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1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- F R E E Z E --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2018, Free Software Foundation, Inc. --
10 -- --
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. --
20 -- --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
23 -- --
24 ------------------------------------------------------------------------------
74 -----------------------
75 -- Local Subprograms --
76 -----------------------
79 -- Typ is a type that is being frozen. If no size clause is given,
80 -- but a default Esize has been computed, then this default Esize is
81 -- adjusted up if necessary to be consistent with a given alignment,
82 -- but never to a value greater than Long_Long_Integer'Size. This
83 -- is used for all discrete types and for fixed-point types.
85 procedure Build_And_Analyze_Renamed_Body
89 -- Build body for a renaming declaration, insert in tree and analyze
92 -- Apply legality checks to address clauses for object declarations,
93 -- at the point the object is frozen. Also ensure any initialization is
94 -- performed only after the object has been frozen.
96 procedure Check_Component_Storage_Order
101 -- For an Encl_Type that has a Scalar_Storage_Order attribute definition
102 -- clause, verify that the component type has an explicit and compatible
103 -- attribute/aspect. For arrays, Comp is Empty; for records, it is the
104 -- entity of the component under consideration. For an Encl_Type that
105 -- does not have a Scalar_Storage_Order attribute definition clause,
106 -- verify that the component also does not have such a clause.
107 -- ADC is the attribute definition clause if present (or Empty). On return,
108 -- Comp_ADC_Present is set True if the component has a Scalar_Storage_Order
109 -- attribute definition clause.
112 -- As each entity is frozen, this routine is called to deal with the
113 -- setting of Debug_Info_Needed for the entity. This flag is set if
114 -- the entity comes from source, or if we are in Debug_Generated_Code
115 -- mode or if the -gnatdV debug flag is set. However, it never sets
116 -- the flag if Debug_Info_Off is set. This procedure also ensures that
117 -- subsidiary entities have the flag set as required.
120 -- When an expression function is frozen by a use of it, the expression
121 -- itself is frozen. Check that the expression does not include references
122 -- to deferred constants without completion. We report this at the freeze
123 -- point of the function, to provide a better error message.
124 --
125 -- In most cases the expression itself is frozen by the time the function
126 -- itself is frozen, because the formals will be frozen by then. However,
127 -- Attribute references to outer types are freeze points for those types;
128 -- this routine generates the required freeze nodes for them.
131 -- For a tagged derived type, create wrappers for inherited operations
132 -- that have a class-wide condition, so it can be properly rewritten if
133 -- it involves calls to other overriding primitives.
136 -- E is a base type. If E is tagged or has a component that is aliased
137 -- or tagged or contains something this is aliased or tagged, set
138 -- Strict_Alignment.
142 -- If E is a fixed-point or discrete type, then all the necessary work
143 -- to freeze it is completed except for possible setting of the flag
144 -- Is_Unsigned_Type, which is done by this procedure. The call has no
145 -- effect if the entity E is not a discrete or fixed-point type.
147 procedure Freeze_And_Append
151 -- Freezes Ent using Freeze_Entity, and appends the resulting list of
152 -- nodes to Result, modifying Result from No_List if necessary. N has
153 -- the same usage as in Freeze_Entity.
156 -- Freeze enumeration type. The Esize field is set as processing
157 -- proceeds (i.e. set by default when the type is declared and then
158 -- adjusted by rep clauses. What this procedure does is to make sure
159 -- that if a foreign convention is specified, and no specific size
160 -- is given, then the size must be at least Integer'Size.
163 -- If an object is frozen which has Is_Statically_Allocated set, then
164 -- all referenced types must also be marked with this flag. This routine
165 -- is in charge of meeting this requirement for the object entity E.
168 -- Perform freezing actions for a subprogram (create extra formals,
169 -- and set proper default mechanism values). Note that this routine
170 -- is not called for internal subprograms, for which neither of these
171 -- actions is needed (or desirable, we do not want for example to have
172 -- these extra formals present in initialization procedures, where they
173 -- would serve no purpose). In this call E is either a subprogram or
174 -- a subprogram type (i.e. an access to a subprogram).
177 -- True if T is not private and has no private components, or has a full
178 -- view. Used to determine whether the designated type of an access type
179 -- should be frozen when the access type is frozen. This is done when an
180 -- allocator is frozen, or an expression that may involve attributes of
181 -- the designated type. Otherwise freezing the access type does not freeze
182 -- the designated type.
184 procedure Process_Default_Expressions
187 -- This procedure is called for each subprogram to complete processing of
188 -- default expressions at the point where all types are known to be frozen.
189 -- The expressions must be analyzed in full, to make sure that all error
190 -- processing is done (they have only been pre-analyzed). If the expression
191 -- is not an entity or literal, its analysis may generate code which must
192 -- not be executed. In that case we build a function body to hold that
193 -- code. This wrapper function serves no other purpose (it used to be
194 -- called to evaluate the default, but now the default is inlined at each
195 -- point of call).
198 -- Typ is a record or array type that is being frozen. This routine sets
199 -- the default component alignment from the scope stack values if the
200 -- alignment is otherwise not specified.
203 -- T is a record or array type that is being frozen. If it is a base type,
204 -- and if SSO_Set_Low/High_By_Default is set, then Reverse_Storage order
205 -- will be set appropriately. Note that an explicit occurrence of aspect
206 -- Scalar_Storage_Order or an explicit setting of this aspect with an
207 -- attribute definition clause occurs, then these two flags are reset in
208 -- any case, so call will have no effect.
211 -- T is a type of a component that we know to be an Itype. We don't want
212 -- this to have a Freeze_Node, so ensure it doesn't. Do the same for any
213 -- Full_View or Corresponding_Record_Type.
216 -- Expr is the expression for an address clause for entity Nam whose type
217 -- is Typ. If Typ has a default initialization, and there is no explicit
218 -- initialization in the source declaration, check whether the address
219 -- clause might cause overlaying of an entity, and emit a warning on the
220 -- side effect that the initialization will cause.
222 -------------------------------
223 -- Adjust_Esize_For_Alignment --
224 -------------------------------
229 begin
235 then
241 ------------------------------------
242 -- Build_And_Analyze_Renamed_Body --
243 ------------------------------------
245 procedure Build_And_Analyze_Renamed_Body
249 is
255 begin
256 -- If the renamed subprogram is intrinsic, there is no need for a
257 -- wrapper body: we set the alias that will be called and expanded which
258 -- completes the declaration. This transformation is only legal if the
259 -- renamed entity has already been elaborated.
261 -- Note that it is legal for a renaming_as_body to rename an intrinsic
262 -- subprogram, as long as the renaming occurs before the new entity
263 -- is frozen (RM 8.5.4 (5)).
267 then
269 else
275 and then
279 -- We can make the renaming entity intrinsic if the renamed function
280 -- has an interface name, or if it is one of the shift/rotate
281 -- operations known to the compiler.
283 and then
286 Name_Rotate_Right,
287 Name_Shift_Left,
288 Name_Shift_Right,
289 Name_Shift_Right_Arithmetic))
290 then
295 else
302 else
311 ------------------------
312 -- Build_Renamed_Body --
313 ------------------------
315 function Build_Renamed_Body
318 is
320 -- We use for the source location of the renamed body, the location of
321 -- the spec entity. It might seem more natural to use the location of
322 -- the renaming declaration itself, but that would be wrong, since then
323 -- the body we create would look as though it was created far too late,
324 -- and this could cause problems with elaboration order analysis,
325 -- particularly in connection with instantiations.
340 -- If the renamed entity is a primitive operation given in prefix form,
341 -- the prefix is the target object and it has to be added as the first
342 -- actual in the generated call.
344 begin
345 -- Determine the entity being renamed, which is the target of the call
346 -- statement. If the name is an explicit dereference, this is a renaming
347 -- of a subprogram type rather than a subprogram. The name itself is
348 -- fully analyzed.
359 else
366 else
372 -- If the renamed entity is a predefined operator, retain full name
373 -- to ensure its visibility.
377 then
379 else
383 else
386 and then
389 then
391 -- Retrieve the target object, to be added as a first actual
392 -- in the call.
397 else
401 -- Original name may have been overloaded, but is fully resolved now
406 -- For simple renamings, subsequent calls can be expanded directly as
407 -- calls to the renamed entity. The body must be generated in any case
408 -- for calls that may appear elsewhere. This is not done in the case
409 -- where the subprogram is an instantiation because the actual proper
410 -- body has not been built yet.
415 then
419 -- Check whether the return type is a limited view. If the subprogram
420 -- is already frozen the generated body may have a non-limited view
421 -- of the type, that must be used, because it is the one in the spec
422 -- of the renaming declaration.
426 then
427 declare
429 begin
431 Set_Result_Definition
437 -- The body generated for this renaming is an internal artifact, and
438 -- does not constitute a freeze point for the called entity.
445 declare
449 begin
450 -- The controlling formal may be an access parameter, or the
451 -- actual may be an access value, so adjust accordingly.
455 then
456 Actuals := New_List
461 then
462 Actuals :=
463 New_List (
467 else
475 else
486 -- If the renamed entity is an entry, inherit its profile. For other
487 -- renamings as bodies, both profiles must be subtype conformant, so it
488 -- is not necessary to replace the profile given in the declaration.
489 -- However, default values that are aggregates are rewritten when
490 -- partially analyzed, so we recover the original aggregate to insure
491 -- that subsequent conformity checking works. Similarly, if the default
492 -- expression was constant-folded, recover the original expression.
502 N_Access_Definition
503 then
511 then
522 -- If the renamed entity is a function, the generated body contains a
523 -- return statement. Otherwise, build a procedure call. If the entity is
524 -- an entry, subsequent analysis of the call will transform it into the
525 -- proper entry or protected operation call. If the renamed entity is
526 -- a character literal, return it directly.
532 then
533 Call_Node :=
535 Expression =>
541 Call_Node :=
546 Call_Node :=
549 else
550 Call_Node :=
556 -- Create entities for subprogram body and formals
569 Body_Node :=
573 Handled_Statement_Sequence =>
583 -- Link the body to the entity whose declaration it completes. If
584 -- the body is analyzed when the renamed entity is frozen, it may
585 -- be necessary to restore the proper scope (see package Exp_Ch13).
589 then
591 else
598 --------------------------
599 -- Check_Address_Clause --
600 --------------------------
611 begin
614 -- For a deferred constant, the initialization value is on full view
618 else
627 -- Has_Delayed_Freeze was set on E when the address clause was
628 -- analyzed, and must remain set because we want the address
629 -- clause to be elaborated only after any entity it references
630 -- has been elaborated.
633 -- If Rep_Clauses are to be ignored, remove address clause from
634 -- list attached to entity, because it may be illegal for gigi,
635 -- for example by breaking order of elaboration..
638 declare
641 begin
647 else
650 loop
660 -- And now remove the address clause
666 then
672 -- If a variable, or a non-imported constant, overlays a constant
673 -- object and has an initialization value, then the initialization
674 -- may end up writing into read-only memory. Detect the cases of
675 -- statically identical values and remove the initialization. In
676 -- the other cases, give a warning. We will give other warnings
677 -- later for the variable if it is assigned.
684 then
685 declare
689 begin
695 and then Compile_Time_Compare
699 then
704 and then Address_Clause_Overlay_Warnings
705 then
707 Error_Msg_NE
714 -- Remove side effects from initial expression, except in the case
715 -- of a build-in-place call, which has its own later expansion.
720 then
722 -- Capture initialization value at point of declaration, and make
723 -- explicit assignment legal, because object may be a constant.
729 -- Move initialization to freeze actions, once the object has
730 -- been frozen and the address clause alignment check has been
731 -- performed.
740 -- If the objet is tagged, check whether the tag must be
741 -- reassigned explicitly.
751 -----------------------------
752 -- Check_Compile_Time_Size --
753 -----------------------------
758 -- Sets the compile time known size (64 bits or less) in the RM_Size
759 -- field of T, checking for a size clause that was given which attempts
760 -- to give a smaller size.
763 -- Recursive function that does all the work
766 -- If T is a constrained subtype, its size is not known if any of its
767 -- discriminant constraints is not static and it is not a null record.
768 -- The test is conservative and doesn't check that the components are
769 -- in fact constrained by non-static discriminant values. Could be made
770 -- more precise ???
772 --------------------
773 -- Set_Small_Size --
774 --------------------
777 begin
781 -- Check for bad size clause given
786 Error_Msg_NE
791 -- Set size if not set already
798 ----------------
799 -- Size_Known --
800 ----------------
809 begin
813 -- Always True for elementary types, even generic formal elementary
814 -- types. We used to return False in the latter case, but the size
815 -- is known at compile time, even in the template, we just do not
816 -- know the exact size but that's not the point of this routine.
821 -- Array types
825 -- String literals always have known size, and we can set it
828 Set_Small_Size
832 -- Unconstrained types never have known at compile time size
837 -- Don't do any recursion on type with error posted, since we may
838 -- have a malformed type that leads us into a loop.
843 -- Otherwise if component size unknown, then array size unknown
849 -- Check for all indexes static, and also compute possible size
850 -- (in case it is not greater than 64 and may be packable).
852 declare
856 begin
865 else
873 then
876 else
881 else
893 -- For non-generic private types, go to underlying type if present
898 then
899 -- Don't do any recursion on type with error posted, since we may
900 -- have a malformed type that leads us into a loop.
904 else
908 -- Record types
912 -- A class-wide type is never considered to have a known size
917 -- A subtype of a variant record must not have non-static
918 -- discriminated components.
922 then
925 -- Don't do any recursion on type with error posted, since we may
926 -- have a malformed type that leads us into a loop.
932 -- Now look at the components of the record
934 declare
935 -- The following two variables are used to keep track of the
936 -- size of packed records if we can tell the size of the packed
937 -- record in the front end. Packed_Size_Known is True if so far
938 -- we can figure out the size. It is initialized to True for a
939 -- packed record, unless the record has discriminants or atomic
940 -- components or independent components.
942 -- The reason we eliminate the discriminated case is that
943 -- we don't know the way the back end lays out discriminated
944 -- packed records. If Packed_Size_Known is True, then
945 -- Packed_Size is the size in bits so far.
954 -- Size in bits so far
956 begin
957 -- Test for variant part present
963 N_Record_Definition
965 and then
966 Present (Variant_Part
968 then
969 -- If variant part is present, and type is unconstrained,
970 -- then we must have defaulted discriminants, or a size
971 -- clause must be present for the type, or else the size
972 -- is definitely not known at compile time.
975 and then
978 then
983 -- Loop through components
989 -- We do not know the packed size if there is a component
990 -- clause present (we possibly could, but this would only
991 -- help in the case of a record with partial rep clauses.
992 -- That's because in the case of full rep clauses, the
993 -- size gets figured out anyway by a different circuit).
999 -- We do not know the packed size for an atomic/VFA type
1000 -- or component, or an independent type or component, or a
1001 -- by-reference type or aliased component (because packing
1002 -- does not touch these).
1010 then
1014 -- We need to identify a component that is an array where
1015 -- the index type is an enumeration type with non-standard
1016 -- representation, and some bound of the type depends on a
1017 -- discriminant.
1019 -- This is because gigi computes the size by doing a
1020 -- substitution of the appropriate discriminant value in
1021 -- the size expression for the base type, and gigi is not
1022 -- clever enough to evaluate the resulting expression (which
1023 -- involves a call to rep_to_pos) at compile time.
1025 -- It would be nice if gigi would either recognize that
1026 -- this expression can be computed at compile time, or
1027 -- alternatively figured out the size from the subtype
1028 -- directly, where all the information is at hand ???
1032 then
1033 declare
1041 begin
1048 then
1054 then
1059 then
1069 -- Clearly size of record is not known if the size of one of
1070 -- the components is not known.
1076 -- Accumulate packed size if possible
1080 -- We can deal with elementary types, small packed arrays
1081 -- if the representation is a modular type and also small
1082 -- record types (if the size is not greater than 64, but
1083 -- the condition is checked by Set_Small_Size).
1087 and then Present
1089 and then Is_Modular_Integer_Type
1092 then
1093 -- If RM_Size is known and static, then we can keep
1094 -- accumulating the packed size.
1100 -- If we have a field whose RM_Size is not known then
1101 -- we can't figure out the packed size here.
1103 else
1107 -- For other types we can't figure out the packed size
1109 else
1124 -- All other cases, size not known at compile time
1126 else
1131 -------------------------------------
1132 -- Static_Discriminated_Components --
1133 -------------------------------------
1135 function Static_Discriminated_Components
1137 is
1140 begin
1144 then
1158 -- Start of processing for Check_Compile_Time_Size
1160 begin
1164 -----------------------------------
1165 -- Check_Component_Storage_Order --
1166 -----------------------------------
1168 procedure Check_Component_Storage_Order
1173 is
1182 -- Set for the record case, True if Comp is aligned on byte boundaries
1183 -- (in which case it is allowed to have different storage order).
