1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2006, 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 2, 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 COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Exp_Tss; use Exp_Tss;
33 with Exp_Util; use Exp_Util;
34 with Freeze; use Freeze;
35 with Itypes; use Itypes;
36 with Lib.Xref; use Lib.Xref;
37 with Namet; use Namet;
38 with Nmake; use Nmake;
39 with Nlists; use Nlists;
42 with Sem_Cat; use Sem_Cat;
43 with Sem_Ch8; use Sem_Ch8;
44 with Sem_Ch13; use Sem_Ch13;
45 with Sem_Eval; use Sem_Eval;
46 with Sem_Res; use Sem_Res;
47 with Sem_Util; use Sem_Util;
48 with Sem_Type; use Sem_Type;
49 with Sem_Warn; use Sem_Warn;
50 with Sinfo; use Sinfo;
51 with Snames; use Snames;
52 with Stringt; use Stringt;
53 with Stand; use Stand;
54 with Targparm; use Targparm;
55 with Tbuild; use Tbuild;
56 with Uintp; use Uintp;
58 with GNAT.Spelling_Checker; use GNAT.Spelling_Checker;
60 package body Sem_Aggr is
62 type Case_Bounds is record
65 Choice_Node : Node_Id;
68 type Case_Table_Type is array (Nat range <>) of Case_Bounds;
69 -- Table type used by Check_Case_Choices procedure
71 -----------------------
72 -- Local Subprograms --
73 -----------------------
75 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
76 -- Sort the Case Table using the Lower Bound of each Choice as the key.
77 -- A simple insertion sort is used since the number of choices in a case
78 -- statement of variant part will usually be small and probably in near
81 procedure Check_Can_Never_Be_Null (Typ : Entity_Id; Expr : Node_Id);
82 -- Ada 2005 (AI-231): Check bad usage of null for a component for which
83 -- null exclusion (NOT NULL) is specified. Typ can be an E_Array_Type for
84 -- the array case (the component type of the array will be used) or an
85 -- E_Component/E_Discriminant entity in the record case, in which case the
86 -- type of the component will be used for the test. If Typ is any other
87 -- kind of entity, the call is ignored. Expr is the component node in the
88 -- aggregate which is an explicit occurrence of NULL. An error will be
89 -- issued if the component is null excluding.
91 -- It would be better to pass the proper type for Typ ???
93 ------------------------------------------------------
94 -- Subprograms used for RECORD AGGREGATE Processing --
95 ------------------------------------------------------
97 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id);
98 -- This procedure performs all the semantic checks required for record
99 -- aggregates. Note that for aggregates analysis and resolution go
100 -- hand in hand. Aggregate analysis has been delayed up to here and
101 -- it is done while resolving the aggregate.
103 -- N is the N_Aggregate node.
104 -- Typ is the record type for the aggregate resolution
106 -- While performing the semantic checks, this procedure builds a new
107 -- Component_Association_List where each record field appears alone in a
108 -- Component_Choice_List along with its corresponding expression. The
109 -- record fields in the Component_Association_List appear in the same order
110 -- in which they appear in the record type Typ.
112 -- Once this new Component_Association_List is built and all the semantic
113 -- checks performed, the original aggregate subtree is replaced with the
114 -- new named record aggregate just built. Note that subtree substitution is
115 -- performed with Rewrite so as to be able to retrieve the original
118 -- The aggregate subtree manipulation performed by Resolve_Record_Aggregate
119 -- yields the aggregate format expected by Gigi. Typically, this kind of
120 -- tree manipulations are done in the expander. However, because the
121 -- semantic checks that need to be performed on record aggregates really go
122 -- hand in hand with the record aggregate normalization, the aggregate
123 -- subtree transformation is performed during resolution rather than
124 -- expansion. Had we decided otherwise we would have had to duplicate most
125 -- of the code in the expansion procedure Expand_Record_Aggregate. Note,
126 -- however, that all the expansion concerning aggegates for tagged records
127 -- is done in Expand_Record_Aggregate.
129 -- The algorithm of Resolve_Record_Aggregate proceeds as follows:
131 -- 1. Make sure that the record type against which the record aggregate
132 -- has to be resolved is not abstract. Furthermore if the type is
133 -- a null aggregate make sure the input aggregate N is also null.
135 -- 2. Verify that the structure of the aggregate is that of a record
136 -- aggregate. Specifically, look for component associations and ensure
137 -- that each choice list only has identifiers or the N_Others_Choice
138 -- node. Also make sure that if present, the N_Others_Choice occurs
139 -- last and by itself.
141 -- 3. If Typ contains discriminants, the values for each discriminant
142 -- is looked for. If the record type Typ has variants, we check
143 -- that the expressions corresponding to each discriminant ruling
144 -- the (possibly nested) variant parts of Typ, are static. This
145 -- allows us to determine the variant parts to which the rest of
146 -- the aggregate must conform. The names of discriminants with their
147 -- values are saved in a new association list, New_Assoc_List which
148 -- is later augmented with the names and values of the remaining
149 -- components in the record type.
151 -- During this phase we also make sure that every discriminant is
152 -- assigned exactly one value. Note that when several values
153 -- for a given discriminant are found, semantic processing continues
154 -- looking for further errors. In this case it's the first
155 -- discriminant value found which we will be recorded.
157 -- IMPORTANT NOTE: For derived tagged types this procedure expects
158 -- First_Discriminant and Next_Discriminant to give the correct list
159 -- of discriminants, in the correct order.
161 -- 4. After all the discriminant values have been gathered, we can
162 -- set the Etype of the record aggregate. If Typ contains no
163 -- discriminants this is straightforward: the Etype of N is just
164 -- Typ, otherwise a new implicit constrained subtype of Typ is
165 -- built to be the Etype of N.
167 -- 5. Gather the remaining record components according to the discriminant
168 -- values. This involves recursively traversing the record type
169 -- structure to see what variants are selected by the given discriminant
170 -- values. This processing is a little more convoluted if Typ is a
171 -- derived tagged types since we need to retrieve the record structure
172 -- of all the ancestors of Typ.
174 -- 6. After gathering the record components we look for their values
175 -- in the record aggregate and emit appropriate error messages
176 -- should we not find such values or should they be duplicated.
178 -- 7. We then make sure no illegal component names appear in the
179 -- record aggegate and make sure that the type of the record
180 -- components appearing in a same choice list is the same.
181 -- Finally we ensure that the others choice, if present, is
182 -- used to provide the value of at least a record component.
184 -- 8. The original aggregate node is replaced with the new named
185 -- aggregate built in steps 3 through 6, as explained earlier.
187 -- Given the complexity of record aggregate resolution, the primary
188 -- goal of this routine is clarity and simplicity rather than execution
189 -- and storage efficiency. If there are only positional components in the
190 -- aggregate the running time is linear. If there are associations
191 -- the running time is still linear as long as the order of the
192 -- associations is not too far off the order of the components in the
193 -- record type. If this is not the case the running time is at worst
194 -- quadratic in the size of the association list.
196 procedure Check_Misspelled_Component
197 (Elements : Elist_Id;
198 Component : Node_Id);
199 -- Give possible misspelling diagnostic if Component is likely to be
200 -- a misspelling of one of the components of the Assoc_List.
201 -- This is called by Resolv_Aggr_Expr after producing
202 -- an invalid component error message.
204 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id);
205 -- An optimization: determine whether a discriminated subtype has a
206 -- static constraint, and contains array components whose length is also
207 -- static, either because they are constrained by the discriminant, or
208 -- because the original component bounds are static.
210 -----------------------------------------------------
211 -- Subprograms used for ARRAY AGGREGATE Processing --
212 -----------------------------------------------------
214 function Resolve_Array_Aggregate
217 Index_Constr : Node_Id;
218 Component_Typ : Entity_Id;
219 Others_Allowed : Boolean)
221 -- This procedure performs the semantic checks for an array aggregate.
222 -- True is returned if the aggregate resolution succeeds.
223 -- The procedure works by recursively checking each nested aggregate.
224 -- Specifically, after checking a sub-aggregate nested at the i-th level
225 -- we recursively check all the subaggregates at the i+1-st level (if any).
226 -- Note that for aggregates analysis and resolution go hand in hand.
227 -- Aggregate analysis has been delayed up to here and it is done while
228 -- resolving the aggregate.
230 -- N is the current N_Aggregate node to be checked.
232 -- Index is the index node corresponding to the array sub-aggregate that
233 -- we are currently checking (RM 4.3.3 (8)). Its Etype is the
234 -- corresponding index type (or subtype).
236 -- Index_Constr is the node giving the applicable index constraint if
237 -- any (RM 4.3.3 (10)). It "is a constraint provided by certain
238 -- contexts [...] that can be used to determine the bounds of the array
239 -- value specified by the aggregate". If Others_Allowed below is False
240 -- there is no applicable index constraint and this node is set to Index.
242 -- Component_Typ is the array component type.
244 -- Others_Allowed indicates whether an others choice is allowed
245 -- in the context where the top-level aggregate appeared.
247 -- The algorithm of Resolve_Array_Aggregate proceeds as follows:
249 -- 1. Make sure that the others choice, if present, is by itself and
250 -- appears last in the sub-aggregate. Check that we do not have
251 -- positional and named components in the array sub-aggregate (unless
252 -- the named association is an others choice). Finally if an others
253 -- choice is present, make sure it is allowed in the aggregate contex.
255 -- 2. If the array sub-aggregate contains discrete_choices:
257 -- (A) Verify their validity. Specifically verify that:
259 -- (a) If a null range is present it must be the only possible
260 -- choice in the array aggregate.
262 -- (b) Ditto for a non static range.
264 -- (c) Ditto for a non static expression.
266 -- In addition this step analyzes and resolves each discrete_choice,
267 -- making sure that its type is the type of the corresponding Index.
268 -- If we are not at the lowest array aggregate level (in the case of
269 -- multi-dimensional aggregates) then invoke Resolve_Array_Aggregate
270 -- recursively on each component expression. Otherwise, resolve the
271 -- bottom level component expressions against the expected component
272 -- type ONLY IF the component corresponds to a single discrete choice
273 -- which is not an others choice (to see why read the DELAYED
274 -- COMPONENT RESOLUTION below).
276 -- (B) Determine the bounds of the sub-aggregate and lowest and
277 -- highest choice values.
279 -- 3. For positional aggregates:
281 -- (A) Loop over the component expressions either recursively invoking
282 -- Resolve_Array_Aggregate on each of these for multi-dimensional
283 -- array aggregates or resolving the bottom level component
284 -- expressions against the expected component type.
286 -- (B) Determine the bounds of the positional sub-aggregates.
288 -- 4. Try to determine statically whether the evaluation of the array
289 -- sub-aggregate raises Constraint_Error. If yes emit proper
290 -- warnings. The precise checks are the following:
292 -- (A) Check that the index range defined by aggregate bounds is
293 -- compatible with corresponding index subtype.
294 -- We also check against the base type. In fact it could be that
295 -- Low/High bounds of the base type are static whereas those of
296 -- the index subtype are not. Thus if we can statically catch
297 -- a problem with respect to the base type we are guaranteed
298 -- that the same problem will arise with the index subtype
300 -- (B) If we are dealing with a named aggregate containing an others
301 -- choice and at least one discrete choice then make sure the range
302 -- specified by the discrete choices does not overflow the
303 -- aggregate bounds. We also check against the index type and base
304 -- type bounds for the same reasons given in (A).
306 -- (C) If we are dealing with a positional aggregate with an others
307 -- choice make sure the number of positional elements specified
308 -- does not overflow the aggregate bounds. We also check against
309 -- the index type and base type bounds as mentioned in (A).
311 -- Finally construct an N_Range node giving the sub-aggregate bounds.
312 -- Set the Aggregate_Bounds field of the sub-aggregate to be this
313 -- N_Range. The routine Array_Aggr_Subtype below uses such N_Ranges
314 -- to build the appropriate aggregate subtype. Aggregate_Bounds
315 -- information is needed during expansion.
