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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. N has
108 -- the same usage as in Freeze_Entity.
111 -- Freeze enumeration type. The Esize field is set as processing
112 -- proceeds (i.e. set by default when the type is declared and then
113 -- adjusted by rep clauses. What this procedure does is to make sure
114 -- that if a foreign convention is specified, and no specific size
115 -- is given, then the size must be at least Integer'Size.
118 -- If an object is frozen which has Is_Statically_Allocated set, then
119 -- all referenced types must also be marked with this flag. This routine
120 -- is in charge of meeting this requirement for the object entity E.
123 -- Perform freezing actions for a subprogram (create extra formals,
124 -- and set proper default mechanism values). Note that this routine
125 -- is not called for internal subprograms, for which neither of these
126 -- actions is needed (or desirable, we do not want for example to have
127 -- these extra formals present in initialization procedures, where they
128 -- would serve no purpose). In this call E is either a subprogram or
129 -- a subprogram type (i.e. an access to a subprogram).
132 -- True if T is not private and has no private components, or has a full
133 -- view. Used to determine whether the designated type of an access type
134 -- should be frozen when the access type is frozen. This is done when an
135 -- allocator is frozen, or an expression that may involve attributes of
136 -- the designated type. Otherwise freezing the access type does not freeze
137 -- the designated type.
139 procedure Process_Default_Expressions
142 -- This procedure is called for each subprogram to complete processing of
143 -- default expressions at the point where all types are known to be frozen.
144 -- The expressions must be analyzed in full, to make sure that all error
145 -- processing is done (they have only been pre-analyzed). If the expression
146 -- is not an entity or literal, its analysis may generate code which must
147 -- not be executed. In that case we build a function body to hold that
148 -- code. This wrapper function serves no other purpose (it used to be
149 -- called to evaluate the default, but now the default is inlined at each
150 -- point of call).
153 -- Typ is a record or array type that is being frozen. This routine sets
154 -- the default component alignment from the scope stack values if the
155 -- alignment is otherwise not specified.
158 -- As each entity is frozen, this routine is called to deal with the
159 -- setting of Debug_Info_Needed for the entity. This flag is set if
160 -- the entity comes from source, or if we are in Debug_Generated_Code
161 -- mode or if the -gnatdV debug flag is set. However, it never sets
162 -- the flag if Debug_Info_Off is set. This procedure also ensures that
163 -- subsidiary entities have the flag set as required.
166 -- T is a type of a component that we know to be an Itype. We don't want
167 -- this to have a Freeze_Node, so ensure it doesn't. Do the same for any
168 -- Full_View or Corresponding_Record_Type.
170 procedure Warn_Overlay
174 -- Expr is the expression for an address clause for entity Nam whose type
175 -- is Typ. If Typ has a default initialization, and there is no explicit
176 -- initialization in the source declaration, check whether the address
177 -- clause might cause overlaying of an entity, and emit a warning on the
178 -- side effect that the initialization will cause.
180 -------------------------------
181 -- Adjust_Esize_For_Alignment --
182 -------------------------------
187 begin
193 then
199 ------------------------------------
200 -- Build_And_Analyze_Renamed_Body --
201 ------------------------------------
203 procedure Build_And_Analyze_Renamed_Body
207 is
213 begin
214 -- If the renamed subprogram is intrinsic, there is no need for a
215 -- wrapper body: we set the alias that will be called and expanded which
216 -- completes the declaration. This transformation is only legal if the
217 -- renamed entity has already been elaborated.
219 -- Note that it is legal for a renaming_as_body to rename an intrinsic
220 -- subprogram, as long as the renaming occurs before the new entity
221 -- is frozen. See RM 8.5.4 (5).
225 then
227 else
233 and then
237 -- We can make the renaming entity intrisic if the renamed function
238 -- has an interface name, or if it is one of the shift/rotate
239 -- operations known to the compiler.
247 then
252 else
259 else
268 ------------------------
269 -- Build_Renamed_Body --
270 ------------------------
272 function Build_Renamed_Body
275 is
277 -- We use for the source location of the renamed body, the location of
278 -- the spec entity. It might seem more natural to use the location of
279 -- the renaming declaration itself, but that would be wrong, since then
280 -- the body we create would look as though it was created far too late,
281 -- and this could cause problems with elaboration order analysis,
282 -- particularly in connection with instantiations.
297 -- If the renamed entity is a primitive operation given in prefix form,
298 -- the prefix is the target object and it has to be added as the first
299 -- actual in the generated call.
301 begin
302 -- Determine the entity being renamed, which is the target of the call
303 -- statement. If the name is an explicit dereference, this is a renaming
304 -- of a subprogram type rather than a subprogram. The name itself is
305 -- fully analyzed.
316 else
323 else
329 -- If the renamed entity is a predefined operator, retain full name
330 -- to ensure its visibility.
334 then
336 else
340 else
343 and then
346 then
348 -- Retrieve the target object, to be added as a first actual
349 -- in the call.
354 else
358 -- Original name may have been overloaded, but is fully resolved now
363 -- For simple renamings, subsequent calls can be expanded directly as
364 -- calls to the renamed entity. The body must be generated in any case
365 -- for calls that may appear elsewhere.
369 then
373 -- The body generated for this renaming is an internal artifact, and
374 -- does not constitute a freeze point for the called entity.
381 declare
385 begin
386 -- The controlling formal may be an access parameter, or the
387 -- actual may be an access value, so adjust accordingly.
391 then
392 Actuals := New_List
397 then
398 Actuals := New_List
402 else
410 else
421 -- If the renamed entity is an entry, inherit its profile. For other
422 -- renamings as bodies, both profiles must be subtype conformant, so it
423 -- is not necessary to replace the profile given in the declaration.
424 -- However, default values that are aggregates are rewritten when
425 -- partially analyzed, so we recover the original aggregate to insure
426 -- that subsequent conformity checking works. Similarly, if the default
427 -- expression was constant-folded, recover the original expression.
437 N_Access_Definition
438 then
446 then
457 -- If the renamed entity is a function, the generated body contains a
458 -- return statement. Otherwise, build a procedure call. If the entity is
459 -- an entry, subsequent analysis of the call will transform it into the
460 -- proper entry or protected operation call. If the renamed entity is
461 -- a character literal, return it directly.
467 then
468 Call_Node :=
470 Expression =>
476 Call_Node :=
481 Call_Node :=
485 else
486 Call_Node :=
492 -- Create entities for subprogram body and formals
505 Body_Node :=
509 Handled_Statement_Sequence =>
519 -- Link the body to the entity whose declaration it completes. If
520 -- the body is analyzed when the renamed entity is frozen, it may
521 -- be necessary to restore the proper scope (see package Exp_Ch13).
525 then
527 else
534 --------------------------
535 -- Check_Address_Clause --
536 --------------------------
544 begin
551 -- Has_Delayed_Freeze was set on E when the address clause was
552 -- analyzed. Reset the flag now unless freeze actions were
553 -- attached to it in the mean time.
560 -- If Rep_Clauses are to be ignored, remove address clause from
561 -- list attached to entity, because it may be illegal for gigi,
562 -- for example by breaking order of elaboration..
565 declare
568 begin
574 else
577 loop
591 then
597 -----------------------------
598 -- Check_Compile_Time_Size --
599 -----------------------------
604 -- Sets the compile time known size (32 bits or less) in the Esize
605 -- field, of T checking for a size clause that was given which attempts
606 -- to give a smaller size, and also checking for an alignment clause.
609 -- Recursive function that does all the work
612 -- If T is a constrained subtype, its size is not known if any of its
613 -- discriminant constraints is not static and it is not a null record.
614 -- The test is conservative and doesn't check that the components are
615 -- in fact constrained by non-static discriminant values. Could be made
616 -- more precise ???
618 --------------------
619 -- Set_Small_Size --
620 --------------------
623 begin
627 -- Don't bother if alignment clause with a value other than 1 is
628 -- present, because size may be padded up to meet back end alignment
629 -- requirements, and only the back end knows the rules!
634 -- Check for bad size clause given
639 Error_Msg_NE
647 -- Set sizes if not set already
649 else
660 ----------------
661 -- Size_Known --
662 ----------------
671 begin
675 -- Always True for scalar types. This is true even for generic formal
676 -- scalar types. We used to return False in the latter case, but the
677 -- size is known at compile time, even in the template, we just do
678 -- not know the exact size but that's not the point of this routine.
682 then
685 -- Array types
689 -- String literals always have known size, and we can set it
696 -- Unconstrained types never have known at compile time size
701 -- Don't do any recursion on type with error posted, since we may
702 -- have a malformed type that leads us into a loop.
707 -- Otherwise if component size unknown, then array size unknown
713 -- Check for all indexes static, and also compute possible size
714 -- (in case it is less than 32 and may be packable).
716 declare
720 begin
729 else
737 then
740 else
745 else
757 -- Access types always have known at compile time sizes
762 -- For non-generic private types, go to underlying type if present
767 then
768 -- Don't do any recursion on type with error posted, since we may
769 -- have a malformed type that leads us into a loop.
773 else
777 -- Record types
781 -- A class-wide type is never considered to have a known size
786 -- A subtype of a variant record must not have non-static
787 -- discriminanted components.
791 then
794 -- Don't do any recursion on type with error posted, since we may
795 -- have a malformed type that leads us into a loop.
801 -- Now look at the components of the record
803 declare
804 -- The following two variables are used to keep track of the
805 -- size of packed records if we can tell the size of the packed
806 -- record in the front end. Packed_Size_Known is True if so far
807 -- we can figure out the size. It is initialized to True for a
808 -- packed record, unless the record has discriminants. The
809 -- reason we eliminate the discriminated case is that we don't
810 -- know the way the back end lays out discriminated packed
811 -- records. If Packed_Size_Known is True, then Packed_Size is
812 -- the size in bits so far.
820 begin
821 -- Test for variant part present
827 N_Record_Definition
831 then
832 -- If variant part is present, and type is unconstrained,
833 -- then we must have defaulted discriminants, or a size
834 -- clause must be present for the type, or else the size
835 -- is definitely not known at compile time.
838 and then
841 then
846 -- Loop through components
852 -- We do not know the packed size if there is a component
853 -- clause present (we possibly could, but this would only
854 -- help in the case of a record with partial rep clauses.
855 -- That's because in the case of full rep clauses, the
856 -- size gets figured out anyway by a different circuit).
862 -- We need to identify a component that is an array where
863 -- the index type is an enumeration type with non-standard
864 -- representation, and some bound of the type depends on a
865 -- discriminant.
