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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 -- --
10 -- Copyright (C) 1992-2002, Free Software Foundation, Inc. --
11 -- --
12 -- GNAT is free software; you can redistribute it and/or modify it under --
13 -- terms of the GNU General Public License as published by the Free Soft- --
14 -- ware Foundation; either version 2, or (at your option) any later ver- --
15 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
16 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
17 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
18 -- for more details. You should have received a copy of the GNU General --
19 -- Public License distributed with GNAT; see file COPYING. If not, write --
20 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
21 -- MA 02111-1307, USA. --
22 -- --
23 -- GNAT was originally developed by the GNAT team at New York University. --
24 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
25 -- --
26 ------------------------------------------------------------------------------
65 -----------------------
66 -- Local Subprograms --
67 -----------------------
70 -- Typ is a type that is being frozen. If no size clause is given,
71 -- but a default Esize has been computed, then this default Esize is
72 -- adjusted up if necessary to be consistent with a given alignment,
73 -- but never to a value greater than Long_Long_Integer'Size. This
74 -- is used for all discrete types and for fixed-point types.
76 procedure Build_And_Analyze_Renamed_Body
80 -- Build body for a renaming declaration, insert in tree and analyze.
83 -- E is a base type. If E is tagged or has a component that is aliased
84 -- or tagged or contains something this is aliased or tagged, set
85 -- Strict_Alignment.
89 -- If E is a fixed-point or discrete type, then all the necessary work
90 -- to freeze it is completed except for possible setting of the flag
91 -- Is_Unsigned_Type, which is done by this procedure. The call has no
92 -- effect if the entity E is not a discrete or fixed-point type.
94 procedure Freeze_And_Append
98 -- Freezes Ent using Freeze_Entity, and appends the resulting list of
99 -- nodes to Result, modifying Result from No_List if necessary.
102 -- Freeze enumeration type. The Esize field is set as processing
103 -- proceeds (i.e. set by default when the type is declared and then
104 -- adjusted by rep clauses. What this procedure does is to make sure
105 -- that if a foreign convention is specified, and no specific size
106 -- is given, then the size must be at least Integer'Size.
109 -- If an object is frozen which has Is_Statically_Allocated set, then
110 -- all referenced types must also be marked with this flag. This routine
111 -- is in charge of meeting this requirement for the object entity E.
114 -- Perform freezing actions for a subprogram (create extra formals,
115 -- and set proper default mechanism values). Note that this routine
116 -- is not called for internal subprograms, for which neither of these
117 -- actions is needed (or desirable, we do not want for example to have
118 -- these extra formals present in initialization procedures, where they
119 -- would serve no purpose). In this call E is either a subprogram or
120 -- a subprogram type (i.e. an access to a subprogram).
123 -- true if T is not private, or has a full view.
125 procedure Process_Default_Expressions
128 -- This procedure is called for each subprogram to complete processing
129 -- of default expressions at the point where all types are known to be
130 -- frozen. The expressions must be analyzed in full, to make sure that
131 -- all error processing is done (they have only been pre-analyzed). If
132 -- the expression is not an entity or literal, its analysis may generate
133 -- code which must not be executed. In that case we build a function
134 -- body to hold that code. This wrapper function serves no other purpose
135 -- (it used to be called to evaluate the default, but now the default is
136 -- inlined at each point of call).
139 -- Typ is a record or array type that is being frozen. This routine
140 -- sets the default component alignment from the scope stack values
141 -- if the alignment is otherwise not specified.
144 -- As each entity is frozen, this routine is called to deal with the
145 -- setting of Debug_Info_Needed for the entity. This flag is set if
146 -- the entity comes from source, or if we are in Debug_Generated_Code
147 -- mode or if the -gnatdV debug flag is set. However, it never sets
148 -- the flag if Debug_Info_Off is set.
151 -- Sets the Debug_Info_Needed flag on entity T if not already set, and
152 -- also on any entities that are needed by T (for an object, the type
153 -- of the object is needed, and for a type, the subsidiary types are
154 -- needed -- see body for details). Never has any effect on T if the
155 -- Debug_Info_Off flag is set.
157 -------------------------------
158 -- Adjust_Esize_For_Alignment --
159 -------------------------------
164 begin
170 then
176 ------------------------------------
177 -- Build_And_Analyze_Renamed_Body --
178 ------------------------------------
180 procedure Build_And_Analyze_Renamed_Body
184 is
187 begin
194 ------------------------
195 -- Build_Renamed_Body --
196 ------------------------
198 function Build_Renamed_Body
201 return Node_Id
202 is
204 -- We use for the source location of the renamed body, the location
205 -- of the spec entity. It might seem more natural to use the location
206 -- of the renaming declaration itself, but that would be wrong, since
207 -- then the body we create would look as though it was created far
208 -- too late, and this could cause problems with elaboration order
209 -- analysis, particularly in connection with instantiations.
223 begin
224 -- Determine the entity being renamed, which is the target of the
225 -- call statement. If the name is an explicit dereference, this is
226 -- a renaming of a subprogram type rather than a subprogram. The
227 -- name itself is fully analyzed.
239 else
246 else
252 -- If the renamed entity is a predefined operator, retain full
253 -- name to ensure its visibility.
257 then
259 else
263 else
266 -- The original name may have been overloaded, but
267 -- is fully resolved now.
272 -- For simple renamings, subsequent calls can be expanded directly
273 -- as called to the renamed entity. The body must be generated in
274 -- any case for calls they may appear elsewhere.
279 then
283 -- The body generated for this renaming is an internal artifact, and
284 -- does not constitute a freeze point for the called entity.
299 -- If the renamed entity is an entry, inherit its profile. For
300 -- other renamings as bodies, both profiles must be subtype
301 -- conformant, so it is not necessary to replace the profile given
302 -- in the declaration. However, default values that are aggregates
303 -- are rewritten when partially analyzed, so we recover the original
304 -- aggregate to insure that subsequent conformity checking works.
305 -- Similarly, if the default expression was constant-folded, recover
306 -- the original expression.
318 N_Access_Definition
319 then
327 then
338 -- If the renamed entity is a function, the generated body contains a
339 -- return statement. Otherwise, build a procedure call. If the entity is
340 -- an entry, subsequent analysis of the call will transform it into the
341 -- proper entry or protected operation call. If the renamed entity is
342 -- a character literal, return it directly.
348 then
349 Call_Node :=
351 Expression =>
357 Call_Node :=
362 Call_Node :=
366 else
367 Call_Node :=
373 -- Create entities for subprogram body and formals.
387 Body_Node :=
391 Handled_Statement_Sequence =>
401 -- Link the body to the entity whose declaration it completes. If
402 -- the body is analyzed when the renamed entity is frozen, it may be
403 -- necessary to restore the proper scope (see package Exp_Ch13).
407 then
409 else
416 -----------------------------
417 -- Check_Compile_Time_Size --
418 -----------------------------
423 -- Sets the compile time known size (32 bits or less) in the Esize
424 -- field, checking for a size clause that was given which attempts
425 -- to give a smaller size.
