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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) 1992-2010, 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. --
17 -- --
18 -- You should have received a copy of the GNU General Public License along --
19 -- with this program; see file COPYING3. If not see --
20 -- <http://www.gnu.org/licenses/>. --
21 -- --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 -- --
25 ------------------------------------------------------------------------------
69 -----------------------
70 -- Local Subprograms --
71 -----------------------
74 -- Typ is a type that is being frozen. If no size clause is given,
75 -- but a default Esize has been computed, then this default Esize is
76 -- adjusted up if necessary to be consistent with a given alignment,
77 -- but never to a value greater than Long_Long_Integer'Size. This
78 -- is used for all discrete types and for fixed-point types.
80 procedure Build_And_Analyze_Renamed_Body
84 -- Build body for a renaming declaration, insert in tree and analyze
87 -- Apply legality checks to address clauses for object declarations,
88 -- at the point the object is frozen.
91 -- E is a base type. If E is tagged or has a component that is aliased
92 -- or tagged or contains something this is aliased or tagged, set
93 -- Strict_Alignment.
97 -- If E is a fixed-point or discrete type, then all the necessary work
98 -- to freeze it is completed except for possible setting of the flag
99 -- Is_Unsigned_Type, which is done by this procedure. The call has no
100 -- effect if the entity E is not a discrete or fixed-point type.
102 procedure Freeze_And_Append
106 -- Freezes Ent using Freeze_Entity, and appends the resulting list of
107 -- nodes to Result, modifying Result from No_List if necessary.
110 -- Freeze enumeration type. The Esize field is set as processing
111 -- proceeds (i.e. set by default when the type is declared and then
112 -- adjusted by rep clauses. What this procedure does is to make sure
113 -- that if a foreign convention is specified, and no specific size
114 -- is given, then the size must be at least Integer'Size.
117 -- If an object is frozen which has Is_Statically_Allocated set, then
118 -- all referenced types must also be marked with this flag. This routine
119 -- is in charge of meeting this requirement for the object entity E.
122 -- Perform freezing actions for a subprogram (create extra formals,
123 -- and set proper default mechanism values). Note that this routine
124 -- is not called for internal subprograms, for which neither of these
125 -- actions is needed (or desirable, we do not want for example to have
126 -- these extra formals present in initialization procedures, where they
127 -- would serve no purpose). In this call E is either a subprogram or
128 -- a subprogram type (i.e. an access to a subprogram).
131 -- True if T is not private and has no private components, or has a full
132 -- view. Used to determine whether the designated type of an access type
133 -- should be frozen when the access type is frozen. This is done when an
134 -- allocator is frozen, or an expression that may involve attributes of
135 -- the designated type. Otherwise freezing the access type does not freeze
136 -- the designated type.
138 procedure Process_Default_Expressions
141 -- This procedure is called for each subprogram to complete processing
142 -- of default expressions at the point where all types are known to be
143 -- frozen. The expressions must be analyzed in full, to make sure that
144 -- all error processing is done (they have only been pre-analyzed). If
145 -- the expression is not an entity or literal, its analysis may generate
146 -- code which must not be executed. In that case we build a function
147 -- body to hold that code. This wrapper function serves no other purpose
148 -- (it used to be called to evaluate the default, but now the default is
149 -- inlined at each point of call).
152 -- Typ is a record or array type that is being frozen. This routine
153 -- sets the default component alignment from the scope stack values
154 -- if the alignment is otherwise not specified.
157 -- As each entity is frozen, this routine is called to deal with the
158 -- setting of Debug_Info_Needed for the entity. This flag is set if
159 -- the entity comes from source, or if we are in Debug_Generated_Code
160 -- mode or if the -gnatdV debug flag is set. However, it never sets
161 -- the flag if Debug_Info_Off is set. This procedure also ensures that
162 -- subsidiary entities have the flag set as required.
165 -- T is a type of a component that we know to be an Itype.
166 -- We don't want this to have a Freeze_Node, so ensure it doesn't.
167 -- Do the same for any Full_View or Corresponding_Record_Type.
169 procedure Warn_Overlay
173 -- Expr is the expression for an address clause for entity Nam whose type
174 -- is Typ. If Typ has a default initialization, and there is no explicit
175 -- initialization in the source declaration, check whether the address
176 -- clause might cause overlaying of an entity, and emit a warning on the
177 -- side effect that the initialization will cause.
179 -------------------------------
180 -- Adjust_Esize_For_Alignment --
181 -------------------------------
186 begin
192 then
198 ------------------------------------
199 -- Build_And_Analyze_Renamed_Body --
200 ------------------------------------
202 procedure Build_And_Analyze_Renamed_Body
206 is
212 begin
213 -- If the renamed subprogram is intrinsic, there is no need for a
214 -- wrapper body: we set the alias that will be called and expanded which
215 -- completes the declaration. This transformation is only legal if the
216 -- renamed entity has already been elaborated.
218 -- Note that it is legal for a renaming_as_body to rename an intrinsic
219 -- subprogram, as long as the renaming occurs before the new entity
220 -- is frozen. See RM 8.5.4 (5).
224 then
226 else
232 and then
236 -- We can make the renaming entity intrisic if the renamed function
237 -- has an interface name, or if it is one of the shift/rotate
238 -- operations known to the compiler.
246 then
251 else
258 else
267 ------------------------
268 -- Build_Renamed_Body --
269 ------------------------
271 function Build_Renamed_Body
274 is
276 -- We use for the source location of the renamed body, the location of
277 -- the spec entity. It might seem more natural to use the location of
278 -- the renaming declaration itself, but that would be wrong, since then
279 -- the body we create would look as though it was created far too late,
280 -- and this could cause problems with elaboration order analysis,
281 -- particularly in connection with instantiations.
296 -- If the renamed entity is a primitive operation given in prefix form,
297 -- the prefix is the target object and it has to be added as the first
298 -- actual in the generated call.
300 begin
301 -- Determine the entity being renamed, which is the target of the call
302 -- statement. If the name is an explicit dereference, this is a renaming
303 -- of a subprogram type rather than a subprogram. The name itself is
304 -- fully analyzed.
315 else
322 else
328 -- If the renamed entity is a predefined operator, retain full name
329 -- to ensure its visibility.
333 then
335 else
339 else
342 and then
345 then
347 -- Retrieve the target object, to be added as a first actual
348 -- in the call.
353 else
357 -- Original name may have been overloaded, but is fully resolved now
362 -- For simple renamings, subsequent calls can be expanded directly as
363 -- calls to the renamed entity. The body must be generated in any case
364 -- for calls that may appear elsewhere.
368 then
372 -- The body generated for this renaming is an internal artifact, and
373 -- does not constitute a freeze point for the called entity.
380 declare
384 begin
385 -- The controlling formal may be an access parameter, or the
386 -- actual may be an access value, so adjust accordingly.
390 then
391 Actuals := New_List
396 then
397 Actuals := New_List
401 else
409 else
420 -- If the renamed entity is an entry, inherit its profile. For other
421 -- renamings as bodies, both profiles must be subtype conformant, so it
422 -- is not necessary to replace the profile given in the declaration.
423 -- However, default values that are aggregates are rewritten when
424 -- partially analyzed, so we recover the original aggregate to insure
425 -- that subsequent conformity checking works. Similarly, if the default
426 -- expression was constant-folded, recover the original expression.
436 N_Access_Definition
437 then
445 then
456 -- If the renamed entity is a function, the generated body contains a
457 -- return statement. Otherwise, build a procedure call. If the entity is
458 -- an entry, subsequent analysis of the call will transform it into the
459 -- proper entry or protected operation call. If the renamed entity is
460 -- a character literal, return it directly.
466 then
467 Call_Node :=
469 Expression =>
475 Call_Node :=
480 Call_Node :=
484 else
485 Call_Node :=
491 -- Create entities for subprogram body and formals
504 Body_Node :=
508 Handled_Statement_Sequence =>
518 -- Link the body to the entity whose declaration it completes. If
519 -- the body is analyzed when the renamed entity is frozen, it may
520 -- be necessary to restore the proper scope (see package Exp_Ch13).
524 then
526 else
533 --------------------------
534 -- Check_Address_Clause --
535 --------------------------
543 begin
550 -- Has_Delayed_Freeze was set on E when the address clause was
551 -- analyzed. Reset the flag now unless freeze actions were
552 -- attached to it in the mean time.
559 -- If Rep_Clauses are to be ignored, remove address clause from
560 -- list attached to entity, because it may be illegal for gigi,
561 -- for example by breaking order of elaboration..
564 declare
567 begin
573 else
576 loop
590 then
596 -----------------------------
597 -- Check_Compile_Time_Size --
598 -----------------------------
603 -- Sets the compile time known size (32 bits or less) in the Esize
604 -- field, of T checking for a size clause that was given which attempts
605 -- to give a smaller size, and also checking for an alignment clause.
608 -- Recursive function that does all the work
611 -- If T is a constrained subtype, its size is not known if any of its
612 -- discriminant constraints is not static and it is not a null record.
613 -- The test is conservative and doesn't check that the components are
614 -- in fact constrained by non-static discriminant values. Could be made
615 -- more precise ???
617 --------------------
618 -- Set_Small_Size --
619 --------------------
622 begin
626 -- Don't bother if alignment clause with a value other than 1 is
627 -- present, because size may be padded up to meet back end alignment
628 -- requirements, and only the back end knows the rules!
633 -- Check for bad size clause given
638 Error_Msg_NE
646 -- Set sizes if not set already
648 else
659 ----------------
660 -- Size_Known --
661 ----------------
670 begin
674 -- Always True for scalar types. This is true even for generic formal
675 -- scalar types. We used to return False in the latter case, but the
676 -- size is known at compile time, even in the template, we just do
677 -- not know the exact size but that's not the point of this routine.
681 then
684 -- Array types
688 -- String literals always have known size, and we can set it
695 -- Unconstrained types never have known at compile time size
700 -- Don't do any recursion on type with error posted, since we may
701 -- have a malformed type that leads us into a loop.
706 -- Otherwise if component size unknown, then array size unknown
712 -- Check for all indexes static, and also compute possible size
713 -- (in case it is less than 32 and may be packable).
715 declare
719 begin
728 else
736 then
739 else
744 else
756 -- Access types always have known at compile time sizes
761 -- For non-generic private types, go to underlying type if present
766 then
767 -- Don't do any recursion on type with error posted, since we may
768 -- have a malformed type that leads us into a loop.
772 else
776 -- Record types
780 -- A class-wide type is never considered to have a known size
785 -- A subtype of a variant record must not have non-static
786 -- discriminanted components.
