1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2012, 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_Eval
; use Sem_Eval
;
51 with Sem_Res
; use Sem_Res
;
52 with Sem_Util
; use Sem_Util
;
53 with Sem_Type
; use Sem_Type
;
54 with Sem_Warn
; use Sem_Warn
;
55 with Sinfo
; use Sinfo
;
56 with Snames
; use Snames
;
57 with Stringt
; use Stringt
;
58 with Stand
; use Stand
;
59 with Style
; use Style
;
60 with Targparm
; use Targparm
;
61 with Tbuild
; use Tbuild
;
62 with Uintp
; use Uintp
;
64 package body Sem_Aggr
is
66 type Case_Bounds
is record
69 Choice_Node
: Node_Id
;
72 type Case_Table_Type
is array (Nat
range <>) of Case_Bounds
;
73 -- Table type used by Check_Case_Choices procedure
75 -----------------------
76 -- Local Subprograms --
77 -----------------------
79 procedure Sort_Case_Table
(Case_Table
: in out Case_Table_Type
);
80 -- Sort the Case Table using the Lower Bound of each Choice as the key.
81 -- A simple insertion sort is used since the number of choices in a case
82 -- statement of variant part will usually be small and probably in near
85 procedure Check_Can_Never_Be_Null
(Typ
: Entity_Id
; Expr
: Node_Id
);
86 -- Ada 2005 (AI-231): Check bad usage of null for a component for which
87 -- null exclusion (NOT NULL) is specified. Typ can be an E_Array_Type for
88 -- the array case (the component type of the array will be used) or an
89 -- E_Component/E_Discriminant entity in the record case, in which case the
90 -- type of the component will be used for the test. If Typ is any other
91 -- kind of entity, the call is ignored. Expr is the component node in the
92 -- aggregate which is known to have a null value. A warning message will be
93 -- issued if the component is null excluding.
95 -- It would be better to pass the proper type for Typ ???
97 procedure Check_Expr_OK_In_Limited_Aggregate
(Expr
: Node_Id
);
98 -- Check that Expr is either not limited or else is one of the cases of
99 -- expressions allowed for a limited component association (namely, an
100 -- aggregate, function call, or <> notation). Report error for violations.
102 procedure Check_Qualified_Aggregate
(Level
: Nat
; Expr
: Node_Id
);
103 -- Given aggregate Expr, check that sub-aggregates of Expr that are nested
104 -- at Level are qualified. If Level = 0, this applies to Expr directly.
105 -- Only issue errors in formal verification mode.
107 function Is_Top_Level_Aggregate
(Expr
: Node_Id
) return Boolean;
108 -- Return True of Expr is an aggregate not contained directly in another
111 ------------------------------------------------------
112 -- Subprograms used for RECORD AGGREGATE Processing --
113 ------------------------------------------------------
115 procedure Resolve_Record_Aggregate
(N
: Node_Id
; Typ
: Entity_Id
);
116 -- This procedure performs all the semantic checks required for record
117 -- aggregates. Note that for aggregates analysis and resolution go
118 -- hand in hand. Aggregate analysis has been delayed up to here and
119 -- it is done while resolving the aggregate.
121 -- N is the N_Aggregate node.
122 -- Typ is the record type for the aggregate resolution
124 -- While performing the semantic checks, this procedure builds a new
125 -- Component_Association_List where each record field appears alone in a
126 -- Component_Choice_List along with its corresponding expression. The
127 -- record fields in the Component_Association_List appear in the same order
128 -- in which they appear in the record type Typ.
130 -- Once this new Component_Association_List is built and all the semantic
131 -- checks performed, the original aggregate subtree is replaced with the
132 -- new named record aggregate just built. Note that subtree substitution is
133 -- performed with Rewrite so as to be able to retrieve the original
136 -- The aggregate subtree manipulation performed by Resolve_Record_Aggregate
137 -- yields the aggregate format expected by Gigi. Typically, this kind of
138 -- tree manipulations are done in the expander. However, because the
139 -- semantic checks that need to be performed on record aggregates really go
140 -- hand in hand with the record aggregate normalization, the aggregate
141 -- subtree transformation is performed during resolution rather than
142 -- expansion. Had we decided otherwise we would have had to duplicate most
143 -- of the code in the expansion procedure Expand_Record_Aggregate. Note,
144 -- however, that all the expansion concerning aggregates for tagged records
145 -- is done in Expand_Record_Aggregate.
147 -- The algorithm of Resolve_Record_Aggregate proceeds as follows:
149 -- 1. Make sure that the record type against which the record aggregate
150 -- has to be resolved is not abstract. Furthermore if the type is a
151 -- null aggregate make sure the input aggregate N is also null.
153 -- 2. Verify that the structure of the aggregate is that of a record
154 -- aggregate. Specifically, look for component associations and ensure
155 -- that each choice list only has identifiers or the N_Others_Choice
156 -- node. Also make sure that if present, the N_Others_Choice occurs
157 -- last and by itself.
159 -- 3. If Typ contains discriminants, the values for each discriminant is
160 -- looked for. If the record type Typ has variants, we check that the
161 -- expressions corresponding to each discriminant ruling the (possibly
162 -- nested) variant parts of Typ, are static. This allows us to determine
163 -- the variant parts to which the rest of the aggregate must conform.
164 -- The names of discriminants with their values are saved in a new
165 -- association list, New_Assoc_List which is later augmented with the
166 -- names and values of the remaining components in the record type.
168 -- During this phase we also make sure that every discriminant is
169 -- assigned exactly one value. Note that when several values for a given
170 -- discriminant are found, semantic processing continues looking for
171 -- further errors. In this case it's the first discriminant value found
172 -- which we will be recorded.
174 -- IMPORTANT NOTE: For derived tagged types this procedure expects
175 -- First_Discriminant and Next_Discriminant to give the correct list
176 -- of discriminants, in the correct order.
178 -- 4. After all the discriminant values have been gathered, we can set the
179 -- Etype of the record aggregate. If Typ contains no discriminants this
180 -- is straightforward: the Etype of N is just Typ, otherwise a new
181 -- implicit constrained subtype of Typ is built to be the Etype of N.
183 -- 5. Gather the remaining record components according to the discriminant
184 -- values. This involves recursively traversing the record type
185 -- structure to see what variants are selected by the given discriminant
186 -- values. This processing is a little more convoluted if Typ is a
187 -- derived tagged types since we need to retrieve the record structure
188 -- of all the ancestors of Typ.
190 -- 6. After gathering the record components we look for their values in the
191 -- record aggregate and emit appropriate error messages should we not
192 -- find such values or should they be duplicated.
194 -- 7. We then make sure no illegal component names appear in the record
195 -- aggregate and make sure that the type of the record components
196 -- appearing in a same choice list is the same. Finally we ensure that
197 -- the others choice, if present, is used to provide the value of at
198 -- least a record component.
200 -- 8. The original aggregate node is replaced with the new named aggregate
201 -- built in steps 3 through 6, as explained earlier.
203 -- Given the complexity of record aggregate resolution, the primary goal of
204 -- this routine is clarity and simplicity rather than execution and storage
205 -- efficiency. If there are only positional components in the aggregate the
206 -- running time is linear. If there are associations the running time is
207 -- still linear as long as the order of the associations is not too far off
208 -- the order of the components in the record type. If this is not the case
209 -- the running time is at worst quadratic in the size of the association
212 procedure Check_Misspelled_Component
213 (Elements
: Elist_Id
;
214 Component
: Node_Id
);
215 -- Give possible misspelling diagnostic if Component is likely to be a
216 -- misspelling of one of the components of the Assoc_List. This is called
217 -- by Resolve_Aggr_Expr after producing an invalid component error message.
219 procedure Check_Static_Discriminated_Subtype
(T
: Entity_Id
; V
: Node_Id
);
220 -- An optimization: determine whether a discriminated subtype has a static
221 -- constraint, and contains array components whose length is also static,
222 -- either because they are constrained by the discriminant, or because the
223 -- original component bounds are static.
225 -----------------------------------------------------
226 -- Subprograms used for ARRAY AGGREGATE Processing --
227 -----------------------------------------------------
229 function Resolve_Array_Aggregate
232 Index_Constr
: Node_Id
;
233 Component_Typ
: Entity_Id
;
234 Others_Allowed
: Boolean) return Boolean;
235 -- This procedure performs the semantic checks for an array aggregate.
236 -- True is returned if the aggregate resolution succeeds.
238 -- The procedure works by recursively checking each nested aggregate.
239 -- Specifically, after checking a sub-aggregate nested at the i-th level
240 -- we recursively check all the subaggregates at the i+1-st level (if any).
241 -- Note that for aggregates analysis and resolution go hand in hand.
242 -- Aggregate analysis has been delayed up to here and it is done while
243 -- resolving the aggregate.
245 -- N is the current N_Aggregate node to be checked.
247 -- Index is the index node corresponding to the array sub-aggregate that
248 -- we are currently checking (RM 4.3.3 (8)). Its Etype is the
249 -- corresponding index type (or subtype).
251 -- Index_Constr is the node giving the applicable index constraint if
252 -- any (RM 4.3.3 (10)). It "is a constraint provided by certain
253 -- contexts [...] that can be used to determine the bounds of the array
254 -- value specified by the aggregate". If Others_Allowed below is False
255 -- there is no applicable index constraint and this node is set to Index.
257 -- Component_Typ is the array component type.
259 -- Others_Allowed indicates whether an others choice is allowed
260 -- in the context where the top-level aggregate appeared.
262 -- The algorithm of Resolve_Array_Aggregate proceeds as follows:
264 -- 1. Make sure that the others choice, if present, is by itself and
265 -- appears last in the sub-aggregate. Check that we do not have
266 -- positional and named components in the array sub-aggregate (unless
267 -- the named association is an others choice). Finally if an others
268 -- choice is present, make sure it is allowed in the aggregate context.
270 -- 2. If the array sub-aggregate contains discrete_choices:
272 -- (A) Verify their validity. Specifically verify that:
274 -- (a) If a null range is present it must be the only possible
275 -- choice in the array aggregate.
277 -- (b) Ditto for a non static range.
279 -- (c) Ditto for a non static expression.
281 -- In addition this step analyzes and resolves each discrete_choice,
282 -- making sure that its type is the type of the corresponding Index.
283 -- If we are not at the lowest array aggregate level (in the case of
284 -- multi-dimensional aggregates) then invoke Resolve_Array_Aggregate
285 -- recursively on each component expression. Otherwise, resolve the
286 -- bottom level component expressions against the expected component
287 -- type ONLY IF the component corresponds to a single discrete choice
288 -- which is not an others choice (to see why read the DELAYED
289 -- COMPONENT RESOLUTION below).
291 -- (B) Determine the bounds of the sub-aggregate and lowest and
292 -- highest choice values.
294 -- 3. For positional aggregates:
296 -- (A) Loop over the component expressions either recursively invoking
297 -- Resolve_Array_Aggregate on each of these for multi-dimensional
298 -- array aggregates or resolving the bottom level component
299 -- expressions against the expected component type.
301 -- (B) Determine the bounds of the positional sub-aggregates.
303 -- 4. Try to determine statically whether the evaluation of the array
304 -- sub-aggregate raises Constraint_Error. If yes emit proper
305 -- warnings. The precise checks are the following:
307 -- (A) Check that the index range defined by aggregate bounds is
308 -- compatible with corresponding index subtype.
309 -- We also check against the base type. In fact it could be that
310 -- Low/High bounds of the base type are static whereas those of
311 -- the index subtype are not. Thus if we can statically catch
312 -- a problem with respect to the base type we are guaranteed
313 -- that the same problem will arise with the index subtype
315 -- (B) If we are dealing with a named aggregate containing an others
316 -- choice and at least one discrete choice then make sure the range
317 -- specified by the discrete choices does not overflow the
318 -- aggregate bounds. We also check against the index type and base
319 -- type bounds for the same reasons given in (A).
321 -- (C) If we are dealing with a positional aggregate with an others
322 -- choice make sure the number of positional elements specified
323 -- does not overflow the aggregate bounds. We also check against
324 -- the index type and base type bounds as mentioned in (A).
326 -- Finally construct an N_Range node giving the sub-aggregate bounds.
327 -- Set the Aggregate_Bounds field of the sub-aggregate to be this
328 -- N_Range. The routine Array_Aggr_Subtype below uses such N_Ranges
329 -- to build the appropriate aggregate subtype. Aggregate_Bounds
330 -- information is needed during expansion.
332 -- DELAYED COMPONENT RESOLUTION: The resolution of bottom level component
333 -- expressions in an array aggregate may call Duplicate_Subexpr or some
334 -- other routine that inserts code just outside the outermost aggregate.
335 -- If the array aggregate contains discrete choices or an others choice,
336 -- this may be wrong. Consider for instance the following example.
338 -- type Rec is record
342 -- type Acc_Rec is access Rec;
343 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => new Rec);
345 -- Then the transformation of "new Rec" that occurs during resolution
346 -- entails the following code modifications
348 -- P7b : constant Acc_Rec := new Rec;
350 -- Arr : array (1..3) of Acc_Rec := (1 .. 3 => P7b);
352 -- This code transformation is clearly wrong, since we need to call
353 -- "new Rec" for each of the 3 array elements. To avoid this problem we
354 -- delay resolution of the components of non positional array aggregates
355 -- to the expansion phase. As an optimization, if the discrete choice
356 -- specifies a single value we do not delay resolution.
358 function Array_Aggr_Subtype
(N
: Node_Id
; Typ
: Node_Id
) return Entity_Id
;
359 -- This routine returns the type or subtype of an array aggregate.
361 -- N is the array aggregate node whose type we return.
363 -- Typ is the context type in which N occurs.
365 -- This routine creates an implicit array subtype whose bounds are
366 -- those defined by the aggregate. When this routine is invoked
367 -- Resolve_Array_Aggregate has already processed aggregate N. Thus the
368 -- Aggregate_Bounds of each sub-aggregate, is an N_Range node giving the
369 -- sub-aggregate bounds. When building the aggregate itype, this function
370 -- traverses the array aggregate N collecting such Aggregate_Bounds and
371 -- constructs the proper array aggregate itype.
373 -- Note that in the case of multidimensional aggregates each inner
374 -- sub-aggregate corresponding to a given array dimension, may provide a
375 -- different bounds. If it is possible to determine statically that
376 -- some sub-aggregates corresponding to the same index do not have the
377 -- same bounds, then a warning is emitted. If such check is not possible
378 -- statically (because some sub-aggregate bounds are dynamic expressions)
379 -- then this job is left to the expander. In all cases the particular
380 -- bounds that this function will chose for a given dimension is the first
381 -- N_Range node for a sub-aggregate corresponding to that dimension.
383 -- Note that the Raises_Constraint_Error flag of an array aggregate
384 -- whose evaluation is determined to raise CE by Resolve_Array_Aggregate,
385 -- is set in Resolve_Array_Aggregate but the aggregate is not
386 -- immediately replaced with a raise CE. In fact, Array_Aggr_Subtype must
387 -- first construct the proper itype for the aggregate (Gigi needs
388 -- this). After constructing the proper itype we will eventually replace
389 -- the top-level aggregate with a raise CE (done in Resolve_Aggregate).
390 -- Of course in cases such as:
392 -- type Arr is array (integer range <>) of Integer;
393 -- A : Arr := (positive range -1 .. 2 => 0);
395 -- The bounds of the aggregate itype are cooked up to look reasonable
396 -- (in this particular case the bounds will be 1 .. 2).
398 procedure Aggregate_Constraint_Checks
400 Check_Typ
: Entity_Id
);
401 -- Checks expression Exp against subtype Check_Typ. If Exp is an
402 -- aggregate and Check_Typ a constrained record type with discriminants,
403 -- we generate the appropriate discriminant checks. If Exp is an array
404 -- aggregate then emit the appropriate length checks. If Exp is a scalar
405 -- type, or a string literal, Exp is changed into Check_Typ'(Exp) to
406 -- ensure that range checks are performed at run time.
408 procedure Make_String_Into_Aggregate
(N
: Node_Id
);
409 -- A string literal can appear in a context in which a one dimensional
410 -- array of characters is expected. This procedure simply rewrites the
411 -- string as an aggregate, prior to resolution.
413 ---------------------------------
414 -- Aggregate_Constraint_Checks --
415 ---------------------------------
417 procedure Aggregate_Constraint_Checks
419 Check_Typ
: Entity_Id
)
421 Exp_Typ
: constant Entity_Id
:= Etype
(Exp
);
424 if Raises_Constraint_Error
(Exp
) then
428 -- Ada 2005 (AI-230): Generate a conversion to an anonymous access
429 -- component's type to force the appropriate accessibility checks.
431 -- Ada 2005 (AI-231): Generate conversion to the null-excluding
432 -- type to force the corresponding run-time check
434 if Is_Access_Type
(Check_Typ
)
435 and then ((Is_Local_Anonymous_Access
(Check_Typ
))
436 or else (Can_Never_Be_Null
(Check_Typ
)
437 and then not Can_Never_Be_Null
(Exp_Typ
)))
439 Rewrite
(Exp
, Convert_To
(Check_Typ
, Relocate_Node
(Exp
)));
440 Analyze_And_Resolve
(Exp
, Check_Typ
);
441 Check_Unset_Reference
(Exp
);
444 -- This is really expansion activity, so make sure that expansion
445 -- is on and is allowed.
447 if not Expander_Active
or else In_Spec_Expression
then
451 -- First check if we have to insert discriminant checks
453 if Has_Discriminants
(Exp_Typ
) then
454 Apply_Discriminant_Check
(Exp
, Check_Typ
);
456 -- Next emit length checks for array aggregates
458 elsif Is_Array_Type
(Exp_Typ
) then
459 Apply_Length_Check
(Exp
, Check_Typ
);
461 -- Finally emit scalar and string checks. If we are dealing with a
462 -- scalar literal we need to check by hand because the Etype of
463 -- literals is not necessarily correct.
