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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 ------------------------------------------------------------------------------
74 -----------------------
75 -- Local Subprograms --
76 -----------------------
79 -- Typ is a type that is being frozen. If no size clause is given,
80 -- but a default Esize has been computed, then this default Esize is
81 -- adjusted up if necessary to be consistent with a given alignment,
82 -- but never to a value greater than Long_Long_Integer'Size. This
83 -- is used for all discrete types and for fixed-point types.
85 procedure Build_And_Analyze_Renamed_Body
89 -- Build body for a renaming declaration, insert in tree and analyze
92 -- Apply legality checks to address clauses for object declarations,
93 -- at the point the object is frozen. Also ensure any initialization is
94 -- performed only after the object has been frozen.
96 procedure Check_Component_Storage_Order
101 -- For an Encl_Type that has a Scalar_Storage_Order attribute definition
102 -- clause, verify that the component type has an explicit and compatible
103 -- attribute/aspect. For arrays, Comp is Empty; for records, it is the
104 -- entity of the component under consideration. For an Encl_Type that
105 -- does not have a Scalar_Storage_Order attribute definition clause,
106 -- verify that the component also does not have such a clause.
107 -- ADC is the attribute definition clause if present (or Empty). On return,
108 -- Comp_ADC_Present is set True if the component has a Scalar_Storage_Order
109 -- attribute definition clause.
112 -- When an expression function is frozen by a use of it, the expression
113 -- itself is frozen. Check that the expression does not include references
114 -- to deferred constants without completion. We report this at the freeze
115 -- point of the function, to provide a better error message.
116 --
117 -- In most cases the expression itself is frozen by the time the function
118 -- itself is frozen, because the formals will be frozen by then. However,
119 -- Attribute references to outer types are freeze points for those types;
120 -- this routine generates the required freeze nodes for them.
123 -- E is a base type. If E is tagged or has a component that is aliased
124 -- or tagged or contains something this is aliased or tagged, set
125 -- Strict_Alignment.
129 -- If E is a fixed-point or discrete type, then all the necessary work
130 -- to freeze it is completed except for possible setting of the flag
131 -- Is_Unsigned_Type, which is done by this procedure. The call has no
132 -- effect if the entity E is not a discrete or fixed-point type.
134 procedure Freeze_And_Append
138 -- Freezes Ent using Freeze_Entity, and appends the resulting list of
139 -- nodes to Result, modifying Result from No_List if necessary. N has
140 -- the same usage as in Freeze_Entity.
143 -- Freeze enumeration type. The Esize field is set as processing
144 -- proceeds (i.e. set by default when the type is declared and then
145 -- adjusted by rep clauses. What this procedure does is to make sure
146 -- that if a foreign convention is specified, and no specific size
147 -- is given, then the size must be at least Integer'Size.
150 -- If an object is frozen which has Is_Statically_Allocated set, then
151 -- all referenced types must also be marked with this flag. This routine
152 -- is in charge of meeting this requirement for the object entity E.
155 -- Perform freezing actions for a subprogram (create extra formals,
156 -- and set proper default mechanism values). Note that this routine
157 -- is not called for internal subprograms, for which neither of these
158 -- actions is needed (or desirable, we do not want for example to have
159 -- these extra formals present in initialization procedures, where they
160 -- would serve no purpose). In this call E is either a subprogram or
161 -- a subprogram type (i.e. an access to a subprogram).
164 -- True if T is not private and has no private components, or has a full
165 -- view. Used to determine whether the designated type of an access type
166 -- should be frozen when the access type is frozen. This is done when an
167 -- allocator is frozen, or an expression that may involve attributes of
168 -- the designated type. Otherwise freezing the access type does not freeze
169 -- the designated type.
171 procedure Process_Default_Expressions
174 -- This procedure is called for each subprogram to complete processing of
175 -- default expressions at the point where all types are known to be frozen.
176 -- The expressions must be analyzed in full, to make sure that all error
177 -- processing is done (they have only been pre-analyzed). If the expression
178 -- is not an entity or literal, its analysis may generate code which must
179 -- not be executed. In that case we build a function body to hold that
180 -- code. This wrapper function serves no other purpose (it used to be
181 -- called to evaluate the default, but now the default is inlined at each
182 -- point of call).
185 -- Typ is a record or array type that is being frozen. This routine sets
186 -- the default component alignment from the scope stack values if the
187 -- alignment is otherwise not specified.
190 -- As each entity is frozen, this routine is called to deal with the
191 -- setting of Debug_Info_Needed for the entity. This flag is set if
192 -- the entity comes from source, or if we are in Debug_Generated_Code
193 -- mode or if the -gnatdV debug flag is set. However, it never sets
194 -- the flag if Debug_Info_Off is set. This procedure also ensures that
195 -- subsidiary entities have the flag set as required.
198 -- T is a record or array type that is being frozen. If it is a base type,
199 -- and if SSO_Set_Low/High_By_Default is set, then Reverse_Storage order
200 -- will be set appropriately. Note that an explicit occurrence of aspect
201 -- Scalar_Storage_Order or an explicit setting of this aspect with an
202 -- attribute definition clause occurs, then these two flags are reset in
203 -- any case, so call will have no effect.
206 -- T is a type of a component that we know to be an Itype. We don't want
207 -- this to have a Freeze_Node, so ensure it doesn't. Do the same for any
208 -- Full_View or Corresponding_Record_Type.
211 -- Expr is the expression for an address clause for entity Nam whose type
212 -- is Typ. If Typ has a default initialization, and there is no explicit
213 -- initialization in the source declaration, check whether the address
214 -- clause might cause overlaying of an entity, and emit a warning on the
215 -- side effect that the initialization will cause.
217 -------------------------------
218 -- Adjust_Esize_For_Alignment --
219 -------------------------------
224 begin
230 then
236 ------------------------------------
237 -- Build_And_Analyze_Renamed_Body --
238 ------------------------------------
240 procedure Build_And_Analyze_Renamed_Body
244 is
250 begin
251 -- If the renamed subprogram is intrinsic, there is no need for a
252 -- wrapper body: we set the alias that will be called and expanded which
253 -- completes the declaration. This transformation is only legal if the
254 -- renamed entity has already been elaborated.
256 -- Note that it is legal for a renaming_as_body to rename an intrinsic
257 -- subprogram, as long as the renaming occurs before the new entity
258 -- is frozen (RM 8.5.4 (5)).
262 then
264 else
270 and then
274 -- We can make the renaming entity intrinsic if the renamed function
275 -- has an interface name, or if it is one of the shift/rotate
276 -- operations known to the compiler.
278 and then
281 Name_Rotate_Right,
282 Name_Shift_Left,
283 Name_Shift_Right,
284 Name_Shift_Right_Arithmetic))
285 then
290 else
297 else
306 ------------------------
307 -- Build_Renamed_Body --
308 ------------------------
310 function Build_Renamed_Body
313 is
315 -- We use for the source location of the renamed body, the location of
316 -- the spec entity. It might seem more natural to use the location of
317 -- the renaming declaration itself, but that would be wrong, since then
318 -- the body we create would look as though it was created far too late,
319 -- and this could cause problems with elaboration order analysis,
320 -- particularly in connection with instantiations.
335 -- If the renamed entity is a primitive operation given in prefix form,
336 -- the prefix is the target object and it has to be added as the first
337 -- actual in the generated call.
339 begin
340 -- Determine the entity being renamed, which is the target of the call
341 -- statement. If the name is an explicit dereference, this is a renaming
342 -- of a subprogram type rather than a subprogram. The name itself is
343 -- fully analyzed.
354 else
361 else
367 -- If the renamed entity is a predefined operator, retain full name
368 -- to ensure its visibility.
372 then
374 else
378 else
381 and then
384 then
386 -- Retrieve the target object, to be added as a first actual
387 -- in the call.
392 else
396 -- Original name may have been overloaded, but is fully resolved now
401 -- For simple renamings, subsequent calls can be expanded directly as
402 -- calls to the renamed entity. The body must be generated in any case
403 -- for calls that may appear elsewhere. This is not done in the case
404 -- where the subprogram is an instantiation because the actual proper
405 -- body has not been built yet.
410 then
414 -- Check whether the return type is a limited view. If the subprogram
415 -- is already frozen the generated body may have a non-limited view
416 -- of the type, that must be used, because it is the one in the spec
417 -- of the renaming declaration.
421 then
422 declare
424 begin
426 Set_Result_Definition
432 -- The body generated for this renaming is an internal artifact, and
433 -- does not constitute a freeze point for the called entity.
440 declare
444 begin
445 -- The controlling formal may be an access parameter, or the
446 -- actual may be an access value, so adjust accordingly.
450 then
451 Actuals := New_List
456 then
457 Actuals :=
458 New_List (
462 else
470 else
481 -- If the renamed entity is an entry, inherit its profile. For other
482 -- renamings as bodies, both profiles must be subtype conformant, so it
483 -- is not necessary to replace the profile given in the declaration.
484 -- However, default values that are aggregates are rewritten when
485 -- partially analyzed, so we recover the original aggregate to insure
486 -- that subsequent conformity checking works. Similarly, if the default
487 -- expression was constant-folded, recover the original expression.
497 N_Access_Definition
498 then
506 then
517 -- If the renamed entity is a function, the generated body contains a
518 -- return statement. Otherwise, build a procedure call. If the entity is
519 -- an entry, subsequent analysis of the call will transform it into the
520 -- proper entry or protected operation call. If the renamed entity is
521 -- a character literal, return it directly.
527 then
528 Call_Node :=
530 Expression =>
536 Call_Node :=
541 Call_Node :=
544 else
545 Call_Node :=
551 -- Create entities for subprogram body and formals
564 Body_Node :=
568 Handled_Statement_Sequence =>
578 -- Link the body to the entity whose declaration it completes. If
579 -- the body is analyzed when the renamed entity is frozen, it may
580 -- be necessary to restore the proper scope (see package Exp_Ch13).
584 then
586 else
593 --------------------------
594 -- Check_Address_Clause --
595 --------------------------
606 begin
609 -- For a deferred constant, the initialization value is on full view
613 else
622 -- Has_Delayed_Freeze was set on E when the address clause was
623 -- analyzed, and must remain set because we want the address
624 -- clause to be elaborated only after any entity it references
625 -- has been elaborated.
628 -- If Rep_Clauses are to be ignored, remove address clause from
629 -- list attached to entity, because it may be illegal for gigi,
630 -- for example by breaking order of elaboration..
633 declare
636 begin
642 else
645 loop
655 -- And now remove the address clause
661 then
667 -- If a variable, or a non-imported constant, overlays a constant
668 -- object and has an initialization value, then the initialization
669 -- may end up writing into read-only memory. Detect the cases of
670 -- statically identical values and remove the initialization. In
671 -- the other cases, give a warning. We will give other warnings
672 -- later for the variable if it is assigned.
679 then
680 declare
684 begin
690 and then Compile_Time_Compare
694 then
699 and then Address_Clause_Overlay_Warnings
700 then
702 Error_Msg_NE
711 -- Capture initialization value at point of declaration,
712 -- and make explicit assignment legal, because object may
713 -- be a constant.
719 -- Move initialization to freeze actions, once the object has
720 -- been frozen and the address clause alignment check has been
721 -- performed.
730 -- If the objet is tagged, check whether the tag must be
731 -- reassigned explicitly.
741 -----------------------------
742 -- Check_Compile_Time_Size --
743 -----------------------------
748 -- Sets the compile time known size (32 bits or less) in the Esize
749 -- field, of T checking for a size clause that was given which attempts
750 -- to give a smaller size, and also checking for an alignment clause.
753 -- Recursive function that does all the work
756 -- If T is a constrained subtype, its size is not known if any of its
757 -- discriminant constraints is not static and it is not a null record.
758 -- The test is conservative and doesn't check that the components are
759 -- in fact constrained by non-static discriminant values. Could be made
760 -- more precise ???
762 --------------------
763 -- Set_Small_Size --
764 --------------------
767 begin
771 -- Check for bad size clause given
776 Error_Msg_NE
781 -- Set size if not set already
788 ----------------
789 -- Size_Known --
790 ----------------
799 begin
803 -- Always True for scalar types. This is true even for generic formal
804 -- scalar types. We used to return False in the latter case, but the
805 -- size is known at compile time, even in the template, we just do
806 -- not know the exact size but that's not the point of this routine.
810 then
813 -- Array types
817 -- String literals always have known size, and we can set it
824 -- Unconstrained types never have known at compile time size
829 -- Don't do any recursion on type with error posted, since we may
830 -- have a malformed type that leads us into a loop.
835 -- Otherwise if component size unknown, then array size unknown
841 -- Check for all indexes static, and also compute possible size
842 -- (in case it is less than 32 and may be packable).
844 declare
848 begin
857 else
865 then
868 else
873 else
885 -- Access types always have known at compile time sizes
890 -- For non-generic private types, go to underlying type if present
895 then
896 -- Don't do any recursion on type with error posted, since we may
897 -- have a malformed type that leads us into a loop.
901 else
905 -- Record types
909 -- A class-wide type is never considered to have a known size
914 -- A subtype of a variant record must not have non-static
915 -- discriminated components.
919 then
922 -- Don't do any recursion on type with error posted, since we may
923 -- have a malformed type that leads us into a loop.
929 -- Now look at the components of the record
931 declare
932 -- The following two variables are used to keep track of the
933 -- size of packed records if we can tell the size of the packed
934 -- record in the front end. Packed_Size_Known is True if so far
935 -- we can figure out the size. It is initialized to True for a
936 -- packed record, unless the record has discriminants or atomic
937 -- components or independent components.
939 -- The reason we eliminate the discriminated case is that
940 -- we don't know the way the back end lays out discriminated
941 -- packed records. If Packed_Size_Known is True, then
942 -- Packed_Size is the size in bits so far.
951 -- Size in bits so far
953 begin
954 -- Test for variant part present
960 N_Record_Definition
962 and then
963 Present (Variant_Part
965 then
966 -- If variant part is present, and type is unconstrained,
967 -- then we must have defaulted discriminants, or a size
968 -- clause must be present for the type, or else the size
969 -- is definitely not known at compile time.
972 and then
975 then
980 -- Loop through components
986 -- We do not know the packed size if there is a component
987 -- clause present (we possibly could, but this would only
988 -- help in the case of a record with partial rep clauses.
989 -- That's because in the case of full rep clauses, the
990 -- size gets figured out anyway by a different circuit).
996 -- We do not know the packed size for an atomic/VFA type
997 -- or component, or an independent type or component, or a
998 -- by-reference type or aliased component (because packing
999 -- does not touch these).
1007 then
1011 -- We need to identify a component that is an array where
1012 -- the index type is an enumeration type with non-standard
1013 -- representation, and some bound of the type depends on a
1014 -- discriminant.
1016 -- This is because gigi computes the size by doing a
1017 -- substitution of the appropriate discriminant value in
1018 -- the size expression for the base type, and gigi is not
1019 -- clever enough to evaluate the resulting expression (which
1020 -- involves a call to rep_to_pos) at compile time.
1022 -- It would be nice if gigi would either recognize that
1023 -- this expression can be computed at compile time, or
1024 -- alternatively figured out the size from the subtype
1025 -- directly, where all the information is at hand ???
1029 then
1030 declare
1038 begin
1045 then
1051 then
1056 then
1066 -- Clearly size of record is not known if the size of one of
1067 -- the components is not known.
1073 -- Accumulate packed size if possible
1077 -- We can only deal with elementary types, since for
1078 -- non-elementary components, alignment enters into the
1079 -- picture, and we don't know enough to handle proper
1080 -- alignment in this context. Packed arrays count as
1081 -- elementary if the representation is a modular type.
1085 and then Present
1087 and then Is_Modular_Integer_Type
1089 then
1090 -- Packed size unknown if we have an atomic/VFA type
1091 -- or a by-reference type, since the back end knows
1092 -- how these are layed out.
