| blob | 392e2db3a99f7181bdb3f490b98a03b3cac8211b |
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 3, 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 COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
24 /* This file is part of the C++ front end.
25 It contains routines to build C++ expressions given their operands,
26 including computing the types of the result, C and C++ specific error
27 checks, and some optimization. */
63 /* Do `exp = require_complete_type (exp);' to make sure exp
64 does not have an incomplete type. (That includes void types.)
65 Returns the error_mark_node if the VALUE does not have
66 complete type when this function returns. */
68 tree
70 {
71 tree type;
78 else
84 /* First, detect a valid value with a complete type. */
90 else
92 }
94 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
95 a template instantiation, do the instantiation. Returns TYPE,
96 whether or not it could be completed, unless something goes
97 horribly wrong, in which case the error_mark_node is returned. */
99 tree
101 {
103 /* Rather than crash, we return something sure to cause an error
104 at some point. */
108 ;
110 {
115 needs_constructing
117 has_nontrivial_dtor
120 {
123 }
124 }
129 }
131 /* Like complete_type, but issue an error if the TYPE cannot be completed.
132 VALUE is used for informative diagnostics.
133 Returns NULL_TREE if the type cannot be made complete. */
135 tree
137 {
140 /* We already issued an error. */
143 {
146 }
147 else
149 }
151 /* Return truthvalue of whether type of EXP is instantiated. */
153 int
155 {
158 }
160 \f
161 /* Return the common type of two parameter lists.
162 We assume that comptypes has already been done and returned 1;
163 if that isn't so, this may crash.
165 As an optimization, free the space we allocate if the parameter
166 lists are already common. */
168 static tree
170 {
180 else
181 {
184 }
193 {
195 {
198 }
200 {
202 {
205 }
206 }
207 else
208 {
212 }
214 {
217 }
218 else
220 }
225 }
227 /* Given a type, perhaps copied for a typedef,
228 find the "original" version of it. */
229 static tree
231 {
235 {
243 }
245 }
247 /* T1 and T2 are arithmetic or enumeration types. Return the type
248 that will result from the "usual arithmetic conversions" on T1 and
249 T2 as described in [expr]. */
251 tree
253 {
256 tree attributes;
258 /* FIXME: Attributes. */
266 /* In what follows, we slightly generalize the rules given in [expr] so
267 as to deal with `long long' and `complex'. First, merge the
268 attributes. */
271 /* If one type is complex, form the common type of the non-complex
272 components, then make that complex. Use T1 or T2 if it is the
273 required type. */
275 {
278 tree subtype
285 else
287 attributes);
288 }
291 {
292 /* When we get here we should have two vectors of the same size.
293 Just prefer the unsigned one if present. */
296 else
298 }
300 /* If only one is real, use it as the result. */
306 /* Perform the integral promotions. */
308 {
311 }
313 /* Both real or both integers; use the one with greater precision. */
319 /* The types are the same; no need to do anything fancy. */
324 {
325 /* If one is unsigned long long, then convert the other to unsigned
326 long long. */
330 attributes);
331 /* If one is a long long, and the other is an unsigned long, and
332 long long can represent all the values of an unsigned long, then
333 convert to a long long. Otherwise, convert to an unsigned long
334 long. Otherwise, if either operand is long long, convert the
335 other to long long.
337 Since we're here, we know the TYPE_PRECISION is the same;
338 therefore converting to long long cannot represent all the values
339 of an unsigned long, so we choose unsigned long long in that
340 case. */
343 {
345 ? long_long_unsigned_type_node
348 }
350 /* Go through the same procedure, but for longs. */
354 attributes);
357 {
361 }
362 /* Otherwise prefer the unsigned one. */
365 else
367 }
368 else
369 {
373 attributes);
377 attributes);
381 attributes);
383 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
384 the standard C++ floating-point types. Logic earlier in this
385 function has already eliminated the possibility that
386 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
387 compelling reason to choose one or the other. */
389 }
390 }
392 /* Subroutine of composite_pointer_type to implement the recursive
393 case. See that function for documentation fo the parameters. */
395 static tree
397 {
398 tree pointee1;
399 tree pointee2;
400 tree result_type;
401 tree attributes;
403 /* Determine the types pointed to by T1 and T2. */
405 {
408 }
409 else
410 {
413 }
415 /* [expr.rel]
417 Otherwise, the composite pointer type is a pointer type
418 similar (_conv.qual_) to the type of one of the operands,
419 with a cv-qualification signature (_conv.qual_) that is the
420 union of the cv-qualification signatures of the operand
421 types. */
429 else
430 {
435 }
439 /* If the original types were pointers to members, so is the
440 result. */
442 {
449 result_type);
450 }
451 else
454 /* Merge the attributes. */
457 }
459 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
460 ARG1 and ARG2 are the values with those types. The LOCATION is a
461 string describing the current location, in case an error occurs.
463 This routine also implements the computation of a common type for
464 pointers-to-members as per [expr.eq]. */
466 tree
469 {
470 tree class1;
471 tree class2;
473 /* [expr.rel]
475 If one operand is a null pointer constant, the composite pointer
476 type is the type of the other operand. */
482 /* We have:
484 [expr.rel]
486 If one of the operands has type "pointer to cv1 void*", then
487 the other has type "pointer to cv2T", and the composite pointer
488 type is "pointer to cv12 void", where cv12 is the union of cv1
489 and cv2.
491 If either type is a pointer to void, make sure it is T1. */
493 {
494 tree t;
498 }
500 /* Now, if T1 is a pointer to void, merge the qualifiers. */
502 {
503 tree attributes;
504 tree result_type;
509 result_type
514 /* Merge the attributes. */
517 }
521 {
524 }
526 /* [expr.eq] permits the application of a pointer conversion to
527 bring the pointers to a common type. */
533 {
538 t2 = (build_pointer_type
541 t1 = (build_pointer_type
543 else
544 {
548 }
549 }
550 /* [expr.eq] permits the application of a pointer-to-member
551 conversion to change the class type of one of the types. */
555 {
563 else
564 {
568 }
569 }
572 }
574 /* Return the merged type of two types.
575 We assume that comptypes has already been done and returned 1;
576 if that isn't so, this may crash.
578 This just combines attributes and default arguments; any other
579 differences would cause the two types to compare unalike. */
581 tree
583 {
586 tree attributes;
588 /* Save time if the two types are the same. */
594 /* If one type is nonsense, use the other. */
600 /* Merge the attributes. */
612 {
615 /* For two pointers, do this recursively on the target type. */
616 {
622 else
631 }
634 {
636 tree pointee;
641 pointee);
644 }
647 {
649 /* Save space: see if the result is identical to one of the args. */
654 /* Merge the element types, and have a size if either arg has one. */
655 t1 = build_cplus_array_type
658 }
661 /* Function types: prefer the one that specified arg types.
662 If both do, merge the arg types. Also merge the return types. */
663 {
669 /* Save space: see if the result is identical to one of the args. */
675 /* Simple way if one arg fails to specify argument types. */
677 {
682 }
685 {
690 }
695 }
698 {
699 /* Get this value the long way, since TYPE_METHOD_BASETYPE
700 is just the main variant of this. */
703 tree t3;
705 /* If this was a member function type, get back to the
706 original type of type member function (i.e., without
707 the class instance variable up front. */
717 }
720 /* There is no need to merge attributes into a TYPENAME_TYPE.
721 When the type is instantiated it will have whatever
722 attributes result from the instantiation. */
726 }
732 else
734 }
736 /* Return the common type of two types.
737 We assume that comptypes has already been done and returned 1;
738 if that isn't so, this may crash.
740 This is the type for the result of most arithmetic operations
741 if the operands have the given two types. */
743 tree
745 {
749 /* If one type is nonsense, bail. */
767 else
769 }
770 \f
771 /* Compare two exception specifier types for exactness or subsetness, if
772 allowed. Returns false for mismatch, true for match (same, or
773 derived and !exact).
775 [except.spec] "If a class X ... objects of class X or any class publicly
776 and unambiguously derived from X. Similarly, if a pointer type Y * ...
777 exceptions of type Y * or that are pointers to any type publicly and
778 unambiguously derived from Y. Otherwise a function only allows exceptions
779 that have the same type ..."
780 This does not mention cv qualifiers and is different to what throw
781 [except.throw] and catch [except.catch] will do. They will ignore the
782 top level cv qualifiers, and allow qualifiers in the pointer to class
783 example.