317 -- DELAYED COMPONENT RESOLUTION: The resolution of bottom level component
318 -- expressions in an array aggregate may call Duplicate_Subexpr or some
319 -- other routine that inserts code just outside the outermost aggregate.
320 -- If the array aggregate contains discrete choices or an others choice,
321 -- this may be wrong. Consider for instance the following example.
323 -- type Rec is record
327 -- type Acc_Rec is access Rec;
328 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => new Rec);
330 -- Then the transformation of "new Rec" that occurs during resolution
331 -- entails the following code modifications
333 -- P7b : constant Acc_Rec := new Rec;
335 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => P7b);
337 -- This code transformation is clearly wrong, since we need to call
338 -- "new Rec" for each of the 3 array elements. To avoid this problem we
339 -- delay resolution of the components of non positional array aggregates
340 -- to the expansion phase. As an optimization, if the discrete choice
341 -- specifies a single value we do not delay resolution.
343 function Array_Aggr_Subtype (N : Node_Id; Typ : Node_Id) return Entity_Id;
344 -- This routine returns the type or subtype of an array aggregate.
346 -- N is the array aggregate node whose type we return.
348 -- Typ is the context type in which N occurs.
350 -- This routine creates an implicit array subtype whose bounds are
351 -- those defined by the aggregate. When this routine is invoked
352 -- Resolve_Array_Aggregate has already processed aggregate N. Thus the
353 -- Aggregate_Bounds of each sub-aggregate, is an N_Range node giving the
354 -- sub-aggregate bounds. When building the aggegate itype, this function
355 -- traverses the array aggregate N collecting such Aggregate_Bounds and
356 -- constructs the proper array aggregate itype.
358 -- Note that in the case of multidimensional aggregates each inner
359 -- sub-aggregate corresponding to a given array dimension, may provide a
360 -- different bounds. If it is possible to determine statically that
361 -- some sub-aggregates corresponding to the same index do not have the
362 -- same bounds, then a warning is emitted. If such check is not possible
363 -- statically (because some sub-aggregate bounds are dynamic expressions)
364 -- then this job is left to the expander. In all cases the particular
365 -- bounds that this function will chose for a given dimension is the first
366 -- N_Range node for a sub-aggregate corresponding to that dimension.
368 -- Note that the Raises_Constraint_Error flag of an array aggregate
369 -- whose evaluation is determined to raise CE by Resolve_Array_Aggregate,
370 -- is set in Resolve_Array_Aggregate but the aggregate is not
371 -- immediately replaced with a raise CE. In fact, Array_Aggr_Subtype must
372 -- first construct the proper itype for the aggregate (Gigi needs
373 -- this). After constructing the proper itype we will eventually replace
374 -- the top-level aggregate with a raise CE (done in Resolve_Aggregate).
375 -- Of course in cases such as:
377 -- type Arr is array (integer range <>) of Integer;
378 -- A : Arr := (positive range -1 .. 2 => 0);
380 -- The bounds of the aggregate itype are cooked up to look reasonable
381 -- (in this particular case the bounds will be 1 .. 2).
383 procedure Aggregate_Constraint_Checks
385 Check_Typ : Entity_Id);
386 -- Checks expression Exp against subtype Check_Typ. If Exp is an
387 -- aggregate and Check_Typ a constrained record type with discriminants,
388 -- we generate the appropriate discriminant checks. If Exp is an array
389 -- aggregate then emit the appropriate length checks. If Exp is a scalar
390 -- type, or a string literal, Exp is changed into Check_Typ'(Exp) to
391 -- ensure that range checks are performed at run time.
393 procedure Make_String_Into_Aggregate (N : Node_Id);
394 -- A string literal can appear in a context in which a one dimensional
395 -- array of characters is expected. This procedure simply rewrites the
396 -- string as an aggregate, prior to resolution.
398 ---------------------------------
399 -- Aggregate_Constraint_Checks --
400 ---------------------------------
402 procedure Aggregate_Constraint_Checks
404 Check_Typ : Entity_Id)
406 Exp_Typ : constant Entity_Id := Etype (Exp);
409 if Raises_Constraint_Error (Exp) then
413 -- This is really expansion activity, so make sure that expansion
414 -- is on and is allowed.
416 if not Expander_Active or else In_Default_Expression then
420 -- First check if we have to insert discriminant checks
422 if Has_Discriminants (Exp_Typ) then
423 Apply_Discriminant_Check (Exp, Check_Typ);
425 -- Next emit length checks for array aggregates
427 elsif Is_Array_Type (Exp_Typ) then
428 Apply_Length_Check (Exp, Check_Typ);
430 -- Finally emit scalar and string checks. If we are dealing with a
431 -- scalar literal we need to check by hand because the Etype of
432 -- literals is not necessarily correct.
434 elsif Is_Scalar_Type (Exp_Typ)
435 and then Compile_Time_Known_Value (Exp)
437 if Is_Out_Of_Range (Exp, Base_Type (Check_Typ)) then
438 Apply_Compile_Time_Constraint_Error
439 (Exp, "value not in range of}?", CE_Range_Check_Failed,
440 Ent => Base_Type (Check_Typ),
441 Typ => Base_Type (Check_Typ));
443 elsif Is_Out_Of_Range (Exp, Check_Typ) then
444 Apply_Compile_Time_Constraint_Error
445 (Exp, "value not in range of}?", CE_Range_Check_Failed,
449 elsif not Range_Checks_Suppressed (Check_Typ) then
450 Apply_Scalar_Range_Check (Exp, Check_Typ);
453 elsif (Is_Scalar_Type (Exp_Typ)
454 or else Nkind (Exp) = N_String_Literal)
455 and then Exp_Typ /= Check_Typ
457 if Is_Entity_Name (Exp)
458 and then Ekind (Entity (Exp)) = E_Constant
460 -- If expression is a constant, it is worthwhile checking whether
461 -- it is a bound of the type.
463 if (Is_Entity_Name (Type_Low_Bound (Check_Typ))
464 and then Entity (Exp) = Entity (Type_Low_Bound (Check_Typ)))
465 or else (Is_Entity_Name (Type_High_Bound (Check_Typ))
466 and then Entity (Exp) = Entity (Type_High_Bound (Check_Typ)))
471 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
472 Analyze_And_Resolve (Exp, Check_Typ);
473 Check_Unset_Reference (Exp);
476 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
477 Analyze_And_Resolve (Exp, Check_Typ);
478 Check_Unset_Reference (Exp);
481 -- Ada 2005 (AI-230): Generate a conversion to an anonymous access
482 -- component's type to force the appropriate accessibility checks.
484 -- Ada 2005 (AI-231): Generate conversion to the null-excluding
485 -- type to force the corresponding run-time check
487 elsif Is_Access_Type (Check_Typ)
488 and then ((Is_Local_Anonymous_Access (Check_Typ))
489 or else (Can_Never_Be_Null (Check_Typ)
490 and then not Can_Never_Be_Null (Exp_Typ)))
492 Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp)));
493 Analyze_And_Resolve (Exp, Check_Typ);
494 Check_Unset_Reference (Exp);
496 end Aggregate_Constraint_Checks;
498 ------------------------
499 -- Array_Aggr_Subtype --
500 ------------------------
502 function Array_Aggr_Subtype
507 Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
508 -- Number of aggregate index dimensions
510 Aggr_Range : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
511 -- Constrained N_Range of each index dimension in our aggregate itype
513 Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
514 Aggr_High : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
515 -- Low and High bounds for each index dimension in our aggregate itype
517 Is_Fully_Positional : Boolean := True;
519 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos);
520 -- N is an array (sub-)aggregate. Dim is the dimension corresponding to
521 -- (sub-)aggregate N. This procedure collects the constrained N_Range
522 -- nodes corresponding to each index dimension of our aggregate itype.
523 -- These N_Range nodes are collected in Aggr_Range above.
525 -- Likewise collect in Aggr_Low & Aggr_High above the low and high
526 -- bounds of each index dimension. If, when collecting, two bounds
527 -- corresponding to the same dimension are static and found to differ,
528 -- then emit a warning, and mark N as raising Constraint_Error.
530 -------------------------
531 -- Collect_Aggr_Bounds --
532 -------------------------
534 procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos) is
535 This_Range : constant Node_Id := Aggregate_Bounds (N);
536 -- The aggregate range node of this specific sub-aggregate
538 This_Low : constant Node_Id := Low_Bound (Aggregate_Bounds (N));
539 This_High : constant Node_Id := High_Bound (Aggregate_Bounds (N));
540 -- The aggregate bounds of this specific sub-aggregate
546 -- Collect the first N_Range for a given dimension that you find.
547 -- For a given dimension they must be all equal anyway.
549 if No (Aggr_Range (Dim)) then
550 Aggr_Low (Dim) := This_Low;
551 Aggr_High (Dim) := This_High;
552 Aggr_Range (Dim) := This_Range;
555 if Compile_Time_Known_Value (This_Low) then
556 if not Compile_Time_Known_Value (Aggr_Low (Dim)) then
557 Aggr_Low (Dim) := This_Low;
559 elsif Expr_Value (This_Low) /= Expr_Value (Aggr_Low (Dim)) then
560 Set_Raises_Constraint_Error (N);
561 Error_Msg_N ("sub-aggregate low bound mismatch?", N);
563 ("\Constraint_Error will be raised at run-time?", N);
567 if Compile_Time_Known_Value (This_High) then
568 if not Compile_Time_Known_Value (Aggr_High (Dim)) then
569 Aggr_High (Dim) := This_High;
572 Expr_Value (This_High) /= Expr_Value (Aggr_High (Dim))
574 Set_Raises_Constraint_Error (N);
575 Error_Msg_N ("sub-aggregate high bound mismatch?", N);
577 ("\Constraint_Error will be raised at run-time?", N);
582 if Dim < Aggr_Dimension then
584 -- Process positional components
586 if Present (Expressions (N)) then
587 Expr := First (Expressions (N));
588 while Present (Expr) loop
589 Collect_Aggr_Bounds (Expr, Dim + 1);
594 -- Process component associations
596 if Present (Component_Associations (N)) then
597 Is_Fully_Positional := False;
599 Assoc := First (Component_Associations (N));
600 while Present (Assoc) loop
601 Expr := Expression (Assoc);
602 Collect_Aggr_Bounds (Expr, Dim + 1);
607 end Collect_Aggr_Bounds;
609 -- Array_Aggr_Subtype variables
612 -- the final itype of the overall aggregate
614 Index_Constraints : constant List_Id := New_List;
615 -- The list of index constraints of the aggregate itype
617 -- Start of processing for Array_Aggr_Subtype
620 -- Make sure that the list of index constraints is properly attached
621 -- to the tree, and then collect the aggregate bounds.
623 Set_Parent (Index_Constraints, N);
624 Collect_Aggr_Bounds (N, 1);
626 -- Build the list of constrained indices of our aggregate itype
628 for J in 1 .. Aggr_Dimension loop
629 Create_Index : declare
630 Index_Base : constant Entity_Id :=
631 Base_Type (Etype (Aggr_Range (J)));
632 Index_Typ : Entity_Id;
635 -- Construct the Index subtype
637 Index_Typ := Create_Itype (Subtype_Kind (Ekind (Index_Base)), N);
639 Set_Etype (Index_Typ, Index_Base);
641 if Is_Character_Type (Index_Base) then
642 Set_Is_Character_Type (Index_Typ);
645 Set_Size_Info (Index_Typ, (Index_Base));
646 Set_RM_Size (Index_Typ, RM_Size (Index_Base));
647 Set_First_Rep_Item (Index_Typ, First_Rep_Item (Index_Base));
648 Set_Scalar_Range (Index_Typ, Aggr_Range (J));
650 if Is_Discrete_Or_Fixed_Point_Type (Index_Typ) then
651 Set_RM_Size (Index_Typ, UI_From_Int (Minimum_Size (Index_Typ)));
654 Set_Etype (Aggr_Range (J), Index_Typ);
656 Append (Aggr_Range (J), To => Index_Constraints);
660 -- Now build the Itype
662 Itype := Create_Itype (E_Array_Subtype, N);
664 Set_First_Rep_Item (Itype, First_Rep_Item (Typ));
665 Set_Convention (Itype, Convention (Typ));
666 Set_Depends_On_Private (Itype, Has_Private_Component (Typ));
667 Set_Etype (Itype, Base_Type (Typ));
668 Set_Has_Alignment_Clause (Itype, Has_Alignment_Clause (Typ));
669 Set_Is_Aliased (Itype, Is_Aliased (Typ));
670 Set_Depends_On_Private (Itype, Depends_On_Private (Typ));
672 Copy_Suppress_Status (Index_Check, Typ, Itype);
673 Copy_Suppress_Status (Length_Check, Typ, Itype);
675 Set_First_Index (Itype, First (Index_Constraints));
676 Set_Is_Constrained (Itype, True);
677 Set_Is_Internal (Itype, True);
678 Init_Size_Align (Itype);
680 -- A simple optimization: purely positional aggregates of static
681 -- components should be passed to gigi unexpanded whenever possible,
682 -- and regardless of the staticness of the bounds themselves. Subse-
683 -- quent checks in exp_aggr verify that type is not packed, etc.