867 -- This is because gigi computes the size by doing a
868 -- substitution of the appropriate discriminant value in
869 -- the size expression for the base type, and gigi is not
870 -- clever enough to evaluate the resulting expression (which
871 -- involves a call to rep_to_pos) at compile time.
873 -- It would be nice if gigi would either recognize that
874 -- this expression can be computed at compile time, or
875 -- alternatively figured out the size from the subtype
876 -- directly, where all the information is at hand ???
880 then
881 declare
889 begin
896 then
902 then
907 then
917 -- Clearly size of record is not known if the size of one of
918 -- the components is not known.
924 -- Accumulate packed size if possible
928 -- We can only deal with elementary types, since for
929 -- non-elementary components, alignment enters into the
930 -- picture, and we don't know enough to handle proper
931 -- alignment in this context. Packed arrays count as
932 -- elementary if the representation is a modular type.
937 and then Is_Modular_Integer_Type
939 then
940 -- If RM_Size is known and static, then we can keep
941 -- accumulating the packed size.
945 -- A little glitch, to be removed sometime ???
946 -- gigi does not understand zero sizes yet.
951 -- Normal case where we can keep accumulating the
952 -- packed array size.
954 else
958 -- If we have a field whose RM_Size is not known then
959 -- we can't figure out the packed size here.
961 else
965 -- If we have a non-elementary type we can't figure out
966 -- the packed array size (alignment issues).
968 else
983 -- All other cases, size not known at compile time
985 else
990 -------------------------------------
991 -- Static_Discriminated_Components --
992 -------------------------------------
994 function Static_Discriminated_Components
996 is
999 begin
1003 then
1017 -- Start of processing for Check_Compile_Time_Size
1019 begin
1023 -----------------------------
1024 -- Check_Debug_Info_Needed --
1025 -----------------------------
1028 begin
1033 or else Debug_Generated_Code
1034 or else Debug_Flag_VV
1036 then
1041 ----------------------------
1042 -- Check_Strict_Alignment --
1043 ----------------------------
1048 begin
1066 then
1076 -------------------------
1077 -- Check_Unsigned_Type --
1078 -------------------------
1085 begin
1090 -- Do not attempt to analyze case where range was in error
1094 then
1098 -- The situation that is non trivial is something like
1100 -- subtype x1 is integer range -10 .. +10;
1101 -- subtype x2 is x1 range 0 .. V1;
1102 -- subtype x3 is x2 range V2 .. V3;
1103 -- subtype x4 is x3 range V4 .. V5;
1105 -- where Vn are variables. Here the base type is signed, but we still
1106 -- know that x4 is unsigned because of the lower bound of x2.
1108 -- The only way to deal with this is to look up the ancestor chain
1111 loop
1126 else
1129 -- If no ancestor had a static lower bound, go to base type
1133 -- Note: the reason we still check for a compile time known
1134 -- value for the base type is that at least in the case of
1135 -- generic formals, we can have bounds that fail this test,
1136 -- and there may be other cases in error situations.
1148 then
1158 -------------------------
1159 -- Is_Atomic_Aggregate --
1160 -------------------------
1162 function Is_Atomic_Aggregate
1165 is
1171 begin
1174 -- Array may be qualified, so find outer context
1182 then
1184 New_N :=
1195 else
1200 ----------------
1201 -- Freeze_All --
1202 ----------------
1204 -- Note: the easy coding for this procedure would be to just build a
1205 -- single list of freeze nodes and then insert them and analyze them
1206 -- all at once. This won't work, because the analysis of earlier freeze
1207 -- nodes may recursively freeze types which would otherwise appear later
1208 -- on in the freeze list. So we must analyze and expand the freeze nodes
1209 -- as they are generated.
1216 -- This is the internal recursive routine that does freezing of entities
1217 -- (but NOT the analysis of default expressions, which should not be
1218 -- recursive, we don't want to analyze those till we are sure that ALL
1219 -- the types are frozen).
1221 --------------------
1222 -- Freeze_All_Ent --
1223 --------------------
1231 -- If freeze nodes are present, insert and analyze, and reset cursor
1232 -- for next insertion.
1234 -------------------
1235 -- Process_Flist --
1236 -------------------
1239 begin
1246 else
1252 -- Start or processing for Freeze_All_Ent
1254 begin
1258 -- If the entity is an inner package which is not a package
1259 -- renaming, then its entities must be frozen at this point. Note
1260 -- that such entities do NOT get frozen at the end of the nested
1261 -- package itself (only library packages freeze).
1263 -- Same is true for task declarations, where anonymous records
1264 -- created for entry parameters must be frozen.
1270 then
1280 and then
1282 or else
1284 then
1287 End_Scope;
1289 -- For a derived tagged type, we must ensure that all the
1290 -- primitive operations of the parent have been frozen, so that
1291 -- their addresses will be in the parent's dispatch table at the
1292 -- point it is inherited.
1298 then
1299 declare
1306 begin
1313 then
1315 Process_Flist;
1325 Process_Flist;
1328 -- If an incomplete type is still not frozen, this may be a
1329 -- premature freezing because of a body declaration that follows.
1330 -- Indicate where the freezing took place.
1332 -- If the freezing is caused by the end of the current declarative
1333 -- part, it is a Taft Amendment type, and there is no error.
1337 then
1338 declare
1341 begin
1343 N_Entry_Body,
1344 N_Package_Body,
1345 N_Protected_Body,
1346 N_Task_Body)
1348 and then
1350 then
1352 Error_Msg_NE
1363 -- Start of processing for Freeze_All
1365 begin
1368 -- Now that all types are frozen, we can deal with default expressions
1369 -- that require us to build a default expression functions. This is the
1370 -- point at which such functions are constructed (after all types that
1371 -- might be used in such expressions have been frozen).
1373 -- For subprograms that are renaming_as_body, we create the wrapper
1374 -- bodies as needed.
1376 -- We also add finalization chains to access types whose designated
1377 -- types are controlled. This is normally done when freezing the type,
1378 -- but this misses recursive type definitions where the later members
1379 -- of the recursion introduce controlled components.
1381 -- Loop through entities
1399 and then
1401 = N_Subprogram_Renaming_Declaration
1402 then
1403 Build_And_Analyze_Renamed_Body
1409 and then
1411 or else
1413 then
1414 declare
1417 begin
1422 then
1435 then
1443 -----------------------
1444 -- Freeze_And_Append --
1445 -----------------------
1447 procedure Freeze_And_Append
1451 is
1453 begin
1457 else
1463 -------------------
1464 -- Freeze_Before --
1465 -------------------
1469 begin
1475 -------------------
1476 -- Freeze_Entity --
1477 -------------------
1490 -- This flag gets set to true for a variable with default initialization
1493 -- Check that an Access or Unchecked_Access attribute with a prefix
1494 -- which is the current instance type can only be applied when the type
1495 -- is limited.
1498 -- Give warning for modulus of 8, 16, 32, or 64 given as an explicit
1499 -- integer literal without an explicit corresponding size clause. The
1500 -- caller has checked that Utype is a modular integer type.
1503 -- If Loc is a freeze_entity that appears after the last declaration
1504 -- in the scope, inhibit error messages on late completion.
1507 -- Freeze each component, handle some representation clauses, and freeze
1508 -- primitive operations if this is a tagged type.
1510 ----------------------------
1511 -- After_Last_Declaration --
1512 ----------------------------
1516 begin
1522 else
1525 else
1530 ----------------------------
1531 -- Check_Current_Instance --
1532 ----------------------------
1542 -- Process routine to apply check to given node
1544 -------------
1545 -- Process --
1546 -------------
1549 begin
1553 or else
1558 then
1559 Error_Msg_N
1562 else
1572 -- Start of processing for Check_Current_Instance
1574 begin
1575 -- In Ada95, the (imprecise) rule is that the current instance of a
1576 -- limited type is aliased. In Ada2005, limitedness must be explicit:
1577 -- either a tagged type, or a limited record.
1581 then
1586 then
1589 else
1594 ------------------------------
1595 -- Check_Suspicious_Modulus --
1596 ------------------------------
1601 begin
1603 declare
1605 begin
1607 declare
1610 begin
1612 declare
1616 begin
1617 -- First case, modulus and size are the same. This
1618 -- happens if you have something like mod 32, with
1619 -- an explicit size of 32, this is for sure a case
1620 -- where the warning is given, since it is seems
1621 -- very unlikely that someone would want e.g. a
1622 -- five bit type stored in 32 bits. It is much
1623 -- more likely they wanted a 32-bit type.
1628 -- Second case, the modulus is 32 or 64 and no
1629 -- size clause is present. This is a less clear
1630 -- case for giving the warning, but in the case
1631 -- of 32/64 (5-bit or 6-bit types) these seem rare
1632 -- enough that it is a likely error (and in any
1633 -- case using 2**5 or 2**6 in these cases seems
1634 -- clearer. We don't include 8 or 16 here, simply
1635 -- because in practice 3-bit and 4-bit types are
1636 -- more common and too many false positives if
1637 -- we warn in these cases.
1641 then
1644 -- No warning needed
1646 else
1650 -- If we fall through, give warning
1653 Error_Msg_N
1655 Modulus);
1664 ------------------------
1665 -- Freeze_Record_Type --
1666 ------------------------
1678 -- Set True if we find at least one component with no component
1679 -- clause (used to warn about useless Pack pragmas).
1682 -- Set True if we find at least one component with a component
1683 -- clause (used to warn about useless Bit_Order pragmas, and also
1684 -- to detect cases where Implicit_Packing may have an effect).
1687 -- Set False if we encounter a component of a non-scalar type
1691 -- Accumulates total RM_Size values and total Esize values of all
1692 -- scalar components. Used for processing of Implicit_Packing.
1695 -- If N is an allocator, possibly wrapped in one or more level of
1696 -- qualified expression(s), return the inner allocator node, else
1697 -- return Empty.
1700 -- If the component subtype is an access to a constrained subtype of
1701 -- an already frozen type, make the subtype frozen as well. It might
1702 -- otherwise be frozen in the wrong scope, and a freeze node on
1703 -- subtype has no effect. Similarly, if the component subtype is a
1704 -- regular (not protected) access to subprogram, set the anonymous
1705 -- subprogram type to frozen as well, to prevent an out-of-scope
1706 -- freeze node at some eventual point of call. Protected operations
1707 -- are handled elsewhere.
1709 ---------------------
1710 -- Check_Allocator --
1711 ---------------------
1715 begin
1717 loop
1722 else
1728 -----------------
1729 -- Check_Itype --
1730 -----------------
1735 begin
1738 then
1741 -- In addition, add an Itype_Reference to ensure that the
1742 -- access subtype is elaborated early enough. This cannot be
1743 -- done if the subtype may depend on discriminants.
