1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2014, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Expander; use Expander;
32 with Exp_Tss; use Exp_Tss;
33 with Exp_Util; use Exp_Util;
34 with Freeze; use Freeze;
35 with Itypes; use Itypes;
37 with Lib.Xref; use Lib.Xref;
38 with Namet; use Namet;
39 with Namet.Sp; use Namet.Sp;
40 with Nmake; use Nmake;
41 with Nlists; use Nlists;
43 with Restrict; use Restrict;
45 with Sem_Aux; use Sem_Aux;
46 with Sem_Cat; use Sem_Cat;
47 with Sem_Ch3; use Sem_Ch3;
48 with Sem_Ch8; use Sem_Ch8;
49 with Sem_Ch13; use Sem_Ch13;
50 with Sem_Dim; use Sem_Dim;
51 with Sem_Eval; use Sem_Eval;
52 with Sem_Res; use Sem_Res;
53 with Sem_Util; use Sem_Util;
54 with Sem_Type; use Sem_Type;
55 with Sem_Warn; use Sem_Warn;
56 with Sinfo; use Sinfo;
57 with Snames; use Snames;
58 with Stringt; use Stringt;
59 with Stand; use Stand;
60 with Style; use Style;
61 with Targparm; use Targparm;
62 with Tbuild; use Tbuild;
63 with Uintp; use Uintp;
65 package body Sem_Aggr is
67 type Case_Bounds is record
69 -- Low bound of choice. Once we sort the Case_Table, then entries
70 -- will be in order of ascending Choice_Lo values.
73 -- High Bound of choice. The sort does not pay any attention to the
74 -- high bound, so choices 1 .. 4 and 1 .. 5 could be in either order.
77 -- If there are duplicates or missing entries, then in the sorted
78 -- table, this records the highest value among Choice_Hi values
79 -- seen so far, including this entry.
82 -- The node of the choice
85 type Case_Table_Type is array (Nat range <>) of Case_Bounds;
86 -- Table type used by Check_Case_Choices procedure. Entry zero is not
87 -- used (reserved for the sort). Real entries start at one.
89 -----------------------
90 -- Local Subprograms --
91 -----------------------
93 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
94 -- Sort the Case Table using the Lower Bound of each Choice as the key. A
95 -- simple insertion sort is used since the choices in a case statement will
96 -- usually be in near sorted order.
98 procedure Check_Can_Never_Be_Null (Typ : Entity_Id; Expr : Node_Id);
99 -- Ada 2005 (AI-231): Check bad usage of null for a component for which
100 -- null exclusion (NOT NULL) is specified. Typ can be an E_Array_Type for
101 -- the array case (the component type of the array will be used) or an
102 -- E_Component/E_Discriminant entity in the record case, in which case the
103 -- type of the component will be used for the test. If Typ is any other
104 -- kind of entity, the call is ignored. Expr is the component node in the
105 -- aggregate which is known to have a null value. A warning message will be
106 -- issued if the component is null excluding.
108 -- It would be better to pass the proper type for Typ ???
110 procedure Check_Expr_OK_In_Limited_Aggregate (Expr : Node_Id);
111 -- Check that Expr is either not limited or else is one of the cases of
112 -- expressions allowed for a limited component association (namely, an
113 -- aggregate, function call, or <> notation). Report error for violations.
115 procedure Check_Qualified_Aggregate (Level : Nat; Expr : Node_Id);
116 -- Given aggregate Expr, check that sub-aggregates of Expr that are nested
117 -- at Level are qualified. If Level = 0, this applies to Expr directly.
118 -- Only issue errors in formal verification mode.
120 function Is_Top_Level_Aggregate (Expr : Node_Id) return Boolean;
121 -- Return True of Expr is an aggregate not contained directly in another
124 ------------------------------------------------------
125 -- Subprograms used for RECORD AGGREGATE Processing --
126 ------------------------------------------------------
128 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id);
129 -- This procedure performs all the semantic checks required for record
130 -- aggregates. Note that for aggregates analysis and resolution go
131 -- hand in hand. Aggregate analysis has been delayed up to here and
132 -- it is done while resolving the aggregate.
134 -- N is the N_Aggregate node.
135 -- Typ is the record type for the aggregate resolution
137 -- While performing the semantic checks, this procedure builds a new
138 -- Component_Association_List where each record field appears alone in a
139 -- Component_Choice_List along with its corresponding expression. The
140 -- record fields in the Component_Association_List appear in the same order
141 -- in which they appear in the record type Typ.
143 -- Once this new Component_Association_List is built and all the semantic
144 -- checks performed, the original aggregate subtree is replaced with the
145 -- new named record aggregate just built. Note that subtree substitution is
146 -- performed with Rewrite so as to be able to retrieve the original
149 -- The aggregate subtree manipulation performed by Resolve_Record_Aggregate
150 -- yields the aggregate format expected by Gigi. Typically, this kind of
151 -- tree manipulations are done in the expander. However, because the
152 -- semantic checks that need to be performed on record aggregates really go
153 -- hand in hand with the record aggregate normalization, the aggregate
154 -- subtree transformation is performed during resolution rather than
155 -- expansion. Had we decided otherwise we would have had to duplicate most
156 -- of the code in the expansion procedure Expand_Record_Aggregate. Note,
157 -- however, that all the expansion concerning aggregates for tagged records
158 -- is done in Expand_Record_Aggregate.
160 -- The algorithm of Resolve_Record_Aggregate proceeds as follows:
162 -- 1. Make sure that the record type against which the record aggregate
163 -- has to be resolved is not abstract. Furthermore if the type is a
164 -- null aggregate make sure the input aggregate N is also null.
166 -- 2. Verify that the structure of the aggregate is that of a record
167 -- aggregate. Specifically, look for component associations and ensure
168 -- that each choice list only has identifiers or the N_Others_Choice
169 -- node. Also make sure that if present, the N_Others_Choice occurs
170 -- last and by itself.
172 -- 3. If Typ contains discriminants, the values for each discriminant is
173 -- looked for. If the record type Typ has variants, we check that the
174 -- expressions corresponding to each discriminant ruling the (possibly
175 -- nested) variant parts of Typ, are static. This allows us to determine
176 -- the variant parts to which the rest of the aggregate must conform.
177 -- The names of discriminants with their values are saved in a new
178 -- association list, New_Assoc_List which is later augmented with the
179 -- names and values of the remaining components in the record type.
181 -- During this phase we also make sure that every discriminant is
182 -- assigned exactly one value. Note that when several values for a given
183 -- discriminant are found, semantic processing continues looking for
184 -- further errors. In this case it's the first discriminant value found
185 -- which we will be recorded.
187 -- IMPORTANT NOTE: For derived tagged types this procedure expects
188 -- First_Discriminant and Next_Discriminant to give the correct list
189 -- of discriminants, in the correct order.
191 -- 4. After all the discriminant values have been gathered, we can set the
192 -- Etype of the record aggregate. If Typ contains no discriminants this
193 -- is straightforward: the Etype of N is just Typ, otherwise a new
194 -- implicit constrained subtype of Typ is built to be the Etype of N.
196 -- 5. Gather the remaining record components according to the discriminant
197 -- values. This involves recursively traversing the record type
198 -- structure to see what variants are selected by the given discriminant
199 -- values. This processing is a little more convoluted if Typ is a
200 -- derived tagged types since we need to retrieve the record structure
201 -- of all the ancestors of Typ.
203 -- 6. After gathering the record components we look for their values in the
204 -- record aggregate and emit appropriate error messages should we not
205 -- find such values or should they be duplicated.
207 -- 7. We then make sure no illegal component names appear in the record
208 -- aggregate and make sure that the type of the record components
209 -- appearing in a same choice list is the same. Finally we ensure that
210 -- the others choice, if present, is used to provide the value of at
211 -- least a record component.
213 -- 8. The original aggregate node is replaced with the new named aggregate
214 -- built in steps 3 through 6, as explained earlier.
216 -- Given the complexity of record aggregate resolution, the primary goal of
217 -- this routine is clarity and simplicity rather than execution and storage
218 -- efficiency. If there are only positional components in the aggregate the
219 -- running time is linear. If there are associations the running time is
220 -- still linear as long as the order of the associations is not too far off
221 -- the order of the components in the record type. If this is not the case
222 -- the running time is at worst quadratic in the size of the association
225 procedure Check_Misspelled_Component
226 (Elements : Elist_Id;
227 Component : Node_Id);
228 -- Give possible misspelling diagnostic if Component is likely to be a
229 -- misspelling of one of the components of the Assoc_List. This is called
230 -- by Resolve_Aggr_Expr after producing an invalid component error message.
232 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id);
233 -- An optimization: determine whether a discriminated subtype has a static
234 -- constraint, and contains array components whose length is also static,
235 -- either because they are constrained by the discriminant, or because the
236 -- original component bounds are static.
238 -----------------------------------------------------
239 -- Subprograms used for ARRAY AGGREGATE Processing --
240 -----------------------------------------------------
242 function Resolve_Array_Aggregate
245 Index_Constr : Node_Id;
246 Component_Typ : Entity_Id;
247 Others_Allowed : Boolean) return Boolean;
248 -- This procedure performs the semantic checks for an array aggregate.
249 -- True is returned if the aggregate resolution succeeds.
251 -- The procedure works by recursively checking each nested aggregate.
252 -- Specifically, after checking a sub-aggregate nested at the i-th level
253 -- we recursively check all the subaggregates at the i+1-st level (if any).
254 -- Note that for aggregates analysis and resolution go hand in hand.
255 -- Aggregate analysis has been delayed up to here and it is done while
256 -- resolving the aggregate.
258 -- N is the current N_Aggregate node to be checked.
260 -- Index is the index node corresponding to the array sub-aggregate that
261 -- we are currently checking (RM 4.3.3 (8)). Its Etype is the
262 -- corresponding index type (or subtype).
264 -- Index_Constr is the node giving the applicable index constraint if
265 -- any (RM 4.3.3 (10)). It "is a constraint provided by certain
266 -- contexts [...] that can be used to determine the bounds of the array
267 -- value specified by the aggregate". If Others_Allowed below is False
268 -- there is no applicable index constraint and this node is set to Index.
270 -- Component_Typ is the array component type.
272 -- Others_Allowed indicates whether an others choice is allowed
273 -- in the context where the top-level aggregate appeared.
275 -- The algorithm of Resolve_Array_Aggregate proceeds as follows:
277 -- 1. Make sure that the others choice, if present, is by itself and
278 -- appears last in the sub-aggregate. Check that we do not have
279 -- positional and named components in the array sub-aggregate (unless
280 -- the named association is an others choice). Finally if an others
281 -- choice is present, make sure it is allowed in the aggregate context.
283 -- 2. If the array sub-aggregate contains discrete_choices:
285 -- (A) Verify their validity. Specifically verify that:
287 -- (a) If a null range is present it must be the only possible
288 -- choice in the array aggregate.
290 -- (b) Ditto for a non static range.
292 -- (c) Ditto for a non static expression.
294 -- In addition this step analyzes and resolves each discrete_choice,
295 -- making sure that its type is the type of the corresponding Index.
296 -- If we are not at the lowest array aggregate level (in the case of
297 -- multi-dimensional aggregates) then invoke Resolve_Array_Aggregate
298 -- recursively on each component expression. Otherwise, resolve the
299 -- bottom level component expressions against the expected component
300 -- type ONLY IF the component corresponds to a single discrete choice
301 -- which is not an others choice (to see why read the DELAYED
302 -- COMPONENT RESOLUTION below).
304 -- (B) Determine the bounds of the sub-aggregate and lowest and
305 -- highest choice values.
307 -- 3. For positional aggregates:
309 -- (A) Loop over the component expressions either recursively invoking
310 -- Resolve_Array_Aggregate on each of these for multi-dimensional
311 -- array aggregates or resolving the bottom level component
312 -- expressions against the expected component type.
314 -- (B) Determine the bounds of the positional sub-aggregates.
316 -- 4. Try to determine statically whether the evaluation of the array
317 -- sub-aggregate raises Constraint_Error. If yes emit proper
318 -- warnings. The precise checks are the following:
320 -- (A) Check that the index range defined by aggregate bounds is
321 -- compatible with corresponding index subtype.
322 -- We also check against the base type. In fact it could be that
323 -- Low/High bounds of the base type are static whereas those of
324 -- the index subtype are not. Thus if we can statically catch
325 -- a problem with respect to the base type we are guaranteed
326 -- that the same problem will arise with the index subtype
328 -- (B) If we are dealing with a named aggregate containing an others
329 -- choice and at least one discrete choice then make sure the range
330 -- specified by the discrete choices does not overflow the
331 -- aggregate bounds. We also check against the index type and base
332 -- type bounds for the same reasons given in (A).
334 -- (C) If we are dealing with a positional aggregate with an others
335 -- choice make sure the number of positional elements specified
336 -- does not overflow the aggregate bounds. We also check against
337 -- the index type and base type bounds as mentioned in (A).
339 -- Finally construct an N_Range node giving the sub-aggregate bounds.
340 -- Set the Aggregate_Bounds field of the sub-aggregate to be this
341 -- N_Range. The routine Array_Aggr_Subtype below uses such N_Ranges
342 -- to build the appropriate aggregate subtype. Aggregate_Bounds
343 -- information is needed during expansion.
345 -- DELAYED COMPONENT RESOLUTION: The resolution of bottom level component
346 -- expressions in an array aggregate may call Duplicate_Subexpr or some
347 -- other routine that inserts code just outside the outermost aggregate.
348 -- If the array aggregate contains discrete choices or an others choice,
349 -- this may be wrong. Consider for instance the following example.
351 -- type Rec is record
355 -- type Acc_Rec is access Rec;
356 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => new Rec);
358 -- Then the transformation of "new Rec" that occurs during resolution
359 -- entails the following code modifications
361 -- P7b : constant Acc_Rec := new Rec;
363 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => P7b);
365 -- This code transformation is clearly wrong, since we need to call
366 -- "new Rec" for each of the 3 array elements. To avoid this problem we
367 -- delay resolution of the components of non positional array aggregates
368 -- to the expansion phase. As an optimization, if the discrete choice
369 -- specifies a single value we do not delay resolution.
371 function Array_Aggr_Subtype (N : Node_Id; Typ : Node_Id) return Entity_Id;
372 -- This routine returns the type or subtype of an array aggregate.
374 -- N is the array aggregate node whose type we return.
376 -- Typ is the context type in which N occurs.
378 -- This routine creates an implicit array subtype whose bounds are
379 -- those defined by the aggregate. When this routine is invoked
380 -- Resolve_Array_Aggregate has already processed aggregate N. Thus the
381 -- Aggregate_Bounds of each sub-aggregate, is an N_Range node giving the
382 -- sub-aggregate bounds. When building the aggregate itype, this function
383 -- traverses the array aggregate N collecting such Aggregate_Bounds and
384 -- constructs the proper array aggregate itype.
386 -- Note that in the case of multidimensional aggregates each inner
387 -- sub-aggregate corresponding to a given array dimension, may provide a
388 -- different bounds. If it is possible to determine statically that
389 -- some sub-aggregates corresponding to the same index do not have the
390 -- same bounds, then a warning is emitted. If such check is not possible
391 -- statically (because some sub-aggregate bounds are dynamic expressions)
392 -- then this job is left to the expander. In all cases the particular
393 -- bounds that this function will chose for a given dimension is the first
394 -- N_Range node for a sub-aggregate corresponding to that dimension.
396 -- Note that the Raises_Constraint_Error flag of an array aggregate
397 -- whose evaluation is determined to raise CE by Resolve_Array_Aggregate,
398 -- is set in Resolve_Array_Aggregate but the aggregate is not
399 -- immediately replaced with a raise CE. In fact, Array_Aggr_Subtype must
400 -- first construct the proper itype for the aggregate (Gigi needs
401 -- this). After constructing the proper itype we will eventually replace
402 -- the top-level aggregate with a raise CE (done in Resolve_Aggregate).
403 -- Of course in cases such as:
405 -- type Arr is array (integer range <>) of Integer;
406 -- A : Arr := (positive range -1 .. 2 => 0);
408 -- The bounds of the aggregate itype are cooked up to look reasonable
409 -- (in this particular case the bounds will be 1 .. 2).
411 procedure Make_String_Into_Aggregate (N : Node_Id);
412 -- A string literal can appear in a context in which a one dimensional
413 -- array of characters is expected. This procedure simply rewrites the
414 -- string as an aggregate, prior to resolution.
416 ------------------------
417 -- Array_Aggr_Subtype --
418 ------------------------
420 function Array_Aggr_Subtype
422 Typ : Entity_Id) return Entity_Id
424 Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
425 -- Number of aggregate index dimensions
427 Aggr_Range : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
428 -- Constrained N_Range of each index dimension in our aggregate itype
430 Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
431 Aggr_High : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
432 -- Low and High bounds for each index dimension in our aggregate itype
434 Is_Fully_Positional : Boolean := True;
436 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos);
437 -- N is an array (sub-)aggregate. Dim is the dimension corresponding
438 -- to (sub-)aggregate N. This procedure collects and removes the side
439 -- effects of the constrained N_Range nodes corresponding to each index
440 -- dimension of our aggregate itype. These N_Range nodes are collected
441 -- in Aggr_Range above.
