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 Free Software Foundation, Inc.
4 Hacked by Michael Tiemann (tiemann@cygnus.com)
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to
20 the Free Software Foundation, 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
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. */
31 #include "coretypes.h"
41 #include "diagnostic.h"
46 static tree convert_for_assignment (tree, tree, const char *, tree, int);
47 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
48 static tree rationalize_conditional_expr (enum tree_code, tree);
49 static int comp_ptr_ttypes_real (tree, tree, int);
50 static int comp_ptr_ttypes_const (tree, tree);
51 static bool comp_except_types (tree, tree, bool);
52 static bool comp_array_types (tree, tree, bool);
53 static tree common_base_type (tree, tree);
54 static tree pointer_diff (tree, tree, tree);
55 static tree get_delta_difference (tree, tree, bool, bool);
56 static void casts_away_constness_r (tree *, tree *);
57 static bool casts_away_constness (tree, tree);
58 static void maybe_warn_about_returning_address_of_local (tree);
59 static tree lookup_destructor (tree, tree, tree);
60 static tree convert_arguments (tree, tree, tree, int);
62 /* Do `exp = require_complete_type (exp);' to make sure exp
63 does not have an incomplete type. (That includes void types.)
64 Returns the error_mark_node if the VALUE does not have
65 complete type when this function returns. */
68 require_complete_type (tree value)
72 if (processing_template_decl || value == error_mark_node)
75 if (TREE_CODE (value) == OVERLOAD)
76 type = unknown_type_node;
78 type = TREE_TYPE (value);
80 if (type == error_mark_node)
81 return error_mark_node;
83 /* First, detect a valid value with a complete type. */
84 if (COMPLETE_TYPE_P (type))
87 if (complete_type_or_else (type, value))
90 return error_mark_node;
93 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
94 a template instantiation, do the instantiation. Returns TYPE,
95 whether or not it could be completed, unless something goes
96 horribly wrong, in which case the error_mark_node is returned. */
99 complete_type (tree type)
101 if (type == NULL_TREE)
102 /* Rather than crash, we return something sure to cause an error
104 return error_mark_node;
106 if (type == error_mark_node || COMPLETE_TYPE_P (type))
108 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
110 tree t = complete_type (TREE_TYPE (type));
111 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
113 TYPE_NEEDS_CONSTRUCTING (type)
114 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
115 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
116 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
118 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
119 instantiate_class_template (TYPE_MAIN_VARIANT (type));
124 /* Like complete_type, but issue an error if the TYPE cannot be completed.
125 VALUE is used for informative diagnostics.
126 Returns NULL_TREE if the type cannot be made complete. */
129 complete_type_or_else (tree type, tree value)
131 type = complete_type (type);
132 if (type == error_mark_node)
133 /* We already issued an error. */
135 else if (!COMPLETE_TYPE_P (type))
137 cxx_incomplete_type_diagnostic (value, type, 0);
144 /* Return truthvalue of whether type of EXP is instantiated. */
147 type_unknown_p (tree exp)
149 return (TREE_CODE (exp) == TREE_LIST
150 || TREE_TYPE (exp) == unknown_type_node);
154 /* Return the common type of two parameter lists.
155 We assume that comptypes has already been done and returned 1;
156 if that isn't so, this may crash.
158 As an optimization, free the space we allocate if the parameter
159 lists are already common. */
162 commonparms (tree p1, tree p2)
164 tree oldargs = p1, newargs, n;
168 len = list_length (p1);
169 newargs = tree_last (p1);
171 if (newargs == void_list_node)
180 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
185 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
187 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
189 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
192 else if (! TREE_PURPOSE (p1))
194 if (TREE_PURPOSE (p2))
196 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
202 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
204 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
206 if (TREE_VALUE (p1) != TREE_VALUE (p2))
209 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
212 TREE_VALUE (n) = TREE_VALUE (p1);
220 /* Given a type, perhaps copied for a typedef,
221 find the "original" version of it. */
223 original_type (tree t)
225 while (TYPE_NAME (t) != NULL_TREE)
227 tree x = TYPE_NAME (t);
228 if (TREE_CODE (x) != TYPE_DECL)
230 x = DECL_ORIGINAL_TYPE (x);
238 /* T1 and T2 are arithmetic or enumeration types. Return the type
239 that will result from the "usual arithmetic conversions" on T1 and
240 T2 as described in [expr]. */
243 type_after_usual_arithmetic_conversions (tree t1, tree t2)
245 enum tree_code code1 = TREE_CODE (t1);
246 enum tree_code code2 = TREE_CODE (t2);
249 /* FIXME: Attributes. */
250 gcc_assert (ARITHMETIC_TYPE_P (t1)
251 || TREE_CODE (t1) == COMPLEX_TYPE
252 || TREE_CODE (t1) == ENUMERAL_TYPE);
253 gcc_assert (ARITHMETIC_TYPE_P (t2)
254 || TREE_CODE (t2) == COMPLEX_TYPE
255 || TREE_CODE (t2) == ENUMERAL_TYPE);
257 /* In what follows, we slightly generalize the rules given in [expr] so
258 as to deal with `long long' and `complex'. First, merge the
260 attributes = (*targetm.merge_type_attributes) (t1, t2);
262 /* If one type is complex, form the common type of the non-complex
263 components, then make that complex. Use T1 or T2 if it is the
265 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
267 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
268 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
270 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
272 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
273 return build_type_attribute_variant (t1, attributes);
274 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
275 return build_type_attribute_variant (t2, attributes);
277 return build_type_attribute_variant (build_complex_type (subtype),
281 /* If only one is real, use it as the result. */
282 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
283 return build_type_attribute_variant (t1, attributes);
284 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
285 return build_type_attribute_variant (t2, attributes);
287 /* Perform the integral promotions. */
288 if (code1 != REAL_TYPE)
290 t1 = type_promotes_to (t1);
291 t2 = type_promotes_to (t2);
294 /* Both real or both integers; use the one with greater precision. */
295 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
296 return build_type_attribute_variant (t1, attributes);
297 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
298 return build_type_attribute_variant (t2, attributes);
300 /* The types are the same; no need to do anything fancy. */
301 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
302 return build_type_attribute_variant (t1, attributes);
304 if (code1 != REAL_TYPE)
306 /* If one is a sizetype, use it so size_binop doesn't blow up. */
307 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
308 return build_type_attribute_variant (t1, attributes);
309 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
310 return build_type_attribute_variant (t2, attributes);
312 /* If one is unsigned long long, then convert the other to unsigned
314 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
315 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
316 return build_type_attribute_variant (long_long_unsigned_type_node,
318 /* If one is a long long, and the other is an unsigned long, and
319 long long can represent all the values of an unsigned long, then
320 convert to a long long. Otherwise, convert to an unsigned long
321 long. Otherwise, if either operand is long long, convert the
324 Since we're here, we know the TYPE_PRECISION is the same;
325 therefore converting to long long cannot represent all the values
326 of an unsigned long, so we choose unsigned long long in that
328 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
329 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
331 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
332 ? long_long_unsigned_type_node
333 : long_long_integer_type_node);
334 return build_type_attribute_variant (t, attributes);
337 /* Go through the same procedure, but for longs. */
338 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
339 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
340 return build_type_attribute_variant (long_unsigned_type_node,
342 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
343 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
345 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
346 ? long_unsigned_type_node : long_integer_type_node);
347 return build_type_attribute_variant (t, attributes);
349 /* Otherwise prefer the unsigned one. */
350 if (TYPE_UNSIGNED (t1))
351 return build_type_attribute_variant (t1, attributes);
353 return build_type_attribute_variant (t2, attributes);
357 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
358 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
359 return build_type_attribute_variant (long_double_type_node,
361 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
362 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
363 return build_type_attribute_variant (double_type_node,
365 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
366 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
367 return build_type_attribute_variant (float_type_node,
370 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
371 the standard C++ floating-point types. Logic earlier in this
372 function has already eliminated the possibility that
373 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
374 compelling reason to choose one or the other. */
375 return build_type_attribute_variant (t1, attributes);
379 /* Subroutine of composite_pointer_type to implement the recursive
380 case. See that function for documentation fo the parameters. */
383 composite_pointer_type_r (tree t1, tree t2, const char* location)
390 /* Determine the types pointed to by T1 and T2. */
391 if (TREE_CODE (t1) == POINTER_TYPE)
393 pointee1 = TREE_TYPE (t1);
394 pointee2 = TREE_TYPE (t2);
398 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
399 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
404 Otherwise, the composite pointer type is a pointer type
405 similar (_conv.qual_) to the type of one of the operands,
406 with a cv-qualification signature (_conv.qual_) that is the
407 union of the cv-qualification signatures of the operand
409 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
410 result_type = pointee1;
411 else if ((TREE_CODE (pointee1) == POINTER_TYPE
412 && TREE_CODE (pointee2) == POINTER_TYPE)
413 || (TYPE_PTR_TO_MEMBER_P (pointee1)
414 && TYPE_PTR_TO_MEMBER_P (pointee2)))
415 result_type = composite_pointer_type_r (pointee1, pointee2, location);
418 pedwarn ("%s between distinct pointer types %qT and %qT "
421 result_type = void_type_node;
423 result_type = cp_build_qualified_type (result_type,
424 (cp_type_quals (pointee1)
425 | cp_type_quals (pointee2)));
426 /* If the original types were pointers to members, so is the
428 if (TYPE_PTR_TO_MEMBER_P (t1))
430 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
431 TYPE_PTRMEM_CLASS_TYPE (t2)))
432 pedwarn ("%s between distinct pointer types %qT and %qT "
435 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
439 result_type = build_pointer_type (result_type);
441 /* Merge the attributes. */
442 attributes = (*targetm.merge_type_attributes) (t1, t2);
443 return build_type_attribute_variant (result_type, attributes);
446 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
447 ARG1 and ARG2 are the values with those types. The LOCATION is a
448 string describing the current location, in case an error occurs.
450 This routine also implements the computation of a common type for
451 pointers-to-members as per [expr.eq]. */
454 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
455 const char* location)
462 If one operand is a null pointer constant, the composite pointer
463 type is the type of the other operand. */
464 if (null_ptr_cst_p (arg1))
466 if (null_ptr_cst_p (arg2))
473 If one of the operands has type "pointer to cv1 void*", then
474 the other has type "pointer to cv2T", and the composite pointer
475 type is "pointer to cv12 void", where cv12 is the union of cv1
478 If either type is a pointer to void, make sure it is T1. */
479 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
487 /* Now, if T1 is a pointer to void, merge the qualifiers. */
488 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
493 if (pedantic && TYPE_PTRFN_P (t2))
494 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
495 "and pointer-to-function", location);
497 = cp_build_qualified_type (void_type_node,
498 (cp_type_quals (TREE_TYPE (t1))
499 | cp_type_quals (TREE_TYPE (t2))));
500 result_type = build_pointer_type (result_type);
501 /* Merge the attributes. */
502 attributes = (*targetm.merge_type_attributes) (t1, t2);
503 return build_type_attribute_variant (result_type, attributes);
506 /* [expr.eq] permits the application of a pointer conversion to
507 bring the pointers to a common type. */
508 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
509 && CLASS_TYPE_P (TREE_TYPE (t1))
510 && CLASS_TYPE_P (TREE_TYPE (t2))
511 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
514 class1 = TREE_TYPE (t1);
515 class2 = TREE_TYPE (t2);
517 if (DERIVED_FROM_P (class1, class2))
518 t2 = (build_pointer_type
519 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
520 else if (DERIVED_FROM_P (class2, class1))
521 t1 = (build_pointer_type
522 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
525 error ("%s between distinct pointer types %qT and %qT "
526 "lacks a cast", location, t1, t2);
527 return error_mark_node;
530 /* [expr.eq] permits the application of a pointer-to-member
531 conversion to change the class type of one of the types. */
532 else if (TYPE_PTR_TO_MEMBER_P (t1)
533 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
534 TYPE_PTRMEM_CLASS_TYPE (t2)))
536 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
537 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
539 if (DERIVED_FROM_P (class1, class2))
540 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
541 else if (DERIVED_FROM_P (class2, class1))
542 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
545 error ("%s between distinct pointer-to-member types %qT and %qT "
546 "lacks a cast", location, t1, t2);
547 return error_mark_node;
551 return composite_pointer_type_r (t1, t2, location);
554 /* Return the merged type of two types.
555 We assume that comptypes has already been done and returned 1;
556 if that isn't so, this may crash.
558 This just combines attributes and default arguments; any other
559 differences would cause the two types to compare unalike. */
562 merge_types (tree t1, tree t2)
564 enum tree_code code1;
565 enum tree_code code2;
568 /* Save time if the two types are the same. */
571 if (original_type (t1) == original_type (t2))
574 /* If one type is nonsense, use the other. */
575 if (t1 == error_mark_node)
577 if (t2 == error_mark_node)
580 /* Merge the attributes. */
581 attributes = (*targetm.merge_type_attributes) (t1, t2);
583 if (TYPE_PTRMEMFUNC_P (t1))
584 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
585 if (TYPE_PTRMEMFUNC_P (t2))
586 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
588 code1 = TREE_CODE (t1);
589 code2 = TREE_CODE (t2);
595 /* For two pointers, do this recursively on the target type. */
597 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
598 int quals = cp_type_quals (t1);
600 if (code1 == POINTER_TYPE)
601 t1 = build_pointer_type (target);
603 t1 = build_reference_type (target);
604 t1 = build_type_attribute_variant (t1, attributes);
605 t1 = cp_build_qualified_type (t1, quals);
607 if (TREE_CODE (target) == METHOD_TYPE)
608 t1 = build_ptrmemfunc_type (t1);
617 quals = cp_type_quals (t1);
618 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
619 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
620 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
622 t1 = cp_build_qualified_type (t1, quals);
628 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
629 /* Save space: see if the result is identical to one of the args. */
630 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
631 return build_type_attribute_variant (t1, attributes);
632 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
633 return build_type_attribute_variant (t2, attributes);
634 /* Merge the element types, and have a size if either arg has one. */
635 t1 = build_cplus_array_type
636 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
641 /* Function types: prefer the one that specified arg types.
642 If both do, merge the arg types. Also merge the return types. */
644 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
645 tree p1 = TYPE_ARG_TYPES (t1);
646 tree p2 = TYPE_ARG_TYPES (t2);
649 /* Save space: see if the result is identical to one of the args. */
650 if (valtype == TREE_TYPE (t1) && ! p2)
651 return cp_build_type_attribute_variant (t1, attributes);
652 if (valtype == TREE_TYPE (t2) && ! p1)
653 return cp_build_type_attribute_variant (t2, attributes);
655 /* Simple way if one arg fails to specify argument types. */
656 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
658 rval = build_function_type (valtype, p2);
659 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
660 rval = build_exception_variant (rval, raises);
661 return cp_build_type_attribute_variant (rval, attributes);
663 raises = TYPE_RAISES_EXCEPTIONS (t1);
664 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
666 rval = build_function_type (valtype, p1);
668 rval = build_exception_variant (rval, raises);
669 return cp_build_type_attribute_variant (rval, attributes);
672 rval = build_function_type (valtype, commonparms (p1, p2));
673 t1 = build_exception_variant (rval, raises);
679 /* Get this value the long way, since TYPE_METHOD_BASETYPE
680 is just the main variant of this. */
681 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
682 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
685 /* If this was a member function type, get back to the
686 original type of type member function (i.e., without
687 the class instance variable up front. */
688 t1 = build_function_type (TREE_TYPE (t1),
689 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
690 t2 = build_function_type (TREE_TYPE (t2),
691 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
692 t3 = merge_types (t1, t2);
693 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
694 TYPE_ARG_TYPES (t3));
695 t1 = build_exception_variant (t3, raises);
700 /* There is no need to merge attributes into a TYPENAME_TYPE.
701 When the type is instantiated it will have whatever
702 attributes result from the instantiation. */
707 return cp_build_type_attribute_variant (t1, attributes);
710 /* Return the common type of two types.
711 We assume that comptypes has already been done and returned 1;
712 if that isn't so, this may crash.
714 This is the type for the result of most arithmetic operations
715 if the operands have the given two types. */
718 common_type (tree t1, tree t2)
720 enum tree_code code1;
721 enum tree_code code2;
723 /* If one type is nonsense, bail. */
724 if (t1 == error_mark_node || t2 == error_mark_node)
725 return error_mark_node;
727 code1 = TREE_CODE (t1);
728 code2 = TREE_CODE (t2);
730 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
731 || code1 == COMPLEX_TYPE)
732 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
733 || code2 == COMPLEX_TYPE))
734 return type_after_usual_arithmetic_conversions (t1, t2);
736 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
737 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
738 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
739 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
745 /* Compare two exception specifier types for exactness or subsetness, if
746 allowed. Returns false for mismatch, true for match (same, or
749 [except.spec] "If a class X ... objects of class X or any class publicly
750 and unambiguously derived from X. Similarly, if a pointer type Y * ...
751 exceptions of type Y * or that are pointers to any type publicly and
752 unambiguously derived from Y. Otherwise a function only allows exceptions
753 that have the same type ..."