465 elsif Is_Scalar_Type
(Exp_Typ
)
466 and then Compile_Time_Known_Value
(Exp
)
468 if Is_Out_Of_Range
(Exp
, Base_Type
(Check_Typ
)) then
469 Apply_Compile_Time_Constraint_Error
470 (Exp
, "value not in range of}?", CE_Range_Check_Failed
,
471 Ent
=> Base_Type
(Check_Typ
),
472 Typ
=> Base_Type
(Check_Typ
));
474 elsif Is_Out_Of_Range
(Exp
, Check_Typ
) then
475 Apply_Compile_Time_Constraint_Error
476 (Exp
, "value not in range of}?", CE_Range_Check_Failed
,
480 elsif not Range_Checks_Suppressed
(Check_Typ
) then
481 Apply_Scalar_Range_Check
(Exp
, Check_Typ
);
484 -- Verify that target type is also scalar, to prevent view anomalies
485 -- in instantiations.
487 elsif (Is_Scalar_Type
(Exp_Typ
)
488 or else Nkind
(Exp
) = N_String_Literal
)
489 and then Is_Scalar_Type
(Check_Typ
)
490 and then Exp_Typ
/= Check_Typ
492 if Is_Entity_Name
(Exp
)
493 and then Ekind
(Entity
(Exp
)) = E_Constant
495 -- If expression is a constant, it is worthwhile checking whether
496 -- it is a bound of the type.
498 if (Is_Entity_Name
(Type_Low_Bound
(Check_Typ
))
499 and then Entity
(Exp
) = Entity
(Type_Low_Bound
(Check_Typ
)))
500 or else (Is_Entity_Name
(Type_High_Bound
(Check_Typ
))
501 and then Entity
(Exp
) = Entity
(Type_High_Bound
(Check_Typ
)))
506 Rewrite
(Exp
, Convert_To
(Check_Typ
, Relocate_Node
(Exp
)));
507 Analyze_And_Resolve
(Exp
, Check_Typ
);
508 Check_Unset_Reference
(Exp
);
511 Rewrite
(Exp
, Convert_To
(Check_Typ
, Relocate_Node
(Exp
)));
512 Analyze_And_Resolve
(Exp
, Check_Typ
);
513 Check_Unset_Reference
(Exp
);
517 end Aggregate_Constraint_Checks
;
519 ------------------------
520 -- Array_Aggr_Subtype --
521 ------------------------
523 function Array_Aggr_Subtype
525 Typ
: Entity_Id
) return Entity_Id
527 Aggr_Dimension
: constant Pos
:= Number_Dimensions
(Typ
);
528 -- Number of aggregate index dimensions
530 Aggr_Range
: array (1 .. Aggr_Dimension
) of Node_Id
:= (others => Empty
);
531 -- Constrained N_Range of each index dimension in our aggregate itype
533 Aggr_Low
: array (1 .. Aggr_Dimension
) of Node_Id
:= (others => Empty
);
534 Aggr_High
: array (1 .. Aggr_Dimension
) of Node_Id
:= (others => Empty
);
535 -- Low and High bounds for each index dimension in our aggregate itype
537 Is_Fully_Positional
: Boolean := True;
539 procedure Collect_Aggr_Bounds
(N
: Node_Id
; Dim
: Pos
);
540 -- N is an array (sub-)aggregate. Dim is the dimension corresponding
541 -- to (sub-)aggregate N. This procedure collects and removes the side
542 -- effects of the constrained N_Range nodes corresponding to each index
543 -- dimension of our aggregate itype. These N_Range nodes are collected
544 -- in Aggr_Range above.
546 -- Likewise collect in Aggr_Low & Aggr_High above the low and high
547 -- bounds of each index dimension. If, when collecting, two bounds
548 -- corresponding to the same dimension are static and found to differ,
549 -- then emit a warning, and mark N as raising Constraint_Error.
551 -------------------------
552 -- Collect_Aggr_Bounds --
553 -------------------------
555 procedure Collect_Aggr_Bounds
(N
: Node_Id
; Dim
: Pos
) is
556 This_Range
: constant Node_Id
:= Aggregate_Bounds
(N
);
557 -- The aggregate range node of this specific sub-aggregate
559 This_Low
: constant Node_Id
:= Low_Bound
(Aggregate_Bounds
(N
));
560 This_High
: constant Node_Id
:= High_Bound
(Aggregate_Bounds
(N
));
561 -- The aggregate bounds of this specific sub-aggregate
567 Remove_Side_Effects
(This_Low
, Variable_Ref
=> True);
568 Remove_Side_Effects
(This_High
, Variable_Ref
=> True);
570 -- Collect the first N_Range for a given dimension that you find.
571 -- For a given dimension they must be all equal anyway.
573 if No
(Aggr_Range
(Dim
)) then
574 Aggr_Low
(Dim
) := This_Low
;
575 Aggr_High
(Dim
) := This_High
;
576 Aggr_Range
(Dim
) := This_Range
;
579 if Compile_Time_Known_Value
(This_Low
) then
580 if not Compile_Time_Known_Value
(Aggr_Low
(Dim
)) then
581 Aggr_Low
(Dim
) := This_Low
;
583 elsif Expr_Value
(This_Low
) /= Expr_Value
(Aggr_Low
(Dim
)) then
584 Set_Raises_Constraint_Error
(N
);
585 Error_Msg_N
("sub-aggregate low bound mismatch?", N
);
587 ("\Constraint_Error will be raised at run time?", N
);
591 if Compile_Time_Known_Value
(This_High
) then
592 if not Compile_Time_Known_Value
(Aggr_High
(Dim
)) then
593 Aggr_High
(Dim
) := This_High
;
596 Expr_Value
(This_High
) /= Expr_Value
(Aggr_High
(Dim
))
598 Set_Raises_Constraint_Error
(N
);
599 Error_Msg_N
("sub-aggregate high bound mismatch?", N
);
601 ("\Constraint_Error will be raised at run time?", N
);
606 if Dim
< Aggr_Dimension
then
608 -- Process positional components
610 if Present
(Expressions
(N
)) then
611 Expr
:= First
(Expressions
(N
));
612 while Present
(Expr
) loop
613 Collect_Aggr_Bounds
(Expr
, Dim
+ 1);
618 -- Process component associations
620 if Present
(Component_Associations
(N
)) then
621 Is_Fully_Positional
:= False;
623 Assoc
:= First
(Component_Associations
(N
));
624 while Present
(Assoc
) loop
625 Expr
:= Expression
(Assoc
);
626 Collect_Aggr_Bounds
(Expr
, Dim
+ 1);
631 end Collect_Aggr_Bounds
;
633 -- Array_Aggr_Subtype variables
636 -- The final itype of the overall aggregate
638 Index_Constraints
: constant List_Id
:= New_List
;
639 -- The list of index constraints of the aggregate itype
641 -- Start of processing for Array_Aggr_Subtype
644 -- Make sure that the list of index constraints is properly attached to
645 -- the tree, and then collect the aggregate bounds.
647 Set_Parent
(Index_Constraints
, N
);
648 Collect_Aggr_Bounds
(N
, 1);
650 -- Build the list of constrained indexes of our aggregate itype
652 for J
in 1 .. Aggr_Dimension
loop
653 Create_Index
: declare
654 Index_Base
: constant Entity_Id
:=
655 Base_Type
(Etype
(Aggr_Range
(J
)));
656 Index_Typ
: Entity_Id
;
659 -- Construct the Index subtype, and associate it with the range
660 -- construct that generates it.
663 Create_Itype
(Subtype_Kind
(Ekind
(Index_Base
)), Aggr_Range
(J
));
665 Set_Etype
(Index_Typ
, Index_Base
);
667 if Is_Character_Type
(Index_Base
) then
668 Set_Is_Character_Type
(Index_Typ
);
671 Set_Size_Info
(Index_Typ
, (Index_Base
));
672 Set_RM_Size
(Index_Typ
, RM_Size
(Index_Base
));
673 Set_First_Rep_Item
(Index_Typ
, First_Rep_Item
(Index_Base
));
674 Set_Scalar_Range
(Index_Typ
, Aggr_Range
(J
));
676 if Is_Discrete_Or_Fixed_Point_Type
(Index_Typ
) then
677 Set_RM_Size
(Index_Typ
, UI_From_Int
(Minimum_Size
(Index_Typ
)));
680 Set_Etype
(Aggr_Range
(J
), Index_Typ
);
682 Append
(Aggr_Range
(J
), To
=> Index_Constraints
);
686 -- Now build the Itype
688 Itype
:= Create_Itype
(E_Array_Subtype
, N
);
690 Set_First_Rep_Item
(Itype
, First_Rep_Item
(Typ
));
691 Set_Convention
(Itype
, Convention
(Typ
));
692 Set_Depends_On_Private
(Itype
, Has_Private_Component
(Typ
));
693 Set_Etype
(Itype
, Base_Type
(Typ
));
694 Set_Has_Alignment_Clause
(Itype
, Has_Alignment_Clause
(Typ
));
695 Set_Is_Aliased
(Itype
, Is_Aliased
(Typ
));
696 Set_Depends_On_Private
(Itype
, Depends_On_Private
(Typ
));
698 Copy_Suppress_Status
(Index_Check
, Typ
, Itype
);
699 Copy_Suppress_Status
(Length_Check
, Typ
, Itype
);
701 Set_First_Index
(Itype
, First
(Index_Constraints
));
702 Set_Is_Constrained
(Itype
, True);
703 Set_Is_Internal
(Itype
, True);
705 -- A simple optimization: purely positional aggregates of static
706 -- components should be passed to gigi unexpanded whenever possible, and
707 -- regardless of the staticness of the bounds themselves. Subsequent
708 -- checks in exp_aggr verify that type is not packed, etc.
710 Set_Size_Known_At_Compile_Time
(Itype
,
712 and then Comes_From_Source
(N
)
713 and then Size_Known_At_Compile_Time
(Component_Type
(Typ
)));
715 -- We always need a freeze node for a packed array subtype, so that we
716 -- can build the Packed_Array_Type corresponding to the subtype. If
717 -- expansion is disabled, the packed array subtype is not built, and we
718 -- must not generate a freeze node for the type, or else it will appear
719 -- incomplete to gigi.
722 and then not In_Spec_Expression
723 and then Expander_Active
725 Freeze_Itype
(Itype
, N
);
729 end Array_Aggr_Subtype
;
731 --------------------------------
732 -- Check_Misspelled_Component --
733 --------------------------------
735 procedure Check_Misspelled_Component
736 (Elements
: Elist_Id
;
739 Max_Suggestions
: constant := 2;
741 Nr_Of_Suggestions
: Natural := 0;
742 Suggestion_1
: Entity_Id
:= Empty
;
743 Suggestion_2
: Entity_Id
:= Empty
;
744 Component_Elmt
: Elmt_Id
;
747 -- All the components of List are matched against Component and a count
748 -- is maintained of possible misspellings. When at the end of the the
749 -- analysis there are one or two (not more!) possible misspellings,
750 -- these misspellings will be suggested as possible correction.
752 Component_Elmt
:= First_Elmt
(Elements
);
753 while Nr_Of_Suggestions
<= Max_Suggestions
754 and then Present
(Component_Elmt
)
756 if Is_Bad_Spelling_Of
757 (Chars
(Node
(Component_Elmt
)),
760 Nr_Of_Suggestions
:= Nr_Of_Suggestions
+ 1;
762 case Nr_Of_Suggestions
is
763 when 1 => Suggestion_1
:= Node
(Component_Elmt
);
764 when 2 => Suggestion_2
:= Node
(Component_Elmt
);
769 Next_Elmt
(Component_Elmt
);
772 -- Report at most two suggestions
774 if Nr_Of_Suggestions
= 1 then
775 Error_Msg_NE
-- CODEFIX
776 ("\possible misspelling of&", Component
, Suggestion_1
);
778 elsif Nr_Of_Suggestions
= 2 then
779 Error_Msg_Node_2
:= Suggestion_2
;
780 Error_Msg_NE
-- CODEFIX
781 ("\possible misspelling of& or&", Component
, Suggestion_1
);
783 end Check_Misspelled_Component
;
785 ----------------------------------------
786 -- Check_Expr_OK_In_Limited_Aggregate --
787 ----------------------------------------
789 procedure Check_Expr_OK_In_Limited_Aggregate
(Expr
: Node_Id
) is
791 if Is_Limited_Type
(Etype
(Expr
))
792 and then Comes_From_Source
(Expr
)
793 and then not In_Instance_Body
795 if not OK_For_Limited_Init
(Etype
(Expr
), Expr
) then
796 Error_Msg_N
("initialization not allowed for limited types", Expr
);
797 Explain_Limited_Type
(Etype
(Expr
), Expr
);
800 end Check_Expr_OK_In_Limited_Aggregate
;
802 -------------------------------
803 -- Check_Qualified_Aggregate --
804 -------------------------------
806 procedure Check_Qualified_Aggregate
(Level
: Nat
; Expr
: Node_Id
) is
812 if Nkind
(Parent
(Expr
)) /= N_Qualified_Expression
then
813 Check_SPARK_Restriction
("aggregate should be qualified", Expr
);
817 Comp_Expr
:= First
(Expressions
(Expr
));
818 while Present
(Comp_Expr
) loop
819 if Nkind
(Comp_Expr
) = N_Aggregate
then
820 Check_Qualified_Aggregate
(Level
- 1, Comp_Expr
);
823 Comp_Expr
:= Next
(Comp_Expr
);
826 Comp_Assn
:= First
(Component_Associations
(Expr
));
827 while Present
(Comp_Assn
) loop
828 Comp_Expr
:= Expression
(Comp_Assn
);
830 if Nkind
(Comp_Expr
) = N_Aggregate
then
831 Check_Qualified_Aggregate
(Level
- 1, Comp_Expr
);
834 Comp_Assn
:= Next
(Comp_Assn
);
837 end Check_Qualified_Aggregate
;
839 ----------------------------------------
840 -- Check_Static_Discriminated_Subtype --
841 ----------------------------------------
843 procedure Check_Static_Discriminated_Subtype
(T
: Entity_Id
; V
: Node_Id
) is
844 Disc
: constant Entity_Id
:= First_Discriminant
(T
);
849 if Has_Record_Rep_Clause
(T
) then
852 elsif Present
(Next_Discriminant
(Disc
)) then
855 elsif Nkind
(V
) /= N_Integer_Literal
then
859 Comp
:= First_Component
(T
);
860 while Present
(Comp
) loop
861 if Is_Scalar_Type
(Etype
(Comp
)) then
864 elsif Is_Private_Type
(Etype
(Comp
))
865 and then Present
(Full_View
(Etype
(Comp
)))
866 and then Is_Scalar_Type
(Full_View
(Etype
(Comp
)))
870 elsif Is_Array_Type
(Etype
(Comp
)) then
871 if Is_Bit_Packed_Array
(Etype
(Comp
)) then
875 Ind
:= First_Index
(Etype
(Comp
));
876 while Present
(Ind
) loop
877 if Nkind
(Ind
) /= N_Range
878 or else Nkind
(Low_Bound
(Ind
)) /= N_Integer_Literal
879 or else Nkind
(High_Bound
(Ind
)) /= N_Integer_Literal
891 Next_Component
(Comp
);
894 -- On exit, all components have statically known sizes
896 Set_Size_Known_At_Compile_Time
(T
);
897 end Check_Static_Discriminated_Subtype
;
899 -------------------------
900 -- Is_Others_Aggregate --
901 -------------------------
903 function Is_Others_Aggregate
(Aggr
: Node_Id
) return Boolean is
905 return No
(Expressions
(Aggr
))
907 Nkind
(First
(Choices
(First
(Component_Associations
(Aggr
)))))
909 end Is_Others_Aggregate
;
911 ----------------------------
912 -- Is_Top_Level_Aggregate --
913 ----------------------------
915 function Is_Top_Level_Aggregate
(Expr
: Node_Id
) return Boolean is
917 return Nkind
(Parent
(Expr
)) /= N_Aggregate
918 and then (Nkind
(Parent
(Expr
)) /= N_Component_Association
919 or else Nkind
(Parent
(Parent
(Expr
))) /= N_Aggregate
);
920 end Is_Top_Level_Aggregate
;
922 --------------------------------
923 -- Make_String_Into_Aggregate --
924 --------------------------------
926 procedure Make_String_Into_Aggregate
(N
: Node_Id
) is
927 Exprs
: constant List_Id
:= New_List
;
928 Loc
: constant Source_Ptr
:= Sloc
(N
);
929 Str
: constant String_Id
:= Strval
(N
);
930 Strlen
: constant Nat
:= String_Length
(Str
);
938 for J
in 1 .. Strlen
loop
939 C
:= Get_String_Char
(Str
, J
);
940 Set_Character_Literal_Name
(C
);
943 Make_Character_Literal
(P
,
945 Char_Literal_Value
=> UI_From_CC
(C
));
946 Set_Etype
(C_Node
, Any_Character
);
947 Append_To
(Exprs
, C_Node
);
950 -- Something special for wide strings???
953 New_N
:= Make_Aggregate
(Loc
, Expressions
=> Exprs
);
954 Set_Analyzed
(New_N
);
955 Set_Etype
(New_N
, Any_Composite
);
958 end Make_String_Into_Aggregate
;
960 -----------------------
961 -- Resolve_Aggregate --
962 -----------------------
964 procedure Resolve_Aggregate
(N
: Node_Id
; Typ
: Entity_Id
) is
965 Loc
: constant Source_Ptr
:= Sloc
(N
);
966 Pkind
: constant Node_Kind
:= Nkind
(Parent
(N
));
968 Aggr_Subtyp
: Entity_Id
;
969 -- The actual aggregate subtype. This is not necessarily the same as Typ
970 -- which is the subtype of the context in which the aggregate was found.
973 -- Ignore junk empty aggregate resulting from parser error
975 if No
(Expressions
(N
))
976 and then No
(Component_Associations
(N
))
977 and then not Null_Record_Present
(N
)
982 -- If the aggregate has box-initialized components, its type must be
983 -- frozen so that initialization procedures can properly be called
984 -- in the resolution that follows. The replacement of boxes with
985 -- initialization calls is properly an expansion activity but it must
986 -- be done during revolution.
989 and then Present
(Component_Associations
(N
))
995 Comp
:= First
(Component_Associations
(N
));
996 while Present
(Comp
) loop
997 if Box_Present
(Comp
) then
998 Insert_Actions
(N
, Freeze_Entity
(Typ
, N
));
1007 -- An unqualified aggregate is restricted in SPARK to:
1009 -- An aggregate item inside an aggregate for a multi-dimensional array
1011 -- An expression being assigned to an unconstrained array, but only if
1012 -- the aggregate specifies a value for OTHERS only.
