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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
1177 -- Set for the record case, True if Comp is aligned on byte boundaries
1178 -- (in which case it is allowed to have different storage order).
1181 -- Set True when the component is a nested composite, and it does not
1182 -- have the same scalar storage order as Encl_Type.
1184 begin
1185 -- Record case
1195 else
1196 -- If a component clause is present, check if the component starts
1197 -- and ends on byte boundaries. Otherwise conservatively assume it
1198 -- does so only in the case where the record is not packed.
1201 Comp_Byte_Aligned :=
1203 and then
1205 else
1212 -- Array case
1214 else
1221 -- Note: the Reverse_Storage_Order flag is set on the base type, but
1222 -- the attribute definition clause is attached to the first subtype.
1223 -- Also, if the base type is incomplete or private, go to full view
1224 -- if known
1236 Comp_ADC :=
1237 Get_Attribute_Definition_Clause
1241 -- Case of record or array component: check storage order compatibility.
1242 -- But, if the record has Complex_Representation, then it is treated as
1243 -- a scalar in the back end so the storage order is irrelevant.
1248 then
1249 Comp_SSO_Differs :=
1253 -- Parent and extension must have same storage order
1257 Error_Msg_N
1262 -- If component and composite SSO differs, check that component
1263 -- falls on byte boundaries and isn't bit packed.
1267 -- Component SSO differs from enclosing composite:
1269 -- Reject if composite is a bit-packed array, as it is rewritten
1270 -- into an array of scalars.
1273 Error_Msg_N
1277 -- Reject if not byte aligned
1280 and then not Comp_Byte_Aligned
1281 then
1282 Error_Msg_N
1286 -- Warn if specified only for the outer composite
1289 Error_Msg_NE
1295 -- Enclosing type has explicit SSO: non-composite component must not
1296 -- be aliased.
1299 Error_Msg_N
1305 -----------------------------
1306 -- Check_Debug_Info_Needed --
1307 -----------------------------
1310 begin
1315 or else Debug_Generated_Code
1316 or else Debug_Flag_VV
1318 then
1323 -------------------------------
1324 -- Check_Expression_Function --
1325 -------------------------------
1329 -- Function to search for deferred constant
1331 -------------------
1332 -- Find_Constant --
1333 -------------------
1336 begin
1337 -- When a constant is initialized with the result of a dispatching
1338 -- call, the constant declaration is rewritten as a renaming of the
1339 -- displaced function result. This scenario is not a premature use of
1340 -- a constant even though the Has_Completion flag is not set.
1347 N_Object_Declaration
1351 then
1352 Error_Msg_NE
1360 then
1370 -- Local variables
1374 -- Start of processing for Check_Expression_Function
1376 begin
1379 -- The subprogram body created for the expression function is not
1380 -- itself a freeze point.
1385 then
1390 --------------------------------
1391 -- Check_Inherited_Conditions --
1392 --------------------------------
1403 -- Build corresponding pragmas for an operation whose ancestor has
1404 -- class-wide pre/postconditions. If the operation is inherited, the
1405 -- pragmas force the creation of a wrapper for the inherited operation.
1406 -- If the ancestor is being overridden, the pragmas are constructed only
1407 -- to verify their legality, in case they contain calls to other
1408 -- primitives that may haven been overridden.
1410 ---------------------------------------
1411 -- Build_Inherited_Condition_Pragmas --
1412 ---------------------------------------
1419 begin
1424 Build_Class_Wide_Expression
1431 if Needs_Wrapper
1433 and then Expander_Active
1434 then
1443 Build_Class_Wide_Expression
1450 if Needs_Wrapper
1452 and then Expander_Active
1453 then
1459 -- Start of processing for Check_Inherited_Conditions
1461 begin
1466 -- Map the overridden primitive to the overriding one. This takes
1467 -- care of all overridings and is done only once.
1471 then
1479 -- Perform validity checks on the inherited conditions of overriding
1480 -- operations, for conformance with LSP, and apply SPARK-specific
1481 -- restrictions on inherited conditions.
1489 then
1492 -- Analyze the contract items of the overridden operation, before
1493 -- they are rewritten as pragmas.
1497 -- In GNATprove mode this is where we can collect the inherited
1498 -- conditions, because we do not create the Check pragmas that
1499 -- normally convey the the modified class-wide conditions on
1500 -- overriding operations.
1505 -- Otherwise build the corresponding pragmas to check for legality
1506 -- of the inherited condition.
1508 else
1516 -- Now examine the inherited operations to check whether they require
1517 -- a wrapper to handle inherited conditions that call other primitives,
1518 -- so that LSP can be verified/enforced.
1530 -- Analyze the contract items of the parent operation, and
1531 -- determine whether a wrapper is needed. This is determined
1532 -- when the condition is rewritten in sem_prag, using the
1533 -- mapping between overridden and overriding operations built
1534 -- in the loop above.
1540 if Needs_Wrapper
1542 and then Expander_Active
1543 then
1544 -- We need to build a new primitive that overrides the inherited
1545 -- one, and whose inherited expression has been updated above.
1546 -- These expressions are the arguments of pragmas that are part
1547 -- of the declarations of the wrapper. The wrapper holds a single
1548 -- statement that is a call to the class-wide clone, where the
1549 -- controlling actuals are conversions to the corresponding type
1550 -- in the parent primitive:
1552 -- procedure New_Prim (F1 : T1; ...);
1553 -- procedure New_Prim (F1 : T1; ...) is
1554 -- pragma Check (Precondition, Expr);
1555 -- begin
1556 -- Par_Prim_Clone (Par_Type (F1), ...);
1557 -- end;
1559 -- If the primitive is a function the statement is a return
1560 -- statement with a call.
1562 declare
1569 begin
1571 New_Decl :=
1575 -- Insert the declaration and the body of the wrapper after
1576 -- type declaration that generates inherited operation. For
1577 -- a null procedure, the declaration implies a null body.
1581 then
1584 else
1585 -- Build body as wrapper to a call to the already built
1586 -- class-wide clone.
1588 New_Body :=
1589 Build_Class_Wide_Clone_Call
1592 Insert_List_After_And_Analyze
1604 ----------------------------
1605 -- Check_Strict_Alignment --
1606 ----------------------------
1611 begin
1629 then
1639 -------------------------
1640 -- Check_Unsigned_Type --
1641 -------------------------
1648 begin
1653 -- Do not attempt to analyze case where range was in error
1659 -- The situation that is nontrivial is something like:
1661 -- subtype x1 is integer range -10 .. +10;
1662 -- subtype x2 is x1 range 0 .. V1;
1663 -- subtype x3 is x2 range V2 .. V3;
1664 -- subtype x4 is x3 range V4 .. V5;
1666 -- where Vn are variables. Here the base type is signed, but we still
1667 -- know that x4 is unsigned because of the lower bound of x2.
1669 -- The only way to deal with this is to look up the ancestor chain
1672 loop
1686 else
1689 -- If no ancestor had a static lower bound, go to base type
1693 -- Note: the reason we still check for a compile time known
1694 -- value for the base type is that at least in the case of
1695 -- generic formals, we can have bounds that fail this test,
1696 -- and there may be other cases in error situations.
1708 then
1718 -----------------------------
1719 -- Is_Atomic_VFA_Aggregate --
1720 -----------------------------
1729 begin
1732 -- Array may be qualified, so find outer context
1749 then
1758 then
1767 New_N :=
1779 -----------------------------------------------
1780 -- Explode_Initialization_Compound_Statement --
1781 -----------------------------------------------
1786 begin
1789 then
1792 -- Note that we rewrite Init_Stmts into a NULL statement, rather than
1793 -- just removing it, because Freeze_All may rely on this particular
1794 -- Node_Id still being present in the enclosing list to know where to
1795 -- stop freezing.
1803 ----------------
1804 -- Freeze_All --
1805 ----------------
1807 -- Note: the easy coding for this procedure would be to just build a
1808 -- single list of freeze nodes and then insert them and analyze them
1809 -- all at once. This won't work, because the analysis of earlier freeze
1810 -- nodes may recursively freeze types which would otherwise appear later
1811 -- on in the freeze list. So we must analyze and expand the freeze nodes
1812 -- as they are generated.
1816 -- This is the internal recursive routine that does freezing of entities
1817 -- (but NOT the analysis of default expressions, which should not be
1818 -- recursive, we don't want to analyze those till we are sure that ALL
1819 -- the types are frozen).
1821 --------------------
1822 -- Freeze_All_Ent --
1823 --------------------
1831 -- If freeze nodes are present, insert and analyze, and reset cursor
1832 -- for next insertion.
1834 -------------------
1835 -- Process_Flist --
1836 -------------------
1839 begin
1846 else
1852 -- Start of processing for Freeze_All_Ent
1854 begin
1858 -- If the entity is an inner package which is not a package
1859 -- renaming, then its entities must be frozen at this point. Note
1860 -- that such entities do NOT get frozen at the end of the nested
1861 -- package itself (only library packages freeze).
1863 -- Same is true for task declarations, where anonymous records
1864 -- created for entry parameters must be frozen.
1870 then
1881 then
1888 N_Task_Type_Declaration)
1889 then
1892 End_Scope;
1894 -- For a derived tagged type, we must ensure that all the
1895 -- primitive operations of the parent have been frozen, so that
1896 -- their addresses will be in the parent's dispatch table at the
1897 -- point it is inherited.
1903 then
1904 declare
1911 begin
1918 then
1920 Process_Flist;
1930 Process_Flist;
1932 -- If already frozen, and there are delayed aspects, this is where
1933 -- we do the visibility check for these aspects (see Sem_Ch13 spec
1934 -- for a description of how we handle aspect visibility).
1938 -- Retrieve the visibility to the discriminants in order to
1939 -- analyze properly the aspects.
1943 declare
1946 begin
1952 then
1963 -- If an incomplete type is still not frozen, this may be a
1964 -- premature freezing because of a body declaration that follows.
1965 -- Indicate where the freezing took place. Freezing will happen
1966 -- if the body comes from source, but not if it is internally
1967 -- generated, for example as the body of a type invariant.
1969 -- If the freezing is caused by the end of the current declarative
1970 -- part, it is a Taft Amendment type, and there is no error.
1974 then
1975 declare
1978 begin
1979 -- The presence of a body freezes all entities previously
1980 -- declared in the current list of declarations, but this
1981 -- does not apply if the body does not come from source.
1982 -- A type invariant is transformed into a subprogram body
1983 -- which is placed at the end of the private part of the
1984 -- current package, but this body does not freeze incomplete
1985 -- types that may be declared in this private part.
1988 N_Package_Body,
1989 N_Protected_Body,
1990 N_Subprogram_Body,
1991 N_Task_Body)
1993 and then
1996 then
1998 Error_Msg_NE
2009 -- Local variables
2015 -- Start of processing for Freeze_All
2017 begin
2020 -- Now that all types are frozen, we can deal with default expressions
2021 -- that require us to build a default expression functions. This is the
2022 -- point at which such functions are constructed (after all types that
2023 -- might be used in such expressions have been frozen).
2025 -- For subprograms that are renaming_as_body, we create the wrapper
2026 -- bodies as needed.
2028 -- We also add finalization chains to access types whose designated
2029 -- types are controlled. This is normally done when freezing the type,
2030 -- but this misses recursive type definitions where the later members
2031 -- of the recursion introduce controlled components.
2033 -- Loop through entities
2048 else
2054 and then
2056 N_Subprogram_Renaming_Declaration
2057 then
2058 Build_And_Analyze_Renamed_Body
2063 -- Freeze the default expressions of entries, entry families, and
2064 -- protected subprograms.
2071 then
2079 -- Historical note: We used to create a finalization master for an
2080 -- access type whose designated type is not controlled, but contains
2081 -- private controlled compoments. This form of postprocessing is no
2082 -- longer needed because the finalization master is now created when
2083 -- the access type is frozen (see Exp_Ch3.Freeze_Type).
2089 -----------------------
2090 -- Freeze_And_Append --
2091 -----------------------
2093 procedure Freeze_And_Append
2097 is
2099 begin
2103 else
2109 -------------------
2110 -- Freeze_Before --
2111 -------------------
2113 procedure Freeze_Before
2117 is
2118 -- Freeze T, then insert the generated Freeze nodes before the node N.
2119 -- Flag Freeze_Profile is used when T is an overloadable entity, and
2120 -- indicates whether its profile should be frozen at the same time.
2126 begin
2133 -- If the entity is a type declared in an inner package, it may be
2134 -- frozen by an outer declaration before the package itself is
2135 -- frozen. Install the package scope to analyze the freeze nodes,
2136 -- which may include generated subprograms such as predicate
2137 -- functions, etc.
2146 else
2152 -------------------
2153 -- Freeze_Entity --
2154 -------------------
2156 -- WARNING: This routine manages Ghost regions. Return statements must be
2157 -- replaced by gotos which jump to the end of the routine and restore the
2158 -- Ghost mode.
2160 function Freeze_Entity
2164 is
2173 -- This flag gets set to true for a variable with default initialization
2176 -- List of freezing actions, left at No_List if none
2179 -- This could use a comment ???
2182 -- N is a freezing action to be appended to the Result
2185 -- If Loc is a freeze_entity that appears after the last declaration
2186 -- in the scope, inhibit error messages on late completion.
2189 -- Check that an Access or Unchecked_Access attribute with a prefix
2190 -- which is the current instance type can only be applied when the type
2191 -- is limited.
2194 -- Give a warning for pragma Convention with language C or C++ applied
2195 -- to a discriminated record type. This is suppressed for the unchecked
2196 -- union case, since the whole point in this case is interface C. We
2197 -- also do not generate this within instantiations, since we will have
2198 -- generated a message on the template.
2201 -- Give warning for modulus of 8, 16, 32, or 64 given as an explicit
2202 -- integer literal without an explicit corresponding size clause. The
2203 -- caller has checked that Utype is a modular integer type.
2206 -- Freeze array type, including freezing index and component types
2209 -- Perform checks and generate freeze node if needed for a constant or
2210 -- variable declared by an object declaration.
2213 -- Create Freeze_Generic_Entity nodes for types declared in a generic
2214 -- package. Recurse on inner generic packages.
2217 -- Freeze formals and return type of subprogram. If some type in the
2218 -- profile is incomplete and we are in an instance, freezing of the
2219 -- entity will take place elsewhere, and the function returns False.
2222 -- Freeze record type, including freezing component types, and freezing
2223 -- primitive operations if this is a tagged type.
2226 -- Determine whether an arbitrary entity is subject to Boolean aspect
2227 -- Import and its value is specified as True.
