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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) 1992-2009, 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 ------------------------------------------------------------------------------
68 -----------------------
69 -- Local Subprograms --
70 -----------------------
73 -- Typ is a type that is being frozen. If no size clause is given,
74 -- but a default Esize has been computed, then this default Esize is
75 -- adjusted up if necessary to be consistent with a given alignment,
76 -- but never to a value greater than Long_Long_Integer'Size. This
77 -- is used for all discrete types and for fixed-point types.
79 procedure Build_And_Analyze_Renamed_Body
83 -- Build body for a renaming declaration, insert in tree and analyze
86 -- Apply legality checks to address clauses for object declarations,
87 -- at the point the object is frozen.
90 -- E is a base type. If E is tagged or has a component that is aliased
91 -- or tagged or contains something this is aliased or tagged, set
92 -- Strict_Alignment.
96 -- If E is a fixed-point or discrete type, then all the necessary work
97 -- to freeze it is completed except for possible setting of the flag
98 -- Is_Unsigned_Type, which is done by this procedure. The call has no
99 -- effect if the entity E is not a discrete or fixed-point type.
101 procedure Freeze_And_Append
105 -- Freezes Ent using Freeze_Entity, and appends the resulting list of
106 -- nodes to Result, modifying Result from No_List if necessary.
109 -- Freeze enumeration type. The Esize field is set as processing
110 -- proceeds (i.e. set by default when the type is declared and then
111 -- adjusted by rep clauses. What this procedure does is to make sure
112 -- that if a foreign convention is specified, and no specific size
113 -- is given, then the size must be at least Integer'Size.
116 -- If an object is frozen which has Is_Statically_Allocated set, then
117 -- all referenced types must also be marked with this flag. This routine
118 -- is in charge of meeting this requirement for the object entity E.
121 -- Perform freezing actions for a subprogram (create extra formals,
122 -- and set proper default mechanism values). Note that this routine
123 -- is not called for internal subprograms, for which neither of these
124 -- actions is needed (or desirable, we do not want for example to have
125 -- these extra formals present in initialization procedures, where they
126 -- would serve no purpose). In this call E is either a subprogram or
127 -- a subprogram type (i.e. an access to a subprogram).
130 -- True if T is not private and has no private components, or has a full
131 -- view. Used to determine whether the designated type of an access type
132 -- should be frozen when the access type is frozen. This is done when an
133 -- allocator is frozen, or an expression that may involve attributes of
134 -- the designated type. Otherwise freezing the access type does not freeze
135 -- the designated type.
137 procedure Process_Default_Expressions
140 -- This procedure is called for each subprogram to complete processing
141 -- of default expressions at the point where all types are known to be
142 -- frozen. The expressions must be analyzed in full, to make sure that
143 -- all error processing is done (they have only been pre-analyzed). If
144 -- the expression is not an entity or literal, its analysis may generate
145 -- code which must not be executed. In that case we build a function
146 -- body to hold that code. This wrapper function serves no other purpose
147 -- (it used to be called to evaluate the default, but now the default is
148 -- inlined at each point of call).
151 -- Typ is a record or array type that is being frozen. This routine
152 -- sets the default component alignment from the scope stack values
153 -- if the alignment is otherwise not specified.
156 -- As each entity is frozen, this routine is called to deal with the
157 -- setting of Debug_Info_Needed for the entity. This flag is set if
158 -- the entity comes from source, or if we are in Debug_Generated_Code
159 -- mode or if the -gnatdV debug flag is set. However, it never sets
160 -- the flag if Debug_Info_Off is set. This procedure also ensures that
161 -- subsidiary entities have the flag set as required.
164 -- T is a type of a component that we know to be an Itype.
165 -- We don't want this to have a Freeze_Node, so ensure it doesn't.
166 -- Do the same for any Full_View or Corresponding_Record_Type.
168 procedure Warn_Overlay
172 -- Expr is the expression for an address clause for entity Nam whose type
173 -- is Typ. If Typ has a default initialization, and there is no explicit
174 -- initialization in the source declaration, check whether the address
175 -- clause might cause overlaying of an entity, and emit a warning on the
176 -- side effect that the initialization will cause.
178 -------------------------------
179 -- Adjust_Esize_For_Alignment --
180 -------------------------------
185 begin
191 then
197 ------------------------------------
198 -- Build_And_Analyze_Renamed_Body --
199 ------------------------------------
201 procedure Build_And_Analyze_Renamed_Body
205 is
207 begin
214 ------------------------
215 -- Build_Renamed_Body --
216 ------------------------
218 function Build_Renamed_Body
221 is
223 -- We use for the source location of the renamed body, the location
224 -- of the spec entity. It might seem more natural to use the location
225 -- of the renaming declaration itself, but that would be wrong, since
226 -- then the body we create would look as though it was created far
227 -- too late, and this could cause problems with elaboration order
228 -- analysis, particularly in connection with instantiations.
243 -- If the renamed entity is a primitive operation given in prefix form,
244 -- the prefix is the target object and it has to be added as the first
245 -- actual in the generated call.
247 begin
248 -- Determine the entity being renamed, which is the target of the call
249 -- statement. If the name is an explicit dereference, this is a renaming
250 -- of a subprogram type rather than a subprogram. The name itself is
251 -- fully analyzed.
262 else
269 else
275 -- If the renamed entity is a predefined operator, retain full name
276 -- to ensure its visibility.
280 then
282 else
286 else
289 and then
292 then
294 -- Retrieve the target object, to be added as a first actual
295 -- in the call.
300 else
304 -- The original name may have been overloaded, but
305 -- is fully resolved now.
310 -- For simple renamings, subsequent calls can be expanded directly as
311 -- called to the renamed entity. The body must be generated in any case
312 -- for calls they may appear elsewhere.
317 then
321 -- The body generated for this renaming is an internal artifact, and
322 -- does not constitute a freeze point for the called entity.
329 declare
333 begin
335 -- The controlling formal may be an access parameter, or the
336 -- actual may be an access value, so adjust accordingly.
340 then
341 Actuals := New_List
346 then
347 Actuals := New_List
351 else
359 else
370 -- If the renamed entity is an entry, inherit its profile. For other
371 -- renamings as bodies, both profiles must be subtype conformant, so it
372 -- is not necessary to replace the profile given in the declaration.
373 -- However, default values that are aggregates are rewritten when
374 -- partially analyzed, so we recover the original aggregate to insure
375 -- that subsequent conformity checking works. Similarly, if the default
376 -- expression was constant-folded, recover the original expression.
388 N_Access_Definition
389 then
397 then
408 -- If the renamed entity is a function, the generated body contains a
409 -- return statement. Otherwise, build a procedure call. If the entity is
410 -- an entry, subsequent analysis of the call will transform it into the
411 -- proper entry or protected operation call. If the renamed entity is
412 -- a character literal, return it directly.
418 then
419 Call_Node :=
421 Expression =>
427 Call_Node :=
432 Call_Node :=
436 else
437 Call_Node :=
443 -- Create entities for subprogram body and formals
457 Body_Node :=
461 Handled_Statement_Sequence =>
471 -- Link the body to the entity whose declaration it completes. If
472 -- the body is analyzed when the renamed entity is frozen, it may
473 -- be necessary to restore the proper scope (see package Exp_Ch13).
477 then
479 else
486 --------------------------
487 -- Check_Address_Clause --
488 --------------------------
496 begin
500 -- If we have no initialization of any kind, then we don't need to
501 -- place any restrictions on the address clause, because the object
502 -- will be elaborated after the address clause is evaluated. This
503 -- happens if the declaration has no initial expression, or the type
504 -- has no implicit initialization, or the object is imported.
506 -- The same holds for all initialized scalar types and all access
507 -- types. Packed bit arrays of size up to 64 are represented using a
508 -- modular type with an initialization (to zero) and can be processed
509 -- like other initialized scalar types.
511 -- If the type is controlled, code to attach the object to a
512 -- finalization chain is generated at the point of declaration,
513 -- and therefore the elaboration of the object cannot be delayed:
514 -- the address expression must be a constant.
518 and then
522 or else
526 or else
529 or else
531 and then
533 then
536 -- Otherwise, we require the address clause to be constant because
537 -- the call to the initialization procedure (or the attach code) has
538 -- to happen at the point of the declaration.
539 -- Actually the IP call has been moved to the freeze actions
540 -- anyway, so maybe we can relax this restriction???
542 else
545 -- Has_Delayed_Freeze was set on E when the address clause was
546 -- analyzed. Reset the flag now unless freeze actions were
547 -- attached to it in the mean time.
556 then
562 -----------------------------
563 -- Check_Compile_Time_Size --
564 -----------------------------
569 -- Sets the compile time known size (32 bits or less) in the Esize
570 -- field, of T checking for a size clause that was given which attempts
571 -- to give a smaller size, and also checking for an alignment clause.
574 -- Recursive function that does all the work
577 -- If T is a constrained subtype, its size is not known if any of its
578 -- discriminant constraints is not static and it is not a null record.
579 -- The test is conservative and doesn't check that the components are
580 -- in fact constrained by non-static discriminant values. Could be made
581 -- more precise ???
583 --------------------
584 -- Set_Small_Size --
585 --------------------
588 begin
592 -- Don't bother if alignment clause with a value other than 1 is
593 -- present, because size may be padded up to meet back end alignment
594 -- requirements, and only the back end knows the rules!
599 -- Check for bad size clause given
604 Error_Msg_NE
612 -- Set sizes if not set already
614 else
625 ----------------
626 -- Size_Known --
627 ----------------
636 begin
640 -- Always True for scalar types. This is true even for generic formal
641 -- scalar types. We used to return False in the latter case, but the
642 -- size is known at compile time, even in the template, we just do
643 -- not know the exact size but that's not the point of this routine.
647 then
650 -- Array types
654 -- String literals always have known size, and we can set it
661 -- Unconstrained types never have known at compile time size
666 -- Don't do any recursion on type with error posted, since we may
667 -- have a malformed type that leads us into a loop.
672 -- Otherwise if component size unknown, then array size unknown
678 -- Check for all indexes static, and also compute possible size
679 -- (in case it is less than 32 and may be packable).
681 declare
685 begin
694 else
702 then
705 else
710 else
722 -- Access types always have known at compile time sizes
727 -- For non-generic private types, go to underlying type if present
732 then
733 -- Don't do any recursion on type with error posted, since we may
734 -- have a malformed type that leads us into a loop.
738 else
742 -- Record types
746 -- A class-wide type is never considered to have a known size
751 -- A subtype of a variant record must not have non-static
752 -- discriminanted components.
756 then
759 -- Don't do any recursion on type with error posted, since we may
760 -- have a malformed type that leads us into a loop.