443 -- Likewise collect in Aggr_Low & Aggr_High above the low and high
444 -- bounds of each index dimension. If, when collecting, two bounds
445 -- corresponding to the same dimension are static and found to differ,
446 -- then emit a warning, and mark N as raising Constraint_Error.
448 -------------------------
449 -- Collect_Aggr_Bounds --
450 -------------------------
452 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos) is
453 This_Range : constant Node_Id := Aggregate_Bounds (N);
454 -- The aggregate range node of this specific sub-aggregate
456 This_Low : constant Node_Id := Low_Bound (Aggregate_Bounds (N));
457 This_High : constant Node_Id := High_Bound (Aggregate_Bounds (N));
458 -- The aggregate bounds of this specific sub-aggregate
464 Remove_Side_Effects (This_Low, Variable_Ref => True);
465 Remove_Side_Effects (This_High, Variable_Ref => True);
467 -- Collect the first N_Range for a given dimension that you find.
468 -- For a given dimension they must be all equal anyway.
470 if No (Aggr_Range (Dim)) then
471 Aggr_Low (Dim) := This_Low;
472 Aggr_High (Dim) := This_High;
473 Aggr_Range (Dim) := This_Range;
476 if Compile_Time_Known_Value (This_Low) then
477 if not Compile_Time_Known_Value (Aggr_Low (Dim)) then
478 Aggr_Low (Dim) := This_Low;
480 elsif Expr_Value (This_Low) /= Expr_Value (Aggr_Low (Dim)) then
481 Set_Raises_Constraint_Error (N);
482 Error_Msg_Warn := SPARK_Mode /= On;
483 Error_Msg_N ("sub-aggregate low bound mismatch<<", N);
484 Error_Msg_N ("\Constraint_Error [<<", N);
488 if Compile_Time_Known_Value (This_High) then
489 if not Compile_Time_Known_Value (Aggr_High (Dim)) then
490 Aggr_High (Dim) := This_High;
493 Expr_Value (This_High) /= Expr_Value (Aggr_High (Dim))
495 Set_Raises_Constraint_Error (N);
496 Error_Msg_Warn := SPARK_Mode /= On;
497 Error_Msg_N ("sub-aggregate high bound mismatch<<", N);
498 Error_Msg_N ("\Constraint_Error [<<", N);
503 if Dim < Aggr_Dimension then
505 -- Process positional components
507 if Present (Expressions (N)) then
508 Expr := First (Expressions (N));
509 while Present (Expr) loop
510 Collect_Aggr_Bounds (Expr, Dim + 1);
515 -- Process component associations
517 if Present (Component_Associations (N)) then
518 Is_Fully_Positional := False;
520 Assoc := First (Component_Associations (N));
521 while Present (Assoc) loop
522 Expr := Expression (Assoc);
523 Collect_Aggr_Bounds (Expr, Dim + 1);
528 end Collect_Aggr_Bounds;
530 -- Array_Aggr_Subtype variables
533 -- The final itype of the overall aggregate
535 Index_Constraints : constant List_Id := New_List;
536 -- The list of index constraints of the aggregate itype
538 -- Start of processing for Array_Aggr_Subtype
541 -- Make sure that the list of index constraints is properly attached to
542 -- the tree, and then collect the aggregate bounds.
544 Set_Parent (Index_Constraints, N);
545 Collect_Aggr_Bounds (N, 1);
547 -- Build the list of constrained indexes of our aggregate itype
549 for J in 1 .. Aggr_Dimension loop
550 Create_Index : declare
551 Index_Base : constant Entity_Id :=
552 Base_Type (Etype (Aggr_Range (J)));
553 Index_Typ : Entity_Id;
556 -- Construct the Index subtype, and associate it with the range
557 -- construct that generates it.
560 Create_Itype (Subtype_Kind (Ekind (Index_Base)), Aggr_Range (J));
562 Set_Etype (Index_Typ, Index_Base);
564 if Is_Character_Type (Index_Base) then
565 Set_Is_Character_Type (Index_Typ);
568 Set_Size_Info (Index_Typ, (Index_Base));
569 Set_RM_Size (Index_Typ, RM_Size (Index_Base));
570 Set_First_Rep_Item (Index_Typ, First_Rep_Item (Index_Base));
571 Set_Scalar_Range (Index_Typ, Aggr_Range (J));
573 if Is_Discrete_Or_Fixed_Point_Type (Index_Typ) then
574 Set_RM_Size (Index_Typ, UI_From_Int (Minimum_Size (Index_Typ)));
577 Set_Etype (Aggr_Range (J), Index_Typ);
579 Append (Aggr_Range (J), To => Index_Constraints);
583 -- Now build the Itype
585 Itype := Create_Itype (E_Array_Subtype, N);
587 Set_First_Rep_Item (Itype, First_Rep_Item (Typ));
588 Set_Convention (Itype, Convention (Typ));
589 Set_Depends_On_Private (Itype, Has_Private_Component (Typ));
590 Set_Etype (Itype, Base_Type (Typ));
591 Set_Has_Alignment_Clause (Itype, Has_Alignment_Clause (Typ));
592 Set_Is_Aliased (Itype, Is_Aliased (Typ));
593 Set_Depends_On_Private (Itype, Depends_On_Private (Typ));
595 Copy_Suppress_Status (Index_Check, Typ, Itype);
596 Copy_Suppress_Status (Length_Check, Typ, Itype);
598 Set_First_Index (Itype, First (Index_Constraints));
599 Set_Is_Constrained (Itype, True);
600 Set_Is_Internal (Itype, True);
602 -- A simple optimization: purely positional aggregates of static
603 -- components should be passed to gigi unexpanded whenever possible, and
604 -- regardless of the staticness of the bounds themselves. Subsequent
605 -- checks in exp_aggr verify that type is not packed, etc.
607 Set_Size_Known_At_Compile_Time (Itype,
609 and then Comes_From_Source (N)
610 and then Size_Known_At_Compile_Time (Component_Type (Typ)));
612 -- We always need a freeze node for a packed array subtype, so that we
613 -- can build the Packed_Array_Type corresponding to the subtype. If
614 -- expansion is disabled, the packed array subtype is not built, and we
615 -- must not generate a freeze node for the type, or else it will appear
616 -- incomplete to gigi.
619 and then not In_Spec_Expression
620 and then Expander_Active
622 Freeze_Itype (Itype, N);
626 end Array_Aggr_Subtype;
628 --------------------------------
629 -- Check_Misspelled_Component --
630 --------------------------------
632 procedure Check_Misspelled_Component
633 (Elements : Elist_Id;
636 Max_Suggestions : constant := 2;
638 Nr_Of_Suggestions : Natural := 0;
639 Suggestion_1 : Entity_Id := Empty;
640 Suggestion_2 : Entity_Id := Empty;
641 Component_Elmt : Elmt_Id;
644 -- All the components of List are matched against Component and a count
645 -- is maintained of possible misspellings. When at the end of the the
646 -- analysis there are one or two (not more) possible misspellings,
647 -- these misspellings will be suggested as possible correction.
649 Component_Elmt := First_Elmt (Elements);
650 while Nr_Of_Suggestions <= Max_Suggestions
651 and then Present (Component_Elmt)
653 if Is_Bad_Spelling_Of
654 (Chars (Node (Component_Elmt)),
657 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
659 case Nr_Of_Suggestions is
660 when 1 => Suggestion_1 := Node (Component_Elmt);
661 when 2 => Suggestion_2 := Node (Component_Elmt);
666 Next_Elmt (Component_Elmt);
669 -- Report at most two suggestions
671 if Nr_Of_Suggestions = 1 then
672 Error_Msg_NE -- CODEFIX
673 ("\possible misspelling of&", Component, Suggestion_1);
675 elsif Nr_Of_Suggestions = 2 then
676 Error_Msg_Node_2 := Suggestion_2;
677 Error_Msg_NE -- CODEFIX
678 ("\possible misspelling of& or&", Component, Suggestion_1);
680 end Check_Misspelled_Component;
682 ----------------------------------------
683 -- Check_Expr_OK_In_Limited_Aggregate --
684 ----------------------------------------
686 procedure Check_Expr_OK_In_Limited_Aggregate (Expr : Node_Id) is
688 if Is_Limited_Type (Etype (Expr))
689 and then Comes_From_Source (Expr)
690 and then not In_Instance_Body
692 if not OK_For_Limited_Init (Etype (Expr), Expr) then
693 Error_Msg_N ("initialization not allowed for limited types", Expr);
694 Explain_Limited_Type (Etype (Expr), Expr);
697 end Check_Expr_OK_In_Limited_Aggregate;
699 -------------------------------
700 -- Check_Qualified_Aggregate --
701 -------------------------------
703 procedure Check_Qualified_Aggregate (Level : Nat; Expr : Node_Id) is
709 if Nkind (Parent (Expr)) /= N_Qualified_Expression then
710 Check_SPARK_Restriction ("aggregate should be qualified", Expr);
714 Comp_Expr := First (Expressions (Expr));
715 while Present (Comp_Expr) loop
716 if Nkind (Comp_Expr) = N_Aggregate then
717 Check_Qualified_Aggregate (Level - 1, Comp_Expr);
720 Comp_Expr := Next (Comp_Expr);
723 Comp_Assn := First (Component_Associations (Expr));
724 while Present (Comp_Assn) loop
725 Comp_Expr := Expression (Comp_Assn);
727 if Nkind (Comp_Expr) = N_Aggregate then
728 Check_Qualified_Aggregate (Level - 1, Comp_Expr);
731 Comp_Assn := Next (Comp_Assn);
734 end Check_Qualified_Aggregate;
736 ----------------------------------------
737 -- Check_Static_Discriminated_Subtype --
738 ----------------------------------------
740 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id) is
741 Disc : constant Entity_Id := First_Discriminant (T);
746 if Has_Record_Rep_Clause (T) then
749 elsif Present (Next_Discriminant (Disc)) then
752 elsif Nkind (V) /= N_Integer_Literal then
756 Comp := First_Component (T);
757 while Present (Comp) loop
758 if Is_Scalar_Type (Etype (Comp)) then
761 elsif Is_Private_Type (Etype (Comp))
762 and then Present (Full_View (Etype (Comp)))
763 and then Is_Scalar_Type (Full_View (Etype (Comp)))
767 elsif Is_Array_Type (Etype (Comp)) then
768 if Is_Bit_Packed_Array (Etype (Comp)) then
772 Ind := First_Index (Etype (Comp));
773 while Present (Ind) loop
774 if Nkind (Ind) /= N_Range
775 or else Nkind (Low_Bound (Ind)) /= N_Integer_Literal
776 or else Nkind (High_Bound (Ind)) /= N_Integer_Literal
788 Next_Component (Comp);
791 -- On exit, all components have statically known sizes
793 Set_Size_Known_At_Compile_Time (T);
794 end Check_Static_Discriminated_Subtype;
796 -------------------------
797 -- Is_Others_Aggregate --
798 -------------------------
800 function Is_Others_Aggregate (Aggr : Node_Id) return Boolean is
802 return No (Expressions (Aggr))
804 Nkind (First (Choices (First (Component_Associations (Aggr)))))
806 end Is_Others_Aggregate;
808 ----------------------------
809 -- Is_Top_Level_Aggregate --
810 ----------------------------
812 function Is_Top_Level_Aggregate (Expr : Node_Id) return Boolean is
814 return Nkind (Parent (Expr)) /= N_Aggregate
815 and then (Nkind (Parent (Expr)) /= N_Component_Association
816 or else Nkind (Parent (Parent (Expr))) /= N_Aggregate);
817 end Is_Top_Level_Aggregate;
819 --------------------------------
820 -- Make_String_Into_Aggregate --
821 --------------------------------
823 procedure Make_String_Into_Aggregate (N : Node_Id) is
824 Exprs : constant List_Id := New_List;
825 Loc : constant Source_Ptr := Sloc (N);
826 Str : constant String_Id := Strval (N);
827 Strlen : constant Nat := String_Length (Str);
835 for J in 1 .. Strlen loop
836 C := Get_String_Char (Str, J);
837 Set_Character_Literal_Name (C);
840 Make_Character_Literal (P,
842 Char_Literal_Value => UI_From_CC (C));
843 Set_Etype (C_Node, Any_Character);
844 Append_To (Exprs, C_Node);
847 -- Something special for wide strings???
850 New_N := Make_Aggregate (Loc, Expressions => Exprs);
851 Set_Analyzed (New_N);
852 Set_Etype (New_N, Any_Composite);
855 end Make_String_Into_Aggregate;
857 -----------------------
858 -- Resolve_Aggregate --
859 -----------------------
861 procedure Resolve_Aggregate (N : Node_Id; Typ : Entity_Id) is
862 Loc : constant Source_Ptr := Sloc (N);
863 Pkind : constant Node_Kind := Nkind (Parent (N));
865 Aggr_Subtyp : Entity_Id;
866 -- The actual aggregate subtype. This is not necessarily the same as Typ
867 -- which is the subtype of the context in which the aggregate was found.
870 -- Ignore junk empty aggregate resulting from parser error
872 if No (Expressions (N))
873 and then No (Component_Associations (N))
874 and then not Null_Record_Present (N)
879 -- If the aggregate has box-initialized components, its type must be
880 -- frozen so that initialization procedures can properly be called
881 -- in the resolution that follows. The replacement of boxes with
882 -- initialization calls is properly an expansion activity but it must
883 -- be done during resolution.
886 and then Present (Component_Associations (N))
892 Comp := First (Component_Associations (N));
893 while Present (Comp) loop
894 if Box_Present (Comp) then
895 Insert_Actions (N, Freeze_Entity (Typ, N));
904 -- An unqualified aggregate is restricted in SPARK to:
906 -- An aggregate item inside an aggregate for a multi-dimensional array
908 -- An expression being assigned to an unconstrained array, but only if
909 -- the aggregate specifies a value for OTHERS only.
911 if Nkind (Parent (N)) = N_Qualified_Expression then
912 if Is_Array_Type (Typ) then
913 Check_Qualified_Aggregate (Number_Dimensions (Typ), N);
915 Check_Qualified_Aggregate (1, N);
918 if Is_Array_Type (Typ)
919 and then Nkind (Parent (N)) = N_Assignment_Statement
920 and then not Is_Constrained (Etype (Name (Parent (N))))
922 if not Is_Others_Aggregate (N) then
923 Check_SPARK_Restriction
924 ("array aggregate should have only OTHERS", N);
927 elsif Is_Top_Level_Aggregate (N) then
928 Check_SPARK_Restriction ("aggregate should be qualified", N);
930 -- The legality of this unqualified aggregate is checked by calling
931 -- Check_Qualified_Aggregate from one of its enclosing aggregate,
932 -- unless one of these already causes an error to be issued.
939 -- Check for aggregates not allowed in configurable run-time mode.
940 -- We allow all cases of aggregates that do not come from source, since
941 -- these are all assumed to be small (e.g. bounds of a string literal).
942 -- We also allow aggregates of types we know to be small.
944 if not Support_Aggregates_On_Target
945 and then Comes_From_Source (N)
946 and then (not Known_Static_Esize (Typ) or else Esize (Typ) > 64)
948 Error_Msg_CRT ("aggregate", N);
951 -- Ada 2005 (AI-287): Limited aggregates allowed
953 -- In an instance, ignore aggregate subcomponents tnat may be limited,
954 -- because they originate in view conflicts. If the original aggregate
955 -- is legal and the actuals are legal, the aggregate itself is legal.
957 if Is_Limited_Type (Typ)
958 and then Ada_Version < Ada_2005
959 and then not In_Instance
961 Error_Msg_N ("aggregate type cannot be limited", N);
962 Explain_Limited_Type (Typ, N);
964 elsif Is_Class_Wide_Type (Typ) then
965 Error_Msg_N ("type of aggregate cannot be class-wide", N);
967 elsif Typ = Any_String
968 or else Typ = Any_Composite
970 Error_Msg_N ("no unique type for aggregate", N);
971 Set_Etype (N, Any_Composite);
973 elsif Is_Array_Type (Typ) and then Null_Record_Present (N) then
974 Error_Msg_N ("null record forbidden in array aggregate", N);
976 elsif Is_Record_Type (Typ) then
977 Resolve_Record_Aggregate (N, Typ);
979 elsif Is_Array_Type (Typ) then
981 -- First a special test, for the case of a positional aggregate
982 -- of characters which can be replaced by a string literal.
984 -- Do not perform this transformation if this was a string literal to
985 -- start with, whose components needed constraint checks, or if the
986 -- component type is non-static, because it will require those checks
987 -- and be transformed back into an aggregate.
989 if Number_Dimensions (Typ) = 1
990 and then Is_Standard_Character_Type (Component_Type (Typ))
991 and then No (Component_Associations (N))
992 and then not Is_Limited_Composite (Typ)
993 and then not Is_Private_Composite (Typ)
994 and then not Is_Bit_Packed_Array (Typ)
995 and then Nkind (Original_Node (Parent (N))) /= N_String_Literal
996 and then Is_Static_Subtype (Component_Type (Typ))
1002 Expr := First (Expressions (N));
1003 while Present (Expr) loop
1004 exit when Nkind (Expr) /= N_Character_Literal;
1011 Expr := First (Expressions (N));
1012 while Present (Expr) loop
1013 Store_String_Char (UI_To_CC (Char_Literal_Value (Expr)));
1017 Rewrite (N, Make_String_Literal (Loc, End_String));
1019 Analyze_And_Resolve (N, Typ);
1025 -- Here if we have a real aggregate to deal with
1027 Array_Aggregate : declare
1028 Aggr_Resolved : Boolean;
1030 Aggr_Typ : constant Entity_Id := Etype (Typ);
1031 -- This is the unconstrained array type, which is the type against
1032 -- which the aggregate is to be resolved. Typ itself is the array
1033 -- type of the context which may not be the same subtype as the
1034 -- subtype for the final aggregate.
