1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with 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_Aux; use Sem_Aux;
44 with Sem_Cat; use Sem_Cat;
45 with Sem_Ch3; use Sem_Ch3;
46 with Sem_Ch13; use Sem_Ch13;
47 with Sem_Eval; use Sem_Eval;
48 with Sem_Res; use Sem_Res;
49 with Sem_Util; use Sem_Util;
50 with Sem_Type; use Sem_Type;
51 with Sem_Warn; use Sem_Warn;
52 with Sinfo; use Sinfo;
53 with Snames; use Snames;
54 with Stringt; use Stringt;
55 with Stand; use Stand;
56 with Targparm; use Targparm;
57 with Tbuild; use Tbuild;
58 with Uintp; use Uintp;
60 package body Sem_Aggr is
62 type Case_Bounds is record
65 Choice_Node : Node_Id;
68 type Case_Table_Type is array (Nat range <>) of Case_Bounds;
69 -- Table type used by Check_Case_Choices procedure
71 -----------------------
72 -- Local Subprograms --
73 -----------------------
75 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
76 -- Sort the Case Table using the Lower Bound of each Choice as the key.
77 -- A simple insertion sort is used since the number of choices in a case
78 -- statement of variant part will usually be small and probably in near
81 procedure Check_Can_Never_Be_Null (Typ : Entity_Id; Expr : Node_Id);
82 -- Ada 2005 (AI-231): Check bad usage of null for a component for which
83 -- null exclusion (NOT NULL) is specified. Typ can be an E_Array_Type for
84 -- the array case (the component type of the array will be used) or an
85 -- E_Component/E_Discriminant entity in the record case, in which case the
86 -- type of the component will be used for the test. If Typ is any other
87 -- kind of entity, the call is ignored. Expr is the component node in the
88 -- aggregate which is known to have a null value. A warning message will be
89 -- issued if the component is null excluding.
91 -- It would be better to pass the proper type for Typ ???
93 procedure Check_Expr_OK_In_Limited_Aggregate (Expr : Node_Id);
94 -- Check that Expr is either not limited or else is one of the cases of
95 -- expressions allowed for a limited component association (namely, an
96 -- aggregate, function call, or <> notation). Report error for violations.
98 ------------------------------------------------------
99 -- Subprograms used for RECORD AGGREGATE Processing --
100 ------------------------------------------------------
102 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id);
103 -- This procedure performs all the semantic checks required for record
104 -- aggregates. Note that for aggregates analysis and resolution go
105 -- hand in hand. Aggregate analysis has been delayed up to here and
106 -- it is done while resolving the aggregate.
108 -- N is the N_Aggregate node.
109 -- Typ is the record type for the aggregate resolution
111 -- While performing the semantic checks, this procedure builds a new
112 -- Component_Association_List where each record field appears alone in a
113 -- Component_Choice_List along with its corresponding expression. The
114 -- record fields in the Component_Association_List appear in the same order
115 -- in which they appear in the record type Typ.
117 -- Once this new Component_Association_List is built and all the semantic
118 -- checks performed, the original aggregate subtree is replaced with the
119 -- new named record aggregate just built. Note that subtree substitution is
120 -- performed with Rewrite so as to be able to retrieve the original
123 -- The aggregate subtree manipulation performed by Resolve_Record_Aggregate
124 -- yields the aggregate format expected by Gigi. Typically, this kind of
125 -- tree manipulations are done in the expander. However, because the
126 -- semantic checks that need to be performed on record aggregates really go
127 -- hand in hand with the record aggregate normalization, the aggregate
128 -- subtree transformation is performed during resolution rather than
129 -- expansion. Had we decided otherwise we would have had to duplicate most
130 -- of the code in the expansion procedure Expand_Record_Aggregate. Note,
131 -- however, that all the expansion concerning aggregates for tagged records
132 -- is done in Expand_Record_Aggregate.
134 -- The algorithm of Resolve_Record_Aggregate proceeds as follows:
136 -- 1. Make sure that the record type against which the record aggregate
137 -- has to be resolved is not abstract. Furthermore if the type is a
138 -- null aggregate make sure the input aggregate N is also null.
140 -- 2. Verify that the structure of the aggregate is that of a record
141 -- aggregate. Specifically, look for component associations and ensure
142 -- that each choice list only has identifiers or the N_Others_Choice
143 -- node. Also make sure that if present, the N_Others_Choice occurs
144 -- last and by itself.
146 -- 3. If Typ contains discriminants, the values for each discriminant is
147 -- looked for. If the record type Typ has variants, we check that the
148 -- expressions corresponding to each discriminant ruling the (possibly
149 -- nested) variant parts of Typ, are static. This allows us to determine
150 -- the variant parts to which the rest of the aggregate must conform.
151 -- The names of discriminants with their values are saved in a new
152 -- association list, New_Assoc_List which is later augmented with the
153 -- names and values of the remaining 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 for a given
157 -- discriminant are found, semantic processing continues looking for
158 -- further errors. In this case it's the first discriminant value found
159 -- 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 set the
166 -- Etype of the record aggregate. If Typ contains no discriminants this
167 -- is straightforward: the Etype of N is just Typ, otherwise a new
168 -- implicit constrained subtype of Typ is built to be the Etype of N.
170 -- 5. Gather the remaining record components according to the discriminant
171 -- values. This involves recursively traversing the record type
172 -- structure to see what variants are selected by the given discriminant
173 -- values. This processing is a little more convoluted if Typ is a
174 -- derived tagged types since we need to retrieve the record structure
175 -- of all the ancestors of Typ.
177 -- 6. After gathering the record components we look for their values in the
178 -- record aggregate and emit appropriate error messages should we not
179 -- find such values or should they be duplicated.
181 -- 7. We then make sure no illegal component names appear in the record
182 -- aggregate and make sure that the type of the record components
183 -- appearing in a same choice list is the same. Finally we ensure that
184 -- the others choice, if present, is used to provide the value of at
185 -- least a record component.
187 -- 8. The original aggregate node is replaced with the new named aggregate
188 -- built in steps 3 through 6, as explained earlier.
190 -- Given the complexity of record aggregate resolution, the primary goal of
191 -- this routine is clarity and simplicity rather than execution and storage
192 -- efficiency. If there are only positional components in the aggregate the
193 -- running time is linear. If there are associations the running time is
194 -- still linear as long as the order of the associations is not too far off
195 -- the order of the components in the record type. If this is not the case
196 -- the running time is at worst quadratic in the size of the association
199 procedure Check_Misspelled_Component
200 (Elements : Elist_Id;
201 Component : Node_Id);
202 -- Give possible misspelling diagnostic if Component is likely to be a
203 -- misspelling of one of the components of the Assoc_List. This is called
204 -- by Resolve_Aggr_Expr after producing an invalid component error message.
206 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id);
207 -- An optimization: determine whether a discriminated subtype has a static
208 -- constraint, and contains array components whose length is also static,
209 -- either because they are constrained by the discriminant, or because the
210 -- original component bounds are static.
212 -----------------------------------------------------
213 -- Subprograms used for ARRAY AGGREGATE Processing --
214 -----------------------------------------------------
216 function Resolve_Array_Aggregate
219 Index_Constr : Node_Id;
220 Component_Typ : Entity_Id;
221 Others_Allowed : Boolean) return Boolean;
222 -- This procedure performs the semantic checks for an array aggregate.
223 -- True is returned if the aggregate resolution succeeds.
225 -- The procedure works by recursively checking each nested aggregate.
226 -- Specifically, after checking a sub-aggregate nested at the i-th level
227 -- we recursively check all the subaggregates at the i+1-st level (if any).
228 -- Note that for aggregates analysis and resolution go hand in hand.
229 -- Aggregate analysis has been delayed up to here and it is done while
230 -- resolving the aggregate.
232 -- N is the current N_Aggregate node to be checked.
234 -- Index is the index node corresponding to the array sub-aggregate that
235 -- we are currently checking (RM 4.3.3 (8)). Its Etype is the
236 -- corresponding index type (or subtype).
238 -- Index_Constr is the node giving the applicable index constraint if
239 -- any (RM 4.3.3 (10)). It "is a constraint provided by certain
240 -- contexts [...] that can be used to determine the bounds of the array
241 -- value specified by the aggregate". If Others_Allowed below is False
242 -- there is no applicable index constraint and this node is set to Index.
244 -- Component_Typ is the array component type.
246 -- Others_Allowed indicates whether an others choice is allowed
247 -- in the context where the top-level aggregate appeared.
249 -- The algorithm of Resolve_Array_Aggregate proceeds as follows:
251 -- 1. Make sure that the others choice, if present, is by itself and
252 -- appears last in the sub-aggregate. Check that we do not have
253 -- positional and named components in the array sub-aggregate (unless
254 -- the named association is an others choice). Finally if an others
255 -- choice is present, make sure it is allowed in the aggregate context.
257 -- 2. If the array sub-aggregate contains discrete_choices:
259 -- (A) Verify their validity. Specifically verify that:
261 -- (a) If a null range is present it must be the only possible
262 -- choice in the array aggregate.
264 -- (b) Ditto for a non static range.
266 -- (c) Ditto for a non static expression.
268 -- In addition this step analyzes and resolves each discrete_choice,
269 -- making sure that its type is the type of the corresponding Index.
270 -- If we are not at the lowest array aggregate level (in the case of
271 -- multi-dimensional aggregates) then invoke Resolve_Array_Aggregate
272 -- recursively on each component expression. Otherwise, resolve the
273 -- bottom level component expressions against the expected component
274 -- type ONLY IF the component corresponds to a single discrete choice
275 -- which is not an others choice (to see why read the DELAYED
276 -- COMPONENT RESOLUTION below).
278 -- (B) Determine the bounds of the sub-aggregate and lowest and
279 -- highest choice values.
281 -- 3. For positional aggregates:
283 -- (A) Loop over the component expressions either recursively invoking
284 -- Resolve_Array_Aggregate on each of these for multi-dimensional
285 -- array aggregates or resolving the bottom level component
286 -- expressions against the expected component type.
288 -- (B) Determine the bounds of the positional sub-aggregates.
290 -- 4. Try to determine statically whether the evaluation of the array
291 -- sub-aggregate raises Constraint_Error. If yes emit proper
292 -- warnings. The precise checks are the following:
294 -- (A) Check that the index range defined by aggregate bounds is
295 -- compatible with corresponding index subtype.
296 -- We also check against the base type. In fact it could be that
297 -- Low/High bounds of the base type are static whereas those of
298 -- the index subtype are not. Thus if we can statically catch
299 -- a problem with respect to the base type we are guaranteed
300 -- that the same problem will arise with the index subtype
302 -- (B) If we are dealing with a named aggregate containing an others
303 -- choice and at least one discrete choice then make sure the range
304 -- specified by the discrete choices does not overflow the
305 -- aggregate bounds. We also check against the index type and base
306 -- type bounds for the same reasons given in (A).
308 -- (C) If we are dealing with a positional aggregate with an others
309 -- choice make sure the number of positional elements specified
310 -- does not overflow the aggregate bounds. We also check against
311 -- the index type and base type bounds as mentioned in (A).
313 -- Finally construct an N_Range node giving the sub-aggregate bounds.
314 -- Set the Aggregate_Bounds field of the sub-aggregate to be this
315 -- N_Range. The routine Array_Aggr_Subtype below uses such N_Ranges
316 -- to build the appropriate aggregate subtype. Aggregate_Bounds
317 -- information is needed during expansion.
319 -- DELAYED COMPONENT RESOLUTION: The resolution of bottom level component
320 -- expressions in an array aggregate may call Duplicate_Subexpr or some
321 -- other routine that inserts code just outside the outermost aggregate.
322 -- If the array aggregate contains discrete choices or an others choice,
323 -- this may be wrong. Consider for instance the following example.
325 -- type Rec is record
329 -- type Acc_Rec is access Rec;
330 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => new Rec);
332 -- Then the transformation of "new Rec" that occurs during resolution
333 -- entails the following code modifications
335 -- P7b : constant Acc_Rec := new Rec;
337 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => P7b);
339 -- This code transformation is clearly wrong, since we need to call
340 -- "new Rec" for each of the 3 array elements. To avoid this problem we
341 -- delay resolution of the components of non positional array aggregates
342 -- to the expansion phase. As an optimization, if the discrete choice
343 -- specifies a single value we do not delay resolution.