754 This does not mention cv qualifiers and is different to what throw
755 [except.throw] and catch [except.catch] will do. They will ignore the
756 top level cv qualifiers, and allow qualifiers in the pointer to class
759 We implement the letter of the standard. */
762 comp_except_types (tree a, tree b, bool exact)
764 if (same_type_p (a, b))
768 if (cp_type_quals (a) || cp_type_quals (b))
771 if (TREE_CODE (a) == POINTER_TYPE
772 && TREE_CODE (b) == POINTER_TYPE)
776 if (cp_type_quals (a) || cp_type_quals (b))
780 if (TREE_CODE (a) != RECORD_TYPE
781 || TREE_CODE (b) != RECORD_TYPE)
784 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
790 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
791 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
792 otherwise it must be exact. Exception lists are unordered, but
793 we've already filtered out duplicates. Most lists will be in order,
794 we should try to make use of that. */
797 comp_except_specs (tree t1, tree t2, bool exact)
806 if (t1 == NULL_TREE) /* T1 is ... */
807 return t2 == NULL_TREE || !exact;
808 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
809 return t2 != NULL_TREE && !TREE_VALUE (t2);
810 if (t2 == NULL_TREE) /* T2 is ... */
812 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
815 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
816 Count how many we find, to determine exactness. For exact matching and
817 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
819 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
821 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
823 tree a = TREE_VALUE (probe);
824 tree b = TREE_VALUE (t2);
826 if (comp_except_types (a, b, exact))
828 if (probe == base && exact)
829 base = TREE_CHAIN (probe);
834 if (probe == NULL_TREE)
837 return !exact || base == NULL_TREE || length == list_length (t1);
840 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
841 [] can match [size]. */
844 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
853 /* The type of the array elements must be the same. */
854 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
857 d1 = TYPE_DOMAIN (t1);
858 d2 = TYPE_DOMAIN (t2);
863 /* If one of the arrays is dimensionless, and the other has a
864 dimension, they are of different types. However, it is valid to
872 declarations for an array object can specify
873 array types that differ by the presence or absence of a major
874 array bound (_dcl.array_). */
876 return allow_redeclaration;
878 /* Check that the dimensions are the same. */
880 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
882 max1 = TYPE_MAX_VALUE (d1);
883 max2 = TYPE_MAX_VALUE (d2);
884 if (processing_template_decl && !abi_version_at_least (2)
885 && !value_dependent_expression_p (max1)
886 && !value_dependent_expression_p (max2))
888 /* With abi-1 we do not fold non-dependent array bounds, (and
889 consequently mangle them incorrectly). We must therefore
890 fold them here, to verify the domains have the same
896 if (!cp_tree_equal (max1, max2))
902 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
903 is a bitwise-or of the COMPARE_* flags. */
906 comptypes (tree t1, tree t2, int strict)
911 /* Suppress errors caused by previously reported errors. */
912 if (t1 == error_mark_node || t2 == error_mark_node)
915 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
917 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
918 current instantiation. */
919 if (TREE_CODE (t1) == TYPENAME_TYPE)
921 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
923 if (resolved != error_mark_node)
927 if (TREE_CODE (t2) == TYPENAME_TYPE)
929 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
931 if (resolved != error_mark_node)
935 /* If either type is the internal version of sizetype, use the
937 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
938 && TYPE_ORIG_SIZE_TYPE (t1))
939 t1 = TYPE_ORIG_SIZE_TYPE (t1);
941 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
942 && TYPE_ORIG_SIZE_TYPE (t2))
943 t2 = TYPE_ORIG_SIZE_TYPE (t2);
945 if (TYPE_PTRMEMFUNC_P (t1))
946 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
947 if (TYPE_PTRMEMFUNC_P (t2))
948 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
950 /* Different classes of types can't be compatible. */
951 if (TREE_CODE (t1) != TREE_CODE (t2))
954 /* Qualifiers must match. For array types, we will check when we
955 recur on the array element types. */
956 if (TREE_CODE (t1) != ARRAY_TYPE
957 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
959 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
962 /* Allow for two different type nodes which have essentially the same
963 definition. Note that we already checked for equality of the type
964 qualifiers (just above). */
966 if (TREE_CODE (t1) != ARRAY_TYPE
967 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
970 /* Compare the types. Break out if they could be the same. */
971 switch (TREE_CODE (t1))
973 case TEMPLATE_TEMPLATE_PARM:
974 case BOUND_TEMPLATE_TEMPLATE_PARM:
975 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
976 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
978 if (!comp_template_parms
979 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
980 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
982 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
984 /* Don't check inheritance. */
985 strict = COMPARE_STRICT;
990 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
991 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
992 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
993 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
996 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
998 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1001 /* We may be dealing with Objective-C instances. */
1002 if (TREE_CODE (t1) == RECORD_TYPE
1003 && objc_comptypes (t1, t2, 0) > 0)
1009 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1010 strict & ~COMPARE_REDECLARATION))
1012 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1017 case REFERENCE_TYPE:
1018 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1019 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1020 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1026 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1028 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1033 /* Target types must match incl. qualifiers. */
1034 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1038 case TEMPLATE_TYPE_PARM:
1039 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1040 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1045 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1046 TYPENAME_TYPE_FULLNAME (t2)))
1048 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1052 case UNBOUND_CLASS_TEMPLATE:
1053 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1055 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1060 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1065 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1066 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1074 /* If we get here, we know that from a target independent POV the
1075 types are the same. Make sure the target attributes are also
1077 return targetm.comp_type_attributes (t1, t2);
1080 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1083 at_least_as_qualified_p (tree type1, tree type2)
1085 int q1 = cp_type_quals (type1);
1086 int q2 = cp_type_quals (type2);
1088 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1089 return (q1 & q2) == q2;
1092 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1093 more cv-qualified that TYPE1, and 0 otherwise. */
1096 comp_cv_qualification (tree type1, tree type2)
1098 int q1 = cp_type_quals (type1);
1099 int q2 = cp_type_quals (type2);
1104 if ((q1 & q2) == q2)
1106 else if ((q1 & q2) == q1)
1112 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1113 subset of the cv-qualification signature of TYPE2, and the types
1114 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1117 comp_cv_qual_signature (tree type1, tree type2)
1119 if (comp_ptr_ttypes_real (type2, type1, -1))
1121 else if (comp_ptr_ttypes_real (type1, type2, -1))
1127 /* If two types share a common base type, return that basetype.
1128 If there is not a unique most-derived base type, this function
1129 returns ERROR_MARK_NODE. */
1132 common_base_type (tree tt1, tree tt2)
1134 tree best = NULL_TREE;
1137 /* If one is a baseclass of another, that's good enough. */
1138 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1140 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1143 /* Otherwise, try to find a unique baseclass of TT1
1144 that is shared by TT2, and follow that down. */
1145 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1147 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1148 tree trial = common_base_type (basetype, tt2);
1152 if (trial == error_mark_node)
1154 if (best == NULL_TREE)
1156 else if (best != trial)
1157 return error_mark_node;
1162 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1164 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1165 tree trial = common_base_type (tt1, basetype);
1169 if (trial == error_mark_node)
1171 if (best == NULL_TREE)
1173 else if (best != trial)
1174 return error_mark_node;
1180 /* Subroutines of `comptypes'. */
1182 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1183 equivalent in the sense that functions with those parameter types
1184 can have equivalent types. The two lists must be equivalent,
1185 element by element. */
1188 compparms (tree parms1, tree parms2)
1192 /* An unspecified parmlist matches any specified parmlist
1193 whose argument types don't need default promotions. */
1195 for (t1 = parms1, t2 = parms2;
1197 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1199 /* If one parmlist is shorter than the other,
1200 they fail to match. */
1203 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1210 /* Process a sizeof or alignof expression where the operand is a
1214 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1216 enum tree_code type_code;
1218 const char *op_name;
1220 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1221 if (type == error_mark_node)
1222 return error_mark_node;
1224 if (dependent_type_p (type))
1226 value = build_min (op, size_type_node, type);
1227 TREE_READONLY (value) = 1;
1231 op_name = operator_name_info[(int) op].name;
1233 type = non_reference (type);
1234 type_code = TREE_CODE (type);
1236 if (type_code == METHOD_TYPE)
1238 if (complain && (pedantic || warn_pointer_arith))
1239 pedwarn ("invalid application of %qs to a member function", op_name);
1240 value = size_one_node;
1243 value = c_sizeof_or_alignof_type (complete_type (type), op, complain);
1248 /* Process a sizeof or alignof expression where the operand is an
1252 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1254 const char *op_name = operator_name_info[(int) op].name;
1256 if (e == error_mark_node)
1257 return error_mark_node;
1259 if (processing_template_decl)
1261 e = build_min (op, size_type_node, e);
1262 TREE_SIDE_EFFECTS (e) = 0;
1263 TREE_READONLY (e) = 1;
1268 if (TREE_CODE (e) == COMPONENT_REF
1269 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1270 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1272 error ("invalid application of %qs to a bit-field", op_name);
1275 else if (is_overloaded_fn (e))
1277 pedwarn ("ISO C++ forbids applying %qs to an expression of "
1278 "function type", op_name);
1281 else if (type_unknown_p (e))
1283 cxx_incomplete_type_error (e, TREE_TYPE (e));
1289 return cxx_sizeof_or_alignof_type (e, op, true);
1293 /* EXPR is being used in a context that is not a function call.
1298 The expression can be used only as the left-hand operand of a
1299 member function call.
1301 [expr.mptr.operator]
1303 If the result of .* or ->* is a function, then that result can be
1304 used only as the operand for the function call operator ().
1306 by issuing an error message if appropriate. Returns true iff EXPR
1307 violates these rules. */
1310 invalid_nonstatic_memfn_p (tree expr)
1312 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1314 error ("invalid use of non-static member function");
1320 /* Perform the conversions in [expr] that apply when an lvalue appears
1321 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1322 function-to-pointer conversions.
1324 In addition manifest constants are replaced by their values. */
1327 decay_conversion (tree exp)
1330 enum tree_code code;
1332 type = TREE_TYPE (exp);
1333 code = TREE_CODE (type);
1335 if (type == error_mark_node)
1336 return error_mark_node;
1338 if (type_unknown_p (exp))
1340 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1341 return error_mark_node;
1344 exp = integral_constant_value (exp);
1346 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1347 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1349 if (code == VOID_TYPE)
1351 error ("void value not ignored as it ought to be");
1352 return error_mark_node;
1354 if (invalid_nonstatic_memfn_p (exp))
1355 return error_mark_node;
1356 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1357 return build_unary_op (ADDR_EXPR, exp, 0);
1358 if (code == ARRAY_TYPE)
1363 if (TREE_CODE (exp) == INDIRECT_REF)
1364 return build_nop (build_pointer_type (TREE_TYPE (type)),
1365 TREE_OPERAND (exp, 0));
1367 if (TREE_CODE (exp) == COMPOUND_EXPR)
1369 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1370 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1371 TREE_OPERAND (exp, 0), op1);
1375 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1377 error ("invalid use of non-lvalue array");
1378 return error_mark_node;
1381 ptrtype = build_pointer_type (TREE_TYPE (type));
1383 if (TREE_CODE (exp) == VAR_DECL)
1385 if (!cxx_mark_addressable (exp))
1386 return error_mark_node;
1387 adr = build_nop (ptrtype, build_address (exp));
1390 /* This way is better for a COMPONENT_REF since it can
1391 simplify the offset for a component. */
1392 adr = build_unary_op (ADDR_EXPR, exp, 1);
1393 return cp_convert (ptrtype, adr);
1396 /* [basic.lval]: Class rvalues can have cv-qualified types; non-class
1397 rvalues always have cv-unqualified types. */
1398 if (! CLASS_TYPE_P (type))
1399 exp = cp_convert (TYPE_MAIN_VARIANT (type), exp);
1405 default_conversion (tree exp)
1407 exp = decay_conversion (exp);
1409 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1410 exp = perform_integral_promotions (exp);
1415 /* EXPR is an expression with an integral or enumeration type.
1416 Perform the integral promotions in [conv.prom], and return the
1420 perform_integral_promotions (tree expr)
1425 type = TREE_TYPE (expr);
1426 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1427 promoted_type = type_promotes_to (type);
1428 if (type != promoted_type)
1429 expr = cp_convert (promoted_type, expr);
1433 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1437 inline_conversion (tree exp)
1439 if (TREE_CODE (exp) == FUNCTION_DECL)
1440 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1445 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1446 decay_conversion to one. */
1449 string_conv_p (tree totype, tree exp, int warn)
1453 if (! flag_const_strings || TREE_CODE (totype) != POINTER_TYPE)
1456 t = TREE_TYPE (totype);
1457 if (!same_type_p (t, char_type_node)
1458 && !same_type_p (t, wchar_type_node))
1461 if (TREE_CODE (exp) == STRING_CST)
1463 /* Make sure that we don't try to convert between char and wchar_t. */
1464 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1469 /* Is this a string constant which has decayed to 'const char *'? */
1470 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1471 if (!same_type_p (TREE_TYPE (exp), t))
1474 if (TREE_CODE (exp) != ADDR_EXPR
1475 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1479 /* This warning is not very useful, as it complains about printf. */
1480 if (warn && warn_write_strings)
1481 warning ("deprecated conversion from string constant to %qT'", totype);
1486 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1487 can, for example, use as an lvalue. This code used to be in
1488 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1489 expressions, where we're dealing with aggregates. But now it's again only
1490 called from unary_complex_lvalue. The case (in particular) that led to
1491 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1495 rationalize_conditional_expr (enum tree_code code, tree t)
1497 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1498 the first operand is always the one to be used if both operands
1499 are equal, so we know what conditional expression this used to be. */
1500 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1502 /* The following code is incorrect if either operand side-effects. */
1503 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
1504 && !TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)));
1506 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1507 ? LE_EXPR : GE_EXPR),
1508 TREE_OPERAND (t, 0),
1509 TREE_OPERAND (t, 1),
1510 /*overloaded_p=*/NULL),
1511 build_unary_op (code, TREE_OPERAND (t, 0), 0),
1512 build_unary_op (code, TREE_OPERAND (t, 1), 0));
1516 build_conditional_expr (TREE_OPERAND (t, 0),
1517 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1518 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1521 /* Given the TYPE of an anonymous union field inside T, return the
1522 FIELD_DECL for the field. If not found return NULL_TREE. Because
1523 anonymous unions can nest, we must also search all anonymous unions
1524 that are directly reachable. */
1527 lookup_anon_field (tree t, tree type)
1531 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1533 if (TREE_STATIC (field))
1535 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1538 /* If we find it directly, return the field. */
1539 if (DECL_NAME (field) == NULL_TREE
1540 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1545 /* Otherwise, it could be nested, search harder. */
1546 if (DECL_NAME (field) == NULL_TREE
1547 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1549 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1557 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1558 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1559 non-NULL, it indicates the path to the base used to name MEMBER.
1560 If PRESERVE_REFERENCE is true, the expression returned will have
1561 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1562 returned will have the type referred to by the reference.
1564 This function does not perform access control; that is either done
1565 earlier by the parser when the name of MEMBER is resolved to MEMBER
1566 itself, or later when overload resolution selects one of the
1567 functions indicated by MEMBER. */
1570 build_class_member_access_expr (tree object, tree member,
1571 tree access_path, bool preserve_reference)
1575 tree result = NULL_TREE;
1577 if (object == error_mark_node || member == error_mark_node)
1578 return error_mark_node;
1580 gcc_assert (DECL_P (member) || BASELINK_P (member));
1584 The type of the first expression shall be "class object" (of a
1586 object_type = TREE_TYPE (object);
1587 if (!currently_open_class (object_type)
1588 && !complete_type_or_else (object_type, object))
1589 return error_mark_node;
1590 if (!CLASS_TYPE_P (object_type))
1592 error ("request for member %qD in %qE, which is of non-class type %qT",
1593 member, object, object_type);
1594 return error_mark_node;
1597 /* The standard does not seem to actually say that MEMBER must be a
1598 member of OBJECT_TYPE. However, that is clearly what is
1600 if (DECL_P (member))
1602 member_scope = DECL_CLASS_CONTEXT (member);
1604 if (TREE_DEPRECATED (member))
1605 warn_deprecated_use (member);
1608 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1609 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1610 presently be the anonymous union. Go outwards until we find a
1611 type related to OBJECT_TYPE. */
1612 while (ANON_AGGR_TYPE_P (member_scope)
1613 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1615 member_scope = TYPE_CONTEXT (member_scope);
1616 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1618 if (TREE_CODE (member) == FIELD_DECL)
1619 error ("invalid use of nonstatic data member %qE", member);
1621 error ("%qD is not a member of %qT", member, object_type);
1622 return error_mark_node;
1625 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1626 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1627 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1629 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1631 object = build_indirect_ref (temp, NULL);
1634 /* In [expr.ref], there is an explicit list of the valid choices for
1635 MEMBER. We check for each of those cases here. */
1636 if (TREE_CODE (member) == VAR_DECL)
1638 /* A static data member. */
1640 /* If OBJECT has side-effects, they are supposed to occur. */
1641 if (TREE_SIDE_EFFECTS (object))
1642 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1644 else if (TREE_CODE (member) == FIELD_DECL)
1646 /* A non-static data member. */
1651 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1652 && integer_zerop (TREE_OPERAND (object, 0)));
1654 /* Convert OBJECT to the type of MEMBER. */
1655 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1656 TYPE_MAIN_VARIANT (member_scope)))
1661 binfo = lookup_base (access_path ? access_path : object_type,
1662 member_scope, ba_unique, &kind);
1663 if (binfo == error_mark_node)
1664 return error_mark_node;
1666 /* It is invalid to try to get to a virtual base of a
1667 NULL object. The most common cause is invalid use of
1669 if (null_object_p && kind == bk_via_virtual)
1671 error ("invalid access to non-static data member %qD of "
1674 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1675 return error_mark_node;
1678 /* Convert to the base. */
1679 object = build_base_path (PLUS_EXPR, object, binfo,
1681 /* If we found the base successfully then we should be able
1682 to convert to it successfully. */
1683 gcc_assert (object != error_mark_node);
1686 /* Complain about other invalid uses of offsetof, even though they will
1687 give the right answer. Note that we complain whether or not they
1688 actually used the offsetof macro, since there's no way to know at this
1689 point. So we just give a warning, instead of a pedwarn. */
1690 /* Do not produce this warning for base class field references, because
1691 we know for a fact that didn't come from offsetof. This does occur
1692 in various testsuite cases where a null object is passed where a
1693 vtable access is required. */
1694 if (null_object_p && warn_invalid_offsetof
1695 && CLASSTYPE_NON_POD_P (object_type)
1696 && !DECL_FIELD_IS_BASE (member)
1697 && !skip_evaluation)
1699 warning ("invalid access to non-static data member %qD of NULL object",
1701 warning ("(perhaps the %<offsetof%> macro was used incorrectly)");
1704 /* If MEMBER is from an anonymous aggregate, we have converted
1705 OBJECT so that it refers to the class containing the
1706 anonymous union. Generate a reference to the anonymous union
1707 itself, and recur to find MEMBER. */
1708 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1709 /* When this code is called from build_field_call, the
1710 object already has the type of the anonymous union.
