1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2008, 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 Exp_Tss; use Exp_Tss;
32 with Exp_Util; use Exp_Util;
33 with Freeze; use Freeze;
34 with Itypes; use Itypes;
36 with Lib.Xref; use Lib.Xref;
37 with Namet; use Namet;
38 with Namet.Sp; use Namet.Sp;
39 with Nmake; use Nmake;
40 with Nlists; use Nlists;
43 with Sem_Cat; use Sem_Cat;
44 with Sem_Ch3; use Sem_Ch3;
45 with Sem_Ch13; use Sem_Ch13;
46 with Sem_Eval; use Sem_Eval;
47 with Sem_Res; use Sem_Res;
48 with Sem_Util; use Sem_Util;
49 with Sem_Type; use Sem_Type;
50 with Sem_Warn; use Sem_Warn;
51 with Sinfo; use Sinfo;
52 with Snames; use Snames;
53 with Stringt; use Stringt;
54 with Stand; use Stand;
55 with Targparm; use Targparm;
56 with Tbuild; use Tbuild;
57 with Uintp; use Uintp;
59 package body Sem_Aggr is
61 type Case_Bounds is record
64 Choice_Node : Node_Id;
67 type Case_Table_Type is array (Nat range <>) of Case_Bounds;
68 -- Table type used by Check_Case_Choices procedure
70 -----------------------
71 -- Local Subprograms --
72 -----------------------
74 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
75 -- Sort the Case Table using the Lower Bound of each Choice as the key.
76 -- A simple insertion sort is used since the number of choices in a case
77 -- statement of variant part will usually be small and probably in near
80 procedure Check_Can_Never_Be_Null (Typ : Entity_Id; Expr : Node_Id);
81 -- Ada 2005 (AI-231): Check bad usage of null for a component for which
82 -- null exclusion (NOT NULL) is specified. Typ can be an E_Array_Type for
83 -- the array case (the component type of the array will be used) or an
84 -- E_Component/E_Discriminant entity in the record case, in which case the
85 -- type of the component will be used for the test. If Typ is any other
86 -- kind of entity, the call is ignored. Expr is the component node in the
87 -- aggregate which is known to have a null value. A warning message will be
88 -- issued if the component is null excluding.
90 -- It would be better to pass the proper type for Typ ???
92 procedure Check_Expr_OK_In_Limited_Aggregate (Expr : Node_Id);
93 -- Check that Expr is either not limited or else is one of the cases of
94 -- expressions allowed for a limited component association (namely, an
95 -- aggregate, function call, or <> notation). Report error for violations.
97 ------------------------------------------------------
98 -- Subprograms used for RECORD AGGREGATE Processing --
99 ------------------------------------------------------
101 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id);
102 -- This procedure performs all the semantic checks required for record
103 -- aggregates. Note that for aggregates analysis and resolution go
104 -- hand in hand. Aggregate analysis has been delayed up to here and
105 -- it is done while resolving the aggregate.
107 -- N is the N_Aggregate node.
108 -- Typ is the record type for the aggregate resolution
110 -- While performing the semantic checks, this procedure builds a new
111 -- Component_Association_List where each record field appears alone in a
112 -- Component_Choice_List along with its corresponding expression. The
113 -- record fields in the Component_Association_List appear in the same order
114 -- in which they appear in the record type Typ.
116 -- Once this new Component_Association_List is built and all the semantic
117 -- checks performed, the original aggregate subtree is replaced with the
118 -- new named record aggregate just built. Note that subtree substitution is
119 -- performed with Rewrite so as to be able to retrieve the original
122 -- The aggregate subtree manipulation performed by Resolve_Record_Aggregate
123 -- yields the aggregate format expected by Gigi. Typically, this kind of
124 -- tree manipulations are done in the expander. However, because the
125 -- semantic checks that need to be performed on record aggregates really go
126 -- hand in hand with the record aggregate normalization, the aggregate
127 -- subtree transformation is performed during resolution rather than
128 -- expansion. Had we decided otherwise we would have had to duplicate most
129 -- of the code in the expansion procedure Expand_Record_Aggregate. Note,
130 -- however, that all the expansion concerning aggregates for tagged records
131 -- is done in Expand_Record_Aggregate.
133 -- The algorithm of Resolve_Record_Aggregate proceeds as follows:
135 -- 1. Make sure that the record type against which the record aggregate
136 -- has to be resolved is not abstract. Furthermore if the type is
137 -- a null aggregate make sure the input aggregate N is also null.
139 -- 2. Verify that the structure of the aggregate is that of a record
140 -- aggregate. Specifically, look for component associations and ensure
141 -- that each choice list only has identifiers or the N_Others_Choice
142 -- node. Also make sure that if present, the N_Others_Choice occurs
143 -- last and by itself.
145 -- 3. If Typ contains discriminants, the values for each discriminant
146 -- is looked for. If the record type Typ has variants, we check
147 -- that the expressions corresponding to each discriminant ruling
148 -- the (possibly nested) variant parts of Typ, are static. This
149 -- allows us to determine the variant parts to which the rest of
150 -- the aggregate must conform. The names of discriminants with their
151 -- values are saved in a new association list, New_Assoc_List which
152 -- is later augmented with the names and values of the remaining
153 -- components in the record type.
155 -- During this phase we also make sure that every discriminant is
156 -- assigned exactly one value. Note that when several values
157 -- for a given discriminant are found, semantic processing continues
158 -- looking for further errors. In this case it's the first
159 -- discriminant value found which we will be recorded.
161 -- IMPORTANT NOTE: For derived tagged types this procedure expects
162 -- First_Discriminant and Next_Discriminant to give the correct list
163 -- of discriminants, in the correct order.
165 -- 4. After all the discriminant values have been gathered, we can
166 -- set the Etype of the record aggregate. If Typ contains no
167 -- discriminants this is straightforward: the Etype of N is just
168 -- Typ, otherwise a new implicit constrained subtype of Typ is
169 -- 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
179 -- in the record aggregate and emit appropriate error messages
180 -- should we not find such values or should they be duplicated.
182 -- 7. We then make sure no illegal component names appear in the
183 -- record aggregate and make sure that the type of the record
184 -- components appearing in a same choice list is the same.
185 -- Finally we ensure that the others choice, if present, is
186 -- used to provide the value of at least a record component.
188 -- 8. The original aggregate node is replaced with the new named
189 -- aggregate built in steps 3 through 6, as explained earlier.
191 -- Given the complexity of record aggregate resolution, the primary
192 -- goal of this routine is clarity and simplicity rather than execution
193 -- and storage efficiency. If there are only positional components in the
194 -- aggregate the running time is linear. If there are associations
195 -- the running time is still linear as long as the order of the
196 -- associations is not too far off the order of the components in the
197 -- record type. If this is not the case the running time is at worst
198 -- quadratic in the size of the association list.
200 procedure Check_Misspelled_Component
201 (Elements : Elist_Id;
202 Component : Node_Id);
203 -- Give possible misspelling diagnostic if Component is likely to be
204 -- a misspelling of one of the components of the Assoc_List.
205 -- This is called by Resolve_Aggr_Expr after producing
206 -- an invalid component error message.
208 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id);
209 -- An optimization: determine whether a discriminated subtype has a
210 -- static constraint, and contains array components whose length is also
211 -- static, either because they are constrained by the discriminant, or
212 -- because the original component bounds are static.
214 -----------------------------------------------------
215 -- Subprograms used for ARRAY AGGREGATE Processing --
216 -----------------------------------------------------
218 function Resolve_Array_Aggregate
221 Index_Constr : Node_Id;
222 Component_Typ : Entity_Id;
223 Others_Allowed : Boolean) return Boolean;
224 -- This procedure performs the semantic checks for an array aggregate.
225 -- True is returned if the aggregate resolution succeeds.
227 -- The procedure works by recursively checking each nested aggregate.
228 -- Specifically, after checking a sub-aggregate nested at the i-th level
229 -- we recursively check all the subaggregates at the i+1-st level (if any).
230 -- Note that for aggregates analysis and resolution go hand in hand.
231 -- Aggregate analysis has been delayed up to here and it is done while
232 -- resolving the aggregate.
234 -- N is the current N_Aggregate node to be checked.
236 -- Index is the index node corresponding to the array sub-aggregate that
237 -- we are currently checking (RM 4.3.3 (8)). Its Etype is the
238 -- corresponding index type (or subtype).
240 -- Index_Constr is the node giving the applicable index constraint if
241 -- any (RM 4.3.3 (10)). It "is a constraint provided by certain
242 -- contexts [...] that can be used to determine the bounds of the array
243 -- value specified by the aggregate". If Others_Allowed below is False
244 -- there is no applicable index constraint and this node is set to Index.
246 -- Component_Typ is the array component type.
248 -- Others_Allowed indicates whether an others choice is allowed
249 -- in the context where the top-level aggregate appeared.
251 -- The algorithm of Resolve_Array_Aggregate proceeds as follows:
253 -- 1. Make sure that the others choice, if present, is by itself and
254 -- appears last in the sub-aggregate. Check that we do not have
255 -- positional and named components in the array sub-aggregate (unless
256 -- the named association is an others choice). Finally if an others
257 -- choice is present, make sure it is allowed in the aggregate context.
259 -- 2. If the array sub-aggregate contains discrete_choices:
261 -- (A) Verify their validity. Specifically verify that:
263 -- (a) If a null range is present it must be the only possible
264 -- choice in the array aggregate.
266 -- (b) Ditto for a non static range.
268 -- (c) Ditto for a non static expression.
270 -- In addition this step analyzes and resolves each discrete_choice,
271 -- making sure that its type is the type of the corresponding Index.
272 -- If we are not at the lowest array aggregate level (in the case of
273 -- multi-dimensional aggregates) then invoke Resolve_Array_Aggregate
274 -- recursively on each component expression. Otherwise, resolve the
275 -- bottom level component expressions against the expected component
276 -- type ONLY IF the component corresponds to a single discrete choice
277 -- which is not an others choice (to see why read the DELAYED
278 -- COMPONENT RESOLUTION below).
280 -- (B) Determine the bounds of the sub-aggregate and lowest and
281 -- highest choice values.
283 -- 3. For positional aggregates:
285 -- (A) Loop over the component expressions either recursively invoking
286 -- Resolve_Array_Aggregate on each of these for multi-dimensional
287 -- array aggregates or resolving the bottom level component
288 -- expressions against the expected component type.
290 -- (B) Determine the bounds of the positional sub-aggregates.
292 -- 4. Try to determine statically whether the evaluation of the array
293 -- sub-aggregate raises Constraint_Error. If yes emit proper
294 -- warnings. The precise checks are the following:
296 -- (A) Check that the index range defined by aggregate bounds is
297 -- compatible with corresponding index subtype.
298 -- We also check against the base type. In fact it could be that
299 -- Low/High bounds of the base type are static whereas those of
300 -- the index subtype are not. Thus if we can statically catch
301 -- a problem with respect to the base type we are guaranteed
302 -- that the same problem will arise with the index subtype
304 -- (B) If we are dealing with a named aggregate containing an others
305 -- choice and at least one discrete choice then make sure the range
306 -- specified by the discrete choices does not overflow the
307 -- aggregate bounds. We also check against the index type and base
308 -- type bounds for the same reasons given in (A).
310 -- (C) If we are dealing with a positional aggregate with an others
311 -- choice make sure the number of positional elements specified
312 -- does not overflow the aggregate bounds. We also check against
313 -- the index type and base type bounds as mentioned in (A).
315 -- Finally construct an N_Range node giving the sub-aggregate bounds.
316 -- Set the Aggregate_Bounds field of the sub-aggregate to be this
317 -- N_Range. The routine Array_Aggr_Subtype below uses such N_Ranges
318 -- to build the appropriate aggregate subtype. Aggregate_Bounds
319 -- information is needed during expansion.
321 -- DELAYED COMPONENT RESOLUTION: The resolution of bottom level component
322 -- expressions in an array aggregate may call Duplicate_Subexpr or some
323 -- other routine that inserts code just outside the outermost aggregate.
324 -- If the array aggregate contains discrete choices or an others choice,
325 -- this may be wrong. Consider for instance the following example.
327 -- type Rec is record
331 -- type Acc_Rec is access Rec;
332 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => new Rec);
334 -- Then the transformation of "new Rec" that occurs during resolution
335 -- entails the following code modifications
337 -- P7b : constant Acc_Rec := new Rec;
339 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => P7b);
341 -- This code transformation is clearly wrong, since we need to call
342 -- "new Rec" for each of the 3 array elements. To avoid this problem we
343 -- delay resolution of the components of non positional array aggregates
344 -- to the expansion phase. As an optimization, if the discrete choice
345 -- specifies a single value we do not delay resolution.
347 function Array_Aggr_Subtype (N : Node_Id; Typ : Node_Id) return Entity_Id;
348 -- This routine returns the type or subtype of an array aggregate.
350 -- N is the array aggregate node whose type we return.
352 -- Typ is the context type in which N occurs.
