| blob | 6478b3725bd5949443e4d9882272a962319beaf5 |
1 /* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
5 Hacked by Michael Tiemann (tiemann@cygnus.com)
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2, or (at your option)
12 any later version.
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING. If not, write to
21 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
22 Boston, MA 02110-1301, USA. */
25 /* This file is part of the C++ front end.
26 It contains routines to build C++ expressions given their operands,
27 including computing the types of the result, C and C++ specific error
28 checks, and some optimization. */
64 /* Do `exp = require_complete_type (exp);' to make sure exp
65 does not have an incomplete type. (That includes void types.)
66 Returns the error_mark_node if the VALUE does not have
67 complete type when this function returns. */
69 tree
71 {
72 tree type;
79 else
85 /* First, detect a valid value with a complete type. */
91 else
93 }
95 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
96 a template instantiation, do the instantiation. Returns TYPE,
97 whether or not it could be completed, unless something goes
98 horribly wrong, in which case the error_mark_node is returned. */
100 tree
102 {
104 /* Rather than crash, we return something sure to cause an error
105 at some point. */
109 ;
111 {
116 needs_constructing
118 has_nontrivial_dtor
121 {
124 }
125 }
130 }
132 /* Like complete_type, but issue an error if the TYPE cannot be completed.
133 VALUE is used for informative diagnostics.
134 Returns NULL_TREE if the type cannot be made complete. */
136 tree
138 {
141 /* We already issued an error. */
144 {
147 }
148 else
150 }
152 /* Return truthvalue of whether type of EXP is instantiated. */
154 int
156 {
159 }
161 \f
162 /* Return the common type of two parameter lists.
163 We assume that comptypes has already been done and returned 1;
164 if that isn't so, this may crash.
166 As an optimization, free the space we allocate if the parameter
167 lists are already common. */
169 static tree
171 {
181 else
182 {
185 }
194 {
196 {
199 }
201 {
203 {
206 }
207 }
208 else
209 {
213 }
215 {
218 }
219 else
221 }
226 }
228 /* Given a type, perhaps copied for a typedef,
229 find the "original" version of it. */
230 static tree
232 {
236 {
244 }
246 }
248 /* T1 and T2 are arithmetic or enumeration types. Return the type
249 that will result from the "usual arithmetic conversions" on T1 and
250 T2 as described in [expr]. */
252 tree
254 {
257 tree attributes;
259 /* FIXME: Attributes. */
269 /* In what follows, we slightly generalize the rules given in [expr] so
270 as to deal with `long long' and `complex'. First, merge the
271 attributes. */
274 /* If one type is complex, form the common type of the non-complex
275 components, then make that complex. Use T1 or T2 if it is the
276 required type. */
278 {
281 tree subtype
288 else
290 attributes);
291 }
294 {
295 /* When we get here we should have two vectors of the same size.
296 Just prefer the unsigned one if present. */
299 else
301 }
303 /* If only one is real, use it as the result. */
309 /* Perform the integral promotions. */
311 {
314 }
316 /* Both real or both integers; use the one with greater precision. */
322 /* The types are the same; no need to do anything fancy. */
327 {
328 /* If one is unsigned long long, then convert the other to unsigned
329 long long. */
333 attributes);
334 /* If one is a long long, and the other is an unsigned long, and
335 long long can represent all the values of an unsigned long, then
336 convert to a long long. Otherwise, convert to an unsigned long
337 long. Otherwise, if either operand is long long, convert the
338 other to long long.
340 Since we're here, we know the TYPE_PRECISION is the same;
341 therefore converting to long long cannot represent all the values
342 of an unsigned long, so we choose unsigned long long in that
343 case. */
346 {
348 ? long_long_unsigned_type_node
351 }
353 /* Go through the same procedure, but for longs. */
357 attributes);
360 {
364 }
365 /* Otherwise prefer the unsigned one. */
368 else
370 }
371 else
372 {
376 attributes);
380 attributes);
384 attributes);
386 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
387 the standard C++ floating-point types. Logic earlier in this
388 function has already eliminated the possibility that
389 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
390 compelling reason to choose one or the other. */
392 }
393 }
395 /* Subroutine of composite_pointer_type to implement the recursive
396 case. See that function for documentation fo the parameters. */
398 static tree
400 {
401 tree pointee1;
402 tree pointee2;
403 tree result_type;
404 tree attributes;
406 /* Determine the types pointed to by T1 and T2. */
408 {
411 }
412 else
413 {
416 }
418 /* [expr.rel]
420 Otherwise, the composite pointer type is a pointer type
421 similar (_conv.qual_) to the type of one of the operands,
422 with a cv-qualification signature (_conv.qual_) that is the
423 union of the cv-qualification signatures of the operand
424 types. */
432 else
433 {
438 }
442 /* If the original types were pointers to members, so is the
443 result. */
445 {
452 result_type);
453 }
454 else
457 /* Merge the attributes. */
460 }
462 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
463 ARG1 and ARG2 are the values with those types. The LOCATION is a
464 string describing the current location, in case an error occurs.
466 This routine also implements the computation of a common type for
467 pointers-to-members as per [expr.eq]. */
469 tree
472 {
473 tree class1;
474 tree class2;
476 /* [expr.rel]
478 If one operand is a null pointer constant, the composite pointer
479 type is the type of the other operand. */
485 /* We have:
487 [expr.rel]
489 If one of the operands has type "pointer to cv1 void*", then
490 the other has type "pointer to cv2T", and the composite pointer
491 type is "pointer to cv12 void", where cv12 is the union of cv1
492 and cv2.
494 If either type is a pointer to void, make sure it is T1. */
496 {
497 tree t;
501 }
503 /* Now, if T1 is a pointer to void, merge the qualifiers. */
505 {
506 tree attributes;
507 tree result_type;
512 result_type
517 /* Merge the attributes. */
520 }
524 {
527 }
529 /* [expr.eq] permits the application of a pointer conversion to
530 bring the pointers to a common type. */
536 {
541 t2 = (build_pointer_type
544 t1 = (build_pointer_type
546 else
547 {
551 }
552 }
553 /* [expr.eq] permits the application of a pointer-to-member
554 conversion to change the class type of one of the types. */
558 {
566 else
567 {
571 }
572 }
575 }
577 /* Return the merged type of two types.
578 We assume that comptypes has already been done and returned 1;
579 if that isn't so, this may crash.
581 This just combines attributes and default arguments; any other
582 differences would cause the two types to compare unalike. */
584 tree
586 {
589 tree attributes;
591 /* Save time if the two types are the same. */
597 /* If one type is nonsense, use the other. */
603 /* Merge the attributes. */
615 {
618 /* For two pointers, do this recursively on the target type. */
619 {
625 else
634 }
637 {
639 tree pointee;
644 pointee);
647 }
650 {
652 /* Save space: see if the result is identical to one of the args. */
657 /* Merge the element types, and have a size if either arg has one. */
658 t1 = build_cplus_array_type
661 }
664 /* Function types: prefer the one that specified arg types.
665 If both do, merge the arg types. Also merge the return types. */
666 {
672 /* Save space: see if the result is identical to one of the args. */
678 /* Simple way if one arg fails to specify argument types. */
680 {
685 }
688 {
693 }
698 }
701 {
702 /* Get this value the long way, since TYPE_METHOD_BASETYPE
703 is just the main variant of this. */
706 tree t3;
708 /* If this was a member function type, get back to the
709 original type of type member function (i.e., without
710 the class instance variable up front. */
720 }
723 /* There is no need to merge attributes into a TYPENAME_TYPE.
724 When the type is instantiated it will have whatever
725 attributes result from the instantiation. */
729 }
735 else
737 }
739 /* Return the common type of two types.
740 We assume that comptypes has already been done and returned 1;
741 if that isn't so, this may crash.
743 This is the type for the result of most arithmetic operations
744 if the operands have the given two types. */
746 tree
748 {
752 /* If one type is nonsense, bail. */
770 else
772 }
773 \f
774 /* Compare two exception specifier types for exactness or subsetness, if
775 allowed. Returns false for mismatch, true for match (same, or
776 derived and !exact).
778 [except.spec] "If a class X ... objects of class X or any class publicly
779 and unambiguously derived from X. Similarly, if a pointer type Y * ...
780 exceptions of type Y * or that are pointers to any type publicly and
781 unambiguously derived from Y. Otherwise a function only allows exceptions
782 that have the same type ..."
783 This does not mention cv qualifiers and is different to what throw
784 [except.throw] and catch [except.catch] will do. They will ignore the
785 top level cv qualifiers, and allow qualifiers in the pointer to class
786 example.