1711 That is because the COMPONENT_REF was already
1712 constructed, and was then disassembled before calling
1713 build_field_call. After the function-call code is
1714 cleaned up, this waste can be eliminated. */
1715 && (!same_type_ignoring_top_level_qualifiers_p
1716 (TREE_TYPE (object), DECL_CONTEXT (member))))
1718 tree anonymous_union;
1720 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1721 DECL_CONTEXT (member));
1722 object = build_class_member_access_expr (object,
1724 /*access_path=*/NULL_TREE,
1725 preserve_reference);
1728 /* Compute the type of the field, as described in [expr.ref]. */
1729 type_quals = TYPE_UNQUALIFIED;
1730 member_type = TREE_TYPE (member);
1731 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1733 type_quals = (cp_type_quals (member_type)
1734 | cp_type_quals (object_type));
1736 /* A field is const (volatile) if the enclosing object, or the
1737 field itself, is const (volatile). But, a mutable field is
1738 not const, even within a const object. */
1739 if (DECL_MUTABLE_P (member))
1740 type_quals &= ~TYPE_QUAL_CONST;
1741 member_type = cp_build_qualified_type (member_type, type_quals);
1744 result = build3 (COMPONENT_REF, member_type, object, member,
1746 result = fold_if_not_in_template (result);
1748 /* Mark the expression const or volatile, as appropriate. Even
1749 though we've dealt with the type above, we still have to mark the
1750 expression itself. */
1751 if (type_quals & TYPE_QUAL_CONST)
1752 TREE_READONLY (result) = 1;
1753 if (type_quals & TYPE_QUAL_VOLATILE)
1754 TREE_THIS_VOLATILE (result) = 1;
1756 else if (BASELINK_P (member))
1758 /* The member is a (possibly overloaded) member function. */
1762 /* If the MEMBER is exactly one static member function, then we
1763 know the type of the expression. Otherwise, we must wait
1764 until overload resolution has been performed. */
1765 functions = BASELINK_FUNCTIONS (member);
1766 if (TREE_CODE (functions) == FUNCTION_DECL
1767 && DECL_STATIC_FUNCTION_P (functions))
1768 type = TREE_TYPE (functions);
1770 type = unknown_type_node;
1771 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1772 base. That will happen when the function is called. */
1773 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1775 else if (TREE_CODE (member) == CONST_DECL)
1777 /* The member is an enumerator. */
1779 /* If OBJECT has side-effects, they are supposed to occur. */
1780 if (TREE_SIDE_EFFECTS (object))
1781 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1786 error ("invalid use of %qD", member);
1787 return error_mark_node;
1790 if (!preserve_reference)
1793 If E2 is declared to have type "reference to T", then ... the
1794 type of E1.E2 is T. */
1795 result = convert_from_reference (result);
1800 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1801 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1804 lookup_destructor (tree object, tree scope, tree dtor_name)
1806 tree object_type = TREE_TYPE (object);
1807 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1810 if (scope && !check_dtor_name (scope, dtor_name))
1812 error ("qualified type %qT does not match destructor name ~%qT",
1814 return error_mark_node;
1816 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
1818 error ("the type being destroyed is %qT, but the destructor refers to %qT",
1819 TYPE_MAIN_VARIANT (object_type), dtor_type);
1820 return error_mark_node;
1822 expr = lookup_member (dtor_type, complete_dtor_identifier,
1823 /*protect=*/1, /*want_type=*/false);
1824 expr = (adjust_result_of_qualified_name_lookup
1825 (expr, dtor_type, object_type));
1829 /* This function is called by the parser to process a class member
1830 access expression of the form OBJECT.NAME. NAME is a node used by
1831 the parser to represent a name; it is not yet a DECL. It may,
1832 however, be a BASELINK where the BASELINK_FUNCTIONS is a
1833 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
1834 there is no reason to do the lookup twice, so the parser keeps the
1838 finish_class_member_access_expr (tree object, tree name)
1843 tree access_path = NULL_TREE;
1844 tree orig_object = object;
1845 tree orig_name = name;
1847 if (object == error_mark_node || name == error_mark_node)
1848 return error_mark_node;
1850 object_type = TREE_TYPE (object);
1852 if (processing_template_decl)
1854 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
1855 dependent_type_p (object_type)
1856 /* If NAME is just an IDENTIFIER_NODE, then the expression
1858 || TREE_CODE (object) == IDENTIFIER_NODE
1859 /* If NAME is "f<args>", where either 'f' or 'args' is
1860 dependent, then the expression is dependent. */
1861 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
1862 && dependent_template_id_p (TREE_OPERAND (name, 0),
1863 TREE_OPERAND (name, 1)))
1864 /* If NAME is "T::X" where "T" is dependent, then the
1865 expression is dependent. */
1866 || (TREE_CODE (name) == SCOPE_REF
1867 && TYPE_P (TREE_OPERAND (name, 0))
1868 && dependent_type_p (TREE_OPERAND (name, 0))))
1869 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
1870 object = build_non_dependent_expr (object);
1875 The type of the first expression shall be "class object" (of a
1877 if (!currently_open_class (object_type)
1878 && !complete_type_or_else (object_type, object))
1879 return error_mark_node;
1880 if (!CLASS_TYPE_P (object_type))
1882 error ("request for member %qD in %qE, which is of non-class type %qT",
1883 name, object, object_type);
1884 return error_mark_node;
1887 if (BASELINK_P (name))
1889 /* A member function that has already been looked up. */
1890 gcc_assert (TREE_CODE (BASELINK_FUNCTIONS (name)) == TEMPLATE_ID_EXPR);
1895 bool is_template_id = false;
1896 tree template_args = NULL_TREE;
1899 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
1901 is_template_id = true;
1902 template_args = TREE_OPERAND (name, 1);
1903 name = TREE_OPERAND (name, 0);
1905 if (TREE_CODE (name) == OVERLOAD)
1906 name = DECL_NAME (get_first_fn (name));
1907 else if (DECL_P (name))
1908 name = DECL_NAME (name);
1911 if (TREE_CODE (name) == SCOPE_REF)
1913 /* A qualified name. The qualifying class or namespace `S' has
1914 already been looked up; it is either a TYPE or a
1915 NAMESPACE_DECL. The member name is either an IDENTIFIER_NODE
1916 or a BIT_NOT_EXPR. */
1917 scope = TREE_OPERAND (name, 0);
1918 name = TREE_OPERAND (name, 1);
1919 gcc_assert (CLASS_TYPE_P (scope)
1920 || TREE_CODE (scope) == NAMESPACE_DECL);
1921 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
1922 || TREE_CODE (name) == BIT_NOT_EXPR);
1924 /* If SCOPE is a namespace, then the qualified name does not
1925 name a member of OBJECT_TYPE. */
1926 if (TREE_CODE (scope) == NAMESPACE_DECL)
1928 error ("%<%D::%D%> is not a member of %qT",
1929 scope, name, object_type);
1930 return error_mark_node;
1933 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
1934 access_path = lookup_base (object_type, scope, ba_check, NULL);
1935 if (access_path == error_mark_node)
1936 return error_mark_node;
1939 error ("%qT is not a base of %qT", scope, object_type);
1940 return error_mark_node;
1946 access_path = object_type;
1949 if (TREE_CODE (name) == BIT_NOT_EXPR)
1950 member = lookup_destructor (object, scope, name);
1953 /* Look up the member. */
1954 member = lookup_member (access_path, name, /*protect=*/1,
1955 /*want_type=*/false);
1956 if (member == NULL_TREE)
1958 error ("%qD has no member named %qE", object_type, name);
1959 return error_mark_node;
1961 if (member == error_mark_node)
1962 return error_mark_node;
1967 tree template = member;
1969 if (BASELINK_P (template))
1970 template = lookup_template_function (template, template_args);
1973 error ("%qD is not a member template function", name);
1974 return error_mark_node;
1979 if (TREE_DEPRECATED (member))
1980 warn_deprecated_use (member);
1982 expr = build_class_member_access_expr (object, member, access_path,
1983 /*preserve_reference=*/false);
1984 if (processing_template_decl && expr != error_mark_node)
1985 return build_min_non_dep (COMPONENT_REF, expr,
1986 orig_object, orig_name, NULL_TREE);
1990 /* Return an expression for the MEMBER_NAME field in the internal
1991 representation of PTRMEM, a pointer-to-member function. (Each
1992 pointer-to-member function type gets its own RECORD_TYPE so it is
1993 more convenient to access the fields by name than by FIELD_DECL.)
1994 This routine converts the NAME to a FIELD_DECL and then creates the
1995 node for the complete expression. */
1998 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2004 /* This code is a stripped down version of
2005 build_class_member_access_expr. It does not work to use that
2006 routine directly because it expects the object to be of class
2008 ptrmem_type = TREE_TYPE (ptrmem);
2009 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2010 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2011 /*want_type=*/false);
2012 member_type = cp_build_qualified_type (TREE_TYPE (member),
2013 cp_type_quals (ptrmem_type));
2014 return fold_build3 (COMPONENT_REF, member_type,
2015 ptrmem, member, NULL_TREE);
2018 /* Given an expression PTR for a pointer, return an expression
2019 for the value pointed to.
2020 ERRORSTRING is the name of the operator to appear in error messages.
2022 This function may need to overload OPERATOR_FNNAME.
2023 Must also handle REFERENCE_TYPEs for C++. */
2026 build_x_indirect_ref (tree expr, const char *errorstring)
2028 tree orig_expr = expr;
2031 if (processing_template_decl)
2033 if (type_dependent_expression_p (expr))
2034 return build_min_nt (INDIRECT_REF, expr);
2035 expr = build_non_dependent_expr (expr);
2038 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2039 NULL_TREE, /*overloaded_p=*/NULL);
2041 rval = build_indirect_ref (expr, errorstring);
2043 if (processing_template_decl && rval != error_mark_node)
2044 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2050 build_indirect_ref (tree ptr, const char *errorstring)
2054 if (ptr == error_mark_node)
2055 return error_mark_node;
2057 if (ptr == current_class_ptr)
2058 return current_class_ref;
2060 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2061 ? ptr : decay_conversion (ptr));
2062 type = TREE_TYPE (pointer);
2064 if (POINTER_TYPE_P (type))
2068 If the type of the expression is "pointer to T," the type
2069 of the result is "T."
2071 We must use the canonical variant because certain parts of
2072 the back end, like fold, do pointer comparisons between
2074 tree t = canonical_type_variant (TREE_TYPE (type));
2076 if (VOID_TYPE_P (t))
2078 /* A pointer to incomplete type (other than cv void) can be
2079 dereferenced [expr.unary.op]/1 */
2080 error ("%qT is not a pointer-to-object type", type);
2081 return error_mark_node;
2083 else if (TREE_CODE (pointer) == ADDR_EXPR
2084 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2085 /* The POINTER was something like `&x'. We simplify `*&x' to
2087 return TREE_OPERAND (pointer, 0);
2090 tree ref = build1 (INDIRECT_REF, t, pointer);
2092 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2093 so that we get the proper error message if the result is used
2094 to assign to. Also, &* is supposed to be a no-op. */
2095 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2096 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2097 TREE_SIDE_EFFECTS (ref)
2098 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2102 /* `pointer' won't be an error_mark_node if we were given a
2103 pointer to member, so it's cool to check for this here. */
2104 else if (TYPE_PTR_TO_MEMBER_P (type))
2105 error ("invalid use of %qs on pointer to member", errorstring);
2106 else if (pointer != error_mark_node)
2109 error ("invalid type argument of %qs", errorstring);
2111 error ("invalid type argument");
2113 return error_mark_node;
2116 /* This handles expressions of the form "a[i]", which denotes
2119 This is logically equivalent in C to *(a+i), but we may do it differently.
2120 If A is a variable or a member, we generate a primitive ARRAY_REF.
2121 This avoids forcing the array out of registers, and can work on
2122 arrays that are not lvalues (for example, members of structures returned
2125 If INDEX is of some user-defined type, it must be converted to
2126 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2127 will inherit the type of the array, which will be some pointer type. */
2130 build_array_ref (tree array, tree idx)
2134 error ("subscript missing in array reference");
2135 return error_mark_node;
2138 if (TREE_TYPE (array) == error_mark_node
2139 || TREE_TYPE (idx) == error_mark_node)
2140 return error_mark_node;
2142 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2144 switch (TREE_CODE (array))
2148 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2149 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2150 TREE_OPERAND (array, 0), value);
2154 return build_conditional_expr
2155 (TREE_OPERAND (array, 0),
2156 build_array_ref (TREE_OPERAND (array, 1), idx),
2157 build_array_ref (TREE_OPERAND (array, 2), idx));
2163 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2167 /* Subscripting with type char is likely to lose
2168 on a machine where chars are signed.
2169 So warn on any machine, but optionally.
2170 Don't warn for unsigned char since that type is safe.
2171 Don't warn for signed char because anyone who uses that
2172 must have done so deliberately. */
2173 if (warn_char_subscripts
2174 && TYPE_MAIN_VARIANT (TREE_TYPE (idx)) == char_type_node)
2175 warning ("array subscript has type %<char%>");
2177 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2179 error ("array subscript is not an integer");
2180 return error_mark_node;
2183 /* Apply integral promotions *after* noticing character types.
2184 (It is unclear why we do these promotions -- the standard
2185 does not say that we should. In fact, the natural thing would
2186 seem to be to convert IDX to ptrdiff_t; we're performing
2187 pointer arithmetic.) */
2188 idx = perform_integral_promotions (idx);
2190 /* An array that is indexed by a non-constant
2191 cannot be stored in a register; we must be able to do
2192 address arithmetic on its address.
2193 Likewise an array of elements of variable size. */
2194 if (TREE_CODE (idx) != INTEGER_CST
2195 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2196 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2199 if (!cxx_mark_addressable (array))
2200 return error_mark_node;
2203 /* An array that is indexed by a constant value which is not within
2204 the array bounds cannot be stored in a register either; because we
2205 would get a crash in store_bit_field/extract_bit_field when trying
2206 to access a non-existent part of the register. */
2207 if (TREE_CODE (idx) == INTEGER_CST
2208 && TYPE_DOMAIN (TREE_TYPE (array))
2209 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2211 if (!cxx_mark_addressable (array))
2212 return error_mark_node;
2215 if (pedantic && !lvalue_p (array))
2216 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2218 /* Note in C++ it is valid to subscript a `register' array, since
2219 it is valid to take the address of something with that
2220 storage specification. */
2224 while (TREE_CODE (foo) == COMPONENT_REF)
2225 foo = TREE_OPERAND (foo, 0);
2226 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2227 warning ("subscripting array declared %<register%>");
2230 type = TREE_TYPE (TREE_TYPE (array));
2231 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2232 /* Array ref is const/volatile if the array elements are
2233 or if the array is.. */
2234 TREE_READONLY (rval)
2235 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2236 TREE_SIDE_EFFECTS (rval)
2237 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2238 TREE_THIS_VOLATILE (rval)
2239 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2240 return require_complete_type (fold_if_not_in_template (rval));
2244 tree ar = default_conversion (array);
2245 tree ind = default_conversion (idx);
2247 /* Put the integer in IND to simplify error checking. */
2248 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2255 if (ar == error_mark_node)
2258 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2260 error ("subscripted value is neither array nor pointer");
2261 return error_mark_node;
2263 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2265 error ("array subscript is not an integer");
2266 return error_mark_node;
2269 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2274 /* Resolve a pointer to member function. INSTANCE is the object
2275 instance to use, if the member points to a virtual member.
2277 This used to avoid checking for virtual functions if basetype
2278 has no virtual functions, according to an earlier ANSI draft.
2279 With the final ISO C++ rules, such an optimization is
2280 incorrect: A pointer to a derived member can be static_cast
2281 to pointer-to-base-member, as long as the dynamic object
2282 later has the right member. */
2285 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2287 if (TREE_CODE (function) == OFFSET_REF)
2288 function = TREE_OPERAND (function, 1);
2290 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2292 tree idx, delta, e1, e2, e3, vtbl, basetype;
2293 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2295 tree instance_ptr = *instance_ptrptr;
2296 tree instance_save_expr = 0;
2297 if (instance_ptr == error_mark_node)
2299 if (TREE_CODE (function) == PTRMEM_CST)
2301 /* Extracting the function address from a pmf is only
2302 allowed with -Wno-pmf-conversions. It only works for
2304 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2305 e1 = convert (fntype, e1);
2310 error ("object missing in use of %qE", function);
2311 return error_mark_node;
2315 if (TREE_SIDE_EFFECTS (instance_ptr))
2316 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2318 if (TREE_SIDE_EFFECTS (function))
2319 function = save_expr (function);
2321 /* Start by extracting all the information from the PMF itself. */
2322 e3 = pfn_from_ptrmemfunc (function);
2323 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2324 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2325 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2327 case ptrmemfunc_vbit_in_pfn:
2328 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2329 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2332 case ptrmemfunc_vbit_in_delta:
2333 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2334 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2341 /* Convert down to the right base before using the instance. First
2343 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2344 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2345 basetype, ba_check, NULL);
2346 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype, 1);
2347 if (instance_ptr == error_mark_node)
2348 return error_mark_node;
2349 /* ...and then the delta in the PMF. */
2350 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2351 instance_ptr, delta);
2353 /* Hand back the adjusted 'this' argument to our caller. */
2354 *instance_ptrptr = instance_ptr;
2356 /* Next extract the vtable pointer from the object. */
2357 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2359 vtbl = build_indirect_ref (vtbl, NULL);
2361 /* Finally, extract the function pointer from the vtable. */
2362 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2363 e2 = build_indirect_ref (e2, NULL);
2364 TREE_CONSTANT (e2) = 1;
2365 TREE_INVARIANT (e2) = 1;
2367 /* When using function descriptors, the address of the
2368 vtable entry is treated as a function pointer. */
2369 if (TARGET_VTABLE_USES_DESCRIPTORS)
2370 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2371 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2373 TREE_TYPE (e2) = TREE_TYPE (e3);
2374 e1 = build_conditional_expr (e1, e2, e3);
2376 /* Make sure this doesn't get evaluated first inside one of the
2377 branches of the COND_EXPR. */
2378 if (instance_save_expr)
2379 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2380 instance_save_expr, e1);
2388 build_function_call (tree function, tree params)
2390 tree fntype, fndecl;
2391 tree coerced_params;
2392 tree name = NULL_TREE;
2394 tree original = function;
2396 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2397 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2398 if (TREE_CODE (function) == NOP_EXPR
2399 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2400 function = TREE_OPERAND (function, 0);
2402 if (TREE_CODE (function) == FUNCTION_DECL)
2404 name = DECL_NAME (function);
2406 mark_used (function);
2409 /* Convert anything with function type to a pointer-to-function. */
2410 if (pedantic && DECL_MAIN_P (function))
2411 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2413 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2414 (because calling an inline function does not mean the function
2415 needs to be separately compiled). */
2417 if (DECL_INLINE (function))
2418 function = inline_conversion (function);
2420 function = build_addr_func (function);
2426 function = build_addr_func (function);
2429 if (function == error_mark_node)
2430 return error_mark_node;
2432 fntype = TREE_TYPE (function);
2434 if (TYPE_PTRMEMFUNC_P (fntype))
2436 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2437 "function in %<%E (...)%>",
2439 return error_mark_node;
2442 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2443 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2445 if (!((TREE_CODE (fntype) == POINTER_TYPE
2446 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2448 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2450 error ("%qE cannot be used as a function", original);
2451 return error_mark_node;
2454 /* fntype now gets the type of function pointed to. */
2455 fntype = TREE_TYPE (fntype);
2457 /* Convert the parameters to the types declared in the
2458 function prototype, or apply default promotions. */
2460 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2461 params, fndecl, LOOKUP_NORMAL);
2462 if (coerced_params == error_mark_node)
2463 return error_mark_node;
2465 /* Check for errors in format strings and inappropriately
2468 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params);
2470 return build_cxx_call (function, coerced_params);
2473 /* Convert the actual parameter expressions in the list VALUES
2474 to the types in the list TYPELIST.
2475 If parmdecls is exhausted, or when an element has NULL as its type,
2476 perform the default conversions.
2478 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2480 This is also where warnings about wrong number of args are generated.
2482 Return a list of expressions for the parameters as converted.
2484 Both VALUES and the returned value are chains of TREE_LIST nodes
2485 with the elements of the list in the TREE_VALUE slots of those nodes.
2487 In C++, unspecified trailing parameters can be filled in with their
2488 default arguments, if such were specified. Do so here. */
2491 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2493 tree typetail, valtail;
2494 tree result = NULL_TREE;
2495 const char *called_thing = 0;
2498 /* Argument passing is always copy-initialization. */
2499 flags |= LOOKUP_ONLYCONVERTING;
2503 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2505 if (DECL_NAME (fndecl) == NULL_TREE
2506 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2507 called_thing = "constructor";
2509 called_thing = "member function";
2512 called_thing = "function";
2515 for (valtail = values, typetail = typelist;
2517 valtail = TREE_CHAIN (valtail), i++)
2519 tree type = typetail ? TREE_VALUE (typetail) : 0;
2520 tree val = TREE_VALUE (valtail);
2522 if (val == error_mark_node)
2523 return error_mark_node;
2525 if (type == void_type_node)
2529 cp_error_at ("too many arguments to %s %q+#D", called_thing,
2531 error ("at this point in file");
2534 error ("too many arguments to function");
2535 /* In case anybody wants to know if this argument
2538 TREE_TYPE (tree_last (result)) = error_mark_node;
2542 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2543 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2544 if (TREE_CODE (val) == NOP_EXPR
2545 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2546 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2547 val = TREE_OPERAND (val, 0);
2549 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2551 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2552 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2553 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2554 val = decay_conversion (val);
2557 if (val == error_mark_node)
2558 return error_mark_node;
2562 /* Formal parm type is specified by a function prototype. */
2565 if (!COMPLETE_TYPE_P (complete_type (type)))
2568 error ("parameter %P of %qD has incomplete type %qT",
2571 error ("parameter %P has incomplete type %qT", i, type);
2572 parmval = error_mark_node;
2576 parmval = convert_for_initialization
2577 (NULL_TREE, type, val, flags,
2578 "argument passing", fndecl, i);
2579 parmval = convert_for_arg_passing (type, parmval);
2582 if (parmval == error_mark_node)
2583 return error_mark_node;
2585 result = tree_cons (NULL_TREE, parmval, result);
2589 if (fndecl && DECL_BUILT_IN (fndecl)
2590 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2591 /* Don't do ellipsis conversion for __built_in_constant_p
2592 as this will result in spurious warnings for non-POD
2594 val = require_complete_type (val);
2596 val = convert_arg_to_ellipsis (val);
2598 result = tree_cons (NULL_TREE, val, result);
2602 typetail = TREE_CHAIN (typetail);
2605 if (typetail != 0 && typetail != void_list_node)
2607 /* See if there are default arguments that can be used. */
2608 if (TREE_PURPOSE (typetail)
2609 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2611 for (; typetail != void_list_node; ++i)
2614 = convert_default_arg (TREE_VALUE (typetail),
2615 TREE_PURPOSE (typetail),
2618 if (parmval == error_mark_node)
2619 return error_mark_node;
2621 result = tree_cons (0, parmval, result);
2622 typetail = TREE_CHAIN (typetail);
2623 /* ends with `...'. */
2624 if (typetail == NULL_TREE)
2632 cp_error_at ("too few arguments to %s %q+#D",
2633 called_thing, fndecl);
2634 error ("at this point in file");
2637 error ("too few arguments to function");
2638 return error_mark_list;
2642 return nreverse (result);
2645 /* Build a binary-operation expression, after performing default
2646 conversions on the operands. CODE is the kind of expression to build. */
2649 build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
2659 if (processing_template_decl)
2661 if (type_dependent_expression_p (arg1)
2662 || type_dependent_expression_p (arg2))
2663 return build_min_nt (code, arg1, arg2);
2664 arg1 = build_non_dependent_expr (arg1);
2665 arg2 = build_non_dependent_expr (arg2);
2668 if (code == DOTSTAR_EXPR)
2669 expr = build_m_component_ref (arg1, arg2);
2671 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2674 if (processing_template_decl && expr != error_mark_node)
2675 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2680 /* Build a binary-operation expression without default conversions.