790 then
793 -- Don't do any recursion on type with error posted, since we may
794 -- have a malformed type that leads us into a loop.
800 -- Now look at the components of the record
802 declare
803 -- The following two variables are used to keep track of the
804 -- size of packed records if we can tell the size of the packed
805 -- record in the front end. Packed_Size_Known is True if so far
806 -- we can figure out the size. It is initialized to True for a
807 -- packed record, unless the record has discriminants. The
808 -- reason we eliminate the discriminated case is that we don't
809 -- know the way the back end lays out discriminated packed
810 -- records. If Packed_Size_Known is True, then Packed_Size is
811 -- the size in bits so far.
819 begin
820 -- Test for variant part present
826 N_Record_Definition
830 then
831 -- If variant part is present, and type is unconstrained,
832 -- then we must have defaulted discriminants, or a size
833 -- clause must be present for the type, or else the size
834 -- is definitely not known at compile time.
837 and then
840 then
845 -- Loop through components
851 -- We do not know the packed size if there is a component
852 -- clause present (we possibly could, but this would only
853 -- help in the case of a record with partial rep clauses.
854 -- That's because in the case of full rep clauses, the
855 -- size gets figured out anyway by a different circuit).
861 -- We need to identify a component that is an array where
862 -- the index type is an enumeration type with non-standard
863 -- representation, and some bound of the type depends on a
864 -- discriminant.
866 -- This is because gigi computes the size by doing a
867 -- substitution of the appropriate discriminant value in
868 -- the size expression for the base type, and gigi is not
869 -- clever enough to evaluate the resulting expression (which
870 -- involves a call to rep_to_pos) at compile time.
872 -- It would be nice if gigi would either recognize that
873 -- this expression can be computed at compile time, or
874 -- alternatively figured out the size from the subtype
875 -- directly, where all the information is at hand ???
879 then
880 declare
888 begin
895 then
901 then
906 then
916 -- Clearly size of record is not known if the size of one of
917 -- the components is not known.
923 -- Accumulate packed size if possible
927 -- We can only deal with elementary types, since for
928 -- non-elementary components, alignment enters into the
929 -- picture, and we don't know enough to handle proper
930 -- alignment in this context. Packed arrays count as
931 -- elementary if the representation is a modular type.
936 and then Is_Modular_Integer_Type
938 then
939 -- If RM_Size is known and static, then we can keep
940 -- accumulating the packed size.
944 -- A little glitch, to be removed sometime ???
945 -- gigi does not understand zero sizes yet.
950 -- Normal case where we can keep accumulating the
951 -- packed array size.
953 else
957 -- If we have a field whose RM_Size is not known then
958 -- we can't figure out the packed size here.
960 else
964 -- If we have a non-elementary type we can't figure out
965 -- the packed array size (alignment issues).
967 else
982 -- All other cases, size not known at compile time
984 else
989 -------------------------------------
990 -- Static_Discriminated_Components --
991 -------------------------------------
993 function Static_Discriminated_Components
995 is
998 begin
1002 then
1016 -- Start of processing for Check_Compile_Time_Size
1018 begin
1022 -----------------------------
1023 -- Check_Debug_Info_Needed --
1024 -----------------------------
1027 begin
1032 or else Debug_Generated_Code
1033 or else Debug_Flag_VV
1035 then
1040 ----------------------------
1041 -- Check_Strict_Alignment --
1042 ----------------------------
1047 begin
1066 then
1076 -------------------------
1077 -- Check_Unsigned_Type --
1078 -------------------------
1085 begin
1090 -- Do not attempt to analyze case where range was in error
1096 -- The situation that is non trivial is something like
1098 -- subtype x1 is integer range -10 .. +10;
1099 -- subtype x2 is x1 range 0 .. V1;
1100 -- subtype x3 is x2 range V2 .. V3;
1101 -- subtype x4 is x3 range V4 .. V5;
1103 -- where Vn are variables. Here the base type is signed, but we still
1104 -- know that x4 is unsigned because of the lower bound of x2.
1106 -- The only way to deal with this is to look up the ancestor chain
1109 loop
1124 else
1127 -- If no ancestor had a static lower bound, go to base type
1131 -- Note: the reason we still check for a compile time known
1132 -- value for the base type is that at least in the case of
1133 -- generic formals, we can have bounds that fail this test,
1134 -- and there may be other cases in error situations.
1146 then
1156 -------------------------
1157 -- Is_Atomic_Aggregate --
1158 -------------------------
1160 function Is_Atomic_Aggregate
1163 is
1169 begin
1172 -- Array may be qualified, so find outer context
1180 then
1182 New_N :=
1193 else
1198 ----------------
1199 -- Freeze_All --
1200 ----------------
1202 -- Note: the easy coding for this procedure would be to just build a
1203 -- single list of freeze nodes and then insert them and analyze them
1204 -- all at once. This won't work, because the analysis of earlier freeze
1205 -- nodes may recursively freeze types which would otherwise appear later
1206 -- on in the freeze list. So we must analyze and expand the freeze nodes
1207 -- as they are generated.
1215 -- This is the internal recursive routine that does freezing of entities
1216 -- (but NOT the analysis of default expressions, which should not be
1217 -- recursive, we don't want to analyze those till we are sure that ALL
1218 -- the types are frozen).
1220 --------------------
1221 -- Freeze_All_Ent --
1222 --------------------
1230 -- If freeze nodes are present, insert and analyze, and reset cursor
1231 -- for next insertion.
1233 -------------------
1234 -- Process_Flist --
1235 -------------------
1238 begin
1245 else
1251 -- Start or processing for Freeze_All_Ent
1253 begin
1257 -- If the entity is an inner package which is not a package
1258 -- renaming, then its entities must be frozen at this point. Note
1259 -- that such entities do NOT get frozen at the end of the nested
1260 -- package itself (only library packages freeze).
1262 -- Same is true for task declarations, where anonymous records
1263 -- created for entry parameters must be frozen.
1269 then
1279 and then
1281 or else
1283 then
1286 End_Scope;
1288 -- For a derived tagged type, we must ensure that all the
1289 -- primitive operations of the parent have been frozen, so that
1290 -- their addresses will be in the parent's dispatch table at the
1291 -- point it is inherited.
1297 then
1298 declare
1305 begin
1312 then
1314 Process_Flist;
1324 Process_Flist;
1327 -- If an incomplete type is still not frozen, this may be a
1328 -- premature freezing because of a body declaration that follows.
1329 -- Indicate where the freezing took place.
1331 -- If the freezing is caused by the end of the current declarative
1332 -- part, it is a Taft Amendment type, and there is no error.
1336 then
1337 declare
1340 begin
1342 N_Entry_Body,
1343 N_Package_Body,
1344 N_Protected_Body,
1345 N_Task_Body)
1347 and then
1349 then
1351 Error_Msg_NE
1362 -- Start of processing for Freeze_All
1364 begin
1367 -- Now that all types are frozen, we can deal with default expressions
1368 -- that require us to build a default expression functions. This is the
1369 -- point at which such functions are constructed (after all types that
1370 -- might be used in such expressions have been frozen).
1372 -- For subprograms that are renaming_as_body, we create the wrapper
1373 -- bodies as needed.
1375 -- We also add finalization chains to access types whose designated
1376 -- types are controlled. This is normally done when freezing the type,
1377 -- but this misses recursive type definitions where the later members
1378 -- of the recursion introduce controlled components.
1380 -- Loop through entities
1398 and then
1400 = N_Subprogram_Renaming_Declaration
1401 then
1402 Build_And_Analyze_Renamed_Body
1408 and then
1410 or else
1412 then
1413 declare
1416 begin
1421 then
1434 then
1442 -----------------------
1443 -- Freeze_And_Append --
1444 -----------------------
1446 procedure Freeze_And_Append
1450 is
1452 begin
1456 else
1462 -------------------
1463 -- Freeze_Before --
1464 -------------------
1468 begin
1474 -------------------
1475 -- Freeze_Entity --
1476 -------------------
1488 -- This flag gets set to true for a variable with default initialization
1491 -- Check that an Access or Unchecked_Access attribute with a prefix
1492 -- which is the current instance type can only be applied when the type
1493 -- is limited.
1496 -- Give warning for modulus of 8, 16, 32, or 64 given as an explicit
1497 -- integer literal without an explicit corresponding size clause. The
1498 -- caller has checked that Utype is a modular integer type.
1501 -- If Loc is a freeze_entity that appears after the last declaration
1502 -- in the scope, inhibit error messages on late completion.
1505 -- Freeze each component, handle some representation clauses, and freeze
1506 -- primitive operations if this is a tagged type.
1508 ----------------------------
1509 -- After_Last_Declaration --
1510 ----------------------------
1514 begin
1520 else
1523 else
1528 ----------------------------
1529 -- Check_Current_Instance --
1530 ----------------------------
1540 -- Process routine to apply check to given node
1542 -------------
1543 -- Process --
1544 -------------
1547 begin
1551 or else
1556 then
1557 Error_Msg_N
1560 else
1570 -- Start of processing for Check_Current_Instance
1572 begin
1573 -- In Ada95, the (imprecise) rule is that the current instance of a
1574 -- limited type is aliased. In Ada2005, limitedness must be explicit:
1575 -- either a tagged type, or a limited record.
1579 then
1584 then
1587 else
1592 ------------------------------
1593 -- Check_Suspicious_Modulus --
1594 ------------------------------
1599 begin
1601 declare
1603 begin
1605 declare
1608 begin
1610 declare
1614 begin
1615 -- First case, modulus and size are the same. This
1616 -- happens if you have something like mod 32, with
1617 -- an explicit size of 32, this is for sure a case
1618 -- where the warning is given, since it is seems
1619 -- very unlikely that someone would want e.g. a
1620 -- five bit type stored in 32 bits. It is much
1621 -- more likely they wanted a 32-bit type.
1626 -- Second case, the modulus is 32 or 64 and no
1627 -- size clause is present. This is a less clear
1628 -- case for giving the warning, but in the case
1629 -- of 32/64 (5-bit or 6-bit types) these seem rare
1630 -- enough that it is a likely error (and in any
1631 -- case using 2**5 or 2**6 in these cases seems
1632 -- clearer. We don't include 8 or 16 here, simply
1633 -- because in practice 3-bit and 4-bit types are
1634 -- more common and too many false positives if
1635 -- we warn in these cases.
1639 then
1642 -- No warning needed
1644 else
1648 -- If we fall through, give warning
1651 Error_Msg_N
1653 Modulus);
1662 ------------------------
1663 -- Freeze_Record_Type --
1664 ------------------------
1676 -- Set True if we find at least one component with no component
1677 -- clause (used to warn about useless Pack pragmas).
