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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) 1992-2017, 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
716 -- Capture initialization value at point of declaration,
717 -- and make explicit assignment legal, because object may
718 -- be a constant.
724 -- Move initialization to freeze actions, once the object has
725 -- been frozen and the address clause alignment check has been
726 -- performed.
735 -- If the objet is tagged, check whether the tag must be
736 -- reassigned explicitly.
746 -----------------------------
747 -- Check_Compile_Time_Size --
748 -----------------------------
753 -- Sets the compile time known size (64 bits or less) in the RM_Size
754 -- field of T, checking for a size clause that was given which attempts
755 -- to give a smaller size.
758 -- Recursive function that does all the work
761 -- If T is a constrained subtype, its size is not known if any of its
762 -- discriminant constraints is not static and it is not a null record.
763 -- The test is conservative and doesn't check that the components are
764 -- in fact constrained by non-static discriminant values. Could be made
765 -- more precise ???
767 --------------------
768 -- Set_Small_Size --
769 --------------------
772 begin
776 -- Check for bad size clause given
781 Error_Msg_NE
786 -- Set size if not set already
793 ----------------
794 -- Size_Known --
795 ----------------
804 begin
808 -- Always True for elementary types, even generic formal elementary
809 -- types. We used to return False in the latter case, but the size
810 -- is known at compile time, even in the template, we just do not
811 -- know the exact size but that's not the point of this routine.
816 -- Array types
820 -- String literals always have known size, and we can set it
823 Set_Small_Size
827 -- Unconstrained types never have known at compile time size
832 -- Don't do any recursion on type with error posted, since we may
833 -- have a malformed type that leads us into a loop.
838 -- Otherwise if component size unknown, then array size unknown
844 -- Check for all indexes static, and also compute possible size
845 -- (in case it is not greater than 64 and may be packable).
847 declare
851 begin
860 else
868 then
871 else
876 else
888 -- For non-generic private types, go to underlying type if present
893 then
894 -- Don't do any recursion on type with error posted, since we may
895 -- have a malformed type that leads us into a loop.
899 else
903 -- Record types
907 -- A class-wide type is never considered to have a known size
912 -- A subtype of a variant record must not have non-static
913 -- discriminated components.
917 then
920 -- Don't do any recursion on type with error posted, since we may
921 -- have a malformed type that leads us into a loop.
927 -- Now look at the components of the record
929 declare
930 -- The following two variables are used to keep track of the
931 -- size of packed records if we can tell the size of the packed
932 -- record in the front end. Packed_Size_Known is True if so far
933 -- we can figure out the size. It is initialized to True for a
934 -- packed record, unless the record has discriminants or atomic
935 -- components or independent components.
937 -- The reason we eliminate the discriminated case is that
938 -- we don't know the way the back end lays out discriminated
939 -- packed records. If Packed_Size_Known is True, then
940 -- Packed_Size is the size in bits so far.
949 -- Size in bits so far
951 begin
952 -- Test for variant part present
958 N_Record_Definition
960 and then
961 Present (Variant_Part
963 then
964 -- If variant part is present, and type is unconstrained,
965 -- then we must have defaulted discriminants, or a size
966 -- clause must be present for the type, or else the size
967 -- is definitely not known at compile time.
970 and then
973 then
978 -- Loop through components
984 -- We do not know the packed size if there is a component
985 -- clause present (we possibly could, but this would only
986 -- help in the case of a record with partial rep clauses.
987 -- That's because in the case of full rep clauses, the
988 -- size gets figured out anyway by a different circuit).
994 -- We do not know the packed size for an atomic/VFA type
995 -- or component, or an independent type or component, or a
996 -- by-reference type or aliased component (because packing
997 -- does not touch these).
1005 then
1009 -- We need to identify a component that is an array where
1010 -- the index type is an enumeration type with non-standard
1011 -- representation, and some bound of the type depends on a
1012 -- discriminant.
1014 -- This is because gigi computes the size by doing a
1015 -- substitution of the appropriate discriminant value in
1016 -- the size expression for the base type, and gigi is not
1017 -- clever enough to evaluate the resulting expression (which
1018 -- involves a call to rep_to_pos) at compile time.
1020 -- It would be nice if gigi would either recognize that
1021 -- this expression can be computed at compile time, or
1022 -- alternatively figured out the size from the subtype
1023 -- directly, where all the information is at hand ???
1027 then
1028 declare
1036 begin
1043 then
1049 then
1054 then
1064 -- Clearly size of record is not known if the size of one of
1065 -- the components is not known.
1071 -- Accumulate packed size if possible
1075 -- We can deal with elementary types, small packed arrays
1076 -- if the representation is a modular type and also small
1077 -- record types (if the size is not greater than 64, but
1078 -- the condition is checked by Set_Small_Size).
1082 and then Present
1084 and then Is_Modular_Integer_Type
1087 then
1088 -- If RM_Size is known and static, then we can keep
1089 -- accumulating the packed size.
1095 -- If we have a field whose RM_Size is not known then
1096 -- we can't figure out the packed size here.
1098 else
1102 -- For other types we can't figure out the packed size
1104 else
1119 -- All other cases, size not known at compile time
1121 else
1126 -------------------------------------
1127 -- Static_Discriminated_Components --
1128 -------------------------------------
1130 function Static_Discriminated_Components
1132 is
1135 begin
1139 then
1153 -- Start of processing for Check_Compile_Time_Size
1155 begin
1159 -----------------------------------
1160 -- Check_Component_Storage_Order --
1161 -----------------------------------
1163 procedure Check_Component_Storage_Order
1168 is
1178 -- Set for the record case, True if Comp is aligned on byte boundaries
1179 -- (in which case it is allowed to have different storage order).
1182 -- Set True when the component is a nested composite, and it does not
1183 -- have the same scalar storage order as Encl_Type.
1185 begin
1186 -- Record case
1196 else
1197 -- If a component clause is present, check if the component starts
1198 -- and ends on byte boundaries. Otherwise conservatively assume it
1199 -- does so only in the case where the record is not packed.
1202 Comp_Byte_Aligned :=
1204 and then
1206 else
1213 -- Array case
1215 else
1222 -- Note: the Reverse_Storage_Order flag is set on the base type, but
1223 -- the attribute definition clause is attached to the first subtype.
1224 -- Also, if the base type is incomplete or private, go to full view
1225 -- if known
1237 Comp_ADC :=
1238 Get_Attribute_Definition_Clause
1242 -- Case of record or array component: check storage order compatibility.
1243 -- But, if the record has Complex_Representation, then it is treated as
1244 -- a scalar in the back end so the storage order is irrelevant.
1249 then
1250 Comp_SSO_Differs :=
1254 -- Parent and extension must have same storage order
1258 Error_Msg_N
1263 -- If component and composite SSO differs, check that component
1264 -- falls on byte boundaries and isn't bit packed.
1268 -- Component SSO differs from enclosing composite:
1270 -- Reject if composite is a bit-packed array, as it is rewritten
1271 -- into an array of scalars.
1274 Error_Msg_N
1278 -- Reject if not byte aligned
1281 and then not Comp_Byte_Aligned
1282 then
1283 Error_Msg_N
1287 -- Warn if specified only for the outer composite
1290 Error_Msg_NE
1296 -- Enclosing type has explicit SSO: non-composite component must not
1297 -- be aliased.
1300 Error_Msg_N
1306 -----------------------------
1307 -- Check_Debug_Info_Needed --
1308 -----------------------------
1311 begin
1316 or else Debug_Generated_Code
1317 or else Debug_Flag_VV
1319 then
1324 -------------------------------
1325 -- Check_Expression_Function --
1326 -------------------------------
1330 -- Function to search for deferred constant
1332 -------------------
1333 -- Find_Constant --
1334 -------------------
1337 begin
1338 -- When a constant is initialized with the result of a dispatching
1339 -- call, the constant declaration is rewritten as a renaming of the
1340 -- displaced function result. This scenario is not a premature use of
1341 -- a constant even though the Has_Completion flag is not set.
1348 N_Object_Declaration
1352 then
1353 Error_Msg_NE
1361 then
1371 -- Local variables
1375 -- Start of processing for Check_Expression_Function
1377 begin
1380 -- The subprogram body created for the expression function is not
1381 -- itself a freeze point.
1386 then
1391 --------------------------------
1392 -- Check_Inherited_Conditions --
1393 --------------------------------
1404 -- Build corresponding pragmas for an operation whose ancestor has
1405 -- class-wide pre/postconditions. If the operation is inherited, the
1406 -- pragmas force the creation of a wrapper for the inherited operation.
1407 -- If the ancestor is being overridden, the pragmas are constructed only
1408 -- to verify their legality, in case they contain calls to other
1409 -- primitives that may haven been overridden.
1411 ---------------------------------------
1412 -- Build_Inherited_Condition_Pragmas --
1413 ---------------------------------------
1420 begin
1425 Build_Class_Wide_Expression
1432 if Needs_Wrapper
1434 and then Expander_Active
1435 then
1444 Build_Class_Wide_Expression
1451 if Needs_Wrapper
1453 and then Expander_Active
1454 then
1460 -- Start of processing for Check_Inherited_Conditions
1462 begin
1467 -- Map the overridden primitive to the overriding one. This takes
1468 -- care of all overridings and is done only once.
1472 then
1480 -- Perform validity checks on the inherited conditions of overriding
1481 -- operations, for conformance with LSP, and apply SPARK-specific
1482 -- restrictions on inherited conditions.
1490 then
1493 -- Analyze the contract items of the overridden operation, before
1494 -- they are rewritten as pragmas.
1498 -- In GNATprove mode this is where we can collect the inherited
1499 -- conditions, because we do not create the Check pragmas that
1500 -- normally convey the the modified class-wide conditions on
1501 -- overriding operations.
1506 -- Otherwise build the corresponding pragmas to check for legality
1507 -- of the inherited condition.
1509 else
1517 -- Now examine the inherited operations to check whether they require
1518 -- a wrapper to handle inherited conditions that call other primitives,
1519 -- so that LSP can be verified/enforced.
1531 -- Analyze the contract items of the parent operation, and
1532 -- determine whether a wrapper is needed. This is determined
1533 -- when the condition is rewritten in sem_prag, using the
1534 -- mapping between overridden and overriding operations built
1535 -- in the loop above.
1541 if Needs_Wrapper
1543 and then Expander_Active
1544 then
1545 -- We need to build a new primitive that overrides the inherited
1546 -- one, and whose inherited expression has been updated above.
1547 -- These expressions are the arguments of pragmas that are part
1548 -- of the declarations of the wrapper. The wrapper holds a single
1549 -- statement that is a call to the class-wide clone, where the
1550 -- controlling actuals are conversions to the corresponding type
1551 -- in the parent primitive:
1553 -- procedure New_Prim (F1 : T1; ...);
1554 -- procedure New_Prim (F1 : T1; ...) is
1555 -- pragma Check (Precondition, Expr);
1556 -- begin
1557 -- Par_Prim_Clone (Par_Type (F1), ...);
1558 -- end;
1560 -- If the primitive is a function the statement is a return
1561 -- statement with a call.
1563 declare
1570 begin
1572 New_Decl :=
1576 -- Insert the declaration and the body of the wrapper after
1577 -- type declaration that generates inherited operation. For
1578 -- a null procedure, the declaration implies a null body.
1582 then
1585 else
1586 -- Build body as wrapper to a call to the already built
1587 -- class-wide clone.
1589 New_Body :=
1590 Build_Class_Wide_Clone_Call
1593 Insert_List_After_And_Analyze
1605 ----------------------------
1606 -- Check_Strict_Alignment --
1607 ----------------------------
1612 begin
1630 then
1640 -------------------------
1641 -- Check_Unsigned_Type --
1642 -------------------------
1649 begin
1654 -- Do not attempt to analyze case where range was in error
1660 -- The situation that is nontrivial is something like:
1662 -- subtype x1 is integer range -10 .. +10;
1663 -- subtype x2 is x1 range 0 .. V1;
1664 -- subtype x3 is x2 range V2 .. V3;
1665 -- subtype x4 is x3 range V4 .. V5;
1667 -- where Vn are variables. Here the base type is signed, but we still
1668 -- know that x4 is unsigned because of the lower bound of x2.
1670 -- The only way to deal with this is to look up the ancestor chain
1673 loop
1687 else
1690 -- If no ancestor had a static lower bound, go to base type
1694 -- Note: the reason we still check for a compile time known
1695 -- value for the base type is that at least in the case of
1696 -- generic formals, we can have bounds that fail this test,
1697 -- and there may be other cases in error situations.
1709 then
1719 -----------------------------
1720 -- Is_Atomic_VFA_Aggregate --
1721 -----------------------------
1730 begin
1733 -- Array may be qualified, so find outer context
1750 then
1759 then
1768 New_N :=
1780 -----------------------------------------------
1781 -- Explode_Initialization_Compound_Statement --
1782 -----------------------------------------------
1787 begin
1790 then
1793 -- Note that we rewrite Init_Stmts into a NULL statement, rather than
1794 -- just removing it, because Freeze_All may rely on this particular
1795 -- Node_Id still being present in the enclosing list to know where to
1796 -- stop freezing.
1804 ----------------
1805 -- Freeze_All --
1806 ----------------
1808 -- Note: the easy coding for this procedure would be to just build a
1809 -- single list of freeze nodes and then insert them and analyze them
1810 -- all at once. This won't work, because the analysis of earlier freeze
1811 -- nodes may recursively freeze types which would otherwise appear later
1812 -- on in the freeze list. So we must analyze and expand the freeze nodes
1813 -- as they are generated.
1817 -- This is the internal recursive routine that does freezing of entities
1818 -- (but NOT the analysis of default expressions, which should not be
1819 -- recursive, we don't want to analyze those till we are sure that ALL
1820 -- the types are frozen).
1822 --------------------
1823 -- Freeze_All_Ent --
1824 --------------------
1832 -- If freeze nodes are present, insert and analyze, and reset cursor
1833 -- for next insertion.
1835 -------------------
1836 -- Process_Flist --
1837 -------------------
1840 begin
1847 else
1853 -- Start of processing for Freeze_All_Ent
1855 begin
1859 -- If the entity is an inner package which is not a package
1860 -- renaming, then its entities must be frozen at this point. Note
1861 -- that such entities do NOT get frozen at the end of the nested
1862 -- package itself (only library packages freeze).
1864 -- Same is true for task declarations, where anonymous records
1865 -- created for entry parameters must be frozen.
1871 then
1882 then
1889 N_Task_Type_Declaration)
1890 then
1893 End_Scope;
1895 -- For a derived tagged type, we must ensure that all the
1896 -- primitive operations of the parent have been frozen, so that
1897 -- their addresses will be in the parent's dispatch table at the
1898 -- point it is inherited.
1904 then
1905 declare
1912 begin
1919 then
1921 Process_Flist;
1931 Process_Flist;
1933 -- If already frozen, and there are delayed aspects, this is where
1934 -- we do the visibility check for these aspects (see Sem_Ch13 spec
1935 -- for a description of how we handle aspect visibility).
1939 -- Retrieve the visibility to the discriminants in order to
1940 -- analyze properly the aspects.
1944 declare
1947 begin
1953 then
1964 -- If an incomplete type is still not frozen, this may be a
1965 -- premature freezing because of a body declaration that follows.