1037 -- In the following we determine whether an OTHERS choice is
1038 -- allowed inside the array aggregate. The test checks the context
1039 -- in which the array aggregate occurs. If the context does not
1040 -- permit it, or the aggregate type is unconstrained, an OTHERS
1041 -- choice is not allowed (except that it is always allowed on the
1042 -- right-hand side of an assignment statement; in this case the
1043 -- constrainedness of the type doesn't matter).
1045 -- If expansion is disabled (generic context, or semantics-only
1046 -- mode) actual subtypes cannot be constructed, and the type of an
1047 -- object may be its unconstrained nominal type. However, if the
1048 -- context is an assignment, we assume that OTHERS is allowed,
1049 -- because the target of the assignment will have a constrained
1050 -- subtype when fully compiled.
1052 -- Note that there is no node for Explicit_Actual_Parameter.
1053 -- To test for this context we therefore have to test for node
1054 -- N_Parameter_Association which itself appears only if there is a
1055 -- formal parameter. Consequently we also need to test for
1056 -- N_Procedure_Call_Statement or N_Function_Call.
1058 Set_Etype (N, Aggr_Typ); -- May be overridden later on
1060 if Pkind = N_Assignment_Statement
1061 or else (Is_Constrained (Typ)
1063 (Pkind = N_Parameter_Association or else
1064 Pkind = N_Function_Call or else
1065 Pkind = N_Procedure_Call_Statement or else
1066 Pkind = N_Generic_Association or else
1067 Pkind = N_Formal_Object_Declaration or else
1068 Pkind = N_Simple_Return_Statement or else
1069 Pkind = N_Object_Declaration or else
1070 Pkind = N_Component_Declaration or else
1071 Pkind = N_Parameter_Specification or else
1072 Pkind = N_Qualified_Expression or else
1073 Pkind = N_Aggregate or else
1074 Pkind = N_Extension_Aggregate or else
1075 Pkind = N_Component_Association))
1078 Resolve_Array_Aggregate
1080 Index => First_Index (Aggr_Typ),
1081 Index_Constr => First_Index (Typ),
1082 Component_Typ => Component_Type (Typ),
1083 Others_Allowed => True);
1085 elsif not Expander_Active
1086 and then Pkind = N_Assignment_Statement
1089 Resolve_Array_Aggregate
1091 Index => First_Index (Aggr_Typ),
1092 Index_Constr => First_Index (Typ),
1093 Component_Typ => Component_Type (Typ),
1094 Others_Allowed => True);
1098 Resolve_Array_Aggregate
1100 Index => First_Index (Aggr_Typ),
1101 Index_Constr => First_Index (Aggr_Typ),
1102 Component_Typ => Component_Type (Typ),
1103 Others_Allowed => False);
1106 if not Aggr_Resolved then
1108 -- A parenthesized expression may have been intended as an
1109 -- aggregate, leading to a type error when analyzing the
1110 -- component. This can also happen for a nested component
1111 -- (see Analyze_Aggr_Expr).
1113 if Paren_Count (N) > 0 then
1115 ("positional aggregate cannot have one component", N);
1118 Aggr_Subtyp := Any_Composite;
1121 Aggr_Subtyp := Array_Aggr_Subtype (N, Typ);
1124 Set_Etype (N, Aggr_Subtyp);
1125 end Array_Aggregate;
1127 elsif Is_Private_Type (Typ)
1128 and then Present (Full_View (Typ))
1129 and then (In_Inlined_Body or In_Instance_Body)
1130 and then Is_Composite_Type (Full_View (Typ))
1132 Resolve (N, Full_View (Typ));
1135 Error_Msg_N ("illegal context for aggregate", N);
1138 -- If we can determine statically that the evaluation of the aggregate
1139 -- raises Constraint_Error, then replace the aggregate with an
1140 -- N_Raise_Constraint_Error node, but set the Etype to the right
1141 -- aggregate subtype. Gigi needs this.
1143 if Raises_Constraint_Error (N) then
1144 Aggr_Subtyp := Etype (N);
1146 Make_Raise_Constraint_Error (Loc, Reason => CE_Range_Check_Failed));
1147 Set_Raises_Constraint_Error (N);
1148 Set_Etype (N, Aggr_Subtyp);
1152 Check_Function_Writable_Actuals (N);
1153 end Resolve_Aggregate;
1155 -----------------------------
1156 -- Resolve_Array_Aggregate --
1157 -----------------------------
1159 function Resolve_Array_Aggregate
1162 Index_Constr : Node_Id;
1163 Component_Typ : Entity_Id;
1164 Others_Allowed : Boolean) return Boolean
1166 Loc : constant Source_Ptr := Sloc (N);
1168 Failure : constant Boolean := False;
1169 Success : constant Boolean := True;
1171 Index_Typ : constant Entity_Id := Etype (Index);
1172 Index_Typ_Low : constant Node_Id := Type_Low_Bound (Index_Typ);
1173 Index_Typ_High : constant Node_Id := Type_High_Bound (Index_Typ);
1174 -- The type of the index corresponding to the array sub-aggregate along
1175 -- with its low and upper bounds.
1177 Index_Base : constant Entity_Id := Base_Type (Index_Typ);
1178 Index_Base_Low : constant Node_Id := Type_Low_Bound (Index_Base);
1179 Index_Base_High : constant Node_Id := Type_High_Bound (Index_Base);
1180 -- Ditto for the base type
1182 function Add (Val : Uint; To : Node_Id) return Node_Id;
1183 -- Creates a new expression node where Val is added to expression To.
1184 -- Tries to constant fold whenever possible. To must be an already
1185 -- analyzed expression.
1187 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id);
1188 -- Checks that AH (the upper bound of an array aggregate) is less than
1189 -- or equal to BH (the upper bound of the index base type). If the check
1190 -- fails, a warning is emitted, the Raises_Constraint_Error flag of N is
1191 -- set, and AH is replaced with a duplicate of BH.
1193 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id);
1194 -- Checks that range AL .. AH is compatible with range L .. H. Emits a
1195 -- warning if not and sets the Raises_Constraint_Error flag in N.
1197 procedure Check_Length (L, H : Node_Id; Len : Uint);
1198 -- Checks that range L .. H contains at least Len elements. Emits a
1199 -- warning if not and sets the Raises_Constraint_Error flag in N.
1201 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean;
1202 -- Returns True if range L .. H is dynamic or null
1204 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean);
1205 -- Given expression node From, this routine sets OK to False if it
1206 -- cannot statically evaluate From. Otherwise it stores this static
1207 -- value into Value.
1209 function Resolve_Aggr_Expr
1211 Single_Elmt : Boolean) return Boolean;
1212 -- Resolves aggregate expression Expr. Returns False if resolution
1213 -- fails. If Single_Elmt is set to False, the expression Expr may be
1214 -- used to initialize several array aggregate elements (this can happen
1215 -- for discrete choices such as "L .. H => Expr" or the OTHERS choice).
1216 -- In this event we do not resolve Expr unless expansion is disabled.
1217 -- To know why, see the DELAYED COMPONENT RESOLUTION note above.
1219 -- NOTE: In the case of "... => <>", we pass the in the
1220 -- N_Component_Association node as Expr, since there is no Expression in
1221 -- that case, and we need a Sloc for the error message.
1227 function Add (Val : Uint; To : Node_Id) return Node_Id is
1233 if Raises_Constraint_Error (To) then
1237 -- First test if we can do constant folding
1239 if Compile_Time_Known_Value (To)
1240 or else Nkind (To) = N_Integer_Literal
1242 Expr_Pos := Make_Integer_Literal (Loc, Expr_Value (To) + Val);
1243 Set_Is_Static_Expression (Expr_Pos);
1244 Set_Etype (Expr_Pos, Etype (To));
1245 Set_Analyzed (Expr_Pos, Analyzed (To));
1247 if not Is_Enumeration_Type (Index_Typ) then
1250 -- If we are dealing with enumeration return
1251 -- Index_Typ'Val (Expr_Pos)
1255 Make_Attribute_Reference
1257 Prefix => New_Occurrence_Of (Index_Typ, Loc),
1258 Attribute_Name => Name_Val,
1259 Expressions => New_List (Expr_Pos));
1265 -- If we are here no constant folding possible
1267 if not Is_Enumeration_Type (Index_Base) then
1270 Left_Opnd => Duplicate_Subexpr (To),
1271 Right_Opnd => Make_Integer_Literal (Loc, Val));
1273 -- If we are dealing with enumeration return
1274 -- Index_Typ'Val (Index_Typ'Pos (To) + Val)
1278 Make_Attribute_Reference
1280 Prefix => New_Occurrence_Of (Index_Typ, Loc),
1281 Attribute_Name => Name_Pos,
1282 Expressions => New_List (Duplicate_Subexpr (To)));
1286 Left_Opnd => To_Pos,
1287 Right_Opnd => Make_Integer_Literal (Loc, Val));
1290 Make_Attribute_Reference
1292 Prefix => New_Occurrence_Of (Index_Typ, Loc),
1293 Attribute_Name => Name_Val,
1294 Expressions => New_List (Expr_Pos));
1296 -- If the index type has a non standard representation, the
1297 -- attributes 'Val and 'Pos expand into function calls and the
1298 -- resulting expression is considered non-safe for reevaluation
1299 -- by the backend. Relocate it into a constant temporary in order
1300 -- to make it safe for reevaluation.
1302 if Has_Non_Standard_Rep (Etype (N)) then
1307 Def_Id := Make_Temporary (Loc, 'R', Expr);
1308 Set_Etype (Def_Id, Index_Typ);
1310 Make_Object_Declaration (Loc,
1311 Defining_Identifier => Def_Id,
1312 Object_Definition =>
1313 New_Occurrence_Of (Index_Typ, Loc),
1314 Constant_Present => True,
1315 Expression => Relocate_Node (Expr)));
1317 Expr := New_Occurrence_Of (Def_Id, Loc);
1329 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id) is
1337 Get (Value => Val_BH, From => BH, OK => OK_BH);
1338 Get (Value => Val_AH, From => AH, OK => OK_AH);
1340 if OK_BH and then OK_AH and then Val_BH < Val_AH then
1341 Set_Raises_Constraint_Error (N);
1342 Error_Msg_Warn := SPARK_Mode /= On;
1343 Error_Msg_N ("upper bound out of range<<", AH);
1344 Error_Msg_N ("\Constraint_Error [<<", AH);
1346 -- You need to set AH to BH or else in the case of enumerations
1347 -- indexes we will not be able to resolve the aggregate bounds.
1349 AH := Duplicate_Subexpr (BH);
1357 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id) is
1368 pragma Warnings (Off, OK_AL);
1369 pragma Warnings (Off, OK_AH);
1372 if Raises_Constraint_Error (N)
1373 or else Dynamic_Or_Null_Range (AL, AH)
1378 Get (Value => Val_L, From => L, OK => OK_L);
1379 Get (Value => Val_H, From => H, OK => OK_H);
1381 Get (Value => Val_AL, From => AL, OK => OK_AL);
1382 Get (Value => Val_AH, From => AH, OK => OK_AH);
1384 if OK_L and then Val_L > Val_AL then
1385 Set_Raises_Constraint_Error (N);
1386 Error_Msg_Warn := SPARK_Mode /= On;
1387 Error_Msg_N ("lower bound of aggregate out of range<<", N);
1388 Error_Msg_N ("\Constraint_Error [<<", N);
1391 if OK_H and then Val_H < Val_AH then
1392 Set_Raises_Constraint_Error (N);
1393 Error_Msg_Warn := SPARK_Mode /= On;
1394 Error_Msg_N ("upper bound of aggregate out of range<<", N);
1395 Error_Msg_N ("\Constraint_Error [<<", N);
1403 procedure Check_Length (L, H : Node_Id; Len : Uint) is
1413 if Raises_Constraint_Error (N) then
1417 Get (Value => Val_L, From => L, OK => OK_L);
1418 Get (Value => Val_H, From => H, OK => OK_H);
1420 if not OK_L or else not OK_H then
1424 -- If null range length is zero
1426 if Val_L > Val_H then
1427 Range_Len := Uint_0;
1429 Range_Len := Val_H - Val_L + 1;
1432 if Range_Len < Len then
1433 Set_Raises_Constraint_Error (N);
1434 Error_Msg_Warn := SPARK_Mode /= On;
1435 Error_Msg_N ("too many elements<<", N);
1436 Error_Msg_N ("\Constraint_Error [<<", N);
1440 ---------------------------
1441 -- Dynamic_Or_Null_Range --
1442 ---------------------------
1444 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean is
1452 Get (Value => Val_L, From => L, OK => OK_L);
1453 Get (Value => Val_H, From => H, OK => OK_H);
1455 return not OK_L or else not OK_H
1456 or else not Is_OK_Static_Expression (L)
1457 or else not Is_OK_Static_Expression (H)
1458 or else Val_L > Val_H;
1459 end Dynamic_Or_Null_Range;
1465 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean) is
1469 if Compile_Time_Known_Value (From) then
1470 Value := Expr_Value (From);
1472 -- If expression From is something like Some_Type'Val (10) then
1475 elsif Nkind (From) = N_Attribute_Reference
1476 and then Attribute_Name (From) = Name_Val
1477 and then Compile_Time_Known_Value (First (Expressions (From)))
1479 Value := Expr_Value (First (Expressions (From)));
1487 -----------------------
1488 -- Resolve_Aggr_Expr --
1489 -----------------------
1491 function Resolve_Aggr_Expr
1493 Single_Elmt : Boolean) return Boolean
1495 Nxt_Ind : constant Node_Id := Next_Index (Index);
1496 Nxt_Ind_Constr : constant Node_Id := Next_Index (Index_Constr);
1497 -- Index is the current index corresponding to the expression
1499 Resolution_OK : Boolean := True;
1500 -- Set to False if resolution of the expression failed
1503 -- Defend against previous errors
1505 if Nkind (Expr) = N_Error
1506 or else Error_Posted (Expr)
1511 -- If the array type against which we are resolving the aggregate
1512 -- has several dimensions, the expressions nested inside the
1513 -- aggregate must be further aggregates (or strings).
1515 if Present (Nxt_Ind) then
1516 if Nkind (Expr) /= N_Aggregate then
1518 -- A string literal can appear where a one-dimensional array
1519 -- of characters is expected. If the literal looks like an
1520 -- operator, it is still an operator symbol, which will be
1521 -- transformed into a string when analyzed.
1523 if Is_Character_Type (Component_Typ)
1524 and then No (Next_Index (Nxt_Ind))
1525 and then Nkind_In (Expr, N_String_Literal, N_Operator_Symbol)
1527 -- A string literal used in a multidimensional array
1528 -- aggregate in place of the final one-dimensional
1529 -- aggregate must not be enclosed in parentheses.
1531 if Paren_Count (Expr) /= 0 then
1532 Error_Msg_N ("no parenthesis allowed here", Expr);
1535 Make_String_Into_Aggregate (Expr);
1538 Error_Msg_N ("nested array aggregate expected", Expr);
1540 -- If the expression is parenthesized, this may be
1541 -- a missing component association for a 1-aggregate.
1543 if Paren_Count (Expr) > 0 then
1545 ("\if single-component aggregate is intended,"
1546 & " write e.g. (1 ='> ...)", Expr);
1553 -- If it's "... => <>", nothing to resolve
1555 if Nkind (Expr) = N_Component_Association then
1556 pragma Assert (Box_Present (Expr));
1560 -- Ada 2005 (AI-231): Propagate the type to the nested aggregate.
1561 -- Required to check the null-exclusion attribute (if present).
1562 -- This value may be overridden later on.
1564 Set_Etype (Expr, Etype (N));
1566 Resolution_OK := Resolve_Array_Aggregate
1567 (Expr, Nxt_Ind, Nxt_Ind_Constr, Component_Typ, Others_Allowed);
1570 -- If it's "... => <>", nothing to resolve
1572 if Nkind (Expr) = N_Component_Association then
1573 pragma Assert (Box_Present (Expr));
1577 -- Do not resolve the expressions of discrete or others choices
1578 -- unless the expression covers a single component, or the
1579 -- expander is inactive.
1581 -- In SPARK mode, expressions that can perform side-effects will
1582 -- be recognized by the gnat2why back-end, and the whole
1583 -- subprogram will be ignored. So semantic analysis can be
1584 -- performed safely.
1587 or else not Expander_Active
1588 or else In_Spec_Expression
1590 Analyze_And_Resolve (Expr, Component_Typ);
1591 Check_Expr_OK_In_Limited_Aggregate (Expr);
1592 Check_Non_Static_Context (Expr);
1593 Aggregate_Constraint_Checks (Expr, Component_Typ);
1594 Check_Unset_Reference (Expr);
1598 -- If an aggregate component has a type with predicates, an explicit
1599 -- predicate check must be applied, as for an assignment statement,
1600 -- because the aggegate might not be expanded into individual
1601 -- component assignments.