354 -- This routine creates an implicit array subtype whose bounds are
355 -- those defined by the aggregate. When this routine is invoked
356 -- Resolve_Array_Aggregate has already processed aggregate N. Thus the
357 -- Aggregate_Bounds of each sub-aggregate, is an N_Range node giving the
358 -- sub-aggregate bounds. When building the aggregate itype, this function
359 -- traverses the array aggregate N collecting such Aggregate_Bounds and
360 -- constructs the proper array aggregate itype.
362 -- Note that in the case of multidimensional aggregates each inner
363 -- sub-aggregate corresponding to a given array dimension, may provide a
364 -- different bounds. If it is possible to determine statically that
365 -- some sub-aggregates corresponding to the same index do not have the
366 -- same bounds, then a warning is emitted. If such check is not possible
367 -- statically (because some sub-aggregate bounds are dynamic expressions)
368 -- then this job is left to the expander. In all cases the particular
369 -- bounds that this function will chose for a given dimension is the first
370 -- N_Range node for a sub-aggregate corresponding to that dimension.
372 -- Note that the Raises_Constraint_Error flag of an array aggregate
373 -- whose evaluation is determined to raise CE by Resolve_Array_Aggregate,
374 -- is set in Resolve_Array_Aggregate but the aggregate is not
375 -- immediately replaced with a raise CE. In fact, Array_Aggr_Subtype must
376 -- first construct the proper itype for the aggregate (Gigi needs
377 -- this). After constructing the proper itype we will eventually replace
378 -- the top-level aggregate with a raise CE (done in Resolve_Aggregate).
379 -- Of course in cases such as:
381 -- type Arr is array (integer range <>) of Integer;
382 -- A : Arr := (positive range -1 .. 2 => 0);
384 -- The bounds of the aggregate itype are cooked up to look reasonable
385 -- (in this particular case the bounds will be 1 .. 2).
387 procedure Aggregate_Constraint_Checks
389 Check_Typ : Entity_Id);
390 -- Checks expression Exp against subtype Check_Typ. If Exp is an
391 -- aggregate and Check_Typ a constrained record type with discriminants,
392 -- we generate the appropriate discriminant checks. If Exp is an array
393 -- aggregate then emit the appropriate length checks. If Exp is a scalar
394 -- type, or a string literal, Exp is changed into Check_Typ'(Exp) to
395 -- ensure that range checks are performed at run time.
397 procedure Make_String_Into_Aggregate (N : Node_Id);
398 -- A string literal can appear in a context in which a one dimensional
399 -- array of characters is expected. This procedure simply rewrites the
400 -- string as an aggregate, prior to resolution.
402 ---------------------------------
403 -- Aggregate_Constraint_Checks --
404 ---------------------------------
406 procedure Aggregate_Constraint_Checks
408 Check_Typ : Entity_Id)
410 Exp_Typ : constant Entity_Id := Etype (Exp);
413 if Raises_Constraint_Error (Exp) then
417 -- This is really expansion activity, so make sure that expansion
418 -- is on and is allowed.
420 if not Expander_Active or else In_Spec_Expression then
424 -- First check if we have to insert discriminant checks
426 if Has_Discriminants (Exp_Typ) then
427 Apply_Discriminant_Check (Exp, Check_Typ);
429 -- Next emit length checks for array aggregates
431 elsif Is_Array_Type (Exp_Typ) then
432 Apply_Length_Check (Exp, Check_Typ);
434 -- Finally emit scalar and string checks. If we are dealing with a
435 -- scalar literal we need to check by hand because the Etype of
436 -- literals is not necessarily correct.
438 elsif Is_Scalar_Type (Exp_Typ)
439 and then Compile_Time_Known_Value (Exp)
441 if Is_Out_Of_Range (Exp, Base_Type (Check_Typ)) then
442 Apply_Compile_Time_Constraint_Error
443 (Exp, "value not in range of}?", CE_Range_Check_Failed,
444 Ent => Base_Type (Check_Typ),
445 Typ => Base_Type (Check_Typ));
447 elsif Is_Out_Of_Range (Exp, Check_Typ) then
448 Apply_Compile_Time_Constraint_Error
449 (Exp, "value not in range of}?", CE_Range_Check_Failed,
453 elsif not Range_Checks_Suppressed (Check_Typ) then
454 Apply_Scalar_Range_Check (Exp, Check_Typ);
457 -- Verify that target type is also scalar, to prevent view anomalies
458 -- in instantiations.
460 elsif (Is_Scalar_Type (Exp_Typ)
461 or else Nkind (Exp) = N_String_Literal)
462 and then Is_Scalar_Type (Check_Typ)
463 and then Exp_Typ /= Check_Typ
465 if Is_Entity_Name (Exp)
466 and then Ekind (Entity (Exp)) = E_Constant
468 -- If expression is a constant, it is worthwhile checking whether
469 -- it is a bound of the type.
471 if (Is_Entity_Name (Type_Low_Bound (Check_Typ))
472 and then Entity (Exp) = Entity (Type_Low_Bound (Check_Typ)))
473 or else (Is_Entity_Name (Type_High_Bound (Check_Typ))
474 and then Entity (Exp) = Entity (Type_High_Bound (Check_Typ)))
479 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
480 Analyze_And_Resolve (Exp, Check_Typ);
481 Check_Unset_Reference (Exp);
484 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
485 Analyze_And_Resolve (Exp, Check_Typ);
486 Check_Unset_Reference (Exp);
489 -- Ada 2005 (AI-230): Generate a conversion to an anonymous access
490 -- component's type to force the appropriate accessibility checks.
492 -- Ada 2005 (AI-231): Generate conversion to the null-excluding
493 -- type to force the corresponding run-time check
495 elsif Is_Access_Type (Check_Typ)
496 and then ((Is_Local_Anonymous_Access (Check_Typ))
497 or else (Can_Never_Be_Null (Check_Typ)
498 and then not Can_Never_Be_Null (Exp_Typ)))
500 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
501 Analyze_And_Resolve (Exp, Check_Typ);
502 Check_Unset_Reference (Exp);
504 end Aggregate_Constraint_Checks;
506 ------------------------
507 -- Array_Aggr_Subtype --
508 ------------------------
510 function Array_Aggr_Subtype
515 Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
516 -- Number of aggregate index dimensions
518 Aggr_Range : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
519 -- Constrained N_Range of each index dimension in our aggregate itype
521 Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
522 Aggr_High : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
523 -- Low and High bounds for each index dimension in our aggregate itype
525 Is_Fully_Positional : Boolean := True;
527 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos);
528 -- N is an array (sub-)aggregate. Dim is the dimension corresponding to
529 -- (sub-)aggregate N. This procedure collects the constrained N_Range
530 -- nodes corresponding to each index dimension of our aggregate itype.
531 -- These N_Range nodes are collected in Aggr_Range above.
533 -- Likewise collect in Aggr_Low & Aggr_High above the low and high
534 -- bounds of each index dimension. If, when collecting, two bounds
535 -- corresponding to the same dimension are static and found to differ,
536 -- then emit a warning, and mark N as raising Constraint_Error.
538 -------------------------
539 -- Collect_Aggr_Bounds --
540 -------------------------
542 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos) is
543 This_Range : constant Node_Id := Aggregate_Bounds (N);
544 -- The aggregate range node of this specific sub-aggregate
546 This_Low : constant Node_Id := Low_Bound (Aggregate_Bounds (N));
547 This_High : constant Node_Id := High_Bound (Aggregate_Bounds (N));
548 -- The aggregate bounds of this specific sub-aggregate
554 -- Collect the first N_Range for a given dimension that you find.
555 -- For a given dimension they must be all equal anyway.
557 if No (Aggr_Range (Dim)) then
558 Aggr_Low (Dim) := This_Low;
559 Aggr_High (Dim) := This_High;
560 Aggr_Range (Dim) := This_Range;
563 if Compile_Time_Known_Value (This_Low) then
564 if not Compile_Time_Known_Value (Aggr_Low (Dim)) then
565 Aggr_Low (Dim) := This_Low;
567 elsif Expr_Value (This_Low) /= Expr_Value (Aggr_Low (Dim)) then
568 Set_Raises_Constraint_Error (N);
569 Error_Msg_N ("sub-aggregate low bound mismatch?", N);
571 ("\Constraint_Error will be raised at run-time?", N);
575 if Compile_Time_Known_Value (This_High) then
576 if not Compile_Time_Known_Value (Aggr_High (Dim)) then
577 Aggr_High (Dim) := This_High;
580 Expr_Value (This_High) /= Expr_Value (Aggr_High (Dim))
582 Set_Raises_Constraint_Error (N);
583 Error_Msg_N ("sub-aggregate high bound mismatch?", N);
585 ("\Constraint_Error will be raised at run-time?", N);
590 if Dim < Aggr_Dimension then
592 -- Process positional components
594 if Present (Expressions (N)) then
595 Expr := First (Expressions (N));
596 while Present (Expr) loop
597 Collect_Aggr_Bounds (Expr, Dim + 1);
602 -- Process component associations
604 if Present (Component_Associations (N)) then
605 Is_Fully_Positional := False;
607 Assoc := First (Component_Associations (N));
608 while Present (Assoc) loop
609 Expr := Expression (Assoc);
610 Collect_Aggr_Bounds (Expr, Dim + 1);
615 end Collect_Aggr_Bounds;
617 -- Array_Aggr_Subtype variables
620 -- the final itype of the overall aggregate
622 Index_Constraints : constant List_Id := New_List;
623 -- The list of index constraints of the aggregate itype
625 -- Start of processing for Array_Aggr_Subtype
628 -- Make sure that the list of index constraints is properly attached
629 -- to the tree, and then collect the aggregate bounds.
631 Set_Parent (Index_Constraints, N);
632 Collect_Aggr_Bounds (N, 1);
634 -- Build the list of constrained indices of our aggregate itype
636 for J in 1 .. Aggr_Dimension loop
637 Create_Index : declare
638 Index_Base : constant Entity_Id :=
639 Base_Type (Etype (Aggr_Range (J)));
640 Index_Typ : Entity_Id;
643 -- Construct the Index subtype, and associate it with the range
644 -- construct that generates it.
647 Create_Itype (Subtype_Kind (Ekind (Index_Base)), Aggr_Range (J));
649 Set_Etype (Index_Typ, Index_Base);
651 if Is_Character_Type (Index_Base) then
652 Set_Is_Character_Type (Index_Typ);
655 Set_Size_Info (Index_Typ, (Index_Base));
656 Set_RM_Size (Index_Typ, RM_Size (Index_Base));
657 Set_First_Rep_Item (Index_Typ, First_Rep_Item (Index_Base));
658 Set_Scalar_Range (Index_Typ, Aggr_Range (J));
660 if Is_Discrete_Or_Fixed_Point_Type (Index_Typ) then
661 Set_RM_Size (Index_Typ, UI_From_Int (Minimum_Size (Index_Typ)));
664 Set_Etype (Aggr_Range (J), Index_Typ);
666 Append (Aggr_Range (J), To => Index_Constraints);
670 -- Now build the Itype
672 Itype := Create_Itype (E_Array_Subtype, N);
674 Set_First_Rep_Item (Itype, First_Rep_Item (Typ));
675 Set_Convention (Itype, Convention (Typ));
676 Set_Depends_On_Private (Itype, Has_Private_Component (Typ));
677 Set_Etype (Itype, Base_Type (Typ));
678 Set_Has_Alignment_Clause (Itype, Has_Alignment_Clause (Typ));
679 Set_Is_Aliased (Itype, Is_Aliased (Typ));
680 Set_Depends_On_Private (Itype, Depends_On_Private (Typ));
682 Copy_Suppress_Status (Index_Check, Typ, Itype);
683 Copy_Suppress_Status (Length_Check, Typ, Itype);
685 Set_First_Index (Itype, First (Index_Constraints));
686 Set_Is_Constrained (Itype, True);
687 Set_Is_Internal (Itype, True);
689 -- A simple optimization: purely positional aggregates of static
690 -- components should be passed to gigi unexpanded whenever possible,
691 -- and regardless of the staticness of the bounds themselves. Subse-
692 -- quent checks in exp_aggr verify that type is not packed, etc.
694 Set_Size_Known_At_Compile_Time (Itype,
696 and then Comes_From_Source (N)
697 and then Size_Known_At_Compile_Time (Component_Type (Typ)));
699 -- We always need a freeze node for a packed array subtype, so that
700 -- we can build the Packed_Array_Type corresponding to the subtype.
701 -- If expansion is disabled, the packed array subtype is not built,
702 -- and we must not generate a freeze node for the type, or else it
703 -- will appear incomplete to gigi.
705 if Is_Packed (Itype) and then not In_Spec_Expression
706 and then Expander_Active
708 Freeze_Itype (Itype, N);
712 end Array_Aggr_Subtype;
714 --------------------------------
715 -- Check_Misspelled_Component --
716 --------------------------------
718 procedure Check_Misspelled_Component
719 (Elements : Elist_Id;
722 Max_Suggestions : constant := 2;
724 Nr_Of_Suggestions : Natural := 0;
725 Suggestion_1 : Entity_Id := Empty;
726 Suggestion_2 : Entity_Id := Empty;
727 Component_Elmt : Elmt_Id;
730 -- All the components of List are matched against Component and
731 -- a count is maintained of possible misspellings. When at the
732 -- end of the analysis there are one or two (not more!) possible
733 -- misspellings, these misspellings will be suggested as
734 -- possible correction.
