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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) 1992-2007, 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 2, 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 COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
21 -- --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 -- --
25 ------------------------------------------------------------------------------
66 -----------------------
67 -- Local Subprograms --
68 -----------------------
71 -- Typ is a type that is being frozen. If no size clause is given,
72 -- but a default Esize has been computed, then this default Esize is
73 -- adjusted up if necessary to be consistent with a given alignment,
74 -- but never to a value greater than Long_Long_Integer'Size. This
75 -- is used for all discrete types and for fixed-point types.
77 procedure Build_And_Analyze_Renamed_Body
81 -- Build body for a renaming declaration, insert in tree and analyze
84 -- Apply legality checks to address clauses for object declarations,
85 -- at the point the object is frozen.
88 -- E is a base type. If E is tagged or has a component that is aliased
89 -- or tagged or contains something this is aliased or tagged, set
90 -- Strict_Alignment.
94 -- If E is a fixed-point or discrete type, then all the necessary work
95 -- to freeze it is completed except for possible setting of the flag
96 -- Is_Unsigned_Type, which is done by this procedure. The call has no
97 -- effect if the entity E is not a discrete or fixed-point type.
99 procedure Freeze_And_Append
103 -- Freezes Ent using Freeze_Entity, and appends the resulting list of
104 -- nodes to Result, modifying Result from No_List if necessary.
107 -- Freeze enumeration type. The Esize field is set as processing
108 -- proceeds (i.e. set by default when the type is declared and then
109 -- adjusted by rep clauses. What this procedure does is to make sure
110 -- that if a foreign convention is specified, and no specific size
111 -- is given, then the size must be at least Integer'Size.
114 -- If an object is frozen which has Is_Statically_Allocated set, then
115 -- all referenced types must also be marked with this flag. This routine
116 -- is in charge of meeting this requirement for the object entity E.
119 -- Perform freezing actions for a subprogram (create extra formals,
120 -- and set proper default mechanism values). Note that this routine
121 -- is not called for internal subprograms, for which neither of these
122 -- actions is needed (or desirable, we do not want for example to have
123 -- these extra formals present in initialization procedures, where they
124 -- would serve no purpose). In this call E is either a subprogram or
125 -- a subprogram type (i.e. an access to a subprogram).
128 -- True if T is not private and has no private components, or has a full
129 -- view. Used to determine whether the designated type of an access type
130 -- should be frozen when the access type is frozen. This is done when an
131 -- allocator is frozen, or an expression that may involve attributes of
132 -- the designated type. Otherwise freezing the access type does not freeze
133 -- the designated type.
135 procedure Process_Default_Expressions
138 -- This procedure is called for each subprogram to complete processing
139 -- of default expressions at the point where all types are known to be
140 -- frozen. The expressions must be analyzed in full, to make sure that
141 -- all error processing is done (they have only been pre-analyzed). If
142 -- the expression is not an entity or literal, its analysis may generate
143 -- code which must not be executed. In that case we build a function
144 -- body to hold that code. This wrapper function serves no other purpose
145 -- (it used to be called to evaluate the default, but now the default is
146 -- inlined at each point of call).
149 -- Typ is a record or array type that is being frozen. This routine
150 -- sets the default component alignment from the scope stack values
151 -- if the alignment is otherwise not specified.
154 -- As each entity is frozen, this routine is called to deal with the
155 -- setting of Debug_Info_Needed for the entity. This flag is set if
156 -- the entity comes from source, or if we are in Debug_Generated_Code
157 -- mode or if the -gnatdV debug flag is set. However, it never sets
158 -- the flag if Debug_Info_Off is set.
161 -- Sets the Debug_Info_Needed flag on entity T if not already set, and
162 -- also on any entities that are needed by T (for an object, the type
163 -- of the object is needed, and for a type, the subsidiary types are
164 -- needed -- see body for details). Never has any effect on T if the
165 -- Debug_Info_Off flag is set.
168 -- T is a type of a component that we know to be an Itype.
169 -- We don't want this to have a Freeze_Node, so ensure it doesn't.
170 -- Do the same for any Full_View or Corresponding_Record_Type.
172 procedure Warn_Overlay
176 -- Expr is the expression for an address clause for entity Nam whose type
177 -- is Typ. If Typ has a default initialization, and there is no explicit
178 -- initialization in the source declaration, check whether the address
179 -- clause might cause overlaying of an entity, and emit a warning on the
180 -- side effect that the initialization will cause.
182 -------------------------------
183 -- Adjust_Esize_For_Alignment --
184 -------------------------------
189 begin
195 then
201 ------------------------------------
202 -- Build_And_Analyze_Renamed_Body --
203 ------------------------------------
205 procedure Build_And_Analyze_Renamed_Body
209 is
211 begin
218 ------------------------
219 -- Build_Renamed_Body --
220 ------------------------
222 function Build_Renamed_Body
225 is
227 -- We use for the source location of the renamed body, the location
228 -- of the spec entity. It might seem more natural to use the location
229 -- of the renaming declaration itself, but that would be wrong, since
230 -- then the body we create would look as though it was created far
231 -- too late, and this could cause problems with elaboration order
232 -- analysis, particularly in connection with instantiations.
246 begin
247 -- Determine the entity being renamed, which is the target of the
248 -- call statement. If the name is an explicit dereference, this is
249 -- a renaming of a subprogram type rather than a subprogram. The
250 -- name itself is fully analyzed.
261 else
268 else
274 -- If the renamed entity is a predefined operator, retain full
275 -- name to ensure its visibility.
279 then
281 else
285 else
288 -- The original name may have been overloaded, but
289 -- is fully resolved now.
294 -- For simple renamings, subsequent calls can be expanded directly
295 -- as called to the renamed entity. The body must be generated in
296 -- any case for calls they may appear elsewhere.
301 then
305 -- The body generated for this renaming is an internal artifact, and
306 -- does not constitute a freeze point for the called entity.
321 -- If the renamed entity is an entry, inherit its profile. For
322 -- other renamings as bodies, both profiles must be subtype
323 -- conformant, so it is not necessary to replace the profile given
324 -- in the declaration. However, default values that are aggregates
325 -- are rewritten when partially analyzed, so we recover the original
326 -- aggregate to insure that subsequent conformity checking works.
327 -- Similarly, if the default expression was constant-folded, recover
328 -- the original expression.
340 N_Access_Definition
341 then
349 then
360 -- If the renamed entity is a function, the generated body contains a
361 -- return statement. Otherwise, build a procedure call. If the entity is
362 -- an entry, subsequent analysis of the call will transform it into the
363 -- proper entry or protected operation call. If the renamed entity is
364 -- a character literal, return it directly.
370 then
371 Call_Node :=
373 Expression =>
379 Call_Node :=
384 Call_Node :=
388 else
389 Call_Node :=
395 -- Create entities for subprogram body and formals
409 Body_Node :=
413 Handled_Statement_Sequence =>
423 -- Link the body to the entity whose declaration it completes. If
424 -- the body is analyzed when the renamed entity is frozen, it may be
425 -- necessary to restore the proper scope (see package Exp_Ch13).
429 then
431 else
438 --------------------------
439 -- Check_Address_Clause --
440 --------------------------
448 begin
452 -- If we have no initialization of any kind, then we don't
453 -- need to place any restrictions on the address clause, because
454 -- the object will be elaborated after the address clause is
455 -- evaluated. This happens if the declaration has no initial
456 -- expression, or the type has no implicit initialization, or
457 -- the object is imported.
459 -- The same holds for all initialized scalar types and all
460 -- access types. Packed bit arrays of size up to 64 are
461 -- represented using a modular type with an initialization
462 -- (to zero) and can be processed like other initialized
463 -- scalar types.
465 -- If the type is controlled, code to attach the object to a
466 -- finalization chain is generated at the point of declaration,
467 -- and therefore the elaboration of the object cannot be delayed:
468 -- the address expression must be a constant.
472 and then
476 or else
480 or else
483 or else
485 and then
487 then
490 -- Otherwise, we require the address clause to be constant
491 -- because the call to the initialization procedure (or the
492 -- attach code) has to happen at the point of the declaration.
494 else
501 then
507 -----------------------------
508 -- Check_Compile_Time_Size --
509 -----------------------------
514 -- Sets the compile time known size (32 bits or less) in the Esize
515 -- field, of T checking for a size clause that was given which attempts
516 -- to give a smaller size.
519 -- Recursive function that does all the work
522 -- If T is a constrained subtype, its size is not known if any of its
523 -- discriminant constraints is not static and it is not a null record.
524 -- The test is conservative and doesn't check that the components are
525 -- in fact constrained by non-static discriminant values. Could be made
526 -- more precise ???
528 --------------------
529 -- Set_Small_Size --
530 --------------------
533 begin
540 Error_Msg_NE
548 -- Set sizes if not set already
550 else
561 ----------------
562 -- Size_Known --
563 ----------------
572 begin
578 then
590 -- Don't do any recursion on type with error posted, since
591 -- we may have a malformed type that leads us into a loop
600 -- Check for all indexes static, and also compute possible
601 -- size (in case it is less than 32 and may be packable).
603 declare
607 begin
616 else
624 then
627 else
632 else
650 then
651 -- Don't do any recursion on type with error posted, since
652 -- we may have a malformed type that leads us into a loop
656 else
662 -- A class-wide type is never considered to have a known size
667 -- A subtype of a variant record must not have non-static
668 -- discriminanted components.
672 then
675 -- Don't do any recursion on type with error posted, since
676 -- we may have a malformed type that leads us into a loop
682 -- Now look at the components of the record
684 declare
685 -- The following two variables are used to keep track of
686 -- the size of packed records if we can tell the size of
687 -- the packed record in the front end. Packed_Size_Known
688 -- is True if so far we can figure out the size. It is
689 -- initialized to True for a packed record, unless the
690 -- record has discriminants. The reason we eliminate the
691 -- discriminated case is that we don't know the way the
692 -- back end lays out discriminated packed records. If
693 -- Packed_Size_Known is True, then Packed_Size is the
694 -- size in bits so far.
