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1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- F R E E Z E --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2017, Free Software Foundation, Inc. --
10 -- --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
20 -- --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
23 -- --
24 ------------------------------------------------------------------------------
74 -----------------------
75 -- Local Subprograms --
76 -----------------------
79 -- Typ is a type that is being frozen. If no size clause is given,
80 -- but a default Esize has been computed, then this default Esize is
81 -- adjusted up if necessary to be consistent with a given alignment,
82 -- but never to a value greater than Long_Long_Integer'Size. This
83 -- is used for all discrete types and for fixed-point types.
85 procedure Build_And_Analyze_Renamed_Body
89 -- Build body for a renaming declaration, insert in tree and analyze
92 -- Apply legality checks to address clauses for object declarations,
93 -- at the point the object is frozen. Also ensure any initialization is
94 -- performed only after the object has been frozen.
96 procedure Check_Component_Storage_Order
101 -- For an Encl_Type that has a Scalar_Storage_Order attribute definition
102 -- clause, verify that the component type has an explicit and compatible
103 -- attribute/aspect. For arrays, Comp is Empty; for records, it is the
104 -- entity of the component under consideration. For an Encl_Type that
105 -- does not have a Scalar_Storage_Order attribute definition clause,
106 -- verify that the component also does not have such a clause.
107 -- ADC is the attribute definition clause if present (or Empty). On return,
108 -- Comp_ADC_Present is set True if the component has a Scalar_Storage_Order
109 -- attribute definition clause.
112 -- As each entity is frozen, this routine is called to deal with the
113 -- setting of Debug_Info_Needed for the entity. This flag is set if
114 -- the entity comes from source, or if we are in Debug_Generated_Code
115 -- mode or if the -gnatdV debug flag is set. However, it never sets
116 -- the flag if Debug_Info_Off is set. This procedure also ensures that
117 -- subsidiary entities have the flag set as required.
120 -- When an expression function is frozen by a use of it, the expression
121 -- itself is frozen. Check that the expression does not include references
122 -- to deferred constants without completion. We report this at the freeze
123 -- point of the function, to provide a better error message.
124 --
125 -- In most cases the expression itself is frozen by the time the function
126 -- itself is frozen, because the formals will be frozen by then. However,
127 -- Attribute references to outer types are freeze points for those types;
128 -- this routine generates the required freeze nodes for them.
131 -- For a tagged derived type, create wrappers for inherited operations
132 -- that have a class-wide condition, so it can be properly rewritten if
133 -- it involves calls to other overriding primitives.
136 -- E is a base type. If E is tagged or has a component that is aliased
137 -- or tagged or contains something this is aliased or tagged, set
138 -- Strict_Alignment.
142 -- If E is a fixed-point or discrete type, then all the necessary work
143 -- to freeze it is completed except for possible setting of the flag
144 -- Is_Unsigned_Type, which is done by this procedure. The call has no
145 -- effect if the entity E is not a discrete or fixed-point type.
147 procedure Freeze_And_Append
151 -- Freezes Ent using Freeze_Entity, and appends the resulting list of
152 -- nodes to Result, modifying Result from No_List if necessary. N has
153 -- the same usage as in Freeze_Entity.
156 -- Freeze enumeration type. The Esize field is set as processing
157 -- proceeds (i.e. set by default when the type is declared and then
158 -- adjusted by rep clauses. What this procedure does is to make sure
159 -- that if a foreign convention is specified, and no specific size
160 -- is given, then the size must be at least Integer'Size.
163 -- If an object is frozen which has Is_Statically_Allocated set, then
164 -- all referenced types must also be marked with this flag. This routine
165 -- is in charge of meeting this requirement for the object entity E.
168 -- Perform freezing actions for a subprogram (create extra formals,
169 -- and set proper default mechanism values). Note that this routine
170 -- is not called for internal subprograms, for which neither of these
171 -- actions is needed (or desirable, we do not want for example to have
172 -- these extra formals present in initialization procedures, where they
173 -- would serve no purpose). In this call E is either a subprogram or
174 -- a subprogram type (i.e. an access to a subprogram).
177 -- True if T is not private and has no private components, or has a full
178 -- view. Used to determine whether the designated type of an access type
179 -- should be frozen when the access type is frozen. This is done when an
180 -- allocator is frozen, or an expression that may involve attributes of
181 -- the designated type. Otherwise freezing the access type does not freeze
182 -- the designated type.
184 procedure Process_Default_Expressions
187 -- This procedure is called for each subprogram to complete processing of
188 -- default expressions at the point where all types are known to be frozen.
189 -- The expressions must be analyzed in full, to make sure that all error
190 -- processing is done (they have only been pre-analyzed). If the expression
191 -- is not an entity or literal, its analysis may generate code which must
192 -- not be executed. In that case we build a function body to hold that
193 -- code. This wrapper function serves no other purpose (it used to be
194 -- called to evaluate the default, but now the default is inlined at each
195 -- point of call).
198 -- Typ is a record or array type that is being frozen. This routine sets
199 -- the default component alignment from the scope stack values if the
200 -- alignment is otherwise not specified.
203 -- T is a record or array type that is being frozen. If it is a base type,
204 -- and if SSO_Set_Low/High_By_Default is set, then Reverse_Storage order
205 -- will be set appropriately. Note that an explicit occurrence of aspect
206 -- Scalar_Storage_Order or an explicit setting of this aspect with an
207 -- attribute definition clause occurs, then these two flags are reset in
208 -- any case, so call will have no effect.
211 -- T is a type of a component that we know to be an Itype. We don't want
212 -- this to have a Freeze_Node, so ensure it doesn't. Do the same for any
213 -- Full_View or Corresponding_Record_Type.
216 -- Expr is the expression for an address clause for entity Nam whose type
217 -- is Typ. If Typ has a default initialization, and there is no explicit
218 -- initialization in the source declaration, check whether the address
219 -- clause might cause overlaying of an entity, and emit a warning on the
220 -- side effect that the initialization will cause.
222 -------------------------------
223 -- Adjust_Esize_For_Alignment --
224 -------------------------------
229 begin
235 then
241 ------------------------------------
242 -- Build_And_Analyze_Renamed_Body --
243 ------------------------------------
245 procedure Build_And_Analyze_Renamed_Body
249 is
255 begin
256 -- If the renamed subprogram is intrinsic, there is no need for a
257 -- wrapper body: we set the alias that will be called and expanded which
258 -- completes the declaration. This transformation is only legal if the
259 -- renamed entity has already been elaborated.
261 -- Note that it is legal for a renaming_as_body to rename an intrinsic
262 -- subprogram, as long as the renaming occurs before the new entity
263 -- is frozen (RM 8.5.4 (5)).
267 then
269 else
275 and then
279 -- We can make the renaming entity intrinsic if the renamed function
280 -- has an interface name, or if it is one of the shift/rotate
281 -- operations known to the compiler.
283 and then
286 Name_Rotate_Right,
287 Name_Shift_Left,
288 Name_Shift_Right,
289 Name_Shift_Right_Arithmetic))
290 then
295 else
302 else
311 ------------------------
312 -- Build_Renamed_Body --
313 ------------------------
315 function Build_Renamed_Body
318 is
320 -- We use for the source location of the renamed body, the location of
321 -- the spec entity. It might seem more natural to use the location of
322 -- the renaming declaration itself, but that would be wrong, since then
323 -- the body we create would look as though it was created far too late,
324 -- and this could cause problems with elaboration order analysis,
325 -- particularly in connection with instantiations.
340 -- If the renamed entity is a primitive operation given in prefix form,
341 -- the prefix is the target object and it has to be added as the first
342 -- actual in the generated call.
344 begin
345 -- Determine the entity being renamed, which is the target of the call
346 -- statement. If the name is an explicit dereference, this is a renaming
347 -- of a subprogram type rather than a subprogram. The name itself is
348 -- fully analyzed.
359 else
366 else
372 -- If the renamed entity is a predefined operator, retain full name
373 -- to ensure its visibility.
377 then
379 else
383 else
386 and then
389 then
391 -- Retrieve the target object, to be added as a first actual
392 -- in the call.
397 else
401 -- Original name may have been overloaded, but is fully resolved now
406 -- For simple renamings, subsequent calls can be expanded directly as
407 -- calls to the renamed entity. The body must be generated in any case
408 -- for calls that may appear elsewhere. This is not done in the case
409 -- where the subprogram is an instantiation because the actual proper
410 -- body has not been built yet.
415 then
419 -- Check whether the return type is a limited view. If the subprogram
420 -- is already frozen the generated body may have a non-limited view
421 -- of the type, that must be used, because it is the one in the spec
422 -- of the renaming declaration.
426 then
427 declare
429 begin
431 Set_Result_Definition
437 -- The body generated for this renaming is an internal artifact, and
438 -- does not constitute a freeze point for the called entity.
445 declare
449 begin
450 -- The controlling formal may be an access parameter, or the
451 -- actual may be an access value, so adjust accordingly.
455 then
456 Actuals := New_List
461 then
462 Actuals :=
463 New_List (
467 else
475 else
486 -- If the renamed entity is an entry, inherit its profile. For other
487 -- renamings as bodies, both profiles must be subtype conformant, so it
488 -- is not necessary to replace the profile given in the declaration.
489 -- However, default values that are aggregates are rewritten when
490 -- partially analyzed, so we recover the original aggregate to insure
491 -- that subsequent conformity checking works. Similarly, if the default
492 -- expression was constant-folded, recover the original expression.
502 N_Access_Definition
503 then
511 then
522 -- If the renamed entity is a function, the generated body contains a
523 -- return statement. Otherwise, build a procedure call. If the entity is
524 -- an entry, subsequent analysis of the call will transform it into the
525 -- proper entry or protected operation call. If the renamed entity is
526 -- a character literal, return it directly.
532 then
533 Call_Node :=
535 Expression =>
541 Call_Node :=
546 Call_Node :=
549 else
550 Call_Node :=
556 -- Create entities for subprogram body and formals
569 Body_Node :=
573 Handled_Statement_Sequence =>
583 -- Link the body to the entity whose declaration it completes. If
584 -- the body is analyzed when the renamed entity is frozen, it may
585 -- be necessary to restore the proper scope (see package Exp_Ch13).
589 then
591 else
598 --------------------------
599 -- Check_Address_Clause --
600 --------------------------
611 begin
614 -- For a deferred constant, the initialization value is on full view
618 else
627 -- Has_Delayed_Freeze was set on E when the address clause was
628 -- analyzed, and must remain set because we want the address
629 -- clause to be elaborated only after any entity it references
630 -- has been elaborated.
633 -- If Rep_Clauses are to be ignored, remove address clause from
634 -- list attached to entity, because it may be illegal for gigi,
635 -- for example by breaking order of elaboration..
638 declare
641 begin
647 else
650 loop
660 -- And now remove the address clause
666 then
672 -- If a variable, or a non-imported constant, overlays a constant
673 -- object and has an initialization value, then the initialization
674 -- may end up writing into read-only memory. Detect the cases of
675 -- statically identical values and remove the initialization. In
676 -- the other cases, give a warning. We will give other warnings
677 -- later for the variable if it is assigned.
684 then
685 declare
689 begin
695 and then Compile_Time_Compare
699 then
704 and then Address_Clause_Overlay_Warnings
705 then
707 Error_Msg_NE
716 -- Capture initialization value at point of declaration,
717 -- and make explicit assignment legal, because object may
718 -- be a constant.
724 -- Move initialization to freeze actions, once the object has
725 -- been frozen and the address clause alignment check has been
726 -- performed.
735 -- If the objet is tagged, check whether the tag must be
736 -- reassigned explicitly.
746 -----------------------------
747 -- Check_Compile_Time_Size --
748 -----------------------------
753 -- Sets the compile time known size (64 bits or less) in the RM_Size
754 -- field of T, checking for a size clause that was given which attempts
755 -- to give a smaller size.
758 -- Recursive function that does all the work
761 -- If T is a constrained subtype, its size is not known if any of its
762 -- discriminant constraints is not static and it is not a null record.
763 -- The test is conservative and doesn't check that the components are
764 -- in fact constrained by non-static discriminant values. Could be made
765 -- more precise ???
767 --------------------
768 -- Set_Small_Size --
769 --------------------
772 begin
776 -- Check for bad size clause given
781 Error_Msg_NE
786 -- Set size if not set already
793 ----------------
794 -- Size_Known --
795 ----------------
804 begin
808 -- Always True for elementary types, even generic formal elementary
809 -- types. We used to return False in the latter case, but the size
810 -- is known at compile time, even in the template, we just do not
811 -- know the exact size but that's not the point of this routine.
816 -- Array types
820 -- String literals always have known size, and we can set it
823 Set_Small_Size
827 -- Unconstrained types never have known at compile time size
832 -- Don't do any recursion on type with error posted, since we may
833 -- have a malformed type that leads us into a loop.
838 -- Otherwise if component size unknown, then array size unknown
844 -- Check for all indexes static, and also compute possible size
845 -- (in case it is not greater than 64 and may be packable).
847 declare
851 begin
860 else
868 then
871 else
876 else
888 -- For non-generic private types, go to underlying type if present
893 then
894 -- Don't do any recursion on type with error posted, since we may
895 -- have a malformed type that leads us into a loop.
899 else
903 -- Record types
907 -- A class-wide type is never considered to have a known size
912 -- A subtype of a variant record must not have non-static
913 -- discriminated components.
917 then
920 -- Don't do any recursion on type with error posted, since we may
921 -- have a malformed type that leads us into a loop.
927 -- Now look at the components of the record
929 declare
930 -- The following two variables are used to keep track of the
931 -- size of packed records if we can tell the size of the packed
932 -- record in the front end. Packed_Size_Known is True if so far
933 -- we can figure out the size. It is initialized to True for a
934 -- packed record, unless the record has discriminants or atomic
935 -- components or independent components.
937 -- The reason we eliminate the discriminated case is that
938 -- we don't know the way the back end lays out discriminated
939 -- packed records. If Packed_Size_Known is True, then
940 -- Packed_Size is the size in bits so far.
949 -- Size in bits so far
951 begin
952 -- Test for variant part present
958 N_Record_Definition
960 and then
961 Present (Variant_Part
963 then
964 -- If variant part is present, and type is unconstrained,
965 -- then we must have defaulted discriminants, or a size
966 -- clause must be present for the type, or else the size
967 -- is definitely not known at compile time.