1748 then
1754 else
1761 then
1766 -- Start of processing for Freeze_Record_Type
1768 begin
1769 -- If this is a subtype of a controlled type, declared without a
1770 -- constraint, the _controller may not appear in the component list
1771 -- if the parent was not frozen at the point of subtype declaration.
1772 -- Inherit the _controller component now.
1776 then
1779 then
1782 -- If this is an internal type without a declaration, as for
1783 -- record component, the base type may not yet be frozen, and its
1784 -- controller has not been created. Add an explicit freeze node
1785 -- for the itype, so it will be frozen after the base type. This
1786 -- freeze node is used to communicate with the expander, in order
1787 -- to create the controller for the enclosing record, and it is
1788 -- deleted afterwards (see exp_ch3). It must not be created when
1789 -- expansion is off, because it might appear in the wrong context
1790 -- for the back end.
1794 and then
1796 N_Component_Declaration
1797 and then Expander_Active
1798 then
1803 -- Freeze components and embedded subtypes
1809 -- First handle the component case
1813 then
1814 declare
1817 begin
1818 -- Freezing a record type freezes the type of each of its
1819 -- components. However, if the type of the component is
1820 -- part of this record, we do not want or need a separate
1821 -- Freeze_Node. Note that Is_Itype is wrong because that's
1822 -- also set in private type cases. We also can't check for
1823 -- the Scope being exactly Rec because of private types and
1824 -- record extensions.
1829 then
1835 -- Check for error of component clause given for variable
1836 -- sized type. We have to delay this test till this point,
1837 -- since the component type has to be frozen for us to know
1838 -- if it is variable length. We omit this test in a generic
1839 -- context, it will be applied at instantiation time.
1847 elsif not
1848 Size_Known_At_Compile_Time
1850 then
1851 Error_Msg_N
1856 else
1860 -- Case of component requires byte alignment
1864 -- Set the enclosing record to also require byte align
1868 -- Check for component clause that is inconsistent with
1869 -- the required byte boundary alignment.
1874 then
1875 Error_Msg_N
1883 -- Gather data for possible Implicit_Packing later. Note that at
1884 -- this stage we might be dealing with a real component, or with
1885 -- an implicit subtype declaration.
1889 else
1890 Scalar_Component_Total_RM_Size :=
1892 Scalar_Component_Total_Esize :=
1896 -- If the component is an Itype with Delayed_Freeze and is either
1897 -- a record or array subtype and its base type has not yet been
1898 -- frozen, we must remove this from the entity list of this record
1899 -- and put it on the entity list of the scope of its base type.
1900 -- Note that we know that this is not the type of a component
1901 -- since we cleared Has_Delayed_Freeze for it in the previous
1902 -- loop. Thus this must be the Designated_Type of an access type,
1903 -- which is the type of a component.
1911 then
1912 declare
1916 begin
1917 -- We have a pretty bad kludge here. Suppose Rec is subtype
1918 -- being defined in a subprogram that's created as part of
1919 -- the freezing of Rec'Base. In that case, we know that
1920 -- Comp'Base must have already been frozen by the time we
1921 -- get to elaborate this because Gigi doesn't elaborate any
1922 -- bodies until it has elaborated all of the declarative
1923 -- part. But Is_Frozen will not be set at this point because
1924 -- we are processing code in lexical order.
1926 -- We detect this case by going up the Scope chain of Rec
1927 -- and seeing if we have a subprogram scope before reaching
1928 -- the top of the scope chain or that of Comp'Base. If we
1929 -- do, then mark that Comp'Base will actually be frozen. If
1930 -- so, we merely undelay it.
1946 else
1949 else
1953 -- Insert in entity list of scope of base type (which
1954 -- must be an enclosing scope, because still unfrozen).
1960 -- If the component is an access type with an allocator as default
1961 -- value, the designated type will be frozen by the corresponding
1962 -- expression in init_proc. In order to place the freeze node for
1963 -- the designated type before that for the current record type,
1964 -- freeze it now.
1966 -- Same process if the component is an array of access types,
1967 -- initialized with an aggregate. If the designated type is
1968 -- private, it cannot contain allocators, and it is premature
1969 -- to freeze the type, so we check for this as well.
1974 then
1975 declare
1979 begin
1982 -- If component is pointer to a classwide type, freeze
1983 -- the specific type in the expression being allocated.
1984 -- The expression may be a subtype indication, in which
1985 -- case freeze the subtype mark.
1987 if Is_Class_Wide_Type
1989 then
1991 Freeze_And_Append
1993 elsif
1995 then
1996 Freeze_And_Append
2004 else
2005 Freeze_And_Append
2013 then
2022 and then Is_Fully_Defined
2024 then
2025 Freeze_And_Append
2026 (Designated_Type
2034 -- Deal with pragma Bit_Order setting non-standard bit order
2038 ADC :=
2041 Error_Msg_N
2044 -- Here is where we do the processing for reversed bit order
2046 else
2051 -- Complete error checking on record representation clause (e.g.
2052 -- overlap of components). This is called after adjusting the
2053 -- record for reverse bit order.
2055 declare
2057 begin
2063 -- Set OK_To_Reorder_Components depending on debug flags
2067 then
2069 or else
2071 then
2076 -- Check for useless pragma Pack when all components placed. We only
2077 -- do this check for record types, not subtypes, since a subtype may
2078 -- have all its components placed, and it still makes perfectly good
2079 -- sense to pack other subtypes or the parent type. We do not give
2080 -- this warning if Optimize_Alignment is set to Space, since the
2081 -- pragma Pack does have an effect in this case (it always resets
2082 -- the alignment to one).
2086 and then not Unplaced_Component
2088 then
2089 -- Reset packed status. Probably not necessary, but we do it so
2090 -- that there is no chance of the back end doing something strange
2091 -- with this redundant indication of packing.
2095 -- Give warning if redundant constructs warnings on
2098 Error_Msg_N -- CODEFIX
2104 -- If this is the record corresponding to a remote type, freeze the
2105 -- remote type here since that is what we are semantically freezing.
2106 -- This prevents the freeze node for that type in an inner scope.
2108 -- Also, Check for controlled components and unchecked unions.
2109 -- Finally, enforce the restriction that access attributes with a
2110 -- current instance prefix can only apply to limited types.
2120 -- Do not set Has_Controlled_Component on a class-wide
2121 -- equivalent type. See Make_CW_Equivalent_Type.
2128 and then Present
2129 (Corresponding_Record_Type
2131 and then Has_Controlled_Component
2132 (Corresponding_Record_Type
2134 then
2145 -- Scan component declaration for likely misuses of current
2146 -- instance, either in a constraint or a default expression.
2157 -- For first subtypes, check if there are any fixed-point fields with
2158 -- component clauses, where we must check the size. This is not done
2159 -- till the freeze point, since for fixed-point types, we do not know
2160 -- the size until the type is frozen. Similar processing applies to
2161 -- 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 in this mode, since this generates over-complex
2251 -- code that confuses CodePeer, and in general, CodePeer does not
2252 -- care about the internal representation of objects.
2254 and then not CodePeer_Mode
2255 then
2256 -- If implicit packing enabled, do it
2261 -- Otherwise flag the size clause
2263 else
2264 declare
2266 begin
2267 Error_Msg_NE -- CODEFIX
2269 Error_Msg_N -- CODEFIX
2277 -- Start of processing for Freeze_Entity
2279 begin
2280 -- We are going to test for various reasons why this entity need not be
2281 -- frozen here, but in the case of an Itype that's defined within a
2282 -- record, that test actually applies to the record.
2288 then
2292 -- Do not freeze if already frozen since we only need one freeze node
2297 -- It is improper to freeze an external entity within a generic because
2298 -- its freeze node will appear in a non-valid context. The entity will
2299 -- be frozen in the proper scope after the current generic is analyzed.
2304 -- Do not freeze a global entity within an inner scope created during
2305 -- expansion. A call to subprogram E within some internal procedure
2306 -- (a stream attribute for example) might require freezing E, but the
2307 -- freeze node must appear in the same declarative part as E itself.
2308 -- The two-pass elaboration mechanism in gigi guarantees that E will
2309 -- be frozen before the inner call is elaborated. We exclude constants
2310 -- from this test, because deferred constants may be frozen early, and
2311 -- must be diagnosed (e.g. in the case of a deferred constant being used
2312 -- in a default expression). If the enclosing subprogram comes from
2313 -- source, or is a generic instance, then the freeze point is the one
2314 -- mandated by the language, and we freeze the entity. A subprogram that
2315 -- is a child unit body that acts as a spec does not have a spec that
2316 -- comes from source, but can only come from source.
2321 then
2322 declare
2325 begin
2332 then
2334 else
2343 -- Similarly, an inlined instance body may make reference to global
2344 -- entities, but these references cannot be the proper freezing point
2345 -- for them, and in the absence of inlining freezing will take place in
2346 -- their own scope. Normally instance bodies are analyzed after the
2347 -- enclosing compilation, and everything has been frozen at the proper
2348 -- place, but with front-end inlining an instance body is compiled
2349 -- before the end of the enclosing scope, and as a result out-of-order
2350 -- freezing must be prevented.
2352 elsif Front_End_Inlining
2353 and then In_Instance_Body
2355 then
2356 declare
2359 begin
2364 else
2375 -- Deal with delayed aspect specifications. At the point of occurrence
2376 -- of the aspect definition, we preanalyzed the argument, to capture
2377 -- the visibility at that point, but the actual analysis of the aspect
2378 -- is required to be delayed to the freeze point, so we evalute the
2379 -- pragma or attribute definition clause in the tree at this point.
2382 declare
2386 begin
2401 -- Here to freeze the entity
2406 -- Case of entity being frozen is other than a type
2410 -- If entity is exported or imported and does not have an external
2411 -- name, now is the time to provide the appropriate default name.
2412 -- Skip this if the entity is stubbed, since we don't need a name
2413 -- for any stubbed routine. For the case on intrinsics, if no
2414 -- external name is specified, then calls will be handled in
2415 -- Exp_Intr.Expand_Intrinsic_Call, and no name is needed. If an
2416 -- external name is provided, then Expand_Intrinsic_Call leaves
2417 -- calls in place for expansion by GIGI.
2423 then
2424 Set_Encoded_Interface_Name
2427 -- If entity is an atomic object appearing in a declaration and
2428 -- the expression is an aggregate, assign it to a temporary to
2429 -- ensure that the actual assignment is done atomically rather
2430 -- than component-wise (the assignment to the temp may be done
2431 -- component-wise, but that is harmless).
