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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
97 -- For an Encl_Type that has a Scalar_Storage_Order attribute definition
98 -- clause, verify that the component type has an explicit and compatible
99 -- attribute/aspect. For arrays, Comp is Empty; for records, it is the
100 -- entity of the component under consideration. For an Encl_Type that
101 -- does not have a Scalar_Storage_Order attribute definition clause,
102 -- verify that the component also does not have such a clause.
103 -- ADC is the attribute definition clause if present (or Empty).
106 -- E is a base type. If E is tagged or has a component that is aliased
107 -- or tagged or contains something this is aliased or tagged, set
108 -- Strict_Alignment.
112 -- If E is a fixed-point or discrete type, then all the necessary work
113 -- to freeze it is completed except for possible setting of the flag
114 -- Is_Unsigned_Type, which is done by this procedure. The call has no
115 -- effect if the entity E is not a discrete or fixed-point type.
117 procedure Freeze_And_Append
121 -- Freezes Ent using Freeze_Entity, and appends the resulting list of
122 -- nodes to Result, modifying Result from No_List if necessary. N has
123 -- the same usage as in Freeze_Entity.
126 -- Freeze enumeration type. The Esize field is set as processing
127 -- proceeds (i.e. set by default when the type is declared and then
128 -- adjusted by rep clauses. What this procedure does is to make sure
129 -- that if a foreign convention is specified, and no specific size
130 -- is given, then the size must be at least Integer'Size.
133 -- If an object is frozen which has Is_Statically_Allocated set, then
134 -- all referenced types must also be marked with this flag. This routine
135 -- is in charge of meeting this requirement for the object entity E.
138 -- Perform freezing actions for a subprogram (create extra formals,
139 -- and set proper default mechanism values). Note that this routine
140 -- is not called for internal subprograms, for which neither of these
141 -- actions is needed (or desirable, we do not want for example to have
142 -- these extra formals present in initialization procedures, where they
143 -- would serve no purpose). In this call E is either a subprogram or
144 -- a subprogram type (i.e. an access to a subprogram).
147 -- True if T is not private and has no private components, or has a full
148 -- view. Used to determine whether the designated type of an access type
149 -- should be frozen when the access type is frozen. This is done when an
150 -- allocator is frozen, or an expression that may involve attributes of
151 -- the designated type. Otherwise freezing the access type does not freeze
152 -- the designated type.
154 procedure Process_Default_Expressions
157 -- This procedure is called for each subprogram to complete processing of
158 -- default expressions at the point where all types are known to be frozen.
159 -- The expressions must be analyzed in full, to make sure that all error
160 -- processing is done (they have only been pre-analyzed). If the expression
161 -- is not an entity or literal, its analysis may generate code which must
162 -- not be executed. In that case we build a function body to hold that
163 -- code. This wrapper function serves no other purpose (it used to be
164 -- called to evaluate the default, but now the default is inlined at each
165 -- point of call).
168 -- Typ is a record or array type that is being frozen. This routine sets
169 -- the default component alignment from the scope stack values if the
170 -- alignment is otherwise not specified.
173 -- As each entity is frozen, this routine is called to deal with the
174 -- setting of Debug_Info_Needed for the entity. This flag is set if
175 -- the entity comes from source, or if we are in Debug_Generated_Code
176 -- mode or if the -gnatdV debug flag is set. However, it never sets
177 -- the flag if Debug_Info_Off is set. This procedure also ensures that
178 -- subsidiary entities have the flag set as required.
181 -- T is a type of a component that we know to be an Itype. We don't want
182 -- this to have a Freeze_Node, so ensure it doesn't. Do the same for any
183 -- Full_View or Corresponding_Record_Type.
185 procedure Warn_Overlay
189 -- Expr is the expression for an address clause for entity Nam whose type
190 -- is Typ. If Typ has a default initialization, and there is no explicit
191 -- initialization in the source declaration, check whether the address
192 -- clause might cause overlaying of an entity, and emit a warning on the
193 -- side effect that the initialization will cause.
195 -------------------------------
196 -- Adjust_Esize_For_Alignment --
197 -------------------------------
202 begin
208 then
214 ------------------------------------
215 -- Build_And_Analyze_Renamed_Body --
216 ------------------------------------
218 procedure Build_And_Analyze_Renamed_Body
222 is
228 begin
229 -- If the renamed subprogram is intrinsic, there is no need for a
230 -- wrapper body: we set the alias that will be called and expanded which
231 -- completes the declaration. This transformation is only legal if the
232 -- renamed entity has already been elaborated.
234 -- Note that it is legal for a renaming_as_body to rename an intrinsic
235 -- subprogram, as long as the renaming occurs before the new entity
236 -- is frozen. See RM 8.5.4 (5).
240 then
242 else
248 and then
252 -- We can make the renaming entity intrinsic if the renamed function
253 -- has an interface name, or if it is one of the shift/rotate
254 -- operations known to the compiler.
256 and then
259 Name_Rotate_Right,
260 Name_Shift_Left,
261 Name_Shift_Right,
262 Name_Shift_Right_Arithmetic))
263 then
268 else
275 else
284 ------------------------
285 -- Build_Renamed_Body --
286 ------------------------
288 function Build_Renamed_Body
291 is
293 -- We use for the source location of the renamed body, the location of
294 -- the spec entity. It might seem more natural to use the location of
295 -- the renaming declaration itself, but that would be wrong, since then
296 -- the body we create would look as though it was created far too late,
297 -- and this could cause problems with elaboration order analysis,
298 -- particularly in connection with instantiations.
313 -- If the renamed entity is a primitive operation given in prefix form,
314 -- the prefix is the target object and it has to be added as the first
315 -- actual in the generated call.
317 begin
318 -- Determine the entity being renamed, which is the target of the call
319 -- statement. If the name is an explicit dereference, this is a renaming
320 -- of a subprogram type rather than a subprogram. The name itself is
321 -- fully analyzed.
332 else
339 else
345 -- If the renamed entity is a predefined operator, retain full name
346 -- to ensure its visibility.
350 then
352 else
356 else
359 and then
362 then
364 -- Retrieve the target object, to be added as a first actual
365 -- in the call.
370 else
374 -- Original name may have been overloaded, but is fully resolved now
379 -- For simple renamings, subsequent calls can be expanded directly as
380 -- calls to the renamed entity. The body must be generated in any case
381 -- for calls that may appear elsewhere. This is not done in the case
382 -- where the subprogram is an instantiation because the actual proper
383 -- body has not been built yet.
388 then
392 -- The body generated for this renaming is an internal artifact, and
393 -- does not constitute a freeze point for the called entity.
400 declare
404 begin
405 -- The controlling formal may be an access parameter, or the
406 -- actual may be an access value, so adjust accordingly.
410 then
411 Actuals := New_List
416 then
417 Actuals := New_List
421 else
429 else
440 -- If the renamed entity is an entry, inherit its profile. For other
441 -- renamings as bodies, both profiles must be subtype conformant, so it
442 -- is not necessary to replace the profile given in the declaration.
443 -- However, default values that are aggregates are rewritten when
444 -- partially analyzed, so we recover the original aggregate to insure
445 -- that subsequent conformity checking works. Similarly, if the default
446 -- expression was constant-folded, recover the original expression.
456 N_Access_Definition
457 then
465 then
476 -- If the renamed entity is a function, the generated body contains a
477 -- return statement. Otherwise, build a procedure call. If the entity is
478 -- an entry, subsequent analysis of the call will transform it into the
479 -- proper entry or protected operation call. If the renamed entity is
480 -- a character literal, return it directly.
486 then
487 Call_Node :=
489 Expression =>
495 Call_Node :=
500 Call_Node :=
504 else
505 Call_Node :=
511 -- Create entities for subprogram body and formals
524 Body_Node :=
528 Handled_Statement_Sequence =>
538 -- Link the body to the entity whose declaration it completes. If
539 -- the body is analyzed when the renamed entity is frozen, it may
540 -- be necessary to restore the proper scope (see package Exp_Ch13).
544 then
546 else
553 --------------------------
554 -- Check_Address_Clause --
555 --------------------------
564 begin
571 -- Has_Delayed_Freeze was set on E when the address clause was
572 -- analyzed, and must remain set because we want the address
573 -- clause to be elaborated only after any entity it references
574 -- has been elaborated.
577 -- If Rep_Clauses are to be ignored, remove address clause from
578 -- list attached to entity, because it may be illegal for gigi,
579 -- for example by breaking order of elaboration..
582 declare
585 begin
591 else
594 loop
608 then
614 -- Capture initialization value at point of declaration
618 -- Move initialization to freeze actions (once the object has
619 -- been frozen, and the address clause alignment check has been
620 -- performed.
632 -----------------------------
633 -- Check_Compile_Time_Size --
634 -----------------------------
639 -- Sets the compile time known size (32 bits or less) in the Esize
640 -- field, of T checking for a size clause that was given which attempts
641 -- to give a smaller size, and also checking for an alignment clause.
644 -- Recursive function that does all the work
647 -- If T is a constrained subtype, its size is not known if any of its
648 -- discriminant constraints is not static and it is not a null record.
649 -- The test is conservative and doesn't check that the components are
650 -- in fact constrained by non-static discriminant values. Could be made
651 -- more precise ???
653 --------------------
654 -- Set_Small_Size --
655 --------------------
658 begin
662 -- Check for bad size clause given
667 Error_Msg_NE
672 -- Set size if not set already
679 ----------------
680 -- Size_Known --
681 ----------------
690 begin
694 -- Always True for scalar types. This is true even for generic formal
695 -- scalar types. We used to return False in the latter case, but the
696 -- size is known at compile time, even in the template, we just do
697 -- not know the exact size but that's not the point of this routine.
701 then
704 -- Array types
708 -- String literals always have known size, and we can set it
715 -- Unconstrained types never have known at compile time size
720 -- Don't do any recursion on type with error posted, since we may
721 -- have a malformed type that leads us into a loop.
726 -- Otherwise if component size unknown, then array size unknown
732 -- Check for all indexes static, and also compute possible size
733 -- (in case it is less than 32 and may be packable).
735 declare
739 begin
748 else
756 then
759 else
764 else
776 -- Access types always have known at compile time sizes
781 -- For non-generic private types, go to underlying type if present
786 then
787 -- Don't do any recursion on type with error posted, since we may
788 -- have a malformed type that leads us into a loop.
792 else
796 -- Record types
800 -- A class-wide type is never considered to have a known size
805 -- A subtype of a variant record must not have non-static
806 -- discriminated components.
810 then
813 -- Don't do any recursion on type with error posted, since we may
814 -- have a malformed type that leads us into a loop.
820 -- Now look at the components of the record
822 declare
823 -- The following two variables are used to keep track of the
824 -- size of packed records if we can tell the size of the packed
825 -- record in the front end. Packed_Size_Known is True if so far
826 -- we can figure out the size. It is initialized to True for a
827 -- packed record, unless the record has discriminants or atomic
828 -- components or independent components.
830 -- The reason we eliminate the discriminated case is that
831 -- we don't know the way the back end lays out discriminated
832 -- packed records. If Packed_Size_Known is True, then
833 -- Packed_Size is the size in bits so far.
842 -- Size in bits so far
844 begin
845 -- Test for variant part present
851 N_Record_Definition
853 and then
854 Present (Variant_Part
856 then
857 -- If variant part is present, and type is unconstrained,
858 -- then we must have defaulted discriminants, or a size
859 -- clause must be present for the type, or else the size
860 -- is definitely not known at compile time.
863 and then
866 then
871 -- Loop through components
877 -- We do not know the packed size if there is a component
878 -- clause present (we possibly could, but this would only
879 -- help in the case of a record with partial rep clauses.
880 -- That's because in the case of full rep clauses, the
881 -- size gets figured out anyway by a different circuit).
887 -- We do not know the packed size if we have a by reference
888 -- type, or an atomic type or an atomic component, or an
889 -- aliased component (because packing does not touch these).
895 then
899 -- We need to identify a component that is an array where
900 -- the index type is an enumeration type with non-standard
901 -- representation, and some bound of the type depends on a
902 -- discriminant.
904 -- This is because gigi computes the size by doing a
905 -- substitution of the appropriate discriminant value in
906 -- the size expression for the base type, and gigi is not
907 -- clever enough to evaluate the resulting expression (which
908 -- involves a call to rep_to_pos) at compile time.
910 -- It would be nice if gigi would either recognize that
911 -- this expression can be computed at compile time, or
912 -- alternatively figured out the size from the subtype
913 -- directly, where all the information is at hand ???
917 then
918 declare
926 begin
933 then
939 then
944 then
954 -- Clearly size of record is not known if the size of one of
955 -- the components is not known.
961 -- Accumulate packed size if possible
965 -- We can only deal with elementary types, since for
966 -- non-elementary components, alignment enters into the
967 -- picture, and we don't know enough to handle proper
968 -- alignment in this context. Packed arrays count as
969 -- elementary if the representation is a modular type.
974 and then Is_Modular_Integer_Type
976 then
977 -- Packed size unknown if we have an atomic type
978 -- or a by reference type, since the back end
979 -- knows how these are layed out.
983 then
986 -- If RM_Size is known and static, then we can keep
987 -- accumulating the packed size
991 -- A little glitch, to be removed sometime ???