970 and then
973 then
978 -- Loop through components
984 -- We do not know the packed size if there is a component
985 -- clause present (we possibly could, but this would only
986 -- help in the case of a record with partial rep clauses.
987 -- That's because in the case of full rep clauses, the
988 -- size gets figured out anyway by a different circuit).
994 -- We do not know the packed size for an atomic/VFA type
995 -- or component, or an independent type or component, or a
996 -- by-reference type or aliased component (because packing
997 -- does not touch these).
1005 then
1009 -- We need to identify a component that is an array where
1010 -- the index type is an enumeration type with non-standard
1011 -- representation, and some bound of the type depends on a
1012 -- discriminant.
1014 -- This is because gigi computes the size by doing a
1015 -- substitution of the appropriate discriminant value in
1016 -- the size expression for the base type, and gigi is not
1017 -- clever enough to evaluate the resulting expression (which
1018 -- involves a call to rep_to_pos) at compile time.
1020 -- It would be nice if gigi would either recognize that
1021 -- this expression can be computed at compile time, or
1022 -- alternatively figured out the size from the subtype
1023 -- directly, where all the information is at hand ???
1027 then
1028 declare
1036 begin
1043 then
1049 then
1054 then
1064 -- Clearly size of record is not known if the size of one of
1065 -- the components is not known.
1071 -- Accumulate packed size if possible
1075 -- We can deal with elementary types, small packed arrays
1076 -- if the representation is a modular type and also small
1077 -- record types (if the size is not greater than 64, but
1078 -- the condition is checked by Set_Small_Size).
1082 and then Present
1084 and then Is_Modular_Integer_Type
1087 then
1088 -- If RM_Size is known and static, then we can keep
1089 -- accumulating the packed size.
1095 -- If we have a field whose RM_Size is not known then
1096 -- we can't figure out the packed size here.
1098 else
1102 -- For other types we can't figure out the packed size
1104 else
1119 -- All other cases, size not known at compile time
1121 else
1126 -------------------------------------
1127 -- Static_Discriminated_Components --
1128 -------------------------------------
1130 function Static_Discriminated_Components
1132 is
1135 begin
1139 then
1153 -- Start of processing for Check_Compile_Time_Size
1155 begin
1159 -----------------------------------
1160 -- Check_Component_Storage_Order --
1161 -----------------------------------
1163 procedure Check_Component_Storage_Order
1168 is
1178 -- Set for the record case, True if Comp is aligned on byte boundaries
1179 -- (in which case it is allowed to have different storage order).
1182 -- Set True when the component is a nested composite, and it does not
1183 -- have the same scalar storage order as Encl_Type.
1185 begin
1186 -- Record case
1196 else
1197 -- If a component clause is present, check if the component starts
1198 -- and ends on byte boundaries. Otherwise conservatively assume it
1199 -- does so only in the case where the record is not packed.
1202 Comp_Byte_Aligned :=
1204 and then
1206 else
1213 -- Array case
1215 else
1222 -- Note: the Reverse_Storage_Order flag is set on the base type, but
1223 -- the attribute definition clause is attached to the first subtype.
1224 -- Also, if the base type is incomplete or private, go to full view
1225 -- if known
1237 Comp_ADC :=
1238 Get_Attribute_Definition_Clause
1242 -- Case of record or array component: check storage order compatibility.
1243 -- But, if the record has Complex_Representation, then it is treated as
1244 -- a scalar in the back end so the storage order is irrelevant.
1249 then
1250 Comp_SSO_Differs :=
1254 -- Parent and extension must have same storage order
1258 Error_Msg_N
1263 -- If component and composite SSO differs, check that component
1264 -- falls on byte boundaries and isn't bit packed.
1268 -- Component SSO differs from enclosing composite:
1270 -- Reject if composite is a bit-packed array, as it is rewritten
1271 -- into an array of scalars.
1274 Error_Msg_N
1278 -- Reject if not byte aligned
1281 and then not Comp_Byte_Aligned
1282 then
1283 Error_Msg_N
1287 -- Warn if specified only for the outer composite
1290 Error_Msg_NE
1296 -- Enclosing type has explicit SSO: non-composite component must not
1297 -- be aliased.
1300 Error_Msg_N
1306 -----------------------------
1307 -- Check_Debug_Info_Needed --
1308 -----------------------------
1311 begin
1316 or else Debug_Generated_Code
1317 or else Debug_Flag_VV
1319 then
1324 -------------------------------
1325 -- Check_Expression_Function --
1326 -------------------------------
1330 -- Function to search for deferred constant
1332 -------------------
1333 -- Find_Constant --
1334 -------------------
1337 begin
1338 -- When a constant is initialized with the result of a dispatching
1339 -- call, the constant declaration is rewritten as a renaming of the
1340 -- displaced function result. This scenario is not a premature use of
1341 -- a constant even though the Has_Completion flag is not set.
1348 N_Object_Declaration
1352 then
1353 Error_Msg_NE
1361 then
1371 -- Local variables
1375 -- Start of processing for Check_Expression_Function
1377 begin
1380 -- The subprogram body created for the expression function is not
1381 -- itself a freeze point.
1386 then
1391 --------------------------------
1392 -- Check_Inherited_Conditions --
1393 --------------------------------
1404 -- Build corresponding pragmas for an operation whose ancestor has
1405 -- class-wide pre/postconditions. If the operation is inherited, the
1406 -- pragmas force the creation of a wrapper for the inherited operation.
1407 -- If the ancestor is being overridden, the pragmas are constructed only
1408 -- to verify their legality, in case they contain calls to other
1409 -- primitives that may haven been overridden.
1411 ---------------------------------------
1412 -- Build_Inherited_Condition_Pragmas --
1413 ---------------------------------------
1420 begin
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 SPARK 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
2795 -- In all other cases, bit packing is needed
2797 else
2806 -- Check for Aliased or Atomic_Components/Atomic/VFA with
2807 -- unsuitable packing or explicit component size clause given.
2812 and then
2814 then
2818 -- Outputs error messages for incorrect CS clause or pragma
2819 -- Pack for aliased or atomic/VFA components (T is "aliased"
2820 -- or "atomic/vfa");
2822 -----------------
2823 -- Complain_CS --
2824 -----------------
2827 begin
2829 Clause :=
2830 Get_Attribute_Definition_Clause
2833 Error_Msg_N
2837 Error_Msg_N
2840 else
2841 Error_Msg_N
2847 -- Start of processing for Alias_Atomic_Check
2849 begin
2850 -- If object size of component type isn't known, we cannot
2851 -- be sure so we defer to the back end.
2856 -- Case where component size has no effect. First check for
2857 -- object size of component type multiple of the storage
2858 -- unit size.
2862 -- OK in both packing case and component size case if RM
2863 -- size is known and static and same as the object size.
2865 and then
2869 -- Or if we have an explicit component size clause and
2870 -- the component size and object size are equal.
2872 or else
2875 then
2883 then
2892 -- Check for Independent_Components/Independent with unsuitable
2893 -- packing or explicit component size clause given.
2896 and then
2898 then
2899 begin
2900 -- If object size of component type isn't known, we cannot
2901 -- be sure so we defer to the back end.
2906 -- Case where component size has no effect. First check for
2907 -- object size of component type multiple of the storage
2908 -- unit size.
2912 -- OK in both packing case and component size case if RM
2913 -- size is known and multiple of the storage unit size.
2915 and then
2919 -- Or if we have an explicit component size clause and
2920 -- the component size is larger than the object size.
2922 or else
2925 then
2928 else
2930 Clause :=
2931 Get_Attribute_Definition_Clause
2934 Error_Msg_N
2938 Error_Msg_N
2941 else
2942 Error_Msg_N
2950 -- Warn for case of atomic type
2956 then
2957 Error_Msg_NE
2972 -- Check for scalar storage order
2974 declare
2976 begin
2977 Check_Component_Storage_Order
2980 ADC => Get_Attribute_Definition_Clause
2982 Attribute_Scalar_Storage_Order),
2986 -- Processing that is done only for subtypes
2988 else
2989 -- Acquire alignment from base type
2997 -- Specific checks for bit-packed arrays
3001 -- Check number of elements for bit-packed arrays that come from
3002 -- source and have compile time known ranges. The bit-packed
3003 -- arrays circuitry does not support arrays with more than
3004 -- Integer'Last + 1 elements, and when this restriction is
3005 -- violated, causes incorrect data access.
3007 -- For the case where this is not compile time known, a run-time
3008 -- check should be generated???
3011 declare
3017 begin
3023 -- Never generate an error if any index is of a generic
3024 -- type. We will check this in instances.
3031 Ilen :=
3037 -- No attempt is made to check number of elements if not
3038 -- compile time known.
3051 then
3052 Error_Msg_N
3059 -- Check size
3062 declare
3066 begin
3067 -- It is not clear if it is possible to have no size clause
3068 -- at this stage, but it is not worth worrying about. Post
3069 -- error on the entity name in the size clause if present,
3070 -- else on the type entity itself.
3074 else
3081 -- If any of the index types was an enumeration type with a non-
3082 -- standard rep clause, then we indicate that the array type is
3083 -- always packed (even if it is not bit-packed).
3092 -- If the array is packed and bit-packed or packed to eliminate holes
3093 -- in the non-contiguous enumeration index types, we must create the
3094 -- packed array type to be used to actually implement the type. This
3095 -- is only needed for real array types (not for string literal types,
3096 -- since they are present only for the front end).
3101 then
3105 -- Make sure that we have the necessary routines to implement the
3106 -- packing, and complain now if not. Note that we only test this
3107 -- for constrained array types.
3113 then
3114 declare
3118 begin
3121 then
3122 Error_Msg_CRT
3126 -- Cancel the packing
3136 -- Size information of packed array type is copied to the array
3137 -- type, since this is really the representation. But do not
3138 -- override explicit existing size values. If the ancestor subtype
3139 -- is constrained the Packed_Array_Impl_Type will be inherited
3140 -- from it, but the size may have been provided already, and
3141 -- must not be overridden either.
3144 and then
3147 then
3159 -- For non-packed arrays set the alignment of the array to the
3160 -- alignment of the component type if it is unknown. Skip this
3161 -- in atomic/VFA case (atomic/VFA arrays may need larger alignments).
3170 then
3174 -- A Ghost type cannot have a component of protected or task type
3175 -- (SPARK RM 6.9(19)).
3178 Error_Msg_N
3180 Arr);
3184 -------------------------------
3185 -- Freeze_Object_Declaration --
3186 -------------------------------
3189 begin
3190 -- Abstract type allowed only for C++ imported variables or constants
3192 -- Note: we inhibit this check for objects that do not come from
3193 -- source because there is at least one case (the expansion of
3194 -- x'Class'Input where x is abstract) where we legitimately
3195 -- generate an abstract object.
3200 then
3205 Error_Msg_NE
3210 Error_Msg_N -- CODEFIX
3216 -- For object created by object declaration, perform required
3217 -- categorization (preelaborate and pure) checks. Defer these
3218 -- checks to freeze time since pragma Import inhibits default
3219 -- initialization and thus pragma Import affects these checks.
3223 -- If there is an address clause, check that it is valid
3224 -- and if need be move initialization to the freeze node.
3228 -- Similar processing is needed for aspects that may affect
3229 -- object layout, like Alignment, if there is an initialization
3230 -- expression. We don't do this if there is a pragma Linker_Section,
3231 -- because it would prevent the back end from statically initializing
3232 -- the object; we don't want elaboration code in that case.
3235 and then Expander_Active
3239 then
3240 declare
3244 begin
3246 -- Capture initialization value at point of declaration, and
3247 -- make explicit assignment legal, because object may be a
3248 -- constant.
3253 -- Move initialization to freeze actions.
3261 -- Set_Is_Frozen (E, False);
3265 -- Reset Is_True_Constant for non-constant aliased object. We
3266 -- consider that the fact that a non-constant object is aliased may
3267 -- indicate that some funny business is going on, e.g. an aliased
3268 -- object is passed by reference to a procedure which captures the
3269 -- address of the object, which is later used to assign a new value,
3270 -- even though the compiler thinks that it is not modified. Such
3271 -- code is highly dubious, but we choose to make it "work" for
3272 -- non-constant aliased objects.
3274 -- Note that we used to do this for all aliased objects, whether or
3275 -- not constant, but this caused anomalies down the line because we
3276 -- ended up with static objects that were not Is_True_Constant. Not
3277 -- resetting Is_True_Constant for (aliased) constant objects ensures
3278 -- that this anomaly never occurs.
3280 -- However, we don't do that for internal entities. We figure that if
3281 -- we deliberately set Is_True_Constant for an internal entity, e.g.
3282 -- a dispatch table entry, then we mean it.
3287 then
3291 -- If the object needs any kind of default initialization, an error
3292 -- must be issued if No_Default_Initialization applies. The check
3293 -- doesn't apply to imported objects, which are not ever default
3294 -- initialized, and is why the check is deferred until freezing, at
3295 -- which point we know if Import applies. Deferred constants are also
3296 -- exempted from this test because their completion is explicit, or
3297 -- through an import pragma.
3305 and then
3309 or else
3312 then
3314 Check_Restriction
3318 -- Check that a Thread_Local_Storage variable does not have
3319 -- default initialization, and any explicit initialization must
3320 -- either be the null constant or a static constant.
3323 declare
3325 begin
3326 if Has_Default_Initialization
3327 or else
3329 and then
3331 or else not
3334 then
3335 Error_Msg_NE
3338 Error_Msg_NE
3345 -- For imported objects, set Is_Public unless there is also an
3346 -- address clause, which means that there is no external symbol
3347 -- needed for the Import (Is_Public may still be set for other
3348 -- unrelated reasons). Note that we delayed this processing
3349 -- till freeze time so that we can be sure not to set the flag
3350 -- if there is an address clause. If there is such a clause,
3351 -- then the only purpose of the Import pragma is to suppress
3352 -- implicit initialization.
3358 -- For source objects that are not Imported and are library
3359 -- level, if no linker section pragma was given inherit the
3360 -- appropriate linker section from the corresponding type.
3366 then
3367 Set_Linker_Section_Pragma
3371 -- For convention C objects of an enumeration type, warn if the
3372 -- size is not integer size and no explicit size given. Skip
3373 -- warning for Boolean, and Character, assume programmer expects
3374 -- 8-bit sizes for these cases.