428 -- Recursive function that does all the work
431 -- If T is a constrained subtype, its size is not known if any of its
432 -- discriminant constraints is not static and it is not a null record.
433 -- The test is conservative and doesn't check that the components are
434 -- in fact constrained by non-static discriminant values. Could be made
435 -- more precise ???
437 --------------------
438 -- Set_Small_Size --
439 --------------------
442 begin
449 Error_Msg_NE
457 -- Set sizes if not set already
459 else
470 ----------------
471 -- Size_Known --
472 ----------------
481 begin
487 then
499 -- Don't do any recursion on type with error posted, since
500 -- we may have a malformed type that leads us into a loop
509 -- Check for all indexes static, and also compute possible
510 -- size (in case it is less than 32 and may be packable).
512 declare
516 begin
526 else
534 then
537 else
542 else
560 then
561 -- Don't do any recursion on type with error posted, since
562 -- we may have a malformed type that leads us into a loop
566 else
578 -- Don't do any recursion on type with error posted, since
579 -- we may have a malformed type that leads us into a loop
584 else
585 declare
589 begin
590 -- Test for variant part present
596 N_Record_Definition
600 then
601 -- If variant part is present, and type is unconstrained,
602 -- then we must have defaulted discriminants, or a size
603 -- clause must be present for the type, or else the size
604 -- is definitely not known at compile time.
607 and then
608 No (Discriminant_Default_Value
611 then
613 else
614 -- We do not know the packed size, it is too much
615 -- trouble to figure it out.
625 or else
627 then
639 -- If RM_Size is known and static, then we can
640 -- keep accumulating the packed size.
644 -- A little glitch, to be removed sometime ???
645 -- gigi does not understand zero sizes yet.
651 Packed_Size :=
654 -- If we have a field whose RM_Size is not known
655 -- then we can't figure out the packed size here.
657 else
674 else
679 -------------------------------------
680 -- Static_Discriminated_Components --
681 -------------------------------------
683 function Static_Discriminated_Components
686 is
689 begin
693 then
708 -- Start of processing for Check_Compile_Time_Size
710 begin
714 -----------------------------
715 -- Check_Debug_Info_Needed --
716 -----------------------------
719 begin
724 or else Debug_Generated_Code
725 or else Debug_Flag_VV
726 then
731 ----------------------------
732 -- Check_Strict_Alignment --
733 ----------------------------
738 begin
757 then
767 -------------------------
768 -- Check_Unsigned_Type --
769 -------------------------
776 begin
781 -- Do not attempt to analyze case where range was in error
787 -- The situation that is non trivial is something like
789 -- subtype x1 is integer range -10 .. +10;
790 -- subtype x2 is x1 range 0 .. V1;
791 -- subtype x3 is x2 range V2 .. V3;
792 -- subtype x4 is x3 range V4 .. V5;
794 -- where Vn are variables. Here the base type is signed, but we still
795 -- know that x4 is unsigned because of the lower bound of x2.
797 -- The only way to deal with this is to look up the ancestor chain
800 loop
815 else
818 -- If no ancestor had a static lower bound, go to base type
822 -- Note: the reason we still check for a compile time known
823 -- value for the base type is that at least in the case of
824 -- generic formals, we can have bounds that fail this test,
825 -- and there may be other cases in error situations.
837 then
848 ----------------
849 -- Freeze_All --
850 ----------------
852 -- Note: the easy coding for this procedure would be to just build a
853 -- single list of freeze nodes and then insert them and analyze them
854 -- all at once. This won't work, because the analysis of earlier freeze
855 -- nodes may recursively freeze types which would otherwise appear later
856 -- on in the freeze list. So we must analyze and expand the freeze nodes
857 -- as they are generated.
865 -- This is the internal recursive routine that does freezing of
866 -- entities (but NOT the analysis of default expressions, which
867 -- should not be recursive, we don't want to analyze those till
868 -- we are sure that ALL the types are frozen).
870 procedure Freeze_All_Ent
873 is
879 -- If freeze nodes are present, insert and analyze, and reset
880 -- cursor for next insertion.
883 begin
890 else
896 begin
900 -- If the entity is an inner package which is not a package
901 -- renaming, then its entities must be frozen at this point.
902 -- Note that such entities do NOT get frozen at the end of
903 -- the nested package itself (only library packages freeze).
905 -- Same is true for task declarations, where anonymous records
906 -- created for entry parameters must be frozen.
912 then
922 and then
924 or else
926 then
929 End_Scope;
931 -- For a derived tagged type, we must ensure that all the
932 -- primitive operations of the parent have been frozen, so
933 -- that their addresses will be in the parent's dispatch table
934 -- at the point it is inherited.
940 then
941 declare
947 begin
955 then
957 Process_Flist;
967 Process_Flist;
974 -- Start of processing for Freeze_All
976 begin
979 -- Now that all types are frozen, we can deal with default expressions
980 -- that require us to build a default expression functions. This is the
981 -- point at which such functions are constructed (after all types that
982 -- might be used in such expressions have been frozen).
983 -- We also add finalization chains to access types whose designated
984 -- types are controlled. This is normally done when freezing the type,
985 -- but this misses recursive type definitions where the later members
986 -- of the recursion introduce controlled components (e.g. 5624-001).
988 -- Loop through entities
1007 and then
1009 = N_Subprogram_Renaming_Declaration
1010 then
1011 Build_And_Analyze_Renamed_Body
1017 and then
1019 or else
1021 then
1022 declare
1025 begin
1032 then
1045 then
1054 -----------------------
1055 -- Freeze_And_Append --
1056 -----------------------
1058 procedure Freeze_And_Append
1062 is
1065 begin
1069 else
1075 -------------------
1076 -- Freeze_Before --
1077 -------------------
1083 begin
1093 -------------------
1094 -- Freeze_Entity --
1095 -------------------
1106 -- Check that an Access or Unchecked_Access attribute with
1107 -- a prefix which is the current instance type can only be
1108 -- applied when the type is limited.
1111 -- If Loc is a freeze_entity that appears after the last declaration
1112 -- in the scope, inhibit error messages on late completion.
1115 -- Freeze each component, handle some representation clauses, and
1116 -- freeze primitive operations if this is a tagged type.
1118 ----------------------------
1119 -- After_Last_Declaration --
1120 ----------------------------
1125 begin
1132 else
1136 else
1141 ----------------------------
1142 -- Check_Current_Instance --
1143 ----------------------------
1148 -- Process routine to apply check to given node.
1151 begin
1155 or else
1160 then
1161 Error_Msg_N
1164 else
1174 -- Start of processing for Check_Current_Instance
1176 begin
1180 ------------------------
1181 -- Freeze_Record_Type --
1182 ------------------------
1190 -- Set True if we find at least one component with no component
1191 -- clause (used to warn about useless Pack pragmas).
1194 -- Set True if we find at least one component with a component
1195 -- clause (used to warn about useless Bit_Order pragmas).