1096 then
1099 -- If RM_Size is known and static, then we can keep
1100 -- accumulating the packed size
1104 -- A little glitch, to be removed sometime ???
1105 -- gigi does not understand zero sizes yet.
1110 -- Normal case where we can keep accumulating the
1111 -- packed array size.
1113 else
1117 -- If we have a field whose RM_Size is not known then
1118 -- we can't figure out the packed size here.
1120 else
1124 -- If we have a non-elementary type we can't figure out
1125 -- the packed array size (alignment issues).
1127 else
1142 -- All other cases, size not known at compile time
1144 else
1149 -------------------------------------
1150 -- Static_Discriminated_Components --
1151 -------------------------------------
1153 function Static_Discriminated_Components
1155 is
1158 begin
1162 then
1176 -- Start of processing for Check_Compile_Time_Size
1178 begin
1182 -----------------------------------
1183 -- Check_Component_Storage_Order --
1184 -----------------------------------
1186 procedure Check_Component_Storage_Order
1191 is
1197 -- Set for the record case, True if Comp starts on a byte boundary
1198 -- (in which case it is allowed to have different storage order).
1201 -- Set True when the component is a nested composite, and it does not
1202 -- have the same scalar storage order as Encl_Type.
1206 begin
1207 -- Record case
1217 else
1218 -- If a component clause is present, check if the component starts
1219 -- on a storage element boundary. Otherwise conservatively assume
1220 -- it does so only in the case where the record is not packed.
1223 Comp_Byte_Aligned :=
1225 else
1232 -- Array case
1234 else
1241 -- Note: the Reverse_Storage_Order flag is set on the base type, but
1242 -- the attribute definition clause is attached to the first subtype.
1245 Comp_ADC := Get_Attribute_Definition_Clause
1247 Attribute_Scalar_Storage_Order);
1250 -- Case of record or array component: check storage order compatibility.
1251 -- But, if the record has Complex_Representation, then it is treated as
1252 -- a scalar in the back end so the storage order is irrelevant.
1257 then
1258 Comp_SSO_Differs :=
1260 /=
1263 -- Parent and extension must have same storage order
1267 Error_Msg_N
1272 -- If enclosing composite has explicit SSO then nested composite must
1273 -- have explicit SSO as well.
1279 -- If component and composite SSO differs, check that component
1280 -- falls on byte boundaries and isn't packed.
1284 -- Component SSO differs from enclosing composite:
1286 -- Reject if component is a packed array, as it may be represented
1287 -- as a scalar internally.
1290 Error_Msg_N
1294 -- Reject if composite is a packed array, as it may be rewritten
1295 -- into an array of scalars.
1301 -- Reject if not byte aligned
1304 and then not Comp_Byte_Aligned
1305 then
1306 Error_Msg_N
1312 -- Enclosing type has explicit SSO: non-composite component must not
1313 -- be aliased.
1316 Error_Msg_N
1322 -----------------------------
1323 -- Check_Debug_Info_Needed --
1324 -----------------------------
1327 begin
1332 or else Debug_Generated_Code
1333 or else Debug_Flag_VV
1335 then
1340 -------------------------------
1341 -- Check_Expression_Function --
1342 -------------------------------
1348 -- Function to search for deferred constant
1350 -------------------
1351 -- Find_Constant --
1352 -------------------
1355 begin
1356 -- When a constant is initialized with the result of a dispatching
1357 -- call, the constant declaration is rewritten as a renaming of the
1358 -- displaced function result. This scenario is not a premature use of
1359 -- a constant even though the Has_Completion flag is not set.
1366 N_Object_Declaration
1369 then
1370 Error_Msg_NE
1378 then
1388 -- Start of processing for Check_Expression_Function
1390 begin
1395 then
1400 ----------------------------
1401 -- Check_Strict_Alignment --
1402 ----------------------------
1407 begin
1425 then
1435 -------------------------
1436 -- Check_Unsigned_Type --
1437 -------------------------
1444 begin
1449 -- Do not attempt to analyze case where range was in error
1455 -- The situation that is nontrivial is something like:
1457 -- subtype x1 is integer range -10 .. +10;
1458 -- subtype x2 is x1 range 0 .. V1;
1459 -- subtype x3 is x2 range V2 .. V3;
1460 -- subtype x4 is x3 range V4 .. V5;
1462 -- where Vn are variables. Here the base type is signed, but we still
1463 -- know that x4 is unsigned because of the lower bound of x2.
1465 -- The only way to deal with this is to look up the ancestor chain
1468 loop
1482 else
1485 -- If no ancestor had a static lower bound, go to base type
1489 -- Note: the reason we still check for a compile time known
1490 -- value for the base type is that at least in the case of
1491 -- generic formals, we can have bounds that fail this test,
1492 -- and there may be other cases in error situations.
1504 then
1514 -----------------------------
1515 -- Is_Atomic_VFA_Aggregate --
1516 -----------------------------
1525 begin
1528 -- Array may be qualified, so find outer context
1545 then
1554 then
1563 New_N :=
1575 -----------------------------------------------
1576 -- Explode_Initialization_Compound_Statement --
1577 -----------------------------------------------
1582 begin
1585 then
1588 -- Note that we rewrite Init_Stmts into a NULL statement, rather than
1589 -- just removing it, because Freeze_All may rely on this particular
1590 -- Node_Id still being present in the enclosing list to know where to
1591 -- stop freezing.
1599 ----------------
1600 -- Freeze_All --
1601 ----------------
1603 -- Note: the easy coding for this procedure would be to just build a
1604 -- single list of freeze nodes and then insert them and analyze them
1605 -- all at once. This won't work, because the analysis of earlier freeze
1606 -- nodes may recursively freeze types which would otherwise appear later
1607 -- on in the freeze list. So we must analyze and expand the freeze nodes
1608 -- as they are generated.
1615 -- This is the internal recursive routine that does freezing of entities
1616 -- (but NOT the analysis of default expressions, which should not be
1617 -- recursive, we don't want to analyze those till we are sure that ALL
1618 -- the types are frozen).
1620 --------------------
1621 -- Freeze_All_Ent --
1622 --------------------
1630 -- If freeze nodes are present, insert and analyze, and reset cursor
1631 -- for next insertion.
1633 -------------------
1634 -- Process_Flist --
1635 -------------------
1638 begin
1645 else
1651 -- Start of processing for Freeze_All_Ent
1653 begin
1657 -- If the entity is an inner package which is not a package
1658 -- renaming, then its entities must be frozen at this point. Note
1659 -- that such entities do NOT get frozen at the end of the nested
1660 -- package itself (only library packages freeze).
1662 -- Same is true for task declarations, where anonymous records
1663 -- created for entry parameters must be frozen.
1669 then
1680 then
1687 N_Single_Task_Declaration)
1688 then
1691 End_Scope;
1693 -- For a derived tagged type, we must ensure that all the
1694 -- primitive operations of the parent have been frozen, so that
1695 -- their addresses will be in the parent's dispatch table at the
1696 -- point it is inherited.
1702 then
1703 declare
1710 begin
1717 then
1719 Process_Flist;
1729 Process_Flist;
1731 -- If already frozen, and there are delayed aspects, this is where
1732 -- we do the visibility check for these aspects (see Sem_Ch13 spec
1733 -- for a description of how we handle aspect visibility).
1737 -- Retrieve the visibility to the discriminants in order to
1738 -- analyze properly the aspects.
1742 declare
1745 begin
1751 then
1762 -- If an incomplete type is still not frozen, this may be a
1763 -- premature freezing because of a body declaration that follows.
1764 -- Indicate where the freezing took place. Freezing will happen
1765 -- if the body comes from source, but not if it is internally
1766 -- generated, for example as the body of a type invariant.
1768 -- If the freezing is caused by the end of the current declarative
1769 -- part, it is a Taft Amendment type, and there is no error.
1773 then
1774 declare
1777 begin
1778 -- The presence of a body freezes all entities previously
1779 -- declared in the current list of declarations, but this
1780 -- does not apply if the body does not come from source.
1781 -- A type invariant is transformed into a subprogram body
1782 -- which is placed at the end of the private part of the
1783 -- current package, but this body does not freeze incomplete
1784 -- types that may be declared in this private part.
1787 N_Entry_Body,
1788 N_Package_Body,
1789 N_Protected_Body,
1790 N_Task_Body)
1792 and then
1795 then
1797 Error_Msg_NE
1808 -- Start of processing for Freeze_All
1810 begin
1813 -- Now that all types are frozen, we can deal with default expressions
1814 -- that require us to build a default expression functions. This is the
1815 -- point at which such functions are constructed (after all types that
1816 -- might be used in such expressions have been frozen).
1818 -- For subprograms that are renaming_as_body, we create the wrapper
1819 -- bodies as needed.
1821 -- We also add finalization chains to access types whose designated
1822 -- types are controlled. This is normally done when freezing the type,
1823 -- but this misses recursive type definitions where the later members
1824 -- of the recursion introduce controlled components.
1826 -- Loop through entities
1841 else
1847 and then
1849 = N_Subprogram_Renaming_Declaration
1850 then
1851 Build_And_Analyze_Renamed_Body
1858 N_Single_Task_Declaration)
1859 then
1860 declare
1863 begin
1868 then
1877 -- Historical note: We used to create a finalization master for an
1878 -- access type whose designated type is not controlled, but contains
1879 -- private controlled compoments. This form of postprocessing is no
1880 -- longer needed because the finalization master is now created when
1881 -- the access type is frozen (see Exp_Ch3.Freeze_Type).
1887 -----------------------
1888 -- Freeze_And_Append --
1889 -----------------------
1891 procedure Freeze_And_Append
1895 is
1897 begin
1901 else
1907 -------------------
1908 -- Freeze_Before --
1909 -------------------
1911 procedure Freeze_Before
1915 is
1916 -- Freeze T, then insert the generated Freeze nodes before the node N.
1917 -- Flag Freeze_Profile is used when T is an overloadable entity, and
1918 -- indicates whether its profile should be frozen at the same time.
1923 begin
1933 -------------------
1934 -- Freeze_Entity --
1935 -------------------
1937 function Freeze_Entity
1941 is
1950 -- This flag gets set to true for a variable with default initialization
1953 -- Used to detect attempt to freeze function declared in another unit
1956 -- List of freezing actions, left at No_List if none
1959 -- This could use a comment ???
1962 -- N is a freezing action to be appended to the Result
1965 -- If Loc is a freeze_entity that appears after the last declaration
1966 -- in the scope, inhibit error messages on late completion.
1969 -- Check that an Access or Unchecked_Access attribute with a prefix
1970 -- which is the current instance type can only be applied when the type
1971 -- is limited.
1974 -- Give warning for modulus of 8, 16, 32, or 64 given as an explicit
1975 -- integer literal without an explicit corresponding size clause. The
1976 -- caller has checked that Utype is a modular integer type.
1979 -- Freeze array type, including freezing index and component types
1982 -- Perform checks and generate freeze node if needed for a constant or
1983 -- variable declared by an object declaration.
1986 -- Create Freeze_Generic_Entity nodes for types declared in a generic
1987 -- package. Recurse on inner generic packages.
1990 -- Freeze formals and return type of subprogram. If some type in the
1991 -- profile is a limited view, freezing of the entity will take place
1992 -- elsewhere, and the function returns False. This routine will be
1993 -- modified if and when we can implement AI05-019 efficiently ???
1996 -- Freeze record type, including freezing component types, and freezing
1997 -- primitive operations if this is a tagged type.
2000 -- Determine whether an arbitrary entity is subject to Boolean aspect
2001 -- Import and its value is specified as True.
2004 -- Following AI05-151, a function can return a limited view of a type
2005 -- declared elsewhere. In that case the function cannot be frozen at
2006 -- the end of its enclosing package. If its first use is in a different
2007 -- unit, it cannot be frozen there, but if the call is legal the full
2008 -- view of the return type is available and the subprogram can now be
2009 -- frozen. However the freeze node cannot be inserted at the point of
2010 -- call, but rather must go in the package holding the function, so that
2011 -- the backend can process it in the proper context.
2014 -- Create a new freeze node for entity E
2017 -- If E is an entity for an imported subprogram with pre/post-conditions
2018 -- then this procedure will create a wrapper to ensure that proper run-
2019 -- time checking of the pre/postconditions. See body for details.
2021 -------------------
2022 -- Add_To_Result --
2023 -------------------
2026 begin
2029 else
2034 ----------------------------
2035 -- After_Last_Declaration --
2036 ----------------------------
2041 begin
2047 else
2051 else
2056 ----------------------------
2057 -- Check_Current_Instance --
2058 ----------------------------
2063 -- Determine whether Typ is compatible with the rules for aliased
2064 -- views of types as defined in RM 3.10 in the various dialects.
2067 -- Process routine to apply check to given node
2069 -----------------------------
2070 -- Is_Aliased_View_Of_Type --
2071 -----------------------------
2076 begin
2077 -- Common case
2081 then
2084 -- The following paragraphs describe what a legal aliased view of
2085 -- a type is in the various dialects of Ada.
2087 -- Ada 95
2089 -- The current instance of a limited type, and a formal parameter
2090 -- or generic formal object of a tagged type.
2092 -- Ada 95 limited type
2093 -- * Type with reserved word "limited"
2094 -- * A protected or task type
2095 -- * A composite type with limited component
2100 -- Ada 2005
2102 -- The current instance of a limited tagged type, a protected
2103 -- type, a task type, or a type that has the reserved word
2104 -- "limited" in its full definition ... a formal parameter or
2105 -- generic formal object of a tagged type.
2107 -- Ada 2005 limited type
2108 -- * Type with reserved word "limited", "synchronized", "task"
2109 -- or "protected"
2110 -- * A composite type with limited component
2111 -- * A derived type whose parent is a non-interface limited type
2114 return
2116 or else
2121 -- Ada 2012 and beyond
2123 -- The current instance of an immutably limited type ... a formal
2124 -- parameter or generic formal object of a tagged type.
2126 -- Ada 2012 limited type
2127 -- * Type with reserved word "limited", "synchronized", "task"
2128 -- or "protected"
2129 -- * A composite type with limited component
2130 -- * A derived type whose parent is a non-interface limited type
2131 -- * An incomplete view
2133 -- Ada 2012 immutably limited type
2134 -- * Explicitly limited record type
2135 -- * Record extension with "limited" present
2136 -- * Non-formal limited private type that is either tagged
2137 -- or has at least one access discriminant with a default
2138 -- expression
2139 -- * Task type, protected type or synchronized interface
2140 -- * Type derived from immutably limited type
2142 else
2143 return
2149 -------------
2150 -- Process --
2151 -------------
2154 begin
2158 Name_Unchecked_Access)
2162 then
2164 Error_Msg_N
2167 else
2168 Error_Msg_N
2175 else
2185 -- Local variables
2190 -- Start of processing for Check_Current_Instance
2192 begin
2198 ------------------------------
2199 -- Check_Suspicious_Modulus --
2200 ------------------------------
2205 begin
2211 declare
2214 begin
2216 declare
2220 begin
2222 declare
2226 begin
2227 -- First case, modulus and size are the same. This
2228 -- happens if you have something like mod 32, with
2229 -- an explicit size of 32, this is for sure a case
2230 -- where the warning is given, since it is seems
2231 -- very unlikely that someone would want e.g. a
2232 -- five bit type stored in 32 bits. It is much
2233 -- more likely they wanted a 32-bit type.
2238 -- Second case, the modulus is 32 or 64 and no
2239 -- size clause is present. This is a less clear
2240 -- case for giving the warning, but in the case
2241 -- of 32/64 (5-bit or 6-bit types) these seem rare
2242 -- enough that it is a likely error (and in any
2243 -- case using 2**5 or 2**6 in these cases seems
2244 -- clearer. We don't include 8 or 16 here, simply
2245 -- because in practice 3-bit and 4-bit types are
2246 -- more common and too many false positives if
2247 -- we warn in these cases.