345 function Array_Aggr_Subtype (N : Node_Id; Typ : Node_Id) return Entity_Id;
346 -- This routine returns the type or subtype of an array aggregate.
348 -- N is the array aggregate node whose type we return.
350 -- Typ is the context type in which N occurs.
352 -- This routine creates an implicit array subtype whose bounds are
353 -- those defined by the aggregate. When this routine is invoked
354 -- Resolve_Array_Aggregate has already processed aggregate N. Thus the
355 -- Aggregate_Bounds of each sub-aggregate, is an N_Range node giving the
356 -- sub-aggregate bounds. When building the aggregate itype, this function
357 -- traverses the array aggregate N collecting such Aggregate_Bounds and
358 -- constructs the proper array aggregate itype.
360 -- Note that in the case of multidimensional aggregates each inner
361 -- sub-aggregate corresponding to a given array dimension, may provide a
362 -- different bounds. If it is possible to determine statically that
363 -- some sub-aggregates corresponding to the same index do not have the
364 -- same bounds, then a warning is emitted. If such check is not possible
365 -- statically (because some sub-aggregate bounds are dynamic expressions)
366 -- then this job is left to the expander. In all cases the particular
367 -- bounds that this function will chose for a given dimension is the first
368 -- N_Range node for a sub-aggregate corresponding to that dimension.
370 -- Note that the Raises_Constraint_Error flag of an array aggregate
371 -- whose evaluation is determined to raise CE by Resolve_Array_Aggregate,
372 -- is set in Resolve_Array_Aggregate but the aggregate is not
373 -- immediately replaced with a raise CE. In fact, Array_Aggr_Subtype must
374 -- first construct the proper itype for the aggregate (Gigi needs
375 -- this). After constructing the proper itype we will eventually replace
376 -- the top-level aggregate with a raise CE (done in Resolve_Aggregate).
377 -- Of course in cases such as:
379 -- type Arr is array (integer range <>) of Integer;
380 -- A : Arr := (positive range -1 .. 2 => 0);
382 -- The bounds of the aggregate itype are cooked up to look reasonable
383 -- (in this particular case the bounds will be 1 .. 2).
385 procedure Aggregate_Constraint_Checks
387 Check_Typ : Entity_Id);
388 -- Checks expression Exp against subtype Check_Typ. If Exp is an
389 -- aggregate and Check_Typ a constrained record type with discriminants,
390 -- we generate the appropriate discriminant checks. If Exp is an array
391 -- aggregate then emit the appropriate length checks. If Exp is a scalar
392 -- type, or a string literal, Exp is changed into Check_Typ'(Exp) to
393 -- ensure that range checks are performed at run time.
395 procedure Make_String_Into_Aggregate (N : Node_Id);
396 -- A string literal can appear in a context in which a one dimensional
397 -- array of characters is expected. This procedure simply rewrites the
398 -- string as an aggregate, prior to resolution.
400 ---------------------------------
401 -- Aggregate_Constraint_Checks --
402 ---------------------------------
404 procedure Aggregate_Constraint_Checks
406 Check_Typ : Entity_Id)
408 Exp_Typ : constant Entity_Id := Etype (Exp);
411 if Raises_Constraint_Error (Exp) then
415 -- Ada 2005 (AI-230): Generate a conversion to an anonymous access
416 -- component's type to force the appropriate accessibility checks.
418 -- Ada 2005 (AI-231): Generate conversion to the null-excluding
419 -- type to force the corresponding run-time check
421 if Is_Access_Type (Check_Typ)
422 and then ((Is_Local_Anonymous_Access (Check_Typ))
423 or else (Can_Never_Be_Null (Check_Typ)
424 and then not Can_Never_Be_Null (Exp_Typ)))
426 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
427 Analyze_And_Resolve (Exp, Check_Typ);
428 Check_Unset_Reference (Exp);
431 -- This is really expansion activity, so make sure that expansion
432 -- is on and is allowed.
434 if not Expander_Active or else In_Spec_Expression then
438 -- First check if we have to insert discriminant checks
440 if Has_Discriminants (Exp_Typ) then
441 Apply_Discriminant_Check (Exp, Check_Typ);
443 -- Next emit length checks for array aggregates
445 elsif Is_Array_Type (Exp_Typ) then
446 Apply_Length_Check (Exp, Check_Typ);
448 -- Finally emit scalar and string checks. If we are dealing with a
449 -- scalar literal we need to check by hand because the Etype of
450 -- literals is not necessarily correct.
452 elsif Is_Scalar_Type (Exp_Typ)
453 and then Compile_Time_Known_Value (Exp)
455 if Is_Out_Of_Range (Exp, Base_Type (Check_Typ)) then
456 Apply_Compile_Time_Constraint_Error
457 (Exp, "value not in range of}?", CE_Range_Check_Failed,
458 Ent => Base_Type (Check_Typ),
459 Typ => Base_Type (Check_Typ));
461 elsif Is_Out_Of_Range (Exp, Check_Typ) then
462 Apply_Compile_Time_Constraint_Error
463 (Exp, "value not in range of}?", CE_Range_Check_Failed,
467 elsif not Range_Checks_Suppressed (Check_Typ) then
468 Apply_Scalar_Range_Check (Exp, Check_Typ);
471 -- Verify that target type is also scalar, to prevent view anomalies
472 -- in instantiations.
474 elsif (Is_Scalar_Type (Exp_Typ)
475 or else Nkind (Exp) = N_String_Literal)
476 and then Is_Scalar_Type (Check_Typ)
477 and then Exp_Typ /= Check_Typ
479 if Is_Entity_Name (Exp)
480 and then Ekind (Entity (Exp)) = E_Constant
482 -- If expression is a constant, it is worthwhile checking whether
483 -- it is a bound of the type.
485 if (Is_Entity_Name (Type_Low_Bound (Check_Typ))
486 and then Entity (Exp) = Entity (Type_Low_Bound (Check_Typ)))
487 or else (Is_Entity_Name (Type_High_Bound (Check_Typ))
488 and then Entity (Exp) = Entity (Type_High_Bound (Check_Typ)))
493 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
494 Analyze_And_Resolve (Exp, Check_Typ);
495 Check_Unset_Reference (Exp);
498 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
499 Analyze_And_Resolve (Exp, Check_Typ);
500 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 -- Ignore junk empty aggregate resulting from parser error
898 if No (Expressions (N))
899 and then No (Component_Associations (N))
900 and then not Null_Record_Present (N)
905 -- Check for aggregates not allowed in configurable run-time mode.
906 -- We allow all cases of aggregates that do not come from source,
907 -- since these are all assumed to be small (e.g. bounds of a string
908 -- literal). We also allow aggregates of types we know to be small.
910 if not Support_Aggregates_On_Target
911 and then Comes_From_Source (N)
912 and then (not Known_Static_Esize (Typ) or else Esize (Typ) > 64)
914 Error_Msg_CRT ("aggregate", N);
917 -- Ada 2005 (AI-287): Limited aggregates allowed
919 if Is_Limited_Type (Typ) and then Ada_Version < Ada_05 then
920 Error_Msg_N ("aggregate type cannot be limited", N);
921 Explain_Limited_Type (Typ, N);
923 elsif Is_Class_Wide_Type (Typ) then
924 Error_Msg_N ("type of aggregate cannot be class-wide", N);
926 elsif Typ = Any_String
927 or else Typ = Any_Composite
929 Error_Msg_N ("no unique type for aggregate", N);
930 Set_Etype (N, Any_Composite);
932 elsif Is_Array_Type (Typ) and then Null_Record_Present (N) then
933 Error_Msg_N ("null record forbidden in array aggregate", N);
935 elsif Is_Record_Type (Typ) then
936 Resolve_Record_Aggregate (N, Typ);
938 elsif Is_Array_Type (Typ) then
940 -- First a special test, for the case of a positional aggregate
941 -- of characters which can be replaced by a string literal.
943 -- Do not perform this transformation if this was a string literal
944 -- to start with, whose components needed constraint checks, or if
945 -- the component type is non-static, because it will require those
946 -- checks and be transformed back into an aggregate.
948 if Number_Dimensions (Typ) = 1
949 and then Is_Standard_Character_Type (Component_Type (Typ))
950 and then No (Component_Associations (N))
951 and then not Is_Limited_Composite (Typ)
952 and then not Is_Private_Composite (Typ)
953 and then not Is_Bit_Packed_Array (Typ)
954 and then Nkind (Original_Node (Parent (N))) /= N_String_Literal
955 and then Is_Static_Subtype (Component_Type (Typ))
961 Expr := First (Expressions (N));
962 while Present (Expr) loop
963 exit when Nkind (Expr) /= N_Character_Literal;
970 Expr := First (Expressions (N));
971 while Present (Expr) loop
972 Store_String_Char (UI_To_CC (Char_Literal_Value (Expr)));
977 Make_String_Literal (Sloc (N), End_String));
979 Analyze_And_Resolve (N, Typ);
985 -- Here if we have a real aggregate to deal with
987 Array_Aggregate : declare
988 Aggr_Resolved : Boolean;
990 Aggr_Typ : constant Entity_Id := Etype (Typ);
991 -- This is the unconstrained array type, which is the type
992 -- against which the aggregate is to be resolved. Typ itself
993 -- is the array type of the context which may not be the same
994 -- subtype as the subtype for the final aggregate.
997 -- In the following we determine whether an others choice is
998 -- allowed inside the array aggregate. The test checks the context
999 -- in which the array aggregate occurs. If the context does not
1000 -- permit it, or the aggregate type is unconstrained, an others
1001 -- choice is not allowed.
1003 -- If expansion is disabled (generic context, or semantics-only
1004 -- mode) actual subtypes cannot be constructed, and the type of
1005 -- an object may be its unconstrained nominal type. However, if
1006 -- the context is an assignment, we assume that "others" is
1007 -- allowed, because the target of the assignment will have a
1008 -- constrained subtype when fully compiled.
1010 -- Note that there is no node for Explicit_Actual_Parameter.
1011 -- To test for this context we therefore have to test for node
1012 -- N_Parameter_Association which itself appears only if there is a
1013 -- formal parameter. Consequently we also need to test for
1014 -- N_Procedure_Call_Statement or N_Function_Call.
1016 Set_Etype (N, Aggr_Typ); -- may be overridden later on
1018 if Is_Constrained (Typ) and then
1019 (Pkind = N_Assignment_Statement or else
1020 Pkind = N_Parameter_Association or else
1021 Pkind = N_Function_Call or else
1022 Pkind = N_Procedure_Call_Statement or else
1023 Pkind = N_Generic_Association or else
1024 Pkind = N_Formal_Object_Declaration or else
1025 Pkind = N_Simple_Return_Statement or else
1026 Pkind = N_Object_Declaration or else
1027 Pkind = N_Component_Declaration or else
1028 Pkind = N_Parameter_Specification or else
1029 Pkind = N_Qualified_Expression or else
1030 Pkind = N_Aggregate or else
1031 Pkind = N_Extension_Aggregate or else
1032 Pkind = N_Component_Association)
1035 Resolve_Array_Aggregate
1037 Index => First_Index (Aggr_Typ),
1038 Index_Constr => First_Index (Typ),
1039 Component_Typ => Component_Type (Typ),
1040 Others_Allowed => True);
1042 elsif not Expander_Active
1043 and then Pkind = N_Assignment_Statement
1046 Resolve_Array_Aggregate
1048 Index => First_Index (Aggr_Typ),
1049 Index_Constr => First_Index (Typ),
1050 Component_Typ => Component_Type (Typ),
1051 Others_Allowed => True);
1054 Resolve_Array_Aggregate
1056 Index => First_Index (Aggr_Typ),
1057 Index_Constr => First_Index (Aggr_Typ),
1058 Component_Typ => Component_Type (Typ),
1059 Others_Allowed => False);
1062 if not Aggr_Resolved then
1063 Aggr_Subtyp := Any_Composite;
1065 Aggr_Subtyp := Array_Aggr_Subtype (N, Typ);
1068 Set_Etype (N, Aggr_Subtyp);
1069 end Array_Aggregate;
1071 elsif Is_Private_Type (Typ)
1072 and then Present (Full_View (Typ))
1073 and then In_Inlined_Body
1074 and then Is_Composite_Type (Full_View (Typ))
1076 Resolve (N, Full_View (Typ));
1079 Error_Msg_N ("illegal context for aggregate", N);
1082 -- If we can determine statically that the evaluation of the
1083 -- aggregate raises Constraint_Error, then replace the
1084 -- aggregate with an N_Raise_Constraint_Error node, but set the
1085 -- Etype to the right aggregate subtype. Gigi needs this.