2437 and then
2439 then
2443 -- For a subprogram, freeze all parameter types and also the return
2444 -- type (RM 13.14(14)). However skip this for internal subprograms.
2445 -- This is also the point where any extra formal parameters are
2446 -- created since we now know whether the subprogram will use a
2447 -- foreign convention.
2451 declare
2456 begin
2457 -- Loop through formals
2469 then
2470 -- If the type of a formal is incomplete, subprogram
2471 -- is being frozen prematurely. Within an instance
2472 -- (but not within a wrapper package) this is an
2473 -- artifact of our need to regard the end of an
2474 -- instantiation as a freeze point. Otherwise it is
2475 -- a definite error.
2481 elsif not After_Last_Declaration
2482 and then not Freezing_Library_Level_Tagged_Type
2483 then
2485 Error_Msg
2487 Loc);
2491 -- Check suspicious parameter for C function. These tests
2492 -- apply only to exported/imported subprograms.
2494 if Warn_On_Export_Import
2497 or else
2504 then
2505 -- Qualify mention of formals with subprogram name
2509 -- Check suspicious use of fat C pointer
2513 then
2514 Error_Msg_N
2516 Formal);
2518 -- Check suspicious return of boolean
2525 then
2527 Error_Msg_N
2531 -- Check suspicious tagged type
2535 and then
2536 Is_Tagged_Type
2539 then
2540 Error_Msg_N
2544 -- Check wrong convention subprogram pointer
2548 then
2549 Error_Msg_N
2553 Error_Msg_NE
2558 -- Turn off name qualification after message output
2563 -- Check for unconstrained array in exported foreign
2564 -- convention case.
2570 and then Warn_On_Export_Import
2572 -- Exclude VM case, since both .NET and JVM can handle
2573 -- unconstrained arrays without a problem.
2576 then
2579 -- If this is an inherited operation, place the
2580 -- warning on the derived type declaration, rather
2581 -- than on the original subprogram.
2584 N_Full_Type_Declaration
2585 then
2589 Error_Msg_NE
2592 else
2596 Error_Msg_NE
2599 Error_Msg_NE
2610 -- If the formal is an anonymous_access_to_subprogram
2611 -- freeze the subprogram type as well, to prevent
2612 -- scope anomalies in gigi, because there is no other
2613 -- clear point at which it could be frozen.
2617 then
2625 -- Case of function: similar checks on return type
2629 -- Freeze return type
2634 -- Check suspicious return type for C function
2636 if Warn_On_Export_Import
2638 or else
2641 then
2642 -- Check suspicious return of fat C pointer
2648 then
2649 Error_Msg_N
2653 -- Check suspicious return of boolean
2661 then
2662 declare
2665 begin
2666 Error_Msg_NE
2669 Error_Msg_NE
2674 -- Check suspicious return tagged type
2678 and then
2679 Is_Tagged_Type
2684 then
2685 Error_Msg_N
2689 -- Check return of wrong convention subprogram pointer
2695 then
2696 Error_Msg_N
2700 Error_Msg_NE
2706 -- Give warning for suspicous return of a result of an
2707 -- unconstrained array type in a foreign convention
2708 -- function.
2712 -- We are looking for a return of unconstrained array
2717 -- Exclude imported routines, the warning does not
2718 -- belong on the import, but on the routine definition.
2722 -- Exclude VM case, since both .NET and JVM can handle
2723 -- return of unconstrained arrays without a problem.
2727 -- Check that general warning is enabled, and that it
2728 -- is not suppressed for this particular case.
2730 and then Warn_On_Export_Import
2733 then
2734 Error_Msg_N
2742 -- Must freeze its parent first if it is a derived subprogram
2748 -- We don't freeze internal subprograms, because we don't normally
2749 -- want addition of extra formals or mechanism setting to happen
2750 -- for those. However we do pass through predefined dispatching
2751 -- cases, since extra formals may be needed in some cases, such as
2752 -- for the stream 'Input function (build-in-place formals).
2756 then
2760 -- Here for other than a subprogram or type
2762 else
2763 -- If entity has a type, and it is not a generic unit, then
2764 -- freeze it first (RM 13.14(10)).
2768 then
2772 -- Special processing for objects created by object declaration
2776 -- Abstract type allowed only for C++ imported variables or
2777 -- constants.
2779 -- Note: we inhibit this check for objects that do not come
2780 -- from source because there is at least one case (the
2781 -- expansion of x'class'input where x is abstract) where we
2782 -- legitimately generate an abstract object.
2788 then
2793 Error_Msg_NE
2799 -- For object created by object declaration, perform required
2800 -- categorization (preelaborate and pure) checks. Defer these
2801 -- checks to freeze time since pragma Import inhibits default
2802 -- initialization and thus pragma Import affects these checks.
2806 -- If there is an address clause, check that it is valid
2810 -- If the object needs any kind of default initialization, an
2811 -- error must be issued if No_Default_Initialization applies.
2812 -- The check doesn't apply to imported objects, which are not
2813 -- ever default initialized, and is why the check is deferred
2814 -- until freezing, at which point we know if Import applies.
2815 -- Deferred constants are also exempted from this test because
2816 -- their completion is explicit, or through an import pragma.
2820 then
2826 and then
2831 or else
2834 then
2836 Check_Restriction
2840 -- Check that a Thread_Local_Storage variable does not have
2841 -- default initialization, and any explicit initialization must
2842 -- either be the null constant or a static constant.
2845 declare
2847 begin
2848 if Has_Default_Initialization
2849 or else
2851 and then
2853 or else not
2855 or else
2857 then
2858 Error_Msg_NE
2861 Error_Msg_NE
2868 -- For imported objects, set Is_Public unless there is also an
2869 -- address clause, which means that there is no external symbol
2870 -- needed for the Import (Is_Public may still be set for other
2871 -- unrelated reasons). Note that we delayed this processing
2872 -- till freeze time so that we can be sure not to set the flag
2873 -- if there is an address clause. If there is such a clause,
2874 -- then the only purpose of the Import pragma is to suppress
2875 -- implicit initialization.
2879 then
2883 -- For convention C objects of an enumeration type, warn if
2884 -- the size is not integer size and no explicit size given.
2885 -- Skip warning for Boolean, and Character, assume programmer
2886 -- expects 8-bit sizes for these cases.
2889 or else
2896 then
2898 Error_Msg_N
2900 E);
2905 -- Check that a constant which has a pragma Volatile[_Components]
2906 -- or Atomic[_Components] also has a pragma Import (RM C.6(13)).
2908 -- Note: Atomic[_Components] also sets Volatile[_Components]
2913 then
2914 -- Make sure we actually have a pragma, and have not merely
2915 -- inherited the indication from elsewhere (e.g. an address
2916 -- clause, which is not good enough in RM terms!)
2919 or else
2921 then
2922 Error_Msg_N
2927 or else
2929 then
2930 Error_Msg_N
2936 -- Static objects require special handling
2940 then
2944 -- Remaining step is to layout objects
2947 or else
2949 or else
2951 or else
2953 then
2958 -- Case of a type or subtype being frozen
2960 else
2961 -- We used to check here that a full type must have preelaborable
2962 -- initialization if it completes a private type specified with
2963 -- pragma Preelaborable_Intialization, but that missed cases where
2964 -- the types occur within a generic package, since the freezing
2965 -- that occurs within a containing scope generally skips traversal
2966 -- of a generic unit's declarations (those will be frozen within
2967 -- instances). This check was moved to Analyze_Package_Specification.
2969 -- The type may be defined in a generic unit. This can occur when
2970 -- freezing a generic function that returns the type (which is
2971 -- defined in a parent unit). It is clearly meaningless to freeze
2972 -- this type. However, if it is a subtype, its size may be determi-
2973 -- nable and used in subsequent checks, so might as well try to
2974 -- compute it.
2978 then
2983 -- Deal with special cases of freezing for subtype
2987 -- Before we do anything else, a specialized test for the case of
2988 -- a size given for an array where the array needs to be packed,
2989 -- but was not so the size cannot be honored. This would of course
2990 -- be caught by the backend, and indeed we don't catch all cases.
2991 -- The point is that we can give a better error message in those
2992 -- cases that we do catch with the circuitry here. Also if pragma
2993 -- Implicit_Packing is set, this is where the packing occurs.
2995 -- The reason we do this so early is that the processing in the
2996 -- automatic packing case affects the layout of the base type, so
2997 -- it must be done before we freeze the base type.
3000 declare
3004 begin
3005 -- Check enabling conditions. These are straightforward
3006 -- except for the test for a limited composite type. This
3007 -- eliminates the rare case of a array of limited components
3008 -- where there are issues of whether or not we can go ahead
3009 -- and pack the array (since we can't freely pack and unpack
3010 -- arrays if they are limited).
3012 -- Note that we check the root type explicitly because the
3013 -- whole point is we are doing this test before we have had
3014 -- a chance to freeze the base type (and it is that freeze
3015 -- action that causes stuff to be inherited).
3027 and then not CodePeer_Mode
3028 then
3035 then
3036 declare
3046 -- What we are looking for here is the situation where
3047 -- the RM_Size given would be exactly right if there
3048 -- was a pragma Pack (resulting in the component size
3049 -- being the same as the RM_Size). Furthermore, the
3050 -- component type size must be an odd size (not a
3051 -- multiple of storage unit). If the component RM size
3052 -- is an exact number of storage units that is a power
3053 -- of two, the array is not packed and has a standard
3054 -- representation.
3056 begin
3059 then
3060 -- For implicit packing mode, just set the
3061 -- component size silently.
3069 -- Otherwise give an error message
3071 else
3072 Error_Msg_NE
3074 Error_Msg_N -- CODEFIX
3080 and then Implicit_Packing
3081 and then
3085 then
3087 -- Not a packed array, but indicate the desired
3088 -- component size, for the back-end.
3098 -- If ancestor subtype present, freeze that first. Note that this
3099 -- will also get the base type frozen.
3106 -- Otherwise freeze the base type of the entity before freezing
3107 -- the entity itself (RM 13.14(15)).
3113 -- For a derived type, freeze its parent type first (RM 13.14(15))
3120 -- For array type, freeze index types and component type first
3121 -- before freezing the array (RM 13.14(15)).
3124 declare
3130 -- Set true if any of the index types is an enumeration type
3131 -- with a non-standard representation.