1186 -- Set True when the component is a nested composite, and it does not
1187 -- have the same scalar storage order as Encl_Type.
1189 begin
1190 -- Record case
1200 else
1201 -- If a component clause is present, check if the component starts
1202 -- and ends on byte boundaries. Otherwise conservatively assume it
1203 -- does so only in the case where the record is not packed.
1206 Comp_Byte_Aligned :=
1208 and then
1210 else
1217 -- Array case
1219 else
1226 -- Note: the Reverse_Storage_Order flag is set on the base type, but
1227 -- the attribute definition clause is attached to the first subtype.
1228 -- Also, if the base type is incomplete or private, go to full view
1229 -- if known
1241 Comp_ADC :=
1242 Get_Attribute_Definition_Clause
1246 -- Case of record or array component: check storage order compatibility.
1247 -- But, if the record has Complex_Representation, then it is treated as
1248 -- a scalar in the back end so the storage order is irrelevant.
1253 then
1254 Comp_SSO_Differs :=
1258 -- Parent and extension must have same storage order
1262 Error_Msg_N
1267 -- If component and composite SSO differs, check that component
1268 -- falls on byte boundaries and isn't bit packed.
1272 -- Component SSO differs from enclosing composite:
1274 -- Reject if composite is a bit-packed array, as it is rewritten
1275 -- into an array of scalars.
1278 Error_Msg_N
1282 -- Reject if not byte aligned
1285 and then not Comp_Byte_Aligned
1286 then
1287 Error_Msg_N
1291 -- Warn if specified only for the outer composite
1294 Error_Msg_NE
1300 -- Enclosing type has explicit SSO: non-composite component must not
1301 -- be aliased.
1304 Error_Msg_N
1310 -----------------------------
1311 -- Check_Debug_Info_Needed --
1312 -----------------------------
1315 begin
1320 or else Debug_Generated_Code
1321 or else Debug_Flag_VV
1323 then
1328 -------------------------------
1329 -- Check_Expression_Function --
1330 -------------------------------
1334 -- Function to search for deferred constant
1336 -------------------
1337 -- Find_Constant --
1338 -------------------
1341 begin
1342 -- When a constant is initialized with the result of a dispatching
1343 -- call, the constant declaration is rewritten as a renaming of the
1344 -- displaced function result. This scenario is not a premature use of
1345 -- a constant even though the Has_Completion flag is not set.
1352 N_Object_Declaration
1356 then
1357 Error_Msg_NE
1365 then
1375 -- Local variables
1379 -- Start of processing for Check_Expression_Function
1381 begin
1384 -- The subprogram body created for the expression function is not
1385 -- itself a freeze point.
1390 then
1395 --------------------------------
1396 -- Check_Inherited_Conditions --
1397 --------------------------------
1408 -- Build corresponding pragmas for an operation whose ancestor has
1409 -- class-wide pre/postconditions. If the operation is inherited, the
1410 -- pragmas force the creation of a wrapper for the inherited operation.
1411 -- If the ancestor is being overridden, the pragmas are constructed only
1412 -- to verify their legality, in case they contain calls to other
1413 -- primitives that may haven been overridden.
1415 ---------------------------------------
1416 -- Build_Inherited_Condition_Pragmas --
1417 ---------------------------------------
1424 begin
1429 Build_Class_Wide_Expression
1436 if Needs_Wrapper
1438 and then Expander_Active
1439 then
1448 Build_Class_Wide_Expression
1455 if Needs_Wrapper
1457 and then Expander_Active
1458 then
1464 -- Start of processing for Check_Inherited_Conditions
1466 begin
1471 -- Map the overridden primitive to the overriding one. This takes
1472 -- care of all overridings and is done only once.
1476 then
1484 -- Perform validity checks on the inherited conditions of overriding
1485 -- operations, for conformance with LSP, and apply SPARK-specific
1486 -- restrictions on inherited conditions.
1494 then
1497 -- Analyze the contract items of the overridden operation, before
1498 -- they are rewritten as pragmas.
1502 -- In GNATprove mode this is where we can collect the inherited
1503 -- conditions, because we do not create the Check pragmas that
1504 -- normally convey the the modified class-wide conditions on
1505 -- overriding operations.
1510 -- Otherwise build the corresponding pragmas to check for legality
1511 -- of the inherited condition.
1513 else
1521 -- Now examine the inherited operations to check whether they require
1522 -- a wrapper to handle inherited conditions that call other primitives,
1523 -- so that LSP can be verified/enforced.
1535 -- Analyze the contract items of the parent operation, and
1536 -- determine whether a wrapper is needed. This is determined
1537 -- when the condition is rewritten in sem_prag, using the
1538 -- mapping between overridden and overriding operations built
1539 -- in the loop above.
1545 if Needs_Wrapper
1547 and then Expander_Active
1548 then
1549 -- We need to build a new primitive that overrides the inherited
1550 -- one, and whose inherited expression has been updated above.
1551 -- These expressions are the arguments of pragmas that are part
1552 -- of the declarations of the wrapper. The wrapper holds a single
1553 -- statement that is a call to the class-wide clone, where the
1554 -- controlling actuals are conversions to the corresponding type
1555 -- in the parent primitive:
1557 -- procedure New_Prim (F1 : T1; ...);
1558 -- procedure New_Prim (F1 : T1; ...) is
1559 -- pragma Check (Precondition, Expr);
1560 -- begin
1561 -- Par_Prim_Clone (Par_Type (F1), ...);
1562 -- end;
1564 -- If the primitive is a function the statement is a return
1565 -- statement with a call.
1567 declare
1574 begin
1576 New_Decl :=
1580 -- Insert the declaration and the body of the wrapper after
1581 -- type declaration that generates inherited operation. For
1582 -- a null procedure, the declaration implies a null body.
1586 then
1589 else
1590 -- Build body as wrapper to a call to the already built
1591 -- class-wide clone.
1593 New_Body :=
1594 Build_Class_Wide_Clone_Call
1597 Insert_List_After_And_Analyze
1609 ----------------------------
1610 -- Check_Strict_Alignment --
1611 ----------------------------
1616 begin
1634 then
1644 -------------------------
1645 -- Check_Unsigned_Type --
1646 -------------------------
1653 begin
1658 -- Do not attempt to analyze case where range was in error
1664 -- The situation that is nontrivial is something like:
1666 -- subtype x1 is integer range -10 .. +10;
1667 -- subtype x2 is x1 range 0 .. V1;
1668 -- subtype x3 is x2 range V2 .. V3;
1669 -- subtype x4 is x3 range V4 .. V5;
1671 -- where Vn are variables. Here the base type is signed, but we still
1672 -- know that x4 is unsigned because of the lower bound of x2.
1674 -- The only way to deal with this is to look up the ancestor chain
1677 loop
1691 else
1694 -- If no ancestor had a static lower bound, go to base type
1698 -- Note: the reason we still check for a compile time known
1699 -- value for the base type is that at least in the case of
1700 -- generic formals, we can have bounds that fail this test,
1701 -- and there may be other cases in error situations.
1713 then
1723 -----------------------------
1724 -- Is_Atomic_VFA_Aggregate --
1725 -----------------------------
1734 begin
1737 -- Array may be qualified, so find outer context
1754 then
1763 then
1772 New_N :=
1784 -----------------------------------------------
1785 -- Explode_Initialization_Compound_Statement --
1786 -----------------------------------------------
1791 begin
1794 then
1797 -- Note that we rewrite Init_Stmts into a NULL statement, rather than
1798 -- just removing it, because Freeze_All may rely on this particular
1799 -- Node_Id still being present in the enclosing list to know where to
1800 -- stop freezing.
1808 ----------------
1809 -- Freeze_All --
1810 ----------------
1812 -- Note: the easy coding for this procedure would be to just build a
1813 -- single list of freeze nodes and then insert them and analyze them
1814 -- all at once. This won't work, because the analysis of earlier freeze
1815 -- nodes may recursively freeze types which would otherwise appear later
1816 -- on in the freeze list. So we must analyze and expand the freeze nodes
1817 -- as they are generated.
1821 -- This is the internal recursive routine that does freezing of entities
1822 -- (but NOT the analysis of default expressions, which should not be
1823 -- recursive, we don't want to analyze those till we are sure that ALL
1824 -- the types are frozen).
1826 --------------------
1827 -- Freeze_All_Ent --
1828 --------------------
1836 -- If freeze nodes are present, insert and analyze, and reset cursor
1837 -- for next insertion.
1839 -------------------
1840 -- Process_Flist --
1841 -------------------
1844 begin
1851 else
1857 -- Start of processing for Freeze_All_Ent
1859 begin
1863 -- If the entity is an inner package which is not a package
1864 -- renaming, then its entities must be frozen at this point. Note
1865 -- that such entities do NOT get frozen at the end of the nested
1866 -- package itself (only library packages freeze).
1868 -- Same is true for task declarations, where anonymous records
1869 -- created for entry parameters must be frozen.
1875 then
1886 then
1893 N_Task_Type_Declaration)
1894 then
1897 End_Scope;
1899 -- For a derived tagged type, we must ensure that all the
1900 -- primitive operations of the parent have been frozen, so that
1901 -- their addresses will be in the parent's dispatch table at the
1902 -- point it is inherited.
1908 then
1909 declare
1916 begin
1923 then
1925 Process_Flist;
1935 Process_Flist;
1937 -- If already frozen, and there are delayed aspects, this is where
1938 -- we do the visibility check for these aspects (see Sem_Ch13 spec
1939 -- for a description of how we handle aspect visibility).
1943 -- Retrieve the visibility to the discriminants in order to
1944 -- analyze properly the aspects.
1948 declare
1951 begin
1957 then
1968 -- If an incomplete type is still not frozen, this may be a
1969 -- premature freezing because of a body declaration that follows.
1970 -- Indicate where the freezing took place. Freezing will happen
1971 -- if the body comes from source, but not if it is internally
1972 -- generated, for example as the body of a type invariant.
1974 -- If the freezing is caused by the end of the current declarative
1975 -- part, it is a Taft Amendment type, and there is no error.
1979 then
1980 declare
1983 begin
1984 -- The presence of a body freezes all entities previously
1985 -- declared in the current list of declarations, but this
1986 -- does not apply if the body does not come from source.
1987 -- A type invariant is transformed into a subprogram body
1988 -- which is placed at the end of the private part of the
1989 -- current package, but this body does not freeze incomplete
1990 -- types that may be declared in this private part.
1993 N_Package_Body,
1994 N_Protected_Body,
1995 N_Subprogram_Body,
1996 N_Task_Body)
1998 and then
2001 then
2003 Error_Msg_NE
2014 -- Local variables
2020 -- Start of processing for Freeze_All
2022 begin
2025 -- Now that all types are frozen, we can deal with default expressions
2026 -- that require us to build a default expression functions. This is the
2027 -- point at which such functions are constructed (after all types that
2028 -- might be used in such expressions have been frozen).
2030 -- For subprograms that are renaming_as_body, we create the wrapper
2031 -- bodies as needed.
2033 -- We also add finalization chains to access types whose designated
2034 -- types are controlled. This is normally done when freezing the type,
2035 -- but this misses recursive type definitions where the later members
2036 -- of the recursion introduce controlled components.
2038 -- Loop through entities
2053 else
2059 and then
2061 N_Subprogram_Renaming_Declaration
2062 then
2063 Build_And_Analyze_Renamed_Body
2068 -- Freeze the default expressions of entries, entry families, and
2069 -- protected subprograms.
2076 then
2084 -- Historical note: We used to create a finalization master for an
2085 -- access type whose designated type is not controlled, but contains
2086 -- private controlled compoments. This form of postprocessing is no
2087 -- longer needed because the finalization master is now created when
2088 -- the access type is frozen (see Exp_Ch3.Freeze_Type).
2094 -----------------------
2095 -- Freeze_And_Append --
2096 -----------------------
2098 procedure Freeze_And_Append
2102 is
2104 begin
2108 else
2114 -------------------
2115 -- Freeze_Before --
2116 -------------------
2118 procedure Freeze_Before
2122 is
2123 -- Freeze T, then insert the generated Freeze nodes before the node N.
2124 -- Flag Freeze_Profile is used when T is an overloadable entity, and
2125 -- indicates whether its profile should be frozen at the same time.
2131 begin
2138 -- If the entity is a type declared in an inner package, it may be
2139 -- frozen by an outer declaration before the package itself is
2140 -- frozen. Install the package scope to analyze the freeze nodes,
2141 -- which may include generated subprograms such as predicate
2142 -- functions, etc.
2151 else
2157 -------------------
2158 -- Freeze_Entity --
2159 -------------------
2161 -- WARNING: This routine manages Ghost regions. Return statements must be
2162 -- replaced by gotos which jump to the end of the routine and restore the
2163 -- Ghost mode.
2165 function Freeze_Entity
2169 is
2178 -- This flag gets set to true for a variable with default initialization
2181 -- List of freezing actions, left at No_List if none
2184 -- This could use a comment ???
2187 -- N is a freezing action to be appended to the Result
2190 -- If Loc is a freeze_entity that appears after the last declaration
2191 -- in the scope, inhibit error messages on late completion.
2194 -- Check that an Access or Unchecked_Access attribute with a prefix
2195 -- which is the current instance type can only be applied when the type
2196 -- is limited.
2199 -- Give a warning for pragma Convention with language C or C++ applied
2200 -- to a discriminated record type. This is suppressed for the unchecked
2201 -- union case, since the whole point in this case is interface C. We
2202 -- also do not generate this within instantiations, since we will have
2203 -- generated a message on the template.
2206 -- Give warning for modulus of 8, 16, 32, or 64 given as an explicit
2207 -- integer literal without an explicit corresponding size clause. The
2208 -- caller has checked that Utype is a modular integer type.
2211 -- Freeze array type, including freezing index and component types
2214 -- Perform checks and generate freeze node if needed for a constant or
2215 -- variable declared by an object declaration.
2218 -- Create Freeze_Generic_Entity nodes for types declared in a generic
2219 -- package. Recurse on inner generic packages.
2222 -- Freeze formals and return type of subprogram. If some type in the
2223 -- profile is incomplete and we are in an instance, freezing of the
2224 -- entity will take place elsewhere, and the function returns False.
2227 -- Freeze record type, including freezing component types, and freezing
2228 -- primitive operations if this is a tagged type.
2231 -- Determine whether an arbitrary entity is subject to Boolean aspect
2232 -- Import and its value is specified as True.
2234 procedure Inherit_Freeze_Node
2237 -- Set type Typ's freeze node to refer to Fnode. This routine ensures
2238 -- that any attributes attached to Typ's original node are preserved.
2241 -- If E is an entity for an imported subprogram with pre/post-conditions
2242 -- then this procedure will create a wrapper to ensure that proper run-
2243 -- time checking of the pre/postconditions. See body for details.
2245 -------------------
2246 -- Add_To_Result --
2247 -------------------
2250 begin
2253 else
2258 ----------------------------
2259 -- After_Last_Declaration --
2260 ----------------------------
2265 begin
2271 else
2275 else
2280 ----------------------------
2281 -- Check_Current_Instance --
2282 ----------------------------
2287 -- Determine whether Typ is compatible with the rules for aliased
2288 -- views of types as defined in RM 3.10 in the various dialects.
2291 -- Process routine to apply check to given node
2293 -----------------------------
2294 -- Is_Aliased_View_Of_Type --
2295 -----------------------------
2300 begin
2301 -- Common case
2305 then
2308 -- The following paragraphs describe what a legal aliased view of
2309 -- a type is in the various dialects of Ada.
2311 -- Ada 95
2313 -- The current instance of a limited type, and a formal parameter
2314 -- or generic formal object of a tagged type.
2316 -- Ada 95 limited type
2317 -- * Type with reserved word "limited"
2318 -- * A protected or task type
2319 -- * A composite type with limited component
2324 -- Ada 2005
2326 -- The current instance of a limited tagged type, a protected
2327 -- type, a task type, or a type that has the reserved word
2328 -- "limited" in its full definition ... a formal parameter or
2329 -- generic formal object of a tagged type.
2331 -- Ada 2005 limited type
2332 -- * Type with reserved word "limited", "synchronized", "task"
2333 -- or "protected"
2334 -- * A composite type with limited component
2335 -- * A derived type whose parent is a non-interface limited type
2338 return
2340 or else
2345 -- Ada 2012 and beyond
2347 -- The current instance of an immutably limited type ... a formal
2348 -- parameter or generic formal object of a tagged type.