785 We implement the letter of the standard. */
787 static bool
789 {
793 {
799 {
804 }
812 }
814 }
816 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
817 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
818 otherwise it must be exact. Exception lists are unordered, but
819 we've already filtered out duplicates. Most lists will be in order,
820 we should try to make use of that. */
822 bool
824 {
825 const_tree probe;
826 const_tree base;
841 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
842 Count how many we find, to determine exactness. For exact matching and
843 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
844 O(nm). */
846 {
848 {
853 {
856 length++;
858 }
859 }
862 }
864 }
866 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
867 [] can match [size]. */
869 static bool
871 {
872 tree d1;
873 tree d2;
879 /* The type of the array elements must be the same. */
889 /* If one of the arrays is dimensionless, and the other has a
890 dimension, they are of different types. However, it is valid to
891 write:
893 extern int a[];
894 int a[3];
896 by [basic.link]:
898 declarations for an array object can specify
899 array types that differ by the presence or absence of a major
900 array bound (_dcl.array_). */
904 /* Check that the dimensions are the same. */
913 {
914 /* With abi-1 we do not fold non-dependent array bounds, (and
915 consequently mangle them incorrectly). We must therefore
916 fold them here, to verify the domains have the same
917 value. */
920 }
926 }
928 /* Subroutine in comptypes. */
930 static bool
932 {
936 /* Suppress errors caused by previously reported errors. */
942 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
943 current instantiation. */
955 /* Different classes of types can't be compatible. */
959 /* Qualifiers must match. For array types, we will check when we
960 recur on the array element types. */
967 /* Allow for two different type nodes which have essentially the same
968 definition. Note that we already checked for equality of the type
969 qualifiers (just above). */
975 /* Compare the types. Break out if they could be the same. */
977 {
991 /* Don't check inheritance. */
993 /* Fall through. */
1021 /* fall through to checks for pointer types */
1039 /* Target types must match incl. qualifiers. */
1092 }
1094 /* If we get here, we know that from a target independent POV the
1095 types are the same. Make sure the target attributes are also
1096 the same. */
1098 }
1100 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
1101 is a bitwise-or of the COMPARE_* flags. */
1103 bool
1105 {
1107 {
1115 /* At least one of the types requires structural equality, so
1116 perform a deep check. */
1119 #ifdef ENABLE_CHECKING
1121 {
1125 /* The two types are structurally equivalent, but their
1126 canonical types were different. This is a failure of the
1127 canonical type propagation code.*/
1128 internal_error
1132 /* Two types are structurally different, but the canonical
1133 types are the same. This means we were over-eager in
1134 assigning canonical types. */
1135 internal_error
1140 }
1141 #else
1144 #endif
1145 else
1147 }
1150 else
1152 }
1154 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1156 bool
1158 {
1162 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1164 }
1166 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1167 more cv-qualified that TYPE1, and 0 otherwise. */
1169 int
1171 {
1184 }
1186 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1187 subset of the cv-qualification signature of TYPE2, and the types
1188 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1190 int
1192 {
1197 else
1199 }
1200 \f
1201 /* Subroutines of `comptypes'. */
1203 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1204 equivalent in the sense that functions with those parameter types
1205 can have equivalent types. The two lists must be equivalent,
1206 element by element. */
1208 bool
1210 {
1213 /* An unspecified parmlist matches any specified parmlist
1214 whose argument types don't need default promotions. */
1219 {
1220 /* If one parmlist is shorter than the other,
1221 they fail to match. */
1226 }
1228 }
1230 \f
1231 /* Process a sizeof or alignof expression where the operand is a
1232 type. */
1234 tree
1236 {
1237 tree value;
1246 {
1251 }
1257 /* VLA types will have a non-constant size. In the body of an
1258 uninstantiated template, we don't need to try to compute the
1259 value, because the sizeof expression is not an integral
1260 constant expression in that case. And, if we do try to
1261 compute the value, we'll likely end up with SAVE_EXPRs, which
1262 the template substitution machinery does not expect to see. */
1263 || (processing_template_decl
1266 {
1270 }
1274 complain);
1275 }
1277 /* Process a sizeof expression where the operand is an expression. */
1279 static tree
1281 {
1286 {
1292 }
1297 {
1300 }
1302 {
1306 }
1308 {
1311 }
1312 else
1316 }
1318 /* Implement the __alignof keyword: Return the minimum required
1319 alignment of E, measured in bytes. For VAR_DECL's and
1320 FIELD_DECL's return DECL_ALIGN (which can be set from an
1321 "aligned" __attribute__ specification). */
1323 static tree
1325 {
1326 tree t;
1332 {
1338 }
1345 {
1348 }
1353 {
1358 else
1360 }
1362 {
1365 }
1366 else
1370 }
1372 /* Process a sizeof or alignof expression E with code OP where the operand
1373 is an expression. */
1375 tree
1377 {
1380 else
1382 }
1383 \f
1384 /* EXPR is being used in a context that is not a function call.
1385 Enforce:
1387 [expr.ref]
1389 The expression can be used only as the left-hand operand of a
1390 member function call.
1392 [expr.mptr.operator]
1394 If the result of .* or ->* is a function, then that result can be
1395 used only as the operand for the function call operator ().
1397 by issuing an error message if appropriate. Returns true iff EXPR
1398 violates these rules. */
1400 bool
1402 {
1404 {
1407 }
1409 }
1411 /* If EXP is a reference to a bitfield, and the type of EXP does not
1412 match the declared type of the bitfield, return the declared type
1413 of the bitfield. Otherwise, return NULL_TREE. */
1415 tree
1417 {
1419 {
1433 {
1434 tree field;
1443 }
1447 }
1448 }
1450 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1451 bitfield with a lowered type, the type of EXP is returned, rather
1452 than NULL_TREE. */
1454 tree
1456 {
1457 tree type;
1464 }
1466 /* Perform the conversions in [expr] that apply when an lvalue appears
1467 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1468 function-to-pointer conversions. In addition, manifest constants
1469 are replaced by their values, and bitfield references are converted
1470 to their declared types.
1472 Although the returned value is being used as an rvalue, this
1473 function does not wrap the returned expression in a
1474 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1475 that the return value is no longer an lvalue. */
1477 tree
1479 {
1480 tree type;
1488 {
1491 }
1497 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1498 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1501 {
1504 }
1510 {
1511 tree adr;
1512 tree ptrtype;
1519 {
1523 }
1527 {
1530 }
1535 {
1540 }
1541 /* This way is better for a COMPONENT_REF since it can
1542 simplify the offset for a component. */
1545 }
1547 /* If a bitfield is used in a context where integral promotion
1548 applies, then the caller is expected to have used
1549 default_conversion. That function promotes bitfields correctly
1550 before calling this function. At this point, if we have a
1551 bitfield referenced, we may assume that is not subject to
1552 promotion, and that, therefore, the type of the resulting rvalue
1553 is the declared type of the bitfield. */
1556 /* We do not call rvalue() here because we do not want to wrap EXP
1557 in a NON_LVALUE_EXPR. */
1559 /* [basic.lval]
1561 Non-class rvalues always have cv-unqualified types. */
1567 }
1569 /* Perform prepatory conversions, as part of the "usual arithmetic
1570 conversions". In particular, as per [expr]:
1572 Whenever an lvalue expression appears as an operand of an
1573 operator that expects the rvalue for that operand, the
1574 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1575 standard conversions are applied to convert the expression to an
1576 rvalue.
1578 In addition, we perform integral promotions here, as those are
1579 applied to both operands to a binary operator before determining
1580 what additional conversions should apply. */
1582 tree
1584 {
1585 /* Perform the integral promotions first so that bitfield
1586 expressions (which may promote to "int", even if the bitfield is
1587 declared "unsigned") are promoted correctly. */
1590 /* Perform the other conversions. */
1594 }
1596 /* EXPR is an expression with an integral or enumeration type.
1597 Perform the integral promotions in [conv.prom], and return the
1598 converted value. */
1600 tree
1602 {
1603 tree type;
1604 tree promoted_type;
1606 /* [conv.prom]
1608 If the bitfield has an enumerated type, it is treated as any
1609 other value of that type for promotion purposes. */
1618 }
1620 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1621 or TREE_USED. */
1623 tree
1625 {
1630 }
1632 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1633 decay_conversion to one. */
1635 int
1637 {
1638 tree t;
1649 {
1650 /* Make sure that we don't try to convert between char and wchar_t. */
1653 }
1654 else
1655 {
1656 /* Is this a string constant which has decayed to 'const char *'? */
1664 }
1666 /* This warning is not very useful, as it complains about printf. */
1670 totype);
1673 }
1675 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1676 can, for example, use as an lvalue. This code used to be in
1677 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1678 expressions, where we're dealing with aggregates. But now it's again only
1679 called from unary_complex_lvalue. The case (in particular) that led to
1680 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1681 get it there. */
1683 static tree
1685 {
1686 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1687 the first operand is always the one to be used if both operands
1688 are equal, so we know what conditional expression this used to be. */
1690 {
1694 /* The following code is incorrect if either operand side-effects. */
1697 return
1705 }
1707 return
1711 }
1713 /* Given the TYPE of an anonymous union field inside T, return the
1714 FIELD_DECL for the field. If not found return NULL_TREE. Because
1715 anonymous unions can nest, we must also search all anonymous unions
1716 that are directly reachable. */
1718 tree
1720 {
1721 tree field;
1724 {
1730 /* If we find it directly, return the field. */
1733 {
1735 }
1737 /* Otherwise, it could be nested, search harder. */
1740 {
1744 }
1745 }
1747 }
1749 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1750 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1751 non-NULL, it indicates the path to the base used to name MEMBER.
1752 If PRESERVE_REFERENCE is true, the expression returned will have
1753 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1754 returned will have the type referred to by the reference.
1756 This function does not perform access control; that is either done
1757 earlier by the parser when the name of MEMBER is resolved to MEMBER
1758 itself, or later when overload resolution selects one of the
1759 functions indicated by MEMBER. */
1761 tree
1764 {
1765 tree object_type;
1766 tree member_scope;
1774 /* [expr.ref]
1776 The type of the first expression shall be "class object" (of a
1777 complete type). */
1783 {
1787 }
1789 /* The standard does not seem to actually say that MEMBER must be a
1790 member of OBJECT_TYPE. However, that is clearly what is
1791 intended. */
1793 {
1798 }
1799 else
1801 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1802 presently be the anonymous union. Go outwards until we find a
1803 type related to OBJECT_TYPE. */
1806 object_type))
1809 {
1812 else
1815 }
1817 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1818 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1819 in the front end; only _DECLs and _REFs are lvalues in the back end. */
1820 {
1824 }
1826 /* In [expr.ref], there is an explicit list of the valid choices for
1827 MEMBER. We check for each of those cases here. */
1829 {
1830 /* A static data member. */
1832 /* If OBJECT has side-effects, they are supposed to occur. */
1835 }
1837 {
1838 /* A non-static data member. */
1841 tree member_type;
1846 /* Convert OBJECT to the type of MEMBER. */
1849 {
1850 tree binfo;
1851 base_kind kind;
1858 /* It is invalid to try to get to a virtual base of a
1859 NULL object. The most common cause is invalid use of
1860 offsetof macro. */
1862 {
1865 member);
1868 }
1870 /* Convert to the base. */
1873 /* If we found the base successfully then we should be able
1874 to convert to it successfully. */
1876 }
1878 /* Complain about other invalid uses of offsetof, even though they will
1879 give the right answer. Note that we complain whether or not they
1880 actually used the offsetof macro, since there's no way to know at this
1881 point. So we just give a warning, instead of a pedwarn. */
1882 /* Do not produce this warning for base class field references, because
1883 we know for a fact that didn't come from offsetof. This does occur
1884 in various testsuite cases where a null object is passed where a
1885 vtable access is required. */
1890 {
1892 member);
1894 }
1896 /* If MEMBER is from an anonymous aggregate, we have converted
1897 OBJECT so that it refers to the class containing the
1898 anonymous union. Generate a reference to the anonymous union
1899 itself, and recur to find MEMBER. */
1901 /* When this code is called from build_field_call, the
1902 object already has the type of the anonymous union.