992 -- gigi does not understand zero sizes yet.
997 -- Normal case where we can keep accumulating the
998 -- packed array size.
1000 else
1004 -- If we have a field whose RM_Size is not known then
1005 -- we can't figure out the packed size here.
1007 else
1011 -- If we have a non-elementary type we can't figure out
1012 -- the packed array size (alignment issues).
1014 else
1029 -- All other cases, size not known at compile time
1031 else
1036 -------------------------------------
1037 -- Static_Discriminated_Components --
1038 -------------------------------------
1040 function Static_Discriminated_Components
1042 is
1045 begin
1049 then
1063 -- Start of processing for Check_Compile_Time_Size
1065 begin
1069 -----------------------------------
1070 -- Check_Component_Storage_Order --
1071 -----------------------------------
1073 procedure Check_Component_Storage_Order
1077 is
1083 -- Set True for the record case, when Comp starts on a byte boundary
1084 -- (in which case it is allowed to have different storage order).
1088 begin
1089 -- Record case
1099 else
1100 Comp_Byte_Aligned :=
1102 and then
1107 -- Array case
1109 else
1117 -- Note: the Reverse_Storage_Order flag is set on the base type, but
1118 -- the attribute definition clause is attached to the first subtype.
1121 Comp_ADC := Get_Attribute_Definition_Clause
1123 Attribute_Scalar_Storage_Order);
1125 -- Case of enclosing type not having explicit SSO: component cannot
1126 -- have it either.
1130 Error_Msg_N
1132 Err_Node);
1135 -- Case of enclosing type having explicit SSO: check compatible
1136 -- attribute on Comp_Type if composite.
1141 /=
1143 then
1144 Error_Msg_N
1154 /=
1156 and then not Comp_Byte_Aligned
1157 then
1158 Error_Msg_N
1163 -- Enclosing type has explicit SSO, non-composite component must not
1164 -- be aliased.
1167 Error_Msg_N
1173 -----------------------------
1174 -- Check_Debug_Info_Needed --
1175 -----------------------------
1178 begin
1183 or else Debug_Generated_Code
1184 or else Debug_Flag_VV
1186 then
1191 ----------------------------
1192 -- Check_Strict_Alignment --
1193 ----------------------------
1198 begin
1216 then
1226 -------------------------
1227 -- Check_Unsigned_Type --
1228 -------------------------
1235 begin
1240 -- Do not attempt to analyze case where range was in error
1244 then
1248 -- The situation that is non trivial is something like
1250 -- subtype x1 is integer range -10 .. +10;
1251 -- subtype x2 is x1 range 0 .. V1;
1252 -- subtype x3 is x2 range V2 .. V3;
1253 -- subtype x4 is x3 range V4 .. V5;
1255 -- where Vn are variables. Here the base type is signed, but we still
1256 -- know that x4 is unsigned because of the lower bound of x2.
1258 -- The only way to deal with this is to look up the ancestor chain
1261 loop
1276 else
1279 -- If no ancestor had a static lower bound, go to base type
1283 -- Note: the reason we still check for a compile time known
1284 -- value for the base type is that at least in the case of
1285 -- generic formals, we can have bounds that fail this test,
1286 -- and there may be other cases in error situations.
1298 then
1308 -------------------------
1309 -- Is_Atomic_Aggregate --
1310 -------------------------
1312 function Is_Atomic_Aggregate
1315 is
1321 begin
1324 -- Array may be qualified, so find outer context
1332 then
1334 New_N :=
1345 else
1350 ----------------
1351 -- Freeze_All --
1352 ----------------
1354 -- Note: the easy coding for this procedure would be to just build a
1355 -- single list of freeze nodes and then insert them and analyze them
1356 -- all at once. This won't work, because the analysis of earlier freeze
1357 -- nodes may recursively freeze types which would otherwise appear later
1358 -- on in the freeze list. So we must analyze and expand the freeze nodes
1359 -- as they are generated.
1366 -- This is the internal recursive routine that does freezing of entities
1367 -- (but NOT the analysis of default expressions, which should not be
1368 -- recursive, we don't want to analyze those till we are sure that ALL
1369 -- the types are frozen).
1371 --------------------
1372 -- Freeze_All_Ent --
1373 --------------------
1381 -- If freeze nodes are present, insert and analyze, and reset cursor
1382 -- for next insertion.
1384 -------------------
1385 -- Process_Flist --
1386 -------------------
1389 begin
1396 else
1402 -- Start or processing for Freeze_All_Ent
1404 begin
1408 -- If the entity is an inner package which is not a package
1409 -- renaming, then its entities must be frozen at this point. Note
1410 -- that such entities do NOT get frozen at the end of the nested
1411 -- package itself (only library packages freeze).
1413 -- Same is true for task declarations, where anonymous records
1414 -- created for entry parameters must be frozen.
1420 then
1431 then
1437 and then
1439 or else
1441 then
1444 End_Scope;
1446 -- For a derived tagged type, we must ensure that all the
1447 -- primitive operations of the parent have been frozen, so that
1448 -- their addresses will be in the parent's dispatch table at the
1449 -- point it is inherited.
1455 then
1456 declare
1463 begin
1470 then
1472 Process_Flist;
1482 Process_Flist;
1484 -- If already frozen, and there are delayed aspects, this is where
1485 -- we do the visibility check for these aspects (see Sem_Ch13 spec
1486 -- for a description of how we handle aspect visibility).
1490 -- Retrieve the visibility to the discriminants in order to
1491 -- analyze properly the aspects.
1495 declare
1498 begin
1504 then
1515 -- If an incomplete type is still not frozen, this may be a
1516 -- premature freezing because of a body declaration that follows.
1517 -- Indicate where the freezing took place. Freezing will happen
1518 -- if the body comes from source, but not if it is internally
1519 -- generated, for example as the body of a type invariant.
1521 -- If the freezing is caused by the end of the current declarative
1522 -- part, it is a Taft Amendment type, and there is no error.
1526 then
1527 declare
1530 begin
1531 -- The presence of a body freezes all entities previously
1532 -- declared in the current list of declarations, but this
1533 -- does not apply if the body does not come from source.
1534 -- A type invariant is transformed into a subprogram body
1535 -- which is placed at the end of the private part of the
1536 -- current package, but this body does not freeze incomplete
1537 -- types that may be declared in this private part.
1540 N_Entry_Body,
1541 N_Package_Body,
1542 N_Protected_Body,
1543 N_Task_Body)
1545 and then
1548 then
1550 Error_Msg_NE
1561 -- Start of processing for Freeze_All
1563 begin
1566 -- Now that all types are frozen, we can deal with default expressions
1567 -- that require us to build a default expression functions. This is the
1568 -- point at which such functions are constructed (after all types that
1569 -- might be used in such expressions have been frozen).
1571 -- For subprograms that are renaming_as_body, we create the wrapper
1572 -- bodies as needed.
1574 -- We also add finalization chains to access types whose designated
1575 -- types are controlled. This is normally done when freezing the type,
1576 -- but this misses recursive type definitions where the later members
1577 -- of the recursion introduce controlled components.
1579 -- Loop through entities
1595 else
1601 and then
1603 = N_Subprogram_Renaming_Declaration
1604 then
1605 Build_And_Analyze_Renamed_Body
1611 and then
1613 or else
1615 then
1616 declare
1619 begin
1624 then
1632 -- We add finalization masters to access types whose designated types
1633 -- require finalization. This is normally done when freezing the
1634 -- type, but this misses recursive type definitions where the later
1635 -- members of the recursion introduce controlled components (such as
1636 -- can happen when incomplete types are involved), as well cases
1637 -- where a component type is private and the controlled full type
1638 -- occurs after the access type is frozen. Cases that don't need a
1639 -- finalization master are generic formal types (the actual type will
1640 -- have it) and types with Java and CIL conventions, since those are
1641 -- used for API bindings. (Are there any other cases that should be
1642 -- excluded here???)
1648 then
1656 -----------------------
1657 -- Freeze_And_Append --
1658 -----------------------
1660 procedure Freeze_And_Append
1664 is
1666 begin
1670 else
1676 -------------------
1677 -- Freeze_Before --
1678 -------------------
1682 begin
1688 -------------------
1689 -- Freeze_Entity --
1690 -------------------
1702 -- List of freezing actions, left at No_List if none
1705 -- This flag gets set to true for a variable with default initialization
1708 -- N is a freezing action to be appended to the Result
1711 -- If Loc is a freeze_entity that appears after the last declaration
1712 -- in the scope, inhibit error messages on late completion.
1715 -- Check that an Access or Unchecked_Access attribute with a prefix
1716 -- which is the current instance type can only be applied when the type
1717 -- is limited.
1720 -- Give warning for modulus of 8, 16, 32, or 64 given as an explicit
1721 -- integer literal without an explicit corresponding size clause. The
1722 -- caller has checked that Utype is a modular integer type.
1725 -- Freeze array type, including freezing index and component types
1728 -- Create Freeze_Generic_Entity nodes for types declared in a generic
1729 -- package. Recurse on inner generic packages.
1732 -- Freeze record type, including freezing component types, and freezing
1733 -- primitive operations if this is a tagged type.
1735 -------------------
1736 -- Add_To_Result --
1737 -------------------
1740 begin
1743 else
1748 ----------------------------
1749 -- After_Last_Declaration --
1750 ----------------------------
1754 begin
1760 else
1763 else
1768 ----------------------------
1769 -- Check_Current_Instance --
1770 ----------------------------
1775 -- Determine whether Typ is compatible with the rules for aliased
1776 -- views of types as defined in RM 3.10 in the various dialects.
1779 -- Process routine to apply check to given node
1781 -----------------------------
1782 -- Is_Aliased_View_Of_Type --
1783 -----------------------------
1788 begin
1789 -- Common case
1793 then
1796 -- The following paragraphs describe what a legal aliased view of
1797 -- a type is in the various dialects of Ada.
1799 -- Ada 95
1801 -- The current instance of a limited type, and a formal parameter
1802 -- or generic formal object of a tagged type.
1804 -- Ada 95 limited type
1805 -- * Type with reserved word "limited"
1806 -- * A protected or task type
1807 -- * A composite type with limited component
1812 -- Ada 2005
1814 -- The current instance of a limited tagged type, a protected
1815 -- type, a task type, or a type that has the reserved word
1816 -- "limited" in its full definition ... a formal parameter or
1817 -- generic formal object of a tagged type.
1819 -- Ada 2005 limited type
1820 -- * Type with reserved word "limited", "synchronized", "task"
1821 -- or "protected"
1822 -- * A composite type with limited component
1823 -- * A derived type whose parent is a non-interface limited type
1826 return
1828 or else
1833 -- Ada 2012 and beyond
1835 -- The current instance of an immutably limited type ... a formal
1836 -- parameter or generic formal object of a tagged type.
1838 -- Ada 2012 limited type
1839 -- * Type with reserved word "limited", "synchronized", "task"
1840 -- or "protected"
1841 -- * A composite type with limited component
1842 -- * A derived type whose parent is a non-interface limited type
1843 -- * An incomplete view
1845 -- Ada 2012 immutably limited type
1846 -- * Explicitly limited record type
1847 -- * Record extension with "limited" present
1848 -- * Non-formal limited private type that is either tagged
1849 -- or has at least one access discriminant with a default
1850 -- expression
1851 -- * Task type, protected type or synchronized interface
1852 -- * Type derived from immutably limited type
1854 else
1855 return
1861 -------------
1862 -- Process --
1863 -------------
1866 begin
1870 Name_Unchecked_Access)
1874 then
1876 Error_Msg_N
1879 else
1880 Error_Msg_N
1886 else
1896 -- Local variables
1901 -- Start of processing for Check_Current_Instance
1903 begin
1909 ------------------------------
1910 -- Check_Suspicious_Modulus --
1911 ------------------------------
1916 begin
1922 declare
1925 begin
1927 declare
1931 begin
1933 declare
1937 begin
1938 -- First case, modulus and size are the same. This
1939 -- happens if you have something like mod 32, with
1940 -- an explicit size of 32, this is for sure a case
1941 -- where the warning is given, since it is seems
1942 -- very unlikely that someone would want e.g. a
1943 -- five bit type stored in 32 bits. It is much
1944 -- more likely they wanted a 32-bit type.
1949 -- Second case, the modulus is 32 or 64 and no
1950 -- size clause is present. This is a less clear
1951 -- case for giving the warning, but in the case
1952 -- of 32/64 (5-bit or 6-bit types) these seem rare
1953 -- enough that it is a likely error (and in any
1954 -- case using 2**5 or 2**6 in these cases seems
1955 -- clearer. We don't include 8 or 16 here, simply
1956 -- because in practice 3-bit and 4-bit types are
1957 -- more common and too many false positives if
1958 -- we warn in these cases.
1962 then
1965 -- No warning needed
1967 else
1971 -- If we fall through, give warning
1974 Error_Msg_N
1976 Modulus);
1985 -----------------------
1986 -- Freeze_Array_Type --
1987 -----------------------
1995 -- Set true if any of the index types is an enumeration type with a
1996 -- non-standard representation.