2229 procedure Inherit_Freeze_Node
2232 -- Set type Typ's freeze node to refer to Fnode. This routine ensures
2233 -- that any attributes attached to Typ's original node are preserved.
2236 -- If E is an entity for an imported subprogram with pre/post-conditions
2237 -- then this procedure will create a wrapper to ensure that proper run-
2238 -- time checking of the pre/postconditions. See body for details.
2240 -------------------
2241 -- Add_To_Result --
2242 -------------------
2245 begin
2248 else
2253 ----------------------------
2254 -- After_Last_Declaration --
2255 ----------------------------
2260 begin
2266 else
2270 else
2275 ----------------------------
2276 -- Check_Current_Instance --
2277 ----------------------------
2282 -- Determine whether Typ is compatible with the rules for aliased
2283 -- views of types as defined in RM 3.10 in the various dialects.
2286 -- Process routine to apply check to given node
2288 -----------------------------
2289 -- Is_Aliased_View_Of_Type --
2290 -----------------------------
2295 begin
2296 -- Common case
2300 then
2303 -- The following paragraphs describe what a legal aliased view of
2304 -- a type is in the various dialects of Ada.
2306 -- Ada 95
2308 -- The current instance of a limited type, and a formal parameter
2309 -- or generic formal object of a tagged type.
2311 -- Ada 95 limited type
2312 -- * Type with reserved word "limited"
2313 -- * A protected or task type
2314 -- * A composite type with limited component
2319 -- Ada 2005
2321 -- The current instance of a limited tagged type, a protected
2322 -- type, a task type, or a type that has the reserved word
2323 -- "limited" in its full definition ... a formal parameter or
2324 -- generic formal object of a tagged type.
2326 -- Ada 2005 limited type
2327 -- * Type with reserved word "limited", "synchronized", "task"
2328 -- or "protected"
2329 -- * A composite type with limited component
2330 -- * A derived type whose parent is a non-interface limited type
2333 return
2335 or else
2340 -- Ada 2012 and beyond
2342 -- The current instance of an immutably limited type ... a formal
2343 -- parameter or generic formal object of a tagged type.
2345 -- Ada 2012 limited type
2346 -- * Type with reserved word "limited", "synchronized", "task"
2347 -- or "protected"
2348 -- * A composite type with limited component
2349 -- * A derived type whose parent is a non-interface limited type
2350 -- * An incomplete view
2352 -- Ada 2012 immutably limited type
2353 -- * Explicitly limited record type
2354 -- * Record extension with "limited" present
2355 -- * Non-formal limited private type that is either tagged
2356 -- or has at least one access discriminant with a default
2357 -- expression
2358 -- * Task type, protected type or synchronized interface
2359 -- * Type derived from immutably limited type
2361 else
2362 return
2368 -------------
2369 -- Process --
2370 -------------
2373 begin
2377 Name_Unchecked_Access)
2381 then
2383 Error_Msg_N
2386 else
2387 Error_Msg_N
2394 else
2405 -- Local variables
2410 -- Start of processing for Check_Current_Instance
2412 begin
2418 ---------------------------------
2419 -- Check_Suspicious_Convention --
2420 ---------------------------------
2423 begin
2428 or else
2431 and then not In_Instance
2433 then
2434 declare
2439 begin
2444 Error_Msg_N
2447 else
2448 Error_Msg_N
2453 Error_Msg_NE
2461 ------------------------------
2462 -- Check_Suspicious_Modulus --
2463 ------------------------------
2468 begin
2474 declare
2477 begin
2479 declare
2483 begin
2485 declare
2489 begin
2490 -- First case, modulus and size are the same. This
2491 -- happens if you have something like mod 32, with
2492 -- an explicit size of 32, this is for sure a case
2493 -- where the warning is given, since it is seems
2494 -- very unlikely that someone would want e.g. a
2495 -- five bit type stored in 32 bits. It is much
2496 -- more likely they wanted a 32-bit type.
2501 -- Second case, the modulus is 32 or 64 and no
2502 -- size clause is present. This is a less clear
2503 -- case for giving the warning, but in the case
2504 -- of 32/64 (5-bit or 6-bit types) these seem rare
2505 -- enough that it is a likely error (and in any
2506 -- case using 2**5 or 2**6 in these cases seems
2507 -- clearer. We don't include 8 or 16 here, simply
2508 -- because in practice 3-bit and 4-bit types are
2509 -- more common and too many false positives if
2510 -- we warn in these cases.
2514 then
2517 -- No warning needed
2519 else
2523 -- If we fall through, give warning
2526 Error_Msg_N
2528 Modulus);
2537 -----------------------
2538 -- Freeze_Array_Type --
2539 -----------------------
2547 -- Set true if any of the index types is an enumeration type with a
2548 -- non-standard representation.
2550 begin
2559 then
2566 -- Processing that is done only for base types
2570 -- Deal with default setting of reverse storage order
2574 -- Propagate flags for component type
2578 then
2586 -- The array type requires its own invariant procedure in order to
2587 -- verify the component invariant over all elements. In GNATprove
2588 -- mode, the component invariants are checked by other means. They
2589 -- should not be added to the array type invariant procedure, so
2590 -- that the procedure can be used to check the array type
2591 -- invariants if any.
2594 and then not GNATprove_Mode
2595 then
2598 -- The array type is an implementation base type. Propagate the
2599 -- same property to the first subtype.
2606 -- Warn for pragma Pack overriding foreign convention
2610 then
2611 declare
2616 begin
2620 Error_Msg_N
2623 Error_Msg_N
2630 -- If packing was requested or if the component size was
2631 -- set explicitly, then see if bit packing is required. This
2632 -- processing is only done for base types, since all of the
2633 -- representation aspects involved are type-related.
2635 -- This is not just an optimization, if we start processing the
2636 -- subtypes, they interfere with the settings on the base type
2637 -- (this is because Is_Packed has a slightly different meaning
2638 -- before and after freezing).
2640 declare
2644 begin
2648 then
2657 else
2660 -- We can set the component size if it is less than 16,
2661 -- rounding it up to the next storage unit size.
2667 else
2671 -- Set component size up to match alignment if it would
2672 -- otherwise be less than the alignment. This deals with
2673 -- cases of types whose alignment exceeds their size (the
2674 -- padded type cases).
2677 declare
2679 begin
2687 -- Case of component size that may result in bit packing
2690 declare
2696 Get_Attribute_Definition_Clause
2699 begin
2700 -- Warn if we have pack and component size so that the
2701 -- pack is ignored.
2703 -- Note: here we must check for the presence of a
2704 -- component size before checking for a Pack pragma to
2705 -- deal with the case where the array type is a derived
2706 -- type whose parent is currently private.
2710 and then Warn_On_Redundant_Constructs
2711 then
2713 Error_Msg_NE
2715 Error_Msg_N
2721 -- Set component size if not already set by a component
2722 -- size clause.
2728 -- Check for base type of 8, 16, 32 bits, where an
2729 -- unsigned subtype has a length one less than the
2730 -- base type (e.g. Natural subtype of Integer).
2732 -- In such cases, if a component size was not set
2733 -- explicitly, then generate a warning.
2739 then
2743 Error_Msg_N
2745 Pack_Pragma);
2746 Error_Msg_N
2748 Pack_Pragma);
2752 -- Bit packing is never needed for 8, 16, 32, 64
2756 -- If the Esize of the component is known and equal to
2757 -- the component size then even packing is not needed.
2761 then
2762 -- Here the array was requested to be packed, but
2763 -- the packing request had no effect whatsoever,
2764 -- so flag Is_Packed is reset.
2766 -- Note: semantically this means that we lose track
2767 -- of the fact that a derived type inherited pragma
2768 -- Pack that was non-effective, but that is fine.
2770 -- We regard a Pack pragma as a request to set a
2771 -- representation characteristic, and this request
2772 -- may be ignored.
2776 else
2783 -- Bit packing is not needed for multiples of the storage
2784 -- unit if the type is composite because the back end can
2785 -- byte pack composite types.
2789 then
2794 -- In all other cases, bit packing is needed
2796 else
2805 -- Check for Aliased or Atomic_Components/Atomic/VFA with
2806 -- unsuitable packing or explicit component size clause given.
2811 and then
2813 then
2817 -- Outputs error messages for incorrect CS clause or pragma
2818 -- Pack for aliased or atomic/VFA components (T is "aliased"
2819 -- or "atomic/vfa");
2821 -----------------
2822 -- Complain_CS --
2823 -----------------
2826 begin
2828 Clause :=
2829 Get_Attribute_Definition_Clause
2832 Error_Msg_N
2836 Error_Msg_N
2839 else
2840 Error_Msg_N
2846 -- Start of processing for Alias_Atomic_Check
2848 begin
2849 -- If object size of component type isn't known, we cannot
2850 -- be sure so we defer to the back end.
2855 -- Case where component size has no effect. First check for
2856 -- object size of component type multiple of the storage
2857 -- unit size.
2861 -- OK in both packing case and component size case if RM
2862 -- size is known and static and same as the object size.
2864 and then
2868 -- Or if we have an explicit component size clause and
2869 -- the component size and object size are equal.
2871 or else
2874 then
2882 then
2891 -- Check for Independent_Components/Independent with unsuitable
2892 -- packing or explicit component size clause given.
2895 and then
2897 then
2898 begin
2899 -- If object size of component type isn't known, we cannot
2900 -- be sure so we defer to the back end.
2905 -- Case where component size has no effect. First check for
2906 -- object size of component type multiple of the storage
2907 -- unit size.
2911 -- OK in both packing case and component size case if RM
2912 -- size is known and multiple of the storage unit size.
2914 and then
2918 -- Or if we have an explicit component size clause and
2919 -- the component size is larger than the object size.
2921 or else
2924 then
2927 else
2929 Clause :=
2930 Get_Attribute_Definition_Clause
2933 Error_Msg_N
2937 Error_Msg_N
2940 else
2941 Error_Msg_N
2949 -- Warn for case of atomic type
2955 then
2956 Error_Msg_NE
2971 -- Check for scalar storage order
2973 declare
2975 begin
2976 Check_Component_Storage_Order
2979 ADC => Get_Attribute_Definition_Clause
2981 Attribute_Scalar_Storage_Order),
2985 -- Processing that is done only for subtypes
2987 else
2988 -- Acquire alignment from base type
2996 -- Specific checks for bit-packed arrays
3000 -- Check number of elements for bit-packed arrays that come from
3001 -- source and have compile time known ranges. The bit-packed
3002 -- arrays circuitry does not support arrays with more than
3003 -- Integer'Last + 1 elements, and when this restriction is
3004 -- violated, causes incorrect data access.
3006 -- For the case where this is not compile time known, a run-time
3007 -- check should be generated???
3010 declare
3016 begin
3022 -- Never generate an error if any index is of a generic
3023 -- type. We will check this in instances.
3030 Ilen :=
3036 -- No attempt is made to check number of elements if not
3037 -- compile time known.
3050 then
3051 Error_Msg_N
3058 -- Check size
3061 declare
3065 begin
3066 -- It is not clear if it is possible to have no size clause
3067 -- at this stage, but it is not worth worrying about. Post
3068 -- error on the entity name in the size clause if present,
3069 -- else on the type entity itself.
3073 else
3080 -- If any of the index types was an enumeration type with a non-
3081 -- standard rep clause, then we indicate that the array type is
3082 -- always packed (even if it is not bit-packed).
3091 -- If the array is packed and bit-packed or packed to eliminate holes
3092 -- in the non-contiguous enumeration index types, we must create the
3093 -- packed array type to be used to actually implement the type. This
3094 -- is only needed for real array types (not for string literal types,
3095 -- since they are present only for the front end).
3100 then
3104 -- Make sure that we have the necessary routines to implement the
3105 -- packing, and complain now if not. Note that we only test this
3106 -- for constrained array types.
3112 then
3113 declare
3117 begin
3120 then
3121 Error_Msg_CRT
3125 -- Cancel the packing
3135 -- Size information of packed array type is copied to the array
3136 -- type, since this is really the representation. But do not
3137 -- override explicit existing size values. If the ancestor subtype
3138 -- is constrained the Packed_Array_Impl_Type will be inherited
3139 -- from it, but the size may have been provided already, and
3140 -- must not be overridden either.
3143 and then
3146 then
3158 -- For non-packed arrays set the alignment of the array to the
3159 -- alignment of the component type if it is unknown. Skip this
3160 -- in atomic/VFA case (atomic/VFA arrays may need larger alignments).
3169 then
3173 -- A Ghost type cannot have a component of protected or task type
3174 -- (SPARK RM 6.9(19)).
3177 Error_Msg_N
3179 Arr);
3183 -------------------------------
3184 -- Freeze_Object_Declaration --
3185 -------------------------------
3188 begin
3189 -- Abstract type allowed only for C++ imported variables or constants
3191 -- Note: we inhibit this check for objects that do not come from
3192 -- source because there is at least one case (the expansion of
3193 -- x'Class'Input where x is abstract) where we legitimately
3194 -- generate an abstract object.
3199 then
3204 Error_Msg_NE
3209 Error_Msg_N -- CODEFIX
3215 -- For object created by object declaration, perform required
3216 -- categorization (preelaborate and pure) checks. Defer these
3217 -- checks to freeze time since pragma Import inhibits default
3218 -- initialization and thus pragma Import affects these checks.
3222 -- If there is an address clause, check that it is valid
3223 -- and if need be move initialization to the freeze node.
3227 -- Similar processing is needed for aspects that may affect
3228 -- object layout, like Alignment, if there is an initialization
3229 -- expression. We don't do this if there is a pragma Linker_Section,
3230 -- because it would prevent the back end from statically initializing
3231 -- the object; we don't want elaboration code in that case.
3234 and then Expander_Active
3238 then
3239 declare
3243 begin
3245 -- Capture initialization value at point of declaration, and
3246 -- make explicit assignment legal, because object may be a
3247 -- constant.
3252 -- Move initialization to freeze actions.
3260 -- Set_Is_Frozen (E, False);
3264 -- Reset Is_True_Constant for non-constant aliased object. We
3265 -- consider that the fact that a non-constant object is aliased may
3266 -- indicate that some funny business is going on, e.g. an aliased
3267 -- object is passed by reference to a procedure which captures the
3268 -- address of the object, which is later used to assign a new value,
3269 -- even though the compiler thinks that it is not modified. Such
3270 -- code is highly dubious, but we choose to make it "work" for
3271 -- non-constant aliased objects.
3273 -- Note that we used to do this for all aliased objects, whether or
3274 -- not constant, but this caused anomalies down the line because we
3275 -- ended up with static objects that were not Is_True_Constant. Not
3276 -- resetting Is_True_Constant for (aliased) constant objects ensures
3277 -- that this anomaly never occurs.