2350 -- Ada 2012 limited type
2351 -- * Type with reserved word "limited", "synchronized", "task"
2352 -- or "protected"
2353 -- * A composite type with limited component
2354 -- * A derived type whose parent is a non-interface limited type
2355 -- * An incomplete view
2357 -- Ada 2012 immutably limited type
2358 -- * Explicitly limited record type
2359 -- * Record extension with "limited" present
2360 -- * Non-formal limited private type that is either tagged
2361 -- or has at least one access discriminant with a default
2362 -- expression
2363 -- * Task type, protected type or synchronized interface
2364 -- * Type derived from immutably limited type
2366 else
2367 return
2373 -------------
2374 -- Process --
2375 -------------
2378 begin
2382 Name_Unchecked_Access)
2386 then
2388 Error_Msg_N
2391 else
2392 Error_Msg_N
2399 else
2410 -- Local variables
2415 -- Start of processing for Check_Current_Instance
2417 begin
2423 ---------------------------------
2424 -- Check_Suspicious_Convention --
2425 ---------------------------------
2428 begin
2433 or else
2436 and then not In_Instance
2438 then
2439 declare
2444 begin
2449 Error_Msg_N
2452 else
2453 Error_Msg_N
2458 Error_Msg_NE
2466 ------------------------------
2467 -- Check_Suspicious_Modulus --
2468 ------------------------------
2473 begin
2479 declare
2482 begin
2484 declare
2488 begin
2490 declare
2494 begin
2495 -- First case, modulus and size are the same. This
2496 -- happens if you have something like mod 32, with
2497 -- an explicit size of 32, this is for sure a case
2498 -- where the warning is given, since it is seems
2499 -- very unlikely that someone would want e.g. a
2500 -- five bit type stored in 32 bits. It is much
2501 -- more likely they wanted a 32-bit type.
2506 -- Second case, the modulus is 32 or 64 and no
2507 -- size clause is present. This is a less clear
2508 -- case for giving the warning, but in the case
2509 -- of 32/64 (5-bit or 6-bit types) these seem rare
2510 -- enough that it is a likely error (and in any
2511 -- case using 2**5 or 2**6 in these cases seems
2512 -- clearer. We don't include 8 or 16 here, simply
2513 -- because in practice 3-bit and 4-bit types are
2514 -- more common and too many false positives if
2515 -- we warn in these cases.
2519 then
2522 -- No warning needed
2524 else
2528 -- If we fall through, give warning
2531 Error_Msg_N
2533 Modulus);
2542 -----------------------
2543 -- Freeze_Array_Type --
2544 -----------------------
2552 -- Set true if any of the index types is an enumeration type with a
2553 -- non-standard representation.
2555 begin
2564 then
2571 -- Processing that is done only for base types
2575 -- Deal with default setting of reverse storage order
2579 -- Propagate flags for component type
2583 then
2591 -- The array type requires its own invariant procedure in order to
2592 -- verify the component invariant over all elements. In GNATprove
2593 -- mode, the component invariants are checked by other means. They
2594 -- should not be added to the array type invariant procedure, so
2595 -- that the procedure can be used to check the array type
2596 -- invariants if any.
2599 and then not GNATprove_Mode
2600 then
2603 -- The array type is an implementation base type. Propagate the
2604 -- same property to the first subtype.
2611 -- Warn for pragma Pack overriding foreign convention
2615 then
2616 declare
2621 begin
2625 Error_Msg_N
2628 Error_Msg_N
2635 -- If packing was requested or if the component size was
2636 -- set explicitly, then see if bit packing is required. This
2637 -- processing is only done for base types, since all of the
2638 -- representation aspects involved are type-related.
2640 -- This is not just an optimization, if we start processing the
2641 -- subtypes, they interfere with the settings on the base type
2642 -- (this is because Is_Packed has a slightly different meaning
2643 -- before and after freezing).
2645 declare
2649 begin
2653 then
2662 else
2665 -- We can set the component size if it is less than 16,
2666 -- rounding it up to the next storage unit size.
2672 else
2676 -- Set component size up to match alignment if it would
2677 -- otherwise be less than the alignment. This deals with
2678 -- cases of types whose alignment exceeds their size (the
2679 -- padded type cases).
2682 declare
2684 begin
2692 -- Case of component size that may result in bit packing
2695 declare
2701 Get_Attribute_Definition_Clause
2704 begin
2705 -- Warn if we have pack and component size so that the
2706 -- pack is ignored.
2708 -- Note: here we must check for the presence of a
2709 -- component size before checking for a Pack pragma to
2710 -- deal with the case where the array type is a derived
2711 -- type whose parent is currently private.
2715 and then Warn_On_Redundant_Constructs
2716 then
2718 Error_Msg_NE
2720 Error_Msg_N
2726 -- Set component size if not already set by a component
2727 -- size clause.
2733 -- Check for base type of 8, 16, 32 bits, where an
2734 -- unsigned subtype has a length one less than the
2735 -- base type (e.g. Natural subtype of Integer).
2737 -- In such cases, if a component size was not set
2738 -- explicitly, then generate a warning.
2744 then
2748 Error_Msg_N
2750 Pack_Pragma);
2751 Error_Msg_N
2753 Pack_Pragma);
2757 -- Bit packing is never needed for 8, 16, 32, 64
2761 -- If the Esize of the component is known and equal to
2762 -- the component size then even packing is not needed.
2766 then
2767 -- Here the array was requested to be packed, but
2768 -- the packing request had no effect whatsoever,
2769 -- so flag Is_Packed is reset.
2771 -- Note: semantically this means that we lose track
2772 -- of the fact that a derived type inherited pragma
2773 -- Pack that was non-effective, but that is fine.
2775 -- We regard a Pack pragma as a request to set a
2776 -- representation characteristic, and this request
2777 -- may be ignored.
2781 else
2788 -- Bit packing is not needed for multiples of the storage
2789 -- unit if the type is composite because the back end can
2790 -- byte pack composite types.
2794 then
2799 -- In all other cases, bit packing is needed
2801 else
2810 -- Check for Aliased or Atomic_Components/Atomic/VFA with
2811 -- unsuitable packing or explicit component size clause given.
2816 and then
2818 then
2822 -- Outputs error messages for incorrect CS clause or pragma
2823 -- Pack for aliased or atomic/VFA components (T is "aliased"
2824 -- or "atomic/vfa");
2826 -----------------
2827 -- Complain_CS --
2828 -----------------
2831 begin
2833 Clause :=
2834 Get_Attribute_Definition_Clause
2837 Error_Msg_N
2841 Error_Msg_N
2844 else
2845 Error_Msg_N
2851 -- Start of processing for Alias_Atomic_Check
2853 begin
2854 -- If object size of component type isn't known, we cannot
2855 -- be sure so we defer to the back end.
2860 -- Case where component size has no effect. First check for
2861 -- object size of component type multiple of the storage
2862 -- unit size.
2866 -- OK in both packing case and component size case if RM
2867 -- size is known and static and same as the object size.
2869 and then
2873 -- Or if we have an explicit component size clause and
2874 -- the component size and object size are equal.
2876 or else
2879 then
2887 then
2896 -- Check for Independent_Components/Independent with unsuitable
2897 -- packing or explicit component size clause given.
2900 and then
2902 then
2903 begin
2904 -- If object size of component type isn't known, we cannot
2905 -- be sure so we defer to the back end.
2910 -- Case where component size has no effect. First check for
2911 -- object size of component type multiple of the storage
2912 -- unit size.
2916 -- OK in both packing case and component size case if RM
2917 -- size is known and multiple of the storage unit size.
2919 and then
2923 -- Or if we have an explicit component size clause and
2924 -- the component size is larger than the object size.
2926 or else
2929 then
2932 else
2934 Clause :=
2935 Get_Attribute_Definition_Clause
2938 Error_Msg_N
2942 Error_Msg_N
2945 else
2946 Error_Msg_N
2954 -- Warn for case of atomic type
2960 then
2961 Error_Msg_NE
2976 -- Check for scalar storage order
2978 declare
2980 begin
2981 Check_Component_Storage_Order
2984 ADC => Get_Attribute_Definition_Clause
2986 Attribute_Scalar_Storage_Order),
2990 -- Processing that is done only for subtypes
2992 else
2993 -- Acquire alignment from base type
3001 -- Specific checks for bit-packed arrays
3005 -- Check number of elements for bit-packed arrays that come from
3006 -- source and have compile time known ranges. The bit-packed
3007 -- arrays circuitry does not support arrays with more than
3008 -- Integer'Last + 1 elements, and when this restriction is
3009 -- violated, causes incorrect data access.
3011 -- For the case where this is not compile time known, a run-time
3012 -- check should be generated???
3015 declare
3021 begin
3027 -- Never generate an error if any index is of a generic
3028 -- type. We will check this in instances.
3035 Ilen :=
3041 -- No attempt is made to check number of elements if not
3042 -- compile time known.
3055 then
3056 Error_Msg_N
3063 -- Check size
3066 declare
3070 begin
3071 -- It is not clear if it is possible to have no size clause
3072 -- at this stage, but it is not worth worrying about. Post
3073 -- error on the entity name in the size clause if present,
3074 -- else on the type entity itself.
3078 else
3085 -- If any of the index types was an enumeration type with a non-
3086 -- standard rep clause, then we indicate that the array type is
3087 -- always packed (even if it is not bit-packed).
3096 -- If the array is packed and bit-packed or packed to eliminate holes
3097 -- in the non-contiguous enumeration index types, we must create the
3098 -- packed array type to be used to actually implement the type. This
3099 -- is only needed for real array types (not for string literal types,
3100 -- since they are present only for the front end).
3105 then
3109 -- Make sure that we have the necessary routines to implement the
3110 -- packing, and complain now if not. Note that we only test this
3111 -- for constrained array types.
3117 then
3118 declare
3122 begin
3125 then
3126 Error_Msg_CRT
3130 -- Cancel the packing
3140 -- Size information of packed array type is copied to the array
3141 -- type, since this is really the representation. But do not
3142 -- override explicit existing size values. If the ancestor subtype
3143 -- is constrained the Packed_Array_Impl_Type will be inherited
3144 -- from it, but the size may have been provided already, and
3145 -- must not be overridden either.
3148 and then
3151 then
3163 -- For non-packed arrays set the alignment of the array to the
3164 -- alignment of the component type if it is unknown. Skip this
3165 -- in atomic/VFA case (atomic/VFA arrays may need larger alignments).
3174 then
3178 -- A Ghost type cannot have a component of protected or task type
3179 -- (SPARK RM 6.9(19)).
3182 Error_Msg_N
3184 Arr);
3188 -------------------------------
3189 -- Freeze_Object_Declaration --
3190 -------------------------------
3193 begin
3194 -- Abstract type allowed only for C++ imported variables or constants
3196 -- Note: we inhibit this check for objects that do not come from
3197 -- source because there is at least one case (the expansion of
3198 -- x'Class'Input where x is abstract) where we legitimately
3199 -- generate an abstract object.
3204 then
3209 Error_Msg_NE
3214 Error_Msg_N -- CODEFIX
3220 -- For object created by object declaration, perform required
3221 -- categorization (preelaborate and pure) checks. Defer these
3222 -- checks to freeze time since pragma Import inhibits default
3223 -- initialization and thus pragma Import affects these checks.
3227 -- If there is an address clause, check that it is valid
3228 -- and if need be move initialization to the freeze node.
3232 -- Similar processing is needed for aspects that may affect
3233 -- object layout, like Alignment, if there is an initialization
3234 -- expression. We don't do this if there is a pragma Linker_Section,
3235 -- because it would prevent the back end from statically initializing
3236 -- the object; we don't want elaboration code in that case.
3239 and then Expander_Active
3243 then
3244 declare
3248 begin
3250 -- Capture initialization value at point of declaration, and
3251 -- make explicit assignment legal, because object may be a
3252 -- constant.
3257 -- Move initialization to freeze actions.
3265 -- Set_Is_Frozen (E, False);
3269 -- Reset Is_True_Constant for non-constant aliased object. We
3270 -- consider that the fact that a non-constant object is aliased may
3271 -- indicate that some funny business is going on, e.g. an aliased
3272 -- object is passed by reference to a procedure which captures the
3273 -- address of the object, which is later used to assign a new value,
3274 -- even though the compiler thinks that it is not modified. Such
3275 -- code is highly dubious, but we choose to make it "work" for
3276 -- non-constant aliased objects.
3278 -- Note that we used to do this for all aliased objects, whether or
3279 -- not constant, but this caused anomalies down the line because we
3280 -- ended up with static objects that were not Is_True_Constant. Not
3281 -- resetting Is_True_Constant for (aliased) constant objects ensures
3282 -- that this anomaly never occurs.
3284 -- However, we don't do that for internal entities. We figure that if
3285 -- we deliberately set Is_True_Constant for an internal entity, e.g.
3286 -- a dispatch table entry, then we mean it.
3291 then
3295 -- If the object needs any kind of default initialization, an error
3296 -- must be issued if No_Default_Initialization applies. The check
3297 -- doesn't apply to imported objects, which are not ever default
3298 -- initialized, and is why the check is deferred until freezing, at
3299 -- which point we know if Import applies. Deferred constants are also
3300 -- exempted from this test because their completion is explicit, or
3301 -- through an import pragma.
3309 and then
3313 or else
3316 then
3318 Check_Restriction
3322 -- Check that a Thread_Local_Storage variable does not have
3323 -- default initialization, and any explicit initialization must
3324 -- either be the null constant or a static constant.
3327 declare
3329 begin
3330 if Has_Default_Initialization
3331 or else
3333 and then
3335 or else not
3338 then
3339 Error_Msg_NE
3342 Error_Msg_NE
3349 -- For imported objects, set Is_Public unless there is also an
3350 -- address clause, which means that there is no external symbol
3351 -- needed for the Import (Is_Public may still be set for other
3352 -- unrelated reasons). Note that we delayed this processing
3353 -- till freeze time so that we can be sure not to set the flag
3354 -- if there is an address clause. If there is such a clause,
3355 -- then the only purpose of the Import pragma is to suppress
3356 -- implicit initialization.
3362 -- For source objects that are not Imported and are library
3363 -- level, if no linker section pragma was given inherit the
3364 -- appropriate linker section from the corresponding type.
3370 then
3371 Set_Linker_Section_Pragma
3375 -- For convention C objects of an enumeration type, warn if the
3376 -- size is not integer size and no explicit size given. Skip
3377 -- warning for Boolean, and Character, assume programmer expects
3378 -- 8-bit sizes for these cases.
3381 or else
3388 then
3390 Error_Msg_N
3396 -----------------------------
3397 -- Freeze_Generic_Entities --
3398 -----------------------------
3405 begin
3424 --------------------
3425 -- Freeze_Profile --
3426 --------------------
3433 begin
3434 -- Loop through formals
3440 -- AI05-0151: incomplete types can appear in a profile. By the
3441 -- time the entity is frozen, the full view must be available,
3442 -- unless it is a limited view.
3447 then
3461 then
3462 -- If the type of a formal is incomplete, subprogram is being
3463 -- frozen prematurely. Within an instance (but not within a
3464 -- wrapper package) this is an artifact of our need to regard
3465 -- the end of an instantiation as a freeze point. Otherwise it
3466 -- is a definite error.
3473 elsif not After_Last_Declaration
3474 and then not Freezing_Library_Level_Tagged_Type
3475 then
3477 Error_Msg
3482 -- Check suspicious parameter for C function. These tests apply
3483 -- only to exported/imported subprograms.
3485 if Warn_On_Export_Import
3488 or else
3495 then
3496 -- Qualify mention of formals with subprogram name
3500 -- Check suspicious use of fat C pointer
3504 then
3505 Error_Msg_N
3508 -- Check suspicious return of boolean
3514 then
3515 Error_Msg_N
3517 Error_Msg_N
3521 -- Check suspicious tagged type
3524 or else
3528 then
3529 Error_Msg_N
3533 -- Check wrong convention subprogram pointer
3537 then
3538 Error_Msg_N
3542 Error_Msg_NE
3547 -- Turn off name qualification after message output
3552 -- Check for unconstrained array in exported foreign convention
3553 -- case.
3559 and then Warn_On_Export_Import
3560 then
3563 -- If this is an inherited operation, place the warning on
3564 -- the derived type declaration, rather than on the original
3565 -- subprogram.
3568 then
3574 else
3590 -- If the formal is an anonymous_access_to_subprogram
3591 -- freeze the subprogram type as well, to prevent
3592 -- scope anomalies in gigi, because there is no other
3593 -- clear point at which it could be frozen.