766 -- Now look at the components of the record
768 declare
769 -- The following two variables are used to keep track of the
770 -- size of packed records if we can tell the size of the packed
771 -- record in the front end. Packed_Size_Known is True if so far
772 -- we can figure out the size. It is initialized to True for a
773 -- packed record, unless the record has discriminants. The
774 -- reason we eliminate the discriminated case is that we don't
775 -- know the way the back end lays out discriminated packed
776 -- records. If Packed_Size_Known is True, then Packed_Size is
777 -- the size in bits so far.
785 begin
786 -- Test for variant part present
792 N_Record_Definition
796 then
797 -- If variant part is present, and type is unconstrained,
798 -- then we must have defaulted discriminants, or a size
799 -- clause must be present for the type, or else the size
800 -- is definitely not known at compile time.
803 and then
804 No (Discriminant_Default_Value
807 then
812 -- Loop through components
818 -- We do not know the packed size if there is a component
819 -- clause present (we possibly could, but this would only
820 -- help in the case of a record with partial rep clauses.
821 -- That's because in the case of full rep clauses, the
822 -- size gets figured out anyway by a different circuit).
828 -- We need to identify a component that is an array where
829 -- the index type is an enumeration type with non-standard
830 -- representation, and some bound of the type depends on a
831 -- discriminant.
833 -- This is because gigi computes the size by doing a
834 -- substitution of the appropriate discriminant value in
835 -- the size expression for the base type, and gigi is not
836 -- clever enough to evaluate the resulting expression (which
837 -- involves a call to rep_to_pos) at compile time.
839 -- It would be nice if gigi would either recognize that
840 -- this expression can be computed at compile time, or
841 -- alternatively figured out the size from the subtype
842 -- directly, where all the information is at hand ???
846 then
847 declare
855 begin
862 then
868 then
873 then
883 -- Clearly size of record is not known if the size of one of
884 -- the components is not known.
890 -- Accumulate packed size if possible
894 -- We can only deal with elementary types, since for
895 -- non-elementary components, alignment enters into the
896 -- picture, and we don't know enough to handle proper
897 -- alignment in this context. Packed arrays count as
898 -- elementary if the representation is a modular type.
903 and then Is_Modular_Integer_Type
905 then
906 -- If RM_Size is known and static, then we can keep
907 -- accumulating the packed size.
911 -- A little glitch, to be removed sometime ???
912 -- gigi does not understand zero sizes yet.
917 -- Normal case where we can keep accumulating the
918 -- packed array size.
920 else
924 -- If we have a field whose RM_Size is not known then
925 -- we can't figure out the packed size here.
927 else
931 -- If we have a non-elementary type we can't figure out
932 -- the packed array size (alignment issues).
934 else
949 -- All other cases, size not known at compile time
951 else
956 -------------------------------------
957 -- Static_Discriminated_Components --
958 -------------------------------------
960 function Static_Discriminated_Components
962 is
965 begin
969 then
983 -- Start of processing for Check_Compile_Time_Size
985 begin
989 -----------------------------
990 -- Check_Debug_Info_Needed --
991 -----------------------------
994 begin
999 or else Debug_Generated_Code
1000 or else Debug_Flag_VV
1002 then
1007 ----------------------------
1008 -- Check_Strict_Alignment --
1009 ----------------------------
1014 begin
1033 then
1043 -------------------------
1044 -- Check_Unsigned_Type --
1045 -------------------------
1052 begin
1057 -- Do not attempt to analyze case where range was in error
1063 -- The situation that is non trivial is something like
1065 -- subtype x1 is integer range -10 .. +10;
1066 -- subtype x2 is x1 range 0 .. V1;
1067 -- subtype x3 is x2 range V2 .. V3;
1068 -- subtype x4 is x3 range V4 .. V5;
1070 -- where Vn are variables. Here the base type is signed, but we still
1071 -- know that x4 is unsigned because of the lower bound of x2.
1073 -- The only way to deal with this is to look up the ancestor chain
1076 loop
1091 else
1094 -- If no ancestor had a static lower bound, go to base type
1098 -- Note: the reason we still check for a compile time known
1099 -- value for the base type is that at least in the case of
1100 -- generic formals, we can have bounds that fail this test,
1101 -- and there may be other cases in error situations.
1113 then
1123 -------------------------
1124 -- Is_Atomic_Aggregate --
1125 -------------------------
1127 function Is_Atomic_Aggregate
1130 is
1136 begin
1139 -- Array may be qualified, so find outer context
1147 then
1148 Temp :=
1152 New_N :=
1163 else
1168 ----------------
1169 -- Freeze_All --
1170 ----------------
1172 -- Note: the easy coding for this procedure would be to just build a
1173 -- single list of freeze nodes and then insert them and analyze them
1174 -- all at once. This won't work, because the analysis of earlier freeze
1175 -- nodes may recursively freeze types which would otherwise appear later
1176 -- on in the freeze list. So we must analyze and expand the freeze nodes
1177 -- as they are generated.
1185 -- This is the internal recursive routine that does freezing of entities
1186 -- (but NOT the analysis of default expressions, which should not be
1187 -- recursive, we don't want to analyze those till we are sure that ALL
1188 -- the types are frozen).
1190 --------------------
1191 -- Freeze_All_Ent --
1192 --------------------
1194 procedure Freeze_All_Ent
1197 is
1203 -- If freeze nodes are present, insert and analyze, and reset cursor
1204 -- for next insertion.
1206 -------------------
1207 -- Process_Flist --
1208 -------------------
1211 begin
1218 else
1224 -- Start or processing for Freeze_All_Ent
1226 begin
1230 -- If the entity is an inner package which is not a package
1231 -- renaming, then its entities must be frozen at this point. Note
1232 -- that such entities do NOT get frozen at the end of the nested
1233 -- package itself (only library packages freeze).
1235 -- Same is true for task declarations, where anonymous records
1236 -- created for entry parameters must be frozen.
1242 then
1252 and then
1254 or else
1256 then
1259 End_Scope;
1261 -- For a derived tagged type, we must ensure that all the
1262 -- primitive operations of the parent have been frozen, so that
1263 -- their addresses will be in the parent's dispatch table at the
1264 -- point it is inherited.
1270 then
1271 declare
1278 begin
1286 then
1288 Process_Flist;
1298 Process_Flist;
1301 -- If an incomplete type is still not frozen, this may be a
1302 -- premature freezing because of a body declaration that follows.
1303 -- Indicate where the freezing took place.
1305 -- If the freezing is caused by the end of the current declarative
1306 -- part, it is a Taft Amendment type, and there is no error.
1310 then
1311 declare
1314 begin
1321 and then
1323 then
1325 Error_Msg_NE
1336 -- Start of processing for Freeze_All
1338 begin
1341 -- Now that all types are frozen, we can deal with default expressions
1342 -- that require us to build a default expression functions. This is the
1343 -- point at which such functions are constructed (after all types that
1344 -- might be used in such expressions have been frozen).
1346 -- We also add finalization chains to access types whose designated
1347 -- types are controlled. This is normally done when freezing the type,
1348 -- but this misses recursive type definitions where the later members
1349 -- of the recursion introduce controlled components.
1351 -- Loop through entities
1369 and then
1371 = N_Subprogram_Renaming_Declaration
1372 then
1373 Build_And_Analyze_Renamed_Body
1379 and then
1381 or else
1383 then
1384 declare
1386 begin
1393 then
1406 then
1414 -----------------------
1415 -- Freeze_And_Append --
1416 -----------------------
1418 procedure Freeze_And_Append
1422 is
1424 begin
1428 else
1434 -------------------
1435 -- Freeze_Before --
1436 -------------------
1440 begin
1446 -------------------
1447 -- Freeze_Entity --
1448 -------------------
1460 -- This flag gets set to true for a variable with default initialization
1463 -- Check that an Access or Unchecked_Access attribute with a prefix
1464 -- which is the current instance type can only be applied when the type
1465 -- is limited.
1468 -- Give warning for modulus of 8, 16, 32, or 64 given as an explicit
1469 -- integer literal without an explicit corresponding size clause. The
1470 -- caller has checked that Utype is a modular integer type.
1473 -- If Loc is a freeze_entity that appears after the last declaration
1474 -- in the scope, inhibit error messages on late completion.
1477 -- Freeze each component, handle some representation clauses, and freeze
1478 -- primitive operations if this is a tagged type.
1480 ----------------------------
1481 -- After_Last_Declaration --
1482 ----------------------------
1486 begin
1492 else
1495 else
1500 ----------------------------
1501 -- Check_Current_Instance --
1502 ----------------------------
1512 -- Process routine to apply check to given node
1514 -------------
1515 -- Process --
1516 -------------
1519 begin
1523 or else
1528 then
1529 Error_Msg_N
1532 else
1542 -- Start of processing for Check_Current_Instance
1544 begin
1545 -- In Ada95, the (imprecise) rule is that the current instance of a
1546 -- limited type is aliased. In Ada2005, limitedness must be explicit:
1547 -- either a tagged type, or a limited record.
1551 then
1556 then
1559 else
1564 ------------------------------
1565 -- Check_Suspicious_Modulus --
1566 ------------------------------
1571 begin
1573 declare
1575 begin
1577 declare
1580 begin
1582 declare
1586 begin
1587 -- First case, modulus and size are the same. This
1588 -- happens if you have something like mod 32, with
1589 -- an explicit size of 32, this is for sure a case
1590 -- where the warning is given, since it is seems
1591 -- very unlikely that someone would want e.g. a
1592 -- five bit type stored in 32 bits. It is much
1593 -- more likely they wanted a 32-bit type.
1598 -- Second case, the modulus is 32 or 64 and no
1599 -- size clause is present. This is a less clear
1600 -- case for giving the warning, but in the case
1601 -- of 32/64 (5-bit or 6-bit types) these seem rare
1602 -- enough that it is a likely error (and in any
1603 -- case using 2**5 or 2**6 in these cases seems
1604 -- clearer. We don't include 8 or 16 here, simply
1605 -- because in practice 3-bit and 4-bit types are
1606 -- more common and too many false positives if
1607 -- we warn in these cases.
1611 then
1614 -- No warning needed
1616 else
1620 -- If we fall through, give warning
1623 Error_Msg_N
1625 Modulus);
1634 ------------------------
1635 -- Freeze_Record_Type --
1636 ------------------------
1648 -- Set True if we find at least one component with no component
1649 -- clause (used to warn about useless Pack pragmas).
1652 -- Set True if we find at least one component with a component
1653 -- clause (used to warn about useless Bit_Order pragmas, and also
1654 -- to detect cases where Implicit_Packing may have an effect).
1657 -- Set False if we encounter a component of a non-scalar type
1661 -- Accumulates total RM_Size values and total Esize values of all
1662 -- scalar components. Used for processing of Implicit_Packing.