685 Set_Size_Known_At_Compile_Time (Itype,
687 and then Comes_From_Source (N)
688 and then Size_Known_At_Compile_Time (Component_Type (Typ)));
690 -- We always need a freeze node for a packed array subtype, so that
691 -- we can build the Packed_Array_Type corresponding to the subtype.
692 -- If expansion is disabled, the packed array subtype is not built,
693 -- and we must not generate a freeze node for the type, or else it
694 -- will appear incomplete to gigi.
696 if Is_Packed (Itype) and then not In_Default_Expression
697 and then Expander_Active
699 Freeze_Itype (Itype, N);
703 end Array_Aggr_Subtype;
705 --------------------------------
706 -- Check_Misspelled_Component --
707 --------------------------------
709 procedure Check_Misspelled_Component
710 (Elements : Elist_Id;
713 Max_Suggestions : constant := 2;
715 Nr_Of_Suggestions : Natural := 0;
716 Suggestion_1 : Entity_Id := Empty;
717 Suggestion_2 : Entity_Id := Empty;
718 Component_Elmt : Elmt_Id;
721 -- All the components of List are matched against Component and
722 -- a count is maintained of possible misspellings. When at the
723 -- end of the analysis there are one or two (not more!) possible
724 -- misspellings, these misspellings will be suggested as
725 -- possible correction.
727 Get_Name_String (Chars (Component));
730 S : constant String (1 .. Name_Len) :=
731 Name_Buffer (1 .. Name_Len);
734 Component_Elmt := First_Elmt (Elements);
735 while Nr_Of_Suggestions <= Max_Suggestions
736 and then Present (Component_Elmt)
738 Get_Name_String (Chars (Node (Component_Elmt)));
740 if Is_Bad_Spelling_Of (Name_Buffer (1 .. Name_Len), S) then
741 Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
743 case Nr_Of_Suggestions is
744 when 1 => Suggestion_1 := Node (Component_Elmt);
745 when 2 => Suggestion_2 := Node (Component_Elmt);
750 Next_Elmt (Component_Elmt);
753 -- Report at most two suggestions
755 if Nr_Of_Suggestions = 1 then
756 Error_Msg_NE ("\possible misspelling of&",
757 Component, Suggestion_1);
759 elsif Nr_Of_Suggestions = 2 then
760 Error_Msg_Node_2 := Suggestion_2;
761 Error_Msg_NE ("\possible misspelling of& or&",
762 Component, Suggestion_1);
765 end Check_Misspelled_Component;
767 ----------------------------------------
768 -- Check_Static_Discriminated_Subtype --
769 ----------------------------------------
771 procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id) is
772 Disc : constant Entity_Id := First_Discriminant (T);
777 if Has_Record_Rep_Clause (T) then
780 elsif Present (Next_Discriminant (Disc)) then
783 elsif Nkind (V) /= N_Integer_Literal then
786 elsif Is_Access_Type (Etype (Disc)) then
789 -- If the bounds of the discriminant type are not compile time known,
790 -- the back-end will treat this as a variable-size object.
793 (Compile_Time_Known_Value (Type_Low_Bound (Etype (Disc)))
795 Compile_Time_Known_Value (Type_High_Bound (Etype (Disc))))
800 Comp := First_Component (T);
801 while Present (Comp) loop
802 if Is_Scalar_Type (Etype (Comp)) then
805 elsif Is_Private_Type (Etype (Comp))
806 and then Present (Full_View (Etype (Comp)))
807 and then Is_Scalar_Type (Full_View (Etype (Comp)))
811 elsif Is_Array_Type (Etype (Comp)) then
812 if Is_Bit_Packed_Array (Etype (Comp)) then
816 Ind := First_Index (Etype (Comp));
817 while Present (Ind) loop
818 if Nkind (Ind) /= N_Range
819 or else Nkind (Low_Bound (Ind)) /= N_Integer_Literal
820 or else Nkind (High_Bound (Ind)) /= N_Integer_Literal
832 Next_Component (Comp);
835 -- On exit, all components have statically known sizes
837 Set_Size_Known_At_Compile_Time (T);
838 end Check_Static_Discriminated_Subtype;
840 --------------------------------
841 -- Make_String_Into_Aggregate --
842 --------------------------------
844 procedure Make_String_Into_Aggregate (N : Node_Id) is
845 Exprs : constant List_Id := New_List;
846 Loc : constant Source_Ptr := Sloc (N);
847 Str : constant String_Id := Strval (N);
848 Strlen : constant Nat := String_Length (Str);
856 for J in 1 .. Strlen loop
857 C := Get_String_Char (Str, J);
858 Set_Character_Literal_Name (C);
861 Make_Character_Literal (P,
863 Char_Literal_Value => UI_From_CC (C));
864 Set_Etype (C_Node, Any_Character);
865 Append_To (Exprs, C_Node);
868 -- something special for wide strings ???
871 New_N := Make_Aggregate (Loc, Expressions => Exprs);
872 Set_Analyzed (New_N);
873 Set_Etype (New_N, Any_Composite);
876 end Make_String_Into_Aggregate;
878 -----------------------
879 -- Resolve_Aggregate --
880 -----------------------
882 procedure Resolve_Aggregate (N : Node_Id; Typ : Entity_Id) is
883 Pkind : constant Node_Kind := Nkind (Parent (N));
885 Aggr_Subtyp : Entity_Id;
886 -- The actual aggregate subtype. This is not necessarily the same as Typ
887 -- which is the subtype of the context in which the aggregate was found.
890 -- Check for aggregates not allowed in configurable run-time mode.
891 -- We allow all cases of aggregates that do not come from source,
892 -- since these are all assumed to be small (e.g. bounds of a string
893 -- literal). We also allow aggregates of types we know to be small.
895 if not Support_Aggregates_On_Target
896 and then Comes_From_Source (N)
897 and then (not Known_Static_Esize (Typ) or else Esize (Typ) > 64)
899 Error_Msg_CRT ("aggregate", N);
902 if Is_Limited_Composite (Typ) then
903 Error_Msg_N ("aggregate type cannot have limited component", N);
904 Explain_Limited_Type (Typ, N);
906 -- Ada 2005 (AI-287): Limited aggregates allowed
908 elsif Is_Limited_Type (Typ)
909 and Ada_Version < Ada_05
911 Error_Msg_N ("aggregate type cannot be limited", N);
912 Explain_Limited_Type (Typ, N);
914 elsif Is_Class_Wide_Type (Typ) then
915 Error_Msg_N ("type of aggregate cannot be class-wide", N);
917 elsif Typ = Any_String
918 or else Typ = Any_Composite
920 Error_Msg_N ("no unique type for aggregate", N);
921 Set_Etype (N, Any_Composite);
923 elsif Is_Array_Type (Typ) and then Null_Record_Present (N) then
924 Error_Msg_N ("null record forbidden in array aggregate", N);
926 elsif Is_Record_Type (Typ) then
927 Resolve_Record_Aggregate (N, Typ);
929 elsif Is_Array_Type (Typ) then
931 -- First a special test, for the case of a positional aggregate
932 -- of characters which can be replaced by a string literal.
933 -- Do not perform this transformation if this was a string literal
934 -- to start with, whose components needed constraint checks, or if
935 -- the component type is non-static, because it will require those
936 -- checks and be transformed back into an aggregate.
938 if Number_Dimensions (Typ) = 1
940 (Root_Type (Component_Type (Typ)) = Standard_Character
942 Root_Type (Component_Type (Typ)) = Standard_Wide_Character
944 Root_Type (Component_Type (Typ)) = Standard_Wide_Wide_Character)
945 and then No (Component_Associations (N))
946 and then not Is_Limited_Composite (Typ)
947 and then not Is_Private_Composite (Typ)
948 and then not Is_Bit_Packed_Array (Typ)
949 and then Nkind (Original_Node (Parent (N))) /= N_String_Literal
950 and then Is_Static_Subtype (Component_Type (Typ))
956 Expr := First (Expressions (N));
957 while Present (Expr) loop
958 exit when Nkind (Expr) /= N_Character_Literal;
965 Expr := First (Expressions (N));
966 while Present (Expr) loop
967 Store_String_Char (UI_To_CC (Char_Literal_Value (Expr)));
972 Make_String_Literal (Sloc (N), End_String));
974 Analyze_And_Resolve (N, Typ);
980 -- Here if we have a real aggregate to deal with
982 Array_Aggregate : declare
983 Aggr_Resolved : Boolean;
985 Aggr_Typ : constant Entity_Id := Etype (Typ);
986 -- This is the unconstrained array type, which is the type
987 -- against which the aggregate is to be resolved. Typ itself
988 -- is the array type of the context which may not be the same
989 -- subtype as the subtype for the final aggregate.
992 -- In the following we determine whether an others choice is
993 -- allowed inside the array aggregate. The test checks the context
994 -- in which the array aggregate occurs. If the context does not
995 -- permit it, or the aggregate type is unconstrained, an others
996 -- choice is not allowed.
998 -- If expansion is disabled (generic context, or semantics-only
999 -- mode) actual subtypes cannot be constructed, and the type of
1000 -- an object may be its unconstrained nominal type. However, if
1001 -- the context is an assignment, we assume that "others" is
1002 -- allowed, because the target of the assignment will have a
1003 -- constrained subtype when fully compiled.
1005 -- Note that there is no node for Explicit_Actual_Parameter.
1006 -- To test for this context we therefore have to test for node
1007 -- N_Parameter_Association which itself appears only if there is a
1008 -- formal parameter. Consequently we also need to test for
1009 -- N_Procedure_Call_Statement or N_Function_Call.
1011 Set_Etype (N, Aggr_Typ); -- may be overridden later on
1013 if Is_Constrained (Typ) and then
1014 (Pkind = N_Assignment_Statement or else
1015 Pkind = N_Parameter_Association or else
1016 Pkind = N_Function_Call or else
1017 Pkind = N_Procedure_Call_Statement or else
1018 Pkind = N_Generic_Association or else
1019 Pkind = N_Formal_Object_Declaration or else
1020 Pkind = N_Return_Statement or else
1021 Pkind = N_Object_Declaration or else
1022 Pkind = N_Component_Declaration or else
1023 Pkind = N_Parameter_Specification or else
1024 Pkind = N_Qualified_Expression or else
1025 Pkind = N_Aggregate or else
1026 Pkind = N_Extension_Aggregate or else
1027 Pkind = N_Component_Association)
1030 Resolve_Array_Aggregate
1032 Index => First_Index (Aggr_Typ),
1033 Index_Constr => First_Index (Typ),
1034 Component_Typ => Component_Type (Typ),
1035 Others_Allowed => True);
1037 elsif not Expander_Active
1038 and then Pkind = N_Assignment_Statement
1041 Resolve_Array_Aggregate
1043 Index => First_Index (Aggr_Typ),
1044 Index_Constr => First_Index (Typ),
1045 Component_Typ => Component_Type (Typ),
1046 Others_Allowed => True);
1049 Resolve_Array_Aggregate
1051 Index => First_Index (Aggr_Typ),
1052 Index_Constr => First_Index (Aggr_Typ),
1053 Component_Typ => Component_Type (Typ),
1054 Others_Allowed => False);
1057 if not Aggr_Resolved then
1058 Aggr_Subtyp := Any_Composite;
1060 Aggr_Subtyp := Array_Aggr_Subtype (N, Typ);
1063 Set_Etype (N, Aggr_Subtyp);
1064 end Array_Aggregate;
1066 elsif Is_Private_Type (Typ)
1067 and then Present (Full_View (Typ))
1068 and then In_Inlined_Body
1069 and then Is_Composite_Type (Full_View (Typ))
1071 Resolve (N, Full_View (Typ));
1074 Error_Msg_N ("illegal context for aggregate", N);
1077 -- If we can determine statically that the evaluation of the
1078 -- aggregate raises Constraint_Error, then replace the
1079 -- aggregate with an N_Raise_Constraint_Error node, but set the
1080 -- Etype to the right aggregate subtype. Gigi needs this.
