ada_05
1751 and then Known_Null (Expression (Assoc))
1753 Check_Can_Never_Be_Null (Etype (N), Expression (Assoc));
1756 -- Ada 2005 (AI-287): In case of default initialized component
1757 -- we delay the resolution to the expansion phase
1759 if Box_Present (Assoc) then
1761 -- Ada 2005 (AI-287): In case of default initialization
1762 -- of a component the expander will generate calls to
1763 -- the corresponding initialization subprogram.
1767 elsif not Resolve_Aggr_Expr (Expression (Assoc),
1768 Single_Elmt => Single_Choice)
1772 -- Check incorrect use of dynamically tagged expression
1774 -- We differentiate here two cases because the expression may
1775 -- not be decorated. For example, the analysis and resolution
1776 -- of the expression associated with the others choice will
1777 -- be done later with the full aggregate. In such case we
1778 -- duplicate the expression tree to analyze the copy and
1779 -- perform the required check.
1781 elsif not Present (Etype (Expression (Assoc))) then
1783 Save_Analysis : constant Boolean := Full_Analysis;
1784 Expr : constant Node_Id :=
1785 New_Copy_Tree (Expression (Assoc));
1788 Expander_Mode_Save_And_Set (False);
1789 Full_Analysis := False;
1791 Full_Analysis := Save_Analysis;
1792 Expander_Mode_Restore;
1794 if Is_Tagged_Type (Etype (Expr)) then
1795 Check_Dynamically_Tagged_Expression
1797 Typ => Component_Type (Etype (N)),
1802 elsif Is_Tagged_Type (Etype (Expression (Assoc))) then
1803 Check_Dynamically_Tagged_Expression
1804 (Expr => Expression (Assoc),
1805 Typ => Component_Type (Etype (N)),
1812 -- If aggregate contains more than one choice then these must be
1813 -- static. Sort them and check that they are contiguous
1815 if Nb_Discrete_Choices > 1 then
1816 Sort_Case_Table (Table);
1817 Missing_Values := False;
1819 Outer : for J in 1 .. Nb_Discrete_Choices - 1 loop
1820 if Expr_Value (Table (J).Choice_Hi) >=
1821 Expr_Value (Table (J + 1).Choice_Lo)
1824 ("duplicate choice values in array aggregate",
1825 Table (J).Choice_Hi);
1828 elsif not Others_Present then
1829 Hi_Val := Expr_Value (Table (J).Choice_Hi);
1830 Lo_Val := Expr_Value (Table (J + 1).Choice_Lo);
1832 -- If missing values, output error messages
1834 if Lo_Val - Hi_Val > 1 then
1836 -- Header message if not first missing value
1838 if not Missing_Values then
1840 ("missing index value(s) in array aggregate", N);
1841 Missing_Values := True;
1844 -- Output values of missing indexes
1846 Lo_Val := Lo_Val - 1;
1847 Hi_Val := Hi_Val + 1;
1849 -- Enumeration type case
1851 if Is_Enumeration_Type (Index_Typ) then
1854 (Get_Enum_Lit_From_Pos
1855 (Index_Typ, Hi_Val, Loc));
1857 if Lo_Val = Hi_Val then
1858 Error_Msg_N ("\ %", N);
1862 (Get_Enum_Lit_From_Pos
1863 (Index_Typ, Lo_Val, Loc));
1864 Error_Msg_N ("\ % .. %", N);
1867 -- Integer types case
1870 Error_Msg_Uint_1 := Hi_Val;
1872 if Lo_Val = Hi_Val then
1873 Error_Msg_N ("\ ^", N);
1875 Error_Msg_Uint_2 := Lo_Val;
1876 Error_Msg_N ("\ ^ .. ^", N);
1883 if Missing_Values then
1884 Set_Etype (N, Any_Composite);
1889 -- STEP 2 (B): Compute aggregate bounds and min/max choices values
1891 if Nb_Discrete_Choices > 0 then
1892 Choices_Low := Table (1).Choice_Lo;
1893 Choices_High := Table (Nb_Discrete_Choices).Choice_Hi;
1896 -- If Others is present, then bounds of aggregate come from the
1897 -- index constraint (not the choices in the aggregate itself).
1899 if Others_Present then
1900 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
1902 -- No others clause present
1905 -- Special processing if others allowed and not present. This
1906 -- means that the bounds of the aggregate come from the index
1907 -- constraint (and the length must match).
1909 if Others_Allowed then
1910 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
1912 -- If others allowed, and no others present, then the array
1913 -- should cover all index values. If it does not, we will
1914 -- get a length check warning, but there is two cases where
1915 -- an additional warning is useful:
1917 -- If we have no positional components, and the length is
1918 -- wrong (which we can tell by others being allowed with
1919 -- missing components), and the index type is an enumeration
1920 -- type, then issue appropriate warnings about these missing
1921 -- components. They are only warnings, since the aggregate
1922 -- is fine, it's just the wrong length. We skip this check
1923 -- for standard character types (since there are no literals
1924 -- and it is too much trouble to concoct them), and also if
1925 -- any of the bounds have not-known-at-compile-time values.
1927 -- Another case warranting a warning is when the length is
1928 -- right, but as above we have an index type that is an
1929 -- enumeration, and the bounds do not match. This is a
1930 -- case where dubious sliding is allowed and we generate
1931 -- a warning that the bounds do not match.
1933 if No (Expressions (N))
1934 and then Nkind (Index) = N_Range
1935 and then Is_Enumeration_Type (Etype (Index))
1936 and then not Is_Standard_Character_Type (Etype (Index))
1937 and then Compile_Time_Known_Value (Aggr_Low)
1938 and then Compile_Time_Known_Value (Aggr_High)
1939 and then Compile_Time_Known_Value (Choices_Low)
1940 and then Compile_Time_Known_Value (Choices_High)
1943 ALo : constant Node_Id := Expr_Value_E (Aggr_Low);
1944 AHi : constant Node_Id := Expr_Value_E (Aggr_High);
1945 CLo : constant Node_Id := Expr_Value_E (Choices_Low);
1946 CHi : constant Node_Id := Expr_Value_E (Choices_High);
1951 -- Warning case one, missing values at start/end. Only
1952 -- do the check if the number of entries is too small.
1954 if (Enumeration_Pos (CHi) - Enumeration_Pos (CLo))
1956 (Enumeration_Pos (AHi) - Enumeration_Pos (ALo))
1959 ("missing index value(s) in array aggregate?", N);
1961 -- Output missing value(s) at start
1963 if Chars (ALo) /= Chars (CLo) then
1966 if Chars (ALo) = Chars (Ent) then
1967 Error_Msg_Name_1 := Chars (ALo);
1968 Error_Msg_N ("\ %?", N);
1970 Error_Msg_Name_1 := Chars (ALo);
1971 Error_Msg_Name_2 := Chars (Ent);
1972 Error_Msg_N ("\ % .. %?", N);
1976 -- Output missing value(s) at end
1978 if Chars (AHi) /= Chars (CHi) then
1981 if Chars (AHi) = Chars (Ent) then
1982 Error_Msg_Name_1 := Chars (Ent);
1983 Error_Msg_N ("\ %?", N);
1985 Error_Msg_Name_1 := Chars (Ent);
1986 Error_Msg_Name_2 := Chars (AHi);
1987 Error_Msg_N ("\ % .. %?", N);
1991 -- Warning case 2, dubious sliding. The First_Subtype
1992 -- test distinguishes between a constrained type where
1993 -- sliding is not allowed (so we will get a warning
1994 -- later that Constraint_Error will be raised), and
1995 -- the unconstrained case where sliding is permitted.
