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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) 1992-2016, 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 ------------------------------------------------------------------------------
75 -----------------------
76 -- Local Subprograms --
77 -----------------------
80 -- Typ is a type that is being frozen. If no size clause is given,
81 -- but a default Esize has been computed, then this default Esize is
82 -- adjusted up if necessary to be consistent with a given alignment,
83 -- but never to a value greater than Long_Long_Integer'Size. This
84 -- is used for all discrete types and for fixed-point types.
86 procedure Build_And_Analyze_Renamed_Body
90 -- Build body for a renaming declaration, insert in tree and analyze
93 -- Apply legality checks to address clauses for object declarations,
94 -- at the point the object is frozen. Also ensure any initialization is
95 -- performed only after the object has been frozen.
97 procedure Check_Component_Storage_Order
102 -- For an Encl_Type that has a Scalar_Storage_Order attribute definition
103 -- clause, verify that the component type has an explicit and compatible
104 -- attribute/aspect. For arrays, Comp is Empty; for records, it is the
105 -- entity of the component under consideration. For an Encl_Type that
106 -- does not have a Scalar_Storage_Order attribute definition clause,
107 -- verify that the component also does not have such a clause.
108 -- ADC is the attribute definition clause if present (or Empty). On return,
109 -- Comp_ADC_Present is set True if the component has a Scalar_Storage_Order
110 -- attribute definition clause.
113 -- As each entity is frozen, this routine is called to deal with the
114 -- setting of Debug_Info_Needed for the entity. This flag is set if
115 -- the entity comes from source, or if we are in Debug_Generated_Code
116 -- mode or if the -gnatdV debug flag is set. However, it never sets
117 -- the flag if Debug_Info_Off is set. This procedure also ensures that
118 -- subsidiary entities have the flag set as required.
121 -- When an expression function is frozen by a use of it, the expression
122 -- itself is frozen. Check that the expression does not include references
123 -- to deferred constants without completion. We report this at the freeze
124 -- point of the function, to provide a better error message.
125 --
126 -- In most cases the expression itself is frozen by the time the function
127 -- itself is frozen, because the formals will be frozen by then. However,
128 -- Attribute references to outer types are freeze points for those types;
129 -- this routine generates the required freeze nodes for them.
132 -- For a tagged derived type, create wrappers for inherited operations
133 -- that have a class-wide condition, so it can be properly rewritten if
134 -- it involves calls to other overriding primitives.
137 -- E is a base type. If E is tagged or has a component that is aliased
138 -- or tagged or contains something this is aliased or tagged, set
139 -- Strict_Alignment.
143 -- If E is a fixed-point or discrete type, then all the necessary work
144 -- to freeze it is completed except for possible setting of the flag
145 -- Is_Unsigned_Type, which is done by this procedure. The call has no
146 -- effect if the entity E is not a discrete or fixed-point type.
148 procedure Freeze_And_Append
152 -- Freezes Ent using Freeze_Entity, and appends the resulting list of
153 -- nodes to Result, modifying Result from No_List if necessary. N has
154 -- the same usage as in Freeze_Entity.
157 -- Freeze enumeration type. The Esize field is set as processing
158 -- proceeds (i.e. set by default when the type is declared and then
159 -- adjusted by rep clauses. What this procedure does is to make sure
160 -- that if a foreign convention is specified, and no specific size
161 -- is given, then the size must be at least Integer'Size.
164 -- If an object is frozen which has Is_Statically_Allocated set, then
165 -- all referenced types must also be marked with this flag. This routine
166 -- is in charge of meeting this requirement for the object entity E.
169 -- Perform freezing actions for a subprogram (create extra formals,
170 -- and set proper default mechanism values). Note that this routine
171 -- is not called for internal subprograms, for which neither of these
172 -- actions is needed (or desirable, we do not want for example to have
173 -- these extra formals present in initialization procedures, where they
174 -- would serve no purpose). In this call E is either a subprogram or
175 -- a subprogram type (i.e. an access to a subprogram).
178 -- True if T is not private and has no private components, or has a full
179 -- view. Used to determine whether the designated type of an access type
180 -- should be frozen when the access type is frozen. This is done when an
181 -- allocator is frozen, or an expression that may involve attributes of
182 -- the designated type. Otherwise freezing the access type does not freeze
183 -- the designated type.
185 procedure Process_Default_Expressions
188 -- This procedure is called for each subprogram to complete processing of
189 -- default expressions at the point where all types are known to be frozen.
190 -- The expressions must be analyzed in full, to make sure that all error
191 -- processing is done (they have only been pre-analyzed). If the expression
192 -- is not an entity or literal, its analysis may generate code which must
193 -- not be executed. In that case we build a function body to hold that
194 -- code. This wrapper function serves no other purpose (it used to be
195 -- called to evaluate the default, but now the default is inlined at each
196 -- point of call).
199 -- Typ is a record or array type that is being frozen. This routine sets
200 -- the default component alignment from the scope stack values if the
201 -- alignment is otherwise not specified.
204 -- T is a record or array type that is being frozen. If it is a base type,
205 -- and if SSO_Set_Low/High_By_Default is set, then Reverse_Storage order
206 -- will be set appropriately. Note that an explicit occurrence of aspect
207 -- Scalar_Storage_Order or an explicit setting of this aspect with an
208 -- attribute definition clause occurs, then these two flags are reset in
209 -- any case, so call will have no effect.
212 -- T is a type of a component that we know to be an Itype. We don't want
213 -- this to have a Freeze_Node, so ensure it doesn't. Do the same for any
214 -- Full_View or Corresponding_Record_Type.
217 -- Expr is the expression for an address clause for entity Nam whose type
218 -- is Typ. If Typ has a default initialization, and there is no explicit
219 -- initialization in the source declaration, check whether the address
220 -- clause might cause overlaying of an entity, and emit a warning on the
221 -- side effect that the initialization will cause.
223 -------------------------------
224 -- Adjust_Esize_For_Alignment --
225 -------------------------------
230 begin
236 then
242 ------------------------------------
243 -- Build_And_Analyze_Renamed_Body --
244 ------------------------------------
246 procedure Build_And_Analyze_Renamed_Body
250 is
256 begin
257 -- If the renamed subprogram is intrinsic, there is no need for a
258 -- wrapper body: we set the alias that will be called and expanded which
259 -- completes the declaration. This transformation is only legal if the
260 -- renamed entity has already been elaborated.
262 -- Note that it is legal for a renaming_as_body to rename an intrinsic
263 -- subprogram, as long as the renaming occurs before the new entity
264 -- is frozen (RM 8.5.4 (5)).
268 then
270 else
276 and then
280 -- We can make the renaming entity intrinsic if the renamed function
281 -- has an interface name, or if it is one of the shift/rotate
282 -- operations known to the compiler.
284 and then
287 Name_Rotate_Right,
288 Name_Shift_Left,
289 Name_Shift_Right,
290 Name_Shift_Right_Arithmetic))
291 then
296 else
303 else
312 ------------------------
313 -- Build_Renamed_Body --
314 ------------------------
316 function Build_Renamed_Body
319 is
321 -- We use for the source location of the renamed body, the location of
322 -- the spec entity. It might seem more natural to use the location of
323 -- the renaming declaration itself, but that would be wrong, since then
324 -- the body we create would look as though it was created far too late,
325 -- and this could cause problems with elaboration order analysis,
326 -- particularly in connection with instantiations.
341 -- If the renamed entity is a primitive operation given in prefix form,
342 -- the prefix is the target object and it has to be added as the first
343 -- actual in the generated call.
345 begin
346 -- Determine the entity being renamed, which is the target of the call
347 -- statement. If the name is an explicit dereference, this is a renaming
348 -- of a subprogram type rather than a subprogram. The name itself is
349 -- fully analyzed.
360 else
367 else
373 -- If the renamed entity is a predefined operator, retain full name
374 -- to ensure its visibility.
378 then
380 else
384 else
387 and then
390 then
392 -- Retrieve the target object, to be added as a first actual
393 -- in the call.
398 else
402 -- Original name may have been overloaded, but is fully resolved now
407 -- For simple renamings, subsequent calls can be expanded directly as
408 -- calls to the renamed entity. The body must be generated in any case
409 -- for calls that may appear elsewhere. This is not done in the case
410 -- where the subprogram is an instantiation because the actual proper
411 -- body has not been built yet.
416 then
420 -- Check whether the return type is a limited view. If the subprogram
421 -- is already frozen the generated body may have a non-limited view
422 -- of the type, that must be used, because it is the one in the spec
423 -- of the renaming declaration.
427 then
428 declare
430 begin
432 Set_Result_Definition
438 -- The body generated for this renaming is an internal artifact, and
439 -- does not constitute a freeze point for the called entity.
446 declare
450 begin
451 -- The controlling formal may be an access parameter, or the
452 -- actual may be an access value, so adjust accordingly.
456 then
457 Actuals := New_List
462 then
463 Actuals :=
464 New_List (
468 else
476 else
487 -- If the renamed entity is an entry, inherit its profile. For other
488 -- renamings as bodies, both profiles must be subtype conformant, so it
489 -- is not necessary to replace the profile given in the declaration.
490 -- However, default values that are aggregates are rewritten when
491 -- partially analyzed, so we recover the original aggregate to insure
492 -- that subsequent conformity checking works. Similarly, if the default
493 -- expression was constant-folded, recover the original expression.
503 N_Access_Definition
504 then
512 then
523 -- If the renamed entity is a function, the generated body contains a
524 -- return statement. Otherwise, build a procedure call. If the entity is
525 -- an entry, subsequent analysis of the call will transform it into the
526 -- proper entry or protected operation call. If the renamed entity is
527 -- a character literal, return it directly.
533 then
534 Call_Node :=
536 Expression =>
542 Call_Node :=
547 Call_Node :=
550 else
551 Call_Node :=
557 -- Create entities for subprogram body and formals
570 Body_Node :=
574 Handled_Statement_Sequence =>
584 -- Link the body to the entity whose declaration it completes. If
585 -- the body is analyzed when the renamed entity is frozen, it may
586 -- be necessary to restore the proper scope (see package Exp_Ch13).
590 then
592 else
599 --------------------------
600 -- Check_Address_Clause --
601 --------------------------
612 begin
615 -- For a deferred constant, the initialization value is on full view
619 else
628 -- Has_Delayed_Freeze was set on E when the address clause was
629 -- analyzed, and must remain set because we want the address
630 -- clause to be elaborated only after any entity it references
631 -- has been elaborated.
634 -- If Rep_Clauses are to be ignored, remove address clause from
635 -- list attached to entity, because it may be illegal for gigi,
636 -- for example by breaking order of elaboration..
639 declare
642 begin
648 else
651 loop
661 -- And now remove the address clause
667 then
673 -- If a variable, or a non-imported constant, overlays a constant
674 -- object and has an initialization value, then the initialization
675 -- may end up writing into read-only memory. Detect the cases of
676 -- statically identical values and remove the initialization. In
677 -- the other cases, give a warning. We will give other warnings
678 -- later for the variable if it is assigned.
685 then
686 declare
690 begin
696 and then Compile_Time_Compare
700 then
705 and then Address_Clause_Overlay_Warnings
706 then
708 Error_Msg_NE
717 -- Capture initialization value at point of declaration,
718 -- and make explicit assignment legal, because object may
719 -- be a constant.
725 -- Move initialization to freeze actions, once the object has
726 -- been frozen and the address clause alignment check has been
727 -- performed.
736 -- If the objet is tagged, check whether the tag must be
737 -- reassigned explicitly.
747 -----------------------------
748 -- Check_Compile_Time_Size --
749 -----------------------------
754 -- Sets the compile time known size (64 bits or less) in the RM_Size
755 -- field of T, checking for a size clause that was given which attempts
756 -- to give a smaller size.
759 -- Recursive function that does all the work
762 -- If T is a constrained subtype, its size is not known if any of its
763 -- discriminant constraints is not static and it is not a null record.
764 -- The test is conservative and doesn't check that the components are
765 -- in fact constrained by non-static discriminant values. Could be made
766 -- more precise ???
768 --------------------
769 -- Set_Small_Size --
770 --------------------
773 begin
777 -- Check for bad size clause given
782 Error_Msg_NE
787 -- Set size if not set already
794 ----------------
795 -- Size_Known --
796 ----------------
805 begin
809 -- Always True for elementary types, even generic formal elementary
810 -- types. We used to return False in the latter case, but the size
811 -- is known at compile time, even in the template, we just do not
812 -- know the exact size but that's not the point of this routine.
817 -- Array types
821 -- String literals always have known size, and we can set it
824 Set_Small_Size
828 -- Unconstrained types never have known at compile time size
833 -- Don't do any recursion on type with error posted, since we may
834 -- have a malformed type that leads us into a loop.
839 -- Otherwise if component size unknown, then array size unknown
845 -- Check for all indexes static, and also compute possible size
846 -- (in case it is not greater than 64 and may be packable).
848 declare
852 begin
861 else
869 then
872 else
877 else
889 -- For non-generic private types, go to underlying type if present
894 then
895 -- Don't do any recursion on type with error posted, since we may
896 -- have a malformed type that leads us into a loop.
900 else
904 -- Record types
908 -- A class-wide type is never considered to have a known size
913 -- A subtype of a variant record must not have non-static
914 -- discriminated components.
918 then
921 -- Don't do any recursion on type with error posted, since we may
922 -- have a malformed type that leads us into a loop.
928 -- Now look at the components of the record
930 declare
931 -- The following two variables are used to keep track of the
932 -- size of packed records if we can tell the size of the packed
933 -- record in the front end. Packed_Size_Known is True if so far
934 -- we can figure out the size. It is initialized to True for a
935 -- packed record, unless the record has discriminants or atomic
936 -- components or independent components.
938 -- The reason we eliminate the discriminated case is that
939 -- we don't know the way the back end lays out discriminated
940 -- packed records. If Packed_Size_Known is True, then
941 -- Packed_Size is the size in bits so far.
950 -- Size in bits so far
952 begin
953 -- Test for variant part present
959 N_Record_Definition
961 and then
962 Present (Variant_Part
964 then
965 -- If variant part is present, and type is unconstrained,
966 -- then we must have defaulted discriminants, or a size
967 -- clause must be present for the type, or else the size
968 -- is definitely not known at compile time.
971 and then
974 then
979 -- Loop through components
985 -- We do not know the packed size if there is a component
986 -- clause present (we possibly could, but this would only
987 -- help in the case of a record with partial rep clauses.
988 -- That's because in the case of full rep clauses, the
989 -- size gets figured out anyway by a different circuit).
995 -- We do not know the packed size for an atomic/VFA type
996 -- or component, or an independent type or component, or a
997 -- by-reference type or aliased component (because packing
998 -- does not touch these).
1006 then
1010 -- We need to identify a component that is an array where
1011 -- the index type is an enumeration type with non-standard
1012 -- representation, and some bound of the type depends on a
1013 -- discriminant.
1015 -- This is because gigi computes the size by doing a
1016 -- substitution of the appropriate discriminant value in
1017 -- the size expression for the base type, and gigi is not
1018 -- clever enough to evaluate the resulting expression (which
1019 -- involves a call to rep_to_pos) at compile time.
1021 -- It would be nice if gigi would either recognize that
1022 -- this expression can be computed at compile time, or
1023 -- alternatively figured out the size from the subtype
1024 -- directly, where all the information is at hand ???
1028 then
1029 declare
1037 begin
1044 then
1050 then
1055 then
1065 -- Clearly size of record is not known if the size of one of
1066 -- the components is not known.
1072 -- Accumulate packed size if possible
1076 -- We can deal with elementary types, small packed arrays
1077 -- if the representation is a modular type and also small
1078 -- record types (if the size is not greater than 64, but
1079 -- the condition is checked by Set_Small_Size).
1083 and then Present
1085 and then Is_Modular_Integer_Type
1088 then
1089 -- If RM_Size is known and static, then we can keep
1090 -- accumulating the packed size.