2681 CODE is the kind of expression to build.
2682 This function differs from `build' in several ways:
2683 the data type of the result is computed and recorded in it,
2684 warnings are generated if arg data types are invalid,
2685 special handling for addition and subtraction of pointers is known,
2686 and some optimization is done (operations on narrow ints
2687 are done in the narrower type when that gives the same result).
2688 Constant folding is also done before the result is returned.
2690 Note that the operands will never have enumeral types
2691 because either they have just had the default conversions performed
2692 or they have both just been converted to some other type in which
2693 the arithmetic is to be done.
2695 C++: must do special pointer arithmetic when implementing
2696 multiple inheritance, and deal with pointer to member functions. */
2699 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2700 int convert_p ATTRIBUTE_UNUSED)
2703 enum tree_code code0, code1;
2706 /* Expression code to give to the expression when it is built.
2707 Normally this is CODE, which is what the caller asked for,
2708 but in some special cases we change it. */
2709 enum tree_code resultcode = code;
2711 /* Data type in which the computation is to be performed.
2712 In the simplest cases this is the common type of the arguments. */
2713 tree result_type = NULL;
2715 /* Nonzero means operands have already been type-converted
2716 in whatever way is necessary.
2717 Zero means they need to be converted to RESULT_TYPE. */
2720 /* Nonzero means create the expression with this type, rather than
2722 tree build_type = 0;
2724 /* Nonzero means after finally constructing the expression
2725 convert it to this type. */
2726 tree final_type = 0;
2730 /* Nonzero if this is an operation like MIN or MAX which can
2731 safely be computed in short if both args are promoted shorts.
2732 Also implies COMMON.
2733 -1 indicates a bitwise operation; this makes a difference
2734 in the exact conditions for when it is safe to do the operation
2735 in a narrower mode. */
2738 /* Nonzero if this is a comparison operation;
2739 if both args are promoted shorts, compare the original shorts.
2740 Also implies COMMON. */
2741 int short_compare = 0;
2743 /* Nonzero if this is a right-shift operation, which can be computed on the
2744 original short and then promoted if the operand is a promoted short. */
2745 int short_shift = 0;
2747 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2750 /* True if both operands have arithmetic type. */
2751 bool arithmetic_types_p;
2753 /* Apply default conversions. */
2757 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2758 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2759 || code == TRUTH_XOR_EXPR)
2761 if (!really_overloaded_fn (op0))
2762 op0 = decay_conversion (op0);
2763 if (!really_overloaded_fn (op1))
2764 op1 = decay_conversion (op1);
2768 if (!really_overloaded_fn (op0))
2769 op0 = default_conversion (op0);
2770 if (!really_overloaded_fn (op1))
2771 op1 = default_conversion (op1);
2774 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2775 STRIP_TYPE_NOPS (op0);
2776 STRIP_TYPE_NOPS (op1);
2778 /* DTRT if one side is an overloaded function, but complain about it. */
2779 if (type_unknown_p (op0))
2781 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
2782 if (t != error_mark_node)
2784 pedwarn ("assuming cast to type %qT from overloaded function",
2789 if (type_unknown_p (op1))
2791 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
2792 if (t != error_mark_node)
2794 pedwarn ("assuming cast to type %qT from overloaded function",
2800 type0 = TREE_TYPE (op0);
2801 type1 = TREE_TYPE (op1);
2803 /* The expression codes of the data types of the arguments tell us
2804 whether the arguments are integers, floating, pointers, etc. */
2805 code0 = TREE_CODE (type0);
2806 code1 = TREE_CODE (type1);
2808 /* If an error was already reported for one of the arguments,
2809 avoid reporting another error. */
2811 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
2812 return error_mark_node;
2817 /* Handle the pointer + int case. */
2818 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2819 return cp_pointer_int_sum (PLUS_EXPR, op0, op1);
2820 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
2821 return cp_pointer_int_sum (PLUS_EXPR, op1, op0);
2827 /* Subtraction of two similar pointers.
2828 We must subtract them as integers, then divide by object size. */
2829 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
2830 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
2832 return pointer_diff (op0, op1, common_type (type0, type1));
2833 /* Handle pointer minus int. Just like pointer plus int. */
2834 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2835 return cp_pointer_int_sum (MINUS_EXPR, op0, op1);
2844 case TRUNC_DIV_EXPR:
2846 case FLOOR_DIV_EXPR:
2847 case ROUND_DIV_EXPR:
2848 case EXACT_DIV_EXPR:
2849 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2850 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2851 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2852 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
2854 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
2855 warning ("division by zero in %<%E / 0%>", op0);
2856 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
2857 warning ("division by zero in %<%E / 0.%>", op0);
2859 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2860 code0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
2861 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
2862 code1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
2864 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
2865 resultcode = RDIV_EXPR;
2867 /* When dividing two signed integers, we have to promote to int.
2868 unless we divide by a constant != -1. Note that default
2869 conversion will have been performed on the operands at this
2870 point, so we have to dig out the original type to find out if
2872 shorten = ((TREE_CODE (op0) == NOP_EXPR
2873 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2874 || (TREE_CODE (op1) == INTEGER_CST
2875 && ! integer_all_onesp (op1)));
2884 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2888 case TRUNC_MOD_EXPR:
2889 case FLOOR_MOD_EXPR:
2890 if (code1 == INTEGER_TYPE && integer_zerop (op1))
2891 warning ("division by zero in %<%E %% 0%>", op0);
2892 else if (code1 == REAL_TYPE && real_zerop (op1))
2893 warning ("division by zero in %<%E %% 0.%>", op0);
2895 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2897 /* Although it would be tempting to shorten always here, that loses
2898 on some targets, since the modulo instruction is undefined if the
2899 quotient can't be represented in the computation mode. We shorten
2900 only if unsigned or if dividing by something we know != -1. */
2901 shorten = ((TREE_CODE (op0) == NOP_EXPR
2902 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2903 || (TREE_CODE (op1) == INTEGER_CST
2904 && ! integer_all_onesp (op1)));
2909 case TRUTH_ANDIF_EXPR:
2910 case TRUTH_ORIF_EXPR:
2911 case TRUTH_AND_EXPR:
2913 result_type = boolean_type_node;
2916 /* Shift operations: result has same type as first operand;
2917 always convert second operand to int.
2918 Also set SHORT_SHIFT if shifting rightward. */
2921 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2923 result_type = type0;
2924 if (TREE_CODE (op1) == INTEGER_CST)
2926 if (tree_int_cst_lt (op1, integer_zero_node))
2927 warning ("right shift count is negative");
2930 if (! integer_zerop (op1))
2932 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2933 warning ("right shift count >= width of type");
2936 /* Convert the shift-count to an integer, regardless of
2937 size of value being shifted. */
2938 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2939 op1 = cp_convert (integer_type_node, op1);
2940 /* Avoid converting op1 to result_type later. */
2946 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2948 result_type = type0;
2949 if (TREE_CODE (op1) == INTEGER_CST)
2951 if (tree_int_cst_lt (op1, integer_zero_node))
2952 warning ("left shift count is negative");
2953 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2954 warning ("left shift count >= width of type");
2956 /* Convert the shift-count to an integer, regardless of
2957 size of value being shifted. */
2958 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2959 op1 = cp_convert (integer_type_node, op1);
2960 /* Avoid converting op1 to result_type later. */
2967 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2969 result_type = type0;
2970 if (TREE_CODE (op1) == INTEGER_CST)
2972 if (tree_int_cst_lt (op1, integer_zero_node))
2973 warning ("%s rotate count is negative",
2974 (code == LROTATE_EXPR) ? "left" : "right");
2975 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2976 warning ("%s rotate count >= width of type",
2977 (code == LROTATE_EXPR) ? "left" : "right");
2979 /* Convert the shift-count to an integer, regardless of
2980 size of value being shifted. */
2981 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2982 op1 = cp_convert (integer_type_node, op1);
2988 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
2989 warning ("comparing floating point with == or != is unsafe");
2991 build_type = boolean_type_node;
2992 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2993 || code0 == COMPLEX_TYPE)
2994 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2995 || code1 == COMPLEX_TYPE))
2997 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
2998 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
2999 result_type = composite_pointer_type (type0, type1, op0, op1,
3001 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3002 && null_ptr_cst_p (op1))
3003 result_type = type0;
3004 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3005 && null_ptr_cst_p (op0))
3006 result_type = type1;
3007 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3009 result_type = type0;
3010 error ("ISO C++ forbids comparison between pointer and integer");
3012 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3014 result_type = type1;
3015 error ("ISO C++ forbids comparison between pointer and integer");
3017 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3019 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3020 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3021 result_type = TREE_TYPE (op0);
3023 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3024 return cp_build_binary_op (code, op1, op0);
3025 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3026 && same_type_p (type0, type1))
3028 /* E will be the final comparison. */
3030 /* E1 and E2 are for scratch. */
3038 if (TREE_SIDE_EFFECTS (op0))
3039 op0 = save_expr (op0);
3040 if (TREE_SIDE_EFFECTS (op1))
3041 op1 = save_expr (op1);
3046 && (!op0.pfn || op0.delta == op1.delta))
3048 The reason for the `!op0.pfn' bit is that a NULL
3049 pointer-to-member is any member with a zero PFN; the
3050 DELTA field is unspecified. */
3051 pfn0 = pfn_from_ptrmemfunc (op0);
3052 pfn1 = pfn_from_ptrmemfunc (op1);
3053 delta0 = build_ptrmemfunc_access_expr (op0,
3055 delta1 = build_ptrmemfunc_access_expr (op1,
3057 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3058 e2 = cp_build_binary_op (EQ_EXPR,
3060 cp_convert (TREE_TYPE (pfn0),
3061 integer_zero_node));
3062 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3063 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3064 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3065 if (code == EQ_EXPR)
3067 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3071 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3072 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3074 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3075 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3083 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3084 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3086 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3087 result_type = composite_pointer_type (type0, type1, op0, op1,
3095 build_type = boolean_type_node;
3096 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3097 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3099 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3100 result_type = composite_pointer_type (type0, type1, op0, op1,
3102 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3103 && integer_zerop (op1))
3104 result_type = type0;
3105 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3106 && integer_zerop (op0))
3107 result_type = type1;
3108 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3110 result_type = type0;
3111 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3113 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3115 result_type = type1;
3116 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3120 case UNORDERED_EXPR:
3127 build_type = integer_type_node;
3128 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3130 error ("unordered comparison on non-floating point argument");
3131 return error_mark_node;
3140 arithmetic_types_p =
3141 ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3142 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3143 || code1 == COMPLEX_TYPE));
3144 /* Determine the RESULT_TYPE, if it is not already known. */
3146 && arithmetic_types_p
3147 && (shorten || common || short_compare))
3148 result_type = common_type (type0, type1);
3152 error ("invalid operands of types %qT and %qT to binary %qO",
3153 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3154 return error_mark_node;
3157 /* If we're in a template, the only thing we need to know is the
3159 if (processing_template_decl)
3160 return build2 (resultcode,
3161 build_type ? build_type : result_type,
3164 if (arithmetic_types_p)
3166 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3168 /* For certain operations (which identify themselves by shorten != 0)
3169 if both args were extended from the same smaller type,
3170 do the arithmetic in that type and then extend.
3172 shorten !=0 and !=1 indicates a bitwise operation.
3173 For them, this optimization is safe only if
3174 both args are zero-extended or both are sign-extended.
3175 Otherwise, we might change the result.
3176 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3177 but calculated in (unsigned short) it would be (unsigned short)-1. */
3179 if (shorten && none_complex)
3181 int unsigned0, unsigned1;
3182 tree arg0 = get_narrower (op0, &unsigned0);
3183 tree arg1 = get_narrower (op1, &unsigned1);
3184 /* UNS is 1 if the operation to be done is an unsigned one. */
3185 int uns = TYPE_UNSIGNED (result_type);
3188 final_type = result_type;
3190 /* Handle the case that OP0 does not *contain* a conversion
3191 but it *requires* conversion to FINAL_TYPE. */
3193 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3194 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3195 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3196 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3198 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3200 /* For bitwise operations, signedness of nominal type
3201 does not matter. Consider only how operands were extended. */
3205 /* Note that in all three cases below we refrain from optimizing
3206 an unsigned operation on sign-extended args.
3207 That would not be valid. */
3209 /* Both args variable: if both extended in same way
3210 from same width, do it in that width.
3211 Do it unsigned if args were zero-extended. */
3212 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3213 < TYPE_PRECISION (result_type))
3214 && (TYPE_PRECISION (TREE_TYPE (arg1))
3215 == TYPE_PRECISION (TREE_TYPE (arg0)))
3216 && unsigned0 == unsigned1
3217 && (unsigned0 || !uns))
3218 result_type = c_common_signed_or_unsigned_type
3219 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3220 else if (TREE_CODE (arg0) == INTEGER_CST
3221 && (unsigned1 || !uns)
3222 && (TYPE_PRECISION (TREE_TYPE (arg1))
3223 < TYPE_PRECISION (result_type))
3224 && (type = c_common_signed_or_unsigned_type
3225 (unsigned1, TREE_TYPE (arg1)),
3226 int_fits_type_p (arg0, type)))
3228 else if (TREE_CODE (arg1) == INTEGER_CST
3229 && (unsigned0 || !uns)
3230 && (TYPE_PRECISION (TREE_TYPE (arg0))
3231 < TYPE_PRECISION (result_type))
3232 && (type = c_common_signed_or_unsigned_type
3233 (unsigned0, TREE_TYPE (arg0)),
3234 int_fits_type_p (arg1, type)))
3238 /* Shifts can be shortened if shifting right. */
3243 tree arg0 = get_narrower (op0, &unsigned_arg);
3245 final_type = result_type;
3247 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3248 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3250 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3251 /* We can shorten only if the shift count is less than the
3252 number of bits in the smaller type size. */
3253 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3254 /* If arg is sign-extended and then unsigned-shifted,
3255 we can simulate this with a signed shift in arg's type
3256 only if the extended result is at least twice as wide
3257 as the arg. Otherwise, the shift could use up all the
3258 ones made by sign-extension and bring in zeros.
3259 We can't optimize that case at all, but in most machines
3260 it never happens because available widths are 2**N. */
3261 && (!TYPE_UNSIGNED (final_type)
3263 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3264 <= TYPE_PRECISION (result_type))))
3266 /* Do an unsigned shift if the operand was zero-extended. */
3268 = c_common_signed_or_unsigned_type (unsigned_arg,
3270 /* Convert value-to-be-shifted to that type. */
3271 if (TREE_TYPE (op0) != result_type)
3272 op0 = cp_convert (result_type, op0);
3277 /* Comparison operations are shortened too but differently.
3278 They identify themselves by setting short_compare = 1. */
3282 /* Don't write &op0, etc., because that would prevent op0
3283 from being kept in a register.
3284 Instead, make copies of the our local variables and
3285 pass the copies by reference, then copy them back afterward. */
3286 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3287 enum tree_code xresultcode = resultcode;
3289 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3291 return cp_convert (boolean_type_node, val);
3292 op0 = xop0, op1 = xop1;
3294 resultcode = xresultcode;
3297 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3298 && warn_sign_compare
3299 /* Do not warn until the template is instantiated; we cannot
3300 bound the ranges of the arguments until that point. */
3301 && !processing_template_decl)
3303 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3304 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3306 int unsignedp0, unsignedp1;
3307 tree primop0 = get_narrower (op0, &unsignedp0);
3308 tree primop1 = get_narrower (op1, &unsignedp1);
3310 /* Check for comparison of different enum types. */
3311 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3312 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3313 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3314 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3316 warning ("comparison between types %q#T and %q#T",
3317 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3320 /* Give warnings for comparisons between signed and unsigned
3321 quantities that may fail. */
3322 /* Do the checking based on the original operand trees, so that
3323 casts will be considered, but default promotions won't be. */
3325 /* Do not warn if the comparison is being done in a signed type,
3326 since the signed type will only be chosen if it can represent
3327 all the values of the unsigned type. */
3328 if (!TYPE_UNSIGNED (result_type))
3330 /* Do not warn if both operands are unsigned. */
3331 else if (op0_signed == op1_signed)
3333 /* Do not warn if the signed quantity is an unsuffixed
3334 integer literal (or some static constant expression
3335 involving such literals or a conditional expression
3336 involving such literals) and it is non-negative. */
3337 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3338 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3340 /* Do not warn if the comparison is an equality operation,
3341 the unsigned quantity is an integral constant and it does
3342 not use the most significant bit of result_type. */
3343 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3344 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3345 && int_fits_type_p (orig_op1, c_common_signed_type
3347 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3348 && int_fits_type_p (orig_op0, c_common_signed_type
3352 warning ("comparison between signed and unsigned integer expressions");
3354 /* Warn if two unsigned values are being compared in a size
3355 larger than their original size, and one (and only one) is the
3356 result of a `~' operator. This comparison will always fail.
3358 Also warn if one operand is a constant, and the constant does not
3359 have all bits set that are set in the ~ operand when it is
3362 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3363 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3365 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3366 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3367 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3368 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3370 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3373 HOST_WIDE_INT constant, mask;
3377 if (host_integerp (primop0, 0))
3380 unsignedp = unsignedp1;
3381 constant = tree_low_cst (primop0, 0);
3386 unsignedp = unsignedp0;
3387 constant = tree_low_cst (primop1, 0);
3390 bits = TYPE_PRECISION (TREE_TYPE (primop));
3391 if (bits < TYPE_PRECISION (result_type)
3392 && bits < HOST_BITS_PER_LONG && unsignedp)
3394 mask = (~ (HOST_WIDE_INT) 0) << bits;
3395 if ((mask & constant) != mask)
3396 warning ("comparison of promoted ~unsigned with constant");
3399 else if (unsignedp0 && unsignedp1
3400 && (TYPE_PRECISION (TREE_TYPE (primop0))
3401 < TYPE_PRECISION (result_type))
3402 && (TYPE_PRECISION (TREE_TYPE (primop1))
3403 < TYPE_PRECISION (result_type)))
3404 warning ("comparison of promoted ~unsigned with unsigned");
3409 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3410 Then the expression will be built.