1680 -- Set True if we find at least one component with a component
1681 -- clause (used to warn about useless Bit_Order pragmas, and also
1682 -- to detect cases where Implicit_Packing may have an effect).
1685 -- Set False if we encounter a component of a non-scalar type
1689 -- Accumulates total RM_Size values and total Esize values of all
1690 -- scalar components. Used for processing of Implicit_Packing.
1693 -- If N is an allocator, possibly wrapped in one or more level of
1694 -- qualified expression(s), return the inner allocator node, else
1695 -- return Empty.
1698 -- If the component subtype is an access to a constrained subtype of
1699 -- an already frozen type, make the subtype frozen as well. It might
1700 -- otherwise be frozen in the wrong scope, and a freeze node on
1701 -- subtype has no effect. Similarly, if the component subtype is a
1702 -- regular (not protected) access to subprogram, set the anonymous
1703 -- subprogram type to frozen as well, to prevent an out-of-scope
1704 -- freeze node at some eventual point of call. Protected operations
1705 -- are handled elsewhere.
1707 ---------------------
1708 -- Check_Allocator --
1709 ---------------------
1713 begin
1715 loop
1720 else
1726 -----------------
1727 -- Check_Itype --
1728 -----------------
1733 begin
1736 then
1739 -- In addition, add an Itype_Reference to ensure that the
1740 -- access subtype is elaborated early enough. This cannot be
1741 -- done if the subtype may depend on discriminants.
1746 then
1752 else
1759 then
1764 -- Start of processing for Freeze_Record_Type
1766 begin
1767 -- If this is a subtype of a controlled type, declared without a
1768 -- constraint, the _controller may not appear in the component list
1769 -- if the parent was not frozen at the point of subtype declaration.
1770 -- Inherit the _controller component now.
1774 then
1777 then
1780 -- If this is an internal type without a declaration, as for
1781 -- record component, the base type may not yet be frozen, and its
1782 -- controller has not been created. Add an explicit freeze node
1783 -- for the itype, so it will be frozen after the base type. This
1784 -- freeze node is used to communicate with the expander, in order
1785 -- to create the controller for the enclosing record, and it is
1786 -- deleted afterwards (see exp_ch3). It must not be created when
1787 -- expansion is off, because it might appear in the wrong context
1788 -- for the back end.
1792 and then
1794 N_Component_Declaration
1795 and then Expander_Active
1796 then
1801 -- Freeze components and embedded subtypes
1807 -- First handle the component case
1811 then
1812 declare
1815 begin
1816 -- Freezing a record type freezes the type of each of its
1817 -- components. However, if the type of the component is
1818 -- part of this record, we do not want or need a separate
1819 -- Freeze_Node. Note that Is_Itype is wrong because that's
1820 -- also set in private type cases. We also can't check for
1821 -- the Scope being exactly Rec because of private types and
1822 -- record extensions.
1827 then
1833 -- Check for error of component clause given for variable
1834 -- sized type. We have to delay this test till this point,
1835 -- since the component type has to be frozen for us to know
1836 -- if it is variable length. We omit this test in a generic
1837 -- context, it will be applied at instantiation time.
1845 elsif not
1846 Size_Known_At_Compile_Time
1848 then
1849 Error_Msg_N
1854 else
1858 -- Case of component requires byte alignment
1862 -- Set the enclosing record to also require byte align
1866 -- Check for component clause that is inconsistent with
1867 -- the required byte boundary alignment.
1872 then
1873 Error_Msg_N
1881 -- Gather data for possible Implicit_Packing later. Note that at
1882 -- this stage we might be dealing with a real component, or with
1883 -- an implicit subtype declaration.
1887 else
1888 Scalar_Component_Total_RM_Size :=
1890 Scalar_Component_Total_Esize :=
1894 -- If the component is an Itype with Delayed_Freeze and is either
1895 -- a record or array subtype and its base type has not yet been
1896 -- frozen, we must remove this from the entity list of this record
1897 -- and put it on the entity list of the scope of its base type.
1898 -- Note that we know that this is not the type of a component
1899 -- since we cleared Has_Delayed_Freeze for it in the previous
1900 -- loop. Thus this must be the Designated_Type of an access type,
1901 -- which is the type of a component.
1909 then
1910 declare
1914 begin
1915 -- We have a pretty bad kludge here. Suppose Rec is subtype
1916 -- being defined in a subprogram that's created as part of
1917 -- the freezing of Rec'Base. In that case, we know that
1918 -- Comp'Base must have already been frozen by the time we
1919 -- get to elaborate this because Gigi doesn't elaborate any
1920 -- bodies until it has elaborated all of the declarative
1921 -- part. But Is_Frozen will not be set at this point because
1922 -- we are processing code in lexical order.
1924 -- We detect this case by going up the Scope chain of Rec
1925 -- and seeing if we have a subprogram scope before reaching
1926 -- the top of the scope chain or that of Comp'Base. If we
1927 -- do, then mark that Comp'Base will actually be frozen. If
1928 -- so, we merely undelay it.
1944 else
1947 else
1951 -- Insert in entity list of scope of base type (which
1952 -- must be an enclosing scope, because still unfrozen).
1958 -- If the component is an access type with an allocator as default
1959 -- value, the designated type will be frozen by the corresponding
1960 -- expression in init_proc. In order to place the freeze node for
1961 -- the designated type before that for the current record type,
1962 -- freeze it now.
1964 -- Same process if the component is an array of access types,
1965 -- initialized with an aggregate. If the designated type is
1966 -- private, it cannot contain allocators, and it is premature
1967 -- to freeze the type, so we check for this as well.
1972 then
1973 declare
1977 begin
1980 -- If component is pointer to a classwide type, freeze
1981 -- the specific type in the expression being allocated.
1982 -- The expression may be a subtype indication, in which
1983 -- case freeze the subtype mark.
1985 if Is_Class_Wide_Type
1987 then
1989 Freeze_And_Append
1991 elsif
1993 then
1994 Freeze_And_Append
2002 else
2003 Freeze_And_Append
2011 then
2020 and then Is_Fully_Defined
2022 then
2023 Freeze_And_Append
2024 (Designated_Type
2032 -- Deal with pragma Bit_Order setting non-standard bit order
2036 ADC :=
2039 Error_Msg_N
2042 -- Here is where we do the processing for reversed bit order
2044 else
2049 -- Complete error checking on record representation clause (e.g.
2050 -- overlap of components). This is called after adjusting the
2051 -- record for reverse bit order.
2053 declare
2055 begin
2061 -- Set OK_To_Reorder_Components depending on debug flags
2065 then
2067 or else
2069 then
2074 -- Check for useless pragma Pack when all components placed. We only
2075 -- do this check for record types, not subtypes, since a subtype may
2076 -- have all its components placed, and it still makes perfectly good
2077 -- sense to pack other subtypes or the parent type. We do not give
2078 -- this warning if Optimize_Alignment is set to Space, since the
2079 -- pragma Pack does have an effect in this case (it always resets
2080 -- the alignment to one).
2084 and then not Unplaced_Component
2086 then
2087 -- Reset packed status. Probably not necessary, but we do it so
2088 -- that there is no chance of the back end doing something strange
2089 -- with this redundant indication of packing.
2093 -- Give warning if redundant constructs warnings on
2096 Error_Msg_N -- CODEFIX
2102 -- If this is the record corresponding to a remote type, freeze the
2103 -- remote type here since that is what we are semantically freezing.
2104 -- This prevents the freeze node for that type in an inner scope.
2106 -- Also, Check for controlled components and unchecked unions.
2107 -- Finally, enforce the restriction that access attributes with a
2108 -- current instance prefix can only apply to limited types.
2112 Freeze_And_Append
2119 -- Do not set Has_Controlled_Component on a class-wide
2120 -- equivalent type. See Make_CW_Equivalent_Type.
2127 and then Present
2128 (Corresponding_Record_Type
2130 and then Has_Controlled_Component
2131 (Corresponding_Record_Type
2133 then
2144 -- Scan component declaration for likely misuses of current
2145 -- instance, either in a constraint or a default expression.
2156 -- For first subtypes, check if there are any fixed-point fields with
2157 -- component clauses, where we must check the size. This is not done
2158 -- till the freeze point, since for fixed-point types, we do not know
2159 -- the size until the type is frozen. Similar processing applies to
2160 -- bit packed arrays.
2168 or else
2170 then
2171 Check_Size
2175 Junk);
2182 -- Generate warning for applying C or C++ convention to a record
2183 -- with discriminants. This is suppressed for the unchecked union
2184 -- case, since the whole point in this case is interface C. We also
2185 -- do not generate this within instantiations, since we will have
2186 -- generated a message on the template.
2191 or else
2194 and then not In_Instance
2197 then
2198 declare
2202 begin
2207 Error_Msg_N
2209 else
2210 Error_Msg_N
2214 Error_Msg_NE
2220 -- See if Size is too small as is (and implicit packing might help)
2224 -- No implicit packing if even one component is explicitly placed
2226 and then not Placed_Component
2228 -- Must have size clause and all scalar components
2231 and then All_Scalar_Components
2233 -- Do not try implicit packing on records with discriminants, too
2234 -- complicated, especially in the variant record case.
2238 -- We can implicitly pack if the specified size of the record is
2239 -- less than the sum of the object sizes (no point in packing if
2240 -- this is not the case).
2244 -- And the total RM size cannot be greater than the specified size
2245 -- since otherwise packing will not get us where we have to be!
2249 -- Never do implicit packing in CodePeer mode since we don't do
2250 -- any packing ever in this mode (why not???)
2252 and then not CodePeer_Mode
2253 then
2254 -- If implicit packing enabled, do it
2259 -- Otherwise flag the size clause
2261 else
2262 declare
2264 begin
2265 Error_Msg_NE -- CODEFIX
2267 Error_Msg_N -- CODEFIX
2275 -- Start of processing for Freeze_Entity
2277 begin
2278 -- We are going to test for various reasons why this entity need not be
2279 -- frozen here, but in the case of an Itype that's defined within a
2280 -- record, that test actually applies to the record.
2286 then
2290 -- Do not freeze if already frozen since we only need one freeze node
2295 -- It is improper to freeze an external entity within a generic because
2296 -- its freeze node will appear in a non-valid context. The entity will
2297 -- be frozen in the proper scope after the current generic is analyzed.
2302 -- Do not freeze a global entity within an inner scope created during
2303 -- expansion. A call to subprogram E within some internal procedure
2304 -- (a stream attribute for example) might require freezing E, but the
2305 -- freeze node must appear in the same declarative part as E itself.