1096 -- If we have a field whose RM_Size is not known then
1097 -- we can't figure out the packed size here.
1099 else
1103 -- For other types we can't figure out the packed size
1105 else
1120 -- All other cases, size not known at compile time
1122 else
1127 -------------------------------------
1128 -- Static_Discriminated_Components --
1129 -------------------------------------
1131 function Static_Discriminated_Components
1133 is
1136 begin
1140 then
1154 -- Start of processing for Check_Compile_Time_Size
1156 begin
1160 -----------------------------------
1161 -- Check_Component_Storage_Order --
1162 -----------------------------------
1164 procedure Check_Component_Storage_Order
1169 is
1178 -- Set for the record case, True if Comp starts on a byte boundary
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 -- on a storage element boundary. Otherwise conservatively assume
1199 -- it does so only in the case where the record is not packed.
1202 Comp_Byte_Aligned :=
1204 else
1211 -- Array case
1213 else
1220 -- Note: the Reverse_Storage_Order flag is set on the base type, but
1221 -- the attribute definition clause is attached to the first subtype.
1222 -- Also, if the base type is incomplete or private, go to full view
1223 -- if known
1235 Comp_ADC :=
1236 Get_Attribute_Definition_Clause
1240 -- Case of record or array component: check storage order compatibility.
1241 -- But, if the record has Complex_Representation, then it is treated as
1242 -- a scalar in the back end so the storage order is irrelevant.
1247 then
1248 Comp_SSO_Differs :=
1252 -- Parent and extension must have same storage order
1256 Error_Msg_N
1261 -- If component and composite SSO differs, check that component
1262 -- falls on byte boundaries and isn't bit packed.
1266 -- Component SSO differs from enclosing composite:
1268 -- Reject if component is a bit-packed array, as it is represented
1269 -- as a scalar internally.
1272 Error_Msg_N
1276 -- Reject if composite is a bit-packed array, as it is rewritten
1277 -- into an array of scalars.
1280 Error_Msg_N
1284 -- Reject if not byte aligned
1287 and then not Comp_Byte_Aligned
1288 then
1289 Error_Msg_N
1293 -- Warn if specified only for the outer composite
1296 Error_Msg_NE
1302 -- Enclosing type has explicit SSO: non-composite component must not
1303 -- be aliased.
1306 Error_Msg_N
1312 -----------------------------
1313 -- Check_Debug_Info_Needed --
1314 -----------------------------
1317 begin
1322 or else Debug_Generated_Code
1323 or else Debug_Flag_VV
1325 then
1330 -------------------------------
1331 -- Check_Expression_Function --
1332 -------------------------------
1338 -- Function to search for deferred constant
1340 -------------------
1341 -- Find_Constant --
1342 -------------------
1345 begin
1346 -- When a constant is initialized with the result of a dispatching
1347 -- call, the constant declaration is rewritten as a renaming of the
1348 -- displaced function result. This scenario is not a premature use of
1349 -- a constant even though the Has_Completion flag is not set.
1356 N_Object_Declaration
1359 then
1360 Error_Msg_NE
1368 then
1378 -- Start of processing for Check_Expression_Function
1380 begin
1385 then
1390 --------------------------------
1391 -- Check_Inherited_Conditions --
1392 --------------------------------
1402 begin
1407 -- Map the overridden primitive to the overriding one. This takes
1408 -- care of all overridings and is done only once.
1412 then
1415 -- In SPARK mode this is where we can collect the inherited
1416 -- conditions, because we do not create the Check pragmas that
1417 -- normally convey the the modified class-wide conditions on
1418 -- overriding operations.
1422 -- Analyze the contract items of the parent operation, before
1423 -- they are rewritten when inherited.
1425 Analyze_Entry_Or_Subprogram_Contract
1428 -- Now verify the legality of inherited contracts for LSP
1429 -- conformance.
1438 -- In all cases, we examine inherited operations to check whether they
1439 -- require a wrapper to handle inherited conditions that call other
1440 -- primitives, so that LSP can be verified/enforced.
1442 -- Wrapper construction TBD.
1452 Build_Class_Wide_Expression
1459 Build_Class_Wide_Expression
1468 ----------------------------
1469 -- Check_Strict_Alignment --
1470 ----------------------------
1475 begin
1493 then
1503 -------------------------
1504 -- Check_Unsigned_Type --
1505 -------------------------
1512 begin
1517 -- Do not attempt to analyze case where range was in error
1523 -- The situation that is nontrivial is something like:
1525 -- subtype x1 is integer range -10 .. +10;
1526 -- subtype x2 is x1 range 0 .. V1;
1527 -- subtype x3 is x2 range V2 .. V3;
1528 -- subtype x4 is x3 range V4 .. V5;
1530 -- where Vn are variables. Here the base type is signed, but we still
1531 -- know that x4 is unsigned because of the lower bound of x2.
1533 -- The only way to deal with this is to look up the ancestor chain
1536 loop
1550 else
1553 -- If no ancestor had a static lower bound, go to base type
1557 -- Note: the reason we still check for a compile time known
1558 -- value for the base type is that at least in the case of
1559 -- generic formals, we can have bounds that fail this test,
1560 -- and there may be other cases in error situations.
1572 then
1582 -----------------------------
1583 -- Is_Atomic_VFA_Aggregate --
1584 -----------------------------
1593 begin
1596 -- Array may be qualified, so find outer context
1613 then
1622 then
1631 New_N :=
1643 -----------------------------------------------
1644 -- Explode_Initialization_Compound_Statement --
1645 -----------------------------------------------
1650 begin
1653 then
1656 -- Note that we rewrite Init_Stmts into a NULL statement, rather than
1657 -- just removing it, because Freeze_All may rely on this particular
1658 -- Node_Id still being present in the enclosing list to know where to
1659 -- stop freezing.
1667 ----------------
1668 -- Freeze_All --
1669 ----------------
1671 -- Note: the easy coding for this procedure would be to just build a
1672 -- single list of freeze nodes and then insert them and analyze them
1673 -- all at once. This won't work, because the analysis of earlier freeze
1674 -- nodes may recursively freeze types which would otherwise appear later
1675 -- on in the freeze list. So we must analyze and expand the freeze nodes
1676 -- as they are generated.
1683 -- This is the internal recursive routine that does freezing of entities
1684 -- (but NOT the analysis of default expressions, which should not be
1685 -- recursive, we don't want to analyze those till we are sure that ALL
1686 -- the types are frozen).
1688 --------------------
1689 -- Freeze_All_Ent --
1690 --------------------
1698 -- If freeze nodes are present, insert and analyze, and reset cursor
1699 -- for next insertion.
1701 -------------------
1702 -- Process_Flist --
1703 -------------------
1706 begin
1713 else
1719 -- Start of processing for Freeze_All_Ent
1721 begin
1725 -- If the entity is an inner package which is not a package
1726 -- renaming, then its entities must be frozen at this point. Note
1727 -- that such entities do NOT get frozen at the end of the nested
1728 -- package itself (only library packages freeze).
1730 -- Same is true for task declarations, where anonymous records
1731 -- created for entry parameters must be frozen.
1737 then
1748 then
1755 N_Task_Type_Declaration)
1756 then
1759 End_Scope;
1761 -- For a derived tagged type, we must ensure that all the
1762 -- primitive operations of the parent have been frozen, so that
1763 -- their addresses will be in the parent's dispatch table at the
1764 -- point it is inherited.
1770 then
1771 declare
1778 begin
1785 then
1787 Process_Flist;
1797 Process_Flist;
1799 -- If already frozen, and there are delayed aspects, this is where
1800 -- we do the visibility check for these aspects (see Sem_Ch13 spec
1801 -- for a description of how we handle aspect visibility).
1805 -- Retrieve the visibility to the discriminants in order to
1806 -- analyze properly the aspects.
1810 declare
1813 begin
1819 then
1830 -- If an incomplete type is still not frozen, this may be a
1831 -- premature freezing because of a body declaration that follows.
1832 -- Indicate where the freezing took place. Freezing will happen
1833 -- if the body comes from source, but not if it is internally
1834 -- generated, for example as the body of a type invariant.
1836 -- If the freezing is caused by the end of the current declarative
1837 -- part, it is a Taft Amendment type, and there is no error.
1841 then
1842 declare
1845 begin
1846 -- The presence of a body freezes all entities previously
1847 -- declared in the current list of declarations, but this
1848 -- does not apply if the body does not come from source.
1849 -- A type invariant is transformed into a subprogram body
1850 -- which is placed at the end of the private part of the
1851 -- current package, but this body does not freeze incomplete
1852 -- types that may be declared in this private part.
1855 N_Entry_Body,
1856 N_Package_Body,
1857 N_Protected_Body,
1858 N_Task_Body)
1860 and then
1863 then
1865 Error_Msg_NE
1876 -- Start of processing for Freeze_All
1878 begin
1881 -- Now that all types are frozen, we can deal with default expressions
1882 -- that require us to build a default expression functions. This is the
1883 -- point at which such functions are constructed (after all types that
1884 -- might be used in such expressions have been frozen).
1886 -- For subprograms that are renaming_as_body, we create the wrapper
1887 -- bodies as needed.
1889 -- We also add finalization chains to access types whose designated
1890 -- types are controlled. This is normally done when freezing the type,
1891 -- but this misses recursive type definitions where the later members
1892 -- of the recursion introduce controlled components.
1894 -- Loop through entities
1909 else
1915 and then
1917 = N_Subprogram_Renaming_Declaration
1918 then
1919 Build_And_Analyze_Renamed_Body
1926 N_Single_Task_Declaration)
1927 then
1928 declare
1931 begin
1936 then
1945 -- Historical note: We used to create a finalization master for an
1946 -- access type whose designated type is not controlled, but contains
1947 -- private controlled compoments. This form of postprocessing is no
1948 -- longer needed because the finalization master is now created when
1949 -- the access type is frozen (see Exp_Ch3.Freeze_Type).
1955 -----------------------
1956 -- Freeze_And_Append --
1957 -----------------------
1959 procedure Freeze_And_Append
1963 is
1965 begin
1969 else
1975 -------------------
1976 -- Freeze_Before --
1977 -------------------
1979 procedure Freeze_Before
1983 is
1984 -- Freeze T, then insert the generated Freeze nodes before the node N.
1985 -- Flag Freeze_Profile is used when T is an overloadable entity, and
1986 -- indicates whether its profile should be frozen at the same time.
1991 begin
2001 -------------------
2002 -- Freeze_Entity --
2003 -------------------
2005 function Freeze_Entity
2009 is
2018 -- This flag gets set to true for a variable with default initialization
2021 -- List of freezing actions, left at No_List if none
2024 -- This could use a comment ???
2027 -- N is a freezing action to be appended to the Result
2030 -- If Loc is a freeze_entity that appears after the last declaration
2031 -- in the scope, inhibit error messages on late completion.
2034 -- Check that an Access or Unchecked_Access attribute with a prefix
2035 -- which is the current instance type can only be applied when the type
2036 -- is limited.
2039 -- Give warning for modulus of 8, 16, 32, or 64 given as an explicit
2040 -- integer literal without an explicit corresponding size clause. The
2041 -- caller has checked that Utype is a modular integer type.
2044 -- Freeze array type, including freezing index and component types
2047 -- Perform checks and generate freeze node if needed for a constant or
2048 -- variable declared by an object declaration.
2051 -- Create Freeze_Generic_Entity nodes for types declared in a generic
2052 -- package. Recurse on inner generic packages.
2055 -- Freeze formals and return type of subprogram. If some type in the
2056 -- profile is incomplete and we are in an instance, freezing of the
2057 -- entity will take place elsewhere, and the function returns False.
2060 -- Freeze record type, including freezing component types, and freezing
2061 -- primitive operations if this is a tagged type.
2064 -- Determine whether an arbitrary entity is subject to Boolean aspect
2065 -- Import and its value is specified as True.
2068 -- Create a new freeze node for entity E
2071 -- If E is an entity for an imported subprogram with pre/post-conditions
2072 -- then this procedure will create a wrapper to ensure that proper run-
2073 -- time checking of the pre/postconditions. See body for details.
2075 -------------------
2076 -- Add_To_Result --
2077 -------------------
2080 begin
2083 else
2088 ----------------------------
2089 -- After_Last_Declaration --
2090 ----------------------------
2095 begin
2101 else
2105 else
2110 ----------------------------
2111 -- Check_Current_Instance --
2112 ----------------------------
2117 -- Determine whether Typ is compatible with the rules for aliased
2118 -- views of types as defined in RM 3.10 in the various dialects.
2121 -- Process routine to apply check to given node
2123 -----------------------------
2124 -- Is_Aliased_View_Of_Type --
2125 -----------------------------
2130 begin
2131 -- Common case
2135 then
2138 -- The following paragraphs describe what a legal aliased view of
2139 -- a type is in the various dialects of Ada.
2141 -- Ada 95
2143 -- The current instance of a limited type, and a formal parameter
2144 -- or generic formal object of a tagged type.
2146 -- Ada 95 limited type
2147 -- * Type with reserved word "limited"
2148 -- * A protected or task type
2149 -- * A composite type with limited component
2154 -- Ada 2005
2156 -- The current instance of a limited tagged type, a protected
2157 -- type, a task type, or a type that has the reserved word
2158 -- "limited" in its full definition ... a formal parameter or
2159 -- generic formal object of a tagged type.
2161 -- Ada 2005 limited type
2162 -- * Type with reserved word "limited", "synchronized", "task"
2163 -- or "protected"
2164 -- * A composite type with limited component
2165 -- * A derived type whose parent is a non-interface limited type
2168 return
2170 or else
2175 -- Ada 2012 and beyond
2177 -- The current instance of an immutably limited type ... a formal
2178 -- parameter or generic formal object of a tagged type.
2180 -- Ada 2012 limited type
2181 -- * Type with reserved word "limited", "synchronized", "task"
2182 -- or "protected"
2183 -- * A composite type with limited component
2184 -- * A derived type whose parent is a non-interface limited type
2185 -- * An incomplete view
2187 -- Ada 2012 immutably limited type
2188 -- * Explicitly limited record type
2189 -- * Record extension with "limited" present
2190 -- * Non-formal limited private type that is either tagged
2191 -- or has at least one access discriminant with a default
2192 -- expression
2193 -- * Task type, protected type or synchronized interface
2194 -- * Type derived from immutably limited type
2196 else
2197 return
2203 -------------
2204 -- Process --
2205 -------------
2208 begin
2212 Name_Unchecked_Access)
2216 then
2218 Error_Msg_N
2221 else
2222 Error_Msg_N
2229 else
2239 -- Local variables
2244 -- Start of processing for Check_Current_Instance
2246 begin
2252 ------------------------------
2253 -- Check_Suspicious_Modulus --
2254 ------------------------------
2259 begin
2265 declare
2268 begin
2270 declare
2274 begin
2276 declare
2280 begin
2281 -- First case, modulus and size are the same. This
2282 -- happens if you have something like mod 32, with
2283 -- an explicit size of 32, this is for sure a case
2284 -- where the warning is given, since it is seems
2285 -- very unlikely that someone would want e.g. a
2286 -- five bit type stored in 32 bits. It is much
2287 -- more likely they wanted a 32-bit type.
2292 -- Second case, the modulus is 32 or 64 and no
2293 -- size clause is present. This is a less clear
2294 -- case for giving the warning, but in the case
2295 -- of 32/64 (5-bit or 6-bit types) these seem rare
2296 -- enough that it is a likely error (and in any
2297 -- case using 2**5 or 2**6 in these cases seems
2298 -- clearer. We don't include 8 or 16 here, simply
2299 -- because in practice 3-bit and 4-bit types are
2300 -- more common and too many false positives if
2301 -- we warn in these cases.
2305 then
2308 -- No warning needed
2310 else
2314 -- If we fall through, give warning
2317 Error_Msg_N
2319 Modulus);
2328 -----------------------
2329 -- Freeze_Array_Type --
2330 -----------------------
2338 -- Set true if any of the index types is an enumeration type with a
2339 -- non-standard representation.
