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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) 1992-2013, 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 ------------------------------------------------------------------------------
71 -----------------------
72 -- Local Subprograms --
73 -----------------------
76 -- Typ is a type that is being frozen. If no size clause is given,
77 -- but a default Esize has been computed, then this default Esize is
78 -- adjusted up if necessary to be consistent with a given alignment,
79 -- but never to a value greater than Long_Long_Integer'Size. This
80 -- is used for all discrete types and for fixed-point types.
82 procedure Build_And_Analyze_Renamed_Body
86 -- Build body for a renaming declaration, insert in tree and analyze
89 -- Apply legality checks to address clauses for object declarations,
90 -- at the point the object is frozen. Also ensure any initialization is
91 -- performed only after the object has been frozen.
93 procedure Check_Component_Storage_Order
96 -- For an Encl_Type that has a Scalar_Storage_Order attribute definition
97 -- clause, verify that the component type is compatible. For arrays,
98 -- Comp is Empty; for records, it is the entity of the component under
99 -- consideration.
102 -- E is a base type. If E is tagged or has a component that is aliased
103 -- or tagged or contains something this is aliased or tagged, set
104 -- Strict_Alignment.
108 -- If E is a fixed-point or discrete type, then all the necessary work
109 -- to freeze it is completed except for possible setting of the flag
110 -- Is_Unsigned_Type, which is done by this procedure. The call has no
111 -- effect if the entity E is not a discrete or fixed-point type.
113 procedure Freeze_And_Append
117 -- Freezes Ent using Freeze_Entity, and appends the resulting list of
118 -- nodes to Result, modifying Result from No_List if necessary. N has
119 -- the same usage as in Freeze_Entity.
122 -- Freeze enumeration type. The Esize field is set as processing
123 -- proceeds (i.e. set by default when the type is declared and then
124 -- adjusted by rep clauses. What this procedure does is to make sure
125 -- that if a foreign convention is specified, and no specific size
126 -- is given, then the size must be at least Integer'Size.
129 -- If an object is frozen which has Is_Statically_Allocated set, then
130 -- all referenced types must also be marked with this flag. This routine
131 -- is in charge of meeting this requirement for the object entity E.
134 -- Perform freezing actions for a subprogram (create extra formals,
135 -- and set proper default mechanism values). Note that this routine
136 -- is not called for internal subprograms, for which neither of these
137 -- actions is needed (or desirable, we do not want for example to have
138 -- these extra formals present in initialization procedures, where they
139 -- would serve no purpose). In this call E is either a subprogram or
140 -- a subprogram type (i.e. an access to a subprogram).
143 -- True if T is not private and has no private components, or has a full
144 -- view. Used to determine whether the designated type of an access type
145 -- should be frozen when the access type is frozen. This is done when an
146 -- allocator is frozen, or an expression that may involve attributes of
147 -- the designated type. Otherwise freezing the access type does not freeze
148 -- the designated type.
150 procedure Process_Default_Expressions
153 -- This procedure is called for each subprogram to complete processing of
154 -- default expressions at the point where all types are known to be frozen.
155 -- The expressions must be analyzed in full, to make sure that all error
156 -- processing is done (they have only been pre-analyzed). If the expression
157 -- is not an entity or literal, its analysis may generate code which must
158 -- not be executed. In that case we build a function body to hold that
159 -- code. This wrapper function serves no other purpose (it used to be
160 -- called to evaluate the default, but now the default is inlined at each
161 -- point of call).
164 -- Typ is a record or array type that is being frozen. This routine sets
165 -- the default component alignment from the scope stack values if the
166 -- alignment is otherwise not specified.
169 -- As each entity is frozen, this routine is called to deal with the
170 -- setting of Debug_Info_Needed for the entity. This flag is set if
171 -- the entity comes from source, or if we are in Debug_Generated_Code
172 -- mode or if the -gnatdV debug flag is set. However, it never sets
173 -- the flag if Debug_Info_Off is set. This procedure also ensures that
174 -- subsidiary entities have the flag set as required.
177 -- T is a type of a component that we know to be an Itype. We don't want
178 -- this to have a Freeze_Node, so ensure it doesn't. Do the same for any
179 -- Full_View or Corresponding_Record_Type.
181 procedure Warn_Overlay
185 -- Expr is the expression for an address clause for entity Nam whose type
186 -- is Typ. If Typ has a default initialization, and there is no explicit
187 -- initialization in the source declaration, check whether the address
188 -- clause might cause overlaying of an entity, and emit a warning on the
189 -- side effect that the initialization will cause.
191 -------------------------------
192 -- Adjust_Esize_For_Alignment --
193 -------------------------------
198 begin
204 then
210 ------------------------------------
211 -- Build_And_Analyze_Renamed_Body --
212 ------------------------------------
214 procedure Build_And_Analyze_Renamed_Body
218 is
224 begin
225 -- If the renamed subprogram is intrinsic, there is no need for a
226 -- wrapper body: we set the alias that will be called and expanded which
227 -- completes the declaration. This transformation is only legal if the
228 -- renamed entity has already been elaborated.
230 -- Note that it is legal for a renaming_as_body to rename an intrinsic
231 -- subprogram, as long as the renaming occurs before the new entity
232 -- is frozen. See RM 8.5.4 (5).
236 then
238 else
244 and then
248 -- We can make the renaming entity intrinsic if the renamed function
249 -- has an interface name, or if it is one of the shift/rotate
250 -- operations known to the compiler.
252 and then
255 Name_Rotate_Right,
256 Name_Shift_Left,
257 Name_Shift_Right,
258 Name_Shift_Right_Arithmetic))
259 then
264 else
271 else
280 ------------------------
281 -- Build_Renamed_Body --
282 ------------------------
284 function Build_Renamed_Body
287 is
289 -- We use for the source location of the renamed body, the location of
290 -- the spec entity. It might seem more natural to use the location of
291 -- the renaming declaration itself, but that would be wrong, since then
292 -- the body we create would look as though it was created far too late,
293 -- and this could cause problems with elaboration order analysis,
294 -- particularly in connection with instantiations.
309 -- If the renamed entity is a primitive operation given in prefix form,
310 -- the prefix is the target object and it has to be added as the first
311 -- actual in the generated call.
313 begin
314 -- Determine the entity being renamed, which is the target of the call
315 -- statement. If the name is an explicit dereference, this is a renaming
316 -- of a subprogram type rather than a subprogram. The name itself is
317 -- fully analyzed.
328 else
335 else
341 -- If the renamed entity is a predefined operator, retain full name
342 -- to ensure its visibility.
346 then
348 else
352 else
355 and then
358 then
360 -- Retrieve the target object, to be added as a first actual
361 -- in the call.
366 else
370 -- Original name may have been overloaded, but is fully resolved now
375 -- For simple renamings, subsequent calls can be expanded directly as
376 -- calls to the renamed entity. The body must be generated in any case
377 -- for calls that may appear elsewhere. This is not done in the case
378 -- where the subprogram is an instantiation because the actual proper
379 -- body has not been built yet.
384 then
388 -- The body generated for this renaming is an internal artifact, and
389 -- does not constitute a freeze point for the called entity.
396 declare
400 begin
401 -- The controlling formal may be an access parameter, or the
402 -- actual may be an access value, so adjust accordingly.
406 then
407 Actuals := New_List
412 then
413 Actuals := New_List
417 else
425 else
436 -- If the renamed entity is an entry, inherit its profile. For other
437 -- renamings as bodies, both profiles must be subtype conformant, so it
438 -- is not necessary to replace the profile given in the declaration.
439 -- However, default values that are aggregates are rewritten when
440 -- partially analyzed, so we recover the original aggregate to insure
441 -- that subsequent conformity checking works. Similarly, if the default
442 -- expression was constant-folded, recover the original expression.
452 N_Access_Definition
453 then
461 then
472 -- If the renamed entity is a function, the generated body contains a
473 -- return statement. Otherwise, build a procedure call. If the entity is
474 -- an entry, subsequent analysis of the call will transform it into the
475 -- proper entry or protected operation call. If the renamed entity is
476 -- a character literal, return it directly.
482 then
483 Call_Node :=
485 Expression =>
491 Call_Node :=
496 Call_Node :=
500 else
501 Call_Node :=
507 -- Create entities for subprogram body and formals
520 Body_Node :=
524 Handled_Statement_Sequence =>
534 -- Link the body to the entity whose declaration it completes. If
535 -- the body is analyzed when the renamed entity is frozen, it may
536 -- be necessary to restore the proper scope (see package Exp_Ch13).
540 then
542 else
549 --------------------------
550 -- Check_Address_Clause --
551 --------------------------
560 begin
567 -- Has_Delayed_Freeze was set on E when the address clause was
568 -- analyzed, and must remain set because we want the address
569 -- clause to be elaborated only after any entity it references
570 -- has been elaborated.
573 -- If Rep_Clauses are to be ignored, remove address clause from
574 -- list attached to entity, because it may be illegal for gigi,
575 -- for example by breaking order of elaboration..
578 declare
581 begin
587 else
590 loop
604 then
610 -- Capture initialization value at point of declaration
614 -- Move initialization to freeze actions (once the object has
615 -- been frozen, and the address clause alignment check has been
616 -- performed.
628 -----------------------------
629 -- Check_Compile_Time_Size --
630 -----------------------------
635 -- Sets the compile time known size (32 bits or less) in the Esize
636 -- field, of T checking for a size clause that was given which attempts
637 -- to give a smaller size, and also checking for an alignment clause.
640 -- Recursive function that does all the work
643 -- If T is a constrained subtype, its size is not known if any of its
644 -- discriminant constraints is not static and it is not a null record.
645 -- The test is conservative and doesn't check that the components are
646 -- in fact constrained by non-static discriminant values. Could be made
647 -- more precise ???
649 --------------------
650 -- Set_Small_Size --
651 --------------------
654 begin
658 -- Check for bad size clause given
663 Error_Msg_NE
668 -- Set size if not set already
675 ----------------
676 -- Size_Known --
677 ----------------
686 begin
690 -- Always True for scalar types. This is true even for generic formal
691 -- scalar types. We used to return False in the latter case, but the
692 -- size is known at compile time, even in the template, we just do
693 -- not know the exact size but that's not the point of this routine.
697 then
700 -- Array types
704 -- String literals always have known size, and we can set it
711 -- Unconstrained types never have known at compile time size
716 -- Don't do any recursion on type with error posted, since we may
717 -- have a malformed type that leads us into a loop.
722 -- Otherwise if component size unknown, then array size unknown
728 -- Check for all indexes static, and also compute possible size
729 -- (in case it is less than 32 and may be packable).
731 declare
735 begin
744 else
752 then
755 else
760 else
772 -- Access types always have known at compile time sizes
777 -- For non-generic private types, go to underlying type if present
782 then
783 -- Don't do any recursion on type with error posted, since we may
784 -- have a malformed type that leads us into a loop.
788 else
792 -- Record types
796 -- A class-wide type is never considered to have a known size
801 -- A subtype of a variant record must not have non-static
802 -- discriminated components.
806 then
809 -- Don't do any recursion on type with error posted, since we may
810 -- have a malformed type that leads us into a loop.
816 -- Now look at the components of the record
818 declare
819 -- The following two variables are used to keep track of the
820 -- size of packed records if we can tell the size of the packed
821 -- record in the front end. Packed_Size_Known is True if so far
822 -- we can figure out the size. It is initialized to True for a
823 -- packed record, unless the record has discriminants or atomic
824 -- components or independent components.
826 -- The reason we eliminate the discriminated case is that
827 -- we don't know the way the back end lays out discriminated
828 -- packed records. If Packed_Size_Known is True, then
829 -- Packed_Size is the size in bits so far.
838 -- SIze in bis so far
840 begin
841 -- Test for variant part present
847 N_Record_Definition
851 then
852 -- If variant part is present, and type is unconstrained,
853 -- then we must have defaulted discriminants, or a size
854 -- clause must be present for the type, or else the size
855 -- is definitely not known at compile time.
858 and then
861 then
866 -- Loop through components
872 -- We do not know the packed size if there is a component
873 -- clause present (we possibly could, but this would only
874 -- help in the case of a record with partial rep clauses.
875 -- That's because in the case of full rep clauses, the
876 -- size gets figured out anyway by a different circuit).
882 -- We do not know the packed size if we have a by reference
883 -- type, or an atomic type or an atomic component.
888 then
892 -- We need to identify a component that is an array where
893 -- the index type is an enumeration type with non-standard
894 -- representation, and some bound of the type depends on a
895 -- discriminant.
897 -- This is because gigi computes the size by doing a
898 -- substitution of the appropriate discriminant value in
899 -- the size expression for the base type, and gigi is not
900 -- clever enough to evaluate the resulting expression (which
901 -- involves a call to rep_to_pos) at compile time.