3597 then
3605 -- Case of function: similar checks on return type
3609 -- Freeze return type
3613 -- AI05-0151: the return type may have been incomplete at the
3614 -- point of declaration. Replace it with the full view, unless the
3615 -- current type is a limited view. In that case the full view is
3616 -- in a different unit, and gigi finds the non-limited view after
3617 -- the other unit is elaborated.
3622 then
3629 -- Check suspicious return type for C function
3631 if Warn_On_Export_Import
3633 or else
3636 then
3637 -- Check suspicious return of fat C pointer
3643 then
3644 Error_Msg_N
3646 E);
3648 -- Check suspicious return of boolean
3655 then
3656 declare
3659 begin
3660 Error_Msg_NE
3662 Error_Msg_NE
3667 -- Check suspicious return tagged type
3671 and then
3672 Is_Tagged_Type
3677 then
3681 -- Check return of wrong convention subprogram pointer
3687 then
3691 Error_Msg_NE
3697 -- Give warning for suspicious return of a result of an
3698 -- unconstrained array type in a foreign convention function.
3702 -- We are looking for a return of unconstrained array
3707 -- Exclude imported routines, the warning does not belong on
3708 -- the import, but rather on the routine definition.
3712 -- Check that general warning is enabled, and that it is not
3713 -- suppressed for this particular case.
3715 and then Warn_On_Export_Import
3718 then
3719 Error_Msg_N
3725 -- Check suspicious use of Import in pure unit (cases where the RM
3726 -- allows calls to be omitted).
3730 -- It might be suspicious if the compilation unit has the Pure
3731 -- aspect/pragma.
3735 -- The RM allows omission of calls only in the case of
3736 -- library-level subprograms (see RM-10.2.1(18)).
3740 -- Ignore internally generated entity. This happens in some cases
3741 -- of subprograms in specs, where we generate an implied body.
3745 -- Assume run-time knows what it is doing
3747 and then not GNAT_Mode
3749 -- Assume explicit Pure_Function means import is pure
3753 -- Don't need warning in relaxed semantics mode
3755 and then not Relaxed_RM_Semantics
3757 -- Assume convention Intrinsic is OK, since this is specialized.
3758 -- This deals with the DEC unit current_exception.ads
3762 -- Assume that ASM interface knows what it is doing. This deals
3763 -- with e.g. unsigned.ads in the AAMP back end.
3766 then
3767 Error_Msg_N
3769 Error_Msg_NE
3777 ------------------------
3778 -- Freeze_Record_Type --
3779 ------------------------
3791 -- Set True if we find at least one component which is aliased. This
3792 -- is used to prevent Implicit_Packing of the record, since packing
3793 -- cannot modify the size of alignment of an aliased component.
3796 -- True if all components are of a type whose underlying type is
3797 -- elementary.
3800 -- True if all components have a known RM_Size
3803 -- True if all components have an RM_Size that is a multiple of the
3804 -- storage unit.
3807 -- Accumulates total Esize values of all elementary components. Used
3808 -- for processing of Implicit_Packing.
3811 -- Set True if we find at least one component with a component
3812 -- clause (used to warn about useless Bit_Order pragmas, and also
3813 -- to detect cases where Implicit_Packing may have an effect).
3816 -- Set True if the record type scope Rec has been pushed on the scope
3817 -- stack. Needed for the analysis of delayed aspects specified to the
3818 -- components of Rec.
3821 -- Accumulates total RM_Size values of all sized components. Used
3822 -- for processing of Implicit_Packing.
3825 -- Accumulates total RM_Size values of all sized components, rounded
3826 -- individually to a multiple of the storage unit.
3829 -- Scalar_Storage_Order attribute definition clause for the record
3832 -- Set True if we find at least one component whose type has a
3833 -- Scalar_Storage_Order attribute definition clause.
3836 -- Set True if we find at least one component with no component
3837 -- clause (used to warn about useless Pack pragmas).
3840 -- If N is an allocator, possibly wrapped in one or more level of
3841 -- qualified expression(s), return the inner allocator node, else
3842 -- return Empty.
3845 -- If the component subtype is an access to a constrained subtype of
3846 -- an already frozen type, make the subtype frozen as well. It might
3847 -- otherwise be frozen in the wrong scope, and a freeze node on
3848 -- subtype has no effect. Similarly, if the component subtype is a
3849 -- regular (not protected) access to subprogram, set the anonymous
3850 -- subprogram type to frozen as well, to prevent an out-of-scope
3851 -- freeze node at some eventual point of call. Protected operations
3852 -- are handled elsewhere.
3855 -- Make sure that all types mentioned in Discrete_Choices of the
3856 -- variants referenceed by the Variant_Part VP are frozen. This is
3857 -- a recursive routine to deal with nested variants.
3859 ---------------------
3860 -- Check_Allocator --
3861 ---------------------
3865 begin
3867 loop
3872 else
3878 -----------------
3879 -- Check_Itype --
3880 -----------------
3885 begin
3888 then
3891 -- In addition, add an Itype_Reference to ensure that the
3892 -- access subtype is elaborated early enough. This cannot be
3893 -- done if the subtype may depend on discriminants.
3898 then
3906 then
3911 ------------------------------------
3912 -- Freeze_Choices_In_Variant_Part --
3913 ------------------------------------
3922 begin
3923 -- Loop through variants
3928 -- Loop through choices, checking that all types are frozen
3934 then
3941 -- Check for nested variant part to process
3955 -- Start of processing for Freeze_Record_Type
3957 begin
3958 -- Deal with delayed aspect specifications for components. The
3959 -- analysis of the aspect is required to be delayed to the freeze
3960 -- point, thus we analyze the pragma or attribute definition
3961 -- clause in the tree at this point. We also analyze the aspect
3962 -- specification node at the freeze point when the aspect doesn't
3963 -- correspond to pragma/attribute definition clause.
3969 then
3974 -- The visibility to the discriminants must be restored in
3975 -- order to properly analyze the aspects.
3988 -- Pop the scope if Rec scope has been pushed on the scope stack
3989 -- during the delayed aspect analysis process.
3996 Pop_Scope;
3999 -- Freeze components and embedded subtypes
4008 -- Handle the component and discriminant case
4011 declare
4014 begin
4015 -- Freezing a record type freezes the type of each of its
4016 -- components. However, if the type of the component is
4017 -- part of this record, we do not want or need a separate
4018 -- Freeze_Node. Note that Is_Itype is wrong because that's
4019 -- also set in private type cases. We also can't check for
4020 -- the Scope being exactly Rec because of private types and
4021 -- record extensions.
4026 then
4032 -- Warn for pragma Pack overriding foreign convention
4037 -- Don't warn for aliased components, since override
4038 -- cannot happen in that case.
4041 then
4042 declare
4047 begin
4051 Error_Msg_N
4053 PP);
4055 Error_Msg_NE
4062 -- Check for error of component clause given for variable
4063 -- sized type. We have to delay this test till this point,
4064 -- since the component type has to be frozen for us to know
4065 -- if it is variable length.
4070 -- We omit this test in a generic context, it will be
4071 -- applied at instantiation time.
4076 -- Also omit this test in CodePeer mode, since we do not
4077 -- have sufficient info on size and rep clauses.
4082 -- Omit check if component has a generic type. This can
4083 -- happen in an instantiation within a generic in ASIS
4084 -- mode, where we force freeze actions without full
4085 -- expansion.
4090 -- Do the check
4092 elsif not
4093 Size_Known_At_Compile_Time
4095 then
4096 Error_Msg_N
4101 else
4105 -- Case of component requires byte alignment
4109 -- Set the enclosing record to also require byte align
4113 -- Check for component clause that is inconsistent with
4114 -- the required byte boundary alignment.
4119 then
4120 Error_Msg_N
4128 -- Gather data for possible Implicit_Packing later. Note that at
4129 -- this stage we might be dealing with a real component, or with
4130 -- an implicit subtype declaration.
4133 declare
4138 begin
4139 Sized_Component_Total_RM_Size :=
4142 Sized_Component_Total_Round_RM_Size :=
4143 Sized_Component_Total_Round_RM_Size +
4148 then
4149 Elem_Component_Total_Esize :=
4151 else
4159 else
4163 -- If the component is an Itype with Delayed_Freeze and is either
4164 -- a record or array subtype and its base type has not yet been
4165 -- frozen, we must remove this from the entity list of this record
4166 -- and put it on the entity list of the scope of its base type.
4167 -- Note that we know that this is not the type of a component
4168 -- since we cleared Has_Delayed_Freeze for it in the previous
4169 -- loop. Thus this must be the Designated_Type of an access type,
4170 -- which is the type of a component.
4178 then
4179 declare
4183 begin
4184 -- We have a difficult case to handle here. Suppose Rec is
4185 -- subtype being defined in a subprogram that's created as
4186 -- part of the freezing of Rec'Base. In that case, we know
4187 -- that Comp'Base must have already been frozen by the time
4188 -- we get to elaborate this because Gigi doesn't elaborate
4189 -- any bodies until it has elaborated all of the declarative
4190 -- part. But Is_Frozen will not be set at this point because
4191 -- we are processing code in lexical order.
4193 -- We detect this case by going up the Scope chain of Rec
4194 -- and seeing if we have a subprogram scope before reaching
4195 -- the top of the scope chain or that of Comp'Base. If we
4196 -- do, then mark that Comp'Base will actually be frozen. If
4197 -- so, we merely undelay it.
4214 else
4217 else
4221 -- Insert in entity list of scope of base type (which
4222 -- must be an enclosing scope, because still unfrozen).
4228 -- If the component is an access type with an allocator as default
4229 -- value, the designated type will be frozen by the corresponding
4230 -- expression in init_proc. In order to place the freeze node for
4231 -- the designated type before that for the current record type,
4232 -- freeze it now.
4234 -- Same process if the component is an array of access types,
4235 -- initialized with an aggregate. If the designated type is
4236 -- private, it cannot contain allocators, and it is premature
4237 -- to freeze the type, so we check for this as well.
4242 then
4243 declare
4247 begin
4250 -- If component is pointer to a class-wide type, freeze
4251 -- the specific type in the expression being allocated.
4252 -- The expression may be a subtype indication, in which
4253 -- case freeze the subtype mark.
4255 if Is_Class_Wide_Type
4257 then
4259 Freeze_And_Append
4263 then
4264 Freeze_And_Append
4272 else
4273 Freeze_And_Append
4281 then
4284 -- Freeze the designated type when initializing a component with
4285 -- an aggregate in case the aggregate contains allocators.
4287 -- type T is ...;
4288 -- type T_Ptr is access all T;
4289 -- type T_Array is array ... of T_Ptr;
4291 -- type Rec is record
4292 -- Comp : T_Array := (others => ...);
4293 -- end record;
4297 then
4298 declare
4301 Designated_Type
4304 begin
4305 -- The only case when this sort of freezing is not done is
4306 -- when the designated type is class-wide and the root type
4307 -- is the record owning the component. This scenario results
4308 -- in a circularity because the class-wide type requires
4309 -- primitives that have not been created yet as the root
4310 -- type is in the process of being frozen.
4312 -- type Rec is tagged;
4313 -- type Rec_Ptr is access all Rec'Class;
4314 -- type Rec_Array is array ... of Rec_Ptr;
4316 -- type Rec is record
4317 -- Comp : Rec_Array := (others => ...);
4318 -- end record;
4322 then
4330 then
4340 SSO_ADC :=
4341 Get_Attribute_Definition_Clause
4344 -- If the record type has Complex_Representation, then it is treated
4345 -- as a scalar in the back end so the storage order is irrelevant.
4349 Error_Msg_N
4351 SSO_ADC);
4354 else
4355 -- Deal with default setting of reverse storage order
4359 -- Check consistent attribute setting on component types
4361 declare
4363 begin
4366 Check_Component_Storage_Order
4376 -- Now deal with reverse storage order/bit order issues
4380 -- Check compatibility of Scalar_Storage_Order with Bit_Order,
4381 -- if the former is specified.
4385 -- Note: report error on Rec, not on SSO_ADC, as ADC may
4386 -- apply to some ancestor type.
4389 Error_Msg_N
4394 -- Warn if there is a Scalar_Storage_Order attribute definition
4395 -- clause but no component clause, no component that itself has
4396 -- such an attribute definition, and no pragma Pack.
4399 or else
4400 SSO_ADC_Component
4401 or else
4403 then
4404 Error_Msg_N
4411 -- Deal with Bit_Order aspect
4419 then
4420 -- Warn if clause has no effect when no component clause is
4421 -- present, but suppress warning if the Bit_Order is required
4422 -- due to the presence of a Scalar_Storage_Order attribute.
4424 Error_Msg_N
4426 Error_Msg_N
4429 -- Here is where we do the processing to adjust component clauses
4430 -- for reversed bit order, when not using reverse SSO. If an error
4431 -- has been reported on Rec already (such as SSO incompatible with
4432 -- bit order), don't bother adjusting as this may generate extra
4433 -- noise.
4438 then
4441 -- Case where we have both an explicit Bit_Order and the same
4442 -- Scalar_Storage_Order: leave record untouched, the back-end
4443 -- will take care of required layout conversions.
4445 else
4451 -- Complete error checking on record representation clause (e.g.
4452 -- overlap of components). This is called after adjusting the
4453 -- record for reverse bit order.
4455 declare
4457 begin
4463 -- Check for useless pragma Pack when all components placed. We only
4464 -- do this check for record types, not subtypes, since a subtype may
4465 -- have all its components placed, and it still makes perfectly good
4466 -- sense to pack other subtypes or the parent type. We do not give
4467 -- this warning if Optimize_Alignment is set to Space, since the
4468 -- pragma Pack does have an effect in this case (it always resets
4469 -- the alignment to one).
4473 and then not Unplaced_Component
4475 then
4476 -- Reset packed status. Probably not necessary, but we do it so
4477 -- that there is no chance of the back end doing something strange
4478 -- with this redundant indication of packing.
4482 -- Give warning if redundant constructs warnings on
4485 Error_Msg_N -- CODEFIX
4491 -- If this is the record corresponding to a remote type, freeze the
4492 -- remote type here since that is what we are semantically freezing.
4493 -- This prevents the freeze node for that type in an inner scope.
4500 -- Check for controlled components, unchecked unions, and type
4501 -- invariants.
4506 -- Do not set Has_Controlled_Component on a class-wide
4507 -- equivalent type. See Make_CW_Equivalent_Type.
4510 and then
4512 or else
4515 or else
4517 and then
4519 and then
4520 Has_Controlled_Component
4522 then
4530 -- The record type requires its own invariant procedure in
4531 -- order to verify the invariant of each individual component.
4532 -- Do not consider internal components such as _parent because
4533 -- parent class-wide invariants are always inherited.
4534 -- In GNATprove mode, the component invariants are checked by
4535 -- other means. They should not be added to the record type
4536 -- invariant procedure, so that the procedure can be used to
4537 -- check the recordy type invariants if any.
4541 and then not GNATprove_Mode
4542 then
4546 -- Scan component declaration for likely misuses of current
4547 -- instance, either in a constraint or a default expression.
4557 -- Enforce the restriction that access attributes with a current
4558 -- instance prefix can only apply to limited types. This comment
4559 -- is floating here, but does not seem to belong here???
4561 -- Set component alignment if not otherwise already set
4565 -- For first subtypes, check if there are any fixed-point fields with
4566 -- component clauses, where we must check the size. This is not done
4567 -- till the freeze point since for fixed-point types, we do not know
4568 -- the size until the type is frozen. Similar processing applies to
4569 -- bit-packed arrays.
4577 then
4578 Check_Size
4582 Junk);
4589 -- See if Size is too small as is (and implicit packing might help)
4593 -- No implicit packing if even one component is explicitly placed
4595 and then not Placed_Component
4597 -- Or even one component is aliased
4599 and then not Aliased_Component
4601 -- Must have size clause and all sized components
4604 and then All_Sized_Components
4606 -- Do not try implicit packing on records with discriminants, too
4607 -- complicated, especially in the variant record case.
4611 -- We want to implicitly pack if the specified size of the record
4612 -- is less than the sum of the object sizes (no point in packing
4613 -- if this is not the case), if we can compute it, i.e. if we have
4614 -- only elementary components. Otherwise, we have at least one
4615 -- composite component and we want to implicitly pack only if bit
4616 -- packing is required for it, as we are sure in this case that
4617 -- the back end cannot do the expected layout without packing.
4619 and then
4620 ((All_Elem_Components
4622 or else
4624 and then not All_Storage_Unit_Components
4627 -- And the total RM size cannot be greater than the specified size
4628 -- since otherwise packing will not get us where we have to be.
4632 -- Never do implicit packing in CodePeer or SPARK modes since
4633 -- we don't do any packing in these modes, since this generates
4634 -- over-complex code that confuses static analysis, and in
4635 -- general, neither CodePeer not GNATprove care about the
4636 -- internal representation of objects.