1665 -- If N is an allocator, possibly wrapped in one or more level of
1666 -- qualified expression(s), return the inner allocator node, else
1667 -- return Empty.
1670 -- If the component subtype is an access to a constrained subtype of
1671 -- an already frozen type, make the subtype frozen as well. It might
1672 -- otherwise be frozen in the wrong scope, and a freeze node on
1673 -- subtype has no effect. Similarly, if the component subtype is a
1674 -- regular (not protected) access to subprogram, set the anonymous
1675 -- subprogram type to frozen as well, to prevent an out-of-scope
1676 -- freeze node at some eventual point of call. Protected operations
1677 -- are handled elsewhere.
1679 ---------------------
1680 -- Check_Allocator --
1681 ---------------------
1685 begin
1687 loop
1692 else
1698 -----------------
1699 -- Check_Itype --
1700 -----------------
1705 begin
1708 then
1711 -- In addition, add an Itype_Reference to ensure that the
1712 -- access subtype is elaborated early enough. This cannot be
1713 -- done if the subtype may depend on discriminants.
1718 then
1724 else
1731 then
1736 -- Start of processing for Freeze_Record_Type
1738 begin
1739 -- If this is a subtype of a controlled type, declared without a
1740 -- constraint, the _controller may not appear in the component list
1741 -- if the parent was not frozen at the point of subtype declaration.
1742 -- Inherit the _controller component now.
1746 then
1749 then
1752 -- If this is an internal type without a declaration, as for
1753 -- record component, the base type may not yet be frozen, and its
1754 -- controller has not been created. Add an explicit freeze node
1755 -- for the itype, so it will be frozen after the base type. This
1756 -- freeze node is used to communicate with the expander, in order
1757 -- to create the controller for the enclosing record, and it is
1758 -- deleted afterwards (see exp_ch3). It must not be created when
1759 -- expansion is off, because it might appear in the wrong context
1760 -- for the back end.
1764 and then
1766 N_Component_Declaration
1767 and then Expander_Active
1768 then
1773 -- Freeze components and embedded subtypes
1779 -- First handle the (real) component case
1783 then
1784 declare
1787 begin
1788 -- Freezing a record type freezes the type of each of its
1789 -- components. However, if the type of the component is
1790 -- part of this record, we do not want or need a separate
1791 -- Freeze_Node. Note that Is_Itype is wrong because that's
1792 -- also set in private type cases. We also can't check for
1793 -- the Scope being exactly Rec because of private types and
1794 -- record extensions.
1799 then
1805 -- Check for error of component clause given for variable
1806 -- sized type. We have to delay this test till this point,
1807 -- since the component type has to be frozen for us to know
1808 -- if it is variable length. We omit this test in a generic
1809 -- context, it will be applied at instantiation time.
1817 elsif not
1818 Size_Known_At_Compile_Time
1820 then
1821 Error_Msg_N
1826 else
1830 -- Case of component requires byte alignment
1834 -- Set the enclosing record to also require byte align
1838 -- Check for component clause that is inconsistent with
1839 -- the required byte boundary alignment.
1844 then
1845 Error_Msg_N
1851 -- If component clause is present, then deal with the non-
1852 -- default bit order case for Ada 95 mode. The required
1853 -- processing for Ada 2005 mode is handled separately after
1854 -- processing all components.
1856 -- We only do this processing for the base type, and in
1857 -- fact that's important, since otherwise if there are
1858 -- record subtypes, we could reverse the bits once for
1859 -- each subtype, which would be incorrect.
1865 then
1866 declare
1879 begin
1880 -- Cases where field goes over storage unit boundary
1884 -- Allow multi-byte field but generate warning
1888 then
1889 Error_Msg_N
1894 Error_Msg_N
1897 else
1898 Error_Msg_N
1903 -- Do not allow non-contiguous field
1905 else
1906 Error_Msg_N
1909 Error_Msg_N
1912 Error_Msg_N
1917 -- Case where field fits in one storage unit
1919 else
1920 -- Give warning if suspicious component clause
1923 and then Warn_On_Reverse_Bit_Order
1924 then
1925 Error_Msg_N
1928 Error_Msg_Uint_1 :=
1930 System_Storage_Unit;
1931 Error_Msg_N
1936 -- Here is where we fix up the Component_Bit_Offset
1937 -- value to account for the reverse bit order.
1938 -- Some examples of what needs to be done are:
1940 -- First_Bit .. Last_Bit Component_Bit_Offset
1941 -- old new old new
1943 -- 0 .. 0 7 .. 7 0 7
1944 -- 0 .. 1 6 .. 7 0 6
1945 -- 0 .. 2 5 .. 7 0 5
1946 -- 0 .. 7 0 .. 7 0 4
1948 -- 1 .. 1 6 .. 6 1 6
1949 -- 1 .. 4 3 .. 6 1 3
1950 -- 4 .. 7 0 .. 3 4 0
1952 -- The general rule is that the first bit is
1953 -- is obtained by subtracting the old ending bit
1954 -- from storage_unit - 1.
1956 Set_Component_Bit_Offset
1962 Set_Normalized_First_Bit
1965 System_Storage_Unit);
1972 -- Gather data for possible Implicit_Packing later
1976 else
1977 Scalar_Component_Total_RM_Size :=
1979 Scalar_Component_Total_Esize :=
1983 -- If the component is an Itype with Delayed_Freeze and is either
1984 -- a record or array subtype and its base type has not yet been
1985 -- frozen, we must remove this from the entity list of this
1986 -- record and put it on the entity list of the scope of its base
1987 -- type. Note that we know that this is not the type of a
1988 -- component since we cleared Has_Delayed_Freeze for it in the
1989 -- previous loop. Thus this must be the Designated_Type of an
1990 -- access type, which is the type of a component.
1998 then
1999 declare
2003 begin
2004 -- We have a pretty bad kludge here. Suppose Rec is subtype
2005 -- being defined in a subprogram that's created as part of
2006 -- the freezing of Rec'Base. In that case, we know that
2007 -- Comp'Base must have already been frozen by the time we
2008 -- get to elaborate this because Gigi doesn't elaborate any
2009 -- bodies until it has elaborated all of the declarative
2010 -- part. But Is_Frozen will not be set at this point because
2011 -- we are processing code in lexical order.
2013 -- We detect this case by going up the Scope chain of Rec
2014 -- and seeing if we have a subprogram scope before reaching
2015 -- the top of the scope chain or that of Comp'Base. If we
2016 -- do, then mark that Comp'Base will actually be frozen. If
2017 -- so, we merely undelay it.
2033 else
2036 else
2040 -- Insert in entity list of scope of base type (which
2041 -- must be an enclosing scope, because still unfrozen).
2047 -- If the component is an access type with an allocator as default
2048 -- value, the designated type will be frozen by the corresponding
2049 -- expression in init_proc. In order to place the freeze node for
2050 -- the designated type before that for the current record type,
2051 -- freeze it now.
2053 -- Same process if the component is an array of access types,
2054 -- initialized with an aggregate. If the designated type is
2055 -- private, it cannot contain allocators, and it is premature
2056 -- to freeze the type, so we check for this as well.
2061 then
2062 declare
2066 begin
2069 -- If component is pointer to a classwide type, freeze
2070 -- the specific type in the expression being allocated.
2071 -- The expression may be a subtype indication, in which
2072 -- case freeze the subtype mark.
2074 if Is_Class_Wide_Type
2076 then
2078 Freeze_And_Append
2080 elsif
2082 then
2083 Freeze_And_Append
2091 else
2092 Freeze_And_Append
2100 then
2109 and then Is_Fully_Defined
2111 then
2112 Freeze_And_Append
2113 (Designated_Type
2121 -- Deal with pragma Bit_Order
2125 ADC :=
2127 Error_Msg_N
2129 Error_Msg_N
2132 -- Here is where we do Ada 2005 processing for bit order (the Ada
2133 -- 95 case was already taken care of above).
2140 -- Set OK_To_Reorder_Components depending on debug flags
2144 then
2146 or else
2148 then
2153 -- Check for useless pragma Pack when all components placed. We only
2154 -- do this check for record types, not subtypes, since a subtype may
2155 -- have all its components placed, and it still makes perfectly good
2156 -- sense to pack other subtypes or the parent type. We do not give
2157 -- this warning if Optimize_Alignment is set to Space, since the
2158 -- pragma Pack does have an effect in this case (it always resets
2159 -- the alignment to one).
2163 and then not Unplaced_Component
2165 then
2166 -- Reset packed status. Probably not necessary, but we do it so
2167 -- that there is no chance of the back end doing something strange
2168 -- with this redundant indication of packing.
2172 -- Give warning if redundant constructs warnings on
2175 Error_Msg_N
2181 -- If this is the record corresponding to a remote type, freeze the
2182 -- remote type here since that is what we are semantically freezing.
2183 -- This prevents the freeze node for that type in an inner scope.
2185 -- Also, Check for controlled components and unchecked unions.
2186 -- Finally, enforce the restriction that access attributes with a
2187 -- current instance prefix can only apply to limited types.
2191 Freeze_And_Append
2198 -- Do not set Has_Controlled_Component on a class-wide
2199 -- equivalent type. See Make_CW_Equivalent_Type.
2206 and then Present
2207 (Corresponding_Record_Type
2209 and then Has_Controlled_Component
2210 (Corresponding_Record_Type
2212 then
2223 -- Scan component declaration for likely misuses of current
2224 -- instance, either in a constraint or a default expression.
2235 -- For first subtypes, check if there are any fixed-point fields with
2236 -- component clauses, where we must check the size. This is not done
2237 -- till the freeze point, since for fixed-point types, we do not know
2238 -- the size until the type is frozen. Similar processing applies to
2239 -- bit packed arrays.
2247 or else
2249 then
2250 Check_Size
2254 Junk);
2261 -- Generate warning for applying C or C++ convention to a record
2262 -- with discriminants. This is suppressed for the unchecked union
2263 -- case, since the whole point in this case is interface C. We also
2264 -- do not generate this within instantiations, since we will have
2265 -- generated a message on the template.
2270 or else
2273 and then not In_Instance
2276 then
2277 declare
2281 begin
2286 Error_Msg_N
2288 else
2289 Error_Msg_N
2293 Error_Msg_NE
2299 -- See if Size is too small as is (and implicit packing might help)
2303 -- No implicit packing if even one component is explicitly placed
2305 and then not Placed_Component
2307 -- Must have size clause and all scalar components
2310 and then All_Scalar_Components
2312 -- Do not try implicit packing on records with discriminants, too
2313 -- complicated, especially in the variant record case.
2317 -- We can implicitly pack if the specified size of the record is
2318 -- less than the sum of the object sizes (no point in packing if
2319 -- this is not the case).
2323 -- And the total RM size cannot be greater than the specified size
2324 -- since otherwise packing will not get us where we have to be!