1997 elsif (Enumeration_Pos (CHi) - Enumeration_Pos (CLo))
1999 (Enumeration_Pos (AHi) - Enumeration_Pos (ALo))
2000 and then Chars (ALo) /= Chars (CLo)
2002 not Is_Constrained (First_Subtype (Etype (N)))
2005 ("bounds of aggregate do not match target?", N);
2011 -- If no others, aggregate bounds come from aggregate
2013 Aggr_Low := Choices_Low;
2014 Aggr_High := Choices_High;
2018 -- STEP 3: Process positional components
2021 -- STEP 3 (A): Process positional elements
2023 Expr := First (Expressions (N));
2024 Nb_Elements := Uint_0;
2025 while Present (Expr) loop
2026 Nb_Elements := Nb_Elements + 1;
2028 -- Ada 2005 (AI-231)
2030 if Ada_Version >= Ada_05
2031 and then Known_Null (Expr)
2033 Check_Can_Never_Be_Null (Etype (N), Expr);
2036 if not Resolve_Aggr_Expr (Expr, Single_Elmt => True) then
2040 -- Check incorrect use of dynamically tagged expression
2042 if Is_Tagged_Type (Etype (Expr)) then
2043 Check_Dynamically_Tagged_Expression
2045 Typ => Component_Type (Etype (N)),
2052 if Others_Present then
2053 Assoc := Last (Component_Associations (N));
2055 -- Ada 2005 (AI-231)
2057 if Ada_Version >= Ada_05
2058 and then Known_Null (Assoc)
2060 Check_Can_Never_Be_Null (Etype (N), Expression (Assoc));
2063 -- Ada 2005 (AI-287): In case of default initialized component
2064 -- we delay the resolution to the expansion phase.
2066 if Box_Present (Assoc) then
2068 -- Ada 2005 (AI-287): In case of default initialization
2069 -- of a component the expander will generate calls to
2070 -- the corresponding initialization subprogram.
2074 elsif not Resolve_Aggr_Expr (Expression (Assoc),
2075 Single_Elmt => False)
2079 -- Check incorrect use of dynamically tagged expression. The
2080 -- expression of the others choice has not been resolved yet.
2081 -- In order to diagnose the semantic error we create a duplicate
2082 -- tree to analyze it and perform the check.
2086 Save_Analysis : constant Boolean := Full_Analysis;
2087 Expr : constant Node_Id :=
2088 New_Copy_Tree (Expression (Assoc));
2091 Expander_Mode_Save_And_Set (False);
2092 Full_Analysis := False;
2094 Full_Analysis := Save_Analysis;
2095 Expander_Mode_Restore;
2097 if Is_Tagged_Type (Etype (Expr)) then
2098 Check_Dynamically_Tagged_Expression
2100 Typ => Component_Type (Etype (N)),
2107 -- STEP 3 (B): Compute the aggregate bounds
2109 if Others_Present then
2110 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
2113 if Others_Allowed then
2114 Get_Index_Bounds (Index_Constr, Aggr_Low, Discard);
2116 Aggr_Low := Index_Typ_Low;
2119 Aggr_High := Add (Nb_Elements - 1, To => Aggr_Low);
2120 Check_Bound (Index_Base_High, Aggr_High);
2124 -- STEP 4: Perform static aggregate checks and save the bounds
2128 Check_Bounds (Index_Typ_Low, Index_Typ_High, Aggr_Low, Aggr_High);
2129 Check_Bounds (Index_Base_Low, Index_Base_High, Aggr_Low, Aggr_High);
2133 if Others_Present and then Nb_Discrete_Choices > 0 then
2134 Check_Bounds (Aggr_Low, Aggr_High, Choices_Low, Choices_High);
2135 Check_Bounds (Index_Typ_Low, Index_Typ_High,
2136 Choices_Low, Choices_High);
2137 Check_Bounds (Index_Base_Low, Index_Base_High,
2138 Choices_Low, Choices_High);
2142 elsif Others_Present and then Nb_Elements > 0 then
2143 Check_Length (Aggr_Low, Aggr_High, Nb_Elements);
2144 Check_Length (Index_Typ_Low, Index_Typ_High, Nb_Elements);
2145 Check_Length (Index_Base_Low, Index_Base_High, Nb_Elements);
2148 if Raises_Constraint_Error (Aggr_Low)
2149 or else Raises_Constraint_Error (Aggr_High)
2151 Set_Raises_Constraint_Error (N);
2154 Aggr_Low := Duplicate_Subexpr (Aggr_Low);
2156 -- Do not duplicate Aggr_High if Aggr_High = Aggr_Low + Nb_Elements
2157 -- since the addition node returned by Add is not yet analyzed. Attach
2158 -- to tree and analyze first. Reset analyzed flag to insure it will get
2159 -- analyzed when it is a literal bound whose type must be properly set.
2161 if Others_Present or else Nb_Discrete_Choices > 0 then
2162 Aggr_High := Duplicate_Subexpr (Aggr_High);
2164 if Etype (Aggr_High) = Universal_Integer then
2165 Set_Analyzed (Aggr_High, False);
2169 Set_Aggregate_Bounds
2170 (N, Make_Range (Loc, Low_Bound => Aggr_Low, High_Bound => Aggr_High));
2172 -- The bounds may contain expressions that must be inserted upwards.
2173 -- Attach them fully to the tree. After analysis, remove side effects
2174 -- from upper bound, if still needed.
2176 Set_Parent (Aggregate_Bounds (N), N);
2177 Analyze_And_Resolve (Aggregate_Bounds (N), Index_Typ);
2178 Check_Unset_Reference (Aggregate_Bounds (N));
2180 if not Others_Present and then Nb_Discrete_Choices = 0 then
2181 Set_High_Bound (Aggregate_Bounds (N),
2182 Duplicate_Subexpr (High_Bound (Aggregate_Bounds (N))));
2186 end Resolve_Array_Aggregate;
2188 ---------------------------------
2189 -- Resolve_Extension_Aggregate --
2190 ---------------------------------
2192 -- There are two cases to consider:
2194 -- a) If the ancestor part is a type mark, the components needed are
2195 -- the difference between the components of the expected type and the
2196 -- components of the given type mark.
2198 -- b) If the ancestor part is an expression, it must be unambiguous,
2199 -- and once we have its type we can also compute the needed components
2200 -- as in the previous case. In both cases, if the ancestor type is not
2201 -- the immediate ancestor, we have to build this ancestor recursively.
2203 -- In both cases discriminants of the ancestor type do not play a
2204 -- role in the resolution of the needed components, because inherited
2205 -- discriminants cannot be used in a type extension. As a result we can
2206 -- compute independently the list of components of the ancestor type and
2207 -- of the expected type.
2209 procedure Resolve_Extension_Aggregate (N : Node_Id; Typ : Entity_Id) is
2210 A : constant Node_Id := Ancestor_Part (N);
2215 function Valid_Limited_Ancestor (Anc : Node_Id) return Boolean;
2216 -- If the type is limited, verify that the ancestor part is a legal
2217 -- expression (aggregate or function call, including 'Input)) that
2218 -- does not require a copy, as specified in 7.5 (2).
2220 function Valid_Ancestor_Type return Boolean;
2221 -- Verify that the type of the ancestor part is a non-private ancestor
2222 -- of the expected type, which must be a type extension.