3133 begin
3142 then
3149 -- Processing that is done only for base types
3153 -- Propagate flags for component type
3157 then
3165 -- If packing was requested or if the component size was set
3166 -- explicitly, then see if bit packing is required. This
3167 -- processing is only done for base types, since all the
3168 -- representation aspects involved are type-related. This
3169 -- is not just an optimization, if we start processing the
3170 -- subtypes, they interfere with the settings on the base
3171 -- type (this is because Is_Packed has a slightly different
3172 -- meaning before and after freezing).
3174 declare
3178 begin
3182 then
3191 else
3194 -- We can set the component size if it is less than
3195 -- 16, rounding it up to the next storage unit size.
3201 else
3205 -- Set component size up to match alignment if it
3206 -- would otherwise be less than the alignment. This
3207 -- deals with cases of types whose alignment exceeds
3208 -- their size (padded types).
3211 declare
3213 begin
3221 -- Case of component size that may result in packing
3224 declare
3230 Get_Attribute_Definition_Clause
3232 begin
3233 -- Warn if we have pack and component size so that
3234 -- the pack is ignored.
3236 -- Note: here we must check for the presence of a
3237 -- component size before checking for a Pack pragma
3238 -- to deal with the case where the array type is a
3239 -- derived type whose parent is currently private.
3243 and then Warn_On_Redundant_Constructs
3244 then
3246 Error_Msg_NE
3249 Error_Msg_N
3251 Pack_Pragma);
3256 -- Set component size if not already set by a
3257 -- component size clause.
3263 -- Check for base type of 8, 16, 32 bits, where an
3264 -- unsigned subtype has a length one less than the
3265 -- base type (e.g. Natural subtype of Integer).
3267 -- In such cases, if a component size was not set
3268 -- explicitly, then generate a warning.
3272 and then
3275 then
3279 Error_Msg_N
3282 Error_Msg_N
3288 -- Actual packing is not needed for 8, 16, 32, 64.
3289 -- Also not needed for 24 if alignment is 1.
3296 then
3297 -- Here the array was requested to be packed,
3298 -- but the packing request had no effect, so
3299 -- Is_Packed is reset.
3301 -- Note: semantically this means that we lose
3302 -- track of the fact that a derived type
3303 -- inherited a pragma Pack that was non-
3304 -- effective, but that seems fine.
3306 -- We regard a Pack pragma as a request to set
3307 -- a representation characteristic, and this
3308 -- request may be ignored.
3315 then
3316 Set_Has_Non_Standard_Rep
3320 -- In all other cases, packing is indeed needed
3322 else
3331 -- Check for Atomic_Components or Aliased with unsuitable
3332 -- packing or explicit component size clause given.
3338 then
3342 -- Outputs error messages for incorrect CS clause or
3343 -- pragma Pack for aliased or atomic components (T is
3344 -- "aliased" or "atomic");
3346 -----------------
3347 -- Complain_CS --
3348 -----------------
3351 begin
3353 Clause :=
3354 Get_Attribute_Definition_Clause
3358 Error_Msg_N
3362 Error_Msg_N
3365 else
3366 Error_Msg_N
3371 else
3372 Error_Msg_N
3380 -- Start of processing for Alias_Atomic_Check
3382 begin
3383 -- Case where component size has no effect
3389 then
3394 then
3399 then
3405 -- Warn for case of atomic type
3411 then
3412 Error_Msg_NE
3417 Error_Msg_Sloc :=
3418 Sloc
3419 (Get_Attribute_Definition_Clause
3421 Error_Msg_N
3423 Clause);
3426 Error_Msg_Sloc :=
3428 Error_Msg_N
3433 -- Processing that is done only for subtypes
3435 else
3436 -- Acquire alignment from base type
3444 -- For bit-packed arrays, check the size
3447 declare
3453 begin
3454 -- It is not clear if it is possible to have no size
3455 -- clause at this stage, but it is not worth worrying
3456 -- about. Post error on the entity name in the size
3457 -- clause if present, else on the type entity itself.
3461 else
3467 -- If any of the index types was an enumeration type with
3468 -- a non-standard rep clause, then we indicate that the
3469 -- array type is always packed (even if it is not bit packed).
3478 -- If the array is packed, we must create the packed array
3479 -- type to be used to actually implement the type. This is
3480 -- only needed for real array types (not for string literal
3481 -- types, since they are present only for the front end).
3485 then
3489 -- Size information of packed array type is copied to the
3490 -- array type, since this is really the representation. But
3491 -- do not override explicit existing size values. If the
3492 -- ancestor subtype is constrained the packed_array_type
3493 -- will be inherited from it, but the size may have been
3494 -- provided already, and must not be overridden either.
3497 and then
3500 then
3510 -- For non-packed arrays set the alignment of the array to the
3511 -- alignment of the component type if it is unknown. Skip this
3512 -- in atomic case (atomic arrays may need larger alignments).
3521 then
3526 -- For a class-wide type, the corresponding specific type is
3527 -- frozen as well (RM 13.14(15))
3532 -- If the base type of the class-wide type is still incomplete,
3533 -- the class-wide remains unfrozen as well. This is legal when
3534 -- E is the formal of a primitive operation of some other type
3535 -- which is being frozen.
3542 -- If the Class_Wide_Type is an Itype (when type is the anonymous
3543 -- parent of a derived type) and it is a library-level entity,
3544 -- generate an itype reference for it. Otherwise, its first
3545 -- explicit reference may be in an inner scope, which will be
3546 -- rejected by the back-end.
3550 then
3551 declare
3554 begin
3558 else
3564 -- The equivalent type associated with a class-wide subtype needs
3565 -- to be frozen to ensure that its layout is done.
3569 then
3573 -- For a record (sub)type, freeze all the component types (RM
3574 -- 13.14(15). We test for E_Record_(sub)Type here, rather than using
3575 -- Is_Record_Type, because we don't want to attempt the freeze for
3576 -- the case of a private type with record extension (we will do that
3577 -- later when the full type is frozen).
3581 then
3584 -- For a concurrent type, freeze corresponding record type. This
3585 -- does not correspond to any specific rule in the RM, but the
3586 -- record type is essentially part of the concurrent type.
3587 -- Freeze as well all local entities. This includes record types
3588 -- created for entry parameter blocks, and whatever local entities
3589 -- may appear in the private part.
3593 Freeze_And_Append
3605 then
3615 -- Private types are required to point to the same freeze node as
3616 -- their corresponding full views. The freeze node itself has to
3617 -- point to the partial view of the entity (because from the partial
3618 -- view, we can retrieve the full view, but not the reverse).
3619 -- However, in order to freeze correctly, we need to freeze the full
3620 -- view. If we are freezing at the end of a scope (or within the
3621 -- scope of the private type), the partial and full views will have
3622 -- been swapped, the full view appears first in the entity chain and
3623 -- the swapping mechanism ensures that the pointers are properly set
3624 -- (on scope exit).
3626 -- If we encounter the partial view before the full view (e.g. when
3627 -- freezing from another scope), we freeze the full view, and then
3628 -- set the pointers appropriately since we cannot rely on swapping to
3629 -- fix things up (subtypes in an outer scope might not get swapped).
3633 then
3634 -- The construction of the dispatch table associated with library
3635 -- level tagged types forces freezing of all the primitives of the
3636 -- type, which may cause premature freezing of the partial view.
3637 -- For example:
3639 -- package Pkg is
3640 -- type T is tagged private;
3641 -- type DT is new T with private;
3642 -- procedure Prim (X : in out T; Y : in out DT'class);
3643 -- private
3644 -- type T is tagged null record;
3645 -- Obj : T;
3646 -- type DT is new T with null record;
3647 -- end;
3649 -- In this case the type will be frozen later by the usual
3650 -- mechanism: an object declaration, an instantiation, or the
3651 -- end of a declarative part.
3655 then
3659 -- Case of full view present
3663 -- If full view has already been frozen, then no further
3664 -- processing is required
3671 -- Otherwise freeze full view and patch the pointers so that
3672 -- the freeze node will elaborate both views in the back-end.
3674 else
3675 declare
3678 begin
3681 then
3682 Freeze_And_Append
3695 else
3696 -- {Incomplete,Private}_Subtypes with Full_Views
3697 -- constrained by discriminants.
3708 -- AI-117 requires that the convention of a partial view be the
3709 -- same as the convention of the full view. Note that this is a
3710 -- recognized breach of privacy, but it's essential for logical
3711 -- consistency of representation, and the lack of a rule in
3712 -- RM95 was an oversight.
3719 -- Size information is copied from the full view to the
3720 -- incomplete or private view for consistency.
3722 -- We skip this is the full view is not a type. This is very
3723 -- strange of course, and can only happen as a result of
3724 -- certain illegalities, such as a premature attempt to derive
3725 -- from an incomplete type.
3734 -- Case of no full view present. If entity is derived or subtype,
3735 -- it is safe to freeze, correctness depends on the frozen status
3736 -- of parent. Otherwise it is either premature usage, or a Taft
3737 -- amendment type, so diagnosis is at the point of use and the
3738 -- type might be frozen later.
3742 then
3745 else
3750 -- For access subprogram, freeze types of all formals, the return
3751 -- type was already frozen, since it is the Etype of the function.
3752 -- Formal types can be tagged Taft amendment types, but otherwise
3753 -- they cannot be incomplete.
3761 then
3765 -- AI05-151: Incomplete types are allowed in access to
3766 -- subprogram specifications.
3769 Error_Msg_NE
3780 -- For access to a protected subprogram, freeze the equivalent type
3781 -- (however this is not set if we are not generating code or if this
3782 -- is an anonymous type used just for resolution).
3790 -- Generic types are never seen by the back-end, and are also not
3791 -- processed by the expander (since the expander is turned off for
3792 -- generic processing), so we never need freeze nodes for them.
3798 -- Some special processing for non-generic types to complete
3799 -- representation details not known till the freeze point.
3804 -- Some error checks required for ordinary fixed-point type. Defer
3805 -- these till the freeze-point since we need the small and range
3806 -- values. We only do these checks for base types
3810 then
3813 Error_Msg_N
3818 Error_Msg_N
3824 Error_Msg_N
3830 Error_Msg_N
3842 and then Warn_On_Suspicious_Modulus_Value
3843 then
3849 -- If a pragma Default_Storage_Pool applies, and this type has no
3850 -- Storage_Pool or Storage_Size clause (which must have occurred
3851 -- before the freezing point), then use the default. This applies
3852 -- only to base types.
3858 then
3859 -- Case of pragma Default_Storage_Pool (null)
3864 -- Case of pragma Default_Storage_Pool (storage_pool_NAME)
3866 else
3871 -- Check restriction for standard storage pool
3877 -- Deal with error message for pure access type. This is not an
3878 -- error in Ada 2005 if there is no pool (see AI-366).