1998 begin
2007 then
2014 -- Processing that is done only for base types
2018 -- Propagate flags for component type
2022 then
2030 -- Warn for pragma Pack overriding foreign convention
2034 then
2035 declare
2040 begin
2044 Error_Msg_N
2046 PP);
2048 Error_Msg_N
2055 -- If packing was requested or if the component size was
2056 -- set explicitly, then see if bit packing is required. This
2057 -- processing is only done for base types, since all of the
2058 -- representation aspects involved are type-related. This is not
2059 -- just an optimization, if we start processing the subtypes, they
2060 -- interfere with the settings on the base type (this is because
2061 -- Is_Packed has a slightly different meaning before and after
2062 -- freezing).
2064 declare
2068 begin
2072 then
2081 else
2084 -- We can set the component size if it is less than 16,
2085 -- rounding it up to the next storage unit size.
2091 else
2095 -- Set component size up to match alignment if it would
2096 -- otherwise be less than the alignment. This deals with
2097 -- cases of types whose alignment exceeds their size (the
2098 -- padded type cases).
2101 declare
2103 begin
2111 -- Case of component size that may result in packing
2114 declare
2120 Get_Attribute_Definition_Clause
2122 begin
2123 -- Warn if we have pack and component size so that the
2124 -- pack is ignored.
2126 -- Note: here we must check for the presence of a
2127 -- component size before checking for a Pack pragma to
2128 -- deal with the case where the array type is a derived
2129 -- type whose parent is currently private.
2133 and then Warn_On_Redundant_Constructs
2134 then
2136 Error_Msg_NE
2139 Error_Msg_N
2141 Pack_Pragma);
2146 -- Set component size if not already set by a component
2147 -- size clause.
2153 -- Check for base type of 8, 16, 32 bits, where an
2154 -- unsigned subtype has a length one less than the
2155 -- base type (e.g. Natural subtype of Integer).
2157 -- In such cases, if a component size was not set
2158 -- explicitly, then generate a warning.
2162 and then
2165 then
2169 Error_Msg_N
2172 Error_Msg_N
2178 -- Actual packing is not needed for 8, 16, 32, 64. Also
2179 -- not needed for 24 if alignment is 1.
2186 then
2187 -- Here the array was requested to be packed, but
2188 -- the packing request had no effect, so Is_Packed
2189 -- is reset.
2191 -- Note: semantically this means that we lose track
2192 -- of the fact that a derived type inherited a pragma
2193 -- Pack that was non- effective, but that seems fine.
2195 -- We regard a Pack pragma as a request to set a
2196 -- representation characteristic, and this request
2197 -- may be ignored.
2204 then
2205 Set_Has_Non_Standard_Rep
2209 -- In all other cases, packing is indeed needed
2211 else
2220 -- Check for Atomic_Components or Aliased with unsuitable packing
2221 -- or explicit component size clause given.
2227 then
2231 -- Outputs error messages for incorrect CS clause or pragma
2232 -- Pack for aliased or atomic components (T is "aliased" or
2233 -- "atomic");
2235 -----------------
2236 -- Complain_CS --
2237 -----------------
2240 begin
2242 Clause :=
2243 Get_Attribute_Definition_Clause
2247 Error_Msg_N
2251 Error_Msg_N
2254 else
2255 Error_Msg_N
2260 else
2261 Error_Msg_N
2269 -- Start of processing for Alias_Atomic_Check
2271 begin
2273 -- If object size of component type isn't known, we cannot
2274 -- be sure so we defer to the back end.
2279 -- Case where component size has no effect. First check for
2280 -- object size of component type multiple of the storage
2281 -- unit size.
2285 -- OK in both packing case and component size case if RM
2286 -- size is known and static and same as the object size.
2288 and then
2292 -- Or if we have an explicit component size clause and
2293 -- the component size and object size are equal.
2295 or else
2298 then
2303 then
2308 then
2314 -- Warn for case of atomic type
2320 then
2321 Error_Msg_NE
2326 Error_Msg_Sloc :=
2327 Sloc
2328 (Get_Attribute_Definition_Clause
2330 Error_Msg_N
2332 Clause);
2335 Error_Msg_Sloc :=
2337 Error_Msg_N
2342 -- Check for scalar storage order
2344 Check_Component_Storage_Order
2347 ADC => Get_Attribute_Definition_Clause
2349 Attribute_Scalar_Storage_Order));
2351 -- Processing that is done only for subtypes
2353 else
2354 -- Acquire alignment from base type
2362 -- Specific checks for bit-packed arrays
2366 -- Check number of elements for bit packed arrays that come from
2367 -- source and have compile time known ranges. The bit-packed
2368 -- arrays circuitry does not support arrays with more than
2369 -- Integer'Last + 1 elements, and when this restriction is
2370 -- violated, causes incorrect data access.
2372 -- For the case where this is not compile time known, a run-time
2373 -- check should be generated???
2376 declare
2382 begin
2388 -- Never generate an error if any index is of a generic
2389 -- type. We will check this in instances.
2396 Ilen :=
2398 Prefix =>
2403 -- No attempt is made to check number of elements
2404 -- if not compile time known.
2416 (Scalar_Range
2418 then
2419 Error_Msg_N
2426 -- Check size
2429 declare
2435 begin
2436 -- It is not clear if it is possible to have no size clause
2437 -- at this stage, but it is not worth worrying about. Post
2438 -- error on the entity name in the size clause if present,
2439 -- else on the type entity itself.
2443 else
2450 -- If any of the index types was an enumeration type with a
2451 -- non-standard rep clause, then we indicate that the array type
2452 -- is always packed (even if it is not bit packed).
2461 -- If the array is packed, we must create the packed array type to be
2462 -- used to actually implement the type. This is only needed for real
2463 -- array types (not for string literal types, since they are present
2464 -- only for the front end).
2468 then
2472 -- Size information of packed array type is copied to the array
2473 -- type, since this is really the representation. But do not
2474 -- override explicit existing size values. If the ancestor subtype
2475 -- is constrained the packed_array_type will be inherited from it,
2476 -- but the size may have been provided already, and must not be
2477 -- overridden either.
2480 and then
2483 then
2493 -- For non-packed arrays set the alignment of the array to the
2494 -- alignment of the component type if it is unknown. Skip this
2495 -- in atomic case (atomic arrays may need larger alignments).
2504 then
2509 -----------------------------
2510 -- Freeze_Generic_Entities --
2511 -----------------------------
2518 begin
2537 ------------------------
2538 -- Freeze_Record_Type --
2539 ------------------------
2551 -- Set True if the record type scope Rec has been pushed on the scope
2552 -- stack. Needed for the analysis of delayed aspects specified to the
2553 -- components of Rec.
2556 -- Set True if we find at least one component with no component
2557 -- clause (used to warn about useless Pack pragmas).
2560 -- Set True if we find at least one component with a component
2561 -- clause (used to warn about useless Bit_Order pragmas, and also
2562 -- to detect cases where Implicit_Packing may have an effect).
2565 -- Set True if we find at least one component which is aliased. This
2566 -- is used to prevent Implicit_Packing of the record, since packing
2567 -- cannot modify the size of alignment of an aliased component.
2570 -- Set False if we encounter a component of a non-scalar type
2574 -- Accumulates total RM_Size values and total Esize values of all
2575 -- scalar components. Used for processing of Implicit_Packing.
2578 -- If N is an allocator, possibly wrapped in one or more level of
2579 -- qualified expression(s), return the inner allocator node, else
2580 -- return Empty.
2583 -- If the component subtype is an access to a constrained subtype of
2584 -- an already frozen type, make the subtype frozen as well. It might
2585 -- otherwise be frozen in the wrong scope, and a freeze node on
2586 -- subtype has no effect. Similarly, if the component subtype is a
2587 -- regular (not protected) access to subprogram, set the anonymous
2588 -- subprogram type to frozen as well, to prevent an out-of-scope
2589 -- freeze node at some eventual point of call. Protected operations
2590 -- are handled elsewhere.
2593 -- Make sure that all types mentioned in Discrete_Choices of the
2594 -- variants referenceed by the Variant_Part VP are frozen. This is
2595 -- a recursive routine to deal with nested variants.
2597 ---------------------
2598 -- Check_Allocator --
2599 ---------------------
2603 begin
2605 loop
2610 else
2616 -----------------
2617 -- Check_Itype --
2618 -----------------
2623 begin
2626 then
2629 -- In addition, add an Itype_Reference to ensure that the
2630 -- access subtype is elaborated early enough. This cannot be
2631 -- done if the subtype may depend on discriminants.
2636 then
2644 then
2649 ------------------------------------
2650 -- Freeze_Choices_In_Variant_Part --
2651 ------------------------------------
2660 begin
2661 -- Loop through variants
2666 -- Loop through choices, checking that all types are frozen
2672 then
2679 -- Check for nested variant part to process
2693 -- Start of processing for Freeze_Record_Type
2695 begin
2696 -- Deal with delayed aspect specifications for components. The
2697 -- analysis of the aspect is required to be delayed to the freeze
2698 -- point, thus we analyze the pragma or attribute definition
2699 -- clause in the tree at this point. We also analyze the aspect
2700 -- specification node at the freeze point when the aspect doesn't
2701 -- correspond to pragma/attribute definition clause.
2707 then
2712 -- The visibility to the discriminants must be restored in
2713 -- order to properly analyze the aspects.
2726 -- Pop the scope if Rec scope has been pushed on the scope stack
2727 -- during the delayed aspect analysis process.
2734 Pop_Scope;
2737 -- Freeze components and embedded subtypes
2746 -- Handle the component and discriminant case
2749 declare
2752 begin
2753 -- Freezing a record type freezes the type of each of its
2754 -- components. However, if the type of the component is
2755 -- part of this record, we do not want or need a separate
2756 -- Freeze_Node. Note that Is_Itype is wrong because that's
2757 -- also set in private type cases. We also can't check for
2758 -- the Scope being exactly Rec because of private types and
2759 -- record extensions.
2764 then
2770 -- Warn for pragma Pack overriding foreign convention
2775 -- Don't warn for aliased components, since override
2776 -- cannot happen in that case.
2779 then
2780 declare
2785 begin
2789 Error_Msg_N
2791 PP);
2793 Error_Msg_NE
2800 -- Check for error of component clause given for variable
2801 -- sized type. We have to delay this test till this point,
2802 -- since the component type has to be frozen for us to know
2803 -- if it is variable length. We omit this test in a generic
2804 -- context, it will be applied at instantiation time.
2806 -- We also omit this test in CodePeer mode, since we do not
2807 -- have sufficient info on size and representation clauses.
2818 elsif not
2819 Size_Known_At_Compile_Time
2821 then
2822 Error_Msg_N
2827 else
2831 -- Case of component requires byte alignment
2835 -- Set the enclosing record to also require byte align
2839 -- Check for component clause that is inconsistent with
2840 -- the required byte boundary alignment.
2845 then
2846 Error_Msg_N
2854 -- Gather data for possible Implicit_Packing later. Note that at
2855 -- this stage we might be dealing with a real component, or with
2856 -- an implicit subtype declaration.
2860 else
2861 Scalar_Component_Total_RM_Size :=
2863 Scalar_Component_Total_Esize :=
2867 -- If the component is an Itype with Delayed_Freeze and is either
2868 -- a record or array subtype and its base type has not yet been
2869 -- frozen, we must remove this from the entity list of this record
2870 -- and put it on the entity list of the scope of its base type.
2871 -- Note that we know that this is not the type of a component
2872 -- since we cleared Has_Delayed_Freeze for it in the previous
2873 -- loop. Thus this must be the Designated_Type of an access type,
2874 -- which is the type of a component.
2882 then
2883 declare
2887 begin
2888 -- We have a pretty bad kludge here. Suppose Rec is subtype
2889 -- being defined in a subprogram that's created as part of
2890 -- the freezing of Rec'Base. In that case, we know that
2891 -- Comp'Base must have already been frozen by the time we
2892 -- get to elaborate this because Gigi doesn't elaborate any
2893 -- bodies until it has elaborated all of the declarative
2894 -- part. But Is_Frozen will not be set at this point because
2895 -- we are processing code in lexical order.
2897 -- We detect this case by going up the Scope chain of Rec
2898 -- and seeing if we have a subprogram scope before reaching
2899 -- the top of the scope chain or that of Comp'Base. If we
2900 -- do, then mark that Comp'Base will actually be frozen. If
2901 -- so, we merely undelay it.
2917 else
2920 else
2924 -- Insert in entity list of scope of base type (which
2925 -- must be an enclosing scope, because still unfrozen).
2931 -- If the component is an access type with an allocator as default
2932 -- value, the designated type will be frozen by the corresponding
2933 -- expression in init_proc. In order to place the freeze node for
2934 -- the designated type before that for the current record type,
2935 -- freeze it now.
2937 -- Same process if the component is an array of access types,
2938 -- initialized with an aggregate. If the designated type is
2939 -- private, it cannot contain allocators, and it is premature
2940 -- to freeze the type, so we check for this as well.
2945 then
2946 declare
2950 begin
2953 -- If component is pointer to a class-wide type, freeze
2954 -- the specific type in the expression being allocated.
2955 -- The expression may be a subtype indication, in which
2956 -- case freeze the subtype mark.