2224 ----------------------------
2225 -- Valid_Limited_Ancestor --
2226 ----------------------------
2228 function Valid_Limited_Ancestor (Anc : Node_Id) return Boolean is
2230 if Is_Entity_Name (Anc)
2231 and then Is_Type (Entity (Anc))
2235 elsif Nkind_In (Anc, N_Aggregate, N_Function_Call) then
2238 elsif Nkind (Anc) = N_Attribute_Reference
2239 and then Attribute_Name (Anc) = Name_Input
2244 Nkind (Anc) = N_Qualified_Expression
2246 return Valid_Limited_Ancestor (Expression (Anc));
2251 end Valid_Limited_Ancestor;
2253 -------------------------
2254 -- Valid_Ancestor_Type --
2255 -------------------------
2257 function Valid_Ancestor_Type return Boolean is
2258 Imm_Type : Entity_Id;
2261 Imm_Type := Base_Type (Typ);
2262 while Is_Derived_Type (Imm_Type) loop
2263 if Etype (Imm_Type) = Base_Type (A_Type) then
2266 -- The base type of the parent type may appear as a private
2267 -- extension if it is declared as such in a parent unit of
2268 -- the current one. For consistency of the subsequent analysis
2269 -- use the partial view for the ancestor part.
2271 elsif Is_Private_Type (Etype (Imm_Type))
2272 and then Present (Full_View (Etype (Imm_Type)))
2273 and then Base_Type (A_Type) = Full_View (Etype (Imm_Type))
2275 A_Type := Etype (Imm_Type);
2278 Imm_Type := Etype (Base_Type (Imm_Type));
2282 -- If previous loop did not find a proper ancestor, report error
2284 Error_Msg_NE ("expect ancestor type of &", A, Typ);
2286 end Valid_Ancestor_Type;
2288 -- Start of processing for Resolve_Extension_Aggregate
2291 -- Analyze the ancestor part and account for the case where it's
2292 -- a parameterless function call.
2295 Check_Parameterless_Call (A);
2297 if not Is_Tagged_Type (Typ) then
2298 Error_Msg_N ("type of extension aggregate must be tagged", N);
2301 elsif Is_Limited_Type (Typ) then
2303 -- Ada 2005 (AI-287): Limited aggregates are allowed
2305 if Ada_Version < Ada_05 then
2306 Error_Msg_N ("aggregate type cannot be limited", N);
2307 Explain_Limited_Type (Typ, N);
2310 elsif Valid_Limited_Ancestor (A) then
2315 ("limited ancestor part must be aggregate or function call", A);
2318 elsif Is_Class_Wide_Type (Typ) then
2319 Error_Msg_N ("aggregate cannot be of a class-wide type", N);
2323 if Is_Entity_Name (A)
2324 and then Is_Type (Entity (A))
2326 A_Type := Get_Full_View (Entity (A));
2328 if Valid_Ancestor_Type then
2329 Set_Entity (A, A_Type);
2330 Set_Etype (A, A_Type);
2332 Validate_Ancestor_Part (N);
2333 Resolve_Record_Aggregate (N, Typ);
2336 elsif Nkind (A) /= N_Aggregate then
2337 if Is_Overloaded (A) then
2340 Get_First_Interp (A, I, It);
2341 while Present (It.Typ) loop
2342 -- Only consider limited interpretations in the Ada 2005 case
2344 if Is_Tagged_Type (It.Typ)
2345 and then (Ada_Version >= Ada_05
2346 or else not Is_Limited_Type (It.Typ))
2348 if A_Type /= Any_Type then
2349 Error_Msg_N ("cannot resolve expression", A);
2356 Get_Next_Interp (I, It);
2359 if A_Type = Any_Type then
2360 if Ada_Version >= Ada_05 then
2361 Error_Msg_N ("ancestor part must be of a tagged type", A);
2364 ("ancestor part must be of a nonlimited tagged type", A);
2371 A_Type := Etype (A);
2374 if Valid_Ancestor_Type then
2375 Resolve (A, A_Type);
2376 Check_Unset_Reference (A);
2377 Check_Non_Static_Context (A);
2379 -- The aggregate is illegal if the ancestor expression is a call
2380 -- to a function with a limited unconstrained result, unless the
2381 -- type of the aggregate is a null extension. This restriction
2382 -- was added in AI05-67 to simplify implementation.
2384 if Nkind (A) = N_Function_Call
2385 and then Is_Limited_Type (A_Type)
2386 and then not Is_Null_Extension (Typ)
2387 and then not Is_Constrained (A_Type)
2390 ("type of limited ancestor part must be constrained", A);
2392 elsif Is_Class_Wide_Type (Etype (A))
2393 and then Nkind (Original_Node (A)) = N_Function_Call
2395 -- If the ancestor part is a dispatching call, it appears
2396 -- statically to be a legal ancestor, but it yields any
2397 -- member of the class, and it is not possible to determine
2398 -- whether it is an ancestor of the extension aggregate (much
2399 -- less which ancestor). It is not possible to determine the
2400 -- required components of the extension part.
2402 -- This check implements AI-306, which in fact was motivated
2403 -- by an ACT query to the ARG after this test was added.
2405 Error_Msg_N ("ancestor part must be statically tagged", A);
2407 Resolve_Record_Aggregate (N, Typ);
2412 Error_Msg_N ("no unique type for this aggregate", A);
2414 end Resolve_Extension_Aggregate;
2416 ------------------------------
2417 -- Resolve_Record_Aggregate --
2418 ------------------------------
2420 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id) is
2422 -- N_Component_Association node belonging to the input aggregate N
2425 Positional_Expr : Node_Id;
2426 Component : Entity_Id;
2427 Component_Elmt : Elmt_Id;
2429 Components : constant Elist_Id := New_Elmt_List;
2430 -- Components is the list of the record components whose value must
2431 -- be provided in the aggregate. This list does include discriminants.
2433 New_Assoc_List : constant List_Id := New_List;
2434 New_Assoc : Node_Id;
2435 -- New_Assoc_List is the newly built list of N_Component_Association
2436 -- nodes. New_Assoc is one such N_Component_Association node in it.
2437 -- Please note that while Assoc and New_Assoc contain the same
2438 -- kind of nodes, they are used to iterate over two different
2439 -- N_Component_Association lists.
2441 Others_Etype : Entity_Id := Empty;
2442 -- This variable is used to save the Etype of the last record component
2443 -- that takes its value from the others choice. Its purpose is:
2445 -- (a) make sure the others choice is useful
2447 -- (b) make sure the type of all the components whose value is
2448 -- subsumed by the others choice are the same.
2450 -- This variable is updated as a side effect of function Get_Value
2452 Is_Box_Present : Boolean := False;
2453 Others_Box : Boolean := False;
2454 -- Ada 2005 (AI-287): Variables used in case of default initialization
2455 -- to provide a functionality similar to Others_Etype. Box_Present
2456 -- indicates that the component takes its default initialization;
2457 -- Others_Box indicates that at least one component takes its default
2458 -- initialization. Similar to Others_Etype, they are also updated as a
2459 -- side effect of function Get_Value.
2461 procedure Add_Association
2462 (Component : Entity_Id;
2464 Assoc_List : List_Id;
2465 Is_Box_Present : Boolean := False);
2466 -- Builds a new N_Component_Association node which associates
2467 -- Component to expression Expr and adds it to the association
2468 -- list being built, either New_Assoc_List, or the association
2469 -- being built for an inner aggregate.
2471 function Discr_Present (Discr : Entity_Id) return Boolean;
2472 -- If aggregate N is a regular aggregate this routine will return True.
2473 -- Otherwise, if N is an extension aggregate, Discr is a discriminant
2474 -- whose value may already have been specified by N's ancestor part,
2475 -- this routine checks whether this is indeed the case and if so
2476 -- returns False, signaling that no value for Discr should appear in the
2477 -- N's aggregate part. Also, in this case, the routine appends to
2478 -- New_Assoc_List Discr the discriminant value specified in the ancestor
2484 Consider_Others_Choice : Boolean := False)
2486 -- Given a record component stored in parameter Compon, the
2487 -- following function returns its value as it appears in the list
2488 -- From, which is a list of N_Component_Association nodes. If no
2489 -- component association has a choice for the searched component,
2490 -- the value provided by the others choice is returned, if there
2491 -- is one and Consider_Others_Choice is set to true. Otherwise
2492 -- Empty is returned. If there is more than one component association
2493 -- giving a value for the searched record component, an error message
2494 -- is emitted and the first found value is returned.