736 Component_Elmt := First_Elmt (Elements);
737 while Nr_Of_Suggestions <= Max_Suggestions
738 and then Present (Component_Elmt)
740 if Is_Bad_Spelling_Of
741 (Chars (Node (Component_Elmt)),
744 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
746 case Nr_Of_Suggestions is
747 when 1 => Suggestion_1 := Node (Component_Elmt);
748 when 2 => Suggestion_2 := Node (Component_Elmt);
753 Next_Elmt (Component_Elmt);
756 -- Report at most two suggestions
758 if Nr_Of_Suggestions = 1 then
760 ("\possible misspelling of&", Component, Suggestion_1);
762 elsif Nr_Of_Suggestions = 2 then
763 Error_Msg_Node_2 := Suggestion_2;
765 ("\possible misspelling of& or&", Component, Suggestion_1);
767 end Check_Misspelled_Component;
769 ----------------------------------------
770 -- Check_Expr_OK_In_Limited_Aggregate --
771 ----------------------------------------
773 procedure Check_Expr_OK_In_Limited_Aggregate (Expr : Node_Id) is
775 if Is_Limited_Type (Etype (Expr))
776 and then Comes_From_Source (Expr)
777 and then not In_Instance_Body
779 if not OK_For_Limited_Init (Expr) then
780 Error_Msg_N ("initialization not allowed for limited types", Expr);
781 Explain_Limited_Type (Etype (Expr), Expr);
784 end Check_Expr_OK_In_Limited_Aggregate;
786 ----------------------------------------
787 -- Check_Static_Discriminated_Subtype --
788 ----------------------------------------
790 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id) is
791 Disc : constant Entity_Id := First_Discriminant (T);
796 if Has_Record_Rep_Clause (T) then
799 elsif Present (Next_Discriminant (Disc)) then
802 elsif Nkind (V) /= N_Integer_Literal then
806 Comp := First_Component (T);
807 while Present (Comp) loop
808 if Is_Scalar_Type (Etype (Comp)) then
811 elsif Is_Private_Type (Etype (Comp))
812 and then Present (Full_View (Etype (Comp)))
813 and then Is_Scalar_Type (Full_View (Etype (Comp)))
817 elsif Is_Array_Type (Etype (Comp)) then
818 if Is_Bit_Packed_Array (Etype (Comp)) then
822 Ind := First_Index (Etype (Comp));
823 while Present (Ind) loop
824 if Nkind (Ind) /= N_Range
825 or else Nkind (Low_Bound (Ind)) /= N_Integer_Literal
826 or else Nkind (High_Bound (Ind)) /= N_Integer_Literal
838 Next_Component (Comp);
841 -- On exit, all components have statically known sizes
843 Set_Size_Known_At_Compile_Time (T);
844 end Check_Static_Discriminated_Subtype;
846 --------------------------------
847 -- Make_String_Into_Aggregate --
848 --------------------------------
850 procedure Make_String_Into_Aggregate (N : Node_Id) is
851 Exprs : constant List_Id := New_List;
852 Loc : constant Source_Ptr := Sloc (N);
853 Str : constant String_Id := Strval (N);
854 Strlen : constant Nat := String_Length (Str);
862 for J in 1 .. Strlen loop
863 C := Get_String_Char (Str, J);
864 Set_Character_Literal_Name (C);
867 Make_Character_Literal (P,
869 Char_Literal_Value => UI_From_CC (C));
870 Set_Etype (C_Node, Any_Character);
871 Append_To (Exprs, C_Node);
874 -- something special for wide strings ???
877 New_N := Make_Aggregate (Loc, Expressions => Exprs);
878 Set_Analyzed (New_N);
879 Set_Etype (New_N, Any_Composite);
882 end Make_String_Into_Aggregate;
884 -----------------------
885 -- Resolve_Aggregate --
886 -----------------------
888 procedure Resolve_Aggregate (N : Node_Id; Typ : Entity_Id) is
889 Pkind : constant Node_Kind := Nkind (Parent (N));
891 Aggr_Subtyp : Entity_Id;
892 -- The actual aggregate subtype. This is not necessarily the same as Typ
893 -- which is the subtype of the context in which the aggregate was found.
896 -- Check for aggregates not allowed in configurable run-time mode.
897 -- We allow all cases of aggregates that do not come from source,
898 -- since these are all assumed to be small (e.g. bounds of a string
899 -- literal). We also allow aggregates of types we know to be small.
901 if not Support_Aggregates_On_Target
902 and then Comes_From_Source (N)
903 and then (not Known_Static_Esize (Typ) or else Esize (Typ) > 64)
905 Error_Msg_CRT ("aggregate", N);
908 -- Ada 2005 (AI-287): Limited aggregates allowed
910 if Is_Limited_Type (Typ) and then Ada_Version < Ada_05 then
911 Error_Msg_N ("aggregate type cannot be limited", N);
912 Explain_Limited_Type (Typ, N);
914 elsif Is_Class_Wide_Type (Typ) then
915 Error_Msg_N ("type of aggregate cannot be class-wide", N);
917 elsif Typ = Any_String
918 or else Typ = Any_Composite
920 Error_Msg_N ("no unique type for aggregate", N);
921 Set_Etype (N, Any_Composite);
923 elsif Is_Array_Type (Typ) and then Null_Record_Present (N) then
924 Error_Msg_N ("null record forbidden in array aggregate", N);
926 elsif Is_Record_Type (Typ) then
927 Resolve_Record_Aggregate (N, Typ);
929 elsif Is_Array_Type (Typ) then
931 -- First a special test, for the case of a positional aggregate
932 -- of characters which can be replaced by a string literal.
934 -- Do not perform this transformation if this was a string literal
935 -- to start with, whose components needed constraint checks, or if
936 -- the component type is non-static, because it will require those
937 -- checks and be transformed back into an aggregate.
939 if Number_Dimensions (Typ) = 1
940 and then Is_Standard_Character_Type (Component_Type (Typ))
941 and then No (Component_Associations (N))
942 and then not Is_Limited_Composite (Typ)
943 and then not Is_Private_Composite (Typ)
944 and then not Is_Bit_Packed_Array (Typ)
945 and then Nkind (Original_Node (Parent (N))) /= N_String_Literal
946 and then Is_Static_Subtype (Component_Type (Typ))
952 Expr := First (Expressions (N));
953 while Present (Expr) loop
954 exit when Nkind (Expr) /= N_Character_Literal;
961 Expr := First (Expressions (N));
962 while Present (Expr) loop
963 Store_String_Char (UI_To_CC (Char_Literal_Value (Expr)));
968 Make_String_Literal (Sloc (N), End_String));
970 Analyze_And_Resolve (N, Typ);
976 -- Here if we have a real aggregate to deal with
978 Array_Aggregate : declare
979 Aggr_Resolved : Boolean;
981 Aggr_Typ : constant Entity_Id := Etype (Typ);
982 -- This is the unconstrained array type, which is the type
983 -- against which the aggregate is to be resolved. Typ itself
984 -- is the array type of the context which may not be the same
985 -- subtype as the subtype for the final aggregate.
988 -- In the following we determine whether an others choice is
989 -- allowed inside the array aggregate. The test checks the context
990 -- in which the array aggregate occurs. If the context does not
991 -- permit it, or the aggregate type is unconstrained, an others
992 -- choice is not allowed.
994 -- If expansion is disabled (generic context, or semantics-only
995 -- mode) actual subtypes cannot be constructed, and the type of
996 -- an object may be its unconstrained nominal type. However, if
997 -- the context is an assignment, we assume that "others" is
998 -- allowed, because the target of the assignment will have a
999 -- constrained subtype when fully compiled.
1001 -- Note that there is no node for Explicit_Actual_Parameter.
1002 -- To test for this context we therefore have to test for node
1003 -- N_Parameter_Association which itself appears only if there is a
1004 -- formal parameter. Consequently we also need to test for
1005 -- N_Procedure_Call_Statement or N_Function_Call.
1007 Set_Etype (N, Aggr_Typ); -- may be overridden later on
1009 if Is_Constrained (Typ) and then
1010 (Pkind = N_Assignment_Statement or else
1011 Pkind = N_Parameter_Association or else
1012 Pkind = N_Function_Call or else
1013 Pkind = N_Procedure_Call_Statement or else
1014 Pkind = N_Generic_Association or else
1015 Pkind = N_Formal_Object_Declaration or else
1016 Pkind = N_Simple_Return_Statement or else
1017 Pkind = N_Object_Declaration or else
1018 Pkind = N_Component_Declaration or else
1019 Pkind = N_Parameter_Specification or else
1020 Pkind = N_Qualified_Expression or else
1021 Pkind = N_Aggregate or else
1022 Pkind = N_Extension_Aggregate or else
1023 Pkind = N_Component_Association)
1026 Resolve_Array_Aggregate
1028 Index => First_Index (Aggr_Typ),
1029 Index_Constr => First_Index (Typ),
1030 Component_Typ => Component_Type (Typ),
1031 Others_Allowed => True);
1033 elsif not Expander_Active
1034 and then Pkind = N_Assignment_Statement
1037 Resolve_Array_Aggregate
1039 Index => First_Index (Aggr_Typ),
1040 Index_Constr => First_Index (Typ),
1041 Component_Typ => Component_Type (Typ),
1042 Others_Allowed => True);
1045 Resolve_Array_Aggregate
1047 Index => First_Index (Aggr_Typ),
1048 Index_Constr => First_Index (Aggr_Typ),
1049 Component_Typ => Component_Type (Typ),
1050 Others_Allowed => False);
1053 if not Aggr_Resolved then
1054 Aggr_Subtyp := Any_Composite;
1056 Aggr_Subtyp := Array_Aggr_Subtype (N, Typ);
1059 Set_Etype (N, Aggr_Subtyp);
1060 end Array_Aggregate;
1062 elsif Is_Private_Type (Typ)
1063 and then Present (Full_View (Typ))
1064 and then In_Inlined_Body
1065 and then Is_Composite_Type (Full_View (Typ))
1067 Resolve (N, Full_View (Typ));
1070 Error_Msg_N ("illegal context for aggregate", N);
1073 -- If we can determine statically that the evaluation of the
1074 -- aggregate raises Constraint_Error, then replace the
1075 -- aggregate with an N_Raise_Constraint_Error node, but set the
1076 -- Etype to the right aggregate subtype. Gigi needs this.
1078 if Raises_Constraint_Error (N) then
1079 Aggr_Subtyp := Etype (N);
1081 Make_Raise_Constraint_Error (Sloc (N),
1082 Reason => CE_Range_Check_Failed));
1083 Set_Raises_Constraint_Error (N);
1084 Set_Etype (N, Aggr_Subtyp);
1087 end Resolve_Aggregate;
1089 -----------------------------
1090 -- Resolve_Array_Aggregate --
1091 -----------------------------
1093 function Resolve_Array_Aggregate
1096 Index_Constr : Node_Id;
1097 Component_Typ : Entity_Id;
1098 Others_Allowed : Boolean) return Boolean
1100 Loc : constant Source_Ptr := Sloc (N);
1102 Failure : constant Boolean := False;
1103 Success : constant Boolean := True;
1105 Index_Typ : constant Entity_Id := Etype (Index);
1106 Index_Typ_Low : constant Node_Id := Type_Low_Bound (Index_Typ);
1107 Index_Typ_High : constant Node_Id := Type_High_Bound (Index_Typ);
1108 -- The type of the index corresponding to the array sub-aggregate
1109 -- along with its low and upper bounds
1111 Index_Base : constant Entity_Id := Base_Type (Index_Typ);
1112 Index_Base_Low : constant Node_Id := Type_Low_Bound (Index_Base);
1113 Index_Base_High : constant Node_Id := Type_High_Bound (Index_Base);
1114 -- ditto for the base type
1116 function Add (Val : Uint; To : Node_Id) return Node_Id;
1117 -- Creates a new expression node where Val is added to expression To.
1118 -- Tries to constant fold whenever possible. To must be an already
1119 -- analyzed expression.
1121 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id);
1122 -- Checks that AH (the upper bound of an array aggregate) is <= BH
1123 -- (the upper bound of the index base type). If the check fails a
1124 -- warning is emitted, the Raises_Constraint_Error Flag of N is set,
1125 -- and AH is replaced with a duplicate of BH.
1127 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id);
1128 -- Checks that range AL .. AH is compatible with range L .. H. Emits a
1129 -- warning if not and sets the Raises_Constraint_Error Flag in N.
1131 procedure Check_Length (L, H : Node_Id; Len : Uint);
1132 -- Checks that range L .. H contains at least Len elements. Emits a
1133 -- warning if not and sets the Raises_Constraint_Error Flag in N.
1135 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean;
1136 -- Returns True if range L .. H is dynamic or null
1138 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean);
1139 -- Given expression node From, this routine sets OK to False if it
1140 -- cannot statically evaluate From. Otherwise it stores this static
1141 -- value into Value.