1082 if Raises_Constraint_Error (N) then
1083 Aggr_Subtyp := Etype (N);
1085 Make_Raise_Constraint_Error (Sloc (N),
1086 Reason => CE_Range_Check_Failed));
1087 Set_Raises_Constraint_Error (N);
1088 Set_Etype (N, Aggr_Subtyp);
1091 end Resolve_Aggregate;
1093 -----------------------------
1094 -- Resolve_Array_Aggregate --
1095 -----------------------------
1097 function Resolve_Array_Aggregate
1100 Index_Constr : Node_Id;
1101 Component_Typ : Entity_Id;
1102 Others_Allowed : Boolean)
1105 Loc : constant Source_Ptr := Sloc (N);
1107 Failure : constant Boolean := False;
1108 Success : constant Boolean := True;
1110 Index_Typ : constant Entity_Id := Etype (Index);
1111 Index_Typ_Low : constant Node_Id := Type_Low_Bound (Index_Typ);
1112 Index_Typ_High : constant Node_Id := Type_High_Bound (Index_Typ);
1113 -- The type of the index corresponding to the array sub-aggregate
1114 -- along with its low and upper bounds
1116 Index_Base : constant Entity_Id := Base_Type (Index_Typ);
1117 Index_Base_Low : constant Node_Id := Type_Low_Bound (Index_Base);
1118 Index_Base_High : constant Node_Id := Type_High_Bound (Index_Base);
1119 -- ditto for the base type
1121 function Add (Val : Uint; To : Node_Id) return Node_Id;
1122 -- Creates a new expression node where Val is added to expression To.
1123 -- Tries to constant fold whenever possible. To must be an already
1124 -- analyzed expression.
1126 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id);
1127 -- Checks that AH (the upper bound of an array aggregate) is <= BH
1128 -- (the upper bound of the index base type). If the check fails a
1129 -- warning is emitted, the Raises_Constraint_Error Flag of N is set,
1130 -- and AH is replaced with a duplicate of BH.
1132 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id);
1133 -- Checks that range AL .. AH is compatible with range L .. H. Emits a
1134 -- warning if not and sets the Raises_Constraint_Error Flag in N.
1136 procedure Check_Length (L, H : Node_Id; Len : Uint);
1137 -- Checks that range L .. H contains at least Len elements. Emits a
1138 -- warning if not and sets the Raises_Constraint_Error Flag in N.
1140 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean;
1141 -- Returns True if range L .. H is dynamic or null
1143 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean);
1144 -- Given expression node From, this routine sets OK to False if it
1145 -- cannot statically evaluate From. Otherwise it stores this static
1146 -- value into Value.
1148 function Resolve_Aggr_Expr
1150 Single_Elmt : Boolean)
1152 -- Resolves aggregate expression Expr. Returs False if resolution
1153 -- fails. If Single_Elmt is set to False, the expression Expr may be
1154 -- used to initialize several array aggregate elements (this can
1155 -- happen for discrete choices such as "L .. H => Expr" or the others
1156 -- choice). In this event we do not resolve Expr unless expansion is
1157 -- disabled. To know why, see the DELAYED COMPONENT RESOLUTION
1164 function Add (Val : Uint; To : Node_Id) return Node_Id is
1170 if Raises_Constraint_Error (To) then
1174 -- First test if we can do constant folding
1176 if Compile_Time_Known_Value (To)
1177 or else Nkind (To) = N_Integer_Literal
1179 Expr_Pos := Make_Integer_Literal (Loc, Expr_Value (To) + Val);
1180 Set_Is_Static_Expression (Expr_Pos);
1181 Set_Etype (Expr_Pos, Etype (To));
1182 Set_Analyzed (Expr_Pos, Analyzed (To));
1184 if not Is_Enumeration_Type (Index_Typ) then
1187 -- If we are dealing with enumeration return
1188 -- Index_Typ'Val (Expr_Pos)
1192 Make_Attribute_Reference
1194 Prefix => New_Reference_To (Index_Typ, Loc),
1195 Attribute_Name => Name_Val,
1196 Expressions => New_List (Expr_Pos));
1202 -- If we are here no constant folding possible
1204 if not Is_Enumeration_Type (Index_Base) then
1207 Left_Opnd => Duplicate_Subexpr (To),
1208 Right_Opnd => Make_Integer_Literal (Loc, Val));
1210 -- If we are dealing with enumeration return
1211 -- Index_Typ'Val (Index_Typ'Pos (To) + Val)
1215 Make_Attribute_Reference
1217 Prefix => New_Reference_To (Index_Typ, Loc),
1218 Attribute_Name => Name_Pos,
1219 Expressions => New_List (Duplicate_Subexpr (To)));
1223 Left_Opnd => To_Pos,
1224 Right_Opnd => Make_Integer_Literal (Loc, Val));
1227 Make_Attribute_Reference
1229 Prefix => New_Reference_To (Index_Typ, Loc),
1230 Attribute_Name => Name_Val,
1231 Expressions => New_List (Expr_Pos));
1241 procedure Check_Bound (BH : Node_Id; AH : in out Node_Id) is
1249 Get (Value => Val_BH, From => BH, OK => OK_BH);
1250 Get (Value => Val_AH, From => AH, OK => OK_AH);
1252 if OK_BH and then OK_AH and then Val_BH < Val_AH then
1253 Set_Raises_Constraint_Error (N);
1254 Error_Msg_N ("upper bound out of range?", AH);
1255 Error_Msg_N ("\Constraint_Error will be raised at run-time?", AH);
1257 -- You need to set AH to BH or else in the case of enumerations
1258 -- indices we will not be able to resolve the aggregate bounds.
1260 AH := Duplicate_Subexpr (BH);
1268 procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id) is
1280 if Raises_Constraint_Error (N)
1281 or else Dynamic_Or_Null_Range (AL, AH)
1286 Get (Value => Val_L, From => L, OK => OK_L);
1287 Get (Value => Val_H, From => H, OK => OK_H);
1289 Get (Value => Val_AL, From => AL, OK => OK_AL);
1290 Get (Value => Val_AH, From => AH, OK => OK_AH);
1292 if OK_L and then Val_L > Val_AL then
1293 Set_Raises_Constraint_Error (N);
1294 Error_Msg_N ("lower bound of aggregate out of range?", N);
1295 Error_Msg_N ("\Constraint_Error will be raised at run-time?", N);
1298 if OK_H and then Val_H < Val_AH then
1299 Set_Raises_Constraint_Error (N);
1300 Error_Msg_N ("upper bound of aggregate out of range?", N);
1301 Error_Msg_N ("\Constraint_Error will be raised at run-time?", N);
1309 procedure Check_Length (L, H : Node_Id; Len : Uint) is
1319 if Raises_Constraint_Error (N) then
1323 Get (Value => Val_L, From => L, OK => OK_L);
1324 Get (Value => Val_H, From => H, OK => OK_H);
1326 if not OK_L or else not OK_H then
1330 -- If null range length is zero
1332 if Val_L > Val_H then
1333 Range_Len := Uint_0;
1335 Range_Len := Val_H - Val_L + 1;
1338 if Range_Len < Len then
1339 Set_Raises_Constraint_Error (N);
1340 Error_Msg_N ("too many elements?", N);
1341 Error_Msg_N ("\Constraint_Error will be raised at run-time?", N);
1345 ---------------------------
1346 -- Dynamic_Or_Null_Range --
1347 ---------------------------
1349 function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean is
1357 Get (Value => Val_L, From => L, OK => OK_L);
1358 Get (Value => Val_H, From => H, OK => OK_H);
1360 return not OK_L or else not OK_H
1361 or else not Is_OK_Static_Expression (L)
1362 or else not Is_OK_Static_Expression (H)
1363 or else Val_L > Val_H;
1364 end Dynamic_Or_Null_Range;
1370 procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean) is
1374 if Compile_Time_Known_Value (From) then
1375 Value := Expr_Value (From);
1377 -- If expression From is something like Some_Type'Val (10) then
1380 elsif Nkind (From) = N_Attribute_Reference
1381 and then Attribute_Name (From) = Name_Val
1382 and then Compile_Time_Known_Value (First (Expressions (From)))
1384 Value := Expr_Value (First (Expressions (From)));
1392 -----------------------
1393 -- Resolve_Aggr_Expr --
1394 -----------------------
1396 function Resolve_Aggr_Expr
1398 Single_Elmt : Boolean)
1401 Nxt_Ind : constant Node_Id := Next_Index (Index);
1402 Nxt_Ind_Constr : constant Node_Id := Next_Index (Index_Constr);
1403 -- Index is the current index corresponding to the expresion
1405 Resolution_OK : Boolean := True;
1406 -- Set to False if resolution of the expression failed
1409 -- If the array type against which we are resolving the aggregate
1410 -- has several dimensions, the expressions nested inside the
1411 -- aggregate must be further aggregates (or strings).
1413 if Present (Nxt_Ind) then
1414 if Nkind (Expr) /= N_Aggregate then
1416 -- A string literal can appear where a one-dimensional array
1417 -- of characters is expected. If the literal looks like an
1418 -- operator, it is still an operator symbol, which will be
1419 -- transformed into a string when analyzed.
1421 if Is_Character_Type (Component_Typ)
1422 and then No (Next_Index (Nxt_Ind))
1423 and then (Nkind (Expr) = N_String_Literal
1424 or else Nkind (Expr) = N_Operator_Symbol)
1426 -- A string literal used in a multidimensional array
1427 -- aggregate in place of the final one-dimensional
1428 -- aggregate must not be enclosed in parentheses.
1430 if Paren_Count (Expr) /= 0 then
1431 Error_Msg_N ("no parenthesis allowed here", Expr);
1434 Make_String_Into_Aggregate (Expr);
1437 Error_Msg_N ("nested array aggregate expected", Expr);
1442 -- Ada 2005 (AI-231): Propagate the type to the nested aggregate.
1443 -- Required to check the null-exclusion attribute (if present).
1444 -- This value may be overridden later on.