2958 if Is_Class_Wide_Type
2960 then
2962 Freeze_And_Append
2964 elsif
2966 then
2967 Freeze_And_Append
2975 else
2976 Freeze_And_Append
2984 then
2993 and then Is_Fully_Defined
2995 then
2996 Freeze_And_Append
2997 (Designated_Type
3005 ADC := Get_Attribute_Definition_Clause
3010 -- Check compatibility of Scalar_Storage_Order with Bit_Order, if
3011 -- the former is specified.
3015 -- Note: report error on Rec, not on ADC, as ADC may apply to
3016 -- an ancestor type.
3019 Error_Msg_N
3024 -- Warn if there is a Scalar_Storage_Order but no component clause
3025 -- (or pragma Pack).
3028 Error_Msg_N
3030 ADC);
3034 -- Check consistent attribute setting on component types
3038 Check_Component_Storage_Order
3043 -- Deal with Bit_Order aspect specifying a non-default bit order
3049 Error_Msg_N
3051 Error_Msg_N
3054 -- Here is where we do the processing for reversed bit order
3058 then
3061 -- Case where we have both an explicit Bit_Order and the same
3062 -- Scalar_Storage_Order: leave record untouched, the back-end
3063 -- will take care of required layout conversions.
3065 else
3071 -- Complete error checking on record representation clause (e.g.
3072 -- overlap of components). This is called after adjusting the
3073 -- record for reverse bit order.
3075 declare
3077 begin
3083 -- Set OK_To_Reorder_Components depending on debug flags
3087 or else
3089 then
3094 -- Check for useless pragma Pack when all components placed. We only
3095 -- do this check for record types, not subtypes, since a subtype may
3096 -- have all its components placed, and it still makes perfectly good
3097 -- sense to pack other subtypes or the parent type. We do not give
3098 -- this warning if Optimize_Alignment is set to Space, since the
3099 -- pragma Pack does have an effect in this case (it always resets
3100 -- the alignment to one).
3104 and then not Unplaced_Component
3106 then
3107 -- Reset packed status. Probably not necessary, but we do it so
3108 -- that there is no chance of the back end doing something strange
3109 -- with this redundant indication of packing.
3113 -- Give warning if redundant constructs warnings on
3116 Error_Msg_N -- CODEFIX
3122 -- If this is the record corresponding to a remote type, freeze the
3123 -- remote type here since that is what we are semantically freezing.
3124 -- This prevents the freeze node for that type in an inner scope.
3131 -- Check for controlled components and unchecked unions.
3136 -- Do not set Has_Controlled_Component on a class-wide
3137 -- equivalent type. See Make_CW_Equivalent_Type.
3140 and then
3142 or else
3145 or else
3147 and then
3149 and then
3150 Has_Controlled_Component
3152 then
3160 -- Scan component declaration for likely misuses of current
3161 -- instance, either in a constraint or a default expression.
3171 -- Enforce the restriction that access attributes with a current
3172 -- instance prefix can only apply to limited types. This comment
3173 -- is floating here, but does not seem to belong here???
3175 -- Set component alignment if not otherwise already set
3179 -- For first subtypes, check if there are any fixed-point fields with
3180 -- component clauses, where we must check the size. This is not done
3181 -- till the freeze point since for fixed-point types, we do not know
3182 -- the size until the type is frozen. Similar processing applies to
3183 -- bit packed arrays.
3190 or else
3192 then
3193 Check_Size
3197 Junk);
3204 -- Generate warning for applying C or C++ convention to a record
3205 -- with discriminants. This is suppressed for the unchecked union
3206 -- case, since the whole point in this case is interface C. We also
3207 -- do not generate this within instantiations, since we will have
3208 -- generated a message on the template.
3213 or else
3216 and then not In_Instance
3219 then
3220 declare
3224 begin
3229 Error_Msg_N
3231 A2);
3232 else
3233 Error_Msg_N
3235 A2);
3238 Error_Msg_NE
3244 -- See if Size is too small as is (and implicit packing might help)
3248 -- No implicit packing if even one component is explicitly placed
3250 and then not Placed_Component
3252 -- Or even one component is aliased
3254 and then not Aliased_Component
3256 -- Must have size clause and all scalar components
3259 and then All_Scalar_Components
3261 -- Do not try implicit packing on records with discriminants, too
3262 -- complicated, especially in the variant record case.
3266 -- We can implicitly pack if the specified size of the record is
3267 -- less than the sum of the object sizes (no point in packing if
3268 -- this is not the case).
3272 -- And the total RM size cannot be greater than the specified size
3273 -- since otherwise packing will not get us where we have to be!
3277 -- Never do implicit packing in CodePeer or SPARK modes since
3278 -- we don't do any packing in these modes, since this generates
3279 -- over-complex code that confuses static analysis, and in
3280 -- general, neither CodePeer not GNATprove care about the
3281 -- internal representation of objects.
3284 then
3285 -- If implicit packing enabled, do it
3290 -- Otherwise flag the size clause
3292 else
3293 declare
3295 begin
3296 Error_Msg_NE -- CODEFIX
3298 Error_Msg_N -- CODEFIX
3305 -- All done if not a full record definition
3311 -- Finally we need to check the variant part to make sure that
3312 -- all types within choices are properly frozen as part of the
3313 -- freezing of the record type.
3320 begin
3321 -- Find component list
3333 then
3338 -- Case of variant part present
3344 -- Note: we used to call Check_Choices here, but it is too early,
3345 -- since predicated subtypes are frozen here, but their freezing
3346 -- actions are in Analyze_Freeze_Entity, which has not been called
3347 -- yet for entities frozen within this procedure, so we moved that
3348 -- call to the Analyze_Freeze_Entity for the record type.
3353 -- Start of processing for Freeze_Entity
3355 begin
3356 -- We are going to test for various reasons why this entity need not be
3357 -- frozen here, but in the case of an Itype that's defined within a
3358 -- record, that test actually applies to the record.
3364 then
3368 -- Do not freeze if already frozen since we only need one freeze node
3373 -- It is improper to freeze an external entity within a generic because
3374 -- its freeze node will appear in a non-valid context. The entity will
3375 -- be frozen in the proper scope after the current generic is analyzed.
3376 -- However, aspects must be analyzed because they may be queried later
3377 -- within the generic itself, and the corresponding pragma or attribute
3378 -- definition has not been analyzed yet.
3387 -- AI05-0213: A formal incomplete type does not freeze the actual. In
3388 -- the instance, the same applies to the subtype renaming the actual.
3394 then
3397 -- Generic types need no freeze node and have no delayed semantic
3398 -- checks.
3403 -- Do not freeze a global entity within an inner scope created during
3404 -- expansion. A call to subprogram E within some internal procedure
3405 -- (a stream attribute for example) might require freezing E, but the
3406 -- freeze node must appear in the same declarative part as E itself.
3407 -- The two-pass elaboration mechanism in gigi guarantees that E will
3408 -- be frozen before the inner call is elaborated. We exclude constants
3409 -- from this test, because deferred constants may be frozen early, and
3410 -- must be diagnosed (e.g. in the case of a deferred constant being used
3411 -- in a default expression). If the enclosing subprogram comes from
3412 -- source, or is a generic instance, then the freeze point is the one
3413 -- mandated by the language, and we freeze the entity. A subprogram that
3414 -- is a child unit body that acts as a spec does not have a spec that
3415 -- comes from source, but can only come from source.
3420 then
3421 declare
3424 begin
3431 then
3433 else
3442 -- Similarly, an inlined instance body may make reference to global
3443 -- entities, but these references cannot be the proper freezing point
3444 -- for them, and in the absence of inlining freezing will take place in
3445 -- their own scope. Normally instance bodies are analyzed after the
3446 -- enclosing compilation, and everything has been frozen at the proper
3447 -- place, but with front-end inlining an instance body is compiled
3448 -- before the end of the enclosing scope, and as a result out-of-order
3449 -- freezing must be prevented.
3451 elsif Front_End_Inlining
3452 and then In_Instance_Body
3454 then
3455 declare
3458 begin
3463 else
3477 -- Add checks to detect proper initialization of scalars that may appear
3478 -- as subprogram parameters.
3484 -- Deal with delayed aspect specifications. The analysis of the aspect
3485 -- is required to be delayed to the freeze point, thus we analyze the
3486 -- pragma or attribute definition clause in the tree at this point. We
3487 -- also analyze the aspect specification node at the freeze point when
3488 -- the aspect doesn't correspond to pragma/attribute definition clause.
3494 -- Here to freeze the entity
3498 -- Case of entity being frozen is other than a type
3502 -- If entity is exported or imported and does not have an external
3503 -- name, now is the time to provide the appropriate default name.
3504 -- Skip this if the entity is stubbed, since we don't need a name
3505 -- for any stubbed routine. For the case on intrinsics, if no
3506 -- external name is specified, then calls will be handled in
3507 -- Exp_Intr.Expand_Intrinsic_Call, and no name is needed. If an
3508 -- external name is provided, then Expand_Intrinsic_Call leaves
3509 -- calls in place for expansion by GIGI.
3515 then
3516 Set_Encoded_Interface_Name
3519 -- If entity is an atomic object appearing in a declaration and
3520 -- the expression is an aggregate, assign it to a temporary to
3521 -- ensure that the actual assignment is done atomically rather
3522 -- than component-wise (the assignment to the temp may be done
3523 -- component-wise, but that is harmless).
3530 then
3534 -- For a subprogram, freeze all parameter types and also the return
3535 -- type (RM 13.14(14)). However skip this for internal subprograms.
3536 -- This is also the point where any extra formal parameters are
3537 -- created since we now know whether the subprogram will use a
3538 -- foreign convention.
3542 declare
3547 begin
3548 -- Loop through formals
3554 -- AI05-0151 : incomplete types can appear in a profile.
3555 -- By the time the entity is frozen, the full view must
3556 -- be available, unless it is a limited view.
3561 then
3573 then
3574 -- If the type of a formal is incomplete, subprogram
3575 -- is being frozen prematurely. Within an instance
3576 -- (but not within a wrapper package) this is an
3577 -- artifact of our need to regard the end of an
3578 -- instantiation as a freeze point. Otherwise it is
3579 -- a definite error.
3585 elsif not After_Last_Declaration
3586 and then not Freezing_Library_Level_Tagged_Type
3587 then
3589 Error_Msg
3591 Loc);
3595 -- Check suspicious parameter for C function. These tests
3596 -- apply only to exported/imported subprograms.
3598 if Warn_On_Export_Import
3601 or else
3608 then
3609 -- Qualify mention of formals with subprogram name
3613 -- Check suspicious use of fat C pointer
3617 then
3618 Error_Msg_N
3620 Formal);
3622 -- Check suspicious return of boolean
3629 then
3630 Error_Msg_N
3632 Error_Msg_N
3636 -- Check suspicious tagged type
3640 and then
3641 Is_Tagged_Type
3644 then
3645 Error_Msg_N
3649 -- Check wrong convention subprogram pointer
3653 then
3654 Error_Msg_N
3658 Error_Msg_NE
3663 -- Turn off name qualification after message output
3668 -- Check for unconstrained array in exported foreign
3669 -- convention case.
3675 and then Warn_On_Export_Import
3677 -- Exclude VM case, since both .NET and JVM can handle
3678 -- unconstrained arrays without a problem.
3681 then
3684 -- If this is an inherited operation, place the
3685 -- warning on the derived type declaration, rather
3686 -- than on the original subprogram.
3689 N_Full_Type_Declaration
3690 then
3694 Error_Msg_NE
3697 else
3701 Error_Msg_NE
3704 Error_Msg_NE
3715 -- If the formal is an anonymous_access_to_subprogram
3716 -- freeze the subprogram type as well, to prevent
3717 -- scope anomalies in gigi, because there is no other
3718 -- clear point at which it could be frozen.
3722 then
3730 -- Case of function: similar checks on return type
3734 -- Freeze return type
3738 -- AI05-0151: the return type may have been incomplete
3739 -- at the point of declaration. Replace it with the full
3740 -- view, unless the current type is a limited view. In
3741 -- that case the full view is in a different unit, and
3742 -- gigi finds the non-limited view after the other unit
3743 -- is elaborated.
3748 then
3755 -- Check suspicious return type for C function
3757 if Warn_On_Export_Import
3759 or else
3762 then
3763 -- Check suspicious return of fat C pointer
3769 then
3770 Error_Msg_N
3774 -- Check suspicious return of boolean
3782 then
3783 declare
3786 begin
3787 Error_Msg_NE
3790 Error_Msg_NE
3795 -- Check suspicious return tagged type
3799 and then
3800 Is_Tagged_Type
3805 then
3806 Error_Msg_N
3810 -- Check return of wrong convention subprogram pointer
3816 then
3817 Error_Msg_N
3821 Error_Msg_NE
3827 -- Give warning for suspicious return of a result of an
3828 -- unconstrained array type in a foreign convention
3829 -- function.
3833 -- We are looking for a return of unconstrained array
3838 -- Exclude imported routines, the warning does not
3839 -- belong on the import, but rather on the routine
3840 -- definition.
3844 -- Exclude VM case, since both .NET and JVM can handle
3845 -- return of unconstrained arrays without a problem.