3411 It will be given type FINAL_TYPE if that is nonzero;
3412 otherwise, it will be given type RESULT_TYPE. */
3414 /* Issue warnings about peculiar, but valid, uses of NULL. */
3415 if (/* It's reasonable to use pointer values as operands of &&
3416 and ||, so NULL is no exception. */
3417 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3418 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3419 (orig_op0 == null_node
3420 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3421 /* Or vice versa. */
3422 || (orig_op1 == null_node
3423 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3424 /* Or, both are NULL and the operation was not a comparison. */
3425 || (orig_op0 == null_node && orig_op1 == null_node
3426 && code != EQ_EXPR && code != NE_EXPR)))
3427 /* Some sort of arithmetic operation involving NULL was
3428 performed. Note that pointer-difference and pointer-addition
3429 have already been handled above, and so we don't end up here in
3431 warning ("NULL used in arithmetic");
3435 if (TREE_TYPE (op0) != result_type)
3436 op0 = cp_convert (result_type, op0);
3437 if (TREE_TYPE (op1) != result_type)
3438 op1 = cp_convert (result_type, op1);
3440 if (op0 == error_mark_node || op1 == error_mark_node)
3441 return error_mark_node;
3444 if (build_type == NULL_TREE)
3445 build_type = result_type;
3447 result = build2 (resultcode, build_type, op0, op1);
3448 result = fold_if_not_in_template (result);
3449 if (final_type != 0)
3450 result = cp_convert (final_type, result);
3454 /* Return a tree for the sum or difference (RESULTCODE says which)
3455 of pointer PTROP and integer INTOP. */
3458 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3460 tree res_type = TREE_TYPE (ptrop);
3462 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3463 in certain circumstance (when it's valid to do so). So we need
3464 to make sure it's complete. We don't need to check here, if we
3465 can actually complete it at all, as those checks will be done in
3466 pointer_int_sum() anyway. */
3467 complete_type (TREE_TYPE (res_type));
3469 return pointer_int_sum (resultcode, ptrop,
3470 fold_if_not_in_template (intop));
3473 /* Return a tree for the difference of pointers OP0 and OP1.
3474 The resulting tree has type int. */
3477 pointer_diff (tree op0, tree op1, tree ptrtype)
3480 tree restype = ptrdiff_type_node;
3481 tree target_type = TREE_TYPE (ptrtype);
3483 if (!complete_type_or_else (target_type, NULL_TREE))
3484 return error_mark_node;
3486 if (pedantic || warn_pointer_arith)
3488 if (TREE_CODE (target_type) == VOID_TYPE)
3489 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3490 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3491 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3492 if (TREE_CODE (target_type) == METHOD_TYPE)
3493 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3496 /* First do the subtraction as integers;
3497 then drop through to build the divide operator. */
3499 op0 = cp_build_binary_op (MINUS_EXPR,
3500 cp_convert (restype, op0),
3501 cp_convert (restype, op1));
3503 /* This generates an error if op1 is a pointer to an incomplete type. */
3504 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3505 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3507 op1 = (TYPE_PTROB_P (ptrtype)
3508 ? size_in_bytes (target_type)
3509 : integer_one_node);
3511 /* Do the division. */
3513 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3514 return fold_if_not_in_template (result);
3517 /* Construct and perhaps optimize a tree representation
3518 for a unary operation. CODE, a tree_code, specifies the operation
3519 and XARG is the operand. */
3522 build_x_unary_op (enum tree_code code, tree xarg)
3524 tree orig_expr = xarg;
3528 if (processing_template_decl)
3530 if (type_dependent_expression_p (xarg))
3531 return build_min_nt (code, xarg, NULL_TREE);
3533 xarg = build_non_dependent_expr (xarg);
3538 /* [expr.unary.op] says:
3540 The address of an object of incomplete type can be taken.
3542 (And is just the ordinary address operator, not an overloaded
3543 "operator &".) However, if the type is a template
3544 specialization, we must complete the type at this point so that
3545 an overloaded "operator &" will be available if required. */
3546 if (code == ADDR_EXPR
3547 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3548 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3549 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3550 || (TREE_CODE (xarg) == OFFSET_REF)))
3551 /* Don't look for a function. */;
3553 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3554 /*overloaded_p=*/NULL);
3555 if (!exp && code == ADDR_EXPR)
3557 /* A pointer to member-function can be formed only by saying
3559 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3560 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3562 if (TREE_CODE (xarg) != OFFSET_REF)
3564 error ("invalid use of %qE to form a pointer-to-member-function."
3565 " Use a qualified-id.",
3567 return error_mark_node;
3571 error ("parenthesis around %qE cannot be used to form a"
3572 " pointer-to-member-function",
3574 PTRMEM_OK_P (xarg) = 1;
3578 if (TREE_CODE (xarg) == OFFSET_REF)
3580 ptrmem = PTRMEM_OK_P (xarg);
3582 if (!ptrmem && !flag_ms_extensions
3583 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3585 /* A single non-static member, make sure we don't allow a
3586 pointer-to-member. */
3587 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3588 TREE_OPERAND (xarg, 0),
3589 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3590 PTRMEM_OK_P (xarg) = ptrmem;
3593 else if (TREE_CODE (xarg) == TARGET_EXPR)
3594 warning ("taking address of temporary");
3595 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3598 if (processing_template_decl && exp != error_mark_node)
3599 exp = build_min_non_dep (code, exp, orig_expr,
3600 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3601 if (TREE_CODE (exp) == ADDR_EXPR)
3602 PTRMEM_OK_P (exp) = ptrmem;
3606 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3607 constants, where a null value is represented by an INTEGER_CST of
3611 cp_truthvalue_conversion (tree expr)
3613 tree type = TREE_TYPE (expr);
3614 if (TYPE_PTRMEM_P (type))
3615 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3617 return c_common_truthvalue_conversion (expr);
3620 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3623 condition_conversion (tree expr)
3626 if (processing_template_decl)
3628 t = perform_implicit_conversion (boolean_type_node, expr);
3629 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3633 /* Return an ADDR_EXPR giving the address of T. This function
3634 attempts no optimizations or simplifications; it is a low-level
3638 build_address (tree t)
3642 if (error_operand_p (t) || !cxx_mark_addressable (t))
3643 return error_mark_node;
3645 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3650 /* Return a NOP_EXPR converting EXPR to TYPE. */
3653 build_nop (tree type, tree expr)
3655 if (type == error_mark_node || error_operand_p (expr))
3657 return build1 (NOP_EXPR, type, expr);
3660 /* C++: Must handle pointers to members.
3662 Perhaps type instantiation should be extended to handle conversion
3663 from aggregates to types we don't yet know we want? (Or are those
3664 cases typically errors which should be reported?)
3666 NOCONVERT nonzero suppresses the default promotions
3667 (such as from short to int). */
3670 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3672 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3675 const char *errstring = NULL;
3678 if (arg == error_mark_node)
3679 return error_mark_node;
3683 /* CONVERT_EXPR stands for unary plus in this context. */
3687 int flags = WANT_ARITH | WANT_ENUM;
3688 /* Unary plus (but not unary minus) is allowed on pointers. */
3689 if (code == CONVERT_EXPR)
3690 flags |= WANT_POINTER;
3691 arg = build_expr_type_conversion (flags, arg, true);
3693 errstring = (code == NEGATE_EXPR
3694 ? "wrong type argument to unary minus"
3695 : "wrong type argument to unary plus");
3698 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
3699 arg = perform_integral_promotions (arg);
3701 /* Make sure the result is not a lvalue: a unary plus or minus
3702 expression is always a rvalue. */
3703 if (real_lvalue_p (arg))
3704 arg = build1 (NON_LVALUE_EXPR, TREE_TYPE (arg), arg);
3710 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3714 arg = default_conversion (arg);
3716 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM,
3718 errstring = "wrong type argument to bit-complement";
3719 else if (!noconvert)
3720 arg = perform_integral_promotions (arg);
3724 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3725 errstring = "wrong type argument to abs";
3726 else if (!noconvert)
3727 arg = default_conversion (arg);
3731 /* Conjugating a real value is a no-op, but allow it anyway. */
3732 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3733 errstring = "wrong type argument to conjugation";
3734 else if (!noconvert)
3735 arg = default_conversion (arg);
3738 case TRUTH_NOT_EXPR:
3739 arg = perform_implicit_conversion (boolean_type_node, arg);
3740 val = invert_truthvalue (arg);
3741 if (arg != error_mark_node)
3743 errstring = "in argument to unary !";
3750 if (TREE_CODE (arg) == COMPLEX_CST)
3751 return TREE_REALPART (arg);
3752 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3754 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3755 return fold_if_not_in_template (arg);
3761 if (TREE_CODE (arg) == COMPLEX_CST)
3762 return TREE_IMAGPART (arg);
3763 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3765 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3766 return fold_if_not_in_template (arg);
3769 return cp_convert (TREE_TYPE (arg), integer_zero_node);
3771 case PREINCREMENT_EXPR:
3772 case POSTINCREMENT_EXPR:
3773 case PREDECREMENT_EXPR:
3774 case POSTDECREMENT_EXPR:
3775 /* Handle complex lvalues (when permitted)
3776 by reduction to simpler cases. */
3778 val = unary_complex_lvalue (code, arg);
3782 /* Increment or decrement the real part of the value,
3783 and don't change the imaginary part. */
3784 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3788 arg = stabilize_reference (arg);
3789 real = build_unary_op (REALPART_EXPR, arg, 1);
3790 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3791 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
3792 build_unary_op (code, real, 1), imag);
3795 /* Report invalid types. */
3797 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
3800 if (code == PREINCREMENT_EXPR)
3801 errstring ="no pre-increment operator for type";
3802 else if (code == POSTINCREMENT_EXPR)
3803 errstring ="no post-increment operator for type";
3804 else if (code == PREDECREMENT_EXPR)
3805 errstring ="no pre-decrement operator for type";
3807 errstring ="no post-decrement operator for type";
3811 /* Report something read-only. */
3813 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
3814 || TREE_READONLY (arg))
3815 readonly_error (arg, ((code == PREINCREMENT_EXPR
3816 || code == POSTINCREMENT_EXPR)
3817 ? "increment" : "decrement"),
3822 tree result_type = TREE_TYPE (arg);
3824 arg = get_unwidened (arg, 0);
3825 argtype = TREE_TYPE (arg);
3827 /* ARM $5.2.5 last annotation says this should be forbidden. */
3828 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
3829 pedwarn ("ISO C++ forbids %sing an enum",
3830 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3831 ? "increment" : "decrement");
3833 /* Compute the increment. */
3835 if (TREE_CODE (argtype) == POINTER_TYPE)
3837 tree type = complete_type (TREE_TYPE (argtype));
3839 if (!COMPLETE_OR_VOID_TYPE_P (type))
3840 error ("cannot %s a pointer to incomplete type %qT",
3841 ((code == PREINCREMENT_EXPR
3842 || code == POSTINCREMENT_EXPR)
3843 ? "increment" : "decrement"), TREE_TYPE (argtype));
3844 else if ((pedantic || warn_pointer_arith)
3845 && !TYPE_PTROB_P (argtype))
3846 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
3847 ((code == PREINCREMENT_EXPR
3848 || code == POSTINCREMENT_EXPR)
3849 ? "increment" : "decrement"), argtype);
3850 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
3853 inc = integer_one_node;
3855 inc = cp_convert (argtype, inc);
3857 /* Handle incrementing a cast-expression. */
3859 switch (TREE_CODE (arg))
3864 case FIX_TRUNC_EXPR:
3865 case FIX_FLOOR_EXPR:
3866 case FIX_ROUND_EXPR:
3869 tree incremented, modify, value, compound;
3870 if (! lvalue_p (arg) && pedantic)
3871 pedwarn ("cast to non-reference type used as lvalue");
3872 arg = stabilize_reference (arg);
3873 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
3876 value = save_expr (arg);
3877 incremented = build2 (((code == PREINCREMENT_EXPR
3878 || code == POSTINCREMENT_EXPR)
3879 ? PLUS_EXPR : MINUS_EXPR),
3880 argtype, value, inc);
3882 modify = build_modify_expr (arg, NOP_EXPR, incremented);
3883 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
3886 /* Eliminate warning about unused result of + or -. */
3887 TREE_NO_WARNING (compound) = 1;
3895 /* Complain about anything else that is not a true lvalue. */
3896 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3897 || code == POSTINCREMENT_EXPR)
3898 ? lv_increment : lv_decrement)))
3899 return error_mark_node;
3901 /* Forbid using -- on `bool'. */
3902 if (TREE_TYPE (arg) == boolean_type_node)
3904 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
3906 error ("invalid use of %<--%> on bool variable %qD", arg);
3907 return error_mark_node;
3909 val = boolean_increment (code, arg);
3912 val = build2 (code, TREE_TYPE (arg), arg, inc);
3914 TREE_SIDE_EFFECTS (val) = 1;
3915 return cp_convert (result_type, val);
3919 /* Note that this operation never does default_conversion
3920 regardless of NOCONVERT. */
3922 argtype = lvalue_type (arg);
3924 if (TREE_CODE (arg) == OFFSET_REF)
3927 if (TREE_CODE (argtype) == REFERENCE_TYPE)
3929 tree type = build_pointer_type (TREE_TYPE (argtype));
3930 arg = build1 (CONVERT_EXPR, type, arg);
3933 else if (pedantic && DECL_MAIN_P (arg))
3935 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
3937 /* Let &* cancel out to simplify resulting code. */
3938 if (TREE_CODE (arg) == INDIRECT_REF)
3940 /* We don't need to have `current_class_ptr' wrapped in a
3941 NON_LVALUE_EXPR node. */
3942 if (arg == current_class_ref)
3943 return current_class_ptr;
3945 arg = TREE_OPERAND (arg, 0);
3946 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
3948 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
3949 arg = build1 (CONVERT_EXPR, type, arg);
3951 else if (lvalue_p (arg))
3952 /* Don't let this be an lvalue. */
3953 return non_lvalue (arg);
3957 /* Uninstantiated types are all functions. Taking the
3958 address of a function is a no-op, so just return the
3961 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
3962 || !IDENTIFIER_OPNAME_P (arg));
3964 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
3965 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
3967 /* They're trying to take the address of a unique non-static
3968 member function. This is ill-formed (except in MS-land),
3969 but let's try to DTRT.
3970 Note: We only handle unique functions here because we don't
3971 want to complain if there's a static overload; non-unique
3972 cases will be handled by instantiate_type. But we need to
3973 handle this case here to allow casts on the resulting PMF.
3974 We could defer this in non-MS mode, but it's easier to give
3975 a useful error here. */
3977 /* Inside constant member functions, the `this' pointer
3978 contains an extra const qualifier. TYPE_MAIN_VARIANT
3979 is used here to remove this const from the diagnostics
3980 and the created OFFSET_REF. */
3981 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
3982 tree name = DECL_NAME (get_first_fn (TREE_OPERAND (arg, 1)));
3984 if (! flag_ms_extensions)
3986 if (current_class_type
3987 && TREE_OPERAND (arg, 0) == current_class_ref)
3988 /* An expression like &memfn. */
3989 pedwarn ("ISO C++ forbids taking the address of an unqualified"
3990 " or parenthesized non-static member function to form"
3991 " a pointer to member function. Say %<&%T::%D%>",
3994 pedwarn ("ISO C++ forbids taking the address of a bound member"
3995 " function to form a pointer to member function."
3999 arg = build_offset_ref (base, name, /*address_p=*/true);
4003 if (type_unknown_p (arg))
4004 return build1 (ADDR_EXPR, unknown_type_node, arg);
4006 /* Handle complex lvalues (when permitted)
4007 by reduction to simpler cases. */
4008 val = unary_complex_lvalue (code, arg);
4012 switch (TREE_CODE (arg))
4017 case FIX_TRUNC_EXPR:
4018 case FIX_FLOOR_EXPR:
4019 case FIX_ROUND_EXPR:
4021 if (! lvalue_p (arg) && pedantic)
4022 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4026 arg = OVL_CURRENT (arg);
4030 /* Turn a reference to a non-static data member into a
4031 pointer-to-member. */
4036 if (!PTRMEM_OK_P (arg))
4037 return build_unary_op (code, arg, 0);
4039 t = TREE_OPERAND (arg, 1);
4040 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4042 error ("cannot create pointer to reference member %qD", t);
4043 return error_mark_node;
4046 type = build_ptrmem_type (context_for_name_lookup (t),
4048 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4056 /* Allow the address of a constructor if all the elements
4058 if (TREE_CODE (arg) == CONSTRUCTOR && TREE_HAS_CONSTRUCTOR (arg)
4059 && TREE_CONSTANT (arg))
4061 /* Anything not already handled and not a true memory reference
4063 else if (TREE_CODE (argtype) != FUNCTION_TYPE
4064 && TREE_CODE (argtype) != METHOD_TYPE
4065 && TREE_CODE (arg) != OFFSET_REF
4066 && !lvalue_or_else (arg, lv_addressof))
4067 return error_mark_node;
4069 if (argtype != error_mark_node)
4070 argtype = build_pointer_type (argtype);
4075 if (TREE_CODE (arg) != COMPONENT_REF
4076 /* Inside a template, we are processing a non-dependent
4077 expression so we can just form an ADDR_EXPR with the
4079 || processing_template_decl)
4081 addr = build_address (arg);
4082 if (TREE_CODE (arg) == OFFSET_REF)
4083 PTRMEM_OK_P (addr) = PTRMEM_OK_P (arg);
4085 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4087 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4089 /* We can only get here with a single static member
4091 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4092 && DECL_STATIC_FUNCTION_P (fn));
4094 addr = build_address (fn);
4095 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4096 /* Do not lose object's side effects. */
4097 addr = build2 (COMPOUND_EXPR, TREE_TYPE (addr),
4098 TREE_OPERAND (arg, 0), addr);
4100 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4102 error ("attempt to take address of bit-field structure member %qD",
4103 TREE_OPERAND (arg, 1));
4104 return error_mark_node;
4108 tree field = TREE_OPERAND (arg, 1);
4109 tree rval = build_unary_op (ADDR_EXPR, TREE_OPERAND (arg, 0), 0);
4110 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (rval)),
4111 decl_type_context (field),
4114 rval = build_base_path (PLUS_EXPR, rval, binfo, 1);
4116 TREE_OPERAND (arg, 0) = build_indirect_ref (rval, NULL);
4117 addr = build_address (arg);
4120 if (TREE_CODE (argtype) == POINTER_TYPE
4121 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4123 build_ptrmemfunc_type (argtype);
4124 addr = build_ptrmemfunc (argtype, addr, 0,
4125 /*c_cast_p=*/false);
4138 argtype = TREE_TYPE (arg);
4139 return fold_if_not_in_template (build1 (code, argtype, arg));
4142 error ("%s", errstring);
4143 return error_mark_node;
4146 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4147 for certain kinds of expressions which are not really lvalues
4148 but which we can accept as lvalues.
4150 If ARG is not a kind of expression we can handle, return
4154 unary_complex_lvalue (enum tree_code code, tree arg)
4156 /* Inside a template, making these kinds of adjustments is
4157 pointless; we are only concerned with the type of the
4159 if (processing_template_decl)
4162 /* Handle (a, b) used as an "lvalue". */
4163 if (TREE_CODE (arg) == COMPOUND_EXPR)
4165 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4166 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4167 TREE_OPERAND (arg, 0), real_result);
4170 /* Handle (a ? b : c) used as an "lvalue". */
4171 if (TREE_CODE (arg) == COND_EXPR
4172 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4173 return rationalize_conditional_expr (code, arg);
4175 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4176 if (TREE_CODE (arg) == MODIFY_EXPR
4177 || TREE_CODE (arg) == PREINCREMENT_EXPR
4178 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4180 tree lvalue = TREE_OPERAND (arg, 0);
4181 if (TREE_SIDE_EFFECTS (lvalue))
4183 lvalue = stabilize_reference (lvalue);
4184 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4185 lvalue, TREE_OPERAND (arg, 1));
4187 return unary_complex_lvalue
4188 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4191 if (code != ADDR_EXPR)
4194 /* Handle (a = b) used as an "lvalue" for `&'. */
4195 if (TREE_CODE (arg) == MODIFY_EXPR
4196 || TREE_CODE (arg) == INIT_EXPR)
4198 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4199 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4201 TREE_NO_WARNING (arg) = 1;
4205 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4206 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4207 || TREE_CODE (arg) == OFFSET_REF)
4210 /* We permit compiler to make function calls returning
4211 objects of aggregate type look like lvalues. */
4215 if (TREE_CODE (targ) == SAVE_EXPR)
4216 targ = TREE_OPERAND (targ, 0);
4218 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4220 if (TREE_CODE (arg) == SAVE_EXPR)
4223 targ = build_cplus_new (TREE_TYPE (arg), arg);
4224 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4227 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4228 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4229 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4232 /* Don't let anything else be handled specially. */
4236 /* Mark EXP saying that we need to be able to take the
4237 address of it; it should not be allocated in a register.