1446 Set_Etype (Expr, Etype (N));
1448 Resolution_OK := Resolve_Array_Aggregate
1449 (Expr, Nxt_Ind, Nxt_Ind_Constr, Component_Typ, Others_Allowed);
1451 -- Do not resolve the expressions of discrete or others choices
1452 -- unless the expression covers a single component, or the expander
1456 or else not Expander_Active
1457 or else In_Default_Expression
1459 Analyze_And_Resolve (Expr, Component_Typ);
1460 Check_Non_Static_Context (Expr);
1461 Aggregate_Constraint_Checks (Expr, Component_Typ);
1462 Check_Unset_Reference (Expr);
1465 if Raises_Constraint_Error (Expr)
1466 and then Nkind (Parent (Expr)) /= N_Component_Association
1468 Set_Raises_Constraint_Error (N);
1471 return Resolution_OK;
1472 end Resolve_Aggr_Expr;
1474 -- Variables local to Resolve_Array_Aggregate
1480 Who_Cares : Node_Id;
1482 Aggr_Low : Node_Id := Empty;
1483 Aggr_High : Node_Id := Empty;
1484 -- The actual low and high bounds of this sub-aggegate
1486 Choices_Low : Node_Id := Empty;
1487 Choices_High : Node_Id := Empty;
1488 -- The lowest and highest discrete choices values for a named aggregate
1490 Nb_Elements : Uint := Uint_0;
1491 -- The number of elements in a positional aggegate
1493 Others_Present : Boolean := False;
1495 Nb_Choices : Nat := 0;
1496 -- Contains the overall number of named choices in this sub-aggregate
1498 Nb_Discrete_Choices : Nat := 0;
1499 -- The overall number of discrete choices (not counting others choice)
1501 Case_Table_Size : Nat;
1502 -- Contains the size of the case table needed to sort aggregate choices
1504 -- Start of processing for Resolve_Array_Aggregate
1507 -- STEP 1: make sure the aggregate is correctly formatted
1509 if Present (Component_Associations (N)) then
1510 Assoc := First (Component_Associations (N));
1511 while Present (Assoc) loop
1512 Choice := First (Choices (Assoc));
1513 while Present (Choice) loop
1514 if Nkind (Choice) = N_Others_Choice then
1515 Others_Present := True;
1517 if Choice /= First (Choices (Assoc))
1518 or else Present (Next (Choice))
1521 ("OTHERS must appear alone in a choice list", Choice);
1525 if Present (Next (Assoc)) then
1527 ("OTHERS must appear last in an aggregate", Choice);
1531 if Ada_Version = Ada_83
1532 and then Assoc /= First (Component_Associations (N))
1533 and then (Nkind (Parent (N)) = N_Assignment_Statement
1535 Nkind (Parent (N)) = N_Object_Declaration)
1538 ("(Ada 83) illegal context for OTHERS choice", N);
1542 Nb_Choices := Nb_Choices + 1;
1550 -- At this point we know that the others choice, if present, is by
1551 -- itself and appears last in the aggregate. Check if we have mixed
1552 -- positional and discrete associations (other than the others choice).
1554 if Present (Expressions (N))
1555 and then (Nb_Choices > 1
1556 or else (Nb_Choices = 1 and then not Others_Present))
1559 ("named association cannot follow positional association",
1560 First (Choices (First (Component_Associations (N)))));
1564 -- Test for the validity of an others choice if present
1566 if Others_Present and then not Others_Allowed then
1568 ("OTHERS choice not allowed here",
1569 First (Choices (First (Component_Associations (N)))));
1573 -- Protect against cascaded errors
1575 if Etype (Index_Typ) = Any_Type then
1579 -- STEP 2: Process named components
1581 if No (Expressions (N)) then
1583 if Others_Present then
1584 Case_Table_Size := Nb_Choices - 1;
1586 Case_Table_Size := Nb_Choices;
1592 -- Denote the lowest and highest values in an aggregate choice
1596 -- High end of one range and Low end of the next. Should be
1597 -- contiguous if there is no hole in the list of values.
1599 Missing_Values : Boolean;
1600 -- Set True if missing index values
1602 S_Low : Node_Id := Empty;
1603 S_High : Node_Id := Empty;
1604 -- if a choice in an aggregate is a subtype indication these
1605 -- denote the lowest and highest values of the subtype
1607 Table : Case_Table_Type (1 .. Case_Table_Size);
1608 -- Used to sort all the different choice values
1610 Single_Choice : Boolean;
1611 -- Set to true every time there is a single discrete choice in a
1612 -- discrete association
1614 Prev_Nb_Discrete_Choices : Nat;
1615 -- Used to keep track of the number of discrete choices
1616 -- in the current association.
1619 -- STEP 2 (A): Check discrete choices validity
1621 Assoc := First (Component_Associations (N));
1622 while Present (Assoc) loop
1623 Prev_Nb_Discrete_Choices := Nb_Discrete_Choices;
1624 Choice := First (Choices (Assoc));
1628 if Nkind (Choice) = N_Others_Choice then
1629 Single_Choice := False;
1632 -- Test for subtype mark without constraint
1634 elsif Is_Entity_Name (Choice) and then
1635 Is_Type (Entity (Choice))
1637 if Base_Type (Entity (Choice)) /= Index_Base then
1639 ("invalid subtype mark in aggregate choice",
1644 elsif Nkind (Choice) = N_Subtype_Indication then
1645 Resolve_Discrete_Subtype_Indication (Choice, Index_Base);
1647 -- Does the subtype indication evaluation raise CE ?
1649 Get_Index_Bounds (Subtype_Mark (Choice), S_Low, S_High);
1650 Get_Index_Bounds (Choice, Low, High);
1651 Check_Bounds (S_Low, S_High, Low, High);
1653 else -- Choice is a range or an expression
1654 Resolve (Choice, Index_Base);
1655 Check_Unset_Reference (Choice);
1656 Check_Non_Static_Context (Choice);
1658 -- Do not range check a choice. This check is redundant
1659 -- since this test is already performed when we check
1660 -- that the bounds of the array aggregate are within
1663 Set_Do_Range_Check (Choice, False);
1666 -- If we could not resolve the discrete choice stop here
1668 if Etype (Choice) = Any_Type then
1671 -- If the discrete choice raises CE get its original bounds
1673 elsif Nkind (Choice) = N_Raise_Constraint_Error then
1674 Set_Raises_Constraint_Error (N);
1675 Get_Index_Bounds (Original_Node (Choice), Low, High);
1677 -- Otherwise get its bounds as usual
1680 Get_Index_Bounds (Choice, Low, High);
1683 if (Dynamic_Or_Null_Range (Low, High)
1684 or else (Nkind (Choice) = N_Subtype_Indication
1686 Dynamic_Or_Null_Range (S_Low, S_High)))
1687 and then Nb_Choices /= 1
1690 ("dynamic or empty choice in aggregate " &
1691 "must be the only choice", Choice);
1695 Nb_Discrete_Choices := Nb_Discrete_Choices + 1;
1696 Table (Nb_Discrete_Choices).Choice_Lo := Low;
1697 Table (Nb_Discrete_Choices).Choice_Hi := High;
1703 -- Check if we have a single discrete choice and whether
1704 -- this discrete choice specifies a single value.
1707 (Nb_Discrete_Choices = Prev_Nb_Discrete_Choices + 1)
1708 and then (Low = High);
1714 -- Ada 2005 (AI-231)
1716 if Ada_Version >= Ada_05
1717 and then Nkind (Expression (Assoc)) = N_Null
1719 Check_Can_Never_Be_Null (Etype (N), Expression (Assoc));
1722 -- Ada 2005 (AI-287): In case of default initialized component
1723 -- we delay the resolution to the expansion phase
1725 if Box_Present (Assoc) then
1727 -- Ada 2005 (AI-287): In case of default initialization
1728 -- of a component the expander will generate calls to
1729 -- the corresponding initialization subprogram.
1733 elsif not Resolve_Aggr_Expr (Expression (Assoc),
1734 Single_Elmt => Single_Choice)
1742 -- If aggregate contains more than one choice then these must be
1743 -- static. Sort them and check that they are contiguous
1745 if Nb_Discrete_Choices > 1 then
1746 Sort_Case_Table (Table);
1747 Missing_Values := False;
1749 Outer : for J in 1 .. Nb_Discrete_Choices - 1 loop
1750 if Expr_Value (Table (J).Choice_Hi) >=
1751 Expr_Value (Table (J + 1).Choice_Lo)
1754 ("duplicate choice values in array aggregate",
1755 Table (J).Choice_Hi);
1758 elsif not Others_Present then
1760 Hi_Val := Expr_Value (Table (J).Choice_Hi);
1761 Lo_Val := Expr_Value (Table (J + 1).Choice_Lo);
1763 -- If missing values, output error messages
1765 if Lo_Val - Hi_Val > 1 then
1767 -- Header message if not first missing value
1769 if not Missing_Values then
1771 ("missing index value(s) in array aggregate", N);
1772 Missing_Values := True;
1775 -- Output values of missing indexes
1777 Lo_Val := Lo_Val - 1;
1778 Hi_Val := Hi_Val + 1;
1780 -- Enumeration type case
1782 if Is_Enumeration_Type (Index_Typ) then
1785 (Get_Enum_Lit_From_Pos
1786 (Index_Typ, Hi_Val, Loc));
1788 if Lo_Val = Hi_Val then
1789 Error_Msg_N ("\ %", N);
1793 (Get_Enum_Lit_From_Pos
1794 (Index_Typ, Lo_Val, Loc));
1795 Error_Msg_N ("\ % .. %", N);
1798 -- Integer types case
1801 Error_Msg_Uint_1 := Hi_Val;
1803 if Lo_Val = Hi_Val then
1804 Error_Msg_N ("\ ^", N);
1806 Error_Msg_Uint_2 := Lo_Val;
1807 Error_Msg_N ("\ ^ .. ^", N);
1814 if Missing_Values then
1815 Set_Etype (N, Any_Composite);
1820 -- STEP 2 (B): Compute aggregate bounds and min/max choices values
1822 if Nb_Discrete_Choices > 0 then
1823 Choices_Low := Table (1).Choice_Lo;
1824 Choices_High := Table (Nb_Discrete_Choices).Choice_Hi;
1827 if Others_Present then
1828 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
1831 Aggr_Low := Choices_Low;
1832 Aggr_High := Choices_High;
1836 -- STEP 3: Process positional components
1839 -- STEP 3 (A): Process positional elements
1841 Expr := First (Expressions (N));
1842 Nb_Elements := Uint_0;
1843 while Present (Expr) loop
1844 Nb_Elements := Nb_Elements + 1;
1846 -- Ada 2005 (AI-231)
1848 if Ada_Version >= Ada_05
1849 and then Nkind (Expr) = N_Null
1851 Check_Can_Never_Be_Null (Etype (N), Expr);
1854 if not Resolve_Aggr_Expr (Expr, Single_Elmt => True) then
1861 if Others_Present then
1862 Assoc := Last (Component_Associations (N));
1864 -- Ada 2005 (AI-231)
1866 if Ada_Version >= Ada_05
1867 and then Nkind (Assoc) = N_Null
1869 Check_Can_Never_Be_Null (Etype (N), Expression (Assoc));
1872 -- Ada 2005 (AI-287): In case of default initialized component
1873 -- we delay the resolution to the expansion phase.
1875 if Box_Present (Assoc) then
1877 -- Ada 2005 (AI-287): In case of default initialization
1878 -- of a component the expander will generate calls to
1879 -- the corresponding initialization subprogram.
1883 elsif not Resolve_Aggr_Expr (Expression (Assoc),
1884 Single_Elmt => False)
1890 -- STEP 3 (B): Compute the aggregate bounds
1892 if Others_Present then
1893 Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
1896 if Others_Allowed then
1897 Get_Index_Bounds (Index_Constr, Aggr_Low, Who_Cares);
1899 Aggr_Low := Index_Typ_Low;
1902 Aggr_High := Add (Nb_Elements - 1, To => Aggr_Low);
1903 Check_Bound (Index_Base_High, Aggr_High);
1907 -- STEP 4: Perform static aggregate checks and save the bounds
1911 Check_Bounds (Index_Typ_Low, Index_Typ_High, Aggr_Low, Aggr_High);
1912 Check_Bounds (Index_Base_Low, Index_Base_High, Aggr_Low, Aggr_High);
1916 if Others_Present and then Nb_Discrete_Choices > 0 then
1917 Check_Bounds (Aggr_Low, Aggr_High, Choices_Low, Choices_High);
1918 Check_Bounds (Index_Typ_Low, Index_Typ_High,
1919 Choices_Low, Choices_High);
1920 Check_Bounds (Index_Base_Low, Index_Base_High,
1921 Choices_Low, Choices_High);
1925 elsif Others_Present and then Nb_Elements > 0 then
1926 Check_Length (Aggr_Low, Aggr_High, Nb_Elements);
1927 Check_Length (Index_Typ_Low, Index_Typ_High, Nb_Elements);
1928 Check_Length (Index_Base_Low, Index_Base_High, Nb_Elements);
1931 if Raises_Constraint_Error (Aggr_Low)
1932 or else Raises_Constraint_Error (Aggr_High)
1934 Set_Raises_Constraint_Error (N);
1937 Aggr_Low := Duplicate_Subexpr (Aggr_Low);
1939 -- Do not duplicate Aggr_High if Aggr_High = Aggr_Low + Nb_Elements
1940 -- since the addition node returned by Add is not yet analyzed. Attach
1941 -- to tree and analyze first. Reset analyzed flag to insure it will get
1942 -- analyzed when it is a literal bound whose type must be properly set.
