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),
1250 /* Process a sizeof or alignof expression where the operand is an
1254 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1256 const char *op_name = operator_name_info[(int) op].name;
1258 if (e == error_mark_node)
1259 return error_mark_node;
1261 if (processing_template_decl)
1263 e = build_min (op, size_type_node, e);
1264 TREE_SIDE_EFFECTS (e) = 0;
1265 TREE_READONLY (e) = 1;
1270 if (TREE_CODE (e) == COMPONENT_REF
1271 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1272 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1274 error ("invalid application of %qs to a bit-field", op_name);
1277 else if (is_overloaded_fn (e))
1279 pedwarn ("ISO C++ forbids applying %qs to an expression of "
1280 "function type", op_name);
1283 else if (type_unknown_p (e))
1285 cxx_incomplete_type_error (e, TREE_TYPE (e));
1291 return cxx_sizeof_or_alignof_type (e, op, true);
1295 /* EXPR is being used in a context that is not a function call.
1300 The expression can be used only as the left-hand operand of a
1301 member function call.
1303 [expr.mptr.operator]
1305 If the result of .* or ->* is a function, then that result can be
1306 used only as the operand for the function call operator ().
1308 by issuing an error message if appropriate. Returns true iff EXPR
1309 violates these rules. */
1312 invalid_nonstatic_memfn_p (tree expr)
1314 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1316 error ("invalid use of non-static member function");
1322 /* Perform the conversions in [expr] that apply when an lvalue appears
1323 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1324 function-to-pointer conversions.
1326 In addition manifest constants are replaced by their values. */
1329 decay_conversion (tree exp)
1332 enum tree_code code;
1334 type = TREE_TYPE (exp);
1335 code = TREE_CODE (type);
1337 if (type == error_mark_node)
1338 return error_mark_node;
1340 if (type_unknown_p (exp))
1342 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1343 return error_mark_node;
1346 exp = integral_constant_value (exp);
1348 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1349 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1351 if (code == VOID_TYPE)
1353 error ("void value not ignored as it ought to be");
1354 return error_mark_node;
1356 if (invalid_nonstatic_memfn_p (exp))
1357 return error_mark_node;
1358 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1359 return build_unary_op (ADDR_EXPR, exp, 0);
1360 if (code == ARRAY_TYPE)
1365 if (TREE_CODE (exp) == INDIRECT_REF)
1366 return build_nop (build_pointer_type (TREE_TYPE (type)),
1367 TREE_OPERAND (exp, 0));
1369 if (TREE_CODE (exp) == COMPOUND_EXPR)
1371 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1372 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1373 TREE_OPERAND (exp, 0), op1);
1377 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1379 error ("invalid use of non-lvalue array");
1380 return error_mark_node;
1383 ptrtype = build_pointer_type (TREE_TYPE (type));
1385 if (TREE_CODE (exp) == VAR_DECL)
1387 if (!cxx_mark_addressable (exp))
1388 return error_mark_node;
1389 adr = build_nop (ptrtype, build_address (exp));
1392 /* This way is better for a COMPONENT_REF since it can
1393 simplify the offset for a component. */
1394 adr = build_unary_op (ADDR_EXPR, exp, 1);
1395 return cp_convert (ptrtype, adr);
1398 /* [basic.lval]: Class rvalues can have cv-qualified types; non-class
1399 rvalues always have cv-unqualified types. */
1400 if (! CLASS_TYPE_P (type))
1401 exp = cp_convert (TYPE_MAIN_VARIANT (type), exp);
1407 default_conversion (tree exp)
1409 exp = decay_conversion (exp);
1411 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1412 exp = perform_integral_promotions (exp);
1417 /* EXPR is an expression with an integral or enumeration type.
1418 Perform the integral promotions in [conv.prom], and return the
1422 perform_integral_promotions (tree expr)
1427 type = TREE_TYPE (expr);
1428 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1429 promoted_type = type_promotes_to (type);
1430 if (type != promoted_type)
1431 expr = cp_convert (promoted_type, expr);
1435 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1439 inline_conversion (tree exp)
1441 if (TREE_CODE (exp) == FUNCTION_DECL)
1442 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1447 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1448 decay_conversion to one. */
1451 string_conv_p (tree totype, tree exp, int warn)
1455 if (! flag_const_strings || TREE_CODE (totype) != POINTER_TYPE)
1458 t = TREE_TYPE (totype);
1459 if (!same_type_p (t, char_type_node)
1460 && !same_type_p (t, wchar_type_node))
1463 if (TREE_CODE (exp) == STRING_CST)
1465 /* Make sure that we don't try to convert between char and wchar_t. */
1466 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1471 /* Is this a string constant which has decayed to 'const char *'? */
1472 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1473 if (!same_type_p (TREE_TYPE (exp), t))
1476 if (TREE_CODE (exp) != ADDR_EXPR
1477 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1481 /* This warning is not very useful, as it complains about printf. */
1482 if (warn && warn_write_strings)
1483 warning (0, "deprecated conversion from string constant to %qT'", totype);
1488 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1489 can, for example, use as an lvalue. This code used to be in
1490 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1491 expressions, where we're dealing with aggregates. But now it's again only
1492 called from unary_complex_lvalue. The case (in particular) that led to
1493 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1497 rationalize_conditional_expr (enum tree_code code, tree t)
1499 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1500 the first operand is always the one to be used if both operands
1501 are equal, so we know what conditional expression this used to be. */
1502 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1504 /* The following code is incorrect if either operand side-effects. */
1505 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
1506 && !TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)));
1508 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1509 ? LE_EXPR : GE_EXPR),
1510 TREE_OPERAND (t, 0),
1511 TREE_OPERAND (t, 1),
1512 /*overloaded_p=*/NULL),
1513 build_unary_op (code, TREE_OPERAND (t, 0), 0),
1514 build_unary_op (code, TREE_OPERAND (t, 1), 0));
1518 build_conditional_expr (TREE_OPERAND (t, 0),
1519 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1520 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1523 /* Given the TYPE of an anonymous union field inside T, return the
1524 FIELD_DECL for the field. If not found return NULL_TREE. Because
1525 anonymous unions can nest, we must also search all anonymous unions
1526 that are directly reachable. */
1529 lookup_anon_field (tree t, tree type)
1533 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1535 if (TREE_STATIC (field))
1537 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1540 /* If we find it directly, return the field. */
1541 if (DECL_NAME (field) == NULL_TREE
1542 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1547 /* Otherwise, it could be nested, search harder. */
1548 if (DECL_NAME (field) == NULL_TREE
1549 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1551 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1559 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1560 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1561 non-NULL, it indicates the path to the base used to name MEMBER.
1562 If PRESERVE_REFERENCE is true, the expression returned will have
1563 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1564 returned will have the type referred to by the reference.
1566 This function does not perform access control; that is either done
1567 earlier by the parser when the name of MEMBER is resolved to MEMBER
1568 itself, or later when overload resolution selects one of the
1569 functions indicated by MEMBER. */
1572 build_class_member_access_expr (tree object, tree member,
1573 tree access_path, bool preserve_reference)
1577 tree result = NULL_TREE;
1579 if (object == error_mark_node || member == error_mark_node)
1580 return error_mark_node;
1582 gcc_assert (DECL_P (member) || BASELINK_P (member));
1586 The type of the first expression shall be "class object" (of a
1588 object_type = TREE_TYPE (object);
1589 if (!currently_open_class (object_type)
1590 && !complete_type_or_else (object_type, object))
1591 return error_mark_node;
1592 if (!CLASS_TYPE_P (object_type))
1594 error ("request for member %qD in %qE, which is of non-class type %qT",
1595 member, object, object_type);
1596 return error_mark_node;
1599 /* The standard does not seem to actually say that MEMBER must be a
1600 member of OBJECT_TYPE. However, that is clearly what is
1602 if (DECL_P (member))
1604 member_scope = DECL_CLASS_CONTEXT (member);
1606 if (TREE_DEPRECATED (member))
1607 warn_deprecated_use (member);
1610 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1611 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1612 presently be the anonymous union. Go outwards until we find a
1613 type related to OBJECT_TYPE. */
1614 while (ANON_AGGR_TYPE_P (member_scope)
1615 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1617 member_scope = TYPE_CONTEXT (member_scope);
1618 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1620 if (TREE_CODE (member) == FIELD_DECL)
1621 error ("invalid use of nonstatic data member %qE", member);
1623 error ("%qD is not a member of %qT", member, object_type);
1624 return error_mark_node;
1627 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1628 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1629 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1631 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1633 object = build_indirect_ref (temp, NULL);
1636 /* In [expr.ref], there is an explicit list of the valid choices for
1637 MEMBER. We check for each of those cases here. */
1638 if (TREE_CODE (member) == VAR_DECL)
1640 /* A static data member. */
1642 /* If OBJECT has side-effects, they are supposed to occur. */
1643 if (TREE_SIDE_EFFECTS (object))
1644 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1646 else if (TREE_CODE (member) == FIELD_DECL)
1648 /* A non-static data member. */
1653 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1654 && integer_zerop (TREE_OPERAND (object, 0)));
1656 /* Convert OBJECT to the type of MEMBER. */
1657 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1658 TYPE_MAIN_VARIANT (member_scope)))
1663 binfo = lookup_base (access_path ? access_path : object_type,
1664 member_scope, ba_unique, &kind);
1665 if (binfo == error_mark_node)
1666 return error_mark_node;
1668 /* It is invalid to try to get to a virtual base of a
1669 NULL object. The most common cause is invalid use of
1671 if (null_object_p && kind == bk_via_virtual)
1673 error ("invalid access to non-static data member %qD of "
1676 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1677 return error_mark_node;
1680 /* Convert to the base. */
1681 object = build_base_path (PLUS_EXPR, object, binfo,
1683 /* If we found the base successfully then we should be able
1684 to convert to it successfully. */
1685 gcc_assert (object != error_mark_node);
1688 /* Complain about other invalid uses of offsetof, even though they will
1689 give the right answer. Note that we complain whether or not they
1690 actually used the offsetof macro, since there's no way to know at this
1691 point. So we just give a warning, instead of a pedwarn. */
1692 /* Do not produce this warning for base class field references, because
1693 we know for a fact that didn't come from offsetof. This does occur
1694 in various testsuite cases where a null object is passed where a
1695 vtable access is required. */
1696 if (null_object_p && warn_invalid_offsetof
1697 && CLASSTYPE_NON_POD_P (object_type)
1698 && !DECL_FIELD_IS_BASE (member)
1699 && !skip_evaluation)
1701 warning (0, "invalid access to non-static data member %qD of NULL object",
1703 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1706 /* If MEMBER is from an anonymous aggregate, we have converted
1707 OBJECT so that it refers to the class containing the
1708 anonymous union. Generate a reference to the anonymous union
1709 itself, and recur to find MEMBER. */
1710 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1711 /* When this code is called from build_field_call, the
1712 object already has the type of the anonymous union.
1713 That is because the COMPONENT_REF was already
1714 constructed, and was then disassembled before calling
1715 build_field_call. After the function-call code is
1716 cleaned up, this waste can be eliminated. */
1717 && (!same_type_ignoring_top_level_qualifiers_p
1718 (TREE_TYPE (object), DECL_CONTEXT (member))))
1720 tree anonymous_union;
1722 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1723 DECL_CONTEXT (member));
1724 object = build_class_member_access_expr (object,
1726 /*access_path=*/NULL_TREE,
1727 preserve_reference);
1730 /* Compute the type of the field, as described in [expr.ref]. */
1731 type_quals = TYPE_UNQUALIFIED;
1732 member_type = TREE_TYPE (member);
1733 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1735 type_quals = (cp_type_quals (member_type)
1736 | cp_type_quals (object_type));
1738 /* A field is const (volatile) if the enclosing object, or the
1739 field itself, is const (volatile). But, a mutable field is
1740 not const, even within a const object. */
1741 if (DECL_MUTABLE_P (member))
1742 type_quals &= ~TYPE_QUAL_CONST;
1743 member_type = cp_build_qualified_type (member_type, type_quals);
1746 result = build3 (COMPONENT_REF, member_type, object, member,
1748 result = fold_if_not_in_template (result);
1750 /* Mark the expression const or volatile, as appropriate. Even
1751 though we've dealt with the type above, we still have to mark the
1752 expression itself. */
1753 if (type_quals & TYPE_QUAL_CONST)
1754 TREE_READONLY (result) = 1;
1755 if (type_quals & TYPE_QUAL_VOLATILE)
1756 TREE_THIS_VOLATILE (result) = 1;
1758 else if (BASELINK_P (member))
1760 /* The member is a (possibly overloaded) member function. */
1764 /* If the MEMBER is exactly one static member function, then we
1765 know the type of the expression. Otherwise, we must wait
1766 until overload resolution has been performed. */
1767 functions = BASELINK_FUNCTIONS (member);
1768 if (TREE_CODE (functions) == FUNCTION_DECL
1769 && DECL_STATIC_FUNCTION_P (functions))
1770 type = TREE_TYPE (functions);
1772 type = unknown_type_node;
1773 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1774 base. That will happen when the function is called. */
1775 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1777 else if (TREE_CODE (member) == CONST_DECL)
1779 /* The member is an enumerator. */
1781 /* If OBJECT has side-effects, they are supposed to occur. */
1782 if (TREE_SIDE_EFFECTS (object))
1783 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1788 error ("invalid use of %qD", member);
1789 return error_mark_node;
1792 if (!preserve_reference)
1795 If E2 is declared to have type "reference to T", then ... the
1796 type of E1.E2 is T. */
1797 result = convert_from_reference (result);
1802 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1803 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1806 lookup_destructor (tree object, tree scope, tree dtor_name)
1808 tree object_type = TREE_TYPE (object);
1809 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1812 if (scope && !check_dtor_name (scope, dtor_name))
1814 error ("qualified type %qT does not match destructor name ~%qT",
1816 return error_mark_node;
1818 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
1820 error ("the type being destroyed is %qT, but the destructor refers to %qT",
1821 TYPE_MAIN_VARIANT (object_type), dtor_type);
1822 return error_mark_node;
1824 expr = lookup_member (dtor_type, complete_dtor_identifier,
1825 /*protect=*/1, /*want_type=*/false);
1826 expr = (adjust_result_of_qualified_name_lookup
1827 (expr, dtor_type, object_type));
1831 /* This function is called by the parser to process a class member
1832 access expression of the form OBJECT.NAME. NAME is a node used by
1833 the parser to represent a name; it is not yet a DECL. It may,
1834 however, be a BASELINK where the BASELINK_FUNCTIONS is a
1835 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
1836 there is no reason to do the lookup twice, so the parser keeps the
1840 finish_class_member_access_expr (tree object, tree name)
1845 tree access_path = NULL_TREE;
1846 tree orig_object = object;
1847 tree orig_name = name;
1849 if (object == error_mark_node || name == error_mark_node)
1850 return error_mark_node;
1852 object_type = TREE_TYPE (object);
1854 if (processing_template_decl)
1856 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
1857 dependent_type_p (object_type)
1858 /* If NAME is just an IDENTIFIER_NODE, then the expression
1860 || TREE_CODE (object) == IDENTIFIER_NODE
1861 /* If NAME is "f<args>", where either 'f' or 'args' is
1862 dependent, then the expression is dependent. */
1863 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
1864 && dependent_template_id_p (TREE_OPERAND (name, 0),
1865 TREE_OPERAND (name, 1)))
1866 /* If NAME is "T::X" where "T" is dependent, then the
1867 expression is dependent. */
1868 || (TREE_CODE (name) == SCOPE_REF
1869 && TYPE_P (TREE_OPERAND (name, 0))
1870 && dependent_type_p (TREE_OPERAND (name, 0))))
1871 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
1872 object = build_non_dependent_expr (object);
1877 The type of the first expression shall be "class object" (of a
1879 if (!currently_open_class (object_type)
1880 && !complete_type_or_else (object_type, object))
1881 return error_mark_node;
1882 if (!CLASS_TYPE_P (object_type))
1884 error ("request for member %qD in %qE, which is of non-class type %qT",
1885 name, object, object_type);
1886 return error_mark_node;
1889 if (BASELINK_P (name))
1891 /* A member function that has already been looked up. */
1892 gcc_assert (TREE_CODE (BASELINK_FUNCTIONS (name)) == TEMPLATE_ID_EXPR);
1897 bool is_template_id = false;
1898 tree template_args = NULL_TREE;
1901 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
1903 is_template_id = true;
1904 template_args = TREE_OPERAND (name, 1);
1905 name = TREE_OPERAND (name, 0);
1907 if (TREE_CODE (name) == OVERLOAD)
1908 name = DECL_NAME (get_first_fn (name));
1909 else if (DECL_P (name))
1910 name = DECL_NAME (name);
1913 if (TREE_CODE (name) == SCOPE_REF)
1915 /* A qualified name. The qualifying class or namespace `S' has
1916 already been looked up; it is either a TYPE or a
1917 NAMESPACE_DECL. The member name is either an IDENTIFIER_NODE
1918 or a BIT_NOT_EXPR. */
1919 scope = TREE_OPERAND (name, 0);
1920 name = TREE_OPERAND (name, 1);
1921 gcc_assert (CLASS_TYPE_P (scope)
1922 || TREE_CODE (scope) == NAMESPACE_DECL);
1923 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
1924 || TREE_CODE (name) == BIT_NOT_EXPR);
1926 /* If SCOPE is a namespace, then the qualified name does not
1927 name a member of OBJECT_TYPE. */
1928 if (TREE_CODE (scope) == NAMESPACE_DECL)
1930 error ("%<%D::%D%> is not a member of %qT",
1931 scope, name, object_type);
1932 return error_mark_node;
1935 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
1936 access_path = lookup_base (object_type, scope, ba_check, NULL);
1937 if (access_path == error_mark_node)
1938 return error_mark_node;
1941 error ("%qT is not a base of %qT", scope, object_type);
1942 return error_mark_node;
1948 access_path = object_type;
1951 if (TREE_CODE (name) == BIT_NOT_EXPR)
1952 member = lookup_destructor (object, scope, name);
1955 /* Look up the member. */
1956 member = lookup_member (access_path, name, /*protect=*/1,
1957 /*want_type=*/false);
1958 if (member == NULL_TREE)
1960 error ("%qD has no member named %qE", object_type, name);
1961 return error_mark_node;
1963 if (member == error_mark_node)
1964 return error_mark_node;
1969 tree template = member;
1971 if (BASELINK_P (template))
1972 template = lookup_template_function (template, template_args);
1975 error ("%qD is not a member template function", name);
1976 return error_mark_node;
1981 if (TREE_DEPRECATED (member))
1982 warn_deprecated_use (member);
1984 expr = build_class_member_access_expr (object, member, access_path,
1985 /*preserve_reference=*/false);
1986 if (processing_template_decl && expr != error_mark_node)
1987 return build_min_non_dep (COMPONENT_REF, expr,
1988 orig_object, orig_name, NULL_TREE);
1992 /* Return an expression for the MEMBER_NAME field in the internal
1993 representation of PTRMEM, a pointer-to-member function. (Each
1994 pointer-to-member function type gets its own RECORD_TYPE so it is
1995 more convenient to access the fields by name than by FIELD_DECL.)