1014 if Nkind
(Parent
(N
)) = N_Qualified_Expression
then
1015 if Is_Array_Type
(Typ
) then
1016 Check_Qualified_Aggregate
(Number_Dimensions
(Typ
), N
);
1018 Check_Qualified_Aggregate
(1, N
);
1021 if Is_Array_Type
(Typ
)
1022 and then Nkind
(Parent
(N
)) = N_Assignment_Statement
1023 and then not Is_Constrained
(Etype
(Name
(Parent
(N
))))
1025 if not Is_Others_Aggregate
(N
) then
1026 Check_SPARK_Restriction
1027 ("array aggregate should have only OTHERS", N
);
1030 elsif Is_Top_Level_Aggregate
(N
) then
1031 Check_SPARK_Restriction
("aggregate should be qualified", N
);
1033 -- The legality of this unqualified aggregate is checked by calling
1034 -- Check_Qualified_Aggregate from one of its enclosing aggregate,
1035 -- unless one of these already causes an error to be issued.
1042 -- Check for aggregates not allowed in configurable run-time mode.
1043 -- We allow all cases of aggregates that do not come from source, since
1044 -- these are all assumed to be small (e.g. bounds of a string literal).
1045 -- We also allow aggregates of types we know to be small.
1047 if not Support_Aggregates_On_Target
1048 and then Comes_From_Source
(N
)
1049 and then (not Known_Static_Esize
(Typ
) or else Esize
(Typ
) > 64)
1051 Error_Msg_CRT
("aggregate", N
);
1054 -- Ada 2005 (AI-287): Limited aggregates allowed
1056 -- In an instance, ignore aggregate subcomponents tnat may be limited,
1057 -- because they originate in view conflicts. If the original aggregate
1058 -- is legal and the actuals are legal, the aggregate itself is legal.
1060 if Is_Limited_Type
(Typ
)
1061 and then Ada_Version
< Ada_2005
1062 and then not In_Instance
1064 Error_Msg_N
("aggregate type cannot be limited", N
);
1065 Explain_Limited_Type
(Typ
, N
);
1067 elsif Is_Class_Wide_Type
(Typ
) then
1068 Error_Msg_N
("type of aggregate cannot be class-wide", N
);
1070 elsif Typ
= Any_String
1071 or else Typ
= Any_Composite
1073 Error_Msg_N
("no unique type for aggregate", N
);
1074 Set_Etype
(N
, Any_Composite
);
1076 elsif Is_Array_Type
(Typ
) and then Null_Record_Present
(N
) then
1077 Error_Msg_N
("null record forbidden in array aggregate", N
);
1079 elsif Is_Record_Type
(Typ
) then
1080 Resolve_Record_Aggregate
(N
, Typ
);
1082 elsif Is_Array_Type
(Typ
) then
1084 -- First a special test, for the case of a positional aggregate
1085 -- of characters which can be replaced by a string literal.
1087 -- Do not perform this transformation if this was a string literal to
1088 -- start with, whose components needed constraint checks, or if the
1089 -- component type is non-static, because it will require those checks
1090 -- and be transformed back into an aggregate.
1092 if Number_Dimensions
(Typ
) = 1
1093 and then Is_Standard_Character_Type
(Component_Type
(Typ
))
1094 and then No
(Component_Associations
(N
))
1095 and then not Is_Limited_Composite
(Typ
)
1096 and then not Is_Private_Composite
(Typ
)
1097 and then not Is_Bit_Packed_Array
(Typ
)
1098 and then Nkind
(Original_Node
(Parent
(N
))) /= N_String_Literal
1099 and then Is_Static_Subtype
(Component_Type
(Typ
))
1105 Expr
:= First
(Expressions
(N
));
1106 while Present
(Expr
) loop
1107 exit when Nkind
(Expr
) /= N_Character_Literal
;
1114 Expr
:= First
(Expressions
(N
));
1115 while Present
(Expr
) loop
1116 Store_String_Char
(UI_To_CC
(Char_Literal_Value
(Expr
)));
1120 Rewrite
(N
, Make_String_Literal
(Loc
, End_String
));
1122 Analyze_And_Resolve
(N
, Typ
);
1128 -- Here if we have a real aggregate to deal with
1130 Array_Aggregate
: declare
1131 Aggr_Resolved
: Boolean;
1133 Aggr_Typ
: constant Entity_Id
:= Etype
(Typ
);
1134 -- This is the unconstrained array type, which is the type against
1135 -- which the aggregate is to be resolved. Typ itself is the array
1136 -- type of the context which may not be the same subtype as the
1137 -- subtype for the final aggregate.
1140 -- In the following we determine whether an OTHERS choice is
1141 -- allowed inside the array aggregate. The test checks the context
1142 -- in which the array aggregate occurs. If the context does not
1143 -- permit it, or the aggregate type is unconstrained, an OTHERS
1144 -- choice is not allowed (except that it is always allowed on the
1145 -- right-hand side of an assignment statement; in this case the
1146 -- constrainedness of the type doesn't matter).
1148 -- If expansion is disabled (generic context, or semantics-only
1149 -- mode) actual subtypes cannot be constructed, and the type of an
1150 -- object may be its unconstrained nominal type. However, if the
1151 -- context is an assignment, we assume that OTHERS is allowed,
1152 -- because the target of the assignment will have a constrained
1153 -- subtype when fully compiled.
1155 -- Note that there is no node for Explicit_Actual_Parameter.
1156 -- To test for this context we therefore have to test for node
1157 -- N_Parameter_Association which itself appears only if there is a
1158 -- formal parameter. Consequently we also need to test for
1159 -- N_Procedure_Call_Statement or N_Function_Call.
1161 Set_Etype
(N
, Aggr_Typ
); -- May be overridden later on
1163 if Pkind
= N_Assignment_Statement
1164 or else (Is_Constrained
(Typ
)
1166 (Pkind
= N_Parameter_Association
or else
1167 Pkind
= N_Function_Call
or else
1168 Pkind
= N_Procedure_Call_Statement
or else
1169 Pkind
= N_Generic_Association
or else
1170 Pkind
= N_Formal_Object_Declaration
or else
1171 Pkind
= N_Simple_Return_Statement
or else
1172 Pkind
= N_Object_Declaration
or else
1173 Pkind
= N_Component_Declaration
or else
1174 Pkind
= N_Parameter_Specification
or else
1175 Pkind
= N_Qualified_Expression
or else
1176 Pkind
= N_Aggregate
or else
1177 Pkind
= N_Extension_Aggregate
or else
1178 Pkind
= N_Component_Association
))
1181 Resolve_Array_Aggregate
1183 Index
=> First_Index
(Aggr_Typ
),
1184 Index_Constr
=> First_Index
(Typ
),
1185 Component_Typ
=> Component_Type
(Typ
),
1186 Others_Allowed
=> True);
1188 elsif not Expander_Active
1189 and then Pkind
= N_Assignment_Statement
1192 Resolve_Array_Aggregate
1194 Index
=> First_Index
(Aggr_Typ
),
1195 Index_Constr
=> First_Index
(Typ
),
1196 Component_Typ
=> Component_Type
(Typ
),
1197 Others_Allowed
=> True);
1201 Resolve_Array_Aggregate
1203 Index
=> First_Index
(Aggr_Typ
),
1204 Index_Constr
=> First_Index
(Aggr_Typ
),
1205 Component_Typ
=> Component_Type
(Typ
),
1206 Others_Allowed
=> False);
1209 if not Aggr_Resolved
then
1211 -- A parenthesized expression may have been intended as an
1212 -- aggregate, leading to a type error when analyzing the
1213 -- component. This can also happen for a nested component
1214 -- (see Analyze_Aggr_Expr).
1216 if Paren_Count
(N
) > 0 then
1218 ("positional aggregate cannot have one component", N
);
1221 Aggr_Subtyp
:= Any_Composite
;
1224 Aggr_Subtyp
:= Array_Aggr_Subtype
(N
, Typ
);
1227 Set_Etype
(N
, Aggr_Subtyp
);
1228 end Array_Aggregate
;
1230 elsif Is_Private_Type
(Typ
)
1231 and then Present
(Full_View
(Typ
))
1232 and then (In_Inlined_Body
or In_Instance_Body
)
1233 and then Is_Composite_Type
(Full_View
(Typ
))
1235 Resolve
(N
, Full_View
(Typ
));
1238 Error_Msg_N
("illegal context for aggregate", N
);
1241 -- If we can determine statically that the evaluation of the aggregate
1242 -- raises Constraint_Error, then replace the aggregate with an
1243 -- N_Raise_Constraint_Error node, but set the Etype to the right
1244 -- aggregate subtype. Gigi needs this.
1246 if Raises_Constraint_Error
(N
) then
1247 Aggr_Subtyp
:= Etype
(N
);
1249 Make_Raise_Constraint_Error
(Loc
, Reason
=> CE_Range_Check_Failed
));
1250 Set_Raises_Constraint_Error
(N
);
1251 Set_Etype
(N
, Aggr_Subtyp
);
1254 end Resolve_Aggregate
;
1256 -----------------------------
1257 -- Resolve_Array_Aggregate --
1258 -----------------------------
1260 function Resolve_Array_Aggregate
1263 Index_Constr
: Node_Id
;
1264 Component_Typ
: Entity_Id
;
1265 Others_Allowed
: Boolean) return Boolean
1267 Loc
: constant Source_Ptr
:= Sloc
(N
);
1269 Failure
: constant Boolean := False;
1270 Success
: constant Boolean := True;
1272 Index_Typ
: constant Entity_Id
:= Etype
(Index
);
1273 Index_Typ_Low
: constant Node_Id
:= Type_Low_Bound
(Index_Typ
);
1274 Index_Typ_High
: constant Node_Id
:= Type_High_Bound
(Index_Typ
);
1275 -- The type of the index corresponding to the array sub-aggregate along
1276 -- with its low and upper bounds.
1278 Index_Base
: constant Entity_Id
:= Base_Type
(Index_Typ
);
1279 Index_Base_Low
: constant Node_Id
:= Type_Low_Bound
(Index_Base
);
1280 Index_Base_High
: constant Node_Id
:= Type_High_Bound
(Index_Base
);
1281 -- Ditto for the base type
1283 function Add
(Val
: Uint
; To
: Node_Id
) return Node_Id
;
1284 -- Creates a new expression node where Val is added to expression To.
1285 -- Tries to constant fold whenever possible. To must be an already
1286 -- analyzed expression.
1288 procedure Check_Bound
(BH
: Node_Id
; AH
: in out Node_Id
);
1289 -- Checks that AH (the upper bound of an array aggregate) is less than
1290 -- or equal to BH (the upper bound of the index base type). If the check
1291 -- fails, a warning is emitted, the Raises_Constraint_Error flag of N is
1292 -- set, and AH is replaced with a duplicate of BH.
1294 procedure Check_Bounds
(L
, H
: Node_Id
; AL
, AH
: Node_Id
);
1295 -- Checks that range AL .. AH is compatible with range L .. H. Emits a
1296 -- warning if not and sets the Raises_Constraint_Error flag in N.
1298 procedure Check_Length
(L
, H
: Node_Id
; Len
: Uint
);
1299 -- Checks that range L .. H contains at least Len elements. Emits a
1300 -- warning if not and sets the Raises_Constraint_Error flag in N.
1302 function Dynamic_Or_Null_Range
(L
, H
: Node_Id
) return Boolean;
1303 -- Returns True if range L .. H is dynamic or null
1305 procedure Get
(Value
: out Uint
; From
: Node_Id
; OK
: out Boolean);
1306 -- Given expression node From, this routine sets OK to False if it
1307 -- cannot statically evaluate From. Otherwise it stores this static
1308 -- value into Value.
1310 function Resolve_Aggr_Expr
1312 Single_Elmt
: Boolean) return Boolean;
1313 -- Resolves aggregate expression Expr. Returns False if resolution
1314 -- fails. If Single_Elmt is set to False, the expression Expr may be
1315 -- used to initialize several array aggregate elements (this can happen
1316 -- for discrete choices such as "L .. H => Expr" or the OTHERS choice).
1317 -- In this event we do not resolve Expr unless expansion is disabled.
1318 -- To know why, see the DELAYED COMPONENT RESOLUTION note above.
1320 -- NOTE: In the case of "... => <>", we pass the in the
1321 -- N_Component_Association node as Expr, since there is no Expression in
1322 -- that case, and we need a Sloc for the error message.
1328 function Add
(Val
: Uint
; To
: Node_Id
) return Node_Id
is
1334 if Raises_Constraint_Error
(To
) then
1338 -- First test if we can do constant folding
1340 if Compile_Time_Known_Value
(To
)
1341 or else Nkind
(To
) = N_Integer_Literal
1343 Expr_Pos
:= Make_Integer_Literal
(Loc
, Expr_Value
(To
) + Val
);
1344 Set_Is_Static_Expression
(Expr_Pos
);
1345 Set_Etype
(Expr_Pos
, Etype
(To
));
1346 Set_Analyzed
(Expr_Pos
, Analyzed
(To
));
1348 if not Is_Enumeration_Type
(Index_Typ
) then
1351 -- If we are dealing with enumeration return
1352 -- Index_Typ'Val (Expr_Pos)
1356 Make_Attribute_Reference
1358 Prefix
=> New_Reference_To
(Index_Typ
, Loc
),
1359 Attribute_Name
=> Name_Val
,
1360 Expressions
=> New_List
(Expr_Pos
));
1366 -- If we are here no constant folding possible
1368 if not Is_Enumeration_Type
(Index_Base
) then
1371 Left_Opnd
=> Duplicate_Subexpr
(To
),
1372 Right_Opnd
=> Make_Integer_Literal
(Loc
, Val
));
1374 -- If we are dealing with enumeration return
1375 -- Index_Typ'Val (Index_Typ'Pos (To) + Val)
1379 Make_Attribute_Reference
1381 Prefix
=> New_Reference_To
(Index_Typ
, Loc
),
1382 Attribute_Name
=> Name_Pos
,
1383 Expressions
=> New_List
(Duplicate_Subexpr
(To
)));
1387 Left_Opnd
=> To_Pos
,
1388 Right_Opnd
=> Make_Integer_Literal
(Loc
, Val
));
1391 Make_Attribute_Reference
1393 Prefix
=> New_Reference_To
(Index_Typ
, Loc
),
1394 Attribute_Name
=> Name_Val
,
1395 Expressions
=> New_List
(Expr_Pos
));
1397 -- If the index type has a non standard representation, the
1398 -- attributes 'Val and 'Pos expand into function calls and the
1399 -- resulting expression is considered non-safe for reevaluation
1400 -- by the backend. Relocate it into a constant temporary in order
1401 -- to make it safe for reevaluation.
1403 if Has_Non_Standard_Rep
(Etype
(N
)) then
1408 Def_Id
:= Make_Temporary
(Loc
, 'R', Expr
);
1409 Set_Etype
(Def_Id
, Index_Typ
);
1411 Make_Object_Declaration
(Loc
,
1412 Defining_Identifier
=> Def_Id
,
1413 Object_Definition
=> New_Reference_To
(Index_Typ
, Loc
),
1414 Constant_Present
=> True,
1415 Expression
=> Relocate_Node
(Expr
)));
1417 Expr
:= New_Reference_To
(Def_Id
, Loc
);
1429 procedure Check_Bound
(BH
: Node_Id
; AH
: in out Node_Id
) is
1437 Get
(Value
=> Val_BH
, From
=> BH
, OK
=> OK_BH
);
1438 Get
(Value
=> Val_AH
, From
=> AH
, OK
=> OK_AH
);
1440 if OK_BH
and then OK_AH
and then Val_BH
< Val_AH
then
1441 Set_Raises_Constraint_Error
(N
);
1442 Error_Msg_N
("upper bound out of range?", AH
);
1443 Error_Msg_N
("\Constraint_Error will be raised at run time?", AH
);
1445 -- You need to set AH to BH or else in the case of enumerations
1446 -- indexes we will not be able to resolve the aggregate bounds.
1448 AH
:= Duplicate_Subexpr
(BH
);
1456 procedure Check_Bounds
(L
, H
: Node_Id
; AL
, AH
: Node_Id
) is
1467 pragma Warnings
(Off
, OK_AL
);
1468 pragma Warnings
(Off
, OK_AH
);
1471 if Raises_Constraint_Error
(N
)
1472 or else Dynamic_Or_Null_Range
(AL
, AH
)
1477 Get
(Value
=> Val_L
, From
=> L
, OK
=> OK_L
);
1478 Get
(Value
=> Val_H
, From
=> H
, OK
=> OK_H
);
1480 Get
(Value
=> Val_AL
, From
=> AL
, OK
=> OK_AL
);
1481 Get
(Value
=> Val_AH
, From
=> AH
, OK
=> OK_AH
);
1483 if OK_L
and then Val_L
> Val_AL
then
1484 Set_Raises_Constraint_Error
(N
);
1485 Error_Msg_N
("lower bound of aggregate out of range?", N
);
1486 Error_Msg_N
("\Constraint_Error will be raised at run time?", N
);
1489 if OK_H
and then Val_H
< Val_AH
then
1490 Set_Raises_Constraint_Error
(N
);
1491 Error_Msg_N
("upper bound of aggregate out of range?", N
);
1492 Error_Msg_N
("\Constraint_Error will be raised at run time?", N
);
1500 procedure Check_Length
(L
, H
: Node_Id
; Len
: Uint
) is
1510 if Raises_Constraint_Error
(N
) then
1514 Get
(Value
=> Val_L
, From
=> L
, OK
=> OK_L
);
1515 Get
(Value
=> Val_H
, From
=> H
, OK
=> OK_H
);
1517 if not OK_L
or else not OK_H
then
1521 -- If null range length is zero
1523 if Val_L
> Val_H
then
1524 Range_Len
:= Uint_0
;
1526 Range_Len
:= Val_H
- Val_L
+ 1;
1529 if Range_Len
< Len
then
1530 Set_Raises_Constraint_Error
(N
);
1531 Error_Msg_N
("too many elements?", N
);
1532 Error_Msg_N
("\Constraint_Error will be raised at run time?", N
);
1536 ---------------------------
1537 -- Dynamic_Or_Null_Range --
1538 ---------------------------
1540 function Dynamic_Or_Null_Range
(L
, H
: Node_Id
) return Boolean is
1548 Get
(Value
=> Val_L
, From
=> L
, OK
=> OK_L
);
1549 Get
(Value
=> Val_H
, From
=> H
, OK
=> OK_H
);
1551 return not OK_L
or else not OK_H
1552 or else not Is_OK_Static_Expression
(L
)
1553 or else not Is_OK_Static_Expression
(H
)
1554 or else Val_L
> Val_H
;
1555 end Dynamic_Or_Null_Range
;
1561 procedure Get
(Value
: out Uint
; From
: Node_Id
; OK
: out Boolean) is
1565 if Compile_Time_Known_Value
(From
) then
1566 Value
:= Expr_Value
(From
);
1568 -- If expression From is something like Some_Type'Val (10) then
1571 elsif Nkind
(From
) = N_Attribute_Reference
1572 and then Attribute_Name
(From
) = Name_Val
1573 and then Compile_Time_Known_Value
(First
(Expressions
(From
)))
1575 Value
:= Expr_Value
(First
(Expressions
(From
)));
1583 -----------------------
1584 -- Resolve_Aggr_Expr --
1585 -----------------------
1587 function Resolve_Aggr_Expr
1589 Single_Elmt
: Boolean) return Boolean
1591 Nxt_Ind
: constant Node_Id
:= Next_Index
(Index
);
1592 Nxt_Ind_Constr
: constant Node_Id
:= Next_Index
(Index_Constr
);
1593 -- Index is the current index corresponding to the expression
1595 Resolution_OK
: Boolean := True;
1596 -- Set to False if resolution of the expression failed
1599 -- Defend against previous errors
1601 if Nkind
(Expr
) = N_Error
1602 or else Error_Posted
(Expr
)
1607 -- If the array type against which we are resolving the aggregate
1608 -- has several dimensions, the expressions nested inside the
1609 -- aggregate must be further aggregates (or strings).