1944 if Others_Present or else Nb_Discrete_Choices > 0 then
1945 Aggr_High := Duplicate_Subexpr (Aggr_High);
1947 if Etype (Aggr_High) = Universal_Integer then
1948 Set_Analyzed (Aggr_High, False);
1952 Set_Aggregate_Bounds
1953 (N, Make_Range (Loc, Low_Bound => Aggr_Low, High_Bound => Aggr_High));
1955 -- The bounds may contain expressions that must be inserted upwards.
1956 -- Attach them fully to the tree. After analysis, remove side effects
1957 -- from upper bound, if still needed.
1959 Set_Parent (Aggregate_Bounds (N), N);
1960 Analyze_And_Resolve (Aggregate_Bounds (N), Index_Typ);
1961 Check_Unset_Reference (Aggregate_Bounds (N));
1963 if not Others_Present and then Nb_Discrete_Choices = 0 then
1964 Set_High_Bound (Aggregate_Bounds (N),
1965 Duplicate_Subexpr (High_Bound (Aggregate_Bounds (N))));
1969 end Resolve_Array_Aggregate;
1971 ---------------------------------
1972 -- Resolve_Extension_Aggregate --
1973 ---------------------------------
1975 -- There are two cases to consider:
1977 -- a) If the ancestor part is a type mark, the components needed are
1978 -- the difference between the components of the expected type and the
1979 -- components of the given type mark.
1981 -- b) If the ancestor part is an expression, it must be unambiguous,
1982 -- and once we have its type we can also compute the needed components
1983 -- as in the previous case. In both cases, if the ancestor type is not
1984 -- the immediate ancestor, we have to build this ancestor recursively.
1986 -- In both cases discriminants of the ancestor type do not play a
1987 -- role in the resolution of the needed components, because inherited
1988 -- discriminants cannot be used in a type extension. As a result we can
1989 -- compute independently the list of components of the ancestor type and
1990 -- of the expected type.
1992 procedure Resolve_Extension_Aggregate (N : Node_Id; Typ : Entity_Id) is
1993 A : constant Node_Id := Ancestor_Part (N);
1998 function Valid_Ancestor_Type return Boolean;
1999 -- Verify that the type of the ancestor part is a non-private ancestor
2000 -- of the expected type.
2002 -------------------------
2003 -- Valid_Ancestor_Type --
2004 -------------------------
2006 function Valid_Ancestor_Type return Boolean is
2007 Imm_Type : Entity_Id;
2010 Imm_Type := Base_Type (Typ);
2011 while Is_Derived_Type (Imm_Type)
2012 and then Etype (Imm_Type) /= Base_Type (A_Type)
2014 Imm_Type := Etype (Base_Type (Imm_Type));
2017 if Etype (Imm_Type) /= Base_Type (A_Type) then
2018 Error_Msg_NE ("expect ancestor type of &", A, Typ);
2023 end Valid_Ancestor_Type;
2025 -- Start of processing for Resolve_Extension_Aggregate
2030 if not Is_Tagged_Type (Typ) then
2031 Error_Msg_N ("type of extension aggregate must be tagged", N);
2034 elsif Is_Limited_Type (Typ) then
2036 -- Ada 2005 (AI-287): Limited aggregates are allowed
2038 if Ada_Version < Ada_05 then
2039 Error_Msg_N ("aggregate type cannot be limited", N);
2040 Explain_Limited_Type (Typ, N);
2044 elsif Is_Class_Wide_Type (Typ) then
2045 Error_Msg_N ("aggregate cannot be of a class-wide type", N);
2049 if Is_Entity_Name (A)
2050 and then Is_Type (Entity (A))
2052 A_Type := Get_Full_View (Entity (A));
2054 if Valid_Ancestor_Type then
2055 Set_Entity (A, A_Type);
2056 Set_Etype (A, A_Type);
2058 Validate_Ancestor_Part (N);
2059 Resolve_Record_Aggregate (N, Typ);
2062 elsif Nkind (A) /= N_Aggregate then
2063 if Is_Overloaded (A) then
2066 Get_First_Interp (A, I, It);
2067 while Present (It.Typ) loop
2068 if Is_Tagged_Type (It.Typ)
2069 and then not Is_Limited_Type (It.Typ)
2071 if A_Type /= Any_Type then
2072 Error_Msg_N ("cannot resolve expression", A);
2079 Get_Next_Interp (I, It);
2082 if A_Type = Any_Type then
2084 ("ancestor part must be non-limited tagged type", A);
2089 A_Type := Etype (A);
2092 if Valid_Ancestor_Type then
2093 Resolve (A, A_Type);
2094 Check_Unset_Reference (A);
2095 Check_Non_Static_Context (A);
2097 if Is_Class_Wide_Type (Etype (A))
2098 and then Nkind (Original_Node (A)) = N_Function_Call
2100 -- If the ancestor part is a dispatching call, it appears
2101 -- statically to be a legal ancestor, but it yields any
2102 -- member of the class, and it is not possible to determine
2103 -- whether it is an ancestor of the extension aggregate (much
2104 -- less which ancestor). It is not possible to determine the
2105 -- required components of the extension part.
2107 -- This check implements AI-306, which in fact was motivated
2108 -- by an ACT query to the ARG after this test was added.
2110 Error_Msg_N ("ancestor part must be statically tagged", A);
2112 Resolve_Record_Aggregate (N, Typ);
2117 Error_Msg_N (" No unique type for this aggregate", A);
2119 end Resolve_Extension_Aggregate;
2121 ------------------------------
2122 -- Resolve_Record_Aggregate --
2123 ------------------------------
2125 procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id) is
2127 -- N_Component_Association node belonging to the input aggregate N
2130 Positional_Expr : Node_Id;
2131 Component : Entity_Id;
2132 Component_Elmt : Elmt_Id;
2134 Components : constant Elist_Id := New_Elmt_List;
2135 -- Components is the list of the record components whose value must
2136 -- be provided in the aggregate. This list does include discriminants.
2138 New_Assoc_List : constant List_Id := New_List;
2139 New_Assoc : Node_Id;
2140 -- New_Assoc_List is the newly built list of N_Component_Association
2141 -- nodes. New_Assoc is one such N_Component_Association node in it.
2142 -- Please note that while Assoc and New_Assoc contain the same
2143 -- kind of nodes, they are used to iterate over two different
2144 -- N_Component_Association lists.
2146 Others_Etype : Entity_Id := Empty;
2147 -- This variable is used to save the Etype of the last record component
2148 -- that takes its value from the others choice. Its purpose is:
2150 -- (a) make sure the others choice is useful
2152 -- (b) make sure the type of all the components whose value is
2153 -- subsumed by the others choice are the same.
2155 -- This variable is updated as a side effect of function Get_Value
2157 Is_Box_Present : Boolean := False;
2158 Others_Box : Boolean := False;
2159 -- Ada 2005 (AI-287): Variables used in case of default initialization
2160 -- to provide a functionality similar to Others_Etype. Box_Present
2161 -- indicates that the component takes its default initialization;
2162 -- Others_Box indicates that at least one component takes its default
2163 -- initialization. Similar to Others_Etype, they are also updated as a
2164 -- side effect of function Get_Value.
2166 procedure Add_Association
2167 (Component : Entity_Id;
2169 Is_Box_Present : Boolean := False);
2170 -- Builds a new N_Component_Association node which associates
2171 -- Component to expression Expr and adds it to the new association
2172 -- list New_Assoc_List being built.
2174 function Discr_Present (Discr : Entity_Id) return Boolean;
2175 -- If aggregate N is a regular aggregate this routine will return True.
2176 -- Otherwise, if N is an extension aggregate, Discr is a discriminant
2177 -- whose value may already have been specified by N's ancestor part,
2178 -- this routine checks whether this is indeed the case and if so
2179 -- returns False, signaling that no value for Discr should appear in the
2180 -- N's aggregate part. Also, in this case, the routine appends to
2181 -- New_Assoc_List Discr the discriminant value specified in the ancestor
2187 Consider_Others_Choice : Boolean := False)
2189 -- Given a record component stored in parameter Compon, the
2190 -- following function returns its value as it appears in the list
2191 -- From, which is a list of N_Component_Association nodes. If no
2192 -- component association has a choice for the searched component,
2193 -- the value provided by the others choice is returned, if there
2194 -- is one and Consider_Others_Choice is set to true. Otherwise
2195 -- Empty is returned. If there is more than one component association
2196 -- giving a value for the searched record component, an error message
2197 -- is emitted and the first found value is returned.
2199 -- If Consider_Others_Choice is set and the returned expression comes
2200 -- from the others choice, then Others_Etype is set as a side effect.
2201 -- An error message is emitted if the components taking their value
2202 -- from the others choice do not have same type.
2204 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id);
2205 -- Analyzes and resolves expression Expr against the Etype of the
2206 -- Component. This routine also applies all appropriate checks to Expr.
2207 -- It finally saves a Expr in the newly created association list that
2208 -- will be attached to the final record aggregate. Note that if the
2209 -- Parent pointer of Expr is not set then Expr was produced with a
2210 -- New_Copy_Tree or some such.
2212 ---------------------
2213 -- Add_Association --
2214 ---------------------
2216 procedure Add_Association
2217 (Component : Entity_Id;
2219 Is_Box_Present : Boolean := False)
2221 Choice_List : constant List_Id := New_List;
2222 New_Assoc : Node_Id;
2225 Append (New_Occurrence_Of (Component, Sloc (Expr)), Choice_List);
2227 Make_Component_Association (Sloc (Expr),
2228 Choices => Choice_List,
2230 Box_Present => Is_Box_Present);
2231 Append (New_Assoc, New_Assoc_List);
2232 end Add_Association;
2238 function Discr_Present (Discr : Entity_Id) return Boolean is
2239 Regular_Aggr : constant Boolean := Nkind (N) /= N_Extension_Aggregate;
2244 Discr_Expr : Node_Id;
2246 Ancestor_Typ : Entity_Id;
2247 Orig_Discr : Entity_Id;
2249 D_Val : Elmt_Id := No_Elmt; -- stop junk warning
2251 Ancestor_Is_Subtyp : Boolean;
2254 if Regular_Aggr then
2258 Ancestor := Ancestor_Part (N);
2259 Ancestor_Typ := Etype (Ancestor);
2260 Loc := Sloc (Ancestor);
2262 Ancestor_Is_Subtyp :=
2263 Is_Entity_Name (Ancestor) and then Is_Type (Entity (Ancestor));
2265 -- If the ancestor part has no discriminants clearly N's aggregate
2266 -- part must provide a value for Discr.
2268 if not Has_Discriminants (Ancestor_Typ) then
2271 -- If the ancestor part is an unconstrained subtype mark then the
2272 -- Discr must be present in N's aggregate part.
2274 elsif Ancestor_Is_Subtyp
2275 and then not Is_Constrained (Entity (Ancestor))
2280 -- Now look to see if Discr was specified in the ancestor part
2282 if Ancestor_Is_Subtyp then
2283 D_Val := First_Elmt (Discriminant_Constraint (Entity (Ancestor)));
2286 Orig_Discr := Original_Record_Component (Discr);
2288 D := First_Discriminant (Ancestor_Typ);
2289 while Present (D) loop
2291 -- If Ancestor has already specified Disc value than insert its
2292 -- value in the final aggregate.