1996 This routine converts the NAME to a FIELD_DECL and then creates the
1997 node for the complete expression. */
2000 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2006 /* This code is a stripped down version of
2007 build_class_member_access_expr. It does not work to use that
2008 routine directly because it expects the object to be of class
2010 ptrmem_type = TREE_TYPE (ptrmem);
2011 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2012 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2013 /*want_type=*/false);
2014 member_type = cp_build_qualified_type (TREE_TYPE (member),
2015 cp_type_quals (ptrmem_type));
2016 return fold_build3 (COMPONENT_REF, member_type,
2017 ptrmem, member, NULL_TREE);
2020 /* Given an expression PTR for a pointer, return an expression
2021 for the value pointed to.
2022 ERRORSTRING is the name of the operator to appear in error messages.
2024 This function may need to overload OPERATOR_FNNAME.
2025 Must also handle REFERENCE_TYPEs for C++. */
2028 build_x_indirect_ref (tree expr, const char *errorstring)
2030 tree orig_expr = expr;
2033 if (processing_template_decl)
2035 if (type_dependent_expression_p (expr))
2036 return build_min_nt (INDIRECT_REF, expr);
2037 expr = build_non_dependent_expr (expr);
2040 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2041 NULL_TREE, /*overloaded_p=*/NULL);
2043 rval = build_indirect_ref (expr, errorstring);
2045 if (processing_template_decl && rval != error_mark_node)
2046 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2052 build_indirect_ref (tree ptr, const char *errorstring)
2056 if (ptr == error_mark_node)
2057 return error_mark_node;
2059 if (ptr == current_class_ptr)
2060 return current_class_ref;
2062 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2063 ? ptr : decay_conversion (ptr));
2064 type = TREE_TYPE (pointer);
2066 if (POINTER_TYPE_P (type))
2070 If the type of the expression is "pointer to T," the type
2071 of the result is "T."
2073 We must use the canonical variant because certain parts of
2074 the back end, like fold, do pointer comparisons between
2076 tree t = canonical_type_variant (TREE_TYPE (type));
2078 if (VOID_TYPE_P (t))
2080 /* A pointer to incomplete type (other than cv void) can be
2081 dereferenced [expr.unary.op]/1 */
2082 error ("%qT is not a pointer-to-object type", type);
2083 return error_mark_node;
2085 else if (TREE_CODE (pointer) == ADDR_EXPR
2086 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2087 /* The POINTER was something like `&x'. We simplify `*&x' to
2089 return TREE_OPERAND (pointer, 0);
2092 tree ref = build1 (INDIRECT_REF, t, pointer);
2094 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2095 so that we get the proper error message if the result is used
2096 to assign to. Also, &* is supposed to be a no-op. */
2097 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2098 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2099 TREE_SIDE_EFFECTS (ref)
2100 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2104 /* `pointer' won't be an error_mark_node if we were given a
2105 pointer to member, so it's cool to check for this here. */
2106 else if (TYPE_PTR_TO_MEMBER_P (type))
2107 error ("invalid use of %qs on pointer to member", errorstring);
2108 else if (pointer != error_mark_node)
2111 error ("invalid type argument of %qs", errorstring);
2113 error ("invalid type argument");
2115 return error_mark_node;
2118 /* This handles expressions of the form "a[i]", which denotes
2121 This is logically equivalent in C to *(a+i), but we may do it differently.
2122 If A is a variable or a member, we generate a primitive ARRAY_REF.
2123 This avoids forcing the array out of registers, and can work on
2124 arrays that are not lvalues (for example, members of structures returned
2127 If INDEX is of some user-defined type, it must be converted to
2128 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2129 will inherit the type of the array, which will be some pointer type. */
2132 build_array_ref (tree array, tree idx)
2136 error ("subscript missing in array reference");
2137 return error_mark_node;
2140 if (TREE_TYPE (array) == error_mark_node
2141 || TREE_TYPE (idx) == error_mark_node)
2142 return error_mark_node;
2144 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2146 switch (TREE_CODE (array))
2150 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2151 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2152 TREE_OPERAND (array, 0), value);
2156 return build_conditional_expr
2157 (TREE_OPERAND (array, 0),
2158 build_array_ref (TREE_OPERAND (array, 1), idx),
2159 build_array_ref (TREE_OPERAND (array, 2), idx));
2165 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2169 /* Subscripting with type char is likely to lose
2170 on a machine where chars are signed.
2171 So warn on any machine, but optionally.
2172 Don't warn for unsigned char since that type is safe.
2173 Don't warn for signed char because anyone who uses that
2174 must have done so deliberately. */
2175 if (warn_char_subscripts
2176 && TYPE_MAIN_VARIANT (TREE_TYPE (idx)) == char_type_node)
2177 warning (0, "array subscript has type %<char%>");
2179 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2181 error ("array subscript is not an integer");
2182 return error_mark_node;
2185 /* Apply integral promotions *after* noticing character types.
2186 (It is unclear why we do these promotions -- the standard
2187 does not say that we should. In fact, the natural thing would
2188 seem to be to convert IDX to ptrdiff_t; we're performing
2189 pointer arithmetic.) */
2190 idx = perform_integral_promotions (idx);
2192 /* An array that is indexed by a non-constant
2193 cannot be stored in a register; we must be able to do
2194 address arithmetic on its address.
2195 Likewise an array of elements of variable size. */
2196 if (TREE_CODE (idx) != INTEGER_CST
2197 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2198 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2201 if (!cxx_mark_addressable (array))
2202 return error_mark_node;
2205 /* An array that is indexed by a constant value which is not within
2206 the array bounds cannot be stored in a register either; because we
2207 would get a crash in store_bit_field/extract_bit_field when trying
2208 to access a non-existent part of the register. */
2209 if (TREE_CODE (idx) == INTEGER_CST
2210 && TYPE_DOMAIN (TREE_TYPE (array))
2211 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2213 if (!cxx_mark_addressable (array))
2214 return error_mark_node;
2217 if (pedantic && !lvalue_p (array))
2218 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2220 /* Note in C++ it is valid to subscript a `register' array, since
2221 it is valid to take the address of something with that
2222 storage specification. */
2226 while (TREE_CODE (foo) == COMPONENT_REF)
2227 foo = TREE_OPERAND (foo, 0);
2228 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2229 warning (0, "subscripting array declared %<register%>");
2232 type = TREE_TYPE (TREE_TYPE (array));
2233 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2234 /* Array ref is const/volatile if the array elements are
2235 or if the array is.. */
2236 TREE_READONLY (rval)
2237 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2238 TREE_SIDE_EFFECTS (rval)
2239 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2240 TREE_THIS_VOLATILE (rval)
2241 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2242 return require_complete_type (fold_if_not_in_template (rval));
2246 tree ar = default_conversion (array);
2247 tree ind = default_conversion (idx);
2249 /* Put the integer in IND to simplify error checking. */
2250 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2257 if (ar == error_mark_node)
2260 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2262 error ("subscripted value is neither array nor pointer");
2263 return error_mark_node;
2265 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2267 error ("array subscript is not an integer");
2268 return error_mark_node;
2271 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2276 /* Resolve a pointer to member function. INSTANCE is the object
2277 instance to use, if the member points to a virtual member.
2279 This used to avoid checking for virtual functions if basetype
2280 has no virtual functions, according to an earlier ANSI draft.
2281 With the final ISO C++ rules, such an optimization is
2282 incorrect: A pointer to a derived member can be static_cast
2283 to pointer-to-base-member, as long as the dynamic object
2284 later has the right member. */
2287 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2289 if (TREE_CODE (function) == OFFSET_REF)
2290 function = TREE_OPERAND (function, 1);
2292 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2294 tree idx, delta, e1, e2, e3, vtbl, basetype;
2295 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2297 tree instance_ptr = *instance_ptrptr;
2298 tree instance_save_expr = 0;
2299 if (instance_ptr == error_mark_node)
2301 if (TREE_CODE (function) == PTRMEM_CST)
2303 /* Extracting the function address from a pmf is only
2304 allowed with -Wno-pmf-conversions. It only works for
2306 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2307 e1 = convert (fntype, e1);
2312 error ("object missing in use of %qE", function);
2313 return error_mark_node;
2317 if (TREE_SIDE_EFFECTS (instance_ptr))
2318 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2320 if (TREE_SIDE_EFFECTS (function))
2321 function = save_expr (function);
2323 /* Start by extracting all the information from the PMF itself. */
2324 e3 = pfn_from_ptrmemfunc (function);
2325 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2326 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2327 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2329 case ptrmemfunc_vbit_in_pfn:
2330 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2331 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2334 case ptrmemfunc_vbit_in_delta:
2335 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2336 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2343 /* Convert down to the right base before using the instance. First
2345 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2346 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2347 basetype, ba_check, NULL);
2348 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype, 1);
2349 if (instance_ptr == error_mark_node)
2350 return error_mark_node;
2351 /* ...and then the delta in the PMF. */
2352 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2353 instance_ptr, delta);
2355 /* Hand back the adjusted 'this' argument to our caller. */
2356 *instance_ptrptr = instance_ptr;
2358 /* Next extract the vtable pointer from the object. */
2359 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2361 vtbl = build_indirect_ref (vtbl, NULL);
2363 /* Finally, extract the function pointer from the vtable. */
2364 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2365 e2 = build_indirect_ref (e2, NULL);
2366 TREE_CONSTANT (e2) = 1;
2367 TREE_INVARIANT (e2) = 1;
2369 /* When using function descriptors, the address of the
2370 vtable entry is treated as a function pointer. */
2371 if (TARGET_VTABLE_USES_DESCRIPTORS)
2372 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2373 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2375 TREE_TYPE (e2) = TREE_TYPE (e3);
2376 e1 = build_conditional_expr (e1, e2, e3);
2378 /* Make sure this doesn't get evaluated first inside one of the
2379 branches of the COND_EXPR. */
2380 if (instance_save_expr)
2381 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2382 instance_save_expr, e1);
2390 build_function_call (tree function, tree params)
2392 tree fntype, fndecl;
2393 tree coerced_params;
2394 tree name = NULL_TREE;
2396 tree original = function;
2398 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2399 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2400 if (TREE_CODE (function) == NOP_EXPR
2401 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2402 function = TREE_OPERAND (function, 0);
2404 if (TREE_CODE (function) == FUNCTION_DECL)
2406 name = DECL_NAME (function);
2408 mark_used (function);
2411 /* Convert anything with function type to a pointer-to-function. */
2412 if (pedantic && DECL_MAIN_P (function))
2413 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2415 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2416 (because calling an inline function does not mean the function
2417 needs to be separately compiled). */
2419 if (DECL_INLINE (function))
2420 function = inline_conversion (function);
2422 function = build_addr_func (function);
2428 function = build_addr_func (function);
2431 if (function == error_mark_node)
2432 return error_mark_node;
2434 fntype = TREE_TYPE (function);
2436 if (TYPE_PTRMEMFUNC_P (fntype))
2438 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2439 "function in %<%E (...)%>",
2441 return error_mark_node;
2444 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2445 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2447 if (!((TREE_CODE (fntype) == POINTER_TYPE
2448 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2450 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2452 error ("%qE cannot be used as a function", original);
2453 return error_mark_node;
2456 /* fntype now gets the type of function pointed to. */
2457 fntype = TREE_TYPE (fntype);
2459 /* Convert the parameters to the types declared in the
2460 function prototype, or apply default promotions. */
2462 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2463 params, fndecl, LOOKUP_NORMAL);
2464 if (coerced_params == error_mark_node)
2465 return error_mark_node;
2467 /* Check for errors in format strings and inappropriately
2470 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params);
2472 return build_cxx_call (function, coerced_params);
2475 /* Convert the actual parameter expressions in the list VALUES
2476 to the types in the list TYPELIST.
2477 If parmdecls is exhausted, or when an element has NULL as its type,
2478 perform the default conversions.
2480 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2482 This is also where warnings about wrong number of args are generated.
2484 Return a list of expressions for the parameters as converted.
2486 Both VALUES and the returned value are chains of TREE_LIST nodes
2487 with the elements of the list in the TREE_VALUE slots of those nodes.
2489 In C++, unspecified trailing parameters can be filled in with their
2490 default arguments, if such were specified. Do so here. */
2493 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2495 tree typetail, valtail;
2496 tree result = NULL_TREE;
2497 const char *called_thing = 0;
2500 /* Argument passing is always copy-initialization. */
2501 flags |= LOOKUP_ONLYCONVERTING;
2505 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2507 if (DECL_NAME (fndecl) == NULL_TREE
2508 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2509 called_thing = "constructor";
2511 called_thing = "member function";
2514 called_thing = "function";
2517 for (valtail = values, typetail = typelist;
2519 valtail = TREE_CHAIN (valtail), i++)
2521 tree type = typetail ? TREE_VALUE (typetail) : 0;
2522 tree val = TREE_VALUE (valtail);
2524 if (val == error_mark_node)
2525 return error_mark_node;
2527 if (type == void_type_node)
2531 cp_error_at ("too many arguments to %s %q+#D", called_thing,
2533 error ("at this point in file");
2536 error ("too many arguments to function");
2537 /* In case anybody wants to know if this argument
2540 TREE_TYPE (tree_last (result)) = error_mark_node;
2544 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2545 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2546 if (TREE_CODE (val) == NOP_EXPR
2547 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2548 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2549 val = TREE_OPERAND (val, 0);
2551 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2553 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2554 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2555 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2556 val = decay_conversion (val);
2559 if (val == error_mark_node)
2560 return error_mark_node;
2564 /* Formal parm type is specified by a function prototype. */
2567 if (!COMPLETE_TYPE_P (complete_type (type)))
2570 error ("parameter %P of %qD has incomplete type %qT",
2573 error ("parameter %P has incomplete type %qT", i, type);
2574 parmval = error_mark_node;
2578 parmval = convert_for_initialization
2579 (NULL_TREE, type, val, flags,
2580 "argument passing", fndecl, i);
2581 parmval = convert_for_arg_passing (type, parmval);
2584 if (parmval == error_mark_node)
2585 return error_mark_node;
2587 result = tree_cons (NULL_TREE, parmval, result);
2591 if (fndecl && DECL_BUILT_IN (fndecl)
2592 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2593 /* Don't do ellipsis conversion for __built_in_constant_p
2594 as this will result in spurious warnings for non-POD
2596 val = require_complete_type (val);
2598 val = convert_arg_to_ellipsis (val);
2600 result = tree_cons (NULL_TREE, val, result);
2604 typetail = TREE_CHAIN (typetail);
2607 if (typetail != 0 && typetail != void_list_node)
2609 /* See if there are default arguments that can be used. */
2610 if (TREE_PURPOSE (typetail)
2611 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2613 for (; typetail != void_list_node; ++i)
2616 = convert_default_arg (TREE_VALUE (typetail),
2617 TREE_PURPOSE (typetail),
2620 if (parmval == error_mark_node)
2621 return error_mark_node;
2623 result = tree_cons (0, parmval, result);
2624 typetail = TREE_CHAIN (typetail);
2625 /* ends with `...'. */
2626 if (typetail == NULL_TREE)
2634 cp_error_at ("too few arguments to %s %q+#D",
2635 called_thing, fndecl);
2636 error ("at this point in file");
2639 error ("too few arguments to function");
2640 return error_mark_list;
2644 return nreverse (result);
2647 /* Build a binary-operation expression, after performing default
2648 conversions on the operands. CODE is the kind of expression to build. */
2651 build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
2661 if (processing_template_decl)
2663 if (type_dependent_expression_p (arg1)
2664 || type_dependent_expression_p (arg2))
2665 return build_min_nt (code, arg1, arg2);
2666 arg1 = build_non_dependent_expr (arg1);
2667 arg2 = build_non_dependent_expr (arg2);
2670 if (code == DOTSTAR_EXPR)
2671 expr = build_m_component_ref (arg1, arg2);
2673 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2676 if (processing_template_decl && expr != error_mark_node)
2677 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2682 /* Build a binary-operation expression without default conversions.