3279 -- However, we don't do that for internal entities. We figure that if
3280 -- we deliberately set Is_True_Constant for an internal entity, e.g.
3281 -- a dispatch table entry, then we mean it.
3286 then
3290 -- If the object needs any kind of default initialization, an error
3291 -- must be issued if No_Default_Initialization applies. The check
3292 -- doesn't apply to imported objects, which are not ever default
3293 -- initialized, and is why the check is deferred until freezing, at
3294 -- which point we know if Import applies. Deferred constants are also
3295 -- exempted from this test because their completion is explicit, or
3296 -- through an import pragma.
3304 and then
3308 or else
3311 then
3313 Check_Restriction
3317 -- Check that a Thread_Local_Storage variable does not have
3318 -- default initialization, and any explicit initialization must
3319 -- either be the null constant or a static constant.
3322 declare
3324 begin
3325 if Has_Default_Initialization
3326 or else
3328 and then
3330 or else not
3333 then
3334 Error_Msg_NE
3337 Error_Msg_NE
3344 -- For imported objects, set Is_Public unless there is also an
3345 -- address clause, which means that there is no external symbol
3346 -- needed for the Import (Is_Public may still be set for other
3347 -- unrelated reasons). Note that we delayed this processing
3348 -- till freeze time so that we can be sure not to set the flag
3349 -- if there is an address clause. If there is such a clause,
3350 -- then the only purpose of the Import pragma is to suppress
3351 -- implicit initialization.
3357 -- For source objects that are not Imported and are library
3358 -- level, if no linker section pragma was given inherit the
3359 -- appropriate linker section from the corresponding type.
3365 then
3366 Set_Linker_Section_Pragma
3370 -- For convention C objects of an enumeration type, warn if the
3371 -- size is not integer size and no explicit size given. Skip
3372 -- warning for Boolean, and Character, assume programmer expects
3373 -- 8-bit sizes for these cases.
3376 or else
3383 then
3385 Error_Msg_N
3391 -----------------------------
3392 -- Freeze_Generic_Entities --
3393 -----------------------------
3400 begin
3419 --------------------
3420 -- Freeze_Profile --
3421 --------------------
3428 begin
3429 -- Loop through formals
3435 -- AI05-0151: incomplete types can appear in a profile. By the
3436 -- time the entity is frozen, the full view must be available,
3437 -- unless it is a limited view.
3442 then
3456 then
3457 -- If the type of a formal is incomplete, subprogram is being
3458 -- frozen prematurely. Within an instance (but not within a
3459 -- wrapper package) this is an artifact of our need to regard
3460 -- the end of an instantiation as a freeze point. Otherwise it
3461 -- is a definite error.
3468 elsif not After_Last_Declaration
3469 and then not Freezing_Library_Level_Tagged_Type
3470 then
3472 Error_Msg
3477 -- Check suspicious parameter for C function. These tests apply
3478 -- only to exported/imported subprograms.
3480 if Warn_On_Export_Import
3483 or else
3490 then
3491 -- Qualify mention of formals with subprogram name
3495 -- Check suspicious use of fat C pointer
3499 then
3500 Error_Msg_N
3503 -- Check suspicious return of boolean
3509 then
3510 Error_Msg_N
3512 Error_Msg_N
3516 -- Check suspicious tagged type
3519 or else
3523 then
3524 Error_Msg_N
3528 -- Check wrong convention subprogram pointer
3532 then
3533 Error_Msg_N
3537 Error_Msg_NE
3542 -- Turn off name qualification after message output
3547 -- Check for unconstrained array in exported foreign convention
3548 -- case.
3554 and then Warn_On_Export_Import
3555 then
3558 -- If this is an inherited operation, place the warning on
3559 -- the derived type declaration, rather than on the original
3560 -- subprogram.
3563 then
3569 else
3585 -- If the formal is an anonymous_access_to_subprogram
3586 -- freeze the subprogram type as well, to prevent
3587 -- scope anomalies in gigi, because there is no other
3588 -- clear point at which it could be frozen.
3592 then
3600 -- Case of function: similar checks on return type
3604 -- Freeze return type
3608 -- AI05-0151: the return type may have been incomplete at the
3609 -- point of declaration. Replace it with the full view, unless the
3610 -- current type is a limited view. In that case the full view is
3611 -- in a different unit, and gigi finds the non-limited view after
3612 -- the other unit is elaborated.
3617 then
3624 -- Check suspicious return type for C function
3626 if Warn_On_Export_Import
3628 or else
3631 then
3632 -- Check suspicious return of fat C pointer
3638 then
3639 Error_Msg_N
3641 E);
3643 -- Check suspicious return of boolean
3650 then
3651 declare
3654 begin
3655 Error_Msg_NE
3657 Error_Msg_NE
3662 -- Check suspicious return tagged type
3666 and then
3667 Is_Tagged_Type
3672 then
3676 -- Check return of wrong convention subprogram pointer
3682 then
3686 Error_Msg_NE
3692 -- Give warning for suspicious return of a result of an
3693 -- unconstrained array type in a foreign convention function.
3697 -- We are looking for a return of unconstrained array
3702 -- Exclude imported routines, the warning does not belong on
3703 -- the import, but rather on the routine definition.
3707 -- Check that general warning is enabled, and that it is not
3708 -- suppressed for this particular case.
3710 and then Warn_On_Export_Import
3713 then
3714 Error_Msg_N
3720 -- Check suspicious use of Import in pure unit (cases where the RM
3721 -- allows calls to be omitted).
3725 -- It might be suspicious if the compilation unit has the Pure
3726 -- aspect/pragma.
3730 -- The RM allows omission of calls only in the case of
3731 -- library-level subprograms (see RM-10.2.1(18)).
3735 -- Ignore internally generated entity. This happens in some cases
3736 -- of subprograms in specs, where we generate an implied body.
3740 -- Assume run-time knows what it is doing
3742 and then not GNAT_Mode
3744 -- Assume explicit Pure_Function means import is pure
3748 -- Don't need warning in relaxed semantics mode
3750 and then not Relaxed_RM_Semantics
3752 -- Assume convention Intrinsic is OK, since this is specialized.
3753 -- This deals with the DEC unit current_exception.ads
3757 -- Assume that ASM interface knows what it is doing. This deals
3758 -- with e.g. unsigned.ads in the AAMP back end.
3761 then
3762 Error_Msg_N
3764 Error_Msg_NE
3772 ------------------------
3773 -- Freeze_Record_Type --
3774 ------------------------
3786 -- Set True if we find at least one component which is aliased. This
3787 -- is used to prevent Implicit_Packing of the record, since packing
3788 -- cannot modify the size of alignment of an aliased component.
3791 -- True if all components are of a type whose underlying type is
3792 -- elementary.
3795 -- True if all components have a known RM_Size
3798 -- True if all components have an RM_Size that is a multiple of the
3799 -- storage unit.
3802 -- Accumulates total Esize values of all elementary components. Used
3803 -- for processing of Implicit_Packing.
3806 -- Set True if we find at least one component with a component
3807 -- clause (used to warn about useless Bit_Order pragmas, and also
3808 -- to detect cases where Implicit_Packing may have an effect).
3811 -- Set True if the record type scope Rec has been pushed on the scope
3812 -- stack. Needed for the analysis of delayed aspects specified to the
3813 -- components of Rec.
3816 -- Accumulates total RM_Size values of all sized components. Used
3817 -- for processing of Implicit_Packing.
3820 -- Accumulates total RM_Size values of all sized components, rounded
3821 -- individually to a multiple of the storage unit.
3824 -- Scalar_Storage_Order attribute definition clause for the record
3827 -- Set True if we find at least one component whose type has a
3828 -- Scalar_Storage_Order attribute definition clause.
3831 -- Set True if we find at least one component with no component
3832 -- clause (used to warn about useless Pack pragmas).
3835 -- If N is an allocator, possibly wrapped in one or more level of
3836 -- qualified expression(s), return the inner allocator node, else
3837 -- return Empty.
3840 -- If the component subtype is an access to a constrained subtype of
3841 -- an already frozen type, make the subtype frozen as well. It might
3842 -- otherwise be frozen in the wrong scope, and a freeze node on
3843 -- subtype has no effect. Similarly, if the component subtype is a
3844 -- regular (not protected) access to subprogram, set the anonymous
3845 -- subprogram type to frozen as well, to prevent an out-of-scope
3846 -- freeze node at some eventual point of call. Protected operations
3847 -- are handled elsewhere.
3850 -- Make sure that all types mentioned in Discrete_Choices of the
3851 -- variants referenceed by the Variant_Part VP are frozen. This is
3852 -- a recursive routine to deal with nested variants.
3854 ---------------------
3855 -- Check_Allocator --
3856 ---------------------
3860 begin
3862 loop
3867 else
3873 -----------------
3874 -- Check_Itype --
3875 -----------------
3880 begin
3883 then
3886 -- In addition, add an Itype_Reference to ensure that the
3887 -- access subtype is elaborated early enough. This cannot be
3888 -- done if the subtype may depend on discriminants.
3893 then
3901 then
3906 ------------------------------------
3907 -- Freeze_Choices_In_Variant_Part --
3908 ------------------------------------
3917 begin
3918 -- Loop through variants
3923 -- Loop through choices, checking that all types are frozen
3929 then
3936 -- Check for nested variant part to process
3950 -- Start of processing for Freeze_Record_Type
3952 begin
3953 -- Deal with delayed aspect specifications for components. The
3954 -- analysis of the aspect is required to be delayed to the freeze
3955 -- point, thus we analyze the pragma or attribute definition
3956 -- clause in the tree at this point. We also analyze the aspect
3957 -- specification node at the freeze point when the aspect doesn't
3958 -- correspond to pragma/attribute definition clause.
3964 then
3969 -- The visibility to the discriminants must be restored in
3970 -- order to properly analyze the aspects.
3983 -- Pop the scope if Rec scope has been pushed on the scope stack
3984 -- during the delayed aspect analysis process.
3991 Pop_Scope;
3994 -- Freeze components and embedded subtypes
4003 -- Handle the component and discriminant case
4006 declare
4009 begin
4010 -- Freezing a record type freezes the type of each of its
4011 -- components. However, if the type of the component is
4012 -- part of this record, we do not want or need a separate
4013 -- Freeze_Node. Note that Is_Itype is wrong because that's
4014 -- also set in private type cases. We also can't check for
4015 -- the Scope being exactly Rec because of private types and
4016 -- record extensions.
4021 then
4027 -- Warn for pragma Pack overriding foreign convention
4032 -- Don't warn for aliased components, since override
4033 -- cannot happen in that case.
4036 then
4037 declare
4042 begin
4046 Error_Msg_N
4048 PP);
4050 Error_Msg_NE
4057 -- Check for error of component clause given for variable
4058 -- sized type. We have to delay this test till this point,
4059 -- since the component type has to be frozen for us to know
4060 -- if it is variable length.
4065 -- We omit this test in a generic context, it will be
4066 -- applied at instantiation time.
4071 -- Also omit this test in CodePeer mode, since we do not
4072 -- have sufficient info on size and rep clauses.
4077 -- Omit check if component has a generic type. This can
4078 -- happen in an instantiation within a generic in ASIS
4079 -- mode, where we force freeze actions without full
4080 -- expansion.
4085 -- Do the check
4087 elsif not
4088 Size_Known_At_Compile_Time
4090 then
4091 Error_Msg_N
4096 else
4100 -- Case of component requires byte alignment
4104 -- Set the enclosing record to also require byte align
4108 -- Check for component clause that is inconsistent with
4109 -- the required byte boundary alignment.
4114 then
4115 Error_Msg_N
4123 -- Gather data for possible Implicit_Packing later. Note that at
4124 -- this stage we might be dealing with a real component, or with
4125 -- an implicit subtype declaration.
4128 declare
4133 begin
4134 Sized_Component_Total_RM_Size :=
4137 Sized_Component_Total_Round_RM_Size :=
4138 Sized_Component_Total_Round_RM_Size +
4143 then
4144 Elem_Component_Total_Esize :=
4146 else
4154 else
4158 -- If the component is an Itype with Delayed_Freeze and is either
4159 -- a record or array subtype and its base type has not yet been
4160 -- frozen, we must remove this from the entity list of this record
4161 -- and put it on the entity list of the scope of its base type.
4162 -- Note that we know that this is not the type of a component
4163 -- since we cleared Has_Delayed_Freeze for it in the previous
4164 -- loop. Thus this must be the Designated_Type of an access type,
4165 -- which is the type of a component.
4173 then
4174 declare
4178 begin
4179 -- We have a difficult case to handle here. Suppose Rec is
4180 -- subtype being defined in a subprogram that's created as
4181 -- part of the freezing of Rec'Base. In that case, we know
4182 -- that Comp'Base must have already been frozen by the time
4183 -- we get to elaborate this because Gigi doesn't elaborate
4184 -- any bodies until it has elaborated all of the declarative
4185 -- part. But Is_Frozen will not be set at this point because
4186 -- we are processing code in lexical order.
4188 -- We detect this case by going up the Scope chain of Rec
4189 -- and seeing if we have a subprogram scope before reaching
4190 -- the top of the scope chain or that of Comp'Base. If we
4191 -- do, then mark that Comp'Base will actually be frozen. If
4192 -- so, we merely undelay it.
4209 else
4212 else
4216 -- Insert in entity list of scope of base type (which
4217 -- must be an enclosing scope, because still unfrozen).
4223 -- If the component is an access type with an allocator as default
4224 -- value, the designated type will be frozen by the corresponding
4225 -- expression in init_proc. In order to place the freeze node for
4226 -- the designated type before that for the current record type,
4227 -- freeze it now.
4229 -- Same process if the component is an array of access types,
4230 -- initialized with an aggregate. If the designated type is
4231 -- private, it cannot contain allocators, and it is premature
4232 -- to freeze the type, so we check for this as well.
4237 then
4238 declare
4242 begin
4245 -- If component is pointer to a class-wide type, freeze
4246 -- the specific type in the expression being allocated.
4247 -- The expression may be a subtype indication, in which
4248 -- case freeze the subtype mark.
4250 if Is_Class_Wide_Type
4252 then
4254 Freeze_And_Append
4258 then
4259 Freeze_And_Append
4267 else
4268 Freeze_And_Append
4276 then
4279 -- Freeze the designated type when initializing a component with
4280 -- an aggregate in case the aggregate contains allocators.