702 begin
703 -- Test for variant part present
709 N_Record_Definition
713 then
714 -- If variant part is present, and type is unconstrained,
715 -- then we must have defaulted discriminants, or a size
716 -- clause must be present for the type, or else the size
717 -- is definitely not known at compile time.
720 and then
721 No (Discriminant_Default_Value
724 then
729 -- Loop through components
735 -- We do not know the packed size if there is a component
736 -- clause present (we possibly could, but this would only
737 -- help in the case of a record with partial rep clauses.
738 -- That's because in the case of full rep clauses, the
739 -- size gets figured out anyway by a different circuit).
745 -- We need to identify a component that is an array where
746 -- the index type is an enumeration type with non-standard
747 -- representation, and some bound of the type depends on a
748 -- discriminant.
750 -- This is because gigi computes the size by doing a
751 -- substituation of the appropriate discriminant value in
752 -- the size expression for the base type, and gigi is not
753 -- clever enough to evaluate the resulting expression (which
754 -- involves a call to rep_to_pos) at compile time.
756 -- It would be nice if gigi would either recognize that
757 -- this expression can be computed at compile time, or
758 -- alternatively figured out the size from the subtype
759 -- directly, where all the information is at hand ???
763 then
764 declare
772 begin
779 then
785 then
790 then
800 -- Clearly size of record is not known if the size of
801 -- one of the components is not known.
807 -- Accumulate packed size if possible
811 -- We can only deal with elementary types, since for
812 -- non-elementary components, alignment enters into the
813 -- picture, and we don't know enough to handle proper
814 -- alignment in this context. Packed arrays count as
815 -- elementary if the representation is a modular type.
820 and then Is_Modular_Integer_Type
822 then
823 -- If RM_Size is known and static, then we can
824 -- keep accumulating the packed size.
828 -- A little glitch, to be removed sometime ???
829 -- gigi does not understand zero sizes yet.
834 -- Normal case where we can keep accumulating the
835 -- packed array size.
837 else
841 -- If we have a field whose RM_Size is not known then
842 -- we can't figure out the packed size here.
844 else
848 -- If we have a non-elementary type we can't figure out
849 -- the packed array size (alignment issues).
851 else
866 else
871 -------------------------------------
872 -- Static_Discriminated_Components --
873 -------------------------------------
875 function Static_Discriminated_Components
877 is
880 begin
884 then
898 -- Start of processing for Check_Compile_Time_Size
900 begin
904 -----------------------------
905 -- Check_Debug_Info_Needed --
906 -----------------------------
909 begin
914 or else Debug_Generated_Code
915 or else Debug_Flag_VV
916 then
921 ----------------------------
922 -- Check_Strict_Alignment --
923 ----------------------------
928 begin
947 then
957 -------------------------
958 -- Check_Unsigned_Type --
959 -------------------------
966 begin
971 -- Do not attempt to analyze case where range was in error
977 -- The situation that is non trivial is something like
979 -- subtype x1 is integer range -10 .. +10;
980 -- subtype x2 is x1 range 0 .. V1;
981 -- subtype x3 is x2 range V2 .. V3;
982 -- subtype x4 is x3 range V4 .. V5;
984 -- where Vn are variables. Here the base type is signed, but we still
985 -- know that x4 is unsigned because of the lower bound of x2.
987 -- The only way to deal with this is to look up the ancestor chain
990 loop
1005 else
1008 -- If no ancestor had a static lower bound, go to base type
1012 -- Note: the reason we still check for a compile time known
1013 -- value for the base type is that at least in the case of
1014 -- generic formals, we can have bounds that fail this test,
1015 -- and there may be other cases in error situations.
1027 then
1037 -----------------------------
1038 -- Expand_Atomic_Aggregate --
1039 -----------------------------
1046 begin
1051 then
1052 Temp :=
1056 New_N :=
1066 -- To prevent the temporary from being constant-folded (which
1067 -- would lead to the same piecemeal assignment on the original
1068 -- target) indicate to the back-end that the temporary is a
1069 -- variable with real storage. See description of this flag
1070 -- in Einfo, and the notes on N_Assignment_Statement and
1071 -- N_Object_Declaration in Sinfo.
1077 ----------------
1078 -- Freeze_All --
1079 ----------------
1081 -- Note: the easy coding for this procedure would be to just build a
1082 -- single list of freeze nodes and then insert them and analyze them
1083 -- all at once. This won't work, because the analysis of earlier freeze
1084 -- nodes may recursively freeze types which would otherwise appear later
1085 -- on in the freeze list. So we must analyze and expand the freeze nodes
1086 -- as they are generated.
1094 -- This is the internal recursive routine that does freezing of
1095 -- entities (but NOT the analysis of default expressions, which
1096 -- should not be recursive, we don't want to analyze those till
1097 -- we are sure that ALL the types are frozen).
1099 --------------------
1100 -- Freeze_All_Ent --
1101 --------------------
1103 procedure Freeze_All_Ent
1106 is
1112 -- If freeze nodes are present, insert and analyze, and reset
1113 -- cursor for next insertion.
1115 -------------------
1116 -- Process_Flist --
1117 -------------------
1120 begin
1127 else
1133 -- Start or processing for Freeze_All_Ent
1135 begin
1139 -- If the entity is an inner package which is not a package
1140 -- renaming, then its entities must be frozen at this point.
1141 -- Note that such entities do NOT get frozen at the end of
1142 -- the nested package itself (only library packages freeze).
1144 -- Same is true for task declarations, where anonymous records
1145 -- created for entry parameters must be frozen.
1151 then
1161 and then
1163 or else
1165 then
1168 End_Scope;
1170 -- For a derived tagged type, we must ensure that all the
1171 -- primitive operations of the parent have been frozen, so
1172 -- that their addresses will be in the parent's dispatch table
1173 -- at the point it is inherited.
1179 then
1180 declare
1187 begin
1195 then
1197 Process_Flist;
1207 Process_Flist;
1210 -- If an incomplete type is still not frozen, this may be
1211 -- a premature freezing because of a body declaration that
1212 -- follows. Indicate where the freezing took place.
1214 -- If the freezing is caused by the end of the current
1215 -- declarative part, it is a Taft Amendment type, and there
1216 -- is no error.
1220 then
1221 declare
1224 begin
1231 and then
1233 then
1235 Error_Msg_NE
1246 -- Start of processing for Freeze_All
1248 begin
1251 -- Now that all types are frozen, we can deal with default expressions
1252 -- that require us to build a default expression functions. This is the
1253 -- point at which such functions are constructed (after all types that
1254 -- might be used in such expressions have been frozen).
1256 -- We also add finalization chains to access types whose designated
1257 -- types are controlled. This is normally done when freezing the type,
1258 -- but this misses recursive type definitions where the later members
1259 -- of the recursion introduce controlled components (e.g. 5624-001).
1261 -- Loop through entities
1279 and then
1281 = N_Subprogram_Renaming_Declaration
1282 then
1283 Build_And_Analyze_Renamed_Body
1289 and then
1291 or else
1293 then
1294 declare
1296 begin
1303 then
1316 then
1324 -----------------------
1325 -- Freeze_And_Append --
1326 -----------------------
1328 procedure Freeze_And_Append
1332 is
1334 begin
1338 else
1344 -------------------
1345 -- Freeze_Before --
1346 -------------------
1350 begin
1356 -------------------
1357 -- Freeze_Entity --
1358 -------------------
1370 -- Check that an Access or Unchecked_Access attribute with a prefix
1371 -- which is the current instance type can only be applied when the type
1372 -- is limited.
1375 -- If Loc is a freeze_entity that appears after the last declaration
1376 -- in the scope, inhibit error messages on late completion.
1379 -- Freeze each component, handle some representation clauses, and freeze
1380 -- primitive operations if this is a tagged type.
1382 ----------------------------
1383 -- After_Last_Declaration --
1384 ----------------------------
1388 begin
1394 else
1397 else
1402 ----------------------------
1403 -- Check_Current_Instance --
1404 ----------------------------
1409 -- Process routine to apply check to given node
1411 -------------
1412 -- Process --
1413 -------------
1416 begin
1420 or else
1425 then
1426 Error_Msg_N
1429 else
1439 -- Start of processing for Check_Current_Instance
1441 begin
1445 ------------------------
1446 -- Freeze_Record_Type --
1447 ------------------------
1457 -- Set True if we find at least one component with no component
1458 -- clause (used to warn about useless Pack pragmas).
1461 -- Set True if we find at least one component with a component
1462 -- clause (used to warn about useless Bit_Order pragmas).
1465 -- If N is an allocator, possibly wrapped in one or more level of
1466 -- qualified expression(s), return the inner allocator node, else
1467 -- return Empty.
1470 -- If the component subtype is an access to a constrained subtype of
1471 -- an already frozen type, make the subtype frozen as well. It might
1472 -- otherwise be frozen in the wrong scope, and a freeze node on
1473 -- subtype has no effect. Similarly, if the component subtype is a
1474 -- regular (not protected) access to subprogram, set the anonymous
1475 -- subprogram type to frozen as well, to prevent an out-of-scope
1476 -- freeze node at some eventual point of call. Protected operations
1477 -- are handled elsewhere.
1479 ---------------------
1480 -- Check_Allocator --
1481 ---------------------
1485 begin
1487 loop
1492 else
1498 -----------------
1499 -- Check_Itype --
1500 -----------------
1505 begin
1508 then
1511 -- In addition, add an Itype_Reference to ensure that the
1512 -- access subtype is elaborated early enough. This cannot be
1513 -- done if the subtype may depend on discriminants.