4639 then
4640 -- If implicit packing enabled, do it
4645 -- Otherwise flag the size clause
4647 else
4648 declare
4650 begin
4651 Error_Msg_NE -- CODEFIX
4653 Error_Msg_N -- CODEFIX
4660 -- The following checks are relevant only when SPARK_Mode is on as
4661 -- they are not standard Ada legality rules.
4665 -- A discriminated type cannot be effectively volatile
4666 -- (SPARK RM 7.1.3(5)).
4673 -- A non-effectively volatile record type cannot contain
4674 -- effectively volatile components (SPARK RM 7.1.3(6)).
4676 else
4681 then
4683 Error_Msg_N
4692 -- A type which does not yield a synchronized object cannot have
4693 -- a component that yields a synchronized object (SPARK RM 9.5).
4700 then
4702 Error_Msg_N
4711 -- A Ghost type cannot have a component of protected or task type
4712 -- (SPARK RM 6.9(19)).
4719 then
4721 Error_Msg_N
4723 Comp);
4731 -- Make sure that if we have an iterator aspect, then we have
4732 -- either Constant_Indexing or Variable_Indexing.
4734 declare
4737 begin
4746 or else
4748 then
4750 else
4751 Error_Msg_N
4753 Iterator_Aspect);
4758 -- All done if not a full record definition
4764 -- Finally we need to check the variant part to make sure that
4765 -- all types within choices are properly frozen as part of the
4766 -- freezing of the record type.
4773 begin
4774 -- Find component list
4786 then
4791 -- Case of variant part present
4797 -- Note: we used to call Check_Choices here, but it is too early,
4798 -- since predicated subtypes are frozen here, but their freezing
4799 -- actions are in Analyze_Freeze_Entity, which has not been called
4800 -- yet for entities frozen within this procedure, so we moved that
4801 -- call to the Analyze_Freeze_Entity for the record type.
4805 -- Check that all the primitives of an interface type are abstract
4806 -- or null procedures.
4810 then
4811 declare
4815 begin
4822 -- Avoid reporting the error on inherited primitives
4825 then
4830 Error_Msg_N
4834 else
4835 Error_Msg_N
4846 -- For a derived tagged type, check whether inherited primitives
4847 -- might require a wrapper to handle class-wide conditions.
4854 -------------------------------
4855 -- Has_Boolean_Aspect_Import --
4856 -------------------------------
4863 begin
4869 -- The value of aspect Import is True when the expression is
4870 -- either missing or it is explicitly set to True.
4876 then
4887 -------------------------
4888 -- Inherit_Freeze_Node --
4889 -------------------------
4891 procedure Inherit_Freeze_Node
4894 is
4897 begin
4901 -- The input type had an existing node. Propagate relevant attributes
4902 -- from the old freeze node to the inherited freeze node.
4904 -- ??? if both freeze nodes have attributes, would they differ?
4908 -- Attribute Access_Types_To_Process
4912 then
4917 -- Attribute Actions
4923 -- Attribute First_Subtype_Link
4927 then
4931 -- Attribute TSS_Elist
4935 then
4941 ------------------------------
4942 -- Wrap_Imported_Subprogram --
4943 ------------------------------
4945 -- The issue here is that our normal approach of checking preconditions
4946 -- and postconditions does not work for imported procedures, since we
4947 -- are not generating code for the body. To get around this we create
4948 -- a wrapper, as shown by the following example:
4950 -- procedure K (A : Integer);
4951 -- pragma Import (C, K);
4953 -- The spec is rewritten by removing the effects of pragma Import, but
4954 -- leaving the convention unchanged, as though the source had said:
4956 -- procedure K (A : Integer);
4957 -- pragma Convention (C, K);
4959 -- and we create a body, added to the entity K freeze actions, which
4960 -- looks like:
4962 -- procedure K (A : Integer) is
4963 -- procedure K (A : Integer);
4964 -- pragma Import (C, K);
4965 -- begin
4966 -- K (A);
4967 -- end K;
4969 -- Now the contract applies in the normal way to the outer procedure,
4970 -- and the inner procedure has no contracts, so there is no problem
4971 -- in just calling it to get the original effect.
4973 -- In the case of a function, we create an appropriate return statement
4974 -- for the subprogram body that calls the inner procedure.
4978 -- Obtain a copy of the Import_Pragma which belongs to subprogram E
4980 ------------------------
4981 -- Copy_Import_Pragma --
4982 ------------------------
4986 -- The subprogram should have an import pragma, otherwise it does
4987 -- need a wrapper.
4992 -- Save all semantic fields of the pragma
5001 begin
5002 -- Reset all semantic fields. This avoids a potential infinite
5003 -- loop when the pragma comes from an aspect as the duplication
5004 -- will copy the aspect, then copy the corresponding pragma and
5005 -- so on.
5014 -- Restore the original semantic fields
5024 -- Local variables
5035 -- Start of processing for Wrap_Imported_Subprogram
5037 begin
5038 -- Nothing to do if not imported
5043 -- Test enabling conditions for wrapping
5048 and then not GNATprove_Mode
5049 then
5050 -- Here we do the wrap
5052 -- Note on calls to Copy_Separate_Tree. The trees we are copying
5053 -- here are fully analyzed, but we definitely want fully syntactic
5054 -- unanalyzed trees in the body we construct, so that the analysis
5055 -- generates the right visibility, and that is exactly what the
5056 -- calls to Copy_Separate_Tree give us.
5060 -- Fix up spec so it is no longer imported and has convention Ada
5068 -- Grab the subprogram declaration and specification
5072 -- Build parameter list that we need
5081 -- Build the call
5084 Stmt :=
5086 Expression =>
5091 else
5092 Stmt :=
5098 -- Now build the body
5100 Bod :=
5102 Specification =>
5107 Prag),
5108 Handled_Statement_Sequence =>
5113 -- Append the body to freeze result
5118 -- Case of imported subprogram that does not get wrapped
5120 else
5121 -- Set Is_Public. All imported entities need an external symbol
5122 -- created for them since they are always referenced from another
5123 -- object file. Note this used to be set when we set Is_Imported
5124 -- back in Sem_Prag, but now we delay it to this point, since we
5125 -- don't want to set this flag if we wrap an imported subprogram.
5131 -- Local variables
5134 -- Save the Ghost mode to restore on exit
5136 -- Start of processing for Freeze_Entity
5138 begin
5139 -- The entity being frozen may be subject to pragma Ghost. Set the mode
5140 -- now to ensure that any nodes generated during freezing are properly
5141 -- flagged as Ghost.
5145 -- We are going to test for various reasons why this entity need not be
5146 -- frozen here, but in the case of an Itype that's defined within a
5147 -- record, that test actually applies to the record.
5153 then
5157 -- Do not freeze if already frozen since we only need one freeze node
5167 -- It is improper to freeze an external entity within a generic because
5168 -- its freeze node will appear in a non-valid context. The entity will
5169 -- be frozen in the proper scope after the current generic is analyzed.
5170 -- However, aspects must be analyzed because they may be queried later
5171 -- within the generic itself, and the corresponding pragma or attribute
5172 -- definition has not been analyzed yet.
5182 -- AI05-0213: A formal incomplete type does not freeze the actual. In
5183 -- the instance, the same applies to the subtype renaming the actual.
5189 then
5193 -- Formal subprograms are never frozen
5199 -- Generic types are never frozen as they lack delayed semantic checks
5205 -- Do not freeze a global entity within an inner scope created during
5206 -- expansion. A call to subprogram E within some internal procedure
5207 -- (a stream attribute for example) might require freezing E, but the
5208 -- freeze node must appear in the same declarative part as E itself.
5209 -- The two-pass elaboration mechanism in gigi guarantees that E will
5210 -- be frozen before the inner call is elaborated. We exclude constants
5211 -- from this test, because deferred constants may be frozen early, and
5212 -- must be diagnosed (e.g. in the case of a deferred constant being used
5213 -- in a default expression). If the enclosing subprogram comes from
5214 -- source, or is a generic instance, then the freeze point is the one
5215 -- mandated by the language, and we freeze the entity. A subprogram that
5216 -- is a child unit body that acts as a spec does not have a spec that
5217 -- comes from source, but can only come from source.
5222 then
5223 declare
5226 begin
5233 then
5235 else
5245 -- Similarly, an inlined instance body may make reference to global
5246 -- entities, but these references cannot be the proper freezing point
5247 -- for them, and in the absence of inlining freezing will take place in
5248 -- their own scope. Normally instance bodies are analyzed after the
5249 -- enclosing compilation, and everything has been frozen at the proper
5250 -- place, but with front-end inlining an instance body is compiled
5251 -- before the end of the enclosing scope, and as a result out-of-order
5252 -- freezing must be prevented.
5254 elsif Front_End_Inlining
5255 and then In_Instance_Body
5257 then
5258 declare
5261 begin
5266 else
5278 -- Add checks to detect proper initialization of scalars that may appear
5279 -- as subprogram parameters.
5285 -- Deal with delayed aspect specifications. The analysis of the aspect
5286 -- is required to be delayed to the freeze point, thus we analyze the
5287 -- pragma or attribute definition clause in the tree at this point. We
5288 -- also analyze the aspect specification node at the freeze point when
5289 -- the aspect doesn't correspond to pragma/attribute definition clause.
5290 -- In addition, a derived type may have inherited aspects that were
5291 -- delayed in the parent, so these must also be captured now.
5295 then
5299 -- Here to freeze the entity
5303 -- Case of entity being frozen is other than a type
5307 -- If entity is exported or imported and does not have an external
5308 -- name, now is the time to provide the appropriate default name.
5309 -- Skip this if the entity is stubbed, since we don't need a name
5310 -- for any stubbed routine. For the case on intrinsics, if no
5311 -- external name is specified, then calls will be handled in
5312 -- Exp_Intr.Expand_Intrinsic_Call, and no name is needed. If an
5313 -- external name is provided, then Expand_Intrinsic_Call leaves
5314 -- calls in place for expansion by GIGI.
5320 then
5321 Set_Encoded_Interface_Name
5324 -- If entity is an atomic object appearing in a declaration and
5325 -- the expression is an aggregate, assign it to a temporary to
5326 -- ensure that the actual assignment is done atomically rather
5327 -- than component-wise (the assignment to the temp may be done
5328 -- component-wise, but that is harmless).
5335 then
5339 -- Subprogram case
5343 -- Check for needing to wrap imported subprogram
5347 -- Freeze all parameter types and the return type (RM 13.14(14)).
5348 -- However skip this for internal subprograms. This is also where
5349 -- any extra formal parameters are created since we now know
5350 -- whether the subprogram will use a foreign convention.
5352 -- In Ada 2012, freezing a subprogram does not always freeze the
5353 -- corresponding profile (see AI05-019). An attribute reference
5354 -- is not a freezing point of the profile. Flag Do_Freeze_Profile
5355 -- indicates whether the profile should be frozen now.
5356 -- Other constructs that should not freeze ???
5358 -- This processing doesn't apply to internal entities (see below)
5366 -- Must freeze its parent first if it is a derived subprogram
5372 -- We don't freeze internal subprograms, because we don't normally
5373 -- want addition of extra formals or mechanism setting to happen
5374 -- for those. However we do pass through predefined dispatching
5375 -- cases, since extra formals may be needed in some cases, such as
5376 -- for the stream 'Input function (build-in-place formals).
5380 then
5384 -- If warning on suspicious contracts then check for the case of
5385 -- a postcondition other than False for a No_Return subprogram.
5388 and then Warn_On_Suspicious_Contract
5390 then
5391 declare
5395 begin
5398 Name_Post,
5399 Name_Postcondition,
5400 Name_Refined_Post)
5401 then
5402 Exp :=
5403 Expression
5408 then
5409 Error_Msg_NE
5420 -- Here for other than a subprogram or type
5422 else
5423 -- If entity has a type, and it is not a generic unit, then
5424 -- freeze it first (RM 13.14(10)).
5428 then
5431 -- For an object of an anonymous array type, aspects on the
5432 -- object declaration apply to the type itself. This is the
5433 -- case for Atomic_Components, Volatile_Components, and
5434 -- Independent_Components. In these cases analysis of the
5435 -- generated pragma will mark the anonymous types accordingly,
5436 -- and the object itself does not require a freeze node.
5442 then
5449 -- Special processing for objects created by object declaration
5455 -- Check that a constant which has a pragma Volatile[_Components]
5456 -- or Atomic[_Components] also has a pragma Import (RM C.6(13)).
5458 -- Note: Atomic[_Components] also sets Volatile[_Components]
5464 then
5465 -- Make sure we actually have a pragma, and have not merely
5466 -- inherited the indication from elsewhere (e.g. an address
5467 -- clause, which is not good enough in RM terms).
5470 or else
5472 then
5473 Error_Msg_N
5478 or else
5480 then
5481 Error_Msg_N
5487 -- Static objects require special handling
5491 then
5495 -- Remaining step is to layout objects
5499 then
5503 -- For an object that does not have delayed freezing, and whose
5504 -- initialization actions have been captured in a compound
5505 -- statement, move them back now directly within the enclosing
5506 -- statement sequence.
5510 then
5514 -- Do not generate a freeze node for a generic unit
5522 -- Case of a type or subtype being frozen
5524 else
5525 -- Verify several SPARK legality rules related to Ghost types now
5526 -- that the type is frozen.
5530 -- We used to check here that a full type must have preelaborable
5531 -- initialization if it completes a private type specified with
5532 -- pragma Preelaborable_Initialization, but that missed cases where
5533 -- the types occur within a generic package, since the freezing
5534 -- that occurs within a containing scope generally skips traversal
5535 -- of a generic unit's declarations (those will be frozen within
5536 -- instances). This check was moved to Analyze_Package_Specification.
5538 -- The type may be defined in a generic unit. This can occur when
5539 -- freezing a generic function that returns the type (which is
5540 -- defined in a parent unit). It is clearly meaningless to freeze
5541 -- this type. However, if it is a subtype, its size may be determi-
5542 -- nable and used in subsequent checks, so might as well try to
5543 -- compute it.
5545 -- In Ada 2012, Freeze_Entities is also used in the front end to
5546 -- trigger the analysis of aspect expressions, so in this case we
5547 -- want to continue the freezing process.
5549 -- Is_Generic_Unit (Scope (E)) is dubious here, do we want instead
5550 -- In_Generic_Scope (E)???
5554 and then
5557 then
5563 -- Check for error of Type_Invariant'Class applied to an untagged
5564 -- type (check delayed to freeze time when full type is available).
5566 declare
5568 begin
5572 then
5573 Error_Msg_NE
5575 Error_Msg_N
5580 -- Deal with special cases of freezing for subtype
5584 -- Before we do anything else, a specific test for the case of a
5585 -- size given for an array where the array would need to be packed
5586 -- in order for the size to be honored, but is not. This is the
5587 -- case where implicit packing may apply. The reason we do this so
5588 -- early is that, if we have implicit packing, the layout of the
5589 -- base type is affected, so we must do this before we freeze the
5590 -- base type.
5592 -- We could do this processing only if implicit packing is enabled
5593 -- since in all other cases, the error would be caught by the back
5594 -- end. However, we choose to do the check even if we do not have
5595 -- implicit packing enabled, since this allows us to give a more
5596 -- useful error message (advising use of pragma Implicit_Packing
5597 -- or pragma Pack).
5600 declare
5612 -- Number of elements in array
5614 begin
5615 -- Check enabling conditions. These are straightforward
5616 -- except for the test for a limited composite type. This
5617 -- eliminates the rare case of a array of limited components
5618 -- where there are issues of whether or not we can go ahead
5619 -- and pack the array (since we can't freely pack and unpack
5620 -- arrays if they are limited).
5622 -- Note that we check the root type explicitly because the
5623 -- whole point is we are doing this test before we have had
5624 -- a chance to freeze the base type (and it is that freeze
5625 -- action that causes stuff to be inherited).
5627 -- The conditions on the size are identical to those used in
5628 -- Freeze_Array_Type to set the Is_Packed flag.
5646 then
5647 -- Compute number of elements in array
5654 and then
5656 then
5664 else
5671 -- What we are looking for here is the situation where
5672 -- the RM_Size given would be exactly right if there was
5673 -- a pragma Pack, resulting in the component size being
5674 -- the RM_Size of the component type.
5678 -- For implicit packing mode, just set the component
5679 -- size and Freeze_Array_Type will do the rest.
5684 -- Otherwise give an error message
5686 else
5687 Error_Msg_NE
5689 Error_Msg_N -- CODEFIX
5700 -- If ancestor subtype present, freeze that first. Note that this
5701 -- will also get the base type frozen. Need RM reference ???