2328 -- Never do implicit packing in CodePeer mode since we don't do
2329 -- any packing ever in this mode (why not???)
2331 and then not CodePeer_Mode
2332 then
2333 -- If implicit packing enabled, do it
2338 -- Otherwise flag the size clause
2340 else
2341 declare
2343 begin
2344 Error_Msg_NE -- CODEFIX
2346 Error_Msg_N -- CODEFIX
2354 -- Start of processing for Freeze_Entity
2356 begin
2357 -- We are going to test for various reasons why this entity need not be
2358 -- frozen here, but in the case of an Itype that's defined within a
2359 -- record, that test actually applies to the record.
2365 then
2369 -- Do not freeze if already frozen since we only need one freeze node
2374 -- It is improper to freeze an external entity within a generic because
2375 -- its freeze node will appear in a non-valid context. The entity will
2376 -- be frozen in the proper scope after the current generic is analyzed.
2381 -- Do not freeze a global entity within an inner scope created during
2382 -- expansion. A call to subprogram E within some internal procedure
2383 -- (a stream attribute for example) might require freezing E, but the
2384 -- freeze node must appear in the same declarative part as E itself.
2385 -- The two-pass elaboration mechanism in gigi guarantees that E will
2386 -- be frozen before the inner call is elaborated. We exclude constants
2387 -- from this test, because deferred constants may be frozen early, and
2388 -- must be diagnosed (e.g. in the case of a deferred constant being used
2389 -- in a default expression). If the enclosing subprogram comes from
2390 -- source, or is a generic instance, then the freeze point is the one
2391 -- mandated by the language, and we freeze the entity. A subprogram that
2392 -- is a child unit body that acts as a spec does not have a spec that
2393 -- comes from source, but can only come from source.
2398 then
2399 declare
2402 begin
2408 then
2410 else
2419 -- Similarly, an inlined instance body may make reference to global
2420 -- entities, but these references cannot be the proper freezing point
2421 -- for them, and in the absence of inlining freezing will take place in
2422 -- their own scope. Normally instance bodies are analyzed after the
2423 -- enclosing compilation, and everything has been frozen at the proper
2424 -- place, but with front-end inlining an instance body is compiled
2425 -- before the end of the enclosing scope, and as a result out-of-order
2426 -- freezing must be prevented.
2428 elsif Front_End_Inlining
2429 and then In_Instance_Body
2431 then
2432 declare
2435 begin
2439 else
2450 -- Here to freeze the entity
2455 -- Case of entity being frozen is other than a type
2459 -- If entity is exported or imported and does not have an external
2460 -- name, now is the time to provide the appropriate default name.
2461 -- Skip this if the entity is stubbed, since we don't need a name
2462 -- for any stubbed routine. For the case on intrinsics, if no
2463 -- external name is specified, then calls will be handled in
2464 -- Exp_Intr.Expand_Intrinsic_Call, and no name is needed; if
2465 -- an external name is provided, then Expand_Intrinsic_Call leaves
2466 -- calls in place for expansion by GIGI.
2472 then
2473 Set_Encoded_Interface_Name
2476 -- If entity is an atomic object appearing in a declaration and
2477 -- the expression is an aggregate, assign it to a temporary to
2478 -- ensure that the actual assignment is done atomically rather
2479 -- than component-wise (the assignment to the temp may be done
2480 -- component-wise, but that is harmless).
2486 and then
2488 then
2492 -- For a subprogram, freeze all parameter types and also the return
2493 -- type (RM 13.14(14)). However skip this for internal subprograms.
2494 -- This is also the point where any extra formal parameters are
2495 -- created since we now know whether the subprogram will use a
2496 -- foreign convention.
2500 declare
2505 begin
2506 -- Loop through formals
2518 then
2519 -- If the type of a formal is incomplete, subprogram
2520 -- is being frozen prematurely. Within an instance
2521 -- (but not within a wrapper package) this is an
2522 -- artifact of our need to regard the end of an
2523 -- instantiation as a freeze point. Otherwise it is
2524 -- a definite error.
2530 elsif not After_Last_Declaration
2531 and then not Freezing_Library_Level_Tagged_Type
2532 then
2534 Error_Msg
2536 Loc);
2540 -- Check suspicious parameter for C function. These tests
2541 -- apply only to exported/imported subprograms.
2543 if Warn_On_Export_Import
2546 or else
2553 then
2554 -- Qualify mention of formals with subprogram name
2558 -- Check suspicious use of fat C pointer
2562 then
2563 Error_Msg_N
2565 Formal);
2567 -- Check suspicious return of boolean
2574 then
2575 Error_Msg_N
2577 Error_Msg_N
2581 -- Check suspicious tagged type
2585 and then
2586 Is_Tagged_Type
2589 then
2590 Error_Msg_N
2594 -- Check wrong convention subprogram pointer
2598 then
2599 Error_Msg_N
2603 Error_Msg_NE
2608 -- Turn off name qualification after message output
2613 -- Check for unconstrained array in exported foreign
2614 -- convention case.
2620 and then Warn_On_Export_Import
2622 -- Exclude VM case, since both .NET and JVM can handle
2623 -- unconstrained arrays without a problem.
2626 then
2629 -- If this is an inherited operation, place the
2630 -- warning on the derived type declaration, rather
2631 -- than on the original subprogram.
2634 N_Full_Type_Declaration
2635 then
2639 Error_Msg_NE
2642 else
2646 Error_Msg_NE
2649 Error_Msg_NE
2660 -- If the formal is an anonymous_access_to_subprogram
2661 -- freeze the subprogram type as well, to prevent
2662 -- scope anomalies in gigi, because there is no other
2663 -- clear point at which it could be frozen.
2667 then
2675 -- Case of function: similar checks on return type
2679 -- Freeze return type
2684 -- Check suspicious return type for C function
2686 if Warn_On_Export_Import
2688 or else
2691 then
2692 -- Check suspicious return of fat C pointer
2698 then
2699 Error_Msg_N
2703 -- Check suspicious return of boolean
2711 then
2712 declare
2715 begin
2716 Error_Msg_NE
2719 Error_Msg_NE
2724 -- Check suspicious return tagged type
2728 and then
2729 Is_Tagged_Type
2734 then
2735 Error_Msg_N
2739 -- Check return of wrong convention subprogram pointer
2745 then
2746 Error_Msg_N
2750 Error_Msg_NE
2756 -- Give warning for suspicous return of a result of an
2757 -- unconstrained array type in a foreign convention
2758 -- function.
2762 -- We are looking for a return of unconstrained array
2767 -- Exclude imported routines, the warning does not
2768 -- belong on the import, but on the routine definition.
2772 -- Exclude VM case, since both .NET and JVM can handle
2773 -- return of unconstrained arrays without a problem.
2777 -- Check that general warning is enabled, and that it
2778 -- is not suppressed for this particular case.
2780 and then Warn_On_Export_Import
2783 then
2784 Error_Msg_N
2792 -- Must freeze its parent first if it is a derived subprogram
2798 -- We don't freeze internal subprograms, because we don't normally
2799 -- want addition of extra formals or mechanism setting to happen
2800 -- for those. However we do pass through predefined dispatching
2801 -- cases, since extra formals may be needed in some cases, such as
2802 -- for the stream 'Input function (build-in-place formals).
2806 then
2810 -- Here for other than a subprogram or type
2812 else
2813 -- If entity has a type, and it is not a generic unit, then
2814 -- freeze it first (RM 13.14(10)).
2818 then
2822 -- Special processing for objects created by object declaration
2826 -- Abstract type allowed only for C++ imported variables or
2827 -- constants.
2829 -- Note: we inhibit this check for objects that do not come
2830 -- from source because there is at least one case (the
2831 -- expansion of x'class'input where x is abstract) where we
2832 -- legitimately generate an abstract object.
2838 then
2848 -- For object created by object declaration, perform required
2849 -- categorization (preelaborate and pure) checks. Defer these
2850 -- checks to freeze time since pragma Import inhibits default
2851 -- initialization and thus pragma Import affects these checks.
2855 -- If there is an address clause, check that it is valid
2859 -- If the object needs any kind of default initialization, an
2860 -- error must be issued if No_Default_Initialization applies.
2861 -- The check doesn't apply to imported objects, which are not
2862 -- ever default initialized, and is why the check is deferred
2863 -- until freezing, at which point we know if Import applies.
2864 -- Deferred constants are also exempted from this test because
2865 -- their completion is explicit, or through an import pragma.
2869 then
2875 and then
2880 or else
2883 then
2885 Check_Restriction
2889 -- Check that a Thread_Local_Storage variable does not have
2890 -- default initialization, and any explicit initialization must
2891 -- either be the null constant or a static constant.
2894 declare
2896 begin
2897 if Has_Default_Initialization
2898 or else
2900 and then
2902 or else not
2904 or else
2906 then
2907 Error_Msg_NE
2910 Error_Msg_NE
2917 -- For imported objects, set Is_Public unless there is also an
2918 -- address clause, which means that there is no external symbol
2919 -- needed for the Import (Is_Public may still be set for other
2920 -- unrelated reasons). Note that we delayed this processing
2921 -- till freeze time so that we can be sure not to set the flag
2922 -- if there is an address clause. If there is such a clause,
2923 -- then the only purpose of the Import pragma is to suppress
2924 -- implicit initialization.
2928 then
2932 -- For convention C objects of an enumeration type, warn if
2933 -- the size is not integer size and no explicit size given.
2934 -- Skip warning for Boolean, and Character, assume programmer
2935 -- expects 8-bit sizes for these cases.
2938 or else
2945 then
2947 Error_Msg_N
2949 E);
2954 -- Check that a constant which has a pragma Volatile[_Components]
2955 -- or Atomic[_Components] also has a pragma Import (RM C.6(13)).
2957 -- Note: Atomic[_Components] also sets Volatile[_Components]
2962 then
2963 -- Make sure we actually have a pragma, and have not merely
2964 -- inherited the indication from elsewhere (e.g. an address
2965 -- clause, which is not good enough in RM terms!)
2968 or else
2970 then
2971 Error_Msg_N
2976 or else
2978 then
2979 Error_Msg_N
2985 -- Static objects require special handling
2989 then
2993 -- Remaining step is to layout objects
2996 or else
2998 or else
3000 or else
3002 then
3007 -- Case of a type or subtype being frozen
3009 else
3010 -- We used to check here that a full type must have preelaborable
3011 -- initialization if it completes a private type specified with
3012 -- pragma Preelaborable_Intialization, but that missed cases where
3013 -- the types occur within a generic package, since the freezing
3014 -- that occurs within a containing scope generally skips traversal
3015 -- of a generic unit's declarations (those will be frozen within
3016 -- instances). This check was moved to Analyze_Package_Specification.