1518 then
1524 else
1531 then
1536 -- Start of processing for Freeze_Record_Type
1538 begin
1539 -- If this is a subtype of a controlled type, declared without a
1540 -- constraint, the _controller may not appear in the component list
1541 -- if the parent was not frozen at the point of subtype declaration.
1542 -- Inherit the _controller component now.
1546 then
1549 then
1552 -- If this is an internal type without a declaration, as for
1553 -- record component, the base type may not yet be frozen, and its
1554 -- controller has not been created. Add an explicit freeze node
1555 -- for the itype, so it will be frozen after the base type. This
1556 -- freeze node is used to communicate with the expander, in order
1557 -- to create the controller for the enclosing record, and it is
1558 -- deleted afterwards (see exp_ch3). It must not be created when
1559 -- expansion is off, because it might appear in the wrong context
1560 -- for the back end.
1564 and then
1566 N_Component_Declaration
1567 and then Expander_Active
1568 then
1573 -- Freeze components and embedded subtypes
1579 -- First handle the (real) component case
1583 then
1584 declare
1587 begin
1588 -- Freezing a record type freezes the type of each of its
1589 -- components. However, if the type of the component is
1590 -- part of this record, we do not want or need a separate
1591 -- Freeze_Node. Note that Is_Itype is wrong because that's
1592 -- also set in private type cases. We also can't check for
1593 -- the Scope being exactly Rec because of private types and
1594 -- record extensions.
1599 then
1605 -- Check for error of component clause given for variable
1606 -- sized type. We have to delay this test till this point,
1607 -- since the component type has to be frozen for us to know
1608 -- if it is variable length. We omit this test in a generic
1609 -- context, it will be applied at instantiation time.
1617 elsif not
1618 Size_Known_At_Compile_Time
1620 then
1621 Error_Msg_N
1626 else
1630 -- Case of component requires byte alignment
1634 -- Set the enclosing record to also require byte align
1638 -- Check for component clause that is inconsistent with
1639 -- the required byte boundary alignment.
1644 then
1645 Error_Msg_N
1651 -- If component clause is present, then deal with the non-
1652 -- default bit order case for Ada 95 mode. The required
1653 -- processing for Ada 2005 mode is handled separately after
1654 -- processing all components.
1656 -- We only do this processing for the base type, and in
1657 -- fact that's important, since otherwise if there are
1658 -- record subtypes, we could reverse the bits once for
1659 -- each subtype, which would be incorrect.
1665 then
1666 declare
1679 begin
1680 -- Cases where field goes over storage unit boundary
1684 -- Allow multi-byte field but generate warning
1688 then
1689 Error_Msg_N
1694 Error_Msg_N
1697 else
1698 Error_Msg_N
1703 -- Do not allow non-contiguous field
1705 else
1706 Error_Msg_N
1709 Error_Msg_N
1714 -- Case where field fits in one storage unit
1716 else
1717 -- Give warning if suspicious component clause
1720 and then Warn_On_Reverse_Bit_Order
1721 then
1722 Error_Msg_N
1725 Error_Msg_Uint_1 :=
1727 System_Storage_Unit;
1728 Error_Msg_N
1733 -- Here is where we fix up the Component_Bit_Offset
1734 -- value to account for the reverse bit order.
1735 -- Some examples of what needs to be done are:
1737 -- First_Bit .. Last_Bit Component_Bit_Offset
1738 -- old new old new
1740 -- 0 .. 0 7 .. 7 0 7
1741 -- 0 .. 1 6 .. 7 0 6
1742 -- 0 .. 2 5 .. 7 0 5
1743 -- 0 .. 7 0 .. 7 0 4
1745 -- 1 .. 1 6 .. 6 1 6
1746 -- 1 .. 4 3 .. 6 1 3
1747 -- 4 .. 7 0 .. 3 4 0
1749 -- The general rule is that the first bit is
1750 -- is obtained by subtracting the old ending bit
1751 -- from storage_unit - 1.
1753 Set_Component_Bit_Offset
1759 Set_Normalized_First_Bit
1762 System_Storage_Unit);
1769 -- If the component is an Itype with Delayed_Freeze and is either
1770 -- a record or array subtype and its base type has not yet been
1771 -- frozen, we must remove this from the entity list of this
1772 -- record and put it on the entity list of the scope of its base
1773 -- type. Note that we know that this is not the type of a
1774 -- component since we cleared Has_Delayed_Freeze for it in the
1775 -- previous loop. Thus this must be the Designated_Type of an
1776 -- access type, which is the type of a component.
1784 then
1785 declare
1789 begin
1790 -- We have a pretty bad kludge here. Suppose Rec is subtype
1791 -- being defined in a subprogram that's created as part of
1792 -- the freezing of Rec'Base. In that case, we know that
1793 -- Comp'Base must have already been frozen by the time we
1794 -- get to elaborate this because Gigi doesn't elaborate any
1795 -- bodies until it has elaborated all of the declarative
1796 -- part. But Is_Frozen will not be set at this point because
1797 -- we are processing code in lexical order.
1799 -- We detect this case by going up the Scope chain of Rec
1800 -- and seeing if we have a subprogram scope before reaching
1801 -- the top of the scope chain or that of Comp'Base. If we
1802 -- do, then mark that Comp'Base will actually be frozen. If
1803 -- so, we merely undelay it.
1818 else
1821 else
1825 -- Insert in entity list of scope of base type (which
1826 -- must be an enclosing scope, because still unfrozen).
1832 -- If the component is an access type with an allocator as
1833 -- default value, the designated type will be frozen by the
1834 -- corresponding expression in init_proc. In order to place the
1835 -- freeze node for the designated type before that for the
1836 -- current record type, freeze it now.
1838 -- Same process if the component is an array of access types,
1839 -- initialized with an aggregate. If the designated type is
1840 -- private, it cannot contain allocators, and it is premature to
1841 -- freeze the type, so we check for this as well.
1846 then
1847 declare
1851 begin
1854 -- If component is pointer to a classwide type, freeze
1855 -- the specific type in the expression being allocated.
1856 -- The expression may be a subtype indication, in which
1857 -- case freeze the subtype mark.
1859 if Is_Class_Wide_Type
1861 then
1863 Freeze_And_Append
1865 elsif
1867 then
1868 Freeze_And_Append
1876 else
1877 Freeze_And_Append
1885 then
1894 and then Is_Fully_Defined
1896 then
1897 Freeze_And_Append
1898 (Designated_Type
1906 -- Deal with pragma Bit_Order
1910 ADC :=
1912 Error_Msg_N
1914 Error_Msg_N
1917 -- Here is where we do Ada 2005 processing for bit order (the
1918 -- Ada 95 case was already taken care of above).
1925 -- Check for useless pragma Pack when all components placed. We only
1926 -- do this check for record types, not subtypes, since a subtype may
1927 -- have all its components placed, and it still makes perfectly good
1928 -- sense to pack other subtypes or the parent type.
1932 and then not Unplaced_Component
1933 then
1934 -- Reset packed status. Probably not necessary, but we do it
1935 -- so that there is no chance of the back end doing something
1936 -- strange with this redundant indication of packing.
1940 -- Give warning if redundant constructs warnings on
1943 Error_Msg_N
1949 -- If this is the record corresponding to a remote type, freeze the
1950 -- remote type here since that is what we are semantically freezing.
1951 -- This prevents the freeze node for that type in an inner scope.
1953 -- Also, Check for controlled components and unchecked unions.
1954 -- Finally, enforce the restriction that access attributes with a
1955 -- current instance prefix can only apply to limited types.
1959 Freeze_And_Append
1969 and then Present
1971 and then Has_Controlled_Component
1973 then
1984 then
1985 -- Scan component declaration for likely misuses of current
1986 -- instance, either in a constraint or a default expression.
1997 -- For first subtypes, check if there are any fixed-point fields with
1998 -- component clauses, where we must check the size. This is not done
1999 -- till the freeze point, since for fixed-point types, we do not know
2000 -- the size until the type is frozen. Similar processing applies to
2001 -- bit packed arrays.
2009 or else
2011 then
2012 Check_Size
2016 Junk);
2023 -- Generate warning for applying C or C++ convention to a record
2024 -- with discriminants. This is suppressed for the unchecked union
2025 -- case, since the whole point in this case is interface C.
2032 or else
2035 then
2036 declare
2040 begin
2045 Error_Msg_N
2047 else
2048 Error_Msg_N
2052 Error_Msg_NE
2059 -- Start of processing for Freeze_Entity
2061 begin
2062 -- We are going to test for various reasons why this entity need not be
2063 -- frozen here, but in the case of an Itype that's defined within a
2064 -- record, that test actually applies to the record.
2070 then
2074 -- Do not freeze if already frozen since we only need one freeze node
2079 -- It is improper to freeze an external entity within a generic because
2080 -- its freeze node will appear in a non-valid context. The entity will
2081 -- be frozen in the proper scope after the current generic is analyzed.
2086 -- Do not freeze a global entity within an inner scope created during
2087 -- expansion. A call to subprogram E within some internal procedure
2088 -- (a stream attribute for example) might require freezing E, but the
2089 -- freeze node must appear in the same declarative part as E itself.
2090 -- The two-pass elaboration mechanism in gigi guarantees that E will
2091 -- be frozen before the inner call is elaborated. We exclude constants
2092 -- from this test, because deferred constants may be frozen early, and
2093 -- must be diagnosed (e.g. in the case of a deferred constant being used
2094 -- in a default expression). If the enclosing subprogram comes from
2095 -- source, or is a generic instance, then the freeze point is the one
2096 -- mandated by the language, and we freeze the entity. A subprogram that
2097 -- is a child unit body that acts as a spec does not have a spec that
2098 -- comes from source, but can only come from source.