3849 -- Check that general warning is enabled, and that it
3850 -- is not suppressed for this particular case.
3852 and then Warn_On_Export_Import
3855 then
3856 Error_Msg_N
3863 -- Pre/post conditions are implemented through a subprogram in
3864 -- the corresponding body, and therefore are not checked on an
3865 -- imported subprogram for which the body is not available.
3867 -- Could consider generating a wrapper to take care of this???
3873 then
3874 Error_Msg_NE
3881 -- Must freeze its parent first if it is a derived subprogram
3887 -- We don't freeze internal subprograms, because we don't normally
3888 -- want addition of extra formals or mechanism setting to happen
3889 -- for those. However we do pass through predefined dispatching
3890 -- cases, since extra formals may be needed in some cases, such as
3891 -- for the stream 'Input function (build-in-place formals).
3895 then
3899 -- Here for other than a subprogram or type
3901 else
3902 -- If entity has a type, and it is not a generic unit, then
3903 -- freeze it first (RM 13.14(10)).
3907 then
3911 -- Special processing for objects created by object declaration
3915 -- Abstract type allowed only for C++ imported variables or
3916 -- constants.
3918 -- Note: we inhibit this check for objects that do not come
3919 -- from source because there is at least one case (the
3920 -- expansion of x'Class'Input where x is abstract) where we
3921 -- legitimately generate an abstract object.
3927 then
3932 Error_Msg_NE
3938 -- For object created by object declaration, perform required
3939 -- categorization (preelaborate and pure) checks. Defer these
3940 -- checks to freeze time since pragma Import inhibits default
3941 -- initialization and thus pragma Import affects these checks.
3945 -- If there is an address clause, check that it is valid
3949 -- Reset Is_True_Constant for aliased object. We consider that
3950 -- the fact that something is aliased may indicate that some
3951 -- funny business is going on, e.g. an aliased object is passed
3952 -- by reference to a procedure which captures the address of
3953 -- the object, which is later used to assign a new value. Such
3954 -- code is highly dubious, but we choose to make it "work" for
3955 -- aliased objects.
3957 -- However, we don't do that for internal entities. We figure
3958 -- that if we deliberately set Is_True_Constant for an internal
3959 -- entity, e.g. a dispatch table entry, then we mean it!
3963 then
3967 -- If the object needs any kind of default initialization, an
3968 -- error must be issued if No_Default_Initialization applies.
3969 -- The check doesn't apply to imported objects, which are not
3970 -- ever default initialized, and is why the check is deferred
3971 -- until freezing, at which point we know if Import applies.
3972 -- Deferred constants are also exempted from this test because
3973 -- their completion is explicit, or through an import pragma.
3977 then
3983 and then
3988 or else
3991 then
3993 Check_Restriction
3997 -- Check that a Thread_Local_Storage variable does not have
3998 -- default initialization, and any explicit initialization must
3999 -- either be the null constant or a static constant.
4002 declare
4004 begin
4005 if Has_Default_Initialization
4006 or else
4008 and then
4010 or else not
4012 or else
4014 then
4015 Error_Msg_NE
4018 Error_Msg_NE
4025 -- For imported objects, set Is_Public unless there is also an
4026 -- address clause, which means that there is no external symbol
4027 -- needed for the Import (Is_Public may still be set for other
4028 -- unrelated reasons). Note that we delayed this processing
4029 -- till freeze time so that we can be sure not to set the flag
4030 -- if there is an address clause. If there is such a clause,
4031 -- then the only purpose of the Import pragma is to suppress
4032 -- implicit initialization.
4038 -- For convention C objects of an enumeration type, warn if
4039 -- the size is not integer size and no explicit size given.
4040 -- Skip warning for Boolean, and Character, assume programmer
4041 -- expects 8-bit sizes for these cases.
4044 or else
4051 then
4053 Error_Msg_N
4055 E);
4060 -- Check that a constant which has a pragma Volatile[_Components]
4061 -- or Atomic[_Components] also has a pragma Import (RM C.6(13)).
4063 -- Note: Atomic[_Components] also sets Volatile[_Components]
4068 then
4069 -- Make sure we actually have a pragma, and have not merely
4070 -- inherited the indication from elsewhere (e.g. an address
4071 -- clause, which is not good enough in RM terms!)
4074 or else
4076 then
4077 Error_Msg_N
4082 or else
4084 then
4085 Error_Msg_N
4091 -- Static objects require special handling
4095 then
4099 -- Remaining step is to layout objects
4102 or else
4104 or else
4106 or else
4108 then
4112 -- If initialization statements were captured in an expression
4113 -- with actions with null expression, and the object does not
4114 -- have delayed freezing, move them back now directly within the
4115 -- enclosing statement sequence.
4119 then
4120 declare
4123 begin
4127 then
4130 -- Note that we rewrite Init_Stmts into a NULL statement,
4131 -- rather than just removing it, because Freeze_All may
4132 -- depend on this particular Node_Id still being present
4133 -- in the enclosing list to signal where to stop
4134 -- freezing.
4145 -- Case of a type or subtype being frozen
4147 else
4148 -- We used to check here that a full type must have preelaborable
4149 -- initialization if it completes a private type specified with
4150 -- pragma Preelaborable_Initialization, but that missed cases where
4151 -- the types occur within a generic package, since the freezing
4152 -- that occurs within a containing scope generally skips traversal
4153 -- of a generic unit's declarations (those will be frozen within
4154 -- instances). This check was moved to Analyze_Package_Specification.
4156 -- The type may be defined in a generic unit. This can occur when
4157 -- freezing a generic function that returns the type (which is
4158 -- defined in a parent unit). It is clearly meaningless to freeze
4159 -- this type. However, if it is a subtype, its size may be determi-
4160 -- nable and used in subsequent checks, so might as well try to
4161 -- compute it.
4163 -- In Ada 2012, Freeze_Entities is also used in the front end to
4164 -- trigger the analysis of aspect expressions, so in this case we
4165 -- want to continue the freezing process.
4169 and then
4172 then
4177 -- Deal with special cases of freezing for subtype
4181 -- Before we do anything else, a specialized test for the case of
4182 -- a size given for an array where the array needs to be packed,
4183 -- but was not so the size cannot be honored. This is the case
4184 -- where implicit packing may apply. The reason we do this so
4185 -- early is that if we have implicit packing, the layout of the
4186 -- base type is affected, so we must do this before we freeze
4187 -- the base type.
4189 -- We could do this processing only if implicit packing is enabled
4190 -- since in all other cases, the error would be caught by the back
4191 -- end. However, we choose to do the check even if we do not have
4192 -- implicit packing enabled, since this allows us to give a more
4193 -- useful error message (advising use of pragmas Implicit_Packing
4194 -- or Pack).
4197 declare
4208 -- Number of elements in array
4210 begin
4211 -- Check enabling conditions. These are straightforward
4212 -- except for the test for a limited composite type. This
4213 -- eliminates the rare case of a array of limited components
4214 -- where there are issues of whether or not we can go ahead
4215 -- and pack the array (since we can't freely pack and unpack
4216 -- arrays if they are limited).
4218 -- Note that we check the root type explicitly because the
4219 -- whole point is we are doing this test before we have had
4220 -- a chance to freeze the base type (and it is that freeze
4221 -- action that causes stuff to be inherited).
4234 then
4235 -- Compute number of elements in array
4243 and then
4245 then
4249 Num_Elmts :=
4250 Num_Elmts *
4256 -- What we are looking for here is the situation where
4257 -- the RM_Size given would be exactly right if there was
4258 -- a pragma Pack (resulting in the component size being
4259 -- the same as the RM_Size). Furthermore, the component
4260 -- type size must be an odd size (not a multiple of
4261 -- storage unit). If the component RM size is an exact
4262 -- number of storage units that is a power of two, the
4263 -- array is not packed and has a standard representation.
4267 then
4268 -- For implicit packing mode, just set the component
4269 -- size silently.
4277 -- Otherwise give an error message
4279 else
4280 Error_Msg_NE
4282 Error_Msg_N -- CODEFIX
4288 and then Implicit_Packing
4289 and then
4291 or else
4293 or else
4295 then
4296 -- Not a packed array, but indicate the desired
4297 -- component size, for the back-end.
4307 -- If ancestor subtype present, freeze that first. Note that this
4308 -- will also get the base type frozen. Need RM reference ???
4315 -- No ancestor subtype present
4317 else
4318 -- See if we have a nearest ancestor that has a predicate.
4319 -- That catches the case of derived type with a predicate.
4320 -- Need RM reference here ???
4328 -- Freeze base type before freezing the entity (RM 13.14(15))
4335 -- A subtype inherits all the type-related representation aspects
4336 -- from its parents (RM 13.1(8)).
4340 -- For a derived type, freeze its parent type first (RM 13.14(15))
4346 -- A derived type inherits each type-related representation aspect
4347 -- of its parent type that was directly specified before the
4348 -- declaration of the derived type (RM 13.1(15)).
4353 -- Array type
4358 -- For a class-wide type, the corresponding specific type is
4359 -- frozen as well (RM 13.14(15))
4364 -- If the base type of the class-wide type is still incomplete,
4365 -- the class-wide remains unfrozen as well. This is legal when
4366 -- E is the formal of a primitive operation of some other type
4367 -- which is being frozen.
4374 -- The equivalent type associated with a class-wide subtype needs
4375 -- to be frozen to ensure that its layout is done.
4379 then
4383 -- Generate an itype reference for a library-level class-wide type
4384 -- at the freeze point. Otherwise the first explicit reference to
4385 -- the type may appear in an inner scope which will be rejected by
4386 -- the back-end.
4390 then
4391 declare
4394 begin
4397 -- From a gigi point of view, a class-wide subtype derives
4398 -- from its record equivalent type. As a result, the itype
4399 -- reference must appear after the freeze node of the
4400 -- equivalent type or gigi will reject the reference.
4404 then
4406 else
4412 -- For a record type or record subtype, freeze all component types
4413 -- (RM 13.14(15)). We test for E_Record_(sub)Type here, rather than
4414 -- using Is_Record_Type, because we don't want to attempt the freeze
4415 -- for the case of a private type with record extension (we will do
4416 -- that later when the full type is frozen).
4420 then
4423 -- For a concurrent type, freeze corresponding record type. This
4424 -- does not correspond to any specific rule in the RM, but the
4425 -- record type is essentially part of the concurrent type.
4426 -- Freeze as well all local entities. This includes record types
4427 -- created for entry parameter blocks, and whatever local entities
4428 -- may appear in the private part.
4432 Freeze_And_Append
4444 then
4454 -- Private types are required to point to the same freeze node as
4455 -- their corresponding full views. The freeze node itself has to
4456 -- point to the partial view of the entity (because from the partial
4457 -- view, we can retrieve the full view, but not the reverse).
4458 -- However, in order to freeze correctly, we need to freeze the full
4459 -- view. If we are freezing at the end of a scope (or within the
4460 -- scope of the private type), the partial and full views will have
4461 -- been swapped, the full view appears first in the entity chain and
4462 -- the swapping mechanism ensures that the pointers are properly set
4463 -- (on scope exit).
4465 -- If we encounter the partial view before the full view (e.g. when
4466 -- freezing from another scope), we freeze the full view, and then
4467 -- set the pointers appropriately since we cannot rely on swapping to
4468 -- fix things up (subtypes in an outer scope might not get swapped).
4472 then
4473 -- The construction of the dispatch table associated with library
4474 -- level tagged types forces freezing of all the primitives of the
4475 -- type, which may cause premature freezing of the partial view.
4476 -- For example:
4478 -- package Pkg is
4479 -- type T is tagged private;
4480 -- type DT is new T with private;
4481 -- procedure Prim (X : in out T; Y : in out DT'Class);
4482 -- private
4483 -- type T is tagged null record;
4484 -- Obj : T;
4485 -- type DT is new T with null record;
4486 -- end;
4488 -- In this case the type will be frozen later by the usual
4489 -- mechanism: an object declaration, an instantiation, or the
4490 -- end of a declarative part.
4494 then
4498 -- Case of full view present
4502 -- If full view has already been frozen, then no further
4503 -- processing is required
4510 -- Otherwise freeze full view and patch the pointers so that
4511 -- the freeze node will elaborate both views in the back-end.
4513 else
4514 declare
4517 begin
4520 then
4521 Freeze_And_Append
4534 else
4535 -- {Incomplete,Private}_Subtypes with Full_Views
4536 -- constrained by discriminants.
4547 -- AI-117 requires that the convention of a partial view be the
4548 -- same as the convention of the full view. Note that this is a
4549 -- recognized breach of privacy, but it's essential for logical
4550 -- consistency of representation, and the lack of a rule in
4551 -- RM95 was an oversight.
4558 -- Size information is copied from the full view to the
4559 -- incomplete or private view for consistency.
4561 -- We skip this is the full view is not a type. This is very
4562 -- strange of course, and can only happen as a result of
4563 -- certain illegalities, such as a premature attempt to derive
4564 -- from an incomplete type.
4573 -- Case of no full view present. If entity is derived or subtype,
4574 -- it is safe to freeze, correctness depends on the frozen status
4575 -- of parent. Otherwise it is either premature usage, or a Taft
4576 -- amendment type, so diagnosis is at the point of use and the
4577 -- type might be frozen later.