3018 -- The type may be defined in a generic unit. This can occur when
3019 -- freezing a generic function that returns the type (which is
3020 -- defined in a parent unit). It is clearly meaningless to freeze
3021 -- this type. However, if it is a subtype, its size may be determi-
3022 -- nable and used in subsequent checks, so might as well try to
3023 -- compute it.
3027 then
3032 -- Deal with special cases of freezing for subtype
3036 -- Before we do anything else, a specialized test for the case of
3037 -- a size given for an array where the array needs to be packed,
3038 -- but was not so the size cannot be honored. This would of course
3039 -- be caught by the backend, and indeed we don't catch all cases.
3040 -- The point is that we can give a better error message in those
3041 -- cases that we do catch with the circuitry here. Also if pragma
3042 -- Implicit_Packing is set, this is where the packing occurs.
3044 -- The reason we do this so early is that the processing in the
3045 -- automatic packing case affects the layout of the base type, so
3046 -- it must be done before we freeze the base type.
3049 declare
3053 begin
3054 -- Check enabling conditions. These are straightforward
3055 -- except for the test for a limited composite type. This
3056 -- eliminates the rare case of a array of limited components
3057 -- where there are issues of whether or not we can go ahead
3058 -- and pack the array (since we can't freely pack and unpack
3059 -- arrays if they are limited).
3061 -- Note that we check the root type explicitly because the
3062 -- whole point is we are doing this test before we have had
3063 -- a chance to freeze the base type (and it is that freeze
3064 -- action that causes stuff to be inherited).
3076 and then not CodePeer_Mode
3077 then
3084 then
3085 declare
3095 -- What we are looking for here is the situation where
3096 -- the RM_Size given would be exactly right if there
3097 -- was a pragma Pack (resulting in the component size
3098 -- being the same as the RM_Size). Furthermore, the
3099 -- component type size must be an odd size (not a
3100 -- multiple of storage unit). If the component RM size
3101 -- is an exact number of storage units that is a power
3102 -- of two, the array is not packed and has a standard
3103 -- representation.
3105 begin
3108 then
3109 -- For implicit packing mode, just set the
3110 -- component size silently.
3118 -- Otherwise give an error message
3120 else
3121 Error_Msg_NE
3123 Error_Msg_N
3129 and then Implicit_Packing
3130 and then
3134 then
3136 -- Not a packed array, but indicate the desired
3137 -- component size, for the back-end.
3147 -- If ancestor subtype present, freeze that first. Note that this
3148 -- will also get the base type frozen.
3155 -- Otherwise freeze the base type of the entity before freezing
3156 -- the entity itself (RM 13.14(15)).
3162 -- For a derived type, freeze its parent type first (RM 13.14(15))
3169 -- For array type, freeze index types and component type first
3170 -- before freezing the array (RM 13.14(15)).
3173 declare
3177 -- Set true if any of the index types is an enumeration type
3178 -- with a non-standard representation.
3180 begin
3189 then
3196 -- Processing that is done only for base types
3200 -- Propagate flags for component type
3204 then
3212 -- If packing was requested or if the component size was set
3213 -- explicitly, then see if bit packing is required. This
3214 -- processing is only done for base types, since all the
3215 -- representation aspects involved are type-related. This
3216 -- is not just an optimization, if we start processing the
3217 -- subtypes, they interfere with the settings on the base
3218 -- type (this is because Is_Packed has a slightly different
3219 -- meaning before and after freezing).
3221 declare
3225 begin
3229 then
3238 else
3241 -- We can set the component size if it is less than
3242 -- 16, rounding it up to the next storage unit size.
3248 else
3252 -- Set component size up to match alignment if it
3253 -- would otherwise be less than the alignment. This
3254 -- deals with cases of types whose alignment exceeds
3255 -- their size (padded types).
3258 declare
3260 begin
3268 -- Case of component size that may result in packing
3271 declare
3277 Get_Attribute_Definition_Clause
3279 begin
3280 -- Warn if we have pack and component size so that
3281 -- the pack is ignored.
3283 -- Note: here we must check for the presence of a
3284 -- component size before checking for a Pack pragma
3285 -- to deal with the case where the array type is a
3286 -- derived type whose parent is currently private.
3290 then
3292 Error_Msg_NE
3295 Error_Msg_N
3297 Pack_Pragma);
3300 -- Set component size if not already set by a
3301 -- component size clause.
3307 -- Check for base type of 8, 16, 32 bits, where an
3308 -- unsigned subtype has a length one less than the
3309 -- base type (e.g. Natural subtype of Integer).
3311 -- In such cases, if a component size was not set
3312 -- explicitly, then generate a warning.
3316 and then
3319 then
3323 Error_Msg_N
3326 Error_Msg_N
3332 -- Actual packing is not needed for 8, 16, 32, 64.
3333 -- Also not needed for 24 if alignment is 1.
3340 then
3341 -- Here the array was requested to be packed,
3342 -- but the packing request had no effect, so
3343 -- Is_Packed is reset.
3345 -- Note: semantically this means that we lose
3346 -- track of the fact that a derived type
3347 -- inherited a pragma Pack that was non-
3348 -- effective, but that seems fine.
3350 -- We regard a Pack pragma as a request to set
3351 -- a representation characteristic, and this
3352 -- request may be ignored.
3356 -- In all other cases, packing is indeed needed
3358 else
3367 -- Processing that is done only for subtypes
3369 else
3370 -- Acquire alignment from base type
3378 -- For bit-packed arrays, check the size
3381 declare
3387 begin
3388 -- It is not clear if it is possible to have no size
3389 -- clause at this stage, but it is not worth worrying
3390 -- about. Post error on the entity name in the size
3391 -- clause if present, else on the type entity itself.
3395 else
3401 -- If any of the index types was an enumeration type with
3402 -- a non-standard rep clause, then we indicate that the
3403 -- array type is always packed (even if it is not bit packed).
3412 -- If the array is packed, we must create the packed array
3413 -- type to be used to actually implement the type. This is
3414 -- only needed for real array types (not for string literal
3415 -- types, since they are present only for the front end).
3419 then
3423 -- Size information of packed array type is copied to the
3424 -- array type, since this is really the representation. But
3425 -- do not override explicit existing size values. If the
3426 -- ancestor subtype is constrained the packed_array_type
3427 -- will be inherited from it, but the size may have been
3428 -- provided already, and must not be overridden either.
3431 and then
3434 then
3444 -- For non-packed arrays set the alignment of the array to the
3445 -- alignment of the component type if it is unknown. Skip this
3446 -- in atomic case (atomic arrays may need larger alignments).
3455 then
3460 -- For a class-wide type, the corresponding specific type is
3461 -- frozen as well (RM 13.14(15))
3466 -- If the base type of the class-wide type is still incomplete,
3467 -- the class-wide remains unfrozen as well. This is legal when
3468 -- E is the formal of a primitive operation of some other type
3469 -- which is being frozen.
3476 -- If the Class_Wide_Type is an Itype (when type is the anonymous
3477 -- parent of a derived type) and it is a library-level entity,
3478 -- generate an itype reference for it. Otherwise, its first
3479 -- explicit reference may be in an inner scope, which will be
3480 -- rejected by the back-end.
3484 then
3485 declare
3488 begin
3492 else
3498 -- The equivalent type associated with a class-wide subtype needs
3499 -- to be frozen to ensure that its layout is done.
3503 then
3507 -- For a record (sub)type, freeze all the component types (RM
3508 -- 13.14(15). We test for E_Record_(sub)Type here, rather than using
3509 -- Is_Record_Type, because we don't want to attempt the freeze for
3510 -- the case of a private type with record extension (we will do that
3511 -- later when the full type is frozen).
3515 then
3518 -- For a concurrent type, freeze corresponding record type. This
3519 -- does not correspond to any specific rule in the RM, but the
3520 -- record type is essentially part of the concurrent type.
3521 -- Freeze as well all local entities. This includes record types
3522 -- created for entry parameter blocks, and whatever local entities
3523 -- may appear in the private part.
3527 Freeze_And_Append
3539 then
3549 -- Private types are required to point to the same freeze node as
3550 -- their corresponding full views. The freeze node itself has to
3551 -- point to the partial view of the entity (because from the partial
3552 -- view, we can retrieve the full view, but not the reverse).
3553 -- However, in order to freeze correctly, we need to freeze the full
3554 -- view. If we are freezing at the end of a scope (or within the
3555 -- scope of the private type), the partial and full views will have
3556 -- been swapped, the full view appears first in the entity chain and
3557 -- the swapping mechanism ensures that the pointers are properly set
3558 -- (on scope exit).
3560 -- If we encounter the partial view before the full view (e.g. when
3561 -- freezing from another scope), we freeze the full view, and then
3562 -- set the pointers appropriately since we cannot rely on swapping to
3563 -- fix things up (subtypes in an outer scope might not get swapped).
3567 then
3568 -- The construction of the dispatch table associated with library
3569 -- level tagged types forces freezing of all the primitives of the
3570 -- type, which may cause premature freezing of the partial view.
3571 -- For example:
3573 -- package Pkg is
3574 -- type T is tagged private;
3575 -- type DT is new T with private;
3576 -- procedure Prim (X : in out T; Y : in out DT'class);
3577 -- private
3578 -- type T is tagged null record;
3579 -- Obj : T;
3580 -- type DT is new T with null record;
3581 -- end;
3583 -- In this case the type will be frozen later by the usual
3584 -- mechanism: an object declaration, an instantiation, or the
3585 -- end of a declarative part.
3589 then
3593 -- Case of full view present
3597 -- If full view has already been frozen, then no further
3598 -- processing is required
3606 -- Otherwise freeze full view and patch the pointers so that
3607 -- the freeze node will elaborate both views in the back-end.
3609 else
3610 declare
3613 begin
3616 then
3617 Freeze_And_Append
3630 else
3631 -- {Incomplete,Private}_Subtypes with Full_Views
3632 -- constrained by discriminants.
3643 -- AI-117 requires that the convention of a partial view be the
3644 -- same as the convention of the full view. Note that this is a
3645 -- recognized breach of privacy, but it's essential for logical
3646 -- consistency of representation, and the lack of a rule in
3647 -- RM95 was an oversight.
3654 -- Size information is copied from the full view to the
3655 -- incomplete or private view for consistency.
3657 -- We skip this is the full view is not a type. This is very
3658 -- strange of course, and can only happen as a result of
3659 -- certain illegalities, such as a premature attempt to derive
3660 -- from an incomplete type.
3669 -- Case of no full view present. If entity is derived or subtype,
3670 -- it is safe to freeze, correctness depends on the frozen status
3671 -- of parent. Otherwise it is either premature usage, or a Taft
3672 -- amendment type, so diagnosis is at the point of use and the
3673 -- type might be frozen later.