2341 begin
2350 then
2357 -- Processing that is done only for base types
2361 -- Deal with default setting of reverse storage order
2365 -- Propagate flags for component type
2369 then
2377 -- The array type requires its own invariant procedure in order to
2378 -- verify the component invariant over all elements.
2381 or else
2383 and then Has_Invariants
2385 then
2388 -- The array type is an implementation base type. Propagate the
2389 -- same property to the first subtype.
2396 -- Warn for pragma Pack overriding foreign convention
2400 then
2401 declare
2406 begin
2410 Error_Msg_N
2413 Error_Msg_N
2420 -- If packing was requested or if the component size was
2421 -- set explicitly, then see if bit packing is required. This
2422 -- processing is only done for base types, since all of the
2423 -- representation aspects involved are type-related.
2425 -- This is not just an optimization, if we start processing the
2426 -- subtypes, they interfere with the settings on the base type
2427 -- (this is because Is_Packed has a slightly different meaning
2428 -- before and after freezing).
2430 declare
2434 begin
2438 then
2447 else
2450 -- We can set the component size if it is less than 16,
2451 -- rounding it up to the next storage unit size.
2457 else
2461 -- Set component size up to match alignment if it would
2462 -- otherwise be less than the alignment. This deals with
2463 -- cases of types whose alignment exceeds their size (the
2464 -- padded type cases).
2467 declare
2469 begin
2477 -- Case of component size that may result in bit packing
2480 declare
2486 Get_Attribute_Definition_Clause
2489 begin
2490 -- Warn if we have pack and component size so that the
2491 -- pack is ignored.
2493 -- Note: here we must check for the presence of a
2494 -- component size before checking for a Pack pragma to
2495 -- deal with the case where the array type is a derived
2496 -- type whose parent is currently private.
2500 and then Warn_On_Redundant_Constructs
2501 then
2503 Error_Msg_NE
2505 Error_Msg_N
2511 -- Set component size if not already set by a component
2512 -- size clause.
2518 -- Check for base type of 8, 16, 32 bits, where an
2519 -- unsigned subtype has a length one less than the
2520 -- base type (e.g. Natural subtype of Integer).
2522 -- In such cases, if a component size was not set
2523 -- explicitly, then generate a warning.
2529 then
2533 Error_Msg_N
2535 Pack_Pragma);
2536 Error_Msg_N
2538 Pack_Pragma);
2542 -- Bit packing is never needed for 8, 16, 32, 64
2546 -- If the Esize of the component is known and equal to
2547 -- the component size then even packing is not needed.
2551 then
2552 -- Here the array was requested to be packed, but
2553 -- the packing request had no effect whatsoever,
2554 -- so flag Is_Packed is reset.
2556 -- Note: semantically this means that we lose track
2557 -- of the fact that a derived type inherited pragma
2558 -- Pack that was non-effective, but that is fine.
2560 -- We regard a Pack pragma as a request to set a
2561 -- representation characteristic, and this request
2562 -- may be ignored.
2566 else
2573 -- Bit packing is not needed for multiples of the storage
2574 -- unit if the type is composite because the back end can
2575 -- byte pack composite types.
2579 then
2585 -- In all other cases, bit packing is needed
2587 else
2596 -- Check for Aliased or Atomic_Components/Atomic/VFA with
2597 -- unsuitable packing or explicit component size clause given.
2602 and then
2604 then
2608 -- Outputs error messages for incorrect CS clause or pragma
2609 -- Pack for aliased or atomic/VFA components (T is "aliased"
2610 -- or "atomic/vfa");
2612 -----------------
2613 -- Complain_CS --
2614 -----------------
2617 begin
2619 Clause :=
2620 Get_Attribute_Definition_Clause
2623 Error_Msg_N
2627 Error_Msg_N
2630 else
2631 Error_Msg_N
2637 -- Start of processing for Alias_Atomic_Check
2639 begin
2640 -- If object size of component type isn't known, we cannot
2641 -- be sure so we defer to the back end.
2646 -- Case where component size has no effect. First check for
2647 -- object size of component type multiple of the storage
2648 -- unit size.
2652 -- OK in both packing case and component size case if RM
2653 -- size is known and static and same as the object size.
2655 and then
2659 -- Or if we have an explicit component size clause and
2660 -- the component size and object size are equal.
2662 or else
2665 then
2673 then
2682 -- Check for Independent_Components/Independent with unsuitable
2683 -- packing or explicit component size clause given.
2686 and then
2688 then
2689 begin
2690 -- If object size of component type isn't known, we cannot
2691 -- be sure so we defer to the back end.
2696 -- Case where component size has no effect. First check for
2697 -- object size of component type multiple of the storage
2698 -- unit size.
2702 -- OK in both packing case and component size case if RM
2703 -- size is known and multiple of the storage unit size.
2705 and then
2709 -- Or if we have an explicit component size clause and
2710 -- the component size is larger than the object size.
2712 or else
2715 then
2718 else
2720 Clause :=
2721 Get_Attribute_Definition_Clause
2724 Error_Msg_N
2728 Error_Msg_N
2731 else
2732 Error_Msg_N
2740 -- Warn for case of atomic type
2746 then
2747 Error_Msg_NE
2762 -- Check for scalar storage order
2764 declare
2766 begin
2767 Check_Component_Storage_Order
2770 ADC => Get_Attribute_Definition_Clause
2772 Attribute_Scalar_Storage_Order),
2776 -- Processing that is done only for subtypes
2778 else
2779 -- Acquire alignment from base type
2787 -- Specific checks for bit-packed arrays
2791 -- Check number of elements for bit-packed arrays that come from
2792 -- source and have compile time known ranges. The bit-packed
2793 -- arrays circuitry does not support arrays with more than
2794 -- Integer'Last + 1 elements, and when this restriction is
2795 -- violated, causes incorrect data access.
2797 -- For the case where this is not compile time known, a run-time
2798 -- check should be generated???
2801 declare
2807 begin
2813 -- Never generate an error if any index is of a generic
2814 -- type. We will check this in instances.
2821 Ilen :=
2827 -- No attempt is made to check number of elements if not
2828 -- compile time known.
2841 then
2842 Error_Msg_N
2849 -- Check size
2852 declare
2856 begin
2857 -- It is not clear if it is possible to have no size clause
2858 -- at this stage, but it is not worth worrying about. Post
2859 -- error on the entity name in the size clause if present,
2860 -- else on the type entity itself.
2864 else
2871 -- If any of the index types was an enumeration type with a non-
2872 -- standard rep clause, then we indicate that the array type is
2873 -- always packed (even if it is not bit-packed).
2882 -- If the array is packed and bit-packed or packed to eliminate holes
2883 -- in the non-contiguous enumeration index types, we must create the
2884 -- packed array type to be used to actually implement the type. This
2885 -- is only needed for real array types (not for string literal types,
2886 -- since they are present only for the front end).
2891 then
2895 -- Make sure that we have the necessary routines to implement the
2896 -- packing, and complain now if not. Note that we only test this
2897 -- for constrained array types.
2903 then
2904 declare
2908 begin
2911 then
2912 Error_Msg_CRT
2916 -- Cancel the packing
2926 -- Size information of packed array type is copied to the array
2927 -- type, since this is really the representation. But do not
2928 -- override explicit existing size values. If the ancestor subtype
2929 -- is constrained the Packed_Array_Impl_Type will be inherited
2930 -- from it, but the size may have been provided already, and
2931 -- must not be overridden either.
2934 and then
2937 then
2949 -- For non-packed arrays set the alignment of the array to the
2950 -- alignment of the component type if it is unknown. Skip this
2951 -- in atomic/VFA case (atomic/VFA arrays may need larger alignments).
2960 then
2964 -- A Ghost type cannot have a component of protected or task type
2965 -- (SPARK RM 6.9(19)).
2968 Error_Msg_N
2970 Arr);
2974 -------------------------------
2975 -- Freeze_Object_Declaration --
2976 -------------------------------
2979 begin
2980 -- Abstract type allowed only for C++ imported variables or constants
2982 -- Note: we inhibit this check for objects that do not come from
2983 -- source because there is at least one case (the expansion of
2984 -- x'Class'Input where x is abstract) where we legitimately
2985 -- generate an abstract object.
2990 then
2995 Error_Msg_NE
3000 Error_Msg_N -- CODEFIX
3006 -- For object created by object declaration, perform required
3007 -- categorization (preelaborate and pure) checks. Defer these
3008 -- checks to freeze time since pragma Import inhibits default
3009 -- initialization and thus pragma Import affects these checks.
3013 -- If there is an address clause, check that it is valid
3014 -- and if need be move initialization to the freeze node.
3018 -- Similar processing is needed for aspects that may affect
3019 -- object layout, like Alignment, if there is an initialization
3020 -- expression.
3023 and then Expander_Active
3026 then
3027 declare
3031 begin
3033 -- Capture initialization value at point of declaration, and
3034 -- make explicit assignment legal, because object may be a
3035 -- constant.
3040 -- Move initialization to freeze actions.
3048 -- Set_Is_Frozen (E, False);
3052 -- Reset Is_True_Constant for non-constant aliased object. We
3053 -- consider that the fact that a non-constant object is aliased may
3054 -- indicate that some funny business is going on, e.g. an aliased
3055 -- object is passed by reference to a procedure which captures the
3056 -- address of the object, which is later used to assign a new value,
3057 -- even though the compiler thinks that it is not modified. Such
3058 -- code is highly dubious, but we choose to make it "work" for
3059 -- non-constant aliased objects.
3061 -- Note that we used to do this for all aliased objects, whether or
3062 -- not constant, but this caused anomalies down the line because we
3063 -- ended up with static objects that were not Is_True_Constant. Not
3064 -- resetting Is_True_Constant for (aliased) constant objects ensures
3065 -- that this anomaly never occurs.
3067 -- However, we don't do that for internal entities. We figure that if
3068 -- we deliberately set Is_True_Constant for an internal entity, e.g.
3069 -- a dispatch table entry, then we mean it.
3074 then
3078 -- If the object needs any kind of default initialization, an error
3079 -- must be issued if No_Default_Initialization applies. The check
3080 -- doesn't apply to imported objects, which are not ever default
3081 -- initialized, and is why the check is deferred until freezing, at
3082 -- which point we know if Import applies. Deferred constants are also
3083 -- exempted from this test because their completion is explicit, or
3084 -- through an import pragma.
3092 and then
3096 or else
3099 then
3101 Check_Restriction
3105 -- Check that a Thread_Local_Storage variable does not have
3106 -- default initialization, and any explicit initialization must
3107 -- either be the null constant or a static constant.
3110 declare
3112 begin
3113 if Has_Default_Initialization
3114 or else
3116 and then
3118 or else not
3121 then
3122 Error_Msg_NE
3125 Error_Msg_NE
3132 -- For imported objects, set Is_Public unless there is also an
3133 -- address clause, which means that there is no external symbol
3134 -- needed for the Import (Is_Public may still be set for other
3135 -- unrelated reasons). Note that we delayed this processing
3136 -- till freeze time so that we can be sure not to set the flag
3137 -- if there is an address clause. If there is such a clause,
3138 -- then the only purpose of the Import pragma is to suppress
3139 -- implicit initialization.
3145 -- For source objects that are not Imported and are library
3146 -- level, if no linker section pragma was given inherit the
3147 -- appropriate linker section from the corresponding type.
3153 then
3154 Set_Linker_Section_Pragma
3158 -- For convention C objects of an enumeration type, warn if the
3159 -- size is not integer size and no explicit size given. Skip
3160 -- warning for Boolean, and Character, assume programmer expects
3161 -- 8-bit sizes for these cases.
3164 or else
3171 then
3173 Error_Msg_N
3179 -----------------------------
3180 -- Freeze_Generic_Entities --
3181 -----------------------------
3188 begin
3207 --------------------
3208 -- Freeze_Profile --
3209 --------------------
3216 begin
3217 -- Loop through formals
3223 -- AI05-0151: incomplete types can appear in a profile. By the
3224 -- time the entity is frozen, the full view must be available,
3225 -- unless it is a limited view.
3230 then
3244 then
3245 -- If the type of a formal is incomplete, subprogram is being
3246 -- frozen prematurely. Within an instance (but not within a
3247 -- wrapper package) this is an artifact of our need to regard
3248 -- the end of an instantiation as a freeze point. Otherwise it
3249 -- is a definite error.
3256 elsif not After_Last_Declaration
3257 and then not Freezing_Library_Level_Tagged_Type
3258 then
3260 Error_Msg
3265 -- Check suspicious parameter for C function. These tests apply
3266 -- only to exported/imported subprograms.
3268 if Warn_On_Export_Import
3271 or else
3278 then
3279 -- Qualify mention of formals with subprogram name
3283 -- Check suspicious use of fat C pointer
3287 then
3288 Error_Msg_N
3291 -- Check suspicious return of boolean
3297 then
3298 Error_Msg_N
3300 Error_Msg_N
3304 -- Check suspicious tagged type
3307 or else
3311 then
3312 Error_Msg_N
3316 -- Check wrong convention subprogram pointer
3320 then
3321 Error_Msg_N
3325 Error_Msg_NE
3330 -- Turn off name qualification after message output
3335 -- Check for unconstrained array in exported foreign convention
3336 -- case.
3342 and then Warn_On_Export_Import
3343 then
3346 -- If this is an inherited operation, place the warning on
3347 -- the derived type declaration, rather than on the original
3348 -- subprogram.
3351 then
3357 else
3373 -- If the formal is an anonymous_access_to_subprogram
3374 -- freeze the subprogram type as well, to prevent
3375 -- scope anomalies in gigi, because there is no other
3376 -- clear point at which it could be frozen.
3380 then
3388 -- Case of function: similar checks on return type
3392 -- Freeze return type
3396 -- AI05-0151: the return type may have been incomplete
3397 -- at the point of declaration. Replace it with the full
3398 -- view, unless the current type is a limited view. In
3399 -- that case the full view is in a different unit, and
3400 -- gigi finds the non-limited view after the other unit
3401 -- is elaborated.
3406 then
3413 -- Check suspicious return type for C function
3415 if Warn_On_Export_Import
3417 or else
3420 then
3421 -- Check suspicious return of fat C pointer
3427 then
3431 -- Check suspicious return of boolean
3438 then
3439 declare
3442 begin
3443 Error_Msg_NE
3445 Error_Msg_NE
3450 -- Check suspicious return tagged type
3454 and then
3455 Is_Tagged_Type
3460 then
3464 -- Check return of wrong convention subprogram pointer
3470 then
3474 Error_Msg_NE
3480 -- Give warning for suspicious return of a result of an
3481 -- unconstrained array type in a foreign convention function.
3485 -- We are looking for a return of unconstrained array
3490 -- Exclude imported routines, the warning does not belong on
3491 -- the import, but rather on the routine definition.
3495 -- Check that general warning is enabled, and that it is not
3496 -- suppressed for this particular case.
3498 and then Warn_On_Export_Import
3501 then
3502 Error_Msg_N
3508 -- Check suspicious use of Import in pure unit (cases where the RM
3509 -- allows calls to be omitted).
3513 -- It might be suspicious if the compilation unit has the Pure
3514 -- aspect/pragma.
3518 -- The RM allows omission of calls only in the case of
3519 -- library-level subprograms (see RM-10.2.1(18)).
3523 -- Ignore internally generated entity. This happens in some cases
3524 -- of subprograms in specs, where we generate an implied body.
3528 -- Assume run-time knows what it is doing
3530 and then not GNAT_Mode
3532 -- Assume explicit Pure_Function means import is pure
3536 -- Don't need warning in relaxed semantics mode
3538 and then not Relaxed_RM_Semantics
3540 -- Assume convention Intrinsic is OK, since this is specialized.
3541 -- This deals with the DEC unit current_exception.ads
3545 -- Assume that ASM interface knows what it is doing. This deals
3546 -- with e.g. unsigned.ads in the AAMP back end.