788 We implement the letter of the standard. */
790 static bool
792 {
796 {
802 {
807 }
815 }
817 }
819 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
820 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
821 otherwise it must be exact. Exception lists are unordered, but
822 we've already filtered out duplicates. Most lists will be in order,
823 we should try to make use of that. */
825 bool
827 {
828 tree probe;
829 tree base;
844 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
845 Count how many we find, to determine exactness. For exact matching and
846 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
847 O(nm). */
849 {
851 {
856 {
859 length++;
861 }
862 }
865 }
867 }
869 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
870 [] can match [size]. */
872 static bool
874 {
875 tree d1;
876 tree d2;
882 /* The type of the array elements must be the same. */
892 /* If one of the arrays is dimensionless, and the other has a
893 dimension, they are of different types. However, it is valid to
894 write:
896 extern int a[];
897 int a[3];
899 by [basic.link]:
901 declarations for an array object can specify
902 array types that differ by the presence or absence of a major
903 array bound (_dcl.array_). */
907 /* Check that the dimensions are the same. */
916 {
917 /* With abi-1 we do not fold non-dependent array bounds, (and
918 consequently mangle them incorrectly). We must therefore
919 fold them here, to verify the domains have the same
920 value. */
923 }
929 }
931 /* Subroutine in comptypes. */
933 static bool
935 {
939 /* Suppress errors caused by previously reported errors. */
945 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
946 current instantiation. */
948 {
953 }
956 {
961 }
968 /* Different classes of types can't be compatible. */
972 /* Qualifiers must match. For array types, we will check when we
973 recur on the array element types. */
980 /* Allow for two different type nodes which have essentially the same
981 definition. Note that we already checked for equality of the type
982 qualifiers (just above). */
988 /* Compare the types. Break out if they could be the same. */
990 {
1004 /* Don't check inheritance. */
1006 /* Fall through. */
1048 /* Target types must match incl. qualifiers. */
1093 }
1095 /* If we get here, we know that from a target independent POV the
1096 types are the same. Make sure the target attributes are also
1097 the same. */
1099 }
1101 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
1102 is a bitwise-or of the COMPARE_* flags. */
1104 bool
1106 {
1108 {
1118 /* At least one of the types requires structural equality, so
1119 perform a deep check. */
1123 {
1127 {
1128 /* The two types are structurally equivalent, but their
1129 canonical types were different. This is a failure of the
1130 canonical type propagation code.*/
1136 }
1138 {
1139 /* Two types are structurally different, but the canonical
1140 types are the same. This means we were over-eager in
1141 assigning canonical types. */
1147 }
1150 }
1151 else
1153 }
1156 else
1158 }
1160 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1162 bool
1164 {
1168 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1170 }
1172 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1173 more cv-qualified that TYPE1, and 0 otherwise. */
1175 int
1177 {
1190 }
1192 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1193 subset of the cv-qualification signature of TYPE2, and the types
1194 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1196 int
1198 {
1203 else
1205 }
1206 \f
1207 /* Subroutines of `comptypes'. */
1209 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1210 equivalent in the sense that functions with those parameter types
1211 can have equivalent types. The two lists must be equivalent,
1212 element by element. */
1214 bool
1216 {
1219 /* An unspecified parmlist matches any specified parmlist
1220 whose argument types don't need default promotions. */
1225 {
1226 /* If one parmlist is shorter than the other,
1227 they fail to match. */
1232 }
1234 }
1236 \f
1237 /* Process a sizeof or alignof expression where the operand is a
1238 type. */
1240 tree
1242 {
1243 tree value;
1252 {
1257 }
1263 /* VLA types will have a non-constant size. In the body of an
1264 uninstantiated template, we don't need to try to compute the
1265 value, because the sizeof expression is not an integral
1266 constant expression in that case. And, if we do try to
1267 compute the value, we'll likely end up with SAVE_EXPRs, which
1268 the template substitution machinery does not expect to see. */
1269 || (processing_template_decl
1272 {
1276 }
1280 complain);
1281 }
1283 /* Process a sizeof expression where the operand is an expression. */
1285 static tree
1287 {
1292 {
1298 }
1303 {
1306 }
1308 {
1312 }
1314 {
1317 }
1318 else
1322 }
1324 /* Implement the __alignof keyword: Return the minimum required
1325 alignment of E, measured in bytes. For VAR_DECL's and
1326 FIELD_DECL's return DECL_ALIGN (which can be set from an
1327 "aligned" __attribute__ specification). */
1329 static tree
1331 {
1332 tree t;
1338 {
1344 }
1351 {
1354 }
1359 {
1363 }
1365 {
1368 }
1369 else
1373 }
1375 /* Process a sizeof or alignof expression E with code OP where the operand
1376 is an expression. */
1378 tree
1380 {
1383 else
1385 }
1386 \f
1387 /* EXPR is being used in a context that is not a function call.
1388 Enforce:
1390 [expr.ref]
1392 The expression can be used only as the left-hand operand of a
1393 member function call.
1395 [expr.mptr.operator]
1397 If the result of .* or ->* is a function, then that result can be
1398 used only as the operand for the function call operator ().
1400 by issuing an error message if appropriate. Returns true iff EXPR
1401 violates these rules. */
1403 bool
1405 {
1407 {
1410 }
1412 }
1414 /* If EXP is a reference to a bitfield, and the type of EXP does not
1415 match the declared type of the bitfield, return the declared type
1416 of the bitfield. Otherwise, return NULL_TREE. */
1418 tree
1420 {
1422 {
1436 {
1437 tree field;
1446 }
1450 }
1451 }
1453 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1454 bitfield with a lowered type, the type of EXP is returned, rather
1455 than NULL_TREE. */
1457 tree
1459 {
1460 tree type;
1467 }
1469 /* Perform the conversions in [expr] that apply when an lvalue appears
1470 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1471 function-to-pointer conversions. In addition, manifest constants
1472 are replaced by their values, and bitfield references are converted
1473 to their declared types.
1475 Although the returned value is being used as an rvalue, this
1476 function does not wrap the returned expression in a
1477 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1478 that the return value is no longer an lvalue. */
1480 tree
1482 {
1483 tree type;
1491 {
1494 }
1500 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1501 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1504 {
1507 }
1513 {
1514 tree adr;
1515 tree ptrtype;
1522 {
1526 }
1530 {
1533 }
1538 {
1543 }
1544 /* This way is better for a COMPONENT_REF since it can
1545 simplify the offset for a component. */
1548 }
1550 /* If a bitfield is used in a context where integral promotion
1551 applies, then the caller is expected to have used
1552 default_conversion. That function promotes bitfields correctly
1553 before calling this function. At this point, if we have a
1554 bitfield referenced, we may assume that is not subject to
1555 promotion, and that, therefore, the type of the resulting rvalue
1556 is the declared type of the bitfield. */
1559 /* We do not call rvalue() here because we do not want to wrap EXP
1560 in a NON_LVALUE_EXPR. */
1562 /* [basic.lval]
1564 Non-class rvalues always have cv-unqualified types. */
1570 }
1572 /* Perform prepatory conversions, as part of the "usual arithmetic
1573 conversions". In particular, as per [expr]:
1575 Whenever an lvalue expression appears as an operand of an
1576 operator that expects the rvalue for that operand, the
1577 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1578 standard conversions are applied to convert the expression to an
1579 rvalue.
1581 In addition, we perform integral promotions here, as those are
1582 applied to both operands to a binary operator before determining
1583 what additional conversions should apply. */
1585 tree
1587 {
1588 /* Perform the integral promotions first so that bitfield
1589 expressions (which may promote to "int", even if the bitfield is
1590 declared "unsigned") are promoted correctly. */
1593 /* Perform the other conversions. */
1597 }
1599 /* EXPR is an expression with an integral or enumeration type.
1600 Perform the integral promotions in [conv.prom], and return the
1601 converted value. */
1603 tree
1605 {
1606 tree type;
1607 tree promoted_type;
1609 /* [conv.prom]
1611 If the bitfield has an enumerated type, it is treated as any
1612 other value of that type for promotion purposes. */
1621 }
1623 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1624 or TREE_USED. */
1626 tree
1628 {
1633 }
1635 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1636 decay_conversion to one. */
1638 int
1640 {
1641 tree t;
1652 {
1653 /* Make sure that we don't try to convert between char and wchar_t. */
1656 }
1657 else
1658 {
1659 /* Is this a string constant which has decayed to 'const char *'? */
1667 }
1669 /* This warning is not very useful, as it complains about printf. */
1673 totype);
1676 }
1678 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1679 can, for example, use as an lvalue. This code used to be in
1680 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1681 expressions, where we're dealing with aggregates. But now it's again only
1682 called from unary_complex_lvalue. The case (in particular) that led to
1683 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1684 get it there. */
1686 static tree
1688 {
1689 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1690 the first operand is always the one to be used if both operands
1691 are equal, so we know what conditional expression this used to be. */
1693 {
1697 /* The following code is incorrect if either operand side-effects. */
1700 return
1708 }
1710 return
1714 }
1716 /* Given the TYPE of an anonymous union field inside T, return the
1717 FIELD_DECL for the field. If not found return NULL_TREE. Because
1718 anonymous unions can nest, we must also search all anonymous unions
1719 that are directly reachable. */
1721 tree
1723 {
1724 tree field;
1727 {
1733 /* If we find it directly, return the field. */
1736 {
1738 }
1740 /* Otherwise, it could be nested, search harder. */
1743 {
1747 }
1748 }
1750 }
1752 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1753 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1754 non-NULL, it indicates the path to the base used to name MEMBER.
1755 If PRESERVE_REFERENCE is true, the expression returned will have
1756 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1757 returned will have the type referred to by the reference.
1759 This function does not perform access control; that is either done
1760 earlier by the parser when the name of MEMBER is resolved to MEMBER
1761 itself, or later when overload resolution selects one of the
1762 functions indicated by MEMBER. */
1764 tree
1767 {
1768 tree object_type;
1769 tree member_scope;
1777 /* [expr.ref]
1779 The type of the first expression shall be "class object" (of a
1780 complete type). */
1786 {
1790 }
1792 /* The standard does not seem to actually say that MEMBER must be a
1793 member of OBJECT_TYPE. However, that is clearly what is
1794 intended. */
1796 {
1801 }
1802 else
1804 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1805 presently be the anonymous union. Go outwards until we find a
1806 type related to OBJECT_TYPE. */
1809 object_type))
1812 {
1815 else
1818 }
1820 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1821 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1822 in the front end; only _DECLs and _REFs are lvalues in the back end. */
1823 {
1827 }
1829 /* In [expr.ref], there is an explicit list of the valid choices for
1830 MEMBER. We check for each of those cases here. */
1832 {
1833 /* A static data member. */
1835 /* If OBJECT has side-effects, they are supposed to occur. */
1838 }
1840 {
1841 /* A non-static data member. */
1844 tree member_type;
1849 /* Convert OBJECT to the type of MEMBER. */
1852 {
1853 tree binfo;
1854 base_kind kind;
1861 /* It is invalid to try to get to a virtual base of a
1862 NULL object. The most common cause is invalid use of
1863 offsetof macro. */
1865 {
1868 member);
1871 }
1873 /* Convert to the base. */
1876 /* If we found the base successfully then we should be able
1877 to convert to it successfully. */
1879 }
1881 /* Complain about other invalid uses of offsetof, even though they will
1882 give the right answer. Note that we complain whether or not they
1883 actually used the offsetof macro, since there's no way to know at this
1884 point. So we just give a warning, instead of a pedwarn. */
1885 /* Do not produce this warning for base class field references, because
1886 we know for a fact that didn't come from offsetof. This does occur
1887 in various testsuite cases where a null object is passed where a
1888 vtable access is required. */
1893 {
1895 member);
1897 }
1899 /* If MEMBER is from an anonymous aggregate, we have converted
1900 OBJECT so that it refers to the class containing the
1901 anonymous union. Generate a reference to the anonymous union
1902 itself, and recur to find MEMBER. */
1904 /* When this code is called from build_field_call, the
1905 object already has the type of the anonymous union.