2496 -- If Consider_Others_Choice is set and the returned expression comes
2497 -- from the others choice, then Others_Etype is set as a side effect.
2498 -- An error message is emitted if the components taking their value
2499 -- from the others choice do not have same type.
2501 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id);
2502 -- Analyzes and resolves expression Expr against the Etype of the
2503 -- Component. This routine also applies all appropriate checks to Expr.
2504 -- It finally saves a Expr in the newly created association list that
2505 -- will be attached to the final record aggregate. Note that if the
2506 -- Parent pointer of Expr is not set then Expr was produced with a
2507 -- New_Copy_Tree or some such.
2509 ---------------------
2510 -- Add_Association --
2511 ---------------------
2513 procedure Add_Association
2514 (Component : Entity_Id;
2516 Assoc_List : List_Id;
2517 Is_Box_Present : Boolean := False)
2519 Choice_List : constant List_Id := New_List;
2520 New_Assoc : Node_Id;
2523 Append (New_Occurrence_Of (Component, Sloc (Expr)), Choice_List);
2525 Make_Component_Association (Sloc (Expr),
2526 Choices => Choice_List,
2528 Box_Present => Is_Box_Present);
2529 Append (New_Assoc, Assoc_List);
2530 end Add_Association;
2536 function Discr_Present (Discr : Entity_Id) return Boolean is
2537 Regular_Aggr : constant Boolean := Nkind (N) /= N_Extension_Aggregate;
2542 Discr_Expr : Node_Id;
2544 Ancestor_Typ : Entity_Id;
2545 Orig_Discr : Entity_Id;
2547 D_Val : Elmt_Id := No_Elmt; -- stop junk warning
2549 Ancestor_Is_Subtyp : Boolean;
2552 if Regular_Aggr then
2556 Ancestor := Ancestor_Part (N);
2557 Ancestor_Typ := Etype (Ancestor);
2558 Loc := Sloc (Ancestor);
2560 -- For a private type with unknown discriminants, use the underlying
2561 -- record view if it is available.
2563 if Has_Unknown_Discriminants (Ancestor_Typ)
2564 and then Present (Full_View (Ancestor_Typ))
2565 and then Present (Underlying_Record_View (Full_View (Ancestor_Typ)))
2567 Ancestor_Typ := Underlying_Record_View (Full_View (Ancestor_Typ));
2570 Ancestor_Is_Subtyp :=
2571 Is_Entity_Name (Ancestor) and then Is_Type (Entity (Ancestor));
2573 -- If the ancestor part has no discriminants clearly N's aggregate
2574 -- part must provide a value for Discr.
2576 if not Has_Discriminants (Ancestor_Typ) then
2579 -- If the ancestor part is an unconstrained subtype mark then the
2580 -- Discr must be present in N's aggregate part.
2582 elsif Ancestor_Is_Subtyp
2583 and then not Is_Constrained (Entity (Ancestor))
2588 -- Now look to see if Discr was specified in the ancestor part
2590 if Ancestor_Is_Subtyp then
2591 D_Val := First_Elmt (Discriminant_Constraint (Entity (Ancestor)));
2594 Orig_Discr := Original_Record_Component (Discr);
2596 D := First_Discriminant (Ancestor_Typ);
2597 while Present (D) loop
2599 -- If Ancestor has already specified Disc value than insert its
2600 -- value in the final aggregate.
2602 if Original_Record_Component (D) = Orig_Discr then
2603 if Ancestor_Is_Subtyp then
2604 Discr_Expr := New_Copy_Tree (Node (D_Val));
2607 Make_Selected_Component (Loc,
2608 Prefix => Duplicate_Subexpr (Ancestor),
2609 Selector_Name => New_Occurrence_Of (Discr, Loc));
2612 Resolve_Aggr_Expr (Discr_Expr, Discr);
2616 Next_Discriminant (D);
2618 if Ancestor_Is_Subtyp then
2633 Consider_Others_Choice : Boolean := False)
2637 Expr : Node_Id := Empty;
2638 Selector_Name : Node_Id;
2641 Is_Box_Present := False;
2643 if Present (From) then
2644 Assoc := First (From);
2649 while Present (Assoc) loop
2650 Selector_Name := First (Choices (Assoc));
2651 while Present (Selector_Name) loop
2652 if Nkind (Selector_Name) = N_Others_Choice then
2653 if Consider_Others_Choice and then No (Expr) then
2655 -- We need to duplicate the expression for each
2656 -- successive component covered by the others choice.
2657 -- This is redundant if the others_choice covers only
2658 -- one component (small optimization possible???), but
2659 -- indispensable otherwise, because each one must be
2660 -- expanded individually to preserve side-effects.
2662 -- Ada 2005 (AI-287): In case of default initialization
2663 -- of components, we duplicate the corresponding default
2664 -- expression (from the record type declaration). The
2665 -- copy must carry the sloc of the association (not the
2666 -- original expression) to prevent spurious elaboration
2667 -- checks when the default includes function calls.
2669 if Box_Present (Assoc) then
2671 Is_Box_Present := True;
2673 if Expander_Active then
2676 (Expression (Parent (Compon)),
2677 New_Sloc => Sloc (Assoc));
2679 return Expression (Parent (Compon));
2683 if Present (Others_Etype) and then
2684 Base_Type (Others_Etype) /= Base_Type (Etype
2687 Error_Msg_N ("components in OTHERS choice must " &
2688 "have same type", Selector_Name);
2691 Others_Etype := Etype (Compon);
2693 if Expander_Active then
2694 return New_Copy_Tree (Expression (Assoc));
2696 return Expression (Assoc);
2701 elsif Chars (Compon) = Chars (Selector_Name) then
2704 -- Ada 2005 (AI-231)
2706 if Ada_Version >= Ada_05
2707 and then Known_Null (Expression (Assoc))
2709 Check_Can_Never_Be_Null (Compon, Expression (Assoc));
2712 -- We need to duplicate the expression when several
2713 -- components are grouped together with a "|" choice.
2714 -- For instance "filed1 | filed2 => Expr"
2716 -- Ada 2005 (AI-287)
2718 if Box_Present (Assoc) then
2719 Is_Box_Present := True;
2721 -- Duplicate the default expression of the component
2722 -- from the record type declaration, so a new copy
2723 -- can be attached to the association.
2725 -- Note that we always copy the default expression,
2726 -- even when the association has a single choice, in
2727 -- order to create a proper association for the
2728 -- expanded aggregate.
2730 Expr := New_Copy_Tree (Expression (Parent (Compon)));
2733 if Present (Next (Selector_Name)) then
2734 Expr := New_Copy_Tree (Expression (Assoc));
2736 Expr := Expression (Assoc);
2740 Generate_Reference (Compon, Selector_Name, 'm');
2744 ("more than one value supplied for &",
2745 Selector_Name, Compon);
2750 Next (Selector_Name);
2759 -----------------------
2760 -- Resolve_Aggr_Expr --
2761 -----------------------
2763 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id) is
2764 New_C : Entity_Id := Component;
2765 Expr_Type : Entity_Id := Empty;
2767 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean;
2768 -- If the expression is an aggregate (possibly qualified) then its
2769 -- expansion is delayed until the enclosing aggregate is expanded
2770 -- into assignments. In that case, do not generate checks on the
2771 -- expression, because they will be generated later, and will other-
2772 -- wise force a copy (to remove side-effects) that would leave a
2773 -- dynamic-sized aggregate in the code, something that gigi cannot
2777 -- Set to True if the resolved Expr node needs to be relocated
2778 -- when attached to the newly created association list. This node
2779 -- need not be relocated if its parent pointer is not set.