1966 -- Indicate where the freezing took place. Freezing will happen
1967 -- if the body comes from source, but not if it is internally
1968 -- generated, for example as the body of a type invariant.
1970 -- If the freezing is caused by the end of the current declarative
1971 -- part, it is a Taft Amendment type, and there is no error.
1975 then
1976 declare
1979 begin
1980 -- The presence of a body freezes all entities previously
1981 -- declared in the current list of declarations, but this
1982 -- does not apply if the body does not come from source.
1983 -- A type invariant is transformed into a subprogram body
1984 -- which is placed at the end of the private part of the
1985 -- current package, but this body does not freeze incomplete
1986 -- types that may be declared in this private part.
1989 N_Package_Body,
1990 N_Protected_Body,
1991 N_Subprogram_Body,
1992 N_Task_Body)
1994 and then
1997 then
1999 Error_Msg_NE
2010 -- Local variables
2016 -- Start of processing for Freeze_All
2018 begin
2021 -- Now that all types are frozen, we can deal with default expressions
2022 -- that require us to build a default expression functions. This is the
2023 -- point at which such functions are constructed (after all types that
2024 -- might be used in such expressions have been frozen).
2026 -- For subprograms that are renaming_as_body, we create the wrapper
2027 -- bodies as needed.
2029 -- We also add finalization chains to access types whose designated
2030 -- types are controlled. This is normally done when freezing the type,
2031 -- but this misses recursive type definitions where the later members
2032 -- of the recursion introduce controlled components.
2034 -- Loop through entities
2049 else
2055 and then
2057 N_Subprogram_Renaming_Declaration
2058 then
2059 Build_And_Analyze_Renamed_Body
2064 -- Freeze the default expressions of entries, entry families, and
2065 -- protected subprograms.
2072 then
2080 -- Historical note: We used to create a finalization master for an
2081 -- access type whose designated type is not controlled, but contains
2082 -- private controlled compoments. This form of postprocessing is no
2083 -- longer needed because the finalization master is now created when
2084 -- the access type is frozen (see Exp_Ch3.Freeze_Type).
2090 -----------------------
2091 -- Freeze_And_Append --
2092 -----------------------
2094 procedure Freeze_And_Append
2098 is
2100 begin
2104 else
2110 -------------------
2111 -- Freeze_Before --
2112 -------------------
2114 procedure Freeze_Before
2118 is
2119 -- Freeze T, then insert the generated Freeze nodes before the node N.
2120 -- Flag Freeze_Profile is used when T is an overloadable entity, and
2121 -- indicates whether its profile should be frozen at the same time.
2127 begin
2134 -- If the entity is a type declared in an inner package, it may be
2135 -- frozen by an outer declaration before the package itself is
2136 -- frozen. Install the package scope to analyze the freeze nodes,
2137 -- which may include generated subprograms such as predicate
2138 -- functions, etc.
2147 else
2153 -------------------
2154 -- Freeze_Entity --
2155 -------------------
2157 -- WARNING: This routine manages Ghost regions. Return statements must be
2158 -- replaced by gotos which jump to the end of the routine and restore the
2159 -- Ghost mode.
2161 function Freeze_Entity
2165 is
2174 -- This flag gets set to true for a variable with default initialization
2177 -- List of freezing actions, left at No_List if none
2180 -- This could use a comment ???
2183 -- N is a freezing action to be appended to the Result
2186 -- If Loc is a freeze_entity that appears after the last declaration
2187 -- in the scope, inhibit error messages on late completion.
2190 -- Check that an Access or Unchecked_Access attribute with a prefix
2191 -- which is the current instance type can only be applied when the type
2192 -- is limited.
2195 -- Give a warning for pragma Convention with language C or C++ applied
2196 -- to a discriminated record type. This is suppressed for the unchecked
2197 -- union case, since the whole point in this case is interface C. We
2198 -- also do not generate this within instantiations, since we will have
2199 -- generated a message on the template.
2202 -- Give warning for modulus of 8, 16, 32, or 64 given as an explicit
2203 -- integer literal without an explicit corresponding size clause. The
2204 -- caller has checked that Utype is a modular integer type.
2207 -- Freeze array type, including freezing index and component types
2210 -- Perform checks and generate freeze node if needed for a constant or
2211 -- variable declared by an object declaration.
2214 -- Create Freeze_Generic_Entity nodes for types declared in a generic
2215 -- package. Recurse on inner generic packages.
2218 -- Freeze formals and return type of subprogram. If some type in the
2219 -- profile is incomplete and we are in an instance, freezing of the
2220 -- entity will take place elsewhere, and the function returns False.
2223 -- Freeze record type, including freezing component types, and freezing
2224 -- primitive operations if this is a tagged type.
2227 -- Determine whether an arbitrary entity is subject to Boolean aspect
2228 -- Import and its value is specified as True.
2230 procedure Inherit_Freeze_Node
2233 -- Set type Typ's freeze node to refer to Fnode. This routine ensures
2234 -- that any attributes attached to Typ's original node are preserved.
2237 -- If E is an entity for an imported subprogram with pre/post-conditions
2238 -- then this procedure will create a wrapper to ensure that proper run-
2239 -- time checking of the pre/postconditions. See body for details.
2241 -------------------
2242 -- Add_To_Result --
2243 -------------------
2246 begin
2249 else
2254 ----------------------------
2255 -- After_Last_Declaration --
2256 ----------------------------
2261 begin
2267 else
2271 else
2276 ----------------------------
2277 -- Check_Current_Instance --
2278 ----------------------------
2283 -- Determine whether Typ is compatible with the rules for aliased
2284 -- views of types as defined in RM 3.10 in the various dialects.
2287 -- Process routine to apply check to given node
2289 -----------------------------
2290 -- Is_Aliased_View_Of_Type --
2291 -----------------------------
2296 begin
2297 -- Common case
2301 then
2304 -- The following paragraphs describe what a legal aliased view of
2305 -- a type is in the various dialects of Ada.
2307 -- Ada 95
2309 -- The current instance of a limited type, and a formal parameter
2310 -- or generic formal object of a tagged type.
2312 -- Ada 95 limited type
2313 -- * Type with reserved word "limited"
2314 -- * A protected or task type
2315 -- * A composite type with limited component
2320 -- Ada 2005
2322 -- The current instance of a limited tagged type, a protected
2323 -- type, a task type, or a type that has the reserved word
2324 -- "limited" in its full definition ... a formal parameter or
2325 -- generic formal object of a tagged type.
2327 -- Ada 2005 limited type
2328 -- * Type with reserved word "limited", "synchronized", "task"
2329 -- or "protected"
2330 -- * A composite type with limited component
2331 -- * A derived type whose parent is a non-interface limited type
2334 return
2336 or else
2341 -- Ada 2012 and beyond
2343 -- The current instance of an immutably limited type ... a formal
2344 -- parameter or generic formal object of a tagged type.
2346 -- Ada 2012 limited type
2347 -- * Type with reserved word "limited", "synchronized", "task"
2348 -- or "protected"
2349 -- * A composite type with limited component
2350 -- * A derived type whose parent is a non-interface limited type
2351 -- * An incomplete view
2353 -- Ada 2012 immutably limited type
2354 -- * Explicitly limited record type
2355 -- * Record extension with "limited" present
2356 -- * Non-formal limited private type that is either tagged
2357 -- or has at least one access discriminant with a default
2358 -- expression
2359 -- * Task type, protected type or synchronized interface
2360 -- * Type derived from immutably limited type
2362 else
2363 return
2369 -------------
2370 -- Process --
2371 -------------
2374 begin
2378 Name_Unchecked_Access)
2382 then
2384 Error_Msg_N
2387 else
2388 Error_Msg_N
2395 else
2406 -- Local variables
2411 -- Start of processing for Check_Current_Instance
2413 begin
2419 ---------------------------------
2420 -- Check_Suspicious_Convention --
2421 ---------------------------------
2424 begin
2429 or else
2432 and then not In_Instance
2434 then
2435 declare
2440 begin
2445 Error_Msg_N
2448 else
2449 Error_Msg_N
2454 Error_Msg_NE
2462 ------------------------------
2463 -- Check_Suspicious_Modulus --
2464 ------------------------------
2469 begin
2475 declare
2478 begin
2480 declare
2484 begin
2486 declare
2490 begin
2491 -- First case, modulus and size are the same. This
2492 -- happens if you have something like mod 32, with
2493 -- an explicit size of 32, this is for sure a case
2494 -- where the warning is given, since it is seems
2495 -- very unlikely that someone would want e.g. a
2496 -- five bit type stored in 32 bits. It is much
2497 -- more likely they wanted a 32-bit type.
2502 -- Second case, the modulus is 32 or 64 and no
2503 -- size clause is present. This is a less clear
2504 -- case for giving the warning, but in the case
2505 -- of 32/64 (5-bit or 6-bit types) these seem rare
2506 -- enough that it is a likely error (and in any
2507 -- case using 2**5 or 2**6 in these cases seems
2508 -- clearer. We don't include 8 or 16 here, simply
2509 -- because in practice 3-bit and 4-bit types are
2510 -- more common and too many false positives if
2511 -- we warn in these cases.
2515 then
2518 -- No warning needed
2520 else
2524 -- If we fall through, give warning
2527 Error_Msg_N
2529 Modulus);
2538 -----------------------
2539 -- Freeze_Array_Type --
2540 -----------------------
2548 -- Set true if any of the index types is an enumeration type with a
2549 -- non-standard representation.
2551 begin
2560 then
2567 -- Processing that is done only for base types
2571 -- Deal with default setting of reverse storage order
2575 -- Propagate flags for component type
2579 then
2587 -- The array type requires its own invariant procedure in order to
2588 -- verify the component invariant over all elements. In GNATprove
2589 -- mode, the component invariants are checked by other means. They
2590 -- should not be added to the array type invariant procedure, so
2591 -- that the procedure can be used to check the array type
2592 -- invariants if any.
2595 and then not GNATprove_Mode
2596 then
2599 -- The array type is an implementation base type. Propagate the
2600 -- same property to the first subtype.
2607 -- Warn for pragma Pack overriding foreign convention
2611 then
2612 declare
2617 begin
2621 Error_Msg_N
2624 Error_Msg_N
2631 -- If packing was requested or if the component size was
2632 -- set explicitly, then see if bit packing is required. This
2633 -- processing is only done for base types, since all of the
2634 -- representation aspects involved are type-related.
2636 -- This is not just an optimization, if we start processing the
2637 -- subtypes, they interfere with the settings on the base type
2638 -- (this is because Is_Packed has a slightly different meaning
2639 -- before and after freezing).
2641 declare
2645 begin
2649 then
2658 else
2661 -- We can set the component size if it is less than 16,
2662 -- rounding it up to the next storage unit size.
2668 else
2672 -- Set component size up to match alignment if it would
2673 -- otherwise be less than the alignment. This deals with
2674 -- cases of types whose alignment exceeds their size (the
2675 -- padded type cases).
2678 declare
2680 begin
2688 -- Case of component size that may result in bit packing
2691 declare
2697 Get_Attribute_Definition_Clause
2700 begin
2701 -- Warn if we have pack and component size so that the
2702 -- pack is ignored.
2704 -- Note: here we must check for the presence of a
2705 -- component size before checking for a Pack pragma to
2706 -- deal with the case where the array type is a derived
2707 -- type whose parent is currently private.
2711 and then Warn_On_Redundant_Constructs
2712 then
2714 Error_Msg_NE
2716 Error_Msg_N
2722 -- Set component size if not already set by a component
2723 -- size clause.
2729 -- Check for base type of 8, 16, 32 bits, where an
2730 -- unsigned subtype has a length one less than the
2731 -- base type (e.g. Natural subtype of Integer).
2733 -- In such cases, if a component size was not set
2734 -- explicitly, then generate a warning.
2740 then
2744 Error_Msg_N
2746 Pack_Pragma);
2747 Error_Msg_N
2749 Pack_Pragma);
2753 -- Bit packing is never needed for 8, 16, 32, 64
2757 -- If the Esize of the component is known and equal to
2758 -- the component size then even packing is not needed.
2762 then
2763 -- Here the array was requested to be packed, but
2764 -- the packing request had no effect whatsoever,
2765 -- so flag Is_Packed is reset.
2767 -- Note: semantically this means that we lose track
2768 -- of the fact that a derived type inherited pragma
2769 -- Pack that was non-effective, but that is fine.
2771 -- We regard a Pack pragma as a request to set a
2772 -- representation characteristic, and this request
2773 -- may be ignored.
2777 else
2784 -- Bit packing is not needed for multiples of the storage
2785 -- unit if the type is composite because the back end can
2786 -- byte pack composite types.
2790 then
2796 -- In all other cases, bit packing is needed
2798 else
2807 -- Check for Aliased or Atomic_Components/Atomic/VFA with
2808 -- unsuitable packing or explicit component size clause given.
2813 and then
2815 then
2819 -- Outputs error messages for incorrect CS clause or pragma
2820 -- Pack for aliased or atomic/VFA components (T is "aliased"
2821 -- or "atomic/vfa");
2823 -----------------
2824 -- Complain_CS --
2825 -----------------
2828 begin
2830 Clause :=
2831 Get_Attribute_Definition_Clause
2834 Error_Msg_N
2838 Error_Msg_N
2841 else
2842 Error_Msg_N
2848 -- Start of processing for Alias_Atomic_Check
2850 begin
2851 -- If object size of component type isn't known, we cannot
2852 -- be sure so we defer to the back end.
2857 -- Case where component size has no effect. First check for
2858 -- object size of component type multiple of the storage
2859 -- unit size.
2863 -- OK in both packing case and component size case if RM
2864 -- size is known and static and same as the object size.
2866 and then
2870 -- Or if we have an explicit component size clause and
2871 -- the component size and object size are equal.
2873 or else
2876 then
2884 then
2893 -- Check for Independent_Components/Independent with unsuitable
2894 -- packing or explicit component size clause given.
2897 and then
2899 then
2900 begin
2901 -- If object size of component type isn't known, we cannot
2902 -- be sure so we defer to the back end.
2907 -- Case where component size has no effect. First check for
2908 -- object size of component type multiple of the storage
2909 -- unit size.
2913 -- OK in both packing case and component size case if RM
2914 -- size is known and multiple of the storage unit size.
2916 and then
2920 -- Or if we have an explicit component size clause and
2921 -- the component size is larger than the object size.
2923 or else
2926 then
2929 else
2931 Clause :=
2932 Get_Attribute_Definition_Clause
2935 Error_Msg_N
2939 Error_Msg_N
2942 else
2943 Error_Msg_N
2951 -- Warn for case of atomic type
2957 then
2958 Error_Msg_NE
2973 -- Check for scalar storage order
2975 declare
2977 begin
2978 Check_Component_Storage_Order
2981 ADC => Get_Attribute_Definition_Clause
2983 Attribute_Scalar_Storage_Order),
2987 -- Processing that is done only for subtypes
2989 else
2990 -- Acquire alignment from base type
2998 -- Specific checks for bit-packed arrays
3002 -- Check number of elements for bit-packed arrays that come from
3003 -- source and have compile time known ranges. The bit-packed
3004 -- arrays circuitry does not support arrays with more than
3005 -- Integer'Last + 1 elements, and when this restriction is
3006 -- violated, causes incorrect data access.