1087 if Raises_Constraint_Error (N) then
1088 Aggr_Subtyp := Etype (N);
1090 Make_Raise_Constraint_Error (Sloc (N),
1091 Reason => CE_Range_Check_Failed));
1092 Set_Raises_Constraint_Error (N);
1093 Set_Etype (N, Aggr_Subtyp);
1096 end Resolve_Aggregate;
1098 -----------------------------
1099 -- Resolve_Array_Aggregate --
1100 -----------------------------
1102 function Resolve_Array_Aggregate
1105 Index_Constr : Node_Id;
1106 Component_Typ : Entity_Id;
1107 Others_Allowed : Boolean) return Boolean
1109 Loc : constant Source_Ptr := Sloc (N);
1111 Failure : constant Boolean := False;
1112 Success : constant Boolean := True;
1114 Index_Typ : constant Entity_Id := Etype (Index);
1115 Index_Typ_Low : constant Node_Id := Type_Low_Bound (Index_Typ);
1116 Index_Typ_High : constant Node_Id := Type_High_Bound (Index_Typ);
1117 -- The type of the index corresponding to the array sub-aggregate
1118 -- along with its low and upper bounds
1120 Index_Base : constant Entity_Id := Base_Type (Index_Typ);
1121 Index_Base_Low : constant Node_Id := Type_Low_Bound (Index_Base);
1122 Index_Base_High : constant Node_Id := Type_High_Bound (Index_Base);
1123 -- ditto for the base type
1125 function Add (Val : Uint; To : Node_Id) return Node_Id;
1126 -- Creates a new expression node where Val is added to expression To.
1127 -- Tries to constant fold whenever possible. To must be an already
1128 -- analyzed expression.
1130 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id);
1131 -- Checks that AH (the upper bound of an array aggregate) is <= BH
1132 -- (the upper bound of the index base type). If the check fails a
1133 -- warning is emitted, the Raises_Constraint_Error Flag of N is set,
1134 -- and AH is replaced with a duplicate of BH.
1136 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id);
1137 -- Checks that range AL .. AH is compatible with range L .. H. Emits a
1138 -- warning if not and sets the Raises_Constraint_Error Flag in N.
1140 procedure Check_Length (L, H : Node_Id; Len : Uint);
1141 -- Checks that range L .. H contains at least Len elements. Emits a
1142 -- warning if not and sets the Raises_Constraint_Error Flag in N.
1144 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean;
1145 -- Returns True if range L .. H is dynamic or null
1147 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean);
1148 -- Given expression node From, this routine sets OK to False if it
1149 -- cannot statically evaluate From. Otherwise it stores this static
1150 -- value into Value.
1152 function Resolve_Aggr_Expr
1154 Single_Elmt : Boolean) return Boolean;
1155 -- Resolves aggregate expression Expr. Returns False if resolution
1156 -- fails. If Single_Elmt is set to False, the expression Expr may be
1157 -- used to initialize several array aggregate elements (this can
1158 -- happen for discrete choices such as "L .. H => Expr" or the others
1159 -- choice). In this event we do not resolve Expr unless expansion is
1160 -- disabled. To know why, see the DELAYED COMPONENT RESOLUTION
1167 function Add (Val : Uint; To : Node_Id) return Node_Id is
1173 if Raises_Constraint_Error (To) then
1177 -- First test if we can do constant folding
1179 if Compile_Time_Known_Value (To)
1180 or else Nkind (To) = N_Integer_Literal
1182 Expr_Pos := Make_Integer_Literal (Loc, Expr_Value (To) + Val);
1183 Set_Is_Static_Expression (Expr_Pos);
1184 Set_Etype (Expr_Pos, Etype (To));
1185 Set_Analyzed (Expr_Pos, Analyzed (To));
1187 if not Is_Enumeration_Type (Index_Typ) then
1190 -- If we are dealing with enumeration return
1191 -- Index_Typ'Val (Expr_Pos)
1195 Make_Attribute_Reference
1197 Prefix => New_Reference_To (Index_Typ, Loc),
1198 Attribute_Name => Name_Val,
1199 Expressions => New_List (Expr_Pos));
1205 -- If we are here no constant folding possible
1207 if not Is_Enumeration_Type (Index_Base) then
1210 Left_Opnd => Duplicate_Subexpr (To),
1211 Right_Opnd => Make_Integer_Literal (Loc, Val));
1213 -- If we are dealing with enumeration return
1214 -- Index_Typ'Val (Index_Typ'Pos (To) + Val)
1218 Make_Attribute_Reference
1220 Prefix => New_Reference_To (Index_Typ, Loc),
1221 Attribute_Name => Name_Pos,
1222 Expressions => New_List (Duplicate_Subexpr (To)));
1226 Left_Opnd => To_Pos,
1227 Right_Opnd => Make_Integer_Literal (Loc, Val));
1230 Make_Attribute_Reference
1232 Prefix => New_Reference_To (Index_Typ, Loc),
1233 Attribute_Name => Name_Val,
1234 Expressions => New_List (Expr_Pos));
1244 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id) is
1252 Get (Value => Val_BH, From => BH, OK => OK_BH);
1253 Get (Value => Val_AH, From => AH, OK => OK_AH);
1255 if OK_BH and then OK_AH and then Val_BH < Val_AH then
1256 Set_Raises_Constraint_Error (N);
1257 Error_Msg_N ("upper bound out of range?", AH);
1258 Error_Msg_N ("\Constraint_Error will be raised at run-time?", AH);
1260 -- You need to set AH to BH or else in the case of enumerations
1261 -- indices we will not be able to resolve the aggregate bounds.
1263 AH := Duplicate_Subexpr (BH);
1271 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id) is
1282 pragma Warnings (Off, OK_AL);
1283 pragma Warnings (Off, OK_AH);
1286 if Raises_Constraint_Error (N)
1287 or else Dynamic_Or_Null_Range (AL, AH)
1292 Get (Value => Val_L, From => L, OK => OK_L);
1293 Get (Value => Val_H, From => H, OK => OK_H);
1295 Get (Value => Val_AL, From => AL, OK => OK_AL);
1296 Get (Value => Val_AH, From => AH, OK => OK_AH);
1298 if OK_L and then Val_L > Val_AL then
1299 Set_Raises_Constraint_Error (N);
1300 Error_Msg_N ("lower bound of aggregate out of range?", N);
1301 Error_Msg_N ("\Constraint_Error will be raised at run-time?", N);
1304 if OK_H and then Val_H < Val_AH then
1305 Set_Raises_Constraint_Error (N);
1306 Error_Msg_N ("upper bound of aggregate out of range?", N);
1307 Error_Msg_N ("\Constraint_Error will be raised at run-time?", N);
1315 procedure Check_Length (L, H : Node_Id; Len : Uint) is
1325 if Raises_Constraint_Error (N) then
1329 Get (Value => Val_L, From => L, OK => OK_L);
1330 Get (Value => Val_H, From => H, OK => OK_H);
1332 if not OK_L or else not OK_H then
1336 -- If null range length is zero
1338 if Val_L > Val_H then
1339 Range_Len := Uint_0;
1341 Range_Len := Val_H - Val_L + 1;
1344 if Range_Len < Len then
1345 Set_Raises_Constraint_Error (N);
1346 Error_Msg_N ("too many elements?", N);
1347 Error_Msg_N ("\Constraint_Error will be raised at run-time?", N);
1351 ---------------------------
1352 -- Dynamic_Or_Null_Range --
1353 ---------------------------
1355 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean is
1363 Get (Value => Val_L, From => L, OK => OK_L);
1364 Get (Value => Val_H, From => H, OK => OK_H);
1366 return not OK_L or else not OK_H
1367 or else not Is_OK_Static_Expression (L)
1368 or else not Is_OK_Static_Expression (H)
1369 or else Val_L > Val_H;
1370 end Dynamic_Or_Null_Range;
1376 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean) is
1380 if Compile_Time_Known_Value (From) then
1381 Value := Expr_Value (From);
1383 -- If expression From is something like Some_Type'Val (10) then
1386 elsif Nkind (From) = N_Attribute_Reference
1387 and then Attribute_Name (From) = Name_Val
1388 and then Compile_Time_Known_Value (First (Expressions (From)))
1390 Value := Expr_Value (First (Expressions (From)));
1398 -----------------------
1399 -- Resolve_Aggr_Expr --
1400 -----------------------
1402 function Resolve_Aggr_Expr
1404 Single_Elmt : Boolean) return Boolean
1406 Nxt_Ind : constant Node_Id := Next_Index (Index);
1407 Nxt_Ind_Constr : constant Node_Id := Next_Index (Index_Constr);
1408 -- Index is the current index corresponding to the expression
1410 Resolution_OK : Boolean := True;
1411 -- Set to False if resolution of the expression failed
1414 -- If the array type against which we are resolving the aggregate
1415 -- has several dimensions, the expressions nested inside the
1416 -- aggregate must be further aggregates (or strings).
1418 if Present (Nxt_Ind) then
1419 if Nkind (Expr) /= N_Aggregate then
1421 -- A string literal can appear where a one-dimensional array
1422 -- of characters is expected. If the literal looks like an
1423 -- operator, it is still an operator symbol, which will be
1424 -- transformed into a string when analyzed.
1426 if Is_Character_Type (Component_Typ)
1427 and then No (Next_Index (Nxt_Ind))
1428 and then Nkind_In (Expr, N_String_Literal, N_Operator_Symbol)
1430 -- A string literal used in a multidimensional array
1431 -- aggregate in place of the final one-dimensional
1432 -- aggregate must not be enclosed in parentheses.
1434 if Paren_Count (Expr) /= 0 then
1435 Error_Msg_N ("no parenthesis allowed here", Expr);
1438 Make_String_Into_Aggregate (Expr);
1441 Error_Msg_N ("nested array aggregate expected", Expr);
1446 -- Ada 2005 (AI-231): Propagate the type to the nested aggregate.
1447 -- Required to check the null-exclusion attribute (if present).
1448 -- This value may be overridden later on.