1197 begin
1198 -- Freeze components and embedded subtypes
1208 -- If the component is an access type with an allocator
1209 -- as default value, the designated type will be frozen
1210 -- by the corresponding expression in init_proc. In order
1211 -- to place the freeze node for the designated type before
1212 -- that for the current record type, freeze it now.
1214 -- Same process if the component is an array of access types,
1215 -- initialized with an aggregate. If the designated type is
1216 -- private, it cannot contain allocators, and it is premature
1217 -- to freeze the type, so we check for this as well.
1223 then
1224 declare
1227 begin
1228 -- If component is pointer to a classwide type, freeze
1229 -- the specific type in the expression being allocated.
1230 -- The expression may be a subtype indication, in which
1231 -- case freeze the subtype mark.
1236 Freeze_And_Append
1238 elsif
1240 then
1241 Freeze_And_Append
1245 else
1246 Freeze_And_Append
1251 -- If this is a constrained subtype of an already frozen type,
1252 -- make the subtype frozen as well. It might otherwise be frozen
1253 -- in the wrong scope, and a freeze node on subtype has no effect.
1259 then
1268 and then Is_Fully_Defined
1270 then
1271 Freeze_And_Append
1272 (Designated_Type
1276 -- Processing for real components (exclude anonymous subtypes)
1280 then
1281 -- Check for error of component clause given for variable
1282 -- sized type. We have to delay this test till this point,
1283 -- since the component type has to be frozen for us to know
1284 -- if it is variable length. We omit this test in a generic
1285 -- context, it will be applied at instantiation time.
1287 declare
1290 begin
1297 elsif not Size_Known_At_Compile_Time
1299 then
1300 Error_Msg_N
1305 else
1310 -- If component clause is present, then deal with the
1311 -- non-default bit order case. We cannot do this before
1312 -- the freeze point, because there is no required order
1313 -- for the component clause and the bit_order clause.
1315 -- We only do this processing for the base type, and in
1316 -- fact that's important, since otherwise if there are
1317 -- record subtypes, we could reverse the bits once for
1318 -- each subtype, which would be incorrect.
1323 then
1324 declare
1337 begin
1338 -- Cases where field goes over storage unit boundary
1342 -- Allow multi-byte field but generate warning
1346 then
1347 Error_Msg_N
1352 Error_Msg_N
1355 else
1356 Error_Msg_N
1361 -- Do not allow non-contiguous field
1363 else
1364 Error_Msg_N
1367 Error_Msg_N
1372 -- Case where field fits in one storage unit
1374 else
1375 -- Give warning if suspicious component clause
1378 Error_Msg_N
1381 Error_Msg_Uint_1 :=
1383 Error_Msg_N
1388 -- Here is where we fix up the Component_Bit_Offset
1389 -- value to account for the reverse bit order.
1390 -- Some examples of what needs to be done are:
1392 -- First_Bit .. Last_Bit Component_Bit_Offset
1393 -- old new old new
1395 -- 0 .. 0 7 .. 7 0 7
1396 -- 0 .. 1 6 .. 7 0 6
1397 -- 0 .. 2 5 .. 7 0 5
1398 -- 0 .. 7 0 .. 7 0 4
1400 -- 1 .. 1 6 .. 6 1 6
1401 -- 1 .. 4 3 .. 6 1 3
1402 -- 4 .. 7 0 .. 3 4 0
1404 -- The general rule is that the first bit is
1405 -- is obtained by subtracting the old ending bit
1406 -- from storage_unit - 1.
1423 -- Check for useless pragma Bit_Order
1431 -- Check for useless pragma Pack when all components placed
1434 and then not Unplaced_Component
1435 and then Warn_On_Redundant_Constructs
1436 then
1437 Error_Msg_N
1443 -- If this is the record corresponding to a remote type,
1444 -- freeze the remote type here since that is what we are
1445 -- semantically freeing. This prevents having the freeze node
1446 -- for that type in an inner scope.
1448 -- Also, Check for controlled components and unchecked unions.
1449 -- Finally, enforce the restriction that access attributes with
1450 -- a current instance prefix can only apply to limited types.
1455 Freeze_And_Append
1466 and then Present
1468 and then Has_Controlled_Component
1470 then
1481 then
1482 -- Scan component declaration for likely misuses of
1483 -- current instance, either in a constraint or in a
1484 -- default expression.
1495 -- For first subtypes, check if there are any fixed-point
1496 -- fields with component clauses, where we must check the size.
1497 -- This is not done till the freeze point, since for fixed-point
1498 -- types, we do not know the size until the type is frozen.
1506 then
1507 Check_Size
1511 Junk);
1519 -- Start of processing for Freeze_Entity
1521 begin
1522 -- Do not freeze if already frozen since we only need one freeze node.
1527 -- It is improper to freeze an external entity within a generic
1528 -- because its freeze node will appear in a non-valid context.
1529 -- ??? We should probably freeze the entity at that point and insert
1530 -- the freeze node in a proper place but this proper place is not
1531 -- easy to find, and the proper scope is not easy to restore. For
1532 -- now, just wait to get out of the generic to freeze ???
1537 -- Do not freeze a global entity within an inner scope created during
1538 -- expansion. A call to subprogram E within some internal procedure
1539 -- (a stream attribute for example) might require freezing E, but the
1540 -- freeze node must appear in the same declarative part as E itself.
1541 -- The two-pass elaboration mechanism in gigi guarantees that E will
1542 -- be frozen before the inner call is elaborated. We exclude constants
1543 -- from this test, because deferred constants may be frozen early, and
1544 -- must be diagnosed (see e.g. 1522-005). If the enclosing subprogram
1545 -- comes from source, or is a generic instance, then the freeze point
1546 -- is the one mandated by the language. and we freze the entity.
1551 then
1552 declare
1555 begin
1560 then
1562 else
1572 -- Here to freeze the entity
1577 -- Case of entity being frozen is other than a type
1581 -- If entity is exported or imported and does not have an external
1582 -- name, now is the time to provide the appropriate default name.
1583 -- Skip this if the entity is stubbed, since we don't need a name
1584 -- for any stubbed routine.
1589 then
1590 Set_Encoded_Interface_Name
1594 -- For a subprogram, freeze all parameter types and also the return
1595 -- type (RM 13.14(13)). However skip this for internal subprograms.
1596 -- This is also the point where any extra formal parameters are
1597 -- created since we now know whether the subprogram will use
1598 -- a foreign convention.
1604 declare
1608 -- Determines if given type entity is a fat pointer type
1609 -- used as an argument type or return type to a subprogram
1610 -- with C or C++ convention set.
1612 --------------------------
1613 -- Is_Fat_C_Access_Type --
1614 --------------------------
1617 begin
1619 or else
1625 begin
1626 -- Loop through formals
1640 then
1641 -- If the type of a formal is incomplete, subprogram
1642 -- is being frozen prematurely. Within an instance
1643 -- (but not within a wrapper package) this is an
1644 -- an artifact of our need to regard the end of an
1645 -- instantiation as a freeze point. Otherwise it is
1646 -- a definite error.
1647 -- and then not Is_Wrapper_Package (Current_Scope) ???