2780 -- In fact in this case Expr is the output of a New_Copy_Tree call.
2781 -- if Relocate is True then we have analyzed the expression node
2782 -- in the original aggregate and hence it needs to be relocated
2783 -- when moved over the new association list.
2785 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean is
2786 Kind : constant Node_Kind := Nkind (Expr);
2788 return (Nkind_In (Kind, N_Aggregate, N_Extension_Aggregate)
2789 and then Present (Etype (Expr))
2790 and then Is_Record_Type (Etype (Expr))
2791 and then Expansion_Delayed (Expr))
2792 or else (Kind = N_Qualified_Expression
2793 and then Has_Expansion_Delayed (Expression (Expr)));
2794 end Has_Expansion_Delayed;
2796 -- Start of processing for Resolve_Aggr_Expr
2799 -- If the type of the component is elementary or the type of the
2800 -- aggregate does not contain discriminants, use the type of the
2801 -- component to resolve Expr.
2803 if Is_Elementary_Type (Etype (Component))
2804 or else not Has_Discriminants (Etype (N))
2806 Expr_Type := Etype (Component);
2808 -- Otherwise we have to pick up the new type of the component from
2809 -- the new constrained subtype of the aggregate. In fact components
2810 -- which are of a composite type might be constrained by a
2811 -- discriminant, and we want to resolve Expr against the subtype were
2812 -- all discriminant occurrences are replaced with their actual value.
2815 New_C := First_Component (Etype (N));
2816 while Present (New_C) loop
2817 if Chars (New_C) = Chars (Component) then
2818 Expr_Type := Etype (New_C);
2822 Next_Component (New_C);
2825 pragma Assert (Present (Expr_Type));
2827 -- For each range in an array type where a discriminant has been
2828 -- replaced with the constraint, check that this range is within
2829 -- the range of the base type. This checks is done in the init
2830 -- proc for regular objects, but has to be done here for
2831 -- aggregates since no init proc is called for them.
2833 if Is_Array_Type (Expr_Type) then
2836 -- Range of the current constrained index in the array
2838 Orig_Index : Node_Id := First_Index (Etype (Component));
2839 -- Range corresponding to the range Index above in the
2840 -- original unconstrained record type. The bounds of this
2841 -- range may be governed by discriminants.
2843 Unconstr_Index : Node_Id := First_Index (Etype (Expr_Type));
2844 -- Range corresponding to the range Index above for the
2845 -- unconstrained array type. This range is needed to apply
2849 Index := First_Index (Expr_Type);
2850 while Present (Index) loop
2851 if Depends_On_Discriminant (Orig_Index) then
2852 Apply_Range_Check (Index, Etype (Unconstr_Index));
2856 Next_Index (Orig_Index);
2857 Next_Index (Unconstr_Index);
2863 -- If the Parent pointer of Expr is not set, Expr is an expression
2864 -- duplicated by New_Tree_Copy (this happens for record aggregates
2865 -- that look like (Field1 | Filed2 => Expr) or (others => Expr)).
2866 -- Such a duplicated expression must be attached to the tree
2867 -- before analysis and resolution to enforce the rule that a tree
2868 -- fragment should never be analyzed or resolved unless it is
2869 -- attached to the current compilation unit.
2871 if No (Parent (Expr)) then
2872 Set_Parent (Expr, N);
2878 Analyze_And_Resolve (Expr, Expr_Type);
2879 Check_Expr_OK_In_Limited_Aggregate (Expr);
2880 Check_Non_Static_Context (Expr);
2881 Check_Unset_Reference (Expr);
2883 -- Check wrong use of class-wide types
2885 if Is_Class_Wide_Type (Etype (Expr)) then
2886 Error_Msg_N ("dynamically tagged expression not allowed", Expr);
2889 if not Has_Expansion_Delayed (Expr) then
2890 Aggregate_Constraint_Checks (Expr, Expr_Type);
2893 if Raises_Constraint_Error (Expr) then
2894 Set_Raises_Constraint_Error (N);
2897 -- If the expression has been marked as requiring a range check,
2898 -- then generate it here.
2900 if Do_Range_Check (Expr) then
2901 Set_Do_Range_Check (Expr, False);
2902 Generate_Range_Check (Expr, Expr_Type, CE_Range_Check_Failed);
2906 Add_Association (New_C, Relocate_Node (Expr), New_Assoc_List);
2908 Add_Association (New_C, Expr, New_Assoc_List);
2910 end Resolve_Aggr_Expr;
2912 -- Start of processing for Resolve_Record_Aggregate
2915 -- We may end up calling Duplicate_Subexpr on expressions that are
2916 -- attached to New_Assoc_List. For this reason we need to attach it
2917 -- to the tree by setting its parent pointer to N. This parent point
2918 -- will change in STEP 8 below.
2920 Set_Parent (New_Assoc_List, N);
2922 -- STEP 1: abstract type and null record verification
2924 if Is_Abstract_Type (Typ) then
2925 Error_Msg_N ("type of aggregate cannot be abstract", N);
2928 if No (First_Entity (Typ)) and then Null_Record_Present (N) then
2932 elsif Present (First_Entity (Typ))
2933 and then Null_Record_Present (N)
2934 and then not Is_Tagged_Type (Typ)
2936 Error_Msg_N ("record aggregate cannot be null", N);
2939 -- If the type has no components, then the aggregate should either
2940 -- have "null record", or in Ada 2005 it could instead have a single
2941 -- component association given by "others => <>". For Ada 95 we flag
2942 -- an error at this point, but for Ada 2005 we proceed with checking
2943 -- the associations below, which will catch the case where it's not
2944 -- an aggregate with "others => <>". Note that the legality of a <>
2945 -- aggregate for a null record type was established by AI05-016.
2947 elsif No (First_Entity (Typ))
2948 and then Ada_Version < Ada_05
2950 Error_Msg_N ("record aggregate must be null", N);
2954 -- STEP 2: Verify aggregate structure
2957 Selector_Name : Node_Id;
2958 Bad_Aggregate : Boolean := False;
2961 if Present (Component_Associations (N)) then
2962 Assoc := First (Component_Associations (N));
2967 while Present (Assoc) loop
2968 Selector_Name := First (Choices (Assoc));
2969 while Present (Selector_Name) loop
2970 if Nkind (Selector_Name) = N_Identifier then
2973 elsif Nkind (Selector_Name) = N_Others_Choice then
2974 if Selector_Name /= First (Choices (Assoc))
2975 or else Present (Next (Selector_Name))
2977 Error_Msg_N ("OTHERS must appear alone in a choice list",
2981 elsif Present (Next (Assoc)) then
2982 Error_Msg_N ("OTHERS must appear last in an aggregate",
2986 -- (Ada2005): If this is an association with a box,
2987 -- indicate that the association need not represent
2990 elsif Box_Present (Assoc) then
2996 ("selector name should be identifier or OTHERS",
2998 Bad_Aggregate := True;
3001 Next (Selector_Name);
3007 if Bad_Aggregate then
3012 -- STEP 3: Find discriminant Values
3015 Discrim : Entity_Id;
3016 Missing_Discriminants : Boolean := False;
3019 if Present (Expressions (N)) then
3020 Positional_Expr := First (Expressions (N));
3022 Positional_Expr := Empty;
3025 if Has_Unknown_Discriminants (Typ)
3026 and then Present (Underlying_Record_View (Typ))
3028 Discrim := First_Discriminant (Underlying_Record_View (Typ));
3029 elsif Has_Discriminants (Typ) then
3030 Discrim := First_Discriminant (Typ);
3035 -- First find the discriminant values in the positional components
3037 while Present (Discrim) and then Present (Positional_Expr) loop
3038 if Discr_Present (Discrim) then
3039 Resolve_Aggr_Expr (Positional_Expr, Discrim);
3041 -- Ada 2005 (AI-231)
3043 if Ada_Version >= Ada_05
3044 and then Known_Null (Positional_Expr)
3046 Check_Can_Never_Be_Null (Discrim, Positional_Expr);
3049 Next (Positional_Expr);
3052 if Present (Get_Value (Discrim, Component_Associations (N))) then
3054 ("more than one value supplied for discriminant&",
3058 Next_Discriminant (Discrim);
3061 -- Find remaining discriminant values, if any, among named components
3063 while Present (Discrim) loop
3064 Expr := Get_Value (Discrim, Component_Associations (N), True);
3066 if not Discr_Present (Discrim) then
3067 if Present (Expr) then
3069 ("more than one value supplied for discriminant&",
3073 elsif No (Expr) then
3075 ("no value supplied for discriminant &", N, Discrim);
3076 Missing_Discriminants := True;
3079 Resolve_Aggr_Expr (Expr, Discrim);
3082 Next_Discriminant (Discrim);
3085 if Missing_Discriminants then
3089 -- At this point and until the beginning of STEP 6, New_Assoc_List
3090 -- contains only the discriminants and their values.