1603 if Present (Predicate_Function (Component_Typ)) then
1604 Apply_Predicate_Check (Expr, Component_Typ);
1607 if Raises_Constraint_Error (Expr)
1608 and then Nkind (Parent (Expr)) /= N_Component_Association
1610 Set_Raises_Constraint_Error (N);
1613 -- If the expression has been marked as requiring a range check,
1614 -- then generate it here.
1616 if Do_Range_Check (Expr) then
1617 Set_Do_Range_Check (Expr, False);
1618 Generate_Range_Check (Expr, Component_Typ, CE_Range_Check_Failed);
1621 return Resolution_OK;
1622 end Resolve_Aggr_Expr;
1624 -- Variables local to Resolve_Array_Aggregate
1631 pragma Warnings (Off, Discard);
1633 Delete_Choice : Boolean;
1634 -- Used when replacing a subtype choice with predicate by a list
1636 Aggr_Low : Node_Id := Empty;
1637 Aggr_High : Node_Id := Empty;
1638 -- The actual low and high bounds of this sub-aggregate
1640 Choices_Low : Node_Id := Empty;
1641 Choices_High : Node_Id := Empty;
1642 -- The lowest and highest discrete choices values for a named aggregate
1644 Nb_Elements : Uint := Uint_0;
1645 -- The number of elements in a positional aggregate
1647 Others_Present : Boolean := False;
1649 Nb_Choices : Nat := 0;
1650 -- Contains the overall number of named choices in this sub-aggregate
1652 Nb_Discrete_Choices : Nat := 0;
1653 -- The overall number of discrete choices (not counting others choice)
1655 Case_Table_Size : Nat;
1656 -- Contains the size of the case table needed to sort aggregate choices
1658 -- Start of processing for Resolve_Array_Aggregate
1661 -- Ignore junk empty aggregate resulting from parser error
1663 if No (Expressions (N))
1664 and then No (Component_Associations (N))
1665 and then not Null_Record_Present (N)
1670 -- STEP 1: make sure the aggregate is correctly formatted
1672 if Present (Component_Associations (N)) then
1673 Assoc := First (Component_Associations (N));
1674 while Present (Assoc) loop
1675 Choice := First (Choices (Assoc));
1676 Delete_Choice := False;
1678 while Present (Choice) loop
1679 if Nkind (Choice) = N_Others_Choice then
1680 Others_Present := True;
1682 if Choice /= First (Choices (Assoc))
1683 or else Present (Next (Choice))
1686 ("OTHERS must appear alone in a choice list", Choice);
1690 if Present (Next (Assoc)) then
1692 ("OTHERS must appear last in an aggregate", Choice);
1696 if Ada_Version = Ada_83
1697 and then Assoc /= First (Component_Associations (N))
1698 and then Nkind_In (Parent (N), N_Assignment_Statement,
1699 N_Object_Declaration)
1702 ("(Ada 83) illegal context for OTHERS choice", N);
1705 elsif Is_Entity_Name (Choice) then
1709 E : constant Entity_Id := Entity (Choice);
1715 if Is_Type (E) and then Has_Predicates (E) then
1716 Freeze_Before (N, E);
1718 -- If the subtype has a static predicate, replace the
1719 -- original choice with the list of individual values
1720 -- covered by the predicate.
1722 if Present (Static_Predicate (E)) then
1723 Delete_Choice := True;
1726 P := First (Static_Predicate (E));
1727 while Present (P) loop
1729 Set_Sloc (C, Sloc (Choice));
1730 Append_To (New_Cs, C);
1734 Insert_List_After (Choice, New_Cs);
1740 Nb_Choices := Nb_Choices + 1;
1743 C : constant Node_Id := Choice;
1748 if Delete_Choice then
1750 Nb_Choices := Nb_Choices - 1;
1751 Delete_Choice := False;
1760 -- At this point we know that the others choice, if present, is by
1761 -- itself and appears last in the aggregate. Check if we have mixed
1762 -- positional and discrete associations (other than the others choice).
1764 if Present (Expressions (N))
1765 and then (Nb_Choices > 1
1766 or else (Nb_Choices = 1 and then not Others_Present))
1769 ("named association cannot follow positional association",
1770 First (Choices (First (Component_Associations (N)))));
1774 -- Test for the validity of an others choice if present
1776 if Others_Present and then not Others_Allowed then
1778 ("OTHERS choice not allowed here",
1779 First (Choices (First (Component_Associations (N)))));
1783 -- Protect against cascaded errors
1785 if Etype (Index_Typ) = Any_Type then
1789 -- STEP 2: Process named components
1791 if No (Expressions (N)) then
1792 if Others_Present then
1793 Case_Table_Size := Nb_Choices - 1;
1795 Case_Table_Size := Nb_Choices;
1801 -- Denote the lowest and highest values in an aggregate choice
1803 S_Low : Node_Id := Empty;
1804 S_High : Node_Id := Empty;
1805 -- if a choice in an aggregate is a subtype indication these
1806 -- denote the lowest and highest values of the subtype
1808 Table : Case_Table_Type (0 .. Case_Table_Size);
1809 -- Used to sort all the different choice values. Entry zero is
1810 -- reserved for sorting purposes.
1812 Single_Choice : Boolean;
1813 -- Set to true every time there is a single discrete choice in a
1814 -- discrete association
1816 Prev_Nb_Discrete_Choices : Nat;
1817 -- Used to keep track of the number of discrete choices in the
1818 -- current association.
1820 Errors_Posted_On_Choices : Boolean := False;
1821 -- Keeps track of whether any choices have semantic errors
1823 function Empty_Range (A : Node_Id) return Boolean;
1824 -- If an association covers an empty range, some warnings on the
1825 -- expression of the association can be disabled.
1831 function Empty_Range (A : Node_Id) return Boolean is
1832 R : constant Node_Id := First (Choices (A));
1834 return No (Next (R))
1835 and then Nkind (R) = N_Range
1836 and then Compile_Time_Compare
1837 (Low_Bound (R), High_Bound (R), False) = GT;
1840 -- Start of processing for Step_2
1843 -- STEP 2 (A): Check discrete choices validity
1845 Assoc := First (Component_Associations (N));
1846 while Present (Assoc) loop
1847 Prev_Nb_Discrete_Choices := Nb_Discrete_Choices;
1848 Choice := First (Choices (Assoc));
1852 if Nkind (Choice) = N_Others_Choice then
1853 Single_Choice := False;
1856 -- Test for subtype mark without constraint
1858 elsif Is_Entity_Name (Choice) and then
1859 Is_Type (Entity (Choice))
1861 if Base_Type (Entity (Choice)) /= Index_Base then
1863 ("invalid subtype mark in aggregate choice",
1868 -- Case of subtype indication
1870 elsif Nkind (Choice) = N_Subtype_Indication then
1871 Resolve_Discrete_Subtype_Indication (Choice, Index_Base);
1873 -- Does the subtype indication evaluation raise CE?
1875 Get_Index_Bounds (Subtype_Mark (Choice), S_Low, S_High);
1876 Get_Index_Bounds (Choice, Low, High);
1877 Check_Bounds (S_Low, S_High, Low, High);
1879 -- Case of range or expression
1882 Resolve (Choice, Index_Base);
1883 Check_Unset_Reference (Choice);
1884 Check_Non_Static_Context (Choice);
1886 -- If semantic errors were posted on the choice, then
1887 -- record that for possible early return from later
1888 -- processing (see handling of enumeration choices).
1890 if Error_Posted (Choice) then
1891 Errors_Posted_On_Choices := True;
1894 -- Do not range check a choice. This check is redundant
1895 -- since this test is already done when we check that the
1896 -- bounds of the array aggregate are within range.
1898 Set_Do_Range_Check (Choice, False);
1900 -- In SPARK, the choice must be static
1902 if not (Is_Static_Expression (Choice)
1903 or else (Nkind (Choice) = N_Range
1904 and then Is_Static_Range (Choice)))
1906 Check_SPARK_Restriction
1907 ("choice should be static", Choice);
1911 -- If we could not resolve the discrete choice stop here
1913 if Etype (Choice) = Any_Type then
1916 -- If the discrete choice raises CE get its original bounds
1918 elsif Nkind (Choice) = N_Raise_Constraint_Error then
1919 Set_Raises_Constraint_Error (N);
1920 Get_Index_Bounds (Original_Node (Choice), Low, High);
1922 -- Otherwise get its bounds as usual
1925 Get_Index_Bounds (Choice, Low, High);
1928 if (Dynamic_Or_Null_Range (Low, High)
1929 or else (Nkind (Choice) = N_Subtype_Indication
1931 Dynamic_Or_Null_Range (S_Low, S_High)))
1932 and then Nb_Choices /= 1
1935 ("dynamic or empty choice in aggregate " &
1936 "must be the only choice", Choice);
1940 Nb_Discrete_Choices := Nb_Discrete_Choices + 1;
1941 Table (Nb_Discrete_Choices).Lo := Low;
1942 Table (Nb_Discrete_Choices).Hi := High;
1943 Table (Nb_Discrete_Choices).Choice := Choice;
1949 -- Check if we have a single discrete choice and whether
1950 -- this discrete choice specifies a single value.
1953 (Nb_Discrete_Choices = Prev_Nb_Discrete_Choices + 1)
1954 and then (Low = High);
1960 -- Ada 2005 (AI-231)
1962 if Ada_Version >= Ada_2005
1963 and then Known_Null (Expression (Assoc))
1964 and then not Empty_Range (Assoc)
1966 Check_Can_Never_Be_Null (Etype (N), Expression (Assoc));
1969 -- Ada 2005 (AI-287): In case of default initialized component
1970 -- we delay the resolution to the expansion phase.
1972 if Box_Present (Assoc) then
1974 -- Ada 2005 (AI-287): In case of default initialization of a
1975 -- component the expander will generate calls to the
1976 -- corresponding initialization subprogram. We need to call
1977 -- Resolve_Aggr_Expr to check the rules about
1980 if not Resolve_Aggr_Expr
1981 (Assoc, Single_Elmt => Single_Choice)
1986 elsif not Resolve_Aggr_Expr
1987 (Expression (Assoc), Single_Elmt => Single_Choice)
1991 -- Check incorrect use of dynamically tagged expression
1993 -- We differentiate here two cases because the expression may
1994 -- not be decorated. For example, the analysis and resolution
1995 -- of the expression associated with the others choice will be
1996 -- done later with the full aggregate. In such case we
1997 -- duplicate the expression tree to analyze the copy and
1998 -- perform the required check.
2000 elsif not Present (Etype (Expression (Assoc))) then
2002 Save_Analysis : constant Boolean := Full_Analysis;
2003 Expr : constant Node_Id :=
2004 New_Copy_Tree (Expression (Assoc));
2007 Expander_Mode_Save_And_Set (False);
2008 Full_Analysis := False;
2010 -- Analyze the expression, making sure it is properly
2011 -- attached to the tree before we do the analysis.
2013 Set_Parent (Expr, Parent (Expression (Assoc)));
2016 -- If the expression is a literal, propagate this info
2017 -- to the expression in the association, to enable some
2018 -- optimizations downstream.
2020 if Is_Entity_Name (Expr)
2021 and then Present (Entity (Expr))
2022 and then Ekind (Entity (Expr)) = E_Enumeration_Literal
2025 (Expression (Assoc), Component_Typ);
2028 Full_Analysis := Save_Analysis;
2029 Expander_Mode_Restore;
2031 if Is_Tagged_Type (Etype (Expr)) then
2032 Check_Dynamically_Tagged_Expression
2034 Typ => Component_Type (Etype (N)),
2039 elsif Is_Tagged_Type (Etype (Expression (Assoc))) then
2040 Check_Dynamically_Tagged_Expression
2041 (Expr => Expression (Assoc),
2042 Typ => Component_Type (Etype (N)),
2049 -- If aggregate contains more than one choice then these must be
2050 -- static. Check for duplicate and missing values.
2052 -- Note: there is duplicated code here wrt Check_Choice_Set in
2053 -- the body of Sem_Case, and it is possible we could just reuse
2054 -- that procedure. To be checked ???
2056 if Nb_Discrete_Choices > 1 then
2057 Check_Choices : declare
2059 -- Location of choice for messages
2063 -- High end of one range and Low end of the next. Should be
2064 -- contiguous if there is no hole in the list of values.
2068 -- End points of duplicated range
2070 Missing_Or_Duplicates : Boolean := False;
2071 -- Set True if missing or duplicate choices found
2073 procedure Output_Bad_Choices (Lo, Hi : Uint; C : Node_Id);
2074 -- Output continuation message with a representation of the
2075 -- bounds (just Lo if Lo = Hi, else Lo .. Hi). C is the
2076 -- choice node where the message is to be posted.
2078 ------------------------
2079 -- Output_Bad_Choices --
2080 ------------------------
2082 procedure Output_Bad_Choices (Lo, Hi : Uint; C : Node_Id) is
2084 -- Enumeration type case
2086 if Is_Enumeration_Type (Index_Typ) then
2088 Chars (Get_Enum_Lit_From_Pos (Index_Typ, Lo, Loc));
2090 Chars (Get_Enum_Lit_From_Pos (Index_Typ, Hi, Loc));
2093 Error_Msg_N ("\\ %!", C);
2095 Error_Msg_N ("\\ % .. %!", C);
2098 -- Integer types case
2101 Error_Msg_Uint_1 := Lo;
2102 Error_Msg_Uint_2 := Hi;
2105 Error_Msg_N ("\\ ^!", C);
2107 Error_Msg_N ("\\ ^ .. ^!", C);
2110 end Output_Bad_Choices;
2112 -- Start of processing for Check_Choices
2115 Sort_Case_Table (Table);
2117 -- First we do a quick linear loop to find out if we have
2118 -- any duplicates or missing entries (usually we have a
2119 -- legal aggregate, so this will get us out quickly).
2121 for J in 1 .. Nb_Discrete_Choices - 1 loop
2122 Hi_Val := Expr_Value (Table (J).Hi);
2123 Lo_Val := Expr_Value (Table (J + 1).Lo);
2126 or else (Lo_Val > Hi_Val + 1
2127 and then not Others_Present)
2129 Missing_Or_Duplicates := True;
2134 -- If we have missing or duplicate entries, first fill in
2135 -- the Highest entries to make life easier in the following
2136 -- loops to detect bad entries.
2138 if Missing_Or_Duplicates then
2139 Table (1).Highest := Expr_Value (Table (1).Hi);
2141 for J in 2 .. Nb_Discrete_Choices loop
2142 Table (J).Highest :=
2144 (Table (J - 1).Highest, Expr_Value (Table (J).Hi));
2147 -- Loop through table entries to find duplicate indexes
2149 for J in 2 .. Nb_Discrete_Choices loop
2150 Lo_Val := Expr_Value (Table (J).Lo);
2151 Hi_Val := Expr_Value (Table (J).Hi);
2153 -- Case where we have duplicates (the lower bound of
2154 -- this choice is less than or equal to the highest
2155 -- high bound found so far).
2157 if Lo_Val <= Table (J - 1).Highest then
2159 -- We move backwards looking for duplicates. We can
2160 -- abandon this loop as soon as we reach a choice
2161 -- highest value that is less than Lo_Val.
2163 for K in reverse 1 .. J - 1 loop
2164 exit when Table (K).Highest < Lo_Val;
2166 -- Here we may have duplicates between entries
2167 -- for K and J. Get range of duplicates.
2170 UI_Max (Lo_Val, Expr_Value (Table (K).Lo));
2172 UI_Min (Hi_Val, Expr_Value (Table (K).Hi));
2174 -- Nothing to do if duplicate range is null
2176 if Lo_Dup > Hi_Dup then
2179 -- Otherwise place proper message
2182 -- We place message on later choice, with a
2183 -- line reference to the earlier choice.
2185 if Sloc (Table (J).Choice) <
2186 Sloc (Table (K).Choice)
2188 Choice := Table (K).Choice;
2189 Error_Msg_Sloc := Sloc (Table (J).Choice);
2191 Choice := Table (J).Choice;
2192 Error_Msg_Sloc := Sloc (Table (K).Choice);
2195 if Lo_Dup = Hi_Dup then
2197 ("index value in array aggregate "
2198 & "duplicates the one given#!", Choice);
2201 ("index values in array aggregate "
2202 & "duplicate those given#!", Choice);
2205 Output_Bad_Choices (Lo_Dup, Hi_Dup, Choice);
2211 -- Loop through entries in table to find missing indexes.
2212 -- Not needed if others, since missing impossible.
2214 if not Others_Present then
2215 for J in 2 .. Nb_Discrete_Choices loop
2216 Lo_Val := Expr_Value (Table (J).Lo);
2217 Hi_Val := Table (J - 1).Highest;
2219 if Lo_Val > Hi_Val + 1 then
2220 Choice := Table (J).Lo;
2222 if Hi_Val + 1 = Lo_Val - 1 then
2224 ("missing index value in array aggregate!",
2228 ("missing index values in array aggregate!",
2233 (Hi_Val + 1, Lo_Val - 1, Choice);
2238 -- If either missing or duplicate values, return failure
2240 Set_Etype (N, Any_Composite);
2246 -- STEP 2 (B): Compute aggregate bounds and min/max choices values
2248 if Nb_Discrete_Choices > 0 then
2249 Choices_Low := Table (1).Lo;
2250 Choices_High := Table (Nb_Discrete_Choices).Hi;
2253 -- If Others is present, then bounds of aggregate come from the
2254 -- index constraint (not the choices in the aggregate itself).