1450 Set_Etype (Expr, Etype (N));
1452 Resolution_OK := Resolve_Array_Aggregate
1453 (Expr, Nxt_Ind, Nxt_Ind_Constr, Component_Typ, Others_Allowed);
1455 -- Do not resolve the expressions of discrete or others choices
1456 -- unless the expression covers a single component, or the expander
1460 or else not Expander_Active
1461 or else In_Spec_Expression
1463 Analyze_And_Resolve (Expr, Component_Typ);
1464 Check_Expr_OK_In_Limited_Aggregate (Expr);
1465 Check_Non_Static_Context (Expr);
1466 Aggregate_Constraint_Checks (Expr, Component_Typ);
1467 Check_Unset_Reference (Expr);
1470 if Raises_Constraint_Error (Expr)
1471 and then Nkind (Parent (Expr)) /= N_Component_Association
1473 Set_Raises_Constraint_Error (N);
1476 return Resolution_OK;
1477 end Resolve_Aggr_Expr;
1479 -- Variables local to Resolve_Array_Aggregate
1486 pragma Warnings (Off, Discard);
1488 Aggr_Low : Node_Id := Empty;
1489 Aggr_High : Node_Id := Empty;
1490 -- The actual low and high bounds of this sub-aggregate
1492 Choices_Low : Node_Id := Empty;
1493 Choices_High : Node_Id := Empty;
1494 -- The lowest and highest discrete choices values for a named aggregate
1496 Nb_Elements : Uint := Uint_0;
1497 -- The number of elements in a positional aggregate
1499 Others_Present : Boolean := False;
1501 Nb_Choices : Nat := 0;
1502 -- Contains the overall number of named choices in this sub-aggregate
1504 Nb_Discrete_Choices : Nat := 0;
1505 -- The overall number of discrete choices (not counting others choice)
1507 Case_Table_Size : Nat;
1508 -- Contains the size of the case table needed to sort aggregate choices
1510 -- Start of processing for Resolve_Array_Aggregate
1513 -- Ignore junk empty aggregate resulting from parser error
1515 if No (Expressions (N))
1516 and then No (Component_Associations (N))
1517 and then not Null_Record_Present (N)
1522 -- STEP 1: make sure the aggregate is correctly formatted
1524 if Present (Component_Associations (N)) then
1525 Assoc := First (Component_Associations (N));
1526 while Present (Assoc) loop
1527 Choice := First (Choices (Assoc));
1528 while Present (Choice) loop
1529 if Nkind (Choice) = N_Others_Choice then
1530 Others_Present := True;
1532 if Choice /= First (Choices (Assoc))
1533 or else Present (Next (Choice))
1536 ("OTHERS must appear alone in a choice list", Choice);
1540 if Present (Next (Assoc)) then
1542 ("OTHERS must appear last in an aggregate", Choice);
1546 if Ada_Version = Ada_83
1547 and then Assoc /= First (Component_Associations (N))
1548 and then Nkind_In (Parent (N), N_Assignment_Statement,
1549 N_Object_Declaration)
1552 ("(Ada 83) illegal context for OTHERS choice", N);
1556 Nb_Choices := Nb_Choices + 1;
1564 -- At this point we know that the others choice, if present, is by
1565 -- itself and appears last in the aggregate. Check if we have mixed
1566 -- positional and discrete associations (other than the others choice).
1568 if Present (Expressions (N))
1569 and then (Nb_Choices > 1
1570 or else (Nb_Choices = 1 and then not Others_Present))
1573 ("named association cannot follow positional association",
1574 First (Choices (First (Component_Associations (N)))));
1578 -- Test for the validity of an others choice if present
1580 if Others_Present and then not Others_Allowed then
1582 ("OTHERS choice not allowed here",
1583 First (Choices (First (Component_Associations (N)))));
1587 -- Protect against cascaded errors
1589 if Etype (Index_Typ) = Any_Type then
1593 -- STEP 2: Process named components
1595 if No (Expressions (N)) then
1596 if Others_Present then
1597 Case_Table_Size := Nb_Choices - 1;
1599 Case_Table_Size := Nb_Choices;
1605 -- Denote the lowest and highest values in an aggregate choice
1609 -- High end of one range and Low end of the next. Should be
1610 -- contiguous if there is no hole in the list of values.
1612 Missing_Values : Boolean;
1613 -- Set True if missing index values
1615 S_Low : Node_Id := Empty;
1616 S_High : Node_Id := Empty;
1617 -- if a choice in an aggregate is a subtype indication these
1618 -- denote the lowest and highest values of the subtype
1620 Table : Case_Table_Type (1 .. Case_Table_Size);
1621 -- Used to sort all the different choice values
1623 Single_Choice : Boolean;
1624 -- Set to true every time there is a single discrete choice in a
1625 -- discrete association
1627 Prev_Nb_Discrete_Choices : Nat;
1628 -- Used to keep track of the number of discrete choices
1629 -- in the current association.
1632 -- STEP 2 (A): Check discrete choices validity
1634 Assoc := First (Component_Associations (N));
1635 while Present (Assoc) loop
1636 Prev_Nb_Discrete_Choices := Nb_Discrete_Choices;
1637 Choice := First (Choices (Assoc));
1641 if Nkind (Choice) = N_Others_Choice then
1642 Single_Choice := False;
1645 -- Test for subtype mark without constraint
1647 elsif Is_Entity_Name (Choice) and then
1648 Is_Type (Entity (Choice))
1650 if Base_Type (Entity (Choice)) /= Index_Base then
1652 ("invalid subtype mark in aggregate choice",
1657 -- Case of subtype indication
1659 elsif Nkind (Choice) = N_Subtype_Indication then
1660 Resolve_Discrete_Subtype_Indication (Choice, Index_Base);
1662 -- Does the subtype indication evaluation raise CE ?
1664 Get_Index_Bounds (Subtype_Mark (Choice), S_Low, S_High);
1665 Get_Index_Bounds (Choice, Low, High);
1666 Check_Bounds (S_Low, S_High, Low, High);
1668 -- Case of range or expression
1671 Resolve (Choice, Index_Base);
1672 Check_Unset_Reference (Choice);
1673 Check_Non_Static_Context (Choice);
1675 -- Do not range check a choice. This check is redundant
1676 -- since this test is already performed when we check
1677 -- that the bounds of the array aggregate are within
1680 Set_Do_Range_Check (Choice, False);
1683 -- If we could not resolve the discrete choice stop here
1685 if Etype (Choice) = Any_Type then
1688 -- If the discrete choice raises CE get its original bounds
1690 elsif Nkind (Choice) = N_Raise_Constraint_Error then
1691 Set_Raises_Constraint_Error (N);
1692 Get_Index_Bounds (Original_Node (Choice), Low, High);
1694 -- Otherwise get its bounds as usual
1697 Get_Index_Bounds (Choice, Low, High);
1700 if (Dynamic_Or_Null_Range (Low, High)
1701 or else (Nkind (Choice) = N_Subtype_Indication
1703 Dynamic_Or_Null_Range (S_Low, S_High)))
1704 and then Nb_Choices /= 1
1707 ("dynamic or empty choice in aggregate " &
1708 "must be the only choice", Choice);
1712 Nb_Discrete_Choices := Nb_Discrete_Choices + 1;
1713 Table (Nb_Discrete_Choices).Choice_Lo := Low;
1714 Table (Nb_Discrete_Choices).Choice_Hi := High;
1720 -- Check if we have a single discrete choice and whether
1721 -- this discrete choice specifies a single value.
1724 (Nb_Discrete_Choices = Prev_Nb_Discrete_Choices + 1)
1725 and then (Low = High);
1731 -- Ada 2005 (AI-231)
1733 if Ada_Version >= Ada_05
1734 and then Known_Null (Expression (Assoc))
1736 Check_Can_Never_Be_Null (Etype (N), Expression (Assoc));
1739 -- Ada 2005 (AI-287): In case of default initialized component
1740 -- we delay the resolution to the expansion phase
1742 if Box_Present (Assoc) then
1744 -- Ada 2005 (AI-287): In case of default initialization
1745 -- of a component the expander will generate calls to
1746 -- the corresponding initialization subprogram.
1750 elsif not Resolve_Aggr_Expr (Expression (Assoc),
1751 Single_Elmt => Single_Choice)
1759 -- If aggregate contains more than one choice then these must be
1760 -- static. Sort them and check that they are contiguous
1762 if Nb_Discrete_Choices > 1 then
1763 Sort_Case_Table (Table);
1764 Missing_Values := False;
1766 Outer : for J in 1 .. Nb_Discrete_Choices - 1 loop
1767 if Expr_Value (Table (J).Choice_Hi) >=
1768 Expr_Value (Table (J + 1).Choice_Lo)
1771 ("duplicate choice values in array aggregate",
1772 Table (J).Choice_Hi);
1775 elsif not Others_Present then
1776 Hi_Val := Expr_Value (Table (J).Choice_Hi);
1777 Lo_Val := Expr_Value (Table (J + 1).Choice_Lo);
1779 -- If missing values, output error messages
1781 if Lo_Val - Hi_Val > 1 then
1783 -- Header message if not first missing value
1785 if not Missing_Values then
1787 ("missing index value(s) in array aggregate", N);
1788 Missing_Values := True;
1791 -- Output values of missing indexes
1793 Lo_Val := Lo_Val - 1;
1794 Hi_Val := Hi_Val + 1;
1796 -- Enumeration type case
1798 if Is_Enumeration_Type (Index_Typ) then
1801 (Get_Enum_Lit_From_Pos
1802 (Index_Typ, Hi_Val, Loc));
1804 if Lo_Val = Hi_Val then
1805 Error_Msg_N ("\ %", N);
1809 (Get_Enum_Lit_From_Pos
1810 (Index_Typ, Lo_Val, Loc));
1811 Error_Msg_N ("\ % .. %", N);
1814 -- Integer types case
1817 Error_Msg_Uint_1 := Hi_Val;
1819 if Lo_Val = Hi_Val then
1820 Error_Msg_N ("\ ^", N);
1822 Error_Msg_Uint_2 := Lo_Val;
1823 Error_Msg_N ("\ ^ .. ^", N);
1830 if Missing_Values then
1831 Set_Etype (N, Any_Composite);
1836 -- STEP 2 (B): Compute aggregate bounds and min/max choices values
1838 if Nb_Discrete_Choices > 0 then
1839 Choices_Low := Table (1).Choice_Lo;
1840 Choices_High := Table (Nb_Discrete_Choices).Choice_Hi;
1843 -- If Others is present, then bounds of aggregate come from the
1844 -- index constraint (not the choices in the aggregate itself).
1846 if Others_Present then
1847 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
1849 -- No others clause present
1852 -- Special processing if others allowed and not present. This
1853 -- means that the bounds of the aggregate come from the index
1854 -- constraint (and the length must match).
1856 if Others_Allowed then
1857 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
1859 -- If others allowed, and no others present, then the array
1860 -- should cover all index values. If it does not, we will
1861 -- get a length check warning, but there is two cases where
1862 -- an additional warning is useful:
1864 -- If we have no positional components, and the length is
1865 -- wrong (which we can tell by others being allowed with
1866 -- missing components), and the index type is an enumeration
1867 -- type, then issue appropriate warnings about these missing
1868 -- components. They are only warnings, since the aggregate
1869 -- is fine, it's just the wrong length. We skip this check
1870 -- for standard character types (since there are no literals
1871 -- and it is too much trouble to concoct them), and also if
1872 -- any of the bounds have not-known-at-compile-time values.
1874 -- Another case warranting a warning is when the length is
1875 -- right, but as above we have an index type that is an
1876 -- enumeration, and the bounds do not match. This is a
1877 -- case where dubious sliding is allowed and we generate
1878 -- a warning that the bounds do not match.
1880 if No (Expressions (N))
1881 and then Nkind (Index) = N_Range
1882 and then Is_Enumeration_Type (Etype (Index))
1883 and then not Is_Standard_Character_Type (Etype (Index))
1884 and then Compile_Time_Known_Value (Aggr_Low)
1885 and then Compile_Time_Known_Value (Aggr_High)
1886 and then Compile_Time_Known_Value (Choices_Low)
1887 and then Compile_Time_Known_Value (Choices_High)
1890 ALo : constant Node_Id := Expr_Value_E (Aggr_Low);
1891 AHi : constant Node_Id := Expr_Value_E (Aggr_High);
1892 CLo : constant Node_Id := Expr_Value_E (Choices_Low);
1893 CHi : constant Node_Id := Expr_Value_E (Choices_High);
1898 -- Warning case one, missing values at start/end. Only
1899 -- do the check if the number of entries is too small.
1901 if (Enumeration_Pos (CHi) - Enumeration_Pos (CLo))
1903 (Enumeration_Pos (AHi) - Enumeration_Pos (ALo))
1906 ("missing index value(s) in array aggregate?", N);
1908 -- Output missing value(s) at start
1910 if Chars (ALo) /= Chars (CLo) then
1913 if Chars (ALo) = Chars (Ent) then
1914 Error_Msg_Name_1 := Chars (ALo);
1915 Error_Msg_N ("\ %?", N);
1917 Error_Msg_Name_1 := Chars (ALo);
1918 Error_Msg_Name_2 := Chars (Ent);
1919 Error_Msg_N ("\ % .. %?", N);
1923 -- Output missing value(s) at end
1925 if Chars (AHi) /= Chars (CHi) then
1928 if Chars (AHi) = Chars (Ent) then
1929 Error_Msg_Name_1 := Chars (Ent);
1930 Error_Msg_N ("\ %?", N);
1932 Error_Msg_Name_1 := Chars (Ent);
1933 Error_Msg_Name_2 := Chars (AHi);
1934 Error_Msg_N ("\ % .. %?", N);
1938 -- Warning case 2, dubious sliding. The First_Subtype
1939 -- test distinguishes between a constrained type where
1940 -- sliding is not allowed (so we will get a warning
1941 -- later that Constraint_Error will be raised), and
1942 -- the unconstrained case where sliding is permitted.