2683 CODE is the kind of expression to build.
2684 This function differs from `build' in several ways:
2685 the data type of the result is computed and recorded in it,
2686 warnings are generated if arg data types are invalid,
2687 special handling for addition and subtraction of pointers is known,
2688 and some optimization is done (operations on narrow ints
2689 are done in the narrower type when that gives the same result).
2690 Constant folding is also done before the result is returned.
2692 Note that the operands will never have enumeral types
2693 because either they have just had the default conversions performed
2694 or they have both just been converted to some other type in which
2695 the arithmetic is to be done.
2697 C++: must do special pointer arithmetic when implementing
2698 multiple inheritance, and deal with pointer to member functions. */
2701 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2702 int convert_p ATTRIBUTE_UNUSED)
2705 enum tree_code code0, code1;
2708 /* Expression code to give to the expression when it is built.
2709 Normally this is CODE, which is what the caller asked for,
2710 but in some special cases we change it. */
2711 enum tree_code resultcode = code;
2713 /* Data type in which the computation is to be performed.
2714 In the simplest cases this is the common type of the arguments. */
2715 tree result_type = NULL;
2717 /* Nonzero means operands have already been type-converted
2718 in whatever way is necessary.
2719 Zero means they need to be converted to RESULT_TYPE. */
2722 /* Nonzero means create the expression with this type, rather than
2724 tree build_type = 0;
2726 /* Nonzero means after finally constructing the expression
2727 convert it to this type. */
2728 tree final_type = 0;
2732 /* Nonzero if this is an operation like MIN or MAX which can
2733 safely be computed in short if both args are promoted shorts.
2734 Also implies COMMON.
2735 -1 indicates a bitwise operation; this makes a difference
2736 in the exact conditions for when it is safe to do the operation
2737 in a narrower mode. */
2740 /* Nonzero if this is a comparison operation;
2741 if both args are promoted shorts, compare the original shorts.
2742 Also implies COMMON. */
2743 int short_compare = 0;
2745 /* Nonzero if this is a right-shift operation, which can be computed on the
2746 original short and then promoted if the operand is a promoted short. */
2747 int short_shift = 0;
2749 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2752 /* True if both operands have arithmetic type. */
2753 bool arithmetic_types_p;
2755 /* Apply default conversions. */
2759 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2760 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2761 || code == TRUTH_XOR_EXPR)
2763 if (!really_overloaded_fn (op0))
2764 op0 = decay_conversion (op0);
2765 if (!really_overloaded_fn (op1))
2766 op1 = decay_conversion (op1);
2770 if (!really_overloaded_fn (op0))
2771 op0 = default_conversion (op0);
2772 if (!really_overloaded_fn (op1))
2773 op1 = default_conversion (op1);
2776 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2777 STRIP_TYPE_NOPS (op0);
2778 STRIP_TYPE_NOPS (op1);
2780 /* DTRT if one side is an overloaded function, but complain about it. */
2781 if (type_unknown_p (op0))
2783 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
2784 if (t != error_mark_node)
2786 pedwarn ("assuming cast to type %qT from overloaded function",
2791 if (type_unknown_p (op1))
2793 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
2794 if (t != error_mark_node)
2796 pedwarn ("assuming cast to type %qT from overloaded function",
2802 type0 = TREE_TYPE (op0);
2803 type1 = TREE_TYPE (op1);
2805 /* The expression codes of the data types of the arguments tell us
2806 whether the arguments are integers, floating, pointers, etc. */
2807 code0 = TREE_CODE (type0);
2808 code1 = TREE_CODE (type1);
2810 /* If an error was already reported for one of the arguments,
2811 avoid reporting another error. */
2813 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
2814 return error_mark_node;
2819 /* Handle the pointer + int case. */
2820 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2821 return cp_pointer_int_sum (PLUS_EXPR, op0, op1);
2822 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
2823 return cp_pointer_int_sum (PLUS_EXPR, op1, op0);
2829 /* Subtraction of two similar pointers.
2830 We must subtract them as integers, then divide by object size. */
2831 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
2832 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
2834 return pointer_diff (op0, op1, common_type (type0, type1));
2835 /* Handle pointer minus int. Just like pointer plus int. */
2836 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2837 return cp_pointer_int_sum (MINUS_EXPR, op0, op1);
2846 case TRUNC_DIV_EXPR:
2848 case FLOOR_DIV_EXPR:
2849 case ROUND_DIV_EXPR:
2850 case EXACT_DIV_EXPR:
2851 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2852 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2853 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2854 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
2856 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
2857 warning (0, "division by zero in %<%E / 0%>", op0);
2858 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
2859 warning (0, "division by zero in %<%E / 0.%>", op0);
2861 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2862 code0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
2863 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
2864 code1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
2866 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
2867 resultcode = RDIV_EXPR;
2869 /* When dividing two signed integers, we have to promote to int.
2870 unless we divide by a constant != -1. Note that default
2871 conversion will have been performed on the operands at this
2872 point, so we have to dig out the original type to find out if
2874 shorten = ((TREE_CODE (op0) == NOP_EXPR
2875 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2876 || (TREE_CODE (op1) == INTEGER_CST
2877 && ! integer_all_onesp (op1)));
2886 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2890 case TRUNC_MOD_EXPR:
2891 case FLOOR_MOD_EXPR:
2892 if (code1 == INTEGER_TYPE && integer_zerop (op1))
2893 warning (0, "division by zero in %<%E %% 0%>", op0);
2894 else if (code1 == REAL_TYPE && real_zerop (op1))
2895 warning (0, "division by zero in %<%E %% 0.%>", op0);
2897 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2899 /* Although it would be tempting to shorten always here, that loses
2900 on some targets, since the modulo instruction is undefined if the
2901 quotient can't be represented in the computation mode. We shorten
2902 only if unsigned or if dividing by something we know != -1. */
2903 shorten = ((TREE_CODE (op0) == NOP_EXPR
2904 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2905 || (TREE_CODE (op1) == INTEGER_CST
2906 && ! integer_all_onesp (op1)));
2911 case TRUTH_ANDIF_EXPR:
2912 case TRUTH_ORIF_EXPR:
2913 case TRUTH_AND_EXPR:
2915 result_type = boolean_type_node;
2918 /* Shift operations: result has same type as first operand;
2919 always convert second operand to int.
2920 Also set SHORT_SHIFT if shifting rightward. */
2923 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2925 result_type = type0;
2926 if (TREE_CODE (op1) == INTEGER_CST)
2928 if (tree_int_cst_lt (op1, integer_zero_node))
2929 warning (0, "right shift count is negative");
2932 if (! integer_zerop (op1))
2934 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2935 warning (0, "right shift count >= width of type");
2938 /* Convert the shift-count to an integer, regardless of
2939 size of value being shifted. */
2940 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2941 op1 = cp_convert (integer_type_node, op1);
2942 /* Avoid converting op1 to result_type later. */
2948 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2950 result_type = type0;
2951 if (TREE_CODE (op1) == INTEGER_CST)
2953 if (tree_int_cst_lt (op1, integer_zero_node))
2954 warning (0, "left shift count is negative");
2955 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2956 warning (0, "left shift count >= width of type");
2958 /* Convert the shift-count to an integer, regardless of
2959 size of value being shifted. */
2960 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2961 op1 = cp_convert (integer_type_node, op1);
2962 /* Avoid converting op1 to result_type later. */
2969 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2971 result_type = type0;
2972 if (TREE_CODE (op1) == INTEGER_CST)
2974 if (tree_int_cst_lt (op1, integer_zero_node))
2975 warning (0, "%s rotate count is negative",
2976 (code == LROTATE_EXPR) ? "left" : "right");
2977 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2978 warning (0, "%s rotate count >= width of type",
2979 (code == LROTATE_EXPR) ? "left" : "right");
2981 /* Convert the shift-count to an integer, regardless of
2982 size of value being shifted. */
2983 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2984 op1 = cp_convert (integer_type_node, op1);
2990 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
2991 warning (0, "comparing floating point with == or != is unsafe");
2993 build_type = boolean_type_node;
2994 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2995 || code0 == COMPLEX_TYPE)
2996 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2997 || code1 == COMPLEX_TYPE))
2999 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3000 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3001 result_type = composite_pointer_type (type0, type1, op0, op1,
3003 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3004 && null_ptr_cst_p (op1))
3005 result_type = type0;
3006 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3007 && null_ptr_cst_p (op0))
3008 result_type = type1;
3009 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3011 result_type = type0;
3012 error ("ISO C++ forbids comparison between pointer and integer");
3014 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3016 result_type = type1;
3017 error ("ISO C++ forbids comparison between pointer and integer");
3019 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3021 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3022 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3023 result_type = TREE_TYPE (op0);
3025 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3026 return cp_build_binary_op (code, op1, op0);
3027 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3028 && same_type_p (type0, type1))
3030 /* E will be the final comparison. */
3032 /* E1 and E2 are for scratch. */
3040 if (TREE_SIDE_EFFECTS (op0))
3041 op0 = save_expr (op0);
3042 if (TREE_SIDE_EFFECTS (op1))
3043 op1 = save_expr (op1);
3048 && (!op0.pfn || op0.delta == op1.delta))
3050 The reason for the `!op0.pfn' bit is that a NULL
3051 pointer-to-member is any member with a zero PFN; the
3052 DELTA field is unspecified. */
3053 pfn0 = pfn_from_ptrmemfunc (op0);
3054 pfn1 = pfn_from_ptrmemfunc (op1);
3055 delta0 = build_ptrmemfunc_access_expr (op0,
3057 delta1 = build_ptrmemfunc_access_expr (op1,
3059 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3060 e2 = cp_build_binary_op (EQ_EXPR,
3062 cp_convert (TREE_TYPE (pfn0),
3063 integer_zero_node));
3064 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3065 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3066 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3067 if (code == EQ_EXPR)
3069 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3073 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3074 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3076 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3077 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3085 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3086 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3088 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3089 result_type = composite_pointer_type (type0, type1, op0, op1,
3097 build_type = boolean_type_node;
3098 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3099 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3101 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3102 result_type = composite_pointer_type (type0, type1, op0, op1,
3104 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3105 && integer_zerop (op1))
3106 result_type = type0;
3107 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3108 && integer_zerop (op0))
3109 result_type = type1;
3110 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3112 result_type = type0;
3113 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3115 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3117 result_type = type1;
3118 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3122 case UNORDERED_EXPR:
3129 build_type = integer_type_node;
3130 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3132 error ("unordered comparison on non-floating point argument");
3133 return error_mark_node;
3142 arithmetic_types_p =
3143 ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3144 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3145 || code1 == COMPLEX_TYPE));
3146 /* Determine the RESULT_TYPE, if it is not already known. */
3148 && arithmetic_types_p
3149 && (shorten || common || short_compare))
3150 result_type = common_type (type0, type1);
3154 error ("invalid operands of types %qT and %qT to binary %qO",
3155 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3156 return error_mark_node;
3159 /* If we're in a template, the only thing we need to know is the
3161 if (processing_template_decl)
3162 return build2 (resultcode,
3163 build_type ? build_type : result_type,
3166 if (arithmetic_types_p)
3168 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3170 /* For certain operations (which identify themselves by shorten != 0)
3171 if both args were extended from the same smaller type,
3172 do the arithmetic in that type and then extend.
3174 shorten !=0 and !=1 indicates a bitwise operation.
3175 For them, this optimization is safe only if
3176 both args are zero-extended or both are sign-extended.
3177 Otherwise, we might change the result.
3178 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3179 but calculated in (unsigned short) it would be (unsigned short)-1. */
3181 if (shorten && none_complex)
3183 int unsigned0, unsigned1;
3184 tree arg0 = get_narrower (op0, &unsigned0);
3185 tree arg1 = get_narrower (op1, &unsigned1);
3186 /* UNS is 1 if the operation to be done is an unsigned one. */
3187 int uns = TYPE_UNSIGNED (result_type);
3190 final_type = result_type;
3192 /* Handle the case that OP0 does not *contain* a conversion
3193 but it *requires* conversion to FINAL_TYPE. */
3195 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3196 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3197 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3198 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3200 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3202 /* For bitwise operations, signedness of nominal type
3203 does not matter. Consider only how operands were extended. */
3207 /* Note that in all three cases below we refrain from optimizing
3208 an unsigned operation on sign-extended args.
3209 That would not be valid. */
3211 /* Both args variable: if both extended in same way
3212 from same width, do it in that width.
3213 Do it unsigned if args were zero-extended. */
3214 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3215 < TYPE_PRECISION (result_type))
3216 && (TYPE_PRECISION (TREE_TYPE (arg1))
3217 == TYPE_PRECISION (TREE_TYPE (arg0)))
3218 && unsigned0 == unsigned1
3219 && (unsigned0 || !uns))
3220 result_type = c_common_signed_or_unsigned_type
3221 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3222 else if (TREE_CODE (arg0) == INTEGER_CST
3223 && (unsigned1 || !uns)
3224 && (TYPE_PRECISION (TREE_TYPE (arg1))
3225 < TYPE_PRECISION (result_type))
3226 && (type = c_common_signed_or_unsigned_type
3227 (unsigned1, TREE_TYPE (arg1)),
3228 int_fits_type_p (arg0, type)))
3230 else if (TREE_CODE (arg1) == INTEGER_CST
3231 && (unsigned0 || !uns)
3232 && (TYPE_PRECISION (TREE_TYPE (arg0))
3233 < TYPE_PRECISION (result_type))
3234 && (type = c_common_signed_or_unsigned_type
3235 (unsigned0, TREE_TYPE (arg0)),
3236 int_fits_type_p (arg1, type)))
3240 /* Shifts can be shortened if shifting right. */
3245 tree arg0 = get_narrower (op0, &unsigned_arg);
3247 final_type = result_type;
3249 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3250 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3252 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3253 /* We can shorten only if the shift count is less than the
3254 number of bits in the smaller type size. */
3255 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3256 /* If arg is sign-extended and then unsigned-shifted,
3257 we can simulate this with a signed shift in arg's type
3258 only if the extended result is at least twice as wide
3259 as the arg. Otherwise, the shift could use up all the
3260 ones made by sign-extension and bring in zeros.
3261 We can't optimize that case at all, but in most machines
3262 it never happens because available widths are 2**N. */
3263 && (!TYPE_UNSIGNED (final_type)
3265 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3266 <= TYPE_PRECISION (result_type))))
3268 /* Do an unsigned shift if the operand was zero-extended. */
3270 = c_common_signed_or_unsigned_type (unsigned_arg,
3272 /* Convert value-to-be-shifted to that type. */
3273 if (TREE_TYPE (op0) != result_type)
3274 op0 = cp_convert (result_type, op0);
3279 /* Comparison operations are shortened too but differently.
3280 They identify themselves by setting short_compare = 1. */
3284 /* Don't write &op0, etc., because that would prevent op0
3285 from being kept in a register.