2306 -- The two-pass elaboration mechanism in gigi guarantees that E will
2307 -- be frozen before the inner call is elaborated. We exclude constants
2308 -- from this test, because deferred constants may be frozen early, and
2309 -- must be diagnosed (e.g. in the case of a deferred constant being used
2310 -- in a default expression). If the enclosing subprogram comes from
2311 -- source, or is a generic instance, then the freeze point is the one
2312 -- mandated by the language, and we freeze the entity. A subprogram that
2313 -- is a child unit body that acts as a spec does not have a spec that
2314 -- comes from source, but can only come from source.
2319 then
2320 declare
2323 begin
2330 then
2332 else
2341 -- Similarly, an inlined instance body may make reference to global
2342 -- entities, but these references cannot be the proper freezing point
2343 -- for them, and in the absence of inlining freezing will take place in
2344 -- their own scope. Normally instance bodies are analyzed after the
2345 -- enclosing compilation, and everything has been frozen at the proper
2346 -- place, but with front-end inlining an instance body is compiled
2347 -- before the end of the enclosing scope, and as a result out-of-order
2348 -- freezing must be prevented.
2350 elsif Front_End_Inlining
2351 and then In_Instance_Body
2353 then
2354 declare
2357 begin
2361 else
2372 -- Here to freeze the entity
2377 -- Case of entity being frozen is other than a type
2381 -- If entity is exported or imported and does not have an external
2382 -- name, now is the time to provide the appropriate default name.
2383 -- Skip this if the entity is stubbed, since we don't need a name
2384 -- for any stubbed routine. For the case on intrinsics, if no
2385 -- external name is specified, then calls will be handled in
2386 -- Exp_Intr.Expand_Intrinsic_Call, and no name is needed. If an
2387 -- external name is provided, then Expand_Intrinsic_Call leaves
2388 -- calls in place for expansion by GIGI.
2394 then
2395 Set_Encoded_Interface_Name
2398 -- If entity is an atomic object appearing in a declaration and
2399 -- the expression is an aggregate, assign it to a temporary to
2400 -- ensure that the actual assignment is done atomically rather
2401 -- than component-wise (the assignment to the temp may be done
2402 -- component-wise, but that is harmless).
2408 and then
2410 then
2414 -- For a subprogram, freeze all parameter types and also the return
2415 -- type (RM 13.14(14)). However skip this for internal subprograms.
2416 -- This is also the point where any extra formal parameters are
2417 -- created since we now know whether the subprogram will use a
2418 -- foreign convention.
2422 declare
2427 begin
2428 -- Loop through formals
2440 then
2441 -- If the type of a formal is incomplete, subprogram
2442 -- is being frozen prematurely. Within an instance
2443 -- (but not within a wrapper package) this is an
2444 -- artifact of our need to regard the end of an
2445 -- instantiation as a freeze point. Otherwise it is
2446 -- a definite error.
2452 elsif not After_Last_Declaration
2453 and then not Freezing_Library_Level_Tagged_Type
2454 then
2456 Error_Msg
2458 Loc);
2462 -- Check suspicious parameter for C function. These tests
2463 -- apply only to exported/imported subprograms.
2465 if Warn_On_Export_Import
2468 or else
2475 then
2476 -- Qualify mention of formals with subprogram name
2480 -- Check suspicious use of fat C pointer
2484 then
2485 Error_Msg_N
2487 Formal);
2489 -- Check suspicious return of boolean
2496 then
2498 Error_Msg_N
2502 -- Check suspicious tagged type
2506 and then
2507 Is_Tagged_Type
2510 then
2511 Error_Msg_N
2515 -- Check wrong convention subprogram pointer
2519 then
2520 Error_Msg_N
2524 Error_Msg_NE
2529 -- Turn off name qualification after message output
2534 -- Check for unconstrained array in exported foreign
2535 -- convention case.
2541 and then Warn_On_Export_Import
2543 -- Exclude VM case, since both .NET and JVM can handle
2544 -- unconstrained arrays without a problem.
2547 then
2550 -- If this is an inherited operation, place the
2551 -- warning on the derived type declaration, rather
2552 -- than on the original subprogram.
2555 N_Full_Type_Declaration
2556 then
2560 Error_Msg_NE
2563 else
2567 Error_Msg_NE
2570 Error_Msg_NE
2581 -- If the formal is an anonymous_access_to_subprogram
2582 -- freeze the subprogram type as well, to prevent
2583 -- scope anomalies in gigi, because there is no other
2584 -- clear point at which it could be frozen.
2588 then
2596 -- Case of function: similar checks on return type
2600 -- Freeze return type
2605 -- Check suspicious return type for C function
2607 if Warn_On_Export_Import
2609 or else
2612 then
2613 -- Check suspicious return of fat C pointer
2619 then
2620 Error_Msg_N
2624 -- Check suspicious return of boolean
2632 then
2633 declare
2636 begin
2637 Error_Msg_NE
2640 Error_Msg_NE
2645 -- Check suspicious return tagged type
2649 and then
2650 Is_Tagged_Type
2655 then
2656 Error_Msg_N
2660 -- Check return of wrong convention subprogram pointer
2666 then
2667 Error_Msg_N
2671 Error_Msg_NE
2677 -- Give warning for suspicous return of a result of an
2678 -- unconstrained array type in a foreign convention
2679 -- function.
2683 -- We are looking for a return of unconstrained array
2688 -- Exclude imported routines, the warning does not
2689 -- belong on the import, but on the routine definition.
2693 -- Exclude VM case, since both .NET and JVM can handle
2694 -- return of unconstrained arrays without a problem.
2698 -- Check that general warning is enabled, and that it
2699 -- is not suppressed for this particular case.
2701 and then Warn_On_Export_Import
2704 then
2705 Error_Msg_N
2713 -- Must freeze its parent first if it is a derived subprogram
2719 -- We don't freeze internal subprograms, because we don't normally
2720 -- want addition of extra formals or mechanism setting to happen
2721 -- for those. However we do pass through predefined dispatching
2722 -- cases, since extra formals may be needed in some cases, such as
2723 -- for the stream 'Input function (build-in-place formals).
2727 then
2731 -- Here for other than a subprogram or type
2733 else
2734 -- If entity has a type, and it is not a generic unit, then
2735 -- freeze it first (RM 13.14(10)).
2739 then
2743 -- Special processing for objects created by object declaration
2747 -- Abstract type allowed only for C++ imported variables or
2748 -- constants.
2750 -- Note: we inhibit this check for objects that do not come
2751 -- from source because there is at least one case (the
2752 -- expansion of x'class'input where x is abstract) where we
2753 -- legitimately generate an abstract object.
2759 then
2764 Error_Msg_NE
2770 -- For object created by object declaration, perform required
2771 -- categorization (preelaborate and pure) checks. Defer these
2772 -- checks to freeze time since pragma Import inhibits default
2773 -- initialization and thus pragma Import affects these checks.
2777 -- If there is an address clause, check that it is valid
2781 -- If the object needs any kind of default initialization, an
2782 -- error must be issued if No_Default_Initialization applies.
2783 -- The check doesn't apply to imported objects, which are not
2784 -- ever default initialized, and is why the check is deferred
2785 -- until freezing, at which point we know if Import applies.
2786 -- Deferred constants are also exempted from this test because
2787 -- their completion is explicit, or through an import pragma.
2791 then
2797 and then
2802 or else
2805 then
2807 Check_Restriction
2811 -- Check that a Thread_Local_Storage variable does not have
2812 -- default initialization, and any explicit initialization must
2813 -- either be the null constant or a static constant.
2816 declare
2818 begin
2819 if Has_Default_Initialization
2820 or else
2822 and then
2824 or else not
2826 or else
2828 then
2829 Error_Msg_NE
2832 Error_Msg_NE
2839 -- For imported objects, set Is_Public unless there is also an
2840 -- address clause, which means that there is no external symbol
2841 -- needed for the Import (Is_Public may still be set for other
2842 -- unrelated reasons). Note that we delayed this processing
2843 -- till freeze time so that we can be sure not to set the flag
2844 -- if there is an address clause. If there is such a clause,
2845 -- then the only purpose of the Import pragma is to suppress
2846 -- implicit initialization.
2850 then
2854 -- For convention C objects of an enumeration type, warn if
2855 -- the size is not integer size and no explicit size given.
2856 -- Skip warning for Boolean, and Character, assume programmer
2857 -- expects 8-bit sizes for these cases.
2860 or else
2867 then
2869 Error_Msg_N
2871 E);
2876 -- Check that a constant which has a pragma Volatile[_Components]
2877 -- or Atomic[_Components] also has a pragma Import (RM C.6(13)).
2879 -- Note: Atomic[_Components] also sets Volatile[_Components]
2884 then
2885 -- Make sure we actually have a pragma, and have not merely
2886 -- inherited the indication from elsewhere (e.g. an address
2887 -- clause, which is not good enough in RM terms!)
2890 or else
2892 then
2893 Error_Msg_N
2898 or else
2900 then
2901 Error_Msg_N
2907 -- Static objects require special handling
2911 then
2915 -- Remaining step is to layout objects
2918 or else
2920 or else
2922 or else
2924 then
2929 -- Case of a type or subtype being frozen
2931 else
2932 -- We used to check here that a full type must have preelaborable
2933 -- initialization if it completes a private type specified with
2934 -- pragma Preelaborable_Intialization, but that missed cases where
2935 -- the types occur within a generic package, since the freezing
2936 -- that occurs within a containing scope generally skips traversal
2937 -- of a generic unit's declarations (those will be frozen within
2938 -- instances). This check was moved to Analyze_Package_Specification.
2940 -- The type may be defined in a generic unit. This can occur when
2941 -- freezing a generic function that returns the type (which is
2942 -- defined in a parent unit). It is clearly meaningless to freeze
2943 -- this type. However, if it is a subtype, its size may be determi-
2944 -- nable and used in subsequent checks, so might as well try to
2945 -- compute it.
2949 then
2954 -- Deal with special cases of freezing for subtype
2958 -- Before we do anything else, a specialized test for the case of
2959 -- a size given for an array where the array needs to be packed,
2960 -- but was not so the size cannot be honored. This would of course
2961 -- be caught by the backend, and indeed we don't catch all cases.
2962 -- The point is that we can give a better error message in those
2963 -- cases that we do catch with the circuitry here. Also if pragma
2964 -- Implicit_Packing is set, this is where the packing occurs.
2966 -- The reason we do this so early is that the processing in the
2967 -- automatic packing case affects the layout of the base type, so
2968 -- it must be done before we freeze the base type.