1143 function Resolve_Aggr_Expr
1145 Single_Elmt : Boolean) return Boolean;
1146 -- Resolves aggregate expression Expr. Returns False if resolution
1147 -- fails. If Single_Elmt is set to False, the expression Expr may be
1148 -- used to initialize several array aggregate elements (this can
1149 -- happen for discrete choices such as "L .. H => Expr" or the others
1150 -- choice). In this event we do not resolve Expr unless expansion is
1151 -- disabled. To know why, see the DELAYED COMPONENT RESOLUTION
1158 function Add (Val : Uint; To : Node_Id) return Node_Id is
1164 if Raises_Constraint_Error (To) then
1168 -- First test if we can do constant folding
1170 if Compile_Time_Known_Value (To)
1171 or else Nkind (To) = N_Integer_Literal
1173 Expr_Pos := Make_Integer_Literal (Loc, Expr_Value (To) + Val);
1174 Set_Is_Static_Expression (Expr_Pos);
1175 Set_Etype (Expr_Pos, Etype (To));
1176 Set_Analyzed (Expr_Pos, Analyzed (To));
1178 if not Is_Enumeration_Type (Index_Typ) then
1181 -- If we are dealing with enumeration return
1182 -- Index_Typ'Val (Expr_Pos)
1186 Make_Attribute_Reference
1188 Prefix => New_Reference_To (Index_Typ, Loc),
1189 Attribute_Name => Name_Val,
1190 Expressions => New_List (Expr_Pos));
1196 -- If we are here no constant folding possible
1198 if not Is_Enumeration_Type (Index_Base) then
1201 Left_Opnd => Duplicate_Subexpr (To),
1202 Right_Opnd => Make_Integer_Literal (Loc, Val));
1204 -- If we are dealing with enumeration return
1205 -- Index_Typ'Val (Index_Typ'Pos (To) + Val)
1209 Make_Attribute_Reference
1211 Prefix => New_Reference_To (Index_Typ, Loc),
1212 Attribute_Name => Name_Pos,
1213 Expressions => New_List (Duplicate_Subexpr (To)));
1217 Left_Opnd => To_Pos,
1218 Right_Opnd => Make_Integer_Literal (Loc, Val));
1221 Make_Attribute_Reference
1223 Prefix => New_Reference_To (Index_Typ, Loc),
1224 Attribute_Name => Name_Val,
1225 Expressions => New_List (Expr_Pos));
1235 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id) is
1243 Get (Value => Val_BH, From => BH, OK => OK_BH);
1244 Get (Value => Val_AH, From => AH, OK => OK_AH);
1246 if OK_BH and then OK_AH and then Val_BH < Val_AH then
1247 Set_Raises_Constraint_Error (N);
1248 Error_Msg_N ("upper bound out of range?", AH);
1249 Error_Msg_N ("\Constraint_Error will be raised at run-time?", AH);
1251 -- You need to set AH to BH or else in the case of enumerations
1252 -- indices we will not be able to resolve the aggregate bounds.
1254 AH := Duplicate_Subexpr (BH);
1262 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id) is
1273 pragma Warnings (Off, OK_AL);
1274 pragma Warnings (Off, OK_AH);
1277 if Raises_Constraint_Error (N)
1278 or else Dynamic_Or_Null_Range (AL, AH)
1283 Get (Value => Val_L, From => L, OK => OK_L);
1284 Get (Value => Val_H, From => H, OK => OK_H);
1286 Get (Value => Val_AL, From => AL, OK => OK_AL);
1287 Get (Value => Val_AH, From => AH, OK => OK_AH);
1289 if OK_L and then Val_L > Val_AL then
1290 Set_Raises_Constraint_Error (N);
1291 Error_Msg_N ("lower bound of aggregate out of range?", N);
1292 Error_Msg_N ("\Constraint_Error will be raised at run-time?", N);
1295 if OK_H and then Val_H < Val_AH then
1296 Set_Raises_Constraint_Error (N);
1297 Error_Msg_N ("upper bound of aggregate out of range?", N);
1298 Error_Msg_N ("\Constraint_Error will be raised at run-time?", N);
1306 procedure Check_Length (L, H : Node_Id; Len : Uint) is
1316 if Raises_Constraint_Error (N) then
1320 Get (Value => Val_L, From => L, OK => OK_L);
1321 Get (Value => Val_H, From => H, OK => OK_H);
1323 if not OK_L or else not OK_H then
1327 -- If null range length is zero
1329 if Val_L > Val_H then
1330 Range_Len := Uint_0;
1332 Range_Len := Val_H - Val_L + 1;
1335 if Range_Len < Len then
1336 Set_Raises_Constraint_Error (N);
1337 Error_Msg_N ("too many elements?", N);
1338 Error_Msg_N ("\Constraint_Error will be raised at run-time?", N);
1342 ---------------------------
1343 -- Dynamic_Or_Null_Range --
1344 ---------------------------
1346 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean is
1354 Get (Value => Val_L, From => L, OK => OK_L);
1355 Get (Value => Val_H, From => H, OK => OK_H);
1357 return not OK_L or else not OK_H
1358 or else not Is_OK_Static_Expression (L)
1359 or else not Is_OK_Static_Expression (H)
1360 or else Val_L > Val_H;
1361 end Dynamic_Or_Null_Range;
1367 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean) is
1371 if Compile_Time_Known_Value (From) then
1372 Value := Expr_Value (From);
1374 -- If expression From is something like Some_Type'Val (10) then
1377 elsif Nkind (From) = N_Attribute_Reference
1378 and then Attribute_Name (From) = Name_Val
1379 and then Compile_Time_Known_Value (First (Expressions (From)))
1381 Value := Expr_Value (First (Expressions (From)));
1389 -----------------------
1390 -- Resolve_Aggr_Expr --
1391 -----------------------
1393 function Resolve_Aggr_Expr
1395 Single_Elmt : Boolean) return Boolean
1397 Nxt_Ind : constant Node_Id := Next_Index (Index);
1398 Nxt_Ind_Constr : constant Node_Id := Next_Index (Index_Constr);
1399 -- Index is the current index corresponding to the expression
1401 Resolution_OK : Boolean := True;
1402 -- Set to False if resolution of the expression failed
1405 -- If the array type against which we are resolving the aggregate
1406 -- has several dimensions, the expressions nested inside the
1407 -- aggregate must be further aggregates (or strings).
1409 if Present (Nxt_Ind) then
1410 if Nkind (Expr) /= N_Aggregate then
1412 -- A string literal can appear where a one-dimensional array
1413 -- of characters is expected. If the literal looks like an
1414 -- operator, it is still an operator symbol, which will be
1415 -- transformed into a string when analyzed.
1417 if Is_Character_Type (Component_Typ)
1418 and then No (Next_Index (Nxt_Ind))
1419 and then Nkind_In (Expr, N_String_Literal, N_Operator_Symbol)
1421 -- A string literal used in a multidimensional array
1422 -- aggregate in place of the final one-dimensional
1423 -- aggregate must not be enclosed in parentheses.
1425 if Paren_Count (Expr) /= 0 then
1426 Error_Msg_N ("no parenthesis allowed here", Expr);
1429 Make_String_Into_Aggregate (Expr);
1432 Error_Msg_N ("nested array aggregate expected", Expr);
1437 -- Ada 2005 (AI-231): Propagate the type to the nested aggregate.
1438 -- Required to check the null-exclusion attribute (if present).
1439 -- This value may be overridden later on.
1441 Set_Etype (Expr, Etype (N));
1443 Resolution_OK := Resolve_Array_Aggregate
1444 (Expr, Nxt_Ind, Nxt_Ind_Constr, Component_Typ, Others_Allowed);
1446 -- Do not resolve the expressions of discrete or others choices
1447 -- unless the expression covers a single component, or the expander
1451 or else not Expander_Active
1452 or else In_Spec_Expression
1454 Analyze_And_Resolve (Expr, Component_Typ);
1455 Check_Expr_OK_In_Limited_Aggregate (Expr);
1456 Check_Non_Static_Context (Expr);
1457 Aggregate_Constraint_Checks (Expr, Component_Typ);
1458 Check_Unset_Reference (Expr);
1461 if Raises_Constraint_Error (Expr)
1462 and then Nkind (Parent (Expr)) /= N_Component_Association
1464 Set_Raises_Constraint_Error (N);
1467 return Resolution_OK;
1468 end Resolve_Aggr_Expr;
1470 -- Variables local to Resolve_Array_Aggregate
1477 pragma Warnings (Off, Discard);
1479 Aggr_Low : Node_Id := Empty;
1480 Aggr_High : Node_Id := Empty;
1481 -- The actual low and high bounds of this sub-aggregate
1483 Choices_Low : Node_Id := Empty;
1484 Choices_High : Node_Id := Empty;
1485 -- The lowest and highest discrete choices values for a named aggregate
1487 Nb_Elements : Uint := Uint_0;
1488 -- The number of elements in a positional aggregate
1490 Others_Present : Boolean := False;
1492 Nb_Choices : Nat := 0;
1493 -- Contains the overall number of named choices in this sub-aggregate
1495 Nb_Discrete_Choices : Nat := 0;
1496 -- The overall number of discrete choices (not counting others choice)
1498 Case_Table_Size : Nat;
1499 -- Contains the size of the case table needed to sort aggregate choices
1501 -- Start of processing for Resolve_Array_Aggregate
1504 -- STEP 1: make sure the aggregate is correctly formatted
1506 if Present (Component_Associations (N)) then
1507 Assoc := First (Component_Associations (N));
1508 while Present (Assoc) loop
1509 Choice := First (Choices (Assoc));
1510 while Present (Choice) loop
1511 if Nkind (Choice) = N_Others_Choice then
1512 Others_Present := True;
1514 if Choice /= First (Choices (Assoc))
1515 or else Present (Next (Choice))
1518 ("OTHERS must appear alone in a choice list", Choice);
1522 if Present (Next (Assoc)) then
1524 ("OTHERS must appear last in an aggregate", Choice);
1528 if Ada_Version = Ada_83
1529 and then Assoc /= First (Component_Associations (N))
1530 and then Nkind_In (Parent (N), N_Assignment_Statement,
1531 N_Object_Declaration)
1534 ("(Ada 83) illegal context for OTHERS choice", N);
1538 Nb_Choices := Nb_Choices + 1;
1546 -- At this point we know that the others choice, if present, is by
1547 -- itself and appears last in the aggregate. Check if we have mixed
1548 -- positional and discrete associations (other than the others choice).
1550 if Present (Expressions (N))
1551 and then (Nb_Choices > 1
1552 or else (Nb_Choices = 1 and then not Others_Present))
1555 ("named association cannot follow positional association",
1556 First (Choices (First (Component_Associations (N)))));
1560 -- Test for the validity of an others choice if present
1562 if Others_Present and then not Others_Allowed then
1564 ("OTHERS choice not allowed here",
1565 First (Choices (First (Component_Associations (N)))));
1569 -- Protect against cascaded errors
1571 if Etype (Index_Typ) = Any_Type then
1575 -- STEP 2: Process named components
1577 if No (Expressions (N)) then
1578 if Others_Present then
1579 Case_Table_Size := Nb_Choices - 1;
1581 Case_Table_Size := Nb_Choices;
1587 -- Denote the lowest and highest values in an aggregate choice
1591 -- High end of one range and Low end of the next. Should be
1592 -- contiguous if there is no hole in the list of values.
1594 Missing_Values : Boolean;
1595 -- Set True if missing index values
1597 S_Low : Node_Id := Empty;
1598 S_High : Node_Id := Empty;
1599 -- if a choice in an aggregate is a subtype indication these
1600 -- denote the lowest and highest values of the subtype
1602 Table : Case_Table_Type (1 .. Case_Table_Size);
1603 -- Used to sort all the different choice values
1605 Single_Choice : Boolean;
1606 -- Set to true every time there is a single discrete choice in a
1607 -- discrete association
1609 Prev_Nb_Discrete_Choices : Nat;
1610 -- Used to keep track of the number of discrete choices
1611 -- in the current association.
1614 -- STEP 2 (A): Check discrete choices validity
1616 Assoc := First (Component_Associations (N));
1617 while Present (Assoc) loop
1618 Prev_Nb_Discrete_Choices := Nb_Discrete_Choices;
1619 Choice := First (Choices (Assoc));
1623 if Nkind (Choice) = N_Others_Choice then
1624 Single_Choice := False;
1627 -- Test for subtype mark without constraint
1629 elsif Is_Entity_Name (Choice) and then
1630 Is_Type (Entity (Choice))
1632 if Base_Type (Entity (Choice)) /= Index_Base then
1634 ("invalid subtype mark in aggregate choice",
1639 -- Case of subtype indication
1641 elsif Nkind (Choice) = N_Subtype_Indication then
1642 Resolve_Discrete_Subtype_Indication (Choice, Index_Base);
1644 -- Does the subtype indication evaluation raise CE ?