903 -- It would be nice if gigi would either recognize that
904 -- this expression can be computed at compile time, or
905 -- alternatively figured out the size from the subtype
906 -- directly, where all the information is at hand ???
910 then
911 declare
919 begin
926 then
932 then
937 then
947 -- Clearly size of record is not known if the size of one of
948 -- the components is not known.
954 -- Accumulate packed size if possible
958 -- We can only deal with elementary types, since for
959 -- non-elementary components, alignment enters into the
960 -- picture, and we don't know enough to handle proper
961 -- alignment in this context. Packed arrays count as
962 -- elementary if the representation is a modular type.
967 and then Is_Modular_Integer_Type
969 then
970 -- Packed size unknown if we have an atomic type
971 -- or a by reference type, since the back end
972 -- knows how these are layed out.
976 then
979 -- If RM_Size is known and static, then we can keep
980 -- accumulating the packed size
984 -- A little glitch, to be removed sometime ???
985 -- gigi does not understand zero sizes yet.
990 -- Normal case where we can keep accumulating the
991 -- packed array size.
993 else
997 -- If we have a field whose RM_Size is not known then
998 -- we can't figure out the packed size here.
1000 else
1004 -- If we have a non-elementary type we can't figure out
1005 -- the packed array size (alignment issues).
1007 else
1022 -- All other cases, size not known at compile time
1024 else
1029 -------------------------------------
1030 -- Static_Discriminated_Components --
1031 -------------------------------------
1033 function Static_Discriminated_Components
1035 is
1038 begin
1042 then
1056 -- Start of processing for Check_Compile_Time_Size
1058 begin
1062 -----------------------------------
1063 -- Check_Component_Storage_Order --
1064 -----------------------------------
1066 procedure Check_Component_Storage_Order
1069 is
1076 -- Set True for the record case, when Comp starts on a byte boundary
1077 -- (in which case it is allowed to have different storage order).
1079 begin
1080 -- Record case
1090 else
1092 Comp_Byte_Aligned :=
1094 and then
1098 -- Array case
1100 else
1103 Comp_Def := Component_Definition
1109 -- Note: the Reverse_Storage_Order flag is set on the base type, but
1110 -- the attribute definition clause is attached to the first subtype.
1113 ADC := Get_Attribute_Definition_Clause
1115 Attribute_Scalar_Storage_Order);
1120 /=
1122 then
1123 Error_Msg_N
1133 /=
1135 and then not Comp_Byte_Aligned
1136 then
1137 Error_Msg_N
1143 Error_Msg_N
1149 -----------------------------
1150 -- Check_Debug_Info_Needed --
1151 -----------------------------
1154 begin
1159 or else Debug_Generated_Code
1160 or else Debug_Flag_VV
1162 then
1167 ----------------------------
1168 -- Check_Strict_Alignment --
1169 ----------------------------
1174 begin
1192 then
1202 -------------------------
1203 -- Check_Unsigned_Type --
1204 -------------------------
1211 begin
1216 -- Do not attempt to analyze case where range was in error
1220 then
1224 -- The situation that is non trivial is something like
1226 -- subtype x1 is integer range -10 .. +10;
1227 -- subtype x2 is x1 range 0 .. V1;
1228 -- subtype x3 is x2 range V2 .. V3;
1229 -- subtype x4 is x3 range V4 .. V5;
1231 -- where Vn are variables. Here the base type is signed, but we still
1232 -- know that x4 is unsigned because of the lower bound of x2.
1234 -- The only way to deal with this is to look up the ancestor chain
1237 loop
1252 else
1255 -- If no ancestor had a static lower bound, go to base type
1259 -- Note: the reason we still check for a compile time known
1260 -- value for the base type is that at least in the case of
1261 -- generic formals, we can have bounds that fail this test,
1262 -- and there may be other cases in error situations.
1274 then
1284 -------------------------
1285 -- Is_Atomic_Aggregate --
1286 -------------------------
1288 function Is_Atomic_Aggregate
1291 is
1297 begin
1300 -- Array may be qualified, so find outer context
1308 then
1310 New_N :=
1321 else
1326 ----------------
1327 -- Freeze_All --
1328 ----------------
1330 -- Note: the easy coding for this procedure would be to just build a
1331 -- single list of freeze nodes and then insert them and analyze them
1332 -- all at once. This won't work, because the analysis of earlier freeze
1333 -- nodes may recursively freeze types which would otherwise appear later
1334 -- on in the freeze list. So we must analyze and expand the freeze nodes
1335 -- as they are generated.
1342 -- This is the internal recursive routine that does freezing of entities
1343 -- (but NOT the analysis of default expressions, which should not be
1344 -- recursive, we don't want to analyze those till we are sure that ALL
1345 -- the types are frozen).
1347 --------------------
1348 -- Freeze_All_Ent --
1349 --------------------
1357 -- If freeze nodes are present, insert and analyze, and reset cursor
1358 -- for next insertion.
1360 -------------------
1361 -- Process_Flist --
1362 -------------------
1365 begin
1372 else
1378 -- Start or processing for Freeze_All_Ent
1380 begin
1384 -- If the entity is an inner package which is not a package
1385 -- renaming, then its entities must be frozen at this point. Note
1386 -- that such entities do NOT get frozen at the end of the nested
1387 -- package itself (only library packages freeze).
1389 -- Same is true for task declarations, where anonymous records
1390 -- created for entry parameters must be frozen.
1396 then
1407 then
1413 and then
1415 or else
1417 then
1420 End_Scope;
1422 -- For a derived tagged type, we must ensure that all the
1423 -- primitive operations of the parent have been frozen, so that
1424 -- their addresses will be in the parent's dispatch table at the
1425 -- point it is inherited.
1431 then
1432 declare
1439 begin
1446 then
1448 Process_Flist;
1458 Process_Flist;
1460 -- If already frozen, and there are delayed aspects, this is where
1461 -- we do the visibility check for these aspects (see Sem_Ch13 spec
1462 -- for a description of how we handle aspect visibility).
1466 -- Retrieve the visibility to the discriminants in order to
1467 -- analyze properly the aspects.
1471 declare
1474 begin
1480 then
1491 -- If an incomplete type is still not frozen, this may be a
1492 -- premature freezing because of a body declaration that follows.
1493 -- Indicate where the freezing took place. Freezing will happen
1494 -- if the body comes from source, but not if it is internally
1495 -- generated, for example as the body of a type invariant.
1497 -- If the freezing is caused by the end of the current declarative
1498 -- part, it is a Taft Amendment type, and there is no error.
1502 then
1503 declare
1506 begin
1507 -- The presence of a body freezes all entities previously
1508 -- declared in the current list of declarations, but this
1509 -- does not apply if the body does not come from source.
1510 -- A type invariant is transformed into a subprogram body
1511 -- which is placed at the end of the private part of the
1512 -- current package, but this body does not freeze incomplete
1513 -- types that may be declared in this private part.
1516 N_Entry_Body,
1517 N_Package_Body,
1518 N_Protected_Body,
1519 N_Task_Body)
1521 and then
1524 then
1526 Error_Msg_NE
1537 -- Start of processing for Freeze_All
1539 begin
1542 -- Now that all types are frozen, we can deal with default expressions
1543 -- that require us to build a default expression functions. This is the
1544 -- point at which such functions are constructed (after all types that
1545 -- might be used in such expressions have been frozen).
1547 -- For subprograms that are renaming_as_body, we create the wrapper
1548 -- bodies as needed.
1550 -- We also add finalization chains to access types whose designated
1551 -- types are controlled. This is normally done when freezing the type,
1552 -- but this misses recursive type definitions where the later members
1553 -- of the recursion introduce controlled components.
1555 -- Loop through entities
1571 else
1577 and then
1579 = N_Subprogram_Renaming_Declaration
1580 then
1581 Build_And_Analyze_Renamed_Body
1587 and then
1589 or else
1591 then
1592 declare
1595 begin
1600 then
1608 -- We add finalization masters to access types whose designated types
1609 -- require finalization. This is normally done when freezing the
1610 -- type, but this misses recursive type definitions where the later
1611 -- members of the recursion introduce controlled components (such as
1612 -- can happen when incomplete types are involved), as well cases
1613 -- where a component type is private and the controlled full type
1614 -- occurs after the access type is frozen. Cases that don't need a
1615 -- finalization master are generic formal types (the actual type will
1616 -- have it) and types with Java and CIL conventions, since those are
1617 -- used for API bindings. (Are there any other cases that should be
1618 -- excluded here???)
1624 then
1632 -----------------------
1633 -- Freeze_And_Append --
1634 -----------------------
1636 procedure Freeze_And_Append
1640 is
1642 begin
1646 else
1652 -------------------
1653 -- Freeze_Before --
1654 -------------------
1658 begin
1664 -------------------
1665 -- Freeze_Entity --
1666 -------------------
1678 -- List of freezing actions, left at No_List if none
1681 -- This flag gets set to true for a variable with default initialization
1684 -- N is a freezing action to be appended to the Result
1687 -- If Loc is a freeze_entity that appears after the last declaration
1688 -- in the scope, inhibit error messages on late completion.
1691 -- Check that an Access or Unchecked_Access attribute with a prefix
1692 -- which is the current instance type can only be applied when the type
1693 -- is limited.
1696 -- Give warning for modulus of 8, 16, 32, or 64 given as an explicit
1697 -- integer literal without an explicit corresponding size clause. The
1698 -- caller has checked that Utype is a modular integer type.
1701 -- Freeze each component, handle some representation clauses, and freeze
1702 -- primitive operations if this is a tagged type.
1704 -------------------
1705 -- Add_To_Result --
1706 -------------------
1709 begin
1712 else
1717 ----------------------------
1718 -- After_Last_Declaration --
1719 ----------------------------
1723 begin
1729 else
1732 else
1737 ----------------------------
1738 -- Check_Current_Instance --
1739 ----------------------------
1744 -- Determine whether Typ is compatible with the rules for aliased
1745 -- views of types as defined in RM 3.10 in the various dialects.
1748 -- Process routine to apply check to given node
1750 -----------------------------
1751 -- Is_Aliased_View_Of_Type --
1752 -----------------------------
1757 begin
1758 -- Common case
1762 then
1765 -- The following paragraphs describe what a legal aliased view of
1766 -- a type is in the various dialects of Ada.
1768 -- Ada 95
1770 -- The current instance of a limited type, and a formal parameter
1771 -- or generic formal object of a tagged type.
1773 -- Ada 95 limited type
1774 -- * Type with reserved word "limited"
1775 -- * A protected or task type
1776 -- * A composite type with limited component
1781 -- Ada 2005
1783 -- The current instance of a limited tagged type, a protected
1784 -- type, a task type, or a type that has the reserved word
1785 -- "limited" in its full definition ... a formal parameter or
1786 -- generic formal object of a tagged type.
1788 -- Ada 2005 limited type
1789 -- * Type with reserved word "limited", "synchronized", "task"
1790 -- or "protected"
1791 -- * A composite type with limited component
1792 -- * A derived type whose parent is a non-interface limited type
1795 return
1797 or else
1802 -- Ada 2012 and beyond
1804 -- The current instance of an immutably limited type ... a formal
1805 -- parameter or generic formal object of a tagged type.
1807 -- Ada 2012 limited type
1808 -- * Type with reserved word "limited", "synchronized", "task"
1809 -- or "protected"
1810 -- * A composite type with limited component
1811 -- * A derived type whose parent is a non-interface limited type
1812 -- * An incomplete view
1814 -- Ada 2012 immutably limited type
1815 -- * Explicitly limited record type
1816 -- * Record extension with "limited" present
1817 -- * Non-formal limited private type that is either tagged
1818 -- or has at least one access discriminant with a default
1819 -- expression
1820 -- * Task type, protected type or synchronized interface
1821 -- * Type derived from immutably limited type
1823 else
1824 return
1830 -------------
1831 -- Process --
1832 -------------
1835 begin
1839 Name_Unchecked_Access)
1843 then
1844 Error_Msg_N
1847 else
1857 -- Local variables
1862 -- Start of processing for Check_Current_Instance
1864 begin
1870 ------------------------------
1871 -- Check_Suspicious_Modulus --
1872 ------------------------------
1877 begin
1883 declare
1886 begin
1888 declare
1892 begin
1894 declare
1898 begin
1899 -- First case, modulus and size are the same. This
1900 -- happens if you have something like mod 32, with
1901 -- an explicit size of 32, this is for sure a case
1902 -- where the warning is given, since it is seems
1903 -- very unlikely that someone would want e.g. a
1904 -- five bit type stored in 32 bits. It is much
1905 -- more likely they wanted a 32-bit type.