2251 then
2254 -- No warning needed
2256 else
2260 -- If we fall through, give warning
2263 Error_Msg_N
2265 Modulus);
2274 -----------------------
2275 -- Freeze_Array_Type --
2276 -----------------------
2284 -- Set true if any of the index types is an enumeration type with a
2285 -- non-standard representation.
2287 begin
2296 then
2303 -- Processing that is done only for base types
2307 -- Deal with default setting of reverse storage order
2311 -- Propagate flags for component type
2315 then
2323 -- Warn for pragma Pack overriding foreign convention
2327 then
2328 declare
2333 begin
2337 Error_Msg_N
2340 Error_Msg_N
2347 -- If packing was requested or if the component size was
2348 -- set explicitly, then see if bit packing is required. This
2349 -- processing is only done for base types, since all of the
2350 -- representation aspects involved are type-related.
2352 -- This is not just an optimization, if we start processing the
2353 -- subtypes, they interfere with the settings on the base type
2354 -- (this is because Is_Packed has a slightly different meaning
2355 -- before and after freezing).
2357 declare
2361 begin
2365 then
2374 else
2377 -- We can set the component size if it is less than 16,
2378 -- rounding it up to the next storage unit size.
2384 else
2388 -- Set component size up to match alignment if it would
2389 -- otherwise be less than the alignment. This deals with
2390 -- cases of types whose alignment exceeds their size (the
2391 -- padded type cases).
2394 declare
2396 begin
2404 -- Case of component size that may result in packing
2407 declare
2413 Get_Attribute_Definition_Clause
2416 begin
2417 -- Warn if we have pack and component size so that the
2418 -- pack is ignored.
2420 -- Note: here we must check for the presence of a
2421 -- component size before checking for a Pack pragma to
2422 -- deal with the case where the array type is a derived
2423 -- type whose parent is currently private.
2427 and then Warn_On_Redundant_Constructs
2428 then
2430 Error_Msg_NE
2432 Error_Msg_N
2438 -- Set component size if not already set by a component
2439 -- size clause.
2445 -- Check for base type of 8, 16, 32 bits, where an
2446 -- unsigned subtype has a length one less than the
2447 -- base type (e.g. Natural subtype of Integer).
2449 -- In such cases, if a component size was not set
2450 -- explicitly, then generate a warning.
2456 then
2460 Error_Msg_N
2462 Pack_Pragma);
2463 Error_Msg_N
2465 Pack_Pragma);
2469 -- Actual packing is not needed for 8, 16, 32, 64. Also
2470 -- not needed for 24 if alignment is 1.
2477 then
2478 -- Here the array was requested to be packed, but
2479 -- the packing request had no effect, so Is_Packed
2480 -- is reset.
2482 -- Note: semantically this means that we lose track
2483 -- of the fact that a derived type inherited a pragma
2484 -- Pack that was non- effective, but that seems fine.
2486 -- We regard a Pack pragma as a request to set a
2487 -- representation characteristic, and this request
2488 -- may be ignored.
2495 then
2499 -- In all other cases, packing is indeed needed
2501 else
2510 -- Check for Aliased or Atomic_Components/Atomic/VFA with
2511 -- unsuitable packing or explicit component size clause given.
2516 and then
2518 then
2522 -- Outputs error messages for incorrect CS clause or pragma
2523 -- Pack for aliased or atomic/VFA components (T is "aliased"
2524 -- or "atomic/vfa");
2526 -----------------
2527 -- Complain_CS --
2528 -----------------
2531 begin
2533 Clause :=
2534 Get_Attribute_Definition_Clause
2537 Error_Msg_N
2541 Error_Msg_N
2544 else
2545 Error_Msg_N
2551 -- Start of processing for Alias_Atomic_Check
2553 begin
2554 -- If object size of component type isn't known, we cannot
2555 -- be sure so we defer to the back end.
2560 -- Case where component size has no effect. First check for
2561 -- object size of component type multiple of the storage
2562 -- unit size.
2566 -- OK in both packing case and component size case if RM
2567 -- size is known and static and same as the object size.
2569 and then
2573 -- Or if we have an explicit component size clause and
2574 -- the component size and object size are equal.
2576 or else
2579 then
2587 then
2596 -- Check for Independent_Components/Independent with unsuitable
2597 -- packing or explicit component size clause given.
2600 and then
2602 then
2603 begin
2604 -- If object size of component type isn't known, we cannot
2605 -- be sure so we defer to the back end.
2610 -- Case where component size has no effect. First check for
2611 -- object size of component type multiple of the storage
2612 -- unit size.
2616 -- OK in both packing case and component size case if RM
2617 -- size is known and multiple of the storage unit size.
2619 and then
2623 -- Or if we have an explicit component size clause and
2624 -- the component size is larger than the object size.
2626 or else
2629 then
2632 else
2634 Clause :=
2635 Get_Attribute_Definition_Clause
2638 Error_Msg_N
2642 Error_Msg_N
2645 else
2646 Error_Msg_N
2654 -- Warn for case of atomic type
2660 then
2661 Error_Msg_NE
2676 -- Check for scalar storage order
2678 declare
2680 begin
2681 Check_Component_Storage_Order
2684 ADC => Get_Attribute_Definition_Clause
2686 Attribute_Scalar_Storage_Order),
2690 -- Processing that is done only for subtypes
2692 else
2693 -- Acquire alignment from base type
2701 -- Specific checks for bit-packed arrays
2705 -- Check number of elements for bit packed arrays that come from
2706 -- source and have compile time known ranges. The bit-packed
2707 -- arrays circuitry does not support arrays with more than
2708 -- Integer'Last + 1 elements, and when this restriction is
2709 -- violated, causes incorrect data access.
2711 -- For the case where this is not compile time known, a run-time
2712 -- check should be generated???
2715 declare
2721 begin
2727 -- Never generate an error if any index is of a generic
2728 -- type. We will check this in instances.
2735 Ilen :=
2741 -- No attempt is made to check number of elements if not
2742 -- compile time known.
2755 then
2756 Error_Msg_N
2763 -- Check size
2766 declare
2770 begin
2771 -- It is not clear if it is possible to have no size clause
2772 -- at this stage, but it is not worth worrying about. Post
2773 -- error on the entity name in the size clause if present,
2774 -- else on the type entity itself.
2778 else
2785 -- If any of the index types was an enumeration type with a non-
2786 -- standard rep clause, then we indicate that the array type is
2787 -- always packed (even if it is not bit packed).
2796 -- If the array is packed, we must create the packed array type to be
2797 -- used to actually implement the type. This is only needed for real
2798 -- array types (not for string literal types, since they are present
2799 -- only for the front end).
2803 then
2807 -- Make sure that we have the necessary routines to implement the
2808 -- packing, and complain now if not. Note that we only test this
2809 -- for constrained array types.
2815 then
2816 declare
2820 begin
2823 then
2824 Error_Msg_CRT
2828 -- Cancel the packing
2838 -- Size information of packed array type is copied to the array
2839 -- type, since this is really the representation. But do not
2840 -- override explicit existing size values. If the ancestor subtype
2841 -- is constrained the Packed_Array_Impl_Type will be inherited
2842 -- from it, but the size may have been provided already, and
2843 -- must not be overridden either.
2846 and then
2849 then
2861 -- For non-packed arrays set the alignment of the array to the
2862 -- alignment of the component type if it is unknown. Skip this
2863 -- in atomic/VFA case (atomic/VFA arrays may need larger alignments).
2872 then
2876 -- A Ghost type cannot have a component of protected or task type
2877 -- (SPARK RM 6.9(19)).
2880 Error_Msg_N
2882 Arr);
2886 -------------------------------
2887 -- Freeze_Object_Declaration --
2888 -------------------------------
2891 begin
2892 -- Abstract type allowed only for C++ imported variables or constants
2894 -- Note: we inhibit this check for objects that do not come from
2895 -- source because there is at least one case (the expansion of
2896 -- x'Class'Input where x is abstract) where we legitimately
2897 -- generate an abstract object.
2902 then
2907 Error_Msg_NE
2912 Error_Msg_N -- CODEFIX
2918 -- For object created by object declaration, perform required
2919 -- categorization (preelaborate and pure) checks. Defer these
2920 -- checks to freeze time since pragma Import inhibits default
2921 -- initialization and thus pragma Import affects these checks.
2925 -- If there is an address clause, check that it is valid
2926 -- and if need be move initialization to the freeze node.
2930 -- Similar processing is needed for aspects that may affect
2931 -- object layout, like Alignment, if there is an initialization
2932 -- expression.
2935 and then Expander_Active
2938 then
2939 declare
2943 begin
2945 -- Capture initialization value at point of declaration, and
2946 -- make explicit assignment legal, because object may be a
2947 -- constant.
2952 -- Move initialization to freeze actions.
2960 -- Set_Is_Frozen (E, False);
2964 -- Reset Is_True_Constant for non-constant aliased object. We
2965 -- consider that the fact that a non-constant object is aliased may
2966 -- indicate that some funny business is going on, e.g. an aliased
2967 -- object is passed by reference to a procedure which captures the
2968 -- address of the object, which is later used to assign a new value,
2969 -- even though the compiler thinks that it is not modified. Such
2970 -- code is highly dubious, but we choose to make it "work" for
2971 -- non-constant aliased objects.
2973 -- Note that we used to do this for all aliased objects, whether or
2974 -- not constant, but this caused anomalies down the line because we
2975 -- ended up with static objects that were not Is_True_Constant. Not
2976 -- resetting Is_True_Constant for (aliased) constant objects ensures
2977 -- that this anomaly never occurs.
2979 -- However, we don't do that for internal entities. We figure that if
2980 -- we deliberately set Is_True_Constant for an internal entity, e.g.
2981 -- a dispatch table entry, then we mean it.
2986 then
2990 -- If the object needs any kind of default initialization, an error
2991 -- must be issued if No_Default_Initialization applies. The check
2992 -- doesn't apply to imported objects, which are not ever default
2993 -- initialized, and is why the check is deferred until freezing, at
2994 -- which point we know if Import applies. Deferred constants are also
2995 -- exempted from this test because their completion is explicit, or
2996 -- through an import pragma.
3004 and then
3008 or else
3011 then
3013 Check_Restriction
3017 -- Check that a Thread_Local_Storage variable does not have
3018 -- default initialization, and any explicit initialization must
3019 -- either be the null constant or a static constant.
3022 declare
3024 begin
3025 if Has_Default_Initialization
3026 or else
3028 and then
3030 or else not
3033 then
3034 Error_Msg_NE
3037 Error_Msg_NE
3044 -- For imported objects, set Is_Public unless there is also an
3045 -- address clause, which means that there is no external symbol
3046 -- needed for the Import (Is_Public may still be set for other
3047 -- unrelated reasons). Note that we delayed this processing
3048 -- till freeze time so that we can be sure not to set the flag
3049 -- if there is an address clause. If there is such a clause,
3050 -- then the only purpose of the Import pragma is to suppress
3051 -- implicit initialization.
3057 -- For source objects that are not Imported and are library
3058 -- level, if no linker section pragma was given inherit the
3059 -- appropriate linker section from the corresponding type.
3065 then
3066 Set_Linker_Section_Pragma
3070 -- For convention C objects of an enumeration type, warn if the
3071 -- size is not integer size and no explicit size given. Skip
3072 -- warning for Boolean, and Character, assume programmer expects
3073 -- 8-bit sizes for these cases.
3076 or else
3083 then
3085 Error_Msg_N
3091 -----------------------------
3092 -- Freeze_Generic_Entities --
3093 -----------------------------
3100 begin
3119 --------------------
3120 -- Freeze_Profile --
3121 --------------------
3128 begin
3129 -- Loop through formals
3135 -- AI05-0151: incomplete types can appear in a profile. By the
3136 -- time the entity is frozen, the full view must be available,
3137 -- unless it is a limited view.
3142 then
3156 then
3157 -- If the type of a formal is incomplete, subprogram is being
3158 -- frozen prematurely. Within an instance (but not within a
3159 -- wrapper package) this is an artifact of our need to regard
3160 -- the end of an instantiation as a freeze point. Otherwise it
3161 -- is a definite error.
3168 elsif not After_Last_Declaration
3169 and then not Freezing_Library_Level_Tagged_Type
3170 then
3172 Error_Msg
3177 -- Check suspicious parameter for C function. These tests apply
3178 -- only to exported/imported subprograms.
3180 if Warn_On_Export_Import
3183 or else
3190 then
3191 -- Qualify mention of formals with subprogram name
3195 -- Check suspicious use of fat C pointer
3199 then
3200 Error_Msg_N
3203 -- Check suspicious return of boolean
3209 then
3210 Error_Msg_N
3212 Error_Msg_N
3216 -- Check suspicious tagged type
3219 or else
3223 then
3224 Error_Msg_N
3228 -- Check wrong convention subprogram pointer
3232 then
3233 Error_Msg_N
3237 Error_Msg_NE
3242 -- Turn off name qualification after message output
3247 -- Check for unconstrained array in exported foreign convention
3248 -- case.
3254 and then Warn_On_Export_Import
3255 then
3258 -- If this is an inherited operation, place the warning on
3259 -- the derived type declaration, rather than on the original
3260 -- subprogram.
3263 then
3269 else
3285 -- If the formal is an anonymous_access_to_subprogram
3286 -- freeze the subprogram type as well, to prevent
3287 -- scope anomalies in gigi, because there is no other
3288 -- clear point at which it could be frozen.
3292 then
3300 -- Case of function: similar checks on return type
3304 -- Check whether function is declared elsewhere. Previous code
3305 -- used Get_Source_Unit on both arguments, but the values are
3306 -- equal in the case of a parent and a child unit.
3307 -- Confusion with subunits in code ????
3309 Late_Freezing :=
3313 -- Freeze return type
3317 -- AI05-0151: the return type may have been incomplete
3318 -- at the point of declaration. Replace it with the full
3319 -- view, unless the current type is a limited view. In
3320 -- that case the full view is in a different unit, and
3321 -- gigi finds the non-limited view after the other unit
3322 -- is elaborated.
3327 then
3331 -- If the return type is a limited view and the non-limited
3332 -- view is still incomplete, the function has to be frozen at a
3333 -- later time. If the function is abstract there is no place at
3334 -- which the full view will become available, and no code to be
3335 -- generated for it, so mark type as frozen.
3340 then
3343 else
3352 -- Check suspicious return type for C function
3354 if Warn_On_Export_Import
3356 or else
3359 then
3360 -- Check suspicious return of fat C pointer
3366 then
3370 -- Check suspicious return of boolean
3377 then
3378 declare
3381 begin
3382 Error_Msg_NE
3384 Error_Msg_NE
3389 -- Check suspicious return tagged type
3393 and then
3394 Is_Tagged_Type
3399 then
3403 -- Check return of wrong convention subprogram pointer
3409 then
3413 Error_Msg_NE
3419 -- Give warning for suspicious return of a result of an
3420 -- unconstrained array type in a foreign convention function.
3424 -- We are looking for a return of unconstrained array
3429 -- Exclude imported routines, the warning does not belong on
3430 -- the import, but rather on the routine definition.
3434 -- Check that general warning is enabled, and that it is not
3435 -- suppressed for this particular case.
3437 and then Warn_On_Export_Import
3440 then
3441 Error_Msg_N
3447 -- Check suspicious use of Import in pure unit (cases where the RM
3448 -- allows calls to be omitted).
3452 -- It might be suspicious if the compilation unit has the Pure
3453 -- aspect/pragma.
3457 -- The RM allows omission of calls only in the case of
3458 -- library-level subprograms (see RM-10.2.1(18)).