1906 That is because the COMPONENT_REF was already
1907 constructed, and was then disassembled before calling
1908 build_field_call. After the function-call code is
1909 cleaned up, this waste can be eliminated. */
1910 && (!same_type_ignoring_top_level_qualifiers_p
1912 {
1913 tree anonymous_union;
1918 anonymous_union,
1920 preserve_reference);
1921 }
1923 /* Compute the type of the field, as described in [expr.ref]. */
1927 {
1931 /* A field is const (volatile) if the enclosing object, or the
1932 field itself, is const (volatile). But, a mutable field is
1933 not const, even within a const object. */
1937 }
1940 NULL_TREE);
1943 /* Mark the expression const or volatile, as appropriate. Even
1944 though we've dealt with the type above, we still have to mark the
1945 expression itself. */
1950 }
1952 {
1953 /* The member is a (possibly overloaded) member function. */
1954 tree functions;
1955 tree type;
1957 /* If the MEMBER is exactly one static member function, then we
1958 know the type of the expression. Otherwise, we must wait
1959 until overload resolution has been performed. */
1964 else
1966 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1967 base. That will happen when the function is called. */
1969 }
1971 {
1972 /* The member is an enumerator. */
1974 /* If OBJECT has side-effects, they are supposed to occur. */
1978 }
1979 else
1980 {
1983 }
1986 /* [expr.ref]
1988 If E2 is declared to have type "reference to T", then ... the
1989 type of E1.E2 is T. */
1993 }
1995 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1996 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1998 static tree
2000 {
2003 tree expr;
2006 {
2010 }
2012 {
2016 }
2019 expr = (adjust_result_of_qualified_name_lookup
2022 }
2024 /* An expression of the form "A::template B" has been resolved to
2025 DECL. Issue a diagnostic if B is not a template or template
2026 specialization. */
2028 void
2030 {
2031 /* The standard says:
2033 [temp.names]
2035 If a name prefixed by the keyword template is not a member
2036 template, the program is ill-formed.
2038 DR 228 removed the restriction that the template be a member
2039 template.
2041 DR 96, if accepted would add the further restriction that explicit
2042 template arguments must be provided if the template keyword is
2043 used, but, as of 2005-10-16, that DR is still in "drafting". If
2044 this DR is accepted, then the semantic checks here can be
2045 simplified, as the entity named must in fact be a template
2046 specialization, rather than, as at present, a set of overloaded
2047 functions containing at least one template function. */
2050 {
2053 else
2054 {
2055 tree fns;
2060 {
2070 }
2073 }
2074 }
2075 }
2077 /* This function is called by the parser to process a class member
2078 access expression of the form OBJECT.NAME. NAME is a node used by
2079 the parser to represent a name; it is not yet a DECL. It may,
2080 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2081 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2082 there is no reason to do the lookup twice, so the parser keeps the
2083 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2084 be a template via the use of the "A::template B" syntax. */
2086 tree
2088 {
2089 tree expr;
2090 tree object_type;
2091 tree member;
2099 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2106 {
2109 /* If NAME is just an IDENTIFIER_NODE, then the expression
2110 is dependent. */
2112 /* If NAME is "f<args>", where either 'f' or 'args' is
2113 dependent, then the expression is dependent. */
2117 /* If NAME is "T::X" where "T" is dependent, then the
2118 expression is dependent. */
2124 }
2126 /* [expr.ref]
2128 The type of the first expression shall be "class object" (of a
2129 complete type). */
2134 {
2138 }
2141 /* A member function that has already been looked up. */
2143 else
2144 {
2147 tree scope;
2150 {
2159 }
2162 {
2163 /* A qualified name. The qualifying class or namespace `S'
2164 has already been looked up; it is either a TYPE or a
2165 NAMESPACE_DECL. */
2169 /* If SCOPE is a namespace, then the qualified name does not
2170 name a member of OBJECT_TYPE. */
2172 {
2176 }
2182 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2187 {
2190 }
2191 }
2192 else
2193 {
2196 }
2200 else
2201 {
2202 /* Look up the member. */
2206 {
2209 }
2212 }
2215 {
2220 else
2221 {
2224 }
2225 }
2226 }
2237 {
2239 {
2243 }
2246 NULL_TREE);
2247 }
2250 }
2252 /* Return an expression for the MEMBER_NAME field in the internal
2253 representation of PTRMEM, a pointer-to-member function. (Each
2254 pointer-to-member function type gets its own RECORD_TYPE so it is
2255 more convenient to access the fields by name than by FIELD_DECL.)
2256 This routine converts the NAME to a FIELD_DECL and then creates the
2257 node for the complete expression. */
2259 tree
2261 {
2262 tree ptrmem_type;
2263 tree member;
2264 tree member_type;
2266 /* This code is a stripped down version of
2267 build_class_member_access_expr. It does not work to use that
2268 routine directly because it expects the object to be of class
2269 type. */
2278 }
2280 /* Given an expression PTR for a pointer, return an expression
2281 for the value pointed to.
2282 ERRORSTRING is the name of the operator to appear in error messages.
2284 This function may need to overload OPERATOR_FNNAME.
2285 Must also handle REFERENCE_TYPEs for C++. */
2287 tree
2289 {
2291 tree rval;
2294 {
2298 }
2307 else
2309 }
2311 tree
2313 {
2327 {
2328 /* [expr.unary.op]
2330 If the type of the expression is "pointer to T," the type
2331 of the result is "T."
2333 We must use the canonical variant because certain parts of
2334 the back end, like fold, do pointer comparisons between
2335 types. */
2339 {
2340 /* A pointer to incomplete type (other than cv void) can be
2341 dereferenced [expr.unary.op]/1 */
2344 }
2347 /* The POINTER was something like `&x'. We simplify `*&x' to
2348 `x'. */
2350 else
2351 {
2354 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2355 so that we get the proper error message if the result is used
2356 to assign to. Also, &* is supposed to be a no-op. */
2362 }
2363 }
2364 /* `pointer' won't be an error_mark_node if we were given a
2365 pointer to member, so it's cool to check for this here. */
2369 {
2372 else
2374 }
2376 }
2378 /* This handles expressions of the form "a[i]", which denotes
2379 an array reference.
2381 This is logically equivalent in C to *(a+i), but we may do it differently.
2382 If A is a variable or a member, we generate a primitive ARRAY_REF.
2383 This avoids forcing the array out of registers, and can work on
2384 arrays that are not lvalues (for example, members of structures returned
2385 by functions).
2387 If INDEX is of some user-defined type, it must be converted to
2388 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2389 will inherit the type of the array, which will be some pointer type. */
2391 tree
2393 {
2395 {
2398 }
2404 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2405 inside it. */
2407 {
2409 {
2413 }
2416 return build_conditional_expr
2423 }
2426 {
2432 {
2435 }
2437 /* Apply integral promotions *after* noticing character types.
2438 (It is unclear why we do these promotions -- the standard
2439 does not say that we should. In fact, the natural thing would
2440 seem to be to convert IDX to ptrdiff_t; we're performing
2441 pointer arithmetic.) */
2444 /* An array that is indexed by a non-constant
2445 cannot be stored in a register; we must be able to do
2446 address arithmetic on its address.
2447 Likewise an array of elements of variable size. */
2452 {
2455 }
2457 /* An array that is indexed by a constant value which is not within
2458 the array bounds cannot be stored in a register either; because we
2459 would get a crash in store_bit_field/extract_bit_field when trying
2460 to access a non-existent part of the register. */
2464 {
2467 }
2472 /* Note in C++ it is valid to subscript a `register' array, since
2473 it is valid to take the address of something with that
2474 storage specification. */
2476 {
2482 }
2486 /* Array ref is const/volatile if the array elements are
2487 or if the array is.. */
2495 }
2497 {
2501 /* Put the integer in IND to simplify error checking. */
2503 {
2507 }
2513 {
2516 }
2518 {
2521 }
2527 }
2528 }
2529 \f
2530 /* Resolve a pointer to member function. INSTANCE is the object
2531 instance to use, if the member points to a virtual member.
2533 This used to avoid checking for virtual functions if basetype
2534 has no virtual functions, according to an earlier ANSI draft.
2535 With the final ISO C++ rules, such an optimization is
2536 incorrect: A pointer to a derived member can be static_cast
2537 to pointer-to-base-member, as long as the dynamic object
2538 later has the right member. */
2540 tree
2542 {
2547 {
2554 {
2556 {
2557 /* Extracting the function address from a pmf is only
2558 allowed with -Wno-pmf-conversions. It only works for
2559 pmf constants. */
2563 }
2564 else
2565 {
2568 }
2569 }
2577 /* Start by extracting all the information from the PMF itself. */
2582 {
2595 }
2597 /* Convert down to the right base before using the instance. A
2598 special case is that in a pointer to member of class C, C may
2599 be incomplete. In that case, the function will of course be
2600 a member of C, and no conversion is required. In fact,
2601 lookup_base will fail in that case, because incomplete
2602 classes do not have BINFOs. */
2606 {
2613 }
2614 /* ...and then the delta in the PMF. */
2618 /* Hand back the adjusted 'this' argument to our caller. */
2621 /* Next extract the vtable pointer from the object. */
2623 instance_ptr);
2626 /* Finally, extract the function pointer from the vtable. */
2632 /* When using function descriptors, the address of the
2633 vtable entry is treated as a function pointer. */
2641 /* Make sure this doesn't get evaluated first inside one of the
2642 branches of the COND_EXPR. */
2648 }
2650 }
2652 tree
2654 {
2661 tree parm_types;
2663 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2664 expressions, like those used for ObjC messenger dispatches. */
2667 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2668 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2674 {
2680 /* Convert anything with function type to a pointer-to-function. */
2684 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2685 (because calling an inline function does not mean the function
2686 needs to be separately compiled). */
2690 else
2692 }
2693 else
2694 {
2698 }
2706 {
2709 original);
2711 }
2718 || is_method
2720 {
2723 }
2725 /* fntype now gets the type of function pointed to. */
2729 /* Allocate storage for converted arguments. */
2736 /* Convert the parameters to the types declared in the
2737 function prototype, or apply default promotions. */
2743 /* Check for errors in format strings and inappropriately
2744 null parameters. */
2747 parm_types);
2750 }
2751 \f
2752 /* Convert the actual parameter expressions in the list VALUES
2753 to the types in the list TYPELIST.