2294 if Original_Record_Component (D) = Orig_Discr then
2295 if Ancestor_Is_Subtyp then
2296 Discr_Expr := New_Copy_Tree (Node (D_Val));
2299 Make_Selected_Component (Loc,
2300 Prefix => Duplicate_Subexpr (Ancestor),
2301 Selector_Name => New_Occurrence_Of (Discr, Loc));
2304 Resolve_Aggr_Expr (Discr_Expr, Discr);
2308 Next_Discriminant (D);
2310 if Ancestor_Is_Subtyp then
2325 Consider_Others_Choice : Boolean := False)
2329 Expr : Node_Id := Empty;
2330 Selector_Name : Node_Id;
2332 procedure Check_Non_Limited_Type;
2333 -- Relax check to allow the default initialization of limited types.
2336 -- C : Lim := (..., others => <>);
2339 ----------------------------
2340 -- Check_Non_Limited_Type --
2341 ----------------------------
2343 procedure Check_Non_Limited_Type is
2345 if Is_Limited_Type (Etype (Compon))
2346 and then Comes_From_Source (Compon)
2347 and then not In_Instance_Body
2349 -- Ada 2005 (AI-287): Limited aggregates are allowed
2351 if Ada_Version >= Ada_05
2352 and then Present (Expression (Assoc))
2353 and then Nkind (Expression (Assoc)) = N_Aggregate
2358 ("initialization not allowed for limited types", N);
2359 Explain_Limited_Type (Etype (Compon), Compon);
2362 end Check_Non_Limited_Type;
2364 -- Start of processing for Get_Value
2367 Is_Box_Present := False;
2369 if Present (From) then
2370 Assoc := First (From);
2375 while Present (Assoc) loop
2376 Selector_Name := First (Choices (Assoc));
2377 while Present (Selector_Name) loop
2378 if Nkind (Selector_Name) = N_Others_Choice then
2379 if Consider_Others_Choice and then No (Expr) then
2381 -- We need to duplicate the expression for each
2382 -- successive component covered by the others choice.
2383 -- This is redundant if the others_choice covers only
2384 -- one component (small optimization possible???), but
2385 -- indispensable otherwise, because each one must be
2386 -- expanded individually to preserve side-effects.
2388 -- Ada 2005 (AI-287): In case of default initialization
2389 -- of components, we duplicate the corresponding default
2390 -- expression (from the record type declaration).
2392 if Box_Present (Assoc) then
2394 Is_Box_Present := True;
2396 if Expander_Active then
2397 return New_Copy_Tree (Expression (Parent (Compon)));
2399 return Expression (Parent (Compon));
2403 Check_Non_Limited_Type;
2405 if Present (Others_Etype) and then
2406 Base_Type (Others_Etype) /= Base_Type (Etype
2409 Error_Msg_N ("components in OTHERS choice must " &
2410 "have same type", Selector_Name);
2413 Others_Etype := Etype (Compon);
2415 if Expander_Active then
2416 return New_Copy_Tree (Expression (Assoc));
2418 return Expression (Assoc);
2423 elsif Chars (Compon) = Chars (Selector_Name) then
2426 -- Ada 2005 (AI-231)
2428 if Ada_Version >= Ada_05
2429 and then Nkind (Expression (Assoc)) = N_Null
2431 Check_Can_Never_Be_Null (Compon, Expression (Assoc));
2434 -- We need to duplicate the expression when several
2435 -- components are grouped together with a "|" choice.
2436 -- For instance "filed1 | filed2 => Expr"
2438 -- Ada 2005 (AI-287)
2440 if Box_Present (Assoc) then
2441 Is_Box_Present := True;
2443 -- Duplicate the default expression of the component
2444 -- from the record type declaration
2446 if Present (Next (Selector_Name)) then
2448 New_Copy_Tree (Expression (Parent (Compon)));
2450 Expr := Expression (Parent (Compon));
2454 Check_Non_Limited_Type;
2456 if Present (Next (Selector_Name)) then
2457 Expr := New_Copy_Tree (Expression (Assoc));
2459 Expr := Expression (Assoc);
2463 Generate_Reference (Compon, Selector_Name);
2467 ("more than one value supplied for &",
2468 Selector_Name, Compon);
2473 Next (Selector_Name);
2482 -----------------------
2483 -- Resolve_Aggr_Expr --
2484 -----------------------
2486 procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id) is
2487 New_C : Entity_Id := Component;
2488 Expr_Type : Entity_Id := Empty;
2490 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean;
2491 -- If the expression is an aggregate (possibly qualified) then its
2492 -- expansion is delayed until the enclosing aggregate is expanded
2493 -- into assignments. In that case, do not generate checks on the
2494 -- expression, because they will be generated later, and will other-
2495 -- wise force a copy (to remove side-effects) that would leave a
2496 -- dynamic-sized aggregate in the code, something that gigi cannot
2500 -- Set to True if the resolved Expr node needs to be relocated
2501 -- when attached to the newly created association list. This node
2502 -- need not be relocated if its parent pointer is not set.
2503 -- In fact in this case Expr is the output of a New_Copy_Tree call.
2504 -- if Relocate is True then we have analyzed the expression node
2505 -- in the original aggregate and hence it needs to be relocated
2506 -- when moved over the new association list.
2508 function Has_Expansion_Delayed (Expr : Node_Id) return Boolean is
2509 Kind : constant Node_Kind := Nkind (Expr);
2512 return ((Kind = N_Aggregate
2513 or else Kind = N_Extension_Aggregate)
2514 and then Present (Etype (Expr))
2515 and then Is_Record_Type (Etype (Expr))
2516 and then Expansion_Delayed (Expr))
2518 or else (Kind = N_Qualified_Expression
2519 and then Has_Expansion_Delayed (Expression (Expr)));
2520 end Has_Expansion_Delayed;
2522 -- Start of processing for Resolve_Aggr_Expr
2525 -- If the type of the component is elementary or the type of the
2526 -- aggregate does not contain discriminants, use the type of the
2527 -- component to resolve Expr.
2529 if Is_Elementary_Type (Etype (Component))
2530 or else not Has_Discriminants (Etype (N))
2532 Expr_Type := Etype (Component);
2534 -- Otherwise we have to pick up the new type of the component from
2535 -- the new costrained subtype of the aggregate. In fact components
2536 -- which are of a composite type might be constrained by a
2537 -- discriminant, and we want to resolve Expr against the subtype were
2538 -- all discriminant occurrences are replaced with their actual value.
2541 New_C := First_Component (Etype (N));
2542 while Present (New_C) loop
2543 if Chars (New_C) = Chars (Component) then
2544 Expr_Type := Etype (New_C);
2548 Next_Component (New_C);
2551 pragma Assert (Present (Expr_Type));
2553 -- For each range in an array type where a discriminant has been
2554 -- replaced with the constraint, check that this range is within
2555 -- the range of the base type. This checks is done in the init
2556 -- proc for regular objects, but has to be done here for
2557 -- aggregates since no init proc is called for them.
2559 if Is_Array_Type (Expr_Type) then
2562 -- Range of the current constrained index in the array
2564 Orig_Index : Node_Id := First_Index (Etype (Component));
2565 -- Range corresponding to the range Index above in the
2566 -- original unconstrained record type. The bounds of this
2567 -- range may be governed by discriminants.
2569 Unconstr_Index : Node_Id := First_Index (Etype (Expr_Type));
2570 -- Range corresponding to the range Index above for the
2571 -- unconstrained array type. This range is needed to apply
2575 Index := First_Index (Expr_Type);
2576 while Present (Index) loop
2577 if Depends_On_Discriminant (Orig_Index) then
2578 Apply_Range_Check (Index, Etype (Unconstr_Index));
2582 Next_Index (Orig_Index);
2583 Next_Index (Unconstr_Index);
2589 -- If the Parent pointer of Expr is not set, Expr is an expression
2590 -- duplicated by New_Tree_Copy (this happens for record aggregates
2591 -- that look like (Field1 | Filed2 => Expr) or (others => Expr)).
2592 -- Such a duplicated expression must be attached to the tree
2593 -- before analysis and resolution to enforce the rule that a tree
2594 -- fragment should never be analyzed or resolved unless it is
2595 -- attached to the current compilation unit.
2597 if No (Parent (Expr)) then
2598 Set_Parent (Expr, N);
2604 Analyze_And_Resolve (Expr, Expr_Type);
2605 Check_Non_Static_Context (Expr);
2606 Check_Unset_Reference (Expr);
2608 if not Has_Expansion_Delayed (Expr) then
2609 Aggregate_Constraint_Checks (Expr, Expr_Type);
2612 if Raises_Constraint_Error (Expr) then
2613 Set_Raises_Constraint_Error (N);
2617 Add_Association (New_C, Relocate_Node (Expr));
2619 Add_Association (New_C, Expr);
2621 end Resolve_Aggr_Expr;
2623 -- Start of processing for Resolve_Record_Aggregate
2626 -- We may end up calling Duplicate_Subexpr on expressions that are
2627 -- attached to New_Assoc_List. For this reason we need to attach it
2628 -- to the tree by setting its parent pointer to N. This parent point
2629 -- will change in STEP 8 below.
2631 Set_Parent (New_Assoc_List, N);
2633 -- STEP 1: abstract type and null record verification
2635 if Is_Abstract (Typ) then
2636 Error_Msg_N ("type of aggregate cannot be abstract", N);
2639 if No (First_Entity (Typ)) and then Null_Record_Present (N) then
2643 elsif Present (First_Entity (Typ))
2644 and then Null_Record_Present (N)
2645 and then not Is_Tagged_Type (Typ)
2647 Error_Msg_N ("record aggregate cannot be null", N);
2650 elsif No (First_Entity (Typ)) then
2651 Error_Msg_N ("record aggregate must be null", N);
2655 -- STEP 2: Verify aggregate structure
2658 Selector_Name : Node_Id;
2659 Bad_Aggregate : Boolean := False;
2662 if Present (Component_Associations (N)) then
2663 Assoc := First (Component_Associations (N));
2668 while Present (Assoc) loop
2669 Selector_Name := First (Choices (Assoc));
2670 while Present (Selector_Name) loop
2671 if Nkind (Selector_Name) = N_Identifier then
2674 elsif Nkind (Selector_Name) = N_Others_Choice then
2675 if Selector_Name /= First (Choices (Assoc))
2676 or else Present (Next (Selector_Name))
2678 Error_Msg_N ("OTHERS must appear alone in a choice list",
2682 elsif Present (Next (Assoc)) then
2683 Error_Msg_N ("OTHERS must appear last in an aggregate",
2690 ("selector name should be identifier or OTHERS",
2692 Bad_Aggregate := True;
2695 Next (Selector_Name);
2701 if Bad_Aggregate then
2706 -- STEP 3: Find discriminant Values
2709 Discrim : Entity_Id;
2710 Missing_Discriminants : Boolean := False;
2713 if Present (Expressions (N)) then
2714 Positional_Expr := First (Expressions (N));
2716 Positional_Expr := Empty;
2719 if Has_Discriminants (Typ) then
2720 Discrim := First_Discriminant (Typ);
2725 -- First find the discriminant values in the positional components
2727 while Present (Discrim) and then Present (Positional_Expr) loop
2728 if Discr_Present (Discrim) then
2729 Resolve_Aggr_Expr (Positional_Expr, Discrim);
2731 -- Ada 2005 (AI-231)
2733 if Ada_Version >= Ada_05
2734 and then Nkind (Positional_Expr) = N_Null
2736 Check_Can_Never_Be_Null (Discrim, Positional_Expr);
2739 Next (Positional_Expr);
2742 if Present (Get_Value (Discrim, Component_Associations (N))) then
2744 ("more than one value supplied for discriminant&",
2748 Next_Discriminant (Discrim);
2751 -- Find remaining discriminant values, if any, among named components
2753 while Present (Discrim) loop
2754 Expr := Get_Value (Discrim, Component_Associations (N), True);
2756 if not Discr_Present (Discrim) then
2757 if Present (Expr) then
2759 ("more than one value supplied for discriminant&",
2763 elsif No (Expr) then
2765 ("no value supplied for discriminant &", N, Discrim);
2766 Missing_Discriminants := True;
2769 Resolve_Aggr_Expr (Expr, Discrim);
2772 Next_Discriminant (Discrim);
2775 if Missing_Discriminants then
2779 -- At this point and until the beginning of STEP 6, New_Assoc_List
2780 -- contains only the discriminants and their values.