3462 -- Ignore internally generated entity. This happens in some cases
3463 -- of subprograms in specs, where we generate an implied body.
3467 -- Assume run-time knows what it is doing
3469 and then not GNAT_Mode
3471 -- Assume explicit Pure_Function means import is pure
3475 -- Don't need warning in relaxed semantics mode
3477 and then not Relaxed_RM_Semantics
3479 -- Assume convention Intrinsic is OK, since this is specialized.
3480 -- This deals with the DEC unit current_exception.ads
3484 -- Assume that ASM interface knows what it is doing. This deals
3485 -- with unsigned.ads in the AAMP back end.
3488 then
3489 Error_Msg_N
3491 Error_Msg_NE
3499 ------------------------
3500 -- Freeze_Record_Type --
3501 ------------------------
3513 -- Set True if the record type scope Rec has been pushed on the scope
3514 -- stack. Needed for the analysis of delayed aspects specified to the
3515 -- components of Rec.
3518 -- Scalar_Storage_Order attribute definition clause for the record
3521 -- Set True if we find at least one component with no component
3522 -- clause (used to warn about useless Pack pragmas).
3525 -- Set True if we find at least one component with a component
3526 -- clause (used to warn about useless Bit_Order pragmas, and also
3527 -- to detect cases where Implicit_Packing may have an effect).
3530 -- Set True if we find at least one component which is aliased. This
3531 -- is used to prevent Implicit_Packing of the record, since packing
3532 -- cannot modify the size of alignment of an aliased component.
3535 -- Set True if we find at least one component whose type has a
3536 -- Scalar_Storage_Order attribute definition clause.
3539 -- Set False if we encounter a component of a non-scalar type
3543 -- Accumulates total RM_Size values and total Esize values of all
3544 -- scalar components. Used for processing of Implicit_Packing.
3547 -- If N is an allocator, possibly wrapped in one or more level of
3548 -- qualified expression(s), return the inner allocator node, else
3549 -- return Empty.
3552 -- If the component subtype is an access to a constrained subtype of
3553 -- an already frozen type, make the subtype frozen as well. It might
3554 -- otherwise be frozen in the wrong scope, and a freeze node on
3555 -- subtype has no effect. Similarly, if the component subtype is a
3556 -- regular (not protected) access to subprogram, set the anonymous
3557 -- subprogram type to frozen as well, to prevent an out-of-scope
3558 -- freeze node at some eventual point of call. Protected operations
3559 -- are handled elsewhere.
3562 -- Make sure that all types mentioned in Discrete_Choices of the
3563 -- variants referenceed by the Variant_Part VP are frozen. This is
3564 -- a recursive routine to deal with nested variants.
3566 ---------------------
3567 -- Check_Allocator --
3568 ---------------------
3572 begin
3574 loop
3579 else
3585 -----------------
3586 -- Check_Itype --
3587 -----------------
3592 begin
3595 then
3598 -- In addition, add an Itype_Reference to ensure that the
3599 -- access subtype is elaborated early enough. This cannot be
3600 -- done if the subtype may depend on discriminants.
3605 then
3613 then
3618 ------------------------------------
3619 -- Freeze_Choices_In_Variant_Part --
3620 ------------------------------------
3629 begin
3630 -- Loop through variants
3635 -- Loop through choices, checking that all types are frozen
3641 then
3648 -- Check for nested variant part to process
3662 -- Start of processing for Freeze_Record_Type
3664 begin
3665 -- Deal with delayed aspect specifications for components. The
3666 -- analysis of the aspect is required to be delayed to the freeze
3667 -- point, thus we analyze the pragma or attribute definition
3668 -- clause in the tree at this point. We also analyze the aspect
3669 -- specification node at the freeze point when the aspect doesn't
3670 -- correspond to pragma/attribute definition clause.
3676 then
3681 -- The visibility to the discriminants must be restored in
3682 -- order to properly analyze the aspects.
3695 -- Pop the scope if Rec scope has been pushed on the scope stack
3696 -- during the delayed aspect analysis process.
3703 Pop_Scope;
3706 -- Freeze components and embedded subtypes
3715 -- Handle the component and discriminant case
3718 declare
3721 begin
3722 -- Freezing a record type freezes the type of each of its
3723 -- components. However, if the type of the component is
3724 -- part of this record, we do not want or need a separate
3725 -- Freeze_Node. Note that Is_Itype is wrong because that's
3726 -- also set in private type cases. We also can't check for
3727 -- the Scope being exactly Rec because of private types and
3728 -- record extensions.
3733 then
3739 -- Warn for pragma Pack overriding foreign convention
3744 -- Don't warn for aliased components, since override
3745 -- cannot happen in that case.
3748 then
3749 declare
3754 begin
3758 Error_Msg_N
3760 PP);
3762 Error_Msg_NE
3769 -- Check for error of component clause given for variable
3770 -- sized type. We have to delay this test till this point,
3771 -- since the component type has to be frozen for us to know
3772 -- if it is variable length.
3777 -- We omit this test in a generic context, it will be
3778 -- applied at instantiation time.
3783 -- Also omit this test in CodePeer mode, since we do not
3784 -- have sufficient info on size and rep clauses.
3789 -- Omit check if component has a generic type. This can
3790 -- happen in an instantiation within a generic in ASIS
3791 -- mode, where we force freeze actions without full
3792 -- expansion.
3797 -- Do the check
3799 elsif not
3800 Size_Known_At_Compile_Time
3802 then
3803 Error_Msg_N
3808 else
3812 -- Case of component requires byte alignment
3816 -- Set the enclosing record to also require byte align
3820 -- Check for component clause that is inconsistent with
3821 -- the required byte boundary alignment.
3826 then
3827 Error_Msg_N
3835 -- Gather data for possible Implicit_Packing later. Note that at
3836 -- this stage we might be dealing with a real component, or with
3837 -- an implicit subtype declaration.
3841 else
3842 Scalar_Component_Total_RM_Size :=
3844 Scalar_Component_Total_Esize :=
3848 -- If the component is an Itype with Delayed_Freeze and is either
3849 -- a record or array subtype and its base type has not yet been
3850 -- frozen, we must remove this from the entity list of this record
3851 -- and put it on the entity list of the scope of its base type.
3852 -- Note that we know that this is not the type of a component
3853 -- since we cleared Has_Delayed_Freeze for it in the previous
3854 -- loop. Thus this must be the Designated_Type of an access type,
3855 -- which is the type of a component.
3863 then
3864 declare
3868 begin
3869 -- We have a difficult case to handle here. Suppose Rec is
3870 -- subtype being defined in a subprogram that's created as
3871 -- part of the freezing of Rec'Base. In that case, we know
3872 -- that Comp'Base must have already been frozen by the time
3873 -- we get to elaborate this because Gigi doesn't elaborate
3874 -- any bodies until it has elaborated all of the declarative
3875 -- part. But Is_Frozen will not be set at this point because
3876 -- we are processing code in lexical order.
3878 -- We detect this case by going up the Scope chain of Rec
3879 -- and seeing if we have a subprogram scope before reaching
3880 -- the top of the scope chain or that of Comp'Base. If we
3881 -- do, then mark that Comp'Base will actually be frozen. If
3882 -- so, we merely undelay it.
3899 else
3902 else
3906 -- Insert in entity list of scope of base type (which
3907 -- must be an enclosing scope, because still unfrozen).
3913 -- If the component is an access type with an allocator as default
3914 -- value, the designated type will be frozen by the corresponding
3915 -- expression in init_proc. In order to place the freeze node for
3916 -- the designated type before that for the current record type,
3917 -- freeze it now.
3919 -- Same process if the component is an array of access types,
3920 -- initialized with an aggregate. If the designated type is
3921 -- private, it cannot contain allocators, and it is premature
3922 -- to freeze the type, so we check for this as well.
3927 then
3928 declare
3932 begin
3935 -- If component is pointer to a class-wide type, freeze
3936 -- the specific type in the expression being allocated.
3937 -- The expression may be a subtype indication, in which
3938 -- case freeze the subtype mark.
3940 if Is_Class_Wide_Type
3942 then
3944 Freeze_And_Append
3948 then
3949 Freeze_And_Append
3957 else
3958 Freeze_And_Append
3966 then
3969 -- Freeze the designated type when initializing a component with
3970 -- an aggregate in case the aggregate contains allocators.
3972 -- type T is ...;
3973 -- type T_Ptr is access all T;
3974 -- type T_Array is array ... of T_Ptr;
3976 -- type Rec is record
3977 -- Comp : T_Array := (others => ...);
3978 -- end record;
3982 then
3983 declare
3986 Designated_Type
3989 begin
3990 -- The only case when this sort of freezing is not done is
3991 -- when the designated type is class-wide and the root type
3992 -- is the record owning the component. This scenario results
3993 -- in a circularity because the class-wide type requires
3994 -- primitives that have not been created yet as the root
3995 -- type is in the process of being frozen.
3997 -- type Rec is tagged;
3998 -- type Rec_Ptr is access all Rec'Class;
3999 -- type Rec_Array is array ... of Rec_Ptr;
4001 -- type Rec is record
4002 -- Comp : Rec_Array := (others => ...);
4003 -- end record;
4007 then
4015 then
4025 SSO_ADC :=
4026 Get_Attribute_Definition_Clause
4029 -- If the record type has Complex_Representation, then it is treated
4030 -- as a scalar in the back end so the storage order is irrelevant.
4034 Error_Msg_N
4036 SSO_ADC);
4039 else
4040 -- Deal with default setting of reverse storage order
4044 -- Check consistent attribute setting on component types
4046 declare
4048 begin
4051 Check_Component_Storage_Order
4061 -- Now deal with reverse storage order/bit order issues
4065 -- Check compatibility of Scalar_Storage_Order with Bit_Order,
4066 -- if the former is specified.
4070 -- Note: report error on Rec, not on SSO_ADC, as ADC may
4071 -- apply to some ancestor type.
4074 Error_Msg_N
4079 -- Warn if there is a Scalar_Storage_Order attribute definition
4080 -- clause but no component clause, no component that itself has
4081 -- such an attribute definition, and no pragma Pack.
4084 or else
4085 SSO_ADC_Component
4086 or else
4088 then
4089 Error_Msg_N
4096 -- Deal with Bit_Order aspect
4104 then
4105 -- Warn if clause has no effect when no component clause is
4106 -- present, but suppress warning if the Bit_Order is required
4107 -- due to the presence of a Scalar_Storage_Order attribute.
4109 Error_Msg_N
4111 Error_Msg_N
4114 -- Here is where we do the processing to adjust component clauses
4115 -- for reversed bit order, when not using reverse SSO.
4119 then
4122 -- Case where we have both an explicit Bit_Order and the same
4123 -- Scalar_Storage_Order: leave record untouched, the back-end
4124 -- will take care of required layout conversions.
4126 else
4132 -- Complete error checking on record representation clause (e.g.
4133 -- overlap of components). This is called after adjusting the
4134 -- record for reverse bit order.
4136 declare
4138 begin
4144 -- Set OK_To_Reorder_Components depending on debug flags
4148 or else
4150 then
4155 -- Check for useless pragma Pack when all components placed. We only
4156 -- do this check for record types, not subtypes, since a subtype may
4157 -- have all its components placed, and it still makes perfectly good
4158 -- sense to pack other subtypes or the parent type. We do not give
4159 -- this warning if Optimize_Alignment is set to Space, since the
4160 -- pragma Pack does have an effect in this case (it always resets
4161 -- the alignment to one).
4165 and then not Unplaced_Component
4167 then
4168 -- Reset packed status. Probably not necessary, but we do it so
4169 -- that there is no chance of the back end doing something strange
4170 -- with this redundant indication of packing.
4174 -- Give warning if redundant constructs warnings on
4177 Error_Msg_N -- CODEFIX
4183 -- If this is the record corresponding to a remote type, freeze the
4184 -- remote type here since that is what we are semantically freezing.
4185 -- This prevents the freeze node for that type in an inner scope.
4192 -- Check for controlled components and unchecked unions.
4197 -- Do not set Has_Controlled_Component on a class-wide
4198 -- equivalent type. See Make_CW_Equivalent_Type.
4201 and then
4203 or else
4206 or else
4208 and then
4210 and then
4211 Has_Controlled_Component
4213 then
4221 -- Scan component declaration for likely misuses of current
4222 -- instance, either in a constraint or a default expression.
4232 -- Enforce the restriction that access attributes with a current
4233 -- instance prefix can only apply to limited types. This comment
4234 -- is floating here, but does not seem to belong here???
4236 -- Set component alignment if not otherwise already set
4240 -- For first subtypes, check if there are any fixed-point fields with
4241 -- component clauses, where we must check the size. This is not done
4242 -- till the freeze point since for fixed-point types, we do not know
4243 -- the size until the type is frozen. Similar processing applies to
4244 -- bit packed arrays.
4252 then
4253 Check_Size
4257 Junk);
4264 -- Generate warning for applying C or C++ convention to a record
4265 -- with discriminants. This is suppressed for the unchecked union
4266 -- case, since the whole point in this case is interface C. We also
4267 -- do not generate this within instantiations, since we will have
4268 -- generated a message on the template.
4273 or else
4276 and then not In_Instance
4279 then
4280 declare
4284 begin
4289 Error_Msg_N
4291 A2);
4292 else
4293 Error_Msg_N
4295 A2);
4298 Error_Msg_NE
4304 -- See if Size is too small as is (and implicit packing might help)
4308 -- No implicit packing if even one component is explicitly placed
4310 and then not Placed_Component
4312 -- Or even one component is aliased
4314 and then not Aliased_Component
4316 -- Must have size clause and all scalar components
4319 and then All_Scalar_Components
4321 -- Do not try implicit packing on records with discriminants, too
4322 -- complicated, especially in the variant record case.
4326 -- We can implicitly pack if the specified size of the record is
4327 -- less than the sum of the object sizes (no point in packing if
4328 -- this is not the case).
4332 -- And the total RM size cannot be greater than the specified size
4333 -- since otherwise packing will not get us where we have to be.
4337 -- Never do implicit packing in CodePeer or SPARK modes since
4338 -- we don't do any packing in these modes, since this generates
4339 -- over-complex code that confuses static analysis, and in
4340 -- general, neither CodePeer not GNATprove care about the
4341 -- internal representation of objects.
4344 then
4345 -- If implicit packing enabled, do it
4350 -- Otherwise flag the size clause
4352 else
4353 declare
4355 begin
4356 Error_Msg_NE -- CODEFIX
4358 Error_Msg_N -- CODEFIX
4365 -- The following checks are relevant only when SPARK_Mode is on as
4366 -- they are not standard Ada legality rules.
4371 -- A discriminated type cannot be effectively volatile
4372 -- (SPARK RM C.6(4)).
4377 -- A tagged type cannot be effectively volatile
4378 -- (SPARK RM C.6(5)).
4384 -- A non-effectively volatile record type cannot contain
4385 -- effectively volatile components (SPARK RM C.6(2)).
4387 else
4392 then
4394 Error_Msg_N
4403 -- A type which does not yield a synchronized object cannot have
4404 -- a component that yields a synchronized object (SPARK RM 9.5).
4411 then
4413 Error_Msg_N
4422 -- A Ghost type cannot have a component of protected or task type
4423 -- (SPARK RM 6.9(19)).
4430 then
4432 Error_Msg_N
4434 Comp);
4442 -- Make sure that if we have an iterator aspect, then we have
4443 -- either Constant_Indexing or Variable_Indexing.
4445 declare
4448 begin
4457 or else
4459 then
4461 else
4462 Error_Msg_N
4464 Iterator_Aspect);
4469 -- All done if not a full record definition
4475 -- Finally we need to check the variant part to make sure that
4476 -- all types within choices are properly frozen as part of the
4477 -- freezing of the record type.