3286 Instead, make copies of the our local variables and
3287 pass the copies by reference, then copy them back afterward. */
3288 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3289 enum tree_code xresultcode = resultcode;
3291 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3293 return cp_convert (boolean_type_node, val);
3294 op0 = xop0, op1 = xop1;
3296 resultcode = xresultcode;
3299 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3300 && warn_sign_compare
3301 /* Do not warn until the template is instantiated; we cannot
3302 bound the ranges of the arguments until that point. */
3303 && !processing_template_decl)
3305 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3306 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3308 int unsignedp0, unsignedp1;
3309 tree primop0 = get_narrower (op0, &unsignedp0);
3310 tree primop1 = get_narrower (op1, &unsignedp1);
3312 /* Check for comparison of different enum types. */
3313 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3314 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3315 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3316 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3318 warning (0, "comparison between types %q#T and %q#T",
3319 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3322 /* Give warnings for comparisons between signed and unsigned
3323 quantities that may fail. */
3324 /* Do the checking based on the original operand trees, so that
3325 casts will be considered, but default promotions won't be. */
3327 /* Do not warn if the comparison is being done in a signed type,
3328 since the signed type will only be chosen if it can represent
3329 all the values of the unsigned type. */
3330 if (!TYPE_UNSIGNED (result_type))
3332 /* Do not warn if both operands are unsigned. */
3333 else if (op0_signed == op1_signed)
3335 /* Do not warn if the signed quantity is an unsuffixed
3336 integer literal (or some static constant expression
3337 involving such literals or a conditional expression
3338 involving such literals) and it is non-negative. */
3339 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3340 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3342 /* Do not warn if the comparison is an equality operation,
3343 the unsigned quantity is an integral constant and it does
3344 not use the most significant bit of result_type. */
3345 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3346 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3347 && int_fits_type_p (orig_op1, c_common_signed_type
3349 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3350 && int_fits_type_p (orig_op0, c_common_signed_type
3354 warning (0, "comparison between signed and unsigned integer expressions");
3356 /* Warn if two unsigned values are being compared in a size
3357 larger than their original size, and one (and only one) is the
3358 result of a `~' operator. This comparison will always fail.
3360 Also warn if one operand is a constant, and the constant does not
3361 have all bits set that are set in the ~ operand when it is
3364 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3365 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3367 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3368 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3369 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3370 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3372 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3375 HOST_WIDE_INT constant, mask;
3379 if (host_integerp (primop0, 0))
3382 unsignedp = unsignedp1;
3383 constant = tree_low_cst (primop0, 0);
3388 unsignedp = unsignedp0;
3389 constant = tree_low_cst (primop1, 0);
3392 bits = TYPE_PRECISION (TREE_TYPE (primop));
3393 if (bits < TYPE_PRECISION (result_type)
3394 && bits < HOST_BITS_PER_LONG && unsignedp)
3396 mask = (~ (HOST_WIDE_INT) 0) << bits;
3397 if ((mask & constant) != mask)
3398 warning (0, "comparison of promoted ~unsigned with constant");
3401 else if (unsignedp0 && unsignedp1
3402 && (TYPE_PRECISION (TREE_TYPE (primop0))
3403 < TYPE_PRECISION (result_type))
3404 && (TYPE_PRECISION (TREE_TYPE (primop1))
3405 < TYPE_PRECISION (result_type)))
3406 warning (0, "comparison of promoted ~unsigned with unsigned");
3411 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3412 Then the expression will be built.
3413 It will be given type FINAL_TYPE if that is nonzero;
3414 otherwise, it will be given type RESULT_TYPE. */
3416 /* Issue warnings about peculiar, but valid, uses of NULL. */
3417 if (/* It's reasonable to use pointer values as operands of &&
3418 and ||, so NULL is no exception. */
3419 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3420 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3421 (orig_op0 == null_node
3422 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3423 /* Or vice versa. */
3424 || (orig_op1 == null_node
3425 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3426 /* Or, both are NULL and the operation was not a comparison. */
3427 || (orig_op0 == null_node && orig_op1 == null_node
3428 && code != EQ_EXPR && code != NE_EXPR)))
3429 /* Some sort of arithmetic operation involving NULL was
3430 performed. Note that pointer-difference and pointer-addition
3431 have already been handled above, and so we don't end up here in
3433 warning (0, "NULL used in arithmetic");
3437 if (TREE_TYPE (op0) != result_type)
3438 op0 = cp_convert (result_type, op0);
3439 if (TREE_TYPE (op1) != result_type)
3440 op1 = cp_convert (result_type, op1);
3442 if (op0 == error_mark_node || op1 == error_mark_node)
3443 return error_mark_node;
3446 if (build_type == NULL_TREE)
3447 build_type = result_type;
3449 result = build2 (resultcode, build_type, op0, op1);
3450 result = fold_if_not_in_template (result);
3451 if (final_type != 0)
3452 result = cp_convert (final_type, result);
3456 /* Return a tree for the sum or difference (RESULTCODE says which)
3457 of pointer PTROP and integer INTOP. */
3460 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3462 tree res_type = TREE_TYPE (ptrop);
3464 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3465 in certain circumstance (when it's valid to do so). So we need
3466 to make sure it's complete. We don't need to check here, if we
3467 can actually complete it at all, as those checks will be done in
3468 pointer_int_sum() anyway. */
3469 complete_type (TREE_TYPE (res_type));
3471 return pointer_int_sum (resultcode, ptrop,
3472 fold_if_not_in_template (intop));
3475 /* Return a tree for the difference of pointers OP0 and OP1.
3476 The resulting tree has type int. */
3479 pointer_diff (tree op0, tree op1, tree ptrtype)
3482 tree restype = ptrdiff_type_node;
3483 tree target_type = TREE_TYPE (ptrtype);
3485 if (!complete_type_or_else (target_type, NULL_TREE))
3486 return error_mark_node;
3488 if (pedantic || warn_pointer_arith)
3490 if (TREE_CODE (target_type) == VOID_TYPE)
3491 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3492 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3493 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3494 if (TREE_CODE (target_type) == METHOD_TYPE)
3495 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3498 /* First do the subtraction as integers;
3499 then drop through to build the divide operator. */
3501 op0 = cp_build_binary_op (MINUS_EXPR,
3502 cp_convert (restype, op0),
3503 cp_convert (restype, op1));
3505 /* This generates an error if op1 is a pointer to an incomplete type. */
3506 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3507 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3509 op1 = (TYPE_PTROB_P (ptrtype)
3510 ? size_in_bytes (target_type)
3511 : integer_one_node);
3513 /* Do the division. */
3515 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3516 return fold_if_not_in_template (result);
3519 /* Construct and perhaps optimize a tree representation
3520 for a unary operation. CODE, a tree_code, specifies the operation
3521 and XARG is the operand. */
3524 build_x_unary_op (enum tree_code code, tree xarg)
3526 tree orig_expr = xarg;
3530 if (processing_template_decl)
3532 if (type_dependent_expression_p (xarg))
3533 return build_min_nt (code, xarg, NULL_TREE);
3535 xarg = build_non_dependent_expr (xarg);
3540 /* [expr.unary.op] says:
3542 The address of an object of incomplete type can be taken.
3544 (And is just the ordinary address operator, not an overloaded
3545 "operator &".) However, if the type is a template
3546 specialization, we must complete the type at this point so that
3547 an overloaded "operator &" will be available if required. */
3548 if (code == ADDR_EXPR
3549 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3550 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3551 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3552 || (TREE_CODE (xarg) == OFFSET_REF)))
3553 /* Don't look for a function. */;
3555 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3556 /*overloaded_p=*/NULL);
3557 if (!exp && code == ADDR_EXPR)
3559 /* A pointer to member-function can be formed only by saying
3561 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3562 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3564 if (TREE_CODE (xarg) != OFFSET_REF)
3566 error ("invalid use of %qE to form a pointer-to-member-function."
3567 " Use a qualified-id.",
3569 return error_mark_node;
3573 error ("parenthesis around %qE cannot be used to form a"
3574 " pointer-to-member-function",
3576 PTRMEM_OK_P (xarg) = 1;
3580 if (TREE_CODE (xarg) == OFFSET_REF)
3582 ptrmem = PTRMEM_OK_P (xarg);
3584 if (!ptrmem && !flag_ms_extensions
3585 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3587 /* A single non-static member, make sure we don't allow a
3588 pointer-to-member. */
3589 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3590 TREE_OPERAND (xarg, 0),
3591 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3592 PTRMEM_OK_P (xarg) = ptrmem;
3595 else if (TREE_CODE (xarg) == TARGET_EXPR)
3596 warning (0, "taking address of temporary");
3597 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3600 if (processing_template_decl && exp != error_mark_node)
3601 exp = build_min_non_dep (code, exp, orig_expr,
3602 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3603 if (TREE_CODE (exp) == ADDR_EXPR)
3604 PTRMEM_OK_P (exp) = ptrmem;
3608 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3609 constants, where a null value is represented by an INTEGER_CST of
3613 cp_truthvalue_conversion (tree expr)
3615 tree type = TREE_TYPE (expr);
3616 if (TYPE_PTRMEM_P (type))
3617 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3619 return c_common_truthvalue_conversion (expr);
3622 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3625 condition_conversion (tree expr)
3628 if (processing_template_decl)
3630 t = perform_implicit_conversion (boolean_type_node, expr);
3631 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3635 /* Return an ADDR_EXPR giving the address of T. This function
3636 attempts no optimizations or simplifications; it is a low-level
3640 build_address (tree t)
3644 if (error_operand_p (t) || !cxx_mark_addressable (t))
3645 return error_mark_node;
3647 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3652 /* Return a NOP_EXPR converting EXPR to TYPE. */
3655 build_nop (tree type, tree expr)
3657 if (type == error_mark_node || error_operand_p (expr))
3659 return build1 (NOP_EXPR, type, expr);
3662 /* C++: Must handle pointers to members.
3664 Perhaps type instantiation should be extended to handle conversion
3665 from aggregates to types we don't yet know we want? (Or are those
3666 cases typically errors which should be reported?)
3668 NOCONVERT nonzero suppresses the default promotions
3669 (such as from short to int). */
3672 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3674 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3677 const char *errstring = NULL;
3680 if (arg == error_mark_node)
3681 return error_mark_node;
3685 /* CONVERT_EXPR stands for unary plus in this context. */
3689 int flags = WANT_ARITH | WANT_ENUM;
3690 /* Unary plus (but not unary minus) is allowed on pointers. */
3691 if (code == CONVERT_EXPR)
3692 flags |= WANT_POINTER;
3693 arg = build_expr_type_conversion (flags, arg, true);
3695 errstring = (code == NEGATE_EXPR
3696 ? "wrong type argument to unary minus"
3697 : "wrong type argument to unary plus");
3700 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
3701 arg = perform_integral_promotions (arg);
3703 /* Make sure the result is not a lvalue: a unary plus or minus
3704 expression is always a rvalue. */
3705 if (real_lvalue_p (arg))
3706 arg = build1 (NON_LVALUE_EXPR, TREE_TYPE (arg), arg);
3712 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3716 arg = default_conversion (arg);
3718 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM,
3720 errstring = "wrong type argument to bit-complement";
3721 else if (!noconvert)
3722 arg = perform_integral_promotions (arg);
3726 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3727 errstring = "wrong type argument to abs";
3728 else if (!noconvert)
3729 arg = default_conversion (arg);
3733 /* Conjugating a real value is a no-op, but allow it anyway. */
3734 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3735 errstring = "wrong type argument to conjugation";
3736 else if (!noconvert)
3737 arg = default_conversion (arg);
3740 case TRUTH_NOT_EXPR:
3741 arg = perform_implicit_conversion (boolean_type_node, arg);
3742 val = invert_truthvalue (arg);
3743 if (arg != error_mark_node)
3745 errstring = "in argument to unary !";
3752 if (TREE_CODE (arg) == COMPLEX_CST)
3753 return TREE_REALPART (arg);
3754 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3756 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3757 return fold_if_not_in_template (arg);
3763 if (TREE_CODE (arg) == COMPLEX_CST)
3764 return TREE_IMAGPART (arg);
3765 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3767 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3768 return fold_if_not_in_template (arg);
3771 return cp_convert (TREE_TYPE (arg), integer_zero_node);
3773 case PREINCREMENT_EXPR:
3774 case POSTINCREMENT_EXPR:
3775 case PREDECREMENT_EXPR:
3776 case POSTDECREMENT_EXPR:
3777 /* Handle complex lvalues (when permitted)
3778 by reduction to simpler cases. */
3780 val = unary_complex_lvalue (code, arg);
3784 /* Increment or decrement the real part of the value,
3785 and don't change the imaginary part. */
3786 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3790 arg = stabilize_reference (arg);
3791 real = build_unary_op (REALPART_EXPR, arg, 1);
3792 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3793 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
3794 build_unary_op (code, real, 1), imag);
3797 /* Report invalid types. */
3799 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
3802 if (code == PREINCREMENT_EXPR)
3803 errstring ="no pre-increment operator for type";
3804 else if (code == POSTINCREMENT_EXPR)
3805 errstring ="no post-increment operator for type";
3806 else if (code == PREDECREMENT_EXPR)
3807 errstring ="no pre-decrement operator for type";
3809 errstring ="no post-decrement operator for type";
3813 /* Report something read-only. */
3815 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
3816 || TREE_READONLY (arg))
3817 readonly_error (arg, ((code == PREINCREMENT_EXPR
3818 || code == POSTINCREMENT_EXPR)
3819 ? "increment" : "decrement"),
3824 tree result_type = TREE_TYPE (arg);
3826 arg = get_unwidened (arg, 0);
3827 argtype = TREE_TYPE (arg);
3829 /* ARM $5.2.5 last annotation says this should be forbidden. */
3830 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
3831 pedwarn ("ISO C++ forbids %sing an enum",
3832 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3833 ? "increment" : "decrement");
3835 /* Compute the increment. */
3837 if (TREE_CODE (argtype) == POINTER_TYPE)
3839 tree type = complete_type (TREE_TYPE (argtype));
3841 if (!COMPLETE_OR_VOID_TYPE_P (type))
3842 error ("cannot %s a pointer to incomplete type %qT",
3843 ((code == PREINCREMENT_EXPR
3844 || code == POSTINCREMENT_EXPR)
3845 ? "increment" : "decrement"), TREE_TYPE (argtype));
3846 else if ((pedantic || warn_pointer_arith)
3847 && !TYPE_PTROB_P (argtype))
3848 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
3849 ((code == PREINCREMENT_EXPR
3850 || code == POSTINCREMENT_EXPR)
3851 ? "increment" : "decrement"), argtype);
3852 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
3855 inc = integer_one_node;
3857 inc = cp_convert (argtype, inc);
3859 /* Handle incrementing a cast-expression. */
3861 switch (TREE_CODE (arg))
3866 case FIX_TRUNC_EXPR:
3867 case FIX_FLOOR_EXPR:
3868 case FIX_ROUND_EXPR:
3871 tree incremented, modify, value, compound;
3872 if (! lvalue_p (arg) && pedantic)
3873 pedwarn ("cast to non-reference type used as lvalue");
3874 arg = stabilize_reference (arg);
3875 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
3878 value = save_expr (arg);
3879 incremented = build2 (((code == PREINCREMENT_EXPR
3880 || code == POSTINCREMENT_EXPR)
3881 ? PLUS_EXPR : MINUS_EXPR),
3882 argtype, value, inc);
3884 modify = build_modify_expr (arg, NOP_EXPR, incremented);
3885 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
3888 /* Eliminate warning about unused result of + or -. */
3889 TREE_NO_WARNING (compound) = 1;
3897 /* Complain about anything else that is not a true lvalue. */
3898 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3899 || code == POSTINCREMENT_EXPR)
3900 ? lv_increment : lv_decrement)))
3901 return error_mark_node;
3903 /* Forbid using -- on `bool'. */
3904 if (TREE_TYPE (arg) == boolean_type_node)
3906 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
3908 error ("invalid use of %<--%> on bool variable %qD", arg);
3909 return error_mark_node;
3911 val = boolean_increment (code, arg);
3914 val = build2 (code, TREE_TYPE (arg), arg, inc);
3916 TREE_SIDE_EFFECTS (val) = 1;
3917 return cp_convert (result_type, val);
3921 /* Note that this operation never does default_conversion
3922 regardless of NOCONVERT. */
3924 argtype = lvalue_type (arg);
3926 if (TREE_CODE (arg) == OFFSET_REF)
3929 if (TREE_CODE (argtype) == REFERENCE_TYPE)
3931 tree type = build_pointer_type (TREE_TYPE (argtype));
3932 arg = build1 (CONVERT_EXPR, type, arg);
3935 else if (pedantic && DECL_MAIN_P (arg))
3937 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
3939 /* Let &* cancel out to simplify resulting code. */
3940 if (TREE_CODE (arg) == INDIRECT_REF)
3942 /* We don't need to have `current_class_ptr' wrapped in a
3943 NON_LVALUE_EXPR node. */
3944 if (arg == current_class_ref)
3945 return current_class_ptr;
3947 arg = TREE_OPERAND (arg, 0);
3948 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
3950 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
3951 arg = build1 (CONVERT_EXPR, type, arg);
3953 else if (lvalue_p (arg))
3954 /* Don't let this be an lvalue. */
3955 return non_lvalue (arg);
3959 /* Uninstantiated types are all functions. Taking the
3960 address of a function is a no-op, so just return the
3963 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
3964 || !IDENTIFIER_OPNAME_P (arg));
3966 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
3967 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
3969 /* They're trying to take the address of a unique non-static
3970 member function. This is ill-formed (except in MS-land),
3971 but let's try to DTRT.