2256 if Others_Present then
2257 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
2259 -- No others clause present
2262 -- Special processing if others allowed and not present. This
2263 -- means that the bounds of the aggregate come from the index
2264 -- constraint (and the length must match).
2266 if Others_Allowed then
2267 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
2269 -- If others allowed, and no others present, then the array
2270 -- should cover all index values. If it does not, we will
2271 -- get a length check warning, but there is two cases where
2272 -- an additional warning is useful:
2274 -- If we have no positional components, and the length is
2275 -- wrong (which we can tell by others being allowed with
2276 -- missing components), and the index type is an enumeration
2277 -- type, then issue appropriate warnings about these missing
2278 -- components. They are only warnings, since the aggregate
2279 -- is fine, it's just the wrong length. We skip this check
2280 -- for standard character types (since there are no literals
2281 -- and it is too much trouble to concoct them), and also if
2282 -- any of the bounds have not-known-at-compile-time values.
2284 -- Another case warranting a warning is when the length is
2285 -- right, but as above we have an index type that is an
2286 -- enumeration, and the bounds do not match. This is a
2287 -- case where dubious sliding is allowed and we generate
2288 -- a warning that the bounds do not match.
2290 if No (Expressions (N))
2291 and then Nkind (Index) = N_Range
2292 and then Is_Enumeration_Type (Etype (Index))
2293 and then not Is_Standard_Character_Type (Etype (Index))
2294 and then Compile_Time_Known_Value (Aggr_Low)
2295 and then Compile_Time_Known_Value (Aggr_High)
2296 and then Compile_Time_Known_Value (Choices_Low)
2297 and then Compile_Time_Known_Value (Choices_High)
2299 -- If any of the expressions or range bounds in choices
2300 -- have semantic errors, then do not attempt further
2301 -- resolution, to prevent cascaded errors.
2303 if Errors_Posted_On_Choices then
2308 ALo : constant Node_Id := Expr_Value_E (Aggr_Low);
2309 AHi : constant Node_Id := Expr_Value_E (Aggr_High);
2310 CLo : constant Node_Id := Expr_Value_E (Choices_Low);
2311 CHi : constant Node_Id := Expr_Value_E (Choices_High);
2316 -- Warning case 1, missing values at start/end. Only
2317 -- do the check if the number of entries is too small.
2319 if (Enumeration_Pos (CHi) - Enumeration_Pos (CLo))
2321 (Enumeration_Pos (AHi) - Enumeration_Pos (ALo))
2324 ("missing index value(s) in array aggregate??",
2327 -- Output missing value(s) at start
2329 if Chars (ALo) /= Chars (CLo) then
2332 if Chars (ALo) = Chars (Ent) then
2333 Error_Msg_Name_1 := Chars (ALo);
2334 Error_Msg_N ("\ %??", N);
2336 Error_Msg_Name_1 := Chars (ALo);
2337 Error_Msg_Name_2 := Chars (Ent);
2338 Error_Msg_N ("\ % .. %??", N);
2342 -- Output missing value(s) at end
2344 if Chars (AHi) /= Chars (CHi) then
2347 if Chars (AHi) = Chars (Ent) then
2348 Error_Msg_Name_1 := Chars (Ent);
2349 Error_Msg_N ("\ %??", N);
2351 Error_Msg_Name_1 := Chars (Ent);
2352 Error_Msg_Name_2 := Chars (AHi);
2353 Error_Msg_N ("\ % .. %??", N);
2357 -- Warning case 2, dubious sliding. The First_Subtype
2358 -- test distinguishes between a constrained type where
2359 -- sliding is not allowed (so we will get a warning
2360 -- later that Constraint_Error will be raised), and
2361 -- the unconstrained case where sliding is permitted.
2363 elsif (Enumeration_Pos (CHi) - Enumeration_Pos (CLo))
2365 (Enumeration_Pos (AHi) - Enumeration_Pos (ALo))
2366 and then Chars (ALo) /= Chars (CLo)
2368 not Is_Constrained (First_Subtype (Etype (N)))
2371 ("bounds of aggregate do not match target??", N);
2377 -- If no others, aggregate bounds come from aggregate
2379 Aggr_Low := Choices_Low;
2380 Aggr_High := Choices_High;
2384 -- STEP 3: Process positional components
2387 -- STEP 3 (A): Process positional elements
2389 Expr := First (Expressions (N));
2390 Nb_Elements := Uint_0;
2391 while Present (Expr) loop
2392 Nb_Elements := Nb_Elements + 1;
2394 -- Ada 2005 (AI-231)
2396 if Ada_Version >= Ada_2005
2397 and then Known_Null (Expr)
2399 Check_Can_Never_Be_Null (Etype (N), Expr);
2402 if not Resolve_Aggr_Expr (Expr, Single_Elmt => True) then
2406 -- Check incorrect use of dynamically tagged expression
2408 if Is_Tagged_Type (Etype (Expr)) then
2409 Check_Dynamically_Tagged_Expression
2411 Typ => Component_Type (Etype (N)),
2418 if Others_Present then
2419 Assoc := Last (Component_Associations (N));
2421 -- Ada 2005 (AI-231)
2423 if Ada_Version >= Ada_2005
2424 and then Known_Null (Assoc)
2426 Check_Can_Never_Be_Null (Etype (N), Expression (Assoc));
2429 -- Ada 2005 (AI-287): In case of default initialized component,
2430 -- we delay the resolution to the expansion phase.
2432 if Box_Present (Assoc) then
2434 -- Ada 2005 (AI-287): In case of default initialization of a
2435 -- component the expander will generate calls to the
2436 -- corresponding initialization subprogram. We need to call
2437 -- Resolve_Aggr_Expr to check the rules about
2440 if not Resolve_Aggr_Expr (Assoc, Single_Elmt => False) then
2444 elsif not Resolve_Aggr_Expr (Expression (Assoc),
2445 Single_Elmt => False)
2449 -- Check incorrect use of dynamically tagged expression. The
2450 -- expression of the others choice has not been resolved yet.
2451 -- In order to diagnose the semantic error we create a duplicate
2452 -- tree to analyze it and perform the check.
2456 Save_Analysis : constant Boolean := Full_Analysis;
2457 Expr : constant Node_Id :=
2458 New_Copy_Tree (Expression (Assoc));
2461 Expander_Mode_Save_And_Set (False);
2462 Full_Analysis := False;
2464 Full_Analysis := Save_Analysis;
2465 Expander_Mode_Restore;
2467 if Is_Tagged_Type (Etype (Expr)) then
2468 Check_Dynamically_Tagged_Expression
2470 Typ => Component_Type (Etype (N)),
2477 -- STEP 3 (B): Compute the aggregate bounds
2479 if Others_Present then
2480 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
2483 if Others_Allowed then
2484 Get_Index_Bounds (Index_Constr, Aggr_Low, Discard);
2486 Aggr_Low := Index_Typ_Low;
2489 Aggr_High := Add (Nb_Elements - 1, To => Aggr_Low);
2490 Check_Bound (Index_Base_High, Aggr_High);
2494 -- STEP 4: Perform static aggregate checks and save the bounds
2498 Check_Bounds (Index_Typ_Low, Index_Typ_High, Aggr_Low, Aggr_High);
2499 Check_Bounds (Index_Base_Low, Index_Base_High, Aggr_Low, Aggr_High);
2503 if Others_Present and then Nb_Discrete_Choices > 0 then
2504 Check_Bounds (Aggr_Low, Aggr_High, Choices_Low, Choices_High);
2505 Check_Bounds (Index_Typ_Low, Index_Typ_High,
2506 Choices_Low, Choices_High);
2507 Check_Bounds (Index_Base_Low, Index_Base_High,
2508 Choices_Low, Choices_High);
2512 elsif Others_Present and then Nb_Elements > 0 then
2513 Check_Length (Aggr_Low, Aggr_High, Nb_Elements);
2514 Check_Length (Index_Typ_Low, Index_Typ_High, Nb_Elements);
2515 Check_Length (Index_Base_Low, Index_Base_High, Nb_Elements);
2518 if Raises_Constraint_Error (Aggr_Low)
2519 or else Raises_Constraint_Error (Aggr_High)
2521 Set_Raises_Constraint_Error (N);
2524 Aggr_Low := Duplicate_Subexpr (Aggr_Low);
2526 -- Do not duplicate Aggr_High if Aggr_High = Aggr_Low + Nb_Elements
2527 -- since the addition node returned by Add is not yet analyzed. Attach
2528 -- to tree and analyze first. Reset analyzed flag to ensure it will get
2529 -- analyzed when it is a literal bound whose type must be properly set.
2531 if Others_Present or else Nb_Discrete_Choices > 0 then
2532 Aggr_High := Duplicate_Subexpr (Aggr_High);
2534 if Etype (Aggr_High) = Universal_Integer then
2535 Set_Analyzed (Aggr_High, False);
2539 -- If the aggregate already has bounds attached to it, it means this is
2540 -- a positional aggregate created as an optimization by
2541 -- Exp_Aggr.Convert_To_Positional, so we don't want to change those
2544 if Present (Aggregate_Bounds (N)) and then not Others_Allowed then
2545 Aggr_Low := Low_Bound (Aggregate_Bounds (N));
2546 Aggr_High := High_Bound (Aggregate_Bounds (N));
2549 Set_Aggregate_Bounds
2550 (N, Make_Range (Loc, Low_Bound => Aggr_Low, High_Bound => Aggr_High));
2552 -- The bounds may contain expressions that must be inserted upwards.
2553 -- Attach them fully to the tree. After analysis, remove side effects
2554 -- from upper bound, if still needed.
2556 Set_Parent (Aggregate_Bounds (N), N);
2557 Analyze_And_Resolve (Aggregate_Bounds (N), Index_Typ);
2558 Check_Unset_Reference (Aggregate_Bounds (N));
2560 if not Others_Present and then Nb_Discrete_Choices = 0 then
2562 (Aggregate_Bounds (N),
2563 Duplicate_Subexpr (High_Bound (Aggregate_Bounds (N))));
2566 -- Check the dimensions of each component in the array aggregate
2568 Analyze_Dimension_Array_Aggregate (N, Component_Typ);
2571 end Resolve_Array_Aggregate;
2573 ---------------------------------
2574 -- Resolve_Extension_Aggregate --
2575 ---------------------------------
2577 -- There are two cases to consider:
2579 -- a) If the ancestor part is a type mark, the components needed are the
2580 -- difference between the components of the expected type and the
2581 -- components of the given type mark.
2583 -- b) If the ancestor part is an expression, it must be unambiguous, and
2584 -- once we have its type we can also compute the needed components as in
2585 -- the previous case. In both cases, if the ancestor type is not the
2586 -- immediate ancestor, we have to build this ancestor recursively.
2588 -- In both cases, discriminants of the ancestor type do not play a role in
2589 -- the resolution of the needed components, because inherited discriminants
2590 -- cannot be used in a type extension. As a result we can compute
2591 -- independently the list of components of the ancestor type and of the
2594 procedure Resolve_Extension_Aggregate (N : Node_Id; Typ : Entity_Id) is
2595 A : constant Node_Id := Ancestor_Part (N);
2600 function Valid_Limited_Ancestor (Anc : Node_Id) return Boolean;
2601 -- If the type is limited, verify that the ancestor part is a legal
2602 -- expression (aggregate or function call, including 'Input)) that does
2603 -- not require a copy, as specified in 7.5(2).
2605 function Valid_Ancestor_Type return Boolean;
2606 -- Verify that the type of the ancestor part is a non-private ancestor
2607 -- of the expected type, which must be a type extension.
2609 ----------------------------
2610 -- Valid_Limited_Ancestor --
2611 ----------------------------
2613 function Valid_Limited_Ancestor (Anc : Node_Id) return Boolean is
2615 if Is_Entity_Name (Anc)
2616 and then Is_Type (Entity (Anc))
2620 elsif Nkind_In (Anc, N_Aggregate, N_Function_Call) then
2623 elsif Nkind (Anc) = N_Attribute_Reference
2624 and then Attribute_Name (Anc) = Name_Input
2628 elsif Nkind (Anc) = N_Qualified_Expression then
2629 return Valid_Limited_Ancestor (Expression (Anc));
2634 end Valid_Limited_Ancestor;
2636 -------------------------
2637 -- Valid_Ancestor_Type --
2638 -------------------------
2640 function Valid_Ancestor_Type return Boolean is
2641 Imm_Type : Entity_Id;
2644 Imm_Type := Base_Type (Typ);
2645 while Is_Derived_Type (Imm_Type) loop
2646 if Etype (Imm_Type) = Base_Type (A_Type) then
2649 -- The base type of the parent type may appear as a private
2650 -- extension if it is declared as such in a parent unit of the
2651 -- current one. For consistency of the subsequent analysis use
2652 -- the partial view for the ancestor part.
2654 elsif Is_Private_Type (Etype (Imm_Type))
2655 and then Present (Full_View (Etype (Imm_Type)))
2656 and then Base_Type (A_Type) = Full_View (Etype (Imm_Type))
2658 A_Type := Etype (Imm_Type);
2661 -- The parent type may be a private extension. The aggregate is
2662 -- legal if the type of the aggregate is an extension of it that
2663 -- is not a private extension.
2665 elsif Is_Private_Type (A_Type)
2666 and then not Is_Private_Type (Imm_Type)
2667 and then Present (Full_View (A_Type))
2668 and then Base_Type (Full_View (A_Type)) = Etype (Imm_Type)
2673 Imm_Type := Etype (Base_Type (Imm_Type));
2677 -- If previous loop did not find a proper ancestor, report error
2679 Error_Msg_NE ("expect ancestor type of &", A, Typ);
2681 end Valid_Ancestor_Type;
2683 -- Start of processing for Resolve_Extension_Aggregate
2686 -- Analyze the ancestor part and account for the case where it is a
2687 -- parameterless function call.
2690 Check_Parameterless_Call (A);
2692 -- In SPARK, the ancestor part cannot be a type mark
2694 if Is_Entity_Name (A)
2695 and then Is_Type (Entity (A))
2697 Check_SPARK_Restriction ("ancestor part cannot be a type mark", A);
2699 -- AI05-0115: if the ancestor part is a subtype mark, the ancestor
2700 -- must not have unknown discriminants.
2702 if Has_Unknown_Discriminants (Root_Type (Typ)) then
2704 ("aggregate not available for type& whose ancestor "
2705 & "has unknown discriminants", N, Typ);
2709 if not Is_Tagged_Type (Typ) then
2710 Error_Msg_N ("type of extension aggregate must be tagged", N);
2713 elsif Is_Limited_Type (Typ) then
2715 -- Ada 2005 (AI-287): Limited aggregates are allowed
2717 if Ada_Version < Ada_2005 then
2718 Error_Msg_N ("aggregate type cannot be limited", N);
2719 Explain_Limited_Type (Typ, N);
2722 elsif Valid_Limited_Ancestor (A) then
2727 ("limited ancestor part must be aggregate or function call", A);
2730 elsif Is_Class_Wide_Type (Typ) then
2731 Error_Msg_N ("aggregate cannot be of a class-wide type", N);
2735 if Is_Entity_Name (A)
2736 and then Is_Type (Entity (A))
2738 A_Type := Get_Full_View (Entity (A));
2740 if Valid_Ancestor_Type then
2741 Set_Entity (A, A_Type);
2742 Set_Etype (A, A_Type);
2744 Validate_Ancestor_Part (N);
2745 Resolve_Record_Aggregate (N, Typ);
2748 elsif Nkind (A) /= N_Aggregate then
2749 if Is_Overloaded (A) then
2752 Get_First_Interp (A, I, It);
2753 while Present (It.Typ) loop
2754 -- Only consider limited interpretations in the Ada 2005 case
2756 if Is_Tagged_Type (It.Typ)
2757 and then (Ada_Version >= Ada_2005
2758 or else not Is_Limited_Type (It.Typ))
2760 if A_Type /= Any_Type then
2761 Error_Msg_N ("cannot resolve expression", A);
2768 Get_Next_Interp (I, It);
2771 if A_Type = Any_Type then
2772 if Ada_Version >= Ada_2005 then
2773 Error_Msg_N ("ancestor part must be of a tagged type", A);
2776 ("ancestor part must be of a nonlimited tagged type", A);
2783 A_Type := Etype (A);
2786 if Valid_Ancestor_Type then
2787 Resolve (A, A_Type);
2788 Check_Unset_Reference (A);
2789 Check_Non_Static_Context (A);
2791 -- The aggregate is illegal if the ancestor expression is a call
2792 -- to a function with a limited unconstrained result, unless the
2793 -- type of the aggregate is a null extension. This restriction
2794 -- was added in AI05-67 to simplify implementation.
2796 if Nkind (A) = N_Function_Call
2797 and then Is_Limited_Type (A_Type)
2798 and then not Is_Null_Extension (Typ)
2799 and then not Is_Constrained (A_Type)
2802 ("type of limited ancestor part must be constrained", A);
2804 -- Reject the use of CPP constructors that leave objects partially
2805 -- initialized. For example:
2807 -- type CPP_Root is tagged limited record ...
2808 -- pragma Import (CPP, CPP_Root);
2810 -- type CPP_DT is new CPP_Root and Iface ...