1646 Get_Index_Bounds (Subtype_Mark (Choice), S_Low, S_High);
1647 Get_Index_Bounds (Choice, Low, High);
1648 Check_Bounds (S_Low, S_High, Low, High);
1650 -- Case of range or expression
1653 Resolve (Choice, Index_Base);
1654 Check_Unset_Reference (Choice);
1655 Check_Non_Static_Context (Choice);
1657 -- Do not range check a choice. This check is redundant
1658 -- since this test is already performed when we check
1659 -- that the bounds of the array aggregate are within
1662 Set_Do_Range_Check (Choice, False);
1665 -- If we could not resolve the discrete choice stop here
1667 if Etype (Choice) = Any_Type then
1670 -- If the discrete choice raises CE get its original bounds
1672 elsif Nkind (Choice) = N_Raise_Constraint_Error then
1673 Set_Raises_Constraint_Error (N);
1674 Get_Index_Bounds (Original_Node (Choice), Low, High);
1676 -- Otherwise get its bounds as usual
1679 Get_Index_Bounds (Choice, Low, High);
1682 if (Dynamic_Or_Null_Range (Low, High)
1683 or else (Nkind (Choice) = N_Subtype_Indication
1685 Dynamic_Or_Null_Range (S_Low, S_High)))
1686 and then Nb_Choices /= 1
1689 ("dynamic or empty choice in aggregate " &
1690 "must be the only choice", Choice);
1694 Nb_Discrete_Choices := Nb_Discrete_Choices + 1;
1695 Table (Nb_Discrete_Choices).Choice_Lo := Low;
1696 Table (Nb_Discrete_Choices).Choice_Hi := High;
1702 -- Check if we have a single discrete choice and whether
1703 -- this discrete choice specifies a single value.
1706 (Nb_Discrete_Choices = Prev_Nb_Discrete_Choices + 1)
1707 and then (Low = High);
1713 -- Ada 2005 (AI-231)
1715 if Ada_Version >= Ada_05
1716 and then Known_Null (Expression (Assoc))
1718 Check_Can_Never_Be_Null (Etype (N), Expression (Assoc));
1721 -- Ada 2005 (AI-287): In case of default initialized component
1722 -- we delay the resolution to the expansion phase
1724 if Box_Present (Assoc) then
1726 -- Ada 2005 (AI-287): In case of default initialization
1727 -- of a component the expander will generate calls to
1728 -- the corresponding initialization subprogram.
1732 elsif not Resolve_Aggr_Expr (Expression (Assoc),
1733 Single_Elmt => Single_Choice)
1741 -- If aggregate contains more than one choice then these must be
1742 -- static. Sort them and check that they are contiguous
1744 if Nb_Discrete_Choices > 1 then
1745 Sort_Case_Table (Table);
1746 Missing_Values := False;
1748 Outer : for J in 1 .. Nb_Discrete_Choices - 1 loop
1749 if Expr_Value (Table (J).Choice_Hi) >=
1750 Expr_Value (Table (J + 1).Choice_Lo)
1753 ("duplicate choice values in array aggregate",
1754 Table (J).Choice_Hi);
1757 elsif not Others_Present then
1758 Hi_Val := Expr_Value (Table (J).Choice_Hi);
1759 Lo_Val := Expr_Value (Table (J + 1).Choice_Lo);
1761 -- If missing values, output error messages
1763 if Lo_Val - Hi_Val > 1 then
1765 -- Header message if not first missing value
1767 if not Missing_Values then
1769 ("missing index value(s) in array aggregate", N);
1770 Missing_Values := True;
1773 -- Output values of missing indexes
1775 Lo_Val := Lo_Val - 1;
1776 Hi_Val := Hi_Val + 1;
1778 -- Enumeration type case
1780 if Is_Enumeration_Type (Index_Typ) then
1783 (Get_Enum_Lit_From_Pos
1784 (Index_Typ, Hi_Val, Loc));
1786 if Lo_Val = Hi_Val then
1787 Error_Msg_N ("\ %", N);
1791 (Get_Enum_Lit_From_Pos
1792 (Index_Typ, Lo_Val, Loc));
1793 Error_Msg_N ("\ % .. %", N);
1796 -- Integer types case
1799 Error_Msg_Uint_1 := Hi_Val;
1801 if Lo_Val = Hi_Val then
1802 Error_Msg_N ("\ ^", N);
1804 Error_Msg_Uint_2 := Lo_Val;
1805 Error_Msg_N ("\ ^ .. ^", N);
1812 if Missing_Values then
1813 Set_Etype (N, Any_Composite);
1818 -- STEP 2 (B): Compute aggregate bounds and min/max choices values
1820 if Nb_Discrete_Choices > 0 then
1821 Choices_Low := Table (1).Choice_Lo;
1822 Choices_High := Table (Nb_Discrete_Choices).Choice_Hi;
1825 -- If Others is present, then bounds of aggregate come from the
1826 -- index constraint (not the choices in the aggregate itself).
1828 if Others_Present then
1829 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
1831 -- No others clause present
1834 -- Special processing if others allowed and not present. This
1835 -- means that the bounds of the aggregate come from the index
1836 -- constraint (and the length must match).
1838 if Others_Allowed then
1839 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
1841 -- If others allowed, and no others present, then the array
1842 -- should cover all index values. If it does not, we will
1843 -- get a length check warning, but there is two cases where
1844 -- an additional warning is useful:
1846 -- If we have no positional components, and the length is
1847 -- wrong (which we can tell by others being allowed with
1848 -- missing components), and the index type is an enumeration
1849 -- type, then issue appropriate warnings about these missing
1850 -- components. They are only warnings, since the aggregate
1851 -- is fine, it's just the wrong length. We skip this check
1852 -- for standard character types (since there are no literals
1853 -- and it is too much trouble to concoct them), and also if
1854 -- any of the bounds have not-known-at-compile-time values.
1856 -- Another case warranting a warning is when the length is
1857 -- right, but as above we have an index type that is an
1858 -- enumeration, and the bounds do not match. This is a
1859 -- case where dubious sliding is allowed and we generate
1860 -- a warning that the bounds do not match.
1862 if No (Expressions (N))
1863 and then Nkind (Index) = N_Range
1864 and then Is_Enumeration_Type (Etype (Index))
1865 and then not Is_Standard_Character_Type (Etype (Index))
1866 and then Compile_Time_Known_Value (Aggr_Low)
1867 and then Compile_Time_Known_Value (Aggr_High)
1868 and then Compile_Time_Known_Value (Choices_Low)
1869 and then Compile_Time_Known_Value (Choices_High)
1872 ALo : constant Node_Id := Expr_Value_E (Aggr_Low);
1873 AHi : constant Node_Id := Expr_Value_E (Aggr_High);
1874 CLo : constant Node_Id := Expr_Value_E (Choices_Low);
1875 CHi : constant Node_Id := Expr_Value_E (Choices_High);
1880 -- Warning case one, missing values at start/end. Only
1881 -- do the check if the number of entries is too small.
1883 if (Enumeration_Pos (CHi) - Enumeration_Pos (CLo))
1885 (Enumeration_Pos (AHi) - Enumeration_Pos (ALo))
1888 ("missing index value(s) in array aggregate?", N);
1890 -- Output missing value(s) at start
1892 if Chars (ALo) /= Chars (CLo) then
1895 if Chars (ALo) = Chars (Ent) then
1896 Error_Msg_Name_1 := Chars (ALo);
1897 Error_Msg_N ("\ %?", N);
1899 Error_Msg_Name_1 := Chars (ALo);
1900 Error_Msg_Name_2 := Chars (Ent);
1901 Error_Msg_N ("\ % .. %?", N);
1905 -- Output missing value(s) at end
1907 if Chars (AHi) /= Chars (CHi) then
1910 if Chars (AHi) = Chars (Ent) then
1911 Error_Msg_Name_1 := Chars (Ent);
1912 Error_Msg_N ("\ %?", N);
1914 Error_Msg_Name_1 := Chars (Ent);
1915 Error_Msg_Name_2 := Chars (AHi);
1916 Error_Msg_N ("\ % .. %?", N);
1920 -- Warning case 2, dubious sliding. The First_Subtype
1921 -- test distinguishes between a constrained type where
1922 -- sliding is not allowed (so we will get a warning
1923 -- later that Constraint_Error will be raised), and
1924 -- the unconstrained case where sliding is permitted.
1926 elsif (Enumeration_Pos (CHi) - Enumeration_Pos (CLo))
1928 (Enumeration_Pos (AHi) - Enumeration_Pos (ALo))
1929 and then Chars (ALo) /= Chars (CLo)
1931 not Is_Constrained (First_Subtype (Etype (N)))
1934 ("bounds of aggregate do not match target?", N);
1940 -- If no others, aggregate bounds come from aggregate
1942 Aggr_Low := Choices_Low;
1943 Aggr_High := Choices_High;
1947 -- STEP 3: Process positional components
1950 -- STEP 3 (A): Process positional elements
1952 Expr := First (Expressions (N));
1953 Nb_Elements := Uint_0;
1954 while Present (Expr) loop
1955 Nb_Elements := Nb_Elements + 1;
1957 -- Ada 2005 (AI-231)
1959 if Ada_Version >= Ada_05
1960 and then Known_Null (Expr)
1962 Check_Can_Never_Be_Null (Etype (N), Expr);
1965 if not Resolve_Aggr_Expr (Expr, Single_Elmt => True) then
1972 if Others_Present then
1973 Assoc := Last (Component_Associations (N));
1975 -- Ada 2005 (AI-231)
1977 if Ada_Version >= Ada_05
1978 and then Known_Null (Assoc)
1980 Check_Can_Never_Be_Null (Etype (N), Expression (Assoc));
1983 -- Ada 2005 (AI-287): In case of default initialized component
1984 -- we delay the resolution to the expansion phase.
1986 if Box_Present (Assoc) then
1988 -- Ada 2005 (AI-287): In case of default initialization
1989 -- of a component the expander will generate calls to
1990 -- the corresponding initialization subprogram.
1994 elsif not Resolve_Aggr_Expr (Expression (Assoc),
1995 Single_Elmt => False)
2001 -- STEP 3 (B): Compute the aggregate bounds
2003 if Others_Present then
2004 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
2007 if Others_Allowed then
2008 Get_Index_Bounds (Index_Constr, Aggr_Low, Discard);
2010 Aggr_Low := Index_Typ_Low;
2013 Aggr_High := Add (Nb_Elements - 1, To => Aggr_Low);
2014 Check_Bound (Index_Base_High, Aggr_High);
2018 -- STEP 4: Perform static aggregate checks and save the bounds
2022 Check_Bounds (Index_Typ_Low, Index_Typ_High, Aggr_Low, Aggr_High);
2023 Check_Bounds (Index_Base_Low, Index_Base_High, Aggr_Low, Aggr_High);
2027 if Others_Present and then Nb_Discrete_Choices > 0 then
2028 Check_Bounds (Aggr_Low, Aggr_High, Choices_Low, Choices_High);
2029 Check_Bounds (Index_Typ_Low, Index_Typ_High,
2030 Choices_Low, Choices_High);
2031 Check_Bounds (Index_Base_Low, Index_Base_High,
2032 Choices_Low, Choices_High);
2036 elsif Others_Present and then Nb_Elements > 0 then
2037 Check_Length (Aggr_Low, Aggr_High, Nb_Elements);
2038 Check_Length (Index_Typ_Low, Index_Typ_High, Nb_Elements);
2039 Check_Length (Index_Base_Low, Index_Base_High, Nb_Elements);
2042 if Raises_Constraint_Error (Aggr_Low)
2043 or else Raises_Constraint_Error (Aggr_High)
2045 Set_Raises_Constraint_Error (N);
2048 Aggr_Low := Duplicate_Subexpr (Aggr_Low);
2050 -- Do not duplicate Aggr_High if Aggr_High = Aggr_Low + Nb_Elements
2051 -- since the addition node returned by Add is not yet analyzed. Attach
2052 -- to tree and analyze first. Reset analyzed flag to insure it will get
2053 -- analyzed when it is a literal bound whose type must be properly set.
2055 if Others_Present or else Nb_Discrete_Choices > 0 then
2056 Aggr_High := Duplicate_Subexpr (Aggr_High);
2058 if Etype (Aggr_High) = Universal_Integer then
2059 Set_Analyzed (Aggr_High, False);
2063 Set_Aggregate_Bounds
2064 (N, Make_Range (Loc, Low_Bound => Aggr_Low, High_Bound => Aggr_High));
2066 -- The bounds may contain expressions that must be inserted upwards.
2067 -- Attach them fully to the tree. After analysis, remove side effects
2068 -- from upper bound, if still needed.
2070 Set_Parent (Aggregate_Bounds (N), N);
2071 Analyze_And_Resolve (Aggregate_Bounds (N), Index_Typ);
2072 Check_Unset_Reference (Aggregate_Bounds (N));
2074 if not Others_Present and then Nb_Discrete_Choices = 0 then
2075 Set_High_Bound (Aggregate_Bounds (N),
2076 Duplicate_Subexpr (High_Bound (Aggregate_Bounds (N))));
2080 end Resolve_Array_Aggregate;
2082 ---------------------------------
2083 -- Resolve_Extension_Aggregate --
2084 ---------------------------------
2086 -- There are two cases to consider:
2088 -- a) If the ancestor part is a type mark, the components needed are
2089 -- the difference between the components of the expected type and the
2090 -- components of the given type mark.