2784 -- STEP 4: Set the Etype of the record aggregate
2786 -- ??? This code is pretty much a copy of Sem_Ch3.Build_Subtype. That
2787 -- routine should really be exported in sem_util or some such and used
2788 -- in sem_ch3 and here rather than have a copy of the code which is a
2789 -- maintenance nightmare.
2791 -- ??? Performace WARNING. The current implementation creates a new
2792 -- itype for all aggregates whose base type is discriminated.
2793 -- This means that for record aggregates nested inside an array
2794 -- aggregate we will create a new itype for each record aggregate
2795 -- if the array cmponent type has discriminants. For large aggregates
2796 -- this may be a problem. What should be done in this case is
2797 -- to reuse itypes as much as possible.
2799 if Has_Discriminants (Typ) then
2800 Build_Constrained_Itype : declare
2801 Loc : constant Source_Ptr := Sloc (N);
2803 Subtyp_Decl : Node_Id;
2806 C : constant List_Id := New_List;
2809 New_Assoc := First (New_Assoc_List);
2810 while Present (New_Assoc) loop
2811 Append (Duplicate_Subexpr (Expression (New_Assoc)), To => C);
2816 Make_Subtype_Indication (Loc,
2817 Subtype_Mark => New_Occurrence_Of (Base_Type (Typ), Loc),
2818 Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C));
2820 Def_Id := Create_Itype (Ekind (Typ), N);
2823 Make_Subtype_Declaration (Loc,
2824 Defining_Identifier => Def_Id,
2825 Subtype_Indication => Indic);
2826 Set_Parent (Subtyp_Decl, Parent (N));
2828 -- Itypes must be analyzed with checks off (see itypes.ads)
2830 Analyze (Subtyp_Decl, Suppress => All_Checks);
2832 Set_Etype (N, Def_Id);
2833 Check_Static_Discriminated_Subtype
2834 (Def_Id, Expression (First (New_Assoc_List)));
2835 end Build_Constrained_Itype;
2841 -- STEP 5: Get remaining components according to discriminant values
2844 Record_Def : Node_Id;
2845 Parent_Typ : Entity_Id;
2846 Root_Typ : Entity_Id;
2847 Parent_Typ_List : Elist_Id;
2848 Parent_Elmt : Elmt_Id;
2849 Errors_Found : Boolean := False;
2853 if Is_Derived_Type (Typ) and then Is_Tagged_Type (Typ) then
2854 Parent_Typ_List := New_Elmt_List;
2856 -- If this is an extension aggregate, the component list must
2857 -- include all components that are not in the given ancestor
2858 -- type. Otherwise, the component list must include components
2859 -- of all ancestors, starting with the root.
2861 if Nkind (N) = N_Extension_Aggregate then
2862 Root_Typ := Base_Type (Etype (Ancestor_Part (N)));
2864 Root_Typ := Root_Type (Typ);
2866 if Nkind (Parent (Base_Type (Root_Typ)))
2867 = N_Private_Type_Declaration
2870 ("type of aggregate has private ancestor&!",
2872 Error_Msg_N ("must use extension aggregate!", N);
2876 Dnode := Declaration_Node (Base_Type (Root_Typ));
2878 -- If we don't get a full declaration, then we have some
2879 -- error which will get signalled later so skip this part.
2880 -- Otherwise, gather components of root that apply to the
2881 -- aggregate type. We use the base type in case there is an
2882 -- applicable stored constraint that renames the discriminants
2885 if Nkind (Dnode) = N_Full_Type_Declaration then
2886 Record_Def := Type_Definition (Dnode);
2887 Gather_Components (Base_Type (Typ),
2888 Component_List (Record_Def),
2889 Governed_By => New_Assoc_List,
2891 Report_Errors => Errors_Found);
2895 Parent_Typ := Base_Type (Typ);
2896 while Parent_Typ /= Root_Typ loop
2897 Prepend_Elmt (Parent_Typ, To => Parent_Typ_List);
2898 Parent_Typ := Etype (Parent_Typ);
2900 if Nkind (Parent (Base_Type (Parent_Typ))) =
2901 N_Private_Type_Declaration
2902 or else Nkind (Parent (Base_Type (Parent_Typ))) =
2903 N_Private_Extension_Declaration
2905 if Nkind (N) /= N_Extension_Aggregate then
2907 ("type of aggregate has private ancestor&!",
2909 Error_Msg_N ("must use extension aggregate!", N);
2912 elsif Parent_Typ /= Root_Typ then
2914 ("ancestor part of aggregate must be private type&",
2915 Ancestor_Part (N), Parent_Typ);
2921 -- Now collect components from all other ancestors
2923 Parent_Elmt := First_Elmt (Parent_Typ_List);
2924 while Present (Parent_Elmt) loop
2925 Parent_Typ := Node (Parent_Elmt);
2926 Record_Def := Type_Definition (Parent (Base_Type (Parent_Typ)));
2927 Gather_Components (Empty,
2928 Component_List (Record_Extension_Part (Record_Def)),
2929 Governed_By => New_Assoc_List,
2931 Report_Errors => Errors_Found);
2933 Next_Elmt (Parent_Elmt);
2937 Record_Def := Type_Definition (Parent (Base_Type (Typ)));
2939 if Null_Present (Record_Def) then
2942 Gather_Components (Base_Type (Typ),
2943 Component_List (Record_Def),
2944 Governed_By => New_Assoc_List,
2946 Report_Errors => Errors_Found);
2950 if Errors_Found then
2955 -- STEP 6: Find component Values
2958 Component_Elmt := First_Elmt (Components);
2960 -- First scan the remaining positional associations in the aggregate.
2961 -- Remember that at this point Positional_Expr contains the current
2962 -- positional association if any is left after looking for discriminant
2963 -- values in step 3.
2965 while Present (Positional_Expr) and then Present (Component_Elmt) loop
2966 Component := Node (Component_Elmt);
2967 Resolve_Aggr_Expr (Positional_Expr, Component);
2969 -- Ada 2005 (AI-231)
2971 if Ada_Version >= Ada_05
2972 and then Nkind (Positional_Expr) = N_Null
2974 Check_Can_Never_Be_Null (Component, Positional_Expr);
2977 if Present (Get_Value (Component, Component_Associations (N))) then
2979 ("more than one value supplied for Component &", N, Component);
2982 Next (Positional_Expr);
2983 Next_Elmt (Component_Elmt);
2986 if Present (Positional_Expr) then
2988 ("too many components for record aggregate", Positional_Expr);
2991 -- Now scan for the named arguments of the aggregate
2993 while Present (Component_Elmt) loop
2994 Component := Node (Component_Elmt);
2995 Expr := Get_Value (Component, Component_Associations (N), True);
2997 -- Note: The previous call to Get_Value sets the value of the
2998 -- variable Is_Box_Present
3000 -- Ada 2005 (AI-287): Handle components with default initialization.
3001 -- Note: This feature was originally added to Ada 2005 for limited
3002 -- but it was finally allowed with any type.
3004 if Is_Box_Present then
3006 Is_Array_Subtype : constant Boolean :=
3007 Ekind (Etype (Component)) =
3013 if Is_Array_Subtype then
3014 Ctyp := Component_Type (Base_Type (Etype (Component)));
3016 Ctyp := Etype (Component);
3019 -- If the component has an initialization procedure (IP) we
3020 -- pass the component to the expander, which will generate
3021 -- the call to such IP.
3023 if Has_Non_Null_Base_Init_Proc (Ctyp) then
3025 (Component => Component,
3027 Is_Box_Present => True);
3029 -- Otherwise we only need to resolve the expression if the
3030 -- component has partially initialized values (required to
3031 -- expand the corresponding assignments and run-time checks).
3033 elsif Present (Expr)
3035 ((not Is_Array_Subtype
3036 and then Is_Partially_Initialized_Type (Component))
3039 and then Is_Partially_Initialized_Type (Ctyp)))
3041 Resolve_Aggr_Expr (Expr, Component);
3045 elsif No (Expr) then
3046 Error_Msg_NE ("no value supplied for component &!", N, Component);
3049 Resolve_Aggr_Expr (Expr, Component);
3052 Next_Elmt (Component_Elmt);
3055 -- STEP 7: check for invalid components + check type in choice list
3062 -- Type of first component in choice list
3065 if Present (Component_Associations (N)) then
3066 Assoc := First (Component_Associations (N));
3071 Verification : while Present (Assoc) loop
3072 Selectr := First (Choices (Assoc));
3075 if Nkind (Selectr) = N_Others_Choice then
3077 -- Ada 2005 (AI-287): others choice may have expression or box
3079 if No (Others_Etype)
3080 and then not Others_Box
3083 ("OTHERS must represent at least one component", Selectr);
3089 while Present (Selectr) loop
3090 New_Assoc := First (New_Assoc_List);
3091 while Present (New_Assoc) loop
3092 Component := First (Choices (New_Assoc));
3093 exit when Chars (Selectr) = Chars (Component);
3097 -- If no association, this is not a legal component of
3098 -- of the type in question, except if this is an internal
3099 -- component supplied by a previous expansion.
3101 if No (New_Assoc) then
3102 if Box_Present (Parent (Selectr)) then
3105 elsif Chars (Selectr) /= Name_uTag
3106 and then Chars (Selectr) /= Name_uParent
3107 and then Chars (Selectr) /= Name_uController
3109 if not Has_Discriminants (Typ) then
3110 Error_Msg_Node_2 := Typ;
3112 ("& is not a component of}",
3116 ("& is not a component of the aggregate subtype",
3120 Check_Misspelled_Component (Components, Selectr);
3123 elsif No (Typech) then
3124 Typech := Base_Type (Etype (Component));
3126 elsif Typech /= Base_Type (Etype (Component)) then
3127 if not Box_Present (Parent (Selectr)) then
3129 ("components in choice list must have same type",
3138 end loop Verification;
3141 -- STEP 8: replace the original aggregate
3144 New_Aggregate : constant Node_Id := New_Copy (N);
3147 Set_Expressions (New_Aggregate, No_List);
3148 Set_Etype (New_Aggregate, Etype (N));
3149 Set_Component_Associations (New_Aggregate, New_Assoc_List);
3151 Rewrite (N, New_Aggregate);
3153 end Resolve_Record_Aggregate;
3155 -----------------------------
3156 -- Check_Can_Never_Be_Null --
3157 -----------------------------
3159 procedure Check_Can_Never_Be_Null (Typ : Entity_Id; Expr : Node_Id) is
3160 Comp_Typ : Entity_Id;
3164 (Ada_Version >= Ada_05
3165 and then Present (Expr)
3166 and then Nkind (Expr) = N_Null);
3169 when E_Array_Type =>
3170 Comp_Typ := Component_Type (Typ);
3174 Comp_Typ := Etype (Typ);
3180 if Can_Never_Be_Null (Comp_Typ) then
3182 -- Here we know we have a constraint error. Note that we do not use
3183 -- Apply_Compile_Time_Constraint_Error here to the Expr, which might
3184 -- seem the more natural approach. That's because in some cases the
3185 -- components are rewritten, and the replacement would be missed.
3188 (Compile_Time_Constraint_Error
3190 "(Ada 2005) NULL not allowed in null-excluding components?"),
3191 Make_Raise_Constraint_Error (Sloc (Expr),
3192 Reason => CE_Access_Check_Failed));
3194 -- Set proper type for bogus component (why is this needed???)
3196 Set_Etype (Expr, Comp_Typ);
3197 Set_Analyzed (Expr);
3199 end Check_Can_Never_Be_Null;
3201 ---------------------
3202 -- Sort_Case_Table --
3203 ---------------------
3205 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
3206 L : constant Int := Case_Table'First;
3207 U : constant Int := Case_Table'Last;
3215 T := Case_Table (K + 1);
3219 and then Expr_Value (Case_Table (J - 1).Choice_Lo) >
3220 Expr_Value (T.Choice_Lo)
3222 Case_Table (J) := Case_Table (J - 1);
3226 Case_Table (J) := T;
3229 end Sort_Case_Table;
OSDN Git Service