1910 -- Second case, the modulus is 32 or 64 and no
1911 -- size clause is present. This is a less clear
1912 -- case for giving the warning, but in the case
1913 -- of 32/64 (5-bit or 6-bit types) these seem rare
1914 -- enough that it is a likely error (and in any
1915 -- case using 2**5 or 2**6 in these cases seems
1916 -- clearer. We don't include 8 or 16 here, simply
1917 -- because in practice 3-bit and 4-bit types are
1918 -- more common and too many false positives if
1919 -- we warn in these cases.
1923 then
1926 -- No warning needed
1928 else
1932 -- If we fall through, give warning
1935 Error_Msg_N
1937 Modulus);
1946 ------------------------
1947 -- Freeze_Record_Type --
1948 ------------------------
1960 -- Set True if the record type scope Rec has been pushed on the scope
1961 -- stack. Needed for the analysis of delayed aspects specified to the
1962 -- components of Rec.
1965 -- Set True if we find at least one component with no component
1966 -- clause (used to warn about useless Pack pragmas).
1969 -- Set True if we find at least one component with a component
1970 -- clause (used to warn about useless Bit_Order pragmas, and also
1971 -- to detect cases where Implicit_Packing may have an effect).
1974 -- Set False if we encounter a component of a non-scalar type
1978 -- Accumulates total RM_Size values and total Esize values of all
1979 -- scalar components. Used for processing of Implicit_Packing.
1982 -- If N is an allocator, possibly wrapped in one or more level of
1983 -- qualified expression(s), return the inner allocator node, else
1984 -- return Empty.
1987 -- If the component subtype is an access to a constrained subtype of
1988 -- an already frozen type, make the subtype frozen as well. It might
1989 -- otherwise be frozen in the wrong scope, and a freeze node on
1990 -- subtype has no effect. Similarly, if the component subtype is a
1991 -- regular (not protected) access to subprogram, set the anonymous
1992 -- subprogram type to frozen as well, to prevent an out-of-scope
1993 -- freeze node at some eventual point of call. Protected operations
1994 -- are handled elsewhere.
1996 ---------------------
1997 -- Check_Allocator --
1998 ---------------------
2002 begin
2004 loop
2009 else
2015 -----------------
2016 -- Check_Itype --
2017 -----------------
2022 begin
2025 then
2028 -- In addition, add an Itype_Reference to ensure that the
2029 -- access subtype is elaborated early enough. This cannot be
2030 -- done if the subtype may depend on discriminants.
2035 then
2043 then
2048 -- Start of processing for Freeze_Record_Type
2050 begin
2051 -- Deal with delayed aspect specifications for components. The
2052 -- analysis of the aspect is required to be delayed to the freeze
2053 -- point, thus we analyze the pragma or attribute definition
2054 -- clause in the tree at this point. We also analyze the aspect
2055 -- specification node at the freeze point when the aspect doesn't
2056 -- correspond to pragma/attribute definition clause.
2062 then
2067 -- The visibility to the discriminants must be restored in
2068 -- order to properly analyze the aspects.
2081 -- Pop the scope if Rec scope has been pushed on the scope stack
2082 -- during the delayed aspect analysis process.
2089 Pop_Scope;
2092 -- Freeze components and embedded subtypes
2098 -- Handle the component and discriminant case
2101 declare
2104 begin
2105 -- Freezing a record type freezes the type of each of its
2106 -- components. However, if the type of the component is
2107 -- part of this record, we do not want or need a separate
2108 -- Freeze_Node. Note that Is_Itype is wrong because that's
2109 -- also set in private type cases. We also can't check for
2110 -- the Scope being exactly Rec because of private types and
2111 -- record extensions.
2116 then
2122 -- Check for error of component clause given for variable
2123 -- sized type. We have to delay this test till this point,
2124 -- since the component type has to be frozen for us to know
2125 -- if it is variable length. We omit this test in a generic
2126 -- context, it will be applied at instantiation time.
2128 -- We also omit this test in CodePeer mode, since we do not
2129 -- have sufficient info on size and representation clauses.
2140 elsif not
2141 Size_Known_At_Compile_Time
2143 then
2144 Error_Msg_N
2149 else
2153 -- Case of component requires byte alignment
2157 -- Set the enclosing record to also require byte align
2161 -- Check for component clause that is inconsistent with
2162 -- the required byte boundary alignment.
2167 then
2168 Error_Msg_N
2176 -- Gather data for possible Implicit_Packing later. Note that at
2177 -- this stage we might be dealing with a real component, or with
2178 -- an implicit subtype declaration.
2182 else
2183 Scalar_Component_Total_RM_Size :=
2185 Scalar_Component_Total_Esize :=
2189 -- If the component is an Itype with Delayed_Freeze and is either
2190 -- a record or array subtype and its base type has not yet been
2191 -- frozen, we must remove this from the entity list of this record
2192 -- and put it on the entity list of the scope of its base type.
2193 -- Note that we know that this is not the type of a component
2194 -- since we cleared Has_Delayed_Freeze for it in the previous
2195 -- loop. Thus this must be the Designated_Type of an access type,
2196 -- which is the type of a component.
2204 then
2205 declare
2209 begin
2210 -- We have a pretty bad kludge here. Suppose Rec is subtype
2211 -- being defined in a subprogram that's created as part of
2212 -- the freezing of Rec'Base. In that case, we know that
2213 -- Comp'Base must have already been frozen by the time we
2214 -- get to elaborate this because Gigi doesn't elaborate any
2215 -- bodies until it has elaborated all of the declarative
2216 -- part. But Is_Frozen will not be set at this point because
2217 -- we are processing code in lexical order.
2219 -- We detect this case by going up the Scope chain of Rec
2220 -- and seeing if we have a subprogram scope before reaching
2221 -- the top of the scope chain or that of Comp'Base. If we
2222 -- do, then mark that Comp'Base will actually be frozen. If
2223 -- so, we merely undelay it.
2239 else
2242 else
2246 -- Insert in entity list of scope of base type (which
2247 -- must be an enclosing scope, because still unfrozen).
2253 -- If the component is an access type with an allocator as default
2254 -- value, the designated type will be frozen by the corresponding
2255 -- expression in init_proc. In order to place the freeze node for
2256 -- the designated type before that for the current record type,
2257 -- freeze it now.
2259 -- Same process if the component is an array of access types,
2260 -- initialized with an aggregate. If the designated type is
2261 -- private, it cannot contain allocators, and it is premature
2262 -- to freeze the type, so we check for this as well.
2267 then
2268 declare
2272 begin
2275 -- If component is pointer to a classwide type, freeze
2276 -- the specific type in the expression being allocated.
2277 -- The expression may be a subtype indication, in which
2278 -- case freeze the subtype mark.
2280 if Is_Class_Wide_Type
2282 then
2284 Freeze_And_Append
2286 elsif
2288 then
2289 Freeze_And_Append
2297 else
2298 Freeze_And_Append
2306 then
2315 and then Is_Fully_Defined
2317 then
2318 Freeze_And_Append
2319 (Designated_Type
2327 ADC := Get_Attribute_Definition_Clause
2332 -- Check compatibility of Scalar_Storage_Order with Bit_Order, if
2333 -- the former is specified.
2337 -- Note: report error on Rec, not on ADC, as ADC may apply to
2338 -- an ancestor type.
2341 Error_Msg_N
2346 -- Warn if there is a Scalar_Storage_Order but no component clause
2347 -- (or pragma Pack).
2350 Error_Msg_N
2352 ADC);
2355 -- Check attribute on component types
2364 -- Deal with Bit_Order aspect specifying a non-default bit order
2371 Error_Msg_N
2374 -- Here is where we do the processing for reversed bit order
2378 then
2381 -- Case where we have both an explicit Bit_Order and the same
2382 -- Scalar_Storage_Order: leave record untouched, the back-end
2383 -- will take care of required layout conversions.
2385 else
2391 -- Complete error checking on record representation clause (e.g.
2392 -- overlap of components). This is called after adjusting the
2393 -- record for reverse bit order.
2395 declare
2397 begin
2403 -- Set OK_To_Reorder_Components depending on debug flags
2407 or else
2409 then
2414 -- Check for useless pragma Pack when all components placed. We only
2415 -- do this check for record types, not subtypes, since a subtype may
2416 -- have all its components placed, and it still makes perfectly good
2417 -- sense to pack other subtypes or the parent type. We do not give
2418 -- this warning if Optimize_Alignment is set to Space, since the
2419 -- pragma Pack does have an effect in this case (it always resets
2420 -- the alignment to one).
2424 and then not Unplaced_Component
2426 then
2427 -- Reset packed status. Probably not necessary, but we do it so
2428 -- that there is no chance of the back end doing something strange
2429 -- with this redundant indication of packing.
2433 -- Give warning if redundant constructs warnings on
2436 Error_Msg_N -- CODEFIX
2442 -- If this is the record corresponding to a remote type, freeze the
2443 -- remote type here since that is what we are semantically freezing.
2444 -- This prevents the freeze node for that type in an inner scope.
2446 -- Also, Check for controlled components and unchecked unions.
2447 -- Finally, enforce the restriction that access attributes with a
2448 -- current instance prefix can only apply to limited types.
2458 -- Do not set Has_Controlled_Component on a class-wide
2459 -- equivalent type. See Make_CW_Equivalent_Type.
2466 and then Present
2467 (Corresponding_Record_Type
2469 and then Has_Controlled_Component
2470 (Corresponding_Record_Type
2472 then
2480 -- Scan component declaration for likely misuses of current
2481 -- instance, either in a constraint or a default expression.
2493 -- For first subtypes, check if there are any fixed-point fields with
2494 -- component clauses, where we must check the size. This is not done
2495 -- till the freeze point, since for fixed-point types, we do not know
2496 -- the size until the type is frozen. Similar processing applies to
2497 -- bit packed arrays.
2504 or else
2506 then
2507 Check_Size
2511 Junk);
2518 -- Generate warning for applying C or C++ convention to a record
2519 -- with discriminants. This is suppressed for the unchecked union
2520 -- case, since the whole point in this case is interface C. We also
2521 -- do not generate this within instantiations, since we will have
2522 -- generated a message on the template.
2527 or else
2530 and then not In_Instance
2533 then
2534 declare
2538 begin
2543 Error_Msg_N
2545 A2);
2546 else
2547 Error_Msg_N
2549 A2);
2552 Error_Msg_NE
2558 -- See if Size is too small as is (and implicit packing might help)
2562 -- No implicit packing if even one component is explicitly placed
2564 and then not Placed_Component
2566 -- Must have size clause and all scalar components
2569 and then All_Scalar_Components
2571 -- Do not try implicit packing on records with discriminants, too
2572 -- complicated, especially in the variant record case.
2576 -- We can implicitly pack if the specified size of the record is
2577 -- less than the sum of the object sizes (no point in packing if
2578 -- this is not the case).
2582 -- And the total RM size cannot be greater than the specified size
2583 -- since otherwise packing will not get us where we have to be!
2587 -- Never do implicit packing in CodePeer or SPARK modes since
2588 -- we don't do any packing in these modes, since this generates
2589 -- over-complex code that confuses static analysis, and in
2590 -- general, neither CodePeer not GNATprove care about the
2591 -- internal representation of objects.
2594 then
2595 -- If implicit packing enabled, do it
2600 -- Otherwise flag the size clause
2602 else
2603 declare
2605 begin
2606 Error_Msg_NE -- CODEFIX
2608 Error_Msg_N -- CODEFIX
2616 -- Start of processing for Freeze_Entity
2618 begin
2619 -- We are going to test for various reasons why this entity need not be
2620 -- frozen here, but in the case of an Itype that's defined within a
2621 -- record, that test actually applies to the record.
2627 then
2631 -- Do not freeze if already frozen since we only need one freeze node
2636 -- It is improper to freeze an external entity within a generic because
2637 -- its freeze node will appear in a non-valid context. The entity will
2638 -- be frozen in the proper scope after the current generic is analyzed.
2639 -- However, aspects must be analyzed because they may be queried later
2640 -- within the generic itself, and the corresponding pragma or attribute
2641 -- definition has not been analyzed yet.
2650 -- AI05-0213: A formal incomplete type does not freeze the actual. In
2651 -- the instance, the same applies to the subtype renaming the actual.
2657 then
2660 -- Do not freeze a global entity within an inner scope created during
2661 -- expansion. A call to subprogram E within some internal procedure
2662 -- (a stream attribute for example) might require freezing E, but the
2663 -- freeze node must appear in the same declarative part as E itself.
2664 -- The two-pass elaboration mechanism in gigi guarantees that E will
2665 -- be frozen before the inner call is elaborated. We exclude constants
2666 -- from this test, because deferred constants may be frozen early, and
2667 -- must be diagnosed (e.g. in the case of a deferred constant being used
2668 -- in a default expression). If the enclosing subprogram comes from
2669 -- source, or is a generic instance, then the freeze point is the one
2670 -- mandated by the language, and we freeze the entity. A subprogram that
2671 -- is a child unit body that acts as a spec does not have a spec that
2672 -- comes from source, but can only come from source.