4484 begin
4485 -- Find component list
4497 then
4502 -- Case of variant part present
4508 -- Note: we used to call Check_Choices here, but it is too early,
4509 -- since predicated subtypes are frozen here, but their freezing
4510 -- actions are in Analyze_Freeze_Entity, which has not been called
4511 -- yet for entities frozen within this procedure, so we moved that
4512 -- call to the Analyze_Freeze_Entity for the record type.
4516 -- Check that all the primitives of an interface type are abstract
4517 -- or null procedures.
4521 then
4522 declare
4526 begin
4533 -- Avoid reporting the error on inherited primitives
4536 then
4541 Error_Msg_N
4545 else
4546 Error_Msg_N
4558 -------------------------------
4559 -- Has_Boolean_Aspect_Import --
4560 -------------------------------
4567 begin
4573 -- The value of aspect Import is True when the expression is
4574 -- either missing or it is explicitly set to True.
4580 then
4591 ----------------------------
4592 -- Late_Freeze_Subprogram --
4593 ----------------------------
4600 begin
4603 else
4610 ---------------------
4611 -- New_Freeze_Node --
4612 ---------------------
4618 begin
4619 -- Handle the case where an ignored Ghost subprogram freezes the type
4620 -- of one of its formals. The type can either be non-Ghost or checked
4621 -- Ghost. Since the freeze node for the type is generated in the
4622 -- context of the subprogram, the node will be incorrectly flagged as
4623 -- ignored Ghost and erroneously removed from the tree.
4625 -- type Typ is ...;
4626 -- procedure Ignored_Ghost_Proc (Formal : Typ) with Ghost;
4628 -- Reset the Ghost mode to "none". This preserves the freeze node.
4633 then
4643 ------------------------------
4644 -- Wrap_Imported_Subprogram --
4645 ------------------------------
4647 -- The issue here is that our normal approach of checking preconditions
4648 -- and postconditions does not work for imported procedures, since we
4649 -- are not generating code for the body. To get around this we create
4650 -- a wrapper, as shown by the following example:
4652 -- procedure K (A : Integer);
4653 -- pragma Import (C, K);
4655 -- The spec is rewritten by removing the effects of pragma Import, but
4656 -- leaving the convention unchanged, as though the source had said:
4658 -- procedure K (A : Integer);
4659 -- pragma Convention (C, K);
4661 -- and we create a body, added to the entity K freeze actions, which
4662 -- looks like:
4664 -- procedure K (A : Integer) is
4665 -- procedure K (A : Integer);
4666 -- pragma Import (C, K);
4667 -- begin
4668 -- K (A);
4669 -- end K;
4671 -- Now the contract applies in the normal way to the outer procedure,
4672 -- and the inner procedure has no contracts, so there is no problem
4673 -- in just calling it to get the original effect.
4675 -- In the case of a function, we create an appropriate return statement
4676 -- for the subprogram body that calls the inner procedure.
4688 begin
4689 -- Nothing to do if not imported
4694 -- Test enabling conditions for wrapping
4699 and then not GNATprove_Mode
4700 then
4701 -- Here we do the wrap
4703 -- Note on calls to Copy_Separate_Tree. The trees we are copying
4704 -- here are fully analyzed, but we definitely want fully syntactic
4705 -- unanalyzed trees in the body we construct, so that the analysis
4706 -- generates the right visibility, and that is exactly what the
4707 -- calls to Copy_Separate_Tree give us.
4709 -- Acquire copy of Inline pragma, and indicate that it does not
4710 -- come from an aspect, as it applies to an internal entity.
4715 -- Fix up spec to be not imported any more
4722 -- Grab the subprogram declaration and specification
4726 -- Build parameter list that we need
4735 -- Build the call
4738 Stmt :=
4740 Expression =>
4745 else
4746 Stmt :=
4752 -- Now build the body
4754 Bod :=
4756 Specification =>
4760 Specification =>
4762 Iprag),
4763 Handled_Statement_Sequence =>
4768 -- Append the body to freeze result
4773 -- Case of imported subprogram that does not get wrapped
4775 else
4776 -- Set Is_Public. All imported entities need an external symbol
4777 -- created for them since they are always referenced from another
4778 -- object file. Note this used to be set when we set Is_Imported
4779 -- back in Sem_Prag, but now we delay it to this point, since we
4780 -- don't want to set this flag if we wrap an imported subprogram.
4786 -- Local variables
4790 -- Start of processing for Freeze_Entity
4792 begin
4793 -- The entity being frozen may be subject to pragma Ghost. Set the mode
4794 -- now to ensure that any nodes generated during freezing are properly
4795 -- flagged as Ghost.
4799 -- We are going to test for various reasons why this entity need not be
4800 -- frozen here, but in the case of an Itype that's defined within a
4801 -- record, that test actually applies to the record.
4807 then
4811 -- Do not freeze if already frozen since we only need one freeze node
4817 -- It is improper to freeze an external entity within a generic because
4818 -- its freeze node will appear in a non-valid context. The entity will
4819 -- be frozen in the proper scope after the current generic is analyzed.
4820 -- However, aspects must be analyzed because they may be queried later
4821 -- within the generic itself, and the corresponding pragma or attribute
4822 -- definition has not been analyzed yet.
4832 -- AI05-0213: A formal incomplete type does not freeze the actual. In
4833 -- the instance, the same applies to the subtype renaming the actual.
4839 then
4843 -- Formal subprograms are never frozen
4849 -- Generic types are never frozen as they lack delayed semantic checks
4855 -- Do not freeze a global entity within an inner scope created during
4856 -- expansion. A call to subprogram E within some internal procedure
4857 -- (a stream attribute for example) might require freezing E, but the
4858 -- freeze node must appear in the same declarative part as E itself.
4859 -- The two-pass elaboration mechanism in gigi guarantees that E will
4860 -- be frozen before the inner call is elaborated. We exclude constants
4861 -- from this test, because deferred constants may be frozen early, and
4862 -- must be diagnosed (e.g. in the case of a deferred constant being used
4863 -- in a default expression). If the enclosing subprogram comes from
4864 -- source, or is a generic instance, then the freeze point is the one
4865 -- mandated by the language, and we freeze the entity. A subprogram that
4866 -- is a child unit body that acts as a spec does not have a spec that
4867 -- comes from source, but can only come from source.
4872 then
4873 declare
4876 begin
4883 then
4885 else
4895 -- Similarly, an inlined instance body may make reference to global
4896 -- entities, but these references cannot be the proper freezing point
4897 -- for them, and in the absence of inlining freezing will take place in
4898 -- their own scope. Normally instance bodies are analyzed after the
4899 -- enclosing compilation, and everything has been frozen at the proper
4900 -- place, but with front-end inlining an instance body is compiled
4901 -- before the end of the enclosing scope, and as a result out-of-order
4902 -- freezing must be prevented.
4904 elsif Front_End_Inlining
4905 and then In_Instance_Body
4907 then
4908 declare
4911 begin
4916 else
4934 -- Add checks to detect proper initialization of scalars that may appear
4935 -- as subprogram parameters.
4941 -- Deal with delayed aspect specifications. The analysis of the aspect
4942 -- is required to be delayed to the freeze point, thus we analyze the
4943 -- pragma or attribute definition clause in the tree at this point. We
4944 -- also analyze the aspect specification node at the freeze point when
4945 -- the aspect doesn't correspond to pragma/attribute definition clause.
4951 -- Here to freeze the entity
4955 -- Case of entity being frozen is other than a type
4959 -- If entity is exported or imported and does not have an external
4960 -- name, now is the time to provide the appropriate default name.
4961 -- Skip this if the entity is stubbed, since we don't need a name
4962 -- for any stubbed routine. For the case on intrinsics, if no
4963 -- external name is specified, then calls will be handled in
4964 -- Exp_Intr.Expand_Intrinsic_Call, and no name is needed. If an
4965 -- external name is provided, then Expand_Intrinsic_Call leaves
4966 -- calls in place for expansion by GIGI.
4972 then
4973 Set_Encoded_Interface_Name
4976 -- If entity is an atomic object appearing in a declaration and
4977 -- the expression is an aggregate, assign it to a temporary to
4978 -- ensure that the actual assignment is done atomically rather
4979 -- than component-wise (the assignment to the temp may be done
4980 -- component-wise, but that is harmless).
4987 then
4991 -- Subprogram case
4995 -- Check for needing to wrap imported subprogram
4999 -- Freeze all parameter types and the return type (RM 13.14(14)).
5000 -- However skip this for internal subprograms. This is also where
5001 -- any extra formal parameters are created since we now know
5002 -- whether the subprogram will use a foreign convention.
5004 -- In Ada 2012, freezing a subprogram does not always freeze the
5005 -- corresponding profile (see AI05-019). An attribute reference
5006 -- is not a freezing point of the profile. Flag Do_Freeze_Profile
5007 -- indicates whether the profile should be frozen now.
5008 -- Other constructs that should not freeze ???
5010 -- This processing doesn't apply to internal entities (see below)
5011 -- In ASIS mode the profile is frozen unconditionally, to prevent
5012 -- backend anomalies.
5016 then
5023 -- Must freeze its parent first if it is a derived subprogram
5029 -- We don't freeze internal subprograms, because we don't normally
5030 -- want addition of extra formals or mechanism setting to happen
5031 -- for those. However we do pass through predefined dispatching
5032 -- cases, since extra formals may be needed in some cases, such as
5033 -- for the stream 'Input function (build-in-place formals).
5037 then
5047 -- If warning on suspicious contracts then check for the case of
5048 -- a postcondition other than False for a No_Return subprogram.
5051 and then Warn_On_Suspicious_Contract
5053 then
5054 declare
5058 begin
5061 Name_Postcondition,
5062 Name_Refined_Post)
5063 then
5064 Exp :=
5065 Expression
5070 then
5071 Error_Msg_NE
5082 -- Here for other than a subprogram or type
5084 else
5085 -- If entity has a type, and it is not a generic unit, then
5086 -- freeze it first (RM 13.14(10)).
5090 then
5093 -- For an object of an anonymous array type, aspects on the
5094 -- object declaration apply to the type itself. This is the
5095 -- case for Atomic_Components, Volatile_Components, and
5096 -- Independent_Components. In these cases analysis of the
5097 -- generated pragma will mark the anonymous types accordingly,
5098 -- and the object itself does not require a freeze node.
5104 then
5111 -- Special processing for objects created by object declaration
5117 -- Check that a constant which has a pragma Volatile[_Components]
5118 -- or Atomic[_Components] also has a pragma Import (RM C.6(13)).
5120 -- Note: Atomic[_Components] also sets Volatile[_Components]
5126 then
5127 -- Make sure we actually have a pragma, and have not merely
5128 -- inherited the indication from elsewhere (e.g. an address
5129 -- clause, which is not good enough in RM terms).
5132 or else
5134 then
5135 Error_Msg_N
5140 or else
5142 then
5143 Error_Msg_N
5149 -- Static objects require special handling
5153 then
5157 -- Remaining step is to layout objects
5161 then
5165 -- For an object that does not have delayed freezing, and whose
5166 -- initialization actions have been captured in a compound
5167 -- statement, move them back now directly within the enclosing
5168 -- statement sequence.
5172 then
5177 -- Case of a type or subtype being frozen
5179 else
5180 -- We used to check here that a full type must have preelaborable
5181 -- initialization if it completes a private type specified with
5182 -- pragma Preelaborable_Initialization, but that missed cases where
5183 -- the types occur within a generic package, since the freezing
5184 -- that occurs within a containing scope generally skips traversal
5185 -- of a generic unit's declarations (those will be frozen within
5186 -- instances). This check was moved to Analyze_Package_Specification.
5188 -- The type may be defined in a generic unit. This can occur when
5189 -- freezing a generic function that returns the type (which is
5190 -- defined in a parent unit). It is clearly meaningless to freeze
5191 -- this type. However, if it is a subtype, its size may be determi-
5192 -- nable and used in subsequent checks, so might as well try to
5193 -- compute it.
5195 -- In Ada 2012, Freeze_Entities is also used in the front end to
5196 -- trigger the analysis of aspect expressions, so in this case we
5197 -- want to continue the freezing process.
5201 and then
5204 then
5210 -- Check for error of Type_Invariant'Class applied to an untagged
5211 -- type (check delayed to freeze time when full type is available).
5213 declare
5215 begin
5219 then
5220 Error_Msg_NE
5223 Error_Msg_N
5230 -- A Ghost type cannot be concurrent (SPARK RM 6.9(19)). Verify
5231 -- this legality rule first to five a finer-grained diagnostic.
5236 -- A Ghost type cannot be effectively volatile (SPARK RM 6.9(7))
5243 -- Deal with special cases of freezing for subtype
5247 -- Before we do anything else, a specialized test for the case of
5248 -- a size given for an array where the array needs to be packed,
5249 -- but was not so the size cannot be honored. This is the case
5250 -- where implicit packing may apply. The reason we do this so
5251 -- early is that if we have implicit packing, the layout of the
5252 -- base type is affected, so we must do this before we freeze
5253 -- the base type.
5255 -- We could do this processing only if implicit packing is enabled
5256 -- since in all other cases, the error would be caught by the back
5257 -- end. However, we choose to do the check even if we do not have
5258 -- implicit packing enabled, since this allows us to give a more
5259 -- useful error message (advising use of pragmas Implicit_Packing
5260 -- or Pack).
5263 declare
5274 -- Number of elements in array
5276 begin
5277 -- Check enabling conditions. These are straightforward
5278 -- except for the test for a limited composite type. This
5279 -- eliminates the rare case of a array of limited components
5280 -- where there are issues of whether or not we can go ahead
5281 -- and pack the array (since we can't freely pack and unpack
5282 -- arrays if they are limited).
5284 -- Note that we check the root type explicitly because the
5285 -- whole point is we are doing this test before we have had
5286 -- a chance to freeze the base type (and it is that freeze
5287 -- action that causes stuff to be inherited).
5300 then
5301 -- Compute number of elements in array
5309 and then
5311 then
5315 Num_Elmts :=
5316 Num_Elmts *
5322 -- What we are looking for here is the situation where
5323 -- the RM_Size given would be exactly right if there was
5324 -- a pragma Pack (resulting in the component size being
5325 -- the same as the RM_Size). Furthermore, the component
5326 -- type size must be an odd size (not a multiple of
5327 -- storage unit). If the component RM size is an exact
5328 -- number of storage units that is a power of two, the
5329 -- array is not packed and has a standard representation.
5333 then
5334 -- For implicit packing mode, just set the component
5335 -- size silently.
5343 -- Otherwise give an error message
5345 else
5346 Error_Msg_NE
5348 Error_Msg_N -- CODEFIX
5354 and then Implicit_Packing
5355 and then
5357 or else
5359 or else
5361 then
5362 -- Not a packed array, but indicate the desired
5363 -- component size, for the back-end.
5373 -- If ancestor subtype present, freeze that first. Note that this
5374 -- will also get the base type frozen. Need RM reference ???
5381 -- No ancestor subtype present
5383 else
5384 -- See if we have a nearest ancestor that has a predicate.
5385 -- That catches the case of derived type with a predicate.
5386 -- Need RM reference here ???
5394 -- Freeze base type before freezing the entity (RM 13.14(15))
5401 -- A subtype inherits all the type-related representation aspects
5402 -- from its parents (RM 13.1(8)).
5406 -- For a derived type, freeze its parent type first (RM 13.14(15))
5412 -- A derived type inherits each type-related representation aspect
5413 -- of its parent type that was directly specified before the
5414 -- declaration of the derived type (RM 13.1(15)).
5419 -- Check for incompatible size and alignment for record type
5421 if Warn_On_Size_Alignment
5425 -- If explicit Object_Size clause given assume that the programmer
5426 -- knows what he is doing, and expects the compiler behavior.