3008 -- For the case where this is not compile time known, a run-time
3009 -- check should be generated???
3012 declare
3018 begin
3024 -- Never generate an error if any index is of a generic
3025 -- type. We will check this in instances.
3032 Ilen :=
3038 -- No attempt is made to check number of elements if not
3039 -- compile time known.
3052 then
3053 Error_Msg_N
3060 -- Check size
3063 declare
3067 begin
3068 -- It is not clear if it is possible to have no size clause
3069 -- at this stage, but it is not worth worrying about. Post
3070 -- error on the entity name in the size clause if present,
3071 -- else on the type entity itself.
3075 else
3082 -- If any of the index types was an enumeration type with a non-
3083 -- standard rep clause, then we indicate that the array type is
3084 -- always packed (even if it is not bit-packed).
3093 -- If the array is packed and bit-packed or packed to eliminate holes
3094 -- in the non-contiguous enumeration index types, we must create the
3095 -- packed array type to be used to actually implement the type. This
3096 -- is only needed for real array types (not for string literal types,
3097 -- since they are present only for the front end).
3102 then
3106 -- Make sure that we have the necessary routines to implement the
3107 -- packing, and complain now if not. Note that we only test this
3108 -- for constrained array types.
3114 then
3115 declare
3119 begin
3122 then
3123 Error_Msg_CRT
3127 -- Cancel the packing
3137 -- Size information of packed array type is copied to the array
3138 -- type, since this is really the representation. But do not
3139 -- override explicit existing size values. If the ancestor subtype
3140 -- is constrained the Packed_Array_Impl_Type will be inherited
3141 -- from it, but the size may have been provided already, and
3142 -- must not be overridden either.
3145 and then
3148 then
3160 -- For non-packed arrays set the alignment of the array to the
3161 -- alignment of the component type if it is unknown. Skip this
3162 -- in atomic/VFA case (atomic/VFA arrays may need larger alignments).
3171 then
3175 -- A Ghost type cannot have a component of protected or task type
3176 -- (SPARK RM 6.9(19)).
3179 Error_Msg_N
3181 Arr);
3185 -------------------------------
3186 -- Freeze_Object_Declaration --
3187 -------------------------------
3190 begin
3191 -- Abstract type allowed only for C++ imported variables or constants
3193 -- Note: we inhibit this check for objects that do not come from
3194 -- source because there is at least one case (the expansion of
3195 -- x'Class'Input where x is abstract) where we legitimately
3196 -- generate an abstract object.
3201 then
3206 Error_Msg_NE
3211 Error_Msg_N -- CODEFIX
3217 -- For object created by object declaration, perform required
3218 -- categorization (preelaborate and pure) checks. Defer these
3219 -- checks to freeze time since pragma Import inhibits default
3220 -- initialization and thus pragma Import affects these checks.
3224 -- If there is an address clause, check that it is valid
3225 -- and if need be move initialization to the freeze node.
3229 -- Similar processing is needed for aspects that may affect
3230 -- object layout, like Alignment, if there is an initialization
3231 -- expression. We don't do this if there is a pragma Linker_Section,
3232 -- because it would prevent the back end from statically initializing
3233 -- the object; we don't want elaboration code in that case.
3236 and then Expander_Active
3240 then
3241 declare
3245 begin
3247 -- Capture initialization value at point of declaration, and
3248 -- make explicit assignment legal, because object may be a
3249 -- constant.
3254 -- Move initialization to freeze actions.
3262 -- Set_Is_Frozen (E, False);
3266 -- Reset Is_True_Constant for non-constant aliased object. We
3267 -- consider that the fact that a non-constant object is aliased may
3268 -- indicate that some funny business is going on, e.g. an aliased
3269 -- object is passed by reference to a procedure which captures the
3270 -- address of the object, which is later used to assign a new value,
3271 -- even though the compiler thinks that it is not modified. Such
3272 -- code is highly dubious, but we choose to make it "work" for
3273 -- non-constant aliased objects.
3275 -- Note that we used to do this for all aliased objects, whether or
3276 -- not constant, but this caused anomalies down the line because we
3277 -- ended up with static objects that were not Is_True_Constant. Not
3278 -- resetting Is_True_Constant for (aliased) constant objects ensures
3279 -- that this anomaly never occurs.
3281 -- However, we don't do that for internal entities. We figure that if
3282 -- we deliberately set Is_True_Constant for an internal entity, e.g.
3283 -- a dispatch table entry, then we mean it.
3288 then
3292 -- If the object needs any kind of default initialization, an error
3293 -- must be issued if No_Default_Initialization applies. The check
3294 -- doesn't apply to imported objects, which are not ever default
3295 -- initialized, and is why the check is deferred until freezing, at
3296 -- which point we know if Import applies. Deferred constants are also
3297 -- exempted from this test because their completion is explicit, or
3298 -- through an import pragma.
3306 and then
3310 or else
3313 then
3315 Check_Restriction
3319 -- Check that a Thread_Local_Storage variable does not have
3320 -- default initialization, and any explicit initialization must
3321 -- either be the null constant or a static constant.
3324 declare
3326 begin
3327 if Has_Default_Initialization
3328 or else
3330 and then
3332 or else not
3335 then
3336 Error_Msg_NE
3339 Error_Msg_NE
3346 -- For imported objects, set Is_Public unless there is also an
3347 -- address clause, which means that there is no external symbol
3348 -- needed for the Import (Is_Public may still be set for other
3349 -- unrelated reasons). Note that we delayed this processing
3350 -- till freeze time so that we can be sure not to set the flag
3351 -- if there is an address clause. If there is such a clause,
3352 -- then the only purpose of the Import pragma is to suppress
3353 -- implicit initialization.
3359 -- For source objects that are not Imported and are library
3360 -- level, if no linker section pragma was given inherit the
3361 -- appropriate linker section from the corresponding type.
3367 then
3368 Set_Linker_Section_Pragma
3372 -- For convention C objects of an enumeration type, warn if the
3373 -- size is not integer size and no explicit size given. Skip
3374 -- warning for Boolean, and Character, assume programmer expects
3375 -- 8-bit sizes for these cases.
3378 or else
3385 then
3387 Error_Msg_N
3393 -----------------------------
3394 -- Freeze_Generic_Entities --
3395 -----------------------------
3402 begin
3421 --------------------
3422 -- Freeze_Profile --
3423 --------------------
3430 begin
3431 -- Loop through formals
3437 -- AI05-0151: incomplete types can appear in a profile. By the
3438 -- time the entity is frozen, the full view must be available,
3439 -- unless it is a limited view.
3444 then
3458 then
3459 -- If the type of a formal is incomplete, subprogram is being
3460 -- frozen prematurely. Within an instance (but not within a
3461 -- wrapper package) this is an artifact of our need to regard
3462 -- the end of an instantiation as a freeze point. Otherwise it
3463 -- is a definite error.
3470 elsif not After_Last_Declaration
3471 and then not Freezing_Library_Level_Tagged_Type
3472 then
3474 Error_Msg
3479 -- Check suspicious parameter for C function. These tests apply
3480 -- only to exported/imported subprograms.
3482 if Warn_On_Export_Import
3485 or else
3492 then
3493 -- Qualify mention of formals with subprogram name
3497 -- Check suspicious use of fat C pointer
3501 then
3502 Error_Msg_N
3505 -- Check suspicious return of boolean
3511 then
3512 Error_Msg_N
3514 Error_Msg_N
3518 -- Check suspicious tagged type
3521 or else
3525 then
3526 Error_Msg_N
3530 -- Check wrong convention subprogram pointer
3534 then
3535 Error_Msg_N
3539 Error_Msg_NE
3544 -- Turn off name qualification after message output
3549 -- Check for unconstrained array in exported foreign convention
3550 -- case.
3556 and then Warn_On_Export_Import
3557 then
3560 -- If this is an inherited operation, place the warning on
3561 -- the derived type declaration, rather than on the original
3562 -- subprogram.
3565 then
3571 else
3587 -- If the formal is an anonymous_access_to_subprogram
3588 -- freeze the subprogram type as well, to prevent
3589 -- scope anomalies in gigi, because there is no other
3590 -- clear point at which it could be frozen.
3594 then
3602 -- Case of function: similar checks on return type
3606 -- Freeze return type
3610 -- AI05-0151: the return type may have been incomplete at the
3611 -- point of declaration. Replace it with the full view, unless the
3612 -- current type is a limited view. In that case the full view is
3613 -- in a different unit, and gigi finds the non-limited view after
3614 -- the other unit is elaborated.
3619 then
3626 -- Check suspicious return type for C function
3628 if Warn_On_Export_Import
3630 or else
3633 then
3634 -- Check suspicious return of fat C pointer
3640 then
3641 Error_Msg_N
3643 E);
3645 -- Check suspicious return of boolean
3652 then
3653 declare
3656 begin
3657 Error_Msg_NE
3659 Error_Msg_NE
3664 -- Check suspicious return tagged type
3668 and then
3669 Is_Tagged_Type
3674 then
3678 -- Check return of wrong convention subprogram pointer
3684 then
3688 Error_Msg_NE
3694 -- Give warning for suspicious return of a result of an
3695 -- unconstrained array type in a foreign convention function.
3699 -- We are looking for a return of unconstrained array
3704 -- Exclude imported routines, the warning does not belong on
3705 -- the import, but rather on the routine definition.
3709 -- Check that general warning is enabled, and that it is not
3710 -- suppressed for this particular case.
3712 and then Warn_On_Export_Import
3715 then
3716 Error_Msg_N
3722 -- Check suspicious use of Import in pure unit (cases where the RM
3723 -- allows calls to be omitted).
3727 -- It might be suspicious if the compilation unit has the Pure
3728 -- aspect/pragma.
3732 -- The RM allows omission of calls only in the case of
3733 -- library-level subprograms (see RM-10.2.1(18)).
3737 -- Ignore internally generated entity. This happens in some cases
3738 -- of subprograms in specs, where we generate an implied body.
3742 -- Assume run-time knows what it is doing
3744 and then not GNAT_Mode
3746 -- Assume explicit Pure_Function means import is pure
3750 -- Don't need warning in relaxed semantics mode
3752 and then not Relaxed_RM_Semantics
3754 -- Assume convention Intrinsic is OK, since this is specialized.
3755 -- This deals with the DEC unit current_exception.ads
3759 -- Assume that ASM interface knows what it is doing. This deals
3760 -- with e.g. unsigned.ads in the AAMP back end.
3763 then
3764 Error_Msg_N
3766 Error_Msg_NE
3774 ------------------------
3775 -- Freeze_Record_Type --
3776 ------------------------
3788 -- Set True if we find at least one component which is aliased. This
3789 -- is used to prevent Implicit_Packing of the record, since packing
3790 -- cannot modify the size of alignment of an aliased component.
3793 -- True if all components are of a type whose underlying type is
3794 -- elementary.
3797 -- True if all components have a known RM_Size
3800 -- True if all components have an RM_Size that is a multiple of the
3801 -- storage unit.
3804 -- Accumulates total Esize values of all elementary components. Used
3805 -- for processing of Implicit_Packing.
3808 -- Set True if we find at least one component with a component
3809 -- clause (used to warn about useless Bit_Order pragmas, and also
3810 -- to detect cases where Implicit_Packing may have an effect).
3813 -- Set True if the record type scope Rec has been pushed on the scope
3814 -- stack. Needed for the analysis of delayed aspects specified to the
3815 -- components of Rec.
3818 -- Accumulates total RM_Size values of all sized components. Used
3819 -- for processing of Implicit_Packing.
3822 -- Accumulates total RM_Size values of all sized components, rounded
3823 -- individually to a multiple of the storage unit.
3826 -- Scalar_Storage_Order attribute definition clause for the record
3829 -- Set True if we find at least one component whose type has a
3830 -- Scalar_Storage_Order attribute definition clause.
3833 -- Set True if we find at least one component with no component
3834 -- clause (used to warn about useless Pack pragmas).
3837 -- If N is an allocator, possibly wrapped in one or more level of
3838 -- qualified expression(s), return the inner allocator node, else
3839 -- return Empty.
3842 -- If the component subtype is an access to a constrained subtype of
3843 -- an already frozen type, make the subtype frozen as well. It might
3844 -- otherwise be frozen in the wrong scope, and a freeze node on
3845 -- subtype has no effect. Similarly, if the component subtype is a
3846 -- regular (not protected) access to subprogram, set the anonymous
3847 -- subprogram type to frozen as well, to prevent an out-of-scope
3848 -- freeze node at some eventual point of call. Protected operations
3849 -- are handled elsewhere.
3852 -- Make sure that all types mentioned in Discrete_Choices of the
3853 -- variants referenceed by the Variant_Part VP are frozen. This is
3854 -- a recursive routine to deal with nested variants.
3856 ---------------------
3857 -- Check_Allocator --
3858 ---------------------
3862 begin
3864 loop
3869 else
3875 -----------------
3876 -- Check_Itype --
3877 -----------------
3882 begin
3885 then
3888 -- In addition, add an Itype_Reference to ensure that the
3889 -- access subtype is elaborated early enough. This cannot be
3890 -- done if the subtype may depend on discriminants.
3895 then
3903 then
3908 ------------------------------------
3909 -- Freeze_Choices_In_Variant_Part --
3910 ------------------------------------
3919 begin
3920 -- Loop through variants
3925 -- Loop through choices, checking that all types are frozen
3931 then
3938 -- Check for nested variant part to process
3952 -- Start of processing for Freeze_Record_Type
3954 begin
3955 -- Deal with delayed aspect specifications for components. The
3956 -- analysis of the aspect is required to be delayed to the freeze
3957 -- point, thus we analyze the pragma or attribute definition
3958 -- clause in the tree at this point. We also analyze the aspect
3959 -- specification node at the freeze point when the aspect doesn't
3960 -- correspond to pragma/attribute definition clause.
3966 then
3971 -- The visibility to the discriminants must be restored in
3972 -- order to properly analyze the aspects.
3985 -- Pop the scope if Rec scope has been pushed on the scope stack
3986 -- during the delayed aspect analysis process.
3993 Pop_Scope;
3996 -- Freeze components and embedded subtypes
4005 -- Handle the component and discriminant case
4008 declare
4011 begin
4012 -- Freezing a record type freezes the type of each of its
4013 -- components. However, if the type of the component is
4014 -- part of this record, we do not want or need a separate
4015 -- Freeze_Node. Note that Is_Itype is wrong because that's
4016 -- also set in private type cases. We also can't check for
4017 -- the Scope being exactly Rec because of private types and
4018 -- record extensions.
4023 then
4029 -- Warn for pragma Pack overriding foreign convention
4034 -- Don't warn for aliased components, since override
4035 -- cannot happen in that case.
4038 then
4039 declare
4044 begin
4048 Error_Msg_N
4050 PP);
4052 Error_Msg_NE
4059 -- Check for error of component clause given for variable
4060 -- sized type. We have to delay this test till this point,
4061 -- since the component type has to be frozen for us to know
4062 -- if it is variable length.
4067 -- We omit this test in a generic context, it will be
4068 -- applied at instantiation time.
4073 -- Also omit this test in CodePeer mode, since we do not
4074 -- have sufficient info on size and rep clauses.
4079 -- Omit check if component has a generic type. This can
4080 -- happen in an instantiation within a generic in ASIS
4081 -- mode, where we force freeze actions without full
4082 -- expansion.