3549 then
3550 Error_Msg_N
3552 Error_Msg_NE
3560 ------------------------
3561 -- Freeze_Record_Type --
3562 ------------------------
3574 -- Set True if we find at least one component which is aliased. This
3575 -- is used to prevent Implicit_Packing of the record, since packing
3576 -- cannot modify the size of alignment of an aliased component.
3579 -- Set False if we encounter a component of a composite type
3582 -- Set False if we encounter a component with unknown RM_Size
3585 -- Set False if we encounter a component of a composite type whose
3586 -- RM_Size is not a multiple of the storage unit.
3589 -- Accumulates total Esize values of all elementary components. Used
3590 -- for processing of Implicit_Packing.
3593 -- Set True if we find at least one component with a component
3594 -- clause (used to warn about useless Bit_Order pragmas, and also
3595 -- to detect cases where Implicit_Packing may have an effect).
3598 -- Set True if the record type scope Rec has been pushed on the scope
3599 -- stack. Needed for the analysis of delayed aspects specified to the
3600 -- components of Rec.
3603 -- Accumulates total RM_Size values of all sized components. Used
3604 -- for processing of Implicit_Packing.
3607 -- Scalar_Storage_Order attribute definition clause for the record
3610 -- Set True if we find at least one component whose type has a
3611 -- Scalar_Storage_Order attribute definition clause.
3614 -- Set True if we find at least one component with no component
3615 -- clause (used to warn about useless Pack pragmas).
3618 -- If N is an allocator, possibly wrapped in one or more level of
3619 -- qualified expression(s), return the inner allocator node, else
3620 -- return Empty.
3623 -- If the component subtype is an access to a constrained subtype of
3624 -- an already frozen type, make the subtype frozen as well. It might
3625 -- otherwise be frozen in the wrong scope, and a freeze node on
3626 -- subtype has no effect. Similarly, if the component subtype is a
3627 -- regular (not protected) access to subprogram, set the anonymous
3628 -- subprogram type to frozen as well, to prevent an out-of-scope
3629 -- freeze node at some eventual point of call. Protected operations
3630 -- are handled elsewhere.
3633 -- Make sure that all types mentioned in Discrete_Choices of the
3634 -- variants referenceed by the Variant_Part VP are frozen. This is
3635 -- a recursive routine to deal with nested variants.
3637 ---------------------
3638 -- Check_Allocator --
3639 ---------------------
3643 begin
3645 loop
3650 else
3656 -----------------
3657 -- Check_Itype --
3658 -----------------
3663 begin
3666 then
3669 -- In addition, add an Itype_Reference to ensure that the
3670 -- access subtype is elaborated early enough. This cannot be
3671 -- done if the subtype may depend on discriminants.
3676 then
3684 then
3689 ------------------------------------
3690 -- Freeze_Choices_In_Variant_Part --
3691 ------------------------------------
3700 begin
3701 -- Loop through variants
3706 -- Loop through choices, checking that all types are frozen
3712 then
3719 -- Check for nested variant part to process
3733 -- Start of processing for Freeze_Record_Type
3735 begin
3736 -- Deal with delayed aspect specifications for components. The
3737 -- analysis of the aspect is required to be delayed to the freeze
3738 -- point, thus we analyze the pragma or attribute definition
3739 -- clause in the tree at this point. We also analyze the aspect
3740 -- specification node at the freeze point when the aspect doesn't
3741 -- correspond to pragma/attribute definition clause.
3747 then
3752 -- The visibility to the discriminants must be restored in
3753 -- order to properly analyze the aspects.
3766 -- Pop the scope if Rec scope has been pushed on the scope stack
3767 -- during the delayed aspect analysis process.
3774 Pop_Scope;
3777 -- Freeze components and embedded subtypes
3786 -- Handle the component and discriminant case
3789 declare
3792 begin
3793 -- Freezing a record type freezes the type of each of its
3794 -- components. However, if the type of the component is
3795 -- part of this record, we do not want or need a separate
3796 -- Freeze_Node. Note that Is_Itype is wrong because that's
3797 -- also set in private type cases. We also can't check for
3798 -- the Scope being exactly Rec because of private types and
3799 -- record extensions.
3804 then
3810 -- Warn for pragma Pack overriding foreign convention
3815 -- Don't warn for aliased components, since override
3816 -- cannot happen in that case.
3819 then
3820 declare
3825 begin
3829 Error_Msg_N
3831 PP);
3833 Error_Msg_NE
3840 -- Check for error of component clause given for variable
3841 -- sized type. We have to delay this test till this point,
3842 -- since the component type has to be frozen for us to know
3843 -- if it is variable length.
3848 -- We omit this test in a generic context, it will be
3849 -- applied at instantiation time.
3854 -- Also omit this test in CodePeer mode, since we do not
3855 -- have sufficient info on size and rep clauses.
3860 -- Omit check if component has a generic type. This can
3861 -- happen in an instantiation within a generic in ASIS
3862 -- mode, where we force freeze actions without full
3863 -- expansion.
3868 -- Do the check
3870 elsif not
3871 Size_Known_At_Compile_Time
3873 then
3874 Error_Msg_N
3879 else
3883 -- Case of component requires byte alignment
3887 -- Set the enclosing record to also require byte align
3891 -- Check for component clause that is inconsistent with
3892 -- the required byte boundary alignment.
3897 then
3898 Error_Msg_N
3906 -- Gather data for possible Implicit_Packing later. Note that at
3907 -- this stage we might be dealing with a real component, or with
3908 -- an implicit subtype declaration.
3911 Sized_Component_Total_RM_Size :=
3915 Elem_Component_Total_Esize :=
3917 else
3924 else
3928 -- If the component is an Itype with Delayed_Freeze and is either
3929 -- a record or array subtype and its base type has not yet been
3930 -- frozen, we must remove this from the entity list of this record
3931 -- and put it on the entity list of the scope of its base type.
3932 -- Note that we know that this is not the type of a component
3933 -- since we cleared Has_Delayed_Freeze for it in the previous
3934 -- loop. Thus this must be the Designated_Type of an access type,
3935 -- which is the type of a component.
3943 then
3944 declare
3948 begin
3949 -- We have a difficult case to handle here. Suppose Rec is
3950 -- subtype being defined in a subprogram that's created as
3951 -- part of the freezing of Rec'Base. In that case, we know
3952 -- that Comp'Base must have already been frozen by the time
3953 -- we get to elaborate this because Gigi doesn't elaborate
3954 -- any bodies until it has elaborated all of the declarative
3955 -- part. But Is_Frozen will not be set at this point because
3956 -- we are processing code in lexical order.
3958 -- We detect this case by going up the Scope chain of Rec
3959 -- and seeing if we have a subprogram scope before reaching
3960 -- the top of the scope chain or that of Comp'Base. If we
3961 -- do, then mark that Comp'Base will actually be frozen. If
3962 -- so, we merely undelay it.
3979 else
3982 else
3986 -- Insert in entity list of scope of base type (which
3987 -- must be an enclosing scope, because still unfrozen).
3993 -- If the component is an access type with an allocator as default
3994 -- value, the designated type will be frozen by the corresponding
3995 -- expression in init_proc. In order to place the freeze node for
3996 -- the designated type before that for the current record type,
3997 -- freeze it now.
3999 -- Same process if the component is an array of access types,
4000 -- initialized with an aggregate. If the designated type is
4001 -- private, it cannot contain allocators, and it is premature
4002 -- to freeze the type, so we check for this as well.
4007 then
4008 declare
4012 begin
4015 -- If component is pointer to a class-wide type, freeze
4016 -- the specific type in the expression being allocated.
4017 -- The expression may be a subtype indication, in which
4018 -- case freeze the subtype mark.
4020 if Is_Class_Wide_Type
4022 then
4024 Freeze_And_Append
4028 then
4029 Freeze_And_Append
4037 else
4038 Freeze_And_Append
4046 then
4049 -- Freeze the designated type when initializing a component with
4050 -- an aggregate in case the aggregate contains allocators.
4052 -- type T is ...;
4053 -- type T_Ptr is access all T;
4054 -- type T_Array is array ... of T_Ptr;
4056 -- type Rec is record
4057 -- Comp : T_Array := (others => ...);
4058 -- end record;
4062 then
4063 declare
4066 Designated_Type
4069 begin
4070 -- The only case when this sort of freezing is not done is
4071 -- when the designated type is class-wide and the root type
4072 -- is the record owning the component. This scenario results
4073 -- in a circularity because the class-wide type requires
4074 -- primitives that have not been created yet as the root
4075 -- type is in the process of being frozen.
4077 -- type Rec is tagged;
4078 -- type Rec_Ptr is access all Rec'Class;
4079 -- type Rec_Array is array ... of Rec_Ptr;
4081 -- type Rec is record
4082 -- Comp : Rec_Array := (others => ...);
4083 -- end record;
4087 then
4095 then
4105 SSO_ADC :=
4106 Get_Attribute_Definition_Clause
4109 -- If the record type has Complex_Representation, then it is treated
4110 -- as a scalar in the back end so the storage order is irrelevant.
4114 Error_Msg_N
4116 SSO_ADC);
4119 else
4120 -- Deal with default setting of reverse storage order
4124 -- Check consistent attribute setting on component types
4126 declare
4128 begin
4131 Check_Component_Storage_Order
4141 -- Now deal with reverse storage order/bit order issues
4145 -- Check compatibility of Scalar_Storage_Order with Bit_Order,
4146 -- if the former is specified.
4150 -- Note: report error on Rec, not on SSO_ADC, as ADC may
4151 -- apply to some ancestor type.
4154 Error_Msg_N
4159 -- Warn if there is a Scalar_Storage_Order attribute definition
4160 -- clause but no component clause, no component that itself has
4161 -- such an attribute definition, and no pragma Pack.
4164 or else
4165 SSO_ADC_Component
4166 or else
4168 then
4169 Error_Msg_N
4176 -- Deal with Bit_Order aspect
4184 then
4185 -- Warn if clause has no effect when no component clause is
4186 -- present, but suppress warning if the Bit_Order is required
4187 -- due to the presence of a Scalar_Storage_Order attribute.
4189 Error_Msg_N
4191 Error_Msg_N
4194 -- Here is where we do the processing to adjust component clauses
4195 -- for reversed bit order, when not using reverse SSO.
4199 then
4202 -- Case where we have both an explicit Bit_Order and the same
4203 -- Scalar_Storage_Order: leave record untouched, the back-end
4204 -- will take care of required layout conversions.
4206 else
4212 -- Complete error checking on record representation clause (e.g.
4213 -- overlap of components). This is called after adjusting the
4214 -- record for reverse bit order.
4216 declare
4218 begin
4224 -- Set OK_To_Reorder_Components depending on debug flags
4228 or else
4230 then
4235 -- Check for useless pragma Pack when all components placed. We only
4236 -- do this check for record types, not subtypes, since a subtype may
4237 -- have all its components placed, and it still makes perfectly good
4238 -- sense to pack other subtypes or the parent type. We do not give
4239 -- this warning if Optimize_Alignment is set to Space, since the
4240 -- pragma Pack does have an effect in this case (it always resets
4241 -- the alignment to one).
4245 and then not Unplaced_Component
4247 then
4248 -- Reset packed status. Probably not necessary, but we do it so
4249 -- that there is no chance of the back end doing something strange
4250 -- with this redundant indication of packing.
4254 -- Give warning if redundant constructs warnings on
4257 Error_Msg_N -- CODEFIX
4263 -- If this is the record corresponding to a remote type, freeze the
4264 -- remote type here since that is what we are semantically freezing.
4265 -- This prevents the freeze node for that type in an inner scope.
4272 -- Check for controlled components, unchecked unions, and type
4273 -- invariants.
4278 -- Do not set Has_Controlled_Component on a class-wide
4279 -- equivalent type. See Make_CW_Equivalent_Type.
4282 and then
4284 or else
4287 or else
4289 and then
4291 and then
4292 Has_Controlled_Component
4294 then
4302 -- The record type requires its own invariant procedure in
4303 -- order to verify the invariant of each individual component.
4304 -- Do not consider internal components such as _parent because
4305 -- parent class-wide invariants are always inherited.
4308 and then
4310 or else
4312 and then Has_Invariants
4314 then
4318 -- Scan component declaration for likely misuses of current
4319 -- instance, either in a constraint or a default expression.
4329 -- Enforce the restriction that access attributes with a current
4330 -- instance prefix can only apply to limited types. This comment
4331 -- is floating here, but does not seem to belong here???
4333 -- Set component alignment if not otherwise already set
4337 -- For first subtypes, check if there are any fixed-point fields with
4338 -- component clauses, where we must check the size. This is not done
4339 -- till the freeze point since for fixed-point types, we do not know
4340 -- the size until the type is frozen. Similar processing applies to
4341 -- bit-packed arrays.
4349 then
4350 Check_Size
4354 Junk);
4361 -- Generate warning for applying C or C++ convention to a record
4362 -- with discriminants. This is suppressed for the unchecked union
4363 -- case, since the whole point in this case is interface C. We also
4364 -- do not generate this within instantiations, since we will have
4365 -- generated a message on the template.
4370 or else
4373 and then not In_Instance
4376 then
4377 declare
4381 begin
4386 Error_Msg_N
4388 A2);
4389 else
4390 Error_Msg_N
4392 A2);
4395 Error_Msg_NE
4401 -- See if Size is too small as is (and implicit packing might help)
4405 -- No implicit packing if even one component is explicitly placed
4407 and then not Placed_Component
4409 -- Or even one component is aliased
4411 and then not Aliased_Component
4413 -- Must have size clause and all sized components
4416 and then All_Sized_Components
4418 -- Do not try implicit packing on records with discriminants, too
4419 -- complicated, especially in the variant record case.
4423 -- We want to implicitly pack if the specified size of the record
4424 -- is less than the sum of the object sizes (no point in packing
4425 -- if this is not the case), if we can compute it, i.e. if we have
4426 -- only elementary components. Otherwise, we have at least one
4427 -- composite component and we want to implicitly pack only if bit
4428 -- packing is required for it, as we are sure in this case that
4429 -- the back end cannot do the expected layout without packing.
4431 and then
4432 ((All_Elem_Components
4434 or else
4438 -- And the total RM size cannot be greater than the specified size
4439 -- since otherwise packing will not get us where we have to be.
4443 -- Never do implicit packing in CodePeer or SPARK modes since
4444 -- we don't do any packing in these modes, since this generates
4445 -- over-complex code that confuses static analysis, and in
4446 -- general, neither CodePeer not GNATprove care about the
4447 -- internal representation of objects.
4450 then
4451 -- If implicit packing enabled, do it
4456 -- Otherwise flag the size clause
4458 else
4459 declare
4461 begin
4462 Error_Msg_NE -- CODEFIX
4464 Error_Msg_N -- CODEFIX
4471 -- The following checks are relevant only when SPARK_Mode is on as
4472 -- they are not standard Ada legality rules.
4477 -- A discriminated type cannot be effectively volatile
4478 -- (SPARK RM C.6(4)).
4483 -- A tagged type cannot be effectively volatile
4484 -- (SPARK RM C.6(5)).
4490 -- A non-effectively volatile record type cannot contain
4491 -- effectively volatile components (SPARK RM C.6(2)).
4493 else
4498 then
4500 Error_Msg_N
4509 -- A type which does not yield a synchronized object cannot have
4510 -- a component that yields a synchronized object (SPARK RM 9.5).
4517 then
4519 Error_Msg_N
4528 -- A Ghost type cannot have a component of protected or task type
4529 -- (SPARK RM 6.9(19)).
4536 then
4538 Error_Msg_N
4540 Comp);
4548 -- Make sure that if we have an iterator aspect, then we have
4549 -- either Constant_Indexing or Variable_Indexing.