3677 then
3680 else
3685 -- For access subprogram, freeze types of all formals, the return
3686 -- type was already frozen, since it is the Etype of the function.
3687 -- Formal types can be tagged Taft amendment types, but otherwise
3688 -- they cannot be incomplete.
3697 then
3700 else
3701 Error_Msg_NE
3712 -- For access to a protected subprogram, freeze the equivalent type
3713 -- (however this is not set if we are not generating code or if this
3714 -- is an anonymous type used just for resolution).
3722 -- Generic types are never seen by the back-end, and are also not
3723 -- processed by the expander (since the expander is turned off for
3724 -- generic processing), so we never need freeze nodes for them.
3730 -- Some special processing for non-generic types to complete
3731 -- representation details not known till the freeze point.
3736 -- Some error checks required for ordinary fixed-point type. Defer
3737 -- these till the freeze-point since we need the small and range
3738 -- values. We only do these checks for base types
3742 then
3745 Error_Msg_N
3750 Error_Msg_N
3756 Error_Msg_N
3762 Error_Msg_N
3774 and then Warn_On_Suspicious_Modulus_Value
3775 then
3781 -- Check restriction for standard storage pool
3787 -- Deal with error message for pure access type. This is not an
3788 -- error in Ada 2005 if there is no pool (see AI-366).
3793 then
3797 Error_Msg_N
3801 Error_Msg_N
3804 else
3805 Error_Msg_N
3812 -- Case of composite types
3816 -- AI-117 requires that all new primitives of a tagged type must
3817 -- inherit the convention of the full view of the type. Inherited
3818 -- and overriding operations are defined to inherit the convention
3819 -- of their parent or overridden subprogram (also specified in
3820 -- AI-117), which will have occurred earlier (in Derive_Subprogram
3821 -- and New_Overloaded_Entity). Here we set the convention of
3822 -- primitives that are still convention Ada, which will ensure
3823 -- that any new primitives inherit the type's convention. Class-
3824 -- wide types can have a foreign convention inherited from their
3825 -- specific type, but are excluded from this since they don't have
3826 -- any associated primitives.
3831 then
3832 declare
3835 begin
3848 -- Now that all types from which E may depend are frozen, see if the
3849 -- size is known at compile time, if it must be unsigned, or if
3850 -- strict alignment is required
3859 -- Do not allow a size clause for a type which does not have a size
3860 -- that is known at compile time
3864 then
3865 -- Suppress this message if errors posted on E, even if we are
3866 -- in all errors mode, since this is often a junk message
3869 Error_Msg_N
3875 -- Remaining process is to set/verify the representation information,
3876 -- in particular the size and alignment values. This processing is
3877 -- not required for generic types, since generic types do not play
3878 -- any part in code generation, and so the size and alignment values
3879 -- for such types are irrelevant.
3884 -- Otherwise we call the layout procedure
3886 else
3890 -- End of freeze processing for type entities
3893 -- Here is where we logically freeze the current entity. If it has a
3894 -- freeze node, then this is the point at which the freeze node is
3895 -- linked into the result list.
3899 -- If a freeze node is already allocated, use it, otherwise allocate
3900 -- a new one. The preallocation happens in the case of anonymous base
3901 -- types, where we preallocate so that we can set First_Subtype_Link.
3902 -- Note that we reset the Sloc to the current freeze location.
3908 else
3920 else
3924 -- A final pass over record types with discriminants. If the type
3925 -- has an incomplete declaration, there may be constrained access
3926 -- subtypes declared elsewhere, which do not depend on the discrimi-
3927 -- nants of the type, and which are used as component types (i.e.
3928 -- the full view is a recursive type). The designated types of these
3929 -- subtypes can only be elaborated after the type itself, and they
3930 -- need an itype reference.
3934 then
3935 declare
3940 begin
3951 then
3963 -- When a type is frozen, the first subtype of the type is frozen as
3964 -- well (RM 13.14(15)). This has to be done after freezing the type,
3965 -- since obviously the first subtype depends on its own base type.
3970 -- If we just froze a tagged non-class wide record, then freeze the
3971 -- corresponding class-wide type. This must be done after the tagged
3972 -- type itself is frozen, because the class-wide type refers to the
3973 -- tagged type which generates the class.
3978 then
3985 -- Special handling for subprograms
3989 -- If subprogram has address clause then reset Is_Public flag, since
3990 -- we do not want the backend to generate external references.
3994 then
3997 -- If no address clause and not intrinsic, then for imported
3998 -- subprogram in main unit, generate descriptor if we are in
3999 -- Propagate_Exceptions mode.
4001 elsif Propagate_Exceptions
4005 then
4015 -----------------------------
4016 -- Freeze_Enumeration_Type --
4017 -----------------------------
4020 begin
4021 -- By default, if no size clause is present, an enumeration type with
4022 -- Convention C is assumed to interface to a C enum, and has integer
4023 -- size. This applies to types. For subtypes, verify that its base
4024 -- type has no size clause either.
4030 then
4033 else
4034 -- If the enumeration type interfaces to C, and it has a size clause
4035 -- that specifies less than int size, it warrants a warning. The
4036 -- user may intend the C type to be an enum or a char, so this is
4037 -- not by itself an error that the Ada compiler can detect, but it
4038 -- it is a worth a heads-up. For Boolean and Character types we
4039 -- assume that the programmer has the proper C type in mind.
4046 then
4047 Error_Msg_N
4055 -----------------------
4056 -- Freeze_Expression --
4057 -----------------------
4068 -- This flag is set true if the entity must be frozen outside the
4069 -- current subprogram. This happens in the case of expander generated
4070 -- subprograms (_Init_Proc, _Input, _Output, _Read, _Write) which do
4071 -- not freeze all entities like other bodies, but which nevertheless
4072 -- may reference entities that have to be frozen before the body and
4073 -- obviously cannot be frozen inside the body.
4076 -- Given an N_Handled_Sequence_Of_Statements node N, determines whether
4077 -- it is the handled statement sequence of an expander-generated
4078 -- subprogram (init proc, stream subprogram, or renaming as body).
4079 -- If so, this is not a freezing context.
4081 -----------------
4082 -- In_Exp_Body --
4083 -----------------
4089 begin
4092 else
4099 else
4109 N_Subprogram_Renaming_Declaration)
4110 then
4112 else
4118 -- Start of processing for Freeze_Expression
4120 begin
4121 -- Immediate return if freezing is inhibited. This flag is set by the
4122 -- analyzer to stop freezing on generated expressions that would cause
4123 -- freezing if they were in the source program, but which are not
4124 -- supposed to freeze, since they are created.
4130 -- If expression is non-static, then it does not freeze in a default
4131 -- expression, see section "Handling of Default Expressions" in the
4132 -- spec of package Sem for further details. Note that we have to
4133 -- make sure that we actually have a real expression (if we have
4134 -- a subtype indication, we can't test Is_Static_Expression!)
4136 if In_Spec_Exp
4139 then
4143 -- Freeze type of expression if not frozen already
4151 -- Base type may be an derived numeric type that is frozen at
4152 -- the point of declaration, but first_subtype is still unfrozen.
4159 -- For entity name, freeze entity if not frozen already. A special
4160 -- exception occurs for an identifier that did not come from source.
4161 -- We don't let such identifiers freeze a non-internal entity, i.e.
4162 -- an entity that did come from source, since such an identifier was
4163 -- generated by the expander, and cannot have any semantic effect on
4164 -- the freezing semantics. For example, this stops the parameter of
4165 -- an initialization procedure from freezing the variable.
4172 then
4174 else
4178 -- For an allocator freeze designated type if not frozen already
4180 -- For an aggregate whose component type is an access type, freeze the
4181 -- designated type now, so that its freeze does not appear within the
4182 -- loop that might be created in the expansion of the aggregate. If the
4183 -- designated type is a private type without full view, the expression
4184 -- cannot contain an allocator, so the type is not frozen.
4186 -- For a function, we freeze the entity when the subprogram declaration
4187 -- is frozen, but a function call may appear in an initialization proc.
4188 -- before the declaration is frozen. We need to generate the extra
4189 -- formals, if any, to ensure that the expansion of the call includes
4190 -- the proper actuals. This only applies to Ada subprograms, not to
4191 -- imported ones.
4202 then
4206 when N_Selected_Component |
4207 N_Indexed_Component |
4208 N_Slice =>
4219 then
4230 then
4234 -- All done if nothing needs freezing
4239 then
4243 -- Loop for looking at the right place to insert the freeze nodes,
4244 -- exiting from the loop when it is appropriate to insert the freeze
4245 -- node before the current node P.
4247 -- Also checks som special exceptions to the freezing rules. These cases
4248 -- result in a direct return, bypassing the freeze action.
4251 loop
4254 -- If we don't have a parent, then we are not in a well-formed tree.
4255 -- This is an unusual case, but there are some legitimate situations
4256 -- in which this occurs, notably when the expressions in the range of
4257 -- a type declaration are resolved. We simply ignore the freeze
4258 -- request in this case. Is this right ???
4264 -- See if we have got to an appropriate point in the tree
4268 -- A special test for the exception of (RM 13.14(8)) for the case
4269 -- of per-object expressions (RM 3.8(18)) occurring in component
4270 -- definition or a discrete subtype definition. Note that we test
4271 -- for a component declaration which includes both cases we are
4272 -- interested in, and furthermore the tree does not have explicit
4273 -- nodes for either of these two constructs.
4277 -- The case we want to test for here is an identifier that is
4278 -- a per-object expression, this is either a discriminant that
4279 -- appears in a context other than the component declaration
4280 -- or it is a reference to the type of the enclosing construct.
4282 -- For either of these cases, we skip the freezing
4284 if not In_Spec_Expression
4287 then
4288 -- We recognize the discriminant case by just looking for
4289 -- a reference to a discriminant. It can only be one for
4290 -- the enclosing construct. Skip freezing in this case.
4295 -- For the case of a reference to the enclosing record,
4296 -- (or task or protected type), we look for a type that
4297 -- matches the current scope.
4304 -- If we have an enumeration literal that appears as the choice in
4305 -- the aggregate of an enumeration representation clause, then
4306 -- freezing does not occur (RM 13.14(10)).
4310 -- The case we are looking for is an enumeration literal
4314 then
4315 -- If enumeration literal appears directly as the choice,
4316 -- do not freeze (this is the normal non-overloaded case)
4320 then
4323 -- If enumeration literal appears as the name of function
4324 -- which is the choice, then also do not freeze. This
4325 -- happens in the overloaded literal case, where the
4326 -- enumeration literal is temporarily changed to a function
4327 -- call for overloading analysis purposes.
4330 and then
4332 and then
4334 then
4339 -- Normally if the parent is a handled sequence of statements,
4340 -- then the current node must be a statement, and that is an
4341 -- appropriate place to insert a freeze node.