1655 Error_Msg
1657 Loc);
1661 -- Check bad use of fat C pointer
1665 Error_Msg_N
1667 Formal);
1671 -- Check for unconstrained array in exported foreign
1672 -- convention case.
1678 then
1680 Error_Msg_N
1682 Formal);
1683 Error_Msg_N
1685 Formal);
1692 -- Check return type
1698 Error_Msg_N
1700 E);
1706 then
1707 Error_Msg_N
1715 -- Must freeze its parent first if it is a derived subprogram
1721 -- If the return type requires a transient scope, and we are on
1722 -- a target allowing functions to return with a depressed stack
1723 -- pointer, then we mark the function as requiring this treatment.
1726 and then Functions_Return_By_DSP_On_Target
1728 then
1736 -- Here for other than a subprogram or type
1738 else
1739 -- If entity has a type, and it is not a generic unit, then
1740 -- freeze it first (RM 13.14(10))
1744 then
1748 -- For object created by object declaration, perform required
1749 -- categorization (preelaborate and pure) checks. Defer these
1750 -- checks to freeze time since pragma Import inhibits default
1751 -- initialization and thus pragma Import affects these checks.
1757 -- Check that a constant which has a pragma Volatile[_Components]
1758 -- or Atomic[_Components] also has a pragma Import (RM C.6(13))
1760 -- Note: Atomic[_Components] also sets Volatile[_Components]
1765 then
1766 -- Make sure we actually have a pragma, and have not merely
1767 -- inherited the indication from elsewhere (e.g. an address
1768 -- clause, which is not good enough in RM terms!)
1774 then
1775 Error_Msg_N
1777 E);
1781 -- Static objects require special handling
1785 then
1789 -- Remaining step is to layout objects
1792 or else
1794 or else
1796 or else
1798 then
1803 -- Case of a type or subtype being frozen
1805 else
1806 -- The type may be defined in a generic unit. This can occur when
1807 -- freezing a generic function that returns the type (which is
1808 -- defined in a parent unit). It is clearly meaningless to freeze
1809 -- this type. However, if it is a subtype, its size may be determi-
1810 -- nable and used in subsequent checks, so might as well try to
1811 -- compute it.
1815 then
1820 -- Deal with special cases of freezing for subtype
1824 -- If ancestor subtype present, freeze that first.
1825 -- Note that this will also get the base type frozen.
1832 -- Otherwise freeze the base type of the entity before
1833 -- freezing the entity itself, (RM 13.14(14)).
1839 -- For a derived type, freeze its parent type first (RM 13.14(14))
1846 -- For array type, freeze index types and component type first
1847 -- before freezing the array (RM 13.14(14)).
1850 declare
1854 -- Set true if any of the index types is an enumeration
1855 -- type with a non-standard representation.
1857 begin
1866 then
1873 -- Processing that is done only for base types
1877 -- Propagate flags for component type
1881 then
1889 -- If packing was requested or if the component size was set
1890 -- explicitly, then see if bit packing is required. This
1891 -- processing is only done for base types, since all the
1892 -- representation aspects involved are type-related. This
1893 -- is not just an optimization, if we start processing the
1894 -- subtypes, they intefere with the settings on the base
1895 -- type (this is because Is_Packed has a slightly different
1896 -- meaning before and after freezing).
1898 declare
1902 begin
1906 then
1915 else
1918 -- We can set the component size if it is less than
1919 -- 16, rounding it up to the next storage unit size.
1925 else
1929 -- Set component size up to match alignment if
1930 -- it would otherwise be less than the alignment.
1931 -- This deals with cases of types whose alignment
1932 -- exceeds their sizes (padded types).
1935 declare
1938 begin
1949 -- We set the component size for all cases 1-64
1953 -- Actual packing is not needed for 8,16,32,64
1954 -- Also not needed for 24 if alignment is 1
1961 then
1962 -- Here the array was requested to be packed, but
1963 -- the packing request had no effect, so Is_Packed
1964 -- is reset.
1966 -- Note: semantically this means that we lose
1967 -- track of the fact that a derived type inherited
1968 -- a pack pragma that was non-effective, but that
1969 -- seems fine.
1971 -- We regard a Pack pragma as a request to set a
1972 -- representation characteristic, and this request
1973 -- may be ignored.
1977 -- In all other cases, packing is indeed needed
1979 else
1987 -- Processing that is done only for subtypes
1989 else
1990 -- Acquire alignment from base type
1997 -- Check one common case of a size given where the array
1998 -- needs to be packed, but was not so the size cannot be
1999 -- honored. This would of course be caught by the backend,
2000 -- and indeed we don't catch all cases. The point is that
2001 -- we can give a better error message in those cases that
2002 -- we do catch with the circuitry here.
2010 then
2011 declare
2015 begin
2022 then
2023 declare
2029 begin
2032 then
2033 Error_Msg_NE
2036 Error_Msg_N
2045 -- If any of the index types was an enumeration type with
2046 -- a non-standard rep clause, then we indicate that the
2047 -- array type is always packed (even if it is not bit packed).
2057 -- If the array is packed, we must create the packed array
2058 -- type to be used to actually implement the type. This is
2059 -- only needed for real array types (not for string literal
2060 -- types, since they are present only for the front end).
2064 then
2068 -- Size information of packed array type is copied to the
2069 -- array type, since this is really the representation.
2075 -- For a class wide type, the corresponding specific type is
2076 -- frozen as well (RM 13.14(14))
2081 -- If the Class_Wide_Type is an Itype (when type is the anonymous
2082 -- parent of a derived type) and it is a library-level entity,
2083 -- generate an itype reference for it. Otherwise, its first
2084 -- explicit reference may be in an inner scope, which will be
2085 -- rejected by the back-end.
2089 then
2091 declare
2094 begin
2098 else
2104 -- For record (sub)type, freeze all the component types (RM
2105 -- 13.14(14). We test for E_Record_(sub)Type here, rather than
2106 -- using Is_Record_Type, because we don't want to attempt the
2107 -- freeze for the case of a private type with record extension
2108 -- (we will do that later when the full type is frozen).
2112 then
2115 -- For a concurrent type, freeze corresponding record type. This
2116 -- does not correpond to any specific rule in the RM, but the
2117 -- record type is essentially part of the concurrent type.
2118 -- Freeze as well all local entities. This includes record types
2119 -- created for entry parameter blocks, and whatever local entities
2120 -- may appear in the private part.
2124 Freeze_And_Append
2141 -- Private types are required to point to the same freeze node
2142 -- as their corresponding full views. The freeze node itself
2143 -- has to point to the partial view of the entity (because
2144 -- from the partial view, we can retrieve the full view, but
2145 -- not the reverse). However, in order to freeze correctly,
2146 -- we need to freeze the full view. If we are freezing at the
2147 -- end of a scope (or within the scope of the private type),
2148 -- the partial and full views will have been swapped, the
2149 -- full view appears first in the entity chain and the swapping
2150 -- mechanism enusres that the pointers are properly set (on
2151 -- scope exit).