3972 Note: We only handle unique functions here because we don't
3973 want to complain if there's a static overload; non-unique
3974 cases will be handled by instantiate_type. But we need to
3975 handle this case here to allow casts on the resulting PMF.
3976 We could defer this in non-MS mode, but it's easier to give
3977 a useful error here. */
3979 /* Inside constant member functions, the `this' pointer
3980 contains an extra const qualifier. TYPE_MAIN_VARIANT
3981 is used here to remove this const from the diagnostics
3982 and the created OFFSET_REF. */
3983 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
3984 tree name = DECL_NAME (get_first_fn (TREE_OPERAND (arg, 1)));
3986 if (! flag_ms_extensions)
3988 if (current_class_type
3989 && TREE_OPERAND (arg, 0) == current_class_ref)
3990 /* An expression like &memfn. */
3991 pedwarn ("ISO C++ forbids taking the address of an unqualified"
3992 " or parenthesized non-static member function to form"
3993 " a pointer to member function. Say %<&%T::%D%>",
3996 pedwarn ("ISO C++ forbids taking the address of a bound member"
3997 " function to form a pointer to member function."
4001 arg = build_offset_ref (base, name, /*address_p=*/true);
4005 if (type_unknown_p (arg))
4006 return build1 (ADDR_EXPR, unknown_type_node, arg);
4008 /* Handle complex lvalues (when permitted)
4009 by reduction to simpler cases. */
4010 val = unary_complex_lvalue (code, arg);
4014 switch (TREE_CODE (arg))
4019 case FIX_TRUNC_EXPR:
4020 case FIX_FLOOR_EXPR:
4021 case FIX_ROUND_EXPR:
4023 if (! lvalue_p (arg) && pedantic)
4024 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4028 arg = OVL_CURRENT (arg);
4032 /* Turn a reference to a non-static data member into a
4033 pointer-to-member. */
4038 if (!PTRMEM_OK_P (arg))
4039 return build_unary_op (code, arg, 0);
4041 t = TREE_OPERAND (arg, 1);
4042 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4044 error ("cannot create pointer to reference member %qD", t);
4045 return error_mark_node;
4048 type = build_ptrmem_type (context_for_name_lookup (t),
4050 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4058 /* Allow the address of a constructor if all the elements
4060 if (TREE_CODE (arg) == CONSTRUCTOR && TREE_HAS_CONSTRUCTOR (arg)
4061 && TREE_CONSTANT (arg))
4063 /* Anything not already handled and not a true memory reference
4065 else if (TREE_CODE (argtype) != FUNCTION_TYPE
4066 && TREE_CODE (argtype) != METHOD_TYPE
4067 && TREE_CODE (arg) != OFFSET_REF
4068 && !lvalue_or_else (arg, lv_addressof))
4069 return error_mark_node;
4071 if (argtype != error_mark_node)
4072 argtype = build_pointer_type (argtype);
4077 if (TREE_CODE (arg) != COMPONENT_REF
4078 /* Inside a template, we are processing a non-dependent
4079 expression so we can just form an ADDR_EXPR with the
4081 || processing_template_decl)
4083 addr = build_address (arg);
4084 if (TREE_CODE (arg) == OFFSET_REF)
4085 PTRMEM_OK_P (addr) = PTRMEM_OK_P (arg);
4087 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4089 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4091 /* We can only get here with a single static member
4093 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4094 && DECL_STATIC_FUNCTION_P (fn));
4096 addr = build_address (fn);
4097 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4098 /* Do not lose object's side effects. */
4099 addr = build2 (COMPOUND_EXPR, TREE_TYPE (addr),
4100 TREE_OPERAND (arg, 0), addr);
4102 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4104 error ("attempt to take address of bit-field structure member %qD",
4105 TREE_OPERAND (arg, 1));
4106 return error_mark_node;
4110 tree object = TREE_OPERAND (arg, 0);
4111 tree field = TREE_OPERAND (arg, 1);
4112 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4113 (TREE_TYPE (object), decl_type_context (field)));
4114 addr = build_address (arg);
4117 if (TREE_CODE (argtype) == POINTER_TYPE
4118 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4120 build_ptrmemfunc_type (argtype);
4121 addr = build_ptrmemfunc (argtype, addr, 0,
4122 /*c_cast_p=*/false);
4135 argtype = TREE_TYPE (arg);
4136 return fold_if_not_in_template (build1 (code, argtype, arg));
4139 error ("%s", errstring);
4140 return error_mark_node;
4143 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4144 for certain kinds of expressions which are not really lvalues
4145 but which we can accept as lvalues.
4147 If ARG is not a kind of expression we can handle, return
4151 unary_complex_lvalue (enum tree_code code, tree arg)
4153 /* Inside a template, making these kinds of adjustments is
4154 pointless; we are only concerned with the type of the
4156 if (processing_template_decl)
4159 /* Handle (a, b) used as an "lvalue". */
4160 if (TREE_CODE (arg) == COMPOUND_EXPR)
4162 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4163 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4164 TREE_OPERAND (arg, 0), real_result);
4167 /* Handle (a ? b : c) used as an "lvalue". */
4168 if (TREE_CODE (arg) == COND_EXPR
4169 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4170 return rationalize_conditional_expr (code, arg);
4172 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4173 if (TREE_CODE (arg) == MODIFY_EXPR
4174 || TREE_CODE (arg) == PREINCREMENT_EXPR
4175 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4177 tree lvalue = TREE_OPERAND (arg, 0);
4178 if (TREE_SIDE_EFFECTS (lvalue))
4180 lvalue = stabilize_reference (lvalue);
4181 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4182 lvalue, TREE_OPERAND (arg, 1));
4184 return unary_complex_lvalue
4185 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4188 if (code != ADDR_EXPR)
4191 /* Handle (a = b) used as an "lvalue" for `&'. */
4192 if (TREE_CODE (arg) == MODIFY_EXPR
4193 || TREE_CODE (arg) == INIT_EXPR)
4195 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4196 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4198 TREE_NO_WARNING (arg) = 1;
4202 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4203 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4204 || TREE_CODE (arg) == OFFSET_REF)
4207 /* We permit compiler to make function calls returning
4208 objects of aggregate type look like lvalues. */
4212 if (TREE_CODE (targ) == SAVE_EXPR)
4213 targ = TREE_OPERAND (targ, 0);
4215 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4217 if (TREE_CODE (arg) == SAVE_EXPR)
4220 targ = build_cplus_new (TREE_TYPE (arg), arg);
4221 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4224 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4225 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4226 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4229 /* Don't let anything else be handled specially. */
4233 /* Mark EXP saying that we need to be able to take the
4234 address of it; it should not be allocated in a register.
4235 Value is true if successful.
4237 C++: we do not allow `current_class_ptr' to be addressable. */
4240 cxx_mark_addressable (tree exp)
4245 switch (TREE_CODE (x))
4252 x = TREE_OPERAND (x, 0);
4256 if (x == current_class_ptr)
4258 error ("cannot take the address of %<this%>, which is an rvalue expression");
4259 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4265 /* Caller should not be trying to mark initialized
4266 constant fields addressable. */
4267 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4268 || DECL_IN_AGGR_P (x) == 0
4270 || DECL_EXTERNAL (x));
4275 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4276 && !DECL_ARTIFICIAL (x))
4278 if (DECL_HARD_REGISTER (x) != 0)
4281 ("address of explicit register variable %qD requested", x);
4284 else if (extra_warnings)
4286 (0, "address requested for %qD, which is declared %<register%>", x);
4288 TREE_ADDRESSABLE (x) = 1;
4292 TREE_ADDRESSABLE (x) = 1;
4296 TREE_ADDRESSABLE (x) = 1;
4300 TREE_ADDRESSABLE (x) = 1;
4301 cxx_mark_addressable (TREE_OPERAND (x, 0));
4309 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4312 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4314 tree orig_ifexp = ifexp;
4315 tree orig_op1 = op1;
4316 tree orig_op2 = op2;
4319 if (processing_template_decl)
4321 /* The standard says that the expression is type-dependent if
4322 IFEXP is type-dependent, even though the eventual type of the
4323 expression doesn't dependent on IFEXP. */
4324 if (type_dependent_expression_p (ifexp)
4325 /* As a GNU extension, the middle operand may be omitted. */
4326 || (op1 && type_dependent_expression_p (op1))
4327 || type_dependent_expression_p (op2))
4328 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4329 ifexp = build_non_dependent_expr (ifexp);
4331 op1 = build_non_dependent_expr (op1);
4332 op2 = build_non_dependent_expr (op2);
4335 expr = build_conditional_expr (ifexp, op1, op2);
4336 if (processing_template_decl && expr != error_mark_node)
4337 return build_min_non_dep (COND_EXPR, expr,
4338 orig_ifexp, orig_op1, orig_op2);
4342 /* Given a list of expressions, return a compound expression
4343 that performs them all and returns the value of the last of them. */
4345 tree build_x_compound_expr_from_list (tree list, const char *msg)
4347 tree expr = TREE_VALUE (list);
4349 if (TREE_CHAIN (list))
4352 pedwarn ("%s expression list treated as compound expression", msg);
4354 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4355 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4361 /* Handle overloading of the ',' operator when needed. */
4364 build_x_compound_expr (tree op1, tree op2)
4367 tree orig_op1 = op1;
4368 tree orig_op2 = op2;
4370 if (processing_template_decl)
4372 if (type_dependent_expression_p (op1)
4373 || type_dependent_expression_p (op2))
4374 return build_min_nt (COMPOUND_EXPR, op1, op2);
4375 op1 = build_non_dependent_expr (op1);
4376 op2 = build_non_dependent_expr (op2);
4379 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4380 /*overloaded_p=*/NULL);
4382 result = build_compound_expr (op1, op2);
4384 if (processing_template_decl && result != error_mark_node)
4385 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4390 /* Build a compound expression. */
4393 build_compound_expr (tree lhs, tree rhs)
4395 lhs = convert_to_void (lhs, "left-hand operand of comma");
4397 if (lhs == error_mark_node || rhs == error_mark_node)
4398 return error_mark_node;
4400 if (TREE_CODE (rhs) == TARGET_EXPR)
4402 /* If the rhs is a TARGET_EXPR, then build the compound
4403 expression inside the target_expr's initializer. This
4404 helps the compiler to eliminate unnecessary temporaries. */
4405 tree init = TREE_OPERAND (rhs, 1);
4407 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4408 TREE_OPERAND (rhs, 1) = init;
4413 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4416 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4417 casts away constness. DIAG_FN gives the function to call if we
4418 need to issue a diagnostic; if it is NULL, no diagnostic will be
4419 issued. DESCRIPTION explains what operation is taking place. */
4422 check_for_casting_away_constness (tree src_type, tree dest_type,
4423 void (*diag_fn)(const char *, ...),
4424 const char *description)
4426 if (diag_fn && casts_away_constness (src_type, dest_type))
4427 error ("%s from type %qT to type %qT casts away constness",
4428 description, src_type, dest_type);
4431 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4432 (another pointer-to-member type in the same hierarchy) and return
4433 the converted expression. If ALLOW_INVERSE_P is permitted, a
4434 pointer-to-derived may be converted to pointer-to-base; otherwise,
4435 only the other direction is permitted. If C_CAST_P is true, this
4436 conversion is taking place as part of a C-style cast. */
4439 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4442 if (TYPE_PTRMEM_P (type))
4446 if (TREE_CODE (expr) == PTRMEM_CST)
4447 expr = cplus_expand_constant (expr);
4448 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4449 TYPE_PTRMEM_CLASS_TYPE (type),
4452 if (!integer_zerop (delta))
4453 expr = cp_build_binary_op (PLUS_EXPR,
4454 build_nop (ptrdiff_type_node, expr),
4456 return build_nop (type, expr);
4459 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4460 allow_inverse_p, c_cast_p);
4463 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4464 this static_cast is being attempted as one of the possible casts
4465 allowed by a C-style cast. (In that case, accessibility of base
4466 classes is not considered, and it is OK to cast away
4467 constness.) Return the result of the cast. *VALID_P is set to
4468 indicate whether or not the cast was valid. */
4471 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4477 void (*diag_fn)(const char*, ...);
4480 /* Assume the cast is valid. */
4483 intype = TREE_TYPE (expr);
4485 /* Determine what to do when casting away constness. */
4488 /* C-style casts are allowed to cast away constness. With
4489 WARN_CAST_QUAL, we still want to issue a warning. */
4490 diag_fn = warn_cast_qual ? warning0 : NULL;
4495 /* A static_cast may not cast away constness. */
4497 desc = "static_cast";
4500 /* [expr.static.cast]
4502 An lvalue of type "cv1 B", where B is a class type, can be cast
4503 to type "reference to cv2 D", where D is a class derived (clause
4504 _class.derived_) from B, if a valid standard conversion from
4505 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4506 same cv-qualification as, or greater cv-qualification than, cv1,
4507 and B is not a virtual base class of D. */
4508 /* We check this case before checking the validity of "TYPE t =
4509 EXPR;" below because for this case:
4512 struct D : public B { D(const B&); };
4514 void f() { static_cast<const D&>(b); }
4516 we want to avoid constructing a new D. The standard is not
4517 completely clear about this issue, but our interpretation is
4518 consistent with other compilers. */
4519 if (TREE_CODE (type) == REFERENCE_TYPE
4520 && CLASS_TYPE_P (TREE_TYPE (type))
4521 && CLASS_TYPE_P (intype)
4522 && real_lvalue_p (expr)
4523 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4524 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4525 build_pointer_type (TYPE_MAIN_VARIANT
4526 (TREE_TYPE (type))))
4528 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4532 /* There is a standard conversion from "D*" to "B*" even if "B"
4533 is ambiguous or inaccessible. If this is really a
4534 static_cast, then we check both for inaccessibility and
4535 ambiguity. However, if this is a static_cast being performed
4536 because the user wrote a C-style cast, then accessibility is
4538 base = lookup_base (TREE_TYPE (type), intype,
4539 c_cast_p ? ba_unique : ba_check,
4542 /* Convert from "B*" to "D*". This function will check that "B"
4543 is not a virtual base of "D". */
4544 expr = build_base_path (MINUS_EXPR, build_address (expr),
4545 base, /*nonnull=*/false);
4546 /* Convert the pointer to a reference -- but then remember that
4547 there are no expressions with reference type in C++. */
4548 return convert_from_reference (build_nop (type, expr));
4553 /* [expr.static.cast]
4555 An expression e can be explicitly converted to a type T using a
4556 static_cast of the form static_cast<T>(e) if the declaration T
4557 t(e);" is well-formed, for some invented temporary variable
4559 result = perform_direct_initialization_if_possible (type, expr,
4563 result = convert_from_reference (result);
4565 /* Ignore any integer overflow caused by the cast. */
4566 if (TREE_CODE (result) == INTEGER_CST
4567 && CONSTANT_CLASS_P (orig))
4569 TREE_OVERFLOW (result) = TREE_OVERFLOW (orig);
4570 TREE_CONSTANT_OVERFLOW (result)
4571 = TREE_CONSTANT_OVERFLOW (orig);
4573 /* [expr.static.cast]
4575 If T is a reference type, the result is an lvalue; otherwise,
4576 the result is an rvalue. */
4577 if (TREE_CODE (type) != REFERENCE_TYPE
4578 && real_lvalue_p (result))
4579 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (result), result);
4583 /* [expr.static.cast]
4585 Any expression can be explicitly converted to type cv void. */
4586 if (TREE_CODE (type) == VOID_TYPE)
4587 return convert_to_void (expr, /*implicit=*/NULL);
4589 /* [expr.static.cast]
4591 The inverse of any standard conversion sequence (clause _conv_),
4592 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4593 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4594 (_conv.bool_) conversions, can be performed explicitly using