2754 If parmdecls is exhausted, or when an element has NULL as its type,
2755 perform the default conversions.
2757 Store the converted arguments in ARGARRAY. NARGS is the size of this array.
2759 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2761 This is also where warnings about wrong number of args are generated.
2763 Returns the actual number of arguments processed (which might be less
2764 than NARGS), or -1 on error.
2766 VALUES is a chain of TREE_LIST nodes with the elements of the list
2767 in the TREE_VALUE slots of those nodes.
2769 In C++, unspecified trailing parameters can be filled in with their
2770 default arguments, if such were specified. Do so here. */
2772 static int
2775 {
2780 /* Argument passing is always copy-initialization. */
2784 {
2786 {
2790 else
2792 }
2793 else
2795 }
2798 valtail;
2800 {
2808 {
2810 {
2813 }
2814 else
2817 }
2819 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2820 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2827 {
2832 }
2838 {
2839 /* Formal parm type is specified by a function prototype. */
2840 tree parmval;
2843 {
2847 else
2850 }
2851 else
2852 {
2853 parmval = convert_for_initialization
2857 }
2863 }
2864 else
2865 {
2868 /* Don't do ellipsis conversion for __built_in_constant_p
2869 as this will result in spurious warnings for non-POD
2870 types. */
2872 else
2876 }
2880 }
2883 {
2884 /* See if there are default arguments that can be used. */
2887 {
2889 {
2890 tree parmval
2900 /* ends with `...'. */
2903 }
2904 }
2905 else
2906 {
2908 {
2911 }
2912 else
2915 }
2916 }
2920 }
2921 \f
2922 /* Build a binary-operation expression, after performing default
2923 conversions on the operands. CODE is the kind of expression to
2924 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
2925 are the tree codes which correspond to ARG1 and ARG2 when issuing
2926 warnings about possibly misplaced parentheses. They may differ
2927 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
2928 folding (e.g., if the parser sees "a | 1 + 1", it may call this
2929 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
2930 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
2931 ARG2_CODE as ERROR_MARK. */
2933 tree
2936 {
2937 tree orig_arg1;
2938 tree orig_arg2;
2939 tree expr;
2945 {
2951 }
2955 else
2957 overloaded_p);
2959 /* Check for cases such as x+y<<z which users are likely to
2960 misinterpret. But don't warn about obj << x + y, since that is a
2961 common idiom for I/O. */
2963 && !processing_template_decl
2974 }
2976 /* Build a binary-operation expression without default conversions.
2977 CODE is the kind of expression to build.
2978 This function differs from `build' in several ways:
2979 the data type of the result is computed and recorded in it,
2980 warnings are generated if arg data types are invalid,
2981 special handling for addition and subtraction of pointers is known,
2982 and some optimization is done (operations on narrow ints
2983 are done in the narrower type when that gives the same result).
2984 Constant folding is also done before the result is returned.
2986 Note that the operands will never have enumeral types
2987 because either they have just had the default conversions performed
2988 or they have both just been converted to some other type in which
2989 the arithmetic is to be done.
2991 C++: must do special pointer arithmetic when implementing
2992 multiple inheritance, and deal with pointer to member functions. */
2994 tree
2997 {
3003 /* Expression code to give to the expression when it is built.
3004 Normally this is CODE, which is what the caller asked for,
3005 but in some special cases we change it. */
3008 /* Data type in which the computation is to be performed.
3009 In the simplest cases this is the common type of the arguments. */
3012 /* Nonzero means operands have already been type-converted
3013 in whatever way is necessary.
3014 Zero means they need to be converted to RESULT_TYPE. */
3017 /* Nonzero means create the expression with this type, rather than
3018 RESULT_TYPE. */
3021 /* Nonzero means after finally constructing the expression
3022 convert it to this type. */
3025 tree result;
3027 /* Nonzero if this is an operation like MIN or MAX which can
3028 safely be computed in short if both args are promoted shorts.
3029 Also implies COMMON.
3030 -1 indicates a bitwise operation; this makes a difference
3031 in the exact conditions for when it is safe to do the operation
3032 in a narrower mode. */
3035 /* Nonzero if this is a comparison operation;
3036 if both args are promoted shorts, compare the original shorts.
3037 Also implies COMMON. */
3040 /* Nonzero if this is a right-shift operation, which can be computed on the
3041 original short and then promoted if the operand is a promoted short. */
3044 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3047 /* True if both operands have arithmetic type. */
3050 /* Apply default conversions. */
3057 {
3062 }
3063 else
3064 {
3069 }
3071 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3075 /* DTRT if one side is an overloaded function, but complain about it. */
3077 {
3080 {
3084 }
3085 }
3087 {
3090 {
3094 }
3095 }
3100 /* The expression codes of the data types of the arguments tell us
3101 whether the arguments are integers, floating, pointers, etc. */
3105 /* If an error was already reported for one of the arguments,
3106 avoid reporting another error. */
3113 {
3116 }
3119 {
3121 /* Subtraction of two similar pointers.
3122 We must subtract them as integers, then divide by object size. */
3127 /* In all other cases except pointer - int, the usual arithmetic
3128 rules aply. */
3130 {
3133 }
3134 /* The pointer - int case is just like pointer + int; fall
3135 through. */
3139 {
3140 tree ptr_operand;
3141 tree int_operand;
3145 {
3148 }
3150 ptr_operand,
3151 int_operand);
3152 }
3169 {
3181 else
3182 /* When dividing two signed integers, we have to promote to int.
3183 unless we divide by a constant != -1. Note that default
3184 conversion will have been performed on the operands at this
3185 point, so we have to dig out the original type to find out if
3186 it was unsigned. */
3193 }
3209 {
3210 /* Although it would be tempting to shorten always here, that loses
3211 on some targets, since the modulo instruction is undefined if the
3212 quotient can't be represented in the computation mode. We shorten
3213 only if unsigned or if dividing by something we know != -1. */
3219 }
3229 /* Shift operations: result has same type as first operand;
3230 always convert second operand to int.
3231 Also set SHORT_SHIFT if shifting rightward. */
3235 {
3238 {
3241 else
3242 {
3247 }
3248 }
3249 /* Convert the shift-count to an integer, regardless of
3250 size of value being shifted. */
3253 /* Avoid converting op1 to result_type later. */
3255 }
3260 {
3263 {
3268 }
3269 /* Convert the shift-count to an integer, regardless of
3270 size of value being shifted. */
3273 /* Avoid converting op1 to result_type later. */
3275 }
3281 {
3284 {
3293 }
3294 /* Convert the shift-count to an integer, regardless of
3295 size of value being shifted. */
3298 }
3322 {
3328 }
3331 {
3337 }
3339 {
3342 }
3344 {
3347 }
3349 {
3352 {
3355 delta_identifier);
3357 pfn0,
3359 integer_zero_node));
3361 delta0,
3362 integer_one_node);
3366 }
3367 else
3368 {
3371 }
3373 }
3378 {
3379 /* E will be the final comparison. */
3380 tree e;
3381 /* E1 and E2 are for scratch. */
3382 tree e1;
3383 tree e2;
3384 tree pfn0;
3385 tree pfn1;
3386 tree delta0;
3387 tree delta1;
3397 delta_identifier);
3399 delta_identifier);
3402 {
3403 /* We generate:
3405 (op0.pfn == op1.pfn
3406 && ((op0.delta == op1.delta)
3407 || (!op0.pfn && op0.delta & 1 == 0
3408 && op1.delta & 1 == 0))
3410 The reason for the `!op0.pfn' bit is that a NULL
3411 pointer-to-member is any member with a zero PFN and
3412 LSB of the DELTA field is 0. */
3415 delta0,
3416 integer_one_node);
3419 delta1,
3420 integer_one_node);
3424 pfn0,
3426 integer_zero_node));
3430 }
3431 else
3432 {
3433 /* We generate:
3435 (op0.pfn == op1.pfn
3436 && (!op0.pfn || op0.delta == op1.delta))
3438 The reason for the `!op0.pfn' bit is that a NULL
3439 pointer-to-member is any member with a zero PFN; the
3440 DELTA field is unspecified. */
3444 pfn0,
3446 integer_zero_node));
3448 }
3454 }
3455 else
3456 {
3459 type1));
3462 type0));
3463 }
3499 {
3502 }
3504 {
3507 }
3519 {
3522 }
3528 }
3534 else
3535 {
3537 /* Vector arithmetic is only allowed when both sides are vectors. */
3539 {
3543 {
3546 }
3548 }
3549 }
3550 /* Determine the RESULT_TYPE, if it is not already known. */
3552 && arithmetic_types_p
3557 {
3561 }
3563 /* If we're in a template, the only thing we need to know is the
3564 RESULT_TYPE. */
3571 {
3574 /* For certain operations (which identify themselves by shorten != 0)
3575 if both args were extended from the same smaller type,
3576 do the arithmetic in that type and then extend.
3578 shorten !=0 and !=1 indicates a bitwise operation.
3579 For them, this optimization is safe only if
3580 both args are zero-extended or both are sign-extended.