1903 That is because the COMPONENT_REF was already
1904 constructed, and was then disassembled before calling
1905 build_field_call. After the function-call code is
1906 cleaned up, this waste can be eliminated. */
1907 && (!same_type_ignoring_top_level_qualifiers_p
1909 {
1910 tree anonymous_union;
1915 anonymous_union,
1917 preserve_reference);
1918 }
1920 /* Compute the type of the field, as described in [expr.ref]. */
1924 {
1928 /* A field is const (volatile) if the enclosing object, or the
1929 field itself, is const (volatile). But, a mutable field is
1930 not const, even within a const object. */
1934 }
1937 NULL_TREE);
1940 /* Mark the expression const or volatile, as appropriate. Even
1941 though we've dealt with the type above, we still have to mark the
1942 expression itself. */
1947 }
1949 {
1950 /* The member is a (possibly overloaded) member function. */
1951 tree functions;
1952 tree type;
1954 /* If the MEMBER is exactly one static member function, then we
1955 know the type of the expression. Otherwise, we must wait
1956 until overload resolution has been performed. */
1961 else
1963 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1964 base. That will happen when the function is called. */
1966 }
1968 {
1969 /* The member is an enumerator. */
1971 /* If OBJECT has side-effects, they are supposed to occur. */
1975 }
1976 else
1977 {
1980 }
1983 /* [expr.ref]
1985 If E2 is declared to have type "reference to T", then ... the
1986 type of E1.E2 is T. */
1990 }
1992 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1993 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1995 static tree
1997 {
2000 tree expr;
2003 {
2007 }
2009 {
2013 }
2016 expr = (adjust_result_of_qualified_name_lookup
2019 }
2021 /* An expression of the form "A::template B" has been resolved to
2022 DECL. Issue a diagnostic if B is not a template or template
2023 specialization. */
2025 void
2027 {
2028 /* The standard says:
2030 [temp.names]
2032 If a name prefixed by the keyword template is not a member
2033 template, the program is ill-formed.
2035 DR 228 removed the restriction that the template be a member
2036 template.
2038 DR 96, if accepted would add the further restriction that explicit
2039 template arguments must be provided if the template keyword is
2040 used, but, as of 2005-10-16, that DR is still in "drafting". If
2041 this DR is accepted, then the semantic checks here can be
2042 simplified, as the entity named must in fact be a template
2043 specialization, rather than, as at present, a set of overloaded
2044 functions containing at least one template function. */
2047 {
2050 else
2051 {
2052 tree fns;
2057 {
2067 }
2070 }
2071 }
2072 }
2074 /* This function is called by the parser to process a class member
2075 access expression of the form OBJECT.NAME. NAME is a node used by
2076 the parser to represent a name; it is not yet a DECL. It may,
2077 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2078 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2079 there is no reason to do the lookup twice, so the parser keeps the
2080 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2081 be a template via the use of the "A::template B" syntax. */
2083 tree
2085 {
2086 tree expr;
2087 tree object_type;
2088 tree member;
2096 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2103 {
2106 /* If NAME is just an IDENTIFIER_NODE, then the expression
2107 is dependent. */
2109 /* If NAME is "f<args>", where either 'f' or 'args' is
2110 dependent, then the expression is dependent. */
2114 /* If NAME is "T::X" where "T" is dependent, then the
2115 expression is dependent. */
2121 }
2123 /* [expr.ref]
2125 The type of the first expression shall be "class object" (of a
2126 complete type). */
2131 {
2135 }
2138 /* A member function that has already been looked up. */
2140 else
2141 {
2144 tree scope;
2147 {
2156 }
2159 {
2160 /* A qualified name. The qualifying class or namespace `S'
2161 has already been looked up; it is either a TYPE or a
2162 NAMESPACE_DECL. */
2166 /* If SCOPE is a namespace, then the qualified name does not
2167 name a member of OBJECT_TYPE. */
2169 {
2173 }
2179 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2184 {
2187 }
2188 }
2189 else
2190 {
2193 }
2197 else
2198 {
2199 /* Look up the member. */
2203 {
2206 }
2209 }
2212 {
2217 else
2218 {
2221 }
2222 }
2223 }
2234 {
2236 {
2240 }
2243 NULL_TREE);
2244 }
2247 }
2249 /* Return an expression for the MEMBER_NAME field in the internal
2250 representation of PTRMEM, a pointer-to-member function. (Each
2251 pointer-to-member function type gets its own RECORD_TYPE so it is
2252 more convenient to access the fields by name than by FIELD_DECL.)
2253 This routine converts the NAME to a FIELD_DECL and then creates the
2254 node for the complete expression. */
2256 tree
2258 {
2259 tree ptrmem_type;
2260 tree member;
2261 tree member_type;
2263 /* This code is a stripped down version of
2264 build_class_member_access_expr. It does not work to use that
2265 routine directly because it expects the object to be of class
2266 type. */
2275 }
2277 /* Given an expression PTR for a pointer, return an expression
2278 for the value pointed to.
2279 ERRORSTRING is the name of the operator to appear in error messages.
2281 This function may need to overload OPERATOR_FNNAME.
2282 Must also handle REFERENCE_TYPEs for C++. */
2284 tree
2286 {
2288 tree rval;
2291 {
2295 }
2304 else
2306 }
2308 tree
2310 {
2324 {
2325 /* [expr.unary.op]
2327 If the type of the expression is "pointer to T," the type
2328 of the result is "T."
2330 We must use the canonical variant because certain parts of
2331 the back end, like fold, do pointer comparisons between
2332 types. */
2338 {
2339 /* If a warning is issued, mark it to avoid duplicates from
2340 the backend. This only needs to be done at
2341 warn_strict_aliasing > 2. */
2346 }
2349 {
2350 /* A pointer to incomplete type (other than cv void) can be
2351 dereferenced [expr.unary.op]/1 */
2354 }
2357 /* The POINTER was something like `&x'. We simplify `*&x' to
2358 `x'. */
2360 else
2361 {
2364 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2365 so that we get the proper error message if the result is used
2366 to assign to. Also, &* is supposed to be a no-op. */
2372 }
2373 }
2374 /* `pointer' won't be an error_mark_node if we were given a
2375 pointer to member, so it's cool to check for this here. */
2379 {
2382 else
2384 }
2386 }
2388 /* This handles expressions of the form "a[i]", which denotes
2389 an array reference.
2391 This is logically equivalent in C to *(a+i), but we may do it differently.
2392 If A is a variable or a member, we generate a primitive ARRAY_REF.
2393 This avoids forcing the array out of registers, and can work on
2394 arrays that are not lvalues (for example, members of structures returned
2395 by functions).
2397 If INDEX is of some user-defined type, it must be converted to
2398 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2399 will inherit the type of the array, which will be some pointer type. */
2401 tree
2403 {
2405 {
2408 }
2414 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2415 inside it. */
2417 {
2419 {
2423 }
2426 return build_conditional_expr
2433 }
2436 {
2442 {
2445 }
2447 /* Apply integral promotions *after* noticing character types.
2448 (It is unclear why we do these promotions -- the standard
2449 does not say that we should. In fact, the natural thing would
2450 seem to be to convert IDX to ptrdiff_t; we're performing
2451 pointer arithmetic.) */
2454 /* An array that is indexed by a non-constant
2455 cannot be stored in a register; we must be able to do
2456 address arithmetic on its address.
2457 Likewise an array of elements of variable size. */
2462 {
2465 }
2467 /* An array that is indexed by a constant value which is not within
2468 the array bounds cannot be stored in a register either; because we
2469 would get a crash in store_bit_field/extract_bit_field when trying
2470 to access a non-existent part of the register. */
2474 {
2477 }
2482 /* Note in C++ it is valid to subscript a `register' array, since
2483 it is valid to take the address of something with that
2484 storage specification. */
2486 {
2492 }
2496 /* Array ref is const/volatile if the array elements are
2497 or if the array is.. */
2505 }
2507 {
2511 /* Put the integer in IND to simplify error checking. */
2513 {
2517 }
2523 {
2526 }
2528 {
2531 }
2537 }
2538 }
2539 \f
2540 /* Resolve a pointer to member function. INSTANCE is the object
2541 instance to use, if the member points to a virtual member.
2543 This used to avoid checking for virtual functions if basetype
2544 has no virtual functions, according to an earlier ANSI draft.
2545 With the final ISO C++ rules, such an optimization is
2546 incorrect: A pointer to a derived member can be static_cast
2547 to pointer-to-base-member, as long as the dynamic object
2548 later has the right member. */
2550 tree
2552 {
2557 {
2564 {
2566 {
2567 /* Extracting the function address from a pmf is only
2568 allowed with -Wno-pmf-conversions. It only works for
2569 pmf constants. */
2573 }
2574 else
2575 {
2578 }
2579 }
2587 /* Start by extracting all the information from the PMF itself. */
2592 {
2605 }
2607 /* Convert down to the right base before using the instance. A
2608 special case is that in a pointer to member of class C, C may
2609 be incomplete. In that case, the function will of course be
2610 a member of C, and no conversion is required. In fact,
2611 lookup_base will fail in that case, because incomplete
2612 classes do not have BINFOs. */
2616 {
2623 }
2624 /* ...and then the delta in the PMF. */
2628 /* Hand back the adjusted 'this' argument to our caller. */
2631 /* Next extract the vtable pointer from the object. */
2633 instance_ptr);
2636 /* Finally, extract the function pointer from the vtable. */
2643 /* When using function descriptors, the address of the
2644 vtable entry is treated as a function pointer. */
2652 /* Make sure this doesn't get evaluated first inside one of the
2653 branches of the COND_EXPR. */
2659 }
2661 }
2663 tree
2665 {
2672 tree parm_types;
2674 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2675 expressions, like those used for ObjC messenger dispatches. */
2678 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2679 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2685 {
2691 /* Convert anything with function type to a pointer-to-function. */
2695 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2696 (because calling an inline function does not mean the function
2697 needs to be separately compiled). */
2701 else
2703 }
2704 else
2705 {
2709 }
2717 {
2720 original);
2722 }
2729 || is_method
2731 {
2734 }
2736 /* fntype now gets the type of function pointed to. */
2740 /* Allocate storage for converted arguments. */
2747 /* Convert the parameters to the types declared in the
2748 function prototype, or apply default promotions. */
2754 /* Check for errors in format strings and inappropriately
2755 null parameters. */
2758 parm_types);
2761 }
2762 \f
2763 /* Convert the actual parameter expressions in the list VALUES
2764 to the types in the list TYPELIST.