4551 declare
4554 begin
4563 or else
4565 then
4567 else
4568 Error_Msg_N
4570 Iterator_Aspect);
4575 -- All done if not a full record definition
4581 -- Finally we need to check the variant part to make sure that
4582 -- all types within choices are properly frozen as part of the
4583 -- freezing of the record type.
4590 begin
4591 -- Find component list
4603 then
4608 -- Case of variant part present
4614 -- Note: we used to call Check_Choices here, but it is too early,
4615 -- since predicated subtypes are frozen here, but their freezing
4616 -- actions are in Analyze_Freeze_Entity, which has not been called
4617 -- yet for entities frozen within this procedure, so we moved that
4618 -- call to the Analyze_Freeze_Entity for the record type.
4622 -- Check that all the primitives of an interface type are abstract
4623 -- or null procedures.
4627 then
4628 declare
4632 begin
4639 -- Avoid reporting the error on inherited primitives
4642 then
4647 Error_Msg_N
4651 else
4652 Error_Msg_N
4663 -- For a derived tagged type, check whether inherited primitives
4664 -- might require a wrapper to handle class-wide conditions.
4671 -------------------------------
4672 -- Has_Boolean_Aspect_Import --
4673 -------------------------------
4680 begin
4686 -- The value of aspect Import is True when the expression is
4687 -- either missing or it is explicitly set to True.
4693 then
4704 ---------------------
4705 -- New_Freeze_Node --
4706 ---------------------
4712 begin
4713 -- Handle the case where an ignored Ghost subprogram freezes the type
4714 -- of one of its formals. The type can either be non-Ghost or checked
4715 -- Ghost. Since the freeze node for the type is generated in the
4716 -- context of the subprogram, the node will be incorrectly flagged as
4717 -- ignored Ghost and erroneously removed from the tree.
4719 -- type Typ is ...;
4720 -- procedure Ignored_Ghost_Proc (Formal : Typ) with Ghost;
4722 -- Reset the Ghost mode to "none". This preserves the freeze node.
4727 then
4737 ------------------------------
4738 -- Wrap_Imported_Subprogram --
4739 ------------------------------
4741 -- The issue here is that our normal approach of checking preconditions
4742 -- and postconditions does not work for imported procedures, since we
4743 -- are not generating code for the body. To get around this we create
4744 -- a wrapper, as shown by the following example:
4746 -- procedure K (A : Integer);
4747 -- pragma Import (C, K);
4749 -- The spec is rewritten by removing the effects of pragma Import, but
4750 -- leaving the convention unchanged, as though the source had said:
4752 -- procedure K (A : Integer);
4753 -- pragma Convention (C, K);
4755 -- and we create a body, added to the entity K freeze actions, which
4756 -- looks like:
4758 -- procedure K (A : Integer) is
4759 -- procedure K (A : Integer);
4760 -- pragma Import (C, K);
4761 -- begin
4762 -- K (A);
4763 -- end K;
4765 -- Now the contract applies in the normal way to the outer procedure,
4766 -- and the inner procedure has no contracts, so there is no problem
4767 -- in just calling it to get the original effect.
4769 -- In the case of a function, we create an appropriate return statement
4770 -- for the subprogram body that calls the inner procedure.
4774 -- Obtain a copy of the Import_Pragma which belongs to subprogram E
4776 ------------------------
4777 -- Copy_Import_Pragma --
4778 ------------------------
4782 -- The subprogram should have an import pragma, otherwise it does
4783 -- need a wrapper.
4788 -- Save all semantic fields of the pragma
4797 begin
4798 -- Reset all semantic fields. This avoids a potential infinite
4799 -- loop when the pragma comes from an aspect as the duplication
4800 -- will copy the aspect, then copy the corresponding pragma and
4801 -- so on.
4810 -- Restore the original semantic fields
4820 -- Local variables
4831 -- Start of processing for Wrap_Imported_Subprogram
4833 begin
4834 -- Nothing to do if not imported
4839 -- Test enabling conditions for wrapping
4844 and then not GNATprove_Mode
4845 then
4846 -- Here we do the wrap
4848 -- Note on calls to Copy_Separate_Tree. The trees we are copying
4849 -- here are fully analyzed, but we definitely want fully syntactic
4850 -- unanalyzed trees in the body we construct, so that the analysis
4851 -- generates the right visibility, and that is exactly what the
4852 -- calls to Copy_Separate_Tree give us.
4856 -- Fix up spec to be not imported any more
4863 -- Grab the subprogram declaration and specification
4867 -- Build parameter list that we need
4876 -- Build the call
4879 Stmt :=
4881 Expression =>
4886 else
4887 Stmt :=
4893 -- Now build the body
4895 Bod :=
4897 Specification =>
4902 Prag),
4903 Handled_Statement_Sequence =>
4908 -- Append the body to freeze result
4913 -- Case of imported subprogram that does not get wrapped
4915 else
4916 -- Set Is_Public. All imported entities need an external symbol
4917 -- created for them since they are always referenced from another
4918 -- object file. Note this used to be set when we set Is_Imported
4919 -- back in Sem_Prag, but now we delay it to this point, since we
4920 -- don't want to set this flag if we wrap an imported subprogram.
4926 -- Local variables
4930 -- Start of processing for Freeze_Entity
4932 begin
4933 -- The entity being frozen may be subject to pragma Ghost. Set the mode
4934 -- now to ensure that any nodes generated during freezing are properly
4935 -- flagged as Ghost.
4939 -- We are going to test for various reasons why this entity need not be
4940 -- frozen here, but in the case of an Itype that's defined within a
4941 -- record, that test actually applies to the record.
4947 then
4951 -- Do not freeze if already frozen since we only need one freeze node
4963 -- It is improper to freeze an external entity within a generic because
4964 -- its freeze node will appear in a non-valid context. The entity will
4965 -- be frozen in the proper scope after the current generic is analyzed.
4966 -- However, aspects must be analyzed because they may be queried later
4967 -- within the generic itself, and the corresponding pragma or attribute
4968 -- definition has not been analyzed yet.
4978 -- AI05-0213: A formal incomplete type does not freeze the actual. In
4979 -- the instance, the same applies to the subtype renaming the actual.
4985 then
4989 -- Formal subprograms are never frozen
4995 -- Generic types are never frozen as they lack delayed semantic checks
5001 -- Do not freeze a global entity within an inner scope created during
5002 -- expansion. A call to subprogram E within some internal procedure
5003 -- (a stream attribute for example) might require freezing E, but the
5004 -- freeze node must appear in the same declarative part as E itself.
5005 -- The two-pass elaboration mechanism in gigi guarantees that E will
5006 -- be frozen before the inner call is elaborated. We exclude constants
5007 -- from this test, because deferred constants may be frozen early, and
5008 -- must be diagnosed (e.g. in the case of a deferred constant being used
5009 -- in a default expression). If the enclosing subprogram comes from
5010 -- source, or is a generic instance, then the freeze point is the one
5011 -- mandated by the language, and we freeze the entity. A subprogram that
5012 -- is a child unit body that acts as a spec does not have a spec that
5013 -- comes from source, but can only come from source.
5018 then
5019 declare
5022 begin
5029 then
5031 else
5041 -- Similarly, an inlined instance body may make reference to global
5042 -- entities, but these references cannot be the proper freezing point
5043 -- for them, and in the absence of inlining freezing will take place in
5044 -- their own scope. Normally instance bodies are analyzed after the
5045 -- enclosing compilation, and everything has been frozen at the proper
5046 -- place, but with front-end inlining an instance body is compiled
5047 -- before the end of the enclosing scope, and as a result out-of-order
5048 -- freezing must be prevented.
5050 elsif Front_End_Inlining
5051 and then In_Instance_Body
5053 then
5054 declare
5057 begin
5062 else
5074 -- Add checks to detect proper initialization of scalars that may appear
5075 -- as subprogram parameters.
5081 -- Deal with delayed aspect specifications. The analysis of the aspect
5082 -- is required to be delayed to the freeze point, thus we analyze the
5083 -- pragma or attribute definition clause in the tree at this point. We
5084 -- also analyze the aspect specification node at the freeze point when
5085 -- the aspect doesn't correspond to pragma/attribute definition clause.
5091 -- Here to freeze the entity
5095 -- Case of entity being frozen is other than a type
5099 -- If entity is exported or imported and does not have an external
5100 -- name, now is the time to provide the appropriate default name.
5101 -- Skip this if the entity is stubbed, since we don't need a name
5102 -- for any stubbed routine. For the case on intrinsics, if no
5103 -- external name is specified, then calls will be handled in
5104 -- Exp_Intr.Expand_Intrinsic_Call, and no name is needed. If an
5105 -- external name is provided, then Expand_Intrinsic_Call leaves
5106 -- calls in place for expansion by GIGI.
5112 then
5113 Set_Encoded_Interface_Name
5116 -- If entity is an atomic object appearing in a declaration and
5117 -- the expression is an aggregate, assign it to a temporary to
5118 -- ensure that the actual assignment is done atomically rather
5119 -- than component-wise (the assignment to the temp may be done
5120 -- component-wise, but that is harmless).
5127 then
5131 -- Subprogram case
5135 -- Check for needing to wrap imported subprogram
5139 -- Freeze all parameter types and the return type (RM 13.14(14)).
5140 -- However skip this for internal subprograms. This is also where
5141 -- any extra formal parameters are created since we now know
5142 -- whether the subprogram will use a foreign convention.
5144 -- In Ada 2012, freezing a subprogram does not always freeze the
5145 -- corresponding profile (see AI05-019). An attribute reference
5146 -- is not a freezing point of the profile. Flag Do_Freeze_Profile
5147 -- indicates whether the profile should be frozen now.
5148 -- Other constructs that should not freeze ???
5150 -- This processing doesn't apply to internal entities (see below)
5159 -- Must freeze its parent first if it is a derived subprogram
5165 -- We don't freeze internal subprograms, because we don't normally
5166 -- want addition of extra formals or mechanism setting to happen
5167 -- for those. However we do pass through predefined dispatching
5168 -- cases, since extra formals may be needed in some cases, such as
5169 -- for the stream 'Input function (build-in-place formals).
5173 then
5177 -- If warning on suspicious contracts then check for the case of
5178 -- a postcondition other than False for a No_Return subprogram.
5181 and then Warn_On_Suspicious_Contract
5183 then
5184 declare
5188 begin
5191 Name_Postcondition,
5192 Name_Refined_Post)
5193 then
5194 Exp :=
5195 Expression
5200 then
5201 Error_Msg_NE
5212 -- Here for other than a subprogram or type
5214 else
5215 -- If entity has a type, and it is not a generic unit, then
5216 -- freeze it first (RM 13.14(10)).
5220 then
5223 -- For an object of an anonymous array type, aspects on the
5224 -- object declaration apply to the type itself. This is the
5225 -- case for Atomic_Components, Volatile_Components, and
5226 -- Independent_Components. In these cases analysis of the
5227 -- generated pragma will mark the anonymous types accordingly,
5228 -- and the object itself does not require a freeze node.
5234 then
5241 -- Special processing for objects created by object declaration
5247 -- Check that a constant which has a pragma Volatile[_Components]
5248 -- or Atomic[_Components] also has a pragma Import (RM C.6(13)).
5250 -- Note: Atomic[_Components] also sets Volatile[_Components]
5256 then
5257 -- Make sure we actually have a pragma, and have not merely
5258 -- inherited the indication from elsewhere (e.g. an address
5259 -- clause, which is not good enough in RM terms).
5262 or else
5264 then
5265 Error_Msg_N
5270 or else
5272 then
5273 Error_Msg_N
5279 -- Static objects require special handling
5283 then
5287 -- Remaining step is to layout objects
5291 then
5295 -- For an object that does not have delayed freezing, and whose
5296 -- initialization actions have been captured in a compound
5297 -- statement, move them back now directly within the enclosing
5298 -- statement sequence.
5302 then
5307 -- Case of a type or subtype being frozen
5309 else
5310 -- We used to check here that a full type must have preelaborable
5311 -- initialization if it completes a private type specified with
5312 -- pragma Preelaborable_Initialization, but that missed cases where
5313 -- the types occur within a generic package, since the freezing
5314 -- that occurs within a containing scope generally skips traversal
5315 -- of a generic unit's declarations (those will be frozen within
5316 -- instances). This check was moved to Analyze_Package_Specification.
5318 -- The type may be defined in a generic unit. This can occur when
5319 -- freezing a generic function that returns the type (which is
5320 -- defined in a parent unit). It is clearly meaningless to freeze
5321 -- this type. However, if it is a subtype, its size may be determi-
5322 -- nable and used in subsequent checks, so might as well try to
5323 -- compute it.
5325 -- In Ada 2012, Freeze_Entities is also used in the front end to
5326 -- trigger the analysis of aspect expressions, so in this case we
5327 -- want to continue the freezing process.
5331 and then
5334 then
5340 -- Check for error of Type_Invariant'Class applied to an untagged
5341 -- type (check delayed to freeze time when full type is available).
5343 declare
5345 begin
5349 then
5350 Error_Msg_NE
5352 Error_Msg_N
5359 -- A Ghost type cannot be concurrent (SPARK RM 6.9(19)). Verify
5360 -- this legality rule first to five a finer-grained diagnostic.
5365 -- A Ghost type cannot be effectively volatile (SPARK RM 6.9(7))
5372 -- Deal with special cases of freezing for subtype
5376 -- Before we do anything else, a specific test for the case of a
5377 -- size given for an array where the array would need to be packed
5378 -- in order for the size to be honored, but is not. This is the
5379 -- case where implicit packing may apply. The reason we do this so
5380 -- early is that, if we have implicit packing, the layout of the
5381 -- base type is affected, so we must do this before we freeze the
5382 -- base type.
5384 -- We could do this processing only if implicit packing is enabled
5385 -- since in all other cases, the error would be caught by the back
5386 -- end. However, we choose to do the check even if we do not have
5387 -- implicit packing enabled, since this allows us to give a more
5388 -- useful error message (advising use of pragma Implicit_Packing
5389 -- or pragma Pack).
5392 declare
5404 -- Number of elements in array
5406 begin
5407 -- Check enabling conditions. These are straightforward
5408 -- except for the test for a limited composite type. This
5409 -- eliminates the rare case of a array of limited components
5410 -- where there are issues of whether or not we can go ahead
5411 -- and pack the array (since we can't freely pack and unpack
5412 -- arrays if they are limited).
5414 -- Note that we check the root type explicitly because the
5415 -- whole point is we are doing this test before we have had
5416 -- a chance to freeze the base type (and it is that freeze
5417 -- action that causes stuff to be inherited).
5419 -- The conditions on the size are identical to those used in
5420 -- Freeze_Array_Type to set the Is_Packed flag.
5438 then
5439 -- Compute number of elements in array
5446 and then
5448 then
5456 else
5463 -- What we are looking for here is the situation where
5464 -- the RM_Size given would be exactly right if there was
5465 -- a pragma Pack, resulting in the component size being
5466 -- the RM_Size of the component type.
5470 -- For implicit packing mode, just set the component
5471 -- size and Freeze_Array_Type will do the rest.
5476 -- Otherwise give an error message
5478 else
5479 Error_Msg_NE
5481 Error_Msg_N -- CODEFIX
5492 -- If ancestor subtype present, freeze that first. Note that this
5493 -- will also get the base type frozen. Need RM reference ???
5500 -- No ancestor subtype present
5502 else
5503 -- See if we have a nearest ancestor that has a predicate.
5504 -- That catches the case of derived type with a predicate.
5505 -- Need RM reference here ???
5513 -- Freeze base type before freezing the entity (RM 13.14(15))
5520 -- A subtype inherits all the type-related representation aspects
5521 -- from its parents (RM 13.1(8)).
5525 -- For a derived type, freeze its parent type first (RM 13.14(15))
5531 -- A derived type inherits each type-related representation aspect
5532 -- of its parent type that was directly specified before the
5533 -- declaration of the derived type (RM 13.1(15)).