4238 Value is true if successful.
4240 C++: we do not allow `current_class_ptr' to be addressable. */
4243 cxx_mark_addressable (tree exp)
4248 switch (TREE_CODE (x))
4255 x = TREE_OPERAND (x, 0);
4259 if (x == current_class_ptr)
4261 error ("cannot take the address of %<this%>, which is an rvalue expression");
4262 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4268 /* Caller should not be trying to mark initialized
4269 constant fields addressable. */
4270 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4271 || DECL_IN_AGGR_P (x) == 0
4273 || DECL_EXTERNAL (x));
4278 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4279 && !DECL_ARTIFICIAL (x))
4281 if (DECL_HARD_REGISTER (x) != 0)
4284 ("address of explicit register variable %qD requested", x);
4287 else if (extra_warnings)
4289 ("address requested for %qD, which is declared %<register%>", x);
4291 TREE_ADDRESSABLE (x) = 1;
4295 TREE_ADDRESSABLE (x) = 1;
4299 TREE_ADDRESSABLE (x) = 1;
4303 TREE_ADDRESSABLE (x) = 1;
4304 cxx_mark_addressable (TREE_OPERAND (x, 0));
4312 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4315 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4317 tree orig_ifexp = ifexp;
4318 tree orig_op1 = op1;
4319 tree orig_op2 = op2;
4322 if (processing_template_decl)
4324 /* The standard says that the expression is type-dependent if
4325 IFEXP is type-dependent, even though the eventual type of the
4326 expression doesn't dependent on IFEXP. */
4327 if (type_dependent_expression_p (ifexp)
4328 /* As a GNU extension, the middle operand may be omitted. */
4329 || (op1 && type_dependent_expression_p (op1))
4330 || type_dependent_expression_p (op2))
4331 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4332 ifexp = build_non_dependent_expr (ifexp);
4334 op1 = build_non_dependent_expr (op1);
4335 op2 = build_non_dependent_expr (op2);
4338 expr = build_conditional_expr (ifexp, op1, op2);
4339 if (processing_template_decl && expr != error_mark_node)
4340 return build_min_non_dep (COND_EXPR, expr,
4341 orig_ifexp, orig_op1, orig_op2);
4345 /* Given a list of expressions, return a compound expression
4346 that performs them all and returns the value of the last of them. */
4348 tree build_x_compound_expr_from_list (tree list, const char *msg)
4350 tree expr = TREE_VALUE (list);
4352 if (TREE_CHAIN (list))
4355 pedwarn ("%s expression list treated as compound expression", msg);
4357 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4358 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4364 /* Handle overloading of the ',' operator when needed. */
4367 build_x_compound_expr (tree op1, tree op2)
4370 tree orig_op1 = op1;
4371 tree orig_op2 = op2;
4373 if (processing_template_decl)
4375 if (type_dependent_expression_p (op1)
4376 || type_dependent_expression_p (op2))
4377 return build_min_nt (COMPOUND_EXPR, op1, op2);
4378 op1 = build_non_dependent_expr (op1);
4379 op2 = build_non_dependent_expr (op2);
4382 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4383 /*overloaded_p=*/NULL);
4385 result = build_compound_expr (op1, op2);
4387 if (processing_template_decl && result != error_mark_node)
4388 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4393 /* Build a compound expression. */
4396 build_compound_expr (tree lhs, tree rhs)
4398 lhs = convert_to_void (lhs, "left-hand operand of comma");
4400 if (lhs == error_mark_node || rhs == error_mark_node)
4401 return error_mark_node;
4403 if (TREE_CODE (rhs) == TARGET_EXPR)
4405 /* If the rhs is a TARGET_EXPR, then build the compound
4406 expression inside the target_expr's initializer. This
4407 helps the compiler to eliminate unnecessary temporaries. */
4408 tree init = TREE_OPERAND (rhs, 1);
4410 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4411 TREE_OPERAND (rhs, 1) = init;
4416 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4419 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4420 casts away constness. DIAG_FN gives the function to call if we
4421 need to issue a diagnostic; if it is NULL, no diagnostic will be
4422 issued. DESCRIPTION explains what operation is taking place. */
4425 check_for_casting_away_constness (tree src_type, tree dest_type,
4426 void (*diag_fn)(const char *, ...),
4427 const char *description)
4429 if (diag_fn && casts_away_constness (src_type, dest_type))
4430 error ("%s from type %qT to type %qT casts away constness",
4431 description, src_type, dest_type);
4434 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4435 (another pointer-to-member type in the same hierarchy) and return
4436 the converted expression. If ALLOW_INVERSE_P is permitted, a
4437 pointer-to-derived may be converted to pointer-to-base; otherwise,
4438 only the other direction is permitted. If C_CAST_P is true, this
4439 conversion is taking place as part of a C-style cast. */
4442 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4445 if (TYPE_PTRMEM_P (type))
4449 if (TREE_CODE (expr) == PTRMEM_CST)
4450 expr = cplus_expand_constant (expr);
4451 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4452 TYPE_PTRMEM_CLASS_TYPE (type),
4455 if (!integer_zerop (delta))
4456 expr = cp_build_binary_op (PLUS_EXPR,
4457 build_nop (ptrdiff_type_node, expr),
4459 return build_nop (type, expr);
4462 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4463 allow_inverse_p, c_cast_p);
4466 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4467 this static_cast is being attempted as one of the possible casts
4468 allowed by a C-style cast. (In that case, accessibility of base
4469 classes is not considered, and it is OK to cast away
4470 constness.) Return the result of the cast. *VALID_P is set to
4471 indicate whether or not the cast was valid. */
4474 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4480 void (*diag_fn)(const char*, ...);
4483 /* Assume the cast is valid. */
4486 intype = TREE_TYPE (expr);
4488 /* Determine what to do when casting away constness. */
4491 /* C-style casts are allowed to cast away constness. With
4492 WARN_CAST_QUAL, we still want to issue a warning. */
4493 diag_fn = warn_cast_qual ? warning : NULL;
4498 /* A static_cast may not cast away constness. */
4500 desc = "static_cast";
4503 /* [expr.static.cast]
4505 An lvalue of type "cv1 B", where B is a class type, can be cast
4506 to type "reference to cv2 D", where D is a class derived (clause
4507 _class.derived_) from B, if a valid standard conversion from
4508 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4509 same cv-qualification as, or greater cv-qualification than, cv1,
4510 and B is not a virtual base class of D. */
4511 /* We check this case before checking the validity of "TYPE t =
4512 EXPR;" below because for this case:
4515 struct D : public B { D(const B&); };
4517 void f() { static_cast<const D&>(b); }
4519 we want to avoid constructing a new D. The standard is not
4520 completely clear about this issue, but our interpretation is
4521 consistent with other compilers. */
4522 if (TREE_CODE (type) == REFERENCE_TYPE
4523 && CLASS_TYPE_P (TREE_TYPE (type))
4524 && CLASS_TYPE_P (intype)
4525 && real_lvalue_p (expr)
4526 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4527 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4528 build_pointer_type (TYPE_MAIN_VARIANT
4529 (TREE_TYPE (type))))
4531 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4535 /* There is a standard conversion from "D*" to "B*" even if "B"
4536 is ambiguous or inaccessible. If this is really a
4537 static_cast, then we check both for inaccessibility and
4538 ambiguity. However, if this is a static_cast being performed
4539 because the user wrote a C-style cast, then accessibility is
4541 base = lookup_base (TREE_TYPE (type), intype,
4542 c_cast_p ? ba_unique : ba_check,
4545 /* Convert from "B*" to "D*". This function will check that "B"
4546 is not a virtual base of "D". */
4547 expr = build_base_path (MINUS_EXPR, build_address (expr),
4548 base, /*nonnull=*/false);
4549 /* Convert the pointer to a reference -- but then remember that
4550 there are no expressions with reference type in C++. */
4551 return convert_from_reference (build_nop (type, expr));
4556 /* [expr.static.cast]
4558 An expression e can be explicitly converted to a type T using a
4559 static_cast of the form static_cast<T>(e) if the declaration T
4560 t(e);" is well-formed, for some invented temporary variable
4562 result = perform_direct_initialization_if_possible (type, expr,
4566 result = convert_from_reference (result);
4568 /* Ignore any integer overflow caused by the cast. */
4569 if (TREE_CODE (result) == INTEGER_CST
4570 && CONSTANT_CLASS_P (orig))
4572 TREE_OVERFLOW (result) = TREE_OVERFLOW (orig);
4573 TREE_CONSTANT_OVERFLOW (result)
4574 = TREE_CONSTANT_OVERFLOW (orig);
4576 /* [expr.static.cast]
4578 If T is a reference type, the result is an lvalue; otherwise,
4579 the result is an rvalue. */
4580 if (TREE_CODE (type) != REFERENCE_TYPE
4581 && real_lvalue_p (result))
4582 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (result), result);
4586 /* [expr.static.cast]
4588 Any expression can be explicitly converted to type cv void. */
4589 if (TREE_CODE (type) == VOID_TYPE)
4590 return convert_to_void (expr, /*implicit=*/NULL);
4592 /* [expr.static.cast]
4594 The inverse of any standard conversion sequence (clause _conv_),
4595 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4596 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4597 (_conv.bool_) conversions, can be performed explicitly using
4598 static_cast subject to the restriction that the explicit
4599 conversion does not cast away constness (_expr.const.cast_), and
4600 the following additional rules for specific cases: */
4601 /* For reference, the conversions not excluded are: integral
4602 promotions, floating point promotion, integral conversions,
4603 floating point conversions, floating-integral conversions,
4604 pointer conversions, and pointer to member conversions. */
4607 A value of integral _or enumeration_ type can be explicitly
4608 converted to an enumeration type. */
4609 /* The effect of all that is that any conversion between any two
4610 types which are integral, floating, or enumeration types can be
4612 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
4613 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
4615 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
4617 /* Ignore any integer overflow caused by the cast. */
4618 if (TREE_CODE (expr) == INTEGER_CST
4619 && CONSTANT_CLASS_P (orig))
4621 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4622 TREE_CONSTANT_OVERFLOW (expr) = TREE_CONSTANT_OVERFLOW (orig);
4627 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4628 && CLASS_TYPE_P (TREE_TYPE (type))
4629 && CLASS_TYPE_P (TREE_TYPE (intype))
4630 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4631 (TREE_TYPE (intype))),
4632 build_pointer_type (TYPE_MAIN_VARIANT
4633 (TREE_TYPE (type)))))
4638 check_for_casting_away_constness (intype, type, diag_fn, desc);
4639 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
4640 c_cast_p ? ba_unique : ba_check,
4642 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4645 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4646 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4653 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
4654 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
4656 if (TYPE_PTRMEM_P (type))
4658 t1 = (build_ptrmem_type
4660 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
4661 t2 = (build_ptrmem_type
4663 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
4670 if (can_convert (t1, t2))
4673 check_for_casting_away_constness (intype, type, diag_fn,
4675 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
4680 /* [expr.static.cast]
4682 An rvalue of type "pointer to cv void" can be explicitly
4683 converted to a pointer to object type. A value of type pointer
4684 to object converted to "pointer to cv void" and back to the
4685 original pointer type will have its original value. */
4686 if (TREE_CODE (intype) == POINTER_TYPE
4687 && VOID_TYPE_P (TREE_TYPE (intype))
4688 && TYPE_PTROB_P (type))
4691 check_for_casting_away_constness (intype, type, diag_fn, desc);
4692 return build_nop (type, expr);
4696 return error_mark_node;
4699 /* Return an expression representing static_cast<TYPE>(EXPR). */
4702 build_static_cast (tree type, tree expr)
4707 if (type == error_mark_node || expr == error_mark_node)
4708 return error_mark_node;
4710 if (processing_template_decl)
4712 expr = build_min (STATIC_CAST_EXPR, type, expr);
4713 /* We don't know if it will or will not have side effects. */
4714 TREE_SIDE_EFFECTS (expr) = 1;
4715 return convert_from_reference (expr);
4718 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4719 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4720 if (TREE_CODE (type) != REFERENCE_TYPE
4721 && TREE_CODE (expr) == NOP_EXPR
4722 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4723 expr = TREE_OPERAND (expr, 0);
4725 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
4729 error ("invalid static_cast from type %qT to type %qT",
4730 TREE_TYPE (expr), type);
4731 return error_mark_node;
4734 /* EXPR is an expression with member function or pointer-to-member
4735 function type. TYPE is a pointer type. Converting EXPR to TYPE is
4736 not permitted by ISO C++, but we accept it in some modes. If we
4737 are not in one of those modes, issue a diagnostic. Return the
4738 converted expression. */
4741 convert_member_func_to_ptr (tree type, tree expr)
4746 intype = TREE_TYPE (expr);
4747 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
4748 || TREE_CODE (intype) == METHOD_TYPE);
4750 if (pedantic || warn_pmf2ptr)
4751 pedwarn ("converting from %qT to %qT", intype, type);
4753 if (TREE_CODE (intype) == METHOD_TYPE)
4754 expr = build_addr_func (expr);
4755 else if (TREE_CODE (expr) == PTRMEM_CST)
4756 expr = build_address (PTRMEM_CST_MEMBER (expr));
4759 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
4760 decl = build_address (decl);
4761 expr = get_member_function_from_ptrfunc (&decl, expr);
4764 return build_nop (type, expr);
4767 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
4768 If C_CAST_P is true, this reinterpret cast is being done as part of
4769 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
4770 indicate whether or not reinterpret_cast was valid. */
4773 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
4778 /* Assume the cast is invalid. */
4782 if (type == error_mark_node || error_operand_p (expr))
4783 return error_mark_node;
4785 intype = TREE_TYPE (expr);
4787 /* [expr.reinterpret.cast]
4788 An lvalue expression of type T1 can be cast to the type
4789 "reference to T2" if an expression of type "pointer to T1" can be
4790 explicitly converted to the type "pointer to T2" using a
4791 reinterpret_cast. */
4792 if (TREE_CODE (type) == REFERENCE_TYPE)
4794 if (! real_lvalue_p (expr))
4796 error ("invalid cast of an rvalue expression of type "
4799 return error_mark_node;
4802 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
4803 "B" are related class types; the reinterpret_cast does not
4804 adjust the pointer. */
4805 if (TYPE_PTR_P (intype)
4806 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
4807 COMPARE_BASE | COMPARE_DERIVED)))
4808 warning ("casting %qT to %qT does not dereference pointer",
4811 expr = build_unary_op (ADDR_EXPR, expr, 0);
4812 if (expr != error_mark_node)
4813 expr = build_reinterpret_cast_1
4814 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
4816 if (expr != error_mark_node)
4817 expr = build_indirect_ref (expr, 0);
4821 /* As a G++ extension, we consider conversions from member
4822 functions, and pointers to member functions to
4823 pointer-to-function and pointer-to-void types. If
4824 -Wno-pmf-conversions has not been specified,
4825 convert_member_func_to_ptr will issue an error message. */
4826 if ((TYPE_PTRMEMFUNC_P (intype)
4827 || TREE_CODE (intype) == METHOD_TYPE)
4828 && TYPE_PTR_P (type)
4829 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
4830 || VOID_TYPE_P (TREE_TYPE (type))))
4831 return convert_member_func_to_ptr (type, expr);
4833 /* If the cast is not to a reference type, the lvalue-to-rvalue,
4834 array-to-pointer, and function-to-pointer conversions are
4836 expr = decay_conversion (expr);
4838 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4839 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4840 if (TREE_CODE (expr) == NOP_EXPR
4841 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4842 expr = TREE_OPERAND (expr, 0);
4844 if (error_operand_p (expr))
4845 return error_mark_node;
4847 intype = TREE_TYPE (expr);
4849 /* [expr.reinterpret.cast]
4850 A pointer can be converted to any integral type large enough to
4852 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
4854 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
4855 pedwarn ("cast from %qT to %qT loses precision",
4858 /* [expr.reinterpret.cast]
4859 A value of integral or enumeration type can be explicitly
4860 converted to a pointer. */
4861 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
4864 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
4865 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4866 return fold_if_not_in_template (build_nop (type, expr));
4867 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4868 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
4871 check_for_casting_away_constness (intype, type, error,
4872 "reinterpret_cast");
4873 /* Warn about possible alignment problems. */
4874 if (STRICT_ALIGNMENT && warn_cast_align
4875 && !VOID_TYPE_P (type)
4876 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
4877 && COMPLETE_TYPE_P (TREE_TYPE (type))
4878 && COMPLETE_TYPE_P (TREE_TYPE (intype))
4879 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
4880 warning ("cast from %qT to %qT increases required alignment of "
4884 return fold_if_not_in_template (build_nop (type, expr));
4886 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
4887 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
4890 /* Only issue a warning, as we have always supported this
4891 where possible, and it is necessary in some cases. DR 195
4892 addresses this issue, but as of 2004/10/26 is still in
4894 warning ("ISO C++ forbids casting between pointer-to-function and pointer-to-object");
4895 return fold_if_not_in_template (build_nop (type, expr));
4897 else if (TREE_CODE (type) == VECTOR_TYPE)
4898 return fold_if_not_in_template (convert_to_vector (type, expr));
4899 else if (TREE_CODE (intype) == VECTOR_TYPE)
4900 return fold_if_not_in_template (convert_to_integer (type, expr));
4905 error ("invalid cast from type %qT to type %qT", intype, type);
4906 return error_mark_node;
4909 return cp_convert (type, expr);
4913 build_reinterpret_cast (tree type, tree expr)
4915 if (type == error_mark_node || expr == error_mark_node)
4916 return error_mark_node;
4918 if (processing_template_decl)
4920 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
4922 if (!TREE_SIDE_EFFECTS (t)
4923 && type_dependent_expression_p (expr))
4924 /* There might turn out to be side effects inside expr. */
4925 TREE_SIDE_EFFECTS (t) = 1;
4926 return convert_from_reference (t);
4929 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
4933 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
4934 return an appropriate expression. Otherwise, return
4935 error_mark_node. If the cast is not valid, and COMPLAIN is true,
4936 then a diagnostic will be issued. If VALID_P is non-NULL, its
4937 value upon return will indicate whether or not the conversion
4941 build_const_cast_1 (tree dst_type, tree expr, bool complain,
4945 tree reference_type;
4947 /* Callers are responsible for handling error_mark_node as a
4948 destination type. */
4949 gcc_assert (dst_type != error_mark_node);
4950 /* In a template, callers should be building syntactic
4951 representations of casts, not using this machinery. */
4952 gcc_assert (!processing_template_decl);
4954 /* Assume the conversion is invalid. */
4958 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
4961 error ("invalid use of const_cast with type %qT, "
4962 "which is not a pointer, "
4963 "reference, nor a pointer-to-data-member type", dst_type);
4964 return error_mark_node;
4967 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
4970 error ("invalid use of const_cast with type %qT, which is a pointer "
4971 "or reference to a function type", dst_type);
4972 return error_mark_node;
4975 src_type = TREE_TYPE (expr);
4976 /* Expressions do not really have reference types. */
4977 if (TREE_CODE (src_type) == REFERENCE_TYPE)
4978 src_type = TREE_TYPE (src_type);
4980 /* [expr.const.cast]
4982 An lvalue of type T1 can be explicitly converted to an lvalue of
4983 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
4984 types) if a pointer to T1 can be explicitly converted to the type
4985 pointer to T2 using a const_cast. */
4986 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
4988 reference_type = dst_type;
4989 if (! real_lvalue_p (expr))
4992 error ("invalid const_cast of an rvalue of type %qT to type %qT",
4993 src_type, dst_type);
4994 return error_mark_node;
4996 dst_type = build_pointer_type (TREE_TYPE (dst_type));
4997 src_type = build_pointer_type (src_type);
5001 reference_type = NULL_TREE;
5002 /* If the destination type is not a reference type, the
5003 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5004 conversions are performed. */
5005 src_type = type_decays_to (src_type);
5006 if (src_type == error_mark_node)
5007 return error_mark_node;
5010 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5011 && comp_ptr_ttypes_const (dst_type, src_type))
5017 expr = build_unary_op (ADDR_EXPR, expr, 0);
5018 expr = build_nop (reference_type, expr);
5019 return convert_from_reference (expr);
5023 expr = decay_conversion (expr);
5024 /* build_c_cast puts on a NOP_EXPR to make the result not an
5025 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5026 non-lvalue context. */
5027 if (TREE_CODE (expr) == NOP_EXPR
5028 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5029 expr = TREE_OPERAND (expr, 0);
5030 return build_nop (dst_type, expr);
5035 error ("invalid const_cast from type %qT to type %qT",
5036 src_type, dst_type);
5037 return error_mark_node;
5041 build_const_cast (tree type, tree expr)
5043 if (type == error_mark_node || error_operand_p (expr))
5044 return error_mark_node;
5046 if (processing_template_decl)
5048 tree t = build_min (CONST_CAST_EXPR, type, expr);
5050 if (!TREE_SIDE_EFFECTS (t)
5051 && type_dependent_expression_p (expr))
5052 /* There might turn out to be side effects inside expr. */
5053 TREE_SIDE_EFFECTS (t) = 1;
5054 return convert_from_reference (t);
5057 return build_const_cast_1 (type, expr, /*complain=*/true,
5061 /* Build an expression representing an explicit C-style cast to type
5062 TYPE of expression EXPR. */
5065 build_c_cast (tree type, tree expr)
5071 if (type == error_mark_node || error_operand_p (expr))
5072 return error_mark_node;
5074 if (processing_template_decl)
5076 tree t = build_min (CAST_EXPR, type,
5077 tree_cons (NULL_TREE, value, NULL_TREE));
5078 /* We don't know if it will or will not have side effects. */
5079 TREE_SIDE_EFFECTS (t) = 1;
5080 return convert_from_reference (t);
5083 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5084 'Class') should always be retained, because this information aids
5085 in method lookup. */
5086 if (objc_is_object_ptr (type)
5087 && objc_is_object_ptr (TREE_TYPE (expr)))
5088 return build_nop (type, expr);
5090 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5091 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5092 if (TREE_CODE (type) != REFERENCE_TYPE
5093 && TREE_CODE (value) == NOP_EXPR
5094 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5095 value = TREE_OPERAND (value, 0);
5097 if (TREE_CODE (type) == ARRAY_TYPE)
5099 /* Allow casting from T1* to T2[] because Cfront allows it.