3094 -- STEP 4: Set the Etype of the record aggregate
3096 -- ??? This code is pretty much a copy of Sem_Ch3.Build_Subtype. That
3097 -- routine should really be exported in sem_util or some such and used
3098 -- in sem_ch3 and here rather than have a copy of the code which is a
3099 -- maintenance nightmare.
3101 -- ??? Performance WARNING. The current implementation creates a new
3102 -- itype for all aggregates whose base type is discriminated.
3103 -- This means that for record aggregates nested inside an array
3104 -- aggregate we will create a new itype for each record aggregate
3105 -- if the array component type has discriminants. For large aggregates
3106 -- this may be a problem. What should be done in this case is
3107 -- to reuse itypes as much as possible.
3109 if Has_Discriminants (Typ)
3110 or else (Has_Unknown_Discriminants (Typ)
3111 and then Present (Underlying_Record_View (Typ)))
3113 Build_Constrained_Itype : declare
3114 Loc : constant Source_Ptr := Sloc (N);
3116 Subtyp_Decl : Node_Id;
3119 C : constant List_Id := New_List;
3122 New_Assoc := First (New_Assoc_List);
3123 while Present (New_Assoc) loop
3124 Append (Duplicate_Subexpr (Expression (New_Assoc)), To => C);
3128 if Has_Unknown_Discriminants (Typ)
3129 and then Present (Underlying_Record_View (Typ))
3132 Make_Subtype_Indication (Loc,
3134 New_Occurrence_Of (Underlying_Record_View (Typ), Loc),
3136 Make_Index_Or_Discriminant_Constraint (Loc, C));
3139 Make_Subtype_Indication (Loc,
3141 New_Occurrence_Of (Base_Type (Typ), Loc),
3143 Make_Index_Or_Discriminant_Constraint (Loc, C));
3146 Def_Id := Create_Itype (Ekind (Typ), N);
3149 Make_Subtype_Declaration (Loc,
3150 Defining_Identifier => Def_Id,
3151 Subtype_Indication => Indic);
3152 Set_Parent (Subtyp_Decl, Parent (N));
3154 -- Itypes must be analyzed with checks off (see itypes.ads)
3156 Analyze (Subtyp_Decl, Suppress => All_Checks);
3158 Set_Etype (N, Def_Id);
3159 Check_Static_Discriminated_Subtype
3160 (Def_Id, Expression (First (New_Assoc_List)));
3161 end Build_Constrained_Itype;
3167 -- STEP 5: Get remaining components according to discriminant values
3170 Record_Def : Node_Id;
3171 Parent_Typ : Entity_Id;
3172 Root_Typ : Entity_Id;
3173 Parent_Typ_List : Elist_Id;
3174 Parent_Elmt : Elmt_Id;
3175 Errors_Found : Boolean := False;
3179 if Is_Derived_Type (Typ) and then Is_Tagged_Type (Typ) then
3180 Parent_Typ_List := New_Elmt_List;
3182 -- If this is an extension aggregate, the component list must
3183 -- include all components that are not in the given ancestor type.
3184 -- Otherwise, the component list must include components of all
3185 -- ancestors, starting with the root.
3187 if Nkind (N) = N_Extension_Aggregate then
3188 Root_Typ := Base_Type (Etype (Ancestor_Part (N)));
3191 Root_Typ := Root_Type (Typ);
3193 if Nkind (Parent (Base_Type (Root_Typ))) =
3194 N_Private_Type_Declaration
3197 ("type of aggregate has private ancestor&!",
3199 Error_Msg_N ("must use extension aggregate!", N);
3203 Dnode := Declaration_Node (Base_Type (Root_Typ));
3205 -- If we don't get a full declaration, then we have some
3206 -- error which will get signalled later so skip this part.
3207 -- Otherwise, gather components of root that apply to the
3208 -- aggregate type. We use the base type in case there is an
3209 -- applicable stored constraint that renames the discriminants
3212 if Nkind (Dnode) = N_Full_Type_Declaration then
3213 Record_Def := Type_Definition (Dnode);
3214 Gather_Components (Base_Type (Typ),
3215 Component_List (Record_Def),
3216 Governed_By => New_Assoc_List,
3218 Report_Errors => Errors_Found);
3222 Parent_Typ := Base_Type (Typ);
3223 while Parent_Typ /= Root_Typ loop
3224 Prepend_Elmt (Parent_Typ, To => Parent_Typ_List);
3225 Parent_Typ := Etype (Parent_Typ);
3227 if Nkind (Parent (Base_Type (Parent_Typ))) =
3228 N_Private_Type_Declaration
3229 or else Nkind (Parent (Base_Type (Parent_Typ))) =
3230 N_Private_Extension_Declaration
3232 if Nkind (N) /= N_Extension_Aggregate then
3234 ("type of aggregate has private ancestor&!",
3236 Error_Msg_N ("must use extension aggregate!", N);
3239 elsif Parent_Typ /= Root_Typ then
3241 ("ancestor part of aggregate must be private type&",
3242 Ancestor_Part (N), Parent_Typ);
3248 -- Now collect components from all other ancestors, beginning
3249 -- with the current type. If the type has unknown discriminants
3250 -- use the component list of the Underlying_Record_View, which
3251 -- needs to be used for the subsequent expansion of the aggregate
3252 -- into assignments.
3254 Parent_Elmt := First_Elmt (Parent_Typ_List);
3255 while Present (Parent_Elmt) loop
3256 Parent_Typ := Node (Parent_Elmt);
3258 if Has_Unknown_Discriminants (Parent_Typ)
3259 and then Present (Underlying_Record_View (Typ))
3261 Parent_Typ := Underlying_Record_View (Parent_Typ);
3264 Record_Def := Type_Definition (Parent (Base_Type (Parent_Typ)));
3265 Gather_Components (Empty,
3266 Component_List (Record_Extension_Part (Record_Def)),
3267 Governed_By => New_Assoc_List,
3269 Report_Errors => Errors_Found);
3271 Next_Elmt (Parent_Elmt);
3275 Record_Def := Type_Definition (Parent (Base_Type (Typ)));
3277 if Null_Present (Record_Def) then
3280 elsif not Has_Unknown_Discriminants (Typ) then
3281 Gather_Components (Base_Type (Typ),
3282 Component_List (Record_Def),
3283 Governed_By => New_Assoc_List,
3285 Report_Errors => Errors_Found);
3289 (Base_Type (Underlying_Record_View (Typ)),
3290 Component_List (Record_Def),
3291 Governed_By => New_Assoc_List,
3293 Report_Errors => Errors_Found);
3297 if Errors_Found then
3302 -- STEP 6: Find component Values
3305 Component_Elmt := First_Elmt (Components);
3307 -- First scan the remaining positional associations in the aggregate.