2765 If parmdecls is exhausted, or when an element has NULL as its type,
2766 perform the default conversions.
2768 Store the converted arguments in ARGARRAY. NARGS is the size of this array.
2770 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2772 This is also where warnings about wrong number of args are generated.
2774 Returns the actual number of arguments processed (which might be less
2775 than NARGS), or -1 on error.
2777 VALUES is a chain of TREE_LIST nodes with the elements of the list
2778 in the TREE_VALUE slots of those nodes.
2780 In C++, unspecified trailing parameters can be filled in with their
2781 default arguments, if such were specified. Do so here. */
2783 static int
2786 {
2791 /* Argument passing is always copy-initialization. */
2795 {
2797 {
2801 else
2803 }
2804 else
2806 }
2809 valtail;
2811 {
2819 {
2821 {
2824 }
2825 else
2828 }
2830 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2831 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2838 {
2843 }
2849 {
2850 /* Formal parm type is specified by a function prototype. */
2851 tree parmval;
2854 {
2858 else
2861 }
2862 else
2863 {
2864 parmval = convert_for_initialization
2868 }
2874 }
2875 else
2876 {
2879 /* Don't do ellipsis conversion for __built_in_constant_p
2880 as this will result in spurious warnings for non-POD
2881 types. */
2883 else
2887 }
2891 }
2894 {
2895 /* See if there are default arguments that can be used. Because
2896 we hold default arguments in the FUNCTION_TYPE (which is so
2897 wrong), we can see default parameters here from deduced
2898 contexts (and via typeof) for indirect function calls.
2899 Fortunately we know whether we have a function decl to
2900 provide default arguments in a language conformant
2901 manner. */
2904 {
2906 {
2907 tree parmval
2917 /* ends with `...'. */
2920 }
2921 }
2922 else
2923 {
2925 {
2928 }
2929 else
2932 }
2933 }
2937 }
2938 \f
2939 /* Build a binary-operation expression, after performing default
2940 conversions on the operands. CODE is the kind of expression to
2941 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
2942 are the tree codes which correspond to ARG1 and ARG2 when issuing
2943 warnings about possibly misplaced parentheses. They may differ
2944 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
2945 folding (e.g., if the parser sees "a | 1 + 1", it may call this
2946 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
2947 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
2948 ARG2_CODE as ERROR_MARK. */
2950 tree
2953 {
2954 tree orig_arg1;
2955 tree orig_arg2;
2956 tree expr;
2962 {
2968 }
2972 else
2974 overloaded_p);
2976 /* Check for cases such as x+y<<z which users are likely to
2977 misinterpret. But don't warn about obj << x + y, since that is a
2978 common idiom for I/O. */
2980 && !processing_template_decl
2991 }
2993 /* Build a binary-operation expression without default conversions.
2994 CODE is the kind of expression to build.
2995 This function differs from `build' in several ways:
2996 the data type of the result is computed and recorded in it,
2997 warnings are generated if arg data types are invalid,
2998 special handling for addition and subtraction of pointers is known,
2999 and some optimization is done (operations on narrow ints
3000 are done in the narrower type when that gives the same result).
3001 Constant folding is also done before the result is returned.
3003 Note that the operands will never have enumeral types
3004 because either they have just had the default conversions performed
3005 or they have both just been converted to some other type in which
3006 the arithmetic is to be done.
3008 C++: must do special pointer arithmetic when implementing
3009 multiple inheritance, and deal with pointer to member functions. */
3011 tree
3014 {
3020 /* Expression code to give to the expression when it is built.
3021 Normally this is CODE, which is what the caller asked for,
3022 but in some special cases we change it. */
3025 /* Data type in which the computation is to be performed.
3026 In the simplest cases this is the common type of the arguments. */
3029 /* Nonzero means operands have already been type-converted
3030 in whatever way is necessary.
3031 Zero means they need to be converted to RESULT_TYPE. */
3034 /* Nonzero means create the expression with this type, rather than
3035 RESULT_TYPE. */
3038 /* Nonzero means after finally constructing the expression
3039 convert it to this type. */
3042 tree result;
3044 /* Nonzero if this is an operation like MIN or MAX which can
3045 safely be computed in short if both args are promoted shorts.
3046 Also implies COMMON.
3047 -1 indicates a bitwise operation; this makes a difference
3048 in the exact conditions for when it is safe to do the operation
3049 in a narrower mode. */
3052 /* Nonzero if this is a comparison operation;
3053 if both args are promoted shorts, compare the original shorts.
3054 Also implies COMMON. */
3057 /* Nonzero if this is a right-shift operation, which can be computed on the
3058 original short and then promoted if the operand is a promoted short. */
3061 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3064 /* True if both operands have arithmetic type. */
3067 /* Apply default conversions. */
3074 {
3079 }
3080 else
3081 {
3086 }
3088 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3092 /* DTRT if one side is an overloaded function, but complain about it. */
3094 {
3097 {
3101 }
3102 }
3104 {
3107 {
3111 }
3112 }
3117 /* The expression codes of the data types of the arguments tell us
3118 whether the arguments are integers, floating, pointers, etc. */
3122 /* If an error was already reported for one of the arguments,
3123 avoid reporting another error. */
3130 {
3133 }
3136 {
3138 /* Subtraction of two similar pointers.
3139 We must subtract them as integers, then divide by object size. */
3144 /* In all other cases except pointer - int, the usual arithmetic
3145 rules aply. */
3147 {
3150 }
3151 /* The pointer - int case is just like pointer + int; fall
3152 through. */
3156 {
3157 tree ptr_operand;
3158 tree int_operand;
3162 {
3165 }
3167 ptr_operand,
3168 int_operand);
3169 }
3186 {
3198 else
3199 /* When dividing two signed integers, we have to promote to int.
3200 unless we divide by a constant != -1. Note that default
3201 conversion will have been performed on the operands at this
3202 point, so we have to dig out the original type to find out if
3203 it was unsigned. */
3210 }
3228 {
3229 /* Although it would be tempting to shorten always here, that loses
3230 on some targets, since the modulo instruction is undefined if the
3231 quotient can't be represented in the computation mode. We shorten
3232 only if unsigned or if dividing by something we know != -1. */
3238 }
3248 /* Shift operations: result has same type as first operand;
3249 always convert second operand to int.
3250 Also set SHORT_SHIFT if shifting rightward. */
3254 {
3257 {
3260 else
3261 {
3266 }
3267 }
3268 /* Convert the shift-count to an integer, regardless of
3269 size of value being shifted. */
3272 /* Avoid converting op1 to result_type later. */
3274 }
3279 {
3282 {
3287 }
3288 /* Convert the shift-count to an integer, regardless of
3289 size of value being shifted. */
3292 /* Avoid converting op1 to result_type later. */
3294 }
3300 {
3303 {
3312 }
3313 /* Convert the shift-count to an integer, regardless of
3314 size of value being shifted. */
3317 }
3341 {
3347 }
3350 {
3356 }
3358 {
3361 }
3363 {
3366 }
3368 {
3371 {
3374 delta_identifier);
3376 pfn0,
3378 integer_zero_node));
3380 delta0,
3381 integer_one_node);
3385 }
3386 else
3387 {
3390 }
3392 }
3397 {
3398 /* E will be the final comparison. */
3399 tree e;
3400 /* E1 and E2 are for scratch. */
3401 tree e1;
3402 tree e2;
3403 tree pfn0;
3404 tree pfn1;
3405 tree delta0;
3406 tree delta1;
3416 delta_identifier);
3418 delta_identifier);
3421 {
3422 /* We generate:
3424 (op0.pfn == op1.pfn
3425 && ((op0.delta == op1.delta)
3426 || (!op0.pfn && op0.delta & 1 == 0
3427 && op1.delta & 1 == 0))
3429 The reason for the `!op0.pfn' bit is that a NULL
3430 pointer-to-member is any member with a zero PFN and
3431 LSB of the DELTA field is 0. */
3434 delta0,
3435 integer_one_node);
3438 delta1,
3439 integer_one_node);
3443 pfn0,
3445 integer_zero_node));
3449 }
3450 else
3451 {
3452 /* We generate:
3454 (op0.pfn == op1.pfn
3455 && (!op0.pfn || op0.delta == op1.delta))
3457 The reason for the `!op0.pfn' bit is that a NULL
3458 pointer-to-member is any member with a zero PFN; the
3459 DELTA field is unspecified. */
3463 pfn0,
3465 integer_zero_node));
3467 }
3473 }
3474 else
3475 {
3478 type1));
3481 type0));
3482 }
3518 {
3521 }
3523 {
3526 }
3538 {
3541 }
3547 }
3553 else
3554 {
3556 /* Vector arithmetic is only allowed when both sides are vectors. */
3558 {
3562 {
3565 }
3567 }
3568 }
3569 /* Determine the RESULT_TYPE, if it is not already known. */
3571 && arithmetic_types_p
3576 {
3580 }
3582 /* If we're in a template, the only thing we need to know is the
3583 RESULT_TYPE. */
3585 {
3586 /* Since the middle-end checks the type when doing a build2, we
3587 need to build the tree in pieces. This built tree will never
3588 get out of the front-end as we replace it when instantiating
3589 the template. */
3595 }
3598 {
3601 /* For certain operations (which identify themselves by shorten != 0)
3602 if both args were extended from the same smaller type,
3603 do the arithmetic in that type and then extend.
3605 shorten !=0 and !=1 indicates a bitwise operation.
3606 For them, this optimization is safe only if
3607 both args are zero-extended or both are sign-extended.
3608 Otherwise, we might change the result.
3609 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3610 but calculated in (unsigned short) it would be (unsigned short)-1. */
3613 {
3617 /* UNS is 1 if the operation to be done is an unsigned one. */
3619 tree type;
3623 /* Handle the case that OP0 does not *contain* a conversion
3624 but it *requires* conversion to FINAL_TYPE. */
3631 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3633 /* For bitwise operations, signedness of nominal type
3634 does not matter. Consider only how operands were extended. */
3638 /* Note that in all three cases below we refrain from optimizing
3639 an unsigned operation on sign-extended args.
3640 That would not be valid. */
3642 /* Both args variable: if both extended in same way
3643 from same width, do it in that width.