4087 -- Do the check
4089 elsif not
4090 Size_Known_At_Compile_Time
4092 then
4093 Error_Msg_N
4098 else
4102 -- Case of component requires byte alignment
4106 -- Set the enclosing record to also require byte align
4110 -- Check for component clause that is inconsistent with
4111 -- the required byte boundary alignment.
4116 then
4117 Error_Msg_N
4125 -- Gather data for possible Implicit_Packing later. Note that at
4126 -- this stage we might be dealing with a real component, or with
4127 -- an implicit subtype declaration.
4130 declare
4135 begin
4136 Sized_Component_Total_RM_Size :=
4139 Sized_Component_Total_Round_RM_Size :=
4140 Sized_Component_Total_Round_RM_Size +
4145 then
4146 Elem_Component_Total_Esize :=
4148 else
4156 else
4160 -- If the component is an Itype with Delayed_Freeze and is either
4161 -- a record or array subtype and its base type has not yet been
4162 -- frozen, we must remove this from the entity list of this record
4163 -- and put it on the entity list of the scope of its base type.
4164 -- Note that we know that this is not the type of a component
4165 -- since we cleared Has_Delayed_Freeze for it in the previous
4166 -- loop. Thus this must be the Designated_Type of an access type,
4167 -- which is the type of a component.
4175 then
4176 declare
4180 begin
4181 -- We have a difficult case to handle here. Suppose Rec is
4182 -- subtype being defined in a subprogram that's created as
4183 -- part of the freezing of Rec'Base. In that case, we know
4184 -- that Comp'Base must have already been frozen by the time
4185 -- we get to elaborate this because Gigi doesn't elaborate
4186 -- any bodies until it has elaborated all of the declarative
4187 -- part. But Is_Frozen will not be set at this point because
4188 -- we are processing code in lexical order.
4190 -- We detect this case by going up the Scope chain of Rec
4191 -- and seeing if we have a subprogram scope before reaching
4192 -- the top of the scope chain or that of Comp'Base. If we
4193 -- do, then mark that Comp'Base will actually be frozen. If
4194 -- so, we merely undelay it.
4211 else
4214 else
4218 -- Insert in entity list of scope of base type (which
4219 -- must be an enclosing scope, because still unfrozen).
4225 -- If the component is an access type with an allocator as default
4226 -- value, the designated type will be frozen by the corresponding
4227 -- expression in init_proc. In order to place the freeze node for
4228 -- the designated type before that for the current record type,
4229 -- freeze it now.
4231 -- Same process if the component is an array of access types,
4232 -- initialized with an aggregate. If the designated type is
4233 -- private, it cannot contain allocators, and it is premature
4234 -- to freeze the type, so we check for this as well.
4239 then
4240 declare
4244 begin
4247 -- If component is pointer to a class-wide type, freeze
4248 -- the specific type in the expression being allocated.
4249 -- The expression may be a subtype indication, in which
4250 -- case freeze the subtype mark.
4252 if Is_Class_Wide_Type
4254 then
4256 Freeze_And_Append
4260 then
4261 Freeze_And_Append
4269 else
4270 Freeze_And_Append
4278 then
4281 -- Freeze the designated type when initializing a component with
4282 -- an aggregate in case the aggregate contains allocators.
4284 -- type T is ...;
4285 -- type T_Ptr is access all T;
4286 -- type T_Array is array ... of T_Ptr;
4288 -- type Rec is record
4289 -- Comp : T_Array := (others => ...);
4290 -- end record;
4294 then
4295 declare
4298 Designated_Type
4301 begin
4302 -- The only case when this sort of freezing is not done is
4303 -- when the designated type is class-wide and the root type
4304 -- is the record owning the component. This scenario results
4305 -- in a circularity because the class-wide type requires
4306 -- primitives that have not been created yet as the root
4307 -- type is in the process of being frozen.
4309 -- type Rec is tagged;
4310 -- type Rec_Ptr is access all Rec'Class;
4311 -- type Rec_Array is array ... of Rec_Ptr;
4313 -- type Rec is record
4314 -- Comp : Rec_Array := (others => ...);
4315 -- end record;
4319 then
4327 then
4337 SSO_ADC :=
4338 Get_Attribute_Definition_Clause
4341 -- If the record type has Complex_Representation, then it is treated
4342 -- as a scalar in the back end so the storage order is irrelevant.
4346 Error_Msg_N
4348 SSO_ADC);
4351 else
4352 -- Deal with default setting of reverse storage order
4356 -- Check consistent attribute setting on component types
4358 declare
4360 begin
4363 Check_Component_Storage_Order
4373 -- Now deal with reverse storage order/bit order issues
4377 -- Check compatibility of Scalar_Storage_Order with Bit_Order,
4378 -- if the former is specified.
4382 -- Note: report error on Rec, not on SSO_ADC, as ADC may
4383 -- apply to some ancestor type.
4386 Error_Msg_N
4391 -- Warn if there is a Scalar_Storage_Order attribute definition
4392 -- clause but no component clause, no component that itself has
4393 -- such an attribute definition, and no pragma Pack.
4396 or else
4397 SSO_ADC_Component
4398 or else
4400 then
4401 Error_Msg_N
4408 -- Deal with Bit_Order aspect
4416 then
4417 -- Warn if clause has no effect when no component clause is
4418 -- present, but suppress warning if the Bit_Order is required
4419 -- due to the presence of a Scalar_Storage_Order attribute.
4421 Error_Msg_N
4423 Error_Msg_N
4426 -- Here is where we do the processing to adjust component clauses
4427 -- for reversed bit order, when not using reverse SSO. If an error
4428 -- has been reported on Rec already (such as SSO incompatible with
4429 -- bit order), don't bother adjusting as this may generate extra
4430 -- noise.
4435 then
4438 -- Case where we have both an explicit Bit_Order and the same
4439 -- Scalar_Storage_Order: leave record untouched, the back-end
4440 -- will take care of required layout conversions.
4442 else
4448 -- Complete error checking on record representation clause (e.g.
4449 -- overlap of components). This is called after adjusting the
4450 -- record for reverse bit order.
4452 declare
4454 begin
4460 -- Check for useless pragma Pack when all components placed. We only
4461 -- do this check for record types, not subtypes, since a subtype may
4462 -- have all its components placed, and it still makes perfectly good
4463 -- sense to pack other subtypes or the parent type. We do not give
4464 -- this warning if Optimize_Alignment is set to Space, since the
4465 -- pragma Pack does have an effect in this case (it always resets
4466 -- the alignment to one).
4470 and then not Unplaced_Component
4472 then
4473 -- Reset packed status. Probably not necessary, but we do it so
4474 -- that there is no chance of the back end doing something strange
4475 -- with this redundant indication of packing.
4479 -- Give warning if redundant constructs warnings on
4482 Error_Msg_N -- CODEFIX
4488 -- If this is the record corresponding to a remote type, freeze the
4489 -- remote type here since that is what we are semantically freezing.
4490 -- This prevents the freeze node for that type in an inner scope.
4497 -- Check for controlled components, unchecked unions, and type
4498 -- invariants.
4503 -- Do not set Has_Controlled_Component on a class-wide
4504 -- equivalent type. See Make_CW_Equivalent_Type.
4507 and then
4509 or else
4512 or else
4514 and then
4516 and then
4517 Has_Controlled_Component
4519 then
4527 -- The record type requires its own invariant procedure in
4528 -- order to verify the invariant of each individual component.
4529 -- Do not consider internal components such as _parent because
4530 -- parent class-wide invariants are always inherited.
4531 -- In GNATprove mode, the component invariants are checked by
4532 -- other means. They should not be added to the record type
4533 -- invariant procedure, so that the procedure can be used to
4534 -- check the recordy type invariants if any.
4538 and then not GNATprove_Mode
4539 then
4543 -- Scan component declaration for likely misuses of current
4544 -- instance, either in a constraint or a default expression.
4554 -- Enforce the restriction that access attributes with a current
4555 -- instance prefix can only apply to limited types. This comment
4556 -- is floating here, but does not seem to belong here???
4558 -- Set component alignment if not otherwise already set
4562 -- For first subtypes, check if there are any fixed-point fields with
4563 -- component clauses, where we must check the size. This is not done
4564 -- till the freeze point since for fixed-point types, we do not know
4565 -- the size until the type is frozen. Similar processing applies to
4566 -- bit-packed arrays.
4574 then
4575 Check_Size
4579 Junk);
4586 -- See if Size is too small as is (and implicit packing might help)
4590 -- No implicit packing if even one component is explicitly placed
4592 and then not Placed_Component
4594 -- Or even one component is aliased
4596 and then not Aliased_Component
4598 -- Must have size clause and all sized components
4601 and then All_Sized_Components
4603 -- Do not try implicit packing on records with discriminants, too
4604 -- complicated, especially in the variant record case.
4608 -- We want to implicitly pack if the specified size of the record
4609 -- is less than the sum of the object sizes (no point in packing
4610 -- if this is not the case), if we can compute it, i.e. if we have
4611 -- only elementary components. Otherwise, we have at least one
4612 -- composite component and we want to implicitly pack only if bit
4613 -- packing is required for it, as we are sure in this case that
4614 -- the back end cannot do the expected layout without packing.
4616 and then
4617 ((All_Elem_Components
4619 or else
4621 and then not All_Storage_Unit_Components
4624 -- And the total RM size cannot be greater than the specified size
4625 -- since otherwise packing will not get us where we have to be.
4629 -- Never do implicit packing in CodePeer or SPARK modes since
4630 -- we don't do any packing in these modes, since this generates
4631 -- over-complex code that confuses static analysis, and in
4632 -- general, neither CodePeer not GNATprove care about the
4633 -- internal representation of objects.
4636 then
4637 -- If implicit packing enabled, do it
4642 -- Otherwise flag the size clause
4644 else
4645 declare
4647 begin
4648 Error_Msg_NE -- CODEFIX
4650 Error_Msg_N -- CODEFIX
4657 -- The following checks are relevant only when SPARK_Mode is on as
4658 -- they are not standard Ada legality rules.
4662 -- A discriminated type cannot be effectively volatile
4663 -- (SPARK RM 7.1.3(5)).
4670 -- A non-effectively volatile record type cannot contain
4671 -- effectively volatile components (SPARK RM 7.1.3(6)).
4673 else
4678 then
4680 Error_Msg_N
4689 -- A type which does not yield a synchronized object cannot have
4690 -- a component that yields a synchronized object (SPARK RM 9.5).
4697 then
4699 Error_Msg_N
4708 -- A Ghost type cannot have a component of protected or task type
4709 -- (SPARK RM 6.9(19)).
4716 then
4718 Error_Msg_N
4720 Comp);
4728 -- Make sure that if we have an iterator aspect, then we have
4729 -- either Constant_Indexing or Variable_Indexing.
4731 declare
4734 begin
4743 or else
4745 then
4747 else
4748 Error_Msg_N
4750 Iterator_Aspect);
4755 -- All done if not a full record definition
4761 -- Finally we need to check the variant part to make sure that
4762 -- all types within choices are properly frozen as part of the
4763 -- freezing of the record type.
4770 begin
4771 -- Find component list
4783 then
4788 -- Case of variant part present
4794 -- Note: we used to call Check_Choices here, but it is too early,
4795 -- since predicated subtypes are frozen here, but their freezing
4796 -- actions are in Analyze_Freeze_Entity, which has not been called
4797 -- yet for entities frozen within this procedure, so we moved that
4798 -- call to the Analyze_Freeze_Entity for the record type.
4802 -- Check that all the primitives of an interface type are abstract
4803 -- or null procedures.
4807 then
4808 declare
4812 begin
4819 -- Avoid reporting the error on inherited primitives
4822 then
4827 Error_Msg_N
4831 else
4832 Error_Msg_N
4843 -- For a derived tagged type, check whether inherited primitives
4844 -- might require a wrapper to handle class-wide conditions.
4851 -------------------------------
4852 -- Has_Boolean_Aspect_Import --
4853 -------------------------------
4860 begin
4866 -- The value of aspect Import is True when the expression is
4867 -- either missing or it is explicitly set to True.
4873 then
4884 -------------------------
4885 -- Inherit_Freeze_Node --
4886 -------------------------
4888 procedure Inherit_Freeze_Node
4891 is
4894 begin
4898 -- The input type had an existing node. Propagate relevant attributes
4899 -- from the old freeze node to the inherited freeze node.
4901 -- ??? if both freeze nodes have attributes, would they differ?
4905 -- Attribute Access_Types_To_Process
4909 then
4914 -- Attribute Actions
4920 -- Attribute First_Subtype_Link
4924 then
4928 -- Attribute TSS_Elist
4932 then
4938 ------------------------------
4939 -- Wrap_Imported_Subprogram --
4940 ------------------------------
4942 -- The issue here is that our normal approach of checking preconditions
4943 -- and postconditions does not work for imported procedures, since we
4944 -- are not generating code for the body. To get around this we create
4945 -- a wrapper, as shown by the following example:
4947 -- procedure K (A : Integer);
4948 -- pragma Import (C, K);
4950 -- The spec is rewritten by removing the effects of pragma Import, but
4951 -- leaving the convention unchanged, as though the source had said:
4953 -- procedure K (A : Integer);
4954 -- pragma Convention (C, K);
4956 -- and we create a body, added to the entity K freeze actions, which
4957 -- looks like:
4959 -- procedure K (A : Integer) is
4960 -- procedure K (A : Integer);
4961 -- pragma Import (C, K);
4962 -- begin
4963 -- K (A);
4964 -- end K;
4966 -- Now the contract applies in the normal way to the outer procedure,
4967 -- and the inner procedure has no contracts, so there is no problem
4968 -- in just calling it to get the original effect.
4970 -- In the case of a function, we create an appropriate return statement
4971 -- for the subprogram body that calls the inner procedure.
4975 -- Obtain a copy of the Import_Pragma which belongs to subprogram E
4977 ------------------------
4978 -- Copy_Import_Pragma --
4979 ------------------------
4983 -- The subprogram should have an import pragma, otherwise it does
4984 -- need a wrapper.
4989 -- Save all semantic fields of the pragma
4998 begin
4999 -- Reset all semantic fields. This avoids a potential infinite
5000 -- loop when the pragma comes from an aspect as the duplication
5001 -- will copy the aspect, then copy the corresponding pragma and
5002 -- so on.
5011 -- Restore the original semantic fields
5021 -- Local variables
5032 -- Start of processing for Wrap_Imported_Subprogram
5034 begin
5035 -- Nothing to do if not imported
5040 -- Test enabling conditions for wrapping
5045 and then not GNATprove_Mode
5046 then
5047 -- Here we do the wrap
5049 -- Note on calls to Copy_Separate_Tree. The trees we are copying
5050 -- here are fully analyzed, but we definitely want fully syntactic
5051 -- unanalyzed trees in the body we construct, so that the analysis
5052 -- generates the right visibility, and that is exactly what the
5053 -- calls to Copy_Separate_Tree give us.