1944 elsif (Enumeration_Pos (CHi) - Enumeration_Pos (CLo))
1946 (Enumeration_Pos (AHi) - Enumeration_Pos (ALo))
1947 and then Chars (ALo) /= Chars (CLo)
1949 not Is_Constrained (First_Subtype (Etype (N)))
1952 ("bounds of aggregate do not match target?", N);
1958 -- If no others, aggregate bounds come from aggregate
1960 Aggr_Low := Choices_Low;
1961 Aggr_High := Choices_High;
1965 -- STEP 3: Process positional components
1968 -- STEP 3 (A): Process positional elements
1970 Expr := First (Expressions (N));
1971 Nb_Elements := Uint_0;
1972 while Present (Expr) loop
1973 Nb_Elements := Nb_Elements + 1;
1975 -- Ada 2005 (AI-231)
1977 if Ada_Version >= Ada_05
1978 and then Known_Null (Expr)
1980 Check_Can_Never_Be_Null (Etype (N), Expr);
1983 if not Resolve_Aggr_Expr (Expr, Single_Elmt => True) then
1990 if Others_Present then
1991 Assoc := Last (Component_Associations (N));
1993 -- Ada 2005 (AI-231)
1995 if Ada_Version >= Ada_05
1996 and then Known_Null (Assoc)
1998 Check_Can_Never_Be_Null (Etype (N), Expression (Assoc));
2001 -- Ada 2005 (AI-287): In case of default initialized component
2002 -- we delay the resolution to the expansion phase.
2004 if Box_Present (Assoc) then
2006 -- Ada 2005 (AI-287): In case of default initialization
2007 -- of a component the expander will generate calls to
2008 -- the corresponding initialization subprogram.
2012 elsif not Resolve_Aggr_Expr (Expression (Assoc),
2013 Single_Elmt => False)
2019 -- STEP 3 (B): Compute the aggregate bounds
2021 if Others_Present then
2022 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
2025 if Others_Allowed then
2026 Get_Index_Bounds (Index_Constr, Aggr_Low, Discard);
2028 Aggr_Low := Index_Typ_Low;
2031 Aggr_High := Add (Nb_Elements - 1, To => Aggr_Low);
2032 Check_Bound (Index_Base_High, Aggr_High);
2036 -- STEP 4: Perform static aggregate checks and save the bounds
2040 Check_Bounds (Index_Typ_Low, Index_Typ_High, Aggr_Low, Aggr_High);
2041 Check_Bounds (Index_Base_Low, Index_Base_High, Aggr_Low, Aggr_High);
2045 if Others_Present and then Nb_Discrete_Choices > 0 then
2046 Check_Bounds (Aggr_Low, Aggr_High, Choices_Low, Choices_High);
2047 Check_Bounds (Index_Typ_Low, Index_Typ_High,
2048 Choices_Low, Choices_High);
2049 Check_Bounds (Index_Base_Low, Index_Base_High,
2050 Choices_Low, Choices_High);
2054 elsif Others_Present and then Nb_Elements > 0 then
2055 Check_Length (Aggr_Low, Aggr_High, Nb_Elements);
2056 Check_Length (Index_Typ_Low, Index_Typ_High, Nb_Elements);
2057 Check_Length (Index_Base_Low, Index_Base_High, Nb_Elements);
2060 if Raises_Constraint_Error (Aggr_Low)
2061 or else Raises_Constraint_Error (Aggr_High)
2063 Set_Raises_Constraint_Error (N);
2066 Aggr_Low := Duplicate_Subexpr (Aggr_Low);
2068 -- Do not duplicate Aggr_High if Aggr_High = Aggr_Low + Nb_Elements
2069 -- since the addition node returned by Add is not yet analyzed. Attach
2070 -- to tree and analyze first. Reset analyzed flag to insure it will get
2071 -- analyzed when it is a literal bound whose type must be properly set.
2073 if Others_Present or else Nb_Discrete_Choices > 0 then
2074 Aggr_High := Duplicate_Subexpr (Aggr_High);
2076 if Etype (Aggr_High) = Universal_Integer then
2077 Set_Analyzed (Aggr_High, False);
2081 Set_Aggregate_Bounds
2082 (N, Make_Range (Loc, Low_Bound => Aggr_Low, High_Bound => Aggr_High));
2084 -- The bounds may contain expressions that must be inserted upwards.
2085 -- Attach them fully to the tree. After analysis, remove side effects
2086 -- from upper bound, if still needed.
2088 Set_Parent (Aggregate_Bounds (N), N);
2089 Analyze_And_Resolve (Aggregate_Bounds (N), Index_Typ);
2090 Check_Unset_Reference (Aggregate_Bounds (N));
2092 if not Others_Present and then Nb_Discrete_Choices = 0 then
2093 Set_High_Bound (Aggregate_Bounds (N),
2094 Duplicate_Subexpr (High_Bound (Aggregate_Bounds (N))));
2098 end Resolve_Array_Aggregate;
2100 ---------------------------------
2101 -- Resolve_Extension_Aggregate --
2102 ---------------------------------
2104 -- There are two cases to consider:
2106 -- a) If the ancestor part is a type mark, the components needed are
2107 -- the difference between the components of the expected type and the
2108 -- components of the given type mark.
2110 -- b) If the ancestor part is an expression, it must be unambiguous,
2111 -- and once we have its type we can also compute the needed components
2112 -- as in the previous case. In both cases, if the ancestor type is not
2113 -- the immediate ancestor, we have to build this ancestor recursively.
2115 -- In both cases discriminants of the ancestor type do not play a
2116 -- role in the resolution of the needed components, because inherited
2117 -- discriminants cannot be used in a type extension. As a result we can
2118 -- compute independently the list of components of the ancestor type and
2119 -- of the expected type.
2121 procedure Resolve_Extension_Aggregate (N : Node_Id; Typ : Entity_Id) is
2122 A : constant Node_Id := Ancestor_Part (N);
2127 function Valid_Limited_Ancestor (Anc : Node_Id) return Boolean;
2128 -- If the type is limited, verify that the ancestor part is a legal
2129 -- expression (aggregate or function call, including 'Input)) that
2130 -- does not require a copy, as specified in 7.5 (2).
2132 function Valid_Ancestor_Type return Boolean;
2133 -- Verify that the type of the ancestor part is a non-private ancestor
2134 -- of the expected type, which must be a type extension.
2136 ----------------------------
2137 -- Valid_Limited_Ancestor --
2138 ----------------------------
2140 function Valid_Limited_Ancestor (Anc : Node_Id) return Boolean is
2142 if Is_Entity_Name (Anc)
2143 and then Is_Type (Entity (Anc))
2147 elsif Nkind_In (Anc, N_Aggregate, N_Function_Call) then
2150 -- Check for a function name, to cover the case of a parameterless
2151 -- function call which hasn't been resolved yet.
2153 elsif Is_Entity_Name (Anc)
2154 and then Ekind (Entity (Anc)) = E_Function
2158 elsif Nkind (Anc) = N_Attribute_Reference
2159 and then Attribute_Name (Anc) = Name_Input
2164 Nkind (Anc) = N_Qualified_Expression
2166 return Valid_Limited_Ancestor (Expression (Anc));
2171 end Valid_Limited_Ancestor;
2173 -------------------------
2174 -- Valid_Ancestor_Type --
2175 -------------------------
2177 function Valid_Ancestor_Type return Boolean is
2178 Imm_Type : Entity_Id;
2181 Imm_Type := Base_Type (Typ);
2182 while Is_Derived_Type (Imm_Type) loop
2183 if Etype (Imm_Type) = Base_Type (A_Type) then
2186 -- The base type of the parent type may appear as a private
2187 -- extension if it is declared as such in a parent unit of
2188 -- the current one. For consistency of the subsequent analysis
2189 -- use the partial view for the ancestor part.
2191 elsif Is_Private_Type (Etype (Imm_Type))
2192 and then Present (Full_View (Etype (Imm_Type)))
2193 and then Base_Type (A_Type) = Full_View (Etype (Imm_Type))
2195 A_Type := Etype (Imm_Type);
2198 Imm_Type := Etype (Base_Type (Imm_Type));
2202 -- If previous loop did not find a proper ancestor, report error
2204 Error_Msg_NE ("expect ancestor type of &", A, Typ);
2206 end Valid_Ancestor_Type;
2208 -- Start of processing for Resolve_Extension_Aggregate
2213 if not Is_Tagged_Type (Typ) then
2214 Error_Msg_N ("type of extension aggregate must be tagged", N);
2217 elsif Is_Limited_Type (Typ) then
2219 -- Ada 2005 (AI-287): Limited aggregates are allowed
2221 if Ada_Version < Ada_05 then
2222 Error_Msg_N ("aggregate type cannot be limited", N);
2223 Explain_Limited_Type (Typ, N);
2226 elsif Valid_Limited_Ancestor (A) then
2231 ("limited ancestor part must be aggregate or function call", A);
2234 elsif Is_Class_Wide_Type (Typ) then
2235 Error_Msg_N ("aggregate cannot be of a class-wide type", N);
2239 if Is_Entity_Name (A)
2240 and then Is_Type (Entity (A))
2242 A_Type := Get_Full_View (Entity (A));
2244 if Valid_Ancestor_Type then
2245 Set_Entity (A, A_Type);
2246 Set_Etype (A, A_Type);
2248 Validate_Ancestor_Part (N);
2249 Resolve_Record_Aggregate (N, Typ);
2252 elsif Nkind (A) /= N_Aggregate then
2253 if Is_Overloaded (A) then
2256 Get_First_Interp (A, I, It);
2257 while Present (It.Typ) loop
2258 if Is_Tagged_Type (It.Typ)
2259 and then not Is_Limited_Type (It.Typ)
2261 if A_Type /= Any_Type then
2262 Error_Msg_N ("cannot resolve expression", A);
2269 Get_Next_Interp (I, It);
2272 if A_Type = Any_Type then
2274 ("ancestor part must be non-limited tagged type", A);
2279 A_Type := Etype (A);
2282 if Valid_Ancestor_Type then
2283 Resolve (A, A_Type);
2284 Check_Unset_Reference (A);
2285 Check_Non_Static_Context (A);
2287 if Is_Class_Wide_Type (Etype (A))
2288 and then Nkind (Original_Node (A)) = N_Function_Call
2290 -- If the ancestor part is a dispatching call, it appears
2291 -- statically to be a legal ancestor, but it yields any
2292 -- member of the class, and it is not possible to determine
2293 -- whether it is an ancestor of the extension aggregate (much
2294 -- less which ancestor). It is not possible to determine the
2295 -- required components of the extension part.
2297 -- This check implements AI-306, which in fact was motivated
2298 -- by an ACT query to the ARG after this test was added.
2300 Error_Msg_N ("ancestor part must be statically tagged", A);
2302 Resolve_Record_Aggregate (N, Typ);
2307 Error_Msg_N ("no unique type for this aggregate", A);
2309 end Resolve_Extension_Aggregate;
2311 ------------------------------
2312 -- Resolve_Record_Aggregate --
2313 ------------------------------
2315 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id) is
2317 -- N_Component_Association node belonging to the input aggregate N
2320 Positional_Expr : Node_Id;
2321 Component : Entity_Id;
2322 Component_Elmt : Elmt_Id;
2324 Components : constant Elist_Id := New_Elmt_List;
2325 -- Components is the list of the record components whose value must
2326 -- be provided in the aggregate. This list does include discriminants.