2092 -- b) If the ancestor part is an expression, it must be unambiguous,
2093 -- and once we have its type we can also compute the needed components
2094 -- as in the previous case. In both cases, if the ancestor type is not
2095 -- the immediate ancestor, we have to build this ancestor recursively.
2097 -- In both cases discriminants of the ancestor type do not play a
2098 -- role in the resolution of the needed components, because inherited
2099 -- discriminants cannot be used in a type extension. As a result we can
2100 -- compute independently the list of components of the ancestor type and
2101 -- of the expected type.
2103 procedure Resolve_Extension_Aggregate (N : Node_Id; Typ : Entity_Id) is
2104 A : constant Node_Id := Ancestor_Part (N);
2109 function Valid_Limited_Ancestor (Anc : Node_Id) return Boolean;
2110 -- If the type is limited, verify that the ancestor part is a legal
2111 -- expression (aggregate or function call, including 'Input)) that
2112 -- does not require a copy, as specified in 7.5 (2).
2114 function Valid_Ancestor_Type return Boolean;
2115 -- Verify that the type of the ancestor part is a non-private ancestor
2116 -- of the expected type, which must be a type extension.
2118 ----------------------------
2119 -- Valid_Limited_Ancestor --
2120 ----------------------------
2122 function Valid_Limited_Ancestor (Anc : Node_Id) return Boolean is
2124 if Is_Entity_Name (Anc)
2125 and then Is_Type (Entity (Anc))
2129 elsif Nkind_In (Anc, N_Aggregate, N_Function_Call) then
2132 elsif Nkind (Anc) = N_Attribute_Reference
2133 and then Attribute_Name (Anc) = Name_Input
2138 Nkind (Anc) = N_Qualified_Expression
2140 return Valid_Limited_Ancestor (Expression (Anc));
2145 end Valid_Limited_Ancestor;
2147 -------------------------
2148 -- Valid_Ancestor_Type --
2149 -------------------------
2151 function Valid_Ancestor_Type return Boolean is
2152 Imm_Type : Entity_Id;
2155 Imm_Type := Base_Type (Typ);
2156 while Is_Derived_Type (Imm_Type)
2157 and then Etype (Imm_Type) /= Base_Type (A_Type)
2159 Imm_Type := Etype (Base_Type (Imm_Type));
2162 if not Is_Derived_Type (Base_Type (Typ))
2163 or else Etype (Imm_Type) /= Base_Type (A_Type)
2165 Error_Msg_NE ("expect ancestor type of &", A, Typ);
2170 end Valid_Ancestor_Type;
2172 -- Start of processing for Resolve_Extension_Aggregate
2177 if not Is_Tagged_Type (Typ) then
2178 Error_Msg_N ("type of extension aggregate must be tagged", N);
2181 elsif Is_Limited_Type (Typ) then
2183 -- Ada 2005 (AI-287): Limited aggregates are allowed
2185 if Ada_Version < Ada_05 then
2186 Error_Msg_N ("aggregate type cannot be limited", N);
2187 Explain_Limited_Type (Typ, N);
2190 elsif Valid_Limited_Ancestor (A) then
2195 ("limited ancestor part must be aggregate or function call", A);
2198 elsif Is_Class_Wide_Type (Typ) then
2199 Error_Msg_N ("aggregate cannot be of a class-wide type", N);
2203 if Is_Entity_Name (A)
2204 and then Is_Type (Entity (A))
2206 A_Type := Get_Full_View (Entity (A));
2208 if Valid_Ancestor_Type then
2209 Set_Entity (A, A_Type);
2210 Set_Etype (A, A_Type);
2212 Validate_Ancestor_Part (N);
2213 Resolve_Record_Aggregate (N, Typ);
2216 elsif Nkind (A) /= N_Aggregate then
2217 if Is_Overloaded (A) then
2220 Get_First_Interp (A, I, It);
2221 while Present (It.Typ) loop
2222 if Is_Tagged_Type (It.Typ)
2223 and then not Is_Limited_Type (It.Typ)
2225 if A_Type /= Any_Type then
2226 Error_Msg_N ("cannot resolve expression", A);
2233 Get_Next_Interp (I, It);
2236 if A_Type = Any_Type then
2238 ("ancestor part must be non-limited tagged type", A);
2243 A_Type := Etype (A);
2246 if Valid_Ancestor_Type then
2247 Resolve (A, A_Type);
2248 Check_Unset_Reference (A);
2249 Check_Non_Static_Context (A);
2251 if Is_Class_Wide_Type (Etype (A))
2252 and then Nkind (Original_Node (A)) = N_Function_Call
2254 -- If the ancestor part is a dispatching call, it appears
2255 -- statically to be a legal ancestor, but it yields any
2256 -- member of the class, and it is not possible to determine
2257 -- whether it is an ancestor of the extension aggregate (much
2258 -- less which ancestor). It is not possible to determine the
2259 -- required components of the extension part.
2261 -- This check implements AI-306, which in fact was motivated
2262 -- by an ACT query to the ARG after this test was added.
2264 Error_Msg_N ("ancestor part must be statically tagged", A);
2266 Resolve_Record_Aggregate (N, Typ);
2271 Error_Msg_N ("no unique type for this aggregate", A);
2273 end Resolve_Extension_Aggregate;
2275 ------------------------------
2276 -- Resolve_Record_Aggregate --
2277 ------------------------------
2279 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id) is
2281 -- N_Component_Association node belonging to the input aggregate N
2284 Positional_Expr : Node_Id;
2285 Component : Entity_Id;
2286 Component_Elmt : Elmt_Id;
2288 Components : constant Elist_Id := New_Elmt_List;
2289 -- Components is the list of the record components whose value must
2290 -- be provided in the aggregate. This list does include discriminants.
2292 New_Assoc_List : constant List_Id := New_List;
2293 New_Assoc : Node_Id;
2294 -- New_Assoc_List is the newly built list of N_Component_Association
2295 -- nodes. New_Assoc is one such N_Component_Association node in it.
2296 -- Please note that while Assoc and New_Assoc contain the same
2297 -- kind of nodes, they are used to iterate over two different
2298 -- N_Component_Association lists.
2300 Others_Etype : Entity_Id := Empty;
2301 -- This variable is used to save the Etype of the last record component
2302 -- that takes its value from the others choice. Its purpose is:
2304 -- (a) make sure the others choice is useful
2306 -- (b) make sure the type of all the components whose value is
2307 -- subsumed by the others choice are the same.
2309 -- This variable is updated as a side effect of function Get_Value
2311 Is_Box_Present : Boolean := False;
2312 Others_Box : Boolean := False;
2313 -- Ada 2005 (AI-287): Variables used in case of default initialization
2314 -- to provide a functionality similar to Others_Etype. Box_Present
2315 -- indicates that the component takes its default initialization;
2316 -- Others_Box indicates that at least one component takes its default
2317 -- initialization. Similar to Others_Etype, they are also updated as a
2318 -- side effect of function Get_Value.
2320 procedure Add_Association
2321 (Component : Entity_Id;
2323 Is_Box_Present : Boolean := False);
2324 -- Builds a new N_Component_Association node which associates
2325 -- Component to expression Expr and adds it to the new association
2326 -- list New_Assoc_List being built.
2328 function Discr_Present (Discr : Entity_Id) return Boolean;
2329 -- If aggregate N is a regular aggregate this routine will return True.
2330 -- Otherwise, if N is an extension aggregate, Discr is a discriminant
2331 -- whose value may already have been specified by N's ancestor part,
2332 -- this routine checks whether this is indeed the case and if so
2333 -- returns False, signaling that no value for Discr should appear in the
2334 -- N's aggregate part. Also, in this case, the routine appends to
2335 -- New_Assoc_List Discr the discriminant value specified in the ancestor
2341 Consider_Others_Choice : Boolean := False)
2343 -- Given a record component stored in parameter Compon, the
2344 -- following function returns its value as it appears in the list
2345 -- From, which is a list of N_Component_Association nodes. If no
2346 -- component association has a choice for the searched component,
2347 -- the value provided by the others choice is returned, if there
2348 -- is one and Consider_Others_Choice is set to true. Otherwise
2349 -- Empty is returned. If there is more than one component association
2350 -- giving a value for the searched record component, an error message
2351 -- is emitted and the first found value is returned.
2353 -- If Consider_Others_Choice is set and the returned expression comes
2354 -- from the others choice, then Others_Etype is set as a side effect.
2355 -- An error message is emitted if the components taking their value
2356 -- from the others choice do not have same type.
2358 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id);
2359 -- Analyzes and resolves expression Expr against the Etype of the
2360 -- Component. This routine also applies all appropriate checks to Expr.
2361 -- It finally saves a Expr in the newly created association list that
2362 -- will be attached to the final record aggregate. Note that if the
2363 -- Parent pointer of Expr is not set then Expr was produced with a
2364 -- New_Copy_Tree or some such.
2366 ---------------------
2367 -- Add_Association --
2368 ---------------------
2370 procedure Add_Association
2371 (Component : Entity_Id;
2373 Is_Box_Present : Boolean := False)
2375 Choice_List : constant List_Id := New_List;
2376 New_Assoc : Node_Id;
2379 Append (New_Occurrence_Of (Component, Sloc (Expr)), Choice_List);
2381 Make_Component_Association (Sloc (Expr),
2382 Choices => Choice_List,
2384 Box_Present => Is_Box_Present);
2385 Append (New_Assoc, New_Assoc_List);
2386 end Add_Association;
2392 function Discr_Present (Discr : Entity_Id) return Boolean is
2393 Regular_Aggr : constant Boolean := Nkind (N) /= N_Extension_Aggregate;
2398 Discr_Expr : Node_Id;
2400 Ancestor_Typ : Entity_Id;
2401 Orig_Discr : Entity_Id;
2403 D_Val : Elmt_Id := No_Elmt; -- stop junk warning
2405 Ancestor_Is_Subtyp : Boolean;
2408 if Regular_Aggr then
2412 Ancestor := Ancestor_Part (N);
2413 Ancestor_Typ := Etype (Ancestor);
2414 Loc := Sloc (Ancestor);
2416 Ancestor_Is_Subtyp :=
2417 Is_Entity_Name (Ancestor) and then Is_Type (Entity (Ancestor));
2419 -- If the ancestor part has no discriminants clearly N's aggregate
2420 -- part must provide a value for Discr.
2422 if not Has_Discriminants (Ancestor_Typ) then
2425 -- If the ancestor part is an unconstrained subtype mark then the
2426 -- Discr must be present in N's aggregate part.
2428 elsif Ancestor_Is_Subtyp
2429 and then not Is_Constrained (Entity (Ancestor))
2434 -- Now look to see if Discr was specified in the ancestor part
2436 if Ancestor_Is_Subtyp then
2437 D_Val := First_Elmt (Discriminant_Constraint (Entity (Ancestor)));
2440 Orig_Discr := Original_Record_Component (Discr);
2442 D := First_Discriminant (Ancestor_Typ);
2443 while Present (D) loop
2445 -- If Ancestor has already specified Disc value than insert its
2446 -- value in the final aggregate.
2448 if Original_Record_Component (D) = Orig_Discr then
2449 if Ancestor_Is_Subtyp then
2450 Discr_Expr := New_Copy_Tree (Node (D_Val));
2453 Make_Selected_Component (Loc,
2454 Prefix => Duplicate_Subexpr (Ancestor),
2455 Selector_Name => New_Occurrence_Of (Discr, Loc));
2458 Resolve_Aggr_Expr (Discr_Expr, Discr);
2462 Next_Discriminant (D);
2464 if Ancestor_Is_Subtyp then
2479 Consider_Others_Choice : Boolean := False)
2483 Expr : Node_Id := Empty;
2484 Selector_Name : Node_Id;
2487 Is_Box_Present := False;
2489 if Present (From) then
2490 Assoc := First (From);
2495 while Present (Assoc) loop
2496 Selector_Name := First (Choices (Assoc));
2497 while Present (Selector_Name) loop
2498 if Nkind (Selector_Name) = N_Others_Choice then
2499 if Consider_Others_Choice and then No (Expr) then
2501 -- We need to duplicate the expression for each
2502 -- successive component covered by the others choice.
2503 -- This is redundant if the others_choice covers only
2504 -- one component (small optimization possible???), but
2505 -- indispensable otherwise, because each one must be
2506 -- expanded individually to preserve side-effects.
2508 -- Ada 2005 (AI-287): In case of default initialization
2509 -- of components, we duplicate the corresponding default
2510 -- expression (from the record type declaration). The
2511 -- copy must carry the sloc of the association (not the
2512 -- original expression) to prevent spurious elaboration
2513 -- checks when the default includes function calls.
2515 if Box_Present (Assoc) then
2517 Is_Box_Present := True;
2519 if Expander_Active then
2522 (Expression (Parent (Compon)),
2523 New_Sloc => Sloc (Assoc));
2525 return Expression (Parent (Compon));
2529 if Present (Others_Etype) and then
2530 Base_Type (Others_Etype) /= Base_Type (Etype
2533 Error_Msg_N ("components in OTHERS choice must " &
2534 "have same type", Selector_Name);
2537 Others_Etype := Etype (Compon);
2539 if Expander_Active then
2540 return New_Copy_Tree (Expression (Assoc));
2542 return Expression (Assoc);
2547 elsif Chars (Compon) = Chars (Selector_Name) then
2550 -- Ada 2005 (AI-231)
2552 if Ada_Version >= Ada_05
2553 and then Known_Null (Expression (Assoc))
2555 Check_Can_Never_Be_Null (Compon, Expression (Assoc));
2558 -- We need to duplicate the expression when several
2559 -- components are grouped together with a "|" choice.