4595 static_cast subject to the restriction that the explicit
4596 conversion does not cast away constness (_expr.const.cast_), and
4597 the following additional rules for specific cases: */
4598 /* For reference, the conversions not excluded are: integral
4599 promotions, floating point promotion, integral conversions,
4600 floating point conversions, floating-integral conversions,
4601 pointer conversions, and pointer to member conversions. */
4604 A value of integral _or enumeration_ type can be explicitly
4605 converted to an enumeration type. */
4606 /* The effect of all that is that any conversion between any two
4607 types which are integral, floating, or enumeration types can be
4609 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
4610 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
4612 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
4614 /* Ignore any integer overflow caused by the cast. */
4615 if (TREE_CODE (expr) == INTEGER_CST
4616 && CONSTANT_CLASS_P (orig))
4618 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4619 TREE_CONSTANT_OVERFLOW (expr) = TREE_CONSTANT_OVERFLOW (orig);
4624 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4625 && CLASS_TYPE_P (TREE_TYPE (type))
4626 && CLASS_TYPE_P (TREE_TYPE (intype))
4627 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4628 (TREE_TYPE (intype))),
4629 build_pointer_type (TYPE_MAIN_VARIANT
4630 (TREE_TYPE (type)))))
4635 check_for_casting_away_constness (intype, type, diag_fn, desc);
4636 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
4637 c_cast_p ? ba_unique : ba_check,
4639 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4642 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4643 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4650 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
4651 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
4653 if (TYPE_PTRMEM_P (type))
4655 t1 = (build_ptrmem_type
4657 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
4658 t2 = (build_ptrmem_type
4660 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
4667 if (can_convert (t1, t2))
4670 check_for_casting_away_constness (intype, type, diag_fn,
4672 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
4677 /* [expr.static.cast]
4679 An rvalue of type "pointer to cv void" can be explicitly
4680 converted to a pointer to object type. A value of type pointer
4681 to object converted to "pointer to cv void" and back to the
4682 original pointer type will have its original value. */
4683 if (TREE_CODE (intype) == POINTER_TYPE
4684 && VOID_TYPE_P (TREE_TYPE (intype))
4685 && TYPE_PTROB_P (type))
4688 check_for_casting_away_constness (intype, type, diag_fn, desc);
4689 return build_nop (type, expr);
4693 return error_mark_node;
4696 /* Return an expression representing static_cast<TYPE>(EXPR). */
4699 build_static_cast (tree type, tree expr)
4704 if (type == error_mark_node || expr == error_mark_node)
4705 return error_mark_node;
4707 if (processing_template_decl)
4709 expr = build_min (STATIC_CAST_EXPR, type, expr);
4710 /* We don't know if it will or will not have side effects. */
4711 TREE_SIDE_EFFECTS (expr) = 1;
4712 return convert_from_reference (expr);
4715 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4716 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4717 if (TREE_CODE (type) != REFERENCE_TYPE
4718 && TREE_CODE (expr) == NOP_EXPR
4719 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4720 expr = TREE_OPERAND (expr, 0);
4722 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
4726 error ("invalid static_cast from type %qT to type %qT",
4727 TREE_TYPE (expr), type);
4728 return error_mark_node;
4731 /* EXPR is an expression with member function or pointer-to-member
4732 function type. TYPE is a pointer type. Converting EXPR to TYPE is
4733 not permitted by ISO C++, but we accept it in some modes. If we
4734 are not in one of those modes, issue a diagnostic. Return the
4735 converted expression. */
4738 convert_member_func_to_ptr (tree type, tree expr)
4743 intype = TREE_TYPE (expr);
4744 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
4745 || TREE_CODE (intype) == METHOD_TYPE);
4747 if (pedantic || warn_pmf2ptr)
4748 pedwarn ("converting from %qT to %qT", intype, type);
4750 if (TREE_CODE (intype) == METHOD_TYPE)
4751 expr = build_addr_func (expr);
4752 else if (TREE_CODE (expr) == PTRMEM_CST)
4753 expr = build_address (PTRMEM_CST_MEMBER (expr));
4756 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
4757 decl = build_address (decl);
4758 expr = get_member_function_from_ptrfunc (&decl, expr);
4761 return build_nop (type, expr);
4764 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
4765 If C_CAST_P is true, this reinterpret cast is being done as part of
4766 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
4767 indicate whether or not reinterpret_cast was valid. */
4770 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
4775 /* Assume the cast is invalid. */
4779 if (type == error_mark_node || error_operand_p (expr))
4780 return error_mark_node;
4782 intype = TREE_TYPE (expr);
4784 /* [expr.reinterpret.cast]
4785 An lvalue expression of type T1 can be cast to the type
4786 "reference to T2" if an expression of type "pointer to T1" can be
4787 explicitly converted to the type "pointer to T2" using a
4788 reinterpret_cast. */
4789 if (TREE_CODE (type) == REFERENCE_TYPE)
4791 if (! real_lvalue_p (expr))
4793 error ("invalid cast of an rvalue expression of type "
4796 return error_mark_node;
4799 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
4800 "B" are related class types; the reinterpret_cast does not
4801 adjust the pointer. */
4802 if (TYPE_PTR_P (intype)
4803 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
4804 COMPARE_BASE | COMPARE_DERIVED)))
4805 warning (0, "casting %qT to %qT does not dereference pointer",
4808 expr = build_unary_op (ADDR_EXPR, expr, 0);
4809 if (expr != error_mark_node)
4810 expr = build_reinterpret_cast_1
4811 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
4813 if (expr != error_mark_node)
4814 expr = build_indirect_ref (expr, 0);
4818 /* As a G++ extension, we consider conversions from member
4819 functions, and pointers to member functions to
4820 pointer-to-function and pointer-to-void types. If
4821 -Wno-pmf-conversions has not been specified,
4822 convert_member_func_to_ptr will issue an error message. */
4823 if ((TYPE_PTRMEMFUNC_P (intype)
4824 || TREE_CODE (intype) == METHOD_TYPE)
4825 && TYPE_PTR_P (type)
4826 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
4827 || VOID_TYPE_P (TREE_TYPE (type))))
4828 return convert_member_func_to_ptr (type, expr);
4830 /* If the cast is not to a reference type, the lvalue-to-rvalue,
4831 array-to-pointer, and function-to-pointer conversions are
4833 expr = decay_conversion (expr);
4835 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4836 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4837 if (TREE_CODE (expr) == NOP_EXPR
4838 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4839 expr = TREE_OPERAND (expr, 0);
4841 if (error_operand_p (expr))
4842 return error_mark_node;
4844 intype = TREE_TYPE (expr);
4846 /* [expr.reinterpret.cast]
4847 A pointer can be converted to any integral type large enough to
4849 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
4851 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
4852 pedwarn ("cast from %qT to %qT loses precision",
4855 /* [expr.reinterpret.cast]
4856 A value of integral or enumeration type can be explicitly
4857 converted to a pointer. */
4858 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
4861 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
4862 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4863 return fold_if_not_in_template (build_nop (type, expr));
4864 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4865 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
4868 check_for_casting_away_constness (intype, type, error,
4869 "reinterpret_cast");
4870 /* Warn about possible alignment problems. */
4871 if (STRICT_ALIGNMENT && warn_cast_align
4872 && !VOID_TYPE_P (type)
4873 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
4874 && COMPLETE_TYPE_P (TREE_TYPE (type))
4875 && COMPLETE_TYPE_P (TREE_TYPE (intype))
4876 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
4877 warning (0, "cast from %qT to %qT increases required alignment of "
4881 return fold_if_not_in_template (build_nop (type, expr));
4883 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
4884 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
4887 /* Only issue a warning, as we have always supported this
4888 where possible, and it is necessary in some cases. DR 195
4889 addresses this issue, but as of 2004/10/26 is still in
4891 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
4892 return fold_if_not_in_template (build_nop (type, expr));
4894 else if (TREE_CODE (type) == VECTOR_TYPE)
4895 return fold_if_not_in_template (convert_to_vector (type, expr));
4896 else if (TREE_CODE (intype) == VECTOR_TYPE)
4897 return fold_if_not_in_template (convert_to_integer (type, expr));
4902 error ("invalid cast from type %qT to type %qT", intype, type);
4903 return error_mark_node;
4906 return cp_convert (type, expr);
4910 build_reinterpret_cast (tree type, tree expr)
4912 if (type == error_mark_node || expr == error_mark_node)
4913 return error_mark_node;
4915 if (processing_template_decl)
4917 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
4919 if (!TREE_SIDE_EFFECTS (t)
4920 && type_dependent_expression_p (expr))
4921 /* There might turn out to be side effects inside expr. */
4922 TREE_SIDE_EFFECTS (t) = 1;
4923 return convert_from_reference (t);
4926 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
4930 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
4931 return an appropriate expression. Otherwise, return
4932 error_mark_node. If the cast is not valid, and COMPLAIN is true,
4933 then a diagnostic will be issued. If VALID_P is non-NULL, its
4934 value upon return will indicate whether or not the conversion
4938 build_const_cast_1 (tree dst_type, tree expr, bool complain,
4942 tree reference_type;
4944 /* Callers are responsible for handling error_mark_node as a
4945 destination type. */
4946 gcc_assert (dst_type != error_mark_node);
4947 /* In a template, callers should be building syntactic
4948 representations of casts, not using this machinery. */
4949 gcc_assert (!processing_template_decl);
4951 /* Assume the conversion is invalid. */
4955 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
4958 error ("invalid use of const_cast with type %qT, "
4959 "which is not a pointer, "
4960 "reference, nor a pointer-to-data-member type", dst_type);
4961 return error_mark_node;
4964 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
4967 error ("invalid use of const_cast with type %qT, which is a pointer "
4968 "or reference to a function type", dst_type);
4969 return error_mark_node;
4972 src_type = TREE_TYPE (expr);
4973 /* Expressions do not really have reference types. */
4974 if (TREE_CODE (src_type) == REFERENCE_TYPE)
4975 src_type = TREE_TYPE (src_type);
4977 /* [expr.const.cast]
4979 An lvalue of type T1 can be explicitly converted to an lvalue of
4980 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
4981 types) if a pointer to T1 can be explicitly converted to the type
4982 pointer to T2 using a const_cast. */
4983 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
4985 reference_type = dst_type;
4986 if (! real_lvalue_p (expr))
4989 error ("invalid const_cast of an rvalue of type %qT to type %qT",
4990 src_type, dst_type);
4991 return error_mark_node;
4993 dst_type = build_pointer_type (TREE_TYPE (dst_type));
4994 src_type = build_pointer_type (src_type);
4998 reference_type = NULL_TREE;
4999 /* If the destination type is not a reference type, the
5000 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5001 conversions are performed. */
5002 src_type = type_decays_to (src_type);
5003 if (src_type == error_mark_node)
5004 return error_mark_node;
5007 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5008 && comp_ptr_ttypes_const (dst_type, src_type))
5014 expr = build_unary_op (ADDR_EXPR, expr, 0);
5015 expr = build_nop (reference_type, expr);
5016 return convert_from_reference (expr);
5020 expr = decay_conversion (expr);
5021 /* build_c_cast puts on a NOP_EXPR to make the result not an
5022 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5023 non-lvalue context. */
5024 if (TREE_CODE (expr) == NOP_EXPR
5025 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5026 expr = TREE_OPERAND (expr, 0);
5027 return build_nop (dst_type, expr);
5032 error ("invalid const_cast from type %qT to type %qT",
5033 src_type, dst_type);
5034 return error_mark_node;
5038 build_const_cast (tree type, tree expr)
5040 if (type == error_mark_node || error_operand_p (expr))
5041 return error_mark_node;
5043 if (processing_template_decl)
5045 tree t = build_min (CONST_CAST_EXPR, type, expr);
5047 if (!TREE_SIDE_EFFECTS (t)
5048 && type_dependent_expression_p (expr))
5049 /* There might turn out to be side effects inside expr. */
5050 TREE_SIDE_EFFECTS (t) = 1;
5051 return convert_from_reference (t);
5054 return build_const_cast_1 (type, expr, /*complain=*/true,
5058 /* Build an expression representing an explicit C-style cast to type
5059 TYPE of expression EXPR. */
5062 build_c_cast (tree type, tree expr)
5068 if (type == error_mark_node || error_operand_p (expr))
5069 return error_mark_node;
5071 if (processing_template_decl)
5073 tree t = build_min (CAST_EXPR, type,
5074 tree_cons (NULL_TREE, value, NULL_TREE));
5075 /* We don't know if it will or will not have side effects. */
5076 TREE_SIDE_EFFECTS (t) = 1;
5077 return convert_from_reference (t);
5080 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5081 'Class') should always be retained, because this information aids
5082 in method lookup. */
5083 if (objc_is_object_ptr (type)
5084 && objc_is_object_ptr (TREE_TYPE (expr)))
5085 return build_nop (type, expr);
5087 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5088 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5089 if (TREE_CODE (type) != REFERENCE_TYPE
5090 && TREE_CODE (value) == NOP_EXPR
5091 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5092 value = TREE_OPERAND (value, 0);
5094 if (TREE_CODE (type) == ARRAY_TYPE)
5096 /* Allow casting from T1* to T2[] because Cfront allows it.
5097 NIHCL uses it. It is not valid ISO C++ however. */
5098 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5100 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5101 type = build_pointer_type (TREE_TYPE (type));
5105 error ("ISO C++ forbids casting to an array type %qT", type);
5106 return error_mark_node;
5110 if (TREE_CODE (type) == FUNCTION_TYPE
5111 || TREE_CODE (type) == METHOD_TYPE)
5113 error ("invalid cast to function type %qT", type);
5114 return error_mark_node;
5117 /* A C-style cast can be a const_cast. */
5118 result = build_const_cast_1 (type, value, /*complain=*/false,
5123 /* Or a static cast. */
5124 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5126 /* Or a reinterpret_cast. */
5128 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5130 /* The static_cast or reinterpret_cast may be followed by a
5133 /* A valid cast may result in errors if, for example, a
5134 conversion to am ambiguous base class is required. */
5135 && !error_operand_p (result))
5139 /* Non-class rvalues always have cv-unqualified type. */
5140 if (!CLASS_TYPE_P (type))
5141 type = TYPE_MAIN_VARIANT (type);
5142 result_type = TREE_TYPE (result);
5143 if (!CLASS_TYPE_P (result_type))
5144 result_type = TYPE_MAIN_VARIANT (result_type);
5145 /* If the type of RESULT does not match TYPE, perform a
5146 const_cast to make it match. If the static_cast or
5147 reinterpret_cast succeeded, we will differ by at most
5148 cv-qualification, so the follow-on const_cast is guaranteed
5150 if (!same_type_p (non_reference (type), non_reference (result_type)))
5152 result = build_const_cast_1 (type, result, false, &valid_p);
5153 gcc_assert (valid_p);
5158 return error_mark_node;
5161 /* Build an assignment expression of lvalue LHS from value RHS.
5162 MODIFYCODE is the code for a binary operator that we use
5163 to combine the old value of LHS with RHS to get the new value.