3581 Otherwise, we might change the result.
3582 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3583 but calculated in (unsigned short) it would be (unsigned short)-1. */
3586 {
3590 /* UNS is 1 if the operation to be done is an unsigned one. */
3592 tree type;
3596 /* Handle the case that OP0 does not *contain* a conversion
3597 but it *requires* conversion to FINAL_TYPE. */
3604 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3606 /* For bitwise operations, signedness of nominal type
3607 does not matter. Consider only how operands were extended. */
3611 /* Note that in all three cases below we refrain from optimizing
3612 an unsigned operation on sign-extended args.
3613 That would not be valid. */
3615 /* Both args variable: if both extended in same way
3616 from same width, do it in that width.
3617 Do it unsigned if args were zero-extended. */
3624 result_type = c_common_signed_or_unsigned_type
3642 }
3644 /* Shifts can be shortened if shifting right. */
3647 {
3657 /* We can shorten only if the shift count is less than the
3658 number of bits in the smaller type size. */
3660 /* If arg is sign-extended and then unsigned-shifted,
3661 we can simulate this with a signed shift in arg's type
3662 only if the extended result is at least twice as wide
3663 as the arg. Otherwise, the shift could use up all the
3664 ones made by sign-extension and bring in zeros.
3665 We can't optimize that case at all, but in most machines
3666 it never happens because available widths are 2**N. */
3668 || unsigned_arg
3671 {
3672 /* Do an unsigned shift if the operand was zero-extended. */
3673 result_type
3676 /* Convert value-to-be-shifted to that type. */
3680 }
3681 }
3683 /* Comparison operations are shortened too but differently.
3684 They identify themselves by setting short_compare = 1. */
3687 {
3688 /* Don't write &op0, etc., because that would prevent op0
3689 from being kept in a register.
3690 Instead, make copies of the our local variables and
3691 pass the copies by reference, then copy them back afterward. */
3694 tree val
3701 }
3704 && warn_sign_compare
3705 /* Do not warn until the template is instantiated; we cannot
3706 bound the ranges of the arguments until that point. */
3708 {
3716 /* Check for comparison of different enum types. */
3721 {
3724 }
3726 /* Give warnings for comparisons between signed and unsigned
3727 quantities that may fail. */
3728 /* Do the checking based on the original operand trees, so that
3729 casts will be considered, but default promotions won't be. */
3731 /* Do not warn if the comparison is being done in a signed type,
3732 since the signed type will only be chosen if it can represent
3733 all the values of the unsigned type. */
3736 /* Do not warn if both operands are unsigned. */
3739 /* Do not warn if the signed quantity is an unsuffixed
3740 integer literal (or some static constant expression
3741 involving such literals or a conditional expression
3742 involving such literals) and it is non-negative. */
3746 /* Do not warn if the comparison is an equality operation,
3747 the unsigned quantity is an integral constant and it does
3748 not use the most significant bit of result_type. */
3757 else
3760 /* Warn if two unsigned values are being compared in a size
3761 larger than their original size, and one (and only one) is the
3762 result of a `~' operator. This comparison will always fail.
3764 Also warn if one operand is a constant, and the constant does not
3765 have all bits set that are set in the ~ operand when it is
3766 extended. */
3770 {
3777 {
3778 tree primop;
3784 {
3788 }
3789 else
3790 {
3794 }
3799 {
3803 }
3804 }
3811 }
3812 }
3813 }
3815 /* Issue warnings about peculiar, but valid, uses of NULL. */
3817 /* It's reasonable to use pointer values as operands of &&
3818 and ||, so NULL is no exception. */
3823 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
3826 /* Some sort of arithmetic operation involving NULL was
3827 performed. Note that pointer-difference and pointer-addition
3828 have already been handled above, and so we don't end up here in
3829 that case. */
3833 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3834 Then the expression will be built.
3835 It will be given type FINAL_TYPE if that is nonzero;
3836 otherwise, it will be given type RESULT_TYPE. */
3838 {
3846 }
3862 }
3863 \f
3864 /* Return a tree for the sum or difference (RESULTCODE says which)
3865 of pointer PTROP and integer INTOP. */
3867 static tree
3869 {
3872 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3873 in certain circumstance (when it's valid to do so). So we need
3874 to make sure it's complete. We don't need to check here, if we
3875 can actually complete it at all, as those checks will be done in
3876 pointer_int_sum() anyway. */
3881 }
3883 /* Return a tree for the difference of pointers OP0 and OP1.
3884 The resulting tree has type int. */
3886 static tree
3888 {
3889 tree result;
3897 {
3904 }
3906 /* First do the subtraction as integers;
3907 then drop through to build the divide operator. */
3913 /* This generates an error if op1 is a pointer to an incomplete type. */
3921 /* Do the division. */
3925 }
3926 \f
3927 /* Construct and perhaps optimize a tree representation
3928 for a unary operation. CODE, a tree_code, specifies the operation
3929 and XARG is the operand. */
3931 tree
3933 {
3935 tree exp;
3939 {
3944 }
3948 /* [expr.unary.op] says:
3950 The address of an object of incomplete type can be taken.
3952 (And is just the ordinary address operator, not an overloaded
3953 "operator &".) However, if the type is a template
3954 specialization, we must complete the type at this point so that
3955 an overloaded "operator &" will be available if required. */
3962 else
3966 {
3967 /* A pointer to member-function can be formed only by saying
3968 &X::mf. */
3971 {
3974 {
3976 xarg);
3980 }
3981 else
3982 {
3985 xarg);
3987 }
3988 }
3991 {
3996 {
3997 /* A single non-static member, make sure we don't allow a
3998 pointer-to-member. */
4003 }
4004 }
4008 }
4016 }
4018 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4019 constants, where a null value is represented by an INTEGER_CST of
4020 -1. */
4022 tree
4024 {
4028 else
4030 }
4032 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4034 tree
4036 {
4037 tree t;
4043 }
4045 /* Return an ADDR_EXPR giving the address of T. This function
4046 attempts no optimizations or simplifications; it is a low-level
4047 primitive. */
4049 tree
4051 {
4052 tree addr;
4060 }
4062 /* Return a NOP_EXPR converting EXPR to TYPE. */
4064 tree
4066 {
4070 }
4072 /* C++: Must handle pointers to members.
4074 Perhaps type instantiation should be extended to handle conversion
4075 from aggregates to types we don't yet know we want? (Or are those
4076 cases typically errors which should be reported?)
4078 NOCONVERT nonzero suppresses the default promotions
4079 (such as from short to int). */
4081 tree
4083 {
4084 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4088 tree val;
4096 ? CONVERT_EXPR
4099 {
4102 }
4105 {
4108 {
4110 /* Unary plus (but not unary minus) is allowed on pointers. */
4118 else
4119 {
4123 /* Make sure the result is not an lvalue: a unary plus or minus
4124 expression is always a rvalue. */
4126 }
4127 }
4132 {
4136 }
4153 /* Conjugating a real value is a no-op, but allow it anyway. */
4175 {
4178 }
4179 else
4186 {
4189 }
4190 else
4197 /* Handle complex lvalues (when permitted)
4198 by reduction to simpler cases. */
4204 /* Increment or decrement the real part of the value,
4205 and don't change the imaginary part. */
4207 {
4215 }
4217 /* Report invalid types. */
4221 {
4228 else
4231 }
4233 /* Report something read-only. */
4241 {
4242 tree inc;
4243 tree declared_type;
4251 /* ARM $5.2.5 last annotation says this should be forbidden. */
4257 /* Compute the increment. */
4260 {
4275 argtype);
4277 }
4278 else
4283 /* Handle incrementing a cast-expression. */
4286 {
4291 {
4298 else
4309 /* Eliminate warning about unused result of + or -. */
4312 }
4316 }
4318 /* Complain about anything else that is not a true lvalue. */
4324 /* Forbid using -- on `bool'. */
4326 {
4328 {
4331 }
4333 }
4334 else
4339 }
4342 /* Note that this operation never does default_conversion
4343 regardless of NOCONVERT. */
4351 {
4355 }
4357 /* ARM $3.4 */
4360 /* Let &* cancel out to simplify resulting code. */
4362 {
4363 /* We don't need to have `current_class_ptr' wrapped in a
4364 NON_LVALUE_EXPR node. */
4370 {
4373 }
4374 else
4375 /* Don't let this be an lvalue. */
4378 }
4380 /* Uninstantiated types are all functions. Taking the
4381 address of a function is a no-op, so just return the
4382 argument. */
4389 {
4390 /* They're trying to take the address of a unique non-static
4391 member function. This is ill-formed (except in MS-land),
4392 but let's try to DTRT.
4393 Note: We only handle unique functions here because we don't
4394 want to complain if there's a static overload; non-unique
4395 cases will be handled by instantiate_type. But we need to
4396 handle this case here to allow casts on the resulting PMF.
4397 We could defer this in non-MS mode, but it's easier to give
4398 a useful error here. */
4400 /* Inside constant member functions, the `this' pointer
4401 contains an extra const qualifier. TYPE_MAIN_VARIANT
4402 is used here to remove this const from the diagnostics
4403 and the created OFFSET_REF. */
4409 {
4413 /* An expression like &memfn. */
4415 " or parenthesized non-static member function to form"
4418 else
4420 " function to form a pointer to member function."
4423 }
4425 }
4427 offset_ref:
4431 /* Handle complex lvalues (when permitted)
4432 by reduction to simpler cases. */
4438 {
4449 /* Fall through. */
4456 /* Turn a reference to a non-static data member into a
4457 pointer-to-member. */
4458 {
4459 tree type;
4460 tree t;
4467 {
4470 }
4476 }
4480 }
4482 /* Anything not already handled and not a true memory reference
4483 is an error. */
4493 /* In a template, we are processing a non-dependent expression
4494 so we can just form an ADDR_EXPR with the correct type. */
4496 {
4501 }
4504 {
4508 }
4510 {
4513 /* We can only get here with a single static member
4514 function. */
4520 /* Do not lose object's side effects. */
4523 }
4525 {
4529 }
4530 else
4531 {
4537 }
4541 {
4545 }
4551 }
4554 {
4558 }
4562 }
4564 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4565 for certain kinds of expressions which are not really lvalues
4566 but which we can accept as lvalues.