2103 then
2104 declare
2107 begin
2113 then
2115 else
2124 -- Similarly, an inlined instance body may make reference to global
2125 -- entities, but these references cannot be the proper freezing point
2126 -- for them, and in the absence of inlining freezing will take place
2127 -- in their own scope. Normally instance bodies are analyzed after
2128 -- the enclosing compilation, and everything has been frozen at the
2129 -- proper place, but with front-end inlining an instance body is
2130 -- compiled before the end of the enclosing scope, and as a result
2131 -- out-of-order freezing must be prevented.
2133 elsif Front_End_Inlining
2134 and then In_Instance_Body
2136 then
2137 declare
2140 begin
2144 else
2155 -- Here to freeze the entity
2160 -- Case of entity being frozen is other than a type
2164 -- If entity is exported or imported and does not have an external
2165 -- name, now is the time to provide the appropriate default name.
2166 -- Skip this if the entity is stubbed, since we don't need a name
2167 -- for any stubbed routine.
2172 then
2173 Set_Encoded_Interface_Name
2176 -- Special processing for atomic objects appearing in object decls
2181 then
2182 declare
2185 begin
2186 -- If expression is an aggregate, assign to a temporary to
2187 -- ensure that the actual assignment is done atomically rather
2188 -- than component-wise (the assignment to the temp may be done
2189 -- component-wise, but that is harmless).
2194 -- If the expression is a reference to a record or array object
2195 -- entity, then reset Is_True_Constant to False so that the
2196 -- compiler will not optimize away the intermediate object,
2197 -- which we need in this case for the same reason (to ensure
2198 -- that the actual assignment is atomic, rather than
2199 -- component-wise).
2203 or else
2205 then
2211 -- For a subprogram, freeze all parameter types and also the return
2212 -- type (RM 13.14(14)). However skip this for internal subprograms.
2213 -- This is also the point where any extra formal parameters are
2214 -- created since we now know whether the subprogram will use
2215 -- a foreign convention.
2219 declare
2224 -- Determines if given type entity is a fat pointer type
2225 -- used as an argument type or return type to a subprogram
2226 -- with C or C++ convention set.
2228 --------------------------
2229 -- Is_Fat_C_Access_Type --
2230 --------------------------
2233 begin
2235 or else
2241 begin
2242 -- Loop through formals
2254 then
2255 -- If the type of a formal is incomplete, subprogram
2256 -- is being frozen prematurely. Within an instance
2257 -- (but not within a wrapper package) this is an
2258 -- an artifact of our need to regard the end of an
2259 -- instantiation as a freeze point. Otherwise it is
2260 -- a definite error.
2262 -- and then not Is_Wrapper_Package (Current_Scope) ???
2268 elsif not After_Last_Declaration
2269 and then not Freezing_Library_Level_Tagged_Type
2270 then
2272 Error_Msg
2274 Loc);
2278 -- Check bad use of fat C pointer
2282 then
2284 Error_Msg_N
2286 Formal);
2290 -- Check for unconstrained array in exported foreign
2291 -- convention case.
2297 and then Warn_On_Export_Import
2298 then
2301 -- If this is an inherited operation, place the
2302 -- warning on the derived type declaration, rather
2303 -- than on the original subprogram.
2306 N_Full_Type_Declaration
2307 then
2311 Error_Msg_NE
2314 else
2318 Error_Msg_NE
2321 Error_Msg_NE
2327 -- Ada 2005 (AI-326): Check wrong use of tag incomplete
2328 -- types with unknown discriminants. For example:
2330 -- type T (<>) is tagged;
2331 -- procedure P (X : access T); -- ERROR
2332 -- procedure P (X : T); -- ERROR
2343 and then Unknown_Discriminants_Present
2346 then
2347 Error_Msg_N
2351 -- If the formal is an anonymous_access_to_subprogram
2352 -- freeze the subprogram type as well, to prevent
2353 -- scope anomalies in gigi, because there is no other
2354 -- clear point at which it could be frozen.
2358 then
2366 -- Check return type
2371 if Warn_On_Export_Import
2373 then
2374 Error_Msg_N
2376 E);
2382 and then Warn_On_Export_Import
2383 then
2384 Error_Msg_N
2388 -- Ada 2005 (AI-326): Check wrong use of tagged
2389 -- incomplete type
2390 --
2391 -- type T is tagged;
2392 -- function F (X : Boolean) return T; -- ERROR
2398 then
2399 Error_Msg_N
2401 E);
2407 -- Must freeze its parent first if it is a derived subprogram
2413 -- We don't freeze internal subprograms, because we don't normally
2414 -- want addition of extra formals or mechanism setting to happen
2415 -- for those. However we do pass through predefined dispatching
2416 -- cases, since extra formals may be needed in some cases, such as
2417 -- for the stream 'Input function (build-in-place formals).
2421 then
2425 -- Here for other than a subprogram or type
2427 else
2428 -- If entity has a type, and it is not a generic unit, then
2429 -- freeze it first (RM 13.14(10)).
2433 then
2437 -- Special processing for objects created by object declaration
2441 -- For object created by object declaration, perform required
2442 -- categorization (preelaborate and pure) checks. Defer these
2443 -- checks to freeze time since pragma Import inhibits default
2444 -- initialization and thus pragma Import affects these checks.
2448 -- If there is an address clause, check it is valid
2452 -- For imported objects, set Is_Public unless there is also
2453 -- an address clause, which means that there is no external
2454 -- symbol needed for the Import (Is_Public may still be set
2455 -- for other unrelated reasons). Note that we delayed this
2456 -- processing till freeze time so that we can be sure not
2457 -- to set the flag if there is an address clause. If there
2458 -- is such a clause, then the only purpose of the Import
2459 -- pragma is to suppress implicit initialization.
2463 then
2467 -- For convention C objects of an enumeration type, warn if
2468 -- the size is not integer size and no explicit size given.
2469 -- Skip warning for Boolean, and Character, assume programmer
2470 -- expects 8-bit sizes for these cases.
2473 or else
2480 then
2482 Error_Msg_N
2484 E);
2489 -- Check that a constant which has a pragma Volatile[_Components]
2490 -- or Atomic[_Components] also has a pragma Import (RM C.6(13)).
2492 -- Note: Atomic[_Components] also sets Volatile[_Components]
2497 then
2498 -- Make sure we actually have a pragma, and have not merely
2499 -- inherited the indication from elsewhere (e.g. an address
2500 -- clause, which is not good enough in RM terms!)
2503 or else
2505 then
2506 Error_Msg_N
2511 or else
2513 then
2514 Error_Msg_N
2520 -- Static objects require special handling
2524 then
2528 -- Remaining step is to layout objects
2531 or else
2533 or else
2535 or else
2537 then
2542 -- Case of a type or subtype being frozen
2544 else
2545 -- We used to check here that a full type must have preelaborable
2546 -- initialization if it completes a private type specified with
2547 -- pragma Preelaborable_Intialization, but that missed cases where
2548 -- the types occur within a generic package, since the freezing
2549 -- that occurs within a containing scope generally skips traversal
2550 -- of a generic unit's declarations (those will be frozen within
2551 -- instances). This check was moved to Analyze_Package_Specification.
2553 -- The type may be defined in a generic unit. This can occur when
2554 -- freezing a generic function that returns the type (which is
2555 -- defined in a parent unit). It is clearly meaningless to freeze
2556 -- this type. However, if it is a subtype, its size may be determi-
2557 -- nable and used in subsequent checks, so might as well try to
2558 -- compute it.
2562 then
2567 -- Deal with special cases of freezing for subtype
2571 -- Before we do anything else, a specialized test for the case of
2572 -- a size given for an array where the array needs to be packed,
2573 -- but was not so the size cannot be honored. This would of course
2574 -- be caught by the backend, and indeed we don't catch all cases.
2575 -- The point is that we can give a better error message in those
2576 -- cases that we do catch with the circuitry here. Also if pragma
2577 -- Implicit_Packing is set, this is where the packing occurs.
2579 -- The reason we do this so early is that the processing in the
2580 -- automatic packing case affects the layout of the base type, so
2581 -- it must be done before we freeze the base type.
2584 declare
2588 begin
2589 -- Check enabling conditions. These are straightforward
2590 -- except for the test for a limited composite type. This
2591 -- eliminates the rare case of a array of limited components
2592 -- where there are issues of whether or not we can go ahead
2593 -- and pack the array (since we can't freely pack and unpack
2594 -- arrays if they are limited).
2596 -- Note that we check the root type explicitly because the
2597 -- whole point is we are doing this test before we have had
2598 -- a chance to freeze the base type (and it is that freeze
2599 -- action that causes stuff to be inherited).
2611 then
2618 then
2619 declare
2629 -- What we are looking for here is the situation where
2630 -- the RM_Size given would be exactly right if there
2631 -- was a pragma Pack (resulting in the component size
2632 -- being the same as the RM_Size). Furthermore, the
2633 -- component type size must be an odd size (not a
2634 -- multiple of storage unit)
2636 begin
2639 then
2640 -- For implicit packing mode, just set the
2641 -- component size silently
2649 -- Otherwise give an error message
2651 else
2652 Error_Msg_NE
2654 Error_Msg_N
2665 -- If ancestor subtype present, freeze that first.
2666 -- Note that this will also get the base type frozen.
2673 -- Otherwise freeze the base type of the entity before
2674 -- freezing the entity itself (RM 13.14(15)).
2680 -- For a derived type, freeze its parent type first (RM 13.14(15))
2687 -- For array type, freeze index types and component type first
2688 -- before freezing the array (RM 13.14(15)).
2691 declare
2695 -- Set true if any of the index types is an enumeration type
2696 -- with a non-standard representation.