5164 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5166 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5169 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5173 tree lhstype = TREE_TYPE (lhs);
5174 tree olhstype = lhstype;
5175 tree olhs = NULL_TREE;
5176 bool plain_assign = (modifycode == NOP_EXPR);
5178 /* Avoid duplicate error messages from operands that had errors. */
5179 if (lhs == error_mark_node || rhs == error_mark_node)
5180 return error_mark_node;
5182 /* Handle control structure constructs used as "lvalues". */
5183 switch (TREE_CODE (lhs))
5185 /* Handle --foo = 5; as these are valid constructs in C++. */
5186 case PREDECREMENT_EXPR:
5187 case PREINCREMENT_EXPR:
5188 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5189 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5190 stabilize_reference (TREE_OPERAND (lhs, 0)),
5191 TREE_OPERAND (lhs, 1));
5192 return build2 (COMPOUND_EXPR, lhstype,
5194 build_modify_expr (TREE_OPERAND (lhs, 0),
5197 /* Handle (a, b) used as an "lvalue". */
5199 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5201 if (newrhs == error_mark_node)
5202 return error_mark_node;
5203 return build2 (COMPOUND_EXPR, lhstype,
5204 TREE_OPERAND (lhs, 0), newrhs);
5207 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5208 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5209 stabilize_reference (TREE_OPERAND (lhs, 0)),
5210 TREE_OPERAND (lhs, 1));
5211 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5212 if (newrhs == error_mark_node)
5213 return error_mark_node;
5214 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5218 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5219 when neither operand has side-effects. */
5220 if (!lvalue_or_else (lhs, lv_assign))
5221 return error_mark_node;
5223 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5224 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5226 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5227 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5229 TREE_OPERAND (lhs, 0),
5230 TREE_OPERAND (lhs, 1)),
5231 TREE_OPERAND (lhs, 0),
5232 TREE_OPERAND (lhs, 1));
5235 /* Handle (a ? b : c) used as an "lvalue". */
5238 /* Produce (a ? (b = rhs) : (c = rhs))
5239 except that the RHS goes through a save-expr
5240 so the code to compute it is only emitted once. */
5242 tree preeval = NULL_TREE;
5244 rhs = stabilize_expr (rhs, &preeval);
5246 /* Check this here to avoid odd errors when trying to convert
5247 a throw to the type of the COND_EXPR. */
5248 if (!lvalue_or_else (lhs, lv_assign))
5249 return error_mark_node;
5251 cond = build_conditional_expr
5252 (TREE_OPERAND (lhs, 0),
5253 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5254 TREE_OPERAND (lhs, 1)),
5256 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5257 TREE_OPERAND (lhs, 2)),
5260 if (cond == error_mark_node)
5262 /* Make sure the code to compute the rhs comes out
5263 before the split. */
5265 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5273 if (modifycode == INIT_EXPR)
5275 if (TREE_CODE (rhs) == CONSTRUCTOR)
5277 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5278 /* Call convert to generate an error; see PR 11063. */
5279 rhs = convert (lhstype, rhs);
5280 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5281 TREE_SIDE_EFFECTS (result) = 1;
5284 else if (! IS_AGGR_TYPE (lhstype))
5285 /* Do the default thing. */;
5288 result = build_special_member_call (lhs, complete_ctor_identifier,
5289 build_tree_list (NULL_TREE, rhs),
5290 lhstype, LOOKUP_NORMAL);
5291 if (result == NULL_TREE)
5292 return error_mark_node;
5298 lhs = require_complete_type (lhs);
5299 if (lhs == error_mark_node)
5300 return error_mark_node;
5302 if (modifycode == NOP_EXPR)
5304 /* `operator=' is not an inheritable operator. */
5305 if (! IS_AGGR_TYPE (lhstype))
5306 /* Do the default thing. */;
5309 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5310 lhs, rhs, make_node (NOP_EXPR),
5311 /*overloaded_p=*/NULL);
5312 if (result == NULL_TREE)
5313 return error_mark_node;
5320 /* A binary op has been requested. Combine the old LHS
5321 value with the RHS producing the value we should actually
5322 store into the LHS. */
5324 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5325 lhs = stabilize_reference (lhs);
5326 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5327 if (newrhs == error_mark_node)
5329 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5330 TREE_TYPE (lhs), TREE_TYPE (rhs));
5331 return error_mark_node;
5334 /* Now it looks like a plain assignment. */
5335 modifycode = NOP_EXPR;
5337 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5338 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5341 /* The left-hand side must be an lvalue. */
5342 if (!lvalue_or_else (lhs, lv_assign))
5343 return error_mark_node;
5345 /* Warn about modifying something that is `const'. Don't warn if
5346 this is initialization. */
5347 if (modifycode != INIT_EXPR
5348 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5349 /* Functions are not modifiable, even though they are
5351 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5352 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5353 /* If it's an aggregate and any field is const, then it is
5354 effectively const. */
5355 || (CLASS_TYPE_P (lhstype)
5356 && C_TYPE_FIELDS_READONLY (lhstype))))
5357 readonly_error (lhs, "assignment", 0);
5359 /* If storing into a structure or union member, it has probably been
5360 given type `int'. Compute the type that would go with the actual
5361 amount of storage the member occupies. */
5363 if (TREE_CODE (lhs) == COMPONENT_REF
5364 && (TREE_CODE (lhstype) == INTEGER_TYPE
5365 || TREE_CODE (lhstype) == REAL_TYPE
5366 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5368 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5370 /* If storing in a field that is in actuality a short or narrower
5371 than one, we must store in the field in its actual type. */
5373 if (lhstype != TREE_TYPE (lhs))
5375 /* Avoid warnings converting integral types back into enums for
5377 if (TREE_CODE (lhstype) == INTEGER_TYPE
5378 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5380 if (TREE_SIDE_EFFECTS (lhs))
5381 lhs = stabilize_reference (lhs);
5384 lhs = copy_node (lhs);
5385 TREE_TYPE (lhs) = lhstype;
5389 /* Convert new value to destination type. */
5391 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5395 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5396 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5398 error ("incompatible types in assignment of %qT to %qT",
5399 TREE_TYPE (rhs), lhstype);
5400 return error_mark_node;
5403 /* Allow array assignment in compiler-generated code. */
5404 if (! DECL_ARTIFICIAL (current_function_decl))
5405 pedwarn ("ISO C++ forbids assignment of arrays");
5407 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5408 ? 1 + (modifycode != INIT_EXPR): 0;
5409 return build_vec_init (lhs, NULL_TREE, newrhs, from_array);
5412 if (modifycode == INIT_EXPR)
5413 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5414 "initialization", NULL_TREE, 0);
5417 /* Avoid warnings on enum bit fields. */
5418 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5419 && TREE_CODE (lhstype) == INTEGER_TYPE)
5421 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5423 newrhs = convert_force (lhstype, newrhs, 0);
5426 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5428 if (TREE_CODE (newrhs) == CALL_EXPR
5429 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5430 newrhs = build_cplus_new (lhstype, newrhs);
5432 /* Can't initialize directly from a TARGET_EXPR, since that would
5433 cause the lhs to be constructed twice, and possibly result in
5434 accidental self-initialization. So we force the TARGET_EXPR to be
5435 expanded without a target. */
5436 if (TREE_CODE (newrhs) == TARGET_EXPR)
5437 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5438 TREE_OPERAND (newrhs, 0));
5441 if (newrhs == error_mark_node)
5442 return error_mark_node;
5444 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5445 lhstype, lhs, newrhs);
5447 TREE_SIDE_EFFECTS (result) = 1;
5449 TREE_NO_WARNING (result) = 1;
5451 /* If we got the LHS in a different type for storing in,
5452 convert the result back to the nominal type of LHS
5453 so that the value we return always has the same type
5454 as the LHS argument. */
5456 if (olhstype == TREE_TYPE (result))
5460 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5461 TREE_NO_WARNING (result) = 1;
5464 return convert_for_assignment (olhstype, result, "assignment",
5469 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5471 if (processing_template_decl)
5472 return build_min_nt (MODOP_EXPR, lhs,
5473 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5475 if (modifycode != NOP_EXPR)
5477 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5478 make_node (modifycode),
5479 /*overloaded_p=*/NULL);
5482 TREE_NO_WARNING (rval) = 1;
5486 return build_modify_expr (lhs, modifycode, rhs);
5490 /* Get difference in deltas for different pointer to member function
5491 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5492 the conversion is invalid, the constant is zero. If
5493 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5494 If C_CAST_P is true this conversion is taking place as part of a
5497 Note that the naming of FROM and TO is kind of backwards; the return
5498 value is what we add to a TO in order to get a FROM. They are named
5499 this way because we call this function to find out how to convert from
5500 a pointer to member of FROM to a pointer to member of TO. */
5503 get_delta_difference (tree from, tree to,
5504 bool allow_inverse_p,
5512 /* Assume no conversion is required. */
5513 result = integer_zero_node;
5514 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5515 if (kind == bk_inaccessible || kind == bk_ambig)
5516 error (" in pointer to member function conversion");
5519 if (!allow_inverse_p)
5521 error_not_base_type (from, to);
5522 error (" in pointer to member conversion");
5526 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check,
5530 virt_binfo = binfo_from_vbase (binfo);
5532 /* This is a reinterpret cast, we choose to do nothing. */
5533 warning (0, "pointer to member cast via virtual base %qT",
5534 BINFO_TYPE (virt_binfo));
5536 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5542 virt_binfo = binfo_from_vbase (binfo);
5544 result = BINFO_OFFSET (binfo);
5547 /* This is a reinterpret cast, we choose to do nothing. */
5548 if (allow_inverse_p)
5549 warning (0, "pointer to member cast via virtual base %qT",
5550 BINFO_TYPE (virt_binfo));
5552 error ("pointer to member conversion via virtual base %qT",
5553 BINFO_TYPE (virt_binfo));
5557 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5561 /* Return a constructor for the pointer-to-member-function TYPE using
5562 the other components as specified. */
5565 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5571 /* Pull the FIELD_DECLs out of the type. */
5572 pfn_field = TYPE_FIELDS (type);
5573 delta_field = TREE_CHAIN (pfn_field);
5575 /* Make sure DELTA has the type we want. */
5576 delta = convert_and_check (delta_type_node, delta);
5578 /* Finish creating the initializer. */
5579 u = tree_cons (pfn_field, pfn,
5580 build_tree_list (delta_field, delta));
5581 u = build_constructor (type, u);
5582 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5583 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5584 TREE_STATIC (u) = (TREE_CONSTANT (u)
5585 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5587 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5592 /* Build a constructor for a pointer to member function. It can be
5593 used to initialize global variables, local variable, or used
5594 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5597 If FORCE is nonzero, then force this conversion, even if
5598 we would rather not do it. Usually set when using an explicit
5599 cast. A C-style cast is being processed iff C_CAST_P is true.
5601 Return error_mark_node, if something goes wrong. */
5604 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
5610 if (error_operand_p (pfn))
5611 return error_mark_node;
5613 pfn_type = TREE_TYPE (pfn);
5614 to_type = build_ptrmemfunc_type (type);
5616 /* Handle multiple conversions of pointer to member functions. */
5617 if (TYPE_PTRMEMFUNC_P (pfn_type))
5619 tree delta = NULL_TREE;
5620 tree npfn = NULL_TREE;
5624 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn))
5625 error ("invalid conversion to type %qT from type %qT",
5628 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
5629 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
5633 /* We don't have to do any conversion to convert a
5634 pointer-to-member to its own type. But, we don't want to
5635 just return a PTRMEM_CST if there's an explicit cast; that
5636 cast should make the expression an invalid template argument. */
5637 if (TREE_CODE (pfn) != PTRMEM_CST)
5639 if (same_type_p (to_type, pfn_type))
5641 else if (integer_zerop (n))
5642 return build_reinterpret_cast (to_type, pfn);
5645 if (TREE_SIDE_EFFECTS (pfn))
5646 pfn = save_expr (pfn);
5648 /* Obtain the function pointer and the current DELTA. */
5649 if (TREE_CODE (pfn) == PTRMEM_CST)
5650 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
5653 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
5654 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
5657 /* Just adjust the DELTA field. */
5658 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5659 (TREE_TYPE (delta), ptrdiff_type_node));
5660 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
5661 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
5662 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
5663 return build_ptrmemfunc1 (to_type, delta, npfn);
5666 /* Handle null pointer to member function conversions. */
5667 if (integer_zerop (pfn))
5669 pfn = build_c_cast (type, integer_zero_node);
5670 return build_ptrmemfunc1 (to_type,
5675 if (type_unknown_p (pfn))
5676 return instantiate_type (type, pfn, tf_error | tf_warning);
5678 fn = TREE_OPERAND (pfn, 0);
5679 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
5680 /* In a template, we will have preserved the
5682 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
5683 return make_ptrmem_cst (to_type, fn);
5686 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
5689 ??? There is no consistency as to the types returned for the above
5690 values. Some code acts as if it were a sizetype and some as if it were
5691 integer_type_node. */
5694 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
5696 tree type = TREE_TYPE (cst);
5697 tree fn = PTRMEM_CST_MEMBER (cst);
5698 tree ptr_class, fn_class;
5700 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5702 /* The class that the function belongs to. */
5703 fn_class = DECL_CONTEXT (fn);
5705 /* The class that we're creating a pointer to member of. */
5706 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
5708 /* First, calculate the adjustment to the function's class. */
5709 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
5712 if (!DECL_VIRTUAL_P (fn))
5713 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
5716 /* If we're dealing with a virtual function, we have to adjust 'this'
5717 again, to point to the base which provides the vtable entry for
5718 fn; the call will do the opposite adjustment. */
5719 tree orig_class = DECL_CONTEXT (fn);
5720 tree binfo = binfo_or_else (orig_class, fn_class);
5721 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5722 *delta, BINFO_OFFSET (binfo));
5723 *delta = fold_if_not_in_template (*delta);
5725 /* We set PFN to the vtable offset at which the function can be
5726 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
5727 case delta is shifted left, and then incremented). */
5728 *pfn = DECL_VINDEX (fn);
5729 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
5730 TYPE_SIZE_UNIT (vtable_entry_type));
5731 *pfn = fold_if_not_in_template (*pfn);
5733 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
5735 case ptrmemfunc_vbit_in_pfn:
5736 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
5738 *pfn = fold_if_not_in_template (*pfn);
5741 case ptrmemfunc_vbit_in_delta:
5742 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
5743 *delta, integer_one_node);
5744 *delta = fold_if_not_in_template (*delta);
5745 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5746 *delta, integer_one_node);
5747 *delta = fold_if_not_in_template (*delta);
5754 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
5755 *pfn = fold_if_not_in_template (*pfn);
5759 /* Return an expression for PFN from the pointer-to-member function
5763 pfn_from_ptrmemfunc (tree t)
5765 if (TREE_CODE (t) == PTRMEM_CST)
5770 expand_ptrmemfunc_cst (t, &delta, &pfn);
5775 return build_ptrmemfunc_access_expr (t, pfn_identifier);
5778 /* Convert value RHS to type TYPE as preparation for an assignment to
5779 an lvalue of type TYPE. ERRTYPE is a string to use in error
5780 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
5781 are doing the conversion in order to pass the PARMNUMth argument of
5785 convert_for_assignment (tree type, tree rhs,
5786 const char *errtype, tree fndecl, int parmnum)
5789 enum tree_code coder;
5791 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
5792 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
5793 rhs = TREE_OPERAND (rhs, 0);
5795 rhstype = TREE_TYPE (rhs);
5796 coder = TREE_CODE (rhstype);
5798 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
5799 && vector_types_convertible_p (type, rhstype))
5800 return convert (type, rhs);
5802 if (rhs == error_mark_node || rhstype == error_mark_node)
5803 return error_mark_node;
5804 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
5805 return error_mark_node;
5807 /* The RHS of an assignment cannot have void type. */
5808 if (coder == VOID_TYPE)
5810 error ("void value not ignored as it ought to be");
5811 return error_mark_node;
5814 /* Simplify the RHS if possible. */
5815 if (TREE_CODE (rhs) == CONST_DECL)
5816 rhs = DECL_INITIAL (rhs);
5820 The expression is implicitly converted (clause _conv_) to the
5821 cv-unqualified type of the left operand.
5823 We allow bad conversions here because by the time we get to this point
5824 we are committed to doing the conversion. If we end up doing a bad
5825 conversion, convert_like will complain. */
5826 if (!can_convert_arg_bad (type, rhstype, rhs))
5828 /* When -Wno-pmf-conversions is use, we just silently allow
5829 conversions from pointers-to-members to plain pointers. If
5830 the conversion doesn't work, cp_convert will complain. */
5832 && TYPE_PTR_P (type)
5833 && TYPE_PTRMEMFUNC_P (rhstype))
5834 rhs = cp_convert (strip_top_quals (type), rhs);
5837 /* If the right-hand side has unknown type, then it is an
5838 overloaded function. Call instantiate_type to get error
5840 if (rhstype == unknown_type_node)
5841 instantiate_type (type, rhs, tf_error | tf_warning);
5843 error ("cannot convert %qT to %qT for argument %qP to %qD",
5844 rhstype, type, parmnum, fndecl);
5846 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
5847 return error_mark_node;
5850 return perform_implicit_conversion (strip_top_quals (type), rhs);
5853 /* Convert RHS to be of type TYPE.
5854 If EXP is nonzero, it is the target of the initialization.
5855 ERRTYPE is a string to use in error messages.
5857 Two major differences between the behavior of
5858 `convert_for_assignment' and `convert_for_initialization'
5859 are that references are bashed in the former, while
5860 copied in the latter, and aggregates are assigned in
5861 the former (operator=) while initialized in the
5864 If using constructor make sure no conversion operator exists, if one does
5865 exist, an ambiguity exists.