3377 or else
3384 then
3386 Error_Msg_N
3392 -----------------------------
3393 -- Freeze_Generic_Entities --
3394 -----------------------------
3401 begin
3420 --------------------
3421 -- Freeze_Profile --
3422 --------------------
3429 begin
3430 -- Loop through formals
3436 -- AI05-0151: incomplete types can appear in a profile. By the
3437 -- time the entity is frozen, the full view must be available,
3438 -- unless it is a limited view.
3443 then
3457 then
3458 -- If the type of a formal is incomplete, subprogram is being
3459 -- frozen prematurely. Within an instance (but not within a
3460 -- wrapper package) this is an artifact of our need to regard
3461 -- the end of an instantiation as a freeze point. Otherwise it
3462 -- is a definite error.
3469 elsif not After_Last_Declaration
3470 and then not Freezing_Library_Level_Tagged_Type
3471 then
3473 Error_Msg
3478 -- Check suspicious parameter for C function. These tests apply
3479 -- only to exported/imported subprograms.
3481 if Warn_On_Export_Import
3484 or else
3491 then
3492 -- Qualify mention of formals with subprogram name
3496 -- Check suspicious use of fat C pointer
3500 then
3501 Error_Msg_N
3504 -- Check suspicious return of boolean
3510 then
3511 Error_Msg_N
3513 Error_Msg_N
3517 -- Check suspicious tagged type
3520 or else
3524 then
3525 Error_Msg_N
3529 -- Check wrong convention subprogram pointer
3533 then
3534 Error_Msg_N
3538 Error_Msg_NE
3543 -- Turn off name qualification after message output
3548 -- Check for unconstrained array in exported foreign convention
3549 -- case.
3555 and then Warn_On_Export_Import
3556 then
3559 -- If this is an inherited operation, place the warning on
3560 -- the derived type declaration, rather than on the original
3561 -- subprogram.
3564 then
3570 else
3586 -- If the formal is an anonymous_access_to_subprogram
3587 -- freeze the subprogram type as well, to prevent
3588 -- scope anomalies in gigi, because there is no other
3589 -- clear point at which it could be frozen.
3593 then
3601 -- Case of function: similar checks on return type
3605 -- Freeze return type
3609 -- AI05-0151: the return type may have been incomplete at the
3610 -- point of declaration. Replace it with the full view, unless the
3611 -- current type is a limited view. In that case the full view is
3612 -- in a different unit, and gigi finds the non-limited view after
3613 -- the other unit is elaborated.
3618 then
3625 -- Check suspicious return type for C function
3627 if Warn_On_Export_Import
3629 or else
3632 then
3633 -- Check suspicious return of fat C pointer
3639 then
3640 Error_Msg_N
3642 E);
3644 -- Check suspicious return of boolean
3651 then
3652 declare
3655 begin
3656 Error_Msg_NE
3658 Error_Msg_NE
3663 -- Check suspicious return tagged type
3667 and then
3668 Is_Tagged_Type
3673 then
3677 -- Check return of wrong convention subprogram pointer
3683 then
3687 Error_Msg_NE
3693 -- Give warning for suspicious return of a result of an
3694 -- unconstrained array type in a foreign convention function.
3698 -- We are looking for a return of unconstrained array
3703 -- Exclude imported routines, the warning does not belong on
3704 -- the import, but rather on the routine definition.
3708 -- Check that general warning is enabled, and that it is not
3709 -- suppressed for this particular case.
3711 and then Warn_On_Export_Import
3714 then
3715 Error_Msg_N
3721 -- Check suspicious use of Import in pure unit (cases where the RM
3722 -- allows calls to be omitted).
3726 -- It might be suspicious if the compilation unit has the Pure
3727 -- aspect/pragma.
3731 -- The RM allows omission of calls only in the case of
3732 -- library-level subprograms (see RM-10.2.1(18)).
3736 -- Ignore internally generated entity. This happens in some cases
3737 -- of subprograms in specs, where we generate an implied body.
3741 -- Assume run-time knows what it is doing
3743 and then not GNAT_Mode
3745 -- Assume explicit Pure_Function means import is pure
3749 -- Don't need warning in relaxed semantics mode
3751 and then not Relaxed_RM_Semantics
3753 -- Assume convention Intrinsic is OK, since this is specialized.
3754 -- This deals with the DEC unit current_exception.ads
3758 -- Assume that ASM interface knows what it is doing. This deals
3759 -- with e.g. unsigned.ads in the AAMP back end.
3762 then
3763 Error_Msg_N
3765 Error_Msg_NE
3773 ------------------------
3774 -- Freeze_Record_Type --
3775 ------------------------
3787 -- Set True if we find at least one component which is aliased. This
3788 -- is used to prevent Implicit_Packing of the record, since packing
3789 -- cannot modify the size of alignment of an aliased component.
3792 -- True if all components are of a type whose underlying type is
3793 -- elementary.
3796 -- True if all components have a known RM_Size
3799 -- True if all components have an RM_Size that is a multiple of the
3800 -- storage unit.
3803 -- Accumulates total Esize values of all elementary components. Used
3804 -- for processing of Implicit_Packing.
3807 -- Set True if we find at least one component with a component
3808 -- clause (used to warn about useless Bit_Order pragmas, and also
3809 -- to detect cases where Implicit_Packing may have an effect).
3812 -- Set True if the record type scope Rec has been pushed on the scope
3813 -- stack. Needed for the analysis of delayed aspects specified to the
3814 -- components of Rec.
3817 -- Accumulates total RM_Size values of all sized components. Used
3818 -- for processing of Implicit_Packing.
3821 -- Scalar_Storage_Order attribute definition clause for the record
3824 -- Set True if we find at least one component whose type has a
3825 -- Scalar_Storage_Order attribute definition clause.
3828 -- Set True if we find at least one component with no component
3829 -- clause (used to warn about useless Pack pragmas).
3832 -- If N is an allocator, possibly wrapped in one or more level of
3833 -- qualified expression(s), return the inner allocator node, else
3834 -- return Empty.
3837 -- If the component subtype is an access to a constrained subtype of
3838 -- an already frozen type, make the subtype frozen as well. It might
3839 -- otherwise be frozen in the wrong scope, and a freeze node on
3840 -- subtype has no effect. Similarly, if the component subtype is a
3841 -- regular (not protected) access to subprogram, set the anonymous
3842 -- subprogram type to frozen as well, to prevent an out-of-scope
3843 -- freeze node at some eventual point of call. Protected operations
3844 -- are handled elsewhere.
3847 -- Make sure that all types mentioned in Discrete_Choices of the
3848 -- variants referenceed by the Variant_Part VP are frozen. This is
3849 -- a recursive routine to deal with nested variants.
3851 ---------------------
3852 -- Check_Allocator --
3853 ---------------------
3857 begin
3859 loop
3864 else
3870 -----------------
3871 -- Check_Itype --
3872 -----------------
3877 begin
3880 then
3883 -- In addition, add an Itype_Reference to ensure that the
3884 -- access subtype is elaborated early enough. This cannot be
3885 -- done if the subtype may depend on discriminants.
3890 then
3898 then
3903 ------------------------------------
3904 -- Freeze_Choices_In_Variant_Part --
3905 ------------------------------------
3914 begin
3915 -- Loop through variants
3920 -- Loop through choices, checking that all types are frozen
3926 then
3933 -- Check for nested variant part to process
3947 -- Start of processing for Freeze_Record_Type
3949 begin
3950 -- Deal with delayed aspect specifications for components. The
3951 -- analysis of the aspect is required to be delayed to the freeze
3952 -- point, thus we analyze the pragma or attribute definition
3953 -- clause in the tree at this point. We also analyze the aspect
3954 -- specification node at the freeze point when the aspect doesn't
3955 -- correspond to pragma/attribute definition clause.
3961 then
3966 -- The visibility to the discriminants must be restored in
3967 -- order to properly analyze the aspects.
3980 -- Pop the scope if Rec scope has been pushed on the scope stack
3981 -- during the delayed aspect analysis process.
3988 Pop_Scope;
3991 -- Freeze components and embedded subtypes
4000 -- Handle the component and discriminant case
4003 declare
4006 begin
4007 -- Freezing a record type freezes the type of each of its
4008 -- components. However, if the type of the component is
4009 -- part of this record, we do not want or need a separate
4010 -- Freeze_Node. Note that Is_Itype is wrong because that's
4011 -- also set in private type cases. We also can't check for
4012 -- the Scope being exactly Rec because of private types and
4013 -- record extensions.
4018 then
4024 -- Warn for pragma Pack overriding foreign convention
4029 -- Don't warn for aliased components, since override
4030 -- cannot happen in that case.
4033 then
4034 declare
4039 begin
4043 Error_Msg_N
4045 PP);
4047 Error_Msg_NE
4054 -- Check for error of component clause given for variable
4055 -- sized type. We have to delay this test till this point,
4056 -- since the component type has to be frozen for us to know
4057 -- if it is variable length.
4062 -- We omit this test in a generic context, it will be
4063 -- applied at instantiation time.
4068 -- Also omit this test in CodePeer mode, since we do not
4069 -- have sufficient info on size and rep clauses.
4074 -- Omit check if component has a generic type. This can
4075 -- happen in an instantiation within a generic in ASIS
4076 -- mode, where we force freeze actions without full
4077 -- expansion.
4082 -- Do the check
4084 elsif not
4085 Size_Known_At_Compile_Time
4087 then
4088 Error_Msg_N
4093 else
4097 -- Case of component requires byte alignment
4101 -- Set the enclosing record to also require byte align
4105 -- Check for component clause that is inconsistent with
4106 -- the required byte boundary alignment.
4111 then
4112 Error_Msg_N
4120 -- Gather data for possible Implicit_Packing later. Note that at
4121 -- this stage we might be dealing with a real component, or with
4122 -- an implicit subtype declaration.
4125 Sized_Component_Total_RM_Size :=
4130 then
4131 Elem_Component_Total_Esize :=
4133 else
4140 else
4144 -- If the component is an Itype with Delayed_Freeze and is either
4145 -- a record or array subtype and its base type has not yet been
4146 -- frozen, we must remove this from the entity list of this record
4147 -- and put it on the entity list of the scope of its base type.
4148 -- Note that we know that this is not the type of a component
4149 -- since we cleared Has_Delayed_Freeze for it in the previous
4150 -- loop. Thus this must be the Designated_Type of an access type,
4151 -- which is the type of a component.
4159 then
4160 declare
4164 begin
4165 -- We have a difficult case to handle here. Suppose Rec is
4166 -- subtype being defined in a subprogram that's created as
4167 -- part of the freezing of Rec'Base. In that case, we know
4168 -- that Comp'Base must have already been frozen by the time
4169 -- we get to elaborate this because Gigi doesn't elaborate
4170 -- any bodies until it has elaborated all of the declarative
4171 -- part. But Is_Frozen will not be set at this point because
4172 -- we are processing code in lexical order.
4174 -- We detect this case by going up the Scope chain of Rec
4175 -- and seeing if we have a subprogram scope before reaching
4176 -- the top of the scope chain or that of Comp'Base. If we
4177 -- do, then mark that Comp'Base will actually be frozen. If
4178 -- so, we merely undelay it.
4195 else
4198 else
4202 -- Insert in entity list of scope of base type (which
4203 -- must be an enclosing scope, because still unfrozen).
4209 -- If the component is an access type with an allocator as default
4210 -- value, the designated type will be frozen by the corresponding
4211 -- expression in init_proc. In order to place the freeze node for
4212 -- the designated type before that for the current record type,
4213 -- freeze it now.
4215 -- Same process if the component is an array of access types,
4216 -- initialized with an aggregate. If the designated type is
4217 -- private, it cannot contain allocators, and it is premature
4218 -- to freeze the type, so we check for this as well.
4223 then
4224 declare
4228 begin
4231 -- If component is pointer to a class-wide type, freeze
4232 -- the specific type in the expression being allocated.
4233 -- The expression may be a subtype indication, in which
4234 -- case freeze the subtype mark.
4236 if Is_Class_Wide_Type
4238 then
4240 Freeze_And_Append
4244 then
4245 Freeze_And_Append
4253 else
4254 Freeze_And_Append
4262 then
4265 -- Freeze the designated type when initializing a component with
4266 -- an aggregate in case the aggregate contains allocators.
4268 -- type T is ...;
4269 -- type T_Ptr is access all T;
4270 -- type T_Array is array ... of T_Ptr;
4272 -- type Rec is record
4273 -- Comp : T_Array := (others => ...);
4274 -- end record;
4278 then
4279 declare
4282 Designated_Type
4285 begin
4286 -- The only case when this sort of freezing is not done is
4287 -- when the designated type is class-wide and the root type
4288 -- is the record owning the component. This scenario results
4289 -- in a circularity because the class-wide type requires
4290 -- primitives that have not been created yet as the root
4291 -- type is in the process of being frozen.
4293 -- type Rec is tagged;
4294 -- type Rec_Ptr is access all Rec'Class;
4295 -- type Rec_Array is array ... of Rec_Ptr;
4297 -- type Rec is record
4298 -- Comp : Rec_Array := (others => ...);
4299 -- end record;
4303 then
4311 then
4321 SSO_ADC :=
4322 Get_Attribute_Definition_Clause
4325 -- If the record type has Complex_Representation, then it is treated
4326 -- as a scalar in the back end so the storage order is irrelevant.
4330 Error_Msg_N
4332 SSO_ADC);
4335 else
4336 -- Deal with default setting of reverse storage order
4340 -- Check consistent attribute setting on component types
4342 declare
4344 begin
4347 Check_Component_Storage_Order
4357 -- Now deal with reverse storage order/bit order issues
4361 -- Check compatibility of Scalar_Storage_Order with Bit_Order,
4362 -- if the former is specified.
4366 -- Note: report error on Rec, not on SSO_ADC, as ADC may
4367 -- apply to some ancestor type.
4370 Error_Msg_N
4375 -- Warn if there is a Scalar_Storage_Order attribute definition
4376 -- clause but no component clause, no component that itself has
4377 -- such an attribute definition, and no pragma Pack.