2328 New_Assoc_List : constant List_Id := New_List;
2329 New_Assoc : Node_Id;
2330 -- New_Assoc_List is the newly built list of N_Component_Association
2331 -- nodes. New_Assoc is one such N_Component_Association node in it.
2332 -- Please note that while Assoc and New_Assoc contain the same
2333 -- kind of nodes, they are used to iterate over two different
2334 -- N_Component_Association lists.
2336 Others_Etype : Entity_Id := Empty;
2337 -- This variable is used to save the Etype of the last record component
2338 -- that takes its value from the others choice. Its purpose is:
2340 -- (a) make sure the others choice is useful
2342 -- (b) make sure the type of all the components whose value is
2343 -- subsumed by the others choice are the same.
2345 -- This variable is updated as a side effect of function Get_Value
2347 Is_Box_Present : Boolean := False;
2348 Others_Box : Boolean := False;
2349 -- Ada 2005 (AI-287): Variables used in case of default initialization
2350 -- to provide a functionality similar to Others_Etype. Box_Present
2351 -- indicates that the component takes its default initialization;
2352 -- Others_Box indicates that at least one component takes its default
2353 -- initialization. Similar to Others_Etype, they are also updated as a
2354 -- side effect of function Get_Value.
2356 procedure Add_Association
2357 (Component : Entity_Id;
2359 Is_Box_Present : Boolean := False);
2360 -- Builds a new N_Component_Association node which associates
2361 -- Component to expression Expr and adds it to the new association
2362 -- list New_Assoc_List being built.
2364 function Discr_Present (Discr : Entity_Id) return Boolean;
2365 -- If aggregate N is a regular aggregate this routine will return True.
2366 -- Otherwise, if N is an extension aggregate, Discr is a discriminant
2367 -- whose value may already have been specified by N's ancestor part,
2368 -- this routine checks whether this is indeed the case and if so
2369 -- returns False, signaling that no value for Discr should appear in the
2370 -- N's aggregate part. Also, in this case, the routine appends to
2371 -- New_Assoc_List Discr the discriminant value specified in the ancestor
2377 Consider_Others_Choice : Boolean := False)
2379 -- Given a record component stored in parameter Compon, the
2380 -- following function returns its value as it appears in the list
2381 -- From, which is a list of N_Component_Association nodes. If no
2382 -- component association has a choice for the searched component,
2383 -- the value provided by the others choice is returned, if there
2384 -- is one and Consider_Others_Choice is set to true. Otherwise
2385 -- Empty is returned. If there is more than one component association
2386 -- giving a value for the searched record component, an error message
2387 -- is emitted and the first found value is returned.
2389 -- If Consider_Others_Choice is set and the returned expression comes
2390 -- from the others choice, then Others_Etype is set as a side effect.
2391 -- An error message is emitted if the components taking their value
2392 -- from the others choice do not have same type.
2394 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id);
2395 -- Analyzes and resolves expression Expr against the Etype of the
2396 -- Component. This routine also applies all appropriate checks to Expr.
2397 -- It finally saves a Expr in the newly created association list that
2398 -- will be attached to the final record aggregate. Note that if the
2399 -- Parent pointer of Expr is not set then Expr was produced with a
2400 -- New_Copy_Tree or some such.
2402 ---------------------
2403 -- Add_Association --
2404 ---------------------
2406 procedure Add_Association
2407 (Component : Entity_Id;
2409 Is_Box_Present : Boolean := False)
2411 Choice_List : constant List_Id := New_List;
2412 New_Assoc : Node_Id;
2415 Append (New_Occurrence_Of (Component, Sloc (Expr)), Choice_List);
2417 Make_Component_Association (Sloc (Expr),
2418 Choices => Choice_List,
2420 Box_Present => Is_Box_Present);
2421 Append (New_Assoc, New_Assoc_List);
2422 end Add_Association;
2428 function Discr_Present (Discr : Entity_Id) return Boolean is
2429 Regular_Aggr : constant Boolean := Nkind (N) /= N_Extension_Aggregate;
2434 Discr_Expr : Node_Id;
2436 Ancestor_Typ : Entity_Id;
2437 Orig_Discr : Entity_Id;
2439 D_Val : Elmt_Id := No_Elmt; -- stop junk warning
2441 Ancestor_Is_Subtyp : Boolean;
2444 if Regular_Aggr then
2448 Ancestor := Ancestor_Part (N);
2449 Ancestor_Typ := Etype (Ancestor);
2450 Loc := Sloc (Ancestor);
2452 -- For a private type with unknown discriminants, use the underlying
2453 -- record view if it is available.
2455 if Has_Unknown_Discriminants (Ancestor_Typ)
2456 and then Present (Full_View (Ancestor_Typ))
2457 and then Present (Underlying_Record_View (Full_View (Ancestor_Typ)))
2459 Ancestor_Typ := Underlying_Record_View (Full_View (Ancestor_Typ));
2462 Ancestor_Is_Subtyp :=
2463 Is_Entity_Name (Ancestor) and then Is_Type (Entity (Ancestor));
2465 -- If the ancestor part has no discriminants clearly N's aggregate
2466 -- part must provide a value for Discr.
2468 if not Has_Discriminants (Ancestor_Typ) then
2471 -- If the ancestor part is an unconstrained subtype mark then the
2472 -- Discr must be present in N's aggregate part.
2474 elsif Ancestor_Is_Subtyp
2475 and then not Is_Constrained (Entity (Ancestor))
2480 -- Now look to see if Discr was specified in the ancestor part
2482 if Ancestor_Is_Subtyp then
2483 D_Val := First_Elmt (Discriminant_Constraint (Entity (Ancestor)));
2486 Orig_Discr := Original_Record_Component (Discr);
2488 D := First_Discriminant (Ancestor_Typ);
2489 while Present (D) loop
2491 -- If Ancestor has already specified Disc value than insert its
2492 -- value in the final aggregate.
2494 if Original_Record_Component (D) = Orig_Discr then
2495 if Ancestor_Is_Subtyp then
2496 Discr_Expr := New_Copy_Tree (Node (D_Val));
2499 Make_Selected_Component (Loc,
2500 Prefix => Duplicate_Subexpr (Ancestor),
2501 Selector_Name => New_Occurrence_Of (Discr, Loc));
2504 Resolve_Aggr_Expr (Discr_Expr, Discr);
2508 Next_Discriminant (D);
2510 if Ancestor_Is_Subtyp then
2525 Consider_Others_Choice : Boolean := False)
2529 Expr : Node_Id := Empty;
2530 Selector_Name : Node_Id;
2533 Is_Box_Present := False;
2535 if Present (From) then
2536 Assoc := First (From);
2541 while Present (Assoc) loop
2542 Selector_Name := First (Choices (Assoc));
2543 while Present (Selector_Name) loop
2544 if Nkind (Selector_Name) = N_Others_Choice then
2545 if Consider_Others_Choice and then No (Expr) then
2547 -- We need to duplicate the expression for each
2548 -- successive component covered by the others choice.
2549 -- This is redundant if the others_choice covers only
2550 -- one component (small optimization possible???), but
2551 -- indispensable otherwise, because each one must be
2552 -- expanded individually to preserve side-effects.
2554 -- Ada 2005 (AI-287): In case of default initialization
2555 -- of components, we duplicate the corresponding default
2556 -- expression (from the record type declaration). The
2557 -- copy must carry the sloc of the association (not the
2558 -- original expression) to prevent spurious elaboration
2559 -- checks when the default includes function calls.
2561 if Box_Present (Assoc) then
2563 Is_Box_Present := True;
2565 if Expander_Active then
2568 (Expression (Parent (Compon)),
2569 New_Sloc => Sloc (Assoc));
2571 return Expression (Parent (Compon));
2575 if Present (Others_Etype) and then
2576 Base_Type (Others_Etype) /= Base_Type (Etype
2579 Error_Msg_N ("components in OTHERS choice must " &
2580 "have same type", Selector_Name);
2583 Others_Etype := Etype (Compon);
2585 if Expander_Active then
2586 return New_Copy_Tree (Expression (Assoc));
2588 return Expression (Assoc);
2593 elsif Chars (Compon) = Chars (Selector_Name) then
2596 -- Ada 2005 (AI-231)
2598 if Ada_Version >= Ada_05
2599 and then Known_Null (Expression (Assoc))
2601 Check_Can_Never_Be_Null (Compon, Expression (Assoc));
2604 -- We need to duplicate the expression when several
2605 -- components are grouped together with a "|" choice.
2606 -- For instance "filed1 | filed2 => Expr"
2608 -- Ada 2005 (AI-287)
2610 if Box_Present (Assoc) then
2611 Is_Box_Present := True;
2613 -- Duplicate the default expression of the component
2614 -- from the record type declaration, so a new copy
2615 -- can be attached to the association.
2617 -- Note that we always copy the default expression,
2618 -- even when the association has a single choice, in
2619 -- order to create a proper association for the
2620 -- expanded aggregate.
2622 Expr := New_Copy_Tree (Expression (Parent (Compon)));
2625 if Present (Next (Selector_Name)) then
2626 Expr := New_Copy_Tree (Expression (Assoc));
2628 Expr := Expression (Assoc);
2632 Generate_Reference (Compon, Selector_Name);
2636 ("more than one value supplied for &",
2637 Selector_Name, Compon);
2642 Next (Selector_Name);
2651 -----------------------
2652 -- Resolve_Aggr_Expr --
2653 -----------------------
2655 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id) is
2656 New_C : Entity_Id := Component;
2657 Expr_Type : Entity_Id := Empty;
2659 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean;
2660 -- If the expression is an aggregate (possibly qualified) then its
2661 -- expansion is delayed until the enclosing aggregate is expanded
2662 -- into assignments. In that case, do not generate checks on the
2663 -- expression, because they will be generated later, and will other-
2664 -- wise force a copy (to remove side-effects) that would leave a
2665 -- dynamic-sized aggregate in the code, something that gigi cannot
2669 -- Set to True if the resolved Expr node needs to be relocated
2670 -- when attached to the newly created association list. This node
2671 -- need not be relocated if its parent pointer is not set.
2672 -- In fact in this case Expr is the output of a New_Copy_Tree call.
2673 -- if Relocate is True then we have analyzed the expression node
2674 -- in the original aggregate and hence it needs to be relocated
2675 -- when moved over the new association list.
2677 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean is
2678 Kind : constant Node_Kind := Nkind (Expr);
2680 return (Nkind_In (Kind, N_Aggregate, N_Extension_Aggregate)
2681 and then Present (Etype (Expr))
2682 and then Is_Record_Type (Etype (Expr))
2683 and then Expansion_Delayed (Expr))
2684 or else (Kind = N_Qualified_Expression
2685 and then Has_Expansion_Delayed (Expression (Expr)));
2686 end Has_Expansion_Delayed;
2688 -- Start of processing for Resolve_Aggr_Expr
2691 -- If the type of the component is elementary or the type of the
2692 -- aggregate does not contain discriminants, use the type of the
2693 -- component to resolve Expr.
2695 if Is_Elementary_Type (Etype (Component))
2696 or else not Has_Discriminants (Etype (N))
2698 Expr_Type := Etype (Component);
2700 -- Otherwise we have to pick up the new type of the component from
2701 -- the new constrained subtype of the aggregate. In fact components
2702 -- which are of a composite type might be constrained by a
2703 -- discriminant, and we want to resolve Expr against the subtype were
2704 -- all discriminant occurrences are replaced with their actual value.
2707 New_C := First_Component (Etype (N));
2708 while Present (New_C) loop
2709 if Chars (New_C) = Chars (Component) then
2710 Expr_Type := Etype (New_C);
2714 Next_Component (New_C);
2717 pragma Assert (Present (Expr_Type));
2719 -- For each range in an array type where a discriminant has been
2720 -- replaced with the constraint, check that this range is within
2721 -- the range of the base type. This checks is done in the init
2722 -- proc for regular objects, but has to be done here for
2723 -- aggregates since no init proc is called for them.