4282 -- type T is ...;
4283 -- type T_Ptr is access all T;
4284 -- type T_Array is array ... of T_Ptr;
4286 -- type Rec is record
4287 -- Comp : T_Array := (others => ...);
4288 -- end record;
4292 then
4293 declare
4296 Designated_Type
4299 begin
4300 -- The only case when this sort of freezing is not done is
4301 -- when the designated type is class-wide and the root type
4302 -- is the record owning the component. This scenario results
4303 -- in a circularity because the class-wide type requires
4304 -- primitives that have not been created yet as the root
4305 -- type is in the process of being frozen.
4307 -- type Rec is tagged;
4308 -- type Rec_Ptr is access all Rec'Class;
4309 -- type Rec_Array is array ... of Rec_Ptr;
4311 -- type Rec is record
4312 -- Comp : Rec_Array := (others => ...);
4313 -- end record;
4317 then
4325 then
4335 SSO_ADC :=
4336 Get_Attribute_Definition_Clause
4339 -- If the record type has Complex_Representation, then it is treated
4340 -- as a scalar in the back end so the storage order is irrelevant.
4344 Error_Msg_N
4346 SSO_ADC);
4349 else
4350 -- Deal with default setting of reverse storage order
4354 -- Check consistent attribute setting on component types
4356 declare
4358 begin
4361 Check_Component_Storage_Order
4371 -- Now deal with reverse storage order/bit order issues
4375 -- Check compatibility of Scalar_Storage_Order with Bit_Order,
4376 -- if the former is specified.
4380 -- Note: report error on Rec, not on SSO_ADC, as ADC may
4381 -- apply to some ancestor type.
4384 Error_Msg_N
4389 -- Warn if there is a Scalar_Storage_Order attribute definition
4390 -- clause but no component clause, no component that itself has
4391 -- such an attribute definition, and no pragma Pack.
4394 or else
4395 SSO_ADC_Component
4396 or else
4398 then
4399 Error_Msg_N
4406 -- Deal with Bit_Order aspect
4414 then
4415 -- Warn if clause has no effect when no component clause is
4416 -- present, but suppress warning if the Bit_Order is required
4417 -- due to the presence of a Scalar_Storage_Order attribute.
4419 Error_Msg_N
4421 Error_Msg_N
4424 -- Here is where we do the processing to adjust component clauses
4425 -- for reversed bit order, when not using reverse SSO. If an error
4426 -- has been reported on Rec already (such as SSO incompatible with
4427 -- bit order), don't bother adjusting as this may generate extra
4428 -- noise.
4433 then
4436 -- Case where we have both an explicit Bit_Order and the same
4437 -- Scalar_Storage_Order: leave record untouched, the back-end
4438 -- will take care of required layout conversions.
4440 else
4446 -- Complete error checking on record representation clause (e.g.
4447 -- overlap of components). This is called after adjusting the
4448 -- record for reverse bit order.
4450 declare
4452 begin
4458 -- Check for useless pragma Pack when all components placed. We only
4459 -- do this check for record types, not subtypes, since a subtype may
4460 -- have all its components placed, and it still makes perfectly good
4461 -- sense to pack other subtypes or the parent type. We do not give
4462 -- this warning if Optimize_Alignment is set to Space, since the
4463 -- pragma Pack does have an effect in this case (it always resets
4464 -- the alignment to one).
4468 and then not Unplaced_Component
4470 then
4471 -- Reset packed status. Probably not necessary, but we do it so
4472 -- that there is no chance of the back end doing something strange
4473 -- with this redundant indication of packing.
4477 -- Give warning if redundant constructs warnings on
4480 Error_Msg_N -- CODEFIX
4486 -- If this is the record corresponding to a remote type, freeze the
4487 -- remote type here since that is what we are semantically freezing.
4488 -- This prevents the freeze node for that type in an inner scope.
4495 -- Check for controlled components, unchecked unions, and type
4496 -- invariants.
4501 -- Do not set Has_Controlled_Component on a class-wide
4502 -- equivalent type. See Make_CW_Equivalent_Type.
4505 and then
4507 or else
4510 or else
4512 and then
4514 and then
4515 Has_Controlled_Component
4517 then
4525 -- The record type requires its own invariant procedure in
4526 -- order to verify the invariant of each individual component.
4527 -- Do not consider internal components such as _parent because
4528 -- parent class-wide invariants are always inherited.
4529 -- In GNATprove mode, the component invariants are checked by
4530 -- other means. They should not be added to the record type
4531 -- invariant procedure, so that the procedure can be used to
4532 -- check the recordy type invariants if any.
4536 and then not GNATprove_Mode
4537 then
4541 -- Scan component declaration for likely misuses of current
4542 -- instance, either in a constraint or a default expression.
4552 -- Enforce the restriction that access attributes with a current
4553 -- instance prefix can only apply to limited types. This comment
4554 -- is floating here, but does not seem to belong here???
4556 -- Set component alignment if not otherwise already set
4560 -- For first subtypes, check if there are any fixed-point fields with
4561 -- component clauses, where we must check the size. This is not done
4562 -- till the freeze point since for fixed-point types, we do not know
4563 -- the size until the type is frozen. Similar processing applies to
4564 -- bit-packed arrays.
4572 then
4573 Check_Size
4577 Junk);
4584 -- See if Size is too small as is (and implicit packing might help)
4588 -- No implicit packing if even one component is explicitly placed
4590 and then not Placed_Component
4592 -- Or even one component is aliased
4594 and then not Aliased_Component
4596 -- Must have size clause and all sized components
4599 and then All_Sized_Components
4601 -- Do not try implicit packing on records with discriminants, too
4602 -- complicated, especially in the variant record case.
4606 -- We want to implicitly pack if the specified size of the record
4607 -- is less than the sum of the object sizes (no point in packing
4608 -- if this is not the case), if we can compute it, i.e. if we have
4609 -- only elementary components. Otherwise, we have at least one
4610 -- composite component and we want to implicitly pack only if bit
4611 -- packing is required for it, as we are sure in this case that
4612 -- the back end cannot do the expected layout without packing.
4614 and then
4615 ((All_Elem_Components
4617 or else
4619 and then not All_Storage_Unit_Components
4622 -- And the total RM size cannot be greater than the specified size
4623 -- since otherwise packing will not get us where we have to be.
4627 -- Never do implicit packing in CodePeer or SPARK modes since
4628 -- we don't do any packing in these modes, since this generates
4629 -- over-complex code that confuses static analysis, and in
4630 -- general, neither CodePeer not GNATprove care about the
4631 -- internal representation of objects.
4634 then
4635 -- If implicit packing enabled, do it
4640 -- Otherwise flag the size clause
4642 else
4643 declare
4645 begin
4646 Error_Msg_NE -- CODEFIX
4648 Error_Msg_N -- CODEFIX
4655 -- The following checks are relevant only when SPARK_Mode is on as
4656 -- they are not standard Ada legality rules.
4660 -- A discriminated type cannot be effectively volatile
4661 -- (SPARK RM 7.1.3(5)).
4668 -- A non-effectively volatile record type cannot contain
4669 -- effectively volatile components (SPARK RM 7.1.3(6)).
4671 else
4676 then
4678 Error_Msg_N
4687 -- A type which does not yield a synchronized object cannot have
4688 -- a component that yields a synchronized object (SPARK RM 9.5).
4695 then
4697 Error_Msg_N
4706 -- A Ghost type cannot have a component of protected or task type
4707 -- (SPARK RM 6.9(19)).
4714 then
4716 Error_Msg_N
4718 Comp);
4726 -- Make sure that if we have an iterator aspect, then we have
4727 -- either Constant_Indexing or Variable_Indexing.
4729 declare
4732 begin
4741 or else
4743 then
4745 else
4746 Error_Msg_N
4748 Iterator_Aspect);
4753 -- All done if not a full record definition
4759 -- Finally we need to check the variant part to make sure that
4760 -- all types within choices are properly frozen as part of the
4761 -- freezing of the record type.
4768 begin
4769 -- Find component list
4781 then
4786 -- Case of variant part present
4792 -- Note: we used to call Check_Choices here, but it is too early,
4793 -- since predicated subtypes are frozen here, but their freezing
4794 -- actions are in Analyze_Freeze_Entity, which has not been called
4795 -- yet for entities frozen within this procedure, so we moved that
4796 -- call to the Analyze_Freeze_Entity for the record type.
4800 -- Check that all the primitives of an interface type are abstract
4801 -- or null procedures.
4805 then
4806 declare
4810 begin
4817 -- Avoid reporting the error on inherited primitives
4820 then
4825 Error_Msg_N
4829 else
4830 Error_Msg_N
4841 -- For a derived tagged type, check whether inherited primitives
4842 -- might require a wrapper to handle class-wide conditions.
4849 -------------------------------
4850 -- Has_Boolean_Aspect_Import --
4851 -------------------------------
4858 begin
4864 -- The value of aspect Import is True when the expression is
4865 -- either missing or it is explicitly set to True.
4871 then
4882 -------------------------
4883 -- Inherit_Freeze_Node --
4884 -------------------------
4886 procedure Inherit_Freeze_Node
4889 is
4892 begin
4896 -- The input type had an existing node. Propagate relevant attributes
4897 -- from the old freeze node to the inherited freeze node.
4899 -- ??? if both freeze nodes have attributes, would they differ?
4903 -- Attribute Access_Types_To_Process
4907 then
4912 -- Attribute Actions
4918 -- Attribute First_Subtype_Link
4922 then
4926 -- Attribute TSS_Elist
4930 then
4936 ------------------------------
4937 -- Wrap_Imported_Subprogram --
4938 ------------------------------
4940 -- The issue here is that our normal approach of checking preconditions
4941 -- and postconditions does not work for imported procedures, since we
4942 -- are not generating code for the body. To get around this we create
4943 -- a wrapper, as shown by the following example:
4945 -- procedure K (A : Integer);
4946 -- pragma Import (C, K);
4948 -- The spec is rewritten by removing the effects of pragma Import, but
4949 -- leaving the convention unchanged, as though the source had said:
4951 -- procedure K (A : Integer);
4952 -- pragma Convention (C, K);
4954 -- and we create a body, added to the entity K freeze actions, which
4955 -- looks like:
4957 -- procedure K (A : Integer) is
4958 -- procedure K (A : Integer);
4959 -- pragma Import (C, K);
4960 -- begin
4961 -- K (A);
4962 -- end K;
4964 -- Now the contract applies in the normal way to the outer procedure,
4965 -- and the inner procedure has no contracts, so there is no problem
4966 -- in just calling it to get the original effect.
4968 -- In the case of a function, we create an appropriate return statement
4969 -- for the subprogram body that calls the inner procedure.
4973 -- Obtain a copy of the Import_Pragma which belongs to subprogram E
4975 ------------------------
4976 -- Copy_Import_Pragma --
4977 ------------------------
4981 -- The subprogram should have an import pragma, otherwise it does
4982 -- need a wrapper.
4987 -- Save all semantic fields of the pragma
4996 begin
4997 -- Reset all semantic fields. This avoids a potential infinite
4998 -- loop when the pragma comes from an aspect as the duplication
4999 -- will copy the aspect, then copy the corresponding pragma and
5000 -- so on.
5009 -- Restore the original semantic fields
5019 -- Local variables
5030 -- Start of processing for Wrap_Imported_Subprogram
5032 begin
5033 -- Nothing to do if not imported
5038 -- Test enabling conditions for wrapping
5043 and then not GNATprove_Mode
5044 then
5045 -- Here we do the wrap
5047 -- Note on calls to Copy_Separate_Tree. The trees we are copying
5048 -- here are fully analyzed, but we definitely want fully syntactic
5049 -- unanalyzed trees in the body we construct, so that the analysis
5050 -- generates the right visibility, and that is exactly what the
5051 -- calls to Copy_Separate_Tree give us.
5055 -- Fix up spec so it is no longer imported and has convention Ada
5063 -- Grab the subprogram declaration and specification
5067 -- Build parameter list that we need
5076 -- Build the call
5079 Stmt :=
5081 Expression =>
5086 else
5087 Stmt :=
5093 -- Now build the body
5095 Bod :=
5097 Specification =>
5102 Prag),
5103 Handled_Statement_Sequence =>
5108 -- Append the body to freeze result
5113 -- Case of imported subprogram that does not get wrapped
5115 else
5116 -- Set Is_Public. All imported entities need an external symbol
5117 -- created for them since they are always referenced from another
5118 -- object file. Note this used to be set when we set Is_Imported
5119 -- back in Sem_Prag, but now we delay it to this point, since we
5120 -- don't want to set this flag if we wrap an imported subprogram.
5126 -- Local variables
5129 -- Save the Ghost mode to restore on exit
5131 -- Start of processing for Freeze_Entity
5133 begin
5134 -- The entity being frozen may be subject to pragma Ghost. Set the mode
5135 -- now to ensure that any nodes generated during freezing are properly
5136 -- flagged as Ghost.
5140 -- We are going to test for various reasons why this entity need not be
5141 -- frozen here, but in the case of an Itype that's defined within a
5142 -- record, that test actually applies to the record.
5148 then
5152 -- Do not freeze if already frozen since we only need one freeze node
5162 -- It is improper to freeze an external entity within a generic because
5163 -- its freeze node will appear in a non-valid context. The entity will
5164 -- be frozen in the proper scope after the current generic is analyzed.
5165 -- However, aspects must be analyzed because they may be queried later
5166 -- within the generic itself, and the corresponding pragma or attribute
5167 -- definition has not been analyzed yet.
5177 -- AI05-0213: A formal incomplete type does not freeze the actual. In
5178 -- the instance, the same applies to the subtype renaming the actual.
5184 then
5188 -- Formal subprograms are never frozen
5194 -- Generic types are never frozen as they lack delayed semantic checks
5200 -- Do not freeze a global entity within an inner scope created during
5201 -- expansion. A call to subprogram E within some internal procedure
5202 -- (a stream attribute for example) might require freezing E, but the
5203 -- freeze node must appear in the same declarative part as E itself.
5204 -- The two-pass elaboration mechanism in gigi guarantees that E will
5205 -- be frozen before the inner call is elaborated. We exclude constants
5206 -- from this test, because deferred constants may be frozen early, and
5207 -- must be diagnosed (e.g. in the case of a deferred constant being used
5208 -- in a default expression). If the enclosing subprogram comes from
5209 -- source, or is a generic instance, then the freeze point is the one
5210 -- mandated by the language, and we freeze the entity. A subprogram that
5211 -- is a child unit body that acts as a spec does not have a spec that
5212 -- comes from source, but can only come from source.
5217 then
5218 declare
5221 begin
5228 then
5230 else
5240 -- Similarly, an inlined instance body may make reference to global
5241 -- entities, but these references cannot be the proper freezing point
5242 -- for them, and in the absence of inlining freezing will take place in
5243 -- their own scope. Normally instance bodies are analyzed after the
5244 -- enclosing compilation, and everything has been frozen at the proper
5245 -- place, but with front-end inlining an instance body is compiled
5246 -- before the end of the enclosing scope, and as a result out-of-order
5247 -- freezing must be prevented.