4380 or else
4381 SSO_ADC_Component
4382 or else
4384 then
4385 Error_Msg_N
4392 -- Deal with Bit_Order aspect
4400 then
4401 -- Warn if clause has no effect when no component clause is
4402 -- present, but suppress warning if the Bit_Order is required
4403 -- due to the presence of a Scalar_Storage_Order attribute.
4405 Error_Msg_N
4407 Error_Msg_N
4410 -- Here is where we do the processing to adjust component clauses
4411 -- for reversed bit order, when not using reverse SSO. If an error
4412 -- has been reported on Rec already (such as SSO incompatible with
4413 -- bit order), don't bother adjusting as this may generate extra
4414 -- noise.
4419 then
4422 -- Case where we have both an explicit Bit_Order and the same
4423 -- Scalar_Storage_Order: leave record untouched, the back-end
4424 -- will take care of required layout conversions.
4426 else
4432 -- Complete error checking on record representation clause (e.g.
4433 -- overlap of components). This is called after adjusting the
4434 -- record for reverse bit order.
4436 declare
4438 begin
4444 -- Set OK_To_Reorder_Components depending on debug flags
4448 or else
4450 then
4455 -- Check for useless pragma Pack when all components placed. We only
4456 -- do this check for record types, not subtypes, since a subtype may
4457 -- have all its components placed, and it still makes perfectly good
4458 -- sense to pack other subtypes or the parent type. We do not give
4459 -- this warning if Optimize_Alignment is set to Space, since the
4460 -- pragma Pack does have an effect in this case (it always resets
4461 -- the alignment to one).
4465 and then not Unplaced_Component
4467 then
4468 -- Reset packed status. Probably not necessary, but we do it so
4469 -- that there is no chance of the back end doing something strange
4470 -- with this redundant indication of packing.
4474 -- Give warning if redundant constructs warnings on
4477 Error_Msg_N -- CODEFIX
4483 -- If this is the record corresponding to a remote type, freeze the
4484 -- remote type here since that is what we are semantically freezing.
4485 -- This prevents the freeze node for that type in an inner scope.
4492 -- Check for controlled components, unchecked unions, and type
4493 -- invariants.
4498 -- Do not set Has_Controlled_Component on a class-wide
4499 -- equivalent type. See Make_CW_Equivalent_Type.
4502 and then
4504 or else
4507 or else
4509 and then
4511 and then
4512 Has_Controlled_Component
4514 then
4522 -- The record type requires its own invariant procedure in
4523 -- order to verify the invariant of each individual component.
4524 -- Do not consider internal components such as _parent because
4525 -- parent class-wide invariants are always inherited.
4526 -- In GNATprove mode, the component invariants are checked by
4527 -- other means. They should not be added to the record type
4528 -- invariant procedure, so that the procedure can be used to
4529 -- check the recordy type invariants if any.
4533 and then not GNATprove_Mode
4534 then
4538 -- Scan component declaration for likely misuses of current
4539 -- instance, either in a constraint or a default expression.
4549 -- Enforce the restriction that access attributes with a current
4550 -- instance prefix can only apply to limited types. This comment
4551 -- is floating here, but does not seem to belong here???
4553 -- Set component alignment if not otherwise already set
4557 -- For first subtypes, check if there are any fixed-point fields with
4558 -- component clauses, where we must check the size. This is not done
4559 -- till the freeze point since for fixed-point types, we do not know
4560 -- the size until the type is frozen. Similar processing applies to
4561 -- bit-packed arrays.
4569 then
4570 Check_Size
4574 Junk);
4581 -- See if Size is too small as is (and implicit packing might help)
4585 -- No implicit packing if even one component is explicitly placed
4587 and then not Placed_Component
4589 -- Or even one component is aliased
4591 and then not Aliased_Component
4593 -- Must have size clause and all sized components
4596 and then All_Sized_Components
4598 -- Do not try implicit packing on records with discriminants, too
4599 -- complicated, especially in the variant record case.
4603 -- We want to implicitly pack if the specified size of the record
4604 -- is less than the sum of the object sizes (no point in packing
4605 -- if this is not the case), if we can compute it, i.e. if we have
4606 -- only elementary components. Otherwise, we have at least one
4607 -- composite component and we want to implicitly pack only if bit
4608 -- packing is required for it, as we are sure in this case that
4609 -- the back end cannot do the expected layout without packing.
4611 and then
4612 ((All_Elem_Components
4614 or else
4618 -- And the total RM size cannot be greater than the specified size
4619 -- since otherwise packing will not get us where we have to be.
4623 -- Never do implicit packing in CodePeer or SPARK modes since
4624 -- we don't do any packing in these modes, since this generates
4625 -- over-complex code that confuses static analysis, and in
4626 -- general, neither CodePeer not GNATprove care about the
4627 -- internal representation of objects.
4630 then
4631 -- If implicit packing enabled, do it
4636 -- Otherwise flag the size clause
4638 else
4639 declare
4641 begin
4642 Error_Msg_NE -- CODEFIX
4644 Error_Msg_N -- CODEFIX
4651 -- The following checks are relevant only when SPARK_Mode is on as
4652 -- they are not standard Ada legality rules.
4656 -- A discriminated type cannot be effectively volatile
4657 -- (SPARK RM 7.1.3(5)).
4664 -- A non-effectively volatile record type cannot contain
4665 -- effectively volatile components (SPARK RM 7.1.3(6)).
4667 else
4672 then
4674 Error_Msg_N
4683 -- A type which does not yield a synchronized object cannot have
4684 -- a component that yields a synchronized object (SPARK RM 9.5).
4691 then
4693 Error_Msg_N
4702 -- A Ghost type cannot have a component of protected or task type
4703 -- (SPARK RM 6.9(19)).
4710 then
4712 Error_Msg_N
4714 Comp);
4722 -- Make sure that if we have an iterator aspect, then we have
4723 -- either Constant_Indexing or Variable_Indexing.
4725 declare
4728 begin
4737 or else
4739 then
4741 else
4742 Error_Msg_N
4744 Iterator_Aspect);
4749 -- All done if not a full record definition
4755 -- Finally we need to check the variant part to make sure that
4756 -- all types within choices are properly frozen as part of the
4757 -- freezing of the record type.
4764 begin
4765 -- Find component list
4777 then
4782 -- Case of variant part present
4788 -- Note: we used to call Check_Choices here, but it is too early,
4789 -- since predicated subtypes are frozen here, but their freezing
4790 -- actions are in Analyze_Freeze_Entity, which has not been called
4791 -- yet for entities frozen within this procedure, so we moved that
4792 -- call to the Analyze_Freeze_Entity for the record type.
4796 -- Check that all the primitives of an interface type are abstract
4797 -- or null procedures.
4801 then
4802 declare
4806 begin
4813 -- Avoid reporting the error on inherited primitives
4816 then
4821 Error_Msg_N
4825 else
4826 Error_Msg_N
4837 -- For a derived tagged type, check whether inherited primitives
4838 -- might require a wrapper to handle class-wide conditions.
4845 -------------------------------
4846 -- Has_Boolean_Aspect_Import --
4847 -------------------------------
4854 begin
4860 -- The value of aspect Import is True when the expression is
4861 -- either missing or it is explicitly set to True.
4867 then
4878 -------------------------
4879 -- Inherit_Freeze_Node --
4880 -------------------------
4882 procedure Inherit_Freeze_Node
4885 is
4888 begin
4892 -- The input type had an existing node. Propagate relevant attributes
4893 -- from the old freeze node to the inherited freeze node.
4895 -- ??? if both freeze nodes have attributes, would they differ?
4899 -- Attribute Access_Types_To_Process
4903 then
4908 -- Attribute Actions
4914 -- Attribute First_Subtype_Link
4918 then
4922 -- Attribute TSS_Elist
4926 then
4932 ------------------------------
4933 -- Wrap_Imported_Subprogram --
4934 ------------------------------
4936 -- The issue here is that our normal approach of checking preconditions
4937 -- and postconditions does not work for imported procedures, since we
4938 -- are not generating code for the body. To get around this we create
4939 -- a wrapper, as shown by the following example:
4941 -- procedure K (A : Integer);
4942 -- pragma Import (C, K);
4944 -- The spec is rewritten by removing the effects of pragma Import, but
4945 -- leaving the convention unchanged, as though the source had said:
4947 -- procedure K (A : Integer);
4948 -- pragma Convention (C, K);
4950 -- and we create a body, added to the entity K freeze actions, which
4951 -- looks like:
4953 -- procedure K (A : Integer) is
4954 -- procedure K (A : Integer);
4955 -- pragma Import (C, K);
4956 -- begin
4957 -- K (A);
4958 -- end K;
4960 -- Now the contract applies in the normal way to the outer procedure,
4961 -- and the inner procedure has no contracts, so there is no problem
4962 -- in just calling it to get the original effect.
4964 -- In the case of a function, we create an appropriate return statement
4965 -- for the subprogram body that calls the inner procedure.
4969 -- Obtain a copy of the Import_Pragma which belongs to subprogram E
4971 ------------------------
4972 -- Copy_Import_Pragma --
4973 ------------------------
4977 -- The subprogram should have an import pragma, otherwise it does
4978 -- need a wrapper.
4983 -- Save all semantic fields of the pragma
4992 begin
4993 -- Reset all semantic fields. This avoids a potential infinite
4994 -- loop when the pragma comes from an aspect as the duplication
4995 -- will copy the aspect, then copy the corresponding pragma and
4996 -- so on.
5005 -- Restore the original semantic fields
5015 -- Local variables
5026 -- Start of processing for Wrap_Imported_Subprogram
5028 begin
5029 -- Nothing to do if not imported
5034 -- Test enabling conditions for wrapping
5039 and then not GNATprove_Mode
5040 then
5041 -- Here we do the wrap
5043 -- Note on calls to Copy_Separate_Tree. The trees we are copying
5044 -- here are fully analyzed, but we definitely want fully syntactic
5045 -- unanalyzed trees in the body we construct, so that the analysis
5046 -- generates the right visibility, and that is exactly what the
5047 -- calls to Copy_Separate_Tree give us.
5051 -- Fix up spec to be not imported any more
5058 -- Grab the subprogram declaration and specification
5062 -- Build parameter list that we need
5071 -- Build the call
5074 Stmt :=
5076 Expression =>
5081 else
5082 Stmt :=
5088 -- Now build the body
5090 Bod :=
5092 Specification =>
5097 Prag),
5098 Handled_Statement_Sequence =>
5103 -- Append the body to freeze result
5108 -- Case of imported subprogram that does not get wrapped
5110 else
5111 -- Set Is_Public. All imported entities need an external symbol
5112 -- created for them since they are always referenced from another
5113 -- object file. Note this used to be set when we set Is_Imported
5114 -- back in Sem_Prag, but now we delay it to this point, since we
5115 -- don't want to set this flag if we wrap an imported subprogram.
5121 -- Local variables
5124 -- Save the Ghost mode to restore on exit
5126 -- Start of processing for Freeze_Entity
5128 begin
5129 -- The entity being frozen may be subject to pragma Ghost. Set the mode
5130 -- now to ensure that any nodes generated during freezing are properly
5131 -- flagged as Ghost.
5135 -- We are going to test for various reasons why this entity need not be
5136 -- frozen here, but in the case of an Itype that's defined within a
5137 -- record, that test actually applies to the record.
5143 then
5147 -- Do not freeze if already frozen since we only need one freeze node
5157 -- It is improper to freeze an external entity within a generic because
5158 -- its freeze node will appear in a non-valid context. The entity will
5159 -- be frozen in the proper scope after the current generic is analyzed.
5160 -- However, aspects must be analyzed because they may be queried later
5161 -- within the generic itself, and the corresponding pragma or attribute
5162 -- definition has not been analyzed yet.
5172 -- AI05-0213: A formal incomplete type does not freeze the actual. In
5173 -- the instance, the same applies to the subtype renaming the actual.
5179 then
5183 -- Formal subprograms are never frozen
5189 -- Generic types are never frozen as they lack delayed semantic checks
5195 -- Do not freeze a global entity within an inner scope created during
5196 -- expansion. A call to subprogram E within some internal procedure
5197 -- (a stream attribute for example) might require freezing E, but the
5198 -- freeze node must appear in the same declarative part as E itself.
5199 -- The two-pass elaboration mechanism in gigi guarantees that E will
5200 -- be frozen before the inner call is elaborated. We exclude constants
5201 -- from this test, because deferred constants may be frozen early, and
5202 -- must be diagnosed (e.g. in the case of a deferred constant being used
5203 -- in a default expression). If the enclosing subprogram comes from
5204 -- source, or is a generic instance, then the freeze point is the one
5205 -- mandated by the language, and we freeze the entity. A subprogram that
5206 -- is a child unit body that acts as a spec does not have a spec that
5207 -- comes from source, but can only come from source.
5212 then
5213 declare
5216 begin
5223 then
5225 else
5235 -- Similarly, an inlined instance body may make reference to global
5236 -- entities, but these references cannot be the proper freezing point
5237 -- for them, and in the absence of inlining freezing will take place in
5238 -- their own scope. Normally instance bodies are analyzed after the
5239 -- enclosing compilation, and everything has been frozen at the proper
5240 -- place, but with front-end inlining an instance body is compiled
5241 -- before the end of the enclosing scope, and as a result out-of-order
5242 -- freezing must be prevented.
5244 elsif Front_End_Inlining
5245 and then In_Instance_Body
5247 then
5248 declare
5251 begin
5256 else
5268 -- Add checks to detect proper initialization of scalars that may appear
5269 -- as subprogram parameters.
5275 -- Deal with delayed aspect specifications. The analysis of the aspect
5276 -- is required to be delayed to the freeze point, thus we analyze the
5277 -- pragma or attribute definition clause in the tree at this point. We
5278 -- also analyze the aspect specification node at the freeze point when
5279 -- the aspect doesn't correspond to pragma/attribute definition clause.
5285 -- Here to freeze the entity
5289 -- Case of entity being frozen is other than a type
5293 -- If entity is exported or imported and does not have an external
5294 -- name, now is the time to provide the appropriate default name.
5295 -- Skip this if the entity is stubbed, since we don't need a name
5296 -- for any stubbed routine. For the case on intrinsics, if no
5297 -- external name is specified, then calls will be handled in
5298 -- Exp_Intr.Expand_Intrinsic_Call, and no name is needed. If an
5299 -- external name is provided, then Expand_Intrinsic_Call leaves
5300 -- calls in place for expansion by GIGI.