2725 if Is_Array_Type (Expr_Type) then
2728 -- Range of the current constrained index in the array
2730 Orig_Index : Node_Id := First_Index (Etype (Component));
2731 -- Range corresponding to the range Index above in the
2732 -- original unconstrained record type. The bounds of this
2733 -- range may be governed by discriminants.
2735 Unconstr_Index : Node_Id := First_Index (Etype (Expr_Type));
2736 -- Range corresponding to the range Index above for the
2737 -- unconstrained array type. This range is needed to apply
2741 Index := First_Index (Expr_Type);
2742 while Present (Index) loop
2743 if Depends_On_Discriminant (Orig_Index) then
2744 Apply_Range_Check (Index, Etype (Unconstr_Index));
2748 Next_Index (Orig_Index);
2749 Next_Index (Unconstr_Index);
2755 -- If the Parent pointer of Expr is not set, Expr is an expression
2756 -- duplicated by New_Tree_Copy (this happens for record aggregates
2757 -- that look like (Field1 | Filed2 => Expr) or (others => Expr)).
2758 -- Such a duplicated expression must be attached to the tree
2759 -- before analysis and resolution to enforce the rule that a tree
2760 -- fragment should never be analyzed or resolved unless it is
2761 -- attached to the current compilation unit.
2763 if No (Parent (Expr)) then
2764 Set_Parent (Expr, N);
2770 Analyze_And_Resolve (Expr, Expr_Type);
2771 Check_Expr_OK_In_Limited_Aggregate (Expr);
2772 Check_Non_Static_Context (Expr);
2773 Check_Unset_Reference (Expr);
2775 if not Has_Expansion_Delayed (Expr) then
2776 Aggregate_Constraint_Checks (Expr, Expr_Type);
2779 if Raises_Constraint_Error (Expr) then
2780 Set_Raises_Constraint_Error (N);
2784 Add_Association (New_C, Relocate_Node (Expr));
2786 Add_Association (New_C, Expr);
2788 end Resolve_Aggr_Expr;
2790 -- Start of processing for Resolve_Record_Aggregate
2793 -- We may end up calling Duplicate_Subexpr on expressions that are
2794 -- attached to New_Assoc_List. For this reason we need to attach it
2795 -- to the tree by setting its parent pointer to N. This parent point
2796 -- will change in STEP 8 below.
2798 Set_Parent (New_Assoc_List, N);
2800 -- STEP 1: abstract type and null record verification
2802 if Is_Abstract_Type (Typ) then
2803 Error_Msg_N ("type of aggregate cannot be abstract", N);
2806 if No (First_Entity (Typ)) and then Null_Record_Present (N) then
2810 elsif Present (First_Entity (Typ))
2811 and then Null_Record_Present (N)
2812 and then not Is_Tagged_Type (Typ)
2814 Error_Msg_N ("record aggregate cannot be null", N);
2817 -- If the type has no components, then the aggregate should either
2818 -- have "null record", or in Ada 2005 it could instead have a single
2819 -- component association given by "others => <>". For Ada 95 we flag
2820 -- an error at this point, but for Ada 2005 we proceed with checking
2821 -- the associations below, which will catch the case where it's not
2822 -- an aggregate with "others => <>". Note that the legality of a <>
2823 -- aggregate for a null record type was established by AI05-016.
2825 elsif No (First_Entity (Typ))
2826 and then Ada_Version < Ada_05
2828 Error_Msg_N ("record aggregate must be null", N);
2832 -- STEP 2: Verify aggregate structure
2835 Selector_Name : Node_Id;
2836 Bad_Aggregate : Boolean := False;
2839 if Present (Component_Associations (N)) then
2840 Assoc := First (Component_Associations (N));
2845 while Present (Assoc) loop
2846 Selector_Name := First (Choices (Assoc));
2847 while Present (Selector_Name) loop
2848 if Nkind (Selector_Name) = N_Identifier then
2851 elsif Nkind (Selector_Name) = N_Others_Choice then
2852 if Selector_Name /= First (Choices (Assoc))
2853 or else Present (Next (Selector_Name))
2855 Error_Msg_N ("OTHERS must appear alone in a choice list",
2859 elsif Present (Next (Assoc)) then
2860 Error_Msg_N ("OTHERS must appear last in an aggregate",
2864 -- (Ada2005): If this is an association with a box,
2865 -- indicate that the association need not represent
2868 elsif Box_Present (Assoc) then
2874 ("selector name should be identifier or OTHERS",
2876 Bad_Aggregate := True;
2879 Next (Selector_Name);
2885 if Bad_Aggregate then
2890 -- STEP 3: Find discriminant Values
2893 Discrim : Entity_Id;
2894 Missing_Discriminants : Boolean := False;
2897 if Present (Expressions (N)) then
2898 Positional_Expr := First (Expressions (N));
2900 Positional_Expr := Empty;
2903 if Has_Unknown_Discriminants (Typ)
2904 and then Present (Underlying_Record_View (Typ))
2906 Discrim := First_Discriminant (Underlying_Record_View (Typ));
2907 elsif Has_Discriminants (Typ) then
2908 Discrim := First_Discriminant (Typ);
2913 -- First find the discriminant values in the positional components
2915 while Present (Discrim) and then Present (Positional_Expr) loop
2916 if Discr_Present (Discrim) then
2917 Resolve_Aggr_Expr (Positional_Expr, Discrim);
2919 -- Ada 2005 (AI-231)
2921 if Ada_Version >= Ada_05
2922 and then Known_Null (Positional_Expr)
2924 Check_Can_Never_Be_Null (Discrim, Positional_Expr);
2927 Next (Positional_Expr);
2930 if Present (Get_Value (Discrim, Component_Associations (N))) then
2932 ("more than one value supplied for discriminant&",
2936 Next_Discriminant (Discrim);
2939 -- Find remaining discriminant values, if any, among named components
2941 while Present (Discrim) loop
2942 Expr := Get_Value (Discrim, Component_Associations (N), True);
2944 if not Discr_Present (Discrim) then
2945 if Present (Expr) then
2947 ("more than one value supplied for discriminant&",
2951 elsif No (Expr) then
2953 ("no value supplied for discriminant &", N, Discrim);
2954 Missing_Discriminants := True;
2957 Resolve_Aggr_Expr (Expr, Discrim);
2960 Next_Discriminant (Discrim);
2963 if Missing_Discriminants then
2967 -- At this point and until the beginning of STEP 6, New_Assoc_List
2968 -- contains only the discriminants and their values.
2972 -- STEP 4: Set the Etype of the record aggregate
2974 -- ??? This code is pretty much a copy of Sem_Ch3.Build_Subtype. That
2975 -- routine should really be exported in sem_util or some such and used
2976 -- in sem_ch3 and here rather than have a copy of the code which is a
2977 -- maintenance nightmare.
2979 -- ??? Performance WARNING. The current implementation creates a new
2980 -- itype for all aggregates whose base type is discriminated.
2981 -- This means that for record aggregates nested inside an array
2982 -- aggregate we will create a new itype for each record aggregate
2983 -- if the array component type has discriminants. For large aggregates
2984 -- this may be a problem. What should be done in this case is
2985 -- to reuse itypes as much as possible.
2987 if Has_Discriminants (Typ)
2988 or else (Has_Unknown_Discriminants (Typ)
2989 and then Present (Underlying_Record_View (Typ)))
2991 Build_Constrained_Itype : declare
2992 Loc : constant Source_Ptr := Sloc (N);
2994 Subtyp_Decl : Node_Id;
2997 C : constant List_Id := New_List;
3000 New_Assoc := First (New_Assoc_List);
3001 while Present (New_Assoc) loop
3002 Append (Duplicate_Subexpr (Expression (New_Assoc)), To => C);
3006 if Has_Unknown_Discriminants (Typ)
3007 and then Present (Underlying_Record_View (Typ))
3010 Make_Subtype_Indication (Loc,
3012 New_Occurrence_Of (Underlying_Record_View (Typ), Loc),
3014 Make_Index_Or_Discriminant_Constraint (Loc, C));
3017 Make_Subtype_Indication (Loc,
3019 New_Occurrence_Of (Base_Type (Typ), Loc),
3021 Make_Index_Or_Discriminant_Constraint (Loc, C));
3024 Def_Id := Create_Itype (Ekind (Typ), N);
3027 Make_Subtype_Declaration (Loc,
3028 Defining_Identifier => Def_Id,
3029 Subtype_Indication => Indic);
3030 Set_Parent (Subtyp_Decl, Parent (N));
3032 -- Itypes must be analyzed with checks off (see itypes.ads)
3034 Analyze (Subtyp_Decl, Suppress => All_Checks);
3036 Set_Etype (N, Def_Id);
3037 Check_Static_Discriminated_Subtype
3038 (Def_Id, Expression (First (New_Assoc_List)));
3039 end Build_Constrained_Itype;
3045 -- STEP 5: Get remaining components according to discriminant values
3048 Record_Def : Node_Id;
3049 Parent_Typ : Entity_Id;
3050 Root_Typ : Entity_Id;
3051 Parent_Typ_List : Elist_Id;
3052 Parent_Elmt : Elmt_Id;
3053 Errors_Found : Boolean := False;
3057 if Is_Derived_Type (Typ) and then Is_Tagged_Type (Typ) then
3058 Parent_Typ_List := New_Elmt_List;
3060 -- If this is an extension aggregate, the component list must
3061 -- include all components that are not in the given ancestor
3062 -- type. Otherwise, the component list must include components
3063 -- of all ancestors, starting with the root.
3065 if Nkind (N) = N_Extension_Aggregate then
3066 Root_Typ := Base_Type (Etype (Ancestor_Part (N)));
3068 Root_Typ := Root_Type (Typ);
3070 if Nkind (Parent (Base_Type (Root_Typ))) =
3071 N_Private_Type_Declaration
3074 ("type of aggregate has private ancestor&!",
3076 Error_Msg_N ("must use extension aggregate!", N);
3080 Dnode := Declaration_Node (Base_Type (Root_Typ));
3082 -- If we don't get a full declaration, then we have some
3083 -- error which will get signalled later so skip this part.
3084 -- Otherwise, gather components of root that apply to the
3085 -- aggregate type. We use the base type in case there is an
3086 -- applicable stored constraint that renames the discriminants
3089 if Nkind (Dnode) = N_Full_Type_Declaration then
3090 Record_Def := Type_Definition (Dnode);
3091 Gather_Components (Base_Type (Typ),
3092 Component_List (Record_Def),
3093 Governed_By => New_Assoc_List,
3095 Report_Errors => Errors_Found);
3099 Parent_Typ := Base_Type (Typ);
3100 while Parent_Typ /= Root_Typ loop
3101 Prepend_Elmt (Parent_Typ, To => Parent_Typ_List);
3102 Parent_Typ := Etype (Parent_Typ);
3104 if Nkind (Parent (Base_Type (Parent_Typ))) =
3105 N_Private_Type_Declaration
3106 or else Nkind (Parent (Base_Type (Parent_Typ))) =
3107 N_Private_Extension_Declaration
3109 if Nkind (N) /= N_Extension_Aggregate then
3111 ("type of aggregate has private ancestor&!",
3113 Error_Msg_N ("must use extension aggregate!", N);
3116 elsif Parent_Typ /= Root_Typ then
3118 ("ancestor part of aggregate must be private type&",
3119 Ancestor_Part (N), Parent_Typ);
3125 -- Now collect components from all other ancestors, beginning
3126 -- with the current type. If the type has unknown discriminants
3127 -- use the component list of the Underlying_Record_View, which
3128 -- needs to be used for the subsequent expansion of the aggregate
3129 -- into assignments.