3308 -- Remember that at this point Positional_Expr contains the current
3309 -- positional association if any is left after looking for discriminant
3310 -- values in step 3.
3312 while Present (Positional_Expr) and then Present (Component_Elmt) loop
3313 Component := Node (Component_Elmt);
3314 Resolve_Aggr_Expr (Positional_Expr, Component);
3316 -- Ada 2005 (AI-231)
3318 if Ada_Version >= Ada_05
3319 and then Known_Null (Positional_Expr)
3321 Check_Can_Never_Be_Null (Component, Positional_Expr);
3324 if Present (Get_Value (Component, Component_Associations (N))) then
3326 ("more than one value supplied for Component &", N, Component);
3329 Next (Positional_Expr);
3330 Next_Elmt (Component_Elmt);
3333 if Present (Positional_Expr) then
3335 ("too many components for record aggregate", Positional_Expr);
3338 -- Now scan for the named arguments of the aggregate
3340 while Present (Component_Elmt) loop
3341 Component := Node (Component_Elmt);
3342 Expr := Get_Value (Component, Component_Associations (N), True);
3344 -- Note: The previous call to Get_Value sets the value of the
3345 -- variable Is_Box_Present.
3347 -- Ada 2005 (AI-287): Handle components with default initialization.
3348 -- Note: This feature was originally added to Ada 2005 for limited
3349 -- but it was finally allowed with any type.
3351 if Is_Box_Present then
3352 Check_Box_Component : declare
3353 Ctyp : constant Entity_Id := Etype (Component);
3356 -- If there is a default expression for the aggregate, copy
3357 -- it into a new association.
3359 -- If the component has an initialization procedure (IP) we
3360 -- pass the component to the expander, which will generate
3361 -- the call to such IP.
3363 -- If the component has discriminants, their values must
3364 -- be taken from their subtype. This is indispensable for
3365 -- constraints that are given by the current instance of an
3366 -- enclosing type, to allow the expansion of the aggregate
3367 -- to replace the reference to the current instance by the
3368 -- target object of the aggregate.
3370 if Present (Parent (Component))
3372 Nkind (Parent (Component)) = N_Component_Declaration
3373 and then Present (Expression (Parent (Component)))
3376 New_Copy_Tree (Expression (Parent (Component)),
3377 New_Sloc => Sloc (N));
3380 (Component => Component,
3382 Assoc_List => New_Assoc_List);
3383 Set_Has_Self_Reference (N);
3385 -- A box-defaulted access component gets the value null. Also
3386 -- included are components of private types whose underlying
3387 -- type is an access type. In either case set the type of the
3388 -- literal, for subsequent use in semantic checks.
3390 elsif Present (Underlying_Type (Ctyp))
3391 and then Is_Access_Type (Underlying_Type (Ctyp))
3393 if not Is_Private_Type (Ctyp) then
3394 Expr := Make_Null (Sloc (N));
3395 Set_Etype (Expr, Ctyp);
3397 (Component => Component,
3399 Assoc_List => New_Assoc_List);
3401 -- If the component's type is private with an access type as
3402 -- its underlying type then we have to create an unchecked
3403 -- conversion to satisfy type checking.
3407 Qual_Null : constant Node_Id :=
3408 Make_Qualified_Expression (Sloc (N),
3411 (Underlying_Type (Ctyp), Sloc (N)),
3412 Expression => Make_Null (Sloc (N)));
3414 Convert_Null : constant Node_Id :=
3415 Unchecked_Convert_To
3419 Analyze_And_Resolve (Convert_Null, Ctyp);
3421 (Component => Component,
3422 Expr => Convert_Null,
3423 Assoc_List => New_Assoc_List);
3427 elsif Has_Non_Null_Base_Init_Proc (Ctyp)
3428 or else not Expander_Active
3430 if Is_Record_Type (Ctyp)
3431 and then Has_Discriminants (Ctyp)
3432 and then not Is_Private_Type (Ctyp)
3434 -- We build a partially initialized aggregate with the
3435 -- values of the discriminants and box initialization
3436 -- for the rest, if other components are present.
3437 -- The type of the aggregate is the known subtype of
3438 -- the component. The capture of discriminants must
3439 -- be recursive because subcomponents may be contrained
3440 -- (transitively) by discriminants of enclosing types.
3441 -- For a private type with discriminants, a call to the
3442 -- initialization procedure will be generated, and no
3443 -- subaggregate is needed.
3445 Capture_Discriminants : declare
3446 Loc : constant Source_Ptr := Sloc (N);
3449 procedure Add_Discriminant_Values
3450 (New_Aggr : Node_Id;
3451 Assoc_List : List_Id);
3452 -- The constraint to a component may be given by a
3453 -- discriminant of the enclosing type, in which case
3454 -- we have to retrieve its value, which is part of the
3455 -- enclosing aggregate. Assoc_List provides the
3456 -- discriminant associations of the current type or
3457 -- of some enclosing record.
3459 procedure Propagate_Discriminants
3461 Assoc_List : List_Id;
3463 -- Nested components may themselves be discriminated
3464 -- types constrained by outer discriminants, whose
3465 -- values must be captured before the aggregate is
3466 -- expanded into assignments.
3468 -----------------------------
3469 -- Add_Discriminant_Values --
3470 -----------------------------
3472 procedure Add_Discriminant_Values
3473 (New_Aggr : Node_Id;
3474 Assoc_List : List_Id)
3478 Discr_Elmt : Elmt_Id;
3479 Discr_Val : Node_Id;
3483 Discr := First_Discriminant (Etype (New_Aggr));
3486 (Discriminant_Constraint (Etype (New_Aggr)));
3487 while Present (Discr_Elmt) loop
3488 Discr_Val := Node (Discr_Elmt);
3490 -- If the constraint is given by a discriminant
3491 -- it is a discriminant of an enclosing record,
3492 -- and its value has already been placed in the
3493 -- association list.
3495 if Is_Entity_Name (Discr_Val)
3497 Ekind (Entity (Discr_Val)) = E_Discriminant
3499 Val := Entity (Discr_Val);
3501 Assoc := First (Assoc_List);
3502 while Present (Assoc) loop
3504 (Entity (First (Choices (Assoc))))
3506 Entity (First (Choices (Assoc)))
3509 Discr_Val := Expression (Assoc);
3517 (Discr, New_Copy_Tree (Discr_Val),
3518 Component_Associations (New_Aggr));
3520 -- If the discriminant constraint is a current
3521 -- instance, mark the current aggregate so that
3522 -- the self-reference can be expanded later.