5057 -- Fix up spec so it is no longer imported and has convention Ada
5065 -- Grab the subprogram declaration and specification
5069 -- Build parameter list that we need
5078 -- Build the call
5081 Stmt :=
5083 Expression =>
5088 else
5089 Stmt :=
5095 -- Now build the body
5097 Bod :=
5099 Specification =>
5104 Prag),
5105 Handled_Statement_Sequence =>
5110 -- Append the body to freeze result
5115 -- Case of imported subprogram that does not get wrapped
5117 else
5118 -- Set Is_Public. All imported entities need an external symbol
5119 -- created for them since they are always referenced from another
5120 -- object file. Note this used to be set when we set Is_Imported
5121 -- back in Sem_Prag, but now we delay it to this point, since we
5122 -- don't want to set this flag if we wrap an imported subprogram.
5128 -- Local variables
5131 -- Save the Ghost mode to restore on exit
5133 -- Start of processing for Freeze_Entity
5135 begin
5136 -- The entity being frozen may be subject to pragma Ghost. Set the mode
5137 -- now to ensure that any nodes generated during freezing are properly
5138 -- flagged as Ghost.
5142 -- We are going to test for various reasons why this entity need not be
5143 -- frozen here, but in the case of an Itype that's defined within a
5144 -- record, that test actually applies to the record.
5150 then
5154 -- Do not freeze if already frozen since we only need one freeze node
5164 -- It is improper to freeze an external entity within a generic because
5165 -- its freeze node will appear in a non-valid context. The entity will
5166 -- be frozen in the proper scope after the current generic is analyzed.
5167 -- However, aspects must be analyzed because they may be queried later
5168 -- within the generic itself, and the corresponding pragma or attribute
5169 -- definition has not been analyzed yet.
5179 -- AI05-0213: A formal incomplete type does not freeze the actual. In
5180 -- the instance, the same applies to the subtype renaming the actual.
5186 then
5190 -- Formal subprograms are never frozen
5196 -- Generic types are never frozen as they lack delayed semantic checks
5202 -- Do not freeze a global entity within an inner scope created during
5203 -- expansion. A call to subprogram E within some internal procedure
5204 -- (a stream attribute for example) might require freezing E, but the
5205 -- freeze node must appear in the same declarative part as E itself.
5206 -- The two-pass elaboration mechanism in gigi guarantees that E will
5207 -- be frozen before the inner call is elaborated. We exclude constants
5208 -- from this test, because deferred constants may be frozen early, and
5209 -- must be diagnosed (e.g. in the case of a deferred constant being used
5210 -- in a default expression). If the enclosing subprogram comes from
5211 -- source, or is a generic instance, then the freeze point is the one
5212 -- mandated by the language, and we freeze the entity. A subprogram that
5213 -- is a child unit body that acts as a spec does not have a spec that
5214 -- comes from source, but can only come from source.
5219 then
5220 declare
5223 begin
5230 then
5232 else
5242 -- Similarly, an inlined instance body may make reference to global
5243 -- entities, but these references cannot be the proper freezing point
5244 -- for them, and in the absence of inlining freezing will take place in
5245 -- their own scope. Normally instance bodies are analyzed after the
5246 -- enclosing compilation, and everything has been frozen at the proper
5247 -- place, but with front-end inlining an instance body is compiled
5248 -- before the end of the enclosing scope, and as a result out-of-order
5249 -- freezing must be prevented.
5251 elsif Front_End_Inlining
5252 and then In_Instance_Body
5254 then
5255 declare
5258 begin
5263 else
5275 -- Add checks to detect proper initialization of scalars that may appear
5276 -- as subprogram parameters.
5282 -- Deal with delayed aspect specifications. The analysis of the aspect
5283 -- is required to be delayed to the freeze point, thus we analyze the
5284 -- pragma or attribute definition clause in the tree at this point. We
5285 -- also analyze the aspect specification node at the freeze point when
5286 -- the aspect doesn't correspond to pragma/attribute definition clause.
5287 -- In addition, a derived type may have inherited aspects that were
5288 -- delayed in the parent, so these must also be captured now.
5292 then
5296 -- Here to freeze the entity
5300 -- Case of entity being frozen is other than a type
5304 -- If entity is exported or imported and does not have an external
5305 -- name, now is the time to provide the appropriate default name.
5306 -- Skip this if the entity is stubbed, since we don't need a name
5307 -- for any stubbed routine. For the case on intrinsics, if no
5308 -- external name is specified, then calls will be handled in
5309 -- Exp_Intr.Expand_Intrinsic_Call, and no name is needed. If an
5310 -- external name is provided, then Expand_Intrinsic_Call leaves
5311 -- calls in place for expansion by GIGI.
5317 then
5318 Set_Encoded_Interface_Name
5321 -- If entity is an atomic object appearing in a declaration and
5322 -- the expression is an aggregate, assign it to a temporary to
5323 -- ensure that the actual assignment is done atomically rather
5324 -- than component-wise (the assignment to the temp may be done
5325 -- component-wise, but that is harmless).
5332 then
5336 -- Subprogram case
5340 -- Check for needing to wrap imported subprogram
5344 -- Freeze all parameter types and the return type (RM 13.14(14)).
5345 -- However skip this for internal subprograms. This is also where
5346 -- any extra formal parameters are created since we now know
5347 -- whether the subprogram will use a foreign convention.
5349 -- In Ada 2012, freezing a subprogram does not always freeze the
5350 -- corresponding profile (see AI05-019). An attribute reference
5351 -- is not a freezing point of the profile. Flag Do_Freeze_Profile
5352 -- indicates whether the profile should be frozen now.
5353 -- Other constructs that should not freeze ???
5355 -- This processing doesn't apply to internal entities (see below)
5363 -- Must freeze its parent first if it is a derived subprogram
5369 -- We don't freeze internal subprograms, because we don't normally
5370 -- want addition of extra formals or mechanism setting to happen
5371 -- for those. However we do pass through predefined dispatching
5372 -- cases, since extra formals may be needed in some cases, such as
5373 -- for the stream 'Input function (build-in-place formals).
5377 then
5381 -- If warning on suspicious contracts then check for the case of
5382 -- a postcondition other than False for a No_Return subprogram.
5385 and then Warn_On_Suspicious_Contract
5387 then
5388 declare
5392 begin
5395 Name_Post,
5396 Name_Postcondition,
5397 Name_Refined_Post)
5398 then
5399 Exp :=
5400 Expression
5405 then
5406 Error_Msg_NE
5417 -- Here for other than a subprogram or type
5419 else
5420 -- If entity has a type, and it is not a generic unit, then
5421 -- freeze it first (RM 13.14(10)).
5425 then
5428 -- For an object of an anonymous array type, aspects on the
5429 -- object declaration apply to the type itself. This is the
5430 -- case for Atomic_Components, Volatile_Components, and
5431 -- Independent_Components. In these cases analysis of the
5432 -- generated pragma will mark the anonymous types accordingly,
5433 -- and the object itself does not require a freeze node.
5439 then
5446 -- Special processing for objects created by object declaration
5452 -- Check that a constant which has a pragma Volatile[_Components]
5453 -- or Atomic[_Components] also has a pragma Import (RM C.6(13)).
5455 -- Note: Atomic[_Components] also sets Volatile[_Components]
5461 then
5462 -- Make sure we actually have a pragma, and have not merely
5463 -- inherited the indication from elsewhere (e.g. an address
5464 -- clause, which is not good enough in RM terms).
5467 or else
5469 then
5470 Error_Msg_N
5475 or else
5477 then
5478 Error_Msg_N
5484 -- Static objects require special handling
5488 then
5492 -- Remaining step is to layout objects
5496 then
5500 -- For an object that does not have delayed freezing, and whose
5501 -- initialization actions have been captured in a compound
5502 -- statement, move them back now directly within the enclosing
5503 -- statement sequence.
5507 then
5511 -- Do not generate a freeze node for a generic unit
5519 -- Case of a type or subtype being frozen
5521 else
5522 -- We used to check here that a full type must have preelaborable
5523 -- initialization if it completes a private type specified with
5524 -- pragma Preelaborable_Initialization, but that missed cases where
5525 -- the types occur within a generic package, since the freezing
5526 -- that occurs within a containing scope generally skips traversal
5527 -- of a generic unit's declarations (those will be frozen within
5528 -- instances). This check was moved to Analyze_Package_Specification.
5530 -- The type may be defined in a generic unit. This can occur when
5531 -- freezing a generic function that returns the type (which is
5532 -- defined in a parent unit). It is clearly meaningless to freeze
5533 -- this type. However, if it is a subtype, its size may be determi-
5534 -- nable and used in subsequent checks, so might as well try to
5535 -- compute it.
5537 -- In Ada 2012, Freeze_Entities is also used in the front end to
5538 -- trigger the analysis of aspect expressions, so in this case we
5539 -- want to continue the freezing process.
5541 -- Is_Generic_Unit (Scope (E)) is dubious here, do we want instead
5542 -- In_Generic_Scope (E)???
5546 and then
5549 then
5555 -- Check for error of Type_Invariant'Class applied to an untagged
5556 -- type (check delayed to freeze time when full type is available).
5558 declare
5560 begin
5564 then
5565 Error_Msg_NE
5567 Error_Msg_N
5574 -- A Ghost type cannot be concurrent (SPARK RM 6.9(19)). Verify
5575 -- this legality rule first to five a finer-grained diagnostic.
5580 -- A Ghost type cannot be effectively volatile (SPARK RM 6.9(7))
5587 -- Deal with special cases of freezing for subtype
5591 -- Before we do anything else, a specific test for the case of a
5592 -- size given for an array where the array would need to be packed
5593 -- in order for the size to be honored, but is not. This is the
5594 -- case where implicit packing may apply. The reason we do this so
5595 -- early is that, if we have implicit packing, the layout of the
5596 -- base type is affected, so we must do this before we freeze the
5597 -- base type.
5599 -- We could do this processing only if implicit packing is enabled
5600 -- since in all other cases, the error would be caught by the back
5601 -- end. However, we choose to do the check even if we do not have
5602 -- implicit packing enabled, since this allows us to give a more
5603 -- useful error message (advising use of pragma Implicit_Packing
5604 -- or pragma Pack).
5607 declare
5619 -- Number of elements in array
5621 begin
5622 -- Check enabling conditions. These are straightforward
5623 -- except for the test for a limited composite type. This
5624 -- eliminates the rare case of a array of limited components
5625 -- where there are issues of whether or not we can go ahead
5626 -- and pack the array (since we can't freely pack and unpack
5627 -- arrays if they are limited).
5629 -- Note that we check the root type explicitly because the
5630 -- whole point is we are doing this test before we have had
5631 -- a chance to freeze the base type (and it is that freeze
5632 -- action that causes stuff to be inherited).
5634 -- The conditions on the size are identical to those used in
5635 -- Freeze_Array_Type to set the Is_Packed flag.
5653 then
5654 -- Compute number of elements in array
5661 and then
5663 then
5671 else
5678 -- What we are looking for here is the situation where
5679 -- the RM_Size given would be exactly right if there was
5680 -- a pragma Pack, resulting in the component size being
5681 -- the RM_Size of the component type.
5685 -- For implicit packing mode, just set the component
5686 -- size and Freeze_Array_Type will do the rest.
5691 -- Otherwise give an error message
5693 else
5694 Error_Msg_NE
5696 Error_Msg_N -- CODEFIX
5707 -- If ancestor subtype present, freeze that first. Note that this
5708 -- will also get the base type frozen. Need RM reference ???
5715 -- No ancestor subtype present
5717 else
5718 -- See if we have a nearest ancestor that has a predicate.
5719 -- That catches the case of derived type with a predicate.
5720 -- Need RM reference here ???
5728 -- Freeze base type before freezing the entity (RM 13.14(15))
5735 -- A subtype inherits all the type-related representation aspects
5736 -- from its parents (RM 13.1(8)).
5740 -- For a derived type, freeze its parent type first (RM 13.14(15))
5746 -- A derived type inherits each type-related representation aspect
5747 -- of its parent type that was directly specified before the
5748 -- declaration of the derived type (RM 13.1(15)).
5753 -- Check for incompatible size and alignment for record type
5755 if Warn_On_Size_Alignment
5759 -- If explicit Object_Size clause given assume that the programmer
5760 -- knows what he is doing, and expects the compiler behavior.
5764 -- Check for size not a multiple of alignment
5767 then
5768 declare
5774 begin
5777 -- Give a warning
5781 Error_Msg_NE
5788 else
5790 Error_Msg_NE
5804 -- Array type
5809 -- For a class-wide type, the corresponding specific type is
5810 -- frozen as well (RM 13.14(15))
5815 -- If the base type of the class-wide type is still incomplete,
5816 -- the class-wide remains unfrozen as well. This is legal when
5817 -- E is the formal of a primitive operation of some other type
5818 -- which is being frozen.
5825 -- The equivalent type associated with a class-wide subtype needs
5826 -- to be frozen to ensure that its layout is done.
5830 then
5834 -- Generate an itype reference for a library-level class-wide type
5835 -- at the freeze point. Otherwise the first explicit reference to
5836 -- the type may appear in an inner scope which will be rejected by
5837 -- the back-end.
5841 then
5842 declare
5845 begin
5848 -- From a gigi point of view, a class-wide subtype derives
5849 -- from its record equivalent type. As a result, the itype
5850 -- reference must appear after the freeze node of the
5851 -- equivalent type or gigi will reject the reference.
5855 then
5857 else
5863 -- For a record type or record subtype, freeze all component types
5864 -- (RM 13.14(15)). We test for E_Record_(sub)Type here, rather than
5865 -- using Is_Record_Type, because we don't want to attempt the freeze
5866 -- for the case of a private type with record extension (we will do
5867 -- that later when the full type is frozen).
5874 -- Report a warning if a discriminated record base type has a
5875 -- convention with language C or C++ applied to it. This check is
5876 -- done even within generic scopes (but not in instantiations),
5877 -- which is why we don't do it as part of Freeze_Record_Type.
5881 -- For a concurrent type, freeze corresponding record type. This does
5882 -- not correspond to any specific rule in the RM, but the record type
5883 -- is essentially part of the concurrent type. Also freeze all local
5884 -- entities. This includes record types created for entry parameter
5885 -- blocks and whatever local entities may appear in the private part.
5899 -- The guard on the presence of the Etype seems to be needed
5900 -- for some CodePeer (-gnatcC) cases, but not clear why???
5905 then
5916 -- Private types are required to point to the same freeze node as
5917 -- their corresponding full views. The freeze node itself has to
5918 -- point to the partial view of the entity (because from the partial
5919 -- view, we can retrieve the full view, but not the reverse).
5920 -- However, in order to freeze correctly, we need to freeze the full
5921 -- view. If we are freezing at the end of a scope (or within the
5922 -- scope) of the private type, the partial and full views will have
5923 -- been swapped, the full view appears first in the entity chain and
5924 -- the swapping mechanism ensures that the pointers are properly set
5925 -- (on scope exit).
5927 -- If we encounter the partial view before the full view (e.g. when
5928 -- freezing from another scope), we freeze the full view, and then
5929 -- set the pointers appropriately since we cannot rely on swapping to
5930 -- fix things up (subtypes in an outer scope might not get swapped).
5932 -- If the full view is itself private, the above requirements apply
5933 -- to the underlying full view instead of the full view. But there is
5934 -- no swapping mechanism for the underlying full view so we need to
5935 -- set the pointers appropriately in both cases.
5939 then
5940 -- The construction of the dispatch table associated with library
5941 -- level tagged types forces freezing of all the primitives of the
5942 -- type, which may cause premature freezing of the partial view.