3644 Do it unsigned if args were zero-extended. */
3651 result_type = c_common_signed_or_unsigned_type
3669 }
3671 /* Shifts can be shortened if shifting right. */
3674 {
3684 /* We can shorten only if the shift count is less than the
3685 number of bits in the smaller type size. */
3687 /* If arg is sign-extended and then unsigned-shifted,
3688 we can simulate this with a signed shift in arg's type
3689 only if the extended result is at least twice as wide
3690 as the arg. Otherwise, the shift could use up all the
3691 ones made by sign-extension and bring in zeros.
3692 We can't optimize that case at all, but in most machines
3693 it never happens because available widths are 2**N. */
3695 || unsigned_arg
3698 {
3699 /* Do an unsigned shift if the operand was zero-extended. */
3700 result_type
3703 /* Convert value-to-be-shifted to that type. */
3707 }
3708 }
3710 /* Comparison operations are shortened too but differently.
3711 They identify themselves by setting short_compare = 1. */
3714 {
3715 /* Don't write &op0, etc., because that would prevent op0
3716 from being kept in a register.
3717 Instead, make copies of the our local variables and
3718 pass the copies by reference, then copy them back afterward. */
3721 tree val
3728 }
3731 && warn_sign_compare
3732 /* Do not warn until the template is instantiated; we cannot
3733 bound the ranges of the arguments until that point. */
3735 {
3743 /* Check for comparison of different enum types. */
3748 {
3751 }
3753 /* Give warnings for comparisons between signed and unsigned
3754 quantities that may fail. */
3755 /* Do the checking based on the original operand trees, so that
3756 casts will be considered, but default promotions won't be. */
3758 /* Do not warn if the comparison is being done in a signed type,
3759 since the signed type will only be chosen if it can represent
3760 all the values of the unsigned type. */
3763 /* Do not warn if both operands are unsigned. */
3766 /* Do not warn if the signed quantity is an unsuffixed
3767 integer literal (or some static constant expression
3768 involving such literals or a conditional expression
3769 involving such literals) and it is non-negative. */
3773 /* Do not warn if the comparison is an equality operation,
3774 the unsigned quantity is an integral constant and it does
3775 not use the most significant bit of result_type. */
3784 else
3788 /* Warn if two unsigned values are being compared in a size
3789 larger than their original size, and one (and only one) is the
3790 result of a `~' operator. This comparison will always fail.
3792 Also warn if one operand is a constant, and the constant does not
3793 have all bits set that are set in the ~ operand when it is
3794 extended. */
3798 {
3805 {
3806 tree primop;
3812 {
3816 }
3817 else
3818 {
3822 }
3827 {
3831 }
3832 }
3839 }
3840 }
3841 }
3843 /* Issue warnings about peculiar, but valid, uses of NULL. */
3845 /* It's reasonable to use pointer values as operands of &&
3846 and ||, so NULL is no exception. */
3851 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
3854 /* Some sort of arithmetic operation involving NULL was
3855 performed. Note that pointer-difference and pointer-addition
3856 have already been handled above, and so we don't end up here in
3857 that case. */
3861 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3862 Then the expression will be built.
3863 It will be given type FINAL_TYPE if that is nonzero;
3864 otherwise, it will be given type RESULT_TYPE. */
3866 {
3874 }
3890 }
3891 \f
3892 /* Return a tree for the sum or difference (RESULTCODE says which)
3893 of pointer PTROP and integer INTOP. */
3895 static tree
3897 {
3900 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3901 in certain circumstance (when it's valid to do so). So we need
3902 to make sure it's complete. We don't need to check here, if we
3903 can actually complete it at all, as those checks will be done in
3904 pointer_int_sum() anyway. */
3909 }
3911 /* Return a tree for the difference of pointers OP0 and OP1.
3912 The resulting tree has type int. */
3914 static tree
3916 {
3917 tree result;
3925 {
3932 }
3934 /* First do the subtraction as integers;
3935 then drop through to build the divide operator. */
3941 /* This generates an error if op1 is a pointer to an incomplete type. */
3949 /* Do the division. */
3953 }
3954 \f
3955 /* Construct and perhaps optimize a tree representation
3956 for a unary operation. CODE, a tree_code, specifies the operation
3957 and XARG is the operand. */
3959 tree
3961 {
3963 tree exp;
3967 {
3972 }
3976 /* [expr.unary.op] says:
3978 The address of an object of incomplete type can be taken.
3980 (And is just the ordinary address operator, not an overloaded
3981 "operator &".) However, if the type is a template
3982 specialization, we must complete the type at this point so that
3983 an overloaded "operator &" will be available if required. */
3990 else
3994 {
3995 /* A pointer to member-function can be formed only by saying
3996 &X::mf. */
3999 {
4002 {
4004 xarg);
4008 }
4009 else
4010 {
4013 xarg);
4015 }
4016 }
4019 {
4024 {
4025 /* A single non-static member, make sure we don't allow a
4026 pointer-to-member. */
4031 }
4032 }
4036 }
4044 }
4046 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4047 constants, where a null value is represented by an INTEGER_CST of
4048 -1. */
4050 tree
4052 {
4056 else
4058 }
4060 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4062 tree
4064 {
4065 tree t;
4071 }
4073 /* Return an ADDR_EXPR giving the address of T. This function
4074 attempts no optimizations or simplifications; it is a low-level
4075 primitive. */
4077 tree
4079 {
4080 tree addr;
4088 }
4090 /* Return a NOP_EXPR converting EXPR to TYPE. */
4092 tree
4094 {
4098 }
4100 /* C++: Must handle pointers to members.
4102 Perhaps type instantiation should be extended to handle conversion
4103 from aggregates to types we don't yet know we want? (Or are those
4104 cases typically errors which should be reported?)
4106 NOCONVERT nonzero suppresses the default promotions
4107 (such as from short to int). */
4109 tree
4111 {
4112 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4116 tree val;
4124 ? CONVERT_EXPR
4127 {
4130 }
4133 {
4136 {
4138 /* Unary plus (but not unary minus) is allowed on pointers. */
4146 else
4147 {
4151 /* Make sure the result is not an lvalue: a unary plus or minus
4152 expression is always a rvalue. */
4154 }
4155 }
4160 {
4164 }
4181 /* Conjugating a real value is a no-op, but allow it anyway. */
4203 {
4206 }
4207 else
4214 {
4217 }
4218 else
4225 /* Handle complex lvalues (when permitted)
4226 by reduction to simpler cases. */
4232 /* Increment or decrement the real part of the value,
4233 and don't change the imaginary part. */
4235 {
4246 }
4248 /* Report invalid types. */
4252 {
4259 else
4262 }
4266 /* Report something read-only. */
4274 {
4275 tree inc;
4276 tree declared_type;
4284 /* ARM $5.2.5 last annotation says this should be forbidden. */
4290 /* Compute the increment. */
4293 {
4308 argtype);
4310 }
4311 else
4316 /* Complain about anything else that is not a true lvalue. */
4322 /* Forbid using -- on `bool'. */
4324 {
4326 {
4330 }
4332 }
4333 else
4338 }
4341 /* Note that this operation never does default_conversion
4342 regardless of NOCONVERT. */
4350 {
4354 }
4356 /* ARM $3.4 */
4359 /* Let &* cancel out to simplify resulting code. */
4361 {
4362 /* We don't need to have `current_class_ptr' wrapped in a
4363 NON_LVALUE_EXPR node. */
4369 {
4372 }
4373 else
4374 /* Don't let this be an lvalue. */
4377 }
4379 /* Uninstantiated types are all functions. Taking the
4380 address of a function is a no-op, so just return the
4381 argument. */
4388 {
4389 /* They're trying to take the address of a unique non-static
4390 member function. This is ill-formed (except in MS-land),
4391 but let's try to DTRT.
4392 Note: We only handle unique functions here because we don't
4393 want to complain if there's a static overload; non-unique
4394 cases will be handled by instantiate_type. But we need to
4395 handle this case here to allow casts on the resulting PMF.
4396 We could defer this in non-MS mode, but it's easier to give
4397 a useful error here. */
4399 /* Inside constant member functions, the `this' pointer
4400 contains an extra const qualifier. TYPE_MAIN_VARIANT
4401 is used here to remove this const from the diagnostics
4402 and the created OFFSET_REF. */
4408 {
4412 /* An expression like &memfn. */
4414 " or parenthesized non-static member function to form"
4417 else
4419 " function to form a pointer to member function."
4422 }
4424 }
4426 offset_ref:
4430 /* Handle complex lvalues (when permitted)
4431 by reduction to simpler cases. */
4437 {
4448 /* Fall through. */
4455 /* Turn a reference to a non-static data member into a
4456 pointer-to-member. */
4457 {
4458 tree type;
4459 tree t;
4466 {
4469 }
4475 }
4479 }
4481 /* Anything not already handled and not a true memory reference
4482 is an error. */
4492 /* In a template, we are processing a non-dependent expression
4493 so we can just form an ADDR_EXPR with the correct type. */
4495 {
4500 }
4503 {
4507 }
4509 {
4512 /* We can only get here with a single static member
4513 function. */
4519 /* Do not lose object's side effects. */
4522 }
4524 {
4528 }
4529 else
4530 {
4536 }
4540 {
4544 }
4550 }
4553 {
4557 }
4561 }
4563 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4564 for certain kinds of expressions which are not really lvalues
4565 but which we can accept as lvalues.
4567 If ARG is not a kind of expression we can handle, return
4568 NULL_TREE. */
4570 tree
4572 {
4573 /* Inside a template, making these kinds of adjustments is
4574 pointless; we are only concerned with the type of the
4575 expression. */
4579 /* Handle (a, b) used as an "lvalue". */
4581 {
4585 }
4587 /* Handle (a ? b : c) used as an "lvalue". */
4592 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4596 {
4599 {
4603 }
4604 return unary_complex_lvalue
4606 }
4611 /* Handle (a = b) used as an "lvalue" for `&'. */
4614 {
4620 }
4627 /* We permit compiler to make function calls returning
4628 objects of aggregate type look like lvalues. */
4629 {
4636 {
4639 else
4642 }
4647 }
4649 /* Don't let anything else be handled specially. */
4651 }
4652 \f
4653 /* Mark EXP saying that we need to be able to take the
4654 address of it; it should not be allocated in a register.