5430 -- Check for size not a multiple of alignment
5433 then
5434 declare
5440 begin
5443 -- Give a warning
5447 Error_Msg_NE
5454 else
5456 Error_Msg_NE
5470 -- Array type
5475 -- For a class-wide type, the corresponding specific type is
5476 -- frozen as well (RM 13.14(15))
5481 -- If the base type of the class-wide type is still incomplete,
5482 -- the class-wide remains unfrozen as well. This is legal when
5483 -- E is the formal of a primitive operation of some other type
5484 -- which is being frozen.
5492 -- The equivalent type associated with a class-wide subtype needs
5493 -- to be frozen to ensure that its layout is done.
5497 then
5501 -- Generate an itype reference for a library-level class-wide type
5502 -- at the freeze point. Otherwise the first explicit reference to
5503 -- the type may appear in an inner scope which will be rejected by
5504 -- the back-end.
5508 then
5509 declare
5512 begin
5515 -- From a gigi point of view, a class-wide subtype derives
5516 -- from its record equivalent type. As a result, the itype
5517 -- reference must appear after the freeze node of the
5518 -- equivalent type or gigi will reject the reference.
5522 then
5524 else
5530 -- For a record type or record subtype, freeze all component types
5531 -- (RM 13.14(15)). We test for E_Record_(sub)Type here, rather than
5532 -- using Is_Record_Type, because we don't want to attempt the freeze
5533 -- for the case of a private type with record extension (we will do
5534 -- that later when the full type is frozen).
5539 then
5542 -- For a concurrent type, freeze corresponding record type. This does
5543 -- not correspond to any specific rule in the RM, but the record type
5544 -- is essentially part of the concurrent type. Also freeze all local
5545 -- entities. This includes record types created for entry parameter
5546 -- blocks and whatever local entities may appear in the private part.
5560 -- The guard on the presence of the Etype seems to be needed
5561 -- for some CodePeer (-gnatcC) cases, but not clear why???
5566 then
5577 -- Private types are required to point to the same freeze node as
5578 -- their corresponding full views. The freeze node itself has to
5579 -- point to the partial view of the entity (because from the partial
5580 -- view, we can retrieve the full view, but not the reverse).
5581 -- However, in order to freeze correctly, we need to freeze the full
5582 -- view. If we are freezing at the end of a scope (or within the
5583 -- scope) of the private type, the partial and full views will have
5584 -- been swapped, the full view appears first in the entity chain and
5585 -- the swapping mechanism ensures that the pointers are properly set
5586 -- (on scope exit).
5588 -- If we encounter the partial view before the full view (e.g. when
5589 -- freezing from another scope), we freeze the full view, and then
5590 -- set the pointers appropriately since we cannot rely on swapping to
5591 -- fix things up (subtypes in an outer scope might not get swapped).
5593 -- If the full view is itself private, the above requirements apply
5594 -- to the underlying full view instead of the full view. But there is
5595 -- no swapping mechanism for the underlying full view so we need to
5596 -- set the pointers appropriately in both cases.
5600 then
5601 -- The construction of the dispatch table associated with library
5602 -- level tagged types forces freezing of all the primitives of the
5603 -- type, which may cause premature freezing of the partial view.
5604 -- For example:
5606 -- package Pkg is
5607 -- type T is tagged private;
5608 -- type DT is new T with private;
5609 -- procedure Prim (X : in out T; Y : in out DT'Class);
5610 -- private
5611 -- type T is tagged null record;
5612 -- Obj : T;
5613 -- type DT is new T with null record;
5614 -- end;
5616 -- In this case the type will be frozen later by the usual
5617 -- mechanism: an object declaration, an instantiation, or the
5618 -- end of a declarative part.
5622 then
5627 -- Case of full view present
5631 -- If full view has already been frozen, then no further
5632 -- processing is required
5638 -- Otherwise freeze full view and patch the pointers so that
5639 -- the freeze node will elaborate both views in the back end.
5640 -- However, if full view is itself private, freeze underlying
5641 -- full view instead and patch the pointers so that the freeze
5642 -- node will elaborate the three views in the back end.
5644 else
5645 declare
5648 begin
5651 then
5659 then
5666 else
5679 else
5680 -- {Incomplete,Private}_Subtypes with Full_Views
5681 -- constrained by discriminants.
5692 -- AI-117 requires that the convention of a partial view be the
5693 -- same as the convention of the full view. Note that this is a
5694 -- recognized breach of privacy, but it's essential for logical
5695 -- consistency of representation, and the lack of a rule in
5696 -- RM95 was an oversight.
5703 -- Size information is copied from the full view to the
5704 -- incomplete or private view for consistency.
5706 -- We skip this is the full view is not a type. This is very
5707 -- strange of course, and can only happen as a result of
5708 -- certain illegalities, such as a premature attempt to derive
5709 -- from an incomplete type.
5719 -- Case of underlying full view present
5723 then
5728 -- Patch the pointers so that the freeze node will elaborate
5729 -- both views in the back end.
5738 else
5749 -- Case of no full view present. If entity is derived or subtype,
5750 -- it is safe to freeze, correctness depends on the frozen status
5751 -- of parent. Otherwise it is either premature usage, or a Taft
5752 -- amendment type, so diagnosis is at the point of use and the
5753 -- type might be frozen later.
5758 else
5764 -- For access subprogram, freeze types of all formals, the return
5765 -- type was already frozen, since it is the Etype of the function.
5766 -- Formal types can be tagged Taft amendment types, but otherwise
5767 -- they cannot be incomplete.
5774 then
5778 -- AI05-151: Incomplete types are allowed in access to
5779 -- subprogram specifications.
5782 Error_Msg_NE
5793 -- For access to a protected subprogram, freeze the equivalent type
5794 -- (however this is not set if we are not generating code or if this
5795 -- is an anonymous type used just for resolution).
5803 -- Generic types are never seen by the back-end, and are also not
5804 -- processed by the expander (since the expander is turned off for
5805 -- generic processing), so we never need freeze nodes for them.
5812 -- Some special processing for non-generic types to complete
5813 -- representation details not known till the freeze point.
5818 -- Some error checks required for ordinary fixed-point type. Defer
5819 -- these till the freeze-point since we need the small and range
5820 -- values. We only do these checks for base types
5825 Error_Msg_N
5830 Error_Msg_N
5836 Error_Msg_N
5842 Error_Msg_N
5854 and then Warn_On_Suspicious_Modulus_Value
5855 then
5859 -- The pool applies to named and anonymous access types, but not
5860 -- to subprogram and to internal types generated for 'Access
5861 -- references.
5866 then
5867 -- If a pragma Default_Storage_Pool applies, and this type has no
5868 -- Storage_Pool or Storage_Size clause (which must have occurred
5869 -- before the freezing point), then use the default. This applies
5870 -- only to base types.
5872 -- None of this applies to access to subprograms, for which there
5873 -- are clearly no pools.
5879 then
5880 -- Case of pragma Default_Storage_Pool (null)
5885 -- Case of pragma Default_Storage_Pool (storage_pool_NAME)
5887 else
5892 -- Check restriction for standard storage pool
5898 -- Deal with error message for pure access type. This is not an
5899 -- error in Ada 2005 if there is no pool (see AI-366).
5905 then
5909 Error_Msg_N
5913 Error_Msg_N
5916 else
5917 Error_Msg_N
5924 -- Case of composite types
5928 -- AI-117 requires that all new primitives of a tagged type must
5929 -- inherit the convention of the full view of the type. Inherited
5930 -- and overriding operations are defined to inherit the convention
5931 -- of their parent or overridden subprogram (also specified in
5932 -- AI-117), which will have occurred earlier (in Derive_Subprogram
5933 -- and New_Overloaded_Entity). Here we set the convention of
5934 -- primitives that are still convention Ada, which will ensure
5935 -- that any new primitives inherit the type's convention. Class-
5936 -- wide types can have a foreign convention inherited from their
5937 -- specific type, but are excluded from this since they don't have
5938 -- any associated primitives.
5943 then
5944 declare
5948 begin
5960 -- If the type is a simple storage pool type, then this is where
5961 -- we attempt to locate and validate its Allocate, Deallocate, and
5962 -- Storage_Size operations (the first is required, and the latter
5963 -- two are optional). We also verify that the full type for a
5964 -- private type is allowed to be a simple storage pool type.
5968 then
5969 -- If the type is marked Has_Private_Declaration, then this is
5970 -- a full type for a private type that was specified with the
5971 -- pragma Simple_Storage_Pool_Type, and here we ensure that the
5972 -- pragma is allowed for the full type (for example, it can't
5973 -- be an array type, or a nonlimited record type).
5978 then
5980 Error_Msg_N
5991 procedure Validate_Simple_Pool_Op_Formal
5998 -- Validate one formal Pool_Op_Formal of the candidate pool
5999 -- operation Pool_Op. The formal must be of Expected_Type
6000 -- and have mode Expected_Mode. OK_Formal will be set to
6001 -- False if the formal doesn't match. If OK_Formal is False
6002 -- on entry, then the formal will effectively be ignored
6003 -- (because validation of the pool op has already failed).
6004 -- Upon return, Pool_Op_Formal will be updated to the next
6005 -- formal, if any.
6007 procedure Validate_Simple_Pool_Operation
6009 -- Search for and validate a simple pool operation with the
6010 -- name Op_Name. If the name is Allocate, then there must be
6011 -- exactly one such primitive operation for the simple pool
6012 -- type. If the name is Deallocate or Storage_Size, then
6013 -- there can be at most one such primitive operation. The
6014 -- profile of the located primitive must conform to what
6015 -- is expected for each operation.
6017 ------------------------------------
6018 -- Validate_Simple_Pool_Op_Formal --
6019 ------------------------------------
6021 procedure Validate_Simple_Pool_Op_Formal
6028 is
6029 begin
6030 -- If OK_Formal is False on entry, then simply ignore
6031 -- the formal, because an earlier formal has already
6032 -- been flagged.
6037 -- If no formal is passed in, then issue an error for a
6038 -- missing formal.
6041 Error_Msg_NE
6051 -- If the pool type was expected for this formal, then
6052 -- this will not be considered a candidate operation
6053 -- for the simple pool, so we unset OK_Formal so that
6054 -- the op and any later formals will be ignored.
6061 else
6062 Error_Msg_NE
6069 -- Issue error if formal's mode is not the expected one
6072 Error_Msg_N
6074 Pool_Op_Formal);
6077 -- Advance to the next formal
6082 ------------------------------------
6083 -- Validate_Simple_Pool_Operation --
6084 ------------------------------------
6086 procedure Validate_Simple_Pool_Operation
6088 is
6094 begin
6095 pragma Assert
6097 Name_Deallocate,
6098 Name_Storage_Size));
6102 -- For each homonym declared immediately in the scope
6103 -- of the simple storage pool type, determine whether
6104 -- the homonym is an operation of the pool type, and,
6105 -- if so, check that its profile is as expected for
6106 -- a simple pool operation of that name.
6112 then
6117 -- The first parameter must be of the pool type
6118 -- in order for the operation to qualify.
6121 Validate_Simple_Pool_Op_Formal
6124 else
6125 Validate_Simple_Pool_Op_Formal
6130 -- If another operation with this name has already
6131 -- been located for the type, then flag an error,
6132 -- since we only allow the type to have a single
6133 -- such primitive.
6136 Error_Msg_NE
6141 -- In the case of Allocate and Deallocate, a formal
6142 -- of type System.Address is required.
6145 Validate_Simple_Pool_Op_Formal
6150 Validate_Simple_Pool_Op_Formal
6155 -- In the case of Allocate and Deallocate, formals
6156 -- of type Storage_Count are required as the third
6157 -- and fourth parameters.
6160 Validate_Simple_Pool_Op_Formal
6163 Validate_Simple_Pool_Op_Formal
6168 -- If no mismatched formals have been found (Is_OK)
6169 -- and no excess formals are present, then this
6170 -- operation has been validated, so record it.
6180 -- There must be a valid Allocate operation for the type,
6181 -- so issue an error if none was found.
6185 then
6191 -- Simple pool operations can't be abstract
6194 Error_Msg_N
6199 -- The Storage_Size operation must be a function with
6200 -- Storage_Count as its result type.
6204 Error_Msg_N
6208 Error_Msg_NE
6213 -- Allocate and Deallocate must be procedures
6216 Error_Msg_N
6222 -- Start of processing for Validate_Simple_Pool_Ops
6224 begin
6232 -- Now that all types from which E may depend are frozen, see if the
6233 -- size is known at compile time, if it must be unsigned, or if
6234 -- strict alignment is required
6243 -- Do not allow a size clause for a type which does not have a size
6244 -- that is known at compile time
6248 then
6249 -- Suppress this message if errors posted on E, even if we are
6250 -- in all errors mode, since this is often a junk message
6253 Error_Msg_N
6259 -- Now we set/verify the representation information, in particular
6260 -- the size and alignment values. This processing is not required for
6261 -- generic types, since generic types do not play any part in code
6262 -- generation, and so the size and alignment values for such types
6263 -- are irrelevant. Ditto for types declared within a generic unit,
6264 -- which may have components that depend on generic parameters, and
6265 -- that will be recreated in an instance.
6270 -- Otherwise we call the layout procedure
6272 else
6276 -- If this is an access to subprogram whose designated type is itself
6277 -- a subprogram type, the return type of this anonymous subprogram
6278 -- type must be decorated as well.
6282 then
6286 -- If the type has a Defaut_Value/Default_Component_Value aspect,
6287 -- this is where we analye the expression (after the type is frozen,
6288 -- since in the case of Default_Value, we are analyzing with the
6289 -- type itself, and we treat Default_Component_Value similarly for
6290 -- the sake of uniformity).
6293 declare
6298 begin
6303 else
6314 Flag_Non_Static_Expr
6321 -- End of freeze processing for type entities
6324 -- Here is where we logically freeze the current entity. If it has a
6325 -- freeze node, then this is the point at which the freeze node is
6326 -- linked into the result list.
6330 -- If a freeze node is already allocated, use it, otherwise allocate
6331 -- a new one. The preallocation happens in the case of anonymous base
6332 -- types, where we preallocate so that we can set First_Subtype_Link.
6333 -- Note that we reset the Sloc to the current freeze location.
6339 else
6350 -- A final pass over record types with discriminants. If the type
6351 -- has an incomplete declaration, there may be constrained access
6352 -- subtypes declared elsewhere, which do not depend on the discrimi-
6353 -- nants of the type, and which are used as component types (i.e.
6354 -- the full view is a recursive type). The designated types of these
6355 -- subtypes can only be elaborated after the type itself, and they
6356 -- need an itype reference.
6359 declare
6364 begin
6374 then
6386 -- When a type is frozen, the first subtype of the type is frozen as
6387 -- well (RM 13.14(15)). This has to be done after freezing the type,
6388 -- since obviously the first subtype depends on its own base type.
6393 -- If we just froze a tagged non-class wide record, then freeze the
6394 -- corresponding class-wide type. This must be done after the tagged
6395 -- type itself is frozen, because the class-wide type refers to the
6396 -- tagged type which generates the class.
6401 then
6408 -- Special handling for subprograms
6412 -- If subprogram has address clause then reset Is_Public flag, since
6413 -- we do not want the backend to generate external references.
6417 then
6426 -----------------------------
6427 -- Freeze_Enumeration_Type --
6428 -----------------------------
6431 begin
6432 -- By default, if no size clause is present, an enumeration type with
6433 -- Convention C is assumed to interface to a C enum, and has integer
6434 -- size. This applies to types. For subtypes, verify that its base
6435 -- type has no size clause either. Treat other foreign conventions
6436 -- in the same way, and also make sure alignment is set right.