5538 -- Check for incompatible size and alignment for record type
5540 if Warn_On_Size_Alignment
5544 -- If explicit Object_Size clause given assume that the programmer
5545 -- knows what he is doing, and expects the compiler behavior.
5549 -- Check for size not a multiple of alignment
5552 then
5553 declare
5559 begin
5562 -- Give a warning
5566 Error_Msg_NE
5573 else
5575 Error_Msg_NE
5589 -- Array type
5594 -- For a class-wide type, the corresponding specific type is
5595 -- frozen as well (RM 13.14(15))
5600 -- If the base type of the class-wide type is still incomplete,
5601 -- the class-wide remains unfrozen as well. This is legal when
5602 -- E is the formal of a primitive operation of some other type
5603 -- which is being frozen.
5611 -- The equivalent type associated with a class-wide subtype needs
5612 -- to be frozen to ensure that its layout is done.
5616 then
5620 -- Generate an itype reference for a library-level class-wide type
5621 -- at the freeze point. Otherwise the first explicit reference to
5622 -- the type may appear in an inner scope which will be rejected by
5623 -- the back-end.
5627 then
5628 declare
5631 begin
5634 -- From a gigi point of view, a class-wide subtype derives
5635 -- from its record equivalent type. As a result, the itype
5636 -- reference must appear after the freeze node of the
5637 -- equivalent type or gigi will reject the reference.
5641 then
5643 else
5649 -- For a record type or record subtype, freeze all component types
5650 -- (RM 13.14(15)). We test for E_Record_(sub)Type here, rather than
5651 -- using Is_Record_Type, because we don't want to attempt the freeze
5652 -- for the case of a private type with record extension (we will do
5653 -- that later when the full type is frozen).
5658 then
5661 -- For a concurrent type, freeze corresponding record type. This does
5662 -- not correspond to any specific rule in the RM, but the record type
5663 -- is essentially part of the concurrent type. Also freeze all local
5664 -- entities. This includes record types created for entry parameter
5665 -- blocks and whatever local entities may appear in the private part.
5679 -- The guard on the presence of the Etype seems to be needed
5680 -- for some CodePeer (-gnatcC) cases, but not clear why???
5685 then
5696 -- Private types are required to point to the same freeze node as
5697 -- their corresponding full views. The freeze node itself has to
5698 -- point to the partial view of the entity (because from the partial
5699 -- view, we can retrieve the full view, but not the reverse).
5700 -- However, in order to freeze correctly, we need to freeze the full
5701 -- view. If we are freezing at the end of a scope (or within the
5702 -- scope) of the private type, the partial and full views will have
5703 -- been swapped, the full view appears first in the entity chain and
5704 -- the swapping mechanism ensures that the pointers are properly set
5705 -- (on scope exit).
5707 -- If we encounter the partial view before the full view (e.g. when
5708 -- freezing from another scope), we freeze the full view, and then
5709 -- set the pointers appropriately since we cannot rely on swapping to
5710 -- fix things up (subtypes in an outer scope might not get swapped).
5712 -- If the full view is itself private, the above requirements apply
5713 -- to the underlying full view instead of the full view. But there is
5714 -- no swapping mechanism for the underlying full view so we need to
5715 -- set the pointers appropriately in both cases.
5719 then
5720 -- The construction of the dispatch table associated with library
5721 -- level tagged types forces freezing of all the primitives of the
5722 -- type, which may cause premature freezing of the partial view.
5723 -- For example:
5725 -- package Pkg is
5726 -- type T is tagged private;
5727 -- type DT is new T with private;
5728 -- procedure Prim (X : in out T; Y : in out DT'Class);
5729 -- private
5730 -- type T is tagged null record;
5731 -- Obj : T;
5732 -- type DT is new T with null record;
5733 -- end;
5735 -- In this case the type will be frozen later by the usual
5736 -- mechanism: an object declaration, an instantiation, or the
5737 -- end of a declarative part.
5741 then
5746 -- Case of full view present
5750 -- If full view has already been frozen, then no further
5751 -- processing is required
5757 -- Otherwise freeze full view and patch the pointers so that
5758 -- the freeze node will elaborate both views in the back end.
5759 -- However, if full view is itself private, freeze underlying
5760 -- full view instead and patch the pointers so that the freeze
5761 -- node will elaborate the three views in the back end.
5763 else
5764 declare
5767 begin
5770 then
5778 then
5785 else
5798 else
5799 -- {Incomplete,Private}_Subtypes with Full_Views
5800 -- constrained by discriminants.
5811 -- AI-117 requires that the convention of a partial view be the
5812 -- same as the convention of the full view. Note that this is a
5813 -- recognized breach of privacy, but it's essential for logical
5814 -- consistency of representation, and the lack of a rule in
5815 -- RM95 was an oversight.
5822 -- Size information is copied from the full view to the
5823 -- incomplete or private view for consistency.
5825 -- We skip this is the full view is not a type. This is very
5826 -- strange of course, and can only happen as a result of
5827 -- certain illegalities, such as a premature attempt to derive
5828 -- from an incomplete type.
5838 -- Case of underlying full view present
5842 then
5847 -- Patch the pointers so that the freeze node will elaborate
5848 -- both views in the back end.
5857 else
5868 -- Case of no full view present. If entity is derived or subtype,
5869 -- it is safe to freeze, correctness depends on the frozen status
5870 -- of parent. Otherwise it is either premature usage, or a Taft
5871 -- amendment type, so diagnosis is at the point of use and the
5872 -- type might be frozen later.
5877 else
5883 -- For access subprogram, freeze types of all formals, the return
5884 -- type was already frozen, since it is the Etype of the function.
5885 -- Formal types can be tagged Taft amendment types, but otherwise
5886 -- they cannot be incomplete.
5893 then
5897 -- AI05-151: Incomplete types are allowed in access to
5898 -- subprogram specifications.
5901 Error_Msg_NE
5912 -- For access to a protected subprogram, freeze the equivalent type
5913 -- (however this is not set if we are not generating code or if this
5914 -- is an anonymous type used just for resolution).
5922 -- Generic types are never seen by the back-end, and are also not
5923 -- processed by the expander (since the expander is turned off for
5924 -- generic processing), so we never need freeze nodes for them.
5931 -- Some special processing for non-generic types to complete
5932 -- representation details not known till the freeze point.
5937 -- Some error checks required for ordinary fixed-point type. Defer
5938 -- these till the freeze-point since we need the small and range
5939 -- values. We only do these checks for base types
5944 Error_Msg_N
5949 Error_Msg_N
5955 Error_Msg_N
5961 Error_Msg_N
5973 and then Warn_On_Suspicious_Modulus_Value
5974 then
5978 -- The pool applies to named and anonymous access types, but not
5979 -- to subprogram and to internal types generated for 'Access
5980 -- references.
5985 then
5986 -- If a pragma Default_Storage_Pool applies, and this type has no
5987 -- Storage_Pool or Storage_Size clause (which must have occurred
5988 -- before the freezing point), then use the default. This applies
5989 -- only to base types.
5991 -- None of this applies to access to subprograms, for which there
5992 -- are clearly no pools.
5998 then
5999 -- Case of pragma Default_Storage_Pool (null)
6004 -- Case of pragma Default_Storage_Pool (storage_pool_NAME)
6006 else
6011 -- Check restriction for standard storage pool
6017 -- Deal with error message for pure access type. This is not an
6018 -- error in Ada 2005 if there is no pool (see AI-366).
6024 then
6028 Error_Msg_N
6032 Error_Msg_N
6035 else
6036 Error_Msg_N
6043 -- Case of composite types
6047 -- AI-117 requires that all new primitives of a tagged type must
6048 -- inherit the convention of the full view of the type. Inherited
6049 -- and overriding operations are defined to inherit the convention
6050 -- of their parent or overridden subprogram (also specified in
6051 -- AI-117), which will have occurred earlier (in Derive_Subprogram
6052 -- and New_Overloaded_Entity). Here we set the convention of
6053 -- primitives that are still convention Ada, which will ensure
6054 -- that any new primitives inherit the type's convention. Class-
6055 -- wide types can have a foreign convention inherited from their
6056 -- specific type, but are excluded from this since they don't have
6057 -- any associated primitives.
6062 then
6063 declare
6067 begin
6079 -- If the type is a simple storage pool type, then this is where
6080 -- we attempt to locate and validate its Allocate, Deallocate, and
6081 -- Storage_Size operations (the first is required, and the latter
6082 -- two are optional). We also verify that the full type for a
6083 -- private type is allowed to be a simple storage pool type.
6087 then
6088 -- If the type is marked Has_Private_Declaration, then this is
6089 -- a full type for a private type that was specified with the
6090 -- pragma Simple_Storage_Pool_Type, and here we ensure that the
6091 -- pragma is allowed for the full type (for example, it can't
6092 -- be an array type, or a nonlimited record type).
6097 then
6099 Error_Msg_N
6110 procedure Validate_Simple_Pool_Op_Formal
6117 -- Validate one formal Pool_Op_Formal of the candidate pool
6118 -- operation Pool_Op. The formal must be of Expected_Type
6119 -- and have mode Expected_Mode. OK_Formal will be set to
6120 -- False if the formal doesn't match. If OK_Formal is False
6121 -- on entry, then the formal will effectively be ignored
6122 -- (because validation of the pool op has already failed).
6123 -- Upon return, Pool_Op_Formal will be updated to the next
6124 -- formal, if any.
6126 procedure Validate_Simple_Pool_Operation
6128 -- Search for and validate a simple pool operation with the
6129 -- name Op_Name. If the name is Allocate, then there must be
6130 -- exactly one such primitive operation for the simple pool
6131 -- type. If the name is Deallocate or Storage_Size, then
6132 -- there can be at most one such primitive operation. The
6133 -- profile of the located primitive must conform to what
6134 -- is expected for each operation.
6136 ------------------------------------
6137 -- Validate_Simple_Pool_Op_Formal --
6138 ------------------------------------
6140 procedure Validate_Simple_Pool_Op_Formal
6147 is
6148 begin
6149 -- If OK_Formal is False on entry, then simply ignore
6150 -- the formal, because an earlier formal has already
6151 -- been flagged.
6156 -- If no formal is passed in, then issue an error for a
6157 -- missing formal.
6160 Error_Msg_NE
6170 -- If the pool type was expected for this formal, then
6171 -- this will not be considered a candidate operation
6172 -- for the simple pool, so we unset OK_Formal so that
6173 -- the op and any later formals will be ignored.
6180 else
6181 Error_Msg_NE
6188 -- Issue error if formal's mode is not the expected one
6191 Error_Msg_N
6193 Pool_Op_Formal);
6196 -- Advance to the next formal
6201 ------------------------------------
6202 -- Validate_Simple_Pool_Operation --
6203 ------------------------------------
6205 procedure Validate_Simple_Pool_Operation
6207 is
6213 begin
6214 pragma Assert
6216 Name_Deallocate,
6217 Name_Storage_Size));
6221 -- For each homonym declared immediately in the scope
6222 -- of the simple storage pool type, determine whether
6223 -- the homonym is an operation of the pool type, and,
6224 -- if so, check that its profile is as expected for
6225 -- a simple pool operation of that name.
6231 then
6236 -- The first parameter must be of the pool type
6237 -- in order for the operation to qualify.
6240 Validate_Simple_Pool_Op_Formal
6243 else
6244 Validate_Simple_Pool_Op_Formal
6249 -- If another operation with this name has already
6250 -- been located for the type, then flag an error,
6251 -- since we only allow the type to have a single
6252 -- such primitive.
6255 Error_Msg_NE
6260 -- In the case of Allocate and Deallocate, a formal
6261 -- of type System.Address is required.
6264 Validate_Simple_Pool_Op_Formal
6269 Validate_Simple_Pool_Op_Formal
6274 -- In the case of Allocate and Deallocate, formals
6275 -- of type Storage_Count are required as the third
6276 -- and fourth parameters.
6279 Validate_Simple_Pool_Op_Formal
6282 Validate_Simple_Pool_Op_Formal
6287 -- If no mismatched formals have been found (Is_OK)
6288 -- and no excess formals are present, then this
6289 -- operation has been validated, so record it.
6299 -- There must be a valid Allocate operation for the type,
6300 -- so issue an error if none was found.
6304 then
6310 -- Simple pool operations can't be abstract
6313 Error_Msg_N
6318 -- The Storage_Size operation must be a function with
6319 -- Storage_Count as its result type.
6323 Error_Msg_N
6327 Error_Msg_NE
6332 -- Allocate and Deallocate must be procedures
6335 Error_Msg_N
6341 -- Start of processing for Validate_Simple_Pool_Ops
6343 begin
6351 -- Now that all types from which E may depend are frozen, see if the
6352 -- size is known at compile time, if it must be unsigned, or if
6353 -- strict alignment is required
6362 -- Do not allow a size clause for a type which does not have a size
6363 -- that is known at compile time
6367 then
6368 -- Suppress this message if errors posted on E, even if we are
6369 -- in all errors mode, since this is often a junk message
6372 Error_Msg_N
6378 -- Now we set/verify the representation information, in particular
6379 -- the size and alignment values. This processing is not required for
6380 -- generic types, since generic types do not play any part in code
6381 -- generation, and so the size and alignment values for such types
6382 -- are irrelevant. Ditto for types declared within a generic unit,
6383 -- which may have components that depend on generic parameters, and
6384 -- that will be recreated in an instance.
6389 -- Otherwise we call the layout procedure
6391 else
6395 -- If this is an access to subprogram whose designated type is itself
6396 -- a subprogram type, the return type of this anonymous subprogram
6397 -- type must be decorated as well.
6401 then
6405 -- If the type has a Defaut_Value/Default_Component_Value aspect,
6406 -- this is where we analye the expression (after the type is frozen,
6407 -- since in the case of Default_Value, we are analyzing with the
6408 -- type itself, and we treat Default_Component_Value similarly for
6409 -- the sake of uniformity).
6412 declare
6417 begin
6422 else
6433 Flag_Non_Static_Expr
6440 -- End of freeze processing for type entities
6443 -- Here is where we logically freeze the current entity. If it has a
6444 -- freeze node, then this is the point at which the freeze node is
6445 -- linked into the result list.
6449 -- If a freeze node is already allocated, use it, otherwise allocate
6450 -- a new one. The preallocation happens in the case of anonymous base
6451 -- types, where we preallocate so that we can set First_Subtype_Link.
6452 -- Note that we reset the Sloc to the current freeze location.
6458 else
6469 -- A final pass over record types with discriminants. If the type
6470 -- has an incomplete declaration, there may be constrained access
6471 -- subtypes declared elsewhere, which do not depend on the discrimi-
6472 -- nants of the type, and which are used as component types (i.e.
6473 -- the full view is a recursive type). The designated types of these
6474 -- subtypes can only be elaborated after the type itself, and they
6475 -- need an itype reference.
6478 declare
6483 begin
6493 then
6505 -- When a type is frozen, the first subtype of the type is frozen as
6506 -- well (RM 13.14(15)). This has to be done after freezing the type,
6507 -- since obviously the first subtype depends on its own base type.
6512 -- If we just froze a tagged non-class wide record, then freeze the
6513 -- corresponding class-wide type. This must be done after the tagged
6514 -- type itself is frozen, because the class-wide type refers to the
6515 -- tagged type which generates the class.
6520 then
6527 -- Special handling for subprograms
6531 -- If subprogram has address clause then reset Is_Public flag, since
6532 -- we do not want the backend to generate external references.
6536 then
6545 -----------------------------
6546 -- Freeze_Enumeration_Type --
6547 -----------------------------
6550 begin
6551 -- By default, if no size clause is present, an enumeration type with
6552 -- Convention C is assumed to interface to a C enum, and has integer
6553 -- size. This applies to types. For subtypes, verify that its base
6554 -- type has no size clause either. Treat other foreign conventions
6555 -- in the same way, and also make sure alignment is set right.