2677 then
2678 declare
2681 begin
2688 then
2690 else
2699 -- Similarly, an inlined instance body may make reference to global
2700 -- entities, but these references cannot be the proper freezing point
2701 -- for them, and in the absence of inlining freezing will take place in
2702 -- their own scope. Normally instance bodies are analyzed after the
2703 -- enclosing compilation, and everything has been frozen at the proper
2704 -- place, but with front-end inlining an instance body is compiled
2705 -- before the end of the enclosing scope, and as a result out-of-order
2706 -- freezing must be prevented.
2708 elsif Front_End_Inlining
2709 and then In_Instance_Body
2711 then
2712 declare
2715 begin
2720 else
2731 -- Add checks to detect proper initialization of scalars that may appear
2732 -- as subprogram parameters.
2735 and then Check_Validity_Of_Parameters
2736 then
2740 -- Deal with delayed aspect specifications. The analysis of the aspect
2741 -- is required to be delayed to the freeze point, thus we analyze the
2742 -- pragma or attribute definition clause in the tree at this point. We
2743 -- also analyze the aspect specification node at the freeze point when
2744 -- the aspect doesn't correspond to pragma/attribute definition clause.
2750 -- Here to freeze the entity
2754 -- Case of entity being frozen is other than a type
2758 -- If entity is exported or imported and does not have an external
2759 -- name, now is the time to provide the appropriate default name.
2760 -- Skip this if the entity is stubbed, since we don't need a name
2761 -- for any stubbed routine. For the case on intrinsics, if no
2762 -- external name is specified, then calls will be handled in
2763 -- Exp_Intr.Expand_Intrinsic_Call, and no name is needed. If an
2764 -- external name is provided, then Expand_Intrinsic_Call leaves
2765 -- calls in place for expansion by GIGI.
2771 then
2772 Set_Encoded_Interface_Name
2775 -- If entity is an atomic object appearing in a declaration and
2776 -- the expression is an aggregate, assign it to a temporary to
2777 -- ensure that the actual assignment is done atomically rather
2778 -- than component-wise (the assignment to the temp may be done
2779 -- component-wise, but that is harmless).
2786 then
2790 -- For a subprogram, freeze all parameter types and also the return
2791 -- type (RM 13.14(14)). However skip this for internal subprograms.
2792 -- This is also the point where any extra formal parameters are
2793 -- created since we now know whether the subprogram will use a
2794 -- foreign convention.
2798 declare
2803 begin
2804 -- Loop through formals
2810 -- AI05-0151 : incomplete types can appear in a profile.
2811 -- By the time the entity is frozen, the full view must
2812 -- be available, unless it is a limited view.
2816 then
2828 then
2829 -- If the type of a formal is incomplete, subprogram
2830 -- is being frozen prematurely. Within an instance
2831 -- (but not within a wrapper package) this is an
2832 -- artifact of our need to regard the end of an
2833 -- instantiation as a freeze point. Otherwise it is
2834 -- a definite error.
2840 elsif not After_Last_Declaration
2841 and then not Freezing_Library_Level_Tagged_Type
2842 then
2844 Error_Msg
2846 Loc);
2850 -- Check suspicious parameter for C function. These tests
2851 -- apply only to exported/imported subprograms.
2853 if Warn_On_Export_Import
2856 or else
2863 then
2864 -- Qualify mention of formals with subprogram name
2868 -- Check suspicious use of fat C pointer
2872 then
2873 Error_Msg_N
2875 Formal);
2877 -- Check suspicious return of boolean
2884 then
2885 Error_Msg_N
2887 Error_Msg_N
2891 -- Check suspicious tagged type
2895 and then
2896 Is_Tagged_Type
2899 then
2900 Error_Msg_N
2904 -- Check wrong convention subprogram pointer
2908 then
2909 Error_Msg_N
2913 Error_Msg_NE
2918 -- Turn off name qualification after message output
2923 -- Check for unconstrained array in exported foreign
2924 -- convention case.
2930 and then Warn_On_Export_Import
2932 -- Exclude VM case, since both .NET and JVM can handle
2933 -- unconstrained arrays without a problem.
2936 then
2939 -- If this is an inherited operation, place the
2940 -- warning on the derived type declaration, rather
2941 -- than on the original subprogram.
2944 N_Full_Type_Declaration
2945 then
2949 Error_Msg_NE
2952 else
2956 Error_Msg_NE
2959 Error_Msg_NE
2970 -- If the formal is an anonymous_access_to_subprogram
2971 -- freeze the subprogram type as well, to prevent
2972 -- scope anomalies in gigi, because there is no other
2973 -- clear point at which it could be frozen.
2977 then
2985 -- Case of function: similar checks on return type
2989 -- Freeze return type
2993 -- AI05-0151: the return type may have been incomplete
2994 -- at the point of declaration.
2998 then
3005 -- Check suspicious return type for C function
3007 if Warn_On_Export_Import
3009 or else
3012 then
3013 -- Check suspicious return of fat C pointer
3019 then
3020 Error_Msg_N
3024 -- Check suspicious return of boolean
3032 then
3033 declare
3036 begin
3037 Error_Msg_NE
3040 Error_Msg_NE
3045 -- Check suspicious return tagged type
3049 and then
3050 Is_Tagged_Type
3055 then
3056 Error_Msg_N
3060 -- Check return of wrong convention subprogram pointer
3066 then
3067 Error_Msg_N
3071 Error_Msg_NE
3077 -- Give warning for suspicious return of a result of an
3078 -- unconstrained array type in a foreign convention
3079 -- function.
3083 -- We are looking for a return of unconstrained array
3088 -- Exclude imported routines, the warning does not
3089 -- belong on the import, but rather on the routine
3090 -- definition.
3094 -- Exclude VM case, since both .NET and JVM can handle
3095 -- return of unconstrained arrays without a problem.
3099 -- Check that general warning is enabled, and that it
3100 -- is not suppressed for this particular case.
3102 and then Warn_On_Export_Import
3105 then
3106 Error_Msg_N
3113 -- Pre/post conditions are implemented through a subprogram in
3114 -- the corresponding body, and therefore are not checked on an
3115 -- imported subprogram for which the body is not available.
3117 -- Could consider generating a wrapper to take care of this???
3123 then
3124 Error_Msg_NE
3131 -- Must freeze its parent first if it is a derived subprogram
3137 -- We don't freeze internal subprograms, because we don't normally
3138 -- want addition of extra formals or mechanism setting to happen
3139 -- for those. However we do pass through predefined dispatching
3140 -- cases, since extra formals may be needed in some cases, such as
3141 -- for the stream 'Input function (build-in-place formals).
3145 then
3149 -- Here for other than a subprogram or type
3151 else
3152 -- If entity has a type, and it is not a generic unit, then
3153 -- freeze it first (RM 13.14(10)).
3157 then
3161 -- Special processing for objects created by object declaration
3165 -- Abstract type allowed only for C++ imported variables or
3166 -- constants.
3168 -- Note: we inhibit this check for objects that do not come
3169 -- from source because there is at least one case (the
3170 -- expansion of x'Class'Input where x is abstract) where we
3171 -- legitimately generate an abstract object.
3177 then
3182 Error_Msg_NE
3188 -- For object created by object declaration, perform required
3189 -- categorization (preelaborate and pure) checks. Defer these
3190 -- checks to freeze time since pragma Import inhibits default
3191 -- initialization and thus pragma Import affects these checks.
3195 -- If there is an address clause, check that it is valid
3199 -- If the object needs any kind of default initialization, an
3200 -- error must be issued if No_Default_Initialization applies.
3201 -- The check doesn't apply to imported objects, which are not
3202 -- ever default initialized, and is why the check is deferred
3203 -- until freezing, at which point we know if Import applies.
3204 -- Deferred constants are also exempted from this test because
3205 -- their completion is explicit, or through an import pragma.
3209 then
3215 and then
3220 or else
3223 then
3225 Check_Restriction
3229 -- Check that a Thread_Local_Storage variable does not have
3230 -- default initialization, and any explicit initialization must
3231 -- either be the null constant or a static constant.
3234 declare
3236 begin
3237 if Has_Default_Initialization
3238 or else
3240 and then
3242 or else not
3244 or else
3246 then
3247 Error_Msg_NE
3250 Error_Msg_NE
3257 -- For imported objects, set Is_Public unless there is also an
3258 -- address clause, which means that there is no external symbol
3259 -- needed for the Import (Is_Public may still be set for other
3260 -- unrelated reasons). Note that we delayed this processing
3261 -- till freeze time so that we can be sure not to set the flag
3262 -- if there is an address clause. If there is such a clause,
3263 -- then the only purpose of the Import pragma is to suppress
3264 -- implicit initialization.
3268 then
3272 -- For convention C objects of an enumeration type, warn if
3273 -- the size is not integer size and no explicit size given.
3274 -- Skip warning for Boolean, and Character, assume programmer
3275 -- expects 8-bit sizes for these cases.
3278 or else
3285 then
3287 Error_Msg_N
3289 E);
3294 -- Check that a constant which has a pragma Volatile[_Components]
3295 -- or Atomic[_Components] also has a pragma Import (RM C.6(13)).
3297 -- Note: Atomic[_Components] also sets Volatile[_Components]
3302 then
3303 -- Make sure we actually have a pragma, and have not merely
3304 -- inherited the indication from elsewhere (e.g. an address
3305 -- clause, which is not good enough in RM terms!)
3308 or else
3310 then
3311 Error_Msg_N
3316 or else
3318 then
3319 Error_Msg_N
3325 -- Static objects require special handling
3329 then
3333 -- Remaining step is to layout objects
3336 or else
3338 or else
3340 or else
3342 then
3346 -- If initialization statements were captured in an expression
3347 -- with actions with null expression, and the object does not
3348 -- have delayed freezing, move them back now directly within the
3349 -- enclosing statement sequence.
3353 then
3354 declare
3357 begin
3361 then
3364 -- Note that we rewrite Init_Stmts into a NULL statement,
3365 -- rather than just removing it, because Freeze_All may
3366 -- depend on this particular Node_Id still being present
3367 -- in the enclosing list to signal where to stop
3368 -- freezing.
3380 -- Case of a type or subtype being frozen
3382 else
3383 -- We used to check here that a full type must have preelaborable
3384 -- initialization if it completes a private type specified with
3385 -- pragma Preelaborable_Initialization, but that missed cases where
3386 -- the types occur within a generic package, since the freezing
3387 -- that occurs within a containing scope generally skips traversal
3388 -- of a generic unit's declarations (those will be frozen within
3389 -- instances). This check was moved to Analyze_Package_Specification.
3391 -- The type may be defined in a generic unit. This can occur when
3392 -- freezing a generic function that returns the type (which is
3393 -- defined in a parent unit). It is clearly meaningless to freeze
3394 -- this type. However, if it is a subtype, its size may be determi-
3395 -- nable and used in subsequent checks, so might as well try to
3396 -- compute it.
3398 -- In Ada 2012, Freeze_Entities is also used in the front end to
3399 -- trigger the analysis of aspect expressions, so in this case we
3400 -- want to continue the freezing process.
3405 then
3410 -- Deal with special cases of freezing for subtype
3414 -- Before we do anything else, a specialized test for the case of
3415 -- a size given for an array where the array needs to be packed,
3416 -- but was not so the size cannot be honored. This is the case
3417 -- where implicit packing may apply. The reason we do this so
3418 -- early is that if we have implicit packing, the layout of the
3419 -- base type is affected, so we must do this before we freeze
3420 -- the base type.
3422 -- We could do this processing only if implicit packing is enabled
3423 -- since in all other cases, the error would be caught by the back
3424 -- end. However, we choose to do the check even if we do not have
3425 -- implicit packing enabled, since this allows us to give a more
3426 -- useful error message (advising use of pragmas Implicit_Packing
3427 -- or Pack).
3430 declare
3441 -- Number of elements in array
3443 begin
3444 -- Check enabling conditions. These are straightforward
3445 -- except for the test for a limited composite type. This
3446 -- eliminates the rare case of a array of limited components
3447 -- where there are issues of whether or not we can go ahead
3448 -- and pack the array (since we can't freely pack and unpack
3449 -- arrays if they are limited).
3451 -- Note that we check the root type explicitly because the
3452 -- whole point is we are doing this test before we have had
3453 -- a chance to freeze the base type (and it is that freeze
3454 -- action that causes stuff to be inherited).
3467 then
3468 -- Compute number of elements in array
3476 and then
3478 then
3482 Num_Elmts :=
3483 Num_Elmts *
3489 -- What we are looking for here is the situation where
3490 -- the RM_Size given would be exactly right if there was
3491 -- a pragma Pack (resulting in the component size being
3492 -- the same as the RM_Size). Furthermore, the component
3493 -- type size must be an odd size (not a multiple of
3494 -- storage unit). If the component RM size is an exact
3495 -- number of storage units that is a power of two, the
3496 -- array is not packed and has a standard representation.