5249 elsif Front_End_Inlining
5250 and then In_Instance_Body
5252 then
5253 declare
5256 begin
5261 else
5273 -- Add checks to detect proper initialization of scalars that may appear
5274 -- as subprogram parameters.
5280 -- Deal with delayed aspect specifications. The analysis of the aspect
5281 -- is required to be delayed to the freeze point, thus we analyze the
5282 -- pragma or attribute definition clause in the tree at this point. We
5283 -- also analyze the aspect specification node at the freeze point when
5284 -- the aspect doesn't correspond to pragma/attribute definition clause.
5285 -- In addition, a derived type may have inherited aspects that were
5286 -- delayed in the parent, so these must also be captured now.
5290 then
5294 -- Here to freeze the entity
5298 -- Case of entity being frozen is other than a type
5302 -- If entity is exported or imported and does not have an external
5303 -- name, now is the time to provide the appropriate default name.
5304 -- Skip this if the entity is stubbed, since we don't need a name
5305 -- for any stubbed routine. For the case on intrinsics, if no
5306 -- external name is specified, then calls will be handled in
5307 -- Exp_Intr.Expand_Intrinsic_Call, and no name is needed. If an
5308 -- external name is provided, then Expand_Intrinsic_Call leaves
5309 -- calls in place for expansion by GIGI.
5315 then
5316 Set_Encoded_Interface_Name
5319 -- If entity is an atomic object appearing in a declaration and
5320 -- the expression is an aggregate, assign it to a temporary to
5321 -- ensure that the actual assignment is done atomically rather
5322 -- than component-wise (the assignment to the temp may be done
5323 -- component-wise, but that is harmless).
5330 then
5334 -- Subprogram case
5338 -- Check for needing to wrap imported subprogram
5342 -- Freeze all parameter types and the return type (RM 13.14(14)).
5343 -- However skip this for internal subprograms. This is also where
5344 -- any extra formal parameters are created since we now know
5345 -- whether the subprogram will use a foreign convention.
5347 -- In Ada 2012, freezing a subprogram does not always freeze the
5348 -- corresponding profile (see AI05-019). An attribute reference
5349 -- is not a freezing point of the profile. Flag Do_Freeze_Profile
5350 -- indicates whether the profile should be frozen now.
5351 -- Other constructs that should not freeze ???
5353 -- This processing doesn't apply to internal entities (see below)
5361 -- Must freeze its parent first if it is a derived subprogram
5367 -- We don't freeze internal subprograms, because we don't normally
5368 -- want addition of extra formals or mechanism setting to happen
5369 -- for those. However we do pass through predefined dispatching
5370 -- cases, since extra formals may be needed in some cases, such as
5371 -- for the stream 'Input function (build-in-place formals).
5375 then
5379 -- If warning on suspicious contracts then check for the case of
5380 -- a postcondition other than False for a No_Return subprogram.
5383 and then Warn_On_Suspicious_Contract
5385 then
5386 declare
5390 begin
5393 Name_Post,
5394 Name_Postcondition,
5395 Name_Refined_Post)
5396 then
5397 Exp :=
5398 Expression
5403 then
5404 Error_Msg_NE
5415 -- Here for other than a subprogram or type
5417 else
5418 -- If entity has a type, and it is not a generic unit, then
5419 -- freeze it first (RM 13.14(10)).
5423 then
5426 -- For an object of an anonymous array type, aspects on the
5427 -- object declaration apply to the type itself. This is the
5428 -- case for Atomic_Components, Volatile_Components, and
5429 -- Independent_Components. In these cases analysis of the
5430 -- generated pragma will mark the anonymous types accordingly,
5431 -- and the object itself does not require a freeze node.
5437 then
5444 -- Special processing for objects created by object declaration
5450 -- Check that a constant which has a pragma Volatile[_Components]
5451 -- or Atomic[_Components] also has a pragma Import (RM C.6(13)).
5453 -- Note: Atomic[_Components] also sets Volatile[_Components]
5459 then
5460 -- Make sure we actually have a pragma, and have not merely
5461 -- inherited the indication from elsewhere (e.g. an address
5462 -- clause, which is not good enough in RM terms).
5465 or else
5467 then
5468 Error_Msg_N
5473 or else
5475 then
5476 Error_Msg_N
5482 -- Static objects require special handling
5486 then
5490 -- Remaining step is to layout objects
5494 then
5498 -- For an object that does not have delayed freezing, and whose
5499 -- initialization actions have been captured in a compound
5500 -- statement, move them back now directly within the enclosing
5501 -- statement sequence.
5505 then
5509 -- Do not generate a freeze node for a generic unit
5517 -- Case of a type or subtype being frozen
5519 else
5520 -- We used to check here that a full type must have preelaborable
5521 -- initialization if it completes a private type specified with
5522 -- pragma Preelaborable_Initialization, but that missed cases where
5523 -- the types occur within a generic package, since the freezing
5524 -- that occurs within a containing scope generally skips traversal
5525 -- of a generic unit's declarations (those will be frozen within
5526 -- instances). This check was moved to Analyze_Package_Specification.
5528 -- The type may be defined in a generic unit. This can occur when
5529 -- freezing a generic function that returns the type (which is
5530 -- defined in a parent unit). It is clearly meaningless to freeze
5531 -- this type. However, if it is a subtype, its size may be determi-
5532 -- nable and used in subsequent checks, so might as well try to
5533 -- compute it.
5535 -- In Ada 2012, Freeze_Entities is also used in the front end to
5536 -- trigger the analysis of aspect expressions, so in this case we
5537 -- want to continue the freezing process.
5539 -- Is_Generic_Unit (Scope (E)) is dubious here, do we want instead
5540 -- In_Generic_Scope (E)???
5544 and then
5547 then
5553 -- Check for error of Type_Invariant'Class applied to an untagged
5554 -- type (check delayed to freeze time when full type is available).
5556 declare
5558 begin
5562 then
5563 Error_Msg_NE
5565 Error_Msg_N
5572 -- A Ghost type cannot be concurrent (SPARK RM 6.9(19)). Verify
5573 -- this legality rule first to five a finer-grained diagnostic.
5578 -- A Ghost type cannot be effectively volatile (SPARK RM 6.9(7))
5585 -- Deal with special cases of freezing for subtype
5589 -- Before we do anything else, a specific test for the case of a
5590 -- size given for an array where the array would need to be packed
5591 -- in order for the size to be honored, but is not. This is the
5592 -- case where implicit packing may apply. The reason we do this so
5593 -- early is that, if we have implicit packing, the layout of the
5594 -- base type is affected, so we must do this before we freeze the
5595 -- base type.
5597 -- We could do this processing only if implicit packing is enabled
5598 -- since in all other cases, the error would be caught by the back
5599 -- end. However, we choose to do the check even if we do not have
5600 -- implicit packing enabled, since this allows us to give a more
5601 -- useful error message (advising use of pragma Implicit_Packing
5602 -- or pragma Pack).
5605 declare
5617 -- Number of elements in array
5619 begin
5620 -- Check enabling conditions. These are straightforward
5621 -- except for the test for a limited composite type. This
5622 -- eliminates the rare case of a array of limited components
5623 -- where there are issues of whether or not we can go ahead
5624 -- and pack the array (since we can't freely pack and unpack
5625 -- arrays if they are limited).
5627 -- Note that we check the root type explicitly because the
5628 -- whole point is we are doing this test before we have had
5629 -- a chance to freeze the base type (and it is that freeze
5630 -- action that causes stuff to be inherited).
5632 -- The conditions on the size are identical to those used in
5633 -- Freeze_Array_Type to set the Is_Packed flag.
5651 then
5652 -- Compute number of elements in array
5659 and then
5661 then
5669 else
5676 -- What we are looking for here is the situation where
5677 -- the RM_Size given would be exactly right if there was
5678 -- a pragma Pack, resulting in the component size being
5679 -- the RM_Size of the component type.
5683 -- For implicit packing mode, just set the component
5684 -- size and Freeze_Array_Type will do the rest.
5689 -- Otherwise give an error message
5691 else
5692 Error_Msg_NE
5694 Error_Msg_N -- CODEFIX
5705 -- If ancestor subtype present, freeze that first. Note that this
5706 -- will also get the base type frozen. Need RM reference ???
5713 -- No ancestor subtype present
5715 else
5716 -- See if we have a nearest ancestor that has a predicate.
5717 -- That catches the case of derived type with a predicate.
5718 -- Need RM reference here ???
5726 -- Freeze base type before freezing the entity (RM 13.14(15))
5733 -- A subtype inherits all the type-related representation aspects
5734 -- from its parents (RM 13.1(8)).
5738 -- For a derived type, freeze its parent type first (RM 13.14(15))
5744 -- A derived type inherits each type-related representation aspect
5745 -- of its parent type that was directly specified before the
5746 -- declaration of the derived type (RM 13.1(15)).
5751 -- Check for incompatible size and alignment for record type
5753 if Warn_On_Size_Alignment
5757 -- If explicit Object_Size clause given assume that the programmer
5758 -- knows what he is doing, and expects the compiler behavior.
5762 -- Check for size not a multiple of alignment
5765 then
5766 declare
5772 begin
5775 -- Give a warning
5779 Error_Msg_NE
5786 else
5788 Error_Msg_NE
5802 -- Array type
5807 -- For a class-wide type, the corresponding specific type is
5808 -- frozen as well (RM 13.14(15))
5813 -- If the base type of the class-wide type is still incomplete,
5814 -- the class-wide remains unfrozen as well. This is legal when
5815 -- E is the formal of a primitive operation of some other type
5816 -- which is being frozen.
5823 -- The equivalent type associated with a class-wide subtype needs
5824 -- to be frozen to ensure that its layout is done.
5828 then
5832 -- Generate an itype reference for a library-level class-wide type
5833 -- at the freeze point. Otherwise the first explicit reference to
5834 -- the type may appear in an inner scope which will be rejected by
5835 -- the back-end.
5839 then
5840 declare
5843 begin
5846 -- From a gigi point of view, a class-wide subtype derives
5847 -- from its record equivalent type. As a result, the itype
5848 -- reference must appear after the freeze node of the
5849 -- equivalent type or gigi will reject the reference.
5853 then
5855 else
5861 -- For a record type or record subtype, freeze all component types
5862 -- (RM 13.14(15)). We test for E_Record_(sub)Type here, rather than
5863 -- using Is_Record_Type, because we don't want to attempt the freeze
5864 -- for the case of a private type with record extension (we will do
5865 -- that later when the full type is frozen).
5872 -- Report a warning if a discriminated record base type has a
5873 -- convention with language C or C++ applied to it. This check is
5874 -- done even within generic scopes (but not in instantiations),
5875 -- which is why we don't do it as part of Freeze_Record_Type.
5879 -- For a concurrent type, freeze corresponding record type. This does
5880 -- not correspond to any specific rule in the RM, but the record type
5881 -- is essentially part of the concurrent type. Also freeze all local
5882 -- entities. This includes record types created for entry parameter
5883 -- blocks and whatever local entities may appear in the private part.
5897 -- The guard on the presence of the Etype seems to be needed
5898 -- for some CodePeer (-gnatcC) cases, but not clear why???
5903 then
5914 -- Private types are required to point to the same freeze node as
5915 -- their corresponding full views. The freeze node itself has to
5916 -- point to the partial view of the entity (because from the partial
5917 -- view, we can retrieve the full view, but not the reverse).
5918 -- However, in order to freeze correctly, we need to freeze the full
5919 -- view. If we are freezing at the end of a scope (or within the
5920 -- scope) of the private type, the partial and full views will have
5921 -- been swapped, the full view appears first in the entity chain and
5922 -- the swapping mechanism ensures that the pointers are properly set
5923 -- (on scope exit).
5925 -- If we encounter the partial view before the full view (e.g. when
5926 -- freezing from another scope), we freeze the full view, and then
5927 -- set the pointers appropriately since we cannot rely on swapping to
5928 -- fix things up (subtypes in an outer scope might not get swapped).
5930 -- If the full view is itself private, the above requirements apply
5931 -- to the underlying full view instead of the full view. But there is
5932 -- no swapping mechanism for the underlying full view so we need to
5933 -- set the pointers appropriately in both cases.
5937 then
5938 -- The construction of the dispatch table associated with library
5939 -- level tagged types forces freezing of all the primitives of the
5940 -- type, which may cause premature freezing of the partial view.
5941 -- For example:
5943 -- package Pkg is
5944 -- type T is tagged private;
5945 -- type DT is new T with private;
5946 -- procedure Prim (X : in out T; Y : in out DT'Class);
5947 -- private
5948 -- type T is tagged null record;
5949 -- Obj : T;
5950 -- type DT is new T with null record;
5951 -- end;
5953 -- In this case the type will be frozen later by the usual
5954 -- mechanism: an object declaration, an instantiation, or the
5955 -- end of a declarative part.
5959 then
5963 -- Case of full view present
5967 -- If full view has already been frozen, then no further
5968 -- processing is required
5974 -- Otherwise freeze full view and patch the pointers so that
5975 -- the freeze node will elaborate both views in the back end.
5976 -- However, if full view is itself private, freeze underlying
5977 -- full view instead and patch the pointers so that the freeze
5978 -- node will elaborate the three views in the back end.
5980 else
5981 declare
5984 begin
5987 then
5995 then
5999 Inherit_Freeze_Node
6002 else
6012 Inherit_Freeze_Node
6015 else
6016 -- {Incomplete,Private}_Subtypes with Full_Views
6017 -- constrained by discriminants.
6028 -- AI-117 requires that the convention of a partial view be the
6029 -- same as the convention of the full view. Note that this is a
6030 -- recognized breach of privacy, but it's essential for logical
6031 -- consistency of representation, and the lack of a rule in
6032 -- RM95 was an oversight.
6039 -- Size information is copied from the full view to the
6040 -- incomplete or private view for consistency.
6042 -- We skip this is the full view is not a type. This is very
6043 -- strange of course, and can only happen as a result of
6044 -- certain illegalities, such as a premature attempt to derive
6045 -- from an incomplete type.
6054 -- Case of underlying full view present
6058 then
6063 -- Patch the pointers so that the freeze node will elaborate
6064 -- both views in the back end.
6070 Inherit_Freeze_Node
6073 else
6083 -- Case of no full view present. If entity is derived or subtype,
6084 -- it is safe to freeze, correctness depends on the frozen status
6085 -- of parent. Otherwise it is either premature usage, or a Taft
6086 -- amendment type, so diagnosis is at the point of use and the
6087 -- type might be frozen later.