5100 NIHCL uses it. It is not valid ISO C++ however. */
5101 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5103 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5104 type = build_pointer_type (TREE_TYPE (type));
5108 error ("ISO C++ forbids casting to an array type %qT", type);
5109 return error_mark_node;
5113 if (TREE_CODE (type) == FUNCTION_TYPE
5114 || TREE_CODE (type) == METHOD_TYPE)
5116 error ("invalid cast to function type %qT", type);
5117 return error_mark_node;
5120 /* A C-style cast can be a const_cast. */
5121 result = build_const_cast_1 (type, value, /*complain=*/false,
5126 /* Or a static cast. */
5127 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5129 /* Or a reinterpret_cast. */
5131 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5133 /* The static_cast or reinterpret_cast may be followed by a
5136 /* A valid cast may result in errors if, for example, a
5137 conversion to am ambiguous base class is required. */
5138 && !error_operand_p (result))
5142 /* Non-class rvalues always have cv-unqualified type. */
5143 if (!CLASS_TYPE_P (type))
5144 type = TYPE_MAIN_VARIANT (type);
5145 result_type = TREE_TYPE (result);
5146 if (!CLASS_TYPE_P (result_type))
5147 result_type = TYPE_MAIN_VARIANT (result_type);
5148 /* If the type of RESULT does not match TYPE, perform a
5149 const_cast to make it match. If the static_cast or
5150 reinterpret_cast succeeded, we will differ by at most
5151 cv-qualification, so the follow-on const_cast is guaranteed
5153 if (!same_type_p (non_reference (type), non_reference (result_type)))
5155 result = build_const_cast_1 (type, result, false, &valid_p);
5156 gcc_assert (valid_p);
5161 return error_mark_node;
5164 /* Build an assignment expression of lvalue LHS from value RHS.
5165 MODIFYCODE is the code for a binary operator that we use
5166 to combine the old value of LHS with RHS to get the new value.
5167 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5169 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5172 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5176 tree lhstype = TREE_TYPE (lhs);
5177 tree olhstype = lhstype;
5178 tree olhs = NULL_TREE;
5179 bool plain_assign = (modifycode == NOP_EXPR);
5181 /* Avoid duplicate error messages from operands that had errors. */
5182 if (lhs == error_mark_node || rhs == error_mark_node)
5183 return error_mark_node;
5185 /* Handle control structure constructs used as "lvalues". */
5186 switch (TREE_CODE (lhs))
5188 /* Handle --foo = 5; as these are valid constructs in C++. */
5189 case PREDECREMENT_EXPR:
5190 case PREINCREMENT_EXPR:
5191 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5192 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5193 stabilize_reference (TREE_OPERAND (lhs, 0)),
5194 TREE_OPERAND (lhs, 1));
5195 return build2 (COMPOUND_EXPR, lhstype,
5197 build_modify_expr (TREE_OPERAND (lhs, 0),
5200 /* Handle (a, b) used as an "lvalue". */
5202 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5204 if (newrhs == error_mark_node)
5205 return error_mark_node;
5206 return build2 (COMPOUND_EXPR, lhstype,
5207 TREE_OPERAND (lhs, 0), newrhs);
5210 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5211 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5212 stabilize_reference (TREE_OPERAND (lhs, 0)),
5213 TREE_OPERAND (lhs, 1));
5214 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5215 if (newrhs == error_mark_node)
5216 return error_mark_node;
5217 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5221 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5222 when neither operand has side-effects. */
5223 if (!lvalue_or_else (lhs, lv_assign))
5224 return error_mark_node;
5226 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5227 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5229 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5230 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5232 TREE_OPERAND (lhs, 0),
5233 TREE_OPERAND (lhs, 1)),
5234 TREE_OPERAND (lhs, 0),
5235 TREE_OPERAND (lhs, 1));
5238 /* Handle (a ? b : c) used as an "lvalue". */
5241 /* Produce (a ? (b = rhs) : (c = rhs))
5242 except that the RHS goes through a save-expr
5243 so the code to compute it is only emitted once. */
5245 tree preeval = NULL_TREE;
5247 rhs = stabilize_expr (rhs, &preeval);
5249 /* Check this here to avoid odd errors when trying to convert
5250 a throw to the type of the COND_EXPR. */
5251 if (!lvalue_or_else (lhs, lv_assign))
5252 return error_mark_node;
5254 cond = build_conditional_expr
5255 (TREE_OPERAND (lhs, 0),
5256 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5257 TREE_OPERAND (lhs, 1)),
5259 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5260 TREE_OPERAND (lhs, 2)),
5263 if (cond == error_mark_node)
5265 /* Make sure the code to compute the rhs comes out
5266 before the split. */
5268 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5276 if (modifycode == INIT_EXPR)
5278 if (TREE_CODE (rhs) == CONSTRUCTOR)
5280 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5281 /* Call convert to generate an error; see PR 11063. */
5282 rhs = convert (lhstype, rhs);
5283 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5284 TREE_SIDE_EFFECTS (result) = 1;
5287 else if (! IS_AGGR_TYPE (lhstype))
5288 /* Do the default thing. */;
5291 result = build_special_member_call (lhs, complete_ctor_identifier,
5292 build_tree_list (NULL_TREE, rhs),
5293 lhstype, LOOKUP_NORMAL);
5294 if (result == NULL_TREE)
5295 return error_mark_node;
5301 lhs = require_complete_type (lhs);
5302 if (lhs == error_mark_node)
5303 return error_mark_node;
5305 if (modifycode == NOP_EXPR)
5307 /* `operator=' is not an inheritable operator. */
5308 if (! IS_AGGR_TYPE (lhstype))
5309 /* Do the default thing. */;
5312 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5313 lhs, rhs, make_node (NOP_EXPR),
5314 /*overloaded_p=*/NULL);
5315 if (result == NULL_TREE)
5316 return error_mark_node;
5323 /* A binary op has been requested. Combine the old LHS
5324 value with the RHS producing the value we should actually
5325 store into the LHS. */
5327 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5328 lhs = stabilize_reference (lhs);
5329 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5330 if (newrhs == error_mark_node)
5332 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5333 TREE_TYPE (lhs), TREE_TYPE (rhs));
5334 return error_mark_node;
5337 /* Now it looks like a plain assignment. */
5338 modifycode = NOP_EXPR;
5340 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5341 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5344 /* The left-hand side must be an lvalue. */
5345 if (!lvalue_or_else (lhs, lv_assign))
5346 return error_mark_node;
5348 /* Warn about modifying something that is `const'. Don't warn if
5349 this is initialization. */
5350 if (modifycode != INIT_EXPR
5351 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5352 /* Functions are not modifiable, even though they are
5354 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5355 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5356 /* If it's an aggregate and any field is const, then it is
5357 effectively const. */
5358 || (CLASS_TYPE_P (lhstype)
5359 && C_TYPE_FIELDS_READONLY (lhstype))))
5360 readonly_error (lhs, "assignment", 0);
5362 /* If storing into a structure or union member, it has probably been
5363 given type `int'. Compute the type that would go with the actual
5364 amount of storage the member occupies. */
5366 if (TREE_CODE (lhs) == COMPONENT_REF
5367 && (TREE_CODE (lhstype) == INTEGER_TYPE
5368 || TREE_CODE (lhstype) == REAL_TYPE
5369 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5371 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5373 /* If storing in a field that is in actuality a short or narrower
5374 than one, we must store in the field in its actual type. */
5376 if (lhstype != TREE_TYPE (lhs))
5378 /* Avoid warnings converting integral types back into enums for
5380 if (TREE_CODE (lhstype) == INTEGER_TYPE
5381 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5383 if (TREE_SIDE_EFFECTS (lhs))
5384 lhs = stabilize_reference (lhs);
5387 lhs = copy_node (lhs);
5388 TREE_TYPE (lhs) = lhstype;
5392 /* Convert new value to destination type. */
5394 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5398 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5399 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5401 error ("incompatible types in assignment of %qT to %qT",
5402 TREE_TYPE (rhs), lhstype);
5403 return error_mark_node;
5406 /* Allow array assignment in compiler-generated code. */
5407 if (! DECL_ARTIFICIAL (current_function_decl))
5408 pedwarn ("ISO C++ forbids assignment of arrays");
5410 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5411 ? 1 + (modifycode != INIT_EXPR): 0;
5412 return build_vec_init (lhs, NULL_TREE, newrhs, from_array);
5415 if (modifycode == INIT_EXPR)
5416 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5417 "initialization", NULL_TREE, 0);
5420 /* Avoid warnings on enum bit fields. */
5421 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5422 && TREE_CODE (lhstype) == INTEGER_TYPE)
5424 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5426 newrhs = convert_force (lhstype, newrhs, 0);
5429 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5431 if (TREE_CODE (newrhs) == CALL_EXPR
5432 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5433 newrhs = build_cplus_new (lhstype, newrhs);
5435 /* Can't initialize directly from a TARGET_EXPR, since that would
5436 cause the lhs to be constructed twice, and possibly result in
5437 accidental self-initialization. So we force the TARGET_EXPR to be
5438 expanded without a target. */
5439 if (TREE_CODE (newrhs) == TARGET_EXPR)
5440 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5441 TREE_OPERAND (newrhs, 0));
5444 if (newrhs == error_mark_node)
5445 return error_mark_node;
5447 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5448 lhstype, lhs, newrhs);
5450 TREE_SIDE_EFFECTS (result) = 1;
5452 TREE_NO_WARNING (result) = 1;
5454 /* If we got the LHS in a different type for storing in,
5455 convert the result back to the nominal type of LHS
5456 so that the value we return always has the same type
5457 as the LHS argument. */
5459 if (olhstype == TREE_TYPE (result))
5463 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5464 TREE_NO_WARNING (result) = 1;
5467 return convert_for_assignment (olhstype, result, "assignment",
5472 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5474 if (processing_template_decl)
5475 return build_min_nt (MODOP_EXPR, lhs,
5476 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5478 if (modifycode != NOP_EXPR)
5480 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5481 make_node (modifycode),
5482 /*overloaded_p=*/NULL);
5485 TREE_NO_WARNING (rval) = 1;
5489 return build_modify_expr (lhs, modifycode, rhs);
5493 /* Get difference in deltas for different pointer to member function
5494 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5495 the conversion is invalid, the constant is zero. If
5496 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5497 If C_CAST_P is true this conversion is taking place as part of a
5500 Note that the naming of FROM and TO is kind of backwards; the return
5501 value is what we add to a TO in order to get a FROM. They are named
5502 this way because we call this function to find out how to convert from
5503 a pointer to member of FROM to a pointer to member of TO. */
5506 get_delta_difference (tree from, tree to,
5507 bool allow_inverse_p,
5515 /* Assume no conversion is required. */
5516 result = integer_zero_node;
5517 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5518 if (kind == bk_inaccessible || kind == bk_ambig)
5519 error (" in pointer to member function conversion");
5522 if (!allow_inverse_p)
5524 error_not_base_type (from, to);
5525 error (" in pointer to member conversion");
5529 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check,
5533 virt_binfo = binfo_from_vbase (binfo);
5535 /* This is a reinterpret cast, we choose to do nothing. */
5536 warning ("pointer to member cast via virtual base %qT",
5537 BINFO_TYPE (virt_binfo));
5539 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5545 virt_binfo = binfo_from_vbase (binfo);
5547 result = BINFO_OFFSET (binfo);
5550 /* This is a reinterpret cast, we choose to do nothing. */
5551 if (allow_inverse_p)
5552 warning ("pointer to member cast via virtual base %qT",
5553 BINFO_TYPE (virt_binfo));
5555 error ("pointer to member conversion via virtual base %qT",
5556 BINFO_TYPE (virt_binfo));
5560 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5564 /* Return a constructor for the pointer-to-member-function TYPE using
5565 the other components as specified. */
5568 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5574 /* Pull the FIELD_DECLs out of the type. */
5575 pfn_field = TYPE_FIELDS (type);
5576 delta_field = TREE_CHAIN (pfn_field);
5578 /* Make sure DELTA has the type we want. */
5579 delta = convert_and_check (delta_type_node, delta);
5581 /* Finish creating the initializer. */
5582 u = tree_cons (pfn_field, pfn,
5583 build_tree_list (delta_field, delta));
5584 u = build_constructor (type, u);
5585 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5586 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5587 TREE_STATIC (u) = (TREE_CONSTANT (u)
5588 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5590 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5595 /* Build a constructor for a pointer to member function. It can be
5596 used to initialize global variables, local variable, or used
5597 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5600 If FORCE is nonzero, then force this conversion, even if
5601 we would rather not do it. Usually set when using an explicit
5602 cast. A C-style cast is being processed iff C_CAST_P is true.
5604 Return error_mark_node, if something goes wrong. */
5607 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
5613 if (error_operand_p (pfn))
5614 return error_mark_node;
5616 pfn_type = TREE_TYPE (pfn);
5617 to_type = build_ptrmemfunc_type (type);
5619 /* Handle multiple conversions of pointer to member functions. */
5620 if (TYPE_PTRMEMFUNC_P (pfn_type))
5622 tree delta = NULL_TREE;
5623 tree npfn = NULL_TREE;
5627 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn))
5628 error ("invalid conversion to type %qT from type %qT",
5631 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
5632 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
5636 /* We don't have to do any conversion to convert a
5637 pointer-to-member to its own type. But, we don't want to
5638 just return a PTRMEM_CST if there's an explicit cast; that
5639 cast should make the expression an invalid template argument. */
5640 if (TREE_CODE (pfn) != PTRMEM_CST)
5642 if (same_type_p (to_type, pfn_type))
5644 else if (integer_zerop (n))
5645 return build_reinterpret_cast (to_type, pfn);
5648 if (TREE_SIDE_EFFECTS (pfn))
5649 pfn = save_expr (pfn);
5651 /* Obtain the function pointer and the current DELTA. */
5652 if (TREE_CODE (pfn) == PTRMEM_CST)
5653 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
5656 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
5657 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
5660 /* Just adjust the DELTA field. */
5661 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5662 (TREE_TYPE (delta), ptrdiff_type_node));
5663 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
5664 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
5665 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
5666 return build_ptrmemfunc1 (to_type, delta, npfn);
5669 /* Handle null pointer to member function conversions. */
5670 if (integer_zerop (pfn))
5672 pfn = build_c_cast (type, integer_zero_node);
5673 return build_ptrmemfunc1 (to_type,
5678 if (type_unknown_p (pfn))
5679 return instantiate_type (type, pfn, tf_error | tf_warning);
5681 fn = TREE_OPERAND (pfn, 0);
5682 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
5683 /* In a template, we will have preserved the
5685 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
5686 return make_ptrmem_cst (to_type, fn);
5689 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
5692 ??? There is no consistency as to the types returned for the above
5693 values. Some code acts as if it were a sizetype and some as if it were
5694 integer_type_node. */
5697 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
5699 tree type = TREE_TYPE (cst);
5700 tree fn = PTRMEM_CST_MEMBER (cst);
5701 tree ptr_class, fn_class;
5703 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5705 /* The class that the function belongs to. */
5706 fn_class = DECL_CONTEXT (fn);
5708 /* The class that we're creating a pointer to member of. */
5709 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
5711 /* First, calculate the adjustment to the function's class. */
5712 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
5715 if (!DECL_VIRTUAL_P (fn))
5716 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
5719 /* If we're dealing with a virtual function, we have to adjust 'this'
5720 again, to point to the base which provides the vtable entry for
5721 fn; the call will do the opposite adjustment. */
5722 tree orig_class = DECL_CONTEXT (fn);
5723 tree binfo = binfo_or_else (orig_class, fn_class);
5724 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5725 *delta, BINFO_OFFSET (binfo));
5726 *delta = fold_if_not_in_template (*delta);
5728 /* We set PFN to the vtable offset at which the function can be
5729 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
5730 case delta is shifted left, and then incremented). */
5731 *pfn = DECL_VINDEX (fn);
5732 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
5733 TYPE_SIZE_UNIT (vtable_entry_type));
5734 *pfn = fold_if_not_in_template (*pfn);
5736 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
5738 case ptrmemfunc_vbit_in_pfn:
5739 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
5741 *pfn = fold_if_not_in_template (*pfn);
5744 case ptrmemfunc_vbit_in_delta:
5745 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
5746 *delta, integer_one_node);
5747 *delta = fold_if_not_in_template (*delta);
5748 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5749 *delta, integer_one_node);
5750 *delta = fold_if_not_in_template (*delta);
5757 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
5758 *pfn = fold_if_not_in_template (*pfn);
5762 /* Return an expression for PFN from the pointer-to-member function
5766 pfn_from_ptrmemfunc (tree t)
5768 if (TREE_CODE (t) == PTRMEM_CST)
5773 expand_ptrmemfunc_cst (t, &delta, &pfn);
5778 return build_ptrmemfunc_access_expr (t, pfn_identifier);
5781 /* Convert value RHS to type TYPE as preparation for an assignment to
5782 an lvalue of type TYPE. ERRTYPE is a string to use in error
5783 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
5784 are doing the conversion in order to pass the PARMNUMth argument of
5788 convert_for_assignment (tree type, tree rhs,
5789 const char *errtype, tree fndecl, int parmnum)
5792 enum tree_code coder;
5794 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
5795 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
5796 rhs = TREE_OPERAND (rhs, 0);
5798 rhstype = TREE_TYPE (rhs);
5799 coder = TREE_CODE (rhstype);
5801 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
5802 && vector_types_convertible_p (type, rhstype))
5803 return convert (type, rhs);
5805 if (rhs == error_mark_node || rhstype == error_mark_node)
5806 return error_mark_node;
5807 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
5808 return error_mark_node;
5810 /* The RHS of an assignment cannot have void type. */
5811 if (coder == VOID_TYPE)
5813 error ("void value not ignored as it ought to be");
5814 return error_mark_node;
5817 /* Simplify the RHS if possible. */
5818 if (TREE_CODE (rhs) == CONST_DECL)
5819 rhs = DECL_INITIAL (rhs);
5823 The expression is implicitly converted (clause _conv_) to the
5824 cv-unqualified type of the left operand.