4655 Value is true if successful.
4657 C++: we do not allow `current_class_ptr' to be addressable. */
4659 bool
4661 {
4666 {
4677 {
4681 }
4682 /* Fall through. */
4685 /* Caller should not be trying to mark initialized
4686 constant fields addressable. */
4691 /* Fall through. */
4697 {
4699 {
4700 error
4703 }
4705 warning
4707 }
4726 }
4727 }
4728 \f
4729 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4731 tree
4733 {
4737 tree expr;
4740 {
4741 /* The standard says that the expression is type-dependent if
4742 IFEXP is type-dependent, even though the eventual type of the
4743 expression doesn't dependent on IFEXP. */
4745 /* As a GNU extension, the middle operand may be omitted. */
4753 }
4760 }
4761 \f
4762 /* Given a list of expressions, return a compound expression
4763 that performs them all and returns the value of the last of them. */
4766 {
4770 {
4776 }
4779 }
4781 /* Handle overloading of the ',' operator when needed. */
4783 tree
4785 {
4786 tree result;
4791 {
4797 }
4808 }
4810 /* Build a compound expression. */
4812 tree
4814 {
4821 {
4822 /* If the rhs is a TARGET_EXPR, then build the compound
4823 expression inside the target_expr's initializer. This
4824 helps the compiler to eliminate unnecessary temporaries. */
4831 }
4834 }
4836 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4837 casts away constness. DIAG_FN gives the function to call if we
4838 need to issue a diagnostic; if it is NULL, no diagnostic will be
4839 issued. DESCRIPTION explains what operation is taking place. */
4841 static void
4845 {
4849 }
4851 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4852 (another pointer-to-member type in the same hierarchy) and return
4853 the converted expression. If ALLOW_INVERSE_P is permitted, a
4854 pointer-to-derived may be converted to pointer-to-base; otherwise,
4855 only the other direction is permitted. If C_CAST_P is true, this
4856 conversion is taking place as part of a C-style cast. */
4858 tree
4861 {
4863 {
4864 tree delta;
4870 allow_inverse_p,
4871 c_cast_p);
4873 {
4877 expr,
4884 }
4887 }
4888 else
4891 }
4893 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4894 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
4895 Otherwise, return EXPR unchanged. */
4897 static tree
4899 {
4904 {
4906 /* Ensure constant sharing. */
4910 else
4911 {
4912 /* Avoid clobbering a shared constant. */
4915 }
4916 }
4918 }
4920 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4921 this static_cast is being attempted as one of the possible casts
4922 allowed by a C-style cast. (In that case, accessibility of base
4923 classes is not considered, and it is OK to cast away
4924 constness.) Return the result of the cast. *VALID_P is set to
4925 indicate whether or not the cast was valid. */
4927 static tree
4930 {
4931 tree intype;
4932 tree result;
4933 tree orig;
4937 /* Assume the cast is valid. */
4942 /* Save casted types in the function's used types hash table. */
4945 /* Determine what to do when casting away constness. */
4947 {
4948 /* C-style casts are allowed to cast away constness. With
4949 WARN_CAST_QUAL, we still want to issue a warning. */
4952 }
4953 else
4954 {
4955 /* A static_cast may not cast away constness. */
4958 }
4960 /* [expr.static.cast]
4962 An lvalue of type "cv1 B", where B is a class type, can be cast
4963 to type "reference to cv2 D", where D is a class derived (clause
4964 _class.derived_) from B, if a valid standard conversion from
4965 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4966 same cv-qualification as, or greater cv-qualification than, cv1,
4967 and B is not a virtual base class of D. */
4968 /* We check this case before checking the validity of "TYPE t =
4969 EXPR;" below because for this case:
4971 struct B {};
4972 struct D : public B { D(const B&); };
4973 extern B& b;
4974 void f() { static_cast<const D&>(b); }
4976 we want to avoid constructing a new D. The standard is not
4977 completely clear about this issue, but our interpretation is
4978 consistent with other compilers. */
4987 && (c_cast_p
4989 {
4990 tree base;
4992 /* There is a standard conversion from "D*" to "B*" even if "B"
4993 is ambiguous or inaccessible. If this is really a
4994 static_cast, then we check both for inaccessibility and
4995 ambiguity. However, if this is a static_cast being performed
4996 because the user wrote a C-style cast, then accessibility is
4997 not considered. */
5000 NULL);
5002 /* Convert from "B*" to "D*". This function will check that "B"
5003 is not a virtual base of "D". */
5006 /* Convert the pointer to a reference -- but then remember that
5007 there are no expressions with reference type in C++. */
5009 }
5013 /* [expr.static.cast]
5015 An expression e can be explicitly converted to a type T using a
5016 static_cast of the form static_cast<T>(e) if the declaration T
5017 t(e);" is well-formed, for some invented temporary variable
5018 t. */
5020 c_cast_p);
5022 {
5025 /* Ignore any integer overflow caused by the cast. */
5028 /* [expr.static.cast]
5030 If T is a reference type, the result is an lvalue; otherwise,
5031 the result is an rvalue. */
5035 }
5037 /* [expr.static.cast]
5039 Any expression can be explicitly converted to type cv void. */
5043 /* [expr.static.cast]
5045 The inverse of any standard conversion sequence (clause _conv_),
5046 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5047 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5048 (_conv.bool_) conversions, can be performed explicitly using
5049 static_cast subject to the restriction that the explicit
5050 conversion does not cast away constness (_expr.const.cast_), and
5051 the following additional rules for specific cases: */
5052 /* For reference, the conversions not excluded are: integral
5053 promotions, floating point promotion, integral conversions,
5054 floating point conversions, floating-integral conversions,
5055 pointer conversions, and pointer to member conversions. */
5056 /* DR 128
5058 A value of integral _or enumeration_ type can be explicitly
5059 converted to an enumeration type. */
5060 /* The effect of all that is that any conversion between any two
5061 types which are integral, floating, or enumeration types can be
5062 performed. */
5065 {
5068 /* Ignore any integer overflow caused by the cast. */
5071 }
5080 {
5081 tree base;
5087 NULL);
5089 }
5093 {
5094 tree c1;
5095 tree c2;
5096 tree t1;
5097 tree t2;
5103 {
5104 t1 = (build_ptrmem_type
5107 t2 = (build_ptrmem_type
5110 }
5111 else
5112 {
5115 }
5117 {
5120 desc);
5122 c_cast_p);
5123 }
5124 }
5126 /* [expr.static.cast]
5128 An rvalue of type "pointer to cv void" can be explicitly
5129 converted to a pointer to object type. A value of type pointer
5130 to object converted to "pointer to cv void" and back to the
5131 original pointer type will have its original value. */
5135 {
5139 }
5143 }
5145 /* Return an expression representing static_cast<TYPE>(EXPR). */
5147 tree
5149 {
5150 tree result;
5157 {
5159 /* We don't know if it will or will not have side effects. */
5162 }
5164 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5165 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5178 }
5180 /* EXPR is an expression with member function or pointer-to-member
5181 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5182 not permitted by ISO C++, but we accept it in some modes. If we
5183 are not in one of those modes, issue a diagnostic. Return the
5184 converted expression. */
5186 tree
5188 {
5189 tree intype;
5190 tree decl;
5203 else
5204 {
5208 }
5211 }
5213 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5214 If C_CAST_P is true, this reinterpret cast is being done as part of
5215 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5216 indicate whether or not reinterpret_cast was valid. */
5218 static tree
5221 {
5222 tree intype;
5224 /* Assume the cast is invalid. */
5233 /* Save casted types in the function's used types hash table. */
5236 /* [expr.reinterpret.cast]
5237 An lvalue expression of type T1 can be cast to the type
5238 "reference to T2" if an expression of type "pointer to T1" can be
5239 explicitly converted to the type "pointer to T2" using a
5240 reinterpret_cast. */
5242 {
5244 {
5249 }
5251 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5252 "B" are related class types; the reinterpret_cast does not
5253 adjust the pointer. */
5262 expr = build_reinterpret_cast_1
5264 valid_p);
5268 }
5270 /* As a G++ extension, we consider conversions from member
5271 functions, and pointers to member functions to
5272 pointer-to-function and pointer-to-void types. If
5273 -Wno-pmf-conversions has not been specified,
5274 convert_member_func_to_ptr will issue an error message. */
5282 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5283 array-to-pointer, and function-to-pointer conversions are
5284 performed. */
5287 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5288 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5298 /* [expr.reinterpret.cast]
5299 A pointer can be converted to any integral type large enough to
5300 hold it. */
5302 {
5306 }
5307 /* [expr.reinterpret.cast]
5308 A value of integral or enumeration type can be explicitly
5309 converted to a pointer. */
5311 /* OK */
5312 ;
5318 {
5324 /* Warn about possible alignment problems. */
5335 /* We need to strip nops here, because the front end likes to
5336 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5342 }
5345 {
5347 /* Only issue a warning, as we have always supported this
5348 where possible, and it is necessary in some cases. DR 195
5349 addresses this issue, but as of 2004/10/26 is still in
5350 drafting. */
5353 }
5358 else
5359 {
5364 }
5367 }
5369 tree
5371 {
5376 {
5381 /* There might turn out to be side effects inside expr. */
5384 }
5388 }
5390 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5391 return an appropriate expression. Otherwise, return
5392 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5393 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5394 performing a C-style cast, its value upon return will indicate
5395 whether or not the conversion succeeded. */
5397 static tree
5400 {
5401 tree src_type;
5402 tree reference_type;
5404 /* Callers are responsible for handling error_mark_node as a
5405 destination type. */
5407 /* In a template, callers should be building syntactic
5408 representations of casts, not using this machinery. */
5411 /* Assume the conversion is invalid. */
5416 {
5419 "which is not a pointer, "
5422 }
5425 {
5430 }
5432 /* Save casted types in the function's used types hash table. */
5436 /* Expressions do not really have reference types. */
5440 /* [expr.const.cast]
5442 An lvalue of type T1 can be explicitly converted to an lvalue of
5443 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5444 types) if a pointer to T1 can be explicitly converted to the type
5445 pointer to T2 using a const_cast. */
5447 {
5450 {
5455 }
5458 }
5459 else
5460 {
5462 /* If the destination type is not a reference type, the
5463 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5464 conversions are performed. */
5468 }
5472 {
5474 {
5476 /* This cast is actually a C-style cast. Issue a warning if
5477 the user is making a potentially unsafe cast. */
5480 warning0,
5482 }
5484 {
5488 }
5489 else
5490 {
5492 /* build_c_cast puts on a NOP_EXPR to make the result not an
5493 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5494 non-lvalue context. */
5499 }
5500 }
5506 }
5508 tree
5510 {
5515 {
5520 /* There might turn out to be side effects inside expr. */
5523 }
5527 }
5529 /* Build an expression representing an explicit C-style cast to type
5530 TYPE of expression EXPR. */
5532 tree
5534 {
5536 tree result;
5543 {
5546 /* We don't know if it will or will not have side effects. */
5549 }
5551 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5552 'Class') should always be retained, because this information aids
5553 in method lookup. */
5558 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5559 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5566 {
5567 /* Allow casting from T1* to T2[] because Cfront allows it.