6092 else
6098 -- For access subprogram, freeze types of all formals, the return
6099 -- type was already frozen, since it is the Etype of the function.
6100 -- Formal types can be tagged Taft amendment types, but otherwise
6101 -- they cannot be incomplete.
6108 then
6112 -- AI05-151: Incomplete types are allowed in access to
6113 -- subprogram specifications.
6116 Error_Msg_NE
6127 -- For access to a protected subprogram, freeze the equivalent type
6128 -- (however this is not set if we are not generating code or if this
6129 -- is an anonymous type used just for resolution).
6137 -- Generic types are never seen by the back-end, and are also not
6138 -- processed by the expander (since the expander is turned off for
6139 -- generic processing), so we never need freeze nodes for them.
6145 -- Some special processing for non-generic types to complete
6146 -- representation details not known till the freeze point.
6151 -- Some error checks required for ordinary fixed-point type. Defer
6152 -- these till the freeze-point since we need the small and range
6153 -- values. We only do these checks for base types
6158 Error_Msg_N
6163 Error_Msg_N
6169 Error_Msg_N
6175 Error_Msg_N
6187 and then Warn_On_Suspicious_Modulus_Value
6188 then
6192 -- The pool applies to named and anonymous access types, but not
6193 -- to subprogram and to internal types generated for 'Access
6194 -- references.
6199 then
6200 -- If a pragma Default_Storage_Pool applies, and this type has no
6201 -- Storage_Pool or Storage_Size clause (which must have occurred
6202 -- before the freezing point), then use the default. This applies
6203 -- only to base types.
6205 -- None of this applies to access to subprograms, for which there
6206 -- are clearly no pools.
6212 then
6213 -- Case of pragma Default_Storage_Pool (null)
6218 -- Case of pragma Default_Storage_Pool (storage_pool_NAME)
6220 else
6225 -- Check restriction for standard storage pool
6231 -- Deal with error message for pure access type. This is not an
6232 -- error in Ada 2005 if there is no pool (see AI-366).
6238 then
6242 Error_Msg_N
6246 Error_Msg_N
6249 else
6250 Error_Msg_N
6257 -- Case of composite types
6261 -- AI-117 requires that all new primitives of a tagged type must
6262 -- inherit the convention of the full view of the type. Inherited
6263 -- and overriding operations are defined to inherit the convention
6264 -- of their parent or overridden subprogram (also specified in
6265 -- AI-117), which will have occurred earlier (in Derive_Subprogram
6266 -- and New_Overloaded_Entity). Here we set the convention of
6267 -- primitives that are still convention Ada, which will ensure
6268 -- that any new primitives inherit the type's convention. Class-
6269 -- wide types can have a foreign convention inherited from their
6270 -- specific type, but are excluded from this since they don't have
6271 -- any associated primitives.
6276 then
6277 declare
6281 begin
6293 -- If the type is a simple storage pool type, then this is where
6294 -- we attempt to locate and validate its Allocate, Deallocate, and
6295 -- Storage_Size operations (the first is required, and the latter
6296 -- two are optional). We also verify that the full type for a
6297 -- private type is allowed to be a simple storage pool type.
6301 then
6302 -- If the type is marked Has_Private_Declaration, then this is
6303 -- a full type for a private type that was specified with the
6304 -- pragma Simple_Storage_Pool_Type, and here we ensure that the
6305 -- pragma is allowed for the full type (for example, it can't
6306 -- be an array type, or a nonlimited record type).
6311 then
6313 Error_Msg_N
6324 procedure Validate_Simple_Pool_Op_Formal
6331 -- Validate one formal Pool_Op_Formal of the candidate pool
6332 -- operation Pool_Op. The formal must be of Expected_Type
6333 -- and have mode Expected_Mode. OK_Formal will be set to
6334 -- False if the formal doesn't match. If OK_Formal is False
6335 -- on entry, then the formal will effectively be ignored
6336 -- (because validation of the pool op has already failed).
6337 -- Upon return, Pool_Op_Formal will be updated to the next
6338 -- formal, if any.
6340 procedure Validate_Simple_Pool_Operation
6342 -- Search for and validate a simple pool operation with the
6343 -- name Op_Name. If the name is Allocate, then there must be
6344 -- exactly one such primitive operation for the simple pool
6345 -- type. If the name is Deallocate or Storage_Size, then
6346 -- there can be at most one such primitive operation. The
6347 -- profile of the located primitive must conform to what
6348 -- is expected for each operation.
6350 ------------------------------------
6351 -- Validate_Simple_Pool_Op_Formal --
6352 ------------------------------------
6354 procedure Validate_Simple_Pool_Op_Formal
6361 is
6362 begin
6363 -- If OK_Formal is False on entry, then simply ignore
6364 -- the formal, because an earlier formal has already
6365 -- been flagged.
6370 -- If no formal is passed in, then issue an error for a
6371 -- missing formal.
6374 Error_Msg_NE
6384 -- If the pool type was expected for this formal, then
6385 -- this will not be considered a candidate operation
6386 -- for the simple pool, so we unset OK_Formal so that
6387 -- the op and any later formals will be ignored.
6394 else
6395 Error_Msg_NE
6402 -- Issue error if formal's mode is not the expected one
6405 Error_Msg_N
6407 Pool_Op_Formal);
6410 -- Advance to the next formal
6415 ------------------------------------
6416 -- Validate_Simple_Pool_Operation --
6417 ------------------------------------
6419 procedure Validate_Simple_Pool_Operation
6421 is
6427 begin
6428 pragma Assert
6430 Name_Deallocate,
6431 Name_Storage_Size));
6435 -- For each homonym declared immediately in the scope
6436 -- of the simple storage pool type, determine whether
6437 -- the homonym is an operation of the pool type, and,
6438 -- if so, check that its profile is as expected for
6439 -- a simple pool operation of that name.
6445 then
6450 -- The first parameter must be of the pool type
6451 -- in order for the operation to qualify.
6454 Validate_Simple_Pool_Op_Formal
6457 else
6458 Validate_Simple_Pool_Op_Formal
6463 -- If another operation with this name has already
6464 -- been located for the type, then flag an error,
6465 -- since we only allow the type to have a single
6466 -- such primitive.
6469 Error_Msg_NE
6474 -- In the case of Allocate and Deallocate, a formal
6475 -- of type System.Address is required.
6478 Validate_Simple_Pool_Op_Formal
6483 Validate_Simple_Pool_Op_Formal
6488 -- In the case of Allocate and Deallocate, formals
6489 -- of type Storage_Count are required as the third
6490 -- and fourth parameters.
6493 Validate_Simple_Pool_Op_Formal
6496 Validate_Simple_Pool_Op_Formal
6501 -- If no mismatched formals have been found (Is_OK)
6502 -- and no excess formals are present, then this
6503 -- operation has been validated, so record it.
6513 -- There must be a valid Allocate operation for the type,
6514 -- so issue an error if none was found.
6518 then
6524 -- Simple pool operations can't be abstract
6527 Error_Msg_N
6532 -- The Storage_Size operation must be a function with
6533 -- Storage_Count as its result type.
6537 Error_Msg_N
6541 Error_Msg_NE
6546 -- Allocate and Deallocate must be procedures
6549 Error_Msg_N
6555 -- Start of processing for Validate_Simple_Pool_Ops
6557 begin
6565 -- Now that all types from which E may depend are frozen, see if the
6566 -- size is known at compile time, if it must be unsigned, or if
6567 -- strict alignment is required
6576 -- Do not allow a size clause for a type which does not have a size
6577 -- that is known at compile time
6581 then
6582 -- Suppress this message if errors posted on E, even if we are
6583 -- in all errors mode, since this is often a junk message
6586 Error_Msg_N
6592 -- Now we set/verify the representation information, in particular
6593 -- the size and alignment values. This processing is not required for
6594 -- generic types, since generic types do not play any part in code
6595 -- generation, and so the size and alignment values for such types
6596 -- are irrelevant. Ditto for types declared within a generic unit,
6597 -- which may have components that depend on generic parameters, and
6598 -- that will be recreated in an instance.
6603 -- Otherwise we call the layout procedure
6605 else
6609 -- If this is an access to subprogram whose designated type is itself
6610 -- a subprogram type, the return type of this anonymous subprogram
6611 -- type must be decorated as well.
6615 then
6619 -- If the type has a Defaut_Value/Default_Component_Value aspect,
6620 -- this is where we analye the expression (after the type is frozen,
6621 -- since in the case of Default_Value, we are analyzing with the
6622 -- type itself, and we treat Default_Component_Value similarly for
6623 -- the sake of uniformity).
6626 declare
6631 begin
6636 else
6647 Flag_Non_Static_Expr
6654 -- End of freeze processing for type entities
6657 -- Here is where we logically freeze the current entity. If it has a
6658 -- freeze node, then this is the point at which the freeze node is
6659 -- linked into the result list.
6663 -- If a freeze node is already allocated, use it, otherwise allocate
6664 -- a new one. The preallocation happens in the case of anonymous base
6665 -- types, where we preallocate so that we can set First_Subtype_Link.
6666 -- Note that we reset the Sloc to the current freeze location.
6672 else
6683 -- A final pass over record types with discriminants. If the type
6684 -- has an incomplete declaration, there may be constrained access
6685 -- subtypes declared elsewhere, which do not depend on the discrimi-
6686 -- nants of the type, and which are used as component types (i.e.
6687 -- the full view is a recursive type). The designated types of these
6688 -- subtypes can only be elaborated after the type itself, and they
6689 -- need an itype reference.
6692 declare
6697 begin
6707 then
6719 -- When a type is frozen, the first subtype of the type is frozen as
6720 -- well (RM 13.14(15)). This has to be done after freezing the type,
6721 -- since obviously the first subtype depends on its own base type.
6726 -- If we just froze a tagged non-class wide record, then freeze the
6727 -- corresponding class-wide type. This must be done after the tagged
6728 -- type itself is frozen, because the class-wide type refers to the
6729 -- tagged type which generates the class.
6734 then
6741 -- Special handling for subprograms
6745 -- If subprogram has address clause then reset Is_Public flag, since
6746 -- we do not want the backend to generate external references.
6750 then
6761 -----------------------------
6762 -- Freeze_Enumeration_Type --
6763 -----------------------------
6766 begin
6767 -- By default, if no size clause is present, an enumeration type with
6768 -- Convention C is assumed to interface to a C enum, and has integer
6769 -- size. This applies to types. For subtypes, verify that its base
6770 -- type has no size clause either. Treat other foreign conventions
6771 -- in the same way, and also make sure alignment is set right.
6778 -- Don't do this if Short_Enums on target
6780 and then not Target_Short_Enums
6781 then
6785 -- Normal Ada case or size clause present or not Long_C_Enums on target
6787 else
6788 -- If the enumeration type interfaces to C, and it has a size clause
6789 -- that specifies less than int size, it warrants a warning. The
6790 -- user may intend the C type to be an enum or a char, so this is
6791 -- not by itself an error that the Ada compiler can detect, but it
6792 -- it is a worth a heads-up. For Boolean and Character types we
6793 -- assume that the programmer has the proper C type in mind.
6801 -- Don't do this if Short_Enums on target
6803 and then not Target_Short_Enums
6804 then
6805 Error_Msg_N
6813 -----------------------
6814 -- Freeze_Expression --
6815 -----------------------
6826 -- This flag is set true if the entity must be frozen outside the
6827 -- current subprogram. This happens in the case of expander generated
6828 -- subprograms (_Init_Proc, _Input, _Output, _Read, _Write) which do
6829 -- not freeze all entities like other bodies, but which nevertheless
6830 -- may reference entities that have to be frozen before the body and
6831 -- obviously cannot be frozen inside the body.
6834 -- If the expression is an array aggregate, the type of the component
6835 -- expressions is also frozen. If the component type is an access type
6836 -- and the expressions include allocators, the designed type is frozen
6837 -- as well.
6840 -- Given an N_Handled_Sequence_Of_Statements node N, determines whether
6841 -- it is the handled statement sequence of an expander-generated
6842 -- subprogram (init proc, stream subprogram, or renaming as body).
6843 -- If so, this is not a freezing context.
6845 -----------------------------------------
6846 -- Find_Aggregate_Component_Desig_Type --
6847 -----------------------------------------
6853 begin
6879 ----------------------
6880 -- In_Expanded_Body --
6881 ----------------------
6887 begin
6890 else
6897 else
6900 -- The following are expander-created bodies, or bodies that
6901 -- are not freeze points.
6910 N_Subprogram_Renaming_Declaration,
6911 N_Expression_Function))
6912 then
6914 else
6920 -- Start of processing for Freeze_Expression
6922 begin
6923 -- Immediate return if freezing is inhibited. This flag is set by the
6924 -- analyzer to stop freezing on generated expressions that would cause
6925 -- freezing if they were in the source program, but which are not
6926 -- supposed to freeze, since they are created.
6932 -- If expression is non-static, then it does not freeze in a default
6933 -- expression, see section "Handling of Default Expressions" in the
6934 -- spec of package Sem for further details. Note that we have to make
6935 -- sure that we actually have a real expression (if we have a subtype
6936 -- indication, we can't test Is_OK_Static_Expression). However, we
6937 -- exclude the case of the prefix of an attribute of a static scalar
6938 -- subtype from this early return, because static subtype attributes
6939 -- should always cause freezing, even in default expressions, but
6940 -- the attribute may not have been marked as static yet (because in
6941 -- Resolve_Attribute, the call to Eval_Attribute follows the call of
6942 -- Freeze_Expression on the prefix).
6944 if In_Spec_Exp
6951 then
6955 -- Freeze type of expression if not frozen already
6963 -- Base type may be an derived numeric type that is frozen at
6964 -- the point of declaration, but first_subtype is still unfrozen.
6971 -- For entity name, freeze entity if not frozen already. A special
6972 -- exception occurs for an identifier that did not come from source.
6973 -- We don't let such identifiers freeze a non-internal entity, i.e.
6974 -- an entity that did come from source, since such an identifier was
6975 -- generated by the expander, and cannot have any semantic effect on
6976 -- the freezing semantics. For example, this stops the parameter of
6977 -- an initialization procedure from freezing the variable.
6984 then
6991 else
6995 -- For an allocator freeze designated type if not frozen already
6997 -- For an aggregate whose component type is an access type, freeze the
6998 -- designated type now, so that its freeze does not appear within the
6999 -- loop that might be created in the expansion of the aggregate. If the
7000 -- designated type is a private type without full view, the expression
7001 -- cannot contain an allocator, so the type is not frozen.