4581 then
4584 else
4589 -- For access subprogram, freeze types of all formals, the return
4590 -- type was already frozen, since it is the Etype of the function.
4591 -- Formal types can be tagged Taft amendment types, but otherwise
4592 -- they cannot be incomplete.
4600 then
4604 -- AI05-151: Incomplete types are allowed in access to
4605 -- subprogram specifications.
4608 Error_Msg_NE
4619 -- For access to a protected subprogram, freeze the equivalent type
4620 -- (however this is not set if we are not generating code or if this
4621 -- is an anonymous type used just for resolution).
4629 -- Generic types are never seen by the back-end, and are also not
4630 -- processed by the expander (since the expander is turned off for
4631 -- generic processing), so we never need freeze nodes for them.
4637 -- Some special processing for non-generic types to complete
4638 -- representation details not known till the freeze point.
4643 -- Some error checks required for ordinary fixed-point type. Defer
4644 -- these till the freeze-point since we need the small and range
4645 -- values. We only do these checks for base types
4650 Error_Msg_N
4655 Error_Msg_N
4661 Error_Msg_N
4667 Error_Msg_N
4679 and then Warn_On_Suspicious_Modulus_Value
4680 then
4686 then
4687 -- If a pragma Default_Storage_Pool applies, and this type has no
4688 -- Storage_Pool or Storage_Size clause (which must have occurred
4689 -- before the freezing point), then use the default. This applies
4690 -- only to base types.
4692 -- None of this applies to access to subprograms, for which there
4693 -- are clearly no pools.
4699 then
4700 -- Case of pragma Default_Storage_Pool (null)
4705 -- Case of pragma Default_Storage_Pool (storage_pool_NAME)
4707 else
4712 -- Check restriction for standard storage pool
4718 -- Deal with error message for pure access type. This is not an
4719 -- error in Ada 2005 if there is no pool (see AI-366).
4725 then
4729 Error_Msg_N
4733 Error_Msg_N
4736 else
4737 Error_Msg_N
4744 -- Case of composite types
4748 -- AI-117 requires that all new primitives of a tagged type must
4749 -- inherit the convention of the full view of the type. Inherited
4750 -- and overriding operations are defined to inherit the convention
4751 -- of their parent or overridden subprogram (also specified in
4752 -- AI-117), which will have occurred earlier (in Derive_Subprogram
4753 -- and New_Overloaded_Entity). Here we set the convention of
4754 -- primitives that are still convention Ada, which will ensure
4755 -- that any new primitives inherit the type's convention. Class-
4756 -- wide types can have a foreign convention inherited from their
4757 -- specific type, but are excluded from this since they don't have
4758 -- any associated primitives.
4763 then
4764 declare
4768 begin
4780 -- If the type is a simple storage pool type, then this is where
4781 -- we attempt to locate and validate its Allocate, Deallocate, and
4782 -- Storage_Size operations (the first is required, and the latter
4783 -- two are optional). We also verify that the full type for a
4784 -- private type is allowed to be a simple storage pool type.
4788 then
4789 -- If the type is marked Has_Private_Declaration, then this is
4790 -- a full type for a private type that was specified with the
4791 -- pragma Simple_Storage_Pool_Type, and here we ensure that the
4792 -- pragma is allowed for the full type (for example, it can't
4793 -- be an array type, or a nonlimited record type).
4799 then
4801 Error_Msg_N
4812 procedure Validate_Simple_Pool_Op_Formal
4819 -- Validate one formal Pool_Op_Formal of the candidate pool
4820 -- operation Pool_Op. The formal must be of Expected_Type
4821 -- and have mode Expected_Mode. OK_Formal will be set to
4822 -- False if the formal doesn't match. If OK_Formal is False
4823 -- on entry, then the formal will effectively be ignored
4824 -- (because validation of the pool op has already failed).
4825 -- Upon return, Pool_Op_Formal will be updated to the next
4826 -- formal, if any.
4829 -- Search for and validate a simple pool operation with the
4830 -- name Op_Name. If the name is Allocate, then there must be
4831 -- exactly one such primitive operation for the simple pool
4832 -- type. If the name is Deallocate or Storage_Size, then
4833 -- there can be at most one such primitive operation. The
4834 -- profile of the located primitive must conform to what
4835 -- is expected for each operation.
4837 ------------------------------------
4838 -- Validate_Simple_Pool_Op_Formal --
4839 ------------------------------------
4841 procedure Validate_Simple_Pool_Op_Formal
4848 is
4849 begin
4850 -- If OK_Formal is False on entry, then simply ignore
4851 -- the formal, because an earlier formal has already
4852 -- been flagged.
4857 -- If no formal is passed in, then issue an error for a
4858 -- missing formal.
4861 Error_Msg_NE
4871 -- If the pool type was expected for this formal, then
4872 -- this will not be considered a candidate operation
4873 -- for the simple pool, so we unset OK_Formal so that
4874 -- the op and any later formals will be ignored.
4881 else
4882 Error_Msg_NE
4889 -- Issue error if formal's mode is not the expected one
4892 Error_Msg_N
4894 Pool_Op_Formal);
4897 -- Advance to the next formal
4902 ------------------------------------
4903 -- Validate_Simple_Pool_Operation --
4904 ------------------------------------
4906 procedure Validate_Simple_Pool_Operation
4908 is
4914 begin
4915 pragma Assert
4917 Name_Deallocate,
4918 Name_Storage_Size));
4922 -- For each homonym declared immediately in the scope
4923 -- of the simple storage pool type, determine whether
4924 -- the homonym is an operation of the pool type, and,
4925 -- if so, check that its profile is as expected for
4926 -- a simple pool operation of that name.
4932 then
4937 -- The first parameter must be of the pool type
4938 -- in order for the operation to qualify.
4941 Validate_Simple_Pool_Op_Formal
4944 else
4945 Validate_Simple_Pool_Op_Formal
4950 -- If another operation with this name has already
4951 -- been located for the type, then flag an error,
4952 -- since we only allow the type to have a single
4953 -- such primitive.
4956 Error_Msg_NE
4961 -- In the case of Allocate and Deallocate, a formal
4962 -- of type System.Address is required.
4965 Validate_Simple_Pool_Op_Formal
4970 Validate_Simple_Pool_Op_Formal
4975 -- In the case of Allocate and Deallocate, formals
4976 -- of type Storage_Count are required as the third
4977 -- and fourth parameters.
4980 Validate_Simple_Pool_Op_Formal
4983 Validate_Simple_Pool_Op_Formal
4988 -- If no mismatched formals have been found (Is_OK)
4989 -- and no excess formals are present, then this
4990 -- operation has been validated, so record it.
5000 -- There must be a valid Allocate operation for the type,
5001 -- so issue an error if none was found.
5005 then
5011 -- Simple pool operations can't be abstract
5014 Error_Msg_N
5019 -- The Storage_Size operation must be a function with
5020 -- Storage_Count as its result type.
5024 Error_Msg_N
5028 Error_Msg_NE
5033 -- Allocate and Deallocate must be procedures
5036 Error_Msg_N
5042 -- Start of processing for Validate_Simple_Pool_Ops
5044 begin
5052 -- Now that all types from which E may depend are frozen, see if the
5053 -- size is known at compile time, if it must be unsigned, or if
5054 -- strict alignment is required
5063 -- Do not allow a size clause for a type which does not have a size
5064 -- that is known at compile time
5068 then
5069 -- Suppress this message if errors posted on E, even if we are
5070 -- in all errors mode, since this is often a junk message
5073 Error_Msg_N
5079 -- Now we set/verify the representation information, in particular
5080 -- the size and alignment values. This processing is not required for
5081 -- generic types, since generic types do not play any part in code
5082 -- generation, and so the size and alignment values for such types
5083 -- are irrelevant. Ditto for types declared within a generic unit,
5084 -- which may have components that depend on generic parameters, and
5085 -- that will be recreated in an instance.
5090 -- Otherwise we call the layout procedure
5092 else
5096 -- If this is an access to subprogram whose designated type is itself
5097 -- a subprogram type, the return type of this anonymous subprogram
5098 -- type must be decorated as well.
5102 then
5106 -- If the type has a Defaut_Value/Default_Component_Value aspect,
5107 -- this is where we analye the expression (after the type is frozen,
5108 -- since in the case of Default_Value, we are analyzing with the
5109 -- type itself, and we treat Default_Component_Value similarly for
5110 -- the sake of uniformity).
5113 declare
5118 begin
5123 else
5134 Flag_Non_Static_Expr
5141 -- End of freeze processing for type entities
5144 -- Here is where we logically freeze the current entity. If it has a
5145 -- freeze node, then this is the point at which the freeze node is
5146 -- linked into the result list.
5150 -- If a freeze node is already allocated, use it, otherwise allocate
5151 -- a new one. The preallocation happens in the case of anonymous base
5152 -- types, where we preallocate so that we can set First_Subtype_Link.
5153 -- Note that we reset the Sloc to the current freeze location.
5159 else
5170 -- A final pass over record types with discriminants. If the type
5171 -- has an incomplete declaration, there may be constrained access
5172 -- subtypes declared elsewhere, which do not depend on the discrimi-
5173 -- nants of the type, and which are used as component types (i.e.
5174 -- the full view is a recursive type). The designated types of these
5175 -- subtypes can only be elaborated after the type itself, and they
5176 -- need an itype reference.
5180 then
5181 declare
5186 begin
5196 then
5208 -- When a type is frozen, the first subtype of the type is frozen as
5209 -- well (RM 13.14(15)). This has to be done after freezing the type,
5210 -- since obviously the first subtype depends on its own base type.
5215 -- If we just froze a tagged non-class wide record, then freeze the
5216 -- corresponding class-wide type. This must be done after the tagged
5217 -- type itself is frozen, because the class-wide type refers to the
5218 -- tagged type which generates the class.
5223 then
5230 -- Special handling for subprograms
5234 -- If subprogram has address clause then reset Is_Public flag, since
5235 -- we do not want the backend to generate external references.
5239 then
5247 -----------------------------
5248 -- Freeze_Enumeration_Type --
5249 -----------------------------
5252 begin
5253 -- By default, if no size clause is present, an enumeration type with
5254 -- Convention C is assumed to interface to a C enum, and has integer
5255 -- size. This applies to types. For subtypes, verify that its base
5256 -- type has no size clause either. Treat other foreign conventions
5257 -- in the same way, and also make sure alignment is set right.
5263 then
5267 else
5268 -- If the enumeration type interfaces to C, and it has a size clause
5269 -- that specifies less than int size, it warrants a warning. The
5270 -- user may intend the C type to be an enum or a char, so this is
5271 -- not by itself an error that the Ada compiler can detect, but it
5272 -- it is a worth a heads-up. For Boolean and Character types we
5273 -- assume that the programmer has the proper C type in mind.
5280 then
5281 Error_Msg_N
5289 -----------------------
5290 -- Freeze_Expression --
5291 -----------------------
5302 -- This flag is set true if the entity must be frozen outside the
5303 -- current subprogram. This happens in the case of expander generated
5304 -- subprograms (_Init_Proc, _Input, _Output, _Read, _Write) which do
5305 -- not freeze all entities like other bodies, but which nevertheless
5306 -- may reference entities that have to be frozen before the body and
5307 -- obviously cannot be frozen inside the body.
5310 -- Given an N_Handled_Sequence_Of_Statements node N, determines whether
5311 -- it is the handled statement sequence of an expander-generated
5312 -- subprogram (init proc, stream subprogram, or renaming as body).
5313 -- If so, this is not a freezing context.
5315 -----------------
5316 -- In_Exp_Body --
5317 -----------------
5323 begin
5326 else
5333 else
5336 -- Following complex conditional could use comments ???
5345 N_Subprogram_Renaming_Declaration,
5346 N_Expression_Function))
5347 then
5349 else
5355 -- Start of processing for Freeze_Expression
5357 begin
5358 -- Immediate return if freezing is inhibited. This flag is set by the
5359 -- analyzer to stop freezing on generated expressions that would cause
5360 -- freezing if they were in the source program, but which are not
5361 -- supposed to freeze, since they are created.
5367 -- If expression is non-static, then it does not freeze in a default
5368 -- expression, see section "Handling of Default Expressions" in the
5369 -- spec of package Sem for further details. Note that we have to make
5370 -- sure that we actually have a real expression (if we have a subtype
5371 -- indication, we can't test Is_Static_Expression!) However, we exclude
5372 -- the case of the prefix of an attribute of a static scalar subtype
5373 -- from this early return, because static subtype attributes should
5374 -- always cause freezing, even in default expressions, but the attribute
5375 -- may not have been marked as static yet (because in Resolve_Attribute,
5376 -- the call to Eval_Attribute follows the call of Freeze_Expression on
5377 -- the prefix).
5379 if In_Spec_Exp
5386 then
5390 -- Freeze type of expression if not frozen already
5398 -- Base type may be an derived numeric type that is frozen at
5399 -- the point of declaration, but first_subtype is still unfrozen.
5406 -- For entity name, freeze entity if not frozen already. A special
5407 -- exception occurs for an identifier that did not come from source.