1611 if Present
(Nxt_Ind
) then
1612 if Nkind
(Expr
) /= N_Aggregate
then
1614 -- A string literal can appear where a one-dimensional array
1615 -- of characters is expected. If the literal looks like an
1616 -- operator, it is still an operator symbol, which will be
1617 -- transformed into a string when analyzed.
1619 if Is_Character_Type
(Component_Typ
)
1620 and then No
(Next_Index
(Nxt_Ind
))
1621 and then Nkind_In
(Expr
, N_String_Literal
, N_Operator_Symbol
)
1623 -- A string literal used in a multidimensional array
1624 -- aggregate in place of the final one-dimensional
1625 -- aggregate must not be enclosed in parentheses.
1627 if Paren_Count
(Expr
) /= 0 then
1628 Error_Msg_N
("no parenthesis allowed here", Expr
);
1631 Make_String_Into_Aggregate
(Expr
);
1634 Error_Msg_N
("nested array aggregate expected", Expr
);
1636 -- If the expression is parenthesized, this may be
1637 -- a missing component association for a 1-aggregate.
1639 if Paren_Count
(Expr
) > 0 then
1641 ("\if single-component aggregate is intended,"
1642 & " write e.g. (1 ='> ...)", Expr
);
1649 -- If it's "... => <>", nothing to resolve
1651 if Nkind
(Expr
) = N_Component_Association
then
1652 pragma Assert
(Box_Present
(Expr
));
1656 -- Ada 2005 (AI-231): Propagate the type to the nested aggregate.
1657 -- Required to check the null-exclusion attribute (if present).
1658 -- This value may be overridden later on.
1660 Set_Etype
(Expr
, Etype
(N
));
1662 Resolution_OK
:= Resolve_Array_Aggregate
1663 (Expr
, Nxt_Ind
, Nxt_Ind_Constr
, Component_Typ
, Others_Allowed
);
1667 -- If it's "... => <>", nothing to resolve
1669 if Nkind
(Expr
) = N_Component_Association
then
1670 pragma Assert
(Box_Present
(Expr
));
1674 -- Do not resolve the expressions of discrete or others choices
1675 -- unless the expression covers a single component, or the
1676 -- expander is inactive.
1678 -- In Alfa mode, expressions that can perform side-effects will be
1679 -- recognized by the gnat2why back-end, and the whole subprogram
1680 -- will be ignored. So semantic analysis can be performed safely.
1683 or else not Full_Expander_Active
1684 or else In_Spec_Expression
1686 Analyze_And_Resolve
(Expr
, Component_Typ
);
1687 Check_Expr_OK_In_Limited_Aggregate
(Expr
);
1688 Check_Non_Static_Context
(Expr
);
1689 Aggregate_Constraint_Checks
(Expr
, Component_Typ
);
1690 Check_Unset_Reference
(Expr
);
1694 -- If an aggregate component has a type with predicates, an explicit
1695 -- predicate check must be applied, as for an assignment statement,
1696 -- because the aggegate might not be expanded into individual
1697 -- component assignments.
1699 if Present
(Predicate_Function
(Component_Typ
)) then
1700 Apply_Predicate_Check
(Expr
, Component_Typ
);
1703 if Raises_Constraint_Error
(Expr
)
1704 and then Nkind
(Parent
(Expr
)) /= N_Component_Association
1706 Set_Raises_Constraint_Error
(N
);
1709 -- If the expression has been marked as requiring a range check,
1710 -- then generate it here.
1712 if Do_Range_Check
(Expr
) then
1713 Set_Do_Range_Check
(Expr
, False);
1714 Generate_Range_Check
(Expr
, Component_Typ
, CE_Range_Check_Failed
);
1717 return Resolution_OK
;
1718 end Resolve_Aggr_Expr
;
1720 -- Variables local to Resolve_Array_Aggregate
1727 pragma Warnings
(Off
, Discard
);
1729 Aggr_Low
: Node_Id
:= Empty
;
1730 Aggr_High
: Node_Id
:= Empty
;
1731 -- The actual low and high bounds of this sub-aggregate
1733 Choices_Low
: Node_Id
:= Empty
;
1734 Choices_High
: Node_Id
:= Empty
;
1735 -- The lowest and highest discrete choices values for a named aggregate
1737 Nb_Elements
: Uint
:= Uint_0
;
1738 -- The number of elements in a positional aggregate
1740 Others_Present
: Boolean := False;
1742 Nb_Choices
: Nat
:= 0;
1743 -- Contains the overall number of named choices in this sub-aggregate
1745 Nb_Discrete_Choices
: Nat
:= 0;
1746 -- The overall number of discrete choices (not counting others choice)
1748 Case_Table_Size
: Nat
;
1749 -- Contains the size of the case table needed to sort aggregate choices
1751 -- Start of processing for Resolve_Array_Aggregate
1754 -- Ignore junk empty aggregate resulting from parser error
1756 if No
(Expressions
(N
))
1757 and then No
(Component_Associations
(N
))
1758 and then not Null_Record_Present
(N
)
1763 -- STEP 1: make sure the aggregate is correctly formatted
1765 if Present
(Component_Associations
(N
)) then
1766 Assoc
:= First
(Component_Associations
(N
));
1767 while Present
(Assoc
) loop
1768 Choice
:= First
(Choices
(Assoc
));
1769 while Present
(Choice
) loop
1770 if Nkind
(Choice
) = N_Others_Choice
then
1771 Others_Present
:= True;
1773 if Choice
/= First
(Choices
(Assoc
))
1774 or else Present
(Next
(Choice
))
1777 ("OTHERS must appear alone in a choice list", Choice
);
1781 if Present
(Next
(Assoc
)) then
1783 ("OTHERS must appear last in an aggregate", Choice
);
1787 if Ada_Version
= Ada_83
1788 and then Assoc
/= First
(Component_Associations
(N
))
1789 and then Nkind_In
(Parent
(N
), N_Assignment_Statement
,
1790 N_Object_Declaration
)
1793 ("(Ada 83) illegal context for OTHERS choice", N
);
1797 Nb_Choices
:= Nb_Choices
+ 1;
1805 -- At this point we know that the others choice, if present, is by
1806 -- itself and appears last in the aggregate. Check if we have mixed
1807 -- positional and discrete associations (other than the others choice).
1809 if Present
(Expressions
(N
))
1810 and then (Nb_Choices
> 1
1811 or else (Nb_Choices
= 1 and then not Others_Present
))
1814 ("named association cannot follow positional association",
1815 First
(Choices
(First
(Component_Associations
(N
)))));
1819 -- Test for the validity of an others choice if present
1821 if Others_Present
and then not Others_Allowed
then
1823 ("OTHERS choice not allowed here",
1824 First
(Choices
(First
(Component_Associations
(N
)))));
1829 and then Nkind
(Parent
(N
)) /= N_Component_Association
1830 and then No
(Expressions
(N
))
1832 Nkind
(First
(Choices
(First
(Component_Associations
(N
)))))
1834 and then Is_Elementary_Type
(Component_Typ
)
1838 Assoc
: constant Node_Id
:= First
(Component_Associations
(N
));
1841 Make_Component_Association
(Loc
,
1844 Make_Attribute_Reference
(Loc
,
1845 Prefix
=> New_Occurrence_Of
(Index_Typ
, Loc
),
1846 Attribute_Name
=> Name_Range
)),
1847 Expression
=> Relocate_Node
(Expression
(Assoc
))));
1848 return Resolve_Array_Aggregate
1849 (N
, Index
, Index_Constr
, Component_Typ
, Others_Allowed
);
1853 -- Protect against cascaded errors
1855 if Etype
(Index_Typ
) = Any_Type
then
1859 -- STEP 2: Process named components
1861 if No
(Expressions
(N
)) then
1862 if Others_Present
then
1863 Case_Table_Size
:= Nb_Choices
- 1;
1865 Case_Table_Size
:= Nb_Choices
;
1871 -- Denote the lowest and highest values in an aggregate choice
1875 -- High end of one range and Low end of the next. Should be
1876 -- contiguous if there is no hole in the list of values.
1878 Missing_Values
: Boolean;
1879 -- Set True if missing index values
1881 S_Low
: Node_Id
:= Empty
;
1882 S_High
: Node_Id
:= Empty
;
1883 -- if a choice in an aggregate is a subtype indication these
1884 -- denote the lowest and highest values of the subtype
1886 Table
: Case_Table_Type
(1 .. Case_Table_Size
);
1887 -- Used to sort all the different choice values
1889 Single_Choice
: Boolean;
1890 -- Set to true every time there is a single discrete choice in a
1891 -- discrete association
1893 Prev_Nb_Discrete_Choices
: Nat
;
1894 -- Used to keep track of the number of discrete choices in the
1895 -- current association.
1897 Errors_Posted_On_Choices
: Boolean := False;
1898 -- Keeps track of whether any choices have semantic errors
1901 -- STEP 2 (A): Check discrete choices validity
1903 Assoc
:= First
(Component_Associations
(N
));
1904 while Present
(Assoc
) loop
1905 Prev_Nb_Discrete_Choices
:= Nb_Discrete_Choices
;
1906 Choice
:= First
(Choices
(Assoc
));
1910 if Nkind
(Choice
) = N_Others_Choice
then
1911 Single_Choice
:= False;
1914 -- Test for subtype mark without constraint
1916 elsif Is_Entity_Name
(Choice
) and then
1917 Is_Type
(Entity
(Choice
))
1919 if Base_Type
(Entity
(Choice
)) /= Index_Base
then
1921 ("invalid subtype mark in aggregate choice",
1926 -- Case of subtype indication
1928 elsif Nkind
(Choice
) = N_Subtype_Indication
then
1929 Resolve_Discrete_Subtype_Indication
(Choice
, Index_Base
);
1931 -- Does the subtype indication evaluation raise CE ?
1933 Get_Index_Bounds
(Subtype_Mark
(Choice
), S_Low
, S_High
);
1934 Get_Index_Bounds
(Choice
, Low
, High
);
1935 Check_Bounds
(S_Low
, S_High
, Low
, High
);
1937 -- Case of range or expression
1940 Resolve
(Choice
, Index_Base
);
1941 Check_Unset_Reference
(Choice
);
1942 Check_Non_Static_Context
(Choice
);
1944 -- If semantic errors were posted on the choice, then
1945 -- record that for possible early return from later
1946 -- processing (see handling of enumeration choices).
1948 if Error_Posted
(Choice
) then
1949 Errors_Posted_On_Choices
:= True;
1952 -- Do not range check a choice. This check is redundant
1953 -- since this test is already done when we check that the
1954 -- bounds of the array aggregate are within range.
1956 Set_Do_Range_Check
(Choice
, False);
1958 -- In SPARK, the choice must be static
1960 if not (Is_Static_Expression
(Choice
)
1961 or else (Nkind
(Choice
) = N_Range
1962 and then Is_Static_Range
(Choice
)))
1964 Check_SPARK_Restriction
1965 ("choice should be static", Choice
);
1969 -- If we could not resolve the discrete choice stop here
1971 if Etype
(Choice
) = Any_Type
then
1974 -- If the discrete choice raises CE get its original bounds
1976 elsif Nkind
(Choice
) = N_Raise_Constraint_Error
then
1977 Set_Raises_Constraint_Error
(N
);
1978 Get_Index_Bounds
(Original_Node
(Choice
), Low
, High
);
1980 -- Otherwise get its bounds as usual
1983 Get_Index_Bounds
(Choice
, Low
, High
);
1986 if (Dynamic_Or_Null_Range
(Low
, High
)
1987 or else (Nkind
(Choice
) = N_Subtype_Indication
1989 Dynamic_Or_Null_Range
(S_Low
, S_High
)))
1990 and then Nb_Choices
/= 1
1993 ("dynamic or empty choice in aggregate " &
1994 "must be the only choice", Choice
);
1998 Nb_Discrete_Choices
:= Nb_Discrete_Choices
+ 1;
1999 Table
(Nb_Discrete_Choices
).Choice_Lo
:= Low
;
2000 Table
(Nb_Discrete_Choices
).Choice_Hi
:= High
;
2006 -- Check if we have a single discrete choice and whether
2007 -- this discrete choice specifies a single value.
2010 (Nb_Discrete_Choices
= Prev_Nb_Discrete_Choices
+ 1)
2011 and then (Low
= High
);
2017 -- Ada 2005 (AI-231)
2019 if Ada_Version
>= Ada_2005
2020 and then Known_Null
(Expression
(Assoc
))
2022 Check_Can_Never_Be_Null
(Etype
(N
), Expression
(Assoc
));
2025 -- Ada 2005 (AI-287): In case of default initialized component
2026 -- we delay the resolution to the expansion phase.
2028 if Box_Present
(Assoc
) then
2030 -- Ada 2005 (AI-287): In case of default initialization of a
2031 -- component the expander will generate calls to the
2032 -- corresponding initialization subprogram. We need to call
2033 -- Resolve_Aggr_Expr to check the rules about
2036 if not Resolve_Aggr_Expr
(Assoc
,
2037 Single_Elmt
=> Single_Choice
)
2042 elsif not Resolve_Aggr_Expr
(Expression
(Assoc
),
2043 Single_Elmt
=> Single_Choice
)
2047 -- Check incorrect use of dynamically tagged expression
2049 -- We differentiate here two cases because the expression may
2050 -- not be decorated. For example, the analysis and resolution
2051 -- of the expression associated with the others choice will be
2052 -- done later with the full aggregate. In such case we
2053 -- duplicate the expression tree to analyze the copy and
2054 -- perform the required check.
2056 elsif not Present
(Etype
(Expression
(Assoc
))) then
2058 Save_Analysis
: constant Boolean := Full_Analysis
;
2059 Expr
: constant Node_Id
:=
2060 New_Copy_Tree
(Expression
(Assoc
));
2063 Expander_Mode_Save_And_Set
(False);
2064 Full_Analysis
:= False;
2066 -- Analyze the expression, making sure it is properly
2067 -- attached to the tree before we do the analysis.
2069 Set_Parent
(Expr
, Parent
(Expression
(Assoc
)));
2072 -- If the expression is a literal, propagate this info
2073 -- to the expression in the association, to enable some
2074 -- optimizations downstream.
2076 if Is_Entity_Name
(Expr
)
2077 and then Present
(Entity
(Expr
))
2078 and then Ekind
(Entity
(Expr
)) = E_Enumeration_Literal
2081 (Expression
(Assoc
), Component_Typ
);
2084 Full_Analysis
:= Save_Analysis
;
2085 Expander_Mode_Restore
;
2087 if Is_Tagged_Type
(Etype
(Expr
)) then
2088 Check_Dynamically_Tagged_Expression
2090 Typ
=> Component_Type
(Etype
(N
)),
2095 elsif Is_Tagged_Type
(Etype
(Expression
(Assoc
))) then
2096 Check_Dynamically_Tagged_Expression
2097 (Expr
=> Expression
(Assoc
),
2098 Typ
=> Component_Type
(Etype
(N
)),
2105 -- If aggregate contains more than one choice then these must be
2106 -- static. Sort them and check that they are contiguous.
2108 if Nb_Discrete_Choices
> 1 then
2109 Sort_Case_Table
(Table
);
2110 Missing_Values
:= False;
2112 Outer
: for J
in 1 .. Nb_Discrete_Choices
- 1 loop
2113 if Expr_Value
(Table
(J
).Choice_Hi
) >=
2114 Expr_Value
(Table
(J
+ 1).Choice_Lo
)
2117 ("duplicate choice values in array aggregate",
2118 Table
(J
).Choice_Hi
);
2121 elsif not Others_Present
then
2122 Hi_Val
:= Expr_Value
(Table
(J
).Choice_Hi
);
2123 Lo_Val
:= Expr_Value
(Table
(J
+ 1).Choice_Lo
);
2125 -- If missing values, output error messages
2127 if Lo_Val
- Hi_Val
> 1 then
2129 -- Header message if not first missing value
2131 if not Missing_Values
then
2133 ("missing index value(s) in array aggregate", N
);
2134 Missing_Values
:= True;
2137 -- Output values of missing indexes
2139 Lo_Val
:= Lo_Val
- 1;
2140 Hi_Val
:= Hi_Val
+ 1;
2142 -- Enumeration type case
2144 if Is_Enumeration_Type
(Index_Typ
) then
2147 (Get_Enum_Lit_From_Pos
2148 (Index_Typ
, Hi_Val
, Loc
));
2150 if Lo_Val
= Hi_Val
then
2151 Error_Msg_N
("\ %", N
);
2155 (Get_Enum_Lit_From_Pos
2156 (Index_Typ
, Lo_Val
, Loc
));
2157 Error_Msg_N
("\ % .. %", N
);
2160 -- Integer types case
2163 Error_Msg_Uint_1
:= Hi_Val
;
2165 if Lo_Val
= Hi_Val
then
2166 Error_Msg_N
("\ ^", N
);
2168 Error_Msg_Uint_2
:= Lo_Val
;
2169 Error_Msg_N
("\ ^ .. ^", N
);
2176 if Missing_Values
then
2177 Set_Etype
(N
, Any_Composite
);
2182 -- STEP 2 (B): Compute aggregate bounds and min/max choices values
2184 if Nb_Discrete_Choices
> 0 then
2185 Choices_Low
:= Table
(1).Choice_Lo
;
2186 Choices_High
:= Table
(Nb_Discrete_Choices
).Choice_Hi
;
2189 -- If Others is present, then bounds of aggregate come from the
2190 -- index constraint (not the choices in the aggregate itself).