5306 then
5307 Set_Encoded_Interface_Name
5310 -- If entity is an atomic object appearing in a declaration and
5311 -- the expression is an aggregate, assign it to a temporary to
5312 -- ensure that the actual assignment is done atomically rather
5313 -- than component-wise (the assignment to the temp may be done
5314 -- component-wise, but that is harmless).
5321 then
5325 -- Subprogram case
5329 -- Check for needing to wrap imported subprogram
5333 -- Freeze all parameter types and the return type (RM 13.14(14)).
5334 -- However skip this for internal subprograms. This is also where
5335 -- any extra formal parameters are created since we now know
5336 -- whether the subprogram will use a foreign convention.
5338 -- In Ada 2012, freezing a subprogram does not always freeze the
5339 -- corresponding profile (see AI05-019). An attribute reference
5340 -- is not a freezing point of the profile. Flag Do_Freeze_Profile
5341 -- indicates whether the profile should be frozen now.
5342 -- Other constructs that should not freeze ???
5344 -- This processing doesn't apply to internal entities (see below)
5352 -- Must freeze its parent first if it is a derived subprogram
5358 -- We don't freeze internal subprograms, because we don't normally
5359 -- want addition of extra formals or mechanism setting to happen
5360 -- for those. However we do pass through predefined dispatching
5361 -- cases, since extra formals may be needed in some cases, such as
5362 -- for the stream 'Input function (build-in-place formals).
5366 then
5370 -- If warning on suspicious contracts then check for the case of
5371 -- a postcondition other than False for a No_Return subprogram.
5374 and then Warn_On_Suspicious_Contract
5376 then
5377 declare
5381 begin
5384 Name_Post,
5385 Name_Postcondition,
5386 Name_Refined_Post)
5387 then
5388 Exp :=
5389 Expression
5394 then
5395 Error_Msg_NE
5406 -- Here for other than a subprogram or type
5408 else
5409 -- If entity has a type, and it is not a generic unit, then
5410 -- freeze it first (RM 13.14(10)).
5414 then
5417 -- For an object of an anonymous array type, aspects on the
5418 -- object declaration apply to the type itself. This is the
5419 -- case for Atomic_Components, Volatile_Components, and
5420 -- Independent_Components. In these cases analysis of the
5421 -- generated pragma will mark the anonymous types accordingly,
5422 -- and the object itself does not require a freeze node.
5428 then
5435 -- Special processing for objects created by object declaration
5441 -- Check that a constant which has a pragma Volatile[_Components]
5442 -- or Atomic[_Components] also has a pragma Import (RM C.6(13)).
5444 -- Note: Atomic[_Components] also sets Volatile[_Components]
5450 then
5451 -- Make sure we actually have a pragma, and have not merely
5452 -- inherited the indication from elsewhere (e.g. an address
5453 -- clause, which is not good enough in RM terms).
5456 or else
5458 then
5459 Error_Msg_N
5464 or else
5466 then
5467 Error_Msg_N
5473 -- Static objects require special handling
5477 then
5481 -- Remaining step is to layout objects
5485 then
5489 -- For an object that does not have delayed freezing, and whose
5490 -- initialization actions have been captured in a compound
5491 -- statement, move them back now directly within the enclosing
5492 -- statement sequence.
5496 then
5501 -- Case of a type or subtype being frozen
5503 else
5504 -- We used to check here that a full type must have preelaborable
5505 -- initialization if it completes a private type specified with
5506 -- pragma Preelaborable_Initialization, but that missed cases where
5507 -- the types occur within a generic package, since the freezing
5508 -- that occurs within a containing scope generally skips traversal
5509 -- of a generic unit's declarations (those will be frozen within
5510 -- instances). This check was moved to Analyze_Package_Specification.
5512 -- The type may be defined in a generic unit. This can occur when
5513 -- freezing a generic function that returns the type (which is
5514 -- defined in a parent unit). It is clearly meaningless to freeze
5515 -- this type. However, if it is a subtype, its size may be determi-
5516 -- nable and used in subsequent checks, so might as well try to
5517 -- compute it.
5519 -- In Ada 2012, Freeze_Entities is also used in the front end to
5520 -- trigger the analysis of aspect expressions, so in this case we
5521 -- want to continue the freezing process.
5523 -- Is_Generic_Unit (Scope (E)) is dubious here, do we want instead
5524 -- In_Generic_Scope (E)???
5528 and then
5531 then
5537 -- Check for error of Type_Invariant'Class applied to an untagged
5538 -- type (check delayed to freeze time when full type is available).
5540 declare
5542 begin
5546 then
5547 Error_Msg_NE
5549 Error_Msg_N
5556 -- A Ghost type cannot be concurrent (SPARK RM 6.9(19)). Verify
5557 -- this legality rule first to five a finer-grained diagnostic.
5562 -- A Ghost type cannot be effectively volatile (SPARK RM 6.9(7))
5569 -- Deal with special cases of freezing for subtype
5573 -- Before we do anything else, a specific test for the case of a
5574 -- size given for an array where the array would need to be packed
5575 -- in order for the size to be honored, but is not. This is the
5576 -- case where implicit packing may apply. The reason we do this so
5577 -- early is that, if we have implicit packing, the layout of the
5578 -- base type is affected, so we must do this before we freeze the
5579 -- base type.
5581 -- We could do this processing only if implicit packing is enabled
5582 -- since in all other cases, the error would be caught by the back
5583 -- end. However, we choose to do the check even if we do not have
5584 -- implicit packing enabled, since this allows us to give a more
5585 -- useful error message (advising use of pragma Implicit_Packing
5586 -- or pragma Pack).
5589 declare
5601 -- Number of elements in array
5603 begin
5604 -- Check enabling conditions. These are straightforward
5605 -- except for the test for a limited composite type. This
5606 -- eliminates the rare case of a array of limited components
5607 -- where there are issues of whether or not we can go ahead
5608 -- and pack the array (since we can't freely pack and unpack
5609 -- arrays if they are limited).
5611 -- Note that we check the root type explicitly because the
5612 -- whole point is we are doing this test before we have had
5613 -- a chance to freeze the base type (and it is that freeze
5614 -- action that causes stuff to be inherited).
5616 -- The conditions on the size are identical to those used in
5617 -- Freeze_Array_Type to set the Is_Packed flag.
5635 then
5636 -- Compute number of elements in array
5643 and then
5645 then
5653 else
5660 -- What we are looking for here is the situation where
5661 -- the RM_Size given would be exactly right if there was
5662 -- a pragma Pack, resulting in the component size being
5663 -- the RM_Size of the component type.
5667 -- For implicit packing mode, just set the component
5668 -- size and Freeze_Array_Type will do the rest.
5673 -- Otherwise give an error message
5675 else
5676 Error_Msg_NE
5678 Error_Msg_N -- CODEFIX
5689 -- If ancestor subtype present, freeze that first. Note that this
5690 -- will also get the base type frozen. Need RM reference ???
5697 -- No ancestor subtype present
5699 else
5700 -- See if we have a nearest ancestor that has a predicate.
5701 -- That catches the case of derived type with a predicate.
5702 -- Need RM reference here ???
5710 -- Freeze base type before freezing the entity (RM 13.14(15))
5717 -- A subtype inherits all the type-related representation aspects
5718 -- from its parents (RM 13.1(8)).
5722 -- For a derived type, freeze its parent type first (RM 13.14(15))
5728 -- A derived type inherits each type-related representation aspect
5729 -- of its parent type that was directly specified before the
5730 -- declaration of the derived type (RM 13.1(15)).
5735 -- Check for incompatible size and alignment for record type
5737 if Warn_On_Size_Alignment
5741 -- If explicit Object_Size clause given assume that the programmer
5742 -- knows what he is doing, and expects the compiler behavior.
5746 -- Check for size not a multiple of alignment
5749 then
5750 declare
5756 begin
5759 -- Give a warning
5763 Error_Msg_NE
5770 else
5772 Error_Msg_NE
5786 -- Array type
5791 -- For a class-wide type, the corresponding specific type is
5792 -- frozen as well (RM 13.14(15))
5797 -- If the base type of the class-wide type is still incomplete,
5798 -- the class-wide remains unfrozen as well. This is legal when
5799 -- E is the formal of a primitive operation of some other type
5800 -- which is being frozen.
5807 -- The equivalent type associated with a class-wide subtype needs
5808 -- to be frozen to ensure that its layout is done.
5812 then
5816 -- Generate an itype reference for a library-level class-wide type
5817 -- at the freeze point. Otherwise the first explicit reference to
5818 -- the type may appear in an inner scope which will be rejected by
5819 -- the back-end.
5823 then
5824 declare
5827 begin
5830 -- From a gigi point of view, a class-wide subtype derives
5831 -- from its record equivalent type. As a result, the itype
5832 -- reference must appear after the freeze node of the
5833 -- equivalent type or gigi will reject the reference.
5837 then
5839 else
5845 -- For a record type or record subtype, freeze all component types
5846 -- (RM 13.14(15)). We test for E_Record_(sub)Type here, rather than
5847 -- using Is_Record_Type, because we don't want to attempt the freeze
5848 -- for the case of a private type with record extension (we will do
5849 -- that later when the full type is frozen).
5856 -- Report a warning if a discriminated record base type has a
5857 -- convention with language C or C++ applied to it. This check is
5858 -- done even within generic scopes (but not in instantiations),
5859 -- which is why we don't do it as part of Freeze_Record_Type.
5863 -- For a concurrent type, freeze corresponding record type. This does
5864 -- not correspond to any specific rule in the RM, but the record type
5865 -- is essentially part of the concurrent type. Also freeze all local
5866 -- entities. This includes record types created for entry parameter
5867 -- blocks and whatever local entities may appear in the private part.
5881 -- The guard on the presence of the Etype seems to be needed
5882 -- for some CodePeer (-gnatcC) cases, but not clear why???
5887 then
5898 -- Private types are required to point to the same freeze node as
5899 -- their corresponding full views. The freeze node itself has to
5900 -- point to the partial view of the entity (because from the partial
5901 -- view, we can retrieve the full view, but not the reverse).
5902 -- However, in order to freeze correctly, we need to freeze the full
5903 -- view. If we are freezing at the end of a scope (or within the
5904 -- scope) of the private type, the partial and full views will have
5905 -- been swapped, the full view appears first in the entity chain and
5906 -- the swapping mechanism ensures that the pointers are properly set
5907 -- (on scope exit).
5909 -- If we encounter the partial view before the full view (e.g. when
5910 -- freezing from another scope), we freeze the full view, and then
5911 -- set the pointers appropriately since we cannot rely on swapping to
5912 -- fix things up (subtypes in an outer scope might not get swapped).
5914 -- If the full view is itself private, the above requirements apply
5915 -- to the underlying full view instead of the full view. But there is
5916 -- no swapping mechanism for the underlying full view so we need to
5917 -- set the pointers appropriately in both cases.
5921 then
5922 -- The construction of the dispatch table associated with library
5923 -- level tagged types forces freezing of all the primitives of the
5924 -- type, which may cause premature freezing of the partial view.
5925 -- For example:
5927 -- package Pkg is
5928 -- type T is tagged private;
5929 -- type DT is new T with private;
5930 -- procedure Prim (X : in out T; Y : in out DT'Class);
5931 -- private
5932 -- type T is tagged null record;
5933 -- Obj : T;
5934 -- type DT is new T with null record;
5935 -- end;
5937 -- In this case the type will be frozen later by the usual
5938 -- mechanism: an object declaration, an instantiation, or the
5939 -- end of a declarative part.
5943 then
5947 -- Case of full view present
5951 -- If full view has already been frozen, then no further
5952 -- processing is required
5958 -- Otherwise freeze full view and patch the pointers so that
5959 -- the freeze node will elaborate both views in the back end.
5960 -- However, if full view is itself private, freeze underlying
5961 -- full view instead and patch the pointers so that the freeze
5962 -- node will elaborate the three views in the back end.
5964 else
5965 declare
5968 begin
5971 then
5979 then
5983 Inherit_Freeze_Node
5986 else
5996 Inherit_Freeze_Node
5999 else
6000 -- {Incomplete,Private}_Subtypes with Full_Views
6001 -- constrained by discriminants.
6012 -- AI-117 requires that the convention of a partial view be the
6013 -- same as the convention of the full view. Note that this is a
6014 -- recognized breach of privacy, but it's essential for logical
6015 -- consistency of representation, and the lack of a rule in
6016 -- RM95 was an oversight.
6023 -- Size information is copied from the full view to the
6024 -- incomplete or private view for consistency.
6026 -- We skip this is the full view is not a type. This is very
6027 -- strange of course, and can only happen as a result of
6028 -- certain illegalities, such as a premature attempt to derive
6029 -- from an incomplete type.
6038 -- Case of underlying full view present
6042 then
6047 -- Patch the pointers so that the freeze node will elaborate
6048 -- both views in the back end.
6054 Inherit_Freeze_Node
6057 else
6067 -- Case of no full view present. If entity is derived or subtype,
6068 -- it is safe to freeze, correctness depends on the frozen status
6069 -- of parent. Otherwise it is either premature usage, or a Taft
6070 -- amendment type, so diagnosis is at the point of use and the
6071 -- type might be frozen later.
6076 else
6082 -- For access subprogram, freeze types of all formals, the return
6083 -- type was already frozen, since it is the Etype of the function.
6084 -- Formal types can be tagged Taft amendment types, but otherwise
6085 -- they cannot be incomplete.
6092 then
6096 -- AI05-151: Incomplete types are allowed in access to
6097 -- subprogram specifications.
6100 Error_Msg_NE
6111 -- For access to a protected subprogram, freeze the equivalent type
6112 -- (however this is not set if we are not generating code or if this
6113 -- is an anonymous type used just for resolution).
6121 -- Generic types are never seen by the back-end, and are also not
6122 -- processed by the expander (since the expander is turned off for
6123 -- generic processing), so we never need freeze nodes for them.
6129 -- Some special processing for non-generic types to complete
6130 -- representation details not known till the freeze point.