5568 NIHCL uses it. It is not valid ISO C++ however. */
5570 {
5573 }
5574 else
5575 {
5578 }
5579 }
5583 {
5586 }
5588 /* A C-style cast can be a const_cast. */
5594 /* Or a static cast. */
5597 /* Or a reinterpret_cast. */
5601 /* The static_cast or reinterpret_cast may be followed by a
5602 const_cast. */
5604 /* A valid cast may result in errors if, for example, a
5605 conversion to am ambiguous base class is required. */
5607 {
5608 tree result_type;
5610 /* Non-class rvalues always have cv-unqualified type. */
5616 /* If the type of RESULT does not match TYPE, perform a
5617 const_cast to make it match. If the static_cast or
5618 reinterpret_cast succeeded, we will differ by at most
5619 cv-qualification, so the follow-on const_cast is guaranteed
5620 to succeed. */
5622 {
5625 }
5627 }
5630 }
5631 \f
5632 /* Build an assignment expression of lvalue LHS from value RHS.
5633 MODIFYCODE is the code for a binary operator that we use
5634 to combine the old value of LHS with RHS to get the new value.
5635 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5637 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5639 tree
5641 {
5642 tree result;
5649 /* Avoid duplicate error messages from operands that had errors. */
5653 /* Handle control structure constructs used as "lvalues". */
5655 {
5656 /* Handle --foo = 5; as these are valid constructs in C++. */
5664 lhs,
5668 /* Handle (a, b) used as an "lvalue". */
5689 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5690 when neither operand has side-effects. */
5699 boolean_type_node,
5704 /* Fall through. */
5706 /* Handle (a ? b : c) used as an "lvalue". */
5708 {
5709 /* Produce (a ? (b = rhs) : (c = rhs))
5710 except that the RHS goes through a save-expr
5711 so the code to compute it is only emitted once. */
5712 tree cond;
5716 {
5719 }
5723 /* Check this here to avoid odd errors when trying to convert
5724 a throw to the type of the COND_EXPR. */
5728 cond = build_conditional_expr
5737 /* Make sure the code to compute the rhs comes out
5738 before the split. */
5742 }
5746 }
5749 {
5751 {
5753 /* Call convert to generate an error; see PR 11063. */
5758 }
5761 else
5762 {
5769 }
5770 }
5771 else
5772 {
5778 {
5779 /* `operator=' is not an inheritable operator. */
5782 else
5783 {
5790 }
5792 }
5793 else
5794 {
5795 /* A binary op has been requested. Combine the old LHS
5796 value with the RHS producing the value we should actually
5797 store into the LHS. */
5803 {
5807 }
5809 /* Now it looks like a plain assignment. */
5811 }
5814 }
5816 /* The left-hand side must be an lvalue. */
5820 /* Warn about modifying something that is `const'. Don't warn if
5821 this is initialization. */
5824 /* Functions are not modifiable, even though they are
5825 lvalues. */
5828 /* If it's an aggregate and any field is const, then it is
5829 effectively const. */
5834 /* If storing into a structure or union member, it has probably been
5835 given type `int'. Compute the type that would go with the actual
5836 amount of storage the member occupies. */
5842 {
5845 /* If storing in a field that is in actuality a short or narrower
5846 than one, we must store in the field in its actual type. */
5849 {
5850 /* Avoid warnings converting integral types back into enums for
5851 enum bit fields. */
5854 {
5858 }
5861 }
5862 }
5864 /* Convert new value to destination type. */
5867 {
5872 {
5876 }
5878 /* Allow array assignment in compiler-generated code. */
5880 {
5881 /* This routine is used for both initialization and assignment.
5882 Make sure the diagnostic message differentiates the context. */
5885 else
5888 }
5894 from_array);
5895 }
5900 else
5901 {
5902 /* Avoid warnings on enum bit fields. */
5905 {
5909 }
5910 else
5917 /* Can't initialize directly from a TARGET_EXPR, since that would
5918 cause the lhs to be constructed twice, and possibly result in
5919 accidental self-initialization. So we force the TARGET_EXPR to be
5920 expanded without a target. */
5924 }
5930 {
5935 }
5944 /* If we got the LHS in a different type for storing in,
5945 convert the result back to the nominal type of LHS
5946 so that the value we return always has the same type
5947 as the LHS argument. */
5952 {
5956 }
5959 }
5961 tree
5963 {
5969 {
5974 {
5977 }
5978 }
5980 }
5982 /* Helper function for get_delta_difference which assumes FROM is a base
5983 class of TO. Returns a delta for the conversion of pointer-to-member
5984 of FROM to pointer-to-member of TO. If the conversion is invalid,
5985 returns zero. If FROM is not a base class of TO, returns NULL_TREE.
5986 If C_CAST_P is true, this conversion is taking place as part of a C-style
5987 cast. */
5989 static tree
5991 {
5992 tree binfo;
5993 base_kind kind;
5997 {
6000 }
6002 {
6005 else
6006 /* FROM is a virtual base class of TO. Issue an error or warning
6007 depending on whether or not this is a reinterpret cast. */
6008 {
6013 }
6014 }
6015 else
6017 }
6019 /* Get difference in deltas for different pointer to member function
6020 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
6021 the conversion is invalid, the constant is zero. If
6022 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
6023 If C_CAST_P is true this conversion is taking place as part of a
6024 C-style cast.
6026 Note that the naming of FROM and TO is kind of backwards; the return
6027 value is what we add to a TO in order to get a FROM. They are named
6028 this way because we call this function to find out how to convert from
6029 a pointer to member of FROM to a pointer to member of TO. */
6031 static tree
6035 {
6036 tree result;
6039 /* Pointer to member of incomplete class is permitted*/
6041 else
6045 {
6047 {
6051 }
6052 else
6053 {
6058 else
6059 {
6063 }
6064 }
6065 }
6068 result));
6069 }
6071 /* Return a constructor for the pointer-to-member-function TYPE using
6072 the other components as specified. */
6074 tree
6076 {
6078 tree delta_field;
6079 tree pfn_field;
6082 /* Pull the FIELD_DECLs out of the type. */
6086 /* Make sure DELTA has the type we want. */
6089 /* Convert to the correct target type if necessary. */
6092 /* Finish creating the initializer. */
6105 }
6107 /* Build a constructor for a pointer to member function. It can be
6108 used to initialize global variables, local variable, or used
6109 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6110 want to be.
6112 If FORCE is nonzero, then force this conversion, even if
6113 we would rather not do it. Usually set when using an explicit
6114 cast. A C-style cast is being processed iff C_CAST_P is true.
6116 Return error_mark_node, if something goes wrong. */
6118 tree
6120 {
6121 tree fn;
6122 tree pfn_type;
6123 tree to_type;
6131 /* Handle multiple conversions of pointer to member functions. */
6133 {
6136 tree n;
6145 force,
6146 c_cast_p);
6148 /* We don't have to do any conversion to convert a
6149 pointer-to-member to its own type. But, we don't want to
6150 just return a PTRMEM_CST if there's an explicit cast; that
6151 cast should make the expression an invalid template argument. */
6153 {
6158 }
6163 /* Obtain the function pointer and the current DELTA. */
6166 else
6167 {
6170 }
6172 /* Just adjust the DELTA field. */
6179 }
6181 /* Handle null pointer to member function conversions. */
6183 {
6186 integer_zero_node,
6187 pfn);
6188 }
6195 /* In a template, we will have preserved the
6196 OFFSET_REF. */
6199 }
6201 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6202 given by CST.
6204 ??? There is no consistency as to the types returned for the above
6205 values. Some code acts as if it were a sizetype and some as if it were
6206 integer_type_node. */
6208 void
6210 {
6217 /* The class that the function belongs to. */
6220 /* The class that we're creating a pointer to member of. */
6223 /* First, calculate the adjustment to the function's class. */
6229 else
6230 {
6231 /* If we're dealing with a virtual function, we have to adjust 'this'
6232 again, to point to the base which provides the vtable entry for
6233 fn; the call will do the opposite adjustment. */
6240 /* We set PFN to the vtable offset at which the function can be
6241 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6242 case delta is shifted left, and then incremented). */
6249 {
6252 integer_one_node);
6267 }
6271 }
6272 }
6274 /* Return an expression for PFN from the pointer-to-member function
6275 given by T. */
6277 static tree
6279 {
6281 {
6282 tree delta;
6283 tree pfn;
6288 }
6291 }
6293 /* Convert value RHS to type TYPE as preparation for an assignment to
6294 an lvalue of type TYPE. ERRTYPE is a string to use in error
6295 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6296 are doing the conversion in order to pass the PARMNUMth argument of
6297 FNDECL. */
6299 static tree
6302 {
6303 tree rhstype;
6306 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6322 /* The RHS of an assignment cannot have void type. */
6324 {
6327 }
6329 /* Simplify the RHS if possible. */
6334 {
6342 else
6343 {
6349 {
6352 }
6353 }
6357 }
6359 /* [expr.ass]
6361 The expression is implicitly converted (clause _conv_) to the
6362 cv-unqualified type of the left operand.
6364 We allow bad conversions here because by the time we get to this point
6365 we are committed to doing the conversion. If we end up doing a bad
6366 conversion, convert_like will complain. */
6368 {
6369 /* When -Wno-pmf-conversions is use, we just silently allow
6370 conversions from pointers-to-members to plain pointers. If
6371 the conversion doesn't work, cp_convert will complain. */
6376 else
6377 {
6378 /* If the right-hand side has unknown type, then it is an
6379 overloaded function. Call instantiate_type to get error
6380 messages. */
6386 else
6389 }
6390 }
6392 {
6399 errtype);
6400 }
6402 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6403 does not. */
6409 {
6413 }
6416 }
6418 /* Convert RHS to be of type TYPE.