3500 then
3501 -- For implicit packing mode, just set the component
3502 -- size silently.
3510 -- Otherwise give an error message
3512 else
3513 Error_Msg_NE
3515 Error_Msg_N -- CODEFIX
3521 and then Implicit_Packing
3522 and then
3524 or else
3526 or else
3528 then
3529 -- Not a packed array, but indicate the desired
3530 -- component size, for the back-end.
3540 -- If ancestor subtype present, freeze that first. Note that this
3541 -- will also get the base type frozen. Need RM reference ???
3548 -- No ancestor subtype present
3550 else
3551 -- See if we have a nearest ancestor that has a predicate.
3552 -- That catches the case of derived type with a predicate.
3553 -- Need RM reference here ???
3561 -- Freeze base type before freezing the entity (RM 13.14(15))
3568 -- A subtype inherits all the type-related representation aspects
3569 -- from its parents (RM 13.1(8)).
3573 -- For a derived type, freeze its parent type first (RM 13.14(15))
3579 -- A derived type inherits each type-related representation aspect
3580 -- of its parent type that was directly specified before the
3581 -- declaration of the derived type (RM 13.1(15)).
3586 -- For array type, freeze index types and component type first
3587 -- before freezing the array (RM 13.14(15)).
3590 declare
3596 -- Set true if any of the index types is an enumeration type
3597 -- with a non-standard representation.
3599 begin
3608 then
3615 -- Processing that is done only for base types
3619 -- Propagate flags for component type
3623 then
3631 -- If packing was requested or if the component size was set
3632 -- explicitly, then see if bit packing is required. This
3633 -- processing is only done for base types, since all the
3634 -- representation aspects involved are type-related. This
3635 -- is not just an optimization, if we start processing the
3636 -- subtypes, they interfere with the settings on the base
3637 -- type (this is because Is_Packed has a slightly different
3638 -- meaning before and after freezing).
3640 declare
3644 begin
3648 then
3657 else
3660 -- We can set the component size if it is less than
3661 -- 16, rounding it up to the next storage unit size.
3667 else
3671 -- Set component size up to match alignment if it
3672 -- would otherwise be less than the alignment. This
3673 -- deals with cases of types whose alignment exceeds
3674 -- their size (padded types).
3677 declare
3679 begin
3687 -- Case of component size that may result in packing
3690 declare
3696 Get_Attribute_Definition_Clause
3698 begin
3699 -- Warn if we have pack and component size so that
3700 -- the pack is ignored.
3702 -- Note: here we must check for the presence of a
3703 -- component size before checking for a Pack pragma
3704 -- to deal with the case where the array type is a
3705 -- derived type whose parent is currently private.
3709 and then Warn_On_Redundant_Constructs
3710 then
3712 Error_Msg_NE
3715 Error_Msg_N
3717 Pack_Pragma);
3722 -- Set component size if not already set by a
3723 -- component size clause.
3729 -- Check for base type of 8, 16, 32 bits, where an
3730 -- unsigned subtype has a length one less than the
3731 -- base type (e.g. Natural subtype of Integer).
3733 -- In such cases, if a component size was not set
3734 -- explicitly, then generate a warning.
3738 and then
3741 then
3745 Error_Msg_N
3748 Error_Msg_N
3754 -- Actual packing is not needed for 8, 16, 32, 64.
3755 -- Also not needed for 24 if alignment is 1.
3762 then
3763 -- Here the array was requested to be packed,
3764 -- but the packing request had no effect, so
3765 -- Is_Packed is reset.
3767 -- Note: semantically this means that we lose
3768 -- track of the fact that a derived type
3769 -- inherited a pragma Pack that was non-
3770 -- effective, but that seems fine.
3772 -- We regard a Pack pragma as a request to set
3773 -- a representation characteristic, and this
3774 -- request may be ignored.
3781 then
3782 Set_Has_Non_Standard_Rep
3786 -- In all other cases, packing is indeed needed
3788 else
3797 -- Check for Atomic_Components or Aliased with unsuitable
3798 -- packing or explicit component size clause given.
3804 then
3808 -- Outputs error messages for incorrect CS clause or
3809 -- pragma Pack for aliased or atomic components (T is
3810 -- "aliased" or "atomic");
3812 -----------------
3813 -- Complain_CS --
3814 -----------------
3817 begin
3819 Clause :=
3820 Get_Attribute_Definition_Clause
3824 Error_Msg_N
3828 Error_Msg_N
3831 else
3832 Error_Msg_N
3837 else
3838 Error_Msg_N
3846 -- Start of processing for Alias_Atomic_Check
3848 begin
3850 -- If object size of component type isn't known, we
3851 -- cannot be sure so we defer to the back end.
3856 -- Case where component size has no effect. First
3857 -- check for object size of component type multiple
3858 -- of the storage unit size.
3862 -- OK in both packing case and component size case
3863 -- if RM size is known and static and the same as
3864 -- the object size.
3866 and then
3870 -- Or if we have an explicit component size
3871 -- clause and the component size and object size
3872 -- are equal.
3874 or else
3877 then
3882 then
3887 then
3893 -- Warn for case of atomic type
3899 then
3900 Error_Msg_NE
3905 Error_Msg_Sloc :=
3906 Sloc
3907 (Get_Attribute_Definition_Clause
3909 Error_Msg_N
3911 Clause);
3914 Error_Msg_Sloc :=
3916 Error_Msg_N
3921 -- Check for scalar storage order
3925 then
3929 -- Processing that is done only for subtypes
3931 else
3932 -- Acquire alignment from base type
3940 -- Specific checks for bit-packed arrays
3944 -- Check number of elements for bit packed arrays that come
3945 -- from source and have compile time known ranges. The
3946 -- bit-packed arrays circuitry does not support arrays
3947 -- with more than Integer'Last + 1 elements, and when this
3948 -- restriction is violated, causes incorrect data access.
3950 -- For the case where this is not compile time known, a
3951 -- run-time check should be generated???
3954 declare
3960 begin
3966 -- Never generate an error if any index is of a
3967 -- generic type. We will check this in instances.
3974 Ilen :=
3976 Prefix =>
3981 -- No attempt is made to check number of elements
3982 -- if not compile time known.
3994 (Scalar_Range
3996 then
3997 Error_Msg_N
4004 -- Check size
4007 declare
4013 begin
4014 -- It is not clear if it is possible to have no size
4015 -- clause at this stage, but it is not worth worrying
4016 -- about. Post error on the entity name in the size
4017 -- clause if present, else on the type entity itself.
4021 else
4028 -- If any of the index types was an enumeration type with a
4029 -- non-standard rep clause, then we indicate that the array
4030 -- type is always packed (even if it is not bit packed).
4039 -- If the array is packed, we must create the packed array
4040 -- type to be used to actually implement the type. This is
4041 -- only needed for real array types (not for string literal
4042 -- types, since they are present only for the front end).
4046 then
4050 -- Size information of packed array type is copied to the
4051 -- array type, since this is really the representation. But
4052 -- do not override explicit existing size values. If the
4053 -- ancestor subtype is constrained the packed_array_type
4054 -- will be inherited from it, but the size may have been
4055 -- provided already, and must not be overridden either.
4058 and then
4061 then
4071 -- For non-packed arrays set the alignment of the array to the
4072 -- alignment of the component type if it is unknown. Skip this
4073 -- in atomic case (atomic arrays may need larger alignments).
4082 then
4087 -- For a class-wide type, the corresponding specific type is
4088 -- frozen as well (RM 13.14(15))
4093 -- If the base type of the class-wide type is still incomplete,
4094 -- the class-wide remains unfrozen as well. This is legal when
4095 -- E is the formal of a primitive operation of some other type
4096 -- which is being frozen.
4103 -- The equivalent type associated with a class-wide subtype needs
4104 -- to be frozen to ensure that its layout is done.
4108 then
4112 -- Generate an itype reference for a library-level class-wide type
4113 -- at the freeze point. Otherwise the first explicit reference to
4114 -- the type may appear in an inner scope which will be rejected by
4115 -- the back-end.
4119 then
4120 declare
4123 begin
4126 -- From a gigi point of view, a class-wide subtype derives
4127 -- from its record equivalent type. As a result, the itype
4128 -- reference must appear after the freeze node of the
4129 -- equivalent type or gigi will reject the reference.
4133 then
4135 else
4141 -- For a record type or record subtype, freeze all component types
4142 -- (RM 13.14(15)). We test for E_Record_(sub)Type here, rather than
4143 -- using Is_Record_Type, because we don't want to attempt the freeze
4144 -- for the case of a private type with record extension (we will do
4145 -- that later when the full type is frozen).
4150 -- For a concurrent type, freeze corresponding record type. This
4151 -- does not correspond to any specific rule in the RM, but the
4152 -- record type is essentially part of the concurrent type.
4153 -- Freeze as well all local entities. This includes record types
4154 -- created for entry parameter blocks, and whatever local entities
4155 -- may appear in the private part.
4159 Freeze_And_Append
4171 then
4181 -- Private types are required to point to the same freeze node as
4182 -- their corresponding full views. The freeze node itself has to
4183 -- point to the partial view of the entity (because from the partial
4184 -- view, we can retrieve the full view, but not the reverse).
4185 -- However, in order to freeze correctly, we need to freeze the full
4186 -- view. If we are freezing at the end of a scope (or within the
4187 -- scope of the private type), the partial and full views will have
4188 -- been swapped, the full view appears first in the entity chain and
4189 -- the swapping mechanism ensures that the pointers are properly set
4190 -- (on scope exit).
4192 -- If we encounter the partial view before the full view (e.g. when
4193 -- freezing from another scope), we freeze the full view, and then
4194 -- set the pointers appropriately since we cannot rely on swapping to
4195 -- fix things up (subtypes in an outer scope might not get swapped).
4199 then
4200 -- The construction of the dispatch table associated with library
4201 -- level tagged types forces freezing of all the primitives of the
4202 -- type, which may cause premature freezing of the partial view.
4203 -- For example:
4205 -- package Pkg is
4206 -- type T is tagged private;
4207 -- type DT is new T with private;
4208 -- procedure Prim (X : in out T; Y : in out DT'Class);
4209 -- private
4210 -- type T is tagged null record;
4211 -- Obj : T;
4212 -- type DT is new T with null record;
4213 -- end;
4215 -- In this case the type will be frozen later by the usual
4216 -- mechanism: an object declaration, an instantiation, or the
4217 -- end of a declarative part.
4221 then
4225 -- Case of full view present
4229 -- If full view has already been frozen, then no further
4230 -- processing is required
4237 -- Otherwise freeze full view and patch the pointers so that
4238 -- the freeze node will elaborate both views in the back-end.
4240 else
4241 declare
4244 begin
4247 then
4248 Freeze_And_Append
4261 else
4262 -- {Incomplete,Private}_Subtypes with Full_Views
4263 -- constrained by discriminants.
4274 -- AI-117 requires that the convention of a partial view be the
4275 -- same as the convention of the full view. Note that this is a
4276 -- recognized breach of privacy, but it's essential for logical
4277 -- consistency of representation, and the lack of a rule in
4278 -- RM95 was an oversight.
4285 -- Size information is copied from the full view to the
4286 -- incomplete or private view for consistency.
4288 -- We skip this is the full view is not a type. This is very
4289 -- strange of course, and can only happen as a result of
4290 -- certain illegalities, such as a premature attempt to derive
4291 -- from an incomplete type.
4300 -- Case of no full view present. If entity is derived or subtype,
4301 -- it is safe to freeze, correctness depends on the frozen status
4302 -- of parent. Otherwise it is either premature usage, or a Taft
4303 -- amendment type, so diagnosis is at the point of use and the
4304 -- type might be frozen later.
4308 then
4311 else
4316 -- For access subprogram, freeze types of all formals, the return
4317 -- type was already frozen, since it is the Etype of the function.
4318 -- Formal types can be tagged Taft amendment types, but otherwise
4319 -- they cannot be incomplete.
4327 then
4331 -- AI05-151: Incomplete types are allowed in access to
4332 -- subprogram specifications.
4335 Error_Msg_NE
4346 -- For access to a protected subprogram, freeze the equivalent type
4347 -- (however this is not set if we are not generating code or if this
4348 -- is an anonymous type used just for resolution).
4356 -- Generic types are never seen by the back-end, and are also not
4357 -- processed by the expander (since the expander is turned off for
4358 -- generic processing), so we never need freeze nodes for them.
4364 -- Some special processing for non-generic types to complete
4365 -- representation details not known till the freeze point.