2971 declare
2975 begin
2976 -- Check enabling conditions. These are straightforward
2977 -- except for the test for a limited composite type. This
2978 -- eliminates the rare case of a array of limited components
2979 -- where there are issues of whether or not we can go ahead
2980 -- and pack the array (since we can't freely pack and unpack
2981 -- arrays if they are limited).
2983 -- Note that we check the root type explicitly because the
2984 -- whole point is we are doing this test before we have had
2985 -- a chance to freeze the base type (and it is that freeze
2986 -- action that causes stuff to be inherited).
2998 and then not CodePeer_Mode
2999 then
3006 then
3007 declare
3017 -- What we are looking for here is the situation where
3018 -- the RM_Size given would be exactly right if there
3019 -- was a pragma Pack (resulting in the component size
3020 -- being the same as the RM_Size). Furthermore, the
3021 -- component type size must be an odd size (not a
3022 -- multiple of storage unit). If the component RM size
3023 -- is an exact number of storage units that is a power
3024 -- of two, the array is not packed and has a standard
3025 -- representation.
3027 begin
3030 then
3031 -- For implicit packing mode, just set the
3032 -- component size silently.
3040 -- Otherwise give an error message
3042 else
3043 Error_Msg_NE
3045 Error_Msg_N -- CODEFIX
3051 and then Implicit_Packing
3052 and then
3056 then
3058 -- Not a packed array, but indicate the desired
3059 -- component size, for the back-end.
3069 -- If ancestor subtype present, freeze that first. Note that this
3070 -- will also get the base type frozen.
3077 -- Otherwise freeze the base type of the entity before freezing
3078 -- the entity itself (RM 13.14(15)).
3084 -- For a derived type, freeze its parent type first (RM 13.14(15))
3091 -- For array type, freeze index types and component type first
3092 -- before freezing the array (RM 13.14(15)).
3095 declare
3099 -- Set true if any of the index types is an enumeration type
3100 -- with a non-standard representation.
3102 begin
3111 then
3118 -- Processing that is done only for base types
3122 -- Propagate flags for component type
3126 then
3134 -- If packing was requested or if the component size was set
3135 -- explicitly, then see if bit packing is required. This
3136 -- processing is only done for base types, since all the
3137 -- representation aspects involved are type-related. This
3138 -- is not just an optimization, if we start processing the
3139 -- subtypes, they interfere with the settings on the base
3140 -- type (this is because Is_Packed has a slightly different
3141 -- meaning before and after freezing).
3143 declare
3147 begin
3151 then
3160 else
3163 -- We can set the component size if it is less than
3164 -- 16, rounding it up to the next storage unit size.
3170 else
3174 -- Set component size up to match alignment if it
3175 -- would otherwise be less than the alignment. This
3176 -- deals with cases of types whose alignment exceeds
3177 -- their size (padded types).
3180 declare
3182 begin
3190 -- Case of component size that may result in packing
3193 declare
3199 Get_Attribute_Definition_Clause
3201 begin
3202 -- Warn if we have pack and component size so that
3203 -- the pack is ignored.
3205 -- Note: here we must check for the presence of a
3206 -- component size before checking for a Pack pragma
3207 -- to deal with the case where the array type is a
3208 -- derived type whose parent is currently private.
3212 then
3214 Error_Msg_NE
3217 Error_Msg_N
3219 Pack_Pragma);
3222 -- Set component size if not already set by a
3223 -- component size clause.
3229 -- Check for base type of 8, 16, 32 bits, where an
3230 -- unsigned subtype has a length one less than the
3231 -- base type (e.g. Natural subtype of Integer).
3233 -- In such cases, if a component size was not set
3234 -- explicitly, then generate a warning.
3238 and then
3241 then
3245 Error_Msg_N
3248 Error_Msg_N
3254 -- Actual packing is not needed for 8, 16, 32, 64.
3255 -- Also not needed for 24 if alignment is 1.
3262 then
3263 -- Here the array was requested to be packed,
3264 -- but the packing request had no effect, so
3265 -- Is_Packed is reset.
3267 -- Note: semantically this means that we lose
3268 -- track of the fact that a derived type
3269 -- inherited a pragma Pack that was non-
3270 -- effective, but that seems fine.
3272 -- We regard a Pack pragma as a request to set
3273 -- a representation characteristic, and this
3274 -- request may be ignored.
3278 -- In all other cases, packing is indeed needed
3280 else
3289 -- Processing that is done only for subtypes
3291 else
3292 -- Acquire alignment from base type
3300 -- For bit-packed arrays, check the size
3303 declare
3309 begin
3310 -- It is not clear if it is possible to have no size
3311 -- clause at this stage, but it is not worth worrying
3312 -- about. Post error on the entity name in the size
3313 -- clause if present, else on the type entity itself.
3317 else
3323 -- If any of the index types was an enumeration type with
3324 -- a non-standard rep clause, then we indicate that the
3325 -- array type is always packed (even if it is not bit packed).
3334 -- If the array is packed, we must create the packed array
3335 -- type to be used to actually implement the type. This is
3336 -- only needed for real array types (not for string literal
3337 -- types, since they are present only for the front end).
3341 then
3345 -- Size information of packed array type is copied to the
3346 -- array type, since this is really the representation. But
3347 -- do not override explicit existing size values. If the
3348 -- ancestor subtype is constrained the packed_array_type
3349 -- will be inherited from it, but the size may have been
3350 -- provided already, and must not be overridden either.
3353 and then
3356 then
3366 -- For non-packed arrays set the alignment of the array to the
3367 -- alignment of the component type if it is unknown. Skip this
3368 -- in atomic case (atomic arrays may need larger alignments).
3377 then
3382 -- For a class-wide type, the corresponding specific type is
3383 -- frozen as well (RM 13.14(15))
3388 -- If the base type of the class-wide type is still incomplete,
3389 -- the class-wide remains unfrozen as well. This is legal when
3390 -- E is the formal of a primitive operation of some other type
3391 -- which is being frozen.
3398 -- If the Class_Wide_Type is an Itype (when type is the anonymous
3399 -- parent of a derived type) and it is a library-level entity,
3400 -- generate an itype reference for it. Otherwise, its first
3401 -- explicit reference may be in an inner scope, which will be
3402 -- rejected by the back-end.
3406 then
3407 declare
3410 begin
3414 else
3420 -- The equivalent type associated with a class-wide subtype needs
3421 -- to be frozen to ensure that its layout is done.
3425 then
3429 -- For a record (sub)type, freeze all the component types (RM
3430 -- 13.14(15). We test for E_Record_(sub)Type here, rather than using
3431 -- Is_Record_Type, because we don't want to attempt the freeze for
3432 -- the case of a private type with record extension (we will do that
3433 -- later when the full type is frozen).
3437 then
3440 -- For a concurrent type, freeze corresponding record type. This
3441 -- does not correspond to any specific rule in the RM, but the
3442 -- record type is essentially part of the concurrent type.
3443 -- Freeze as well all local entities. This includes record types
3444 -- created for entry parameter blocks, and whatever local entities
3445 -- may appear in the private part.
3449 Freeze_And_Append
3461 then
3471 -- Private types are required to point to the same freeze node as
3472 -- their corresponding full views. The freeze node itself has to
3473 -- point to the partial view of the entity (because from the partial
3474 -- view, we can retrieve the full view, but not the reverse).
3475 -- However, in order to freeze correctly, we need to freeze the full
3476 -- view. If we are freezing at the end of a scope (or within the
3477 -- scope of the private type), the partial and full views will have
3478 -- been swapped, the full view appears first in the entity chain and
3479 -- the swapping mechanism ensures that the pointers are properly set
3480 -- (on scope exit).
3482 -- If we encounter the partial view before the full view (e.g. when
3483 -- freezing from another scope), we freeze the full view, and then
3484 -- set the pointers appropriately since we cannot rely on swapping to
3485 -- fix things up (subtypes in an outer scope might not get swapped).
3489 then
3490 -- The construction of the dispatch table associated with library
3491 -- level tagged types forces freezing of all the primitives of the
3492 -- type, which may cause premature freezing of the partial view.
3493 -- For example:
3495 -- package Pkg is
3496 -- type T is tagged private;
3497 -- type DT is new T with private;
3498 -- procedure Prim (X : in out T; Y : in out DT'class);
3499 -- private
3500 -- type T is tagged null record;
3501 -- Obj : T;
3502 -- type DT is new T with null record;
3503 -- end;
3505 -- In this case the type will be frozen later by the usual
3506 -- mechanism: an object declaration, an instantiation, or the
3507 -- end of a declarative part.
3511 then
3515 -- Case of full view present
3519 -- If full view has already been frozen, then no further
3520 -- processing is required
3528 -- Otherwise freeze full view and patch the pointers so that
3529 -- the freeze node will elaborate both views in the back-end.
3531 else
3532 declare
3535 begin
3538 then
3539 Freeze_And_Append
3552 else
3553 -- {Incomplete,Private}_Subtypes with Full_Views
3554 -- constrained by discriminants.
3565 -- AI-117 requires that the convention of a partial view be the
3566 -- same as the convention of the full view. Note that this is a
3567 -- recognized breach of privacy, but it's essential for logical
3568 -- consistency of representation, and the lack of a rule in
3569 -- RM95 was an oversight.
3576 -- Size information is copied from the full view to the
3577 -- incomplete or private view for consistency.
3579 -- We skip this is the full view is not a type. This is very
3580 -- strange of course, and can only happen as a result of
3581 -- certain illegalities, such as a premature attempt to derive
3582 -- from an incomplete type.
3591 -- Case of no full view present. If entity is derived or subtype,
3592 -- it is safe to freeze, correctness depends on the frozen status
3593 -- of parent. Otherwise it is either premature usage, or a Taft
3594 -- amendment type, so diagnosis is at the point of use and the
3595 -- type might be frozen later.
3599 then
3602 else
3607 -- For access subprogram, freeze types of all formals, the return
3608 -- type was already frozen, since it is the Etype of the function.
3609 -- Formal types can be tagged Taft amendment types, but otherwise
3610 -- they cannot be incomplete.
3619 then
3622 else
3623 Error_Msg_NE
3634 -- For access to a protected subprogram, freeze the equivalent type
3635 -- (however this is not set if we are not generating code or if this
3636 -- is an anonymous type used just for resolution).
3644 -- Generic types are never seen by the back-end, and are also not
3645 -- processed by the expander (since the expander is turned off for
3646 -- generic processing), so we never need freeze nodes for them.
3652 -- Some special processing for non-generic types to complete
3653 -- representation details not known till the freeze point.