3883 then
3887 Error_Msg_N
3891 Error_Msg_N
3894 else
3895 Error_Msg_N
3902 -- Case of composite types
3906 -- AI-117 requires that all new primitives of a tagged type must
3907 -- inherit the convention of the full view of the type. Inherited
3908 -- and overriding operations are defined to inherit the convention
3909 -- of their parent or overridden subprogram (also specified in
3910 -- AI-117), which will have occurred earlier (in Derive_Subprogram
3911 -- and New_Overloaded_Entity). Here we set the convention of
3912 -- primitives that are still convention Ada, which will ensure
3913 -- that any new primitives inherit the type's convention. Class-
3914 -- wide types can have a foreign convention inherited from their
3915 -- specific type, but are excluded from this since they don't have
3916 -- any associated primitives.
3921 then
3922 declare
3926 begin
3939 -- Now that all types from which E may depend are frozen, see if the
3940 -- size is known at compile time, if it must be unsigned, or if
3941 -- strict alignment is required
3950 -- Do not allow a size clause for a type which does not have a size
3951 -- that is known at compile time
3955 then
3956 -- Suppress this message if errors posted on E, even if we are
3957 -- in all errors mode, since this is often a junk message
3960 Error_Msg_N
3966 -- Remaining process is to set/verify the representation information,
3967 -- in particular the size and alignment values. This processing is
3968 -- not required for generic types, since generic types do not play
3969 -- any part in code generation, and so the size and alignment values
3970 -- for such types are irrelevant.
3975 -- Otherwise we call the layout procedure
3977 else
3981 -- End of freeze processing for type entities
3984 -- Here is where we logically freeze the current entity. If it has a
3985 -- freeze node, then this is the point at which the freeze node is
3986 -- linked into the result list.
3990 -- If a freeze node is already allocated, use it, otherwise allocate
3991 -- a new one. The preallocation happens in the case of anonymous base
3992 -- types, where we preallocate so that we can set First_Subtype_Link.
3993 -- Note that we reset the Sloc to the current freeze location.
3999 else
4011 else
4015 -- A final pass over record types with discriminants. If the type
4016 -- has an incomplete declaration, there may be constrained access
4017 -- subtypes declared elsewhere, which do not depend on the discrimi-
4018 -- nants of the type, and which are used as component types (i.e.
4019 -- the full view is a recursive type). The designated types of these
4020 -- subtypes can only be elaborated after the type itself, and they
4021 -- need an itype reference.
4025 then
4026 declare
4031 begin
4041 then
4053 -- When a type is frozen, the first subtype of the type is frozen as
4054 -- well (RM 13.14(15)). This has to be done after freezing the type,
4055 -- since obviously the first subtype depends on its own base type.
4060 -- If we just froze a tagged non-class wide record, then freeze the
4061 -- corresponding class-wide type. This must be done after the tagged
4062 -- type itself is frozen, because the class-wide type refers to the
4063 -- tagged type which generates the class.
4068 then
4075 -- Special handling for subprograms
4079 -- If subprogram has address clause then reset Is_Public flag, since
4080 -- we do not want the backend to generate external references.
4084 then
4087 -- If no address clause and not intrinsic, then for imported
4088 -- subprogram in main unit, generate descriptor if we are in
4089 -- Propagate_Exceptions mode.
4091 elsif Propagate_Exceptions
4095 then
4105 -----------------------------
4106 -- Freeze_Enumeration_Type --
4107 -----------------------------
4110 begin
4111 -- By default, if no size clause is present, an enumeration type with
4112 -- Convention C is assumed to interface to a C enum, and has integer
4113 -- size. This applies to types. For subtypes, verify that its base
4114 -- type has no size clause either.
4120 then
4123 else
4124 -- If the enumeration type interfaces to C, and it has a size clause
4125 -- that specifies less than int size, it warrants a warning. The
4126 -- user may intend the C type to be an enum or a char, so this is
4127 -- not by itself an error that the Ada compiler can detect, but it
4128 -- it is a worth a heads-up. For Boolean and Character types we
4129 -- assume that the programmer has the proper C type in mind.
4136 then
4137 Error_Msg_N
4145 -----------------------
4146 -- Freeze_Expression --
4147 -----------------------
4158 -- This flag is set true if the entity must be frozen outside the
4159 -- current subprogram. This happens in the case of expander generated
4160 -- subprograms (_Init_Proc, _Input, _Output, _Read, _Write) which do
4161 -- not freeze all entities like other bodies, but which nevertheless
4162 -- may reference entities that have to be frozen before the body and
4163 -- obviously cannot be frozen inside the body.
4166 -- Given an N_Handled_Sequence_Of_Statements node N, determines whether
4167 -- it is the handled statement sequence of an expander-generated
4168 -- subprogram (init proc, stream subprogram, or renaming as body).
4169 -- If so, this is not a freezing context.
4171 -----------------
4172 -- In_Exp_Body --
4173 -----------------
4179 begin
4182 else
4189 else
4199 N_Subprogram_Renaming_Declaration)
4200 then
4202 else
4208 -- Start of processing for Freeze_Expression
4210 begin
4211 -- Immediate return if freezing is inhibited. This flag is set by the
4212 -- analyzer to stop freezing on generated expressions that would cause
4213 -- freezing if they were in the source program, but which are not
4214 -- supposed to freeze, since they are created.
4220 -- If expression is non-static, then it does not freeze in a default
4221 -- expression, see section "Handling of Default Expressions" in the
4222 -- spec of package Sem for further details. Note that we have to
4223 -- make sure that we actually have a real expression (if we have
4224 -- a subtype indication, we can't test Is_Static_Expression!)
4226 if In_Spec_Exp
4229 then
4233 -- Freeze type of expression if not frozen already
4241 -- Base type may be an derived numeric type that is frozen at
4242 -- the point of declaration, but first_subtype is still unfrozen.
4249 -- For entity name, freeze entity if not frozen already. A special
4250 -- exception occurs for an identifier that did not come from source.
4251 -- We don't let such identifiers freeze a non-internal entity, i.e.
4252 -- an entity that did come from source, since such an identifier was
4253 -- generated by the expander, and cannot have any semantic effect on
4254 -- the freezing semantics. For example, this stops the parameter of
4255 -- an initialization procedure from freezing the variable.
4262 then
4264 else
4268 -- For an allocator freeze designated type if not frozen already
4270 -- For an aggregate whose component type is an access type, freeze the
4271 -- designated type now, so that its freeze does not appear within the
4272 -- loop that might be created in the expansion of the aggregate. If the
4273 -- designated type is a private type without full view, the expression
4274 -- cannot contain an allocator, so the type is not frozen.
4276 -- For a function, we freeze the entity when the subprogram declaration
4277 -- is frozen, but a function call may appear in an initialization proc.
4278 -- before the declaration is frozen. We need to generate the extra
4279 -- formals, if any, to ensure that the expansion of the call includes
4280 -- the proper actuals. This only applies to Ada subprograms, not to
4281 -- imported ones.
4292 then
4296 when N_Selected_Component |
4297 N_Indexed_Component |
4298 N_Slice =>
4309 then
4320 then
4324 -- All done if nothing needs freezing
4329 then
4333 -- Loop for looking at the right place to insert the freeze nodes,
4334 -- exiting from the loop when it is appropriate to insert the freeze
4335 -- node before the current node P.
4337 -- Also checks some special exceptions to the freezing rules. These
4338 -- cases result in a direct return, bypassing the freeze action.
4341 loop
4344 -- If we don't have a parent, then we are not in a well-formed tree.
4345 -- This is an unusual case, but there are some legitimate situations
4346 -- in which this occurs, notably when the expressions in the range of
4347 -- a type declaration are resolved. We simply ignore the freeze
4348 -- request in this case. Is this right ???
4354 -- See if we have got to an appropriate point in the tree
4358 -- A special test for the exception of (RM 13.14(8)) for the case
4359 -- of per-object expressions (RM 3.8(18)) occurring in component
4360 -- definition or a discrete subtype definition. Note that we test
4361 -- for a component declaration which includes both cases we are
4362 -- interested in, and furthermore the tree does not have explicit
4363 -- nodes for either of these two constructs.
4367 -- The case we want to test for here is an identifier that is
4368 -- a per-object expression, this is either a discriminant that
4369 -- appears in a context other than the component declaration
4370 -- or it is a reference to the type of the enclosing construct.
4372 -- For either of these cases, we skip the freezing
4374 if not In_Spec_Expression
4377 then
4378 -- We recognize the discriminant case by just looking for
4379 -- a reference to a discriminant. It can only be one for
4380 -- the enclosing construct. Skip freezing in this case.
4385 -- For the case of a reference to the enclosing record,
4386 -- (or task or protected type), we look for a type that
4387 -- matches the current scope.
4394 -- If we have an enumeration literal that appears as the choice in
4395 -- the aggregate of an enumeration representation clause, then
4396 -- freezing does not occur (RM 13.14(10)).
4400 -- The case we are looking for is an enumeration literal
4404 then
4405 -- If enumeration literal appears directly as the choice,
4406 -- do not freeze (this is the normal non-overloaded case)
4410 then
4413 -- If enumeration literal appears as the name of function
4414 -- which is the choice, then also do not freeze. This
4415 -- happens in the overloaded literal case, where the
4416 -- enumeration literal is temporarily changed to a function
4417 -- call for overloading analysis purposes.
4420 and then
4422 and then
4424 then
4429 -- Normally if the parent is a handled sequence of statements,
4430 -- then the current node must be a statement, and that is an
4431 -- appropriate place to insert a freeze node.
4435 -- An exception occurs when the sequence of statements is for
4436 -- an expander generated body that did not do the usual freeze
4437 -- all operation. In this case we usually want to freeze
4438 -- outside this body, not inside it, and we skip past the
4439 -- subprogram body that we are inside.
4443 -- However, we *do* want to freeze at this point if we have
4444 -- an entity to freeze, and that entity is declared *inside*
4445 -- the body of the expander generated procedure. This case
4446 -- is recognized by the scope of the type, which is either
4447 -- the spec for some enclosing body, or (in the case of
4448 -- init_procs, for which there are no separate specs) the
4449 -- current scope.
4451 declare
4455 begin
4460 or else
4462 then
4468 then
4474 -- If not that exception to the exception, then this is
4475 -- where we delay the freeze till outside the body.
4480 -- Here if normal case where we are in handled statement
4481 -- sequence and want to do the insertion right there.