4568 If ARG is not a kind of expression we can handle, return
4569 NULL_TREE. */
4571 tree
4573 {
4574 /* Inside a template, making these kinds of adjustments is
4575 pointless; we are only concerned with the type of the
4576 expression. */
4580 /* Handle (a, b) used as an "lvalue". */
4582 {
4586 }
4588 /* Handle (a ? b : c) used as an "lvalue". */
4593 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4597 {
4600 {
4604 }
4605 return unary_complex_lvalue
4607 }
4612 /* Handle (a = b) used as an "lvalue" for `&'. */
4615 {
4621 }
4628 /* We permit compiler to make function calls returning
4629 objects of aggregate type look like lvalues. */
4630 {
4637 {
4640 else
4643 }
4648 }
4650 /* Don't let anything else be handled specially. */
4652 }
4653 \f
4654 /* Mark EXP saying that we need to be able to take the
4655 address of it; it should not be allocated in a register.
4656 Value is true if successful.
4658 C++: we do not allow `current_class_ptr' to be addressable. */
4660 bool
4662 {
4667 {
4678 {
4682 }
4683 /* Fall through. */
4686 /* Caller should not be trying to mark initialized
4687 constant fields addressable. */
4692 /* Fall through. */
4698 {
4700 {
4701 error
4704 }
4706 warning
4708 }
4727 }
4728 }
4729 \f
4730 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4732 tree
4734 {
4738 tree expr;
4741 {
4742 /* The standard says that the expression is type-dependent if
4743 IFEXP is type-dependent, even though the eventual type of the
4744 expression doesn't dependent on IFEXP. */
4746 /* As a GNU extension, the middle operand may be omitted. */
4754 }
4761 }
4762 \f
4763 /* Given a list of expressions, return a compound expression
4764 that performs them all and returns the value of the last of them. */
4767 {
4771 {
4777 }
4780 }
4782 /* Handle overloading of the ',' operator when needed. */
4784 tree
4786 {
4787 tree result;
4792 {
4798 }
4809 }
4811 /* Build a compound expression. */
4813 tree
4815 {
4822 {
4823 /* If the rhs is a TARGET_EXPR, then build the compound
4824 expression inside the target_expr's initializer. This
4825 helps the compiler to eliminate unnecessary temporaries. */
4832 }
4835 }
4837 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4838 casts away constness. DIAG_FN gives the function to call if we
4839 need to issue a diagnostic; if it is NULL, no diagnostic will be
4840 issued. DESCRIPTION explains what operation is taking place. */
4842 static void
4846 {
4850 }
4852 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4853 (another pointer-to-member type in the same hierarchy) and return
4854 the converted expression. If ALLOW_INVERSE_P is permitted, a
4855 pointer-to-derived may be converted to pointer-to-base; otherwise,
4856 only the other direction is permitted. If C_CAST_P is true, this
4857 conversion is taking place as part of a C-style cast. */
4859 tree
4862 {
4864 {
4865 tree delta;
4871 allow_inverse_p,
4872 c_cast_p);
4876 delta);
4878 }
4879 else
4882 }
4884 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4885 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
4886 Otherwise, return EXPR unchanged. */
4888 static tree
4890 {
4895 {
4897 /* Ensure constant sharing. */
4901 else
4902 {
4903 /* Avoid clobbering a shared constant. */
4906 }
4907 }
4909 }
4911 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4912 this static_cast is being attempted as one of the possible casts
4913 allowed by a C-style cast. (In that case, accessibility of base
4914 classes is not considered, and it is OK to cast away
4915 constness.) Return the result of the cast. *VALID_P is set to
4916 indicate whether or not the cast was valid. */
4918 static tree
4921 {
4922 tree intype;
4923 tree result;
4924 tree orig;
4928 /* Assume the cast is valid. */
4933 /* Save casted types in the function's used types hash table. */
4936 /* Determine what to do when casting away constness. */
4938 {
4939 /* C-style casts are allowed to cast away constness. With
4940 WARN_CAST_QUAL, we still want to issue a warning. */
4943 }
4944 else
4945 {
4946 /* A static_cast may not cast away constness. */
4949 }
4951 /* [expr.static.cast]
4953 An lvalue of type "cv1 B", where B is a class type, can be cast
4954 to type "reference to cv2 D", where D is a class derived (clause
4955 _class.derived_) from B, if a valid standard conversion from
4956 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4957 same cv-qualification as, or greater cv-qualification than, cv1,
4958 and B is not a virtual base class of D. */
4959 /* We check this case before checking the validity of "TYPE t =
4960 EXPR;" below because for this case:
4962 struct B {};
4963 struct D : public B { D(const B&); };
4964 extern B& b;
4965 void f() { static_cast<const D&>(b); }
4967 we want to avoid constructing a new D. The standard is not
4968 completely clear about this issue, but our interpretation is
4969 consistent with other compilers. */
4978 && (c_cast_p
4980 {
4981 tree base;
4983 /* There is a standard conversion from "D*" to "B*" even if "B"
4984 is ambiguous or inaccessible. If this is really a
4985 static_cast, then we check both for inaccessibility and
4986 ambiguity. However, if this is a static_cast being performed
4987 because the user wrote a C-style cast, then accessibility is
4988 not considered. */
4991 NULL);
4993 /* Convert from "B*" to "D*". This function will check that "B"
4994 is not a virtual base of "D". */
4997 /* Convert the pointer to a reference -- but then remember that
4998 there are no expressions with reference type in C++. */
5000 }
5004 /* [expr.static.cast]
5006 An expression e can be explicitly converted to a type T using a
5007 static_cast of the form static_cast<T>(e) if the declaration T
5008 t(e);" is well-formed, for some invented temporary variable
5009 t. */
5011 c_cast_p);
5013 {
5016 /* Ignore any integer overflow caused by the cast. */
5019 /* [expr.static.cast]
5021 If T is a reference type, the result is an lvalue; otherwise,
5022 the result is an rvalue. */
5026 }
5028 /* [expr.static.cast]
5030 Any expression can be explicitly converted to type cv void. */
5034 /* [expr.static.cast]
5036 The inverse of any standard conversion sequence (clause _conv_),
5037 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5038 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5039 (_conv.bool_) conversions, can be performed explicitly using
5040 static_cast subject to the restriction that the explicit
5041 conversion does not cast away constness (_expr.const.cast_), and
5042 the following additional rules for specific cases: */
5043 /* For reference, the conversions not excluded are: integral
5044 promotions, floating point promotion, integral conversions,
5045 floating point conversions, floating-integral conversions,
5046 pointer conversions, and pointer to member conversions. */
5047 /* DR 128
5049 A value of integral _or enumeration_ type can be explicitly
5050 converted to an enumeration type. */
5051 /* The effect of all that is that any conversion between any two
5052 types which are integral, floating, or enumeration types can be
5053 performed. */
5056 {
5059 /* Ignore any integer overflow caused by the cast. */
5062 }
5071 {
5072 tree base;
5078 NULL);
5080 }
5084 {
5085 tree c1;
5086 tree c2;
5087 tree t1;
5088 tree t2;
5094 {
5095 t1 = (build_ptrmem_type
5098 t2 = (build_ptrmem_type
5101 }
5102 else
5103 {
5106 }
5108 {
5111 desc);
5113 c_cast_p);
5114 }
5115 }
5117 /* [expr.static.cast]
5119 An rvalue of type "pointer to cv void" can be explicitly
5120 converted to a pointer to object type. A value of type pointer
5121 to object converted to "pointer to cv void" and back to the
5122 original pointer type will have its original value. */
5126 {
5130 }
5134 }
5136 /* Return an expression representing static_cast<TYPE>(EXPR). */
5138 tree
5140 {
5141 tree result;
5148 {
5150 /* We don't know if it will or will not have side effects. */
5153 }
5155 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5156 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5169 }
5171 /* EXPR is an expression with member function or pointer-to-member
5172 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5173 not permitted by ISO C++, but we accept it in some modes. If we
5174 are not in one of those modes, issue a diagnostic. Return the
5175 converted expression. */
5177 tree
5179 {
5180 tree intype;
5181 tree decl;
5194 else
5195 {
5199 }
5202 }
5204 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5205 If C_CAST_P is true, this reinterpret cast is being done as part of
5206 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5207 indicate whether or not reinterpret_cast was valid. */
5209 static tree
5212 {
5213 tree intype;
5215 /* Assume the cast is invalid. */
5224 /* Save casted types in the function's used types hash table. */
5227 /* [expr.reinterpret.cast]
5228 An lvalue expression of type T1 can be cast to the type
5229 "reference to T2" if an expression of type "pointer to T1" can be
5230 explicitly converted to the type "pointer to T2" using a
5231 reinterpret_cast. */
5233 {
5235 {
5240 }
5242 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5243 "B" are related class types; the reinterpret_cast does not
5244 adjust the pointer. */
5253 expr = build_reinterpret_cast_1
5255 valid_p);
5259 }
5261 /* As a G++ extension, we consider conversions from member
5262 functions, and pointers to member functions to
5263 pointer-to-function and pointer-to-void types. If
5264 -Wno-pmf-conversions has not been specified,
5265 convert_member_func_to_ptr will issue an error message. */
5273 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5274 array-to-pointer, and function-to-pointer conversions are
5275 performed. */
5278 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5279 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5289 /* [expr.reinterpret.cast]
5290 A pointer can be converted to any integral type large enough to
5291 hold it. */
5293 {
5297 }
5298 /* [expr.reinterpret.cast]
5299 A value of integral or enumeration type can be explicitly
5300 converted to a pointer. */
5302 /* OK */
5303 ;
5309 {
5315 /* Warn about possible alignment problems. */
5326 /* We need to strip nops here, because the front end likes to
5327 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5332 }
5335 {
5337 /* Only issue a warning, as we have always supported this
5338 where possible, and it is necessary in some cases. DR 195
5339 addresses this issue, but as of 2004/10/26 is still in
5340 drafting. */
5343 }
5348 else
5349 {
5354 }
5357 }
5359 tree
5361 {
5366 {
5371 /* There might turn out to be side effects inside expr. */
5374 }
5378 }
5380 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5381 return an appropriate expression. Otherwise, return
5382 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5383 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5384 performing a C-style cast, its value upon return will indicate
5385 whether or not the conversion succeeded. */
5387 static tree
5390 {
5391 tree src_type;
5392 tree reference_type;
5394 /* Callers are responsible for handling error_mark_node as a
5395 destination type. */
5397 /* In a template, callers should be building syntactic
5398 representations of casts, not using this machinery. */
5401 /* Assume the conversion is invalid. */
5406 {
5409 "which is not a pointer, "
5412 }
5415 {
5420 }
5422 /* Save casted types in the function's used types hash table. */
5426 /* Expressions do not really have reference types. */
5430 /* [expr.const.cast]
5432 An lvalue of type T1 can be explicitly converted to an lvalue of
5433 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5434 types) if a pointer to T1 can be explicitly converted to the type
5435 pointer to T2 using a const_cast. */
5437 {
5440 {
5445 }
5448 }
5449 else
5450 {
5452 /* If the destination type is not a reference type, the
5453 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5454 conversions are performed. */
5458 }
5462 {
5464 {
5466 /* This cast is actually a C-style cast. Issue a warning if
5467 the user is making a potentially unsafe cast. */
5470 warning0,
5472 }
5474 {
5478 }
5479 else
5480 {
5482 /* build_c_cast puts on a NOP_EXPR to make the result not an
5483 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5484 non-lvalue context. */
5489 }
5490 }
5496 }
5498 tree
5500 {
5505 {
5510 /* There might turn out to be side effects inside expr. */
5513 }
5517 }
5519 /* Build an expression representing an explicit C-style cast to type
5520 TYPE of expression EXPR. */
5522 tree
5524 {
5526 tree result;
5533 {
5536 /* We don't know if it will or will not have side effects. */
5539 }
5541 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5542 'Class') should always be retained, because this information aids
5543 in method lookup. */
5548 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5549 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5556 {
5557 /* Allow casting from T1* to T2[] because Cfront allows it.