2192 if Others_Present
then
2193 Get_Index_Bounds
(Index_Constr
, Aggr_Low
, Aggr_High
);
2195 -- No others clause present
2198 -- Special processing if others allowed and not present. This
2199 -- means that the bounds of the aggregate come from the index
2200 -- constraint (and the length must match).
2202 if Others_Allowed
then
2203 Get_Index_Bounds
(Index_Constr
, Aggr_Low
, Aggr_High
);
2205 -- If others allowed, and no others present, then the array
2206 -- should cover all index values. If it does not, we will
2207 -- get a length check warning, but there is two cases where
2208 -- an additional warning is useful:
2210 -- If we have no positional components, and the length is
2211 -- wrong (which we can tell by others being allowed with
2212 -- missing components), and the index type is an enumeration
2213 -- type, then issue appropriate warnings about these missing
2214 -- components. They are only warnings, since the aggregate
2215 -- is fine, it's just the wrong length. We skip this check
2216 -- for standard character types (since there are no literals
2217 -- and it is too much trouble to concoct them), and also if
2218 -- any of the bounds have not-known-at-compile-time values.
2220 -- Another case warranting a warning is when the length is
2221 -- right, but as above we have an index type that is an
2222 -- enumeration, and the bounds do not match. This is a
2223 -- case where dubious sliding is allowed and we generate
2224 -- a warning that the bounds do not match.
2226 if No
(Expressions
(N
))
2227 and then Nkind
(Index
) = N_Range
2228 and then Is_Enumeration_Type
(Etype
(Index
))
2229 and then not Is_Standard_Character_Type
(Etype
(Index
))
2230 and then Compile_Time_Known_Value
(Aggr_Low
)
2231 and then Compile_Time_Known_Value
(Aggr_High
)
2232 and then Compile_Time_Known_Value
(Choices_Low
)
2233 and then Compile_Time_Known_Value
(Choices_High
)
2235 -- If any of the expressions or range bounds in choices
2236 -- have semantic errors, then do not attempt further
2237 -- resolution, to prevent cascaded errors.
2239 if Errors_Posted_On_Choices
then
2244 ALo
: constant Node_Id
:= Expr_Value_E
(Aggr_Low
);
2245 AHi
: constant Node_Id
:= Expr_Value_E
(Aggr_High
);
2246 CLo
: constant Node_Id
:= Expr_Value_E
(Choices_Low
);
2247 CHi
: constant Node_Id
:= Expr_Value_E
(Choices_High
);
2252 -- Warning case 1, missing values at start/end. Only
2253 -- do the check if the number of entries is too small.
2255 if (Enumeration_Pos
(CHi
) - Enumeration_Pos
(CLo
))
2257 (Enumeration_Pos
(AHi
) - Enumeration_Pos
(ALo
))
2260 ("missing index value(s) in array aggregate?", N
);
2262 -- Output missing value(s) at start
2264 if Chars
(ALo
) /= Chars
(CLo
) then
2267 if Chars
(ALo
) = Chars
(Ent
) then
2268 Error_Msg_Name_1
:= Chars
(ALo
);
2269 Error_Msg_N
("\ %?", N
);
2271 Error_Msg_Name_1
:= Chars
(ALo
);
2272 Error_Msg_Name_2
:= Chars
(Ent
);
2273 Error_Msg_N
("\ % .. %?", N
);
2277 -- Output missing value(s) at end
2279 if Chars
(AHi
) /= Chars
(CHi
) then
2282 if Chars
(AHi
) = Chars
(Ent
) then
2283 Error_Msg_Name_1
:= Chars
(Ent
);
2284 Error_Msg_N
("\ %?", N
);
2286 Error_Msg_Name_1
:= Chars
(Ent
);
2287 Error_Msg_Name_2
:= Chars
(AHi
);
2288 Error_Msg_N
("\ % .. %?", N
);
2292 -- Warning case 2, dubious sliding. The First_Subtype
2293 -- test distinguishes between a constrained type where
2294 -- sliding is not allowed (so we will get a warning
2295 -- later that Constraint_Error will be raised), and
2296 -- the unconstrained case where sliding is permitted.
2298 elsif (Enumeration_Pos
(CHi
) - Enumeration_Pos
(CLo
))
2300 (Enumeration_Pos
(AHi
) - Enumeration_Pos
(ALo
))
2301 and then Chars
(ALo
) /= Chars
(CLo
)
2303 not Is_Constrained
(First_Subtype
(Etype
(N
)))
2306 ("bounds of aggregate do not match target?", N
);
2312 -- If no others, aggregate bounds come from aggregate
2314 Aggr_Low
:= Choices_Low
;
2315 Aggr_High
:= Choices_High
;
2319 -- STEP 3: Process positional components
2322 -- STEP 3 (A): Process positional elements
2324 Expr
:= First
(Expressions
(N
));
2325 Nb_Elements
:= Uint_0
;
2326 while Present
(Expr
) loop
2327 Nb_Elements
:= Nb_Elements
+ 1;
2329 -- Ada 2005 (AI-231)
2331 if Ada_Version
>= Ada_2005
2332 and then Known_Null
(Expr
)
2334 Check_Can_Never_Be_Null
(Etype
(N
), Expr
);
2337 if not Resolve_Aggr_Expr
(Expr
, Single_Elmt
=> True) then
2341 -- Check incorrect use of dynamically tagged expression
2343 if Is_Tagged_Type
(Etype
(Expr
)) then
2344 Check_Dynamically_Tagged_Expression
2346 Typ
=> Component_Type
(Etype
(N
)),
2353 if Others_Present
then
2354 Assoc
:= Last
(Component_Associations
(N
));
2356 -- Ada 2005 (AI-231)
2358 if Ada_Version
>= Ada_2005
2359 and then Known_Null
(Assoc
)
2361 Check_Can_Never_Be_Null
(Etype
(N
), Expression
(Assoc
));
2364 -- Ada 2005 (AI-287): In case of default initialized component,
2365 -- we delay the resolution to the expansion phase.
2367 if Box_Present
(Assoc
) then
2369 -- Ada 2005 (AI-287): In case of default initialization of a
2370 -- component the expander will generate calls to the
2371 -- corresponding initialization subprogram. We need to call
2372 -- Resolve_Aggr_Expr to check the rules about
2375 if not Resolve_Aggr_Expr
(Assoc
, Single_Elmt
=> False) then
2379 elsif not Resolve_Aggr_Expr
(Expression
(Assoc
),
2380 Single_Elmt
=> False)
2384 -- Check incorrect use of dynamically tagged expression. The
2385 -- expression of the others choice has not been resolved yet.
2386 -- In order to diagnose the semantic error we create a duplicate
2387 -- tree to analyze it and perform the check.
2391 Save_Analysis
: constant Boolean := Full_Analysis
;
2392 Expr
: constant Node_Id
:=
2393 New_Copy_Tree
(Expression
(Assoc
));
2396 Expander_Mode_Save_And_Set
(False);
2397 Full_Analysis
:= False;
2399 Full_Analysis
:= Save_Analysis
;
2400 Expander_Mode_Restore
;
2402 if Is_Tagged_Type
(Etype
(Expr
)) then
2403 Check_Dynamically_Tagged_Expression
2405 Typ
=> Component_Type
(Etype
(N
)),
2412 -- STEP 3 (B): Compute the aggregate bounds
2414 if Others_Present
then
2415 Get_Index_Bounds
(Index_Constr
, Aggr_Low
, Aggr_High
);
2418 if Others_Allowed
then
2419 Get_Index_Bounds
(Index_Constr
, Aggr_Low
, Discard
);
2421 Aggr_Low
:= Index_Typ_Low
;
2424 Aggr_High
:= Add
(Nb_Elements
- 1, To
=> Aggr_Low
);
2425 Check_Bound
(Index_Base_High
, Aggr_High
);
2429 -- STEP 4: Perform static aggregate checks and save the bounds
2433 Check_Bounds
(Index_Typ_Low
, Index_Typ_High
, Aggr_Low
, Aggr_High
);
2434 Check_Bounds
(Index_Base_Low
, Index_Base_High
, Aggr_Low
, Aggr_High
);
2438 if Others_Present
and then Nb_Discrete_Choices
> 0 then
2439 Check_Bounds
(Aggr_Low
, Aggr_High
, Choices_Low
, Choices_High
);
2440 Check_Bounds
(Index_Typ_Low
, Index_Typ_High
,
2441 Choices_Low
, Choices_High
);
2442 Check_Bounds
(Index_Base_Low
, Index_Base_High
,
2443 Choices_Low
, Choices_High
);
2447 elsif Others_Present
and then Nb_Elements
> 0 then
2448 Check_Length
(Aggr_Low
, Aggr_High
, Nb_Elements
);
2449 Check_Length
(Index_Typ_Low
, Index_Typ_High
, Nb_Elements
);
2450 Check_Length
(Index_Base_Low
, Index_Base_High
, Nb_Elements
);
2453 if Raises_Constraint_Error
(Aggr_Low
)
2454 or else Raises_Constraint_Error
(Aggr_High
)
2456 Set_Raises_Constraint_Error
(N
);
2459 Aggr_Low
:= Duplicate_Subexpr
(Aggr_Low
);
2461 -- Do not duplicate Aggr_High if Aggr_High = Aggr_Low + Nb_Elements
2462 -- since the addition node returned by Add is not yet analyzed. Attach
2463 -- to tree and analyze first. Reset analyzed flag to ensure it will get
2464 -- analyzed when it is a literal bound whose type must be properly set.
2466 if Others_Present
or else Nb_Discrete_Choices
> 0 then
2467 Aggr_High
:= Duplicate_Subexpr
(Aggr_High
);
2469 if Etype
(Aggr_High
) = Universal_Integer
then
2470 Set_Analyzed
(Aggr_High
, False);
2474 -- If the aggregate already has bounds attached to it, it means this is
2475 -- a positional aggregate created as an optimization by
2476 -- Exp_Aggr.Convert_To_Positional, so we don't want to change those
2479 if Present
(Aggregate_Bounds
(N
)) and then not Others_Allowed
then
2480 Aggr_Low
:= Low_Bound
(Aggregate_Bounds
(N
));
2481 Aggr_High
:= High_Bound
(Aggregate_Bounds
(N
));
2484 Set_Aggregate_Bounds
2485 (N
, Make_Range
(Loc
, Low_Bound
=> Aggr_Low
, High_Bound
=> Aggr_High
));
2487 -- The bounds may contain expressions that must be inserted upwards.
2488 -- Attach them fully to the tree. After analysis, remove side effects
2489 -- from upper bound, if still needed.
2491 Set_Parent
(Aggregate_Bounds
(N
), N
);
2492 Analyze_And_Resolve
(Aggregate_Bounds
(N
), Index_Typ
);
2493 Check_Unset_Reference
(Aggregate_Bounds
(N
));
2495 if not Others_Present
and then Nb_Discrete_Choices
= 0 then
2496 Set_High_Bound
(Aggregate_Bounds
(N
),
2497 Duplicate_Subexpr
(High_Bound
(Aggregate_Bounds
(N
))));
2501 end Resolve_Array_Aggregate
;
2503 ---------------------------------
2504 -- Resolve_Extension_Aggregate --
2505 ---------------------------------
2507 -- There are two cases to consider:
2509 -- a) If the ancestor part is a type mark, the components needed are the
2510 -- difference between the components of the expected type and the
2511 -- components of the given type mark.
2513 -- b) If the ancestor part is an expression, it must be unambiguous, and
2514 -- once we have its type we can also compute the needed components as in
2515 -- the previous case. In both cases, if the ancestor type is not the
2516 -- immediate ancestor, we have to build this ancestor recursively.
2518 -- In both cases, discriminants of the ancestor type do not play a role in
2519 -- the resolution of the needed components, because inherited discriminants
2520 -- cannot be used in a type extension. As a result we can compute
2521 -- independently the list of components of the ancestor type and of the
2524 procedure Resolve_Extension_Aggregate
(N
: Node_Id
; Typ
: Entity_Id
) is
2525 A
: constant Node_Id
:= Ancestor_Part
(N
);
2530 function Valid_Limited_Ancestor
(Anc
: Node_Id
) return Boolean;
2531 -- If the type is limited, verify that the ancestor part is a legal
2532 -- expression (aggregate or function call, including 'Input)) that does
2533 -- not require a copy, as specified in 7.5(2).
2535 function Valid_Ancestor_Type
return Boolean;
2536 -- Verify that the type of the ancestor part is a non-private ancestor
2537 -- of the expected type, which must be a type extension.
2539 ----------------------------
2540 -- Valid_Limited_Ancestor --
2541 ----------------------------
2543 function Valid_Limited_Ancestor
(Anc
: Node_Id
) return Boolean is
2545 if Is_Entity_Name
(Anc
)
2546 and then Is_Type
(Entity
(Anc
))
2550 elsif Nkind_In
(Anc
, N_Aggregate
, N_Function_Call
) then
2553 elsif Nkind
(Anc
) = N_Attribute_Reference
2554 and then Attribute_Name
(Anc
) = Name_Input
2558 elsif Nkind
(Anc
) = N_Qualified_Expression
then
2559 return Valid_Limited_Ancestor
(Expression
(Anc
));
2564 end Valid_Limited_Ancestor
;
2566 -------------------------
2567 -- Valid_Ancestor_Type --
2568 -------------------------
2570 function Valid_Ancestor_Type
return Boolean is
2571 Imm_Type
: Entity_Id
;
2574 Imm_Type
:= Base_Type
(Typ
);
2575 while Is_Derived_Type
(Imm_Type
) loop
2576 if Etype
(Imm_Type
) = Base_Type
(A_Type
) then
2579 -- The base type of the parent type may appear as a private
2580 -- extension if it is declared as such in a parent unit of the
2581 -- current one. For consistency of the subsequent analysis use
2582 -- the partial view for the ancestor part.
2584 elsif Is_Private_Type
(Etype
(Imm_Type
))
2585 and then Present
(Full_View
(Etype
(Imm_Type
)))
2586 and then Base_Type
(A_Type
) = Full_View
(Etype
(Imm_Type
))
2588 A_Type
:= Etype
(Imm_Type
);
2591 -- The parent type may be a private extension. The aggregate is
2592 -- legal if the type of the aggregate is an extension of it that
2593 -- is not a private extension.
2595 elsif Is_Private_Type
(A_Type
)
2596 and then not Is_Private_Type
(Imm_Type
)
2597 and then Present
(Full_View
(A_Type
))
2598 and then Base_Type
(Full_View
(A_Type
)) = Etype
(Imm_Type
)
2603 Imm_Type
:= Etype
(Base_Type
(Imm_Type
));
2607 -- If previous loop did not find a proper ancestor, report error
2609 Error_Msg_NE
("expect ancestor type of &", A
, Typ
);
2611 end Valid_Ancestor_Type
;
2613 -- Start of processing for Resolve_Extension_Aggregate
2616 -- Analyze the ancestor part and account for the case where it is a
2617 -- parameterless function call.
2620 Check_Parameterless_Call
(A
);
2622 -- In SPARK, the ancestor part cannot be a type mark
2624 if Is_Entity_Name
(A
)
2625 and then Is_Type
(Entity
(A
))
2627 Check_SPARK_Restriction
("ancestor part cannot be a type mark", A
);
2629 -- AI05-0115: if the ancestor part is a subtype mark, the ancestor
2630 -- must not have unknown discriminants.
2632 if Has_Unknown_Discriminants
(Root_Type
(Typ
)) then
2634 ("aggregate not available for type& whose ancestor "
2635 & "has unknown discriminants", N
, Typ
);
2639 if not Is_Tagged_Type
(Typ
) then
2640 Error_Msg_N
("type of extension aggregate must be tagged", N
);
2643 elsif Is_Limited_Type
(Typ
) then
2645 -- Ada 2005 (AI-287): Limited aggregates are allowed
2647 if Ada_Version
< Ada_2005
then
2648 Error_Msg_N
("aggregate type cannot be limited", N
);
2649 Explain_Limited_Type
(Typ
, N
);
2652 elsif Valid_Limited_Ancestor
(A
) then
2657 ("limited ancestor part must be aggregate or function call", A
);
2660 elsif Is_Class_Wide_Type
(Typ
) then
2661 Error_Msg_N
("aggregate cannot be of a class-wide type", N
);
2665 if Is_Entity_Name
(A
)
2666 and then Is_Type
(Entity
(A
))
2668 A_Type
:= Get_Full_View
(Entity
(A
));
2670 if Valid_Ancestor_Type
then
2671 Set_Entity
(A
, A_Type
);
2672 Set_Etype
(A
, A_Type
);
2674 Validate_Ancestor_Part
(N
);
2675 Resolve_Record_Aggregate
(N
, Typ
);
2678 elsif Nkind
(A
) /= N_Aggregate
then
2679 if Is_Overloaded
(A
) then
2682 Get_First_Interp
(A
, I
, It
);
2683 while Present
(It
.Typ
) loop
2684 -- Only consider limited interpretations in the Ada 2005 case
2686 if Is_Tagged_Type
(It
.Typ
)
2687 and then (Ada_Version
>= Ada_2005
2688 or else not Is_Limited_Type
(It
.Typ
))
2690 if A_Type
/= Any_Type
then
2691 Error_Msg_N
("cannot resolve expression", A
);
2698 Get_Next_Interp
(I
, It
);
2701 if A_Type
= Any_Type
then
2702 if Ada_Version
>= Ada_2005
then
2703 Error_Msg_N
("ancestor part must be of a tagged type", A
);
2706 ("ancestor part must be of a nonlimited tagged type", A
);
2713 A_Type
:= Etype
(A
);
2716 if Valid_Ancestor_Type
then
2717 Resolve
(A
, A_Type
);
2718 Check_Unset_Reference
(A
);
2719 Check_Non_Static_Context
(A
);
2721 -- The aggregate is illegal if the ancestor expression is a call
2722 -- to a function with a limited unconstrained result, unless the
2723 -- type of the aggregate is a null extension. This restriction
2724 -- was added in AI05-67 to simplify implementation.