6419 If EXP is nonzero, it is the target of the initialization.
6420 ERRTYPE is a string to use in error messages.
6422 Two major differences between the behavior of
6423 `convert_for_assignment' and `convert_for_initialization'
6424 are that references are bashed in the former, while
6425 copied in the latter, and aggregates are assigned in
6426 the former (operator=) while initialized in the
6427 latter (X(X&)).
6429 If using constructor make sure no conversion operator exists, if one does
6430 exist, an ambiguity exists.
6432 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6434 tree
6437 {
6439 tree rhstype;
6442 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6443 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6470 /* We accept references to incomplete types, so we can
6471 return here before checking if RHS is of complete type. */
6474 {
6475 /* This should eventually happen in convert_arguments. */
6483 {
6488 }
6490 }
6505 }
6506 \f
6507 /* If RETVAL is the address of, or a reference to, a local variable or
6508 temporary give an appropriate warning. */
6510 static void
6512 {
6517 {
6524 else
6526 }
6533 {
6536 {
6539 }
6543 {
6546 }
6547 }
6558 {
6561 whats_returned);
6562 else
6564 whats_returned);
6566 }
6567 }
6569 /* Check that returning RETVAL from the current function is valid.
6570 Return an expression explicitly showing all conversions required to
6571 change RETVAL into the function return type, and to assign it to
6572 the DECL_RESULT for the function. Set *NO_WARNING to true if
6573 code reaches end of non-void function warning shouldn't be issued
6574 on this RETURN_EXPR. */
6576 tree
6578 {
6579 tree result;
6580 /* The type actually returned by the function, after any
6581 promotions. */
6582 tree valtype;
6588 /* A `volatile' function is one that isn't supposed to return, ever.
6589 (This is a G++ extension, used to get better code for functions
6590 that call the `volatile' function.) */
6594 /* Check for various simple errors. */
6596 {
6600 }
6602 {
6604 /* If a return statement appears in a handler of the
6605 function-try-block of a constructor, the program is ill-formed. */
6608 /* You can't return a value from a constructor. */
6611 }
6614 {
6618 }
6620 /* When no explicit return-value is given in a function with a named
6621 return value, the named return value is used. */
6629 /* Check for a return statement with no return value in a function
6630 that's supposed to return a value. */
6632 {
6634 valtype);
6635 /* Clear this, so finish_function won't say that we reach the
6636 end of a non-void function (which we don't, we gave a
6637 return!). */
6639 /* And signal caller that TREE_NO_WARNING should be set on the
6640 RETURN_EXPR to avoid control reaches end of non-void function
6641 warnings in tree-cfg.c. */
6643 }
6644 /* Check for a return statement with a value in a function that
6645 isn't supposed to return a value. */
6647 {
6649 /* You can return a `void' value from a function of `void'
6650 type. In that case, we have to evaluate the expression for
6651 its side-effects. */
6653 else
6659 /* There's really no value to return, after all. */
6661 }
6663 /* Remember that this function can sometimes return without a
6664 value. */
6666 else
6667 /* Remember that this function did return a value. */
6670 /* Check for erroneous operands -- but after giving ourselves a
6671 chance to provide an error about returning a value from a void
6672 function. */
6674 {
6677 }
6679 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6683 && ! flag_check_new
6688 /* Effective C++ rule 15. See also start_function. */
6691 {
6694 /* The function return type must be a reference to the current
6695 class. */
6697 && same_type_ignoring_top_level_qualifiers_p
6699 {
6700 /* Returning '*this' is obviously OK. */
6703 /* If we are calling a function whose return type is the same of
6704 the current class reference, it is ok. */
6708 }
6712 }
6714 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6716 [...] For a function with a class return type, if the expression
6717 in the return statement is the name of a local object, and the cv-
6718 unqualified type of the local object is the same as the function
6719 return type, an implementation is permitted to omit creating the tem-
6720 porary object to hold the function return value [...]
6722 So, if this is a value-returning function that always returns the same
6723 local variable, remember it.
6725 It might be nice to be more flexible, and choose the first suitable
6726 variable even if the function sometimes returns something else, but
6727 then we run the risk of clobbering the variable we chose if the other
6728 returned expression uses the chosen variable somehow. And people expect
6729 this restriction, anyway. (jason 2000-11-19)
6731 See finish_function and finalize_nrv for the rest of this optimization. */
6733 named_return_value_okay_p =
6735 /* Must be a local, automatic variable. */
6742 /* The cv-unqualified type of the returned value must be the
6743 same as the cv-unqualified return type of the
6744 function. */
6746 (TYPE_MAIN_VARIANT
6750 {
6755 else
6757 }
6759 /* We don't need to do any conversions when there's nothing being
6760 returned. */
6764 /* Do any required conversions. */
6766 /* No conversions are required. */
6767 ;
6768 else
6769 {
6770 /* The type the function is declared to return. */
6774 /* The functype's return type will have been set to void, if it
6775 was an incomplete type. Just treat this as 'return;' */
6779 /* Under C++0x [12.8/16 class.copy], a returned lvalue is sometimes
6780 treated as an rvalue for the purposes of overload resolution to
6781 favor move constructors over copy constructors. */
6783 && named_return_value_okay_p
6784 /* The variable must not have the `volatile' qualifier. */
6786 /* The return type must be a class type. */
6790 /* First convert the value to the function's return type, then
6791 to the type of return value's location to handle the
6792 case that functype is smaller than the valtype. */
6793 retval = convert_for_initialization
6797 /* If the conversion failed, treat this just like `return;'. */
6800 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6806 else
6808 }
6810 /* Actually copy the value returned into the appropriate location. */
6815 }
6817 \f
6818 /* Returns nonzero if the pointer-type FROM can be converted to the
6819 pointer-type TO via a qualification conversion. If CONSTP is -1,
6820 then we return nonzero if the pointers are similar, and the
6821 cv-qualification signature of FROM is a proper subset of that of TO.
6823 If CONSTP is positive, then all outer pointers have been
6824 const-qualified. */
6826 static int
6828 {
6832 {
6841 /* Const and volatile mean something different for function types,
6842 so the usual checks are not appropriate. */
6844 {
6845 /* In Objective-C++, some types may have been 'volatilized' by
6846 the compiler for EH; when comparing them here, the volatile
6847 qualification must be ignored. */
6854 {
6858 }
6862 }
6867 }
6868 }
6870 /* When comparing, say, char ** to char const **, this function takes
6871 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6872 types to this function. */
6874 int
6876 {
6878 }
6880 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6881 type or inheritance-related types, regardless of cv-quals. */
6883 int
6885 {
6887 {
6888 /* Any target type is similar enough to void. */
6914 return comptypes
6917 }
6918 }
6920 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6921 pointer-to-member types) are the same, ignoring cv-qualification at
6922 all levels. */
6924 bool
6926 {
6928 {
6939 }
6940 }
6942 /* Returns the type qualifiers for this type, including the qualifiers on the
6943 elements for an array type. */
6945 int
6947 {
6948 /* This CONST_CAST is okay because strip_array_types returns it's
6949 argument unmodified and we assign it to a const_tree. */
6954 }
6956 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
6957 arrays. */
6959 bool
6961 {
6962 /* This CONST_CAST is okay because strip_array_types returns it's
6963 argument unmodified and we assign it to a const_tree. */
6966 }
6968 /* Returns nonzero if the TYPE contains a mutable member. */
6970 bool
6972 {
6973 /* This CONST_CAST is okay because strip_array_types returns it's
6974 argument unmodified and we assign it to a const_tree. */
6978 }
6980 /* Set TREE_READONLY and TREE_VOLATILE on DECL as indicated by the
6981 TYPE_QUALS. For a VAR_DECL, this may be an optimistic
6982 approximation. In particular, consider:
6984 int f();
6985 struct S { int i; };
6986 const S s = { f(); }
6988 Here, we will make "s" as TREE_READONLY (because it is declared
6989 "const") -- only to reverse ourselves upon seeing that the
6990 initializer is non-constant. */
6992 void
6994 {
7002 {
7003 /* This was an error in C++98 (cv-qualifiers cannot be added to
7004 a function type), but DR 295 makes the code well-formed by
7005 dropping the extra qualifiers. */
7007 {
7011 }
7015 }
7017 /* Avoid setting TREE_READONLY incorrectly. */
7019 the object. */
7021 /* If the type isn't complete, we don't know yet if it will need
7022 constructing. */
7024 /* If the type has a mutable component, that component might be
7025 modified. */
7030 }
7032 /* Subroutine of casts_away_constness. Make T1 and T2 point at
7033 exemplar types such that casting T1 to T2 is casting away constness
7034 if and only if there is no implicit conversion from T1 to T2. */
7036 static void
7038 {
7042 /* [expr.const.cast]
7044 For multi-level pointer to members and multi-level mixed pointers
7045 and pointers to members (conv.qual), the "member" aspect of a
7046 pointer to member level is ignored when determining if a const
7047 cv-qualifier has been cast away. */
7048 /* [expr.const.cast]
7050 For two pointer types:
7052 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
7053 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
7054 K is min(N,M)
7056 casting from X1 to X2 casts away constness if, for a non-pointer
7057 type T there does not exist an implicit conversion (clause
7058 _conv_) from:
7060 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
7062 to
7064 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
7067 {
7073 }
7080 else
7084 else
7092 }
7094 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7095 constness. */
7097 static bool
7099 {
7101 {
7102 /* [expr.const.cast]
7104 Casting from an lvalue of type T1 to an lvalue of type T2
7105 using a reference cast casts away constness if a cast from an
7106 rvalue of type "pointer to T1" to the type "pointer to T2"
7107 casts away constness. */
7111 }
7114 /* [expr.const.cast]
7116 Casting from an rvalue of type "pointer to data member of X
7117 of type T1" to the type "pointer to data member of Y of type
7118 T2" casts away constness if a cast from an rvalue of type
7119 "pointer to T1" to the type "pointer to T2" casts away
7120 constness. */
7121 return casts_away_constness
7125 /* Casting away constness is only something that makes sense for
7126 pointer or reference types. */
7131 /* Top-level qualifiers don't matter. */
7139 }
7141 /* If T is a REFERENCE_TYPE return the type to which T refers.
7142 Otherwise, return T itself. */
7144 tree
7146 {
7150 }
7153 /* Return nonzero if REF is an lvalue valid for this language;
7154 otherwise, print an error message and return zero. USE says
7155 how the lvalue is being used and so selects the error message. */
7157 int
7159 {
7166 }