5867 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
5870 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
5871 const char *errtype, tree fndecl, int parmnum)
5873 enum tree_code codel = TREE_CODE (type);
5875 enum tree_code coder;
5877 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5878 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
5879 if (TREE_CODE (rhs) == NOP_EXPR
5880 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
5881 && codel != REFERENCE_TYPE)
5882 rhs = TREE_OPERAND (rhs, 0);
5884 if (rhs == error_mark_node
5885 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
5886 return error_mark_node;
5888 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
5889 && TREE_CODE (type) != ARRAY_TYPE
5890 && (TREE_CODE (type) != REFERENCE_TYPE
5891 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
5892 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
5893 && (TREE_CODE (type) != REFERENCE_TYPE
5894 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
5895 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
5896 rhs = decay_conversion (rhs);
5898 rhstype = TREE_TYPE (rhs);
5899 coder = TREE_CODE (rhstype);
5901 if (coder == ERROR_MARK)
5902 return error_mark_node;
5904 /* We accept references to incomplete types, so we can
5905 return here before checking if RHS is of complete type. */
5907 if (codel == REFERENCE_TYPE)
5909 /* This should eventually happen in convert_arguments. */
5910 int savew = 0, savee = 0;
5913 savew = warningcount, savee = errorcount;
5914 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
5918 if (warningcount > savew)
5919 cp_warning_at ("in passing argument %P of %q+D", parmnum, fndecl);
5920 else if (errorcount > savee)
5921 cp_error_at ("in passing argument %P of %q+D", parmnum, fndecl);
5927 exp = require_complete_type (exp);
5928 if (exp == error_mark_node)
5929 return error_mark_node;
5931 rhstype = non_reference (rhstype);
5933 type = complete_type (type);
5935 if (IS_AGGR_TYPE (type))
5936 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
5938 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
5941 /* If RETVAL is the address of, or a reference to, a local variable or
5942 temporary give an appropriate warning. */
5945 maybe_warn_about_returning_address_of_local (tree retval)
5947 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
5948 tree whats_returned = retval;
5952 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
5953 whats_returned = TREE_OPERAND (whats_returned, 1);
5954 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
5955 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
5956 || TREE_CODE (whats_returned) == NOP_EXPR)
5957 whats_returned = TREE_OPERAND (whats_returned, 0);
5962 if (TREE_CODE (whats_returned) != ADDR_EXPR)
5964 whats_returned = TREE_OPERAND (whats_returned, 0);
5966 if (TREE_CODE (valtype) == REFERENCE_TYPE)
5968 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
5969 || TREE_CODE (whats_returned) == TARGET_EXPR)
5971 warning (0, "returning reference to temporary");
5974 if (TREE_CODE (whats_returned) == VAR_DECL
5975 && DECL_NAME (whats_returned)
5976 && TEMP_NAME_P (DECL_NAME (whats_returned)))
5978 warning (0, "reference to non-lvalue returned");
5983 if (DECL_P (whats_returned)
5984 && DECL_NAME (whats_returned)
5985 && DECL_FUNCTION_SCOPE_P (whats_returned)
5986 && !(TREE_STATIC (whats_returned)
5987 || TREE_PUBLIC (whats_returned)))
5989 if (TREE_CODE (valtype) == REFERENCE_TYPE)
5990 cp_warning_at ("reference to local variable %qD returned",
5993 cp_warning_at ("address of local variable %qD returned",
5999 /* Check that returning RETVAL from the current function is valid.
6000 Return an expression explicitly showing all conversions required to
6001 change RETVAL into the function return type, and to assign it to
6002 the DECL_RESULT for the function. */
6005 check_return_expr (tree retval)
6008 /* The type actually returned by the function, after any
6011 int fn_returns_value_p;
6013 /* A `volatile' function is one that isn't supposed to return, ever.
6014 (This is a G++ extension, used to get better code for functions
6015 that call the `volatile' function.) */
6016 if (TREE_THIS_VOLATILE (current_function_decl))
6017 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6019 /* Check for various simple errors. */
6020 if (DECL_DESTRUCTOR_P (current_function_decl))
6023 error ("returning a value from a destructor");
6026 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6028 if (in_function_try_handler)
6029 /* If a return statement appears in a handler of the
6030 function-try-block of a constructor, the program is ill-formed. */
6031 error ("cannot return from a handler of a function-try-block of a constructor");
6033 /* You can't return a value from a constructor. */
6034 error ("returning a value from a constructor");
6038 if (processing_template_decl)
6040 current_function_returns_value = 1;
6044 /* When no explicit return-value is given in a function with a named
6045 return value, the named return value is used. */
6046 result = DECL_RESULT (current_function_decl);
6047 valtype = TREE_TYPE (result);
6048 gcc_assert (valtype != NULL_TREE);
6049 fn_returns_value_p = !VOID_TYPE_P (valtype);
6050 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6053 /* Check for a return statement with no return value in a function
6054 that's supposed to return a value. */
6055 if (!retval && fn_returns_value_p)
6057 pedwarn ("return-statement with no value, in function returning %qT",
6059 /* Clear this, so finish_function won't say that we reach the
6060 end of a non-void function (which we don't, we gave a
6062 current_function_returns_null = 0;
6064 /* Check for a return statement with a value in a function that
6065 isn't supposed to return a value. */
6066 else if (retval && !fn_returns_value_p)
6068 if (VOID_TYPE_P (TREE_TYPE (retval)))
6069 /* You can return a `void' value from a function of `void'
6070 type. In that case, we have to evaluate the expression for
6071 its side-effects. */
6072 finish_expr_stmt (retval);
6074 pedwarn ("return-statement with a value, in function "
6075 "returning 'void'");
6077 current_function_returns_null = 1;
6079 /* There's really no value to return, after all. */
6083 /* Remember that this function can sometimes return without a
6085 current_function_returns_null = 1;
6087 /* Remember that this function did return a value. */
6088 current_function_returns_value = 1;
6090 /* Check for erroneous operands -- but after giving ourselves a
6091 chance to provide an error about returning a value from a void
6093 if (error_operand_p (retval))
6095 current_function_return_value = error_mark_node;
6096 return error_mark_node;
6099 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6100 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6101 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6102 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6104 && null_ptr_cst_p (retval))
6105 warning (0, "%<operator new%> must not return NULL unless it is "
6106 "declared %<throw()%> (or -fcheck-new is in effect)");
6108 /* Effective C++ rule 15. See also start_function. */
6110 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6114 /* The function return type must be a reference to the current
6116 if (TREE_CODE (valtype) == REFERENCE_TYPE
6117 && same_type_ignoring_top_level_qualifiers_p
6118 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6120 /* Returning '*this' is obviously OK. */
6121 if (retval == current_class_ref)
6123 /* If we are calling a function whose return type is the same of
6124 the current class reference, it is ok. */
6125 else if (TREE_CODE (retval) == INDIRECT_REF
6126 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6131 warning (0, "%<operator=%> should return a reference to %<*this%>");
6134 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6136 [...] For a function with a class return type, if the expression
6137 in the return statement is the name of a local object, and the cv-
6138 unqualified type of the local object is the same as the function
6139 return type, an implementation is permitted to omit creating the tem-
6140 porary object to hold the function return value [...]
6142 So, if this is a value-returning function that always returns the same
6143 local variable, remember it.
6145 It might be nice to be more flexible, and choose the first suitable
6146 variable even if the function sometimes returns something else, but
6147 then we run the risk of clobbering the variable we chose if the other
6148 returned expression uses the chosen variable somehow. And people expect
6149 this restriction, anyway. (jason 2000-11-19)
6151 See finish_function and finalize_nrv for the rest of this optimization. */
6153 if (fn_returns_value_p && flag_elide_constructors)
6155 if (retval != NULL_TREE
6156 && (current_function_return_value == NULL_TREE
6157 || current_function_return_value == retval)
6158 && TREE_CODE (retval) == VAR_DECL
6159 && DECL_CONTEXT (retval) == current_function_decl
6160 && ! TREE_STATIC (retval)
6161 && (DECL_ALIGN (retval)
6162 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6163 && same_type_p ((TYPE_MAIN_VARIANT
6164 (TREE_TYPE (retval))),
6166 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6167 current_function_return_value = retval;
6169 current_function_return_value = error_mark_node;
6172 /* We don't need to do any conversions when there's nothing being
6177 /* Do any required conversions. */
6178 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6179 /* No conversions are required. */
6183 /* The type the function is declared to return. */
6184 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6186 /* First convert the value to the function's return type, then
6187 to the type of return value's location to handle the
6188 case that functype is smaller than the valtype. */
6189 retval = convert_for_initialization
6190 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6191 "return", NULL_TREE, 0);
6192 retval = convert (valtype, retval);
6194 /* If the conversion failed, treat this just like `return;'. */
6195 if (retval == error_mark_node)
6197 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6198 else if (! current_function_returns_struct
6199 && TREE_CODE (retval) == TARGET_EXPR
6200 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6201 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6202 TREE_OPERAND (retval, 0));
6204 maybe_warn_about_returning_address_of_local (retval);
6207 /* Actually copy the value returned into the appropriate location. */
6208 if (retval && retval != result)
6209 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6215 /* Returns nonzero if the pointer-type FROM can be converted to the
6216 pointer-type TO via a qualification conversion. If CONSTP is -1,
6217 then we return nonzero if the pointers are similar, and the
6218 cv-qualification signature of FROM is a proper subset of that of TO.
6220 If CONSTP is positive, then all outer pointers have been
6224 comp_ptr_ttypes_real (tree to, tree from, int constp)
6226 bool to_more_cv_qualified = false;
6228 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6230 if (TREE_CODE (to) != TREE_CODE (from))
6233 if (TREE_CODE (from) == OFFSET_TYPE
6234 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6235 TYPE_OFFSET_BASETYPE (to)))
6238 /* Const and volatile mean something different for function types,
6239 so the usual checks are not appropriate. */
6240 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6242 if (!at_least_as_qualified_p (to, from))
6245 if (!at_least_as_qualified_p (from, to))
6249 to_more_cv_qualified = true;
6253 constp &= TYPE_READONLY (to);
6256 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6257 return ((constp >= 0 || to_more_cv_qualified)
6258 && same_type_ignoring_top_level_qualifiers_p (to, from));
6262 /* When comparing, say, char ** to char const **, this function takes
6263 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6264 types to this function. */
6267 comp_ptr_ttypes (tree to, tree from)
6269 return comp_ptr_ttypes_real (to, from, 1);
6272 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6273 type or inheritance-related types, regardless of cv-quals. */
6276 ptr_reasonably_similar (tree to, tree from)
6278 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6280 /* Any target type is similar enough to void. */
6281 if (TREE_CODE (to) == VOID_TYPE
6282 || TREE_CODE (from) == VOID_TYPE)
6285 if (TREE_CODE (to) != TREE_CODE (from))
6288 if (TREE_CODE (from) == OFFSET_TYPE
6289 && comptypes (TYPE_OFFSET_BASETYPE (to),
6290 TYPE_OFFSET_BASETYPE (from),
6291 COMPARE_BASE | COMPARE_DERIVED))
6294 if (TREE_CODE (to) == VECTOR_TYPE
6295 && vector_types_convertible_p (to, from))
6298 if (TREE_CODE (to) == INTEGER_TYPE
6299 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6302 if (TREE_CODE (to) == FUNCTION_TYPE)
6305 if (TREE_CODE (to) != POINTER_TYPE)
6307 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6308 COMPARE_BASE | COMPARE_DERIVED);
6312 /* Like comp_ptr_ttypes, for const_cast. */
6315 comp_ptr_ttypes_const (tree to, tree from)
6317 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6319 if (TREE_CODE (to) != TREE_CODE (from))
6322 if (TREE_CODE (from) == OFFSET_TYPE
6323 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6324 TYPE_OFFSET_BASETYPE (to)))
6327 if (TREE_CODE (to) != POINTER_TYPE)
6328 return same_type_ignoring_top_level_qualifiers_p (to, from);
6332 /* Returns the type qualifiers for this type, including the qualifiers on the
6333 elements for an array type. */
6336 cp_type_quals (tree type)
6338 type = strip_array_types (type);
6339 if (type == error_mark_node)
6340 return TYPE_UNQUALIFIED;
6341 return TYPE_QUALS (type);
6344 /* Returns nonzero if the TYPE contains a mutable member. */
6347 cp_has_mutable_p (tree type)
6349 type = strip_array_types (type);
6351 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6354 /* Apply the TYPE_QUALS to the new DECL. */
6356 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6358 tree type = TREE_TYPE (decl);
6360 if (type == error_mark_node)
6363 if (TREE_CODE (type) == FUNCTION_TYPE
6364 && type_quals != TYPE_UNQUALIFIED)
6366 /* This was an error in C++98 (cv-qualifiers cannot be added to
6367 a function type), but DR 295 makes the code well-formed by
6368 dropping the extra qualifiers. */
6371 tree bad_type = build_qualified_type (type, type_quals);
6372 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6376 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6380 /* Avoid setting TREE_READONLY incorrectly. */
6381 if (/* If the object has a constructor, the constructor may modify
6383 TYPE_NEEDS_CONSTRUCTING (type)
6384 /* If the type isn't complete, we don't know yet if it will need
6386 || !COMPLETE_TYPE_P (type)
6387 /* If the type has a mutable component, that component might be
6389 || TYPE_HAS_MUTABLE_P (type))
6390 type_quals &= ~TYPE_QUAL_CONST;
6392 c_apply_type_quals_to_decl (type_quals, decl);
6395 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6396 exemplar types such that casting T1 to T2 is casting away constness
6397 if and only if there is no implicit conversion from T1 to T2. */
6400 casts_away_constness_r (tree *t1, tree *t2)
6405 /* [expr.const.cast]
6407 For multi-level pointer to members and multi-level mixed pointers
6408 and pointers to members (conv.qual), the "member" aspect of a
6409 pointer to member level is ignored when determining if a const
6410 cv-qualifier has been cast away. */
6411 if (TYPE_PTRMEM_P (*t1))
6412 *t1 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t1));
6413 if (TYPE_PTRMEM_P (*t2))
6414 *t2 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t2));
6416 /* [expr.const.cast]
6418 For two pointer types:
6420 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6421 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6424 casting from X1 to X2 casts away constness if, for a non-pointer
6425 type T there does not exist an implicit conversion (clause
6428 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6432 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6434 if (TREE_CODE (*t1) != POINTER_TYPE
6435 || TREE_CODE (*t2) != POINTER_TYPE)
6437 *t1 = cp_build_qualified_type (void_type_node,
6438 cp_type_quals (*t1));
6439 *t2 = cp_build_qualified_type (void_type_node,
6440 cp_type_quals (*t2));
6444 quals1 = cp_type_quals (*t1);
6445 quals2 = cp_type_quals (*t2);
6446 *t1 = TREE_TYPE (*t1);
6447 *t2 = TREE_TYPE (*t2);
6448 casts_away_constness_r (t1, t2);
6449 *t1 = build_pointer_type (*t1);
6450 *t2 = build_pointer_type (*t2);
6451 *t1 = cp_build_qualified_type (*t1, quals1);
6452 *t2 = cp_build_qualified_type (*t2, quals2);
6455 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6459 casts_away_constness (tree t1, tree t2)
6461 if (TREE_CODE (t2) == REFERENCE_TYPE)
6463 /* [expr.const.cast]
6465 Casting from an lvalue of type T1 to an lvalue of type T2
6466 using a reference cast casts away constness if a cast from an
6467 rvalue of type "pointer to T1" to the type "pointer to T2"
6468 casts away constness. */
6469 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6470 return casts_away_constness (build_pointer_type (t1),
6471 build_pointer_type (TREE_TYPE (t2)));
6474 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6475 /* [expr.const.cast]
6477 Casting from an rvalue of type "pointer to data member of X
6478 of type T1" to the type "pointer to data member of Y of type
6479 T2" casts away constness if a cast from an rvalue of type
6480 "pointer to T1" to the type "pointer to T2" casts away
6482 return casts_away_constness
6483 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6484 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6486 /* Casting away constness is only something that makes sense for
6487 pointer or reference types. */
6488 if (TREE_CODE (t1) != POINTER_TYPE
6489 || TREE_CODE (t2) != POINTER_TYPE)
6492 /* Top-level qualifiers don't matter. */
6493 t1 = TYPE_MAIN_VARIANT (t1);
6494 t2 = TYPE_MAIN_VARIANT (t2);
6495 casts_away_constness_r (&t1, &t2);
6496 if (!can_convert (t2, t1))
6502 /* If T is a REFERENCE_TYPE return the type to which T refers.
6503 Otherwise, return T itself. */
6506 non_reference (tree t)
6508 if (TREE_CODE (t) == REFERENCE_TYPE)
6514 /* Return nonzero if REF is an lvalue valid for this language;
6515 otherwise, print an error message and return zero. USE says
6516 how the lvalue is being used and so selects the error message. */
6519 lvalue_or_else (tree ref, enum lvalue_use use)
6521 int win = lvalue_p (ref);