2698 begin
2707 then
2714 -- Processing that is done only for base types
2718 -- Propagate flags for component type
2722 then
2730 -- If packing was requested or if the component size was set
2731 -- explicitly, then see if bit packing is required. This
2732 -- processing is only done for base types, since all the
2733 -- representation aspects involved are type-related. This
2734 -- is not just an optimization, if we start processing the
2735 -- subtypes, they intefere with the settings on the base
2736 -- type (this is because Is_Packed has a slightly different
2737 -- meaning before and after freezing).
2739 declare
2743 begin
2747 then
2756 else
2759 -- We can set the component size if it is less than
2760 -- 16, rounding it up to the next storage unit size.
2766 else
2770 -- Set component size up to match alignment if it
2771 -- would otherwise be less than the alignment. This
2772 -- deals with cases of types whose alignment exceeds
2773 -- their size (padded types).
2776 declare
2778 begin
2786 -- Case of component size that may result in packing
2789 declare
2795 Get_Attribute_Definition_Clause
2797 begin
2798 -- Warn if we have pack and component size so that
2799 -- the pack is ignored.
2801 -- Note: here we must check for the presence of a
2802 -- component size before checking for a Pack pragma
2803 -- to deal with the case where the array type is a
2804 -- derived type whose parent is currently private.
2808 then
2810 Error_Msg_NE
2813 Error_Msg_N
2815 Pack_Pragma);
2818 -- Set component size if not already set by a
2819 -- component size clause.
2825 -- Check for base type of 8, 16, 32 bits, where an
2826 -- unsigned subtype has a length one less than the
2827 -- base type (e.g. Natural subtype of Integer).
2829 -- In such cases, if a component size was not set
2830 -- explicitly, then generate a warning.
2834 and then
2837 then
2841 Error_Msg_N
2844 Error_Msg_N
2850 -- Actual packing is not needed for 8, 16, 32, 64.
2851 -- Also not needed for 24 if alignment is 1.
2858 then
2859 -- Here the array was requested to be packed,
2860 -- but the packing request had no effect, so
2861 -- Is_Packed is reset.
2863 -- Note: semantically this means that we lose
2864 -- track of the fact that a derived type
2865 -- inherited a pragma Pack that was non-
2866 -- effective, but that seems fine.
2868 -- We regard a Pack pragma as a request to set
2869 -- a representation characteristic, and this
2870 -- request may be ignored.
2874 -- In all other cases, packing is indeed needed
2876 else
2885 -- Processing that is done only for subtypes
2887 else
2888 -- Acquire alignment from base type
2896 -- For bit-packed arrays, check the size
2900 then
2901 declare
2905 begin
2906 -- It is not clear if it is possible to have no size
2907 -- clause at this stage, but it is not worth worrying
2908 -- about. Post error on the entity name in the size
2909 -- clause if present, else on the type entity itself.
2913 else
2919 -- If any of the index types was an enumeration type with
2920 -- a non-standard rep clause, then we indicate that the
2921 -- array type is always packed (even if it is not bit packed).
2930 -- If the array is packed, we must create the packed array
2931 -- type to be used to actually implement the type. This is
2932 -- only needed for real array types (not for string literal
2933 -- types, since they are present only for the front end).
2937 then
2941 -- Size information of packed array type is copied to the
2942 -- array type, since this is really the representation. But
2943 -- do not override explicit existing size values.
2955 -- For non-packed arrays set the alignment of the array
2956 -- to the alignment of the component type if it is unknown.
2957 -- Skip this in the atomic case, since atomic arrays may
2958 -- need larger alignments.
2967 then
2972 -- For a class-wide type, the corresponding specific type is
2973 -- frozen as well (RM 13.14(15))
2978 -- If the base type of the class-wide type is still incomplete,
2979 -- the class-wide remains unfrozen as well. This is legal when
2980 -- E is the formal of a primitive operation of some other type
2981 -- which is being frozen.
2988 -- If the Class_Wide_Type is an Itype (when type is the anonymous
2989 -- parent of a derived type) and it is a library-level entity,
2990 -- generate an itype reference for it. Otherwise, its first
2991 -- explicit reference may be in an inner scope, which will be
2992 -- rejected by the back-end.
2996 then
2997 declare
3000 begin
3004 else
3010 -- The equivalent type associated with a class-wide subtype
3011 -- needs to be frozen to ensure that its layout is done.
3012 -- Class-wide subtypes are currently only frozen on targets
3013 -- requiring front-end layout (see New_Class_Wide_Subtype
3014 -- and Make_CW_Equivalent_Type in exp_util.adb).
3018 then
3022 -- For a record (sub)type, freeze all the component types (RM
3023 -- 13.14(15). We test for E_Record_(sub)Type here, rather than
3024 -- using Is_Record_Type, because we don't want to attempt the
3025 -- freeze for the case of a private type with record extension
3026 -- (we will do that later when the full type is frozen).
3030 then
3033 -- For a concurrent type, freeze corresponding record type. This
3034 -- does not correpond to any specific rule in the RM, but the
3035 -- record type is essentially part of the concurrent type.
3036 -- Freeze as well all local entities. This includes record types
3037 -- created for entry parameter blocks, and whatever local entities
3038 -- may appear in the private part.
3042 Freeze_And_Append
3055 then
3065 -- Private types are required to point to the same freeze node as
3066 -- their corresponding full views. The freeze node itself has to
3067 -- point to the partial view of the entity (because from the partial
3068 -- view, we can retrieve the full view, but not the reverse).
3069 -- However, in order to freeze correctly, we need to freeze the full
3070 -- view. If we are freezing at the end of a scope (or within the
3071 -- scope of the private type), the partial and full views will have
3072 -- been swapped, the full view appears first in the entity chain and
3073 -- the swapping mechanism ensures that the pointers are properly set
3074 -- (on scope exit).
3076 -- If we encounter the partial view before the full view (e.g. when
3077 -- freezing from another scope), we freeze the full view, and then
3078 -- set the pointers appropriately since we cannot rely on swapping to
3079 -- fix things up (subtypes in an outer scope might not get swapped).
3083 then
3084 -- The construction of the dispatch table associated with library
3085 -- level tagged types forces freezing of all the primitives of the
3086 -- type, which may cause premature freezing of the partial view.
3087 -- For example:
3089 -- package Pkg is
3090 -- type T is tagged private;
3091 -- type DT is new T with private;
3092 -- procedure Prim (X : in out T; Y : in out DT'class);
3093 -- private
3094 -- type T is tagged null record;
3095 -- Obj : T;
3096 -- type DT is new T with null record;
3097 -- end;
3099 -- In this case the type will be frozen later by the usual
3100 -- mechanism: an object declaration, an instantiation, or the
3101 -- end of a declarative part.
3105 then
3109 -- Case of full view present
3113 -- If full view has already been frozen, then no further
3114 -- processing is required
3122 -- Otherwise freeze full view and patch the pointers so that
3123 -- the freeze node will elaborate both views in the back-end.
3125 else
3126 declare
3129 begin
3132 then
3133 Freeze_And_Append
3146 else
3147 -- {Incomplete,Private}_Subtypes
3148 -- with Full_Views constrained by discriminants
3159 -- AI-117 requires that the convention of a partial view be the
3160 -- same as the convention of the full view. Note that this is a
3161 -- recognized breach of privacy, but it's essential for logical
3162 -- consistency of representation, and the lack of a rule in
3163 -- RM95 was an oversight.
3170 -- Size information is copied from the full view to the
3171 -- incomplete or private view for consistency
3173 -- We skip this is the full view is not a type. This is very
3174 -- strange of course, and can only happen as a result of
3175 -- certain illegalities, such as a premature attempt to derive
3176 -- from an incomplete type.
3185 -- Case of no full view present. If entity is derived or subtype,
3186 -- it is safe to freeze, correctness depends on the frozen status
3187 -- of parent. Otherwise it is either premature usage, or a Taft
3188 -- amendment type, so diagnosis is at the point of use and the
3189 -- type might be frozen later.
3193 then
3196 else
3201 -- For access subprogram, freeze types of all formals, the return
3202 -- type was already frozen, since it is the Etype of the function.
3213 -- Ada 2005 (AI-326): Check wrong use of tag incomplete type
3214 --
3215 -- type T is tagged;
3216 -- type Acc is access function (X : T) return T; -- ERROR
3222 then
3223 Error_Msg_N
3227 -- For access to a protected subprogram, freeze the equivalent type
3228 -- (however this is not set if we are not generating code or if this
3229 -- is an anonymous type used just for resolution).
3233 -- AI-326: Check wrong use of tagged incomplete types
3235 -- type T is tagged;
3236 -- type As3D is access protected
3237 -- function (X : Float) return T; -- ERROR
3239 declare
3242 begin
3253 then
3254 Error_Msg_N
3264 -- Generic types are never seen by the back-end, and are also not
3265 -- processed by the expander (since the expander is turned off for
3266 -- generic processing), so we never need freeze nodes for them.
3272 -- Some special processing for non-generic types to complete
3273 -- representation details not known till the freeze point.
3278 -- Some error checks required for ordinary fixed-point type. Defer
3279 -- these till the freeze-point since we need the small and range
3280 -- values. We only do these checks for base types
3284 then
3287 Error_Msg_N
3292 Error_Msg_N
3298 Error_Msg_N
3304 Error_Msg_N
3317 -- Check restriction for standard storage pool
3323 -- Deal with error message for pure access type. This is not an
3324 -- error in Ada 2005 if there is no pool (see AI-366).
3329 then
3334 -- Case of composite types
3338 -- AI-117 requires that all new primitives of a tagged type must
3339 -- inherit the convention of the full view of the type. Inherited
3340 -- and overriding operations are defined to inherit the convention
3341 -- of their parent or overridden subprogram (also specified in
3342 -- AI-117), which will have occurred earlier (in Derive_Subprogram
3343 -- and New_Overloaded_Entity). Here we set the convention of
3344 -- primitives that are still convention Ada, which will ensure
3345 -- that any new primitives inherit the type's convention.