6562 -- Don't do this if Short_Enums on target
6564 and then not Target_Short_Enums
6565 then
6569 -- Normal Ada case or size clause present or not Long_C_Enums on target
6571 else
6572 -- If the enumeration type interfaces to C, and it has a size clause
6573 -- that specifies less than int size, it warrants a warning. The
6574 -- user may intend the C type to be an enum or a char, so this is
6575 -- not by itself an error that the Ada compiler can detect, but it
6576 -- it is a worth a heads-up. For Boolean and Character types we
6577 -- assume that the programmer has the proper C type in mind.
6585 -- Don't do this if Short_Enums on target
6587 and then not Target_Short_Enums
6588 then
6589 Error_Msg_N
6597 -----------------------
6598 -- Freeze_Expression --
6599 -----------------------
6610 -- This flag is set true if the entity must be frozen outside the
6611 -- current subprogram. This happens in the case of expander generated
6612 -- subprograms (_Init_Proc, _Input, _Output, _Read, _Write) which do
6613 -- not freeze all entities like other bodies, but which nevertheless
6614 -- may reference entities that have to be frozen before the body and
6615 -- obviously cannot be frozen inside the body.
6618 -- If the expression is an array aggregate, the type of the component
6619 -- expressions is also frozen. If the component type is an access type
6620 -- and the expressions include allocators, the designed type is frozen
6621 -- as well.
6624 -- Given an N_Handled_Sequence_Of_Statements node N, determines whether
6625 -- it is the handled statement sequence of an expander-generated
6626 -- subprogram (init proc, stream subprogram, or renaming as body).
6627 -- If so, this is not a freezing context.
6629 -----------------------------------------
6630 -- Find_Aggregate_Component_Desig_Type --
6631 -----------------------------------------
6637 begin
6663 ----------------------
6664 -- In_Expanded_Body --
6665 ----------------------
6671 begin
6674 else
6681 else
6684 -- The following are expander-created bodies, or bodies that
6685 -- are not freeze points.
6694 N_Subprogram_Renaming_Declaration,
6695 N_Expression_Function))
6696 then
6698 else
6704 -- Start of processing for Freeze_Expression
6706 begin
6707 -- Immediate return if freezing is inhibited. This flag is set by the
6708 -- analyzer to stop freezing on generated expressions that would cause
6709 -- freezing if they were in the source program, but which are not
6710 -- supposed to freeze, since they are created.
6716 -- If expression is non-static, then it does not freeze in a default
6717 -- expression, see section "Handling of Default Expressions" in the
6718 -- spec of package Sem for further details. Note that we have to make
6719 -- sure that we actually have a real expression (if we have a subtype
6720 -- indication, we can't test Is_OK_Static_Expression). However, we
6721 -- exclude the case of the prefix of an attribute of a static scalar
6722 -- subtype from this early return, because static subtype attributes
6723 -- should always cause freezing, even in default expressions, but
6724 -- the attribute may not have been marked as static yet (because in
6725 -- Resolve_Attribute, the call to Eval_Attribute follows the call of
6726 -- Freeze_Expression on the prefix).
6728 if In_Spec_Exp
6735 then
6739 -- Freeze type of expression if not frozen already
6747 -- Base type may be an derived numeric type that is frozen at
6748 -- the point of declaration, but first_subtype is still unfrozen.
6755 -- For entity name, freeze entity if not frozen already. A special
6756 -- exception occurs for an identifier that did not come from source.
6757 -- We don't let such identifiers freeze a non-internal entity, i.e.
6758 -- an entity that did come from source, since such an identifier was
6759 -- generated by the expander, and cannot have any semantic effect on
6760 -- the freezing semantics. For example, this stops the parameter of
6761 -- an initialization procedure from freezing the variable.
6768 then
6775 else
6779 -- For an allocator freeze designated type if not frozen already
6781 -- For an aggregate whose component type is an access type, freeze the
6782 -- designated type now, so that its freeze does not appear within the
6783 -- loop that might be created in the expansion of the aggregate. If the
6784 -- designated type is a private type without full view, the expression
6785 -- cannot contain an allocator, so the type is not frozen.
6787 -- For a function, we freeze the entity when the subprogram declaration
6788 -- is frozen, but a function call may appear in an initialization proc.
6789 -- before the declaration is frozen. We need to generate the extra
6790 -- formals, if any, to ensure that the expansion of the call includes
6791 -- the proper actuals. This only applies to Ada subprograms, not to
6792 -- imported ones.
6803 then
6805 -- Check whether aggregate includes allocators.
6810 when N_Selected_Component |
6811 N_Indexed_Component |
6812 N_Slice =>
6823 then
6834 then
6838 -- All done if nothing needs freezing
6843 then
6847 -- Examine the enclosing context by climbing the parent chain. The
6848 -- traversal serves two purposes - to detect scenarios where freezeing
6849 -- is not needed and to find the proper insertion point for the freeze
6850 -- nodes. Although somewhat similar to Insert_Actions, this traversal
6851 -- is freezing semantics-sensitive. Inserting freeze nodes blindly in
6852 -- the tree may result in types being frozen too early.
6855 loop
6858 -- If we don't have a parent, then we are not in a well-formed tree.
6859 -- This is an unusual case, but there are some legitimate situations
6860 -- in which this occurs, notably when the expressions in the range of
6861 -- a type declaration are resolved. We simply ignore the freeze
6862 -- request in this case. Is this right ???
6868 -- See if we have got to an appropriate point in the tree
6872 -- A special test for the exception of (RM 13.14(8)) for the case
6873 -- of per-object expressions (RM 3.8(18)) occurring in component
6874 -- definition or a discrete subtype definition. Note that we test
6875 -- for a component declaration which includes both cases we are
6876 -- interested in, and furthermore the tree does not have explicit
6877 -- nodes for either of these two constructs.
6881 -- The case we want to test for here is an identifier that is
6882 -- a per-object expression, this is either a discriminant that
6883 -- appears in a context other than the component declaration
6884 -- or it is a reference to the type of the enclosing construct.
6886 -- For either of these cases, we skip the freezing
6888 if not In_Spec_Expression
6891 then
6892 -- We recognize the discriminant case by just looking for
6893 -- a reference to a discriminant. It can only be one for
6894 -- the enclosing construct. Skip freezing in this case.
6899 -- For the case of a reference to the enclosing record,
6900 -- (or task or protected type), we look for a type that
6901 -- matches the current scope.
6908 -- If we have an enumeration literal that appears as the choice in
6909 -- the aggregate of an enumeration representation clause, then
6910 -- freezing does not occur (RM 13.14(10)).
6914 -- The case we are looking for is an enumeration literal
6918 then
6919 -- If enumeration literal appears directly as the choice,
6920 -- do not freeze (this is the normal non-overloaded case)
6924 then
6927 -- If enumeration literal appears as the name of function
6928 -- which is the choice, then also do not freeze. This
6929 -- happens in the overloaded literal case, where the
6930 -- enumeration literal is temporarily changed to a function
6931 -- call for overloading analysis purposes.
6934 and then
6936 and then
6938 then
6943 -- Normally if the parent is a handled sequence of statements,
6944 -- then the current node must be a statement, and that is an
6945 -- appropriate place to insert a freeze node.
6949 -- An exception occurs when the sequence of statements is for
6950 -- an expander generated body that did not do the usual freeze
6951 -- all operation. In this case we usually want to freeze
6952 -- outside this body, not inside it, and we skip past the
6953 -- subprogram body that we are inside.
6956 declare
6960 begin
6961 -- Freeze the entity only when it is declared inside the
6962 -- body of the expander generated procedure. This case
6963 -- is recognized by the scope of the entity or its type,
6964 -- which is either the spec for some enclosing body, or
6965 -- (in the case of init_procs, for which there are no
6966 -- separate specs) the current scope.
6972 or else
6974 then
6980 then
6985 -- An expression function may act as a completion of
6986 -- a function declaration. As such, it can reference
6987 -- entities declared between the two views:
6989 -- Hidden []; -- 1
6990 -- function F return ...;
6991 -- private
6992 -- function Hidden return ...;
6993 -- function F return ... is (Hidden); -- 2
6995 -- Refering to the example above, freezing the expression
6996 -- of F (2) would place Hidden's freeze node (1) in the
6997 -- wrong place. Avoid explicit freezing and let the usual
6998 -- scenarios do the job - for example, reaching the end
6999 -- of the private declarations, or a call to F.
7002 N_Expression_Function
7003 then
7006 -- Freeze outside the body
7008 else
7014 -- Here if normal case where we are in handled statement
7015 -- sequence and want to do the insertion right there.
7017 else
7021 -- If parent is a body or a spec or a block, then the current node
7022 -- is a statement or declaration and we can insert the freeze node
7023 -- before it.
7025 when N_Block_Statement |
7026 N_Entry_Body |
7027 N_Package_Body |
7028 N_Package_Specification |
7029 N_Protected_Body |
7030 N_Subprogram_Body |
7033 -- The expander is allowed to define types in any statements list,
7034 -- so any of the following parent nodes also mark a freezing point
7035 -- if the actual node is in a list of statements or declarations.
7037 when N_Abortable_Part |
7038 N_Accept_Alternative |
7039 N_And_Then |
7040 N_Case_Statement_Alternative |
7041 N_Compilation_Unit_Aux |
7042 N_Conditional_Entry_Call |
7043 N_Delay_Alternative |
7044 N_Elsif_Part |
7045 N_Entry_Call_Alternative |
7046 N_Exception_Handler |
7047 N_Extended_Return_Statement |
7048 N_Freeze_Entity |
7049 N_If_Statement |
7050 N_Or_Else |
7051 N_Selective_Accept |
7052 N_Triggering_Alternative =>
7056 -- Freeze nodes produced by an expression coming from the Actions
7057 -- list of a N_Expression_With_Actions node must remain within the
7058 -- Actions list. Inserting the freeze nodes further up the tree
7059 -- may lead to use before declaration issues in the case of array
7060 -- types.
7065 then
7069 -- Note: N_Loop_Statement is a special case. A type that appears
7070 -- in the source can never be frozen in a loop (this occurs only
7071 -- because of a loop expanded by the expander), so we keep on
7072 -- going. Otherwise we terminate the search. Same is true of any
7073 -- entity which comes from source. (if they have predefined type,
7074 -- that type does not appear to come from source, but the entity
7075 -- should not be frozen here).
7081 -- For all other cases, keep looking at parents
7087 -- We fall through the case if we did not yet find the proper
7088 -- place in the free for inserting the freeze node, so climb.
7093 -- If the expression appears in a record or an initialization procedure,
7094 -- the freeze nodes are collected and attached to the current scope, to
7095 -- be inserted and analyzed on exit from the scope, to insure that
7096 -- generated entities appear in the correct scope. If the expression is
7097 -- a default for a discriminant specification, the scope is still void.
7098 -- The expression can also appear in the discriminant part of a private
7099 -- or concurrent type.
7101 -- If the expression appears in a constrained subcomponent of an
7102 -- enclosing record declaration, the freeze nodes must be attached to
7103 -- the outer record type so they can eventually be placed in the
7104 -- enclosing declaration list.
7106 -- The other case requiring this special handling is if we are in a
7107 -- default expression, since in that case we are about to freeze a
7108 -- static type, and the freeze scope needs to be the outer scope, not
7109 -- the scope of the subprogram with the default parameter.
7111 -- For default expressions and other spec expressions in generic units,
7112 -- the Move_Freeze_Nodes mechanism (see sem_ch12.adb) takes care of
7113 -- placing them at the proper place, after the generic unit.
7116 or else Freeze_Outside
7121 then
7122 declare
7127 begin
7140 -- The current scope may be that of a constrained component of
7141 -- an enclosing record declaration, or of a loop of an enclosing
7142 -- quantified expression, which is above the current scope in the
7143 -- scope stack. Indeed in the context of a quantified expression,
7144 -- a scope is created and pushed above the current scope in order
7145 -- to emulate the loop-like behavior of the quantified expression.
7146 -- If the expression is within a top-level pragma, as for a pre-
7147 -- condition on a library-level subprogram, nothing to do.
7152 N_Quantified_Expression)
7153 then
7160 Freeze_Nodes;
7161 else
7171 -- Now we have the right place to do the freezing. First, a special
7172 -- adjustment, if we are in spec-expression analysis mode, these freeze
7173 -- actions must not be thrown away (normally all inserted actions are
7174 -- thrown away in this mode. However, the freeze actions are from static
7175 -- expressions and one of the important reasons we are doing this
7176 -- special analysis is to get these freeze actions. Therefore we turn
7177 -- off the In_Spec_Expression mode to propagate these freeze actions.
7178 -- This also means they get properly analyzed and expanded.
7182 -- Freeze the designated type of an allocator (RM 13.14(13))
7188 -- Freeze type of expression (RM 13.14(10)). Note that we took care of
7189 -- the enumeration representation clause exception in the loop above.
7195 -- Freeze name if one is present (RM 13.14(11))
7201 -- Restore In_Spec_Expression flag
7206 -----------------------------
7207 -- Freeze_Fixed_Point_Type --
7208 -----------------------------
7210 -- Certain fixed-point types and subtypes, including implicit base types
7211 -- and declared first subtypes, have not yet set up a range. This is
7212 -- because the range cannot be set until the Small and Size values are
7213 -- known, and these are not known till the type is frozen.
7215 -- To signal this case, Scalar_Range contains an unanalyzed syntactic range
7216 -- whose bounds are unanalyzed real literals. This routine will recognize
7217 -- this case, and transform this range node into a properly typed range
7218 -- with properly analyzed and resolved values.
7235 -- Save original bounds (for shaving tests)
7238 -- Actual size chosen
7241 -- Returns size of type with given bounds. Also leaves these
7242 -- bounds set as the current bounds of the Typ.
7244 -----------
7245 -- Fsize --
7246 -----------
7249 begin
7255 -- Start of processing for Freeze_Fixed_Point_Type
7257 begin
7258 -- If Esize of a subtype has not previously been set, set it now
7265 else
7270 -- Immediate return if the range is already analyzed. This means that
7271 -- the range is already set, and does not need to be computed by this
7272 -- routine.
7278 -- Immediate return if either of the bounds raises Constraint_Error
7282 then
7292 -- Ordinary fixed-point case
7296 -- For the ordinary fixed-point case, we are allowed to fudge the
7297 -- end-points up or down by small. Generally we prefer to fudge up,
7298 -- i.e. widen the bounds for non-model numbers so that the end points
7299 -- are included. However there are cases in which this cannot be
7300 -- done, and indeed cases in which we may need to narrow the bounds.
7301 -- The following circuit makes the decision.
7303 -- Note: our terminology here is that Incl_EP means that the bounds
7304 -- are widened by Small if necessary to include the end points, and
7305 -- Excl_EP means that the bounds are narrowed by Small to exclude the
7306 -- end-points if this reduces the size.
7308 -- Note that in the Incl case, all we care about is including the
7309 -- end-points. In the Excl case, we want to narrow the bounds as
7310 -- much as permitted by the RM, to give the smallest possible size.
7327 begin
7328 -- First step. Base types are required to be symmetrical. Right
7329 -- now, the base type range is a copy of the first subtype range.
7330 -- This will be corrected before we are done, but right away we
7331 -- need to deal with the case where both bounds are non-negative.
7332 -- In this case, we set the low bound to the negative of the high
7333 -- bound, to make sure that the size is computed to include the
7334 -- required sign. Note that we do not need to worry about the
7335 -- case of both bounds negative, because the sign will be dealt
7336 -- with anyway. Furthermore we can't just go making such a bound
7337 -- symmetrical, since in a twos-complement system, there is an
7338 -- extra negative value which could not be accommodated on the
7339 -- positive side.
7344 then
7349 -- Compute the fudged bounds. If the number is a model number,
7350 -- then we do nothing to include it, but we are allowed to backoff
7351 -- to the next adjacent model number when we exclude it. If it is
7352 -- not a model number then we straddle the two values with the
7353 -- model numbers on either side.