3131 Parent_Elmt := First_Elmt (Parent_Typ_List);
3132 while Present (Parent_Elmt) loop
3133 Parent_Typ := Node (Parent_Elmt);
3135 if Has_Unknown_Discriminants (Parent_Typ)
3136 and then Present (Underlying_Record_View (Typ))
3138 Parent_Typ := Underlying_Record_View (Parent_Typ);
3141 Record_Def := Type_Definition (Parent (Base_Type (Parent_Typ)));
3142 Gather_Components (Empty,
3143 Component_List (Record_Extension_Part (Record_Def)),
3144 Governed_By => New_Assoc_List,
3146 Report_Errors => Errors_Found);
3148 Next_Elmt (Parent_Elmt);
3152 Record_Def := Type_Definition (Parent (Base_Type (Typ)));
3154 if Null_Present (Record_Def) then
3157 elsif not Has_Unknown_Discriminants (Typ) then
3158 Gather_Components (Base_Type (Typ),
3159 Component_List (Record_Def),
3160 Governed_By => New_Assoc_List,
3162 Report_Errors => Errors_Found);
3166 (Base_Type (Underlying_Record_View (Typ)),
3167 Component_List (Record_Def),
3168 Governed_By => New_Assoc_List,
3170 Report_Errors => Errors_Found);
3174 if Errors_Found then
3179 -- STEP 6: Find component Values
3182 Component_Elmt := First_Elmt (Components);
3184 -- First scan the remaining positional associations in the aggregate.
3185 -- Remember that at this point Positional_Expr contains the current
3186 -- positional association if any is left after looking for discriminant
3187 -- values in step 3.
3189 while Present (Positional_Expr) and then Present (Component_Elmt) loop
3190 Component := Node (Component_Elmt);
3191 Resolve_Aggr_Expr (Positional_Expr, Component);
3193 -- Ada 2005 (AI-231)
3195 if Ada_Version >= Ada_05
3196 and then Known_Null (Positional_Expr)
3198 Check_Can_Never_Be_Null (Component, Positional_Expr);
3201 if Present (Get_Value (Component, Component_Associations (N))) then
3203 ("more than one value supplied for Component &", N, Component);
3206 Next (Positional_Expr);
3207 Next_Elmt (Component_Elmt);
3210 if Present (Positional_Expr) then
3212 ("too many components for record aggregate", Positional_Expr);
3215 -- Now scan for the named arguments of the aggregate
3217 while Present (Component_Elmt) loop
3218 Component := Node (Component_Elmt);
3219 Expr := Get_Value (Component, Component_Associations (N), True);
3221 -- Note: The previous call to Get_Value sets the value of the
3222 -- variable Is_Box_Present.
3224 -- Ada 2005 (AI-287): Handle components with default initialization.
3225 -- Note: This feature was originally added to Ada 2005 for limited
3226 -- but it was finally allowed with any type.
3228 if Is_Box_Present then
3229 Check_Box_Component : declare
3230 Ctyp : constant Entity_Id := Etype (Component);
3233 -- If there is a default expression for the aggregate, copy
3234 -- it into a new association.
3236 -- If the component has an initialization procedure (IP) we
3237 -- pass the component to the expander, which will generate
3238 -- the call to such IP.
3240 -- If the component has discriminants, their values must
3241 -- be taken from their subtype. This is indispensable for
3242 -- constraints that are given by the current instance of an
3243 -- enclosing type, to allow the expansion of the aggregate
3244 -- to replace the reference to the current instance by the
3245 -- target object of the aggregate.
3247 if Present (Parent (Component))
3249 Nkind (Parent (Component)) = N_Component_Declaration
3250 and then Present (Expression (Parent (Component)))
3253 New_Copy_Tree (Expression (Parent (Component)),
3254 New_Sloc => Sloc (N));
3257 (Component => Component,
3259 Set_Has_Self_Reference (N);
3261 -- A box-defaulted access component gets the value null. Also
3262 -- included are components of private types whose underlying
3263 -- type is an access type. In either case set the type of the
3264 -- literal, for subsequent use in semantic checks.
3266 elsif Present (Underlying_Type (Ctyp))
3267 and then Is_Access_Type (Underlying_Type (Ctyp))
3269 if not Is_Private_Type (Ctyp) then
3270 Expr := Make_Null (Sloc (N));
3271 Set_Etype (Expr, Ctyp);
3273 (Component => Component,
3276 -- If the component's type is private with an access type as
3277 -- its underlying type then we have to create an unchecked
3278 -- conversion to satisfy type checking.
3282 Qual_Null : constant Node_Id :=
3283 Make_Qualified_Expression (Sloc (N),
3286 (Underlying_Type (Ctyp), Sloc (N)),
3287 Expression => Make_Null (Sloc (N)));
3289 Convert_Null : constant Node_Id :=
3290 Unchecked_Convert_To
3294 Analyze_And_Resolve (Convert_Null, Ctyp);
3296 (Component => Component, Expr => Convert_Null);
3300 elsif Has_Non_Null_Base_Init_Proc (Ctyp)
3301 or else not Expander_Active
3303 if Is_Record_Type (Ctyp)
3304 and then Has_Discriminants (Ctyp)
3306 -- We build a partially initialized aggregate with the
3307 -- values of the discriminants and box initialization
3308 -- for the rest, if other components are present.
3309 -- The type of the aggregate is the known subtype of
3313 Loc : constant Source_Ptr := Sloc (N);
3316 Discr_Elmt : Elmt_Id;
3317 Discr_Val : Node_Id;
3321 Expr := Make_Aggregate (Loc, New_List, New_List);
3322 Set_Etype (Expr, Ctyp);
3325 First_Elmt (Discriminant_Constraint (Ctyp));
3326 while Present (Discr_Elmt) loop
3327 Discr_Val := Node (Discr_Elmt);
3329 -- The constraint may be given by a discriminant
3330 -- of the enclosing type, in which case we have
3331 -- to retrieve its value, which is part of the
3332 -- current aggregate.
3334 if Is_Entity_Name (Discr_Val)
3336 Ekind (Entity (Discr_Val)) = E_Discriminant
3338 Discr := Entity (Discr_Val);
3340 Assoc := First (New_Assoc_List);
3341 while Present (Assoc) loop
3343 (Entity (First (Choices (Assoc))))
3345 Entity (First (Choices (Assoc))) = Discr
3347 Discr_Val := Expression (Assoc);
3355 (New_Copy_Tree (Discr_Val), Expressions (Expr));
3357 -- If the discriminant constraint is a current
3358 -- instance, mark the current aggregate so that
3359 -- the self-reference can be expanded later.
3361 if Nkind (Discr_Val) = N_Attribute_Reference
3362 and then Is_Entity_Name (Prefix (Discr_Val))
3363 and then Is_Type (Entity (Prefix (Discr_Val)))
3364 and then Etype (N) = Entity (Prefix (Discr_Val))
3366 Set_Has_Self_Reference (N);
3369 Next_Elmt (Discr_Elmt);
3376 -- Look for a component that is not a discriminant
3377 -- before creating an others box association.
3379 Comp := First_Component (Ctyp);
3380 while Present (Comp) loop
3381 if Ekind (Comp) = E_Component then
3383 (Make_Component_Association (Loc,
3385 New_List (Make_Others_Choice (Loc)),
3386 Expression => Empty,
3387 Box_Present => True),
3388 Component_Associations (Expr));
3392 Next_Component (Comp);
3397 (Component => Component,
3403 (Component => Component,
3405 Is_Box_Present => True);
3408 -- Otherwise we only need to resolve the expression if the
3409 -- component has partially initialized values (required to
3410 -- expand the corresponding assignments and run-time checks).
3412 elsif Present (Expr)
3413 and then Is_Partially_Initialized_Type (Ctyp)
3415 Resolve_Aggr_Expr (Expr, Component);
3417 end Check_Box_Component;
3419 elsif No (Expr) then
3421 -- Ignore hidden components associated with the position of the
3422 -- interface tags: these are initialized dynamically.
3424 if not Present (Related_Type (Component)) then
3426 ("no value supplied for component &!", N, Component);
3430 Resolve_Aggr_Expr (Expr, Component);
3433 Next_Elmt (Component_Elmt);
3436 -- STEP 7: check for invalid components + check type in choice list
3443 -- Type of first component in choice list
3446 if Present (Component_Associations (N)) then
3447 Assoc := First (Component_Associations (N));
3452 Verification : while Present (Assoc) loop
3453 Selectr := First (Choices (Assoc));
3456 if Nkind (Selectr) = N_Others_Choice then
3458 -- Ada 2005 (AI-287): others choice may have expression or box
3460 if No (Others_Etype)
3461 and then not Others_Box
3464 ("OTHERS must represent at least one component", Selectr);
3470 while Present (Selectr) loop
3471 New_Assoc := First (New_Assoc_List);
3472 while Present (New_Assoc) loop
3473 Component := First (Choices (New_Assoc));
3474 exit when Chars (Selectr) = Chars (Component);
3478 -- If no association, this is not a legal component of
3479 -- of the type in question, except if its association
3480 -- is provided with a box.
3482 if No (New_Assoc) then
3483 if Box_Present (Parent (Selectr)) then
3485 -- This may still be a bogus component with a box. Scan
3486 -- list of components to verify that a component with
3487 -- that name exists.
3493 C := First_Component (Typ);
3494 while Present (C) loop
3495 if Chars (C) = Chars (Selectr) then
3497 -- If the context is an extension aggregate,
3498 -- the component must not be inherited from
3499 -- the ancestor part of the aggregate.
3501 if Nkind (N) /= N_Extension_Aggregate
3503 Scope (Original_Record_Component (C)) /=
3504 Etype (Ancestor_Part (N))
3514 Error_Msg_Node_2 := Typ;
3515 Error_Msg_N ("& is not a component of}", Selectr);
3519 elsif Chars (Selectr) /= Name_uTag
3520 and then Chars (Selectr) /= Name_uParent
3521 and then Chars (Selectr) /= Name_uController
3523 if not Has_Discriminants (Typ) then
3524 Error_Msg_Node_2 := Typ;
3525 Error_Msg_N ("& is not a component of}", Selectr);
3528 ("& is not a component of the aggregate subtype",
3532 Check_Misspelled_Component (Components, Selectr);
3535 elsif No (Typech) then
3536 Typech := Base_Type (Etype (Component));
3538 elsif Typech /= Base_Type (Etype (Component)) then
3539 if not Box_Present (Parent (Selectr)) then
3541 ("components in choice list must have same type",
3550 end loop Verification;
3553 -- STEP 8: replace the original aggregate
3556 New_Aggregate : constant Node_Id := New_Copy (N);
3559 Set_Expressions (New_Aggregate, No_List);
3560 Set_Etype (New_Aggregate, Etype (N));
3561 Set_Component_Associations (New_Aggregate, New_Assoc_List);
3563 Rewrite (N, New_Aggregate);
3565 end Resolve_Record_Aggregate;
3567 -----------------------------
3568 -- Check_Can_Never_Be_Null --
3569 -----------------------------
3571 procedure Check_Can_Never_Be_Null (Typ : Entity_Id; Expr : Node_Id) is
3572 Comp_Typ : Entity_Id;
3576 (Ada_Version >= Ada_05
3577 and then Present (Expr)
3578 and then Known_Null (Expr));
3581 when E_Array_Type =>
3582 Comp_Typ := Component_Type (Typ);
3586 Comp_Typ := Etype (Typ);
3592 if Can_Never_Be_Null (Comp_Typ) then
3594 -- Here we know we have a constraint error. Note that we do not use
3595 -- Apply_Compile_Time_Constraint_Error here to the Expr, which might
3596 -- seem the more natural approach. That's because in some cases the
3597 -- components are rewritten, and the replacement would be missed.
3600 (Compile_Time_Constraint_Error
3602 "(Ada 2005) null not allowed in null-excluding component?"),
3603 Make_Raise_Constraint_Error (Sloc (Expr),
3604 Reason => CE_Access_Check_Failed));
3606 -- Set proper type for bogus component (why is this needed???)
3608 Set_Etype (Expr, Comp_Typ);
3609 Set_Analyzed (Expr);
3611 end Check_Can_Never_Be_Null;
3613 ---------------------
3614 -- Sort_Case_Table --
3615 ---------------------
3617 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
3618 L : constant Int := Case_Table'First;
3619 U : constant Int := Case_Table'Last;
3627 T := Case_Table (K + 1);
3631 and then Expr_Value (Case_Table (J - 1).Choice_Lo) >
3632 Expr_Value (T.Choice_Lo)
3634 Case_Table (J) := Case_Table (J - 1);
3638 Case_Table (J) := T;
3641 end Sort_Case_Table;
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