2153 -- If we encounter the partial view before the full view
2154 -- (e.g. when freezing from another scope), we freeze the
2155 -- full view, and then set the pointers appropriately since
2156 -- we cannot rely on swapping to fix things up (subtypes in an
2157 -- outer scope might not get swapped).
2161 then
2162 -- Case of full view present
2166 -- If full view has already been frozen, then no
2167 -- further processing is required
2175 -- Otherwise freeze full view and patch the pointers
2177 else
2180 then
2181 Freeze_And_Append
2193 else
2194 -- {Incomplete,Private}_Subtypes
2195 -- with Full_Views constrained by discriminants
2205 -- AI-117 requires that the convention of a partial view
2206 -- be the same as the convention of the full view. Note
2207 -- that this is a recognized breach of privacy, but it's
2208 -- essential for logical consistency of representation,
2209 -- and the lack of a rule in RM95 was an oversight.
2216 -- Size information is copied from the full view to the
2217 -- incomplete or private view for consistency
2219 -- We skip this is the full view is not a type. This is
2220 -- very strange of course, and can only happen as a result
2221 -- of certain illegalities, such as a premature attempt to
2222 -- derive from an incomplete type.
2231 -- Case of no full view present. If entity is derived or subtype,
2232 -- it is safe to freeze, correctness depends on the frozen status
2233 -- of parent. Otherwise it is either premature usage, or a Taft
2234 -- amendment type, so diagnosis is at the point of use and the
2235 -- type might be frozen later.
2239 then
2242 else
2247 -- For access subprogram, freeze types of all formals, the return
2248 -- type was already frozen, since it is the Etype of the function.
2257 -- If the return type requires a transient scope, and we are on
2258 -- a target allowing functions to return with a depressed stack
2259 -- pointer, then we mark the function as requiring this treatment.
2261 if Functions_Return_By_DSP_On_Target
2263 then
2269 -- For access to a protected subprogram, freeze the equivalent
2270 -- type (however this is not set if we are not generating code)
2271 -- or if this is an anonymous type used just for resolution).
2276 then
2280 -- Generic types are never seen by the back-end, and are also not
2281 -- processed by the expander (since the expander is turned off for
2282 -- generic processing), so we never need freeze nodes for them.
2288 -- Some special processing for non-generic types to complete
2289 -- representation details not known till the freeze point.
2302 then
2306 -- If the current entity is an array or record subtype and has
2307 -- discriminants used to constrain it, it must not freeze, because
2308 -- Freeze_Entity nodes force Gigi to process the frozen type.
2314 declare
2319 begin
2327 then
2344 then
2345 declare
2349 begin
2357 then
2370 -- AI-117 requires that all new primitives of a tagged type
2371 -- must inherit the convention of the full view of the type.
2372 -- Inherited and overriding operations are defined to inherit
2373 -- the convention of their parent or overridden subprogram
2374 -- (also specified in AI-117), and that will have occurred
2375 -- earlier (in Derive_Subprogram and New_Overloaded_Entity).
2376 -- Here we set the convention of primitives that are still
2377 -- convention Ada, which will ensure that any new primitives
2378 -- inherit the type's convention. Class-wide types can have
2379 -- a foreign convention inherited from their specific type,
2380 -- but are excluded from this since they don't have any
2381 -- associated primitives.
2386 then
2387 declare
2391 begin
2404 -- Generate primitive operation references for a tagged type
2408 then
2409 declare
2414 begin
2419 -- If the operation is derived, get the original for
2420 -- cross-reference purposes (it is the original for
2421 -- which we want the xref, and for which the comes
2422 -- from source test needs to be performed).
2432 -- If we get an exception, then something peculiar has happened
2433 -- probably as a result of a previous error. Since this is only
2434 -- for non-critical cross-references, ignore the error.
2436 exception
2441 -- Now that all types from which E may depend are frozen, see
2442 -- if the size is known at compile time, if it must be unsigned,
2443 -- or if strict alignent is required
2452 -- Do not allow a size clause for a type which does not have a size
2453 -- that is known at compile time
2457 then
2458 -- Supress this message if errors posted on E, even if we are
2459 -- in all errors mode, since this is often a junk message
2462 Error_Msg_N
2468 -- Remaining process is to set/verify the representation information,
2469 -- in particular the size and alignment values. This processing is
2470 -- not required for generic types, since generic types do not play
2471 -- any part in code generation, and so the size and alignment values
2472 -- for suhc types are irrelevant.
2477 -- Otherwise we call the layout procedure
2479 else
2483 -- End of freeze processing for type entities
2486 -- Here is where we logically freeze the current entity. If it has a
2487 -- freeze node, then this is the point at which the freeze node is
2488 -- linked into the result list.
2492 -- If a freeze node is already allocated, use it, otherwise allocate
2493 -- a new one. The preallocation happens in the case of anonymous base
2494 -- types, where we preallocate so that we can set First_Subtype_Link.
2495 -- Note that we reset the Sloc to the current freeze location.
2501 else
2513 else
2519 -- When a type is frozen, the first subtype of the type is frozen as
2520 -- well (RM 13.14(15)). This has to be done after freezing the type,
2521 -- since obviously the first subtype depends on its own base type.
2526 -- If we just froze a tagged non-class wide record, then freeze the
2527 -- corresponding class-wide type. This must be done after the tagged
2528 -- type itself is frozen, because the class-wide type refers to the
2529 -- tagged type which generates the class.
2534 then
2541 -- Special handling for subprograms
2545 -- If subprogram has address clause then reset Is_Public flag, since
2546 -- we do not want the backend to generate external references.
2550 then
2553 -- If no address clause and not intrinsic, then for imported
2554 -- subprogram in main unit, generate descriptor if we are in
2555 -- Propagate_Exceptions mode.
2557 elsif Propagate_Exceptions
2561 then
2566 Generate_Subprogram_Descriptor_For_Imported_Subprogram
2575 -----------------------------
2576 -- Freeze_Enumeration_Type --
2577 -----------------------------
2580 begin
2584 then
2587 else
2592 -----------------------
2593 -- Freeze_Expression --
2594 -----------------------
2605 -- This flag is set true if the entity must be frozen outside the
2606 -- current subprogram. This happens in the case of expander generated
2607 -- subprograms (_Init_Proc, _Input, _Output, _Read, _Write) which do
2608 -- not freeze all entities like other bodies, but which nevertheless
2609 -- may reference entities that have to be frozen before the body and
2610 -- obviously cannot be frozen inside the body.
2613 -- Given an N_Handled_Sequence_Of_Statements node N, determines whether
2614 -- it is the handled statement sequence of an expander generated
2615 -- subprogram (init proc, or stream subprogram). If so, it returns
2616 -- True, otherwise False.
2621 begin
2624 else
2631 else
2640 then
2642 else
2649 -- Start of processing for Freeze_Expression
2651 begin
2652 -- Immediate return if freezing is inhibited. This flag is set by
2653 -- the analyzer to stop freezing on generated expressions that would
2654 -- cause freezing if they were in the source program, but which are
2655 -- not supposed to freeze, since they are created.