5708 -- No ancestor subtype present
5710 else
5711 -- See if we have a nearest ancestor that has a predicate.
5712 -- That catches the case of derived type with a predicate.
5713 -- Need RM reference here ???
5721 -- Freeze base type before freezing the entity (RM 13.14(15))
5728 -- A subtype inherits all the type-related representation aspects
5729 -- from its parents (RM 13.1(8)).
5733 -- For a derived type, freeze its parent type first (RM 13.14(15))
5739 -- A derived type inherits each type-related representation aspect
5740 -- of its parent type that was directly specified before the
5741 -- declaration of the derived type (RM 13.1(15)).
5746 -- Check for incompatible size and alignment for record type
5748 if Warn_On_Size_Alignment
5752 -- If explicit Object_Size clause given assume that the programmer
5753 -- knows what he is doing, and expects the compiler behavior.
5757 -- Check for size not a multiple of alignment
5760 then
5761 declare
5767 begin
5770 -- Give a warning
5774 Error_Msg_NE
5781 else
5783 Error_Msg_NE
5797 -- Array type
5802 -- For a class-wide type, the corresponding specific type is
5803 -- frozen as well (RM 13.14(15))
5808 -- If the base type of the class-wide type is still incomplete,
5809 -- the class-wide remains unfrozen as well. This is legal when
5810 -- E is the formal of a primitive operation of some other type
5811 -- which is being frozen.
5818 -- The equivalent type associated with a class-wide subtype needs
5819 -- to be frozen to ensure that its layout is done.
5823 then
5827 -- Generate an itype reference for a library-level class-wide type
5828 -- at the freeze point. Otherwise the first explicit reference to
5829 -- the type may appear in an inner scope which will be rejected by
5830 -- the back-end.
5834 then
5835 declare
5838 begin
5841 -- From a gigi point of view, a class-wide subtype derives
5842 -- from its record equivalent type. As a result, the itype
5843 -- reference must appear after the freeze node of the
5844 -- equivalent type or gigi will reject the reference.
5848 then
5850 else
5856 -- For a record type or record subtype, freeze all component types
5857 -- (RM 13.14(15)). We test for E_Record_(sub)Type here, rather than
5858 -- using Is_Record_Type, because we don't want to attempt the freeze
5859 -- for the case of a private type with record extension (we will do
5860 -- that later when the full type is frozen).
5867 -- Report a warning if a discriminated record base type has a
5868 -- convention with language C or C++ applied to it. This check is
5869 -- done even within generic scopes (but not in instantiations),
5870 -- which is why we don't do it as part of Freeze_Record_Type.
5874 -- For a concurrent type, freeze corresponding record type. This does
5875 -- not correspond to any specific rule in the RM, but the record type
5876 -- is essentially part of the concurrent type. Also freeze all local
5877 -- entities. This includes record types created for entry parameter
5878 -- blocks and whatever local entities may appear in the private part.
5892 -- The guard on the presence of the Etype seems to be needed
5893 -- for some CodePeer (-gnatcC) cases, but not clear why???
5898 then
5909 -- Private types are required to point to the same freeze node as
5910 -- their corresponding full views. The freeze node itself has to
5911 -- point to the partial view of the entity (because from the partial
5912 -- view, we can retrieve the full view, but not the reverse).
5913 -- However, in order to freeze correctly, we need to freeze the full
5914 -- view. If we are freezing at the end of a scope (or within the
5915 -- scope) of the private type, the partial and full views will have
5916 -- been swapped, the full view appears first in the entity chain and
5917 -- the swapping mechanism ensures that the pointers are properly set
5918 -- (on scope exit).
5920 -- If we encounter the partial view before the full view (e.g. when
5921 -- freezing from another scope), we freeze the full view, and then
5922 -- set the pointers appropriately since we cannot rely on swapping to
5923 -- fix things up (subtypes in an outer scope might not get swapped).
5925 -- If the full view is itself private, the above requirements apply
5926 -- to the underlying full view instead of the full view. But there is
5927 -- no swapping mechanism for the underlying full view so we need to
5928 -- set the pointers appropriately in both cases.
5932 then
5933 -- The construction of the dispatch table associated with library
5934 -- level tagged types forces freezing of all the primitives of the
5935 -- type, which may cause premature freezing of the partial view.
5936 -- For example:
5938 -- package Pkg is
5939 -- type T is tagged private;
5940 -- type DT is new T with private;
5941 -- procedure Prim (X : in out T; Y : in out DT'Class);
5942 -- private
5943 -- type T is tagged null record;
5944 -- Obj : T;
5945 -- type DT is new T with null record;
5946 -- end;
5948 -- In this case the type will be frozen later by the usual
5949 -- mechanism: an object declaration, an instantiation, or the
5950 -- end of a declarative part.
5954 then
5958 -- Case of full view present
5962 -- If full view has already been frozen, then no further
5963 -- processing is required
5969 -- Otherwise freeze full view and patch the pointers so that
5970 -- the freeze node will elaborate both views in the back end.
5971 -- However, if full view is itself private, freeze underlying
5972 -- full view instead and patch the pointers so that the freeze
5973 -- node will elaborate the three views in the back end.
5975 else
5976 declare
5979 begin
5982 then
5990 then
5994 Inherit_Freeze_Node
5997 else
6007 Inherit_Freeze_Node
6010 else
6011 -- {Incomplete,Private}_Subtypes with Full_Views
6012 -- constrained by discriminants.
6023 -- AI-117 requires that the convention of a partial view be the
6024 -- same as the convention of the full view. Note that this is a
6025 -- recognized breach of privacy, but it's essential for logical
6026 -- consistency of representation, and the lack of a rule in
6027 -- RM95 was an oversight.
6034 -- Size information is copied from the full view to the
6035 -- incomplete or private view for consistency.
6037 -- We skip this is the full view is not a type. This is very
6038 -- strange of course, and can only happen as a result of
6039 -- certain illegalities, such as a premature attempt to derive
6040 -- from an incomplete type.
6049 -- Case of underlying full view present
6053 then
6058 -- Patch the pointers so that the freeze node will elaborate
6059 -- both views in the back end.
6065 Inherit_Freeze_Node
6068 else
6078 -- Case of no full view present. If entity is derived or subtype,
6079 -- it is safe to freeze, correctness depends on the frozen status
6080 -- of parent. Otherwise it is either premature usage, or a Taft
6081 -- amendment type, so diagnosis is at the point of use and the
6082 -- type might be frozen later.
6087 else
6093 -- For access subprogram, freeze types of all formals, the return
6094 -- type was already frozen, since it is the Etype of the function.
6095 -- Formal types can be tagged Taft amendment types, but otherwise
6096 -- they cannot be incomplete.
6103 then
6107 -- AI05-151: Incomplete types are allowed in access to
6108 -- subprogram specifications.
6111 Error_Msg_NE
6122 -- For access to a protected subprogram, freeze the equivalent type
6123 -- (however this is not set if we are not generating code or if this
6124 -- is an anonymous type used just for resolution).
6132 -- Generic types are never seen by the back-end, and are also not
6133 -- processed by the expander (since the expander is turned off for
6134 -- generic processing), so we never need freeze nodes for them.
6140 -- Some special processing for non-generic types to complete
6141 -- representation details not known till the freeze point.
6146 -- Some error checks required for ordinary fixed-point type. Defer
6147 -- these till the freeze-point since we need the small and range
6148 -- values. We only do these checks for base types
6153 Error_Msg_N
6158 Error_Msg_N
6164 Error_Msg_N
6170 Error_Msg_N
6182 and then Warn_On_Suspicious_Modulus_Value
6183 then
6187 -- The pool applies to named and anonymous access types, but not
6188 -- to subprogram and to internal types generated for 'Access
6189 -- references.
6194 then
6195 -- If a pragma Default_Storage_Pool applies, and this type has no
6196 -- Storage_Pool or Storage_Size clause (which must have occurred
6197 -- before the freezing point), then use the default. This applies
6198 -- only to base types.
6200 -- None of this applies to access to subprograms, for which there
6201 -- are clearly no pools.
6207 then
6208 -- Case of pragma Default_Storage_Pool (null)
6213 -- Case of pragma Default_Storage_Pool (storage_pool_NAME)
6215 else
6220 -- Check restriction for standard storage pool
6226 -- Deal with error message for pure access type. This is not an
6227 -- error in Ada 2005 if there is no pool (see AI-366).
6233 then
6237 Error_Msg_N
6241 Error_Msg_N
6244 else
6245 Error_Msg_N
6252 -- Case of composite types
6256 -- AI-117 requires that all new primitives of a tagged type must
6257 -- inherit the convention of the full view of the type. Inherited
6258 -- and overriding operations are defined to inherit the convention
6259 -- of their parent or overridden subprogram (also specified in
6260 -- AI-117), which will have occurred earlier (in Derive_Subprogram
6261 -- and New_Overloaded_Entity). Here we set the convention of
6262 -- primitives that are still convention Ada, which will ensure
6263 -- that any new primitives inherit the type's convention. Class-
6264 -- wide types can have a foreign convention inherited from their
6265 -- specific type, but are excluded from this since they don't have
6266 -- any associated primitives.
6271 then
6272 declare
6276 begin
6288 -- If the type is a simple storage pool type, then this is where
6289 -- we attempt to locate and validate its Allocate, Deallocate, and
6290 -- Storage_Size operations (the first is required, and the latter
6291 -- two are optional). We also verify that the full type for a
6292 -- private type is allowed to be a simple storage pool type.
6296 then
6297 -- If the type is marked Has_Private_Declaration, then this is
6298 -- a full type for a private type that was specified with the
6299 -- pragma Simple_Storage_Pool_Type, and here we ensure that the
6300 -- pragma is allowed for the full type (for example, it can't
6301 -- be an array type, or a nonlimited record type).
6306 then
6308 Error_Msg_N
6319 procedure Validate_Simple_Pool_Op_Formal
6326 -- Validate one formal Pool_Op_Formal of the candidate pool
6327 -- operation Pool_Op. The formal must be of Expected_Type
6328 -- and have mode Expected_Mode. OK_Formal will be set to
6329 -- False if the formal doesn't match. If OK_Formal is False
6330 -- on entry, then the formal will effectively be ignored
6331 -- (because validation of the pool op has already failed).
6332 -- Upon return, Pool_Op_Formal will be updated to the next
6333 -- formal, if any.
6335 procedure Validate_Simple_Pool_Operation
6337 -- Search for and validate a simple pool operation with the
6338 -- name Op_Name. If the name is Allocate, then there must be
6339 -- exactly one such primitive operation for the simple pool
6340 -- type. If the name is Deallocate or Storage_Size, then
6341 -- there can be at most one such primitive operation. The
6342 -- profile of the located primitive must conform to what
6343 -- is expected for each operation.
6345 ------------------------------------
6346 -- Validate_Simple_Pool_Op_Formal --
6347 ------------------------------------
6349 procedure Validate_Simple_Pool_Op_Formal
6356 is
6357 begin
6358 -- If OK_Formal is False on entry, then simply ignore
6359 -- the formal, because an earlier formal has already
6360 -- been flagged.
6365 -- If no formal is passed in, then issue an error for a
6366 -- missing formal.
6369 Error_Msg_NE
6379 -- If the pool type was expected for this formal, then
6380 -- this will not be considered a candidate operation
6381 -- for the simple pool, so we unset OK_Formal so that
6382 -- the op and any later formals will be ignored.
6389 else
6390 Error_Msg_NE
6397 -- Issue error if formal's mode is not the expected one
6400 Error_Msg_N
6402 Pool_Op_Formal);
6405 -- Advance to the next formal
6410 ------------------------------------
6411 -- Validate_Simple_Pool_Operation --
6412 ------------------------------------
6414 procedure Validate_Simple_Pool_Operation
6416 is
6422 begin
6423 pragma Assert
6425 Name_Deallocate,
6426 Name_Storage_Size));
6430 -- For each homonym declared immediately in the scope
6431 -- of the simple storage pool type, determine whether
6432 -- the homonym is an operation of the pool type, and,
6433 -- if so, check that its profile is as expected for
6434 -- a simple pool operation of that name.
6440 then
6445 -- The first parameter must be of the pool type
6446 -- in order for the operation to qualify.
6449 Validate_Simple_Pool_Op_Formal
6452 else
6453 Validate_Simple_Pool_Op_Formal
6458 -- If another operation with this name has already
6459 -- been located for the type, then flag an error,
6460 -- since we only allow the type to have a single
6461 -- such primitive.
6464 Error_Msg_NE
6469 -- In the case of Allocate and Deallocate, a formal
6470 -- of type System.Address is required.
6473 Validate_Simple_Pool_Op_Formal
6478 Validate_Simple_Pool_Op_Formal
6483 -- In the case of Allocate and Deallocate, formals
6484 -- of type Storage_Count are required as the third
6485 -- and fourth parameters.
6488 Validate_Simple_Pool_Op_Formal
6491 Validate_Simple_Pool_Op_Formal
6496 -- If no mismatched formals have been found (Is_OK)
6497 -- and no excess formals are present, then this
6498 -- operation has been validated, so record it.
6508 -- There must be a valid Allocate operation for the type,
6509 -- so issue an error if none was found.
6513 then
6519 -- Simple pool operations can't be abstract
6522 Error_Msg_N
6527 -- The Storage_Size operation must be a function with
6528 -- Storage_Count as its result type.
6532 Error_Msg_N
6536 Error_Msg_NE
6541 -- Allocate and Deallocate must be procedures
6544 Error_Msg_N
6550 -- Start of processing for Validate_Simple_Pool_Ops
6552 begin
6560 -- Now that all types from which E may depend are frozen, see if the
6561 -- size is known at compile time, if it must be unsigned, or if
6562 -- strict alignment is required
6571 -- Do not allow a size clause for a type which does not have a size
6572 -- that is known at compile time
6576 then
6577 -- Suppress this message if errors posted on E, even if we are
6578 -- in all errors mode, since this is often a junk message
6581 Error_Msg_N
6587 -- Now we set/verify the representation information, in particular
6588 -- the size and alignment values. This processing is not required for
6589 -- generic types, since generic types do not play any part in code
6590 -- generation, and so the size and alignment values for such types
6591 -- are irrelevant. Ditto for types declared within a generic unit,
6592 -- which may have components that depend on generic parameters, and
6593 -- that will be recreated in an instance.
6598 -- Otherwise we call the layout procedure
6600 else
6604 -- If this is an access to subprogram whose designated type is itself
6605 -- a subprogram type, the return type of this anonymous subprogram
6606 -- type must be decorated as well.
6610 then
6614 -- If the type has a Defaut_Value/Default_Component_Value aspect,
6615 -- this is where we analye the expression (after the type is frozen,
6616 -- since in the case of Default_Value, we are analyzing with the
6617 -- type itself, and we treat Default_Component_Value similarly for
6618 -- the sake of uniformity).
6621 declare
6626 begin
6631 else
6642 Flag_Non_Static_Expr
6649 -- End of freeze processing for type entities
6652 -- Here is where we logically freeze the current entity. If it has a
6653 -- freeze node, then this is the point at which the freeze node is
6654 -- linked into the result list.
6658 -- If a freeze node is already allocated, use it, otherwise allocate
6659 -- a new one. The preallocation happens in the case of anonymous base
6660 -- types, where we preallocate so that we can set First_Subtype_Link.
6661 -- Note that we reset the Sloc to the current freeze location.
6667 else
6678 -- A final pass over record types with discriminants. If the type
6679 -- has an incomplete declaration, there may be constrained access
6680 -- subtypes declared elsewhere, which do not depend on the discrimi-
6681 -- nants of the type, and which are used as component types (i.e.
6682 -- the full view is a recursive type). The designated types of these
6683 -- subtypes can only be elaborated after the type itself, and they
6684 -- need an itype reference.
6687 declare
6692 begin
6702 then
6714 -- When a type is frozen, the first subtype of the type is frozen as
6715 -- well (RM 13.14(15)). This has to be done after freezing the type,
6716 -- since obviously the first subtype depends on its own base type.
6721 -- If we just froze a tagged non-class wide record, then freeze the
6722 -- corresponding class-wide type. This must be done after the tagged
6723 -- type itself is frozen, because the class-wide type refers to the
6724 -- tagged type which generates the class.
6729 then
6736 -- Special handling for subprograms
6740 -- If subprogram has address clause then reset Is_Public flag, since
6741 -- we do not want the backend to generate external references.
6745 then
6756 -----------------------------
6757 -- Freeze_Enumeration_Type --
6758 -----------------------------
6761 begin
6762 -- By default, if no size clause is present, an enumeration type with
6763 -- Convention C is assumed to interface to a C enum, and has integer
6764 -- size. This applies to types. For subtypes, verify that its base
6765 -- type has no size clause either. Treat other foreign conventions
6766 -- in the same way, and also make sure alignment is set right.