2726 if Nkind
(A
) = N_Function_Call
2727 and then Is_Limited_Type
(A_Type
)
2728 and then not Is_Null_Extension
(Typ
)
2729 and then not Is_Constrained
(A_Type
)
2732 ("type of limited ancestor part must be constrained", A
);
2734 -- Reject the use of CPP constructors that leave objects partially
2735 -- initialized. For example:
2737 -- type CPP_Root is tagged limited record ...
2738 -- pragma Import (CPP, CPP_Root);
2740 -- type CPP_DT is new CPP_Root and Iface ...
2741 -- pragma Import (CPP, CPP_DT);
2743 -- type Ada_DT is new CPP_DT with ...
2745 -- Obj : Ada_DT := Ada_DT'(New_CPP_Root with others => <>);
2747 -- Using the constructor of CPP_Root the slots of the dispatch
2748 -- table of CPP_DT cannot be set, and the secondary tag of
2749 -- CPP_DT is unknown.
2751 elsif Nkind
(A
) = N_Function_Call
2752 and then Is_CPP_Constructor_Call
(A
)
2753 and then Enclosing_CPP_Parent
(Typ
) /= A_Type
2756 ("?must use 'C'P'P constructor for type &", A
,
2757 Enclosing_CPP_Parent
(Typ
));
2759 -- The following call is not needed if the previous warning
2760 -- is promoted to an error.
2762 Resolve_Record_Aggregate
(N
, Typ
);
2764 elsif Is_Class_Wide_Type
(Etype
(A
))
2765 and then Nkind
(Original_Node
(A
)) = N_Function_Call
2767 -- If the ancestor part is a dispatching call, it appears
2768 -- statically to be a legal ancestor, but it yields any member
2769 -- of the class, and it is not possible to determine whether
2770 -- it is an ancestor of the extension aggregate (much less
2771 -- which ancestor). It is not possible to determine the
2772 -- components of the extension part.
2774 -- This check implements AI-306, which in fact was motivated by
2775 -- an AdaCore query to the ARG after this test was added.
2777 Error_Msg_N
("ancestor part must be statically tagged", A
);
2779 Resolve_Record_Aggregate
(N
, Typ
);
2784 Error_Msg_N
("no unique type for this aggregate", A
);
2786 end Resolve_Extension_Aggregate
;
2788 ------------------------------
2789 -- Resolve_Record_Aggregate --
2790 ------------------------------
2792 procedure Resolve_Record_Aggregate
(N
: Node_Id
; Typ
: Entity_Id
) is
2794 -- N_Component_Association node belonging to the input aggregate N
2797 Positional_Expr
: Node_Id
;
2798 Component
: Entity_Id
;
2799 Component_Elmt
: Elmt_Id
;
2801 Components
: constant Elist_Id
:= New_Elmt_List
;
2802 -- Components is the list of the record components whose value must be
2803 -- provided in the aggregate. This list does include discriminants.
2805 New_Assoc_List
: constant List_Id
:= New_List
;
2806 New_Assoc
: Node_Id
;
2807 -- New_Assoc_List is the newly built list of N_Component_Association
2808 -- nodes. New_Assoc is one such N_Component_Association node in it.
2809 -- Note that while Assoc and New_Assoc contain the same kind of nodes,
2810 -- they are used to iterate over two different N_Component_Association
2813 Others_Etype
: Entity_Id
:= Empty
;
2814 -- This variable is used to save the Etype of the last record component
2815 -- that takes its value from the others choice. Its purpose is:
2817 -- (a) make sure the others choice is useful
2819 -- (b) make sure the type of all the components whose value is
2820 -- subsumed by the others choice are the same.
2822 -- This variable is updated as a side effect of function Get_Value.
2824 Is_Box_Present
: Boolean := False;
2825 Others_Box
: Boolean := False;
2826 -- Ada 2005 (AI-287): Variables used in case of default initialization
2827 -- to provide a functionality similar to Others_Etype. Box_Present
2828 -- indicates that the component takes its default initialization;
2829 -- Others_Box indicates that at least one component takes its default
2830 -- initialization. Similar to Others_Etype, they are also updated as a
2831 -- side effect of function Get_Value.
2833 procedure Add_Association
2834 (Component
: Entity_Id
;
2836 Assoc_List
: List_Id
;
2837 Is_Box_Present
: Boolean := False);
2838 -- Builds a new N_Component_Association node which associates Component
2839 -- to expression Expr and adds it to the association list being built,
2840 -- either New_Assoc_List, or the association being built for an inner
2843 function Discr_Present
(Discr
: Entity_Id
) return Boolean;
2844 -- If aggregate N is a regular aggregate this routine will return True.
2845 -- Otherwise, if N is an extension aggregate, Discr is a discriminant
2846 -- whose value may already have been specified by N's ancestor part.
2847 -- This routine checks whether this is indeed the case and if so returns
2848 -- False, signaling that no value for Discr should appear in N's
2849 -- aggregate part. Also, in this case, the routine appends to
2850 -- New_Assoc_List the discriminant value specified in the ancestor part.
2852 -- If the aggregate is in a context with expansion delayed, it will be
2853 -- reanalyzed. The inherited discriminant values must not be reinserted
2854 -- in the component list to prevent spurious errors, but they must be
2855 -- present on first analysis to build the proper subtype indications.
2856 -- The flag Inherited_Discriminant is used to prevent the re-insertion.
2861 Consider_Others_Choice
: Boolean := False)
2863 -- Given a record component stored in parameter Compon, this function
2864 -- returns its value as it appears in the list From, which is a list
2865 -- of N_Component_Association nodes.
2867 -- If no component association has a choice for the searched component,
2868 -- the value provided by the others choice is returned, if there is one,
2869 -- and Consider_Others_Choice is set to true. Otherwise Empty is
2870 -- returned. If there is more than one component association giving a
2871 -- value for the searched record component, an error message is emitted
2872 -- and the first found value is returned.
2874 -- If Consider_Others_Choice is set and the returned expression comes
2875 -- from the others choice, then Others_Etype is set as a side effect.
2876 -- An error message is emitted if the components taking their value from
2877 -- the others choice do not have same type.
2879 procedure Resolve_Aggr_Expr
(Expr
: Node_Id
; Component
: Node_Id
);
2880 -- Analyzes and resolves expression Expr against the Etype of the
2881 -- Component. This routine also applies all appropriate checks to Expr.
2882 -- It finally saves a Expr in the newly created association list that
2883 -- will be attached to the final record aggregate. Note that if the
2884 -- Parent pointer of Expr is not set then Expr was produced with a
2885 -- New_Copy_Tree or some such.
2887 ---------------------
2888 -- Add_Association --
2889 ---------------------
2891 procedure Add_Association
2892 (Component
: Entity_Id
;
2894 Assoc_List
: List_Id
;
2895 Is_Box_Present
: Boolean := False)
2898 Choice_List
: constant List_Id
:= New_List
;
2899 New_Assoc
: Node_Id
;
2902 -- If this is a box association the expression is missing, so
2903 -- use the Sloc of the aggregate itself for the new association.
2905 if Present
(Expr
) then
2911 Append
(New_Occurrence_Of
(Component
, Loc
), Choice_List
);
2913 Make_Component_Association
(Loc
,
2914 Choices
=> Choice_List
,
2916 Box_Present
=> Is_Box_Present
);
2917 Append
(New_Assoc
, Assoc_List
);
2918 end Add_Association
;
2924 function Discr_Present
(Discr
: Entity_Id
) return Boolean is
2925 Regular_Aggr
: constant Boolean := Nkind
(N
) /= N_Extension_Aggregate
;
2930 Comp_Assoc
: Node_Id
;
2931 Discr_Expr
: Node_Id
;
2933 Ancestor_Typ
: Entity_Id
;
2934 Orig_Discr
: Entity_Id
;
2936 D_Val
: Elmt_Id
:= No_Elmt
; -- stop junk warning
2938 Ancestor_Is_Subtyp
: Boolean;
2941 if Regular_Aggr
then
2945 -- Check whether inherited discriminant values have already been
2946 -- inserted in the aggregate. This will be the case if we are
2947 -- re-analyzing an aggregate whose expansion was delayed.
2949 if Present
(Component_Associations
(N
)) then
2950 Comp_Assoc
:= First
(Component_Associations
(N
));
2951 while Present
(Comp_Assoc
) loop
2952 if Inherited_Discriminant
(Comp_Assoc
) then
2960 Ancestor
:= Ancestor_Part
(N
);
2961 Ancestor_Typ
:= Etype
(Ancestor
);
2962 Loc
:= Sloc
(Ancestor
);
2964 -- For a private type with unknown discriminants, use the underlying
2965 -- record view if it is available.
2967 if Has_Unknown_Discriminants
(Ancestor_Typ
)
2968 and then Present
(Full_View
(Ancestor_Typ
))
2969 and then Present
(Underlying_Record_View
(Full_View
(Ancestor_Typ
)))
2971 Ancestor_Typ
:= Underlying_Record_View
(Full_View
(Ancestor_Typ
));
2974 Ancestor_Is_Subtyp
:=
2975 Is_Entity_Name
(Ancestor
) and then Is_Type
(Entity
(Ancestor
));
2977 -- If the ancestor part has no discriminants clearly N's aggregate
2978 -- part must provide a value for Discr.
2980 if not Has_Discriminants
(Ancestor_Typ
) then
2983 -- If the ancestor part is an unconstrained subtype mark then the
2984 -- Discr must be present in N's aggregate part.
2986 elsif Ancestor_Is_Subtyp
2987 and then not Is_Constrained
(Entity
(Ancestor
))
2992 -- Now look to see if Discr was specified in the ancestor part
2994 if Ancestor_Is_Subtyp
then
2995 D_Val
:= First_Elmt
(Discriminant_Constraint
(Entity
(Ancestor
)));
2998 Orig_Discr
:= Original_Record_Component
(Discr
);
3000 D
:= First_Discriminant
(Ancestor_Typ
);
3001 while Present
(D
) loop
3003 -- If Ancestor has already specified Disc value then insert its
3004 -- value in the final aggregate.
3006 if Original_Record_Component
(D
) = Orig_Discr
then
3007 if Ancestor_Is_Subtyp
then
3008 Discr_Expr
:= New_Copy_Tree
(Node
(D_Val
));
3011 Make_Selected_Component
(Loc
,
3012 Prefix
=> Duplicate_Subexpr
(Ancestor
),
3013 Selector_Name
=> New_Occurrence_Of
(Discr
, Loc
));
3016 Resolve_Aggr_Expr
(Discr_Expr
, Discr
);
3017 Set_Inherited_Discriminant
(Last
(New_Assoc_List
));
3021 Next_Discriminant
(D
);
3023 if Ancestor_Is_Subtyp
then
3038 Consider_Others_Choice
: Boolean := False)
3042 Expr
: Node_Id
:= Empty
;
3043 Selector_Name
: Node_Id
;
3046 Is_Box_Present
:= False;
3048 if Present
(From
) then
3049 Assoc
:= First
(From
);
3054 while Present
(Assoc
) loop
3055 Selector_Name
:= First
(Choices
(Assoc
));
3056 while Present
(Selector_Name
) loop
3057 if Nkind
(Selector_Name
) = N_Others_Choice
then
3058 if Consider_Others_Choice
and then No
(Expr
) then
3060 -- We need to duplicate the expression for each
3061 -- successive component covered by the others choice.
3062 -- This is redundant if the others_choice covers only
3063 -- one component (small optimization possible???), but
3064 -- indispensable otherwise, because each one must be
3065 -- expanded individually to preserve side-effects.
3067 -- Ada 2005 (AI-287): In case of default initialization
3068 -- of components, we duplicate the corresponding default
3069 -- expression (from the record type declaration). The
3070 -- copy must carry the sloc of the association (not the
3071 -- original expression) to prevent spurious elaboration
3072 -- checks when the default includes function calls.
3074 if Box_Present
(Assoc
) then
3076 Is_Box_Present
:= True;
3078 if Expander_Active
then
3081 (Expression
(Parent
(Compon
)),
3082 New_Sloc
=> Sloc
(Assoc
));
3084 return Expression
(Parent
(Compon
));
3088 if Present
(Others_Etype
) and then
3089 Base_Type
(Others_Etype
) /= Base_Type
(Etype
3092 Error_Msg_N
("components in OTHERS choice must " &
3093 "have same type", Selector_Name
);
3096 Others_Etype
:= Etype
(Compon
);
3098 if Expander_Active
then
3099 return New_Copy_Tree
(Expression
(Assoc
));
3101 return Expression
(Assoc
);
3106 elsif Chars
(Compon
) = Chars
(Selector_Name
) then
3109 -- Ada 2005 (AI-231)
3111 if Ada_Version
>= Ada_2005
3112 and then Known_Null
(Expression
(Assoc
))
3114 Check_Can_Never_Be_Null
(Compon
, Expression
(Assoc
));
3117 -- We need to duplicate the expression when several
3118 -- components are grouped together with a "|" choice.
3119 -- For instance "filed1 | filed2 => Expr"
3121 -- Ada 2005 (AI-287)
3123 if Box_Present
(Assoc
) then
3124 Is_Box_Present
:= True;
3126 -- Duplicate the default expression of the component
3127 -- from the record type declaration, so a new copy
3128 -- can be attached to the association.
3130 -- Note that we always copy the default expression,
3131 -- even when the association has a single choice, in
3132 -- order to create a proper association for the
3133 -- expanded aggregate.
3135 Expr
:= New_Copy_Tree
(Expression
(Parent
(Compon
)));
3137 -- Component may have no default, in which case the
3138 -- expression is empty and the component is default-
3139 -- initialized, but an association for the component
3140 -- exists, and it is not covered by an others clause.
3145 if Present
(Next
(Selector_Name
)) then
3146 Expr
:= New_Copy_Tree
(Expression
(Assoc
));
3148 Expr
:= Expression
(Assoc
);
3152 Generate_Reference
(Compon
, Selector_Name
, 'm');
3156 ("more than one value supplied for &",
3157 Selector_Name
, Compon
);
3162 Next
(Selector_Name
);
3171 -----------------------
3172 -- Resolve_Aggr_Expr --
3173 -----------------------
3175 procedure Resolve_Aggr_Expr
(Expr
: Node_Id
; Component
: Node_Id
) is
3176 New_C
: Entity_Id
:= Component
;
3177 Expr_Type
: Entity_Id
:= Empty
;
3179 function Has_Expansion_Delayed
(Expr
: Node_Id
) return Boolean;
3180 -- If the expression is an aggregate (possibly qualified) then its
3181 -- expansion is delayed until the enclosing aggregate is expanded
3182 -- into assignments. In that case, do not generate checks on the
3183 -- expression, because they will be generated later, and will other-
3184 -- wise force a copy (to remove side-effects) that would leave a
3185 -- dynamic-sized aggregate in the code, something that gigi cannot
3189 -- Set to True if the resolved Expr node needs to be relocated when
3190 -- attached to the newly created association list. This node need not
3191 -- be relocated if its parent pointer is not set. In fact in this
3192 -- case Expr is the output of a New_Copy_Tree call. If Relocate is
3193 -- True then we have analyzed the expression node in the original
3194 -- aggregate and hence it needs to be relocated when moved over to
3195 -- the new association list.
3197 ---------------------------
3198 -- Has_Expansion_Delayed --
3199 ---------------------------
3201 function Has_Expansion_Delayed
(Expr
: Node_Id
) return Boolean is
3202 Kind
: constant Node_Kind
:= Nkind
(Expr
);
3204 return (Nkind_In
(Kind
, N_Aggregate
, N_Extension_Aggregate
)
3205 and then Present
(Etype
(Expr
))
3206 and then Is_Record_Type
(Etype
(Expr
))
3207 and then Expansion_Delayed
(Expr
))
3208 or else (Kind
= N_Qualified_Expression
3209 and then Has_Expansion_Delayed
(Expression
(Expr
)));
3210 end Has_Expansion_Delayed
;
3212 -- Start of processing for Resolve_Aggr_Expr
3215 -- If the type of the component is elementary or the type of the
3216 -- aggregate does not contain discriminants, use the type of the
3217 -- component to resolve Expr.
3219 if Is_Elementary_Type
(Etype
(Component
))
3220 or else not Has_Discriminants
(Etype
(N
))
3222 Expr_Type
:= Etype
(Component
);
3224 -- Otherwise we have to pick up the new type of the component from
3225 -- the new constrained subtype of the aggregate. In fact components
3226 -- which are of a composite type might be constrained by a
3227 -- discriminant, and we want to resolve Expr against the subtype were
3228 -- all discriminant occurrences are replaced with their actual value.
3231 New_C
:= First_Component
(Etype
(N
));
3232 while Present
(New_C
) loop
3233 if Chars
(New_C
) = Chars
(Component
) then
3234 Expr_Type
:= Etype
(New_C
);
3238 Next_Component
(New_C
);
3241 pragma Assert
(Present
(Expr_Type
));
3243 -- For each range in an array type where a discriminant has been
3244 -- replaced with the constraint, check that this range is within
3245 -- the range of the base type. This checks is done in the init
3246 -- proc for regular objects, but has to be done here for
3247 -- aggregates since no init proc is called for them.
3249 if Is_Array_Type
(Expr_Type
) then
3252 -- Range of the current constrained index in the array
3254 Orig_Index
: Node_Id
:= First_Index
(Etype
(Component
));
3255 -- Range corresponding to the range Index above in the
3256 -- original unconstrained record type. The bounds of this
3257 -- range may be governed by discriminants.