3658 -- Some error checks required for ordinary fixed-point type. Defer
3659 -- these till the freeze-point since we need the small and range
3660 -- values. We only do these checks for base types
3664 then
3667 Error_Msg_N
3672 Error_Msg_N
3678 Error_Msg_N
3684 Error_Msg_N
3696 and then Warn_On_Suspicious_Modulus_Value
3697 then
3703 -- Check restriction for standard storage pool
3709 -- Deal with error message for pure access type. This is not an
3710 -- error in Ada 2005 if there is no pool (see AI-366).
3715 then
3719 Error_Msg_N
3723 Error_Msg_N
3726 else
3727 Error_Msg_N
3734 -- Case of composite types
3738 -- AI-117 requires that all new primitives of a tagged type must
3739 -- inherit the convention of the full view of the type. Inherited
3740 -- and overriding operations are defined to inherit the convention
3741 -- of their parent or overridden subprogram (also specified in
3742 -- AI-117), which will have occurred earlier (in Derive_Subprogram
3743 -- and New_Overloaded_Entity). Here we set the convention of
3744 -- primitives that are still convention Ada, which will ensure
3745 -- that any new primitives inherit the type's convention. Class-
3746 -- wide types can have a foreign convention inherited from their
3747 -- specific type, but are excluded from this since they don't have
3748 -- any associated primitives.
3753 then
3754 declare
3757 begin
3770 -- Now that all types from which E may depend are frozen, see if the
3771 -- size is known at compile time, if it must be unsigned, or if
3772 -- strict alignment is required
3781 -- Do not allow a size clause for a type which does not have a size
3782 -- that is known at compile time
3786 then
3787 -- Suppress this message if errors posted on E, even if we are
3788 -- in all errors mode, since this is often a junk message
3791 Error_Msg_N
3797 -- Remaining process is to set/verify the representation information,
3798 -- in particular the size and alignment values. This processing is
3799 -- not required for generic types, since generic types do not play
3800 -- any part in code generation, and so the size and alignment values
3801 -- for such types are irrelevant.
3806 -- Otherwise we call the layout procedure
3808 else
3812 -- End of freeze processing for type entities
3815 -- Here is where we logically freeze the current entity. If it has a
3816 -- freeze node, then this is the point at which the freeze node is
3817 -- linked into the result list.
3821 -- If a freeze node is already allocated, use it, otherwise allocate
3822 -- a new one. The preallocation happens in the case of anonymous base
3823 -- types, where we preallocate so that we can set First_Subtype_Link.
3824 -- Note that we reset the Sloc to the current freeze location.
3830 else
3842 else
3846 -- A final pass over record types with discriminants. If the type
3847 -- has an incomplete declaration, there may be constrained access
3848 -- subtypes declared elsewhere, which do not depend on the discrimi-
3849 -- nants of the type, and which are used as component types (i.e.
3850 -- the full view is a recursive type). The designated types of these
3851 -- subtypes can only be elaborated after the type itself, and they
3852 -- need an itype reference.
3856 then
3857 declare
3862 begin
3873 then
3885 -- When a type is frozen, the first subtype of the type is frozen as
3886 -- well (RM 13.14(15)). This has to be done after freezing the type,
3887 -- since obviously the first subtype depends on its own base type.
3892 -- If we just froze a tagged non-class wide record, then freeze the
3893 -- corresponding class-wide type. This must be done after the tagged
3894 -- type itself is frozen, because the class-wide type refers to the
3895 -- tagged type which generates the class.
3900 then
3907 -- Special handling for subprograms
3911 -- If subprogram has address clause then reset Is_Public flag, since
3912 -- we do not want the backend to generate external references.
3916 then
3919 -- If no address clause and not intrinsic, then for imported
3920 -- subprogram in main unit, generate descriptor if we are in
3921 -- Propagate_Exceptions mode.
3923 elsif Propagate_Exceptions
3927 then
3937 -----------------------------
3938 -- Freeze_Enumeration_Type --
3939 -----------------------------
3942 begin
3943 -- By default, if no size clause is present, an enumeration type with
3944 -- Convention C is assumed to interface to a C enum, and has integer
3945 -- size. This applies to types. For subtypes, verify that its base
3946 -- type has no size clause either.
3952 then
3955 else
3956 -- If the enumeration type interfaces to C, and it has a size clause
3957 -- that specifies less than int size, it warrants a warning. The
3958 -- user may intend the C type to be an enum or a char, so this is
3959 -- not by itself an error that the Ada compiler can detect, but it
3960 -- it is a worth a heads-up. For Boolean and Character types we
3961 -- assume that the programmer has the proper C type in mind.
3968 then
3969 Error_Msg_N
3977 -----------------------
3978 -- Freeze_Expression --
3979 -----------------------
3990 -- This flag is set true if the entity must be frozen outside the
3991 -- current subprogram. This happens in the case of expander generated
3992 -- subprograms (_Init_Proc, _Input, _Output, _Read, _Write) which do
3993 -- not freeze all entities like other bodies, but which nevertheless
3994 -- may reference entities that have to be frozen before the body and
3995 -- obviously cannot be frozen inside the body.
3998 -- Given an N_Handled_Sequence_Of_Statements node N, determines whether
3999 -- it is the handled statement sequence of an expander-generated
4000 -- subprogram (init proc, stream subprogram, or renaming as body).
4001 -- If so, this is not a freezing context.
4003 -----------------
4004 -- In_Exp_Body --
4005 -----------------
4011 begin
4014 else
4021 else
4031 N_Subprogram_Renaming_Declaration)
4032 then
4034 else
4040 -- Start of processing for Freeze_Expression
4042 begin
4043 -- Immediate return if freezing is inhibited. This flag is set by the
4044 -- analyzer to stop freezing on generated expressions that would cause
4045 -- freezing if they were in the source program, but which are not
4046 -- supposed to freeze, since they are created.
4052 -- If expression is non-static, then it does not freeze in a default
4053 -- expression, see section "Handling of Default Expressions" in the
4054 -- spec of package Sem for further details. Note that we have to
4055 -- make sure that we actually have a real expression (if we have
4056 -- a subtype indication, we can't test Is_Static_Expression!)
4058 if In_Spec_Exp
4061 then
4065 -- Freeze type of expression if not frozen already
4073 -- Base type may be an derived numeric type that is frozen at
4074 -- the point of declaration, but first_subtype is still unfrozen.
4081 -- For entity name, freeze entity if not frozen already. A special
4082 -- exception occurs for an identifier that did not come from source.
4083 -- We don't let such identifiers freeze a non-internal entity, i.e.
4084 -- an entity that did come from source, since such an identifier was
4085 -- generated by the expander, and cannot have any semantic effect on
4086 -- the freezing semantics. For example, this stops the parameter of
4087 -- an initialization procedure from freezing the variable.
4094 then
4096 else
4100 -- For an allocator freeze designated type if not frozen already
4102 -- For an aggregate whose component type is an access type, freeze the
4103 -- designated type now, so that its freeze does not appear within the
4104 -- loop that might be created in the expansion of the aggregate. If the
4105 -- designated type is a private type without full view, the expression
4106 -- cannot contain an allocator, so the type is not frozen.
4108 -- For a function, we freeze the entity when the subprogram declaration
4109 -- is frozen, but a function call may appear in an initialization proc.
4110 -- before the declaration is frozen. We need to generate the extra
4111 -- formals, if any, to ensure that the expansion of the call includes
4112 -- the proper actuals. This only applies to Ada subprograms, not to
4113 -- imported ones.
4124 then
4128 when N_Selected_Component |
4129 N_Indexed_Component |
4130 N_Slice =>
4141 then
4152 then
4156 -- All done if nothing needs freezing
4161 then
4165 -- Loop for looking at the right place to insert the freeze nodes,
4166 -- exiting from the loop when it is appropriate to insert the freeze
4167 -- node before the current node P.
4169 -- Also checks some special exceptions to the freezing rules. These
4170 -- cases result in a direct return, bypassing the freeze action.
4173 loop
4176 -- If we don't have a parent, then we are not in a well-formed tree.
4177 -- This is an unusual case, but there are some legitimate situations
4178 -- in which this occurs, notably when the expressions in the range of
4179 -- a type declaration are resolved. We simply ignore the freeze
4180 -- request in this case. Is this right ???
4186 -- See if we have got to an appropriate point in the tree
4190 -- A special test for the exception of (RM 13.14(8)) for the case
4191 -- of per-object expressions (RM 3.8(18)) occurring in component
4192 -- definition or a discrete subtype definition. Note that we test
4193 -- for a component declaration which includes both cases we are
4194 -- interested in, and furthermore the tree does not have explicit
4195 -- nodes for either of these two constructs.
4199 -- The case we want to test for here is an identifier that is
4200 -- a per-object expression, this is either a discriminant that
4201 -- appears in a context other than the component declaration
4202 -- or it is a reference to the type of the enclosing construct.
4204 -- For either of these cases, we skip the freezing
4206 if not In_Spec_Expression
4209 then
4210 -- We recognize the discriminant case by just looking for
4211 -- a reference to a discriminant. It can only be one for
4212 -- the enclosing construct. Skip freezing in this case.
4217 -- For the case of a reference to the enclosing record,
4218 -- (or task or protected type), we look for a type that
4219 -- matches the current scope.
4226 -- If we have an enumeration literal that appears as the choice in
4227 -- the aggregate of an enumeration representation clause, then
4228 -- freezing does not occur (RM 13.14(10)).
4232 -- The case we are looking for is an enumeration literal
4236 then
4237 -- If enumeration literal appears directly as the choice,
4238 -- do not freeze (this is the normal non-overloaded case)
4242 then
4245 -- If enumeration literal appears as the name of function
4246 -- which is the choice, then also do not freeze. This
4247 -- happens in the overloaded literal case, where the
4248 -- enumeration literal is temporarily changed to a function
4249 -- call for overloading analysis purposes.
4252 and then
4254 and then
4256 then
4261 -- Normally if the parent is a handled sequence of statements,
4262 -- then the current node must be a statement, and that is an
4263 -- appropriate place to insert a freeze node.
4267 -- An exception occurs when the sequence of statements is for
4268 -- an expander generated body that did not do the usual freeze
4269 -- all operation. In this case we usually want to freeze
4270 -- outside this body, not inside it, and we skip past the
4271 -- subprogram body that we are inside.
4275 -- However, we *do* want to freeze at this point if we have
4276 -- an entity to freeze, and that entity is declared *inside*
4277 -- the body of the expander generated procedure. This case
4278 -- is recognized by the scope of the type, which is either
4279 -- the spec for some enclosing body, or (in the case of
4280 -- init_procs, for which there are no separate specs) the
4281 -- current scope.