5408 -- We don't let such identifiers freeze a non-internal entity, i.e.
5409 -- an entity that did come from source, since such an identifier was
5410 -- generated by the expander, and cannot have any semantic effect on
5411 -- the freezing semantics. For example, this stops the parameter of
5412 -- an initialization procedure from freezing the variable.
5419 then
5421 else
5425 -- For an allocator freeze designated type if not frozen already
5427 -- For an aggregate whose component type is an access type, freeze the
5428 -- designated type now, so that its freeze does not appear within the
5429 -- loop that might be created in the expansion of the aggregate. If the
5430 -- designated type is a private type without full view, the expression
5431 -- cannot contain an allocator, so the type is not frozen.
5433 -- For a function, we freeze the entity when the subprogram declaration
5434 -- is frozen, but a function call may appear in an initialization proc.
5435 -- before the declaration is frozen. We need to generate the extra
5436 -- formals, if any, to ensure that the expansion of the call includes
5437 -- the proper actuals. This only applies to Ada subprograms, not to
5438 -- imported ones.
5449 then
5453 when N_Selected_Component |
5454 N_Indexed_Component |
5455 N_Slice =>
5466 then
5477 then
5481 -- All done if nothing needs freezing
5486 then
5490 -- Loop for looking at the right place to insert the freeze nodes,
5491 -- exiting from the loop when it is appropriate to insert the freeze
5492 -- node before the current node P.
5494 -- Also checks some special exceptions to the freezing rules. These
5495 -- cases result in a direct return, bypassing the freeze action.
5498 loop
5501 -- If we don't have a parent, then we are not in a well-formed tree.
5502 -- This is an unusual case, but there are some legitimate situations
5503 -- in which this occurs, notably when the expressions in the range of
5504 -- a type declaration are resolved. We simply ignore the freeze
5505 -- request in this case. Is this right ???
5511 -- See if we have got to an appropriate point in the tree
5515 -- A special test for the exception of (RM 13.14(8)) for the case
5516 -- of per-object expressions (RM 3.8(18)) occurring in component
5517 -- definition or a discrete subtype definition. Note that we test
5518 -- for a component declaration which includes both cases we are
5519 -- interested in, and furthermore the tree does not have explicit
5520 -- nodes for either of these two constructs.
5524 -- The case we want to test for here is an identifier that is
5525 -- a per-object expression, this is either a discriminant that
5526 -- appears in a context other than the component declaration
5527 -- or it is a reference to the type of the enclosing construct.
5529 -- For either of these cases, we skip the freezing
5531 if not In_Spec_Expression
5534 then
5535 -- We recognize the discriminant case by just looking for
5536 -- a reference to a discriminant. It can only be one for
5537 -- the enclosing construct. Skip freezing in this case.
5542 -- For the case of a reference to the enclosing record,
5543 -- (or task or protected type), we look for a type that
5544 -- matches the current scope.
5551 -- If we have an enumeration literal that appears as the choice in
5552 -- the aggregate of an enumeration representation clause, then
5553 -- freezing does not occur (RM 13.14(10)).
5557 -- The case we are looking for is an enumeration literal
5561 then
5562 -- If enumeration literal appears directly as the choice,
5563 -- do not freeze (this is the normal non-overloaded case)
5567 then
5570 -- If enumeration literal appears as the name of function
5571 -- which is the choice, then also do not freeze. This
5572 -- happens in the overloaded literal case, where the
5573 -- enumeration literal is temporarily changed to a function
5574 -- call for overloading analysis purposes.
5577 and then
5579 and then
5581 then
5586 -- Normally if the parent is a handled sequence of statements,
5587 -- then the current node must be a statement, and that is an
5588 -- appropriate place to insert a freeze node.
5592 -- An exception occurs when the sequence of statements is for
5593 -- an expander generated body that did not do the usual freeze
5594 -- all operation. In this case we usually want to freeze
5595 -- outside this body, not inside it, and we skip past the
5596 -- subprogram body that we are inside.
5599 declare
5603 begin
5604 -- Freeze the entity only when it is declared inside the
5605 -- body of the expander generated procedure. This case
5606 -- is recognized by the scope of the entity or its type,
5607 -- which is either the spec for some enclosing body, or
5608 -- (in the case of init_procs, for which there are no
5609 -- separate specs) the current scope.
5615 or else
5617 then
5623 then
5628 -- An expression function may act as a completion of
5629 -- a function declaration. As such, it can reference
5630 -- entities declared between the two views:
5632 -- Hidden []; -- 1
5633 -- function F return ...;
5634 -- private
5635 -- function Hidden return ...;
5636 -- function F return ... is (Hidden); -- 2
5638 -- Refering to the example above, freezing the expression
5639 -- of F (2) would place Hidden's freeze node (1) in the
5640 -- wrong place. Avoid explicit freezing and let the usual
5641 -- scenarios do the job - for example, reaching the end
5642 -- of the private declarations.
5645 N_Expression_Function
5646 then
5649 -- Freeze outside the body
5651 else
5657 -- Here if normal case where we are in handled statement
5658 -- sequence and want to do the insertion right there.
5660 else
5664 -- If parent is a body or a spec or a block, then the current node
5665 -- is a statement or declaration and we can insert the freeze node
5666 -- before it.
5668 when N_Block_Statement |
5669 N_Entry_Body |
5670 N_Package_Body |
5671 N_Package_Specification |
5672 N_Protected_Body |
5673 N_Subprogram_Body |
5676 -- The expander is allowed to define types in any statements list,
5677 -- so any of the following parent nodes also mark a freezing point
5678 -- if the actual node is in a list of statements or declarations.
5680 when N_Abortable_Part |
5681 N_Accept_Alternative |
5682 N_And_Then |
5683 N_Case_Statement_Alternative |
5684 N_Compilation_Unit_Aux |
5685 N_Conditional_Entry_Call |
5686 N_Delay_Alternative |
5687 N_Elsif_Part |
5688 N_Entry_Call_Alternative |
5689 N_Exception_Handler |
5690 N_Extended_Return_Statement |
5691 N_Freeze_Entity |
5692 N_If_Statement |
5693 N_Or_Else |
5694 N_Selective_Accept |
5695 N_Triggering_Alternative =>
5699 -- Note: The N_Loop_Statement is a special case. A type that
5700 -- appears in the source can never be frozen in a loop (this
5701 -- occurs only because of a loop expanded by the expander), so we
5702 -- keep on going. Otherwise we terminate the search. Same is true
5703 -- of any entity which comes from source. (if they have predefined
5704 -- type, that type does not appear to come from source, but the
5705 -- entity should not be frozen here).
5711 -- For all other cases, keep looking at parents
5717 -- We fall through the case if we did not yet find the proper
5718 -- place in the free for inserting the freeze node, so climb!
5723 -- If the expression appears in a record or an initialization procedure,
5724 -- the freeze nodes are collected and attached to the current scope, to
5725 -- be inserted and analyzed on exit from the scope, to insure that
5726 -- generated entities appear in the correct scope. If the expression is
5727 -- a default for a discriminant specification, the scope is still void.
5728 -- The expression can also appear in the discriminant part of a private
5729 -- or concurrent type.
5731 -- If the expression appears in a constrained subcomponent of an
5732 -- enclosing record declaration, the freeze nodes must be attached to
5733 -- the outer record type so they can eventually be placed in the
5734 -- enclosing declaration list.
5736 -- The other case requiring this special handling is if we are in a
5737 -- default expression, since in that case we are about to freeze a
5738 -- static type, and the freeze scope needs to be the outer scope, not
5739 -- the scope of the subprogram with the default parameter.
5741 -- For default expressions and other spec expressions in generic units,
5742 -- the Move_Freeze_Nodes mechanism (see sem_ch12.adb) takes care of
5743 -- placing them at the proper place, after the generic unit.
5746 or else Freeze_Outside
5751 then
5752 declare
5757 begin
5770 -- The current scope may be that of a constrained component of
5771 -- an enclosing record declaration, or of a loop of an enclosing
5772 -- quantified expression, which is above the current scope in the
5773 -- scope stack. Indeed in the context of a quantified expression,
5774 -- a scope is created and pushed above the current scope in order
5775 -- to emulate the loop-like behavior of the quantified expression.
5776 -- If the expression is within a top-level pragma, as for a pre-
5777 -- condition on a library-level subprogram, nothing to do.
5782 N_Quantified_Expression)
5783 then
5790 Freeze_Nodes;
5791 else
5801 -- Now we have the right place to do the freezing. First, a special
5802 -- adjustment, if we are in spec-expression analysis mode, these freeze
5803 -- actions must not be thrown away (normally all inserted actions are
5804 -- thrown away in this mode. However, the freeze actions are from static
5805 -- expressions and one of the important reasons we are doing this
5806 -- special analysis is to get these freeze actions. Therefore we turn
5807 -- off the In_Spec_Expression mode to propagate these freeze actions.
5808 -- This also means they get properly analyzed and expanded.
5812 -- Freeze the designated type of an allocator (RM 13.14(13))
5818 -- Freeze type of expression (RM 13.14(10)). Note that we took care of
5819 -- the enumeration representation clause exception in the loop above.
5825 -- Freeze name if one is present (RM 13.14(11))
5831 -- Restore In_Spec_Expression flag
5836 -----------------------------
5837 -- Freeze_Fixed_Point_Type --
5838 -----------------------------
5840 -- Certain fixed-point types and subtypes, including implicit base types
5841 -- and declared first subtypes, have not yet set up a range. This is
5842 -- because the range cannot be set until the Small and Size values are
5843 -- known, and these are not known till the type is frozen.
5845 -- To signal this case, Scalar_Range contains an unanalyzed syntactic range
5846 -- whose bounds are unanalyzed real literals. This routine will recognize
5847 -- this case, and transform this range node into a properly typed range
5848 -- with properly analyzed and resolved values.
5866 -- Returns size of type with given bounds. Also leaves these
5867 -- bounds set as the current bounds of the Typ.
5869 -----------
5870 -- Fsize --
5871 -----------
5874 begin
5880 -- Start of processing for Freeze_Fixed_Point_Type
5882 begin
5883 -- If Esize of a subtype has not previously been set, set it now
5890 else
5895 -- Immediate return if the range is already analyzed. This means that
5896 -- the range is already set, and does not need to be computed by this
5897 -- routine.
5903 -- Immediate return if either of the bounds raises Constraint_Error
5907 then
5914 -- Ordinary fixed-point case
5918 -- For the ordinary fixed-point case, we are allowed to fudge the
5919 -- end-points up or down by small. Generally we prefer to fudge up,
5920 -- i.e. widen the bounds for non-model numbers so that the end points
5921 -- are included. However there are cases in which this cannot be
5922 -- done, and indeed cases in which we may need to narrow the bounds.
5923 -- The following circuit makes the decision.
5925 -- Note: our terminology here is that Incl_EP means that the bounds
5926 -- are widened by Small if necessary to include the end points, and
5927 -- Excl_EP means that the bounds are narrowed by Small to exclude the
5928 -- end-points if this reduces the size.
5930 -- Note that in the Incl case, all we care about is including the
5931 -- end-points. In the Excl case, we want to narrow the bounds as
5932 -- much as permitted by the RM, to give the smallest possible size.
5949 begin
5950 -- First step. Base types are required to be symmetrical. Right
5951 -- now, the base type range is a copy of the first subtype range.
5952 -- This will be corrected before we are done, but right away we
5953 -- need to deal with the case where both bounds are non-negative.
5954 -- In this case, we set the low bound to the negative of the high
5955 -- bound, to make sure that the size is computed to include the
5956 -- required sign. Note that we do not need to worry about the
5957 -- case of both bounds negative, because the sign will be dealt
5958 -- with anyway. Furthermore we can't just go making such a bound
5959 -- symmetrical, since in a twos-complement system, there is an
5960 -- extra negative value which could not be accommodated on the
5961 -- positive side.
5966 then
5971 -- Compute the fudged bounds. If the number is a model number,
5972 -- then we do nothing to include it, but we are allowed to backoff
5973 -- to the next adjacent model number when we exclude it. If it is
5974 -- not a model number then we straddle the two values with the
5975 -- model numbers on either side.
5981 else
5985 -- The low value excluding the end point is Small greater, but
5986 -- we do not do this exclusion if the low value is positive,
5987 -- since it can't help the size and could actually hurt by
5988 -- crossing the high bound.
5993 -- If the value went from negative to zero, then we have the
5994 -- case where Loval_Incl_EP is the model number just below
5995 -- zero, so we want to stick to the negative value for the
5996 -- base type to maintain the condition that the size will
5997 -- include signed values.
6001 then
6005 else
6009 -- Similar processing for upper bound and high value
6015 else
6021 else
6025 -- One further adjustment is needed. In the case of subtypes, we
6026 -- cannot go outside the range of the base type, or we get
6027 -- peculiarities, and the base type range is already set. This
6028 -- only applies to the Incl values, since clearly the Excl values
6029 -- are already as restricted as they are allowed to be.
6036 -- Get size including and excluding end points
6041 -- No need to exclude end-points if it does not reduce size
6051 -- Now we set the actual size to be used. We want to use the
6052 -- bounds fudged up to include the end-points but only if this
6053 -- can be done without violating a specifically given size
6054 -- size clause or causing an unacceptable increase in size.