2811 -- pragma Import (CPP, CPP_DT);
2813 -- type Ada_DT is new CPP_DT with ...
2815 -- Obj : Ada_DT := Ada_DT'(New_CPP_Root with others => <>);
2817 -- Using the constructor of CPP_Root the slots of the dispatch
2818 -- table of CPP_DT cannot be set, and the secondary tag of
2819 -- CPP_DT is unknown.
2821 elsif Nkind (A) = N_Function_Call
2822 and then Is_CPP_Constructor_Call (A)
2823 and then Enclosing_CPP_Parent (Typ) /= A_Type
2826 ("??must use 'C'P'P constructor for type &", A,
2827 Enclosing_CPP_Parent (Typ));
2829 -- The following call is not needed if the previous warning
2830 -- is promoted to an error.
2832 Resolve_Record_Aggregate (N, Typ);
2834 elsif Is_Class_Wide_Type (Etype (A))
2835 and then Nkind (Original_Node (A)) = N_Function_Call
2837 -- If the ancestor part is a dispatching call, it appears
2838 -- statically to be a legal ancestor, but it yields any member
2839 -- of the class, and it is not possible to determine whether
2840 -- it is an ancestor of the extension aggregate (much less
2841 -- which ancestor). It is not possible to determine the
2842 -- components of the extension part.
2844 -- This check implements AI-306, which in fact was motivated by
2845 -- an AdaCore query to the ARG after this test was added.
2847 Error_Msg_N ("ancestor part must be statically tagged", A);
2849 Resolve_Record_Aggregate (N, Typ);
2854 Error_Msg_N ("no unique type for this aggregate", A);
2857 Check_Function_Writable_Actuals (N);
2858 end Resolve_Extension_Aggregate;
2860 ------------------------------
2861 -- Resolve_Record_Aggregate --
2862 ------------------------------
2864 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id) is
2866 -- N_Component_Association node belonging to the input aggregate N
2869 Positional_Expr : Node_Id;
2870 Component : Entity_Id;
2871 Component_Elmt : Elmt_Id;
2873 Components : constant Elist_Id := New_Elmt_List;
2874 -- Components is the list of the record components whose value must be
2875 -- provided in the aggregate. This list does include discriminants.
2877 New_Assoc_List : constant List_Id := New_List;
2878 New_Assoc : Node_Id;
2879 -- New_Assoc_List is the newly built list of N_Component_Association
2880 -- nodes. New_Assoc is one such N_Component_Association node in it.
2881 -- Note that while Assoc and New_Assoc contain the same kind of nodes,
2882 -- they are used to iterate over two different N_Component_Association
2885 Others_Etype : Entity_Id := Empty;
2886 -- This variable is used to save the Etype of the last record component
2887 -- that takes its value from the others choice. Its purpose is:
2889 -- (a) make sure the others choice is useful
2891 -- (b) make sure the type of all the components whose value is
2892 -- subsumed by the others choice are the same.
2894 -- This variable is updated as a side effect of function Get_Value.
2896 Is_Box_Present : Boolean := False;
2897 Others_Box : Boolean := False;
2898 -- Ada 2005 (AI-287): Variables used in case of default initialization
2899 -- to provide a functionality similar to Others_Etype. Box_Present
2900 -- indicates that the component takes its default initialization;
2901 -- Others_Box indicates that at least one component takes its default
2902 -- initialization. Similar to Others_Etype, they are also updated as a
2903 -- side effect of function Get_Value.
2905 procedure Add_Association
2906 (Component : Entity_Id;
2908 Assoc_List : List_Id;
2909 Is_Box_Present : Boolean := False);
2910 -- Builds a new N_Component_Association node which associates Component
2911 -- to expression Expr and adds it to the association list being built,
2912 -- either New_Assoc_List, or the association being built for an inner
2915 function Discr_Present (Discr : Entity_Id) return Boolean;
2916 -- If aggregate N is a regular aggregate this routine will return True.
2917 -- Otherwise, if N is an extension aggregate, Discr is a discriminant
2918 -- whose value may already have been specified by N's ancestor part.
2919 -- This routine checks whether this is indeed the case and if so returns
2920 -- False, signaling that no value for Discr should appear in N's
2921 -- aggregate part. Also, in this case, the routine appends to
2922 -- New_Assoc_List the discriminant value specified in the ancestor part.
2924 -- If the aggregate is in a context with expansion delayed, it will be
2925 -- reanalyzed. The inherited discriminant values must not be reinserted
2926 -- in the component list to prevent spurious errors, but they must be
2927 -- present on first analysis to build the proper subtype indications.
2928 -- The flag Inherited_Discriminant is used to prevent the re-insertion.
2933 Consider_Others_Choice : Boolean := False)
2935 -- Given a record component stored in parameter Compon, this function
2936 -- returns its value as it appears in the list From, which is a list
2937 -- of N_Component_Association nodes.
2939 -- If no component association has a choice for the searched component,
2940 -- the value provided by the others choice is returned, if there is one,
2941 -- and Consider_Others_Choice is set to true. Otherwise Empty is
2942 -- returned. If there is more than one component association giving a
2943 -- value for the searched record component, an error message is emitted
2944 -- and the first found value is returned.
2946 -- If Consider_Others_Choice is set and the returned expression comes
2947 -- from the others choice, then Others_Etype is set as a side effect.
2948 -- An error message is emitted if the components taking their value from
2949 -- the others choice do not have same type.
2951 function New_Copy_Tree_And_Copy_Dimensions
2953 Map : Elist_Id := No_Elist;
2954 New_Sloc : Source_Ptr := No_Location;
2955 New_Scope : Entity_Id := Empty) return Node_Id;
2956 -- Same as New_Copy_Tree (defined in Sem_Util), except that this routine
2957 -- also copies the dimensions of Source to the returned node.
2959 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id);
2960 -- Analyzes and resolves expression Expr against the Etype of the
2961 -- Component. This routine also applies all appropriate checks to Expr.
2962 -- It finally saves a Expr in the newly created association list that
2963 -- will be attached to the final record aggregate. Note that if the
2964 -- Parent pointer of Expr is not set then Expr was produced with a
2965 -- New_Copy_Tree or some such.
2967 ---------------------
2968 -- Add_Association --
2969 ---------------------
2971 procedure Add_Association
2972 (Component : Entity_Id;
2974 Assoc_List : List_Id;
2975 Is_Box_Present : Boolean := False)
2978 Choice_List : constant List_Id := New_List;
2979 New_Assoc : Node_Id;
2982 -- If this is a box association the expression is missing, so
2983 -- use the Sloc of the aggregate itself for the new association.
2985 if Present (Expr) then
2991 Append (New_Occurrence_Of (Component, Loc), Choice_List);
2993 Make_Component_Association (Loc,
2994 Choices => Choice_List,
2996 Box_Present => Is_Box_Present);
2997 Append (New_Assoc, Assoc_List);
2998 end Add_Association;
3004 function Discr_Present (Discr : Entity_Id) return Boolean is
3005 Regular_Aggr : constant Boolean := Nkind (N) /= N_Extension_Aggregate;
3010 Comp_Assoc : Node_Id;
3011 Discr_Expr : Node_Id;
3013 Ancestor_Typ : Entity_Id;
3014 Orig_Discr : Entity_Id;
3016 D_Val : Elmt_Id := No_Elmt; -- stop junk warning
3018 Ancestor_Is_Subtyp : Boolean;
3021 if Regular_Aggr then
3025 -- Check whether inherited discriminant values have already been
3026 -- inserted in the aggregate. This will be the case if we are
3027 -- re-analyzing an aggregate whose expansion was delayed.
3029 if Present (Component_Associations (N)) then
3030 Comp_Assoc := First (Component_Associations (N));
3031 while Present (Comp_Assoc) loop
3032 if Inherited_Discriminant (Comp_Assoc) then
3040 Ancestor := Ancestor_Part (N);
3041 Ancestor_Typ := Etype (Ancestor);
3042 Loc := Sloc (Ancestor);
3044 -- For a private type with unknown discriminants, use the underlying
3045 -- record view if it is available.
3047 if Has_Unknown_Discriminants (Ancestor_Typ)
3048 and then Present (Full_View (Ancestor_Typ))
3049 and then Present (Underlying_Record_View (Full_View (Ancestor_Typ)))
3051 Ancestor_Typ := Underlying_Record_View (Full_View (Ancestor_Typ));
3054 Ancestor_Is_Subtyp :=
3055 Is_Entity_Name (Ancestor) and then Is_Type (Entity (Ancestor));
3057 -- If the ancestor part has no discriminants clearly N's aggregate
3058 -- part must provide a value for Discr.
3060 if not Has_Discriminants (Ancestor_Typ) then
3063 -- If the ancestor part is an unconstrained subtype mark then the
3064 -- Discr must be present in N's aggregate part.
3066 elsif Ancestor_Is_Subtyp
3067 and then not Is_Constrained (Entity (Ancestor))
3072 -- Now look to see if Discr was specified in the ancestor part
3074 if Ancestor_Is_Subtyp then
3075 D_Val := First_Elmt (Discriminant_Constraint (Entity (Ancestor)));
3078 Orig_Discr := Original_Record_Component (Discr);
3080 D := First_Discriminant (Ancestor_Typ);
3081 while Present (D) loop
3083 -- If Ancestor has already specified Disc value then insert its
3084 -- value in the final aggregate.
3086 if Original_Record_Component (D) = Orig_Discr then
3087 if Ancestor_Is_Subtyp then
3088 Discr_Expr := New_Copy_Tree (Node (D_Val));
3091 Make_Selected_Component (Loc,
3092 Prefix => Duplicate_Subexpr (Ancestor),
3093 Selector_Name => New_Occurrence_Of (Discr, Loc));
3096 Resolve_Aggr_Expr (Discr_Expr, Discr);
3097 Set_Inherited_Discriminant (Last (New_Assoc_List));
3101 Next_Discriminant (D);
3103 if Ancestor_Is_Subtyp then
3118 Consider_Others_Choice : Boolean := False)
3122 Expr : Node_Id := Empty;
3123 Selector_Name : Node_Id;
3126 Is_Box_Present := False;
3128 if Present (From) then
3129 Assoc := First (From);
3134 while Present (Assoc) loop
3135 Selector_Name := First (Choices (Assoc));
3136 while Present (Selector_Name) loop
3137 if Nkind (Selector_Name) = N_Others_Choice then
3138 if Consider_Others_Choice and then No (Expr) then
3140 -- We need to duplicate the expression for each
3141 -- successive component covered by the others choice.
3142 -- This is redundant if the others_choice covers only
3143 -- one component (small optimization possible???), but
3144 -- indispensable otherwise, because each one must be
3145 -- expanded individually to preserve side-effects.
3147 -- Ada 2005 (AI-287): In case of default initialization
3148 -- of components, we duplicate the corresponding default
3149 -- expression (from the record type declaration). The
3150 -- copy must carry the sloc of the association (not the
3151 -- original expression) to prevent spurious elaboration
3152 -- checks when the default includes function calls.
3154 if Box_Present (Assoc) then
3156 Is_Box_Present := True;
3158 if Expander_Active then
3160 New_Copy_Tree_And_Copy_Dimensions
3161 (Expression (Parent (Compon)),
3162 New_Sloc => Sloc (Assoc));
3164 return Expression (Parent (Compon));
3168 if Present (Others_Etype) and then
3169 Base_Type (Others_Etype) /= Base_Type (Etype
3172 Error_Msg_N ("components in OTHERS choice must " &
3173 "have same type", Selector_Name);
3176 Others_Etype := Etype (Compon);
3178 if Expander_Active then
3180 New_Copy_Tree_And_Copy_Dimensions
3181 (Expression (Assoc));
3183 return Expression (Assoc);
3188 elsif Chars (Compon) = Chars (Selector_Name) then
3191 -- Ada 2005 (AI-231)
3193 if Ada_Version >= Ada_2005
3194 and then Known_Null (Expression (Assoc))
3196 Check_Can_Never_Be_Null (Compon, Expression (Assoc));
3199 -- We need to duplicate the expression when several
3200 -- components are grouped together with a "|" choice.
3201 -- For instance "filed1 | filed2 => Expr"
3203 -- Ada 2005 (AI-287)
3205 if Box_Present (Assoc) then
3206 Is_Box_Present := True;
3208 -- Duplicate the default expression of the component
3209 -- from the record type declaration, so a new copy
3210 -- can be attached to the association.
3212 -- Note that we always copy the default expression,
3213 -- even when the association has a single choice, in
3214 -- order to create a proper association for the
3215 -- expanded aggregate.
3217 -- Component may have no default, in which case the
3218 -- expression is empty and the component is default-
3219 -- initialized, but an association for the component
3220 -- exists, and it is not covered by an others clause.
3223 New_Copy_Tree_And_Copy_Dimensions
3224 (Expression (Parent (Compon)));
3227 if Present (Next (Selector_Name)) then
3229 New_Copy_Tree_And_Copy_Dimensions
3230 (Expression (Assoc));
3232 Expr := Expression (Assoc);
3236 Generate_Reference (Compon, Selector_Name, 'm');
3240 ("more than one value supplied for &",
3241 Selector_Name, Compon);
3246 Next (Selector_Name);
3255 ---------------------------------------
3256 -- New_Copy_Tree_And_Copy_Dimensions --
3257 ---------------------------------------
3259 function New_Copy_Tree_And_Copy_Dimensions
3261 Map : Elist_Id := No_Elist;
3262 New_Sloc : Source_Ptr := No_Location;
3263 New_Scope : Entity_Id := Empty) return Node_Id
3265 New_Copy : constant Node_Id :=
3266 New_Copy_Tree (Source, Map, New_Sloc, New_Scope);
3268 -- Move the dimensions of Source to New_Copy
3270 Copy_Dimensions (Source, New_Copy);
3272 end New_Copy_Tree_And_Copy_Dimensions;
3274 -----------------------
3275 -- Resolve_Aggr_Expr --
3276 -----------------------
3278 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id) is
3279 Expr_Type : Entity_Id := Empty;
3280 New_C : Entity_Id := Component;
3283 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean;
3284 -- If the expression is an aggregate (possibly qualified) then its
3285 -- expansion is delayed until the enclosing aggregate is expanded
3286 -- into assignments. In that case, do not generate checks on the
3287 -- expression, because they will be generated later, and will other-
3288 -- wise force a copy (to remove side-effects) that would leave a
3289 -- dynamic-sized aggregate in the code, something that gigi cannot
3293 -- Set to True if the resolved Expr node needs to be relocated when
3294 -- attached to the newly created association list. This node need not
3295 -- be relocated if its parent pointer is not set. In fact in this
3296 -- case Expr is the output of a New_Copy_Tree call. If Relocate is
3297 -- True then we have analyzed the expression node in the original
3298 -- aggregate and hence it needs to be relocated when moved over to
3299 -- the new association list.
3301 ---------------------------
3302 -- Has_Expansion_Delayed --
3303 ---------------------------
3305 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean is
3306 Kind : constant Node_Kind := Nkind (Expr);
3308 return (Nkind_In (Kind, N_Aggregate, N_Extension_Aggregate)
3309 and then Present (Etype (Expr))
3310 and then Is_Record_Type (Etype (Expr))
3311 and then Expansion_Delayed (Expr))
3312 or else (Kind = N_Qualified_Expression
3313 and then Has_Expansion_Delayed (Expression (Expr)));
3314 end Has_Expansion_Delayed;
3316 -- Start of processing for Resolve_Aggr_Expr
3319 -- If the type of the component is elementary or the type of the
3320 -- aggregate does not contain discriminants, use the type of the
3321 -- component to resolve Expr.
3323 if Is_Elementary_Type (Etype (Component))
3324 or else not Has_Discriminants (Etype (N))
3326 Expr_Type := Etype (Component);
3328 -- Otherwise we have to pick up the new type of the component from
3329 -- the new constrained subtype of the aggregate. In fact components
3330 -- which are of a composite type might be constrained by a
3331 -- discriminant, and we want to resolve Expr against the subtype were
3332 -- all discriminant occurrences are replaced with their actual value.
3335 New_C := First_Component (Etype (N));
3336 while Present (New_C) loop
3337 if Chars (New_C) = Chars (Component) then
3338 Expr_Type := Etype (New_C);
3342 Next_Component (New_C);
3345 pragma Assert (Present (Expr_Type));
3347 -- For each range in an array type where a discriminant has been
3348 -- replaced with the constraint, check that this range is within
3349 -- the range of the base type. This checks is done in the init
3350 -- proc for regular objects, but has to be done here for
3351 -- aggregates since no init proc is called for them.
3353 if Is_Array_Type (Expr_Type) then
3356 -- Range of the current constrained index in the array
3358 Orig_Index : Node_Id := First_Index (Etype (Component));
3359 -- Range corresponding to the range Index above in the
3360 -- original unconstrained record type. The bounds of this
3361 -- range may be governed by discriminants.
3363 Unconstr_Index : Node_Id := First_Index (Etype (Expr_Type));
3364 -- Range corresponding to the range Index above for the
3365 -- unconstrained array type. This range is needed to apply
3369 Index := First_Index (Expr_Type);
3370 while Present (Index) loop
3371 if Depends_On_Discriminant (Orig_Index) then
3372 Apply_Range_Check (Index, Etype (Unconstr_Index));
3376 Next_Index (Orig_Index);
3377 Next_Index (Unconstr_Index);
3383 -- If the Parent pointer of Expr is not set, Expr is an expression
3384 -- duplicated by New_Tree_Copy (this happens for record aggregates
3385 -- that look like (Field1 | Filed2 => Expr) or (others => Expr)).