2661 -- If expression is non-static, then it does not freeze in a default
2662 -- expression, see section "Handling of Default Expressions" in the
2663 -- spec of package Sem for further details. Note that we have to
2664 -- make sure that we actually have a real expression (if we have
2665 -- a subtype indication, we can't test Is_Static_Expression!)
2667 if In_Def_Exp
2670 then
2674 -- Freeze type of expression if not frozen already
2678 then
2680 else
2684 -- For entity name, freeze entity if not frozen already. A special
2685 -- exception occurs for an identifier that did not come from source.
2686 -- We don't let such identifiers freeze a non-internal entity, i.e.
2687 -- an entity that did come from source, since such an identifier was
2688 -- generated by the expander, and cannot have any semantic effect on
2689 -- the freezing semantics. For example, this stops the parameter of
2690 -- an initialization procedure from freezing the variable.
2697 then
2700 else
2704 -- For an allocator freeze designated type if not frozen already.
2706 -- For an aggregate whose component type is an access type, freeze
2707 -- the designated type now, so that its freeze does not appear within
2708 -- the loop that might be created in the expansion of the aggregate.
2709 -- If the designated type is a private type without full view, the
2710 -- expression cannot contain an allocator, so the type is not frozen.
2721 then
2725 when N_Selected_Component |
2726 N_Indexed_Component |
2727 N_Slice =>
2741 then
2745 -- All done if nothing needs freezing
2750 then
2754 -- Loop for looking at the right place to insert the freeze nodes
2755 -- exiting from the loop when it is appropriate to insert the freeze
2756 -- node before the current node P.
2758 -- Also checks some special exceptions to the freezing rules. These
2759 -- cases result in a direct return, bypassing the freeze action.
2762 loop
2765 -- If we don't have a parent, then we are not in a well-formed
2766 -- tree. This is an unusual case, but there are some legitimate
2767 -- situations in which this occurs, notably when the expressions
2768 -- in the range of a type declaration are resolved. We simply
2769 -- ignore the freeze request in this case. Is this right ???
2775 -- See if we have got to an appropriate point in the tree
2779 -- A special test for the exception of (RM 13.14(8)) for the
2780 -- case of per-object expressions (RM 3.8(18)) occurring in a
2781 -- component definition or a discrete subtype definition. Note
2782 -- that we test for a component declaration which includes both
2783 -- cases we are interested in, and furthermore the tree does not
2784 -- have explicit nodes for either of these two constructs.
2788 -- The case we want to test for here is an identifier that is
2789 -- a per-object expression, this is either a discriminant that
2790 -- appears in a context other than the component declaration
2791 -- or it is a reference to the type of the enclosing construct.
2793 -- For either of these cases, we skip the freezing
2795 if not In_Default_Expression
2798 then
2799 -- We recognize the discriminant case by just looking for
2800 -- a reference to a discriminant. It can only be one for
2801 -- the enclosing construct. Skip freezing in this case.
2806 -- For the case of a reference to the enclosing record,
2807 -- (or task or protected type), we look for a type that
2808 -- matches the current scope.
2815 -- If we have an enumeration literal that appears as the
2816 -- choice in the aggregate of an enumeration representation
2817 -- clause, then freezing does not occur (RM 13.14(9)).
2821 -- The case we are looking for is an enumeration literal
2825 then
2826 -- If enumeration literal appears directly as the choice,
2827 -- do not freeze (this is the normal non-overloade case)
2831 then
2834 -- If enumeration literal appears as the name of a
2835 -- function which is the choice, then also do not freeze.
2836 -- This happens in the overloaded literal case, where the
2837 -- enumeration literal is temporarily changed to a function
2838 -- call for overloading analysis purposes.
2841 and then
2843 and then
2845 then
2850 -- Normally if the parent is a handled sequence of statements,
2851 -- then the current node must be a statement, and that is an
2852 -- appropriate place to insert a freeze node.
2856 -- An exception occurs when the sequence of statements is
2857 -- for an expander generated body that did not do the usual
2858 -- freeze all operation. In this case we usually want to
2859 -- freeze outside this body, not inside it, and we skip
2860 -- past the subprogram body that we are inside.
2864 -- However, we *do* want to freeze at this point if we have
2865 -- an entity to freeze, and that entity is declared *inside*
2866 -- the body of the expander generated procedure. This case
2867 -- is recognized by the scope of the type, which is either
2868 -- the spec for some enclosing body, or (in the case of
2869 -- init_procs, for which there are no separate specs) the
2870 -- current scope.
2872 declare
2876 begin
2881 or else
2883 then
2889 then
2895 -- If not that exception to the exception, then this is
2896 -- where we delay the freeze till outside the body.
2901 -- Here if normal case where we are in handled statement
2902 -- sequence and want to do the insertion right there.
2904 else
2908 -- If parent is a body or a spec or a block, then the current
2909 -- node is a statement or declaration and we can insert the
2910 -- freeze node before it.
2912 when N_Package_Specification |
2913 N_Package_Body |
2914 N_Subprogram_Body |
2915 N_Task_Body |
2916 N_Protected_Body |
2917 N_Entry_Body |
2920 -- The expander is allowed to define types in any statements list,
2921 -- so any of the following parent nodes also mark a freezing point
2922 -- if the actual node is in a list of statements or declarations.
2924 when N_Exception_Handler |
2925 N_If_Statement |
2926 N_Elsif_Part |
2927 N_Case_Statement_Alternative |
2928 N_Compilation_Unit_Aux |
2929 N_Selective_Accept |
2930 N_Accept_Alternative |
2931 N_Delay_Alternative |
2932 N_Conditional_Entry_Call |
2933 N_Entry_Call_Alternative |
2934 N_Triggering_Alternative |
2935 N_Abortable_Part |
2936 N_Freeze_Entity =>
2940 -- Note: The N_Loop_Statement is a special case. A type that
2941 -- appears in the source can never be frozen in a loop (this
2942 -- occurs only because of a loop expanded by the expander),
2943 -- so we keep on going. Otherwise we terminate the search.
2944 -- Same is true of any entity which comes from source. (if they
2945 -- have a predefined type, that type does not appear to come
2946 -- from source, but the entity should not be frozen here).
2952 -- For all other cases, keep looking at parents
2958 -- We fall through the case if we did not yet find the proper
2959 -- place in the free for inserting the freeze node, so climb!
2964 -- If the expression appears in a record or an initialization
2965 -- procedure, the freeze nodes are collected and attached to
2966 -- the current scope, to be inserted and analyzed on exit from
2967 -- the scope, to insure that generated entities appear in the
2968 -- correct scope. If the expression is a default for a discriminant
2969 -- specification, the scope is still void. The expression can also
2970 -- appear in the discriminant part of a private or concurrent type.
2972 -- The other case requiring this special handling is if we are in
2973 -- a default expression, since in that case we are about to freeze
2974 -- a static type, and the freeze scope needs to be the outer scope,
2975 -- not the scope of the subprogram with the default parameter.
2977 -- For default expressions in generic units, the Move_Freeze_Nodes
2978 -- mechanism (see sem_ch12.adb) takes care of placing them at the
2979 -- proper place, after the generic unit.