4370 -- Some error checks required for ordinary fixed-point type. Defer
4371 -- these till the freeze-point since we need the small and range
4372 -- values. We only do these checks for base types
4377 Error_Msg_N
4382 Error_Msg_N
4388 Error_Msg_N
4394 Error_Msg_N
4406 and then Warn_On_Suspicious_Modulus_Value
4407 then
4413 then
4414 -- If a pragma Default_Storage_Pool applies, and this type has no
4415 -- Storage_Pool or Storage_Size clause (which must have occurred
4416 -- before the freezing point), then use the default. This applies
4417 -- only to base types.
4419 -- None of this applies to access to subprograms, for which there
4420 -- are clearly no pools.
4426 then
4427 -- Case of pragma Default_Storage_Pool (null)
4432 -- Case of pragma Default_Storage_Pool (storage_pool_NAME)
4434 else
4439 -- Check restriction for standard storage pool
4445 -- Deal with error message for pure access type. This is not an
4446 -- error in Ada 2005 if there is no pool (see AI-366).
4451 then
4455 Error_Msg_N
4459 Error_Msg_N
4462 else
4463 Error_Msg_N
4470 -- Case of composite types
4474 -- AI-117 requires that all new primitives of a tagged type must
4475 -- inherit the convention of the full view of the type. Inherited
4476 -- and overriding operations are defined to inherit the convention
4477 -- of their parent or overridden subprogram (also specified in
4478 -- AI-117), which will have occurred earlier (in Derive_Subprogram
4479 -- and New_Overloaded_Entity). Here we set the convention of
4480 -- primitives that are still convention Ada, which will ensure
4481 -- that any new primitives inherit the type's convention. Class-
4482 -- wide types can have a foreign convention inherited from their
4483 -- specific type, but are excluded from this since they don't have
4484 -- any associated primitives.
4489 then
4490 declare
4494 begin
4506 -- If the type is a simple storage pool type, then this is where
4507 -- we attempt to locate and validate its Allocate, Deallocate, and
4508 -- Storage_Size operations (the first is required, and the latter
4509 -- two are optional). We also verify that the full type for a
4510 -- private type is allowed to be a simple storage pool type.
4514 then
4515 -- If the type is marked Has_Private_Declaration, then this is
4516 -- a full type for a private type that was specified with the
4517 -- pragma Simple_Storage_Pool_Type, and here we ensure that the
4518 -- pragma is allowed for the full type (for example, it can't
4519 -- be an array type, or a nonlimited record type).
4525 then
4527 Error_Msg_N
4538 procedure Validate_Simple_Pool_Op_Formal
4545 -- Validate one formal Pool_Op_Formal of the candidate pool
4546 -- operation Pool_Op. The formal must be of Expected_Type
4547 -- and have mode Expected_Mode. OK_Formal will be set to
4548 -- False if the formal doesn't match. If OK_Formal is False
4549 -- on entry, then the formal will effectively be ignored
4550 -- (because validation of the pool op has already failed).
4551 -- Upon return, Pool_Op_Formal will be updated to the next
4552 -- formal, if any.
4555 -- Search for and validate a simple pool operation with the
4556 -- name Op_Name. If the name is Allocate, then there must be
4557 -- exactly one such primitive operation for the simple pool
4558 -- type. If the name is Deallocate or Storage_Size, then
4559 -- there can be at most one such primitive operation. The
4560 -- profile of the located primitive must conform to what
4561 -- is expected for each operation.
4563 ------------------------------------
4564 -- Validate_Simple_Pool_Op_Formal --
4565 ------------------------------------
4567 procedure Validate_Simple_Pool_Op_Formal
4574 is
4575 begin
4576 -- If OK_Formal is False on entry, then simply ignore
4577 -- the formal, because an earlier formal has already
4578 -- been flagged.
4583 -- If no formal is passed in, then issue an error for a
4584 -- missing formal.
4587 Error_Msg_NE
4597 -- If the pool type was expected for this formal, then
4598 -- this will not be considered a candidate operation
4599 -- for the simple pool, so we unset OK_Formal so that
4600 -- the op and any later formals will be ignored.
4607 else
4608 Error_Msg_NE
4615 -- Issue error if formal's mode is not the expected one
4618 Error_Msg_N
4620 Pool_Op_Formal);
4623 -- Advance to the next formal
4628 ------------------------------------
4629 -- Validate_Simple_Pool_Operation --
4630 ------------------------------------
4632 procedure Validate_Simple_Pool_Operation
4634 is
4640 begin
4641 pragma Assert
4643 Name_Deallocate,
4644 Name_Storage_Size));
4648 -- For each homonym declared immediately in the scope
4649 -- of the simple storage pool type, determine whether
4650 -- the homonym is an operation of the pool type, and,
4651 -- if so, check that its profile is as expected for
4652 -- a simple pool operation of that name.
4658 then
4663 -- The first parameter must be of the pool type
4664 -- in order for the operation to qualify.
4667 Validate_Simple_Pool_Op_Formal
4670 else
4671 Validate_Simple_Pool_Op_Formal
4676 -- If another operation with this name has already
4677 -- been located for the type, then flag an error,
4678 -- since we only allow the type to have a single
4679 -- such primitive.
4682 Error_Msg_NE
4687 -- In the case of Allocate and Deallocate, a formal
4688 -- of type System.Address is required.
4691 Validate_Simple_Pool_Op_Formal
4696 Validate_Simple_Pool_Op_Formal
4701 -- In the case of Allocate and Deallocate, formals
4702 -- of type Storage_Count are required as the third
4703 -- and fourth parameters.
4706 Validate_Simple_Pool_Op_Formal
4709 Validate_Simple_Pool_Op_Formal
4714 -- If no mismatched formals have been found (Is_OK)
4715 -- and no excess formals are present, then this
4716 -- operation has been validated, so record it.
4726 -- There must be a valid Allocate operation for the type,
4727 -- so issue an error if none was found.
4731 then
4737 -- Simple pool operations can't be abstract
4740 Error_Msg_N
4745 -- The Storage_Size operation must be a function with
4746 -- Storage_Count as its result type.
4750 Error_Msg_N
4754 Error_Msg_NE
4759 -- Allocate and Deallocate must be procedures
4762 Error_Msg_N
4768 -- Start of processing for Validate_Simple_Pool_Ops
4770 begin
4778 -- Now that all types from which E may depend are frozen, see if the
4779 -- size is known at compile time, if it must be unsigned, or if
4780 -- strict alignment is required
4789 -- Do not allow a size clause for a type which does not have a size
4790 -- that is known at compile time
4794 then
4795 -- Suppress this message if errors posted on E, even if we are
4796 -- in all errors mode, since this is often a junk message
4799 Error_Msg_N
4805 -- Now we set/verify the representation information, in particular
4806 -- the size and alignment values. This processing is not required for
4807 -- generic types, since generic types do not play any part in code
4808 -- generation, and so the size and alignment values for such types
4809 -- are irrelevant. Ditto for types declared within a generic unit,
4810 -- which may have components that depend on generic parameters, and
4811 -- that will be recreated in an instance.
4816 -- Otherwise we call the layout procedure
4818 else
4822 -- If this is an access to subprogram whose designated type is itself
4823 -- a subprogram type, the return type of this anonymous subprogram
4824 -- type must be decorated as well.
4828 then
4832 -- If the type has a Defaut_Value/Default_Component_Value aspect,
4833 -- this is where we analye the expression (after the type is frozen,
4834 -- since in the case of Default_Value, we are analyzing with the
4835 -- type itself, and we treat Default_Component_Value similarly for
4836 -- the sake of uniformity).
4839 declare
4844 begin
4849 else
4860 Flag_Non_Static_Expr
4867 -- End of freeze processing for type entities
4870 -- Here is where we logically freeze the current entity. If it has a
4871 -- freeze node, then this is the point at which the freeze node is
4872 -- linked into the result list.
4876 -- If a freeze node is already allocated, use it, otherwise allocate
4877 -- a new one. The preallocation happens in the case of anonymous base
4878 -- types, where we preallocate so that we can set First_Subtype_Link.
4879 -- Note that we reset the Sloc to the current freeze location.
4885 else
4896 -- A final pass over record types with discriminants. If the type
4897 -- has an incomplete declaration, there may be constrained access
4898 -- subtypes declared elsewhere, which do not depend on the discrimi-
4899 -- nants of the type, and which are used as component types (i.e.
4900 -- the full view is a recursive type). The designated types of these
4901 -- subtypes can only be elaborated after the type itself, and they
4902 -- need an itype reference.
4906 then
4907 declare
4912 begin
4922 then
4934 -- When a type is frozen, the first subtype of the type is frozen as
4935 -- well (RM 13.14(15)). This has to be done after freezing the type,
4936 -- since obviously the first subtype depends on its own base type.
4941 -- If we just froze a tagged non-class wide record, then freeze the
4942 -- corresponding class-wide type. This must be done after the tagged
4943 -- type itself is frozen, because the class-wide type refers to the
4944 -- tagged type which generates the class.
4949 then
4956 -- Special handling for subprograms
4960 -- If subprogram has address clause then reset Is_Public flag, since
4961 -- we do not want the backend to generate external references.
4965 then
4973 -----------------------------
4974 -- Freeze_Enumeration_Type --
4975 -----------------------------
4978 begin
4979 -- By default, if no size clause is present, an enumeration type with
4980 -- Convention C is assumed to interface to a C enum, and has integer
4981 -- size. This applies to types. For subtypes, verify that its base
4982 -- type has no size clause either. Treat other foreign conventions
4983 -- in the same way, and also make sure alignment is set right.
4989 then
4993 else
4994 -- If the enumeration type interfaces to C, and it has a size clause
4995 -- that specifies less than int size, it warrants a warning. The
4996 -- user may intend the C type to be an enum or a char, so this is
4997 -- not by itself an error that the Ada compiler can detect, but it
4998 -- it is a worth a heads-up. For Boolean and Character types we
4999 -- assume that the programmer has the proper C type in mind.
5006 then
5007 Error_Msg_N
5015 -----------------------
5016 -- Freeze_Expression --
5017 -----------------------
5028 -- This flag is set true if the entity must be frozen outside the
5029 -- current subprogram. This happens in the case of expander generated
5030 -- subprograms (_Init_Proc, _Input, _Output, _Read, _Write) which do
5031 -- not freeze all entities like other bodies, but which nevertheless
5032 -- may reference entities that have to be frozen before the body and
5033 -- obviously cannot be frozen inside the body.
5036 -- Given an N_Handled_Sequence_Of_Statements node N, determines whether
5037 -- it is the handled statement sequence of an expander-generated
5038 -- subprogram (init proc, stream subprogram, or renaming as body).
5039 -- If so, this is not a freezing context.
5041 -----------------
5042 -- In_Exp_Body --
5043 -----------------
5049 begin
5052 else
5059 else
5062 -- Following complex conditional could use comments ???
5071 N_Subprogram_Renaming_Declaration,
5072 N_Expression_Function))
5073 then
5075 else
5081 -- Start of processing for Freeze_Expression
5083 begin
5084 -- Immediate return if freezing is inhibited. This flag is set by the
5085 -- analyzer to stop freezing on generated expressions that would cause
5086 -- freezing if they were in the source program, but which are not
5087 -- supposed to freeze, since they are created.
5093 -- If expression is non-static, then it does not freeze in a default
5094 -- expression, see section "Handling of Default Expressions" in the
5095 -- spec of package Sem for further details. Note that we have to make
5096 -- sure that we actually have a real expression (if we have a subtype
5097 -- indication, we can't test Is_Static_Expression!) However, we exclude
5098 -- the case of the prefix of an attribute of a static scalar subtype
5099 -- from this early return, because static subtype attributes should
5100 -- always cause freezing, even in default expressions, but the attribute
5101 -- may not have been marked as static yet (because in Resolve_Attribute,
5102 -- the call to Eval_Attribute follows the call of Freeze_Expression on
5103 -- the prefix).
5105 if In_Spec_Exp
5112 then
5116 -- Freeze type of expression if not frozen already
5124 -- Base type may be an derived numeric type that is frozen at
5125 -- the point of declaration, but first_subtype is still unfrozen.
5132 -- For entity name, freeze entity if not frozen already. A special
5133 -- exception occurs for an identifier that did not come from source.
5134 -- We don't let such identifiers freeze a non-internal entity, i.e.
5135 -- an entity that did come from source, since such an identifier was
5136 -- generated by the expander, and cannot have any semantic effect on
5137 -- the freezing semantics. For example, this stops the parameter of
5138 -- an initialization procedure from freezing the variable.
5145 then
5147 else
5151 -- For an allocator freeze designated type if not frozen already
5153 -- For an aggregate whose component type is an access type, freeze the
5154 -- designated type now, so that its freeze does not appear within the
5155 -- loop that might be created in the expansion of the aggregate. If the
5156 -- designated type is a private type without full view, the expression
5157 -- cannot contain an allocator, so the type is not frozen.
5159 -- For a function, we freeze the entity when the subprogram declaration
5160 -- is frozen, but a function call may appear in an initialization proc.