7359 else
7363 -- The low value excluding the end point is Small greater, but
7364 -- we do not do this exclusion if the low value is positive,
7365 -- since it can't help the size and could actually hurt by
7366 -- crossing the high bound.
7371 -- If the value went from negative to zero, then we have the
7372 -- case where Loval_Incl_EP is the model number just below
7373 -- zero, so we want to stick to the negative value for the
7374 -- base type to maintain the condition that the size will
7375 -- include signed values.
7379 then
7383 else
7387 -- Similar processing for upper bound and high value
7393 else
7399 else
7403 -- One further adjustment is needed. In the case of subtypes, we
7404 -- cannot go outside the range of the base type, or we get
7405 -- peculiarities, and the base type range is already set. This
7406 -- only applies to the Incl values, since clearly the Excl values
7407 -- are already as restricted as they are allowed to be.
7414 -- Get size including and excluding end points
7419 -- No need to exclude end-points if it does not reduce size
7429 -- Now we set the actual size to be used. We want to use the
7430 -- bounds fudged up to include the end-points but only if this
7431 -- can be done without violating a specifically given size
7432 -- size clause or causing an unacceptable increase in size.
7434 -- Case of size clause given
7438 -- Use the inclusive size only if it is consistent with
7439 -- the explicitly specified size.
7446 -- If the inclusive size is too large, we try excluding
7447 -- the end-points (will be caught later if does not work).
7449 else
7455 -- Case of size clause not given
7457 else
7458 -- If we have a base type whose corresponding first subtype
7459 -- has an explicit size that is large enough to include our
7460 -- end-points, then do so. There is no point in working hard
7461 -- to get a base type whose size is smaller than the specified
7462 -- size of the first subtype.
7468 then
7473 -- If excluding the end-points makes the size smaller and
7474 -- results in a size of 8,16,32,64, then we take the smaller
7475 -- size. For the 64 case, this is compulsory. For the other
7476 -- cases, it seems reasonable. We like to include end points
7477 -- if we can, but not at the expense of moving to the next
7478 -- natural boundary of size.
7482 then
7487 -- Otherwise we can definitely include the end points
7489 else
7495 -- One pathological case: normally we never fudge a low bound
7496 -- down, since it would seem to increase the size (if it has
7497 -- any effect), but for ranges containing single value, or no
7498 -- values, the high bound can be small too large. Consider:
7500 -- type t is delta 2.0**(-14)
7501 -- range 131072.0 .. 0;
7503 -- That lower bound is *just* outside the range of 32 bits, and
7504 -- does need fudging down in this case. Note that the bounds
7505 -- will always have crossed here, since the high bound will be
7506 -- fudged down if necessary, as in the case of:
7508 -- type t is delta 2.0**(-14)
7509 -- range 131072.0 .. 131072.0;
7511 -- So we detect the situation by looking for crossed bounds,
7512 -- and if the bounds are crossed, and the low bound is greater
7513 -- than zero, we will always back it off by small, since this
7514 -- is completely harmless.
7521 -- And of course, we need to do exactly the same parallel
7522 -- fudge for flat ranges in the negative region.
7535 -- For the decimal case, none of this fudging is required, since there
7536 -- are no end-point problems in the decimal case (the end-points are
7537 -- always included).
7539 else
7543 -- At this stage, the actual size has been calculated and the proper
7544 -- required bounds are stored in the low and high bounds.
7548 Error_Msg_N
7550 Typ);
7554 -- Check size against explicit given size
7560 Error_Msg_NE
7564 else
7568 -- Increase size to next natural boundary if no size clause given
7570 else
7577 else
7585 -- If we have a base type, then expand the bounds so that they extend to
7586 -- the full width of the allocated size in bits, to avoid junk range
7587 -- checks on intermediate computations.
7594 -- Final step is to reanalyze the bounds using the proper type
7595 -- and set the Corresponding_Integer_Value fields of the literals.
7601 -- Resolve with universal fixed if the base type, and the base type if
7602 -- it is a subtype. Note we can't resolve the base type with itself,
7603 -- that would be a reference before definition.
7607 else
7611 -- Set corresponding integer value for bound
7613 Set_Corresponding_Integer_Value
7616 -- Similar processing for high bound
7624 else
7628 Set_Corresponding_Integer_Value
7631 -- Set type of range to correspond to bounds
7635 -- Set Esize to calculated size if not set already
7641 -- Set RM_Size if not already set. If already set, check value
7643 declare
7646 begin
7651 Error_Msg_NE
7656 else
7661 -- Check for shaving
7665 -- In SPARK mode the given bounds must be strictly representable
7669 Error_Msg_NE
7675 Error_Msg_NE
7680 else
7682 Error_Msg_N
7684 Error_Msg_N
7689 Error_Msg_N
7691 Typ);
7692 Error_Msg_N
7699 ------------------
7700 -- Freeze_Itype --
7701 ------------------
7706 begin
7715 --------------------------
7716 -- Freeze_Static_Object --
7717 --------------------------
7722 -- Exception raised if the type of a static object cannot be made
7723 -- static. This happens if the type depends on non-global objects.
7726 -- Called to ensure that an expression used as part of a type definition
7727 -- is statically allocatable, which means that the expression type is
7728 -- statically allocatable, and the expression is either static, or a
7729 -- reference to a library level constant.
7732 -- Called to mark a type as static, checking that it is possible
7733 -- to set the type as static. If it is not possible, then the
7734 -- exception Cannot_Be_Static is raised.
7736 -----------------------------
7737 -- Ensure_Expression_Is_SA --
7738 -----------------------------
7743 begin
7755 then
7763 -----------------------
7764 -- Ensure_Type_Is_SA --
7765 -----------------------
7771 begin
7772 -- If type is library level, we are all set
7778 -- We are also OK if the type already marked as statically allocated,
7779 -- which means we processed it before.
7785 -- Mark type as statically allocated
7789 -- Check that it is safe to statically allocate this type
7807 declare
7811 begin
7823 else
7832 then
7851 else
7856 -- Start of processing for Freeze_Static_Object
7858 begin
7861 exception
7864 -- If the object that cannot be static is imported or exported, then
7865 -- issue an error message saying that this object cannot be imported
7866 -- or exported. If it has an address clause it is an overlay in the
7867 -- current partition and the static requirement is not relevant.
7868 -- Do not issue any error message when ignoring rep clauses.
7875 Error_Msg_N
7879 -- Otherwise must be exported, something is wrong if compiler
7880 -- is marking something as statically allocated which cannot be).
7883 Error_Msg_N
7888 -----------------------
7889 -- Freeze_Subprogram --
7890 -----------------------
7896 begin
7897 -- Subprogram may not have an address clause unless it is imported
7901 Error_Msg_N
7908 -- Reset the Pure indication on an imported subprogram unless an
7909 -- explicit Pure_Function pragma was present or the subprogram is an
7910 -- intrinsic. We do this because otherwise it is an insidious error
7911 -- to call a non-pure function from pure unit and have calls
7912 -- mysteriously optimized away. What happens here is that the Import
7913 -- can bypass the normal check to ensure that pure units call only pure
7914 -- subprograms.
7916 -- The reason for the intrinsic exception is that in general, intrinsic
7917 -- functions (such as shifts) are pure anyway. The only exceptions are
7918 -- the intrinsics in GNAT.Source_Info, and that unit is not marked Pure
7919 -- in any case, so no problem arises.
7925 then
7929 -- We also reset the Pure indication on a subprogram with an Address
7930 -- parameter, because the parameter may be used as a pointer and the
7931 -- referenced data may change even if the address value does not.
7933 -- Note that if the programmer gave an explicit Pure_Function pragma,
7934 -- then we believe the programmer, and leave the subprogram Pure.
7935 -- We also suppress this check on run-time files.
7941 then
7945 -- For non-foreign convention subprograms, this is where we create
7946 -- the extra formals (for accessibility level and constrained bit
7947 -- information). We delay this till the freeze point precisely so
7948 -- that we know the convention.
7954 -- If this is convention Ada and a Valued_Procedure, that's odd
7959 and then Warn_On_Export_Import
7960 then
7961 Error_Msg_N
7966 -- Case of foreign convention
7968 else
7971 -- For foreign conventions, warn about return of unconstrained array
7976 -- If no return type, probably some other error, e.g. a
7977 -- missing full declaration, so ignore.
7982 -- If the return type is generic, we have emitted a warning
7983 -- earlier on, and there is nothing else to check here. Specific
7984 -- instantiations may lead to erroneous behavior.
7989 -- Display warning if returning unconstrained array
7994 -- Check appropriate warning is enabled (should we check for
7995 -- Warnings (Off) on specific entities here, probably so???)
7997 and then Warn_On_Export_Import
7998 then
7999 Error_Msg_N
8006 -- If any of the formals for an exported foreign convention
8007 -- subprogram have defaults, then emit an appropriate warning since
8008 -- this is odd (default cannot be used from non-Ada code)
8013 if Warn_On_Export_Import
8015 then
8016 Error_Msg_N
8026 -- Pragma Inline_Always is disallowed for dispatching subprograms
8027 -- because the address of such subprograms is saved in the dispatch
8028 -- table to support dispatching calls, and dispatching calls cannot
8029 -- be inlined. This is consistent with the restriction against using
8030 -- 'Access or 'Address on an Inline_Always subprogram.
8034 then
8035 Error_Msg_N
8039 -- Because of the implicit representation of inherited predefined
8040 -- operators in the front-end, the overriding status of the operation
8041 -- may be affected when a full view of a type is analyzed, and this is
8042 -- not captured by the analysis of the corresponding type declaration.
8043 -- Therefore the correctness of a not-overriding indicator must be
8044 -- rechecked when the subprogram is frozen.
8048 then
8052 if Modify_Tree_For_C
8058 then
8063 ----------------------
8064 -- Is_Fully_Defined --
8065 ----------------------
8068 begin
8077 then
8078 -- Verify that the record type has no components with private types
8079 -- without completion.
8081 declare
8084 begin
8096 -- For the designated type of an access to subprogram, all types in
8097 -- the profile must be fully defined.
8100 declare
8103 begin
8116 else
8122 ---------------------------------
8123 -- Process_Default_Expressions --
8124 ---------------------------------
8126 procedure Process_Default_Expressions
8129 is
8136 begin
8139 -- A subprogram instance and its associated anonymous subprogram share
8140 -- their signature. The default expression functions are defined in the
8141 -- wrapper packages for the anonymous subprogram, and should not be
8142 -- generated again for the instance.
8147 then
8155 -- We work with a copy of the default expression because we
8156 -- do not want to disturb the original, since this would mess
8157 -- up the conformance checking.
8161 -- The analysis of the expression may generate insert actions,
8162 -- which of course must not be executed. We wrap those actions
8163 -- in a procedure that is not called, and later on eliminated.
8164 -- The following cases have no side-effects, and are analyzed
8165 -- directly.
8169 N_Integer_Literal,
8170 N_Character_Literal,
8171 N_String_Literal,
8172 N_Real_Literal)
8176 then
8177 -- If there is no default function, we must still do a full
8178 -- analyze call on the default value, to ensure that all error
8179 -- checks are performed, e.g. those associated with static
8180 -- evaluation. Note: this branch will always be taken if the
8181 -- analyzer is turned off (but we still need the error checks).
8183 -- Note: the setting of parent here is to meet the requirement
8184 -- that we can only analyze the expression while attached to
8185 -- the tree. Really the requirement is that the parent chain
8186 -- be set, we don't actually need to be in the tree.
8191 -- Default expressions are resolved with their own type if the
8192 -- context is generic, to avoid anomalies with private types.
8196 else
8200 -- If that resolved expression will raise constraint error,
8201 -- then flag the default value as raising constraint error.
8202 -- This allows a proper error message on the calls.
8208 -- If the default is a parameterless call, we use the name of
8209 -- the called function directly, and there is no body to build.
8213 then
8216 -- Else construct and analyze the body of a wrapper procedure
8217 -- that contains an object declaration to hold the expression.
8218 -- Given that this is done only to complete the analysis, it is
8219 -- simpler to build a procedure than a function which might
8220 -- involve secondary stack expansion.
8222 else
8225 Dbody :=
8227 Specification =>
8234 Object_Definition =>
8238 Handled_Statement_Sequence =>
8255 ----------------------------------------
8256 -- Set_Component_Alignment_If_Not_Set --
8257 ----------------------------------------
8260 begin
8261 -- Ignore if not base type, subtypes don't need anything
8267 -- Do not override existing representation
8278 else
8279 Set_Component_Alignment
8285 --------------------------
8286 -- Set_SSO_From_Default --
8287 --------------------------
8292 begin
8293 -- Set default SSO for an array or record base type, except in case of
8294 -- a type extension (which always inherits the SSO of its parent type).
8301 then
8302 Reversed :=
8304 or else
8309 -- For a record type, if bit order is specified explicitly,
8310 -- then do not set SSO from default if not consistent. Note that
8311 -- we do not want to look at a Bit_Order attribute definition
8312 -- for a parent: if we were to inherit Bit_Order, then both
8313 -- SSO_Set_*_By_Default flags would have been cleared already
8314 -- (by Inherit_Aspects_At_Freeze_Point).
8316 and then not
8318 and then
8321 then
8322 -- If flags cause reverse storage order, then set the result. Note
8323 -- that we would have ignored the pragma setting the non default
8324 -- storage order in any case, hence the assertion at this point.
8326 pragma Assert
8331 -- For a record type, also set reversed bit order. Note: if a bit
8332 -- order has been specified explicitly, then this is a no-op.
8341 ------------------
8342 -- Undelay_Type --
8343 ------------------
8346 begin
8350 -- Since we don't want T to have a Freeze_Node, we don't want its
8351 -- Full_View or Corresponding_Record_Type to have one either.
8353 -- ??? Fundamentally, this whole handling is unpleasant. What we really
8354 -- want is to be sure that for an Itype that's part of record R and is a
8355 -- subtype of type T, that it's frozen after the later of the freeze
8356 -- points of R and T. We have no way of doing that directly, so what we
8357 -- do is force most such Itypes to be frozen as part of freezing R via
8358 -- this procedure and only delay the ones that need to be delayed
8359 -- (mostly the designated types of access types that are defined as part
8360 -- of the record).
8366 then
8374 then
8379 ------------------
8380 -- Warn_Overlay --
8381 ------------------
8385 -- The object to which the address clause applies
8391 begin
8392 -- No warning if address clause overlay warnings are off
8398 -- No warning if there is an explicit initialization
8406 -- We only give the warning for non-imported entities of a type for
8407 -- which a non-null base init proc is defined, or for objects of access
8408 -- types with implicit null initialization, or when Normalize_Scalars
8409 -- applies and the type is scalar or a string type (the latter being
8410 -- tested for because predefined String types are initialized by inline
8411 -- code rather than by an init_proc). Note that we do not give the
8412 -- warning for Initialize_Scalars, since we suppressed initialization
8413 -- in this case. Also, do not warn if Suppress_Initialization is set.
8423 then
8426 then
8431 then
8438 then
8445 -- A function call (most likely to To_Address) is probably not an
8446 -- overlay, so skip warning. Ditto if the function call was inlined
8447 -- and transformed into an entity.
8453 -- If a pragma Import follows, we assume that it is for the current
8454 -- target of the address clause, and skip the warning. There may be
8455 -- a source pragma or an aspect that specifies import and generates
8456 -- the corresponding pragma. These will indicate that the entity is
8457 -- imported and that is checked above so that the spurious warning
8458 -- (generated when the entity is frozen) will be suppressed. The
8459 -- pragma may be attached to the aspect, so it is not yet a list
8460 -- member.
8468 then
8473 -- Otherwise give warning message
8477 Error_Msg_N
8479 Nam);
8480 else
8481 Error_Msg_N
8483 Nam);
8486 -- Add friendly warning if initialization comes from a packed array
8487 -- component.
8490 declare
8493 begin
8498 then
8502 then
8503 Error_Msg_NE
8508 else
8515 Error_Msg_N
8518 Nam);