7003 -- For a function, we freeze the entity when the subprogram declaration
7004 -- is frozen, but a function call may appear in an initialization proc.
7005 -- before the declaration is frozen. We need to generate the extra
7006 -- formals, if any, to ensure that the expansion of the call includes
7007 -- the proper actuals. This only applies to Ada subprograms, not to
7008 -- imported ones.
7019 then
7021 -- Check whether aggregate includes allocators.
7026 when N_Indexed_Component
7027 | N_Selected_Component
7028 | N_Slice
7029 =>
7039 then
7050 then
7054 -- All done if nothing needs freezing
7059 then
7063 -- Examine the enclosing context by climbing the parent chain. The
7064 -- traversal serves two purposes - to detect scenarios where freezeing
7065 -- is not needed and to find the proper insertion point for the freeze
7066 -- nodes. Although somewhat similar to Insert_Actions, this traversal
7067 -- is freezing semantics-sensitive. Inserting freeze nodes blindly in
7068 -- the tree may result in types being frozen too early.
7071 loop
7074 -- If we don't have a parent, then we are not in a well-formed tree.
7075 -- This is an unusual case, but there are some legitimate situations
7076 -- in which this occurs, notably when the expressions in the range of
7077 -- a type declaration are resolved. We simply ignore the freeze
7078 -- request in this case. Is this right ???
7084 -- See if we have got to an appropriate point in the tree
7088 -- A special test for the exception of (RM 13.14(8)) for the case
7089 -- of per-object expressions (RM 3.8(18)) occurring in component
7090 -- definition or a discrete subtype definition. Note that we test
7091 -- for a component declaration which includes both cases we are
7092 -- interested in, and furthermore the tree does not have explicit
7093 -- nodes for either of these two constructs.
7097 -- The case we want to test for here is an identifier that is
7098 -- a per-object expression, this is either a discriminant that
7099 -- appears in a context other than the component declaration
7100 -- or it is a reference to the type of the enclosing construct.
7102 -- For either of these cases, we skip the freezing
7104 if not In_Spec_Expression
7107 then
7108 -- We recognize the discriminant case by just looking for
7109 -- a reference to a discriminant. It can only be one for
7110 -- the enclosing construct. Skip freezing in this case.
7115 -- For the case of a reference to the enclosing record,
7116 -- (or task or protected type), we look for a type that
7117 -- matches the current scope.
7124 -- If we have an enumeration literal that appears as the choice in
7125 -- the aggregate of an enumeration representation clause, then
7126 -- freezing does not occur (RM 13.14(10)).
7130 -- The case we are looking for is an enumeration literal
7134 then
7135 -- If enumeration literal appears directly as the choice,
7136 -- do not freeze (this is the normal non-overloaded case)
7140 then
7143 -- If enumeration literal appears as the name of function
7144 -- which is the choice, then also do not freeze. This
7145 -- happens in the overloaded literal case, where the
7146 -- enumeration literal is temporarily changed to a function
7147 -- call for overloading analysis purposes.
7150 and then
7152 and then
7154 then
7159 -- Normally if the parent is a handled sequence of statements,
7160 -- then the current node must be a statement, and that is an
7161 -- appropriate place to insert a freeze node.
7165 -- An exception occurs when the sequence of statements is for
7166 -- an expander generated body that did not do the usual freeze
7167 -- all operation. In this case we usually want to freeze
7168 -- outside this body, not inside it, and we skip past the
7169 -- subprogram body that we are inside.
7172 declare
7176 begin
7177 -- Freeze the entity only when it is declared inside the
7178 -- body of the expander generated procedure. This case
7179 -- is recognized by the scope of the entity or its type,
7180 -- which is either the spec for some enclosing body, or
7181 -- (in the case of init_procs, for which there are no
7182 -- separate specs) the current scope.
7188 or else
7190 then
7196 then
7201 -- An expression function may act as a completion of
7202 -- a function declaration. As such, it can reference
7203 -- entities declared between the two views:
7205 -- Hidden []; -- 1
7206 -- function F return ...;
7207 -- private
7208 -- function Hidden return ...;
7209 -- function F return ... is (Hidden); -- 2
7211 -- Refering to the example above, freezing the expression
7212 -- of F (2) would place Hidden's freeze node (1) in the
7213 -- wrong place. Avoid explicit freezing and let the usual
7214 -- scenarios do the job - for example, reaching the end
7215 -- of the private declarations, or a call to F.
7218 N_Expression_Function
7219 then
7222 -- Freeze outside the body
7224 else
7230 -- Here if normal case where we are in handled statement
7231 -- sequence and want to do the insertion right there.
7233 else
7237 -- If parent is a body or a spec or a block, then the current node
7238 -- is a statement or declaration and we can insert the freeze node
7239 -- before it.
7241 when N_Block_Statement
7242 | N_Entry_Body
7243 | N_Package_Body
7244 | N_Package_Specification
7245 | N_Protected_Body
7246 | N_Subprogram_Body
7247 | N_Task_Body
7248 =>
7251 -- The expander is allowed to define types in any statements list,
7252 -- so any of the following parent nodes also mark a freezing point
7253 -- if the actual node is in a list of statements or declarations.
7255 when N_Abortable_Part
7256 | N_Accept_Alternative
7257 | N_And_Then
7258 | N_Case_Statement_Alternative
7259 | N_Compilation_Unit_Aux
7260 | N_Conditional_Entry_Call
7261 | N_Delay_Alternative
7262 | N_Elsif_Part
7263 | N_Entry_Call_Alternative
7264 | N_Exception_Handler
7265 | N_Extended_Return_Statement
7266 | N_Freeze_Entity
7267 | N_If_Statement
7268 | N_Or_Else
7269 | N_Selective_Accept
7270 | N_Triggering_Alternative
7271 =>
7274 -- Freeze nodes produced by an expression coming from the Actions
7275 -- list of a N_Expression_With_Actions node must remain within the
7276 -- Actions list. Inserting the freeze nodes further up the tree
7277 -- may lead to use before declaration issues in the case of array
7278 -- types.
7283 then
7287 -- Note: N_Loop_Statement is a special case. A type that appears
7288 -- in the source can never be frozen in a loop (this occurs only
7289 -- because of a loop expanded by the expander), so we keep on
7290 -- going. Otherwise we terminate the search. Same is true of any
7291 -- entity which comes from source. (if they have predefined type,
7292 -- that type does not appear to come from source, but the entity
7293 -- should not be frozen here).
7299 -- For all other cases, keep looking at parents
7305 -- We fall through the case if we did not yet find the proper
7306 -- place in the free for inserting the freeze node, so climb.
7311 -- If the expression appears in a record or an initialization procedure,
7312 -- the freeze nodes are collected and attached to the current scope, to
7313 -- be inserted and analyzed on exit from the scope, to insure that
7314 -- generated entities appear in the correct scope. If the expression is
7315 -- a default for a discriminant specification, the scope is still void.
7316 -- The expression can also appear in the discriminant part of a private
7317 -- or concurrent type.
7319 -- If the expression appears in a constrained subcomponent of an
7320 -- enclosing record declaration, the freeze nodes must be attached to
7321 -- the outer record type so they can eventually be placed in the
7322 -- enclosing declaration list.
7324 -- The other case requiring this special handling is if we are in a
7325 -- default expression, since in that case we are about to freeze a
7326 -- static type, and the freeze scope needs to be the outer scope, not
7327 -- the scope of the subprogram with the default parameter.
7329 -- For default expressions and other spec expressions in generic units,
7330 -- the Move_Freeze_Nodes mechanism (see sem_ch12.adb) takes care of
7331 -- placing them at the proper place, after the generic unit.
7334 or else Freeze_Outside
7339 then
7340 declare
7345 begin
7358 -- The current scope may be that of a constrained component of
7359 -- an enclosing record declaration, or of a loop of an enclosing
7360 -- quantified expression, which is above the current scope in the
7361 -- scope stack. Indeed in the context of a quantified expression,
7362 -- a scope is created and pushed above the current scope in order
7363 -- to emulate the loop-like behavior of the quantified expression.
7364 -- If the expression is within a top-level pragma, as for a pre-
7365 -- condition on a library-level subprogram, nothing to do.
7370 N_Quantified_Expression)
7371 then
7378 Freeze_Nodes;
7379 else
7389 -- Now we have the right place to do the freezing. First, a special
7390 -- adjustment, if we are in spec-expression analysis mode, these freeze
7391 -- actions must not be thrown away (normally all inserted actions are
7392 -- thrown away in this mode. However, the freeze actions are from static
7393 -- expressions and one of the important reasons we are doing this
7394 -- special analysis is to get these freeze actions. Therefore we turn
7395 -- off the In_Spec_Expression mode to propagate these freeze actions.
7396 -- This also means they get properly analyzed and expanded.
7400 -- Freeze the designated type of an allocator (RM 13.14(13))
7406 -- Freeze type of expression (RM 13.14(10)). Note that we took care of
7407 -- the enumeration representation clause exception in the loop above.
7413 -- Freeze name if one is present (RM 13.14(11))
7419 -- Restore In_Spec_Expression flag
7424 -----------------------------
7425 -- Freeze_Fixed_Point_Type --
7426 -----------------------------
7428 -- Certain fixed-point types and subtypes, including implicit base types
7429 -- and declared first subtypes, have not yet set up a range. This is
7430 -- because the range cannot be set until the Small and Size values are
7431 -- known, and these are not known till the type is frozen.
7433 -- To signal this case, Scalar_Range contains an unanalyzed syntactic range
7434 -- whose bounds are unanalyzed real literals. This routine will recognize
7435 -- this case, and transform this range node into a properly typed range
7436 -- with properly analyzed and resolved values.
7453 -- Save original bounds (for shaving tests)
7456 -- Actual size chosen
7459 -- Returns size of type with given bounds. Also leaves these
7460 -- bounds set as the current bounds of the Typ.
7462 -----------
7463 -- Fsize --
7464 -----------
7467 begin
7473 -- Start of processing for Freeze_Fixed_Point_Type
7475 begin
7476 -- If Esize of a subtype has not previously been set, set it now
7483 else
7488 -- Immediate return if the range is already analyzed. This means that
7489 -- the range is already set, and does not need to be computed by this
7490 -- routine.
7496 -- Immediate return if either of the bounds raises Constraint_Error
7500 then
7510 -- Ordinary fixed-point case
7514 -- For the ordinary fixed-point case, we are allowed to fudge the
7515 -- end-points up or down by small. Generally we prefer to fudge up,
7516 -- i.e. widen the bounds for non-model numbers so that the end points
7517 -- are included. However there are cases in which this cannot be
7518 -- done, and indeed cases in which we may need to narrow the bounds.
7519 -- The following circuit makes the decision.
7521 -- Note: our terminology here is that Incl_EP means that the bounds
7522 -- are widened by Small if necessary to include the end points, and
7523 -- Excl_EP means that the bounds are narrowed by Small to exclude the
7524 -- end-points if this reduces the size.
7526 -- Note that in the Incl case, all we care about is including the
7527 -- end-points. In the Excl case, we want to narrow the bounds as
7528 -- much as permitted by the RM, to give the smallest possible size.
7545 begin
7546 -- First step. Base types are required to be symmetrical. Right
7547 -- now, the base type range is a copy of the first subtype range.
7548 -- This will be corrected before we are done, but right away we
7549 -- need to deal with the case where both bounds are non-negative.
7550 -- In this case, we set the low bound to the negative of the high
7551 -- bound, to make sure that the size is computed to include the
7552 -- required sign. Note that we do not need to worry about the
7553 -- case of both bounds negative, because the sign will be dealt
7554 -- with anyway. Furthermore we can't just go making such a bound
7555 -- symmetrical, since in a twos-complement system, there is an
7556 -- extra negative value which could not be accommodated on the
7557 -- positive side.
7562 then
7567 -- Compute the fudged bounds. If the number is a model number,
7568 -- then we do nothing to include it, but we are allowed to backoff
7569 -- to the next adjacent model number when we exclude it. If it is
7570 -- not a model number then we straddle the two values with the
7571 -- model numbers on either side.
7577 else
7581 -- The low value excluding the end point is Small greater, but
7582 -- we do not do this exclusion if the low value is positive,
7583 -- since it can't help the size and could actually hurt by
7584 -- crossing the high bound.
7589 -- If the value went from negative to zero, then we have the
7590 -- case where Loval_Incl_EP is the model number just below
7591 -- zero, so we want to stick to the negative value for the
7592 -- base type to maintain the condition that the size will
7593 -- include signed values.
7597 then
7601 else
7605 -- Similar processing for upper bound and high value
7611 else
7617 else
7621 -- One further adjustment is needed. In the case of subtypes, we
7622 -- cannot go outside the range of the base type, or we get
7623 -- peculiarities, and the base type range is already set. This
7624 -- only applies to the Incl values, since clearly the Excl values
7625 -- are already as restricted as they are allowed to be.
7632 -- Get size including and excluding end points
7637 -- No need to exclude end-points if it does not reduce size
7647 -- Now we set the actual size to be used. We want to use the
7648 -- bounds fudged up to include the end-points but only if this
7649 -- can be done without violating a specifically given size
7650 -- size clause or causing an unacceptable increase in size.
7652 -- Case of size clause given
7656 -- Use the inclusive size only if it is consistent with
7657 -- the explicitly specified size.
7664 -- If the inclusive size is too large, we try excluding
7665 -- the end-points (will be caught later if does not work).
7667 else
7673 -- Case of size clause not given
7675 else
7676 -- If we have a base type whose corresponding first subtype
7677 -- has an explicit size that is large enough to include our
7678 -- end-points, then do so. There is no point in working hard
7679 -- to get a base type whose size is smaller than the specified
7680 -- size of the first subtype.
7686 then
7691 -- If excluding the end-points makes the size smaller and
7692 -- results in a size of 8,16,32,64, then we take the smaller
7693 -- size. For the 64 case, this is compulsory. For the other
7694 -- cases, it seems reasonable. We like to include end points
7695 -- if we can, but not at the expense of moving to the next
7696 -- natural boundary of size.
7700 then
7705 -- Otherwise we can definitely include the end points
7707 else
7713 -- One pathological case: normally we never fudge a low bound
7714 -- down, since it would seem to increase the size (if it has
7715 -- any effect), but for ranges containing single value, or no
7716 -- values, the high bound can be small too large. Consider:
7718 -- type t is delta 2.0**(-14)
7719 -- range 131072.0 .. 0;
7721 -- That lower bound is *just* outside the range of 32 bits, and
7722 -- does need fudging down in this case. Note that the bounds
7723 -- will always have crossed here, since the high bound will be
7724 -- fudged down if necessary, as in the case of:
7726 -- type t is delta 2.0**(-14)
7727 -- range 131072.0 .. 131072.0;
7729 -- So we detect the situation by looking for crossed bounds,
7730 -- and if the bounds are crossed, and the low bound is greater
7731 -- than zero, we will always back it off by small, since this
7732 -- is completely harmless.