2982 or else Freeze_Outside
2987 then
2988 declare
2992 begin
3009 then
3010 Scope_Stack.Table
3012 Freeze_Nodes;
3013 else
3023 -- Now we have the right place to do the freezing. First, a special
3024 -- adjustment, if we are in default expression analysis mode, these
3025 -- freeze actions must not be thrown away (normally all inserted
3026 -- actions are thrown away in this mode. However, the freeze actions
3027 -- are from static expressions and one of the important reasons we
3028 -- are doing this special analysis is to get these freeze actions.
3029 -- Therefore we turn off the In_Default_Expression mode to propagate
3030 -- these freeze actions. This also means they get properly analyzed
3031 -- and expanded.
3035 -- Freeze the designated type of an allocator (RM 13.14(12))
3041 -- Freeze type of expression (RM 13.14(9)). Note that we took care of
3042 -- the enumeration representation clause exception in the loop above.
3048 -- Freeze name if one is present (RM 13.14(10))
3057 -----------------------------
3058 -- Freeze_Fixed_Point_Type --
3059 -----------------------------
3061 -- Certain fixed-point types and subtypes, including implicit base
3062 -- types and declared first subtypes, have not yet set up a range.
3063 -- This is because the range cannot be set until the Small and Size
3064 -- values are known, and these are not known till the type is frozen.
3066 -- To signal this case, Scalar_Range contains an unanalyzed syntactic
3067 -- range whose bounds are unanalyzed real literals. This routine will
3068 -- recognize this case, and transform this range node into a properly
3069 -- typed range with properly analyzed and resolved values.
3087 -- Returns size of type with given bounds. Also leaves these
3088 -- bounds set as the current bounds of the Typ.
3091 begin
3097 -- Start of processing for Freeze_Fixed_Point_Type;
3099 begin
3100 -- If Esize of a subtype has not previously been set, set it now
3107 else
3112 -- Immediate return if the range is already analyzed. This means
3113 -- that the range is already set, and does not need to be computed
3114 -- by this routine.
3120 -- Immediate return if either of the bounds raises Constraint_Error
3124 then
3131 -- Ordinary fixed-point case
3135 -- For the ordinary fixed-point case, we are allowed to fudge the
3136 -- end-points up or down by small. Generally we prefer to fudge
3137 -- up, i.e. widen the bounds for non-model numbers so that the
3138 -- end points are included. However there are cases in which this
3139 -- cannot be done, and indeed cases in which we may need to narrow
3140 -- the bounds. The following circuit makes the decision.
3142 -- Note: our terminology here is that Incl_EP means that the
3143 -- bounds are widened by Small if necessary to include the end
3144 -- points, and Excl_EP means that the bounds are narrowed by
3145 -- Small to exclude the end-points if this reduces the size.
3147 -- Note that in the Incl case, all we care about is including the
3148 -- end-points. In the Excl case, we want to narrow the bounds as
3149 -- much as permitted by the RM, to give the smallest possible size.
3166 begin
3167 -- First step. Base types are required to be symmetrical. Right
3168 -- now, the base type range is a copy of the first subtype range.
3169 -- This will be corrected before we are done, but right away we
3170 -- need to deal with the case where both bounds are non-negative.
3171 -- In this case, we set the low bound to the negative of the high
3172 -- bound, to make sure that the size is computed to include the
3173 -- required sign. Note that we do not need to worry about the
3174 -- case of both bounds negative, because the sign will be dealt
3175 -- with anyway. Furthermore we can't just go making such a bound
3176 -- symmetrical, since in a twos-complement system, there is an
3177 -- extra negative value which could not be accomodated on the
3178 -- positive side.
3183 then
3188 -- Compute the fudged bounds. If the number is a model number,
3189 -- then we do nothing to include it, but we are allowed to
3190 -- backoff to the next adjacent model number when we exclude
3191 -- it. If it is not a model number then we straddle the two
3192 -- values with the model numbers on either side.
3198 else
3202 -- The low value excluding the end point is Small greater, but
3203 -- we do not do this exclusion if the low value is positive,
3204 -- since it can't help the size and could actually hurt by
3205 -- crossing the high bound.
3209 else
3213 -- Similar processing for upper bound and high value
3219 else
3225 else
3229 -- One further adjustment is needed. In the case of subtypes,
3230 -- we cannot go outside the range of the base type, or we get
3231 -- peculiarities, and the base type range is already set. This
3232 -- only applies to the Incl values, since clearly the Excl
3233 -- values are already as restricted as they are allowed to be.
3240 -- Get size including and excluding end points
3245 -- No need to exclude end-points if it does not reduce size
3255 -- Now we set the actual size to be used. We want to use the
3256 -- bounds fudged up to include the end-points but only if this
3257 -- can be done without violating a specifically given size
3258 -- size clause or causing an unacceptable increase in size.
3260 -- Case of size clause given
3264 -- Use the inclusive size only if it is consistent with
3265 -- the explicitly specified size.
3272 -- If the inclusive size is too large, we try excluding
3273 -- the end-points (will be caught later if does not work).
3275 else
3281 -- Case of size clause not given
3283 else
3284 -- If we have a base type whose corresponding first subtype
3285 -- has an explicit size that is large enough to include our
3286 -- end-points, then do so. There is no point in working hard
3287 -- to get a base type whose size is smaller than the specified
3288 -- size of the first subtype.
3294 then
3299 -- If excluding the end-points makes the size smaller and
3300 -- results in a size of 8,16,32,64, then we take the smaller
3301 -- size. For the 64 case, this is compulsory. For the other
3302 -- cases, it seems reasonable. We like to include end points
3303 -- if we can, but not at the expense of moving to the next
3304 -- natural boundary of size.
3307 and then
3312 then
3317 -- Otherwise we can definitely include the end points
3319 else
3325 -- One pathological case: normally we never fudge a low
3326 -- bound down, since it would seem to increase the size
3327 -- (if it has any effect), but for ranges containing a
3328 -- single value, or no values, the high bound can be
3329 -- small too large. Consider:
3331 -- type t is delta 2.0**(-14)
3332 -- range 131072.0 .. 0;
3334 -- That lower bound is *just* outside the range of 32
3335 -- bits, and does need fudging down in this case. Note
3336 -- that the bounds will always have crossed here, since
3337 -- the high bound will be fudged down if necessary, as
3338 -- in the case of:
3340 -- type t is delta 2.0**(-14)
3341 -- range 131072.0 .. 131072.0;
3343 -- So we can detect the situation by looking for crossed
3344 -- bounds, and if the bounds are crossed, and the low
3345 -- bound is greater than zero, we will always back it
3346 -- off by small, since this is completely harmless.
3353 -- And of course, we need to do exactly the same parallel
3354 -- fudge for flat ranges in the negative region.
3367 -- For the decimal case, none of this fudging is required, since there
3368 -- are no end-point problems in the decimal case (the end-points are
3369 -- always included).