3346 -- Class-wide types can have a foreign convention inherited from
3347 -- their specific type, but are excluded from this since they
3348 -- don't have any associated primitives.
3353 then
3354 declare
3357 begin
3370 -- Generate primitive operation references for a tagged type
3374 then
3375 declare
3381 begin
3382 -- Handle subtypes
3386 then
3388 else
3392 -- Ada 2005 (AI-345): In case of concurrent type generate
3393 -- reference to the wrapper that allow us to dispatch calls
3394 -- through their implemented abstract interface types.
3396 -- The check for Present here is to protect against previously
3397 -- reported critical errors.
3401 then
3402 Prim_List := Primitive_Operations
3404 else
3408 -- Loop to generate references for primitive operations
3414 -- If the operation is derived, get the original for
3415 -- cross-reference purposes (it is the original for
3416 -- which we want the xref, and for which the comes
3417 -- from source test needs to be performed).
3431 -- Now that all types from which E may depend are frozen, see if the
3432 -- size is known at compile time, if it must be unsigned, or if
3433 -- strict alignment is required
3442 -- Do not allow a size clause for a type which does not have a size
3443 -- that is known at compile time
3447 then
3448 -- Supress this message if errors posted on E, even if we are
3449 -- in all errors mode, since this is often a junk message
3452 Error_Msg_N
3458 -- Remaining process is to set/verify the representation information,
3459 -- in particular the size and alignment values. This processing is
3460 -- not required for generic types, since generic types do not play
3461 -- any part in code generation, and so the size and alignment values
3462 -- for such types are irrelevant.
3467 -- Otherwise we call the layout procedure
3469 else
3473 -- End of freeze processing for type entities
3476 -- Here is where we logically freeze the current entity. If it has a
3477 -- freeze node, then this is the point at which the freeze node is
3478 -- linked into the result list.
3482 -- If a freeze node is already allocated, use it, otherwise allocate
3483 -- a new one. The preallocation happens in the case of anonymous base
3484 -- types, where we preallocate so that we can set First_Subtype_Link.
3485 -- Note that we reset the Sloc to the current freeze location.
3491 else
3503 else
3507 -- A final pass over record types with discriminants. If the type
3508 -- has an incomplete declaration, there may be constrained access
3509 -- subtypes declared elsewhere, which do not depend on the discrimi-
3510 -- nants of the type, and which are used as component types (i.e.
3511 -- the full view is a recursive type). The designated types of these
3512 -- subtypes can only be elaborated after the type itself, and they
3513 -- need an itype reference.
3517 then
3518 declare
3523 begin
3534 then
3546 -- When a type is frozen, the first subtype of the type is frozen as
3547 -- well (RM 13.14(15)). This has to be done after freezing the type,
3548 -- since obviously the first subtype depends on its own base type.
3553 -- If we just froze a tagged non-class wide record, then freeze the
3554 -- corresponding class-wide type. This must be done after the tagged
3555 -- type itself is frozen, because the class-wide type refers to the
3556 -- tagged type which generates the class.
3561 then
3568 -- Special handling for subprograms
3572 -- If subprogram has address clause then reset Is_Public flag, since
3573 -- we do not want the backend to generate external references.
3577 then
3580 -- If no address clause and not intrinsic, then for imported
3581 -- subprogram in main unit, generate descriptor if we are in
3582 -- Propagate_Exceptions mode.
3584 elsif Propagate_Exceptions
3588 then
3598 -----------------------------
3599 -- Freeze_Enumeration_Type --
3600 -----------------------------
3603 begin
3607 then
3609 else
3614 -----------------------
3615 -- Freeze_Expression --
3616 -----------------------
3627 -- This flag is set true if the entity must be frozen outside the
3628 -- current subprogram. This happens in the case of expander generated
3629 -- subprograms (_Init_Proc, _Input, _Output, _Read, _Write) which do
3630 -- not freeze all entities like other bodies, but which nevertheless
3631 -- may reference entities that have to be frozen before the body and
3632 -- obviously cannot be frozen inside the body.
3635 -- Given an N_Handled_Sequence_Of_Statements node N, determines whether
3636 -- it is the handled statement sequence of an expander-generated
3637 -- subprogram (init proc, stream subprogram, or renaming as body).
3638 -- If so, this is not a freezing context.
3640 -----------------
3641 -- In_Exp_Body --
3642 -----------------
3648 begin
3651 else
3658 else
3668 N_Subprogram_Renaming_Declaration)
3669 then
3671 else
3677 -- Start of processing for Freeze_Expression
3679 begin
3680 -- Immediate return if freezing is inhibited. This flag is set by the
3681 -- analyzer to stop freezing on generated expressions that would cause
3682 -- freezing if they were in the source program, but which are not
3683 -- supposed to freeze, since they are created.
3689 -- If expression is non-static, then it does not freeze in a default
3690 -- expression, see section "Handling of Default Expressions" in the
3691 -- spec of package Sem for further details. Note that we have to
3692 -- make sure that we actually have a real expression (if we have
3693 -- a subtype indication, we can't test Is_Static_Expression!)
3695 if In_Def_Exp
3698 then
3702 -- Freeze type of expression if not frozen already
3710 -- Base type may be an derived numeric type that is frozen at
3711 -- the point of declaration, but first_subtype is still unfrozen.
3718 -- For entity name, freeze entity if not frozen already. A special
3719 -- exception occurs for an identifier that did not come from source.
3720 -- We don't let such identifiers freeze a non-internal entity, i.e.
3721 -- an entity that did come from source, since such an identifier was
3722 -- generated by the expander, and cannot have any semantic effect on
3723 -- the freezing semantics. For example, this stops the parameter of
3724 -- an initialization procedure from freezing the variable.
3731 then
3733 else
3737 -- For an allocator freeze designated type if not frozen already
3739 -- For an aggregate whose component type is an access type, freeze the
3740 -- designated type now, so that its freeze does not appear within the
3741 -- loop that might be created in the expansion of the aggregate. If the
3742 -- designated type is a private type without full view, the expression
3743 -- cannot contain an allocator, so the type is not frozen.
3754 then
3758 when N_Selected_Component |
3759 N_Indexed_Component |
3760 N_Slice =>
3773 then
3777 -- All done if nothing needs freezing
3782 then
3786 -- Loop for looking at the right place to insert the freeze nodes
3787 -- exiting from the loop when it is appropriate to insert the freeze
3788 -- node before the current node P.
3790 -- Also checks some special exceptions to the freezing rules. These
3791 -- cases result in a direct return, bypassing the freeze action.
3794 loop
3797 -- If we don't have a parent, then we are not in a well-formed tree.
3798 -- This is an unusual case, but there are some legitimate situations
3799 -- in which this occurs, notably when the expressions in the range of
3800 -- a type declaration are resolved. We simply ignore the freeze
3801 -- request in this case. Is this right ???
3807 -- See if we have got to an appropriate point in the tree
3811 -- A special test for the exception of (RM 13.14(8)) for the case
3812 -- of per-object expressions (RM 3.8(18)) occurring in component
3813 -- definition or a discrete subtype definition. Note that we test
3814 -- for a component declaration which includes both cases we are
3815 -- interested in, and furthermore the tree does not have explicit
3816 -- nodes for either of these two constructs.
3820 -- The case we want to test for here is an identifier that is
3821 -- a per-object expression, this is either a discriminant that
3822 -- appears in a context other than the component declaration
3823 -- or it is a reference to the type of the enclosing construct.
3825 -- For either of these cases, we skip the freezing
3827 if not In_Default_Expression
3830 then
3831 -- We recognize the discriminant case by just looking for
3832 -- a reference to a discriminant. It can only be one for
3833 -- the enclosing construct. Skip freezing in this case.
3838 -- For the case of a reference to the enclosing record,
3839 -- (or task or protected type), we look for a type that
3840 -- matches the current scope.
3847 -- If we have an enumeration literal that appears as the choice in
3848 -- the aggregate of an enumeration representation clause, then
3849 -- freezing does not occur (RM 13.14(10)).
3853 -- The case we are looking for is an enumeration literal
3857 then
3858 -- If enumeration literal appears directly as the choice,
3859 -- do not freeze (this is the normal non-overloade case)
3863 then
3866 -- If enumeration literal appears as the name of function
3867 -- which is the choice, then also do not freeze. This
3868 -- happens in the overloaded literal case, where the
3869 -- enumeration literal is temporarily changed to a function
3870 -- call for overloading analysis purposes.
3873 and then
3875 and then
3877 then
3882 -- Normally if the parent is a handled sequence of statements,
3883 -- then the current node must be a statement, and that is an
3884 -- appropriate place to insert a freeze node.
3888 -- An exception occurs when the sequence of statements is for
3889 -- an expander generated body that did not do the usual freeze
3890 -- all operation. In this case we usually want to freeze
3891 -- outside this body, not inside it, and we skip past the
3892 -- subprogram body that we are inside.
3896 -- However, we *do* want to freeze at this point if we have
3897 -- an entity to freeze, and that entity is declared *inside*
3898 -- the body of the expander generated procedure. This case
3899 -- is recognized by the scope of the type, which is either
3900 -- the spec for some enclosing body, or (in the case of
3901 -- init_procs, for which there are no separate specs) the
3902 -- current scope.
3904 declare
3908 begin
3913 or else
3915 then
3921 then
3927 -- If not that exception to the exception, then this is
3928 -- where we delay the freeze till outside the body.
3933 -- Here if normal case where we are in handled statement
3934 -- sequence and want to do the insertion right there.