3386 -- Such a duplicated expression must be attached to the tree
3387 -- before analysis and resolution to enforce the rule that a tree
3388 -- fragment should never be analyzed or resolved unless it is
3389 -- attached to the current compilation unit.
3391 if No (Parent (Expr)) then
3392 Set_Parent (Expr, N);
3398 Analyze_And_Resolve (Expr, Expr_Type);
3399 Check_Expr_OK_In_Limited_Aggregate (Expr);
3400 Check_Non_Static_Context (Expr);
3401 Check_Unset_Reference (Expr);
3403 -- Check wrong use of class-wide types
3405 if Is_Class_Wide_Type (Etype (Expr)) then
3406 Error_Msg_N ("dynamically tagged expression not allowed", Expr);
3409 if not Has_Expansion_Delayed (Expr) then
3410 Aggregate_Constraint_Checks (Expr, Expr_Type);
3413 -- If an aggregate component has a type with predicates, an explicit
3414 -- predicate check must be applied, as for an assignment statement,
3415 -- because the aggegate might not be expanded into individual
3416 -- component assignments.
3418 if Present (Predicate_Function (Expr_Type)) then
3419 Apply_Predicate_Check (Expr, Expr_Type);
3422 if Raises_Constraint_Error (Expr) then
3423 Set_Raises_Constraint_Error (N);
3426 -- If the expression has been marked as requiring a range check, then
3427 -- generate it here.
3429 if Do_Range_Check (Expr) then
3430 Set_Do_Range_Check (Expr, False);
3431 Generate_Range_Check (Expr, Expr_Type, CE_Range_Check_Failed);
3435 New_Expr := Relocate_Node (Expr);
3437 -- Since New_Expr is not gonna be analyzed later on, we need to
3438 -- propagate here the dimensions form Expr to New_Expr.
3440 Copy_Dimensions (Expr, New_Expr);
3446 Add_Association (New_C, New_Expr, New_Assoc_List);
3447 end Resolve_Aggr_Expr;
3449 -- Start of processing for Resolve_Record_Aggregate
3452 -- A record aggregate is restricted in SPARK:
3454 -- Each named association can have only a single choice.
3455 -- OTHERS cannot be used.
3456 -- Positional and named associations cannot be mixed.
3458 if Present (Component_Associations (N))
3459 and then Present (First (Component_Associations (N)))
3462 if Present (Expressions (N)) then
3463 Check_SPARK_Restriction
3464 ("named association cannot follow positional one",
3465 First (Choices (First (Component_Associations (N)))));
3472 Assoc := First (Component_Associations (N));
3473 while Present (Assoc) loop
3474 if List_Length (Choices (Assoc)) > 1 then
3475 Check_SPARK_Restriction
3476 ("component association in record aggregate must "
3477 & "contain a single choice", Assoc);
3480 if Nkind (First (Choices (Assoc))) = N_Others_Choice then
3481 Check_SPARK_Restriction
3482 ("record aggregate cannot contain OTHERS", Assoc);
3485 Assoc := Next (Assoc);
3490 -- We may end up calling Duplicate_Subexpr on expressions that are
3491 -- attached to New_Assoc_List. For this reason we need to attach it
3492 -- to the tree by setting its parent pointer to N. This parent point
3493 -- will change in STEP 8 below.
3495 Set_Parent (New_Assoc_List, N);
3497 -- STEP 1: abstract type and null record verification
3499 if Is_Abstract_Type (Typ) then
3500 Error_Msg_N ("type of aggregate cannot be abstract", N);
3503 if No (First_Entity (Typ)) and then Null_Record_Present (N) then
3507 elsif Present (First_Entity (Typ))
3508 and then Null_Record_Present (N)
3509 and then not Is_Tagged_Type (Typ)
3511 Error_Msg_N ("record aggregate cannot be null", N);
3514 -- If the type has no components, then the aggregate should either
3515 -- have "null record", or in Ada 2005 it could instead have a single
3516 -- component association given by "others => <>". For Ada 95 we flag an
3517 -- error at this point, but for Ada 2005 we proceed with checking the
3518 -- associations below, which will catch the case where it's not an
3519 -- aggregate with "others => <>". Note that the legality of a <>
3520 -- aggregate for a null record type was established by AI05-016.
3522 elsif No (First_Entity (Typ))
3523 and then Ada_Version < Ada_2005
3525 Error_Msg_N ("record aggregate must be null", N);
3529 -- STEP 2: Verify aggregate structure
3532 Selector_Name : Node_Id;
3533 Bad_Aggregate : Boolean := False;
3536 if Present (Component_Associations (N)) then
3537 Assoc := First (Component_Associations (N));
3542 while Present (Assoc) loop
3543 Selector_Name := First (Choices (Assoc));
3544 while Present (Selector_Name) loop
3545 if Nkind (Selector_Name) = N_Identifier then
3548 elsif Nkind (Selector_Name) = N_Others_Choice then
3549 if Selector_Name /= First (Choices (Assoc))
3550 or else Present (Next (Selector_Name))
3553 ("OTHERS must appear alone in a choice list",
3557 elsif Present (Next (Assoc)) then
3559 ("OTHERS must appear last in an aggregate",
3563 -- (Ada 2005): If this is an association with a box,
3564 -- indicate that the association need not represent
3567 elsif Box_Present (Assoc) then
3573 ("selector name should be identifier or OTHERS",
3575 Bad_Aggregate := True;
3578 Next (Selector_Name);
3584 if Bad_Aggregate then
3589 -- STEP 3: Find discriminant Values
3592 Discrim : Entity_Id;
3593 Missing_Discriminants : Boolean := False;
3596 if Present (Expressions (N)) then
3597 Positional_Expr := First (Expressions (N));
3599 Positional_Expr := Empty;
3602 -- AI05-0115: if the ancestor part is a subtype mark, the ancestor
3603 -- must not have unknown discriminants.
3605 if Is_Derived_Type (Typ)
3606 and then Has_Unknown_Discriminants (Root_Type (Typ))
3607 and then Nkind (N) /= N_Extension_Aggregate
3610 ("aggregate not available for type& whose ancestor "
3611 & "has unknown discriminants ", N, Typ);
3614 if Has_Unknown_Discriminants (Typ)
3615 and then Present (Underlying_Record_View (Typ))
3617 Discrim := First_Discriminant (Underlying_Record_View (Typ));
3618 elsif Has_Discriminants (Typ) then
3619 Discrim := First_Discriminant (Typ);
3624 -- First find the discriminant values in the positional components
3626 while Present (Discrim) and then Present (Positional_Expr) loop
3627 if Discr_Present (Discrim) then
3628 Resolve_Aggr_Expr (Positional_Expr, Discrim);
3630 -- Ada 2005 (AI-231)
3632 if Ada_Version >= Ada_2005
3633 and then Known_Null (Positional_Expr)
3635 Check_Can_Never_Be_Null (Discrim, Positional_Expr);
3638 Next (Positional_Expr);
3641 if Present (Get_Value (Discrim, Component_Associations (N))) then
3643 ("more than one value supplied for discriminant&",
3647 Next_Discriminant (Discrim);
3650 -- Find remaining discriminant values if any among named components
3652 while Present (Discrim) loop
3653 Expr := Get_Value (Discrim, Component_Associations (N), True);
3655 if not Discr_Present (Discrim) then
3656 if Present (Expr) then
3658 ("more than one value supplied for discriminant&",
3662 elsif No (Expr) then
3664 ("no value supplied for discriminant &", N, Discrim);
3665 Missing_Discriminants := True;
3668 Resolve_Aggr_Expr (Expr, Discrim);
3671 Next_Discriminant (Discrim);
3674 if Missing_Discriminants then
3678 -- At this point and until the beginning of STEP 6, New_Assoc_List
3679 -- contains only the discriminants and their values.
3683 -- STEP 4: Set the Etype of the record aggregate
3685 -- ??? This code is pretty much a copy of Sem_Ch3.Build_Subtype. That
3686 -- routine should really be exported in sem_util or some such and used
3687 -- in sem_ch3 and here rather than have a copy of the code which is a
3688 -- maintenance nightmare.
3690 -- ??? Performance WARNING. The current implementation creates a new
3691 -- itype for all aggregates whose base type is discriminated. This means
3692 -- that for record aggregates nested inside an array aggregate we will
3693 -- create a new itype for each record aggregate if the array component
3694 -- type has discriminants. For large aggregates this may be a problem.
3695 -- What should be done in this case is to reuse itypes as much as
3698 if Has_Discriminants (Typ)
3699 or else (Has_Unknown_Discriminants (Typ)
3700 and then Present (Underlying_Record_View (Typ)))
3702 Build_Constrained_Itype : declare
3703 Loc : constant Source_Ptr := Sloc (N);
3705 Subtyp_Decl : Node_Id;
3708 C : constant List_Id := New_List;
3711 New_Assoc := First (New_Assoc_List);
3712 while Present (New_Assoc) loop
3713 Append (Duplicate_Subexpr (Expression (New_Assoc)), To => C);
3717 if Has_Unknown_Discriminants (Typ)
3718 and then Present (Underlying_Record_View (Typ))
3721 Make_Subtype_Indication (Loc,
3723 New_Occurrence_Of (Underlying_Record_View (Typ), Loc),
3725 Make_Index_Or_Discriminant_Constraint (Loc, C));
3728 Make_Subtype_Indication (Loc,
3730 New_Occurrence_Of (Base_Type (Typ), Loc),
3732 Make_Index_Or_Discriminant_Constraint (Loc, C));
3735 Def_Id := Create_Itype (Ekind (Typ), N);
3738 Make_Subtype_Declaration (Loc,
3739 Defining_Identifier => Def_Id,
3740 Subtype_Indication => Indic);
3741 Set_Parent (Subtyp_Decl, Parent (N));
3743 -- Itypes must be analyzed with checks off (see itypes.ads)
3745 Analyze (Subtyp_Decl, Suppress => All_Checks);
3747 Set_Etype (N, Def_Id);
3748 Check_Static_Discriminated_Subtype
3749 (Def_Id, Expression (First (New_Assoc_List)));
3750 end Build_Constrained_Itype;
3756 -- STEP 5: Get remaining components according to discriminant values
3759 Record_Def : Node_Id;
3760 Parent_Typ : Entity_Id;
3761 Root_Typ : Entity_Id;
3762 Parent_Typ_List : Elist_Id;
3763 Parent_Elmt : Elmt_Id;
3764 Errors_Found : Boolean := False;
3767 function Find_Private_Ancestor return Entity_Id;
3768 -- AI05-0115: Find earlier ancestor in the derivation chain that is
3769 -- derived from a private view. Whether the aggregate is legal
3770 -- depends on the current visibility of the type as well as that
3771 -- of the parent of the ancestor.
3773 ---------------------------
3774 -- Find_Private_Ancestor --
3775 ---------------------------
3777 function Find_Private_Ancestor return Entity_Id is
3782 if Has_Private_Ancestor (Par)
3783 and then not Has_Private_Ancestor (Etype (Base_Type (Par)))
3787 elsif not Is_Derived_Type (Par) then
3791 Par := Etype (Base_Type (Par));
3794 end Find_Private_Ancestor;
3796 -- Start of processing for Step_5
3799 if Is_Derived_Type (Typ) and then Is_Tagged_Type (Typ) then
3800 Parent_Typ_List := New_Elmt_List;
3802 -- If this is an extension aggregate, the component list must
3803 -- include all components that are not in the given ancestor type.
3804 -- Otherwise, the component list must include components of all
3805 -- ancestors, starting with the root.
3807 if Nkind (N) = N_Extension_Aggregate then
3808 Root_Typ := Base_Type (Etype (Ancestor_Part (N)));
3811 -- AI05-0115: check legality of aggregate for type with
3812 -- aa private ancestor.
3814 Root_Typ := Root_Type (Typ);
3815 if Has_Private_Ancestor (Typ) then
3817 Ancestor : constant Entity_Id :=
3818 Find_Private_Ancestor;
3819 Ancestor_Unit : constant Entity_Id :=
3820 Cunit_Entity (Get_Source_Unit (Ancestor));
3821 Parent_Unit : constant Entity_Id :=
3823 (Get_Source_Unit (Base_Type (Etype (Ancestor))));
3826 -- check whether we are in a scope that has full view
3827 -- over the private ancestor and its parent. This can
3828 -- only happen if the derivation takes place in a child
3829 -- unit of the unit that declares the parent, and we are
3830 -- in the private part or body of that child unit, else
3831 -- the aggregate is illegal.
3833 if Is_Child_Unit (Ancestor_Unit)
3834 and then Scope (Ancestor_Unit) = Parent_Unit
3835 and then In_Open_Scopes (Scope (Ancestor))
3837 (In_Private_Part (Scope (Ancestor))
3838 or else In_Package_Body (Scope (Ancestor)))
3844 ("type of aggregate has private ancestor&!",
3846 Error_Msg_N ("must use extension aggregate!", N);
3852 Dnode := Declaration_Node (Base_Type (Root_Typ));
3854 -- If we don't get a full declaration, then we have some error
3855 -- which will get signalled later so skip this part. Otherwise
3856 -- gather components of root that apply to the aggregate type.
3857 -- We use the base type in case there is an applicable stored
3858 -- constraint that renames the discriminants of the root.
3860 if Nkind (Dnode) = N_Full_Type_Declaration then
3861 Record_Def := Type_Definition (Dnode);
3864 Component_List (Record_Def),
3865 Governed_By => New_Assoc_List,
3867 Report_Errors => Errors_Found);
3871 Parent_Typ := Base_Type (Typ);
3872 while Parent_Typ /= Root_Typ loop
3873 Prepend_Elmt (Parent_Typ, To => Parent_Typ_List);
3874 Parent_Typ := Etype (Parent_Typ);
3876 if Nkind (Parent (Base_Type (Parent_Typ))) =
3877 N_Private_Type_Declaration
3878 or else Nkind (Parent (Base_Type (Parent_Typ))) =
3879 N_Private_Extension_Declaration
3881 if Nkind (N) /= N_Extension_Aggregate then
3883 ("type of aggregate has private ancestor&!",
3885 Error_Msg_N ("must use extension aggregate!", N);
3888 elsif Parent_Typ /= Root_Typ then
3890 ("ancestor part of aggregate must be private type&",
3891 Ancestor_Part (N), Parent_Typ);
3895 -- The current view of ancestor part may be a private type,
3896 -- while the context type is always non-private.
3898 elsif Is_Private_Type (Root_Typ)
3899 and then Present (Full_View (Root_Typ))
3900 and then Nkind (N) = N_Extension_Aggregate
3902 exit when Base_Type (Full_View (Root_Typ)) = Parent_Typ;
3906 -- Now collect components from all other ancestors, beginning
3907 -- with the current type. If the type has unknown discriminants
3908 -- use the component list of the Underlying_Record_View, which
3909 -- needs to be used for the subsequent expansion of the aggregate
3910 -- into assignments.
3912 Parent_Elmt := First_Elmt (Parent_Typ_List);
3913 while Present (Parent_Elmt) loop
3914 Parent_Typ := Node (Parent_Elmt);
3916 if Has_Unknown_Discriminants (Parent_Typ)
3917 and then Present (Underlying_Record_View (Typ))
3919 Parent_Typ := Underlying_Record_View (Parent_Typ);
3922 Record_Def := Type_Definition (Parent (Base_Type (Parent_Typ)));
3923 Gather_Components (Empty,
3924 Component_List (Record_Extension_Part (Record_Def)),
3925 Governed_By => New_Assoc_List,
3927 Report_Errors => Errors_Found);
3929 Next_Elmt (Parent_Elmt);
3932 -- Typ is not a derived tagged type
3935 -- A type derived from an untagged private type whose full view
3936 -- has discriminants is constructed as a record type but there
3937 -- are no legal aggregates for it.
3939 if Is_Derived_Type (Typ)
3940 and then Has_Private_Ancestor (Typ)
3941 and then Nkind (N) /= N_Extension_Aggregate
3943 Error_Msg_Node_2 := Base_Type (Etype (Typ));
3945 ("no aggregate available for type& derived from "
3946 & "private type&", N, Typ);
3950 Record_Def := Type_Definition (Parent (Base_Type (Typ)));
3952 if Null_Present (Record_Def) then
3955 elsif not Has_Unknown_Discriminants (Typ) then
3958 Component_List (Record_Def),
3959 Governed_By => New_Assoc_List,
3961 Report_Errors => Errors_Found);
3965 (Base_Type (Underlying_Record_View (Typ)),
3966 Component_List (Record_Def),
3967 Governed_By => New_Assoc_List,
3969 Report_Errors => Errors_Found);
3973 if Errors_Found then
3978 -- STEP 6: Find component Values
3981 Component_Elmt := First_Elmt (Components);
3983 -- First scan the remaining positional associations in the aggregate.
3984 -- Remember that at this point Positional_Expr contains the current
3985 -- positional association if any is left after looking for discriminant
3986 -- values in step 3.