4483 else
4487 -- If parent is a body or a spec or a block, then the current node
4488 -- is a statement or declaration and we can insert the freeze node
4489 -- before it.
4491 when N_Package_Specification |
4492 N_Package_Body |
4493 N_Subprogram_Body |
4494 N_Task_Body |
4495 N_Protected_Body |
4496 N_Entry_Body |
4499 -- The expander is allowed to define types in any statements list,
4500 -- so any of the following parent nodes also mark a freezing point
4501 -- if the actual node is in a list of statements or declarations.
4503 when N_Exception_Handler |
4504 N_If_Statement |
4505 N_Elsif_Part |
4506 N_Case_Statement_Alternative |
4507 N_Compilation_Unit_Aux |
4508 N_Selective_Accept |
4509 N_Accept_Alternative |
4510 N_Delay_Alternative |
4511 N_Conditional_Entry_Call |
4512 N_Entry_Call_Alternative |
4513 N_Triggering_Alternative |
4514 N_Abortable_Part |
4515 N_And_Then |
4516 N_Or_Else |
4517 N_Freeze_Entity =>
4521 -- Note: The N_Loop_Statement is a special case. A type that
4522 -- appears in the source can never be frozen in a loop (this
4523 -- occurs only because of a loop expanded by the expander), so we
4524 -- keep on going. Otherwise we terminate the search. Same is true
4525 -- of any entity which comes from source. (if they have predefined
4526 -- type, that type does not appear to come from source, but the
4527 -- entity should not be frozen here).
4533 -- For all other cases, keep looking at parents
4539 -- We fall through the case if we did not yet find the proper
4540 -- place in the free for inserting the freeze node, so climb!
4545 -- If the expression appears in a record or an initialization procedure,
4546 -- the freeze nodes are collected and attached to the current scope, to
4547 -- be inserted and analyzed on exit from the scope, to insure that
4548 -- generated entities appear in the correct scope. If the expression is
4549 -- a default for a discriminant specification, the scope is still void.
4550 -- The expression can also appear in the discriminant part of a private
4551 -- or concurrent type.
4553 -- If the expression appears in a constrained subcomponent of an
4554 -- enclosing record declaration, the freeze nodes must be attached to
4555 -- the outer record type so they can eventually be placed in the
4556 -- enclosing declaration list.
4558 -- The other case requiring this special handling is if we are in a
4559 -- default expression, since in that case we are about to freeze a
4560 -- static type, and the freeze scope needs to be the outer scope, not
4561 -- the scope of the subprogram with the default parameter.
4563 -- For default expressions and other spec expressions in generic units,
4564 -- the Move_Freeze_Nodes mechanism (see sem_ch12.adb) takes care of
4565 -- placing them at the proper place, after the generic unit.
4568 or else Freeze_Outside
4573 then
4574 declare
4579 begin
4592 -- The current scope may be that of a constrained component of
4593 -- an enclosing record declaration, which is above the current
4594 -- scope in the scope stack.
4595 -- If the expression is within a top-level pragma, as for a pre-
4596 -- condition on a library-level subprogram, nothing to do.
4600 then
4607 Freeze_Nodes;
4608 else
4618 -- Now we have the right place to do the freezing. First, a special
4619 -- adjustment, if we are in spec-expression analysis mode, these freeze
4620 -- actions must not be thrown away (normally all inserted actions are
4621 -- thrown away in this mode. However, the freeze actions are from static
4622 -- expressions and one of the important reasons we are doing this
4623 -- special analysis is to get these freeze actions. Therefore we turn
4624 -- off the In_Spec_Expression mode to propagate these freeze actions.
4625 -- This also means they get properly analyzed and expanded.
4629 -- Freeze the designated type of an allocator (RM 13.14(13))
4635 -- Freeze type of expression (RM 13.14(10)). Note that we took care of
4636 -- the enumeration representation clause exception in the loop above.
4642 -- Freeze name if one is present (RM 13.14(11))
4648 -- Restore In_Spec_Expression flag
4653 -----------------------------
4654 -- Freeze_Fixed_Point_Type --
4655 -----------------------------
4657 -- Certain fixed-point types and subtypes, including implicit base types
4658 -- and declared first subtypes, have not yet set up a range. This is
4659 -- because the range cannot be set until the Small and Size values are
4660 -- known, and these are not known till the type is frozen.
4662 -- To signal this case, Scalar_Range contains an unanalyzed syntactic range
4663 -- whose bounds are unanalyzed real literals. This routine will recognize
4664 -- this case, and transform this range node into a properly typed range
4665 -- with properly analyzed and resolved values.
4683 -- Returns size of type with given bounds. Also leaves these
4684 -- bounds set as the current bounds of the Typ.
4686 -----------
4687 -- Fsize --
4688 -----------
4691 begin
4697 -- Start of processing for Freeze_Fixed_Point_Type
4699 begin
4700 -- If Esize of a subtype has not previously been set, set it now
4707 else
4712 -- Immediate return if the range is already analyzed. This means that
4713 -- the range is already set, and does not need to be computed by this
4714 -- routine.
4720 -- Immediate return if either of the bounds raises Constraint_Error
4724 then
4731 -- Ordinary fixed-point case
4735 -- For the ordinary fixed-point case, we are allowed to fudge the
4736 -- end-points up or down by small. Generally we prefer to fudge up,
4737 -- i.e. widen the bounds for non-model numbers so that the end points
4738 -- are included. However there are cases in which this cannot be
4739 -- done, and indeed cases in which we may need to narrow the bounds.
4740 -- The following circuit makes the decision.
4742 -- Note: our terminology here is that Incl_EP means that the bounds
4743 -- are widened by Small if necessary to include the end points, and
4744 -- Excl_EP means that the bounds are narrowed by Small to exclude the
4745 -- end-points if this reduces the size.
4747 -- Note that in the Incl case, all we care about is including the
4748 -- end-points. In the Excl case, we want to narrow the bounds as
4749 -- much as permitted by the RM, to give the smallest possible size.
4766 begin
4767 -- First step. Base types are required to be symmetrical. Right
4768 -- now, the base type range is a copy of the first subtype range.
4769 -- This will be corrected before we are done, but right away we
4770 -- need to deal with the case where both bounds are non-negative.
4771 -- In this case, we set the low bound to the negative of the high
4772 -- bound, to make sure that the size is computed to include the
4773 -- required sign. Note that we do not need to worry about the
4774 -- case of both bounds negative, because the sign will be dealt
4775 -- with anyway. Furthermore we can't just go making such a bound
4776 -- symmetrical, since in a twos-complement system, there is an
4777 -- extra negative value which could not be accommodated on the
4778 -- positive side.
4783 then
4788 -- Compute the fudged bounds. If the number is a model number,
4789 -- then we do nothing to include it, but we are allowed to backoff
4790 -- to the next adjacent model number when we exclude it. If it is
4791 -- not a model number then we straddle the two values with the
4792 -- model numbers on either side.
4798 else
4802 -- The low value excluding the end point is Small greater, but
4803 -- we do not do this exclusion if the low value is positive,
4804 -- since it can't help the size and could actually hurt by
4805 -- crossing the high bound.
4810 -- If the value went from negative to zero, then we have the
4811 -- case where Loval_Incl_EP is the model number just below
4812 -- zero, so we want to stick to the negative value for the
4813 -- base type to maintain the condition that the size will
4814 -- include signed values.
4818 then
4822 else
4826 -- Similar processing for upper bound and high value
4832 else
4838 else
4842 -- One further adjustment is needed. In the case of subtypes, we
4843 -- cannot go outside the range of the base type, or we get
4844 -- peculiarities, and the base type range is already set. This
4845 -- only applies to the Incl values, since clearly the Excl values
4846 -- are already as restricted as they are allowed to be.
4853 -- Get size including and excluding end points
4858 -- No need to exclude end-points if it does not reduce size
4868 -- Now we set the actual size to be used. We want to use the
4869 -- bounds fudged up to include the end-points but only if this
4870 -- can be done without violating a specifically given size
4871 -- size clause or causing an unacceptable increase in size.
4873 -- Case of size clause given
4877 -- Use the inclusive size only if it is consistent with
4878 -- the explicitly specified size.
4885 -- If the inclusive size is too large, we try excluding
4886 -- the end-points (will be caught later if does not work).
4888 else
4894 -- Case of size clause not given
4896 else
4897 -- If we have a base type whose corresponding first subtype
4898 -- has an explicit size that is large enough to include our
4899 -- end-points, then do so. There is no point in working hard
4900 -- to get a base type whose size is smaller than the specified
4901 -- size of the first subtype.
4907 then
4912 -- If excluding the end-points makes the size smaller and
4913 -- results in a size of 8,16,32,64, then we take the smaller
4914 -- size. For the 64 case, this is compulsory. For the other
4915 -- cases, it seems reasonable. We like to include end points
4916 -- if we can, but not at the expense of moving to the next
4917 -- natural boundary of size.
4921 then
4926 -- Otherwise we can definitely include the end points
4928 else
4934 -- One pathological case: normally we never fudge a low bound
4935 -- down, since it would seem to increase the size (if it has
4936 -- any effect), but for ranges containing single value, or no
4937 -- values, the high bound can be small too large. Consider:
4939 -- type t is delta 2.0**(-14)
4940 -- range 131072.0 .. 0;
4942 -- That lower bound is *just* outside the range of 32 bits, and
4943 -- does need fudging down in this case. Note that the bounds
4944 -- will always have crossed here, since the high bound will be
4945 -- fudged down if necessary, as in the case of:
4947 -- type t is delta 2.0**(-14)
4948 -- range 131072.0 .. 131072.0;
4950 -- So we detect the situation by looking for crossed bounds,
4951 -- and if the bounds are crossed, and the low bound is greater
4952 -- than zero, we will always back it off by small, since this
4953 -- is completely harmless.
4960 -- And of course, we need to do exactly the same parallel
4961 -- fudge for flat ranges in the negative region.
4974 -- For the decimal case, none of this fudging is required, since there
4975 -- are no end-point problems in the decimal case (the end-points are
4976 -- always included).
4978 else
4982 -- At this stage, the actual size has been calculated and the proper
4983 -- required bounds are stored in the low and high bounds.
4987 Error_Msg_N
4989 Typ);
4993 -- Check size against explicit given size
4999 Error_Msg_NE
5003 else
5007 -- Increase size to next natural boundary if no size clause given
5009 else
5016 else
5024 -- If we have a base type, then expand the bounds so that they extend to
5025 -- the full width of the allocated size in bits, to avoid junk range
5026 -- checks on intermediate computations.