5943 -- For example:
5945 -- package Pkg is
5946 -- type T is tagged private;
5947 -- type DT is new T with private;
5948 -- procedure Prim (X : in out T; Y : in out DT'Class);
5949 -- private
5950 -- type T is tagged null record;
5951 -- Obj : T;
5952 -- type DT is new T with null record;
5953 -- end;
5955 -- In this case the type will be frozen later by the usual
5956 -- mechanism: an object declaration, an instantiation, or the
5957 -- end of a declarative part.
5961 then
5965 -- Case of full view present
5969 -- If full view has already been frozen, then no further
5970 -- processing is required
5976 -- Otherwise freeze full view and patch the pointers so that
5977 -- the freeze node will elaborate both views in the back end.
5978 -- However, if full view is itself private, freeze underlying
5979 -- full view instead and patch the pointers so that the freeze
5980 -- node will elaborate the three views in the back end.
5982 else
5983 declare
5986 begin
5989 then
5997 then
6001 Inherit_Freeze_Node
6004 else
6014 Inherit_Freeze_Node
6017 else
6018 -- {Incomplete,Private}_Subtypes with Full_Views
6019 -- constrained by discriminants.
6030 -- AI-117 requires that the convention of a partial view be the
6031 -- same as the convention of the full view. Note that this is a
6032 -- recognized breach of privacy, but it's essential for logical
6033 -- consistency of representation, and the lack of a rule in
6034 -- RM95 was an oversight.
6041 -- Size information is copied from the full view to the
6042 -- incomplete or private view for consistency.
6044 -- We skip this is the full view is not a type. This is very
6045 -- strange of course, and can only happen as a result of
6046 -- certain illegalities, such as a premature attempt to derive
6047 -- from an incomplete type.
6056 -- Case of underlying full view present
6060 then
6065 -- Patch the pointers so that the freeze node will elaborate
6066 -- both views in the back end.
6072 Inherit_Freeze_Node
6075 else
6085 -- Case of no full view present. If entity is derived or subtype,
6086 -- it is safe to freeze, correctness depends on the frozen status
6087 -- of parent. Otherwise it is either premature usage, or a Taft
6088 -- amendment type, so diagnosis is at the point of use and the
6089 -- type might be frozen later.
6094 else
6100 -- For access subprogram, freeze types of all formals, the return
6101 -- type was already frozen, since it is the Etype of the function.
6102 -- Formal types can be tagged Taft amendment types, but otherwise
6103 -- they cannot be incomplete.
6110 then
6114 -- AI05-151: Incomplete types are allowed in access to
6115 -- subprogram specifications.
6118 Error_Msg_NE
6129 -- For access to a protected subprogram, freeze the equivalent type
6130 -- (however this is not set if we are not generating code or if this
6131 -- is an anonymous type used just for resolution).
6139 -- Generic types are never seen by the back-end, and are also not
6140 -- processed by the expander (since the expander is turned off for
6141 -- generic processing), so we never need freeze nodes for them.
6147 -- Some special processing for non-generic types to complete
6148 -- representation details not known till the freeze point.
6153 -- Some error checks required for ordinary fixed-point type. Defer
6154 -- these till the freeze-point since we need the small and range
6155 -- values. We only do these checks for base types
6160 Error_Msg_N
6165 Error_Msg_N
6171 Error_Msg_N
6177 Error_Msg_N
6189 and then Warn_On_Suspicious_Modulus_Value
6190 then
6194 -- The pool applies to named and anonymous access types, but not
6195 -- to subprogram and to internal types generated for 'Access
6196 -- references.
6201 then
6202 -- If a pragma Default_Storage_Pool applies, and this type has no
6203 -- Storage_Pool or Storage_Size clause (which must have occurred
6204 -- before the freezing point), then use the default. This applies
6205 -- only to base types.
6207 -- None of this applies to access to subprograms, for which there
6208 -- are clearly no pools.
6214 then
6215 -- Case of pragma Default_Storage_Pool (null)
6220 -- Case of pragma Default_Storage_Pool (storage_pool_NAME)
6222 else
6227 -- Check restriction for standard storage pool
6233 -- Deal with error message for pure access type. This is not an
6234 -- error in Ada 2005 if there is no pool (see AI-366).
6240 then
6244 Error_Msg_N
6248 Error_Msg_N
6251 else
6252 Error_Msg_N
6259 -- Case of composite types
6263 -- AI-117 requires that all new primitives of a tagged type must
6264 -- inherit the convention of the full view of the type. Inherited
6265 -- and overriding operations are defined to inherit the convention
6266 -- of their parent or overridden subprogram (also specified in
6267 -- AI-117), which will have occurred earlier (in Derive_Subprogram
6268 -- and New_Overloaded_Entity). Here we set the convention of
6269 -- primitives that are still convention Ada, which will ensure
6270 -- that any new primitives inherit the type's convention. Class-
6271 -- wide types can have a foreign convention inherited from their
6272 -- specific type, but are excluded from this since they don't have
6273 -- any associated primitives.
6278 then
6279 declare
6283 begin
6295 -- If the type is a simple storage pool type, then this is where
6296 -- we attempt to locate and validate its Allocate, Deallocate, and
6297 -- Storage_Size operations (the first is required, and the latter
6298 -- two are optional). We also verify that the full type for a
6299 -- private type is allowed to be a simple storage pool type.
6303 then
6304 -- If the type is marked Has_Private_Declaration, then this is
6305 -- a full type for a private type that was specified with the
6306 -- pragma Simple_Storage_Pool_Type, and here we ensure that the
6307 -- pragma is allowed for the full type (for example, it can't
6308 -- be an array type, or a nonlimited record type).
6313 then
6315 Error_Msg_N
6326 procedure Validate_Simple_Pool_Op_Formal
6333 -- Validate one formal Pool_Op_Formal of the candidate pool
6334 -- operation Pool_Op. The formal must be of Expected_Type
6335 -- and have mode Expected_Mode. OK_Formal will be set to
6336 -- False if the formal doesn't match. If OK_Formal is False
6337 -- on entry, then the formal will effectively be ignored
6338 -- (because validation of the pool op has already failed).
6339 -- Upon return, Pool_Op_Formal will be updated to the next
6340 -- formal, if any.
6342 procedure Validate_Simple_Pool_Operation
6344 -- Search for and validate a simple pool operation with the
6345 -- name Op_Name. If the name is Allocate, then there must be
6346 -- exactly one such primitive operation for the simple pool
6347 -- type. If the name is Deallocate or Storage_Size, then
6348 -- there can be at most one such primitive operation. The
6349 -- profile of the located primitive must conform to what
6350 -- is expected for each operation.
6352 ------------------------------------
6353 -- Validate_Simple_Pool_Op_Formal --
6354 ------------------------------------
6356 procedure Validate_Simple_Pool_Op_Formal
6363 is
6364 begin
6365 -- If OK_Formal is False on entry, then simply ignore
6366 -- the formal, because an earlier formal has already
6367 -- been flagged.
6372 -- If no formal is passed in, then issue an error for a
6373 -- missing formal.
6376 Error_Msg_NE
6386 -- If the pool type was expected for this formal, then
6387 -- this will not be considered a candidate operation
6388 -- for the simple pool, so we unset OK_Formal so that
6389 -- the op and any later formals will be ignored.
6396 else
6397 Error_Msg_NE
6404 -- Issue error if formal's mode is not the expected one
6407 Error_Msg_N
6409 Pool_Op_Formal);
6412 -- Advance to the next formal
6417 ------------------------------------
6418 -- Validate_Simple_Pool_Operation --
6419 ------------------------------------
6421 procedure Validate_Simple_Pool_Operation
6423 is
6429 begin
6430 pragma Assert
6432 Name_Deallocate,
6433 Name_Storage_Size));
6437 -- For each homonym declared immediately in the scope
6438 -- of the simple storage pool type, determine whether
6439 -- the homonym is an operation of the pool type, and,
6440 -- if so, check that its profile is as expected for
6441 -- a simple pool operation of that name.
6447 then
6452 -- The first parameter must be of the pool type
6453 -- in order for the operation to qualify.
6456 Validate_Simple_Pool_Op_Formal
6459 else
6460 Validate_Simple_Pool_Op_Formal
6465 -- If another operation with this name has already
6466 -- been located for the type, then flag an error,
6467 -- since we only allow the type to have a single
6468 -- such primitive.
6471 Error_Msg_NE
6476 -- In the case of Allocate and Deallocate, a formal
6477 -- of type System.Address is required.
6480 Validate_Simple_Pool_Op_Formal
6485 Validate_Simple_Pool_Op_Formal
6490 -- In the case of Allocate and Deallocate, formals
6491 -- of type Storage_Count are required as the third
6492 -- and fourth parameters.
6495 Validate_Simple_Pool_Op_Formal
6498 Validate_Simple_Pool_Op_Formal
6503 -- If no mismatched formals have been found (Is_OK)
6504 -- and no excess formals are present, then this
6505 -- operation has been validated, so record it.
6515 -- There must be a valid Allocate operation for the type,
6516 -- so issue an error if none was found.
6520 then
6526 -- Simple pool operations can't be abstract
6529 Error_Msg_N
6534 -- The Storage_Size operation must be a function with
6535 -- Storage_Count as its result type.
6539 Error_Msg_N
6543 Error_Msg_NE
6548 -- Allocate and Deallocate must be procedures
6551 Error_Msg_N
6557 -- Start of processing for Validate_Simple_Pool_Ops
6559 begin
6567 -- Now that all types from which E may depend are frozen, see if the
6568 -- size is known at compile time, if it must be unsigned, or if
6569 -- strict alignment is required
6578 -- Do not allow a size clause for a type which does not have a size
6579 -- that is known at compile time
6583 then
6584 -- Suppress this message if errors posted on E, even if we are
6585 -- in all errors mode, since this is often a junk message
6588 Error_Msg_N
6594 -- Now we set/verify the representation information, in particular
6595 -- the size and alignment values. This processing is not required for
6596 -- generic types, since generic types do not play any part in code
6597 -- generation, and so the size and alignment values for such types
6598 -- are irrelevant. Ditto for types declared within a generic unit,
6599 -- which may have components that depend on generic parameters, and
6600 -- that will be recreated in an instance.
6605 -- Otherwise we call the layout procedure
6607 else
6611 -- If this is an access to subprogram whose designated type is itself
6612 -- a subprogram type, the return type of this anonymous subprogram
6613 -- type must be decorated as well.
6617 then
6621 -- If the type has a Defaut_Value/Default_Component_Value aspect,
6622 -- this is where we analye the expression (after the type is frozen,
6623 -- since in the case of Default_Value, we are analyzing with the
6624 -- type itself, and we treat Default_Component_Value similarly for
6625 -- the sake of uniformity).
6628 declare
6633 begin
6638 else
6649 Flag_Non_Static_Expr
6656 -- End of freeze processing for type entities
6659 -- Here is where we logically freeze the current entity. If it has a
6660 -- freeze node, then this is the point at which the freeze node is
6661 -- linked into the result list.
6665 -- If a freeze node is already allocated, use it, otherwise allocate
6666 -- a new one. The preallocation happens in the case of anonymous base
6667 -- types, where we preallocate so that we can set First_Subtype_Link.
6668 -- Note that we reset the Sloc to the current freeze location.
6674 else
6685 -- A final pass over record types with discriminants. If the type
6686 -- has an incomplete declaration, there may be constrained access
6687 -- subtypes declared elsewhere, which do not depend on the discrimi-
6688 -- nants of the type, and which are used as component types (i.e.
6689 -- the full view is a recursive type). The designated types of these
6690 -- subtypes can only be elaborated after the type itself, and they
6691 -- need an itype reference.
6694 declare
6699 begin
6709 then
6721 -- When a type is frozen, the first subtype of the type is frozen as
6722 -- well (RM 13.14(15)). This has to be done after freezing the type,
6723 -- since obviously the first subtype depends on its own base type.
6728 -- If we just froze a tagged non-class wide record, then freeze the
6729 -- corresponding class-wide type. This must be done after the tagged
6730 -- type itself is frozen, because the class-wide type refers to the
6731 -- tagged type which generates the class.
6736 then
6743 -- Special handling for subprograms
6747 -- If subprogram has address clause then reset Is_Public flag, since
6748 -- we do not want the backend to generate external references.
6752 then
6763 -----------------------------
6764 -- Freeze_Enumeration_Type --
6765 -----------------------------
6768 begin
6769 -- By default, if no size clause is present, an enumeration type with
6770 -- Convention C is assumed to interface to a C enum, and has integer
6771 -- size. This applies to types. For subtypes, verify that its base
6772 -- type has no size clause either. Treat other foreign conventions
6773 -- in the same way, and also make sure alignment is set right.
6780 -- Don't do this if Short_Enums on target
6782 and then not Target_Short_Enums
6783 then
6787 -- Normal Ada case or size clause present or not Long_C_Enums on target
6789 else
6790 -- If the enumeration type interfaces to C, and it has a size clause
6791 -- that specifies less than int size, it warrants a warning. The
6792 -- user may intend the C type to be an enum or a char, so this is
6793 -- not by itself an error that the Ada compiler can detect, but it
6794 -- it is a worth a heads-up. For Boolean and Character types we
6795 -- assume that the programmer has the proper C type in mind.
6803 -- Don't do this if Short_Enums on target
6805 and then not Target_Short_Enums
6806 then
6807 Error_Msg_N
6815 -----------------------
6816 -- Freeze_Expression --
6817 -----------------------
6828 -- This flag is set true if the entity must be frozen outside the
6829 -- current subprogram. This happens in the case of expander generated
6830 -- subprograms (_Init_Proc, _Input, _Output, _Read, _Write) which do
6831 -- not freeze all entities like other bodies, but which nevertheless
6832 -- may reference entities that have to be frozen before the body and
6833 -- obviously cannot be frozen inside the body.
6836 -- If the expression is an array aggregate, the type of the component
6837 -- expressions is also frozen. If the component type is an access type
6838 -- and the expressions include allocators, the designed type is frozen
6839 -- as well.
6842 -- Given an N_Handled_Sequence_Of_Statements node N, determines whether
6843 -- it is the handled statement sequence of an expander-generated
6844 -- subprogram (init proc, stream subprogram, or renaming as body).
6845 -- If so, this is not a freezing context.
6847 -----------------------------------------
6848 -- Find_Aggregate_Component_Desig_Type --
6849 -----------------------------------------
6855 begin
6881 ----------------------
6882 -- In_Expanded_Body --
6883 ----------------------
6889 begin
6892 else
6899 else
6902 -- The following are expander-created bodies, or bodies that
6903 -- are not freeze points.
6912 N_Subprogram_Renaming_Declaration,
6913 N_Expression_Function))
6914 then
6916 else
6922 -- Start of processing for Freeze_Expression
6924 begin
6925 -- Immediate return if freezing is inhibited. This flag is set by the
6926 -- analyzer to stop freezing on generated expressions that would cause
6927 -- freezing if they were in the source program, but which are not
6928 -- supposed to freeze, since they are created.