4345 -- An exception occurs when the sequence of statements is for
4346 -- an expander generated body that did not do the usual freeze
4347 -- all operation. In this case we usually want to freeze
4348 -- outside this body, not inside it, and we skip past the
4349 -- subprogram body that we are inside.
4353 -- However, we *do* want to freeze at this point if we have
4354 -- an entity to freeze, and that entity is declared *inside*
4355 -- the body of the expander generated procedure. This case
4356 -- is recognized by the scope of the type, which is either
4357 -- the spec for some enclosing body, or (in the case of
4358 -- init_procs, for which there are no separate specs) the
4359 -- current scope.
4361 declare
4365 begin
4370 or else
4372 then
4378 then
4384 -- If not that exception to the exception, then this is
4385 -- where we delay the freeze till outside the body.
4390 -- Here if normal case where we are in handled statement
4391 -- sequence and want to do the insertion right there.
4393 else
4397 -- If parent is a body or a spec or a block, then the current node
4398 -- is a statement or declaration and we can insert the freeze node
4399 -- before it.
4401 when N_Package_Specification |
4402 N_Package_Body |
4403 N_Subprogram_Body |
4404 N_Task_Body |
4405 N_Protected_Body |
4406 N_Entry_Body |
4409 -- The expander is allowed to define types in any statements list,
4410 -- so any of the following parent nodes also mark a freezing point
4411 -- if the actual node is in a list of statements or declarations.
4413 when N_Exception_Handler |
4414 N_If_Statement |
4415 N_Elsif_Part |
4416 N_Case_Statement_Alternative |
4417 N_Compilation_Unit_Aux |
4418 N_Selective_Accept |
4419 N_Accept_Alternative |
4420 N_Delay_Alternative |
4421 N_Conditional_Entry_Call |
4422 N_Entry_Call_Alternative |
4423 N_Triggering_Alternative |
4424 N_Abortable_Part |
4425 N_Freeze_Entity =>
4429 -- Note: The N_Loop_Statement is a special case. A type that
4430 -- appears in the source can never be frozen in a loop (this
4431 -- occurs only because of a loop expanded by the expander), so we
4432 -- keep on going. Otherwise we terminate the search. Same is true
4433 -- of any entity which comes from source. (if they have predefined
4434 -- type, that type does not appear to come from source, but the
4435 -- entity should not be frozen here).
4441 -- For all other cases, keep looking at parents
4447 -- We fall through the case if we did not yet find the proper
4448 -- place in the free for inserting the freeze node, so climb!
4453 -- If the expression appears in a record or an initialization procedure,
4454 -- the freeze nodes are collected and attached to the current scope, to
4455 -- be inserted and analyzed on exit from the scope, to insure that
4456 -- generated entities appear in the correct scope. If the expression is
4457 -- a default for a discriminant specification, the scope is still void.
4458 -- The expression can also appear in the discriminant part of a private
4459 -- or concurrent type.
4461 -- If the expression appears in a constrained subcomponent of an
4462 -- enclosing record declaration, the freeze nodes must be attached to
4463 -- the outer record type so they can eventually be placed in the
4464 -- enclosing declaration list.
4466 -- The other case requiring this special handling is if we are in a
4467 -- default expression, since in that case we are about to freeze a
4468 -- static type, and the freeze scope needs to be the outer scope, not
4469 -- the scope of the subprogram with the default parameter.
4471 -- For default expressions and other spec expressions in generic units,
4472 -- the Move_Freeze_Nodes mechanism (see sem_ch12.adb) takes care of
4473 -- placing them at the proper place, after the generic unit.
4476 or else Freeze_Outside
4481 then
4482 declare
4487 begin
4500 -- The current scope may be that of a constrained component of
4501 -- an enclosing record declaration, which is above the current
4502 -- scope in the scope stack.
4511 Freeze_Nodes;
4512 else
4522 -- Now we have the right place to do the freezing. First, a special
4523 -- adjustment, if we are in spec-expression analysis mode, these freeze
4524 -- actions must not be thrown away (normally all inserted actions are
4525 -- thrown away in this mode. However, the freeze actions are from static
4526 -- expressions and one of the important reasons we are doing this
4527 -- special analysis is to get these freeze actions. Therefore we turn
4528 -- off the In_Spec_Expression mode to propagate these freeze actions.
4529 -- This also means they get properly analyzed and expanded.
4533 -- Freeze the designated type of an allocator (RM 13.14(13))
4539 -- Freeze type of expression (RM 13.14(10)). Note that we took care of
4540 -- the enumeration representation clause exception in the loop above.
4546 -- Freeze name if one is present (RM 13.14(11))
4552 -- Restore In_Spec_Expression flag
4557 -----------------------------
4558 -- Freeze_Fixed_Point_Type --
4559 -----------------------------
4561 -- Certain fixed-point types and subtypes, including implicit base types
4562 -- and declared first subtypes, have not yet set up a range. This is
4563 -- because the range cannot be set until the Small and Size values are
4564 -- known, and these are not known till the type is frozen.
4566 -- To signal this case, Scalar_Range contains an unanalyzed syntactic range
4567 -- whose bounds are unanalyzed real literals. This routine will recognize
4568 -- this case, and transform this range node into a properly typed range
4569 -- with properly analyzed and resolved values.
4587 -- Returns size of type with given bounds. Also leaves these
4588 -- bounds set as the current bounds of the Typ.
4590 -----------
4591 -- Fsize --
4592 -----------
4595 begin
4601 -- Start of processing for Freeze_Fixed_Point_Type
4603 begin
4604 -- If Esize of a subtype has not previously been set, set it now
4611 else
4616 -- Immediate return if the range is already analyzed. This means that
4617 -- the range is already set, and does not need to be computed by this
4618 -- routine.
4624 -- Immediate return if either of the bounds raises Constraint_Error
4628 then
4635 -- Ordinary fixed-point case
4639 -- For the ordinary fixed-point case, we are allowed to fudge the
4640 -- end-points up or down by small. Generally we prefer to fudge up,
4641 -- i.e. widen the bounds for non-model numbers so that the end points
4642 -- are included. However there are cases in which this cannot be
4643 -- done, and indeed cases in which we may need to narrow the bounds.
4644 -- The following circuit makes the decision.
4646 -- Note: our terminology here is that Incl_EP means that the bounds
4647 -- are widened by Small if necessary to include the end points, and
4648 -- Excl_EP means that the bounds are narrowed by Small to exclude the
4649 -- end-points if this reduces the size.
4651 -- Note that in the Incl case, all we care about is including the
4652 -- end-points. In the Excl case, we want to narrow the bounds as
4653 -- much as permitted by the RM, to give the smallest possible size.
4670 begin
4671 -- First step. Base types are required to be symmetrical. Right
4672 -- now, the base type range is a copy of the first subtype range.
4673 -- This will be corrected before we are done, but right away we
4674 -- need to deal with the case where both bounds are non-negative.
4675 -- In this case, we set the low bound to the negative of the high
4676 -- bound, to make sure that the size is computed to include the
4677 -- required sign. Note that we do not need to worry about the
4678 -- case of both bounds negative, because the sign will be dealt
4679 -- with anyway. Furthermore we can't just go making such a bound
4680 -- symmetrical, since in a twos-complement system, there is an
4681 -- extra negative value which could not be accommodated on the
4682 -- positive side.
4687 then
4692 -- Compute the fudged bounds. If the number is a model number,
4693 -- then we do nothing to include it, but we are allowed to backoff
4694 -- to the next adjacent model number when we exclude it. If it is
4695 -- not a model number then we straddle the two values with the
4696 -- model numbers on either side.
4702 else
4706 -- The low value excluding the end point is Small greater, but
4707 -- we do not do this exclusion if the low value is positive,
4708 -- since it can't help the size and could actually hurt by
4709 -- crossing the high bound.
4714 -- If the value went from negative to zero, then we have the
4715 -- case where Loval_Incl_EP is the model number just below
4716 -- zero, so we want to stick to the negative value for the
4717 -- base type to maintain the condition that the size will
4718 -- include signed values.
4722 then
4726 else
4730 -- Similar processing for upper bound and high value
4736 else
4742 else
4746 -- One further adjustment is needed. In the case of subtypes, we
4747 -- cannot go outside the range of the base type, or we get
4748 -- peculiarities, and the base type range is already set. This
4749 -- only applies to the Incl values, since clearly the Excl values
4750 -- are already as restricted as they are allowed to be.
4757 -- Get size including and excluding end points
4762 -- No need to exclude end-points if it does not reduce size
4772 -- Now we set the actual size to be used. We want to use the
4773 -- bounds fudged up to include the end-points but only if this
4774 -- can be done without violating a specifically given size
4775 -- size clause or causing an unacceptable increase in size.
4777 -- Case of size clause given
4781 -- Use the inclusive size only if it is consistent with
4782 -- the explicitly specified size.
4789 -- If the inclusive size is too large, we try excluding
4790 -- the end-points (will be caught later if does not work).
4792 else
4798 -- Case of size clause not given
4800 else
4801 -- If we have a base type whose corresponding first subtype
4802 -- has an explicit size that is large enough to include our
4803 -- end-points, then do so. There is no point in working hard
4804 -- to get a base type whose size is smaller than the specified
4805 -- size of the first subtype.
4811 then
4816 -- If excluding the end-points makes the size smaller and
4817 -- results in a size of 8,16,32,64, then we take the smaller
4818 -- size. For the 64 case, this is compulsory. For the other
4819 -- cases, it seems reasonable. We like to include end points
4820 -- if we can, but not at the expense of moving to the next
4821 -- natural boundary of size.
4824 and then
4829 then
4834 -- Otherwise we can definitely include the end points
4836 else
4842 -- One pathological case: normally we never fudge a low bound
4843 -- down, since it would seem to increase the size (if it has
4844 -- any effect), but for ranges containing single value, or no
4845 -- values, the high bound can be small too large. Consider:
4847 -- type t is delta 2.0**(-14)
4848 -- range 131072.0 .. 0;
4850 -- That lower bound is *just* outside the range of 32 bits, and
4851 -- does need fudging down in this case. Note that the bounds
4852 -- will always have crossed here, since the high bound will be
4853 -- fudged down if necessary, as in the case of:
4855 -- type t is delta 2.0**(-14)
4856 -- range 131072.0 .. 131072.0;
4858 -- So we detect the situation by looking for crossed bounds,
4859 -- and if the bounds are crossed, and the low bound is greater
4860 -- than zero, we will always back it off by small, since this
4861 -- is completely harmless.
4868 -- And of course, we need to do exactly the same parallel
4869 -- fudge for flat ranges in the negative region.
4882 -- For the decimal case, none of this fudging is required, since there
4883 -- are no end-point problems in the decimal case (the end-points are
4884 -- always included).