3936 else
3940 -- If parent is a body or a spec or a block, then the current node
3941 -- is a statement or declaration and we can insert the freeze node
3942 -- before it.
3944 when N_Package_Specification |
3945 N_Package_Body |
3946 N_Subprogram_Body |
3947 N_Task_Body |
3948 N_Protected_Body |
3949 N_Entry_Body |
3952 -- The expander is allowed to define types in any statements list,
3953 -- so any of the following parent nodes also mark a freezing point
3954 -- if the actual node is in a list of statements or declarations.
3956 when N_Exception_Handler |
3957 N_If_Statement |
3958 N_Elsif_Part |
3959 N_Case_Statement_Alternative |
3960 N_Compilation_Unit_Aux |
3961 N_Selective_Accept |
3962 N_Accept_Alternative |
3963 N_Delay_Alternative |
3964 N_Conditional_Entry_Call |
3965 N_Entry_Call_Alternative |
3966 N_Triggering_Alternative |
3967 N_Abortable_Part |
3968 N_Freeze_Entity =>
3972 -- Note: The N_Loop_Statement is a special case. A type that
3973 -- appears in the source can never be frozen in a loop (this
3974 -- occurs only because of a loop expanded by the expander), so we
3975 -- keep on going. Otherwise we terminate the search. Same is true
3976 -- of any entity which comes from source. (if they have predefined
3977 -- type, that type does not appear to come from source, but the
3978 -- entity should not be frozen here).
3984 -- For all other cases, keep looking at parents
3990 -- We fall through the case if we did not yet find the proper
3991 -- place in the free for inserting the freeze node, so climb!
3996 -- If the expression appears in a record or an initialization procedure,
3997 -- the freeze nodes are collected and attached to the current scope, to
3998 -- be inserted and analyzed on exit from the scope, to insure that
3999 -- generated entities appear in the correct scope. If the expression is
4000 -- a default for a discriminant specification, the scope is still void.
4001 -- The expression can also appear in the discriminant part of a private
4002 -- or concurrent type.
4004 -- If the expression appears in a constrained subcomponent of an
4005 -- enclosing record declaration, the freeze nodes must be attached to
4006 -- the outer record type so they can eventually be placed in the
4007 -- enclosing declaration list.
4009 -- The other case requiring this special handling is if we are in a
4010 -- default expression, since in that case we are about to freeze a
4011 -- static type, and the freeze scope needs to be the outer scope, not
4012 -- the scope of the subprogram with the default parameter.
4014 -- For default expressions in generic units, the Move_Freeze_Nodes
4015 -- mechanism (see sem_ch12.adb) takes care of placing them at the proper
4016 -- place, after the generic unit.
4019 or else Freeze_Outside
4024 then
4025 declare
4030 begin
4043 -- The current scope may be that of a constrained component of
4044 -- an enclosing record declaration, which is above the current
4045 -- scope in the scope stack.
4054 Freeze_Nodes;
4055 else
4065 -- Now we have the right place to do the freezing. First, a special
4066 -- adjustment, if we are in default expression analysis mode, these
4067 -- freeze actions must not be thrown away (normally all inserted actions
4068 -- are thrown away in this mode. However, the freeze actions are from
4069 -- static expressions and one of the important reasons we are doing this
4070 -- special analysis is to get these freeze actions. Therefore we turn
4071 -- off the In_Default_Expression mode to propagate these freeze actions.
4072 -- This also means they get properly analyzed and expanded.
4076 -- Freeze the designated type of an allocator (RM 13.14(13))
4082 -- Freeze type of expression (RM 13.14(10)). Note that we took care of
4083 -- the enumeration representation clause exception in the loop above.
4089 -- Freeze name if one is present (RM 13.14(11))
4098 -----------------------------
4099 -- Freeze_Fixed_Point_Type --
4100 -----------------------------
4102 -- Certain fixed-point types and subtypes, including implicit base types
4103 -- and declared first subtypes, have not yet set up a range. This is
4104 -- because the range cannot be set until the Small and Size values are
4105 -- known, and these are not known till the type is frozen.
4107 -- To signal this case, Scalar_Range contains an unanalyzed syntactic range
4108 -- whose bounds are unanalyzed real literals. This routine will recognize
4109 -- this case, and transform this range node into a properly typed range
4110 -- with properly analyzed and resolved values.
4128 -- Returns size of type with given bounds. Also leaves these
4129 -- bounds set as the current bounds of the Typ.
4131 -----------
4132 -- Fsize --
4133 -----------
4136 begin
4142 -- Start of processing for Freeze_Fixed_Point_Type
4144 begin
4145 -- If Esize of a subtype has not previously been set, set it now
4152 else
4157 -- Immediate return if the range is already analyzed. This means that
4158 -- the range is already set, and does not need to be computed by this
4159 -- routine.
4165 -- Immediate return if either of the bounds raises Constraint_Error
4169 then
4176 -- Ordinary fixed-point case
4180 -- For the ordinary fixed-point case, we are allowed to fudge the
4181 -- end-points up or down by small. Generally we prefer to fudge up,
4182 -- i.e. widen the bounds for non-model numbers so that the end points
4183 -- are included. However there are cases in which this cannot be
4184 -- done, and indeed cases in which we may need to narrow the bounds.
4185 -- The following circuit makes the decision.
4187 -- Note: our terminology here is that Incl_EP means that the bounds
4188 -- are widened by Small if necessary to include the end points, and
4189 -- Excl_EP means that the bounds are narrowed by Small to exclude the
4190 -- end-points if this reduces the size.
4192 -- Note that in the Incl case, all we care about is including the
4193 -- end-points. In the Excl case, we want to narrow the bounds as
4194 -- much as permitted by the RM, to give the smallest possible size.
4211 begin
4212 -- First step. Base types are required to be symmetrical. Right
4213 -- now, the base type range is a copy of the first subtype range.
4214 -- This will be corrected before we are done, but right away we
4215 -- need to deal with the case where both bounds are non-negative.
4216 -- In this case, we set the low bound to the negative of the high
4217 -- bound, to make sure that the size is computed to include the
4218 -- required sign. Note that we do not need to worry about the
4219 -- case of both bounds negative, because the sign will be dealt
4220 -- with anyway. Furthermore we can't just go making such a bound
4221 -- symmetrical, since in a twos-complement system, there is an
4222 -- extra negative value which could not be accomodated on the
4223 -- positive side.
4228 then
4233 -- Compute the fudged bounds. If the number is a model number,
4234 -- then we do nothing to include it, but we are allowed to backoff
4235 -- to the next adjacent model number when we exclude it. If it is
4236 -- not a model number then we straddle the two values with the
4237 -- model numbers on either side.
4243 else
4247 -- The low value excluding the end point is Small greater, but
4248 -- we do not do this exclusion if the low value is positive,
4249 -- since it can't help the size and could actually hurt by
4250 -- crossing the high bound.
4254 else
4258 -- Similar processing for upper bound and high value
4264 else
4270 else
4274 -- One further adjustment is needed. In the case of subtypes, we
4275 -- cannot go outside the range of the base type, or we get
4276 -- peculiarities, and the base type range is already set. This
4277 -- only applies to the Incl values, since clearly the Excl values
4278 -- are already as restricted as they are allowed to be.
4285 -- Get size including and excluding end points
4290 -- No need to exclude end-points if it does not reduce size
4300 -- Now we set the actual size to be used. We want to use the
4301 -- bounds fudged up to include the end-points but only if this
4302 -- can be done without violating a specifically given size
4303 -- size clause or causing an unacceptable increase in size.
4305 -- Case of size clause given
4309 -- Use the inclusive size only if it is consistent with
4310 -- the explicitly specified size.
4317 -- If the inclusive size is too large, we try excluding
4318 -- the end-points (will be caught later if does not work).
4320 else
4326 -- Case of size clause not given
4328 else
4329 -- If we have a base type whose corresponding first subtype
4330 -- has an explicit size that is large enough to include our
4331 -- end-points, then do so. There is no point in working hard
4332 -- to get a base type whose size is smaller than the specified
4333 -- size of the first subtype.
4339 then
4344 -- If excluding the end-points makes the size smaller and
4345 -- results in a size of 8,16,32,64, then we take the smaller
4346 -- size. For the 64 case, this is compulsory. For the other
4347 -- cases, it seems reasonable. We like to include end points
4348 -- if we can, but not at the expense of moving to the next
4349 -- natural boundary of size.
4352 and then
4357 then
4362 -- Otherwise we can definitely include the end points
4364 else
4370 -- One pathological case: normally we never fudge a low bound
4371 -- down, since it would seem to increase the size (if it has
4372 -- any effect), but for ranges containing single value, or no
4373 -- values, the high bound can be small too large. Consider:
4375 -- type t is delta 2.0**(-14)
4376 -- range 131072.0 .. 0;
4378 -- That lower bound is *just* outside the range of 32 bits, and
4379 -- does need fudging down in this case. Note that the bounds
4380 -- will always have crossed here, since the high bound will be
4381 -- fudged down if necessary, as in the case of:
4383 -- type t is delta 2.0**(-14)
4384 -- range 131072.0 .. 131072.0;
4386 -- So we detect the situation by looking for crossed bounds,
4387 -- and if the bounds are crossed, and the low bound is greater
4388 -- than zero, we will always back it off by small, since this
4389 -- is completely harmless.
4396 -- And of course, we need to do exactly the same parallel
4397 -- fudge for flat ranges in the negative region.
4410 -- For the decimal case, none of this fudging is required, since there
4411 -- are no end-point problems in the decimal case (the end-points are
4412 -- always included).
4414 else
4418 -- At this stage, the actual size has been calculated and the proper
4419 -- required bounds are stored in the low and high bounds.