6056 -- Case of size clause given
6060 -- Use the inclusive size only if it is consistent with
6061 -- the explicitly specified size.
6068 -- If the inclusive size is too large, we try excluding
6069 -- the end-points (will be caught later if does not work).
6071 else
6077 -- Case of size clause not given
6079 else
6080 -- If we have a base type whose corresponding first subtype
6081 -- has an explicit size that is large enough to include our
6082 -- end-points, then do so. There is no point in working hard
6083 -- to get a base type whose size is smaller than the specified
6084 -- size of the first subtype.
6090 then
6095 -- If excluding the end-points makes the size smaller and
6096 -- results in a size of 8,16,32,64, then we take the smaller
6097 -- size. For the 64 case, this is compulsory. For the other
6098 -- cases, it seems reasonable. We like to include end points
6099 -- if we can, but not at the expense of moving to the next
6100 -- natural boundary of size.
6104 then
6109 -- Otherwise we can definitely include the end points
6111 else
6117 -- One pathological case: normally we never fudge a low bound
6118 -- down, since it would seem to increase the size (if it has
6119 -- any effect), but for ranges containing single value, or no
6120 -- values, the high bound can be small too large. Consider:
6122 -- type t is delta 2.0**(-14)
6123 -- range 131072.0 .. 0;
6125 -- That lower bound is *just* outside the range of 32 bits, and
6126 -- does need fudging down in this case. Note that the bounds
6127 -- will always have crossed here, since the high bound will be
6128 -- fudged down if necessary, as in the case of:
6130 -- type t is delta 2.0**(-14)
6131 -- range 131072.0 .. 131072.0;
6133 -- So we detect the situation by looking for crossed bounds,
6134 -- and if the bounds are crossed, and the low bound is greater
6135 -- than zero, we will always back it off by small, since this
6136 -- is completely harmless.
6143 -- And of course, we need to do exactly the same parallel
6144 -- fudge for flat ranges in the negative region.
6157 -- For the decimal case, none of this fudging is required, since there
6158 -- are no end-point problems in the decimal case (the end-points are
6159 -- always included).
6161 else
6165 -- At this stage, the actual size has been calculated and the proper
6166 -- required bounds are stored in the low and high bounds.
6170 Error_Msg_N
6172 Typ);
6176 -- Check size against explicit given size
6182 Error_Msg_NE
6186 else
6190 -- Increase size to next natural boundary if no size clause given
6192 else
6199 else
6207 -- If we have a base type, then expand the bounds so that they extend to
6208 -- the full width of the allocated size in bits, to avoid junk range
6209 -- checks on intermediate computations.
6216 -- Final step is to reanalyze the bounds using the proper type
6217 -- and set the Corresponding_Integer_Value fields of the literals.
6223 -- Resolve with universal fixed if the base type, and the base type if
6224 -- it is a subtype. Note we can't resolve the base type with itself,
6225 -- that would be a reference before definition.
6229 else
6233 -- Set corresponding integer value for bound
6235 Set_Corresponding_Integer_Value
6238 -- Similar processing for high bound
6246 else
6250 Set_Corresponding_Integer_Value
6253 -- Set type of range to correspond to bounds
6257 -- Set Esize to calculated size if not set already
6263 -- Set RM_Size if not already set. If already set, check value
6265 declare
6268 begin
6273 Error_Msg_NE
6278 else
6284 ------------------
6285 -- Freeze_Itype --
6286 ------------------
6291 begin
6300 --------------------------
6301 -- Freeze_Static_Object --
6302 --------------------------
6307 -- Exception raised if the type of a static object cannot be made
6308 -- static. This happens if the type depends on non-global objects.
6311 -- Called to ensure that an expression used as part of a type definition
6312 -- is statically allocatable, which means that the expression type is
6313 -- statically allocatable, and the expression is either static, or a
6314 -- reference to a library level constant.
6317 -- Called to mark a type as static, checking that it is possible
6318 -- to set the type as static. If it is not possible, then the
6319 -- exception Cannot_Be_Static is raised.
6321 -----------------------------
6322 -- Ensure_Expression_Is_SA --
6323 -----------------------------
6328 begin
6340 then
6348 -----------------------
6349 -- Ensure_Type_Is_SA --
6350 -----------------------
6356 begin
6357 -- If type is library level, we are all set
6363 -- We are also OK if the type already marked as statically allocated,
6364 -- which means we processed it before.
6370 -- Mark type as statically allocated
6374 -- Check that it is safe to statically allocate this type
6392 declare
6396 begin
6408 else
6417 then
6436 else
6441 -- Start of processing for Freeze_Static_Object
6443 begin
6446 exception
6449 -- If the object that cannot be static is imported or exported, then
6450 -- issue an error message saying that this object cannot be imported
6451 -- or exported. If it has an address clause it is an overlay in the
6452 -- current partition and the static requirement is not relevant.
6453 -- Do not issue any error message when ignoring rep clauses.
6460 Error_Msg_N
6464 -- Otherwise must be exported, something is wrong if compiler
6465 -- is marking something as statically allocated which cannot be).
6468 Error_Msg_N
6473 -----------------------
6474 -- Freeze_Subprogram --
6475 -----------------------
6481 begin
6482 -- Subprogram may not have an address clause unless it is imported
6486 Error_Msg_N
6493 -- Reset the Pure indication on an imported subprogram unless an
6494 -- explicit Pure_Function pragma was present. We do this because
6495 -- otherwise it is an insidious error to call a non-pure function from
6496 -- pure unit and have calls mysteriously optimized away. What happens
6497 -- here is that the Import can bypass the normal check to ensure that
6498 -- pure units call only pure subprograms.
6503 then
6507 -- For non-foreign convention subprograms, this is where we create
6508 -- the extra formals (for accessibility level and constrained bit
6509 -- information). We delay this till the freeze point precisely so
6510 -- that we know the convention!
6516 -- If this is convention Ada and a Valued_Procedure, that's odd
6521 and then Warn_On_Export_Import
6522 then
6523 Error_Msg_N
6528 -- Case of foreign convention
6530 else
6533 -- For foreign conventions, warn about return of an
6534 -- unconstrained array.
6536 -- Note: we *do* allow a return by descriptor for the VMS case,
6537 -- though here there is probably more to be done ???
6542 -- If no return type, probably some other error, e.g. a
6543 -- missing full declaration, so ignore.
6548 -- If the return type is generic, we have emitted a warning
6549 -- earlier on, and there is nothing else to check here. Specific
6550 -- instantiations may lead to erroneous behavior.
6555 -- Display warning if returning unconstrained array
6560 -- Exclude cases where descriptor mechanism is set, since the
6561 -- VMS descriptor mechanisms allow such unconstrained returns.
6565 -- Check appropriate warning is enabled (should we check for
6566 -- Warnings (Off) on specific entities here, probably so???)
6568 and then Warn_On_Export_Import
6570 -- Exclude the VM case, since return of unconstrained arrays
6571 -- is properly handled in both the JVM and .NET cases.
6574 then
6575 Error_Msg_N
6582 -- If any of the formals for an exported foreign convention
6583 -- subprogram have defaults, then emit an appropriate warning since
6584 -- this is odd (default cannot be used from non-Ada code)
6589 if Warn_On_Export_Import
6591 then
6592 Error_Msg_N
6602 -- For VMS, descriptor mechanisms for parameters are allowed only for
6603 -- imported/exported subprograms. Moreover, the NCA descriptor is not
6604 -- allowed for parameters of exported subprograms.
6611 Error_Msg_N
6613 Error_Msg_N
6624 Error_Msg_N
6626 Error_Msg_N
6635 -- Pragma Inline_Always is disallowed for dispatching subprograms
6636 -- because the address of such subprograms is saved in the dispatch
6637 -- table to support dispatching calls, and dispatching calls cannot
6638 -- be inlined. This is consistent with the restriction against using
6639 -- 'Access or 'Address on an Inline_Always subprogram.
6643 then
6644 Error_Msg_N
6648 -- Because of the implicit representation of inherited predefined
6649 -- operators in the front-end, the overriding status of the operation
6650 -- may be affected when a full view of a type is analyzed, and this is
6651 -- not captured by the analysis of the corresponding type declaration.
6652 -- Therefore the correctness of a not-overriding indicator must be
6653 -- rechecked when the subprogram is frozen.
6657 then
6662 ----------------------
6663 -- Is_Fully_Defined --
6664 ----------------------
6667 begin
6676 then
6677 -- Verify that the record type has no components with private types
6678 -- without completion.
6680 declare
6683 begin
6695 -- For the designated type of an access to subprogram, all types in
6696 -- the profile must be fully defined.
6699 declare
6702 begin
6715 else
6721 ---------------------------------
6722 -- Process_Default_Expressions --
6723 ---------------------------------
6725 procedure Process_Default_Expressions
6728 is
6735 begin
6738 -- A subprogram instance and its associated anonymous subprogram share
6739 -- their signature. The default expression functions are defined in the
6740 -- wrapper packages for the anonymous subprogram, and should not be
6741 -- generated again for the instance.
6746 then
6754 -- We work with a copy of the default expression because we
6755 -- do not want to disturb the original, since this would mess
6756 -- up the conformance checking.
6760 -- The analysis of the expression may generate insert actions,
6761 -- which of course must not be executed. We wrap those actions
6762 -- in a procedure that is not called, and later on eliminated.
6763 -- The following cases have no side-effects, and are analyzed
6764 -- directly.
6775 and then
6777 then
6779 -- If there is no default function, we must still do a full
6780 -- analyze call on the default value, to ensure that all error
6781 -- checks are performed, e.g. those associated with static
6782 -- evaluation. Note: this branch will always be taken if the
6783 -- analyzer is turned off (but we still need the error checks).
6785 -- Note: the setting of parent here is to meet the requirement
6786 -- that we can only analyze the expression while attached to
6787 -- the tree. Really the requirement is that the parent chain
6788 -- be set, we don't actually need to be in the tree.
6793 -- Default expressions are resolved with their own type if the
6794 -- context is generic, to avoid anomalies with private types.
6798 else
6802 -- If that resolved expression will raise constraint error,
6803 -- then flag the default value as raising constraint error.
6804 -- This allows a proper error message on the calls.
6810 -- If the default is a parameterless call, we use the name of
6811 -- the called function directly, and there is no body to build.
6815 then
6818 -- Else construct and analyze the body of a wrapper procedure
6819 -- that contains an object declaration to hold the expression.
6820 -- Given that this is done only to complete the analysis, it
6821 -- simpler to build a procedure than a function which might
6822 -- involve secondary stack expansion.
6824 else
6827 Dbody :=
6829 Specification =>
6836 Object_Definition =>
6840 Handled_Statement_Sequence =>
6857 ----------------------------------------
6858 -- Set_Component_Alignment_If_Not_Set --
6859 ----------------------------------------
6862 begin
6863 -- Ignore if not base type, subtypes don't need anything
6869 -- Do not override existing representation
6880 else
6881 Set_Component_Alignment
6887 ------------------
6888 -- Undelay_Type --
6889 ------------------
6892 begin
6896 -- Since we don't want T to have a Freeze_Node, we don't want its
6897 -- Full_View or Corresponding_Record_Type to have one either.
6899 -- ??? Fundamentally, this whole handling is a kludge. What we really
6900 -- want is to be sure that for an Itype that's part of record R and is a
6901 -- subtype of type T, that it's frozen after the later of the freeze
6902 -- points of R and T. We have no way of doing that directly, so what we
6903 -- do is force most such Itypes to be frozen as part of freezing R via
6904 -- this procedure and only delay the ones that need to be delayed
6905 -- (mostly the designated types of access types that are defined as part
6906 -- of the record).
6912 then
6920 then
6925 ------------------
6926 -- Warn_Overlay --
6927 ------------------
6929 procedure Warn_Overlay
6933 is
6935 -- The object to which the address clause applies
6941 begin
6942 -- No warning if address clause overlay warnings are off
6948 -- No warning if there is an explicit initialization
6956 -- We only give the warning for non-imported entities of a type for
6957 -- which a non-null base init proc is defined, or for objects of access
6958 -- types with implicit null initialization, or when Normalize_Scalars
6959 -- applies and the type is scalar or a string type (the latter being
6960 -- tested for because predefined String types are initialized by inline
6961 -- code rather than by an init_proc). Note that we do not give the
6962 -- warning for Initialize_Scalars, since we suppressed initialization
6963 -- in this case. Also, do not warn if Suppress_Initialization is set.
6973 then
6976 then
6981 then
6988 then
6995 -- A function call (most likely to To_Address) is probably not an
6996 -- overlay, so skip warning. Ditto if the function call was inlined
6997 -- and transformed into an entity.
7005 -- If a pragma Import follows, we assume that it is for the current
7006 -- target of the address clause, and skip the warning.
7011 then
7017 Error_Msg_N
7019 Nam);
7020 else
7021 Error_Msg_N
7023 Nam);
7026 -- Add friendly warning if initialization comes from a packed array
7027 -- component.
7030 declare
7033 begin
7038 then
7042 then
7043 Error_Msg_NE
7048 else
7055 Error_Msg_N
7058 Nam);