2560 -- For instance "filed1 | filed2 => Expr"
2562 -- Ada 2005 (AI-287)
2564 if Box_Present (Assoc) then
2565 Is_Box_Present := True;
2567 -- Duplicate the default expression of the component
2568 -- from the record type declaration, so a new copy
2569 -- can be attached to the association.
2571 -- Note that we always copy the default expression,
2572 -- even when the association has a single choice, in
2573 -- order to create a proper association for the
2574 -- expanded aggregate.
2576 Expr := New_Copy_Tree (Expression (Parent (Compon)));
2579 if Present (Next (Selector_Name)) then
2580 Expr := New_Copy_Tree (Expression (Assoc));
2582 Expr := Expression (Assoc);
2586 Generate_Reference (Compon, Selector_Name);
2590 ("more than one value supplied for &",
2591 Selector_Name, Compon);
2596 Next (Selector_Name);
2605 -----------------------
2606 -- Resolve_Aggr_Expr --
2607 -----------------------
2609 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id) is
2610 New_C : Entity_Id := Component;
2611 Expr_Type : Entity_Id := Empty;
2613 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean;
2614 -- If the expression is an aggregate (possibly qualified) then its
2615 -- expansion is delayed until the enclosing aggregate is expanded
2616 -- into assignments. In that case, do not generate checks on the
2617 -- expression, because they will be generated later, and will other-
2618 -- wise force a copy (to remove side-effects) that would leave a
2619 -- dynamic-sized aggregate in the code, something that gigi cannot
2623 -- Set to True if the resolved Expr node needs to be relocated
2624 -- when attached to the newly created association list. This node
2625 -- need not be relocated if its parent pointer is not set.
2626 -- In fact in this case Expr is the output of a New_Copy_Tree call.
2627 -- if Relocate is True then we have analyzed the expression node
2628 -- in the original aggregate and hence it needs to be relocated
2629 -- when moved over the new association list.
2631 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean is
2632 Kind : constant Node_Kind := Nkind (Expr);
2634 return (Nkind_In (Kind, N_Aggregate, N_Extension_Aggregate)
2635 and then Present (Etype (Expr))
2636 and then Is_Record_Type (Etype (Expr))
2637 and then Expansion_Delayed (Expr))
2638 or else (Kind = N_Qualified_Expression
2639 and then Has_Expansion_Delayed (Expression (Expr)));
2640 end Has_Expansion_Delayed;
2642 -- Start of processing for Resolve_Aggr_Expr
2645 -- If the type of the component is elementary or the type of the
2646 -- aggregate does not contain discriminants, use the type of the
2647 -- component to resolve Expr.
2649 if Is_Elementary_Type (Etype (Component))
2650 or else not Has_Discriminants (Etype (N))
2652 Expr_Type := Etype (Component);
2654 -- Otherwise we have to pick up the new type of the component from
2655 -- the new constrained subtype of the aggregate. In fact components
2656 -- which are of a composite type might be constrained by a
2657 -- discriminant, and we want to resolve Expr against the subtype were
2658 -- all discriminant occurrences are replaced with their actual value.
2661 New_C := First_Component (Etype (N));
2662 while Present (New_C) loop
2663 if Chars (New_C) = Chars (Component) then
2664 Expr_Type := Etype (New_C);
2668 Next_Component (New_C);
2671 pragma Assert (Present (Expr_Type));
2673 -- For each range in an array type where a discriminant has been
2674 -- replaced with the constraint, check that this range is within
2675 -- the range of the base type. This checks is done in the init
2676 -- proc for regular objects, but has to be done here for
2677 -- aggregates since no init proc is called for them.
2679 if Is_Array_Type (Expr_Type) then
2682 -- Range of the current constrained index in the array
2684 Orig_Index : Node_Id := First_Index (Etype (Component));
2685 -- Range corresponding to the range Index above in the
2686 -- original unconstrained record type. The bounds of this
2687 -- range may be governed by discriminants.
2689 Unconstr_Index : Node_Id := First_Index (Etype (Expr_Type));
2690 -- Range corresponding to the range Index above for the
2691 -- unconstrained array type. This range is needed to apply
2695 Index := First_Index (Expr_Type);
2696 while Present (Index) loop
2697 if Depends_On_Discriminant (Orig_Index) then
2698 Apply_Range_Check (Index, Etype (Unconstr_Index));
2702 Next_Index (Orig_Index);
2703 Next_Index (Unconstr_Index);
2709 -- If the Parent pointer of Expr is not set, Expr is an expression
2710 -- duplicated by New_Tree_Copy (this happens for record aggregates
2711 -- that look like (Field1 | Filed2 => Expr) or (others => Expr)).
2712 -- Such a duplicated expression must be attached to the tree
2713 -- before analysis and resolution to enforce the rule that a tree
2714 -- fragment should never be analyzed or resolved unless it is
2715 -- attached to the current compilation unit.
2717 if No (Parent (Expr)) then
2718 Set_Parent (Expr, N);
2724 Analyze_And_Resolve (Expr, Expr_Type);
2725 Check_Expr_OK_In_Limited_Aggregate (Expr);
2726 Check_Non_Static_Context (Expr);
2727 Check_Unset_Reference (Expr);
2729 if not Has_Expansion_Delayed (Expr) then
2730 Aggregate_Constraint_Checks (Expr, Expr_Type);
2733 if Raises_Constraint_Error (Expr) then
2734 Set_Raises_Constraint_Error (N);
2738 Add_Association (New_C, Relocate_Node (Expr));
2740 Add_Association (New_C, Expr);
2742 end Resolve_Aggr_Expr;
2744 -- Start of processing for Resolve_Record_Aggregate
2747 -- We may end up calling Duplicate_Subexpr on expressions that are
2748 -- attached to New_Assoc_List. For this reason we need to attach it
2749 -- to the tree by setting its parent pointer to N. This parent point
2750 -- will change in STEP 8 below.
2752 Set_Parent (New_Assoc_List, N);
2754 -- STEP 1: abstract type and null record verification
2756 if Is_Abstract_Type (Typ) then
2757 Error_Msg_N ("type of aggregate cannot be abstract", N);
2760 if No (First_Entity (Typ)) and then Null_Record_Present (N) then
2764 elsif Present (First_Entity (Typ))
2765 and then Null_Record_Present (N)
2766 and then not Is_Tagged_Type (Typ)
2768 Error_Msg_N ("record aggregate cannot be null", N);
2771 elsif No (First_Entity (Typ)) then
2772 Error_Msg_N ("record aggregate must be null", N);
2776 -- STEP 2: Verify aggregate structure
2779 Selector_Name : Node_Id;
2780 Bad_Aggregate : Boolean := False;
2783 if Present (Component_Associations (N)) then
2784 Assoc := First (Component_Associations (N));
2789 while Present (Assoc) loop
2790 Selector_Name := First (Choices (Assoc));
2791 while Present (Selector_Name) loop
2792 if Nkind (Selector_Name) = N_Identifier then
2795 elsif Nkind (Selector_Name) = N_Others_Choice then
2796 if Selector_Name /= First (Choices (Assoc))
2797 or else Present (Next (Selector_Name))
2799 Error_Msg_N ("OTHERS must appear alone in a choice list",
2803 elsif Present (Next (Assoc)) then
2804 Error_Msg_N ("OTHERS must appear last in an aggregate",
2808 -- (Ada2005): If this is an association with a box,
2809 -- indicate that the association need not represent
2812 elsif Box_Present (Assoc) then
2818 ("selector name should be identifier or OTHERS",
2820 Bad_Aggregate := True;
2823 Next (Selector_Name);
2829 if Bad_Aggregate then
2834 -- STEP 3: Find discriminant Values
2837 Discrim : Entity_Id;
2838 Missing_Discriminants : Boolean := False;
2841 if Present (Expressions (N)) then
2842 Positional_Expr := First (Expressions (N));
2844 Positional_Expr := Empty;
2847 if Has_Discriminants (Typ) then
2848 Discrim := First_Discriminant (Typ);
2853 -- First find the discriminant values in the positional components
2855 while Present (Discrim) and then Present (Positional_Expr) loop
2856 if Discr_Present (Discrim) then
2857 Resolve_Aggr_Expr (Positional_Expr, Discrim);
2859 -- Ada 2005 (AI-231)
2861 if Ada_Version >= Ada_05
2862 and then Known_Null (Positional_Expr)
2864 Check_Can_Never_Be_Null (Discrim, Positional_Expr);
2867 Next (Positional_Expr);
2870 if Present (Get_Value (Discrim, Component_Associations (N))) then
2872 ("more than one value supplied for discriminant&",
2876 Next_Discriminant (Discrim);
2879 -- Find remaining discriminant values, if any, among named components
2881 while Present (Discrim) loop
2882 Expr := Get_Value (Discrim, Component_Associations (N), True);
2884 if not Discr_Present (Discrim) then
2885 if Present (Expr) then
2887 ("more than one value supplied for discriminant&",
2891 elsif No (Expr) then
2893 ("no value supplied for discriminant &", N, Discrim);
2894 Missing_Discriminants := True;
2897 Resolve_Aggr_Expr (Expr, Discrim);
2900 Next_Discriminant (Discrim);
2903 if Missing_Discriminants then
2907 -- At this point and until the beginning of STEP 6, New_Assoc_List
2908 -- contains only the discriminants and their values.
2912 -- STEP 4: Set the Etype of the record aggregate
2914 -- ??? This code is pretty much a copy of Sem_Ch3.Build_Subtype. That
2915 -- routine should really be exported in sem_util or some such and used
2916 -- in sem_ch3 and here rather than have a copy of the code which is a
2917 -- maintenance nightmare.
2919 -- ??? Performance WARNING. The current implementation creates a new
2920 -- itype for all aggregates whose base type is discriminated.
2921 -- This means that for record aggregates nested inside an array
2922 -- aggregate we will create a new itype for each record aggregate
2923 -- if the array component type has discriminants. For large aggregates
2924 -- this may be a problem. What should be done in this case is
2925 -- to reuse itypes as much as possible.
2927 if Has_Discriminants (Typ) then
2928 Build_Constrained_Itype : declare
2929 Loc : constant Source_Ptr := Sloc (N);
2931 Subtyp_Decl : Node_Id;
2934 C : constant List_Id := New_List;
2937 New_Assoc := First (New_Assoc_List);
2938 while Present (New_Assoc) loop
2939 Append (Duplicate_Subexpr (Expression (New_Assoc)), To => C);
2944 Make_Subtype_Indication (Loc,
2945 Subtype_Mark => New_Occurrence_Of (Base_Type (Typ), Loc),
2946 Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
2948 Def_Id := Create_Itype (Ekind (Typ), N);
2951 Make_Subtype_Declaration (Loc,
2952 Defining_Identifier => Def_Id,
2953 Subtype_Indication => Indic);
2954 Set_Parent (Subtyp_Decl, Parent (N));
2956 -- Itypes must be analyzed with checks off (see itypes.ads)
2958 Analyze (Subtyp_Decl, Suppress => All_Checks);
2960 Set_Etype (N, Def_Id);
2961 Check_Static_Discriminated_Subtype
2962 (Def_Id, Expression (First (New_Assoc_List)));
2963 end Build_Constrained_Itype;
2969 -- STEP 5: Get remaining components according to discriminant values
2972 Record_Def : Node_Id;
2973 Parent_Typ : Entity_Id;
2974 Root_Typ : Entity_Id;
2975 Parent_Typ_List : Elist_Id;
2976 Parent_Elmt : Elmt_Id;
2977 Errors_Found : Boolean := False;
2981 if Is_Derived_Type (Typ) and then Is_Tagged_Type (Typ) then
2982 Parent_Typ_List := New_Elmt_List;
2984 -- If this is an extension aggregate, the component list must
2985 -- include all components that are not in the given ancestor
2986 -- type. Otherwise, the component list must include components
2987 -- of all ancestors, starting with the root.
2989 if Nkind (N) = N_Extension_Aggregate then
2990 Root_Typ := Base_Type (Etype (Ancestor_Part (N)));
2992 Root_Typ := Root_Type (Typ);
2994 if Nkind (Parent (Base_Type (Root_Typ))) =
2995 N_Private_Type_Declaration
2998 ("type of aggregate has private ancestor&!",
3000 Error_Msg_N ("must use extension aggregate!", N);
3004 Dnode := Declaration_Node (Base_Type (Root_Typ));
3006 -- If we don't get a full declaration, then we have some
3007 -- error which will get signalled later so skip this part.