6135 -- Some error checks required for ordinary fixed-point type. Defer
6136 -- these till the freeze-point since we need the small and range
6137 -- values. We only do these checks for base types
6142 Error_Msg_N
6147 Error_Msg_N
6153 Error_Msg_N
6159 Error_Msg_N
6171 and then Warn_On_Suspicious_Modulus_Value
6172 then
6176 -- The pool applies to named and anonymous access types, but not
6177 -- to subprogram and to internal types generated for 'Access
6178 -- references.
6183 then
6184 -- If a pragma Default_Storage_Pool applies, and this type has no
6185 -- Storage_Pool or Storage_Size clause (which must have occurred
6186 -- before the freezing point), then use the default. This applies
6187 -- only to base types.
6189 -- None of this applies to access to subprograms, for which there
6190 -- are clearly no pools.
6196 then
6197 -- Case of pragma Default_Storage_Pool (null)
6202 -- Case of pragma Default_Storage_Pool (storage_pool_NAME)
6204 else
6209 -- Check restriction for standard storage pool
6215 -- Deal with error message for pure access type. This is not an
6216 -- error in Ada 2005 if there is no pool (see AI-366).
6222 then
6226 Error_Msg_N
6230 Error_Msg_N
6233 else
6234 Error_Msg_N
6241 -- Case of composite types
6245 -- AI-117 requires that all new primitives of a tagged type must
6246 -- inherit the convention of the full view of the type. Inherited
6247 -- and overriding operations are defined to inherit the convention
6248 -- of their parent or overridden subprogram (also specified in
6249 -- AI-117), which will have occurred earlier (in Derive_Subprogram
6250 -- and New_Overloaded_Entity). Here we set the convention of
6251 -- primitives that are still convention Ada, which will ensure
6252 -- that any new primitives inherit the type's convention. Class-
6253 -- wide types can have a foreign convention inherited from their
6254 -- specific type, but are excluded from this since they don't have
6255 -- any associated primitives.
6260 then
6261 declare
6265 begin
6277 -- If the type is a simple storage pool type, then this is where
6278 -- we attempt to locate and validate its Allocate, Deallocate, and
6279 -- Storage_Size operations (the first is required, and the latter
6280 -- two are optional). We also verify that the full type for a
6281 -- private type is allowed to be a simple storage pool type.
6285 then
6286 -- If the type is marked Has_Private_Declaration, then this is
6287 -- a full type for a private type that was specified with the
6288 -- pragma Simple_Storage_Pool_Type, and here we ensure that the
6289 -- pragma is allowed for the full type (for example, it can't
6290 -- be an array type, or a nonlimited record type).
6295 then
6297 Error_Msg_N
6308 procedure Validate_Simple_Pool_Op_Formal
6315 -- Validate one formal Pool_Op_Formal of the candidate pool
6316 -- operation Pool_Op. The formal must be of Expected_Type
6317 -- and have mode Expected_Mode. OK_Formal will be set to
6318 -- False if the formal doesn't match. If OK_Formal is False
6319 -- on entry, then the formal will effectively be ignored
6320 -- (because validation of the pool op has already failed).
6321 -- Upon return, Pool_Op_Formal will be updated to the next
6322 -- formal, if any.
6324 procedure Validate_Simple_Pool_Operation
6326 -- Search for and validate a simple pool operation with the
6327 -- name Op_Name. If the name is Allocate, then there must be
6328 -- exactly one such primitive operation for the simple pool
6329 -- type. If the name is Deallocate or Storage_Size, then
6330 -- there can be at most one such primitive operation. The
6331 -- profile of the located primitive must conform to what
6332 -- is expected for each operation.
6334 ------------------------------------
6335 -- Validate_Simple_Pool_Op_Formal --
6336 ------------------------------------
6338 procedure Validate_Simple_Pool_Op_Formal
6345 is
6346 begin
6347 -- If OK_Formal is False on entry, then simply ignore
6348 -- the formal, because an earlier formal has already
6349 -- been flagged.
6354 -- If no formal is passed in, then issue an error for a
6355 -- missing formal.
6358 Error_Msg_NE
6368 -- If the pool type was expected for this formal, then
6369 -- this will not be considered a candidate operation
6370 -- for the simple pool, so we unset OK_Formal so that
6371 -- the op and any later formals will be ignored.
6378 else
6379 Error_Msg_NE
6386 -- Issue error if formal's mode is not the expected one
6389 Error_Msg_N
6391 Pool_Op_Formal);
6394 -- Advance to the next formal
6399 ------------------------------------
6400 -- Validate_Simple_Pool_Operation --
6401 ------------------------------------
6403 procedure Validate_Simple_Pool_Operation
6405 is
6411 begin
6412 pragma Assert
6414 Name_Deallocate,
6415 Name_Storage_Size));
6419 -- For each homonym declared immediately in the scope
6420 -- of the simple storage pool type, determine whether
6421 -- the homonym is an operation of the pool type, and,
6422 -- if so, check that its profile is as expected for
6423 -- a simple pool operation of that name.
6429 then
6434 -- The first parameter must be of the pool type
6435 -- in order for the operation to qualify.
6438 Validate_Simple_Pool_Op_Formal
6441 else
6442 Validate_Simple_Pool_Op_Formal
6447 -- If another operation with this name has already
6448 -- been located for the type, then flag an error,
6449 -- since we only allow the type to have a single
6450 -- such primitive.
6453 Error_Msg_NE
6458 -- In the case of Allocate and Deallocate, a formal
6459 -- of type System.Address is required.
6462 Validate_Simple_Pool_Op_Formal
6467 Validate_Simple_Pool_Op_Formal
6472 -- In the case of Allocate and Deallocate, formals
6473 -- of type Storage_Count are required as the third
6474 -- and fourth parameters.
6477 Validate_Simple_Pool_Op_Formal
6480 Validate_Simple_Pool_Op_Formal
6485 -- If no mismatched formals have been found (Is_OK)
6486 -- and no excess formals are present, then this
6487 -- operation has been validated, so record it.
6497 -- There must be a valid Allocate operation for the type,
6498 -- so issue an error if none was found.
6502 then
6508 -- Simple pool operations can't be abstract
6511 Error_Msg_N
6516 -- The Storage_Size operation must be a function with
6517 -- Storage_Count as its result type.
6521 Error_Msg_N
6525 Error_Msg_NE
6530 -- Allocate and Deallocate must be procedures
6533 Error_Msg_N
6539 -- Start of processing for Validate_Simple_Pool_Ops
6541 begin
6549 -- Now that all types from which E may depend are frozen, see if the
6550 -- size is known at compile time, if it must be unsigned, or if
6551 -- strict alignment is required
6560 -- Do not allow a size clause for a type which does not have a size
6561 -- that is known at compile time
6565 then
6566 -- Suppress this message if errors posted on E, even if we are
6567 -- in all errors mode, since this is often a junk message
6570 Error_Msg_N
6576 -- Now we set/verify the representation information, in particular
6577 -- the size and alignment values. This processing is not required for
6578 -- generic types, since generic types do not play any part in code
6579 -- generation, and so the size and alignment values for such types
6580 -- are irrelevant. Ditto for types declared within a generic unit,
6581 -- which may have components that depend on generic parameters, and
6582 -- that will be recreated in an instance.
6587 -- Otherwise we call the layout procedure
6589 else
6593 -- If this is an access to subprogram whose designated type is itself
6594 -- a subprogram type, the return type of this anonymous subprogram
6595 -- type must be decorated as well.
6599 then
6603 -- If the type has a Defaut_Value/Default_Component_Value aspect,
6604 -- this is where we analye the expression (after the type is frozen,
6605 -- since in the case of Default_Value, we are analyzing with the
6606 -- type itself, and we treat Default_Component_Value similarly for
6607 -- the sake of uniformity).
6610 declare
6615 begin
6620 else
6631 Flag_Non_Static_Expr
6638 -- End of freeze processing for type entities
6641 -- Here is where we logically freeze the current entity. If it has a
6642 -- freeze node, then this is the point at which the freeze node is
6643 -- linked into the result list.
6647 -- If a freeze node is already allocated, use it, otherwise allocate
6648 -- a new one. The preallocation happens in the case of anonymous base
6649 -- types, where we preallocate so that we can set First_Subtype_Link.
6650 -- Note that we reset the Sloc to the current freeze location.
6656 else
6667 -- A final pass over record types with discriminants. If the type
6668 -- has an incomplete declaration, there may be constrained access
6669 -- subtypes declared elsewhere, which do not depend on the discrimi-
6670 -- nants of the type, and which are used as component types (i.e.
6671 -- the full view is a recursive type). The designated types of these
6672 -- subtypes can only be elaborated after the type itself, and they
6673 -- need an itype reference.
6676 declare
6681 begin
6691 then
6703 -- When a type is frozen, the first subtype of the type is frozen as
6704 -- well (RM 13.14(15)). This has to be done after freezing the type,
6705 -- since obviously the first subtype depends on its own base type.
6710 -- If we just froze a tagged non-class wide record, then freeze the
6711 -- corresponding class-wide type. This must be done after the tagged
6712 -- type itself is frozen, because the class-wide type refers to the
6713 -- tagged type which generates the class.
6718 then
6725 -- Special handling for subprograms
6729 -- If subprogram has address clause then reset Is_Public flag, since
6730 -- we do not want the backend to generate external references.
6734 then
6745 -----------------------------
6746 -- Freeze_Enumeration_Type --
6747 -----------------------------
6750 begin
6751 -- By default, if no size clause is present, an enumeration type with
6752 -- Convention C is assumed to interface to a C enum, and has integer
6753 -- size. This applies to types. For subtypes, verify that its base
6754 -- type has no size clause either. Treat other foreign conventions
6755 -- in the same way, and also make sure alignment is set right.
6762 -- Don't do this if Short_Enums on target
6764 and then not Target_Short_Enums
6765 then
6769 -- Normal Ada case or size clause present or not Long_C_Enums on target
6771 else
6772 -- If the enumeration type interfaces to C, and it has a size clause
6773 -- that specifies less than int size, it warrants a warning. The
6774 -- user may intend the C type to be an enum or a char, so this is
6775 -- not by itself an error that the Ada compiler can detect, but it
6776 -- it is a worth a heads-up. For Boolean and Character types we
6777 -- assume that the programmer has the proper C type in mind.
6785 -- Don't do this if Short_Enums on target
6787 and then not Target_Short_Enums
6788 then
6789 Error_Msg_N
6797 -----------------------
6798 -- Freeze_Expression --
6799 -----------------------
6810 -- This flag is set true if the entity must be frozen outside the
6811 -- current subprogram. This happens in the case of expander generated
6812 -- subprograms (_Init_Proc, _Input, _Output, _Read, _Write) which do
6813 -- not freeze all entities like other bodies, but which nevertheless
6814 -- may reference entities that have to be frozen before the body and
6815 -- obviously cannot be frozen inside the body.
6818 -- If the expression is an array aggregate, the type of the component
6819 -- expressions is also frozen. If the component type is an access type
6820 -- and the expressions include allocators, the designed type is frozen
6821 -- as well.
6824 -- Given an N_Handled_Sequence_Of_Statements node N, determines whether
6825 -- it is the handled statement sequence of an expander-generated
6826 -- subprogram (init proc, stream subprogram, or renaming as body).
6827 -- If so, this is not a freezing context.
6829 -----------------------------------------
6830 -- Find_Aggregate_Component_Desig_Type --
6831 -----------------------------------------
6837 begin
6863 ----------------------
6864 -- In_Expanded_Body --
6865 ----------------------
6871 begin
6874 else
6881 else
6884 -- The following are expander-created bodies, or bodies that
6885 -- are not freeze points.
6894 N_Subprogram_Renaming_Declaration,
6895 N_Expression_Function))
6896 then
6898 else
6904 -- Start of processing for Freeze_Expression
6906 begin
6907 -- Immediate return if freezing is inhibited. This flag is set by the
6908 -- analyzer to stop freezing on generated expressions that would cause
6909 -- freezing if they were in the source program, but which are not
6910 -- supposed to freeze, since they are created.
6916 -- If expression is non-static, then it does not freeze in a default
6917 -- expression, see section "Handling of Default Expressions" in the
6918 -- spec of package Sem for further details. Note that we have to make
6919 -- sure that we actually have a real expression (if we have a subtype
6920 -- indication, we can't test Is_OK_Static_Expression). However, we
6921 -- exclude the case of the prefix of an attribute of a static scalar
6922 -- subtype from this early return, because static subtype attributes
6923 -- should always cause freezing, even in default expressions, but
6924 -- the attribute may not have been marked as static yet (because in
6925 -- Resolve_Attribute, the call to Eval_Attribute follows the call of
6926 -- Freeze_Expression on the prefix).
6928 if In_Spec_Exp
6935 then
6939 -- Freeze type of expression if not frozen already
6947 -- Base type may be an derived numeric type that is frozen at
6948 -- the point of declaration, but first_subtype is still unfrozen.
6955 -- For entity name, freeze entity if not frozen already. A special
6956 -- exception occurs for an identifier that did not come from source.
6957 -- We don't let such identifiers freeze a non-internal entity, i.e.
6958 -- an entity that did come from source, since such an identifier was
6959 -- generated by the expander, and cannot have any semantic effect on
6960 -- the freezing semantics. For example, this stops the parameter of
6961 -- an initialization procedure from freezing the variable.
6968 then
6975 else
6979 -- For an allocator freeze designated type if not frozen already
6981 -- For an aggregate whose component type is an access type, freeze the
6982 -- designated type now, so that its freeze does not appear within the
6983 -- loop that might be created in the expansion of the aggregate. If the
6984 -- designated type is a private type without full view, the expression
6985 -- cannot contain an allocator, so the type is not frozen.
6987 -- For a function, we freeze the entity when the subprogram declaration
6988 -- is frozen, but a function call may appear in an initialization proc.
6989 -- before the declaration is frozen. We need to generate the extra
6990 -- formals, if any, to ensure that the expansion of the call includes
6991 -- the proper actuals. This only applies to Ada subprograms, not to
6992 -- imported ones.
7003 then
7005 -- Check whether aggregate includes allocators.
7010 when N_Indexed_Component
7011 | N_Selected_Component
7012 | N_Slice
7013 =>
7023 then
7034 then
7038 -- All done if nothing needs freezing
7043 then
7047 -- Examine the enclosing context by climbing the parent chain. The
7048 -- traversal serves two purposes - to detect scenarios where freezeing
7049 -- is not needed and to find the proper insertion point for the freeze
7050 -- nodes. Although somewhat similar to Insert_Actions, this traversal
7051 -- is freezing semantics-sensitive. Inserting freeze nodes blindly in
7052 -- the tree may result in types being frozen too early.