5161 -- before the declaration is frozen. We need to generate the extra
5162 -- formals, if any, to ensure that the expansion of the call includes
5163 -- the proper actuals. This only applies to Ada subprograms, not to
5164 -- imported ones.
5175 then
5179 when N_Selected_Component |
5180 N_Indexed_Component |
5181 N_Slice =>
5192 then
5203 then
5207 -- All done if nothing needs freezing
5212 then
5216 -- Loop for looking at the right place to insert the freeze nodes,
5217 -- exiting from the loop when it is appropriate to insert the freeze
5218 -- node before the current node P.
5220 -- Also checks some special exceptions to the freezing rules. These
5221 -- cases result in a direct return, bypassing the freeze action.
5224 loop
5227 -- If we don't have a parent, then we are not in a well-formed tree.
5228 -- This is an unusual case, but there are some legitimate situations
5229 -- in which this occurs, notably when the expressions in the range of
5230 -- a type declaration are resolved. We simply ignore the freeze
5231 -- request in this case. Is this right ???
5237 -- See if we have got to an appropriate point in the tree
5241 -- A special test for the exception of (RM 13.14(8)) for the case
5242 -- of per-object expressions (RM 3.8(18)) occurring in component
5243 -- definition or a discrete subtype definition. Note that we test
5244 -- for a component declaration which includes both cases we are
5245 -- interested in, and furthermore the tree does not have explicit
5246 -- nodes for either of these two constructs.
5250 -- The case we want to test for here is an identifier that is
5251 -- a per-object expression, this is either a discriminant that
5252 -- appears in a context other than the component declaration
5253 -- or it is a reference to the type of the enclosing construct.
5255 -- For either of these cases, we skip the freezing
5257 if not In_Spec_Expression
5260 then
5261 -- We recognize the discriminant case by just looking for
5262 -- a reference to a discriminant. It can only be one for
5263 -- the enclosing construct. Skip freezing in this case.
5268 -- For the case of a reference to the enclosing record,
5269 -- (or task or protected type), we look for a type that
5270 -- matches the current scope.
5277 -- If we have an enumeration literal that appears as the choice in
5278 -- the aggregate of an enumeration representation clause, then
5279 -- freezing does not occur (RM 13.14(10)).
5283 -- The case we are looking for is an enumeration literal
5287 then
5288 -- If enumeration literal appears directly as the choice,
5289 -- do not freeze (this is the normal non-overloaded case)
5293 then
5296 -- If enumeration literal appears as the name of function
5297 -- which is the choice, then also do not freeze. This
5298 -- happens in the overloaded literal case, where the
5299 -- enumeration literal is temporarily changed to a function
5300 -- call for overloading analysis purposes.
5303 and then
5305 and then
5307 then
5312 -- Normally if the parent is a handled sequence of statements,
5313 -- then the current node must be a statement, and that is an
5314 -- appropriate place to insert a freeze node.
5318 -- An exception occurs when the sequence of statements is for
5319 -- an expander generated body that did not do the usual freeze
5320 -- all operation. In this case we usually want to freeze
5321 -- outside this body, not inside it, and we skip past the
5322 -- subprogram body that we are inside.
5325 declare
5329 begin
5330 -- Freeze the entity only when it is declared inside the
5331 -- body of the expander generated procedure. This case
5332 -- is recognized by the scope of the entity or its type,
5333 -- which is either the spec for some enclosing body, or
5334 -- (in the case of init_procs, for which there are no
5335 -- separate specs) the current scope.
5341 or else
5343 then
5349 then
5354 -- An expression function may act as a completion of
5355 -- a function declaration. As such, it can reference
5356 -- entities declared between the two views:
5358 -- Hidden []; -- 1
5359 -- function F return ...;
5360 -- private
5361 -- function Hidden return ...;
5362 -- function F return ... is (Hidden); -- 2
5364 -- Refering to the example above, freezing the expression
5365 -- of F (2) would place Hidden's freeze node (1) in the
5366 -- wrong place. Avoid explicit freezing and let the usual
5367 -- scenarios do the job - for example, reaching the end
5368 -- of the private declarations.
5371 N_Expression_Function
5372 then
5375 -- Freeze outside the body
5377 else
5383 -- Here if normal case where we are in handled statement
5384 -- sequence and want to do the insertion right there.
5386 else
5390 -- If parent is a body or a spec or a block, then the current node
5391 -- is a statement or declaration and we can insert the freeze node
5392 -- before it.
5394 when N_Block_Statement |
5395 N_Entry_Body |
5396 N_Package_Body |
5397 N_Package_Specification |
5398 N_Protected_Body |
5399 N_Subprogram_Body |
5402 -- The expander is allowed to define types in any statements list,
5403 -- so any of the following parent nodes also mark a freezing point
5404 -- if the actual node is in a list of statements or declarations.
5406 when N_Abortable_Part |
5407 N_Accept_Alternative |
5408 N_And_Then |
5409 N_Case_Statement_Alternative |
5410 N_Compilation_Unit_Aux |
5411 N_Conditional_Entry_Call |
5412 N_Delay_Alternative |
5413 N_Elsif_Part |
5414 N_Entry_Call_Alternative |
5415 N_Exception_Handler |
5416 N_Extended_Return_Statement |
5417 N_Freeze_Entity |
5418 N_If_Statement |
5419 N_Or_Else |
5420 N_Selective_Accept |
5421 N_Triggering_Alternative =>
5425 -- Note: The N_Loop_Statement is a special case. A type that
5426 -- appears in the source can never be frozen in a loop (this
5427 -- occurs only because of a loop expanded by the expander), so we
5428 -- keep on going. Otherwise we terminate the search. Same is true
5429 -- of any entity which comes from source. (if they have predefined
5430 -- type, that type does not appear to come from source, but the
5431 -- entity should not be frozen here).
5437 -- For all other cases, keep looking at parents
5443 -- We fall through the case if we did not yet find the proper
5444 -- place in the free for inserting the freeze node, so climb!
5449 -- If the expression appears in a record or an initialization procedure,
5450 -- the freeze nodes are collected and attached to the current scope, to
5451 -- be inserted and analyzed on exit from the scope, to insure that
5452 -- generated entities appear in the correct scope. If the expression is
5453 -- a default for a discriminant specification, the scope is still void.
5454 -- The expression can also appear in the discriminant part of a private
5455 -- or concurrent type.
5457 -- If the expression appears in a constrained subcomponent of an
5458 -- enclosing record declaration, the freeze nodes must be attached to
5459 -- the outer record type so they can eventually be placed in the
5460 -- enclosing declaration list.
5462 -- The other case requiring this special handling is if we are in a
5463 -- default expression, since in that case we are about to freeze a
5464 -- static type, and the freeze scope needs to be the outer scope, not
5465 -- the scope of the subprogram with the default parameter.
5467 -- For default expressions and other spec expressions in generic units,
5468 -- the Move_Freeze_Nodes mechanism (see sem_ch12.adb) takes care of
5469 -- placing them at the proper place, after the generic unit.
5472 or else Freeze_Outside
5477 then
5478 declare
5483 begin
5496 -- The current scope may be that of a constrained component of
5497 -- an enclosing record declaration, or of a loop of an enclosing
5498 -- quantified expression, which is above the current scope in the
5499 -- scope stack. Indeed in the context of a quantified expression,
5500 -- a scope is created and pushed above the current scope in order
5501 -- to emulate the loop-like behavior of the quantified expression.
5502 -- If the expression is within a top-level pragma, as for a pre-
5503 -- condition on a library-level subprogram, nothing to do.
5508 N_Quantified_Expression)
5509 then
5516 Freeze_Nodes;
5517 else
5527 -- Now we have the right place to do the freezing. First, a special
5528 -- adjustment, if we are in spec-expression analysis mode, these freeze
5529 -- actions must not be thrown away (normally all inserted actions are
5530 -- thrown away in this mode. However, the freeze actions are from static
5531 -- expressions and one of the important reasons we are doing this
5532 -- special analysis is to get these freeze actions. Therefore we turn
5533 -- off the In_Spec_Expression mode to propagate these freeze actions.
5534 -- This also means they get properly analyzed and expanded.
5538 -- Freeze the designated type of an allocator (RM 13.14(13))
5544 -- Freeze type of expression (RM 13.14(10)). Note that we took care of
5545 -- the enumeration representation clause exception in the loop above.
5551 -- Freeze name if one is present (RM 13.14(11))
5557 -- Restore In_Spec_Expression flag
5562 -----------------------------
5563 -- Freeze_Fixed_Point_Type --
5564 -----------------------------
5566 -- Certain fixed-point types and subtypes, including implicit base types
5567 -- and declared first subtypes, have not yet set up a range. This is
5568 -- because the range cannot be set until the Small and Size values are
5569 -- known, and these are not known till the type is frozen.
5571 -- To signal this case, Scalar_Range contains an unanalyzed syntactic range
5572 -- whose bounds are unanalyzed real literals. This routine will recognize
5573 -- this case, and transform this range node into a properly typed range
5574 -- with properly analyzed and resolved values.
5592 -- Returns size of type with given bounds. Also leaves these
5593 -- bounds set as the current bounds of the Typ.
5595 -----------
5596 -- Fsize --
5597 -----------
5600 begin
5606 -- Start of processing for Freeze_Fixed_Point_Type
5608 begin
5609 -- If Esize of a subtype has not previously been set, set it now
5616 else
5621 -- Immediate return if the range is already analyzed. This means that
5622 -- the range is already set, and does not need to be computed by this
5623 -- routine.
5629 -- Immediate return if either of the bounds raises Constraint_Error
5633 then
5640 -- Ordinary fixed-point case
5644 -- For the ordinary fixed-point case, we are allowed to fudge the
5645 -- end-points up or down by small. Generally we prefer to fudge up,
5646 -- i.e. widen the bounds for non-model numbers so that the end points
5647 -- are included. However there are cases in which this cannot be
5648 -- done, and indeed cases in which we may need to narrow the bounds.
5649 -- The following circuit makes the decision.
5651 -- Note: our terminology here is that Incl_EP means that the bounds
5652 -- are widened by Small if necessary to include the end points, and
5653 -- Excl_EP means that the bounds are narrowed by Small to exclude the
5654 -- end-points if this reduces the size.
5656 -- Note that in the Incl case, all we care about is including the
5657 -- end-points. In the Excl case, we want to narrow the bounds as
5658 -- much as permitted by the RM, to give the smallest possible size.
5675 begin
5676 -- First step. Base types are required to be symmetrical. Right
5677 -- now, the base type range is a copy of the first subtype range.
5678 -- This will be corrected before we are done, but right away we
5679 -- need to deal with the case where both bounds are non-negative.
5680 -- In this case, we set the low bound to the negative of the high
5681 -- bound, to make sure that the size is computed to include the
5682 -- required sign. Note that we do not need to worry about the
5683 -- case of both bounds negative, because the sign will be dealt
5684 -- with anyway. Furthermore we can't just go making such a bound
5685 -- symmetrical, since in a twos-complement system, there is an
5686 -- extra negative value which could not be accommodated on the
5687 -- positive side.
5692 then
5697 -- Compute the fudged bounds. If the number is a model number,
5698 -- then we do nothing to include it, but we are allowed to backoff
5699 -- to the next adjacent model number when we exclude it. If it is
5700 -- not a model number then we straddle the two values with the
5701 -- model numbers on either side.
5707 else
5711 -- The low value excluding the end point is Small greater, but
5712 -- we do not do this exclusion if the low value is positive,
5713 -- since it can't help the size and could actually hurt by
5714 -- crossing the high bound.
5719 -- If the value went from negative to zero, then we have the
5720 -- case where Loval_Incl_EP is the model number just below
5721 -- zero, so we want to stick to the negative value for the
5722 -- base type to maintain the condition that the size will
5723 -- include signed values.
5727 then
5731 else
5735 -- Similar processing for upper bound and high value
5741 else
5747 else
5751 -- One further adjustment is needed. In the case of subtypes, we
5752 -- cannot go outside the range of the base type, or we get
5753 -- peculiarities, and the base type range is already set. This
5754 -- only applies to the Incl values, since clearly the Excl values
5755 -- are already as restricted as they are allowed to be.
5762 -- Get size including and excluding end points
5767 -- No need to exclude end-points if it does not reduce size
5777 -- Now we set the actual size to be used. We want to use the
5778 -- bounds fudged up to include the end-points but only if this
5779 -- can be done without violating a specifically given size
5780 -- size clause or causing an unacceptable increase in size.
5782 -- Case of size clause given
5786 -- Use the inclusive size only if it is consistent with
5787 -- the explicitly specified size.
5794 -- If the inclusive size is too large, we try excluding
5795 -- the end-points (will be caught later if does not work).