5558 NIHCL uses it. It is not valid ISO C++ however. */
5560 {
5563 }
5564 else
5565 {
5568 }
5569 }
5573 {
5576 }
5578 /* A C-style cast can be a const_cast. */
5584 /* Or a static cast. */
5587 /* Or a reinterpret_cast. */
5591 /* The static_cast or reinterpret_cast may be followed by a
5592 const_cast. */
5594 /* A valid cast may result in errors if, for example, a
5595 conversion to am ambiguous base class is required. */
5597 {
5598 tree result_type;
5600 /* Non-class rvalues always have cv-unqualified type. */
5606 /* If the type of RESULT does not match TYPE, perform a
5607 const_cast to make it match. If the static_cast or
5608 reinterpret_cast succeeded, we will differ by at most
5609 cv-qualification, so the follow-on const_cast is guaranteed
5610 to succeed. */
5612 {
5615 }
5617 }
5620 }
5621 \f
5622 /* Build an assignment expression of lvalue LHS from value RHS.
5623 MODIFYCODE is the code for a binary operator that we use
5624 to combine the old value of LHS with RHS to get the new value.
5625 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5627 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5629 tree
5631 {
5632 tree result;
5639 /* Avoid duplicate error messages from operands that had errors. */
5643 /* Handle control structure constructs used as "lvalues". */
5645 {
5646 /* Handle --foo = 5; as these are valid constructs in C++. */
5654 lhs,
5658 /* Handle (a, b) used as an "lvalue". */
5679 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5680 when neither operand has side-effects. */
5689 boolean_type_node,
5694 /* Fall through. */
5696 /* Handle (a ? b : c) used as an "lvalue". */
5698 {
5699 /* Produce (a ? (b = rhs) : (c = rhs))
5700 except that the RHS goes through a save-expr
5701 so the code to compute it is only emitted once. */
5702 tree cond;
5707 /* Check this here to avoid odd errors when trying to convert
5708 a throw to the type of the COND_EXPR. */
5712 cond = build_conditional_expr
5721 /* Make sure the code to compute the rhs comes out
5722 before the split. */
5726 }
5730 }
5733 {
5735 {
5737 /* Call convert to generate an error; see PR 11063. */
5742 }
5745 else
5746 {
5753 }
5754 }
5755 else
5756 {
5762 {
5763 /* `operator=' is not an inheritable operator. */
5766 else
5767 {
5774 }
5776 }
5777 else
5778 {
5779 /* A binary op has been requested. Combine the old LHS
5780 value with the RHS producing the value we should actually
5781 store into the LHS. */
5787 {
5791 }
5793 /* Now it looks like a plain assignment. */
5795 }
5798 }
5800 /* The left-hand side must be an lvalue. */
5804 /* Warn about modifying something that is `const'. Don't warn if
5805 this is initialization. */
5808 /* Functions are not modifiable, even though they are
5809 lvalues. */
5812 /* If it's an aggregate and any field is const, then it is
5813 effectively const. */
5818 /* If storing into a structure or union member, it has probably been
5819 given type `int'. Compute the type that would go with the actual
5820 amount of storage the member occupies. */
5826 {
5829 /* If storing in a field that is in actuality a short or narrower
5830 than one, we must store in the field in its actual type. */
5833 {
5834 /* Avoid warnings converting integral types back into enums for
5835 enum bit fields. */
5838 {
5842 }
5845 }
5846 }
5848 /* Convert new value to destination type. */
5851 {
5856 {
5860 }
5862 /* Allow array assignment in compiler-generated code. */
5864 {
5865 /* This routine is used for both initialization and assignment.
5866 Make sure the diagnostic message differentiates the context. */
5869 else
5872 }
5878 from_array);
5879 }
5884 else
5885 {
5886 /* Avoid warnings on enum bit fields. */
5889 {
5893 }
5894 else
5901 /* Can't initialize directly from a TARGET_EXPR, since that would
5902 cause the lhs to be constructed twice, and possibly result in
5903 accidental self-initialization. So we force the TARGET_EXPR to be
5904 expanded without a target. */
5908 }
5914 {
5919 }
5928 /* If we got the LHS in a different type for storing in,
5929 convert the result back to the nominal type of LHS
5930 so that the value we return always has the same type
5931 as the LHS argument. */
5936 {
5940 }
5943 }
5945 tree
5947 {
5953 {
5958 {
5961 }
5962 }
5964 }
5966 \f
5967 /* Get difference in deltas for different pointer to member function
5968 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5969 the conversion is invalid, the constant is zero. If
5970 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5971 If C_CAST_P is true this conversion is taking place as part of a
5972 C-style cast.
5974 Note that the naming of FROM and TO is kind of backwards; the return
5975 value is what we add to a TO in order to get a FROM. They are named
5976 this way because we call this function to find out how to convert from
5977 a pointer to member of FROM to a pointer to member of TO. */
5979 static tree
5983 {
5984 tree binfo;
5985 base_kind kind;
5986 tree result;
5988 /* Assume no conversion is required. */
5994 {
5997 else
5998 {
6001 /* This is a reinterpret cast, we choose to do nothing. */
6005 else
6008 }
6009 }
6013 {
6016 }
6017 else
6018 {
6021 {
6024 else
6025 {
6026 /* This is a reinterpret cast, we choose to do nothing. */
6031 }
6032 }
6033 }
6036 result));
6037 }
6039 /* Return a constructor for the pointer-to-member-function TYPE using
6040 the other components as specified. */
6042 tree
6044 {
6046 tree delta_field;
6047 tree pfn_field;
6050 /* Pull the FIELD_DECLs out of the type. */
6054 /* Make sure DELTA has the type we want. */
6057 /* Finish creating the initializer. */
6070 }
6072 /* Build a constructor for a pointer to member function. It can be
6073 used to initialize global variables, local variable, or used
6074 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6075 want to be.
6077 If FORCE is nonzero, then force this conversion, even if
6078 we would rather not do it. Usually set when using an explicit
6079 cast. A C-style cast is being processed iff C_CAST_P is true.
6081 Return error_mark_node, if something goes wrong. */
6083 tree
6085 {
6086 tree fn;
6087 tree pfn_type;
6088 tree to_type;
6096 /* Handle multiple conversions of pointer to member functions. */
6098 {
6101 tree n;
6110 force,
6111 c_cast_p);
6113 /* We don't have to do any conversion to convert a
6114 pointer-to-member to its own type. But, we don't want to
6115 just return a PTRMEM_CST if there's an explicit cast; that
6116 cast should make the expression an invalid template argument. */
6118 {
6123 }
6128 /* Obtain the function pointer and the current DELTA. */
6131 else
6132 {
6135 }
6137 /* Just adjust the DELTA field. */
6144 }
6146 /* Handle null pointer to member function conversions. */
6148 {
6151 integer_zero_node,
6152 pfn);
6153 }
6160 /* In a template, we will have preserved the
6161 OFFSET_REF. */
6164 }
6166 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6167 given by CST.
6169 ??? There is no consistency as to the types returned for the above
6170 values. Some code acts as if it were a sizetype and some as if it were
6171 integer_type_node. */
6173 void
6175 {
6182 /* The class that the function belongs to. */
6185 /* The class that we're creating a pointer to member of. */
6188 /* First, calculate the adjustment to the function's class. */
6194 else
6195 {
6196 /* If we're dealing with a virtual function, we have to adjust 'this'
6197 again, to point to the base which provides the vtable entry for
6198 fn; the call will do the opposite adjustment. */
6205 /* We set PFN to the vtable offset at which the function can be
6206 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6207 case delta is shifted left, and then incremented). */
6214 {
6217 integer_one_node);
6232 }
6236 }
6237 }
6239 /* Return an expression for PFN from the pointer-to-member function
6240 given by T. */
6242 static tree
6244 {
6246 {
6247 tree delta;
6248 tree pfn;
6253 }
6256 }
6258 /* Convert value RHS to type TYPE as preparation for an assignment to
6259 an lvalue of type TYPE. ERRTYPE is a string to use in error
6260 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6261 are doing the conversion in order to pass the PARMNUMth argument of
6262 FNDECL. */
6264 static tree
6267 {
6268 tree rhstype;
6271 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6287 /* The RHS of an assignment cannot have void type. */
6289 {
6292 }
6294 /* Simplify the RHS if possible. */
6299 {
6307 else
6308 {
6314 {
6317 }
6318 }
6322 }
6324 /* [expr.ass]
6326 The expression is implicitly converted (clause _conv_) to the
6327 cv-unqualified type of the left operand.