5826 We allow bad conversions here because by the time we get to this point
5827 we are committed to doing the conversion. If we end up doing a bad
5828 conversion, convert_like will complain. */
5829 if (!can_convert_arg_bad (type, rhstype, rhs))
5831 /* When -Wno-pmf-conversions is use, we just silently allow
5832 conversions from pointers-to-members to plain pointers. If
5833 the conversion doesn't work, cp_convert will complain. */
5835 && TYPE_PTR_P (type)
5836 && TYPE_PTRMEMFUNC_P (rhstype))
5837 rhs = cp_convert (strip_top_quals (type), rhs);
5840 /* If the right-hand side has unknown type, then it is an
5841 overloaded function. Call instantiate_type to get error
5843 if (rhstype == unknown_type_node)
5844 instantiate_type (type, rhs, tf_error | tf_warning);
5846 error ("cannot convert %qT to %qT for argument %qP to %qD",
5847 rhstype, type, parmnum, fndecl);
5849 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
5850 return error_mark_node;
5853 return perform_implicit_conversion (strip_top_quals (type), rhs);
5856 /* Convert RHS to be of type TYPE.
5857 If EXP is nonzero, it is the target of the initialization.
5858 ERRTYPE is a string to use in error messages.
5860 Two major differences between the behavior of
5861 `convert_for_assignment' and `convert_for_initialization'
5862 are that references are bashed in the former, while
5863 copied in the latter, and aggregates are assigned in
5864 the former (operator=) while initialized in the
5867 If using constructor make sure no conversion operator exists, if one does
5868 exist, an ambiguity exists.
5870 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
5873 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
5874 const char *errtype, tree fndecl, int parmnum)
5876 enum tree_code codel = TREE_CODE (type);
5878 enum tree_code coder;
5880 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5881 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
5882 if (TREE_CODE (rhs) == NOP_EXPR
5883 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
5884 && codel != REFERENCE_TYPE)
5885 rhs = TREE_OPERAND (rhs, 0);
5887 if (rhs == error_mark_node
5888 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
5889 return error_mark_node;
5891 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
5892 && TREE_CODE (type) != ARRAY_TYPE
5893 && (TREE_CODE (type) != REFERENCE_TYPE
5894 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
5895 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
5896 && (TREE_CODE (type) != REFERENCE_TYPE
5897 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
5898 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
5899 rhs = decay_conversion (rhs);
5901 rhstype = TREE_TYPE (rhs);
5902 coder = TREE_CODE (rhstype);
5904 if (coder == ERROR_MARK)
5905 return error_mark_node;
5907 /* We accept references to incomplete types, so we can
5908 return here before checking if RHS is of complete type. */
5910 if (codel == REFERENCE_TYPE)
5912 /* This should eventually happen in convert_arguments. */
5913 int savew = 0, savee = 0;
5916 savew = warningcount, savee = errorcount;
5917 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
5921 if (warningcount > savew)
5922 cp_warning_at ("in passing argument %P of %q+D", parmnum, fndecl);
5923 else if (errorcount > savee)
5924 cp_error_at ("in passing argument %P of %q+D", parmnum, fndecl);
5930 exp = require_complete_type (exp);
5931 if (exp == error_mark_node)
5932 return error_mark_node;
5934 rhstype = non_reference (rhstype);
5936 type = complete_type (type);
5938 if (IS_AGGR_TYPE (type))
5939 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
5941 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
5944 /* If RETVAL is the address of, or a reference to, a local variable or
5945 temporary give an appropriate warning. */
5948 maybe_warn_about_returning_address_of_local (tree retval)
5950 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
5951 tree whats_returned = retval;
5955 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
5956 whats_returned = TREE_OPERAND (whats_returned, 1);
5957 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
5958 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
5959 || TREE_CODE (whats_returned) == NOP_EXPR)
5960 whats_returned = TREE_OPERAND (whats_returned, 0);
5965 if (TREE_CODE (whats_returned) != ADDR_EXPR)
5967 whats_returned = TREE_OPERAND (whats_returned, 0);
5969 if (TREE_CODE (valtype) == REFERENCE_TYPE)
5971 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
5972 || TREE_CODE (whats_returned) == TARGET_EXPR)
5974 warning ("returning reference to temporary");
5977 if (TREE_CODE (whats_returned) == VAR_DECL
5978 && DECL_NAME (whats_returned)
5979 && TEMP_NAME_P (DECL_NAME (whats_returned)))
5981 warning ("reference to non-lvalue returned");
5986 if (DECL_P (whats_returned)
5987 && DECL_NAME (whats_returned)
5988 && DECL_FUNCTION_SCOPE_P (whats_returned)
5989 && !(TREE_STATIC (whats_returned)
5990 || TREE_PUBLIC (whats_returned)))
5992 if (TREE_CODE (valtype) == REFERENCE_TYPE)
5993 cp_warning_at ("reference to local variable %qD returned",
5996 cp_warning_at ("address of local variable %qD returned",
6002 /* Check that returning RETVAL from the current function is valid.
6003 Return an expression explicitly showing all conversions required to
6004 change RETVAL into the function return type, and to assign it to
6005 the DECL_RESULT for the function. */
6008 check_return_expr (tree retval)
6011 /* The type actually returned by the function, after any
6014 int fn_returns_value_p;
6016 /* A `volatile' function is one that isn't supposed to return, ever.
6017 (This is a G++ extension, used to get better code for functions
6018 that call the `volatile' function.) */
6019 if (TREE_THIS_VOLATILE (current_function_decl))
6020 warning ("function declared %<noreturn%> has a %<return%> statement");
6022 /* Check for various simple errors. */
6023 if (DECL_DESTRUCTOR_P (current_function_decl))
6026 error ("returning a value from a destructor");
6029 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6031 if (in_function_try_handler)
6032 /* If a return statement appears in a handler of the
6033 function-try-block of a constructor, the program is ill-formed. */
6034 error ("cannot return from a handler of a function-try-block of a constructor");
6036 /* You can't return a value from a constructor. */
6037 error ("returning a value from a constructor");
6041 if (processing_template_decl)
6043 current_function_returns_value = 1;
6047 /* When no explicit return-value is given in a function with a named
6048 return value, the named return value is used. */
6049 result = DECL_RESULT (current_function_decl);
6050 valtype = TREE_TYPE (result);
6051 gcc_assert (valtype != NULL_TREE);
6052 fn_returns_value_p = !VOID_TYPE_P (valtype);
6053 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6056 /* Check for a return statement with no return value in a function
6057 that's supposed to return a value. */
6058 if (!retval && fn_returns_value_p)
6060 pedwarn ("return-statement with no value, in function returning %qT",
6062 /* Clear this, so finish_function won't say that we reach the
6063 end of a non-void function (which we don't, we gave a
6065 current_function_returns_null = 0;
6067 /* Check for a return statement with a value in a function that
6068 isn't supposed to return a value. */
6069 else if (retval && !fn_returns_value_p)
6071 if (VOID_TYPE_P (TREE_TYPE (retval)))
6072 /* You can return a `void' value from a function of `void'
6073 type. In that case, we have to evaluate the expression for
6074 its side-effects. */
6075 finish_expr_stmt (retval);
6077 pedwarn ("return-statement with a value, in function "
6078 "returning 'void'");
6080 current_function_returns_null = 1;
6082 /* There's really no value to return, after all. */
6086 /* Remember that this function can sometimes return without a
6088 current_function_returns_null = 1;
6090 /* Remember that this function did return a value. */
6091 current_function_returns_value = 1;
6093 /* Check for erroneous operands -- but after giving ourselves a
6094 chance to provide an error about returning a value from a void
6096 if (error_operand_p (retval))
6098 current_function_return_value = error_mark_node;
6099 return error_mark_node;
6102 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6103 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6104 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6105 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6107 && null_ptr_cst_p (retval))
6108 warning ("%<operator new%> must not return NULL unless it is "
6109 "declared %<throw()%> (or -fcheck-new is in effect)");
6111 /* Effective C++ rule 15. See also start_function. */
6113 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6117 /* The function return type must be a reference to the current
6119 if (TREE_CODE (valtype) == REFERENCE_TYPE
6120 && same_type_ignoring_top_level_qualifiers_p
6121 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6123 /* Returning '*this' is obviously OK. */
6124 if (retval == current_class_ref)
6126 /* If we are calling a function whose return type is the same of
6127 the current class reference, it is ok. */
6128 else if (TREE_CODE (retval) == INDIRECT_REF
6129 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6134 warning ("%<operator=%> should return a reference to %<*this%>");
6137 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6139 [...] For a function with a class return type, if the expression
6140 in the return statement is the name of a local object, and the cv-
6141 unqualified type of the local object is the same as the function
6142 return type, an implementation is permitted to omit creating the tem-
6143 porary object to hold the function return value [...]
6145 So, if this is a value-returning function that always returns the same
6146 local variable, remember it.
6148 It might be nice to be more flexible, and choose the first suitable
6149 variable even if the function sometimes returns something else, but
6150 then we run the risk of clobbering the variable we chose if the other
6151 returned expression uses the chosen variable somehow. And people expect
6152 this restriction, anyway. (jason 2000-11-19)
6154 See finish_function and finalize_nrv for the rest of this optimization. */
6156 if (fn_returns_value_p && flag_elide_constructors)
6158 if (retval != NULL_TREE
6159 && (current_function_return_value == NULL_TREE
6160 || current_function_return_value == retval)
6161 && TREE_CODE (retval) == VAR_DECL
6162 && DECL_CONTEXT (retval) == current_function_decl
6163 && ! TREE_STATIC (retval)
6164 && (DECL_ALIGN (retval)
6165 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6166 && same_type_p ((TYPE_MAIN_VARIANT
6167 (TREE_TYPE (retval))),
6169 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6170 current_function_return_value = retval;
6172 current_function_return_value = error_mark_node;
6175 /* We don't need to do any conversions when there's nothing being
6180 /* Do any required conversions. */
6181 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6182 /* No conversions are required. */
6186 /* The type the function is declared to return. */
6187 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6189 /* First convert the value to the function's return type, then
6190 to the type of return value's location to handle the
6191 case that functype is smaller than the valtype. */
6192 retval = convert_for_initialization
6193 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6194 "return", NULL_TREE, 0);
6195 retval = convert (valtype, retval);
6197 /* If the conversion failed, treat this just like `return;'. */
6198 if (retval == error_mark_node)
6200 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6201 else if (! current_function_returns_struct
6202 && TREE_CODE (retval) == TARGET_EXPR
6203 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6204 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6205 TREE_OPERAND (retval, 0));
6207 maybe_warn_about_returning_address_of_local (retval);
6210 /* Actually copy the value returned into the appropriate location. */
6211 if (retval && retval != result)
6212 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6218 /* Returns nonzero if the pointer-type FROM can be converted to the
6219 pointer-type TO via a qualification conversion. If CONSTP is -1,
6220 then we return nonzero if the pointers are similar, and the
6221 cv-qualification signature of FROM is a proper subset of that of TO.
6223 If CONSTP is positive, then all outer pointers have been
6227 comp_ptr_ttypes_real (tree to, tree from, int constp)
6229 bool to_more_cv_qualified = false;
6231 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6233 if (TREE_CODE (to) != TREE_CODE (from))
6236 if (TREE_CODE (from) == OFFSET_TYPE
6237 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6238 TYPE_OFFSET_BASETYPE (to)))
6241 /* Const and volatile mean something different for function types,
6242 so the usual checks are not appropriate. */
6243 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6245 if (!at_least_as_qualified_p (to, from))
6248 if (!at_least_as_qualified_p (from, to))
6252 to_more_cv_qualified = true;
6256 constp &= TYPE_READONLY (to);
6259 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6260 return ((constp >= 0 || to_more_cv_qualified)
6261 && same_type_ignoring_top_level_qualifiers_p (to, from));
6265 /* When comparing, say, char ** to char const **, this function takes
6266 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6267 types to this function. */
6270 comp_ptr_ttypes (tree to, tree from)
6272 return comp_ptr_ttypes_real (to, from, 1);
6275 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6276 type or inheritance-related types, regardless of cv-quals. */
6279 ptr_reasonably_similar (tree to, tree from)
6281 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6283 /* Any target type is similar enough to void. */
6284 if (TREE_CODE (to) == VOID_TYPE
6285 || TREE_CODE (from) == VOID_TYPE)
6288 if (TREE_CODE (to) != TREE_CODE (from))
6291 if (TREE_CODE (from) == OFFSET_TYPE
6292 && comptypes (TYPE_OFFSET_BASETYPE (to),
6293 TYPE_OFFSET_BASETYPE (from),
6294 COMPARE_BASE | COMPARE_DERIVED))
6297 if (TREE_CODE (to) == VECTOR_TYPE
6298 && vector_types_convertible_p (to, from))
6301 if (TREE_CODE (to) == INTEGER_TYPE
6302 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6305 if (TREE_CODE (to) == FUNCTION_TYPE)
6308 if (TREE_CODE (to) != POINTER_TYPE)
6310 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6311 COMPARE_BASE | COMPARE_DERIVED);
6315 /* Like comp_ptr_ttypes, for const_cast. */
6318 comp_ptr_ttypes_const (tree to, tree from)
6320 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6322 if (TREE_CODE (to) != TREE_CODE (from))
6325 if (TREE_CODE (from) == OFFSET_TYPE
6326 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6327 TYPE_OFFSET_BASETYPE (to)))
6330 if (TREE_CODE (to) != POINTER_TYPE)
6331 return same_type_ignoring_top_level_qualifiers_p (to, from);
6335 /* Returns the type qualifiers for this type, including the qualifiers on the
6336 elements for an array type. */
6339 cp_type_quals (tree type)
6341 type = strip_array_types (type);
6342 if (type == error_mark_node)
6343 return TYPE_UNQUALIFIED;
6344 return TYPE_QUALS (type);
6347 /* Returns nonzero if the TYPE contains a mutable member. */
6350 cp_has_mutable_p (tree type)
6352 type = strip_array_types (type);
6354 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6357 /* Apply the TYPE_QUALS to the new DECL. */
6359 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6361 tree type = TREE_TYPE (decl);
6363 if (type == error_mark_node)
6366 if (TREE_CODE (type) == FUNCTION_TYPE
6367 && type_quals != TYPE_UNQUALIFIED)
6369 /* This was an error in C++98 (cv-qualifiers cannot be added to
6370 a function type), but DR 295 makes the code well-formed by
6371 dropping the extra qualifiers. */
6374 tree bad_type = build_qualified_type (type, type_quals);
6375 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6379 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6383 /* Avoid setting TREE_READONLY incorrectly. */
6384 if (/* If the object has a constructor, the constructor may modify
6386 TYPE_NEEDS_CONSTRUCTING (type)
6387 /* If the type isn't complete, we don't know yet if it will need
6389 || !COMPLETE_TYPE_P (type)
6390 /* If the type has a mutable component, that component might be
6392 || TYPE_HAS_MUTABLE_P (type))
6393 type_quals &= ~TYPE_QUAL_CONST;
6395 c_apply_type_quals_to_decl (type_quals, decl);
6398 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6399 exemplar types such that casting T1 to T2 is casting away constness
6400 if and only if there is no implicit conversion from T1 to T2. */
6403 casts_away_constness_r (tree *t1, tree *t2)
6408 /* [expr.const.cast]
6410 For multi-level pointer to members and multi-level mixed pointers
6411 and pointers to members (conv.qual), the "member" aspect of a
6412 pointer to member level is ignored when determining if a const
6413 cv-qualifier has been cast away. */
6414 if (TYPE_PTRMEM_P (*t1))
6415 *t1 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t1));
6416 if (TYPE_PTRMEM_P (*t2))
6417 *t2 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t2));
6419 /* [expr.const.cast]
6421 For two pointer types:
6423 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6424 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6427 casting from X1 to X2 casts away constness if, for a non-pointer
6428 type T there does not exist an implicit conversion (clause
6431 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6435 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6437 if (TREE_CODE (*t1) != POINTER_TYPE
6438 || TREE_CODE (*t2) != POINTER_TYPE)
6440 *t1 = cp_build_qualified_type (void_type_node,
6441 cp_type_quals (*t1));
6442 *t2 = cp_build_qualified_type (void_type_node,
6443 cp_type_quals (*t2));
6447 quals1 = cp_type_quals (*t1);
6448 quals2 = cp_type_quals (*t2);
6449 *t1 = TREE_TYPE (*t1);
6450 *t2 = TREE_TYPE (*t2);
6451 casts_away_constness_r (t1, t2);
6452 *t1 = build_pointer_type (*t1);
6453 *t2 = build_pointer_type (*t2);
6454 *t1 = cp_build_qualified_type (*t1, quals1);
6455 *t2 = cp_build_qualified_type (*t2, quals2);
6458 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6462 casts_away_constness (tree t1, tree t2)
6464 if (TREE_CODE (t2) == REFERENCE_TYPE)
6466 /* [expr.const.cast]
6468 Casting from an lvalue of type T1 to an lvalue of type T2
6469 using a reference cast casts away constness if a cast from an
6470 rvalue of type "pointer to T1" to the type "pointer to T2"
6471 casts away constness. */
6472 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6473 return casts_away_constness (build_pointer_type (t1),
6474 build_pointer_type (TREE_TYPE (t2)));
6477 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6478 /* [expr.const.cast]
6480 Casting from an rvalue of type "pointer to data member of X
6481 of type T1" to the type "pointer to data member of Y of type
6482 T2" casts away constness if a cast from an rvalue of type
6483 "pointer to T1" to the type "pointer to T2" casts away
6485 return casts_away_constness
6486 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6487 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6489 /* Casting away constness is only something that makes sense for
6490 pointer or reference types. */
6491 if (TREE_CODE (t1) != POINTER_TYPE
6492 || TREE_CODE (t2) != POINTER_TYPE)
6495 /* Top-level qualifiers don't matter. */
6496 t1 = TYPE_MAIN_VARIANT (t1);
6497 t2 = TYPE_MAIN_VARIANT (t2);
6498 casts_away_constness_r (&t1, &t2);
6499 if (!can_convert (t2, t1))
6505 /* If T is a REFERENCE_TYPE return the type to which T refers.
6506 Otherwise, return T itself. */
6509 non_reference (tree t)
6511 if (TREE_CODE (t) == REFERENCE_TYPE)
6517 /* Return nonzero if REF is an lvalue valid for this language;
6518 otherwise, print an error message and return zero. USE says
6519 how the lvalue is being used and so selects the error message. */
6522 lvalue_or_else (tree ref, enum lvalue_use use)
6524 int win = lvalue_p (ref);