3008 -- Otherwise, gather components of root that apply to the
3009 -- aggregate type. We use the base type in case there is an
3010 -- applicable stored constraint that renames the discriminants
3013 if Nkind (Dnode) = N_Full_Type_Declaration then
3014 Record_Def := Type_Definition (Dnode);
3015 Gather_Components (Base_Type (Typ),
3016 Component_List (Record_Def),
3017 Governed_By => New_Assoc_List,
3019 Report_Errors => Errors_Found);
3023 Parent_Typ := Base_Type (Typ);
3024 while Parent_Typ /= Root_Typ loop
3025 Prepend_Elmt (Parent_Typ, To => Parent_Typ_List);
3026 Parent_Typ := Etype (Parent_Typ);
3028 if Nkind (Parent (Base_Type (Parent_Typ))) =
3029 N_Private_Type_Declaration
3030 or else Nkind (Parent (Base_Type (Parent_Typ))) =
3031 N_Private_Extension_Declaration
3033 if Nkind (N) /= N_Extension_Aggregate then
3035 ("type of aggregate has private ancestor&!",
3037 Error_Msg_N ("must use extension aggregate!", N);
3040 elsif Parent_Typ /= Root_Typ then
3042 ("ancestor part of aggregate must be private type&",
3043 Ancestor_Part (N), Parent_Typ);
3049 -- Now collect components from all other ancestors
3051 Parent_Elmt := First_Elmt (Parent_Typ_List);
3052 while Present (Parent_Elmt) loop
3053 Parent_Typ := Node (Parent_Elmt);
3054 Record_Def := Type_Definition (Parent (Base_Type (Parent_Typ)));
3055 Gather_Components (Empty,
3056 Component_List (Record_Extension_Part (Record_Def)),
3057 Governed_By => New_Assoc_List,
3059 Report_Errors => Errors_Found);
3061 Next_Elmt (Parent_Elmt);
3065 Record_Def := Type_Definition (Parent (Base_Type (Typ)));
3067 if Null_Present (Record_Def) then
3070 Gather_Components (Base_Type (Typ),
3071 Component_List (Record_Def),
3072 Governed_By => New_Assoc_List,
3074 Report_Errors => Errors_Found);
3078 if Errors_Found then
3083 -- STEP 6: Find component Values
3086 Component_Elmt := First_Elmt (Components);
3088 -- First scan the remaining positional associations in the aggregate.
3089 -- Remember that at this point Positional_Expr contains the current
3090 -- positional association if any is left after looking for discriminant
3091 -- values in step 3.
3093 while Present (Positional_Expr) and then Present (Component_Elmt) loop
3094 Component := Node (Component_Elmt);
3095 Resolve_Aggr_Expr (Positional_Expr, Component);
3097 -- Ada 2005 (AI-231)
3099 if Ada_Version >= Ada_05
3100 and then Known_Null (Positional_Expr)
3102 Check_Can_Never_Be_Null (Component, Positional_Expr);
3105 if Present (Get_Value (Component, Component_Associations (N))) then
3107 ("more than one value supplied for Component &", N, Component);
3110 Next (Positional_Expr);
3111 Next_Elmt (Component_Elmt);
3114 if Present (Positional_Expr) then
3116 ("too many components for record aggregate", Positional_Expr);
3119 -- Now scan for the named arguments of the aggregate
3121 while Present (Component_Elmt) loop
3122 Component := Node (Component_Elmt);
3123 Expr := Get_Value (Component, Component_Associations (N), True);
3125 -- Note: The previous call to Get_Value sets the value of the
3126 -- variable Is_Box_Present.
3128 -- Ada 2005 (AI-287): Handle components with default initialization.
3129 -- Note: This feature was originally added to Ada 2005 for limited
3130 -- but it was finally allowed with any type.
3132 if Is_Box_Present then
3133 Check_Box_Component : declare
3134 Ctyp : constant Entity_Id := Etype (Component);
3137 -- If there is a default expression for the aggregate, copy
3138 -- it into a new association.
3140 -- If the component has an initialization procedure (IP) we
3141 -- pass the component to the expander, which will generate
3142 -- the call to such IP.
3144 -- If the component has discriminants, their values must
3145 -- be taken from their subtype. This is indispensable for
3146 -- constraints that are given by the current instance of an
3147 -- enclosing type, to allow the expansion of the aggregate
3148 -- to replace the reference to the current instance by the
3149 -- target object of the aggregate.
3151 if Present (Parent (Component))
3153 Nkind (Parent (Component)) = N_Component_Declaration
3154 and then Present (Expression (Parent (Component)))
3157 New_Copy_Tree (Expression (Parent (Component)),
3158 New_Sloc => Sloc (N));
3161 (Component => Component,
3163 Set_Has_Self_Reference (N);
3165 -- A box-defaulted access component gets the value null. Also
3166 -- included are components of private types whose underlying
3167 -- type is an access type. In either case set the type of the
3168 -- literal, for subsequent use in semantic checks.
3170 elsif Present (Underlying_Type (Ctyp))
3171 and then Is_Access_Type (Underlying_Type (Ctyp))
3173 if not Is_Private_Type (Ctyp) then
3174 Expr := Make_Null (Sloc (N));
3175 Set_Etype (Expr, Ctyp);
3177 (Component => Component,
3180 -- If the component's type is private with an access type as
3181 -- its underlying type then we have to create an unchecked
3182 -- conversion to satisfy type checking.
3186 Qual_Null : constant Node_Id :=
3187 Make_Qualified_Expression (Sloc (N),
3190 (Underlying_Type (Ctyp), Sloc (N)),
3191 Expression => Make_Null (Sloc (N)));
3193 Convert_Null : constant Node_Id :=
3194 Unchecked_Convert_To
3198 Analyze_And_Resolve (Convert_Null, Ctyp);
3200 (Component => Component, Expr => Convert_Null);
3204 elsif Has_Non_Null_Base_Init_Proc (Ctyp)
3205 or else not Expander_Active
3207 if Is_Record_Type (Ctyp)
3208 and then Has_Discriminants (Ctyp)
3210 -- We build a partially initialized aggregate with the
3211 -- values of the discriminants and box initialization
3212 -- for the rest, if other components are present.
3215 Loc : constant Source_Ptr := Sloc (N);
3218 Discr_Elmt : Elmt_Id;
3219 Discr_Val : Node_Id;
3223 Expr := Make_Aggregate (Loc, New_List, New_List);
3226 First_Elmt (Discriminant_Constraint (Ctyp));
3227 while Present (Discr_Elmt) loop
3228 Discr_Val := Node (Discr_Elmt);
3230 -- The constraint may be given by a discriminant
3231 -- of the enclosing type, in which case we have
3232 -- to retrieve its value, which is part of the
3233 -- current aggregate.
3235 if Is_Entity_Name (Discr_Val)
3237 Ekind (Entity (Discr_Val)) = E_Discriminant
3239 Discr := Entity (Discr_Val);
3241 Assoc := First (New_Assoc_List);
3242 while Present (Assoc) loop
3244 (Entity (First (Choices (Assoc))))
3246 Entity (First (Choices (Assoc))) = Discr
3248 Discr_Val := Expression (Assoc);
3256 (New_Copy_Tree (Discr_Val), Expressions (Expr));
3258 -- If the discriminant constraint is a current
3259 -- instance, mark the current aggregate so that
3260 -- the self-reference can be expanded later.
3262 if Nkind (Discr_Val) = N_Attribute_Reference
3263 and then Is_Entity_Name (Prefix (Discr_Val))
3264 and then Is_Type (Entity (Prefix (Discr_Val)))
3265 and then Etype (N) = Entity (Prefix (Discr_Val))
3267 Set_Has_Self_Reference (N);
3270 Next_Elmt (Discr_Elmt);
3277 -- Look for a component that is not a discriminant
3278 -- before creating an others box association.
3280 Comp := First_Component (Ctyp);
3281 while Present (Comp) loop
3282 if Ekind (Comp) = E_Component then
3284 (Make_Component_Association (Loc,
3286 New_List (Make_Others_Choice (Loc)),
3287 Expression => Empty,
3288 Box_Present => True),
3289 Component_Associations (Expr));
3293 Next_Component (Comp);
3298 (Component => Component,
3304 (Component => Component,
3306 Is_Box_Present => True);
3309 -- Otherwise we only need to resolve the expression if the
3310 -- component has partially initialized values (required to
3311 -- expand the corresponding assignments and run-time checks).
3313 elsif Present (Expr)
3314 and then Is_Partially_Initialized_Type (Ctyp)
3316 Resolve_Aggr_Expr (Expr, Component);
3318 end Check_Box_Component;
3320 elsif No (Expr) then
3322 -- Ignore hidden components associated with the position of the
3323 -- interface tags: these are initialized dynamically.
3325 if not Present (Related_Type (Component)) then
3327 ("no value supplied for component &!", N, Component);
3331 Resolve_Aggr_Expr (Expr, Component);
3334 Next_Elmt (Component_Elmt);
3337 -- STEP 7: check for invalid components + check type in choice list
3344 -- Type of first component in choice list
3347 if Present (Component_Associations (N)) then
3348 Assoc := First (Component_Associations (N));
3353 Verification : while Present (Assoc) loop
3354 Selectr := First (Choices (Assoc));
3357 if Nkind (Selectr) = N_Others_Choice then
3359 -- Ada 2005 (AI-287): others choice may have expression or box
3361 if No (Others_Etype)
3362 and then not Others_Box
3365 ("OTHERS must represent at least one component", Selectr);
3371 while Present (Selectr) loop
3372 New_Assoc := First (New_Assoc_List);
3373 while Present (New_Assoc) loop
3374 Component := First (Choices (New_Assoc));
3375 exit when Chars (Selectr) = Chars (Component);
3379 -- If no association, this is not a legal component of
3380 -- of the type in question, except if its association
3381 -- is provided with a box.
3383 if No (New_Assoc) then
3384 if Box_Present (Parent (Selectr)) then
3386 -- This may still be a bogus component with a box. Scan
3387 -- list of components to verify that a component with
3388 -- that name exists.
3394 C := First_Component (Typ);
3395 while Present (C) loop
3396 if Chars (C) = Chars (Selectr) then
3398 -- If the context is an extension aggregate,
3399 -- the component must not be inherited from
3400 -- the ancestor part of the aggregate.
3402 if Nkind (N) /= N_Extension_Aggregate
3404 Scope (Original_Record_Component (C)) /=
3405 Etype (Ancestor_Part (N))
3415 Error_Msg_Node_2 := Typ;
3416 Error_Msg_N ("& is not a component of}", Selectr);
3420 elsif Chars (Selectr) /= Name_uTag
3421 and then Chars (Selectr) /= Name_uParent
3422 and then Chars (Selectr) /= Name_uController
3424 if not Has_Discriminants (Typ) then
3425 Error_Msg_Node_2 := Typ;
3426 Error_Msg_N ("& is not a component of}", Selectr);
3429 ("& is not a component of the aggregate subtype",
3433 Check_Misspelled_Component (Components, Selectr);
3436 elsif No (Typech) then
3437 Typech := Base_Type (Etype (Component));
3439 elsif Typech /= Base_Type (Etype (Component)) then
3440 if not Box_Present (Parent (Selectr)) then
3442 ("components in choice list must have same type",
3451 end loop Verification;
3454 -- STEP 8: replace the original aggregate
3457 New_Aggregate : constant Node_Id := New_Copy (N);
3460 Set_Expressions (New_Aggregate, No_List);
3461 Set_Etype (New_Aggregate, Etype (N));
3462 Set_Component_Associations (New_Aggregate, New_Assoc_List);
3464 Rewrite (N, New_Aggregate);
3466 end Resolve_Record_Aggregate;
3468 -----------------------------
3469 -- Check_Can_Never_Be_Null --
3470 -----------------------------
3472 procedure Check_Can_Never_Be_Null (Typ : Entity_Id; Expr : Node_Id) is
3473 Comp_Typ : Entity_Id;
3477 (Ada_Version >= Ada_05
3478 and then Present (Expr)
3479 and then Known_Null (Expr));
3482 when E_Array_Type =>
3483 Comp_Typ := Component_Type (Typ);
3487 Comp_Typ := Etype (Typ);
3493 if Can_Never_Be_Null (Comp_Typ) then
3495 -- Here we know we have a constraint error. Note that we do not use
3496 -- Apply_Compile_Time_Constraint_Error here to the Expr, which might
3497 -- seem the more natural approach. That's because in some cases the
3498 -- components are rewritten, and the replacement would be missed.
3501 (Compile_Time_Constraint_Error
3503 "(Ada 2005) null not allowed in null-excluding component?"),
3504 Make_Raise_Constraint_Error (Sloc (Expr),
3505 Reason => CE_Access_Check_Failed));
3507 -- Set proper type for bogus component (why is this needed???)
3509 Set_Etype (Expr, Comp_Typ);
3510 Set_Analyzed (Expr);
3512 end Check_Can_Never_Be_Null;
3514 ---------------------
3515 -- Sort_Case_Table --
3516 ---------------------
3518 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
3519 L : constant Int := Case_Table'First;
3520 U : constant Int := Case_Table'Last;
3528 T := Case_Table (K + 1);
3532 and then Expr_Value (Case_Table (J - 1).Choice_Lo) >
3533 Expr_Value (T.Choice_Lo)
3535 Case_Table (J) := Case_Table (J - 1);
3539 Case_Table (J) := T;
3542 end Sort_Case_Table;
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