6773 -- Don't do this if Short_Enums on target
6775 and then not Target_Short_Enums
6776 then
6780 -- Normal Ada case or size clause present or not Long_C_Enums on target
6782 else
6783 -- If the enumeration type interfaces to C, and it has a size clause
6784 -- that specifies less than int size, it warrants a warning. The
6785 -- user may intend the C type to be an enum or a char, so this is
6786 -- not by itself an error that the Ada compiler can detect, but it
6787 -- it is a worth a heads-up. For Boolean and Character types we
6788 -- assume that the programmer has the proper C type in mind.
6796 -- Don't do this if Short_Enums on target
6798 and then not Target_Short_Enums
6799 then
6800 Error_Msg_N
6808 -----------------------
6809 -- Freeze_Expression --
6810 -----------------------
6821 -- This flag is set true if the entity must be frozen outside the
6822 -- current subprogram. This happens in the case of expander generated
6823 -- subprograms (_Init_Proc, _Input, _Output, _Read, _Write) which do
6824 -- not freeze all entities like other bodies, but which nevertheless
6825 -- may reference entities that have to be frozen before the body and
6826 -- obviously cannot be frozen inside the body.
6829 -- If the expression is an array aggregate, the type of the component
6830 -- expressions is also frozen. If the component type is an access type
6831 -- and the expressions include allocators, the designed type is frozen
6832 -- as well.
6835 -- Given an N_Handled_Sequence_Of_Statements node N, determines whether
6836 -- it is the handled statement sequence of an expander-generated
6837 -- subprogram (init proc, stream subprogram, or renaming as body).
6838 -- If so, this is not a freezing context.
6840 -----------------------------------------
6841 -- Find_Aggregate_Component_Desig_Type --
6842 -----------------------------------------
6848 begin
6874 ----------------------
6875 -- In_Expanded_Body --
6876 ----------------------
6882 begin
6885 else
6892 else
6895 -- The following are expander-created bodies, or bodies that
6896 -- are not freeze points.
6905 N_Subprogram_Renaming_Declaration,
6906 N_Expression_Function))
6907 then
6909 else
6915 -- Start of processing for Freeze_Expression
6917 begin
6918 -- Immediate return if freezing is inhibited. This flag is set by the
6919 -- analyzer to stop freezing on generated expressions that would cause
6920 -- freezing if they were in the source program, but which are not
6921 -- supposed to freeze, since they are created.
6927 -- If expression is non-static, then it does not freeze in a default
6928 -- expression, see section "Handling of Default Expressions" in the
6929 -- spec of package Sem for further details. Note that we have to make
6930 -- sure that we actually have a real expression (if we have a subtype
6931 -- indication, we can't test Is_OK_Static_Expression). However, we
6932 -- exclude the case of the prefix of an attribute of a static scalar
6933 -- subtype from this early return, because static subtype attributes
6934 -- should always cause freezing, even in default expressions, but
6935 -- the attribute may not have been marked as static yet (because in
6936 -- Resolve_Attribute, the call to Eval_Attribute follows the call of
6937 -- Freeze_Expression on the prefix).
6939 if In_Spec_Exp
6946 then
6950 -- Freeze type of expression if not frozen already
6958 -- Base type may be an derived numeric type that is frozen at
6959 -- the point of declaration, but first_subtype is still unfrozen.
6966 -- For entity name, freeze entity if not frozen already. A special
6967 -- exception occurs for an identifier that did not come from source.
6968 -- We don't let such identifiers freeze a non-internal entity, i.e.
6969 -- an entity that did come from source, since such an identifier was
6970 -- generated by the expander, and cannot have any semantic effect on
6971 -- the freezing semantics. For example, this stops the parameter of
6972 -- an initialization procedure from freezing the variable.
6979 then
6986 else
6990 -- For an allocator freeze designated type if not frozen already
6992 -- For an aggregate whose component type is an access type, freeze the
6993 -- designated type now, so that its freeze does not appear within the
6994 -- loop that might be created in the expansion of the aggregate. If the
6995 -- designated type is a private type without full view, the expression
6996 -- cannot contain an allocator, so the type is not frozen.
6998 -- For a function, we freeze the entity when the subprogram declaration
6999 -- is frozen, but a function call may appear in an initialization proc.
7000 -- before the declaration is frozen. We need to generate the extra
7001 -- formals, if any, to ensure that the expansion of the call includes
7002 -- the proper actuals. This only applies to Ada subprograms, not to
7003 -- imported ones.
7014 then
7016 -- Check whether aggregate includes allocators.
7021 when N_Indexed_Component
7022 | N_Selected_Component
7023 | N_Slice
7024 =>
7034 then
7045 then
7049 -- All done if nothing needs freezing
7054 then
7058 -- Examine the enclosing context by climbing the parent chain. The
7059 -- traversal serves two purposes - to detect scenarios where freezeing
7060 -- is not needed and to find the proper insertion point for the freeze
7061 -- nodes. Although somewhat similar to Insert_Actions, this traversal
7062 -- is freezing semantics-sensitive. Inserting freeze nodes blindly in
7063 -- the tree may result in types being frozen too early.
7066 loop
7069 -- If we don't have a parent, then we are not in a well-formed tree.
7070 -- This is an unusual case, but there are some legitimate situations
7071 -- in which this occurs, notably when the expressions in the range of
7072 -- a type declaration are resolved. We simply ignore the freeze
7073 -- request in this case. Is this right ???
7079 -- See if we have got to an appropriate point in the tree
7083 -- A special test for the exception of (RM 13.14(8)) for the case
7084 -- of per-object expressions (RM 3.8(18)) occurring in component
7085 -- definition or a discrete subtype definition. Note that we test
7086 -- for a component declaration which includes both cases we are
7087 -- interested in, and furthermore the tree does not have explicit
7088 -- nodes for either of these two constructs.
7092 -- The case we want to test for here is an identifier that is
7093 -- a per-object expression, this is either a discriminant that
7094 -- appears in a context other than the component declaration
7095 -- or it is a reference to the type of the enclosing construct.
7097 -- For either of these cases, we skip the freezing
7099 if not In_Spec_Expression
7102 then
7103 -- We recognize the discriminant case by just looking for
7104 -- a reference to a discriminant. It can only be one for
7105 -- the enclosing construct. Skip freezing in this case.
7110 -- For the case of a reference to the enclosing record,
7111 -- (or task or protected type), we look for a type that
7112 -- matches the current scope.
7119 -- If we have an enumeration literal that appears as the choice in
7120 -- the aggregate of an enumeration representation clause, then
7121 -- freezing does not occur (RM 13.14(10)).
7125 -- The case we are looking for is an enumeration literal
7129 then
7130 -- If enumeration literal appears directly as the choice,
7131 -- do not freeze (this is the normal non-overloaded case)
7135 then
7138 -- If enumeration literal appears as the name of function
7139 -- which is the choice, then also do not freeze. This
7140 -- happens in the overloaded literal case, where the
7141 -- enumeration literal is temporarily changed to a function
7142 -- call for overloading analysis purposes.
7145 and then
7147 and then
7149 then
7154 -- Normally if the parent is a handled sequence of statements,
7155 -- then the current node must be a statement, and that is an
7156 -- appropriate place to insert a freeze node.
7160 -- An exception occurs when the sequence of statements is for
7161 -- an expander generated body that did not do the usual freeze
7162 -- all operation. In this case we usually want to freeze
7163 -- outside this body, not inside it, and we skip past the
7164 -- subprogram body that we are inside.
7167 declare
7171 begin
7172 -- Freeze the entity only when it is declared inside the
7173 -- body of the expander generated procedure. This case
7174 -- is recognized by the scope of the entity or its type,
7175 -- which is either the spec for some enclosing body, or
7176 -- (in the case of init_procs, for which there are no
7177 -- separate specs) the current scope.
7183 or else
7185 then
7191 then
7196 -- An expression function may act as a completion of
7197 -- a function declaration. As such, it can reference
7198 -- entities declared between the two views:
7200 -- Hidden []; -- 1
7201 -- function F return ...;
7202 -- private
7203 -- function Hidden return ...;
7204 -- function F return ... is (Hidden); -- 2
7206 -- Refering to the example above, freezing the expression
7207 -- of F (2) would place Hidden's freeze node (1) in the
7208 -- wrong place. Avoid explicit freezing and let the usual
7209 -- scenarios do the job - for example, reaching the end
7210 -- of the private declarations, or a call to F.
7213 N_Expression_Function
7214 then
7217 -- Freeze outside the body
7219 else
7225 -- Here if normal case where we are in handled statement
7226 -- sequence and want to do the insertion right there.
7228 else
7232 -- If parent is a body or a spec or a block, then the current node
7233 -- is a statement or declaration and we can insert the freeze node
7234 -- before it.
7236 when N_Block_Statement
7237 | N_Entry_Body
7238 | N_Package_Body
7239 | N_Package_Specification
7240 | N_Protected_Body
7241 | N_Subprogram_Body
7242 | N_Task_Body
7243 =>
7246 -- The expander is allowed to define types in any statements list,
7247 -- so any of the following parent nodes also mark a freezing point
7248 -- if the actual node is in a list of statements or declarations.
7250 when N_Abortable_Part
7251 | N_Accept_Alternative
7252 | N_And_Then
7253 | N_Case_Statement_Alternative
7254 | N_Compilation_Unit_Aux
7255 | N_Conditional_Entry_Call
7256 | N_Delay_Alternative
7257 | N_Elsif_Part
7258 | N_Entry_Call_Alternative
7259 | N_Exception_Handler
7260 | N_Extended_Return_Statement
7261 | N_Freeze_Entity
7262 | N_If_Statement
7263 | N_Or_Else
7264 | N_Selective_Accept
7265 | N_Triggering_Alternative
7266 =>
7269 -- Freeze nodes produced by an expression coming from the Actions
7270 -- list of a N_Expression_With_Actions node must remain within the
7271 -- Actions list. Inserting the freeze nodes further up the tree
7272 -- may lead to use before declaration issues in the case of array
7273 -- types.
7278 then
7282 -- Note: N_Loop_Statement is a special case. A type that appears
7283 -- in the source can never be frozen in a loop (this occurs only
7284 -- because of a loop expanded by the expander), so we keep on
7285 -- going. Otherwise we terminate the search. Same is true of any
7286 -- entity which comes from source. (if they have predefined type,
7287 -- that type does not appear to come from source, but the entity
7288 -- should not be frozen here).
7294 -- For all other cases, keep looking at parents
7300 -- We fall through the case if we did not yet find the proper
7301 -- place in the free for inserting the freeze node, so climb.
7306 -- If the expression appears in a record or an initialization procedure,
7307 -- the freeze nodes are collected and attached to the current scope, to
7308 -- be inserted and analyzed on exit from the scope, to insure that
7309 -- generated entities appear in the correct scope. If the expression is
7310 -- a default for a discriminant specification, the scope is still void.
7311 -- The expression can also appear in the discriminant part of a private
7312 -- or concurrent type.
7314 -- If the expression appears in a constrained subcomponent of an
7315 -- enclosing record declaration, the freeze nodes must be attached to
7316 -- the outer record type so they can eventually be placed in the
7317 -- enclosing declaration list.
7319 -- The other case requiring this special handling is if we are in a
7320 -- default expression, since in that case we are about to freeze a
7321 -- static type, and the freeze scope needs to be the outer scope, not
7322 -- the scope of the subprogram with the default parameter.
7324 -- For default expressions and other spec expressions in generic units,
7325 -- the Move_Freeze_Nodes mechanism (see sem_ch12.adb) takes care of
7326 -- placing them at the proper place, after the generic unit.
7329 or else Freeze_Outside
7334 then
7335 declare
7340 begin
7353 -- The current scope may be that of a constrained component of
7354 -- an enclosing record declaration, or of a loop of an enclosing
7355 -- quantified expression, which is above the current scope in the
7356 -- scope stack. Indeed in the context of a quantified expression,
7357 -- a scope is created and pushed above the current scope in order
7358 -- to emulate the loop-like behavior of the quantified expression.
7359 -- If the expression is within a top-level pragma, as for a pre-
7360 -- condition on a library-level subprogram, nothing to do.
7365 N_Quantified_Expression)
7366 then
7373 Freeze_Nodes;
7374 else
7384 -- Now we have the right place to do the freezing. First, a special
7385 -- adjustment, if we are in spec-expression analysis mode, these freeze
7386 -- actions must not be thrown away (normally all inserted actions are
7387 -- thrown away in this mode. However, the freeze actions are from static
7388 -- expressions and one of the important reasons we are doing this
7389 -- special analysis is to get these freeze actions. Therefore we turn
7390 -- off the In_Spec_Expression mode to propagate these freeze actions.
7391 -- This also means they get properly analyzed and expanded.
7395 -- Freeze the designated type of an allocator (RM 13.14(13))
7401 -- Freeze type of expression (RM 13.14(10)). Note that we took care of
7402 -- the enumeration representation clause exception in the loop above.
7408 -- Freeze name if one is present (RM 13.14(11))
7414 -- Restore In_Spec_Expression flag
7419 -----------------------------
7420 -- Freeze_Fixed_Point_Type --
7421 -----------------------------
7423 -- Certain fixed-point types and subtypes, including implicit base types
7424 -- and declared first subtypes, have not yet set up a range. This is
7425 -- because the range cannot be set until the Small and Size values are
7426 -- known, and these are not known till the type is frozen.
7428 -- To signal this case, Scalar_Range contains an unanalyzed syntactic range
7429 -- whose bounds are unanalyzed real literals. This routine will recognize
7430 -- this case, and transform this range node into a properly typed range
7431 -- with properly analyzed and resolved values.
7448 -- Save original bounds (for shaving tests)
7451 -- Actual size chosen
7454 -- Returns size of type with given bounds. Also leaves these
7455 -- bounds set as the current bounds of the Typ.
7457 -----------
7458 -- Fsize --
7459 -----------
7462 begin
7468 -- Start of processing for Freeze_Fixed_Point_Type
7470 begin
7471 -- If Esize of a subtype has not previously been set, set it now
7478 else
7483 -- Immediate return if the range is already analyzed. This means that
7484 -- the range is already set, and does not need to be computed by this
7485 -- routine.
7491 -- Immediate return if either of the bounds raises Constraint_Error
7495 then
7505 -- Ordinary fixed-point case
7509 -- For the ordinary fixed-point case, we are allowed to fudge the
7510 -- end-points up or down by small. Generally we prefer to fudge up,
7511 -- i.e. widen the bounds for non-model numbers so that the end points
7512 -- are included. However there are cases in which this cannot be
7513 -- done, and indeed cases in which we may need to narrow the bounds.
7514 -- The following circuit makes the decision.
7516 -- Note: our terminology here is that Incl_EP means that the bounds
7517 -- are widened by Small if necessary to include the end points, and
7518 -- Excl_EP means that the bounds are narrowed by Small to exclude the
7519 -- end-points if this reduces the size.
7521 -- Note that in the Incl case, all we care about is including the
7522 -- end-points. In the Excl case, we want to narrow the bounds as
7523 -- much as permitted by the RM, to give the smallest possible size.
7540 begin
7541 -- First step. Base types are required to be symmetrical. Right
7542 -- now, the base type range is a copy of the first subtype range.
7543 -- This will be corrected before we are done, but right away we
7544 -- need to deal with the case where both bounds are non-negative.
7545 -- In this case, we set the low bound to the negative of the high
7546 -- bound, to make sure that the size is computed to include the
7547 -- required sign. Note that we do not need to worry about the
7548 -- case of both bounds negative, because the sign will be dealt
7549 -- with anyway. Furthermore we can't just go making such a bound
7550 -- symmetrical, since in a twos-complement system, there is an
7551 -- extra negative value which could not be accommodated on the
7552 -- positive side.
7557 then
7562 -- Compute the fudged bounds. If the number is a model number,
7563 -- then we do nothing to include it, but we are allowed to backoff
7564 -- to the next adjacent model number when we exclude it. If it is
7565 -- not a model number then we straddle the two values with the
7566 -- model numbers on either side.
7572 else
7576 -- The low value excluding the end point is Small greater, but
7577 -- we do not do this exclusion if the low value is positive,
7578 -- since it can't help the size and could actually hurt by
7579 -- crossing the high bound.
7584 -- If the value went from negative to zero, then we have the
7585 -- case where Loval_Incl_EP is the model number just below
7586 -- zero, so we want to stick to the negative value for the
7587 -- base type to maintain the condition that the size will
7588 -- include signed values.