7055 loop
7058 -- If we don't have a parent, then we are not in a well-formed tree.
7059 -- This is an unusual case, but there are some legitimate situations
7060 -- in which this occurs, notably when the expressions in the range of
7061 -- a type declaration are resolved. We simply ignore the freeze
7062 -- request in this case. Is this right ???
7068 -- See if we have got to an appropriate point in the tree
7072 -- A special test for the exception of (RM 13.14(8)) for the case
7073 -- of per-object expressions (RM 3.8(18)) occurring in component
7074 -- definition or a discrete subtype definition. Note that we test
7075 -- for a component declaration which includes both cases we are
7076 -- interested in, and furthermore the tree does not have explicit
7077 -- nodes for either of these two constructs.
7081 -- The case we want to test for here is an identifier that is
7082 -- a per-object expression, this is either a discriminant that
7083 -- appears in a context other than the component declaration
7084 -- or it is a reference to the type of the enclosing construct.
7086 -- For either of these cases, we skip the freezing
7088 if not In_Spec_Expression
7091 then
7092 -- We recognize the discriminant case by just looking for
7093 -- a reference to a discriminant. It can only be one for
7094 -- the enclosing construct. Skip freezing in this case.
7099 -- For the case of a reference to the enclosing record,
7100 -- (or task or protected type), we look for a type that
7101 -- matches the current scope.
7108 -- If we have an enumeration literal that appears as the choice in
7109 -- the aggregate of an enumeration representation clause, then
7110 -- freezing does not occur (RM 13.14(10)).
7114 -- The case we are looking for is an enumeration literal
7118 then
7119 -- If enumeration literal appears directly as the choice,
7120 -- do not freeze (this is the normal non-overloaded case)
7124 then
7127 -- If enumeration literal appears as the name of function
7128 -- which is the choice, then also do not freeze. This
7129 -- happens in the overloaded literal case, where the
7130 -- enumeration literal is temporarily changed to a function
7131 -- call for overloading analysis purposes.
7134 and then
7136 and then
7138 then
7143 -- Normally if the parent is a handled sequence of statements,
7144 -- then the current node must be a statement, and that is an
7145 -- appropriate place to insert a freeze node.
7149 -- An exception occurs when the sequence of statements is for
7150 -- an expander generated body that did not do the usual freeze
7151 -- all operation. In this case we usually want to freeze
7152 -- outside this body, not inside it, and we skip past the
7153 -- subprogram body that we are inside.
7156 declare
7160 begin
7161 -- Freeze the entity only when it is declared inside the
7162 -- body of the expander generated procedure. This case
7163 -- is recognized by the scope of the entity or its type,
7164 -- which is either the spec for some enclosing body, or
7165 -- (in the case of init_procs, for which there are no
7166 -- separate specs) the current scope.
7172 or else
7174 then
7180 then
7185 -- An expression function may act as a completion of
7186 -- a function declaration. As such, it can reference
7187 -- entities declared between the two views:
7189 -- Hidden []; -- 1
7190 -- function F return ...;
7191 -- private
7192 -- function Hidden return ...;
7193 -- function F return ... is (Hidden); -- 2
7195 -- Refering to the example above, freezing the expression
7196 -- of F (2) would place Hidden's freeze node (1) in the
7197 -- wrong place. Avoid explicit freezing and let the usual
7198 -- scenarios do the job - for example, reaching the end
7199 -- of the private declarations, or a call to F.
7202 N_Expression_Function
7203 then
7206 -- Freeze outside the body
7208 else
7214 -- Here if normal case where we are in handled statement
7215 -- sequence and want to do the insertion right there.
7217 else
7221 -- If parent is a body or a spec or a block, then the current node
7222 -- is a statement or declaration and we can insert the freeze node
7223 -- before it.
7225 when N_Block_Statement
7226 | N_Entry_Body
7227 | N_Package_Body
7228 | N_Package_Specification
7229 | N_Protected_Body
7230 | N_Subprogram_Body
7231 | N_Task_Body
7232 =>
7235 -- The expander is allowed to define types in any statements list,
7236 -- so any of the following parent nodes also mark a freezing point
7237 -- if the actual node is in a list of statements or declarations.
7239 when N_Abortable_Part
7240 | N_Accept_Alternative
7241 | N_And_Then
7242 | N_Case_Statement_Alternative
7243 | N_Compilation_Unit_Aux
7244 | N_Conditional_Entry_Call
7245 | N_Delay_Alternative
7246 | N_Elsif_Part
7247 | N_Entry_Call_Alternative
7248 | N_Exception_Handler
7249 | N_Extended_Return_Statement
7250 | N_Freeze_Entity
7251 | N_If_Statement
7252 | N_Or_Else
7253 | N_Selective_Accept
7254 | N_Triggering_Alternative
7255 =>
7258 -- Freeze nodes produced by an expression coming from the Actions
7259 -- list of a N_Expression_With_Actions node must remain within the
7260 -- Actions list. Inserting the freeze nodes further up the tree
7261 -- may lead to use before declaration issues in the case of array
7262 -- types.
7267 then
7271 -- Note: N_Loop_Statement is a special case. A type that appears
7272 -- in the source can never be frozen in a loop (this occurs only
7273 -- because of a loop expanded by the expander), so we keep on
7274 -- going. Otherwise we terminate the search. Same is true of any
7275 -- entity which comes from source. (if they have predefined type,
7276 -- that type does not appear to come from source, but the entity
7277 -- should not be frozen here).
7283 -- For all other cases, keep looking at parents
7289 -- We fall through the case if we did not yet find the proper
7290 -- place in the free for inserting the freeze node, so climb.
7295 -- If the expression appears in a record or an initialization procedure,
7296 -- the freeze nodes are collected and attached to the current scope, to
7297 -- be inserted and analyzed on exit from the scope, to insure that
7298 -- generated entities appear in the correct scope. If the expression is
7299 -- a default for a discriminant specification, the scope is still void.
7300 -- The expression can also appear in the discriminant part of a private
7301 -- or concurrent type.
7303 -- If the expression appears in a constrained subcomponent of an
7304 -- enclosing record declaration, the freeze nodes must be attached to
7305 -- the outer record type so they can eventually be placed in the
7306 -- enclosing declaration list.
7308 -- The other case requiring this special handling is if we are in a
7309 -- default expression, since in that case we are about to freeze a
7310 -- static type, and the freeze scope needs to be the outer scope, not
7311 -- the scope of the subprogram with the default parameter.
7313 -- For default expressions and other spec expressions in generic units,
7314 -- the Move_Freeze_Nodes mechanism (see sem_ch12.adb) takes care of
7315 -- placing them at the proper place, after the generic unit.
7318 or else Freeze_Outside
7323 then
7324 declare
7329 begin
7342 -- The current scope may be that of a constrained component of
7343 -- an enclosing record declaration, or of a loop of an enclosing
7344 -- quantified expression, which is above the current scope in the
7345 -- scope stack. Indeed in the context of a quantified expression,
7346 -- a scope is created and pushed above the current scope in order
7347 -- to emulate the loop-like behavior of the quantified expression.
7348 -- If the expression is within a top-level pragma, as for a pre-
7349 -- condition on a library-level subprogram, nothing to do.
7354 N_Quantified_Expression)
7355 then
7362 Freeze_Nodes;
7363 else
7373 -- Now we have the right place to do the freezing. First, a special
7374 -- adjustment, if we are in spec-expression analysis mode, these freeze
7375 -- actions must not be thrown away (normally all inserted actions are
7376 -- thrown away in this mode. However, the freeze actions are from static
7377 -- expressions and one of the important reasons we are doing this
7378 -- special analysis is to get these freeze actions. Therefore we turn
7379 -- off the In_Spec_Expression mode to propagate these freeze actions.
7380 -- This also means they get properly analyzed and expanded.
7384 -- Freeze the designated type of an allocator (RM 13.14(13))
7390 -- Freeze type of expression (RM 13.14(10)). Note that we took care of
7391 -- the enumeration representation clause exception in the loop above.
7397 -- Freeze name if one is present (RM 13.14(11))
7403 -- Restore In_Spec_Expression flag
7408 -----------------------------
7409 -- Freeze_Fixed_Point_Type --
7410 -----------------------------
7412 -- Certain fixed-point types and subtypes, including implicit base types
7413 -- and declared first subtypes, have not yet set up a range. This is
7414 -- because the range cannot be set until the Small and Size values are
7415 -- known, and these are not known till the type is frozen.
7417 -- To signal this case, Scalar_Range contains an unanalyzed syntactic range
7418 -- whose bounds are unanalyzed real literals. This routine will recognize
7419 -- this case, and transform this range node into a properly typed range
7420 -- with properly analyzed and resolved values.
7437 -- Save original bounds (for shaving tests)
7440 -- Actual size chosen
7443 -- Returns size of type with given bounds. Also leaves these
7444 -- bounds set as the current bounds of the Typ.
7446 -----------
7447 -- Fsize --
7448 -----------
7451 begin
7457 -- Start of processing for Freeze_Fixed_Point_Type
7459 begin
7460 -- If Esize of a subtype has not previously been set, set it now
7467 else
7472 -- Immediate return if the range is already analyzed. This means that
7473 -- the range is already set, and does not need to be computed by this
7474 -- routine.
7480 -- Immediate return if either of the bounds raises Constraint_Error
7484 then
7494 -- Ordinary fixed-point case
7498 -- For the ordinary fixed-point case, we are allowed to fudge the
7499 -- end-points up or down by small. Generally we prefer to fudge up,
7500 -- i.e. widen the bounds for non-model numbers so that the end points
7501 -- are included. However there are cases in which this cannot be
7502 -- done, and indeed cases in which we may need to narrow the bounds.
7503 -- The following circuit makes the decision.
7505 -- Note: our terminology here is that Incl_EP means that the bounds
7506 -- are widened by Small if necessary to include the end points, and
7507 -- Excl_EP means that the bounds are narrowed by Small to exclude the
7508 -- end-points if this reduces the size.
7510 -- Note that in the Incl case, all we care about is including the
7511 -- end-points. In the Excl case, we want to narrow the bounds as
7512 -- much as permitted by the RM, to give the smallest possible size.
7529 begin
7530 -- First step. Base types are required to be symmetrical. Right
7531 -- now, the base type range is a copy of the first subtype range.
7532 -- This will be corrected before we are done, but right away we
7533 -- need to deal with the case where both bounds are non-negative.
7534 -- In this case, we set the low bound to the negative of the high
7535 -- bound, to make sure that the size is computed to include the
7536 -- required sign. Note that we do not need to worry about the
7537 -- case of both bounds negative, because the sign will be dealt
7538 -- with anyway. Furthermore we can't just go making such a bound
7539 -- symmetrical, since in a twos-complement system, there is an
7540 -- extra negative value which could not be accommodated on the
7541 -- positive side.
7546 then
7551 -- Compute the fudged bounds. If the number is a model number,
7552 -- then we do nothing to include it, but we are allowed to backoff
7553 -- to the next adjacent model number when we exclude it. If it is
7554 -- not a model number then we straddle the two values with the
7555 -- model numbers on either side.
7561 else
7565 -- The low value excluding the end point is Small greater, but
7566 -- we do not do this exclusion if the low value is positive,
7567 -- since it can't help the size and could actually hurt by
7568 -- crossing the high bound.
7573 -- If the value went from negative to zero, then we have the
7574 -- case where Loval_Incl_EP is the model number just below
7575 -- zero, so we want to stick to the negative value for the
7576 -- base type to maintain the condition that the size will
7577 -- include signed values.
7581 then
7585 else
7589 -- Similar processing for upper bound and high value
7595 else
7601 else
7605 -- One further adjustment is needed. In the case of subtypes, we
7606 -- cannot go outside the range of the base type, or we get
7607 -- peculiarities, and the base type range is already set. This
7608 -- only applies to the Incl values, since clearly the Excl values
7609 -- are already as restricted as they are allowed to be.
7616 -- Get size including and excluding end points
7621 -- No need to exclude end-points if it does not reduce size
7631 -- Now we set the actual size to be used. We want to use the
7632 -- bounds fudged up to include the end-points but only if this
7633 -- can be done without violating a specifically given size
7634 -- size clause or causing an unacceptable increase in size.
7636 -- Case of size clause given
7640 -- Use the inclusive size only if it is consistent with
7641 -- the explicitly specified size.
7648 -- If the inclusive size is too large, we try excluding
7649 -- the end-points (will be caught later if does not work).
7651 else
7657 -- Case of size clause not given
7659 else
7660 -- If we have a base type whose corresponding first subtype
7661 -- has an explicit size that is large enough to include our
7662 -- end-points, then do so. There is no point in working hard
7663 -- to get a base type whose size is smaller than the specified
7664 -- size of the first subtype.
7670 then
7675 -- If excluding the end-points makes the size smaller and
7676 -- results in a size of 8,16,32,64, then we take the smaller
7677 -- size. For the 64 case, this is compulsory. For the other
7678 -- cases, it seems reasonable. We like to include end points
7679 -- if we can, but not at the expense of moving to the next
7680 -- natural boundary of size.
7684 then
7689 -- Otherwise we can definitely include the end points
7691 else
7697 -- One pathological case: normally we never fudge a low bound
7698 -- down, since it would seem to increase the size (if it has
7699 -- any effect), but for ranges containing single value, or no
7700 -- values, the high bound can be small too large. Consider:
7702 -- type t is delta 2.0**(-14)
7703 -- range 131072.0 .. 0;
7705 -- That lower bound is *just* outside the range of 32 bits, and
7706 -- does need fudging down in this case. Note that the bounds
7707 -- will always have crossed here, since the high bound will be
7708 -- fudged down if necessary, as in the case of:
7710 -- type t is delta 2.0**(-14)
7711 -- range 131072.0 .. 131072.0;
7713 -- So we detect the situation by looking for crossed bounds,
7714 -- and if the bounds are crossed, and the low bound is greater
7715 -- than zero, we will always back it off by small, since this
7716 -- is completely harmless.