4423 Error_Msg_N
4425 Typ);
4429 -- Check size against explicit given size
4435 Error_Msg_NE
4439 else
4443 -- Increase size to next natural boundary if no size clause given
4445 else
4452 else
4460 -- If we have a base type, then expand the bounds so that they extend to
4461 -- the full width of the allocated size in bits, to avoid junk range
4462 -- checks on intermediate computations.
4469 -- Final step is to reanalyze the bounds using the proper type
4470 -- and set the Corresponding_Integer_Value fields of the literals.
4476 -- Resolve with universal fixed if the base type, and the base type if
4477 -- it is a subtype. Note we can't resolve the base type with itself,
4478 -- that would be a reference before definition.
4482 else
4486 -- Set corresponding integer value for bound
4488 Set_Corresponding_Integer_Value
4491 -- Similar processing for high bound
4499 else
4503 Set_Corresponding_Integer_Value
4506 -- Set type of range to correspond to bounds
4510 -- Set Esize to calculated size if not set already
4516 -- Set RM_Size if not already set. If already set, check value
4518 declare
4521 begin
4526 Error_Msg_NE
4531 else
4537 ------------------
4538 -- Freeze_Itype --
4539 ------------------
4544 begin
4553 --------------------------
4554 -- Freeze_Static_Object --
4555 --------------------------
4560 -- Exception raised if the type of a static object cannot be made
4561 -- static. This happens if the type depends on non-global objects.
4564 -- Called to ensure that an expression used as part of a type definition
4565 -- is statically allocatable, which means that the expression type is
4566 -- statically allocatable, and the expression is either static, or a
4567 -- reference to a library level constant.
4570 -- Called to mark a type as static, checking that it is possible
4571 -- to set the type as static. If it is not possible, then the
4572 -- exception Cannot_Be_Static is raised.
4574 -----------------------------
4575 -- Ensure_Expression_Is_SA --
4576 -----------------------------
4581 begin
4593 then
4601 -----------------------
4602 -- Ensure_Type_Is_SA --
4603 -----------------------
4609 begin
4610 -- If type is library level, we are all set
4616 -- We are also OK if the type already marked as statically allocated,
4617 -- which means we processed it before.
4623 -- Mark type as statically allocated
4627 -- Check that it is safe to statically allocate this type
4645 declare
4649 begin
4662 else
4671 then
4690 else
4695 -- Start of processing for Freeze_Static_Object
4697 begin
4700 exception
4703 -- If the object that cannot be static is imported or exported,
4704 -- then we give an error message saying that this object cannot
4705 -- be imported or exported.
4708 Error_Msg_N
4711 -- Otherwise must be exported, something is wrong if compiler
4712 -- is marking something as statically allocated which cannot be).
4715 Error_Msg_N
4720 -----------------------
4721 -- Freeze_Subprogram --
4722 -----------------------
4728 begin
4729 -- Subprogram may not have an address clause unless it is imported
4733 Error_Msg_N
4740 -- Reset the Pure indication on an imported subprogram unless an
4741 -- explicit Pure_Function pragma was present. We do this because
4742 -- otherwise it is an insidious error to call a non-pure function from
4743 -- pure unit and have calls mysteriously optimized away. What happens
4744 -- here is that the Import can bypass the normal check to ensure that
4745 -- pure units call only pure subprograms.
4750 then
4754 -- For non-foreign convention subprograms, this is where we create
4755 -- the extra formals (for accessibility level and constrained bit
4756 -- information). We delay this till the freeze point precisely so
4757 -- that we know the convention!
4763 -- If this is convention Ada and a Valued_Procedure, that's odd
4768 and then Warn_On_Export_Import
4769 then
4770 Error_Msg_N
4775 -- Case of foreign convention
4777 else
4780 -- For foreign conventions, warn about return of an
4781 -- unconstrained array.
4783 -- Note: we *do* allow a return by descriptor for the VMS case,
4784 -- though here there is probably more to be done ???
4789 -- If no return type, probably some other error, e.g. a
4790 -- missing full declaration, so ignore.
4795 -- If the return type is generic, we have emitted a warning
4796 -- earlier on, and there is nothing else to check here. Specific
4797 -- instantiations may lead to erroneous behavior.
4805 and then Warn_On_Export_Import
4806 then
4807 Error_Msg_N
4814 -- If any of the formals for an exported foreign convention
4815 -- subprogram have defaults, then emit an appropriate warning since
4816 -- this is odd (default cannot be used from non-Ada code)
4821 if Warn_On_Export_Import
4823 then
4824 Error_Msg_N
4834 -- For VMS, descriptor mechanisms for parameters are allowed only
4835 -- for imported/exported subprograms. Moreover, the NCA descriptor
4836 -- is not allowed for parameters of exported subprograms.
4843 Error_Msg_N
4845 Error_Msg_N
4856 Error_Msg_N
4858 Error_Msg_N
4867 -- Pragma Inline_Always is disallowed for dispatching subprograms
4868 -- because the address of such subprograms is saved in the dispatch
4869 -- table to support dispatching calls, and dispatching calls cannot
4870 -- be inlined. This is consistent with the restriction against using
4871 -- 'Access or 'Address on an Inline_Always subprogram.
4874 Error_Msg_N
4879 ----------------------
4880 -- Is_Fully_Defined --
4881 ----------------------
4884 begin
4893 then
4894 -- Verify that the record type has no components with private types
4895 -- without completion.
4897 declare
4900 begin
4913 else
4919 ---------------------------------
4920 -- Process_Default_Expressions --
4921 ---------------------------------
4923 procedure Process_Default_Expressions
4926 is
4933 begin
4936 -- A subprogram instance and its associated anonymous subprogram share
4937 -- their signature. The default expression functions are defined in the
4938 -- wrapper packages for the anonymous subprogram, and should not be
4939 -- generated again for the instance.
4944 then
4952 -- We work with a copy of the default expression because we
4953 -- do not want to disturb the original, since this would mess
4954 -- up the conformance checking.
4958 -- The analysis of the expression may generate insert actions,
4959 -- which of course must not be executed. We wrap those actions
4960 -- in a procedure that is not called, and later on eliminated.
4961 -- The following cases have no side-effects, and are analyzed
4962 -- directly.
4973 and then
4975 then
4977 -- If there is no default function, we must still do a full
4978 -- analyze call on the default value, to ensure that all error
4979 -- checks are performed, e.g. those associated with static
4980 -- evaluation. Note: this branch will always be taken if the
4981 -- analyzer is turned off (but we still need the error checks).
4983 -- Note: the setting of parent here is to meet the requirement
4984 -- that we can only analyze the expression while attached to
4985 -- the tree. Really the requirement is that the parent chain
4986 -- be set, we don't actually need to be in the tree.
4991 -- Default expressions are resolved with their own type if the
4992 -- context is generic, to avoid anomalies with private types.
4996 else
5000 -- If that resolved expression will raise constraint error,
5001 -- then flag the default value as raising constraint error.
5002 -- This allows a proper error message on the calls.
5008 -- If the default is a parameterless call, we use the name of
5009 -- the called function directly, and there is no body to build.
5013 then
5016 -- Else construct and analyze the body of a wrapper procedure
5017 -- that contains an object declaration to hold the expression.
5018 -- Given that this is done only to complete the analysis, it
5019 -- simpler to build a procedure than a function which might
5020 -- involve secondary stack expansion.
5022 else
5023 Dnam :=
5026 Dbody :=
5028 Specification =>
5034 Defining_Identifier =>
5037 Object_Definition =>
5041 Handled_Statement_Sequence =>
5059 ----------------------------------------
5060 -- Set_Component_Alignment_If_Not_Set --
5061 ----------------------------------------
5064 begin
5065 -- Ignore if not base type, subtypes don't need anything
5071 -- Do not override existing representation
5082 else
5083 Set_Component_Alignment
5089 ---------------------------
5090 -- Set_Debug_Info_Needed --
5091 ---------------------------
5094 begin
5098 then
5100 else
5111 declare
5113 begin
5123 declare
5125 begin
5148 ------------------
5149 -- Undelay_Type --
5150 ------------------
5153 begin
5157 -- Since we don't want T to have a Freeze_Node, we don't want its
5158 -- Full_View or Corresponding_Record_Type to have one either.
5160 -- ??? Fundamentally, this whole handling is a kludge. What we really
5161 -- want is to be sure that for an Itype that's part of record R and is a
5162 -- subtype of type T, that it's frozen after the later of the freeze
5163 -- points of R and T. We have no way of doing that directly, so what we
5164 -- do is force most such Itypes to be frozen as part of freezing R via
5165 -- this procedure and only delay the ones that need to be delayed
5166 -- (mostly the designated types of access types that are defined as part
5167 -- of the record).
5173 then
5181 then
5186 ------------------
5187 -- Warn_Overlay --
5188 ------------------
5190 procedure Warn_Overlay
5194 is
5196 -- The object to which the address clause applies
5202 begin
5203 -- No warning if address clause overlay warnings are off
5209 -- No warning if there is an explicit initialization
5217 -- We only give the warning for non-imported entities of a type for
5218 -- which a non-null base init proc is defined (or for access types which
5219 -- have implicit null initialization).
5225 then
5228 then
5233 then
5240 then
5247 -- A function call (most likely to To_Address) is probably not an
5248 -- overlay, so skip warning. Ditto if the function call was inlined
5249 -- and transformed into an entity.
5257 -- If a pragma Import follows, we assume that it is for the current
5258 -- target of the address clause, and skip the warning.
5263 then
5269 Error_Msg_N
5271 Nam);
5272 else
5273 Error_Msg_N
5275 Nam);
5278 -- Add friendly warning if initialization comes from a packed array
5279 -- component.
5282 declare
5285 begin
5291 then
5295 then
5296 Error_Msg_NE
5301 else
5308 Error_Msg_N
5311 Nam);