6329 We allow bad conversions here because by the time we get to this point
6330 we are committed to doing the conversion. If we end up doing a bad
6331 conversion, convert_like will complain. */
6333 {
6334 /* When -Wno-pmf-conversions is use, we just silently allow
6335 conversions from pointers-to-members to plain pointers. If
6336 the conversion doesn't work, cp_convert will complain. */
6341 else
6342 {
6343 /* If the right-hand side has unknown type, then it is an
6344 overloaded function. Call instantiate_type to get error
6345 messages. */
6351 else
6354 }
6355 }
6357 {
6364 errtype);
6365 }
6367 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6368 does not. */
6374 {
6378 }
6381 }
6383 /* Convert RHS to be of type TYPE.
6384 If EXP is nonzero, it is the target of the initialization.
6385 ERRTYPE is a string to use in error messages.
6387 Two major differences between the behavior of
6388 `convert_for_assignment' and `convert_for_initialization'
6389 are that references are bashed in the former, while
6390 copied in the latter, and aggregates are assigned in
6391 the former (operator=) while initialized in the
6392 latter (X(X&)).
6394 If using constructor make sure no conversion operator exists, if one does
6395 exist, an ambiguity exists.
6397 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6399 tree
6402 {
6404 tree rhstype;
6407 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6408 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6435 /* We accept references to incomplete types, so we can
6436 return here before checking if RHS is of complete type. */
6439 {
6440 /* This should eventually happen in convert_arguments. */
6448 {
6453 }
6455 }
6470 }
6471 \f
6472 /* If RETVAL is the address of, or a reference to, a local variable or
6473 temporary give an appropriate warning. */
6475 static void
6477 {
6482 {
6489 else
6491 }
6498 {
6501 {
6504 }
6508 {
6511 }
6512 }
6523 {
6526 whats_returned);
6527 else
6529 whats_returned);
6531 }
6532 }
6534 /* Check that returning RETVAL from the current function is valid.
6535 Return an expression explicitly showing all conversions required to
6536 change RETVAL into the function return type, and to assign it to
6537 the DECL_RESULT for the function. Set *NO_WARNING to true if
6538 code reaches end of non-void function warning shouldn't be issued
6539 on this RETURN_EXPR. */
6541 tree
6543 {
6544 tree result;
6545 /* The type actually returned by the function, after any
6546 promotions. */
6547 tree valtype;
6552 /* A `volatile' function is one that isn't supposed to return, ever.
6553 (This is a G++ extension, used to get better code for functions
6554 that call the `volatile' function.) */
6558 /* Check for various simple errors. */
6560 {
6564 }
6566 {
6568 /* If a return statement appears in a handler of the
6569 function-try-block of a constructor, the program is ill-formed. */
6572 /* You can't return a value from a constructor. */
6575 }
6578 {
6582 }
6584 /* When no explicit return-value is given in a function with a named
6585 return value, the named return value is used. */
6593 /* Check for a return statement with no return value in a function
6594 that's supposed to return a value. */
6596 {
6598 valtype);
6599 /* Clear this, so finish_function won't say that we reach the
6600 end of a non-void function (which we don't, we gave a
6601 return!). */
6603 /* And signal caller that TREE_NO_WARNING should be set on the
6604 RETURN_EXPR to avoid control reaches end of non-void function
6605 warnings in tree-cfg.c. */
6607 }
6608 /* Check for a return statement with a value in a function that
6609 isn't supposed to return a value. */
6611 {
6613 /* You can return a `void' value from a function of `void'
6614 type. In that case, we have to evaluate the expression for
6615 its side-effects. */
6617 else
6623 /* There's really no value to return, after all. */
6625 }
6627 /* Remember that this function can sometimes return without a
6628 value. */
6630 else
6631 /* Remember that this function did return a value. */
6634 /* Check for erroneous operands -- but after giving ourselves a
6635 chance to provide an error about returning a value from a void
6636 function. */
6638 {
6641 }
6643 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6647 && ! flag_check_new
6652 /* Effective C++ rule 15. See also start_function. */
6655 {
6658 /* The function return type must be a reference to the current
6659 class. */
6661 && same_type_ignoring_top_level_qualifiers_p
6663 {
6664 /* Returning '*this' is obviously OK. */
6667 /* If we are calling a function whose return type is the same of
6668 the current class reference, it is ok. */
6672 }
6676 }
6678 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6680 [...] For a function with a class return type, if the expression
6681 in the return statement is the name of a local object, and the cv-
6682 unqualified type of the local object is the same as the function
6683 return type, an implementation is permitted to omit creating the tem-
6684 porary object to hold the function return value [...]
6686 So, if this is a value-returning function that always returns the same
6687 local variable, remember it.
6689 It might be nice to be more flexible, and choose the first suitable
6690 variable even if the function sometimes returns something else, but
6691 then we run the risk of clobbering the variable we chose if the other
6692 returned expression uses the chosen variable somehow. And people expect
6693 this restriction, anyway. (jason 2000-11-19)
6695 See finish_function and finalize_nrv for the rest of this optimization. */
6698 {
6709 (TYPE_MAIN_VARIANT
6712 else
6714 }
6716 /* We don't need to do any conversions when there's nothing being
6717 returned. */
6721 /* Do any required conversions. */
6723 /* No conversions are required. */
6724 ;
6725 else
6726 {
6727 /* The type the function is declared to return. */
6730 /* The functype's return type will have been set to void, if it
6731 was an incomplete type. Just treat this as 'return;' */
6735 /* First convert the value to the function's return type, then
6736 to the type of return value's location to handle the
6737 case that functype is smaller than the valtype. */
6738 retval = convert_for_initialization
6743 /* If the conversion failed, treat this just like `return;'. */
6746 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6752 else
6754 }
6756 /* Actually copy the value returned into the appropriate location. */
6761 }
6763 \f
6764 /* Returns nonzero if the pointer-type FROM can be converted to the
6765 pointer-type TO via a qualification conversion. If CONSTP is -1,
6766 then we return nonzero if the pointers are similar, and the
6767 cv-qualification signature of FROM is a proper subset of that of TO.
6769 If CONSTP is positive, then all outer pointers have been
6770 const-qualified. */
6772 static int
6774 {
6778 {
6787 /* Const and volatile mean something different for function types,
6788 so the usual checks are not appropriate. */
6790 {
6791 /* In Objective-C++, some types may have been 'volatilized' by
6792 the compiler for EH; when comparing them here, the volatile
6793 qualification must be ignored. */
6800 {
6804 }
6808 }
6813 }
6814 }
6816 /* When comparing, say, char ** to char const **, this function takes
6817 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6818 types to this function. */
6820 int
6822 {
6824 }
6826 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6827 type or inheritance-related types, regardless of cv-quals. */
6829 int
6831 {
6833 {
6834 /* Any target type is similar enough to void. */
6860 return comptypes
6863 }
6864 }
6866 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6867 pointer-to-member types) are the same, ignoring cv-qualification at
6868 all levels. */
6870 bool
6872 {
6874 {
6885 }
6886 }
6888 /* Returns the type qualifiers for this type, including the qualifiers on the
6889 elements for an array type. */
6891 int
6893 {
6898 }
6900 /* Returns nonzero if the TYPE contains a mutable member. */
6902 bool
6904 {
6908 }
6910 /* Apply the TYPE_QUALS to the new DECL. */
6911 void
6913 {
6921 {
6922 /* This was an error in C++98 (cv-qualifiers cannot be added to
6923 a function type), but DR 295 makes the code well-formed by
6924 dropping the extra qualifiers. */
6926 {
6930 }
6934 }
6936 /* Avoid setting TREE_READONLY incorrectly. */
6938 the object. */
6940 /* If the type isn't complete, we don't know yet if it will need
6941 constructing. */
6943 /* If the type has a mutable component, that component might be
6944 modified. */
6949 }
6951 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6952 exemplar types such that casting T1 to T2 is casting away constness
6953 if and only if there is no implicit conversion from T1 to T2. */
6955 static void
6957 {
6961 /* [expr.const.cast]
6963 For multi-level pointer to members and multi-level mixed pointers
6964 and pointers to members (conv.qual), the "member" aspect of a
6965 pointer to member level is ignored when determining if a const
6966 cv-qualifier has been cast away. */
6967 /* [expr.const.cast]
6969 For two pointer types:
6971 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6972 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6973 K is min(N,M)
6975 casting from X1 to X2 casts away constness if, for a non-pointer
6976 type T there does not exist an implicit conversion (clause
6977 _conv_) from:
6979 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6981 to
6983 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6986 {
6992 }
6999 else
7003 else
7011 }
7013 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7014 constness. */
7016 static bool
7018 {
7020 {
7021 /* [expr.const.cast]
7023 Casting from an lvalue of type T1 to an lvalue of type T2
7024 using a reference cast casts away constness if a cast from an
7025 rvalue of type "pointer to T1" to the type "pointer to T2"
7026 casts away constness. */
7030 }
7033 /* [expr.const.cast]
7035 Casting from an rvalue of type "pointer to data member of X
7036 of type T1" to the type "pointer to data member of Y of type
7037 T2" casts away constness if a cast from an rvalue of type
7038 "pointer to T1" to the type "pointer to T2" casts away
7039 constness. */
7040 return casts_away_constness
7044 /* Casting away constness is only something that makes sense for
7045 pointer or reference types. */
7050 /* Top-level qualifiers don't matter. */
7058 }
7060 /* If T is a REFERENCE_TYPE return the type to which T refers.
7061 Otherwise, return T itself. */
7063 tree
7065 {
7069 }
7072 /* Return nonzero if REF is an lvalue valid for this language;
7073 otherwise, print an error message and return zero. USE says
7074 how the lvalue is being used and so selects the error message. */
7076 int
7078 {
7085 }