5033 -- Final step is to reanalyze the bounds using the proper type
5034 -- and set the Corresponding_Integer_Value fields of the literals.
5040 -- Resolve with universal fixed if the base type, and the base type if
5041 -- it is a subtype. Note we can't resolve the base type with itself,
5042 -- that would be a reference before definition.
5046 else
5050 -- Set corresponding integer value for bound
5052 Set_Corresponding_Integer_Value
5055 -- Similar processing for high bound
5063 else
5067 Set_Corresponding_Integer_Value
5070 -- Set type of range to correspond to bounds
5074 -- Set Esize to calculated size if not set already
5080 -- Set RM_Size if not already set. If already set, check value
5082 declare
5085 begin
5090 Error_Msg_NE
5095 else
5101 ------------------
5102 -- Freeze_Itype --
5103 ------------------
5108 begin
5117 --------------------------
5118 -- Freeze_Static_Object --
5119 --------------------------
5124 -- Exception raised if the type of a static object cannot be made
5125 -- static. This happens if the type depends on non-global objects.
5128 -- Called to ensure that an expression used as part of a type definition
5129 -- is statically allocatable, which means that the expression type is
5130 -- statically allocatable, and the expression is either static, or a
5131 -- reference to a library level constant.
5134 -- Called to mark a type as static, checking that it is possible
5135 -- to set the type as static. If it is not possible, then the
5136 -- exception Cannot_Be_Static is raised.
5138 -----------------------------
5139 -- Ensure_Expression_Is_SA --
5140 -----------------------------
5145 begin
5157 then
5165 -----------------------
5166 -- Ensure_Type_Is_SA --
5167 -----------------------
5173 begin
5174 -- If type is library level, we are all set
5180 -- We are also OK if the type already marked as statically allocated,
5181 -- which means we processed it before.
5187 -- Mark type as statically allocated
5191 -- Check that it is safe to statically allocate this type
5209 declare
5213 begin
5225 else
5234 then
5253 else
5258 -- Start of processing for Freeze_Static_Object
5260 begin
5263 exception
5266 -- If the object that cannot be static is imported or exported, then
5267 -- issue an error message saying that this object cannot be imported
5268 -- or exported. If it has an address clause it is an overlay in the
5269 -- current partition and the static requirement is not relevant.
5270 -- Do not issue any error message when ignoring rep clauses.
5277 Error_Msg_N
5281 -- Otherwise must be exported, something is wrong if compiler
5282 -- is marking something as statically allocated which cannot be).
5285 Error_Msg_N
5290 -----------------------
5291 -- Freeze_Subprogram --
5292 -----------------------
5298 begin
5299 -- Subprogram may not have an address clause unless it is imported
5303 Error_Msg_N
5310 -- Reset the Pure indication on an imported subprogram unless an
5311 -- explicit Pure_Function pragma was present. We do this because
5312 -- otherwise it is an insidious error to call a non-pure function from
5313 -- pure unit and have calls mysteriously optimized away. What happens
5314 -- here is that the Import can bypass the normal check to ensure that
5315 -- pure units call only pure subprograms.
5320 then
5324 -- For non-foreign convention subprograms, this is where we create
5325 -- the extra formals (for accessibility level and constrained bit
5326 -- information). We delay this till the freeze point precisely so
5327 -- that we know the convention!
5333 -- If this is convention Ada and a Valued_Procedure, that's odd
5338 and then Warn_On_Export_Import
5339 then
5340 Error_Msg_N
5345 -- Case of foreign convention
5347 else
5350 -- For foreign conventions, warn about return of an
5351 -- unconstrained array.
5353 -- Note: we *do* allow a return by descriptor for the VMS case,
5354 -- though here there is probably more to be done ???
5359 -- If no return type, probably some other error, e.g. a
5360 -- missing full declaration, so ignore.
5365 -- If the return type is generic, we have emitted a warning
5366 -- earlier on, and there is nothing else to check here. Specific
5367 -- instantiations may lead to erroneous behavior.
5372 -- Display warning if returning unconstrained array
5377 -- Exclude cases where descriptor mechanism is set, since the
5378 -- VMS descriptor mechanisms allow such unconstrained returns.
5382 -- Check appropriate warning is enabled (should we check for
5383 -- Warnings (Off) on specific entities here, probably so???)
5385 and then Warn_On_Export_Import
5387 -- Exclude the VM case, since return of unconstrained arrays
5388 -- is properly handled in both the JVM and .NET cases.
5391 then
5392 Error_Msg_N
5399 -- If any of the formals for an exported foreign convention
5400 -- subprogram have defaults, then emit an appropriate warning since
5401 -- this is odd (default cannot be used from non-Ada code)
5406 if Warn_On_Export_Import
5408 then
5409 Error_Msg_N
5419 -- For VMS, descriptor mechanisms for parameters are allowed only for
5420 -- imported/exported subprograms. Moreover, the NCA descriptor is not
5421 -- allowed for parameters of exported subprograms.
5428 Error_Msg_N
5430 Error_Msg_N
5441 Error_Msg_N
5443 Error_Msg_N
5452 -- Pragma Inline_Always is disallowed for dispatching subprograms
5453 -- because the address of such subprograms is saved in the dispatch
5454 -- table to support dispatching calls, and dispatching calls cannot
5455 -- be inlined. This is consistent with the restriction against using
5456 -- 'Access or 'Address on an Inline_Always subprogram.
5460 then
5461 Error_Msg_N
5465 -- Because of the implicit representation of inherited predefined
5466 -- operators in the front-end, the overriding status of the operation
5467 -- may be affected when a full view of a type is analyzed, and this is
5468 -- not captured by the analysis of the corresponding type declaration.
5469 -- Therefore the correctness of a not-overriding indicator must be
5470 -- rechecked when the subprogram is frozen.
5474 then
5479 ----------------------
5480 -- Is_Fully_Defined --
5481 ----------------------
5484 begin
5493 then
5494 -- Verify that the record type has no components with private types
5495 -- without completion.
5497 declare
5500 begin
5512 -- For the designated type of an access to subprogram, all types in
5513 -- the profile must be fully defined.
5516 declare
5519 begin
5532 else
5538 ---------------------------------
5539 -- Process_Default_Expressions --
5540 ---------------------------------
5542 procedure Process_Default_Expressions
5545 is
5552 begin
5555 -- A subprogram instance and its associated anonymous subprogram share
5556 -- their signature. The default expression functions are defined in the
5557 -- wrapper packages for the anonymous subprogram, and should not be
5558 -- generated again for the instance.
5563 then
5571 -- We work with a copy of the default expression because we
5572 -- do not want to disturb the original, since this would mess
5573 -- up the conformance checking.
5577 -- The analysis of the expression may generate insert actions,
5578 -- which of course must not be executed. We wrap those actions
5579 -- in a procedure that is not called, and later on eliminated.
5580 -- The following cases have no side-effects, and are analyzed
5581 -- directly.
5592 and then
5594 then
5596 -- If there is no default function, we must still do a full
5597 -- analyze call on the default value, to ensure that all error
5598 -- checks are performed, e.g. those associated with static
5599 -- evaluation. Note: this branch will always be taken if the
5600 -- analyzer is turned off (but we still need the error checks).
5602 -- Note: the setting of parent here is to meet the requirement
5603 -- that we can only analyze the expression while attached to
5604 -- the tree. Really the requirement is that the parent chain
5605 -- be set, we don't actually need to be in the tree.
5610 -- Default expressions are resolved with their own type if the
5611 -- context is generic, to avoid anomalies with private types.
5615 else
5619 -- If that resolved expression will raise constraint error,
5620 -- then flag the default value as raising constraint error.
5621 -- This allows a proper error message on the calls.
5627 -- If the default is a parameterless call, we use the name of
5628 -- the called function directly, and there is no body to build.
5632 then
5635 -- Else construct and analyze the body of a wrapper procedure
5636 -- that contains an object declaration to hold the expression.
5637 -- Given that this is done only to complete the analysis, it
5638 -- simpler to build a procedure than a function which might
5639 -- involve secondary stack expansion.
5641 else
5644 Dbody :=
5646 Specification =>
5652 Defining_Identifier =>
5655 Object_Definition =>
5659 Handled_Statement_Sequence =>
5676 ----------------------------------------
5677 -- Set_Component_Alignment_If_Not_Set --
5678 ----------------------------------------
5681 begin
5682 -- Ignore if not base type, subtypes don't need anything
5688 -- Do not override existing representation
5699 else
5700 Set_Component_Alignment
5706 ------------------
5707 -- Undelay_Type --
5708 ------------------
5711 begin
5715 -- Since we don't want T to have a Freeze_Node, we don't want its
5716 -- Full_View or Corresponding_Record_Type to have one either.
5718 -- ??? Fundamentally, this whole handling is a kludge. What we really
5719 -- want is to be sure that for an Itype that's part of record R and is a
5720 -- subtype of type T, that it's frozen after the later of the freeze
5721 -- points of R and T. We have no way of doing that directly, so what we
5722 -- do is force most such Itypes to be frozen as part of freezing R via
5723 -- this procedure and only delay the ones that need to be delayed
5724 -- (mostly the designated types of access types that are defined as part
5725 -- of the record).
5731 then
5739 then
5744 ------------------
5745 -- Warn_Overlay --
5746 ------------------
5748 procedure Warn_Overlay
5752 is
5754 -- The object to which the address clause applies
5760 begin
5761 -- No warning if address clause overlay warnings are off
5767 -- No warning if there is an explicit initialization
5775 -- We only give the warning for non-imported entities of a type for
5776 -- which a non-null base init proc is defined, or for objects of access
5777 -- types with implicit null initialization, or when Normalize_Scalars
5778 -- applies and the type is scalar or a string type (the latter being
5779 -- tested for because predefined String types are initialized by inline
5780 -- code rather than by an init_proc). Note that we do not give the
5781 -- warning for Initialize_Scalars, since we suppressed initialization
5782 -- in this case.
5791 then
5794 then
5799 then
5806 then
5813 -- A function call (most likely to To_Address) is probably not an
5814 -- overlay, so skip warning. Ditto if the function call was inlined
5815 -- and transformed into an entity.
5823 -- If a pragma Import follows, we assume that it is for the current
5824 -- target of the address clause, and skip the warning.
5829 then
5835 Error_Msg_N
5837 Nam);
5838 else
5839 Error_Msg_N
5841 Nam);
5844 -- Add friendly warning if initialization comes from a packed array
5845 -- component.
5848 declare
5851 begin
5856 then
5860 then
5861 Error_Msg_NE
5866 else
5873 Error_Msg_N
5876 Nam);