3259 Unconstr_Index
: Node_Id
:= First_Index
(Etype
(Expr_Type
));
3260 -- Range corresponding to the range Index above for the
3261 -- unconstrained array type. This range is needed to apply
3265 Index
:= First_Index
(Expr_Type
);
3266 while Present
(Index
) loop
3267 if Depends_On_Discriminant
(Orig_Index
) then
3268 Apply_Range_Check
(Index
, Etype
(Unconstr_Index
));
3272 Next_Index
(Orig_Index
);
3273 Next_Index
(Unconstr_Index
);
3279 -- If the Parent pointer of Expr is not set, Expr is an expression
3280 -- duplicated by New_Tree_Copy (this happens for record aggregates
3281 -- that look like (Field1 | Filed2 => Expr) or (others => Expr)).
3282 -- Such a duplicated expression must be attached to the tree
3283 -- before analysis and resolution to enforce the rule that a tree
3284 -- fragment should never be analyzed or resolved unless it is
3285 -- attached to the current compilation unit.
3287 if No
(Parent
(Expr
)) then
3288 Set_Parent
(Expr
, N
);
3294 Analyze_And_Resolve
(Expr
, Expr_Type
);
3295 Check_Expr_OK_In_Limited_Aggregate
(Expr
);
3296 Check_Non_Static_Context
(Expr
);
3297 Check_Unset_Reference
(Expr
);
3299 -- Check wrong use of class-wide types
3301 if Is_Class_Wide_Type
(Etype
(Expr
)) then
3302 Error_Msg_N
("dynamically tagged expression not allowed", Expr
);
3305 if not Has_Expansion_Delayed
(Expr
) then
3306 Aggregate_Constraint_Checks
(Expr
, Expr_Type
);
3309 -- If an aggregate component has a type with predicates, an explicit
3310 -- predicate check must be applied, as for an assignment statement,
3311 -- because the aggegate might not be expanded into individual
3312 -- component assignments.
3314 if Present
(Predicate_Function
(Expr_Type
)) then
3315 Apply_Predicate_Check
(Expr
, Expr_Type
);
3318 if Raises_Constraint_Error
(Expr
) then
3319 Set_Raises_Constraint_Error
(N
);
3322 -- If the expression has been marked as requiring a range check, then
3323 -- generate it here.
3325 if Do_Range_Check
(Expr
) then
3326 Set_Do_Range_Check
(Expr
, False);
3327 Generate_Range_Check
(Expr
, Expr_Type
, CE_Range_Check_Failed
);
3331 Add_Association
(New_C
, Relocate_Node
(Expr
), New_Assoc_List
);
3333 Add_Association
(New_C
, Expr
, New_Assoc_List
);
3335 end Resolve_Aggr_Expr
;
3337 -- Start of processing for Resolve_Record_Aggregate
3340 -- A record aggregate is restricted in SPARK:
3341 -- Each named association can have only a single choice.
3342 -- OTHERS cannot be used.
3343 -- Positional and named associations cannot be mixed.
3345 if Present
(Component_Associations
(N
))
3346 and then Present
(First
(Component_Associations
(N
)))
3349 if Present
(Expressions
(N
)) then
3350 Check_SPARK_Restriction
3351 ("named association cannot follow positional one",
3352 First
(Choices
(First
(Component_Associations
(N
)))));
3359 Assoc
:= First
(Component_Associations
(N
));
3360 while Present
(Assoc
) loop
3361 if List_Length
(Choices
(Assoc
)) > 1 then
3362 Check_SPARK_Restriction
3363 ("component association in record aggregate must "
3364 & "contain a single choice", Assoc
);
3367 if Nkind
(First
(Choices
(Assoc
))) = N_Others_Choice
then
3368 Check_SPARK_Restriction
3369 ("record aggregate cannot contain OTHERS", Assoc
);
3372 Assoc
:= Next
(Assoc
);
3377 -- We may end up calling Duplicate_Subexpr on expressions that are
3378 -- attached to New_Assoc_List. For this reason we need to attach it
3379 -- to the tree by setting its parent pointer to N. This parent point
3380 -- will change in STEP 8 below.
3382 Set_Parent
(New_Assoc_List
, N
);
3384 -- STEP 1: abstract type and null record verification
3386 if Is_Abstract_Type
(Typ
) then
3387 Error_Msg_N
("type of aggregate cannot be abstract", N
);
3390 if No
(First_Entity
(Typ
)) and then Null_Record_Present
(N
) then
3394 elsif Present
(First_Entity
(Typ
))
3395 and then Null_Record_Present
(N
)
3396 and then not Is_Tagged_Type
(Typ
)
3398 Error_Msg_N
("record aggregate cannot be null", N
);
3401 -- If the type has no components, then the aggregate should either
3402 -- have "null record", or in Ada 2005 it could instead have a single
3403 -- component association given by "others => <>". For Ada 95 we flag an
3404 -- error at this point, but for Ada 2005 we proceed with checking the
3405 -- associations below, which will catch the case where it's not an
3406 -- aggregate with "others => <>". Note that the legality of a <>
3407 -- aggregate for a null record type was established by AI05-016.
3409 elsif No
(First_Entity
(Typ
))
3410 and then Ada_Version
< Ada_2005
3412 Error_Msg_N
("record aggregate must be null", N
);
3416 -- STEP 2: Verify aggregate structure
3419 Selector_Name
: Node_Id
;
3420 Bad_Aggregate
: Boolean := False;
3423 if Present
(Component_Associations
(N
)) then
3424 Assoc
:= First
(Component_Associations
(N
));
3429 while Present
(Assoc
) loop
3430 Selector_Name
:= First
(Choices
(Assoc
));
3431 while Present
(Selector_Name
) loop
3432 if Nkind
(Selector_Name
) = N_Identifier
then
3435 elsif Nkind
(Selector_Name
) = N_Others_Choice
then
3436 if Selector_Name
/= First
(Choices
(Assoc
))
3437 or else Present
(Next
(Selector_Name
))
3440 ("OTHERS must appear alone in a choice list",
3444 elsif Present
(Next
(Assoc
)) then
3446 ("OTHERS must appear last in an aggregate",
3450 -- (Ada 2005): If this is an association with a box,
3451 -- indicate that the association need not represent
3454 elsif Box_Present
(Assoc
) then
3460 ("selector name should be identifier or OTHERS",
3462 Bad_Aggregate
:= True;
3465 Next
(Selector_Name
);
3471 if Bad_Aggregate
then
3476 -- STEP 3: Find discriminant Values
3479 Discrim
: Entity_Id
;
3480 Missing_Discriminants
: Boolean := False;
3483 if Present
(Expressions
(N
)) then
3484 Positional_Expr
:= First
(Expressions
(N
));
3486 Positional_Expr
:= Empty
;
3489 -- AI05-0115: if the ancestor part is a subtype mark, the ancestor
3490 -- must npt have unknown discriminants.
3492 if Is_Derived_Type
(Typ
)
3493 and then Has_Unknown_Discriminants
(Root_Type
(Typ
))
3494 and then Nkind
(N
) /= N_Extension_Aggregate
3497 ("aggregate not available for type& whose ancestor "
3498 & "has unknown discriminants ", N
, Typ
);
3501 if Has_Unknown_Discriminants
(Typ
)
3502 and then Present
(Underlying_Record_View
(Typ
))
3504 Discrim
:= First_Discriminant
(Underlying_Record_View
(Typ
));
3505 elsif Has_Discriminants
(Typ
) then
3506 Discrim
:= First_Discriminant
(Typ
);
3511 -- First find the discriminant values in the positional components
3513 while Present
(Discrim
) and then Present
(Positional_Expr
) loop
3514 if Discr_Present
(Discrim
) then
3515 Resolve_Aggr_Expr
(Positional_Expr
, Discrim
);
3517 -- Ada 2005 (AI-231)
3519 if Ada_Version
>= Ada_2005
3520 and then Known_Null
(Positional_Expr
)
3522 Check_Can_Never_Be_Null
(Discrim
, Positional_Expr
);
3525 Next
(Positional_Expr
);
3528 if Present
(Get_Value
(Discrim
, Component_Associations
(N
))) then
3530 ("more than one value supplied for discriminant&",
3534 Next_Discriminant
(Discrim
);
3537 -- Find remaining discriminant values if any among named components
3539 while Present
(Discrim
) loop
3540 Expr
:= Get_Value
(Discrim
, Component_Associations
(N
), True);
3542 if not Discr_Present
(Discrim
) then
3543 if Present
(Expr
) then
3545 ("more than one value supplied for discriminant&",
3549 elsif No
(Expr
) then
3551 ("no value supplied for discriminant &", N
, Discrim
);
3552 Missing_Discriminants
:= True;
3555 Resolve_Aggr_Expr
(Expr
, Discrim
);
3558 Next_Discriminant
(Discrim
);
3561 if Missing_Discriminants
then
3565 -- At this point and until the beginning of STEP 6, New_Assoc_List
3566 -- contains only the discriminants and their values.
3570 -- STEP 4: Set the Etype of the record aggregate
3572 -- ??? This code is pretty much a copy of Sem_Ch3.Build_Subtype. That
3573 -- routine should really be exported in sem_util or some such and used
3574 -- in sem_ch3 and here rather than have a copy of the code which is a
3575 -- maintenance nightmare.
3577 -- ??? Performance WARNING. The current implementation creates a new
3578 -- itype for all aggregates whose base type is discriminated. This means
3579 -- that for record aggregates nested inside an array aggregate we will
3580 -- create a new itype for each record aggregate if the array component
3581 -- type has discriminants. For large aggregates this may be a problem.
3582 -- What should be done in this case is to reuse itypes as much as
3585 if Has_Discriminants
(Typ
)
3586 or else (Has_Unknown_Discriminants
(Typ
)
3587 and then Present
(Underlying_Record_View
(Typ
)))
3589 Build_Constrained_Itype
: declare
3590 Loc
: constant Source_Ptr
:= Sloc
(N
);
3592 Subtyp_Decl
: Node_Id
;
3595 C
: constant List_Id
:= New_List
;
3598 New_Assoc
:= First
(New_Assoc_List
);
3599 while Present
(New_Assoc
) loop
3600 Append
(Duplicate_Subexpr
(Expression
(New_Assoc
)), To
=> C
);
3604 if Has_Unknown_Discriminants
(Typ
)
3605 and then Present
(Underlying_Record_View
(Typ
))
3608 Make_Subtype_Indication
(Loc
,
3610 New_Occurrence_Of
(Underlying_Record_View
(Typ
), Loc
),
3612 Make_Index_Or_Discriminant_Constraint
(Loc
, C
));
3615 Make_Subtype_Indication
(Loc
,
3617 New_Occurrence_Of
(Base_Type
(Typ
), Loc
),
3619 Make_Index_Or_Discriminant_Constraint
(Loc
, C
));
3622 Def_Id
:= Create_Itype
(Ekind
(Typ
), N
);
3625 Make_Subtype_Declaration
(Loc
,
3626 Defining_Identifier
=> Def_Id
,
3627 Subtype_Indication
=> Indic
);
3628 Set_Parent
(Subtyp_Decl
, Parent
(N
));
3630 -- Itypes must be analyzed with checks off (see itypes.ads)
3632 Analyze
(Subtyp_Decl
, Suppress
=> All_Checks
);
3634 Set_Etype
(N
, Def_Id
);
3635 Check_Static_Discriminated_Subtype
3636 (Def_Id
, Expression
(First
(New_Assoc_List
)));
3637 end Build_Constrained_Itype
;
3643 -- STEP 5: Get remaining components according to discriminant values
3646 Record_Def
: Node_Id
;
3647 Parent_Typ
: Entity_Id
;
3648 Root_Typ
: Entity_Id
;
3649 Parent_Typ_List
: Elist_Id
;
3650 Parent_Elmt
: Elmt_Id
;
3651 Errors_Found
: Boolean := False;
3654 function Find_Private_Ancestor
return Entity_Id
;
3655 -- AI05-0115: Find earlier ancestor in the derivation chain that is
3656 -- derived from a private view. Whether the aggregate is legal
3657 -- depends on the current visibility of the type as well as that
3658 -- of the parent of the ancestor.
3660 ---------------------------
3661 -- Find_Private_Ancestor --
3662 ---------------------------
3664 function Find_Private_Ancestor
return Entity_Id
is
3669 if Has_Private_Ancestor
(Par
)
3670 and then not Has_Private_Ancestor
(Etype
(Base_Type
(Par
)))
3674 elsif not Is_Derived_Type
(Par
) then
3678 Par
:= Etype
(Base_Type
(Par
));
3681 end Find_Private_Ancestor
;
3684 if Is_Derived_Type
(Typ
) and then Is_Tagged_Type
(Typ
) then
3685 Parent_Typ_List
:= New_Elmt_List
;
3687 -- If this is an extension aggregate, the component list must
3688 -- include all components that are not in the given ancestor type.
3689 -- Otherwise, the component list must include components of all
3690 -- ancestors, starting with the root.
3692 if Nkind
(N
) = N_Extension_Aggregate
then
3693 Root_Typ
:= Base_Type
(Etype
(Ancestor_Part
(N
)));
3696 -- AI05-0115: check legality of aggregate for type with
3697 -- aa private ancestor.
3699 Root_Typ
:= Root_Type
(Typ
);
3700 if Has_Private_Ancestor
(Typ
) then
3702 Ancestor
: constant Entity_Id
:=
3703 Find_Private_Ancestor
;
3704 Ancestor_Unit
: constant Entity_Id
:=
3705 Cunit_Entity
(Get_Source_Unit
(Ancestor
));
3706 Parent_Unit
: constant Entity_Id
:=
3708 (Get_Source_Unit
(Base_Type
(Etype
(Ancestor
))));
3711 -- check whether we are in a scope that has full view
3712 -- over the private ancestor and its parent. This can
3713 -- only happen if the derivation takes place in a child
3714 -- unit of the unit that declares the parent, and we are
3715 -- in the private part or body of that child unit, else
3716 -- the aggregate is illegal.
3718 if Is_Child_Unit
(Ancestor_Unit
)
3719 and then Scope
(Ancestor_Unit
) = Parent_Unit
3720 and then In_Open_Scopes
(Scope
(Ancestor
))
3722 (In_Private_Part
(Scope
(Ancestor
))
3723 or else In_Package_Body
(Scope
(Ancestor
)))
3729 ("type of aggregate has private ancestor&!",
3731 Error_Msg_N
("must use extension aggregate!", N
);
3737 Dnode
:= Declaration_Node
(Base_Type
(Root_Typ
));
3739 -- If we don't get a full declaration, then we have some error
3740 -- which will get signalled later so skip this part. Otherwise
3741 -- gather components of root that apply to the aggregate type.
3742 -- We use the base type in case there is an applicable stored
3743 -- constraint that renames the discriminants of the root.
3745 if Nkind
(Dnode
) = N_Full_Type_Declaration
then
3746 Record_Def
:= Type_Definition
(Dnode
);
3747 Gather_Components
(Base_Type
(Typ
),
3748 Component_List
(Record_Def
),
3749 Governed_By
=> New_Assoc_List
,
3751 Report_Errors
=> Errors_Found
);
3755 Parent_Typ
:= Base_Type
(Typ
);
3756 while Parent_Typ
/= Root_Typ
loop
3757 Prepend_Elmt
(Parent_Typ
, To
=> Parent_Typ_List
);
3758 Parent_Typ
:= Etype
(Parent_Typ
);
3760 if Nkind
(Parent
(Base_Type
(Parent_Typ
))) =
3761 N_Private_Type_Declaration
3762 or else Nkind
(Parent
(Base_Type
(Parent_Typ
))) =
3763 N_Private_Extension_Declaration
3765 if Nkind
(N
) /= N_Extension_Aggregate
then
3767 ("type of aggregate has private ancestor&!",
3769 Error_Msg_N
("must use extension aggregate!", N
);
3772 elsif Parent_Typ
/= Root_Typ
then
3774 ("ancestor part of aggregate must be private type&",
3775 Ancestor_Part
(N
), Parent_Typ
);
3779 -- The current view of ancestor part may be a private type,
3780 -- while the context type is always non-private.
3782 elsif Is_Private_Type
(Root_Typ
)
3783 and then Present
(Full_View
(Root_Typ
))
3784 and then Nkind
(N
) = N_Extension_Aggregate
3786 exit when Base_Type
(Full_View
(Root_Typ
)) = Parent_Typ
;
3790 -- Now collect components from all other ancestors, beginning
3791 -- with the current type. If the type has unknown discriminants
3792 -- use the component list of the Underlying_Record_View, which
3793 -- needs to be used for the subsequent expansion of the aggregate
3794 -- into assignments.
3796 Parent_Elmt
:= First_Elmt
(Parent_Typ_List
);
3797 while Present
(Parent_Elmt
) loop
3798 Parent_Typ
:= Node
(Parent_Elmt
);
3800 if Has_Unknown_Discriminants
(Parent_Typ
)
3801 and then Present
(Underlying_Record_View
(Typ
))
3803 Parent_Typ
:= Underlying_Record_View
(Parent_Typ
);
3806 Record_Def
:= Type_Definition
(Parent
(Base_Type
(Parent_Typ
)));
3807 Gather_Components
(Empty
,
3808 Component_List
(Record_Extension_Part
(Record_Def
)),
3809 Governed_By
=> New_Assoc_List
,
3811 Report_Errors
=> Errors_Found
);
3813 Next_Elmt
(Parent_Elmt
);
3817 Record_Def
:= Type_Definition
(Parent
(Base_Type
(Typ
)));
3819 if Null_Present
(Record_Def
) then
3822 elsif not Has_Unknown_Discriminants
(Typ
) then
3823 Gather_Components
(Base_Type
(Typ
),
3824 Component_List
(Record_Def
),
3825 Governed_By
=> New_Assoc_List
,
3827 Report_Errors
=> Errors_Found
);
3831 (Base_Type
(Underlying_Record_View
(Typ
)),
3832 Component_List
(Record_Def
),
3833 Governed_By
=> New_Assoc_List
,
3835 Report_Errors
=> Errors_Found
);
3839 if Errors_Found
then
3844 -- STEP 6: Find component Values
3847 Component_Elmt
:= First_Elmt
(Components
);
3849 -- First scan the remaining positional associations in the aggregate.
3850 -- Remember that at this point Positional_Expr contains the current
3851 -- positional association if any is left after looking for discriminant
3852 -- values in step 3.