6443 -- Don't do this if Short_Enums on target
6445 and then not Target_Short_Enums
6446 then
6450 -- Normal Ada case or size clause present or not Long_C_Enums on target
6452 else
6453 -- If the enumeration type interfaces to C, and it has a size clause
6454 -- that specifies less than int size, it warrants a warning. The
6455 -- user may intend the C type to be an enum or a char, so this is
6456 -- not by itself an error that the Ada compiler can detect, but it
6457 -- it is a worth a heads-up. For Boolean and Character types we
6458 -- assume that the programmer has the proper C type in mind.
6466 -- Don't do this if Short_Enums on target
6468 and then not Target_Short_Enums
6469 then
6470 Error_Msg_N
6478 -----------------------
6479 -- Freeze_Expression --
6480 -----------------------
6491 -- This flag is set true if the entity must be frozen outside the
6492 -- current subprogram. This happens in the case of expander generated
6493 -- subprograms (_Init_Proc, _Input, _Output, _Read, _Write) which do
6494 -- not freeze all entities like other bodies, but which nevertheless
6495 -- may reference entities that have to be frozen before the body and
6496 -- obviously cannot be frozen inside the body.
6499 -- If the expression is an array aggregate, the type of the component
6500 -- expressions is also frozen. If the component type is an access type
6501 -- and the expressions include allocators, the designed type is frozen
6502 -- as well.
6505 -- Given an N_Handled_Sequence_Of_Statements node N, determines whether
6506 -- it is the handled statement sequence of an expander-generated
6507 -- subprogram (init proc, stream subprogram, or renaming as body).
6508 -- If so, this is not a freezing context.
6510 -----------------------------------------
6511 -- Find_Aggregate_Component_Desig_Type --
6512 -----------------------------------------
6518 begin
6544 ----------------------
6545 -- In_Expanded_Body --
6546 ----------------------
6552 begin
6555 else
6562 else
6565 -- The following are expander-created bodies, or bodies that
6566 -- are not freeze points.
6575 N_Subprogram_Renaming_Declaration,
6576 N_Expression_Function))
6577 then
6579 else
6585 -- Start of processing for Freeze_Expression
6587 begin
6588 -- Immediate return if freezing is inhibited. This flag is set by the
6589 -- analyzer to stop freezing on generated expressions that would cause
6590 -- freezing if they were in the source program, but which are not
6591 -- supposed to freeze, since they are created.
6597 -- If expression is non-static, then it does not freeze in a default
6598 -- expression, see section "Handling of Default Expressions" in the
6599 -- spec of package Sem for further details. Note that we have to make
6600 -- sure that we actually have a real expression (if we have a subtype
6601 -- indication, we can't test Is_OK_Static_Expression). However, we
6602 -- exclude the case of the prefix of an attribute of a static scalar
6603 -- subtype from this early return, because static subtype attributes
6604 -- should always cause freezing, even in default expressions, but
6605 -- the attribute may not have been marked as static yet (because in
6606 -- Resolve_Attribute, the call to Eval_Attribute follows the call of
6607 -- Freeze_Expression on the prefix).
6609 if In_Spec_Exp
6616 then
6620 -- Freeze type of expression if not frozen already
6628 -- Base type may be an derived numeric type that is frozen at
6629 -- the point of declaration, but first_subtype is still unfrozen.
6636 -- For entity name, freeze entity if not frozen already. A special
6637 -- exception occurs for an identifier that did not come from source.
6638 -- We don't let such identifiers freeze a non-internal entity, i.e.
6639 -- an entity that did come from source, since such an identifier was
6640 -- generated by the expander, and cannot have any semantic effect on
6641 -- the freezing semantics. For example, this stops the parameter of
6642 -- an initialization procedure from freezing the variable.
6649 then
6656 else
6660 -- For an allocator freeze designated type if not frozen already
6662 -- For an aggregate whose component type is an access type, freeze the
6663 -- designated type now, so that its freeze does not appear within the
6664 -- loop that might be created in the expansion of the aggregate. If the
6665 -- designated type is a private type without full view, the expression
6666 -- cannot contain an allocator, so the type is not frozen.
6668 -- For a function, we freeze the entity when the subprogram declaration
6669 -- is frozen, but a function call may appear in an initialization proc.
6670 -- before the declaration is frozen. We need to generate the extra
6671 -- formals, if any, to ensure that the expansion of the call includes
6672 -- the proper actuals. This only applies to Ada subprograms, not to
6673 -- imported ones.
6684 then
6686 -- Check whether aggregate includes allocators.
6691 when N_Selected_Component |
6692 N_Indexed_Component |
6693 N_Slice =>
6704 then
6715 then
6719 -- All done if nothing needs freezing
6724 then
6728 -- Examine the enclosing context by climbing the parent chain. The
6729 -- traversal serves two purposes - to detect scenarios where freezeing
6730 -- is not needed and to find the proper insertion point for the freeze
6731 -- nodes. Although somewhat similar to Insert_Actions, this traversal
6732 -- is freezing semantics-sensitive. Inserting freeze nodes blindly in
6733 -- the tree may result in types being frozen too early.
6736 loop
6739 -- If we don't have a parent, then we are not in a well-formed tree.
6740 -- This is an unusual case, but there are some legitimate situations
6741 -- in which this occurs, notably when the expressions in the range of
6742 -- a type declaration are resolved. We simply ignore the freeze
6743 -- request in this case. Is this right ???
6749 -- See if we have got to an appropriate point in the tree
6753 -- A special test for the exception of (RM 13.14(8)) for the case
6754 -- of per-object expressions (RM 3.8(18)) occurring in component
6755 -- definition or a discrete subtype definition. Note that we test
6756 -- for a component declaration which includes both cases we are
6757 -- interested in, and furthermore the tree does not have explicit
6758 -- nodes for either of these two constructs.
6762 -- The case we want to test for here is an identifier that is
6763 -- a per-object expression, this is either a discriminant that
6764 -- appears in a context other than the component declaration
6765 -- or it is a reference to the type of the enclosing construct.
6767 -- For either of these cases, we skip the freezing
6769 if not In_Spec_Expression
6772 then
6773 -- We recognize the discriminant case by just looking for
6774 -- a reference to a discriminant. It can only be one for
6775 -- the enclosing construct. Skip freezing in this case.
6780 -- For the case of a reference to the enclosing record,
6781 -- (or task or protected type), we look for a type that
6782 -- matches the current scope.
6789 -- If we have an enumeration literal that appears as the choice in
6790 -- the aggregate of an enumeration representation clause, then
6791 -- freezing does not occur (RM 13.14(10)).
6795 -- The case we are looking for is an enumeration literal
6799 then
6800 -- If enumeration literal appears directly as the choice,
6801 -- do not freeze (this is the normal non-overloaded case)
6805 then
6808 -- If enumeration literal appears as the name of function
6809 -- which is the choice, then also do not freeze. This
6810 -- happens in the overloaded literal case, where the
6811 -- enumeration literal is temporarily changed to a function
6812 -- call for overloading analysis purposes.
6815 and then
6817 and then
6819 then
6824 -- Normally if the parent is a handled sequence of statements,
6825 -- then the current node must be a statement, and that is an
6826 -- appropriate place to insert a freeze node.
6830 -- An exception occurs when the sequence of statements is for
6831 -- an expander generated body that did not do the usual freeze
6832 -- all operation. In this case we usually want to freeze
6833 -- outside this body, not inside it, and we skip past the
6834 -- subprogram body that we are inside.
6837 declare
6841 begin
6842 -- Freeze the entity only when it is declared inside the
6843 -- body of the expander generated procedure. This case
6844 -- is recognized by the scope of the entity or its type,
6845 -- which is either the spec for some enclosing body, or
6846 -- (in the case of init_procs, for which there are no
6847 -- separate specs) the current scope.
6853 or else
6855 then
6861 then
6866 -- An expression function may act as a completion of
6867 -- a function declaration. As such, it can reference
6868 -- entities declared between the two views:
6870 -- Hidden []; -- 1
6871 -- function F return ...;
6872 -- private
6873 -- function Hidden return ...;
6874 -- function F return ... is (Hidden); -- 2
6876 -- Refering to the example above, freezing the expression
6877 -- of F (2) would place Hidden's freeze node (1) in the
6878 -- wrong place. Avoid explicit freezing and let the usual
6879 -- scenarios do the job - for example, reaching the end
6880 -- of the private declarations, or a call to F.
6883 N_Expression_Function
6884 then
6887 -- Freeze outside the body
6889 else
6895 -- Here if normal case where we are in handled statement
6896 -- sequence and want to do the insertion right there.
6898 else
6902 -- If parent is a body or a spec or a block, then the current node
6903 -- is a statement or declaration and we can insert the freeze node
6904 -- before it.
6906 when N_Block_Statement |
6907 N_Entry_Body |
6908 N_Package_Body |
6909 N_Package_Specification |
6910 N_Protected_Body |
6911 N_Subprogram_Body |
6914 -- The expander is allowed to define types in any statements list,
6915 -- so any of the following parent nodes also mark a freezing point
6916 -- if the actual node is in a list of statements or declarations.
6918 when N_Abortable_Part |
6919 N_Accept_Alternative |
6920 N_And_Then |
6921 N_Case_Statement_Alternative |
6922 N_Compilation_Unit_Aux |
6923 N_Conditional_Entry_Call |
6924 N_Delay_Alternative |
6925 N_Elsif_Part |
6926 N_Entry_Call_Alternative |
6927 N_Exception_Handler |
6928 N_Extended_Return_Statement |
6929 N_Freeze_Entity |
6930 N_If_Statement |
6931 N_Or_Else |
6932 N_Selective_Accept |
6933 N_Triggering_Alternative =>
6937 -- Freeze nodes produced by an expression coming from the Actions
6938 -- list of a N_Expression_With_Actions node must remain within the
6939 -- Actions list. Inserting the freeze nodes further up the tree
6940 -- may lead to use before declaration issues in the case of array
6941 -- types.
6946 then
6950 -- Note: N_Loop_Statement is a special case. A type that appears
6951 -- in the source can never be frozen in a loop (this occurs only
6952 -- because of a loop expanded by the expander), so we keep on
6953 -- going. Otherwise we terminate the search. Same is true of any
6954 -- entity which comes from source. (if they have predefined type,
6955 -- that type does not appear to come from source, but the entity
6956 -- should not be frozen here).
6962 -- For all other cases, keep looking at parents
6968 -- We fall through the case if we did not yet find the proper
6969 -- place in the free for inserting the freeze node, so climb.
6974 -- If the expression appears in a record or an initialization procedure,
6975 -- the freeze nodes are collected and attached to the current scope, to
6976 -- be inserted and analyzed on exit from the scope, to insure that
6977 -- generated entities appear in the correct scope. If the expression is
6978 -- a default for a discriminant specification, the scope is still void.
6979 -- The expression can also appear in the discriminant part of a private
6980 -- or concurrent type.
6982 -- If the expression appears in a constrained subcomponent of an
6983 -- enclosing record declaration, the freeze nodes must be attached to
6984 -- the outer record type so they can eventually be placed in the
6985 -- enclosing declaration list.
6987 -- The other case requiring this special handling is if we are in a
6988 -- default expression, since in that case we are about to freeze a
6989 -- static type, and the freeze scope needs to be the outer scope, not
6990 -- the scope of the subprogram with the default parameter.
6992 -- For default expressions and other spec expressions in generic units,
6993 -- the Move_Freeze_Nodes mechanism (see sem_ch12.adb) takes care of
6994 -- placing them at the proper place, after the generic unit.
6997 or else Freeze_Outside
7002 then
7003 declare
7008 begin
7021 -- The current scope may be that of a constrained component of
7022 -- an enclosing record declaration, or of a loop of an enclosing
7023 -- quantified expression, which is above the current scope in the
7024 -- scope stack. Indeed in the context of a quantified expression,
7025 -- a scope is created and pushed above the current scope in order
7026 -- to emulate the loop-like behavior of the quantified expression.
7027 -- If the expression is within a top-level pragma, as for a pre-
7028 -- condition on a library-level subprogram, nothing to do.
7033 N_Quantified_Expression)
7034 then
7041 Freeze_Nodes;
7042 else
7052 -- Now we have the right place to do the freezing. First, a special
7053 -- adjustment, if we are in spec-expression analysis mode, these freeze
7054 -- actions must not be thrown away (normally all inserted actions are
7055 -- thrown away in this mode. However, the freeze actions are from static
7056 -- expressions and one of the important reasons we are doing this
7057 -- special analysis is to get these freeze actions. Therefore we turn
7058 -- off the In_Spec_Expression mode to propagate these freeze actions.
7059 -- This also means they get properly analyzed and expanded.
7063 -- Freeze the designated type of an allocator (RM 13.14(13))
7069 -- Freeze type of expression (RM 13.14(10)). Note that we took care of
7070 -- the enumeration representation clause exception in the loop above.
7076 -- Freeze name if one is present (RM 13.14(11))
7082 -- Restore In_Spec_Expression flag
7087 -----------------------------
7088 -- Freeze_Fixed_Point_Type --
7089 -----------------------------
7091 -- Certain fixed-point types and subtypes, including implicit base types
7092 -- and declared first subtypes, have not yet set up a range. This is
7093 -- because the range cannot be set until the Small and Size values are
7094 -- known, and these are not known till the type is frozen.
7096 -- To signal this case, Scalar_Range contains an unanalyzed syntactic range
7097 -- whose bounds are unanalyzed real literals. This routine will recognize
7098 -- this case, and transform this range node into a properly typed range
7099 -- with properly analyzed and resolved values.
7116 -- Save original bounds (for shaving tests)
7119 -- Actual size chosen
7122 -- Returns size of type with given bounds. Also leaves these
7123 -- bounds set as the current bounds of the Typ.
7125 -----------
7126 -- Fsize --
7127 -----------
7130 begin
7136 -- Start of processing for Freeze_Fixed_Point_Type
7138 begin
7139 -- If Esize of a subtype has not previously been set, set it now
7146 else
7151 -- Immediate return if the range is already analyzed. This means that
7152 -- the range is already set, and does not need to be computed by this
7153 -- routine.
7159 -- Immediate return if either of the bounds raises Constraint_Error
7163 then
7173 -- Ordinary fixed-point case
7177 -- For the ordinary fixed-point case, we are allowed to fudge the
7178 -- end-points up or down by small. Generally we prefer to fudge up,
7179 -- i.e. widen the bounds for non-model numbers so that the end points
7180 -- are included. However there are cases in which this cannot be
7181 -- done, and indeed cases in which we may need to narrow the bounds.
7182 -- The following circuit makes the decision.
7184 -- Note: our terminology here is that Incl_EP means that the bounds
7185 -- are widened by Small if necessary to include the end points, and
7186 -- Excl_EP means that the bounds are narrowed by Small to exclude the
7187 -- end-points if this reduces the size.
7189 -- Note that in the Incl case, all we care about is including the
7190 -- end-points. In the Excl case, we want to narrow the bounds as
7191 -- much as permitted by the RM, to give the smallest possible size.
7208 begin
7209 -- First step. Base types are required to be symmetrical. Right
7210 -- now, the base type range is a copy of the first subtype range.
7211 -- This will be corrected before we are done, but right away we
7212 -- need to deal with the case where both bounds are non-negative.
7213 -- In this case, we set the low bound to the negative of the high
7214 -- bound, to make sure that the size is computed to include the
7215 -- required sign. Note that we do not need to worry about the
7216 -- case of both bounds negative, because the sign will be dealt
7217 -- with anyway. Furthermore we can't just go making such a bound
7218 -- symmetrical, since in a twos-complement system, there is an
7219 -- extra negative value which could not be accommodated on the
7220 -- positive side.
7225 then
7230 -- Compute the fudged bounds. If the number is a model number,
7231 -- then we do nothing to include it, but we are allowed to backoff
7232 -- to the next adjacent model number when we exclude it. If it is
7233 -- not a model number then we straddle the two values with the
7234 -- model numbers on either side.