6934 -- If expression is non-static, then it does not freeze in a default
6935 -- expression, see section "Handling of Default Expressions" in the
6936 -- spec of package Sem for further details. Note that we have to make
6937 -- sure that we actually have a real expression (if we have a subtype
6938 -- indication, we can't test Is_OK_Static_Expression). However, we
6939 -- exclude the case of the prefix of an attribute of a static scalar
6940 -- subtype from this early return, because static subtype attributes
6941 -- should always cause freezing, even in default expressions, but
6942 -- the attribute may not have been marked as static yet (because in
6943 -- Resolve_Attribute, the call to Eval_Attribute follows the call of
6944 -- Freeze_Expression on the prefix).
6946 if In_Spec_Exp
6953 then
6957 -- Freeze type of expression if not frozen already
6965 -- Base type may be an derived numeric type that is frozen at
6966 -- the point of declaration, but first_subtype is still unfrozen.
6973 -- For entity name, freeze entity if not frozen already. A special
6974 -- exception occurs for an identifier that did not come from source.
6975 -- We don't let such identifiers freeze a non-internal entity, i.e.
6976 -- an entity that did come from source, since such an identifier was
6977 -- generated by the expander, and cannot have any semantic effect on
6978 -- the freezing semantics. For example, this stops the parameter of
6979 -- an initialization procedure from freezing the variable.
6986 then
6993 else
6997 -- For an allocator freeze designated type if not frozen already
6999 -- For an aggregate whose component type is an access type, freeze the
7000 -- designated type now, so that its freeze does not appear within the
7001 -- loop that might be created in the expansion of the aggregate. If the
7002 -- designated type is a private type without full view, the expression
7003 -- cannot contain an allocator, so the type is not frozen.
7005 -- For a function, we freeze the entity when the subprogram declaration
7006 -- is frozen, but a function call may appear in an initialization proc.
7007 -- before the declaration is frozen. We need to generate the extra
7008 -- formals, if any, to ensure that the expansion of the call includes
7009 -- the proper actuals. This only applies to Ada subprograms, not to
7010 -- imported ones.
7021 then
7023 -- Check whether aggregate includes allocators.
7028 when N_Indexed_Component
7029 | N_Selected_Component
7030 | N_Slice
7031 =>
7041 then
7052 then
7056 -- All done if nothing needs freezing
7061 then
7065 -- Examine the enclosing context by climbing the parent chain. The
7066 -- traversal serves two purposes - to detect scenarios where freezeing
7067 -- is not needed and to find the proper insertion point for the freeze
7068 -- nodes. Although somewhat similar to Insert_Actions, this traversal
7069 -- is freezing semantics-sensitive. Inserting freeze nodes blindly in
7070 -- the tree may result in types being frozen too early.
7073 loop
7076 -- If we don't have a parent, then we are not in a well-formed tree.
7077 -- This is an unusual case, but there are some legitimate situations
7078 -- in which this occurs, notably when the expressions in the range of
7079 -- a type declaration are resolved. We simply ignore the freeze
7080 -- request in this case. Is this right ???
7086 -- See if we have got to an appropriate point in the tree
7090 -- A special test for the exception of (RM 13.14(8)) for the case
7091 -- of per-object expressions (RM 3.8(18)) occurring in component
7092 -- definition or a discrete subtype definition. Note that we test
7093 -- for a component declaration which includes both cases we are
7094 -- interested in, and furthermore the tree does not have explicit
7095 -- nodes for either of these two constructs.
7099 -- The case we want to test for here is an identifier that is
7100 -- a per-object expression, this is either a discriminant that
7101 -- appears in a context other than the component declaration
7102 -- or it is a reference to the type of the enclosing construct.
7104 -- For either of these cases, we skip the freezing
7106 if not In_Spec_Expression
7109 then
7110 -- We recognize the discriminant case by just looking for
7111 -- a reference to a discriminant. It can only be one for
7112 -- the enclosing construct. Skip freezing in this case.
7117 -- For the case of a reference to the enclosing record,
7118 -- (or task or protected type), we look for a type that
7119 -- matches the current scope.
7126 -- If we have an enumeration literal that appears as the choice in
7127 -- the aggregate of an enumeration representation clause, then
7128 -- freezing does not occur (RM 13.14(10)).
7132 -- The case we are looking for is an enumeration literal
7136 then
7137 -- If enumeration literal appears directly as the choice,
7138 -- do not freeze (this is the normal non-overloaded case)
7142 then
7145 -- If enumeration literal appears as the name of function
7146 -- which is the choice, then also do not freeze. This
7147 -- happens in the overloaded literal case, where the
7148 -- enumeration literal is temporarily changed to a function
7149 -- call for overloading analysis purposes.
7152 and then
7154 and then
7156 then
7161 -- Normally if the parent is a handled sequence of statements,
7162 -- then the current node must be a statement, and that is an
7163 -- appropriate place to insert a freeze node.
7167 -- An exception occurs when the sequence of statements is for
7168 -- an expander generated body that did not do the usual freeze
7169 -- all operation. In this case we usually want to freeze
7170 -- outside this body, not inside it, and we skip past the
7171 -- subprogram body that we are inside.
7174 declare
7178 begin
7179 -- Freeze the entity only when it is declared inside the
7180 -- body of the expander generated procedure. This case
7181 -- is recognized by the scope of the entity or its type,
7182 -- which is either the spec for some enclosing body, or
7183 -- (in the case of init_procs, for which there are no
7184 -- separate specs) the current scope.
7190 or else
7192 then
7198 then
7203 -- An expression function may act as a completion of
7204 -- a function declaration. As such, it can reference
7205 -- entities declared between the two views:
7207 -- Hidden []; -- 1
7208 -- function F return ...;
7209 -- private
7210 -- function Hidden return ...;
7211 -- function F return ... is (Hidden); -- 2
7213 -- Refering to the example above, freezing the expression
7214 -- of F (2) would place Hidden's freeze node (1) in the
7215 -- wrong place. Avoid explicit freezing and let the usual
7216 -- scenarios do the job - for example, reaching the end
7217 -- of the private declarations, or a call to F.
7220 N_Expression_Function
7221 then
7224 -- Freeze outside the body
7226 else
7232 -- Here if normal case where we are in handled statement
7233 -- sequence and want to do the insertion right there.
7235 else
7239 -- If parent is a body or a spec or a block, then the current node
7240 -- is a statement or declaration and we can insert the freeze node
7241 -- before it.
7243 when N_Block_Statement
7244 | N_Entry_Body
7245 | N_Package_Body
7246 | N_Package_Specification
7247 | N_Protected_Body
7248 | N_Subprogram_Body
7249 | N_Task_Body
7250 =>
7253 -- The expander is allowed to define types in any statements list,
7254 -- so any of the following parent nodes also mark a freezing point
7255 -- if the actual node is in a list of statements or declarations.
7257 when N_Abortable_Part
7258 | N_Accept_Alternative
7259 | N_And_Then
7260 | N_Case_Statement_Alternative
7261 | N_Compilation_Unit_Aux
7262 | N_Conditional_Entry_Call
7263 | N_Delay_Alternative
7264 | N_Elsif_Part
7265 | N_Entry_Call_Alternative
7266 | N_Exception_Handler
7267 | N_Extended_Return_Statement
7268 | N_Freeze_Entity
7269 | N_If_Statement
7270 | N_Or_Else
7271 | N_Selective_Accept
7272 | N_Triggering_Alternative
7273 =>
7276 -- Freeze nodes produced by an expression coming from the Actions
7277 -- list of a N_Expression_With_Actions node must remain within the
7278 -- Actions list. Inserting the freeze nodes further up the tree
7279 -- may lead to use before declaration issues in the case of array
7280 -- types.
7285 then
7289 -- Note: N_Loop_Statement is a special case. A type that appears
7290 -- in the source can never be frozen in a loop (this occurs only
7291 -- because of a loop expanded by the expander), so we keep on
7292 -- going. Otherwise we terminate the search. Same is true of any
7293 -- entity which comes from source. (if they have predefined type,
7294 -- that type does not appear to come from source, but the entity
7295 -- should not be frozen here).
7301 -- For all other cases, keep looking at parents
7307 -- We fall through the case if we did not yet find the proper
7308 -- place in the free for inserting the freeze node, so climb.
7313 -- If the expression appears in a record or an initialization procedure,
7314 -- the freeze nodes are collected and attached to the current scope, to
7315 -- be inserted and analyzed on exit from the scope, to insure that
7316 -- generated entities appear in the correct scope. If the expression is
7317 -- a default for a discriminant specification, the scope is still void.
7318 -- The expression can also appear in the discriminant part of a private
7319 -- or concurrent type.
7321 -- If the expression appears in a constrained subcomponent of an
7322 -- enclosing record declaration, the freeze nodes must be attached to
7323 -- the outer record type so they can eventually be placed in the
7324 -- enclosing declaration list.
7326 -- The other case requiring this special handling is if we are in a
7327 -- default expression, since in that case we are about to freeze a
7328 -- static type, and the freeze scope needs to be the outer scope, not
7329 -- the scope of the subprogram with the default parameter.
7331 -- For default expressions and other spec expressions in generic units,
7332 -- the Move_Freeze_Nodes mechanism (see sem_ch12.adb) takes care of
7333 -- placing them at the proper place, after the generic unit.
7336 or else Freeze_Outside
7341 then
7342 declare
7347 begin
7360 -- The current scope may be that of a constrained component of
7361 -- an enclosing record declaration, or of a loop of an enclosing
7362 -- quantified expression, which is above the current scope in the
7363 -- scope stack. Indeed in the context of a quantified expression,
7364 -- a scope is created and pushed above the current scope in order
7365 -- to emulate the loop-like behavior of the quantified expression.
7366 -- If the expression is within a top-level pragma, as for a pre-
7367 -- condition on a library-level subprogram, nothing to do.
7372 N_Quantified_Expression)
7373 then
7380 Freeze_Nodes;
7381 else
7391 -- Now we have the right place to do the freezing. First, a special
7392 -- adjustment, if we are in spec-expression analysis mode, these freeze
7393 -- actions must not be thrown away (normally all inserted actions are
7394 -- thrown away in this mode. However, the freeze actions are from static
7395 -- expressions and one of the important reasons we are doing this
7396 -- special analysis is to get these freeze actions. Therefore we turn
7397 -- off the In_Spec_Expression mode to propagate these freeze actions.
7398 -- This also means they get properly analyzed and expanded.
7402 -- Freeze the designated type of an allocator (RM 13.14(13))
7408 -- Freeze type of expression (RM 13.14(10)). Note that we took care of
7409 -- the enumeration representation clause exception in the loop above.
7415 -- Freeze name if one is present (RM 13.14(11))
7421 -- Restore In_Spec_Expression flag
7426 -----------------------------
7427 -- Freeze_Fixed_Point_Type --
7428 -----------------------------
7430 -- Certain fixed-point types and subtypes, including implicit base types
7431 -- and declared first subtypes, have not yet set up a range. This is
7432 -- because the range cannot be set until the Small and Size values are
7433 -- known, and these are not known till the type is frozen.
7435 -- To signal this case, Scalar_Range contains an unanalyzed syntactic range
7436 -- whose bounds are unanalyzed real literals. This routine will recognize
7437 -- this case, and transform this range node into a properly typed range
7438 -- with properly analyzed and resolved values.
7455 -- Save original bounds (for shaving tests)
7458 -- Actual size chosen
7461 -- Returns size of type with given bounds. Also leaves these
7462 -- bounds set as the current bounds of the Typ.
7464 -----------
7465 -- Fsize --
7466 -----------
7469 begin
7475 -- Start of processing for Freeze_Fixed_Point_Type
7477 begin
7478 -- If Esize of a subtype has not previously been set, set it now
7485 else
7490 -- Immediate return if the range is already analyzed. This means that
7491 -- the range is already set, and does not need to be computed by this
7492 -- routine.
7498 -- Immediate return if either of the bounds raises Constraint_Error
7502 then
7512 -- Ordinary fixed-point case
7516 -- For the ordinary fixed-point case, we are allowed to fudge the
7517 -- end-points up or down by small. Generally we prefer to fudge up,
7518 -- i.e. widen the bounds for non-model numbers so that the end points
7519 -- are included. However there are cases in which this cannot be
7520 -- done, and indeed cases in which we may need to narrow the bounds.
7521 -- The following circuit makes the decision.
7523 -- Note: our terminology here is that Incl_EP means that the bounds
7524 -- are widened by Small if necessary to include the end points, and
7525 -- Excl_EP means that the bounds are narrowed by Small to exclude the
7526 -- end-points if this reduces the size.
7528 -- Note that in the Incl case, all we care about is including the
7529 -- end-points. In the Excl case, we want to narrow the bounds as
7530 -- much as permitted by the RM, to give the smallest possible size.
7547 begin
7548 -- First step. Base types are required to be symmetrical. Right
7549 -- now, the base type range is a copy of the first subtype range.
7550 -- This will be corrected before we are done, but right away we
7551 -- need to deal with the case where both bounds are non-negative.
7552 -- In this case, we set the low bound to the negative of the high
7553 -- bound, to make sure that the size is computed to include the
7554 -- required sign. Note that we do not need to worry about the
7555 -- case of both bounds negative, because the sign will be dealt
7556 -- with anyway. Furthermore we can't just go making such a bound
7557 -- symmetrical, since in a twos-complement system, there is an
7558 -- extra negative value which could not be accommodated on the
7559 -- positive side.
7564 then
7569 -- Compute the fudged bounds. If the number is a model number,
7570 -- then we do nothing to include it, but we are allowed to backoff
7571 -- to the next adjacent model number when we exclude it. If it is
7572 -- not a model number then we straddle the two values with the
7573 -- model numbers on either side.
7579 else
7583 -- The low value excluding the end point is Small greater, but
7584 -- we do not do this exclusion if the low value is positive,
7585 -- since it can't help the size and could actually hurt by
7586 -- crossing the high bound.
7591 -- If the value went from negative to zero, then we have the
7592 -- case where Loval_Incl_EP is the model number just below
7593 -- zero, so we want to stick to the negative value for the
7594 -- base type to maintain the condition that the size will
7595 -- include signed values.
7599 then
7603 else
7607 -- Similar processing for upper bound and high value
7613 else
7619 else
7623 -- One further adjustment is needed. In the case of subtypes, we
7624 -- cannot go outside the range of the base type, or we get
7625 -- peculiarities, and the base type range is already set. This
7626 -- only applies to the Incl values, since clearly the Excl values
7627 -- are already as restricted as they are allowed to be.
7634 -- Get size including and excluding end points
7639 -- No need to exclude end-points if it does not reduce size
7649 -- Now we set the actual size to be used. We want to use the
7650 -- bounds fudged up to include the end-points but only if this
7651 -- can be done without violating a specifically given size
7652 -- size clause or causing an unacceptable increase in size.
7654 -- Case of size clause given
7658 -- Use the inclusive size only if it is consistent with
7659 -- the explicitly specified size.
7666 -- If the inclusive size is too large, we try excluding
7667 -- the end-points (will be caught later if does not work).
7669 else
7675 -- Case of size clause not given
7677 else
7678 -- If we have a base type whose corresponding first subtype
7679 -- has an explicit size that is large enough to include our
7680 -- end-points, then do so. There is no point in working hard
7681 -- to get a base type whose size is smaller than the specified
7682 -- size of the first subtype.
7688 then
7693 -- If excluding the end-points makes the size smaller and
7694 -- results in a size of 8,16,32,64, then we take the smaller
7695 -- size. For the 64 case, this is compulsory. For the other
7696 -- cases, it seems reasonable. We like to include end points
7697 -- if we can, but not at the expense of moving to the next
7698 -- natural boundary of size.