3524 if Nkind (Discr_Val) = N_Attribute_Reference
3525 and then Is_Entity_Name (Prefix (Discr_Val))
3526 and then Is_Type (Entity (Prefix (Discr_Val)))
3527 and then Etype (N) =
3528 Entity (Prefix (Discr_Val))
3530 Set_Has_Self_Reference (N);
3533 Next_Elmt (Discr_Elmt);
3534 Next_Discriminant (Discr);
3536 end Add_Discriminant_Values;
3538 ------------------------------
3539 -- Propagate_Discriminants --
3540 ------------------------------
3542 procedure Propagate_Discriminants
3544 Assoc_List : List_Id;
3547 Inner_Comp : Entity_Id;
3548 Comp_Type : Entity_Id;
3549 Needs_Box : Boolean := False;
3554 Inner_Comp := First_Component (Etype (Comp));
3555 while Present (Inner_Comp) loop
3556 Comp_Type := Etype (Inner_Comp);
3558 if Is_Record_Type (Comp_Type)
3559 and then Has_Discriminants (Comp_Type)
3562 Make_Aggregate (Loc, New_List, New_List);
3563 Set_Etype (New_Aggr, Comp_Type);
3565 (Inner_Comp, New_Aggr,
3566 Component_Associations (Aggr));
3568 -- Collect discriminant values and recurse
3570 Add_Discriminant_Values
3571 (New_Aggr, Assoc_List);
3572 Propagate_Discriminants
3573 (New_Aggr, Assoc_List, Inner_Comp);
3579 Next_Component (Inner_Comp);
3584 (Make_Component_Association (Loc,
3586 New_List (Make_Others_Choice (Loc)),
3587 Expression => Empty,
3588 Box_Present => True),
3589 Component_Associations (Aggr));
3591 end Propagate_Discriminants;
3594 Expr := Make_Aggregate (Loc, New_List, New_List);
3595 Set_Etype (Expr, Ctyp);
3597 -- If the enclosing type has discriminants, they
3598 -- have been collected in the aggregate earlier, and
3599 -- they may appear as constraints of subcomponents.
3600 -- Similarly if this component has discriminants, they
3601 -- might in turn be propagated to their components.
3603 if Has_Discriminants (Typ) then
3604 Add_Discriminant_Values (Expr, New_Assoc_List);
3605 Propagate_Discriminants
3606 (Expr, New_Assoc_List, Component);
3608 elsif Has_Discriminants (Ctyp) then
3609 Add_Discriminant_Values
3610 (Expr, Component_Associations (Expr));
3611 Propagate_Discriminants
3612 (Expr, Component_Associations (Expr), Component);
3619 -- If the type has additional components, create
3620 -- an OTHERS box association for them.
3622 Comp := First_Component (Ctyp);
3623 while Present (Comp) loop
3624 if Ekind (Comp) = E_Component then
3625 if not Is_Record_Type (Etype (Comp)) then
3627 (Make_Component_Association (Loc,
3630 (Make_Others_Choice (Loc)),
3631 Expression => Empty,
3632 Box_Present => True),
3633 Component_Associations (Expr));
3638 Next_Component (Comp);
3644 (Component => Component,
3646 Assoc_List => New_Assoc_List);
3647 end Capture_Discriminants;
3651 (Component => Component,
3653 Assoc_List => New_Assoc_List,
3654 Is_Box_Present => True);
3657 -- Otherwise we only need to resolve the expression if the
3658 -- component has partially initialized values (required to
3659 -- expand the corresponding assignments and run-time checks).
3661 elsif Present (Expr)
3662 and then Is_Partially_Initialized_Type (Ctyp)
3664 Resolve_Aggr_Expr (Expr, Component);
3666 end Check_Box_Component;
3668 elsif No (Expr) then
3670 -- Ignore hidden components associated with the position of the
3671 -- interface tags: these are initialized dynamically.
3673 if not Present (Related_Type (Component)) then
3675 ("no value supplied for component &!", N, Component);
3679 Resolve_Aggr_Expr (Expr, Component);
3682 Next_Elmt (Component_Elmt);
3685 -- STEP 7: check for invalid components + check type in choice list
3692 -- Type of first component in choice list
3695 if Present (Component_Associations (N)) then
3696 Assoc := First (Component_Associations (N));
3701 Verification : while Present (Assoc) loop
3702 Selectr := First (Choices (Assoc));
3705 if Nkind (Selectr) = N_Others_Choice then
3707 -- Ada 2005 (AI-287): others choice may have expression or box
3709 if No (Others_Etype)
3710 and then not Others_Box
3713 ("OTHERS must represent at least one component", Selectr);
3719 while Present (Selectr) loop
3720 New_Assoc := First (New_Assoc_List);
3721 while Present (New_Assoc) loop
3722 Component := First (Choices (New_Assoc));
3723 exit when Chars (Selectr) = Chars (Component);
3727 -- If no association, this is not a legal component of
3728 -- of the type in question, except if its association
3729 -- is provided with a box.
3731 if No (New_Assoc) then
3732 if Box_Present (Parent (Selectr)) then
3734 -- This may still be a bogus component with a box. Scan
3735 -- list of components to verify that a component with
3736 -- that name exists.
3742 C := First_Component (Typ);
3743 while Present (C) loop
3744 if Chars (C) = Chars (Selectr) then
3746 -- If the context is an extension aggregate,
3747 -- the component must not be inherited from
3748 -- the ancestor part of the aggregate.
3750 if Nkind (N) /= N_Extension_Aggregate
3752 Scope (Original_Record_Component (C)) /=
3753 Etype (Ancestor_Part (N))
3763 Error_Msg_Node_2 := Typ;
3764 Error_Msg_N ("& is not a component of}", Selectr);
3768 elsif Chars (Selectr) /= Name_uTag
3769 and then Chars (Selectr) /= Name_uParent
3770 and then Chars (Selectr) /= Name_uController
3772 if not Has_Discriminants (Typ) then
3773 Error_Msg_Node_2 := Typ;
3774 Error_Msg_N ("& is not a component of}", Selectr);
3777 ("& is not a component of the aggregate subtype",
3781 Check_Misspelled_Component (Components, Selectr);
3784 elsif No (Typech) then
3785 Typech := Base_Type (Etype (Component));
3787 elsif Typech /= Base_Type (Etype (Component)) then
3788 if not Box_Present (Parent (Selectr)) then
3790 ("components in choice list must have same type",
3799 end loop Verification;
3802 -- STEP 8: replace the original aggregate
3805 New_Aggregate : constant Node_Id := New_Copy (N);
3808 Set_Expressions (New_Aggregate, No_List);
3809 Set_Etype (New_Aggregate, Etype (N));
3810 Set_Component_Associations (New_Aggregate, New_Assoc_List);
3812 Rewrite (N, New_Aggregate);
3814 end Resolve_Record_Aggregate;
3816 -----------------------------
3817 -- Check_Can_Never_Be_Null --
3818 -----------------------------
3820 procedure Check_Can_Never_Be_Null (Typ : Entity_Id; Expr : Node_Id) is
3821 Comp_Typ : Entity_Id;
3825 (Ada_Version >= Ada_05
3826 and then Present (Expr)
3827 and then Known_Null (Expr));
3830 when E_Array_Type =>
3831 Comp_Typ := Component_Type (Typ);
3835 Comp_Typ := Etype (Typ);
3841 if Can_Never_Be_Null (Comp_Typ) then
3843 -- Here we know we have a constraint error. Note that we do not use
3844 -- Apply_Compile_Time_Constraint_Error here to the Expr, which might
3845 -- seem the more natural approach. That's because in some cases the
3846 -- components are rewritten, and the replacement would be missed.
3849 (Compile_Time_Constraint_Error
3851 "(Ada 2005) null not allowed in null-excluding component?"),
3852 Make_Raise_Constraint_Error (Sloc (Expr),
3853 Reason => CE_Access_Check_Failed));
3855 -- Set proper type for bogus component (why is this needed???)
3857 Set_Etype (Expr, Comp_Typ);
3858 Set_Analyzed (Expr);
3860 end Check_Can_Never_Be_Null;
3862 ---------------------
3863 -- Sort_Case_Table --
3864 ---------------------
3866 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
3867 L : constant Int := Case_Table'First;
3868 U : constant Int := Case_Table'Last;
3876 T := Case_Table (K + 1);
3880 and then Expr_Value (Case_Table (J - 1).Choice_Lo) >
3881 Expr_Value (T.Choice_Lo)
3883 Case_Table (J) := Case_Table (J - 1);
3887 Case_Table (J) := T;
3890 end Sort_Case_Table;
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