3988 while Present (Positional_Expr) and then Present (Component_Elmt) loop
3989 Component := Node (Component_Elmt);
3990 Resolve_Aggr_Expr (Positional_Expr, Component);
3992 -- Ada 2005 (AI-231)
3994 if Ada_Version >= Ada_2005
3995 and then Known_Null (Positional_Expr)
3997 Check_Can_Never_Be_Null (Component, Positional_Expr);
4000 if Present (Get_Value (Component, Component_Associations (N))) then
4002 ("more than one value supplied for Component &", N, Component);
4005 Next (Positional_Expr);
4006 Next_Elmt (Component_Elmt);
4009 if Present (Positional_Expr) then
4011 ("too many components for record aggregate", Positional_Expr);
4014 -- Now scan for the named arguments of the aggregate
4016 while Present (Component_Elmt) loop
4017 Component := Node (Component_Elmt);
4018 Expr := Get_Value (Component, Component_Associations (N), True);
4020 -- Note: The previous call to Get_Value sets the value of the
4021 -- variable Is_Box_Present.
4023 -- Ada 2005 (AI-287): Handle components with default initialization.
4024 -- Note: This feature was originally added to Ada 2005 for limited
4025 -- but it was finally allowed with any type.
4027 if Is_Box_Present then
4028 Check_Box_Component : declare
4029 Ctyp : constant Entity_Id := Etype (Component);
4032 -- If there is a default expression for the aggregate, copy
4033 -- it into a new association. This copy must modify the scopes
4034 -- of internal types that may be attached to the expression
4035 -- (e.g. index subtypes of arrays) because in general the type
4036 -- declaration and the aggregate appear in different scopes,
4037 -- and the backend requires the scope of the type to match the
4038 -- point at which it is elaborated.
4040 -- If the component has an initialization procedure (IP) we
4041 -- pass the component to the expander, which will generate
4042 -- the call to such IP.
4044 -- If the component has discriminants, their values must
4045 -- be taken from their subtype. This is indispensable for
4046 -- constraints that are given by the current instance of an
4047 -- enclosing type, to allow the expansion of the aggregate to
4048 -- replace the reference to the current instance by the target
4049 -- object of the aggregate.
4051 if Present (Parent (Component))
4053 Nkind (Parent (Component)) = N_Component_Declaration
4054 and then Present (Expression (Parent (Component)))
4057 New_Copy_Tree_And_Copy_Dimensions
4058 (Expression (Parent (Component)),
4059 New_Scope => Current_Scope,
4060 New_Sloc => Sloc (N));
4063 (Component => Component,
4065 Assoc_List => New_Assoc_List);
4066 Set_Has_Self_Reference (N);
4068 -- A box-defaulted access component gets the value null. Also
4069 -- included are components of private types whose underlying
4070 -- type is an access type. In either case set the type of the
4071 -- literal, for subsequent use in semantic checks.
4073 elsif Present (Underlying_Type (Ctyp))
4074 and then Is_Access_Type (Underlying_Type (Ctyp))
4076 if not Is_Private_Type (Ctyp) then
4077 Expr := Make_Null (Sloc (N));
4078 Set_Etype (Expr, Ctyp);
4080 (Component => Component,
4082 Assoc_List => New_Assoc_List);
4084 -- If the component's type is private with an access type as
4085 -- its underlying type then we have to create an unchecked
4086 -- conversion to satisfy type checking.
4090 Qual_Null : constant Node_Id :=
4091 Make_Qualified_Expression (Sloc (N),
4094 (Underlying_Type (Ctyp), Sloc (N)),
4095 Expression => Make_Null (Sloc (N)));
4097 Convert_Null : constant Node_Id :=
4098 Unchecked_Convert_To
4102 Analyze_And_Resolve (Convert_Null, Ctyp);
4104 (Component => Component,
4105 Expr => Convert_Null,
4106 Assoc_List => New_Assoc_List);
4110 -- Ada 2012: If component is scalar with default value, use it
4112 elsif Is_Scalar_Type (Ctyp)
4113 and then Has_Default_Aspect (Ctyp)
4116 (Component => Component,
4117 Expr => Default_Aspect_Value
4118 (First_Subtype (Underlying_Type (Ctyp))),
4119 Assoc_List => New_Assoc_List);
4121 elsif Has_Non_Null_Base_Init_Proc (Ctyp)
4122 or else not Expander_Active
4124 if Is_Record_Type (Ctyp)
4125 and then Has_Discriminants (Ctyp)
4126 and then not Is_Private_Type (Ctyp)
4128 -- We build a partially initialized aggregate with the
4129 -- values of the discriminants and box initialization
4130 -- for the rest, if other components are present.
4132 -- The type of the aggregate is the known subtype of
4133 -- the component. The capture of discriminants must
4134 -- be recursive because subcomponents may be constrained
4135 -- (transitively) by discriminants of enclosing types.
4136 -- For a private type with discriminants, a call to the
4137 -- initialization procedure will be generated, and no
4138 -- subaggregate is needed.
4140 Capture_Discriminants : declare
4141 Loc : constant Source_Ptr := Sloc (N);
4144 procedure Add_Discriminant_Values
4145 (New_Aggr : Node_Id;
4146 Assoc_List : List_Id);
4147 -- The constraint to a component may be given by a
4148 -- discriminant of the enclosing type, in which case
4149 -- we have to retrieve its value, which is part of the
4150 -- enclosing aggregate. Assoc_List provides the
4151 -- discriminant associations of the current type or
4152 -- of some enclosing record.
4154 procedure Propagate_Discriminants
4156 Assoc_List : List_Id);
4157 -- Nested components may themselves be discriminated
4158 -- types constrained by outer discriminants, whose
4159 -- values must be captured before the aggregate is
4160 -- expanded into assignments.
4162 -----------------------------
4163 -- Add_Discriminant_Values --
4164 -----------------------------
4166 procedure Add_Discriminant_Values
4167 (New_Aggr : Node_Id;
4168 Assoc_List : List_Id)
4172 Discr_Elmt : Elmt_Id;
4173 Discr_Val : Node_Id;
4177 Discr := First_Discriminant (Etype (New_Aggr));
4180 (Discriminant_Constraint (Etype (New_Aggr)));
4181 while Present (Discr_Elmt) loop
4182 Discr_Val := Node (Discr_Elmt);
4184 -- If the constraint is given by a discriminant
4185 -- it is a discriminant of an enclosing record,
4186 -- and its value has already been placed in the
4187 -- association list.
4189 if Is_Entity_Name (Discr_Val)
4191 Ekind (Entity (Discr_Val)) = E_Discriminant
4193 Val := Entity (Discr_Val);
4195 Assoc := First (Assoc_List);
4196 while Present (Assoc) loop
4198 (Entity (First (Choices (Assoc))))
4200 Entity (First (Choices (Assoc)))
4203 Discr_Val := Expression (Assoc);
4211 (Discr, New_Copy_Tree (Discr_Val),
4212 Component_Associations (New_Aggr));
4214 -- If the discriminant constraint is a current
4215 -- instance, mark the current aggregate so that
4216 -- the self-reference can be expanded later.
4218 if Nkind (Discr_Val) = N_Attribute_Reference
4219 and then Is_Entity_Name (Prefix (Discr_Val))
4220 and then Is_Type (Entity (Prefix (Discr_Val)))
4221 and then Etype (N) =
4222 Entity (Prefix (Discr_Val))
4224 Set_Has_Self_Reference (N);
4227 Next_Elmt (Discr_Elmt);
4228 Next_Discriminant (Discr);
4230 end Add_Discriminant_Values;
4232 ------------------------------
4233 -- Propagate_Discriminants --
4234 ------------------------------
4236 procedure Propagate_Discriminants
4238 Assoc_List : List_Id)
4240 Aggr_Type : constant Entity_Id :=
4241 Base_Type (Etype (Aggr));
4242 Def_Node : constant Node_Id :=
4244 (Declaration_Node (Aggr_Type));
4247 Comp_Elmt : Elmt_Id;
4248 Components : constant Elist_Id := New_Elmt_List;
4249 Needs_Box : Boolean := False;
4252 procedure Process_Component (Comp : Entity_Id);
4253 -- Add one component with a box association to the
4254 -- inner aggregate, and recurse if component is
4255 -- itself composite.
4257 ------------------------
4258 -- Process_Component --
4259 ------------------------
4261 procedure Process_Component (Comp : Entity_Id) is
4262 T : constant Entity_Id := Etype (Comp);
4266 if Is_Record_Type (T)
4267 and then Has_Discriminants (T)
4270 Make_Aggregate (Loc, New_List, New_List);
4271 Set_Etype (New_Aggr, T);
4274 Component_Associations (Aggr));
4276 -- Collect discriminant values and recurse
4278 Add_Discriminant_Values
4279 (New_Aggr, Assoc_List);
4280 Propagate_Discriminants
4281 (New_Aggr, Assoc_List);
4286 end Process_Component;
4288 -- Start of processing for Propagate_Discriminants
4291 -- The component type may be a variant type, so
4292 -- collect the components that are ruled by the
4293 -- known values of the discriminants. Their values
4294 -- have already been inserted into the component
4295 -- list of the current aggregate.
4297 if Nkind (Def_Node) = N_Record_Definition
4299 Present (Component_List (Def_Node))
4302 (Variant_Part (Component_List (Def_Node)))
4304 Gather_Components (Aggr_Type,
4305 Component_List (Def_Node),
4306 Governed_By => Component_Associations (Aggr),
4308 Report_Errors => Errors);
4310 Comp_Elmt := First_Elmt (Components);
4311 while Present (Comp_Elmt) loop
4313 Ekind (Node (Comp_Elmt)) /= E_Discriminant
4315 Process_Component (Node (Comp_Elmt));
4318 Next_Elmt (Comp_Elmt);
4321 -- No variant part, iterate over all components
4324 Comp := First_Component (Etype (Aggr));
4325 while Present (Comp) loop
4326 Process_Component (Comp);
4327 Next_Component (Comp);
4333 (Make_Component_Association (Loc,
4335 New_List (Make_Others_Choice (Loc)),
4336 Expression => Empty,
4337 Box_Present => True),
4338 Component_Associations (Aggr));
4340 end Propagate_Discriminants;
4342 -- Start of processing for Capture_Discriminants
4345 Expr := Make_Aggregate (Loc, New_List, New_List);
4346 Set_Etype (Expr, Ctyp);
4348 -- If the enclosing type has discriminants, they have
4349 -- been collected in the aggregate earlier, and they
4350 -- may appear as constraints of subcomponents.
4352 -- Similarly if this component has discriminants, they
4353 -- might in turn be propagated to their components.
4355 if Has_Discriminants (Typ) then
4356 Add_Discriminant_Values (Expr, New_Assoc_List);
4357 Propagate_Discriminants (Expr, New_Assoc_List);
4359 elsif Has_Discriminants (Ctyp) then
4360 Add_Discriminant_Values
4361 (Expr, Component_Associations (Expr));
4362 Propagate_Discriminants
4363 (Expr, Component_Associations (Expr));
4370 -- If the type has additional components, create
4371 -- an OTHERS box association for them.
4373 Comp := First_Component (Ctyp);
4374 while Present (Comp) loop
4375 if Ekind (Comp) = E_Component then
4376 if not Is_Record_Type (Etype (Comp)) then
4378 (Make_Component_Association (Loc,
4381 (Make_Others_Choice (Loc)),
4382 Expression => Empty,
4383 Box_Present => True),
4384 Component_Associations (Expr));
4389 Next_Component (Comp);
4395 (Component => Component,
4397 Assoc_List => New_Assoc_List);
4398 end Capture_Discriminants;
4402 (Component => Component,
4404 Assoc_List => New_Assoc_List,
4405 Is_Box_Present => True);
4408 -- Otherwise we only need to resolve the expression if the
4409 -- component has partially initialized values (required to
4410 -- expand the corresponding assignments and run-time checks).
4412 elsif Present (Expr)
4413 and then Is_Partially_Initialized_Type (Ctyp)
4415 Resolve_Aggr_Expr (Expr, Component);
4417 end Check_Box_Component;
4419 elsif No (Expr) then
4421 -- Ignore hidden components associated with the position of the
4422 -- interface tags: these are initialized dynamically.
4424 if not Present (Related_Type (Component)) then
4426 ("no value supplied for component &!", N, Component);
4430 Resolve_Aggr_Expr (Expr, Component);
4433 Next_Elmt (Component_Elmt);
4436 -- STEP 7: check for invalid components + check type in choice list
4443 -- Type of first component in choice list
4446 if Present (Component_Associations (N)) then
4447 Assoc := First (Component_Associations (N));
4452 Verification : while Present (Assoc) loop
4453 Selectr := First (Choices (Assoc));
4456 if Nkind (Selectr) = N_Others_Choice then
4458 -- Ada 2005 (AI-287): others choice may have expression or box
4460 if No (Others_Etype)
4461 and then not Others_Box
4464 ("OTHERS must represent at least one component", Selectr);
4470 while Present (Selectr) loop
4471 New_Assoc := First (New_Assoc_List);
4472 while Present (New_Assoc) loop
4473 Component := First (Choices (New_Assoc));
4475 if Chars (Selectr) = Chars (Component) then
4477 Check_Identifier (Selectr, Entity (Component));
4486 -- If no association, this is not a legal component of the type
4487 -- in question, unless its association is provided with a box.
4489 if No (New_Assoc) then
4490 if Box_Present (Parent (Selectr)) then
4492 -- This may still be a bogus component with a box. Scan
4493 -- list of components to verify that a component with
4494 -- that name exists.
4500 C := First_Component (Typ);
4501 while Present (C) loop
4502 if Chars (C) = Chars (Selectr) then
4504 -- If the context is an extension aggregate,
4505 -- the component must not be inherited from
4506 -- the ancestor part of the aggregate.
4508 if Nkind (N) /= N_Extension_Aggregate
4510 Scope (Original_Record_Component (C)) /=
4511 Etype (Ancestor_Part (N))
4521 Error_Msg_Node_2 := Typ;
4522 Error_Msg_N ("& is not a component of}", Selectr);
4526 elsif Chars (Selectr) /= Name_uTag
4527 and then Chars (Selectr) /= Name_uParent
4529 if not Has_Discriminants (Typ) then
4530 Error_Msg_Node_2 := Typ;
4531 Error_Msg_N ("& is not a component of}", Selectr);
4534 ("& is not a component of the aggregate subtype",
4538 Check_Misspelled_Component (Components, Selectr);
4541 elsif No (Typech) then
4542 Typech := Base_Type (Etype (Component));
4544 -- AI05-0199: In Ada 2012, several components of anonymous
4545 -- access types can appear in a choice list, as long as the
4546 -- designated types match.
4548 elsif Typech /= Base_Type (Etype (Component)) then
4549 if Ada_Version >= Ada_2012
4550 and then Ekind (Typech) = E_Anonymous_Access_Type
4552 Ekind (Etype (Component)) = E_Anonymous_Access_Type
4553 and then Base_Type (Designated_Type (Typech)) =
4554 Base_Type (Designated_Type (Etype (Component)))
4556 Subtypes_Statically_Match (Typech, (Etype (Component)))
4560 elsif not Box_Present (Parent (Selectr)) then
4562 ("components in choice list must have same type",
4571 end loop Verification;
4574 -- STEP 8: replace the original aggregate
4577 New_Aggregate : constant Node_Id := New_Copy (N);
4580 Set_Expressions (New_Aggregate, No_List);
4581 Set_Etype (New_Aggregate, Etype (N));
4582 Set_Component_Associations (New_Aggregate, New_Assoc_List);
4584 Rewrite (N, New_Aggregate);
4587 -- Check the dimensions of the components in the record aggregate
4589 Analyze_Dimension_Extension_Or_Record_Aggregate (N);
4590 end Resolve_Record_Aggregate;
4592 -----------------------------
4593 -- Check_Can_Never_Be_Null --
4594 -----------------------------
4596 procedure Check_Can_Never_Be_Null (Typ : Entity_Id; Expr : Node_Id) is
4597 Comp_Typ : Entity_Id;
4601 (Ada_Version >= Ada_2005
4602 and then Present (Expr)
4603 and then Known_Null (Expr));
4606 when E_Array_Type =>
4607 Comp_Typ := Component_Type (Typ);
4611 Comp_Typ := Etype (Typ);
4617 if Can_Never_Be_Null (Comp_Typ) then
4619 -- Here we know we have a constraint error. Note that we do not use
4620 -- Apply_Compile_Time_Constraint_Error here to the Expr, which might
4621 -- seem the more natural approach. That's because in some cases the
4622 -- components are rewritten, and the replacement would be missed.
4623 -- We do not mark the whole aggregate as raising a constraint error,
4624 -- because the association may be a null array range.
4627 ("(Ada 2005) null not allowed in null-excluding component??", Expr);
4629 ("\Constraint_Error will be raised at run time??", Expr);
4632 Make_Raise_Constraint_Error
4633 (Sloc (Expr), Reason => CE_Access_Check_Failed));
4634 Set_Etype (Expr, Comp_Typ);
4635 Set_Analyzed (Expr);
4637 end Check_Can_Never_Be_Null;
4639 ---------------------
4640 -- Sort_Case_Table --
4641 ---------------------
4643 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
4644 U : constant Int := Case_Table'Last;
4652 T := Case_Table (K + 1);
4656 and then Expr_Value (Case_Table (J - 1).Lo) > Expr_Value (T.Lo)
4658 Case_Table (J) := Case_Table (J - 1);
4662 Case_Table (J) := T;
4665 end Sort_Case_Table;
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