7702 then
7707 -- Otherwise we can definitely include the end points
7709 else
7715 -- One pathological case: normally we never fudge a low bound
7716 -- down, since it would seem to increase the size (if it has
7717 -- any effect), but for ranges containing single value, or no
7718 -- values, the high bound can be small too large. Consider:
7720 -- type t is delta 2.0**(-14)
7721 -- range 131072.0 .. 0;
7723 -- That lower bound is *just* outside the range of 32 bits, and
7724 -- does need fudging down in this case. Note that the bounds
7725 -- will always have crossed here, since the high bound will be
7726 -- fudged down if necessary, as in the case of:
7728 -- type t is delta 2.0**(-14)
7729 -- range 131072.0 .. 131072.0;
7731 -- So we detect the situation by looking for crossed bounds,
7732 -- and if the bounds are crossed, and the low bound is greater
7733 -- than zero, we will always back it off by small, since this
7734 -- is completely harmless.
7741 -- And of course, we need to do exactly the same parallel
7742 -- fudge for flat ranges in the negative region.
7755 -- For the decimal case, none of this fudging is required, since there
7756 -- are no end-point problems in the decimal case (the end-points are
7757 -- always included).
7759 else
7763 -- At this stage, the actual size has been calculated and the proper
7764 -- required bounds are stored in the low and high bounds.
7768 Error_Msg_N
7770 Typ);
7774 -- Check size against explicit given size
7780 Error_Msg_NE
7784 else
7788 -- Increase size to next natural boundary if no size clause given
7790 else
7797 else
7805 -- If we have a base type, then expand the bounds so that they extend to
7806 -- the full width of the allocated size in bits, to avoid junk range
7807 -- checks on intermediate computations.
7814 -- Final step is to reanalyze the bounds using the proper type
7815 -- and set the Corresponding_Integer_Value fields of the literals.
7821 -- Resolve with universal fixed if the base type, and the base type if
7822 -- it is a subtype. Note we can't resolve the base type with itself,
7823 -- that would be a reference before definition.
7827 else
7831 -- Set corresponding integer value for bound
7833 Set_Corresponding_Integer_Value
7836 -- Similar processing for high bound
7844 else
7848 Set_Corresponding_Integer_Value
7851 -- Set type of range to correspond to bounds
7855 -- Set Esize to calculated size if not set already
7861 -- Set RM_Size if not already set. If already set, check value
7863 declare
7866 begin
7871 Error_Msg_NE
7876 else
7881 -- Check for shaving
7885 -- In SPARK mode the given bounds must be strictly representable
7889 Error_Msg_NE
7895 Error_Msg_NE
7900 else
7902 Error_Msg_N
7904 Error_Msg_N
7909 Error_Msg_N
7911 Typ);
7912 Error_Msg_N
7919 ------------------
7920 -- Freeze_Itype --
7921 ------------------
7926 begin
7935 --------------------------
7936 -- Freeze_Static_Object --
7937 --------------------------
7942 -- Exception raised if the type of a static object cannot be made
7943 -- static. This happens if the type depends on non-global objects.
7946 -- Called to ensure that an expression used as part of a type definition
7947 -- is statically allocatable, which means that the expression type is
7948 -- statically allocatable, and the expression is either static, or a
7949 -- reference to a library level constant.
7952 -- Called to mark a type as static, checking that it is possible
7953 -- to set the type as static. If it is not possible, then the
7954 -- exception Cannot_Be_Static is raised.
7956 -----------------------------
7957 -- Ensure_Expression_Is_SA --
7958 -----------------------------
7963 begin
7975 then
7983 -----------------------
7984 -- Ensure_Type_Is_SA --
7985 -----------------------
7991 begin
7992 -- If type is library level, we are all set
7998 -- We are also OK if the type already marked as statically allocated,
7999 -- which means we processed it before.
8005 -- Mark type as statically allocated
8009 -- Check that it is safe to statically allocate this type
8027 declare
8031 begin
8043 else
8052 then
8071 else
8076 -- Start of processing for Freeze_Static_Object
8078 begin
8081 exception
8084 -- If the object that cannot be static is imported or exported, then
8085 -- issue an error message saying that this object cannot be imported
8086 -- or exported. If it has an address clause it is an overlay in the
8087 -- current partition and the static requirement is not relevant.
8088 -- Do not issue any error message when ignoring rep clauses.
8095 Error_Msg_N
8099 -- Otherwise must be exported, something is wrong if compiler
8100 -- is marking something as statically allocated which cannot be).
8103 Error_Msg_N
8108 -----------------------
8109 -- Freeze_Subprogram --
8110 -----------------------
8114 -- Set the conventions of all anonymous access-to-subprogram formals and
8115 -- result subtype of subprogram Subp_Id to the convention of Subp_Id.
8117 ----------------------------
8118 -- Set_Profile_Convention --
8119 ----------------------------
8125 -- Set the convention of anonymous access-to-subprogram type Typ and
8126 -- its designated type to Conv.
8128 -------------------------
8129 -- Set_Type_Convention --
8130 -------------------------
8133 begin
8134 -- Set the convention on both the anonymous access-to-subprogram
8135 -- type and the subprogram type it points to because both types
8136 -- participate in conformance-related checks.
8144 -- Local variables
8148 -- Start of processing for Set_Profile_Convention
8150 begin
8162 -- Local variables
8167 -- Start of processing for Freeze_Subprogram
8169 begin
8170 -- Subprogram may not have an address clause unless it is imported
8174 Error_Msg_N
8180 -- Reset the Pure indication on an imported subprogram unless an
8181 -- explicit Pure_Function pragma was present or the subprogram is an
8182 -- intrinsic. We do this because otherwise it is an insidious error
8183 -- to call a non-pure function from pure unit and have calls
8184 -- mysteriously optimized away. What happens here is that the Import
8185 -- can bypass the normal check to ensure that pure units call only pure
8186 -- subprograms.
8188 -- The reason for the intrinsic exception is that in general, intrinsic
8189 -- functions (such as shifts) are pure anyway. The only exceptions are
8190 -- the intrinsics in GNAT.Source_Info, and that unit is not marked Pure
8191 -- in any case, so no problem arises.
8197 then
8201 -- We also reset the Pure indication on a subprogram with an Address
8202 -- parameter, because the parameter may be used as a pointer and the
8203 -- referenced data may change even if the address value does not.
8205 -- Note that if the programmer gave an explicit Pure_Function pragma,
8206 -- then we believe the programmer, and leave the subprogram Pure. We
8207 -- also suppress this check on run-time files.
8213 then
8217 -- Ensure that all anonymous access-to-subprogram types inherit the
8218 -- convention of their related subprogram (RM 6.3.1 13.1/3). This is
8219 -- not done for a defaulted convention Ada because those types also
8220 -- default to Ada. Convention Protected must not be propagated when
8221 -- the subprogram is an entry because this would be illegal. The only
8222 -- way to force convention Protected on these kinds of types is to
8223 -- include keyword "protected" in the access definition.
8227 then
8231 -- For non-foreign convention subprograms, this is where we create
8232 -- the extra formals (for accessibility level and constrained bit
8233 -- information). We delay this till the freeze point precisely so
8234 -- that we know the convention.
8242 -- If this is convention Ada and a Valued_Procedure, that's odd
8247 and then Warn_On_Export_Import
8248 then
8249 Error_Msg_N
8254 -- Case of foreign convention
8256 else
8259 -- For foreign conventions, warn about return of unconstrained array
8264 -- If no return type, probably some other error, e.g. a
8265 -- missing full declaration, so ignore.
8270 -- If the return type is generic, we have emitted a warning
8271 -- earlier on, and there is nothing else to check here. Specific
8272 -- instantiations may lead to erroneous behavior.
8277 -- Display warning if returning unconstrained array
8282 -- Check appropriate warning is enabled (should we check for
8283 -- Warnings (Off) on specific entities here, probably so???)
8285 and then Warn_On_Export_Import
8286 then
8287 Error_Msg_N
8294 -- If any of the formals for an exported foreign convention
8295 -- subprogram have defaults, then emit an appropriate warning since
8296 -- this is odd (default cannot be used from non-Ada code)
8301 if Warn_On_Export_Import
8303 then
8304 Error_Msg_N
8314 -- Pragma Inline_Always is disallowed for dispatching subprograms
8315 -- because the address of such subprograms is saved in the dispatch
8316 -- table to support dispatching calls, and dispatching calls cannot
8317 -- be inlined. This is consistent with the restriction against using
8318 -- 'Access or 'Address on an Inline_Always subprogram.
8322 then
8323 Error_Msg_N
8327 -- Because of the implicit representation of inherited predefined
8328 -- operators in the front-end, the overriding status of the operation
8329 -- may be affected when a full view of a type is analyzed, and this is
8330 -- not captured by the analysis of the corresponding type declaration.
8331 -- Therefore the correctness of a not-overriding indicator must be
8332 -- rechecked when the subprogram is frozen.
8336 then
8340 if Modify_Tree_For_C
8346 then
8351 ----------------------
8352 -- Is_Fully_Defined --
8353 ----------------------
8356 begin
8365 then
8366 -- Verify that the record type has no components with private types
8367 -- without completion.
8369 declare
8372 begin
8384 -- For the designated type of an access to subprogram, all types in
8385 -- the profile must be fully defined.
8388 declare
8391 begin
8404 else
8410 ---------------------------------
8411 -- Process_Default_Expressions --
8412 ---------------------------------
8414 procedure Process_Default_Expressions
8417 is
8424 begin
8427 -- A subprogram instance and its associated anonymous subprogram share
8428 -- their signature. The default expression functions are defined in the
8429 -- wrapper packages for the anonymous subprogram, and should not be
8430 -- generated again for the instance.
8435 then
8443 -- We work with a copy of the default expression because we
8444 -- do not want to disturb the original, since this would mess
8445 -- up the conformance checking.
8449 -- The analysis of the expression may generate insert actions,
8450 -- which of course must not be executed. We wrap those actions
8451 -- in a procedure that is not called, and later on eliminated.
8452 -- The following cases have no side-effects, and are analyzed
8453 -- directly.
8457 N_Integer_Literal,
8458 N_Character_Literal,
8459 N_String_Literal,
8460 N_Real_Literal)
8464 then
8465 -- If there is no default function, we must still do a full
8466 -- analyze call on the default value, to ensure that all error
8467 -- checks are performed, e.g. those associated with static
8468 -- evaluation. Note: this branch will always be taken if the
8469 -- analyzer is turned off (but we still need the error checks).
8471 -- Note: the setting of parent here is to meet the requirement
8472 -- that we can only analyze the expression while attached to
8473 -- the tree. Really the requirement is that the parent chain
8474 -- be set, we don't actually need to be in the tree.
8479 -- Default expressions are resolved with their own type if the
8480 -- context is generic, to avoid anomalies with private types.
8484 else
8488 -- If that resolved expression will raise constraint error,
8489 -- then flag the default value as raising constraint error.
8490 -- This allows a proper error message on the calls.
8496 -- If the default is a parameterless call, we use the name of
8497 -- the called function directly, and there is no body to build.
8501 then
8504 -- Else construct and analyze the body of a wrapper procedure
8505 -- that contains an object declaration to hold the expression.
8506 -- Given that this is done only to complete the analysis, it is
8507 -- simpler to build a procedure than a function which might
8508 -- involve secondary stack expansion.
8510 else
8513 Dbody :=
8515 Specification =>
8522 Object_Definition =>
8526 Handled_Statement_Sequence =>
8543 ----------------------------------------
8544 -- Set_Component_Alignment_If_Not_Set --
8545 ----------------------------------------
8548 begin
8549 -- Ignore if not base type, subtypes don't need anything
8555 -- Do not override existing representation
8566 else
8567 Set_Component_Alignment
8573 --------------------------
8574 -- Set_SSO_From_Default --
8575 --------------------------
8580 begin
8581 -- Set default SSO for an array or record base type, except in case of
8582 -- a type extension (which always inherits the SSO of its parent type).
8589 then
8590 Reversed :=
8592 or else
8597 -- For a record type, if bit order is specified explicitly,
8598 -- then do not set SSO from default if not consistent. Note that
8599 -- we do not want to look at a Bit_Order attribute definition
8600 -- for a parent: if we were to inherit Bit_Order, then both
8601 -- SSO_Set_*_By_Default flags would have been cleared already
8602 -- (by Inherit_Aspects_At_Freeze_Point).
8604 and then not
8606 and then
8609 then
8610 -- If flags cause reverse storage order, then set the result. Note
8611 -- that we would have ignored the pragma setting the non default
8612 -- storage order in any case, hence the assertion at this point.
8614 pragma Assert
8619 -- For a record type, also set reversed bit order. Note: if a bit
8620 -- order has been specified explicitly, then this is a no-op.
8629 ------------------
8630 -- Undelay_Type --
8631 ------------------
8634 begin
8638 -- Since we don't want T to have a Freeze_Node, we don't want its
8639 -- Full_View or Corresponding_Record_Type to have one either.
8641 -- ??? Fundamentally, this whole handling is unpleasant. What we really
8642 -- want is to be sure that for an Itype that's part of record R and is a
8643 -- subtype of type T, that it's frozen after the later of the freeze
8644 -- points of R and T. We have no way of doing that directly, so what we
8645 -- do is force most such Itypes to be frozen as part of freezing R via
8646 -- this procedure and only delay the ones that need to be delayed
8647 -- (mostly the designated types of access types that are defined as part
8648 -- of the record).
8654 then
8662 then
8667 ------------------
8668 -- Warn_Overlay --
8669 ------------------
8673 -- The object to which the address clause applies
8679 begin
8680 -- No warning if address clause overlay warnings are off
8686 -- No warning if there is an explicit initialization
8694 -- We only give the warning for non-imported entities of a type for
8695 -- which a non-null base init proc is defined, or for objects of access
8696 -- types with implicit null initialization, or when Normalize_Scalars
8697 -- applies and the type is scalar or a string type (the latter being
8698 -- tested for because predefined String types are initialized by inline
8699 -- code rather than by an init_proc). Note that we do not give the
8700 -- warning for Initialize_Scalars, since we suppressed initialization
8701 -- in this case. Also, do not warn if Suppress_Initialization is set.
8711 then
8714 then
8719 then
8726 then
8733 -- A function call (most likely to To_Address) is probably not an
8734 -- overlay, so skip warning. Ditto if the function call was inlined
8735 -- and transformed into an entity.
8741 -- If a pragma Import follows, we assume that it is for the current
8742 -- target of the address clause, and skip the warning. There may be
8743 -- a source pragma or an aspect that specifies import and generates
8744 -- the corresponding pragma. These will indicate that the entity is
8745 -- imported and that is checked above so that the spurious warning
8746 -- (generated when the entity is frozen) will be suppressed. The
8747 -- pragma may be attached to the aspect, so it is not yet a list
8748 -- member.
8756 then
8761 -- Otherwise give warning message
8765 Error_Msg_N
8767 Nam);
8768 else
8769 Error_Msg_N
8771 Nam);
8774 -- Add friendly warning if initialization comes from a packed array
8775 -- component.
8778 declare
8781 begin
8786 then
8790 then
8791 Error_Msg_NE
8796 else
8803 Error_Msg_N
8806 Nam);