3371 else
3375 -- At this stage, the actual size has been calculated and the proper
3376 -- required bounds are stored in the low and high bounds.
3380 Error_Msg_N
3385 -- Check size against explicit given size
3391 Error_Msg_NE
3395 else
3399 -- Increase size to next natural boundary if no size clause given
3401 else
3408 else
3416 -- If we have a base type, then expand the bounds so that they
3417 -- extend to the full width of the allocated size in bits, to
3418 -- avoid junk range checks on intermediate computations.
3425 -- Final step is to reanalyze the bounds using the proper type
3426 -- and set the Corresponding_Integer_Value fields of the literals.
3432 -- Resolve with universal fixed if the base type, and the base
3433 -- type if it is a subtype. Note we can't resolve the base type
3434 -- with itself, that would be a reference before definition.
3438 else
3442 -- Set corresponding integer value for bound
3444 Set_Corresponding_Integer_Value
3447 -- Similar processing for high bound
3455 else
3459 Set_Corresponding_Integer_Value
3462 -- Set type of range to correspond to bounds
3466 -- Set Esize to calculated size and also set RM_Size
3470 -- Set RM_Size if not already set. If already set, check value
3472 declare
3475 begin
3480 Error_Msg_NE
3485 else
3492 ------------------
3493 -- Freeze_Itype --
3494 ------------------
3499 begin
3508 --------------------------
3509 -- Freeze_Static_Object --
3510 --------------------------
3515 -- Exception raised if the type of a static object cannot be made
3516 -- static. This happens if the type depends on non-global objects.
3519 -- Called to ensure that an expression used as part of a type
3520 -- definition is statically allocatable, which means that the type
3521 -- of the expression is statically allocatable, and the expression
3522 -- is either static, or a reference to a library level constant.
3525 -- Called to mark a type as static, checking that it is possible
3526 -- to set the type as static. If it is not possible, then the
3527 -- exception Cannot_Be_Static is raised.
3529 -----------------------------
3530 -- Ensure_Expression_Is_SA --
3531 -----------------------------
3536 begin
3548 then
3556 -----------------------
3557 -- Ensure_Type_Is_SA --
3558 -----------------------
3564 begin
3565 -- If type is library level, we are all set
3571 -- We are also OK if the type is already marked as statically
3572 -- allocated, which means we processed it before.
3578 -- Mark type as statically allocated
3582 -- Check that it is safe to statically allocate this type
3600 declare
3604 begin
3617 else
3627 then
3646 else
3651 -- Start of processing for Freeze_Static_Object
3653 begin
3656 exception
3659 -- If the object that cannot be static is imported or exported,
3660 -- then we give an error message saying that this object cannot
3661 -- be imported or exported.
3664 Error_Msg_N
3667 -- Otherwise must be exported, something is wrong if compiler
3668 -- is marking something as statically allocated which cannot be).
3671 Error_Msg_N
3676 -----------------------
3677 -- Freeze_Subprogram --
3678 -----------------------
3684 begin
3685 -- Subprogram may not have an address clause unless it is imported
3689 Error_Msg_N
3696 -- For non-foreign convention subprograms, this is where we create
3697 -- the extra formals (for accessibility level and constrained bit
3698 -- information). We delay this till the freeze point precisely so
3699 -- that we know the convention!
3705 -- If this is convention Ada and a Valued_Procedure, that's odd
3710 then
3711 Error_Msg_N
3716 -- Case of foreign convention
3718 else
3721 -- For foreign conventions, do not permit return of an
3722 -- unconstrained array.
3724 -- Note: we *do* allow a return by descriptor for the VMS case,
3725 -- though here there is probably more to be done ???
3730 -- If no return type, probably some other error, e.g. a
3731 -- missing full declaration, so ignore.
3736 -- If the return type is generic, we have emitted a warning
3737 -- earlier on, and there is nothing else to check here.
3738 -- Specific instantiations may lead to erroneous behavior.
3746 then
3747 Error_Msg_NE
3754 -- If any of the formals for an exported foreign convention
3755 -- subprogram have defaults, then emit an appropriate warning
3756 -- since this is odd (default cannot be used from non-Ada code)
3762 Error_Msg_N
3772 -- For VMS, descriptor mechanisms for parameters are allowed only
3773 -- for imported subprograms.
3780 Error_Msg_N
3782 Error_Msg_N
3793 -----------------------
3794 -- Is_Fully_Defined --
3795 -----------------------
3797 -- Should this be in Sem_Util ???
3800 begin
3803 else
3809 ---------------------------------
3810 -- Process_Default_Expressions --
3811 ---------------------------------
3813 procedure Process_Default_Expressions
3816 is
3823 begin
3826 -- A subprogram instance and its associated anonymous subprogram
3827 -- share their signature. The default expression functions are defined
3828 -- in the wrapper packages for the anonymous subprogram, and should
3829 -- not be generated again for the instance.
3834 then
3843 -- We work with a copy of the default expression because we
3844 -- do not want to disturb the original, since this would mess
3845 -- up the conformance checking.
3849 -- The analysis of the expression may generate insert actions,
3850 -- which of course must not be executed. We wrap those actions
3851 -- in a procedure that is not called, and later on eliminated.
3852 -- The following cases have no side-effects, and are analyzed
3853 -- directly.
3864 and then
3867 then
3869 -- If there is no default function, we must still do a full
3870 -- analyze call on the default value, to ensure that all
3871 -- error checks are performed, e.g. those associated with
3872 -- static evaluation. Note that this branch will always be
3873 -- taken if the analyzer is turned off (but we still need the
3874 -- error checks).
3876 -- Note: the setting of parent here is to meet the requirement
3877 -- that we can only analyze the expression while attached to
3878 -- the tree. Really the requirement is that the parent chain
3879 -- be set, we don't actually need to be in the tree.
3884 -- Default expressions are resolved with their own type if the
3885 -- context is generic, to avoid anomalies with private types.
3889 else
3893 -- If that resolved expression will raise constraint error,
3894 -- then flag the default value as raising constraint error.
3895 -- This allows a proper error message on the calls.
3901 -- If the default is a parameterless call, we use the name of
3902 -- the called function directly, and there is no body to build.
3906 then
3909 -- Else construct and analyze the body of a wrapper procedure
3910 -- that contains an object declaration to hold the expression.
3911 -- Given that this is done only to complete the analysis, it
3912 -- simpler to build a procedure than a function which might
3913 -- involve secondary stack expansion.
3915 else
3916 Dnam :=
3919 Dbody :=
3921 Specification =>
3927 Defining_Identifier =>
3930 Object_Definition =>
3934 Handled_Statement_Sequence =>
3952 ----------------------------------------
3953 -- Set_Component_Alignment_If_Not_Set --
3954 ----------------------------------------
3957 begin
3958 -- Ignore if not base type, subtypes don't need anything
3964 -- Do not override existing representation
3975 else
3976 Set_Component_Alignment
3982 ---------------------------
3983 -- Set_Debug_Info_Needed --
3984 ---------------------------
3987 begin
3991 then
3993 else
4004 declare
4006 begin
4016 declare
4018 begin