4283 declare
4287 begin
4292 or else
4294 then
4300 then
4306 -- If not that exception to the exception, then this is
4307 -- where we delay the freeze till outside the body.
4312 -- Here if normal case where we are in handled statement
4313 -- sequence and want to do the insertion right there.
4315 else
4319 -- If parent is a body or a spec or a block, then the current node
4320 -- is a statement or declaration and we can insert the freeze node
4321 -- before it.
4323 when N_Package_Specification |
4324 N_Package_Body |
4325 N_Subprogram_Body |
4326 N_Task_Body |
4327 N_Protected_Body |
4328 N_Entry_Body |
4331 -- The expander is allowed to define types in any statements list,
4332 -- so any of the following parent nodes also mark a freezing point
4333 -- if the actual node is in a list of statements or declarations.
4335 when N_Exception_Handler |
4336 N_If_Statement |
4337 N_Elsif_Part |
4338 N_Case_Statement_Alternative |
4339 N_Compilation_Unit_Aux |
4340 N_Selective_Accept |
4341 N_Accept_Alternative |
4342 N_Delay_Alternative |
4343 N_Conditional_Entry_Call |
4344 N_Entry_Call_Alternative |
4345 N_Triggering_Alternative |
4346 N_Abortable_Part |
4347 N_And_Then |
4348 N_Or_Else |
4349 N_Freeze_Entity =>
4353 -- Note: The N_Loop_Statement is a special case. A type that
4354 -- appears in the source can never be frozen in a loop (this
4355 -- occurs only because of a loop expanded by the expander), so we
4356 -- keep on going. Otherwise we terminate the search. Same is true
4357 -- of any entity which comes from source. (if they have predefined
4358 -- type, that type does not appear to come from source, but the
4359 -- entity should not be frozen here).
4365 -- For all other cases, keep looking at parents
4371 -- We fall through the case if we did not yet find the proper
4372 -- place in the free for inserting the freeze node, so climb!
4377 -- If the expression appears in a record or an initialization procedure,
4378 -- the freeze nodes are collected and attached to the current scope, to
4379 -- be inserted and analyzed on exit from the scope, to insure that
4380 -- generated entities appear in the correct scope. If the expression is
4381 -- a default for a discriminant specification, the scope is still void.
4382 -- The expression can also appear in the discriminant part of a private
4383 -- or concurrent type.
4385 -- If the expression appears in a constrained subcomponent of an
4386 -- enclosing record declaration, the freeze nodes must be attached to
4387 -- the outer record type so they can eventually be placed in the
4388 -- enclosing declaration list.
4390 -- The other case requiring this special handling is if we are in a
4391 -- default expression, since in that case we are about to freeze a
4392 -- static type, and the freeze scope needs to be the outer scope, not
4393 -- the scope of the subprogram with the default parameter.
4395 -- For default expressions and other spec expressions in generic units,
4396 -- the Move_Freeze_Nodes mechanism (see sem_ch12.adb) takes care of
4397 -- placing them at the proper place, after the generic unit.
4400 or else Freeze_Outside
4405 then
4406 declare
4411 begin
4424 -- The current scope may be that of a constrained component of
4425 -- an enclosing record declaration, which is above the current
4426 -- scope in the scope stack.
4435 Freeze_Nodes;
4436 else
4446 -- Now we have the right place to do the freezing. First, a special
4447 -- adjustment, if we are in spec-expression analysis mode, these freeze
4448 -- actions must not be thrown away (normally all inserted actions are
4449 -- thrown away in this mode. However, the freeze actions are from static
4450 -- expressions and one of the important reasons we are doing this
4451 -- special analysis is to get these freeze actions. Therefore we turn
4452 -- off the In_Spec_Expression mode to propagate these freeze actions.
4453 -- This also means they get properly analyzed and expanded.
4457 -- Freeze the designated type of an allocator (RM 13.14(13))
4463 -- Freeze type of expression (RM 13.14(10)). Note that we took care of
4464 -- the enumeration representation clause exception in the loop above.
4470 -- Freeze name if one is present (RM 13.14(11))
4476 -- Restore In_Spec_Expression flag
4481 -----------------------------
4482 -- Freeze_Fixed_Point_Type --
4483 -----------------------------
4485 -- Certain fixed-point types and subtypes, including implicit base types
4486 -- and declared first subtypes, have not yet set up a range. This is
4487 -- because the range cannot be set until the Small and Size values are
4488 -- known, and these are not known till the type is frozen.
4490 -- To signal this case, Scalar_Range contains an unanalyzed syntactic range
4491 -- whose bounds are unanalyzed real literals. This routine will recognize
4492 -- this case, and transform this range node into a properly typed range
4493 -- with properly analyzed and resolved values.
4511 -- Returns size of type with given bounds. Also leaves these
4512 -- bounds set as the current bounds of the Typ.
4514 -----------
4515 -- Fsize --
4516 -----------
4519 begin
4525 -- Start of processing for Freeze_Fixed_Point_Type
4527 begin
4528 -- If Esize of a subtype has not previously been set, set it now
4535 else
4540 -- Immediate return if the range is already analyzed. This means that
4541 -- the range is already set, and does not need to be computed by this
4542 -- routine.
4548 -- Immediate return if either of the bounds raises Constraint_Error
4552 then
4559 -- Ordinary fixed-point case
4563 -- For the ordinary fixed-point case, we are allowed to fudge the
4564 -- end-points up or down by small. Generally we prefer to fudge up,
4565 -- i.e. widen the bounds for non-model numbers so that the end points
4566 -- are included. However there are cases in which this cannot be
4567 -- done, and indeed cases in which we may need to narrow the bounds.
4568 -- The following circuit makes the decision.
4570 -- Note: our terminology here is that Incl_EP means that the bounds
4571 -- are widened by Small if necessary to include the end points, and
4572 -- Excl_EP means that the bounds are narrowed by Small to exclude the
4573 -- end-points if this reduces the size.
4575 -- Note that in the Incl case, all we care about is including the
4576 -- end-points. In the Excl case, we want to narrow the bounds as
4577 -- much as permitted by the RM, to give the smallest possible size.
4594 begin
4595 -- First step. Base types are required to be symmetrical. Right
4596 -- now, the base type range is a copy of the first subtype range.
4597 -- This will be corrected before we are done, but right away we
4598 -- need to deal with the case where both bounds are non-negative.
4599 -- In this case, we set the low bound to the negative of the high
4600 -- bound, to make sure that the size is computed to include the
4601 -- required sign. Note that we do not need to worry about the
4602 -- case of both bounds negative, because the sign will be dealt
4603 -- with anyway. Furthermore we can't just go making such a bound
4604 -- symmetrical, since in a twos-complement system, there is an
4605 -- extra negative value which could not be accommodated on the
4606 -- positive side.
4611 then
4616 -- Compute the fudged bounds. If the number is a model number,
4617 -- then we do nothing to include it, but we are allowed to backoff
4618 -- to the next adjacent model number when we exclude it. If it is
4619 -- not a model number then we straddle the two values with the
4620 -- model numbers on either side.
4626 else
4630 -- The low value excluding the end point is Small greater, but
4631 -- we do not do this exclusion if the low value is positive,
4632 -- since it can't help the size and could actually hurt by
4633 -- crossing the high bound.
4638 -- If the value went from negative to zero, then we have the
4639 -- case where Loval_Incl_EP is the model number just below
4640 -- zero, so we want to stick to the negative value for the
4641 -- base type to maintain the condition that the size will
4642 -- include signed values.
4646 then
4650 else
4654 -- Similar processing for upper bound and high value
4660 else
4666 else
4670 -- One further adjustment is needed. In the case of subtypes, we
4671 -- cannot go outside the range of the base type, or we get
4672 -- peculiarities, and the base type range is already set. This
4673 -- only applies to the Incl values, since clearly the Excl values
4674 -- are already as restricted as they are allowed to be.
4681 -- Get size including and excluding end points
4686 -- No need to exclude end-points if it does not reduce size
4696 -- Now we set the actual size to be used. We want to use the
4697 -- bounds fudged up to include the end-points but only if this
4698 -- can be done without violating a specifically given size
4699 -- size clause or causing an unacceptable increase in size.
4701 -- Case of size clause given
4705 -- Use the inclusive size only if it is consistent with
4706 -- the explicitly specified size.
4713 -- If the inclusive size is too large, we try excluding
4714 -- the end-points (will be caught later if does not work).
4716 else
4722 -- Case of size clause not given
4724 else
4725 -- If we have a base type whose corresponding first subtype
4726 -- has an explicit size that is large enough to include our
4727 -- end-points, then do so. There is no point in working hard
4728 -- to get a base type whose size is smaller than the specified
4729 -- size of the first subtype.
4735 then
4740 -- If excluding the end-points makes the size smaller and
4741 -- results in a size of 8,16,32,64, then we take the smaller
4742 -- size. For the 64 case, this is compulsory. For the other
4743 -- cases, it seems reasonable. We like to include end points
4744 -- if we can, but not at the expense of moving to the next
4745 -- natural boundary of size.
4748 and then
4753 then
4758 -- Otherwise we can definitely include the end points
4760 else
4766 -- One pathological case: normally we never fudge a low bound
4767 -- down, since it would seem to increase the size (if it has
4768 -- any effect), but for ranges containing single value, or no
4769 -- values, the high bound can be small too large. Consider:
4771 -- type t is delta 2.0**(-14)
4772 -- range 131072.0 .. 0;
4774 -- That lower bound is *just* outside the range of 32 bits, and
4775 -- does need fudging down in this case. Note that the bounds
4776 -- will always have crossed here, since the high bound will be
4777 -- fudged down if necessary, as in the case of:
4779 -- type t is delta 2.0**(-14)
4780 -- range 131072.0 .. 131072.0;
4782 -- So we detect the situation by looking for crossed bounds,
4783 -- and if the bounds are crossed, and the low bound is greater
4784 -- than zero, we will always back it off by small, since this
4785 -- is completely harmless.
4792 -- And of course, we need to do exactly the same parallel
4793 -- fudge for flat ranges in the negative region.
4806 -- For the decimal case, none of this fudging is required, since there
4807 -- are no end-point problems in the decimal case (the end-points are
4808 -- always included).
4810 else
4814 -- At this stage, the actual size has been calculated and the proper
4815 -- required bounds are stored in the low and high bounds.
4819 Error_Msg_N
4821 Typ);
4825 -- Check size against explicit given size
4831 Error_Msg_NE
4835 else
4839 -- Increase size to next natural boundary if no size clause given
4841 else
4848 else
4856 -- If we have a base type, then expand the bounds so that they extend to
4857 -- the full width of the allocated size in bits, to avoid junk range
4858 -- checks on intermediate computations.