7592 then
7596 else
7600 -- Similar processing for upper bound and high value
7606 else
7612 else
7616 -- One further adjustment is needed. In the case of subtypes, we
7617 -- cannot go outside the range of the base type, or we get
7618 -- peculiarities, and the base type range is already set. This
7619 -- only applies to the Incl values, since clearly the Excl values
7620 -- are already as restricted as they are allowed to be.
7627 -- Get size including and excluding end points
7632 -- No need to exclude end-points if it does not reduce size
7642 -- Now we set the actual size to be used. We want to use the
7643 -- bounds fudged up to include the end-points but only if this
7644 -- can be done without violating a specifically given size
7645 -- size clause or causing an unacceptable increase in size.
7647 -- Case of size clause given
7651 -- Use the inclusive size only if it is consistent with
7652 -- the explicitly specified size.
7659 -- If the inclusive size is too large, we try excluding
7660 -- the end-points (will be caught later if does not work).
7662 else
7668 -- Case of size clause not given
7670 else
7671 -- If we have a base type whose corresponding first subtype
7672 -- has an explicit size that is large enough to include our
7673 -- end-points, then do so. There is no point in working hard
7674 -- to get a base type whose size is smaller than the specified
7675 -- size of the first subtype.
7681 then
7686 -- If excluding the end-points makes the size smaller and
7687 -- results in a size of 8,16,32,64, then we take the smaller
7688 -- size. For the 64 case, this is compulsory. For the other
7689 -- cases, it seems reasonable. We like to include end points
7690 -- if we can, but not at the expense of moving to the next
7691 -- natural boundary of size.
7695 then
7700 -- Otherwise we can definitely include the end points
7702 else
7708 -- One pathological case: normally we never fudge a low bound
7709 -- down, since it would seem to increase the size (if it has
7710 -- any effect), but for ranges containing single value, or no
7711 -- values, the high bound can be small too large. Consider:
7713 -- type t is delta 2.0**(-14)
7714 -- range 131072.0 .. 0;
7716 -- That lower bound is *just* outside the range of 32 bits, and
7717 -- does need fudging down in this case. Note that the bounds
7718 -- will always have crossed here, since the high bound will be
7719 -- fudged down if necessary, as in the case of:
7721 -- type t is delta 2.0**(-14)
7722 -- range 131072.0 .. 131072.0;
7724 -- So we detect the situation by looking for crossed bounds,
7725 -- and if the bounds are crossed, and the low bound is greater
7726 -- than zero, we will always back it off by small, since this
7727 -- is completely harmless.
7734 -- And of course, we need to do exactly the same parallel
7735 -- fudge for flat ranges in the negative region.
7748 -- For the decimal case, none of this fudging is required, since there
7749 -- are no end-point problems in the decimal case (the end-points are
7750 -- always included).
7752 else
7756 -- At this stage, the actual size has been calculated and the proper
7757 -- required bounds are stored in the low and high bounds.
7761 Error_Msg_N
7763 Typ);
7767 -- Check size against explicit given size
7773 Error_Msg_NE
7777 else
7781 -- Increase size to next natural boundary if no size clause given
7783 else
7790 else
7798 -- If we have a base type, then expand the bounds so that they extend to
7799 -- the full width of the allocated size in bits, to avoid junk range
7800 -- checks on intermediate computations.
7807 -- Final step is to reanalyze the bounds using the proper type
7808 -- and set the Corresponding_Integer_Value fields of the literals.
7814 -- Resolve with universal fixed if the base type, and the base type if
7815 -- it is a subtype. Note we can't resolve the base type with itself,
7816 -- that would be a reference before definition.
7820 else
7824 -- Set corresponding integer value for bound
7826 Set_Corresponding_Integer_Value
7829 -- Similar processing for high bound
7837 else
7841 Set_Corresponding_Integer_Value
7844 -- Set type of range to correspond to bounds
7848 -- Set Esize to calculated size if not set already
7854 -- Set RM_Size if not already set. If already set, check value
7856 declare
7859 begin
7864 Error_Msg_NE
7869 else
7874 -- Check for shaving
7878 -- In SPARK mode the given bounds must be strictly representable
7882 Error_Msg_NE
7888 Error_Msg_NE
7893 else
7895 Error_Msg_N
7897 Error_Msg_N
7902 Error_Msg_N
7904 Typ);
7905 Error_Msg_N
7912 ------------------
7913 -- Freeze_Itype --
7914 ------------------
7919 begin
7928 --------------------------
7929 -- Freeze_Static_Object --
7930 --------------------------
7935 -- Exception raised if the type of a static object cannot be made
7936 -- static. This happens if the type depends on non-global objects.
7939 -- Called to ensure that an expression used as part of a type definition
7940 -- is statically allocatable, which means that the expression type is
7941 -- statically allocatable, and the expression is either static, or a
7942 -- reference to a library level constant.
7945 -- Called to mark a type as static, checking that it is possible
7946 -- to set the type as static. If it is not possible, then the
7947 -- exception Cannot_Be_Static is raised.
7949 -----------------------------
7950 -- Ensure_Expression_Is_SA --
7951 -----------------------------
7956 begin
7968 then
7976 -----------------------
7977 -- Ensure_Type_Is_SA --
7978 -----------------------
7984 begin
7985 -- If type is library level, we are all set
7991 -- We are also OK if the type already marked as statically allocated,
7992 -- which means we processed it before.
7998 -- Mark type as statically allocated
8002 -- Check that it is safe to statically allocate this type
8020 declare
8024 begin
8036 else
8045 then
8064 else
8069 -- Start of processing for Freeze_Static_Object
8071 begin
8074 exception
8077 -- If the object that cannot be static is imported or exported, then
8078 -- issue an error message saying that this object cannot be imported
8079 -- or exported. If it has an address clause it is an overlay in the
8080 -- current partition and the static requirement is not relevant.
8081 -- Do not issue any error message when ignoring rep clauses.
8088 Error_Msg_N
8092 -- Otherwise must be exported, something is wrong if compiler
8093 -- is marking something as statically allocated which cannot be).
8096 Error_Msg_N
8101 -----------------------
8102 -- Freeze_Subprogram --
8103 -----------------------
8107 -- Set the conventions of all anonymous access-to-subprogram formals and
8108 -- result subtype of subprogram Subp_Id to the convention of Subp_Id.
8110 ----------------------------
8111 -- Set_Profile_Convention --
8112 ----------------------------
8118 -- Set the convention of anonymous access-to-subprogram type Typ and
8119 -- its designated type to Conv.
8121 -------------------------
8122 -- Set_Type_Convention --
8123 -------------------------
8126 begin
8127 -- Set the convention on both the anonymous access-to-subprogram
8128 -- type and the subprogram type it points to because both types
8129 -- participate in conformance-related checks.
8137 -- Local variables
8141 -- Start of processing for Set_Profile_Convention
8143 begin
8155 -- Local variables
8160 -- Start of processing for Freeze_Subprogram
8162 begin
8163 -- Subprogram may not have an address clause unless it is imported
8167 Error_Msg_N
8173 -- Reset the Pure indication on an imported subprogram unless an
8174 -- explicit Pure_Function pragma was present or the subprogram is an
8175 -- intrinsic. We do this because otherwise it is an insidious error
8176 -- to call a non-pure function from pure unit and have calls
8177 -- mysteriously optimized away. What happens here is that the Import
8178 -- can bypass the normal check to ensure that pure units call only pure
8179 -- subprograms.
8181 -- The reason for the intrinsic exception is that in general, intrinsic
8182 -- functions (such as shifts) are pure anyway. The only exceptions are
8183 -- the intrinsics in GNAT.Source_Info, and that unit is not marked Pure
8184 -- in any case, so no problem arises.
8190 then
8194 -- We also reset the Pure indication on a subprogram with an Address
8195 -- parameter, because the parameter may be used as a pointer and the
8196 -- referenced data may change even if the address value does not.
8198 -- Note that if the programmer gave an explicit Pure_Function pragma,
8199 -- then we believe the programmer, and leave the subprogram Pure. We
8200 -- also suppress this check on run-time files.
8206 then
8210 -- Ensure that all anonymous access-to-subprogram types inherit the
8211 -- convention of their related subprogram (RM 6.3.1 13.1/3). This is
8212 -- not done for a defaulted convention Ada because those types also
8213 -- default to Ada. Convention Protected must not be propagated when
8214 -- the subprogram is an entry because this would be illegal. The only
8215 -- way to force convention Protected on these kinds of types is to
8216 -- include keyword "protected" in the access definition.
8220 then
8224 -- For non-foreign convention subprograms, this is where we create
8225 -- the extra formals (for accessibility level and constrained bit
8226 -- information). We delay this till the freeze point precisely so
8227 -- that we know the convention.
8236 -- If this is convention Ada and a Valued_Procedure, that's odd
8241 and then Warn_On_Export_Import
8242 then
8243 Error_Msg_N
8248 -- Case of foreign convention
8250 else
8253 -- For foreign conventions, warn about return of unconstrained array
8258 -- If no return type, probably some other error, e.g. a
8259 -- missing full declaration, so ignore.
8264 -- If the return type is generic, we have emitted a warning
8265 -- earlier on, and there is nothing else to check here. Specific
8266 -- instantiations may lead to erroneous behavior.
8271 -- Display warning if returning unconstrained array
8276 -- Check appropriate warning is enabled (should we check for
8277 -- Warnings (Off) on specific entities here, probably so???)
8279 and then Warn_On_Export_Import
8280 then
8281 Error_Msg_N
8288 -- If any of the formals for an exported foreign convention
8289 -- subprogram have defaults, then emit an appropriate warning since
8290 -- this is odd (default cannot be used from non-Ada code)
8295 if Warn_On_Export_Import
8297 then
8298 Error_Msg_N
8308 -- Pragma Inline_Always is disallowed for dispatching subprograms
8309 -- because the address of such subprograms is saved in the dispatch
8310 -- table to support dispatching calls, and dispatching calls cannot
8311 -- be inlined. This is consistent with the restriction against using
8312 -- 'Access or 'Address on an Inline_Always subprogram.
8316 then
8317 Error_Msg_N
8321 -- Because of the implicit representation of inherited predefined
8322 -- operators in the front-end, the overriding status of the operation
8323 -- may be affected when a full view of a type is analyzed, and this is
8324 -- not captured by the analysis of the corresponding type declaration.
8325 -- Therefore the correctness of a not-overriding indicator must be
8326 -- rechecked when the subprogram is frozen.
8330 then
8334 if Modify_Tree_For_C
8340 then
8345 ----------------------
8346 -- Is_Fully_Defined --
8347 ----------------------
8350 begin
8359 then
8360 -- Verify that the record type has no components with private types
8361 -- without completion.
8363 declare
8366 begin
8378 -- For the designated type of an access to subprogram, all types in
8379 -- the profile must be fully defined.
8382 declare
8385 begin
8398 else
8404 ---------------------------------
8405 -- Process_Default_Expressions --
8406 ---------------------------------
8408 procedure Process_Default_Expressions
8411 is
8418 begin
8421 -- A subprogram instance and its associated anonymous subprogram share
8422 -- their signature. The default expression functions are defined in the
8423 -- wrapper packages for the anonymous subprogram, and should not be
8424 -- generated again for the instance.
8429 then
8437 -- We work with a copy of the default expression because we
8438 -- do not want to disturb the original, since this would mess
8439 -- up the conformance checking.
8443 -- The analysis of the expression may generate insert actions,
8444 -- which of course must not be executed. We wrap those actions
8445 -- in a procedure that is not called, and later on eliminated.
8446 -- The following cases have no side effects, and are analyzed
8447 -- directly.
8451 N_Integer_Literal,
8452 N_Character_Literal,
8453 N_String_Literal,
8454 N_Real_Literal)
8458 then
8459 -- If there is no default function, we must still do a full
8460 -- analyze call on the default value, to ensure that all error
8461 -- checks are performed, e.g. those associated with static
8462 -- evaluation. Note: this branch will always be taken if the
8463 -- analyzer is turned off (but we still need the error checks).
8465 -- Note: the setting of parent here is to meet the requirement
8466 -- that we can only analyze the expression while attached to
8467 -- the tree. Really the requirement is that the parent chain
8468 -- be set, we don't actually need to be in the tree.
8473 -- Default expressions are resolved with their own type if the
8474 -- context is generic, to avoid anomalies with private types.
8478 else
8482 -- If that resolved expression will raise constraint error,
8483 -- then flag the default value as raising constraint error.
8484 -- This allows a proper error message on the calls.
8490 -- If the default is a parameterless call, we use the name of
8491 -- the called function directly, and there is no body to build.
8495 then
8498 -- Else construct and analyze the body of a wrapper procedure
8499 -- that contains an object declaration to hold the expression.
8500 -- Given that this is done only to complete the analysis, it is
8501 -- simpler to build a procedure than a function which might
8502 -- involve secondary stack expansion.
8504 else
8507 Dbody :=
8509 Specification =>
8516 Object_Definition =>
8520 Handled_Statement_Sequence =>
8537 ----------------------------------------
8538 -- Set_Component_Alignment_If_Not_Set --
8539 ----------------------------------------
8542 begin
8543 -- Ignore if not base type, subtypes don't need anything
8549 -- Do not override existing representation
8560 else
8561 Set_Component_Alignment
8567 --------------------------
8568 -- Set_SSO_From_Default --
8569 --------------------------
8574 begin
8575 -- Set default SSO for an array or record base type, except in case of
8576 -- a type extension (which always inherits the SSO of its parent type).
8583 then
8584 Reversed :=
8586 or else
8591 -- For a record type, if bit order is specified explicitly,
8592 -- then do not set SSO from default if not consistent. Note that
8593 -- we do not want to look at a Bit_Order attribute definition
8594 -- for a parent: if we were to inherit Bit_Order, then both
8595 -- SSO_Set_*_By_Default flags would have been cleared already
8596 -- (by Inherit_Aspects_At_Freeze_Point).
8598 and then not
8600 and then
8603 then
8604 -- If flags cause reverse storage order, then set the result. Note
8605 -- that we would have ignored the pragma setting the non default
8606 -- storage order in any case, hence the assertion at this point.
8608 pragma Assert
8613 -- For a record type, also set reversed bit order. Note: if a bit
8614 -- order has been specified explicitly, then this is a no-op.
8623 ------------------
8624 -- Undelay_Type --
8625 ------------------
8628 begin
8632 -- Since we don't want T to have a Freeze_Node, we don't want its
8633 -- Full_View or Corresponding_Record_Type to have one either.
8635 -- ??? Fundamentally, this whole handling is unpleasant. What we really
8636 -- want is to be sure that for an Itype that's part of record R and is a
8637 -- subtype of type T, that it's frozen after the later of the freeze
8638 -- points of R and T. We have no way of doing that directly, so what we
8639 -- do is force most such Itypes to be frozen as part of freezing R via
8640 -- this procedure and only delay the ones that need to be delayed
8641 -- (mostly the designated types of access types that are defined as part
8642 -- of the record).
8648 then
8656 then
8661 ------------------
8662 -- Warn_Overlay --
8663 ------------------
8667 -- The object to which the address clause applies
8673 begin
8674 -- No warning if address clause overlay warnings are off
8680 -- No warning if there is an explicit initialization
8688 -- We only give the warning for non-imported entities of a type for
8689 -- which a non-null base init proc is defined, or for objects of access
8690 -- types with implicit null initialization, or when Normalize_Scalars
8691 -- applies and the type is scalar or a string type (the latter being
8692 -- tested for because predefined String types are initialized by inline
8693 -- code rather than by an init_proc). Note that we do not give the
8694 -- warning for Initialize_Scalars, since we suppressed initialization
8695 -- in this case. Also, do not warn if Suppress_Initialization is set.
8705 then
8708 then
8713 then
8720 then
8727 -- A function call (most likely to To_Address) is probably not an
8728 -- overlay, so skip warning. Ditto if the function call was inlined
8729 -- and transformed into an entity.
8735 -- If a pragma Import follows, we assume that it is for the current
8736 -- target of the address clause, and skip the warning. There may be
8737 -- a source pragma or an aspect that specifies import and generates
8738 -- the corresponding pragma. These will indicate that the entity is
8739 -- imported and that is checked above so that the spurious warning
8740 -- (generated when the entity is frozen) will be suppressed. The
8741 -- pragma may be attached to the aspect, so it is not yet a list
8742 -- member.
8750 then
8755 -- Otherwise give warning message
8759 Error_Msg_N
8761 Nam);
8762 else
8763 Error_Msg_N
8765 Nam);
8768 -- Add friendly warning if initialization comes from a packed array
8769 -- component.
8772 declare
8775 begin
8780 then
8784 then
8785 Error_Msg_NE
8790 else
8797 Error_Msg_N
8800 Nam);