7739 -- And of course, we need to do exactly the same parallel
7740 -- fudge for flat ranges in the negative region.
7753 -- For the decimal case, none of this fudging is required, since there
7754 -- are no end-point problems in the decimal case (the end-points are
7755 -- always included).
7757 else
7761 -- At this stage, the actual size has been calculated and the proper
7762 -- required bounds are stored in the low and high bounds.
7766 Error_Msg_N
7768 Typ);
7772 -- Check size against explicit given size
7778 Error_Msg_NE
7782 else
7786 -- Increase size to next natural boundary if no size clause given
7788 else
7795 else
7803 -- If we have a base type, then expand the bounds so that they extend to
7804 -- the full width of the allocated size in bits, to avoid junk range
7805 -- checks on intermediate computations.
7812 -- Final step is to reanalyze the bounds using the proper type
7813 -- and set the Corresponding_Integer_Value fields of the literals.
7819 -- Resolve with universal fixed if the base type, and the base type if
7820 -- it is a subtype. Note we can't resolve the base type with itself,
7821 -- that would be a reference before definition.
7825 else
7829 -- Set corresponding integer value for bound
7831 Set_Corresponding_Integer_Value
7834 -- Similar processing for high bound
7842 else
7846 Set_Corresponding_Integer_Value
7849 -- Set type of range to correspond to bounds
7853 -- Set Esize to calculated size if not set already
7859 -- Set RM_Size if not already set. If already set, check value
7861 declare
7864 begin
7869 Error_Msg_NE
7874 else
7879 -- Check for shaving
7883 -- In SPARK mode the given bounds must be strictly representable
7887 Error_Msg_NE
7893 Error_Msg_NE
7898 else
7900 Error_Msg_N
7902 Error_Msg_N
7907 Error_Msg_N
7909 Typ);
7910 Error_Msg_N
7917 ------------------
7918 -- Freeze_Itype --
7919 ------------------
7924 begin
7933 --------------------------
7934 -- Freeze_Static_Object --
7935 --------------------------
7940 -- Exception raised if the type of a static object cannot be made
7941 -- static. This happens if the type depends on non-global objects.
7944 -- Called to ensure that an expression used as part of a type definition
7945 -- is statically allocatable, which means that the expression type is
7946 -- statically allocatable, and the expression is either static, or a
7947 -- reference to a library level constant.
7950 -- Called to mark a type as static, checking that it is possible
7951 -- to set the type as static. If it is not possible, then the
7952 -- exception Cannot_Be_Static is raised.
7954 -----------------------------
7955 -- Ensure_Expression_Is_SA --
7956 -----------------------------
7961 begin
7973 then
7981 -----------------------
7982 -- Ensure_Type_Is_SA --
7983 -----------------------
7989 begin
7990 -- If type is library level, we are all set
7996 -- We are also OK if the type already marked as statically allocated,
7997 -- which means we processed it before.
8003 -- Mark type as statically allocated
8007 -- Check that it is safe to statically allocate this type
8025 declare
8029 begin
8041 else
8050 then
8069 else
8074 -- Start of processing for Freeze_Static_Object
8076 begin
8079 exception
8082 -- If the object that cannot be static is imported or exported, then
8083 -- issue an error message saying that this object cannot be imported
8084 -- or exported. If it has an address clause it is an overlay in the
8085 -- current partition and the static requirement is not relevant.
8086 -- Do not issue any error message when ignoring rep clauses.
8093 Error_Msg_N
8097 -- Otherwise must be exported, something is wrong if compiler
8098 -- is marking something as statically allocated which cannot be).
8101 Error_Msg_N
8106 -----------------------
8107 -- Freeze_Subprogram --
8108 -----------------------
8112 -- Set the conventions of all anonymous access-to-subprogram formals and
8113 -- result subtype of subprogram Subp_Id to the convention of Subp_Id.
8115 ----------------------------
8116 -- Set_Profile_Convention --
8117 ----------------------------
8123 -- Set the convention of anonymous access-to-subprogram type Typ and
8124 -- its designated type to Conv.
8126 -------------------------
8127 -- Set_Type_Convention --
8128 -------------------------
8131 begin
8132 -- Set the convention on both the anonymous access-to-subprogram
8133 -- type and the subprogram type it points to because both types
8134 -- participate in conformance-related checks.
8142 -- Local variables
8146 -- Start of processing for Set_Profile_Convention
8148 begin
8160 -- Local variables
8165 -- Start of processing for Freeze_Subprogram
8167 begin
8168 -- Subprogram may not have an address clause unless it is imported
8172 Error_Msg_N
8178 -- Reset the Pure indication on an imported subprogram unless an
8179 -- explicit Pure_Function pragma was present or the subprogram is an
8180 -- intrinsic. We do this because otherwise it is an insidious error
8181 -- to call a non-pure function from pure unit and have calls
8182 -- mysteriously optimized away. What happens here is that the Import
8183 -- can bypass the normal check to ensure that pure units call only pure
8184 -- subprograms.
8186 -- The reason for the intrinsic exception is that in general, intrinsic
8187 -- functions (such as shifts) are pure anyway. The only exceptions are
8188 -- the intrinsics in GNAT.Source_Info, and that unit is not marked Pure
8189 -- in any case, so no problem arises.
8195 then
8199 -- We also reset the Pure indication on a subprogram with an Address
8200 -- parameter, because the parameter may be used as a pointer and the
8201 -- referenced data may change even if the address value does not.
8203 -- Note that if the programmer gave an explicit Pure_Function pragma,
8204 -- then we believe the programmer, and leave the subprogram Pure. We
8205 -- also suppress this check on run-time files.
8211 then
8215 -- Ensure that all anonymous access-to-subprogram types inherit the
8216 -- convention of their related subprogram (RM 6.3.1 13.1/3). This is
8217 -- not done for a defaulted convention Ada because those types also
8218 -- default to Ada. Convention Protected must not be propagated when
8219 -- the subprogram is an entry because this would be illegal. The only
8220 -- way to force convention Protected on these kinds of types is to
8221 -- include keyword "protected" in the access definition.
8225 then
8229 -- For non-foreign convention subprograms, this is where we create
8230 -- the extra formals (for accessibility level and constrained bit
8231 -- information). We delay this till the freeze point precisely so
8232 -- that we know the convention.
8241 -- If this is convention Ada and a Valued_Procedure, that's odd
8246 and then Warn_On_Export_Import
8247 then
8248 Error_Msg_N
8253 -- Case of foreign convention
8255 else
8258 -- For foreign conventions, warn about return of unconstrained array
8263 -- If no return type, probably some other error, e.g. a
8264 -- missing full declaration, so ignore.
8269 -- If the return type is generic, we have emitted a warning
8270 -- earlier on, and there is nothing else to check here. Specific
8271 -- instantiations may lead to erroneous behavior.
8276 -- Display warning if returning unconstrained array
8281 -- Check appropriate warning is enabled (should we check for
8282 -- Warnings (Off) on specific entities here, probably so???)
8284 and then Warn_On_Export_Import
8285 then
8286 Error_Msg_N
8293 -- If any of the formals for an exported foreign convention
8294 -- subprogram have defaults, then emit an appropriate warning since
8295 -- this is odd (default cannot be used from non-Ada code)
8300 if Warn_On_Export_Import
8302 then
8303 Error_Msg_N
8313 -- Pragma Inline_Always is disallowed for dispatching subprograms
8314 -- because the address of such subprograms is saved in the dispatch
8315 -- table to support dispatching calls, and dispatching calls cannot
8316 -- be inlined. This is consistent with the restriction against using
8317 -- 'Access or 'Address on an Inline_Always subprogram.
8321 then
8322 Error_Msg_N
8326 -- Because of the implicit representation of inherited predefined
8327 -- operators in the front-end, the overriding status of the operation
8328 -- may be affected when a full view of a type is analyzed, and this is
8329 -- not captured by the analysis of the corresponding type declaration.
8330 -- Therefore the correctness of a not-overriding indicator must be
8331 -- rechecked when the subprogram is frozen.
8335 then
8339 if Modify_Tree_For_C
8345 then
8350 ----------------------
8351 -- Is_Fully_Defined --
8352 ----------------------
8355 begin
8364 then
8365 -- Verify that the record type has no components with private types
8366 -- without completion.
8368 declare
8371 begin
8383 -- For the designated type of an access to subprogram, all types in
8384 -- the profile must be fully defined.
8387 declare
8390 begin
8403 else
8409 ---------------------------------
8410 -- Process_Default_Expressions --
8411 ---------------------------------
8413 procedure Process_Default_Expressions
8416 is
8423 begin
8426 -- A subprogram instance and its associated anonymous subprogram share
8427 -- their signature. The default expression functions are defined in the
8428 -- wrapper packages for the anonymous subprogram, and should not be
8429 -- generated again for the instance.
8434 then
8442 -- We work with a copy of the default expression because we
8443 -- do not want to disturb the original, since this would mess
8444 -- up the conformance checking.
8448 -- The analysis of the expression may generate insert actions,
8449 -- which of course must not be executed. We wrap those actions
8450 -- in a procedure that is not called, and later on eliminated.
8451 -- The following cases have no side effects, and are analyzed
8452 -- directly.
8456 N_Integer_Literal,
8457 N_Character_Literal,
8458 N_String_Literal,
8459 N_Real_Literal)
8463 then
8464 -- If there is no default function, we must still do a full
8465 -- analyze call on the default value, to ensure that all error
8466 -- checks are performed, e.g. those associated with static
8467 -- evaluation. Note: this branch will always be taken if the
8468 -- analyzer is turned off (but we still need the error checks).
8470 -- Note: the setting of parent here is to meet the requirement
8471 -- that we can only analyze the expression while attached to
8472 -- the tree. Really the requirement is that the parent chain
8473 -- be set, we don't actually need to be in the tree.
8478 -- Default expressions are resolved with their own type if the
8479 -- context is generic, to avoid anomalies with private types.
8483 else
8487 -- If that resolved expression will raise constraint error,
8488 -- then flag the default value as raising constraint error.
8489 -- This allows a proper error message on the calls.
8495 -- If the default is a parameterless call, we use the name of
8496 -- the called function directly, and there is no body to build.
8500 then
8503 -- Else construct and analyze the body of a wrapper procedure
8504 -- that contains an object declaration to hold the expression.
8505 -- Given that this is done only to complete the analysis, it is
8506 -- simpler to build a procedure than a function which might
8507 -- involve secondary stack expansion.
8509 else
8512 Dbody :=
8514 Specification =>
8521 Object_Definition =>
8525 Handled_Statement_Sequence =>
8542 ----------------------------------------
8543 -- Set_Component_Alignment_If_Not_Set --
8544 ----------------------------------------
8547 begin
8548 -- Ignore if not base type, subtypes don't need anything
8554 -- Do not override existing representation
8565 else
8566 Set_Component_Alignment
8572 --------------------------
8573 -- Set_SSO_From_Default --
8574 --------------------------
8579 begin
8580 -- Set default SSO for an array or record base type, except in case of
8581 -- a type extension (which always inherits the SSO of its parent type).
8588 then
8589 Reversed :=
8591 or else
8596 -- For a record type, if bit order is specified explicitly,
8597 -- then do not set SSO from default if not consistent. Note that
8598 -- we do not want to look at a Bit_Order attribute definition
8599 -- for a parent: if we were to inherit Bit_Order, then both
8600 -- SSO_Set_*_By_Default flags would have been cleared already
8601 -- (by Inherit_Aspects_At_Freeze_Point).
8603 and then not
8605 and then
8608 then
8609 -- If flags cause reverse storage order, then set the result. Note
8610 -- that we would have ignored the pragma setting the non default
8611 -- storage order in any case, hence the assertion at this point.
8613 pragma Assert
8618 -- For a record type, also set reversed bit order. Note: if a bit
8619 -- order has been specified explicitly, then this is a no-op.
8628 ------------------
8629 -- Undelay_Type --
8630 ------------------
8633 begin
8637 -- Since we don't want T to have a Freeze_Node, we don't want its
8638 -- Full_View or Corresponding_Record_Type to have one either.
8640 -- ??? Fundamentally, this whole handling is unpleasant. What we really
8641 -- want is to be sure that for an Itype that's part of record R and is a
8642 -- subtype of type T, that it's frozen after the later of the freeze
8643 -- points of R and T. We have no way of doing that directly, so what we
8644 -- do is force most such Itypes to be frozen as part of freezing R via
8645 -- this procedure and only delay the ones that need to be delayed
8646 -- (mostly the designated types of access types that are defined as part
8647 -- of the record).
8653 then
8661 then
8666 ------------------
8667 -- Warn_Overlay --
8668 ------------------
8672 -- The object to which the address clause applies
8678 begin
8679 -- No warning if address clause overlay warnings are off
8685 -- No warning if there is an explicit initialization
8693 -- We only give the warning for non-imported entities of a type for
8694 -- which a non-null base init proc is defined, or for objects of access
8695 -- types with implicit null initialization, or when Normalize_Scalars
8696 -- applies and the type is scalar or a string type (the latter being
8697 -- tested for because predefined String types are initialized by inline
8698 -- code rather than by an init_proc). Note that we do not give the
8699 -- warning for Initialize_Scalars, since we suppressed initialization
8700 -- in this case. Also, do not warn if Suppress_Initialization is set.
8710 then
8713 then
8718 then
8725 then
8732 -- A function call (most likely to To_Address) is probably not an
8733 -- overlay, so skip warning. Ditto if the function call was inlined
8734 -- and transformed into an entity.
8740 -- If a pragma Import follows, we assume that it is for the current
8741 -- target of the address clause, and skip the warning. There may be
8742 -- a source pragma or an aspect that specifies import and generates
8743 -- the corresponding pragma. These will indicate that the entity is
8744 -- imported and that is checked above so that the spurious warning
8745 -- (generated when the entity is frozen) will be suppressed. The
8746 -- pragma may be attached to the aspect, so it is not yet a list
8747 -- member.
8755 then
8760 -- Otherwise give warning message
8764 Error_Msg_N
8766 Nam);
8767 else
8768 Error_Msg_N
8770 Nam);
8773 -- Add friendly warning if initialization comes from a packed array
8774 -- component.
8777 declare
8780 begin
8785 then
8789 then
8790 Error_Msg_NE
8795 else
8802 Error_Msg_N
8805 Nam);