7723 -- And of course, we need to do exactly the same parallel
7724 -- fudge for flat ranges in the negative region.
7737 -- For the decimal case, none of this fudging is required, since there
7738 -- are no end-point problems in the decimal case (the end-points are
7739 -- always included).
7741 else
7745 -- At this stage, the actual size has been calculated and the proper
7746 -- required bounds are stored in the low and high bounds.
7750 Error_Msg_N
7752 Typ);
7756 -- Check size against explicit given size
7762 Error_Msg_NE
7766 else
7770 -- Increase size to next natural boundary if no size clause given
7772 else
7779 else
7787 -- If we have a base type, then expand the bounds so that they extend to
7788 -- the full width of the allocated size in bits, to avoid junk range
7789 -- checks on intermediate computations.
7796 -- Final step is to reanalyze the bounds using the proper type
7797 -- and set the Corresponding_Integer_Value fields of the literals.
7803 -- Resolve with universal fixed if the base type, and the base type if
7804 -- it is a subtype. Note we can't resolve the base type with itself,
7805 -- that would be a reference before definition.
7809 else
7813 -- Set corresponding integer value for bound
7815 Set_Corresponding_Integer_Value
7818 -- Similar processing for high bound
7826 else
7830 Set_Corresponding_Integer_Value
7833 -- Set type of range to correspond to bounds
7837 -- Set Esize to calculated size if not set already
7843 -- Set RM_Size if not already set. If already set, check value
7845 declare
7848 begin
7853 Error_Msg_NE
7858 else
7863 -- Check for shaving
7867 -- In SPARK mode the given bounds must be strictly representable
7871 Error_Msg_NE
7877 Error_Msg_NE
7882 else
7884 Error_Msg_N
7886 Error_Msg_N
7891 Error_Msg_N
7893 Typ);
7894 Error_Msg_N
7901 ------------------
7902 -- Freeze_Itype --
7903 ------------------
7908 begin
7917 --------------------------
7918 -- Freeze_Static_Object --
7919 --------------------------
7924 -- Exception raised if the type of a static object cannot be made
7925 -- static. This happens if the type depends on non-global objects.
7928 -- Called to ensure that an expression used as part of a type definition
7929 -- is statically allocatable, which means that the expression type is
7930 -- statically allocatable, and the expression is either static, or a
7931 -- reference to a library level constant.
7934 -- Called to mark a type as static, checking that it is possible
7935 -- to set the type as static. If it is not possible, then the
7936 -- exception Cannot_Be_Static is raised.
7938 -----------------------------
7939 -- Ensure_Expression_Is_SA --
7940 -----------------------------
7945 begin
7957 then
7965 -----------------------
7966 -- Ensure_Type_Is_SA --
7967 -----------------------
7973 begin
7974 -- If type is library level, we are all set
7980 -- We are also OK if the type already marked as statically allocated,
7981 -- which means we processed it before.
7987 -- Mark type as statically allocated
7991 -- Check that it is safe to statically allocate this type
8009 declare
8013 begin
8025 else
8034 then
8053 else
8058 -- Start of processing for Freeze_Static_Object
8060 begin
8063 exception
8066 -- If the object that cannot be static is imported or exported, then
8067 -- issue an error message saying that this object cannot be imported
8068 -- or exported. If it has an address clause it is an overlay in the
8069 -- current partition and the static requirement is not relevant.
8070 -- Do not issue any error message when ignoring rep clauses.
8077 Error_Msg_N
8081 -- Otherwise must be exported, something is wrong if compiler
8082 -- is marking something as statically allocated which cannot be).
8085 Error_Msg_N
8090 -----------------------
8091 -- Freeze_Subprogram --
8092 -----------------------
8096 -- Set the conventions of all anonymous access-to-subprogram formals and
8097 -- result subtype of subprogram Subp_Id to the convention of Subp_Id.
8099 ----------------------------
8100 -- Set_Profile_Convention --
8101 ----------------------------
8107 -- Set the convention of anonymous access-to-subprogram type Typ and
8108 -- its designated type to Conv.
8110 -------------------------
8111 -- Set_Type_Convention --
8112 -------------------------
8115 begin
8116 -- Set the convention on both the anonymous access-to-subprogram
8117 -- type and the subprogram type it points to because both types
8118 -- participate in conformance-related checks.
8126 -- Local variables
8130 -- Start of processing for Set_Profile_Convention
8132 begin
8144 -- Local variables
8149 -- Start of processing for Freeze_Subprogram
8151 begin
8152 -- Subprogram may not have an address clause unless it is imported
8156 Error_Msg_N
8162 -- Reset the Pure indication on an imported subprogram unless an
8163 -- explicit Pure_Function pragma was present or the subprogram is an
8164 -- intrinsic. We do this because otherwise it is an insidious error
8165 -- to call a non-pure function from pure unit and have calls
8166 -- mysteriously optimized away. What happens here is that the Import
8167 -- can bypass the normal check to ensure that pure units call only pure
8168 -- subprograms.
8170 -- The reason for the intrinsic exception is that in general, intrinsic
8171 -- functions (such as shifts) are pure anyway. The only exceptions are
8172 -- the intrinsics in GNAT.Source_Info, and that unit is not marked Pure
8173 -- in any case, so no problem arises.
8179 then
8183 -- We also reset the Pure indication on a subprogram with an Address
8184 -- parameter, because the parameter may be used as a pointer and the
8185 -- referenced data may change even if the address value does not.
8187 -- Note that if the programmer gave an explicit Pure_Function pragma,
8188 -- then we believe the programmer, and leave the subprogram Pure. We
8189 -- also suppress this check on run-time files.
8195 then
8199 -- Ensure that all anonymous access-to-subprogram types inherit the
8200 -- convention of their related subprogram (RM 6.3.1 13.1/3). This is
8201 -- not done for a defaulted convention Ada because those types also
8202 -- default to Ada. Convention Protected must not be propagated when
8203 -- the subprogram is an entry because this would be illegal. The only
8204 -- way to force convention Protected on these kinds of types is to
8205 -- include keyword "protected" in the access definition.
8209 then
8213 -- For non-foreign convention subprograms, this is where we create
8214 -- the extra formals (for accessibility level and constrained bit
8215 -- information). We delay this till the freeze point precisely so
8216 -- that we know the convention.
8222 -- If this is convention Ada and a Valued_Procedure, that's odd
8227 and then Warn_On_Export_Import
8228 then
8229 Error_Msg_N
8234 -- Case of foreign convention
8236 else
8239 -- For foreign conventions, warn about return of unconstrained array
8244 -- If no return type, probably some other error, e.g. a
8245 -- missing full declaration, so ignore.
8250 -- If the return type is generic, we have emitted a warning
8251 -- earlier on, and there is nothing else to check here. Specific
8252 -- instantiations may lead to erroneous behavior.
8257 -- Display warning if returning unconstrained array
8262 -- Check appropriate warning is enabled (should we check for
8263 -- Warnings (Off) on specific entities here, probably so???)
8265 and then Warn_On_Export_Import
8266 then
8267 Error_Msg_N
8274 -- If any of the formals for an exported foreign convention
8275 -- subprogram have defaults, then emit an appropriate warning since
8276 -- this is odd (default cannot be used from non-Ada code)
8281 if Warn_On_Export_Import
8283 then
8284 Error_Msg_N
8294 -- Pragma Inline_Always is disallowed for dispatching subprograms
8295 -- because the address of such subprograms is saved in the dispatch
8296 -- table to support dispatching calls, and dispatching calls cannot
8297 -- be inlined. This is consistent with the restriction against using
8298 -- 'Access or 'Address on an Inline_Always subprogram.
8302 then
8303 Error_Msg_N
8307 -- Because of the implicit representation of inherited predefined
8308 -- operators in the front-end, the overriding status of the operation
8309 -- may be affected when a full view of a type is analyzed, and this is
8310 -- not captured by the analysis of the corresponding type declaration.
8311 -- Therefore the correctness of a not-overriding indicator must be
8312 -- rechecked when the subprogram is frozen.
8316 then
8320 if Modify_Tree_For_C
8326 then
8331 ----------------------
8332 -- Is_Fully_Defined --
8333 ----------------------
8336 begin
8345 then
8346 -- Verify that the record type has no components with private types
8347 -- without completion.
8349 declare
8352 begin
8364 -- For the designated type of an access to subprogram, all types in
8365 -- the profile must be fully defined.
8368 declare
8371 begin
8384 else
8390 ---------------------------------
8391 -- Process_Default_Expressions --
8392 ---------------------------------
8394 procedure Process_Default_Expressions
8397 is
8404 begin
8407 -- A subprogram instance and its associated anonymous subprogram share
8408 -- their signature. The default expression functions are defined in the
8409 -- wrapper packages for the anonymous subprogram, and should not be
8410 -- generated again for the instance.
8415 then
8423 -- We work with a copy of the default expression because we
8424 -- do not want to disturb the original, since this would mess
8425 -- up the conformance checking.
8429 -- The analysis of the expression may generate insert actions,
8430 -- which of course must not be executed. We wrap those actions
8431 -- in a procedure that is not called, and later on eliminated.
8432 -- The following cases have no side-effects, and are analyzed
8433 -- directly.
8437 N_Integer_Literal,
8438 N_Character_Literal,
8439 N_String_Literal,
8440 N_Real_Literal)
8444 then
8445 -- If there is no default function, we must still do a full
8446 -- analyze call on the default value, to ensure that all error
8447 -- checks are performed, e.g. those associated with static
8448 -- evaluation. Note: this branch will always be taken if the
8449 -- analyzer is turned off (but we still need the error checks).
8451 -- Note: the setting of parent here is to meet the requirement
8452 -- that we can only analyze the expression while attached to
8453 -- the tree. Really the requirement is that the parent chain
8454 -- be set, we don't actually need to be in the tree.
8459 -- Default expressions are resolved with their own type if the
8460 -- context is generic, to avoid anomalies with private types.
8464 else
8468 -- If that resolved expression will raise constraint error,
8469 -- then flag the default value as raising constraint error.
8470 -- This allows a proper error message on the calls.
8476 -- If the default is a parameterless call, we use the name of
8477 -- the called function directly, and there is no body to build.
8481 then
8484 -- Else construct and analyze the body of a wrapper procedure
8485 -- that contains an object declaration to hold the expression.
8486 -- Given that this is done only to complete the analysis, it is
8487 -- simpler to build a procedure than a function which might
8488 -- involve secondary stack expansion.
8490 else
8493 Dbody :=
8495 Specification =>
8502 Object_Definition =>
8506 Handled_Statement_Sequence =>
8523 ----------------------------------------
8524 -- Set_Component_Alignment_If_Not_Set --
8525 ----------------------------------------
8528 begin
8529 -- Ignore if not base type, subtypes don't need anything
8535 -- Do not override existing representation
8546 else
8547 Set_Component_Alignment
8553 --------------------------
8554 -- Set_SSO_From_Default --
8555 --------------------------
8560 begin
8561 -- Set default SSO for an array or record base type, except in case of
8562 -- a type extension (which always inherits the SSO of its parent type).
8569 then
8570 Reversed :=
8572 or else
8577 -- For a record type, if bit order is specified explicitly,
8578 -- then do not set SSO from default if not consistent. Note that
8579 -- we do not want to look at a Bit_Order attribute definition
8580 -- for a parent: if we were to inherit Bit_Order, then both
8581 -- SSO_Set_*_By_Default flags would have been cleared already
8582 -- (by Inherit_Aspects_At_Freeze_Point).
8584 and then not
8586 and then
8589 then
8590 -- If flags cause reverse storage order, then set the result. Note
8591 -- that we would have ignored the pragma setting the non default
8592 -- storage order in any case, hence the assertion at this point.
8594 pragma Assert
8599 -- For a record type, also set reversed bit order. Note: if a bit
8600 -- order has been specified explicitly, then this is a no-op.
8609 ------------------
8610 -- Undelay_Type --
8611 ------------------
8614 begin
8618 -- Since we don't want T to have a Freeze_Node, we don't want its
8619 -- Full_View or Corresponding_Record_Type to have one either.
8621 -- ??? Fundamentally, this whole handling is unpleasant. What we really
8622 -- want is to be sure that for an Itype that's part of record R and is a
8623 -- subtype of type T, that it's frozen after the later of the freeze
8624 -- points of R and T. We have no way of doing that directly, so what we
8625 -- do is force most such Itypes to be frozen as part of freezing R via
8626 -- this procedure and only delay the ones that need to be delayed
8627 -- (mostly the designated types of access types that are defined as part
8628 -- of the record).
8634 then
8642 then
8647 ------------------
8648 -- Warn_Overlay --
8649 ------------------
8653 -- The object to which the address clause applies
8659 begin
8660 -- No warning if address clause overlay warnings are off
8666 -- No warning if there is an explicit initialization
8674 -- We only give the warning for non-imported entities of a type for
8675 -- which a non-null base init proc is defined, or for objects of access
8676 -- types with implicit null initialization, or when Normalize_Scalars
8677 -- applies and the type is scalar or a string type (the latter being
8678 -- tested for because predefined String types are initialized by inline
8679 -- code rather than by an init_proc). Note that we do not give the
8680 -- warning for Initialize_Scalars, since we suppressed initialization
8681 -- in this case. Also, do not warn if Suppress_Initialization is set.
8691 then
8694 then
8699 then
8706 then
8713 -- A function call (most likely to To_Address) is probably not an
8714 -- overlay, so skip warning. Ditto if the function call was inlined
8715 -- and transformed into an entity.
8721 -- If a pragma Import follows, we assume that it is for the current
8722 -- target of the address clause, and skip the warning. There may be
8723 -- a source pragma or an aspect that specifies import and generates
8724 -- the corresponding pragma. These will indicate that the entity is
8725 -- imported and that is checked above so that the spurious warning
8726 -- (generated when the entity is frozen) will be suppressed. The
8727 -- pragma may be attached to the aspect, so it is not yet a list
8728 -- member.
8736 then
8741 -- Otherwise give warning message
8745 Error_Msg_N
8747 Nam);
8748 else
8749 Error_Msg_N
8751 Nam);
8754 -- Add friendly warning if initialization comes from a packed array
8755 -- component.
8758 declare
8761 begin
8766 then
8770 then
8771 Error_Msg_NE
8776 else
8783 Error_Msg_N
8786 Nam);