5797 else
5803 -- Case of size clause not given
5805 else
5806 -- If we have a base type whose corresponding first subtype
5807 -- has an explicit size that is large enough to include our
5808 -- end-points, then do so. There is no point in working hard
5809 -- to get a base type whose size is smaller than the specified
5810 -- size of the first subtype.
5816 then
5821 -- If excluding the end-points makes the size smaller and
5822 -- results in a size of 8,16,32,64, then we take the smaller
5823 -- size. For the 64 case, this is compulsory. For the other
5824 -- cases, it seems reasonable. We like to include end points
5825 -- if we can, but not at the expense of moving to the next
5826 -- natural boundary of size.
5830 then
5835 -- Otherwise we can definitely include the end points
5837 else
5843 -- One pathological case: normally we never fudge a low bound
5844 -- down, since it would seem to increase the size (if it has
5845 -- any effect), but for ranges containing single value, or no
5846 -- values, the high bound can be small too large. Consider:
5848 -- type t is delta 2.0**(-14)
5849 -- range 131072.0 .. 0;
5851 -- That lower bound is *just* outside the range of 32 bits, and
5852 -- does need fudging down in this case. Note that the bounds
5853 -- will always have crossed here, since the high bound will be
5854 -- fudged down if necessary, as in the case of:
5856 -- type t is delta 2.0**(-14)
5857 -- range 131072.0 .. 131072.0;
5859 -- So we detect the situation by looking for crossed bounds,
5860 -- and if the bounds are crossed, and the low bound is greater
5861 -- than zero, we will always back it off by small, since this
5862 -- is completely harmless.
5869 -- And of course, we need to do exactly the same parallel
5870 -- fudge for flat ranges in the negative region.
5883 -- For the decimal case, none of this fudging is required, since there
5884 -- are no end-point problems in the decimal case (the end-points are
5885 -- always included).
5887 else
5891 -- At this stage, the actual size has been calculated and the proper
5892 -- required bounds are stored in the low and high bounds.
5896 Error_Msg_N
5898 Typ);
5902 -- Check size against explicit given size
5908 Error_Msg_NE
5912 else
5916 -- Increase size to next natural boundary if no size clause given
5918 else
5925 else
5933 -- If we have a base type, then expand the bounds so that they extend to
5934 -- the full width of the allocated size in bits, to avoid junk range
5935 -- checks on intermediate computations.
5942 -- Final step is to reanalyze the bounds using the proper type
5943 -- and set the Corresponding_Integer_Value fields of the literals.
5949 -- Resolve with universal fixed if the base type, and the base type if
5950 -- it is a subtype. Note we can't resolve the base type with itself,
5951 -- that would be a reference before definition.
5955 else
5959 -- Set corresponding integer value for bound
5961 Set_Corresponding_Integer_Value
5964 -- Similar processing for high bound
5972 else
5976 Set_Corresponding_Integer_Value
5979 -- Set type of range to correspond to bounds
5983 -- Set Esize to calculated size if not set already
5989 -- Set RM_Size if not already set. If already set, check value
5991 declare
5994 begin
5999 Error_Msg_NE
6004 else
6010 ------------------
6011 -- Freeze_Itype --
6012 ------------------
6017 begin
6026 --------------------------
6027 -- Freeze_Static_Object --
6028 --------------------------
6033 -- Exception raised if the type of a static object cannot be made
6034 -- static. This happens if the type depends on non-global objects.
6037 -- Called to ensure that an expression used as part of a type definition
6038 -- is statically allocatable, which means that the expression type is
6039 -- statically allocatable, and the expression is either static, or a
6040 -- reference to a library level constant.
6043 -- Called to mark a type as static, checking that it is possible
6044 -- to set the type as static. If it is not possible, then the
6045 -- exception Cannot_Be_Static is raised.
6047 -----------------------------
6048 -- Ensure_Expression_Is_SA --
6049 -----------------------------
6054 begin
6066 then
6074 -----------------------
6075 -- Ensure_Type_Is_SA --
6076 -----------------------
6082 begin
6083 -- If type is library level, we are all set
6089 -- We are also OK if the type already marked as statically allocated,
6090 -- which means we processed it before.
6096 -- Mark type as statically allocated
6100 -- Check that it is safe to statically allocate this type
6118 declare
6122 begin
6134 else
6143 then
6162 else
6167 -- Start of processing for Freeze_Static_Object
6169 begin
6172 exception
6175 -- If the object that cannot be static is imported or exported, then
6176 -- issue an error message saying that this object cannot be imported
6177 -- or exported. If it has an address clause it is an overlay in the
6178 -- current partition and the static requirement is not relevant.
6179 -- Do not issue any error message when ignoring rep clauses.
6186 Error_Msg_N
6190 -- Otherwise must be exported, something is wrong if compiler
6191 -- is marking something as statically allocated which cannot be).
6194 Error_Msg_N
6199 -----------------------
6200 -- Freeze_Subprogram --
6201 -----------------------
6207 begin
6208 -- Subprogram may not have an address clause unless it is imported
6212 Error_Msg_N
6219 -- Reset the Pure indication on an imported subprogram unless an
6220 -- explicit Pure_Function pragma was present. We do this because
6221 -- otherwise it is an insidious error to call a non-pure function from
6222 -- pure unit and have calls mysteriously optimized away. What happens
6223 -- here is that the Import can bypass the normal check to ensure that
6224 -- pure units call only pure subprograms.
6229 then
6233 -- For non-foreign convention subprograms, this is where we create
6234 -- the extra formals (for accessibility level and constrained bit
6235 -- information). We delay this till the freeze point precisely so
6236 -- that we know the convention!
6242 -- If this is convention Ada and a Valued_Procedure, that's odd
6247 and then Warn_On_Export_Import
6248 then
6249 Error_Msg_N
6254 -- Case of foreign convention
6256 else
6259 -- For foreign conventions, warn about return of an
6260 -- unconstrained array.
6262 -- Note: we *do* allow a return by descriptor for the VMS case,
6263 -- though here there is probably more to be done ???
6268 -- If no return type, probably some other error, e.g. a
6269 -- missing full declaration, so ignore.
6274 -- If the return type is generic, we have emitted a warning
6275 -- earlier on, and there is nothing else to check here. Specific
6276 -- instantiations may lead to erroneous behavior.
6281 -- Display warning if returning unconstrained array
6286 -- Exclude cases where descriptor mechanism is set, since the
6287 -- VMS descriptor mechanisms allow such unconstrained returns.
6291 -- Check appropriate warning is enabled (should we check for
6292 -- Warnings (Off) on specific entities here, probably so???)
6294 and then Warn_On_Export_Import
6296 -- Exclude the VM case, since return of unconstrained arrays
6297 -- is properly handled in both the JVM and .NET cases.
6300 then
6301 Error_Msg_N
6308 -- If any of the formals for an exported foreign convention
6309 -- subprogram have defaults, then emit an appropriate warning since
6310 -- this is odd (default cannot be used from non-Ada code)
6315 if Warn_On_Export_Import
6317 then
6318 Error_Msg_N
6328 -- For VMS, descriptor mechanisms for parameters are allowed only for
6329 -- imported/exported subprograms. Moreover, the NCA descriptor is not
6330 -- allowed for parameters of exported subprograms.
6337 Error_Msg_N
6339 Error_Msg_N
6350 Error_Msg_N
6352 Error_Msg_N
6361 -- Pragma Inline_Always is disallowed for dispatching subprograms
6362 -- because the address of such subprograms is saved in the dispatch
6363 -- table to support dispatching calls, and dispatching calls cannot
6364 -- be inlined. This is consistent with the restriction against using
6365 -- 'Access or 'Address on an Inline_Always subprogram.
6369 then
6370 Error_Msg_N
6374 -- Because of the implicit representation of inherited predefined
6375 -- operators in the front-end, the overriding status of the operation
6376 -- may be affected when a full view of a type is analyzed, and this is
6377 -- not captured by the analysis of the corresponding type declaration.
6378 -- Therefore the correctness of a not-overriding indicator must be
6379 -- rechecked when the subprogram is frozen.
6383 then
6388 ----------------------
6389 -- Is_Fully_Defined --
6390 ----------------------
6393 begin
6402 then
6403 -- Verify that the record type has no components with private types
6404 -- without completion.
6406 declare
6409 begin
6421 -- For the designated type of an access to subprogram, all types in
6422 -- the profile must be fully defined.
6425 declare
6428 begin
6441 else
6447 ---------------------------------
6448 -- Process_Default_Expressions --
6449 ---------------------------------
6451 procedure Process_Default_Expressions
6454 is
6461 begin
6464 -- A subprogram instance and its associated anonymous subprogram share
6465 -- their signature. The default expression functions are defined in the
6466 -- wrapper packages for the anonymous subprogram, and should not be
6467 -- generated again for the instance.
6472 then
6480 -- We work with a copy of the default expression because we
6481 -- do not want to disturb the original, since this would mess
6482 -- up the conformance checking.
6486 -- The analysis of the expression may generate insert actions,
6487 -- which of course must not be executed. We wrap those actions
6488 -- in a procedure that is not called, and later on eliminated.
6489 -- The following cases have no side-effects, and are analyzed
6490 -- directly.
6501 and then
6503 then
6505 -- If there is no default function, we must still do a full
6506 -- analyze call on the default value, to ensure that all error
6507 -- checks are performed, e.g. those associated with static
6508 -- evaluation. Note: this branch will always be taken if the
6509 -- analyzer is turned off (but we still need the error checks).
6511 -- Note: the setting of parent here is to meet the requirement
6512 -- that we can only analyze the expression while attached to
6513 -- the tree. Really the requirement is that the parent chain
6514 -- be set, we don't actually need to be in the tree.
6519 -- Default expressions are resolved with their own type if the
6520 -- context is generic, to avoid anomalies with private types.
6524 else
6528 -- If that resolved expression will raise constraint error,
6529 -- then flag the default value as raising constraint error.
6530 -- This allows a proper error message on the calls.
6536 -- If the default is a parameterless call, we use the name of
6537 -- the called function directly, and there is no body to build.
6541 then
6544 -- Else construct and analyze the body of a wrapper procedure
6545 -- that contains an object declaration to hold the expression.
6546 -- Given that this is done only to complete the analysis, it
6547 -- simpler to build a procedure than a function which might
6548 -- involve secondary stack expansion.
6550 else
6553 Dbody :=
6555 Specification =>
6562 Object_Definition =>
6566 Handled_Statement_Sequence =>
6583 ----------------------------------------
6584 -- Set_Component_Alignment_If_Not_Set --
6585 ----------------------------------------
6588 begin
6589 -- Ignore if not base type, subtypes don't need anything
6595 -- Do not override existing representation
6606 else
6607 Set_Component_Alignment
6613 ------------------
6614 -- Undelay_Type --
6615 ------------------
6618 begin
6622 -- Since we don't want T to have a Freeze_Node, we don't want its
6623 -- Full_View or Corresponding_Record_Type to have one either.
6625 -- ??? Fundamentally, this whole handling is a kludge. What we really
6626 -- want is to be sure that for an Itype that's part of record R and is a
6627 -- subtype of type T, that it's frozen after the later of the freeze
6628 -- points of R and T. We have no way of doing that directly, so what we
6629 -- do is force most such Itypes to be frozen as part of freezing R via
6630 -- this procedure and only delay the ones that need to be delayed
6631 -- (mostly the designated types of access types that are defined as part
6632 -- of the record).
6638 then
6646 then
6651 ------------------
6652 -- Warn_Overlay --
6653 ------------------
6655 procedure Warn_Overlay
6659 is
6661 -- The object to which the address clause applies
6667 begin
6668 -- No warning if address clause overlay warnings are off
6674 -- No warning if there is an explicit initialization
6682 -- We only give the warning for non-imported entities of a type for
6683 -- which a non-null base init proc is defined, or for objects of access
6684 -- types with implicit null initialization, or when Normalize_Scalars
6685 -- applies and the type is scalar or a string type (the latter being
6686 -- tested for because predefined String types are initialized by inline
6687 -- code rather than by an init_proc). Note that we do not give the
6688 -- warning for Initialize_Scalars, since we suppressed initialization
6689 -- in this case. Also, do not warn if Suppress_Initialization is set.
6699 then
6702 then
6707 then
6714 then
6721 -- A function call (most likely to To_Address) is probably not an
6722 -- overlay, so skip warning. Ditto if the function call was inlined
6723 -- and transformed into an entity.
6731 -- If a pragma Import follows, we assume that it is for the current
6732 -- target of the address clause, and skip the warning.
6737 then
6743 Error_Msg_N
6745 Nam);
6746 else
6747 Error_Msg_N
6749 Nam);
6752 -- Add friendly warning if initialization comes from a packed array
6753 -- component.
6756 declare
6759 begin
6764 then
6768 then
6769 Error_Msg_NE
6774 else
6781 Error_Msg_N
6784 Nam);