4865 -- Final step is to reanalyze the bounds using the proper type
4866 -- and set the Corresponding_Integer_Value fields of the literals.
4872 -- Resolve with universal fixed if the base type, and the base type if
4873 -- it is a subtype. Note we can't resolve the base type with itself,
4874 -- that would be a reference before definition.
4878 else
4882 -- Set corresponding integer value for bound
4884 Set_Corresponding_Integer_Value
4887 -- Similar processing for high bound
4895 else
4899 Set_Corresponding_Integer_Value
4902 -- Set type of range to correspond to bounds
4906 -- Set Esize to calculated size if not set already
4912 -- Set RM_Size if not already set. If already set, check value
4914 declare
4917 begin
4922 Error_Msg_NE
4927 else
4933 ------------------
4934 -- Freeze_Itype --
4935 ------------------
4940 begin
4949 --------------------------
4950 -- Freeze_Static_Object --
4951 --------------------------
4956 -- Exception raised if the type of a static object cannot be made
4957 -- static. This happens if the type depends on non-global objects.
4960 -- Called to ensure that an expression used as part of a type definition
4961 -- is statically allocatable, which means that the expression type is
4962 -- statically allocatable, and the expression is either static, or a
4963 -- reference to a library level constant.
4966 -- Called to mark a type as static, checking that it is possible
4967 -- to set the type as static. If it is not possible, then the
4968 -- exception Cannot_Be_Static is raised.
4970 -----------------------------
4971 -- Ensure_Expression_Is_SA --
4972 -----------------------------
4977 begin
4989 then
4997 -----------------------
4998 -- Ensure_Type_Is_SA --
4999 -----------------------
5005 begin
5006 -- If type is library level, we are all set
5012 -- We are also OK if the type already marked as statically allocated,
5013 -- which means we processed it before.
5019 -- Mark type as statically allocated
5023 -- Check that it is safe to statically allocate this type
5041 declare
5045 begin
5058 else
5067 then
5086 else
5091 -- Start of processing for Freeze_Static_Object
5093 begin
5096 exception
5099 -- If the object that cannot be static is imported or exported, then
5100 -- issue an error message saying that this object cannot be imported
5101 -- or exported. If it has an address clause it is an overlay in the
5102 -- current partition and the static requirement is not relevant.
5103 -- Do not issue any error message when ignoring rep clauses.
5110 Error_Msg_N
5114 -- Otherwise must be exported, something is wrong if compiler
5115 -- is marking something as statically allocated which cannot be).
5118 Error_Msg_N
5123 -----------------------
5124 -- Freeze_Subprogram --
5125 -----------------------
5131 begin
5132 -- Subprogram may not have an address clause unless it is imported
5136 Error_Msg_N
5143 -- Reset the Pure indication on an imported subprogram unless an
5144 -- explicit Pure_Function pragma was present. We do this because
5145 -- otherwise it is an insidious error to call a non-pure function from
5146 -- pure unit and have calls mysteriously optimized away. What happens
5147 -- here is that the Import can bypass the normal check to ensure that
5148 -- pure units call only pure subprograms.
5153 then
5157 -- For non-foreign convention subprograms, this is where we create
5158 -- the extra formals (for accessibility level and constrained bit
5159 -- information). We delay this till the freeze point precisely so
5160 -- that we know the convention!
5166 -- If this is convention Ada and a Valued_Procedure, that's odd
5171 and then Warn_On_Export_Import
5172 then
5173 Error_Msg_N
5178 -- Case of foreign convention
5180 else
5183 -- For foreign conventions, warn about return of an
5184 -- unconstrained array.
5186 -- Note: we *do* allow a return by descriptor for the VMS case,
5187 -- though here there is probably more to be done ???
5192 -- If no return type, probably some other error, e.g. a
5193 -- missing full declaration, so ignore.
5198 -- If the return type is generic, we have emitted a warning
5199 -- earlier on, and there is nothing else to check here. Specific
5200 -- instantiations may lead to erroneous behavior.
5205 -- Display warning if returning unconstrained array
5210 -- Exclude cases where descriptor mechanism is set, since the
5211 -- VMS descriptor mechanisms allow such unconstrained returns.
5215 -- Check appropriate warning is enabled (should we check for
5216 -- Warnings (Off) on specific entities here, probably so???)
5218 and then Warn_On_Export_Import
5220 -- Exclude the VM case, since return of unconstrained arrays
5221 -- is properly handled in both the JVM and .NET cases.
5224 then
5225 Error_Msg_N
5232 -- If any of the formals for an exported foreign convention
5233 -- subprogram have defaults, then emit an appropriate warning since
5234 -- this is odd (default cannot be used from non-Ada code)
5239 if Warn_On_Export_Import
5241 then
5242 Error_Msg_N
5252 -- For VMS, descriptor mechanisms for parameters are allowed only for
5253 -- imported/exported subprograms. Moreover, the NCA descriptor is not
5254 -- allowed for parameters of exported subprograms.
5261 Error_Msg_N
5263 Error_Msg_N
5274 Error_Msg_N
5276 Error_Msg_N
5285 -- Pragma Inline_Always is disallowed for dispatching subprograms
5286 -- because the address of such subprograms is saved in the dispatch
5287 -- table to support dispatching calls, and dispatching calls cannot
5288 -- be inlined. This is consistent with the restriction against using
5289 -- 'Access or 'Address on an Inline_Always subprogram.
5293 then
5294 Error_Msg_N
5298 -- Because of the implicit representation of inherited predefined
5299 -- operators in the front-end, the overriding status of the operation
5300 -- may be affected when a full view of a type is analyzed, and this is
5301 -- not captured by the analysis of the corresponding type declaration.
5302 -- Therefore the correctness of a not-overriding indicator must be
5303 -- rechecked when the subprogram is frozen.
5307 then
5312 ----------------------
5313 -- Is_Fully_Defined --
5314 ----------------------
5317 begin
5326 then
5327 -- Verify that the record type has no components with private types
5328 -- without completion.
5330 declare
5333 begin
5346 -- For the designated type of an access to subprogram, all types in
5347 -- the profile must be fully defined.
5350 declare
5353 begin
5366 else
5372 ---------------------------------
5373 -- Process_Default_Expressions --
5374 ---------------------------------
5376 procedure Process_Default_Expressions
5379 is
5386 begin
5389 -- A subprogram instance and its associated anonymous subprogram share
5390 -- their signature. The default expression functions are defined in the
5391 -- wrapper packages for the anonymous subprogram, and should not be
5392 -- generated again for the instance.
5397 then
5405 -- We work with a copy of the default expression because we
5406 -- do not want to disturb the original, since this would mess
5407 -- up the conformance checking.
5411 -- The analysis of the expression may generate insert actions,
5412 -- which of course must not be executed. We wrap those actions
5413 -- in a procedure that is not called, and later on eliminated.
5414 -- The following cases have no side-effects, and are analyzed
5415 -- directly.
5426 and then
5428 then
5430 -- If there is no default function, we must still do a full
5431 -- analyze call on the default value, to ensure that all error
5432 -- checks are performed, e.g. those associated with static
5433 -- evaluation. Note: this branch will always be taken if the
5434 -- analyzer is turned off (but we still need the error checks).
5436 -- Note: the setting of parent here is to meet the requirement
5437 -- that we can only analyze the expression while attached to
5438 -- the tree. Really the requirement is that the parent chain
5439 -- be set, we don't actually need to be in the tree.
5444 -- Default expressions are resolved with their own type if the
5445 -- context is generic, to avoid anomalies with private types.
5449 else
5453 -- If that resolved expression will raise constraint error,
5454 -- then flag the default value as raising constraint error.
5455 -- This allows a proper error message on the calls.
5461 -- If the default is a parameterless call, we use the name of
5462 -- the called function directly, and there is no body to build.
5466 then
5469 -- Else construct and analyze the body of a wrapper procedure
5470 -- that contains an object declaration to hold the expression.
5471 -- Given that this is done only to complete the analysis, it
5472 -- simpler to build a procedure than a function which might
5473 -- involve secondary stack expansion.
5475 else
5478 Dbody :=
5480 Specification =>
5486 Defining_Identifier =>
5489 Object_Definition =>
5493 Handled_Statement_Sequence =>
5510 ----------------------------------------
5511 -- Set_Component_Alignment_If_Not_Set --
5512 ----------------------------------------
5515 begin
5516 -- Ignore if not base type, subtypes don't need anything
5522 -- Do not override existing representation
5533 else
5534 Set_Component_Alignment
5540 ------------------
5541 -- Undelay_Type --
5542 ------------------
5545 begin
5549 -- Since we don't want T to have a Freeze_Node, we don't want its
5550 -- Full_View or Corresponding_Record_Type to have one either.
5552 -- ??? Fundamentally, this whole handling is a kludge. What we really
5553 -- want is to be sure that for an Itype that's part of record R and is a
5554 -- subtype of type T, that it's frozen after the later of the freeze
5555 -- points of R and T. We have no way of doing that directly, so what we
5556 -- do is force most such Itypes to be frozen as part of freezing R via
5557 -- this procedure and only delay the ones that need to be delayed
5558 -- (mostly the designated types of access types that are defined as part
5559 -- of the record).
5565 then
5573 then
5578 ------------------
5579 -- Warn_Overlay --
5580 ------------------
5582 procedure Warn_Overlay
5586 is
5588 -- The object to which the address clause applies
5594 begin
5595 -- No warning if address clause overlay warnings are off
5601 -- No warning if there is an explicit initialization
5609 -- We only give the warning for non-imported entities of a type for
5610 -- which a non-null base init proc is defined, or for objects of access
5611 -- types with implicit null initialization, or when Normalize_Scalars
5612 -- applies and the type is scalar or a string type (the latter being
5613 -- tested for because predefined String types are initialized by inline
5614 -- code rather than by an init_proc). Note that we do not give the
5615 -- warning for Initialize_Scalars, since we suppressed initialization
5616 -- in this case.
5625 then
5628 then
5633 then
5640 then
5647 -- A function call (most likely to To_Address) is probably not an
5648 -- overlay, so skip warning. Ditto if the function call was inlined
5649 -- and transformed into an entity.
5657 -- If a pragma Import follows, we assume that it is for the current
5658 -- target of the address clause, and skip the warning.
5663 then
5669 Error_Msg_N
5671 Nam);
5672 else
5673 Error_Msg_N
5675 Nam);
5678 -- Add friendly warning if initialization comes from a packed array
5679 -- component.
5682 declare
5685 begin
5691 then
5695 then
5696 Error_Msg_NE
5701 else
5708 Error_Msg_N
5711 Nam);