4886 else
4890 -- At this stage, the actual size has been calculated and the proper
4891 -- required bounds are stored in the low and high bounds.
4895 Error_Msg_N
4897 Typ);
4901 -- Check size against explicit given size
4907 Error_Msg_NE
4911 else
4915 -- Increase size to next natural boundary if no size clause given
4917 else
4924 else
4932 -- If we have a base type, then expand the bounds so that they extend to
4933 -- the full width of the allocated size in bits, to avoid junk range
4934 -- checks on intermediate computations.
4941 -- Final step is to reanalyze the bounds using the proper type
4942 -- and set the Corresponding_Integer_Value fields of the literals.
4948 -- Resolve with universal fixed if the base type, and the base type if
4949 -- it is a subtype. Note we can't resolve the base type with itself,
4950 -- that would be a reference before definition.
4954 else
4958 -- Set corresponding integer value for bound
4960 Set_Corresponding_Integer_Value
4963 -- Similar processing for high bound
4971 else
4975 Set_Corresponding_Integer_Value
4978 -- Set type of range to correspond to bounds
4982 -- Set Esize to calculated size if not set already
4988 -- Set RM_Size if not already set. If already set, check value
4990 declare
4993 begin
4998 Error_Msg_NE
5003 else
5009 ------------------
5010 -- Freeze_Itype --
5011 ------------------
5016 begin
5025 --------------------------
5026 -- Freeze_Static_Object --
5027 --------------------------
5032 -- Exception raised if the type of a static object cannot be made
5033 -- static. This happens if the type depends on non-global objects.
5036 -- Called to ensure that an expression used as part of a type definition
5037 -- is statically allocatable, which means that the expression type is
5038 -- statically allocatable, and the expression is either static, or a
5039 -- reference to a library level constant.
5042 -- Called to mark a type as static, checking that it is possible
5043 -- to set the type as static. If it is not possible, then the
5044 -- exception Cannot_Be_Static is raised.
5046 -----------------------------
5047 -- Ensure_Expression_Is_SA --
5048 -----------------------------
5053 begin
5065 then
5073 -----------------------
5074 -- Ensure_Type_Is_SA --
5075 -----------------------
5081 begin
5082 -- If type is library level, we are all set
5088 -- We are also OK if the type already marked as statically allocated,
5089 -- which means we processed it before.
5095 -- Mark type as statically allocated
5099 -- Check that it is safe to statically allocate this type
5117 declare
5121 begin
5134 else
5143 then
5162 else
5167 -- Start of processing for Freeze_Static_Object
5169 begin
5172 exception
5175 -- If the object that cannot be static is imported or exported, then
5176 -- issue an error message saying that this object cannot be imported
5177 -- or exported. If it has an address clause it is an overlay in the
5178 -- current partition and the static requirement is not relevant.
5181 Error_Msg_N
5184 -- Otherwise must be exported, something is wrong if compiler
5185 -- is marking something as statically allocated which cannot be).
5188 Error_Msg_N
5193 -----------------------
5194 -- Freeze_Subprogram --
5195 -----------------------
5201 begin
5202 -- Subprogram may not have an address clause unless it is imported
5206 Error_Msg_N
5213 -- Reset the Pure indication on an imported subprogram unless an
5214 -- explicit Pure_Function pragma was present. We do this because
5215 -- otherwise it is an insidious error to call a non-pure function from
5216 -- pure unit and have calls mysteriously optimized away. What happens
5217 -- here is that the Import can bypass the normal check to ensure that
5218 -- pure units call only pure subprograms.
5223 then
5227 -- For non-foreign convention subprograms, this is where we create
5228 -- the extra formals (for accessibility level and constrained bit
5229 -- information). We delay this till the freeze point precisely so
5230 -- that we know the convention!
5236 -- If this is convention Ada and a Valued_Procedure, that's odd
5241 and then Warn_On_Export_Import
5242 then
5243 Error_Msg_N
5248 -- Case of foreign convention
5250 else
5253 -- For foreign conventions, warn about return of an
5254 -- unconstrained array.
5256 -- Note: we *do* allow a return by descriptor for the VMS case,
5257 -- though here there is probably more to be done ???
5262 -- If no return type, probably some other error, e.g. a
5263 -- missing full declaration, so ignore.
5268 -- If the return type is generic, we have emitted a warning
5269 -- earlier on, and there is nothing else to check here. Specific
5270 -- instantiations may lead to erroneous behavior.
5275 -- Display warning if returning unconstrained array
5280 -- Exclude cases where descriptor mechanism is set, since the
5281 -- VMS descriptor mechanisms allow such unconstrained returns.
5285 -- Check appropriate warning is enabled (should we check for
5286 -- Warnings (Off) on specific entities here, probably so???)
5288 and then Warn_On_Export_Import
5290 -- Exclude the VM case, since return of unconstrained arrays
5291 -- is properly handled in both the JVM and .NET cases.
5294 then
5295 Error_Msg_N
5302 -- If any of the formals for an exported foreign convention
5303 -- subprogram have defaults, then emit an appropriate warning since
5304 -- this is odd (default cannot be used from non-Ada code)
5309 if Warn_On_Export_Import
5311 then
5312 Error_Msg_N
5322 -- For VMS, descriptor mechanisms for parameters are allowed only for
5323 -- imported/exported subprograms. Moreover, the NCA descriptor is not
5324 -- allowed for parameters of exported subprograms.
5331 Error_Msg_N
5333 Error_Msg_N
5344 Error_Msg_N
5346 Error_Msg_N
5355 -- Pragma Inline_Always is disallowed for dispatching subprograms
5356 -- because the address of such subprograms is saved in the dispatch
5357 -- table to support dispatching calls, and dispatching calls cannot
5358 -- be inlined. This is consistent with the restriction against using
5359 -- 'Access or 'Address on an Inline_Always subprogram.
5363 then
5364 Error_Msg_N
5368 -- Because of the implicit representation of inherited predefined
5369 -- operators in the front-end, the overriding status of the operation
5370 -- may be affected when a full view of a type is analyzed, and this is
5371 -- not captured by the analysis of the corresponding type declaration.
5372 -- Therefore the correctness of a not-overriding indicator must be
5373 -- rechecked when the subprogram is frozen.
5377 then
5382 ----------------------
5383 -- Is_Fully_Defined --
5384 ----------------------
5387 begin
5396 then
5397 -- Verify that the record type has no components with private types
5398 -- without completion.
5400 declare
5403 begin
5416 else
5422 ---------------------------------
5423 -- Process_Default_Expressions --
5424 ---------------------------------
5426 procedure Process_Default_Expressions
5429 is
5436 begin
5439 -- A subprogram instance and its associated anonymous subprogram share
5440 -- their signature. The default expression functions are defined in the
5441 -- wrapper packages for the anonymous subprogram, and should not be
5442 -- generated again for the instance.
5447 then
5455 -- We work with a copy of the default expression because we
5456 -- do not want to disturb the original, since this would mess
5457 -- up the conformance checking.
5461 -- The analysis of the expression may generate insert actions,
5462 -- which of course must not be executed. We wrap those actions
5463 -- in a procedure that is not called, and later on eliminated.
5464 -- The following cases have no side-effects, and are analyzed
5465 -- directly.
5476 and then
5478 then
5480 -- If there is no default function, we must still do a full
5481 -- analyze call on the default value, to ensure that all error
5482 -- checks are performed, e.g. those associated with static
5483 -- evaluation. Note: this branch will always be taken if the
5484 -- analyzer is turned off (but we still need the error checks).
5486 -- Note: the setting of parent here is to meet the requirement
5487 -- that we can only analyze the expression while attached to
5488 -- the tree. Really the requirement is that the parent chain
5489 -- be set, we don't actually need to be in the tree.
5494 -- Default expressions are resolved with their own type if the
5495 -- context is generic, to avoid anomalies with private types.
5499 else
5503 -- If that resolved expression will raise constraint error,
5504 -- then flag the default value as raising constraint error.
5505 -- This allows a proper error message on the calls.
5511 -- If the default is a parameterless call, we use the name of
5512 -- the called function directly, and there is no body to build.
5516 then
5519 -- Else construct and analyze the body of a wrapper procedure
5520 -- that contains an object declaration to hold the expression.
5521 -- Given that this is done only to complete the analysis, it
5522 -- simpler to build a procedure than a function which might
5523 -- involve secondary stack expansion.
5525 else
5526 Dnam :=
5529 Dbody :=
5531 Specification =>
5537 Defining_Identifier =>
5540 Object_Definition =>
5544 Handled_Statement_Sequence =>
5561 ----------------------------------------
5562 -- Set_Component_Alignment_If_Not_Set --
5563 ----------------------------------------
5566 begin
5567 -- Ignore if not base type, subtypes don't need anything
5573 -- Do not override existing representation
5584 else
5585 Set_Component_Alignment
5591 ------------------
5592 -- Undelay_Type --
5593 ------------------
5596 begin
5600 -- Since we don't want T to have a Freeze_Node, we don't want its
5601 -- Full_View or Corresponding_Record_Type to have one either.
5603 -- ??? Fundamentally, this whole handling is a kludge. What we really
5604 -- want is to be sure that for an Itype that's part of record R and is a
5605 -- subtype of type T, that it's frozen after the later of the freeze
5606 -- points of R and T. We have no way of doing that directly, so what we
5607 -- do is force most such Itypes to be frozen as part of freezing R via
5608 -- this procedure and only delay the ones that need to be delayed
5609 -- (mostly the designated types of access types that are defined as part
5610 -- of the record).
5616 then
5624 then
5629 ------------------
5630 -- Warn_Overlay --
5631 ------------------
5633 procedure Warn_Overlay
5637 is
5639 -- The object to which the address clause applies
5645 begin
5646 -- No warning if address clause overlay warnings are off
5652 -- No warning if there is an explicit initialization
5660 -- We only give the warning for non-imported entities of a type for
5661 -- which a non-null base init proc is defined, or for objects of access
5662 -- types with implicit null initialization, or when Initialize_Scalars
5663 -- applies and the type is scalar or a string type (the latter being
5664 -- tested for because predefined String types are initialized by inline
5665 -- code rather than by an init_proc).
5674 then
5677 then
5682 then
5689 then
5696 -- A function call (most likely to To_Address) is probably not an
5697 -- overlay, so skip warning. Ditto if the function call was inlined
5698 -- and transformed into an entity.
5706 -- If a pragma Import follows, we assume that it is for the current
5707 -- target of the address clause, and skip the warning.
5712 then
5718 Error_Msg_N
5720 Nam);
5721 else
5722 Error_Msg_N
5724 Nam);
5727 -- Add friendly warning if initialization comes from a packed array
5728 -- component.
5731 declare
5734 begin
5740 then
5744 then
5745 Error_Msg_NE
5750 else
5757 Error_Msg_N
5760 Nam);