3854 while Present
(Positional_Expr
) and then Present
(Component_Elmt
) loop
3855 Component
:= Node
(Component_Elmt
);
3856 Resolve_Aggr_Expr
(Positional_Expr
, Component
);
3858 -- Ada 2005 (AI-231)
3860 if Ada_Version
>= Ada_2005
3861 and then Known_Null
(Positional_Expr
)
3863 Check_Can_Never_Be_Null
(Component
, Positional_Expr
);
3866 if Present
(Get_Value
(Component
, Component_Associations
(N
))) then
3868 ("more than one value supplied for Component &", N
, Component
);
3871 Next
(Positional_Expr
);
3872 Next_Elmt
(Component_Elmt
);
3875 if Present
(Positional_Expr
) then
3877 ("too many components for record aggregate", Positional_Expr
);
3880 -- Now scan for the named arguments of the aggregate
3882 while Present
(Component_Elmt
) loop
3883 Component
:= Node
(Component_Elmt
);
3884 Expr
:= Get_Value
(Component
, Component_Associations
(N
), True);
3886 -- Note: The previous call to Get_Value sets the value of the
3887 -- variable Is_Box_Present.
3889 -- Ada 2005 (AI-287): Handle components with default initialization.
3890 -- Note: This feature was originally added to Ada 2005 for limited
3891 -- but it was finally allowed with any type.
3893 if Is_Box_Present
then
3894 Check_Box_Component
: declare
3895 Ctyp
: constant Entity_Id
:= Etype
(Component
);
3898 -- If there is a default expression for the aggregate, copy
3899 -- it into a new association. This copy must modify the scopes
3900 -- of internal types that may be attached to the expression
3901 -- (e.g. index subtypes of arrays) because in general the type
3902 -- declaration and the aggregate appear in different scopes,
3903 -- and the backend requires the scope of the type to match the
3904 -- point at which it is elaborated.
3906 -- If the component has an initialization procedure (IP) we
3907 -- pass the component to the expander, which will generate
3908 -- the call to such IP.
3910 -- If the component has discriminants, their values must
3911 -- be taken from their subtype. This is indispensable for
3912 -- constraints that are given by the current instance of an
3913 -- enclosing type, to allow the expansion of the aggregate to
3914 -- replace the reference to the current instance by the target
3915 -- object of the aggregate.
3917 if Present
(Parent
(Component
))
3919 Nkind
(Parent
(Component
)) = N_Component_Declaration
3920 and then Present
(Expression
(Parent
(Component
)))
3924 (Expression
(Parent
(Component
)),
3925 New_Scope
=> Current_Scope
,
3926 New_Sloc
=> Sloc
(N
));
3929 (Component
=> Component
,
3931 Assoc_List
=> New_Assoc_List
);
3932 Set_Has_Self_Reference
(N
);
3934 -- A box-defaulted access component gets the value null. Also
3935 -- included are components of private types whose underlying
3936 -- type is an access type. In either case set the type of the
3937 -- literal, for subsequent use in semantic checks.
3939 elsif Present
(Underlying_Type
(Ctyp
))
3940 and then Is_Access_Type
(Underlying_Type
(Ctyp
))
3942 if not Is_Private_Type
(Ctyp
) then
3943 Expr
:= Make_Null
(Sloc
(N
));
3944 Set_Etype
(Expr
, Ctyp
);
3946 (Component
=> Component
,
3948 Assoc_List
=> New_Assoc_List
);
3950 -- If the component's type is private with an access type as
3951 -- its underlying type then we have to create an unchecked
3952 -- conversion to satisfy type checking.
3956 Qual_Null
: constant Node_Id
:=
3957 Make_Qualified_Expression
(Sloc
(N
),
3960 (Underlying_Type
(Ctyp
), Sloc
(N
)),
3961 Expression
=> Make_Null
(Sloc
(N
)));
3963 Convert_Null
: constant Node_Id
:=
3964 Unchecked_Convert_To
3968 Analyze_And_Resolve
(Convert_Null
, Ctyp
);
3970 (Component
=> Component
,
3971 Expr
=> Convert_Null
,
3972 Assoc_List
=> New_Assoc_List
);
3976 elsif Has_Non_Null_Base_Init_Proc
(Ctyp
)
3977 or else not Expander_Active
3979 if Is_Record_Type
(Ctyp
)
3980 and then Has_Discriminants
(Ctyp
)
3981 and then not Is_Private_Type
(Ctyp
)
3983 -- We build a partially initialized aggregate with the
3984 -- values of the discriminants and box initialization
3985 -- for the rest, if other components are present.
3986 -- The type of the aggregate is the known subtype of
3987 -- the component. The capture of discriminants must
3988 -- be recursive because subcomponents may be constrained
3989 -- (transitively) by discriminants of enclosing types.
3990 -- For a private type with discriminants, a call to the
3991 -- initialization procedure will be generated, and no
3992 -- subaggregate is needed.
3994 Capture_Discriminants
: declare
3995 Loc
: constant Source_Ptr
:= Sloc
(N
);
3998 procedure Add_Discriminant_Values
3999 (New_Aggr
: Node_Id
;
4000 Assoc_List
: List_Id
);
4001 -- The constraint to a component may be given by a
4002 -- discriminant of the enclosing type, in which case
4003 -- we have to retrieve its value, which is part of the
4004 -- enclosing aggregate. Assoc_List provides the
4005 -- discriminant associations of the current type or
4006 -- of some enclosing record.
4008 procedure Propagate_Discriminants
4010 Assoc_List
: List_Id
);
4011 -- Nested components may themselves be discriminated
4012 -- types constrained by outer discriminants, whose
4013 -- values must be captured before the aggregate is
4014 -- expanded into assignments.
4016 -----------------------------
4017 -- Add_Discriminant_Values --
4018 -----------------------------
4020 procedure Add_Discriminant_Values
4021 (New_Aggr
: Node_Id
;
4022 Assoc_List
: List_Id
)
4026 Discr_Elmt
: Elmt_Id
;
4027 Discr_Val
: Node_Id
;
4031 Discr
:= First_Discriminant
(Etype
(New_Aggr
));
4034 (Discriminant_Constraint
(Etype
(New_Aggr
)));
4035 while Present
(Discr_Elmt
) loop
4036 Discr_Val
:= Node
(Discr_Elmt
);
4038 -- If the constraint is given by a discriminant
4039 -- it is a discriminant of an enclosing record,
4040 -- and its value has already been placed in the
4041 -- association list.
4043 if Is_Entity_Name
(Discr_Val
)
4045 Ekind
(Entity
(Discr_Val
)) = E_Discriminant
4047 Val
:= Entity
(Discr_Val
);
4049 Assoc
:= First
(Assoc_List
);
4050 while Present
(Assoc
) loop
4052 (Entity
(First
(Choices
(Assoc
))))
4054 Entity
(First
(Choices
(Assoc
)))
4057 Discr_Val
:= Expression
(Assoc
);
4065 (Discr
, New_Copy_Tree
(Discr_Val
),
4066 Component_Associations
(New_Aggr
));
4068 -- If the discriminant constraint is a current
4069 -- instance, mark the current aggregate so that
4070 -- the self-reference can be expanded later.
4072 if Nkind
(Discr_Val
) = N_Attribute_Reference
4073 and then Is_Entity_Name
(Prefix
(Discr_Val
))
4074 and then Is_Type
(Entity
(Prefix
(Discr_Val
)))
4075 and then Etype
(N
) =
4076 Entity
(Prefix
(Discr_Val
))
4078 Set_Has_Self_Reference
(N
);
4081 Next_Elmt
(Discr_Elmt
);
4082 Next_Discriminant
(Discr
);
4084 end Add_Discriminant_Values
;
4086 ------------------------------
4087 -- Propagate_Discriminants --
4088 ------------------------------
4090 procedure Propagate_Discriminants
4092 Assoc_List
: List_Id
)
4094 Aggr_Type
: constant Entity_Id
:=
4095 Base_Type
(Etype
(Aggr
));
4096 Def_Node
: constant Node_Id
:=
4098 (Declaration_Node
(Aggr_Type
));
4101 Comp_Elmt
: Elmt_Id
;
4102 Components
: constant Elist_Id
:= New_Elmt_List
;
4103 Needs_Box
: Boolean := False;
4106 procedure Process_Component
(Comp
: Entity_Id
);
4107 -- Add one component with a box association to the
4108 -- inner aggregate, and recurse if component is
4109 -- itself composite.
4111 ------------------------
4112 -- Process_Component --
4113 ------------------------
4115 procedure Process_Component
(Comp
: Entity_Id
) is
4116 T
: constant Entity_Id
:= Etype
(Comp
);
4120 if Is_Record_Type
(T
)
4121 and then Has_Discriminants
(T
)
4124 Make_Aggregate
(Loc
, New_List
, New_List
);
4125 Set_Etype
(New_Aggr
, T
);
4128 Component_Associations
(Aggr
));
4130 -- Collect discriminant values and recurse
4132 Add_Discriminant_Values
4133 (New_Aggr
, Assoc_List
);
4134 Propagate_Discriminants
4135 (New_Aggr
, Assoc_List
);
4140 end Process_Component
;
4142 -- Start of processing for Propagate_Discriminants
4145 -- The component type may be a variant type, so
4146 -- collect the components that are ruled by the
4147 -- known values of the discriminants. Their values
4148 -- have already been inserted into the component
4149 -- list of the current aggregate.
4151 if Nkind
(Def_Node
) = N_Record_Definition
4153 Present
(Component_List
(Def_Node
))
4156 (Variant_Part
(Component_List
(Def_Node
)))
4158 Gather_Components
(Aggr_Type
,
4159 Component_List
(Def_Node
),
4160 Governed_By
=> Component_Associations
(Aggr
),
4162 Report_Errors
=> Errors
);
4164 Comp_Elmt
:= First_Elmt
(Components
);
4165 while Present
(Comp_Elmt
) loop
4167 Ekind
(Node
(Comp_Elmt
)) /= E_Discriminant
4169 Process_Component
(Node
(Comp_Elmt
));
4172 Next_Elmt
(Comp_Elmt
);
4175 -- No variant part, iterate over all components
4178 Comp
:= First_Component
(Etype
(Aggr
));
4179 while Present
(Comp
) loop
4180 Process_Component
(Comp
);
4181 Next_Component
(Comp
);
4187 (Make_Component_Association
(Loc
,
4189 New_List
(Make_Others_Choice
(Loc
)),
4190 Expression
=> Empty
,
4191 Box_Present
=> True),
4192 Component_Associations
(Aggr
));
4194 end Propagate_Discriminants
;
4196 -- Start of processing for Capture_Discriminants
4199 Expr
:= Make_Aggregate
(Loc
, New_List
, New_List
);
4200 Set_Etype
(Expr
, Ctyp
);
4202 -- If the enclosing type has discriminants, they have
4203 -- been collected in the aggregate earlier, and they
4204 -- may appear as constraints of subcomponents.
4206 -- Similarly if this component has discriminants, they
4207 -- might in turn be propagated to their components.
4209 if Has_Discriminants
(Typ
) then
4210 Add_Discriminant_Values
(Expr
, New_Assoc_List
);
4211 Propagate_Discriminants
(Expr
, New_Assoc_List
);
4213 elsif Has_Discriminants
(Ctyp
) then
4214 Add_Discriminant_Values
4215 (Expr
, Component_Associations
(Expr
));
4216 Propagate_Discriminants
4217 (Expr
, Component_Associations
(Expr
));
4224 -- If the type has additional components, create
4225 -- an OTHERS box association for them.
4227 Comp
:= First_Component
(Ctyp
);
4228 while Present
(Comp
) loop
4229 if Ekind
(Comp
) = E_Component
then
4230 if not Is_Record_Type
(Etype
(Comp
)) then
4232 (Make_Component_Association
(Loc
,
4235 (Make_Others_Choice
(Loc
)),
4236 Expression
=> Empty
,
4237 Box_Present
=> True),
4238 Component_Associations
(Expr
));
4243 Next_Component
(Comp
);
4249 (Component
=> Component
,
4251 Assoc_List
=> New_Assoc_List
);
4252 end Capture_Discriminants
;
4256 (Component
=> Component
,
4258 Assoc_List
=> New_Assoc_List
,
4259 Is_Box_Present
=> True);
4262 -- Otherwise we only need to resolve the expression if the
4263 -- component has partially initialized values (required to
4264 -- expand the corresponding assignments and run-time checks).
4266 elsif Present
(Expr
)
4267 and then Is_Partially_Initialized_Type
(Ctyp
)
4269 Resolve_Aggr_Expr
(Expr
, Component
);
4271 end Check_Box_Component
;
4273 elsif No
(Expr
) then
4275 -- Ignore hidden components associated with the position of the
4276 -- interface tags: these are initialized dynamically.
4278 if not Present
(Related_Type
(Component
)) then
4280 ("no value supplied for component &!", N
, Component
);
4284 Resolve_Aggr_Expr
(Expr
, Component
);
4287 Next_Elmt
(Component_Elmt
);
4290 -- STEP 7: check for invalid components + check type in choice list
4297 -- Type of first component in choice list
4300 if Present
(Component_Associations
(N
)) then
4301 Assoc
:= First
(Component_Associations
(N
));
4306 Verification
: while Present
(Assoc
) loop
4307 Selectr
:= First
(Choices
(Assoc
));
4310 if Nkind
(Selectr
) = N_Others_Choice
then
4312 -- Ada 2005 (AI-287): others choice may have expression or box
4314 if No
(Others_Etype
)
4315 and then not Others_Box
4318 ("OTHERS must represent at least one component", Selectr
);
4324 while Present
(Selectr
) loop
4325 New_Assoc
:= First
(New_Assoc_List
);
4326 while Present
(New_Assoc
) loop
4327 Component
:= First
(Choices
(New_Assoc
));
4329 if Chars
(Selectr
) = Chars
(Component
) then
4331 Check_Identifier
(Selectr
, Entity
(Component
));
4340 -- If no association, this is not a legal component of
4341 -- of the type in question, except if its association
4342 -- is provided with a box.
4344 if No
(New_Assoc
) then
4345 if Box_Present
(Parent
(Selectr
)) then
4347 -- This may still be a bogus component with a box. Scan
4348 -- list of components to verify that a component with
4349 -- that name exists.
4355 C
:= First_Component
(Typ
);
4356 while Present
(C
) loop
4357 if Chars
(C
) = Chars
(Selectr
) then
4359 -- If the context is an extension aggregate,
4360 -- the component must not be inherited from
4361 -- the ancestor part of the aggregate.
4363 if Nkind
(N
) /= N_Extension_Aggregate
4365 Scope
(Original_Record_Component
(C
)) /=
4366 Etype
(Ancestor_Part
(N
))
4376 Error_Msg_Node_2
:= Typ
;
4377 Error_Msg_N
("& is not a component of}", Selectr
);
4381 elsif Chars
(Selectr
) /= Name_uTag
4382 and then Chars
(Selectr
) /= Name_uParent
4384 if not Has_Discriminants
(Typ
) then
4385 Error_Msg_Node_2
:= Typ
;
4386 Error_Msg_N
("& is not a component of}", Selectr
);
4389 ("& is not a component of the aggregate subtype",
4393 Check_Misspelled_Component
(Components
, Selectr
);
4396 elsif No
(Typech
) then
4397 Typech
:= Base_Type
(Etype
(Component
));
4399 -- AI05-0199: In Ada 2012, several components of anonymous
4400 -- access types can appear in a choice list, as long as the
4401 -- designated types match.
4403 elsif Typech
/= Base_Type
(Etype
(Component
)) then
4404 if Ada_Version
>= Ada_2012
4405 and then Ekind
(Typech
) = E_Anonymous_Access_Type
4407 Ekind
(Etype
(Component
)) = E_Anonymous_Access_Type
4408 and then Base_Type
(Designated_Type
(Typech
)) =
4409 Base_Type
(Designated_Type
(Etype
(Component
)))
4411 Subtypes_Statically_Match
(Typech
, (Etype
(Component
)))
4415 elsif not Box_Present
(Parent
(Selectr
)) then
4417 ("components in choice list must have same type",
4426 end loop Verification
;
4429 -- STEP 8: replace the original aggregate
4432 New_Aggregate
: constant Node_Id
:= New_Copy
(N
);
4435 Set_Expressions
(New_Aggregate
, No_List
);
4436 Set_Etype
(New_Aggregate
, Etype
(N
));
4437 Set_Component_Associations
(New_Aggregate
, New_Assoc_List
);
4439 Rewrite
(N
, New_Aggregate
);
4441 end Resolve_Record_Aggregate
;
4443 -----------------------------
4444 -- Check_Can_Never_Be_Null --
4445 -----------------------------
4447 procedure Check_Can_Never_Be_Null
(Typ
: Entity_Id
; Expr
: Node_Id
) is
4448 Comp_Typ
: Entity_Id
;
4452 (Ada_Version
>= Ada_2005
4453 and then Present
(Expr
)
4454 and then Known_Null
(Expr
));
4457 when E_Array_Type
=>
4458 Comp_Typ
:= Component_Type
(Typ
);
4462 Comp_Typ
:= Etype
(Typ
);
4468 if Can_Never_Be_Null
(Comp_Typ
) then
4470 -- Here we know we have a constraint error. Note that we do not use
4471 -- Apply_Compile_Time_Constraint_Error here to the Expr, which might
4472 -- seem the more natural approach. That's because in some cases the
4473 -- components are rewritten, and the replacement would be missed.
4476 (Compile_Time_Constraint_Error
4478 "(Ada 2005) null not allowed in null-excluding component?"),
4479 Make_Raise_Constraint_Error
(Sloc
(Expr
),
4480 Reason
=> CE_Access_Check_Failed
));
4482 -- Set proper type for bogus component (why is this needed???)
4484 Set_Etype
(Expr
, Comp_Typ
);
4485 Set_Analyzed
(Expr
);
4487 end Check_Can_Never_Be_Null
;
4489 ---------------------
4490 -- Sort_Case_Table --
4491 ---------------------
4493 procedure Sort_Case_Table
(Case_Table
: in out Case_Table_Type
) is
4494 L
: constant Int
:= Case_Table
'First;
4495 U
: constant Int
:= Case_Table
'Last;
4503 T
:= Case_Table
(K
+ 1);
4507 and then Expr_Value
(Case_Table
(J
- 1).Choice_Lo
) >
4508 Expr_Value
(T
.Choice_Lo
)
4510 Case_Table
(J
) := Case_Table
(J
- 1);
4514 Case_Table
(J
) := T
;
4517 end Sort_Case_Table
;