7240 else
7244 -- The low value excluding the end point is Small greater, but
7245 -- we do not do this exclusion if the low value is positive,
7246 -- since it can't help the size and could actually hurt by
7247 -- crossing the high bound.
7252 -- If the value went from negative to zero, then we have the
7253 -- case where Loval_Incl_EP is the model number just below
7254 -- zero, so we want to stick to the negative value for the
7255 -- base type to maintain the condition that the size will
7256 -- include signed values.
7260 then
7264 else
7268 -- Similar processing for upper bound and high value
7274 else
7280 else
7284 -- One further adjustment is needed. In the case of subtypes, we
7285 -- cannot go outside the range of the base type, or we get
7286 -- peculiarities, and the base type range is already set. This
7287 -- only applies to the Incl values, since clearly the Excl values
7288 -- are already as restricted as they are allowed to be.
7295 -- Get size including and excluding end points
7300 -- No need to exclude end-points if it does not reduce size
7310 -- Now we set the actual size to be used. We want to use the
7311 -- bounds fudged up to include the end-points but only if this
7312 -- can be done without violating a specifically given size
7313 -- size clause or causing an unacceptable increase in size.
7315 -- Case of size clause given
7319 -- Use the inclusive size only if it is consistent with
7320 -- the explicitly specified size.
7327 -- If the inclusive size is too large, we try excluding
7328 -- the end-points (will be caught later if does not work).
7330 else
7336 -- Case of size clause not given
7338 else
7339 -- If we have a base type whose corresponding first subtype
7340 -- has an explicit size that is large enough to include our
7341 -- end-points, then do so. There is no point in working hard
7342 -- to get a base type whose size is smaller than the specified
7343 -- size of the first subtype.
7349 then
7354 -- If excluding the end-points makes the size smaller and
7355 -- results in a size of 8,16,32,64, then we take the smaller
7356 -- size. For the 64 case, this is compulsory. For the other
7357 -- cases, it seems reasonable. We like to include end points
7358 -- if we can, but not at the expense of moving to the next
7359 -- natural boundary of size.
7363 then
7368 -- Otherwise we can definitely include the end points
7370 else
7376 -- One pathological case: normally we never fudge a low bound
7377 -- down, since it would seem to increase the size (if it has
7378 -- any effect), but for ranges containing single value, or no
7379 -- values, the high bound can be small too large. Consider:
7381 -- type t is delta 2.0**(-14)
7382 -- range 131072.0 .. 0;
7384 -- That lower bound is *just* outside the range of 32 bits, and
7385 -- does need fudging down in this case. Note that the bounds
7386 -- will always have crossed here, since the high bound will be
7387 -- fudged down if necessary, as in the case of:
7389 -- type t is delta 2.0**(-14)
7390 -- range 131072.0 .. 131072.0;
7392 -- So we detect the situation by looking for crossed bounds,
7393 -- and if the bounds are crossed, and the low bound is greater
7394 -- than zero, we will always back it off by small, since this
7395 -- is completely harmless.
7402 -- And of course, we need to do exactly the same parallel
7403 -- fudge for flat ranges in the negative region.
7416 -- For the decimal case, none of this fudging is required, since there
7417 -- are no end-point problems in the decimal case (the end-points are
7418 -- always included).
7420 else
7424 -- At this stage, the actual size has been calculated and the proper
7425 -- required bounds are stored in the low and high bounds.
7429 Error_Msg_N
7431 Typ);
7435 -- Check size against explicit given size
7441 Error_Msg_NE
7445 else
7449 -- Increase size to next natural boundary if no size clause given
7451 else
7458 else
7466 -- If we have a base type, then expand the bounds so that they extend to
7467 -- the full width of the allocated size in bits, to avoid junk range
7468 -- checks on intermediate computations.
7475 -- Final step is to reanalyze the bounds using the proper type
7476 -- and set the Corresponding_Integer_Value fields of the literals.
7482 -- Resolve with universal fixed if the base type, and the base type if
7483 -- it is a subtype. Note we can't resolve the base type with itself,
7484 -- that would be a reference before definition.
7488 else
7492 -- Set corresponding integer value for bound
7494 Set_Corresponding_Integer_Value
7497 -- Similar processing for high bound
7505 else
7509 Set_Corresponding_Integer_Value
7512 -- Set type of range to correspond to bounds
7516 -- Set Esize to calculated size if not set already
7522 -- Set RM_Size if not already set. If already set, check value
7524 declare
7527 begin
7532 Error_Msg_NE
7537 else
7542 -- Check for shaving
7546 Error_Msg_N
7548 Error_Msg_N
7553 Error_Msg_N
7555 Error_Msg_N
7561 ------------------
7562 -- Freeze_Itype --
7563 ------------------
7568 begin
7577 --------------------------
7578 -- Freeze_Static_Object --
7579 --------------------------
7584 -- Exception raised if the type of a static object cannot be made
7585 -- static. This happens if the type depends on non-global objects.
7588 -- Called to ensure that an expression used as part of a type definition
7589 -- is statically allocatable, which means that the expression type is
7590 -- statically allocatable, and the expression is either static, or a
7591 -- reference to a library level constant.
7594 -- Called to mark a type as static, checking that it is possible
7595 -- to set the type as static. If it is not possible, then the
7596 -- exception Cannot_Be_Static is raised.
7598 -----------------------------
7599 -- Ensure_Expression_Is_SA --
7600 -----------------------------
7605 begin
7617 then
7625 -----------------------
7626 -- Ensure_Type_Is_SA --
7627 -----------------------
7633 begin
7634 -- If type is library level, we are all set
7640 -- We are also OK if the type already marked as statically allocated,
7641 -- which means we processed it before.
7647 -- Mark type as statically allocated
7651 -- Check that it is safe to statically allocate this type
7669 declare
7673 begin
7685 else
7694 then
7713 else
7718 -- Start of processing for Freeze_Static_Object
7720 begin
7723 exception
7726 -- If the object that cannot be static is imported or exported, then
7727 -- issue an error message saying that this object cannot be imported
7728 -- or exported. If it has an address clause it is an overlay in the
7729 -- current partition and the static requirement is not relevant.
7730 -- Do not issue any error message when ignoring rep clauses.
7737 Error_Msg_N
7741 -- Otherwise must be exported, something is wrong if compiler
7742 -- is marking something as statically allocated which cannot be).
7745 Error_Msg_N
7750 -----------------------
7751 -- Freeze_Subprogram --
7752 -----------------------
7758 begin
7759 -- Subprogram may not have an address clause unless it is imported
7763 Error_Msg_N
7770 -- Reset the Pure indication on an imported subprogram unless an
7771 -- explicit Pure_Function pragma was present or the subprogram is an
7772 -- intrinsic. We do this because otherwise it is an insidious error
7773 -- to call a non-pure function from pure unit and have calls
7774 -- mysteriously optimized away. What happens here is that the Import
7775 -- can bypass the normal check to ensure that pure units call only pure
7776 -- subprograms.
7778 -- The reason for the intrinsic exception is that in general, intrinsic
7779 -- functions (such as shifts) are pure anyway. The only exceptions are
7780 -- the intrinsics in GNAT.Source_Info, and that unit is not marked Pure
7781 -- in any case, so no problem arises.
7787 then
7791 -- We also reset the Pure indication on a subprogram with an Address
7792 -- parameter, because the parameter may be used as a pointer and the
7793 -- referenced data may change even if the address value does not.
7795 -- Note that if the programmer gave an explicit Pure_Function pragma,
7796 -- then we believe the programmer, and leave the subprogram Pure.
7797 -- We also suppress this check on run-time files.
7803 then
7807 -- For non-foreign convention subprograms, this is where we create
7808 -- the extra formals (for accessibility level and constrained bit
7809 -- information). We delay this till the freeze point precisely so
7810 -- that we know the convention.
7816 -- If this is convention Ada and a Valued_Procedure, that's odd
7821 and then Warn_On_Export_Import
7822 then
7823 Error_Msg_N
7828 -- Case of foreign convention
7830 else
7833 -- For foreign conventions, warn about return of unconstrained array
7838 -- If no return type, probably some other error, e.g. a
7839 -- missing full declaration, so ignore.
7844 -- If the return type is generic, we have emitted a warning
7845 -- earlier on, and there is nothing else to check here. Specific
7846 -- instantiations may lead to erroneous behavior.
7851 -- Display warning if returning unconstrained array
7856 -- Check appropriate warning is enabled (should we check for
7857 -- Warnings (Off) on specific entities here, probably so???)
7859 and then Warn_On_Export_Import
7860 then
7861 Error_Msg_N
7868 -- If any of the formals for an exported foreign convention
7869 -- subprogram have defaults, then emit an appropriate warning since
7870 -- this is odd (default cannot be used from non-Ada code)
7875 if Warn_On_Export_Import
7877 then
7878 Error_Msg_N
7888 -- Pragma Inline_Always is disallowed for dispatching subprograms
7889 -- because the address of such subprograms is saved in the dispatch
7890 -- table to support dispatching calls, and dispatching calls cannot
7891 -- be inlined. This is consistent with the restriction against using
7892 -- 'Access or 'Address on an Inline_Always subprogram.
7896 then
7897 Error_Msg_N
7901 -- Because of the implicit representation of inherited predefined
7902 -- operators in the front-end, the overriding status of the operation
7903 -- may be affected when a full view of a type is analyzed, and this is
7904 -- not captured by the analysis of the corresponding type declaration.
7905 -- Therefore the correctness of a not-overriding indicator must be
7906 -- rechecked when the subprogram is frozen.
7910 then
7914 if Modify_Tree_For_C
7920 then
7925 ----------------------
7926 -- Is_Fully_Defined --
7927 ----------------------
7930 begin
7939 then
7940 -- Verify that the record type has no components with private types
7941 -- without completion.
7943 declare
7946 begin
7958 -- For the designated type of an access to subprogram, all types in
7959 -- the profile must be fully defined.
7962 declare
7965 begin
7978 else
7984 ---------------------------------
7985 -- Process_Default_Expressions --
7986 ---------------------------------
7988 procedure Process_Default_Expressions
7991 is
7998 begin
8001 -- A subprogram instance and its associated anonymous subprogram share
8002 -- their signature. The default expression functions are defined in the
8003 -- wrapper packages for the anonymous subprogram, and should not be
8004 -- generated again for the instance.
8009 then
8017 -- We work with a copy of the default expression because we
8018 -- do not want to disturb the original, since this would mess
8019 -- up the conformance checking.
8023 -- The analysis of the expression may generate insert actions,
8024 -- which of course must not be executed. We wrap those actions
8025 -- in a procedure that is not called, and later on eliminated.
8026 -- The following cases have no side-effects, and are analyzed
8027 -- directly.
8031 N_Integer_Literal,
8032 N_Character_Literal,
8033 N_String_Literal,
8034 N_Real_Literal)
8038 then
8039 -- If there is no default function, we must still do a full
8040 -- analyze call on the default value, to ensure that all error
8041 -- checks are performed, e.g. those associated with static
8042 -- evaluation. Note: this branch will always be taken if the
8043 -- analyzer is turned off (but we still need the error checks).
8045 -- Note: the setting of parent here is to meet the requirement
8046 -- that we can only analyze the expression while attached to
8047 -- the tree. Really the requirement is that the parent chain
8048 -- be set, we don't actually need to be in the tree.
8053 -- Default expressions are resolved with their own type if the
8054 -- context is generic, to avoid anomalies with private types.
8058 else
8062 -- If that resolved expression will raise constraint error,
8063 -- then flag the default value as raising constraint error.
8064 -- This allows a proper error message on the calls.
8070 -- If the default is a parameterless call, we use the name of
8071 -- the called function directly, and there is no body to build.
8075 then
8078 -- Else construct and analyze the body of a wrapper procedure
8079 -- that contains an object declaration to hold the expression.
8080 -- Given that this is done only to complete the analysis, it
8081 -- simpler to build a procedure than a function which might
8082 -- involve secondary stack expansion.
8084 else
8087 Dbody :=
8089 Specification =>
8096 Object_Definition =>
8100 Handled_Statement_Sequence =>
8117 ----------------------------------------
8118 -- Set_Component_Alignment_If_Not_Set --
8119 ----------------------------------------
8122 begin
8123 -- Ignore if not base type, subtypes don't need anything
8129 -- Do not override existing representation
8140 else
8141 Set_Component_Alignment
8147 --------------------------
8148 -- Set_SSO_From_Default --
8149 --------------------------
8154 begin
8155 -- Set default SSO for an array or record base type, except in case of
8156 -- a type extension (which always inherits the SSO of its parent type).
8163 then
8164 Reversed :=
8166 or else
8171 -- For a record type, if bit order is specified explicitly,
8172 -- then do not set SSO from default if not consistent. Note that
8173 -- we do not want to look at a Bit_Order attribute definition
8174 -- for a parent: if we were to inherit Bit_Order, then both
8175 -- SSO_Set_*_By_Default flags would have been cleared already
8176 -- (by Inherit_Aspects_At_Freeze_Point).
8178 and then not
8180 and then
8183 then
8184 -- If flags cause reverse storage order, then set the result. Note
8185 -- that we would have ignored the pragma setting the non default
8186 -- storage order in any case, hence the assertion at this point.
8188 pragma Assert
8193 -- For a record type, also set reversed bit order. Note: if a bit
8194 -- order has been specified explicitly, then this is a no-op.
8203 ------------------
8204 -- Undelay_Type --
8205 ------------------
8208 begin
8212 -- Since we don't want T to have a Freeze_Node, we don't want its
8213 -- Full_View or Corresponding_Record_Type to have one either.
8215 -- ??? Fundamentally, this whole handling is unpleasant. What we really
8216 -- want is to be sure that for an Itype that's part of record R and is a
8217 -- subtype of type T, that it's frozen after the later of the freeze
8218 -- points of R and T. We have no way of doing that directly, so what we
8219 -- do is force most such Itypes to be frozen as part of freezing R via
8220 -- this procedure and only delay the ones that need to be delayed
8221 -- (mostly the designated types of access types that are defined as part
8222 -- of the record).
8228 then
8236 then
8241 ------------------
8242 -- Warn_Overlay --
8243 ------------------
8247 -- The object to which the address clause applies
8253 begin
8254 -- No warning if address clause overlay warnings are off
8260 -- No warning if there is an explicit initialization
8268 -- We only give the warning for non-imported entities of a type for
8269 -- which a non-null base init proc is defined, or for objects of access
8270 -- types with implicit null initialization, or when Normalize_Scalars
8271 -- applies and the type is scalar or a string type (the latter being
8272 -- tested for because predefined String types are initialized by inline
8273 -- code rather than by an init_proc). Note that we do not give the
8274 -- warning for Initialize_Scalars, since we suppressed initialization
8275 -- in this case. Also, do not warn if Suppress_Initialization is set.
8285 then
8288 then
8293 then
8300 then
8307 -- A function call (most likely to To_Address) is probably not an
8308 -- overlay, so skip warning. Ditto if the function call was inlined
8309 -- and transformed into an entity.
8315 -- If a pragma Import follows, we assume that it is for the current
8316 -- target of the address clause, and skip the warning. There may be
8317 -- a source pragma or an aspect that specifies import and generates
8318 -- the corresponding pragma. These will indicate that the entity is
8319 -- imported and that is checked above so that the spurious warning
8320 -- (generated when the entity is frozen) will be suppressed. The
8321 -- pragma may be attached to the aspect, so it is not yet a list
8322 -- member.
8330 then
8335 -- Otherwise give warning message
8339 Error_Msg_N
8341 Nam);
8342 else
8343 Error_Msg_N
8345 Nam);
8348 -- Add friendly warning if initialization comes from a packed array
8349 -- component.
8352 declare
8355 begin
8360 then
8364 then
8365 Error_Msg_NE
8370 else
8377 Error_Msg_N
8380 Nam);